FN Thomson Reuters Web of Science™ VR 1.0 PT B AU Arzoumanian, Z AF Arzoumanian, Z BE Bailes, M Nice, DJ Thorsett, SE TI Improved bounds on violation of the strong equivalence principle SO RADIO PULSARS, PROCEEDINGS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Meeting on Radio Pulsars CY AUG 26-29, 2002 CL MEDITERRANEAN AGRON INST CHANAI, Khania, GREECE HO MEDITERRANEAN AGRON INST CHANAI ID BINARY PULSARS; RELATIVISTIC GRAVITY; NEUTRON-STARS; FIELD; SYSTEM; DECAY AB I describe a unique, 20-year-long timing program for the binary pulsar B0655+64, the stalwart control experiment for measurements of gravitational radiation damping in relativistic neutron-star binaries. Observed limits on evolution of the B0655+64 orbit provide new bounds on the existence of dipolar gravitational radiation, and hence on violation of the Strong Equivalence Principle. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Univ Space Res Assoc, Greenbelt, MD 20771 USA. RP Arzoumanian, Z (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Univ Space Res Assoc, Greenbelt, MD 20771 USA. NR 21 TC 6 Z9 6 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-151-6 J9 ASTR SOC P PY 2003 VL 302 BP 69 EP 74 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX51M UT WOS:000185575800008 ER PT J AU Talbot, HM Summons, R Jahnke, L Farrimond, P AF Talbot, HM Summons, R Jahnke, L Farrimond, P TI Characteristic fragmentation of bacteriohopanepolyols during atmospheric pressure chemical ionisation liquid chromatography/ion trap mass spectrometry SO RAPID COMMUNICATIONS IN MASS SPECTROMETRY LA English DT Article ID INTACT BACTERIOHOPANEPOLYOLS; BACTERIAL TRITERPENOIDS; HOPANE SERIES; BIOSYNTHESIS; DIAGENESIS; SEDIMENTS AB Bacteriohopanepolyols (BHPs) fragment via characteristic pathways during atmospheric pressure chemical ionisation liquid chromatography/ion trap mass spectrometry (APCI-LC/MSn). Comparison of the MS2 spectra of bacteriohopane-32,33,34,35-tetrol (BHT) and 2beta-methylbacteriohopane-32,33,34,35-tetrol has confirmed the previously proposed ring-C cleavage occurring between C-9 and 11 and C-8 and 14. This fragmentation, diagnostic of all hopanoids, also occurs in BHPs containing an amino group (-NH2) at C-35 although the higher relative stability of the ion limits this fragmentation to a minor process after protonation of the basic nitrogen function. Studies of a number of cell cultures including a prochlorophyte (Prochlorothrix hollandica) and a cyanobacterium (Chlorogloeopsis LA) demonstrate the power of this technique to detect composite BHPs with a complex biological functionality at C-35. We also report the first observation of intact pentafunctionalised bacteriohopanepolyols using this method. Copyright (C) 2003 John Wiley Sons, Ltd. C1 Univ Newcastle Upon Tyne, Sch Civil Engn & Geosci, NRG, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Talbot, HM (reprint author), Univ Newcastle Upon Tyne, Sch Civil Engn & Geosci, NRG, Drummond Bldg, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England. NR 12 TC 62 Z9 62 U1 1 U2 14 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0951-4198 J9 RAPID COMMUN MASS SP JI Rapid Commun. Mass Spectrom. PY 2003 VL 17 IS 24 BP 2788 EP 2796 DI 10.1002/rcm.1265 PG 9 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 758AR UT WOS:000187610800014 PM 14673828 ER PT S AU Moss, JN LeBeau, GJ Glass, CE AF Moss, JN LeBeau, GJ Glass, CE BE Ketsdever, AD Muntz, EP TI Hypersonic shock interactions about a 25 degrees/65 degrees sharp double cone SO RAREFIED GAS DYNAMICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 23rd International Symposium on Rarefied Gas Dynamics CY JUL 20-25, 2002 CL WHISTLER, CANADA SP USAF, Univ SO Calif, Amer Inst Aeronaut & Astronaut ID SIMULATION AB This paper presents the results of a numerical study of shock interactions resulting from Mach 10 air flow about a sharp double cone. Computations axe made with the direct simulation Monte Carlo (DSMC) method by using two different codes: the G2 code of Bird and the DAC (DSMC Analysis Code) code of LeBeau. The flow conditions axe the pretest nominal free-stream conditions specified for the ONERA R5Ch low-density wind tunnel. The focus is on the sensitivity of the interactions to grid resolution while providing information concerning the flow structure and surface results for the extent of separation, heating, pressure, and skin friction. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Moss, JN (reprint author), NASA, Langley Res Ctr, MS 408A, Hampton, VA 23681 USA. NR 17 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0124-1 J9 AIP CONF PROC PY 2003 VL 663 BP 425 EP 432 PG 8 WC Physics, Fluids & Plasmas SC Physics GA BW84R UT WOS:000183372100053 ER PT S AU Glass, CE Horvath, TJ AF Glass, CE Horvath, TJ BE Ketsdever, AD Muntz, EP TI Comparison of a 3-D CFD-DSMC solution methodology with a wind tunnel experiment SO RAREFIED GAS DYNAMICS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 23rd International Symposium on Rarefied Gas Dynamics CY JUL 20-25, 2002 CL WHISTLER, CANADA SP USAF, Univ SO Calif, Amer Inst Aeronaut & Astronaut ID SIMULATION MONTE-CARLO AB A solution method for problems that contain both continuum and rarefied flow regions is presented. The methodology is applied to flow about the Mars Sample Return Orbiter.(MSRO), a 3-D blunt body, which contains a region of highly compressed forebody flow, a shear layer where the flow separates from a forebody lip (i.e., where the base plane intersects the forebody), and a low density wake region about the afterbody. Because the blunt body flow contains such disparate regions, employing a single numerical technique to solve the entire flow field for a 3-D configuration is often impractical, or the technique does not apply. Direct simulation Monte Carlo (DSMC) could be employed to solve the entire flow field; however, the technique would require inordinate computational resources for continuum to near continuum regions, since, it is best suited for the rarefied wake region. Computational fluid dynamics (CFD) is appropriate for the high-density region on the forebody, but in the rarefied wake region, continuum assumptions do not apply. This problem poses a situation where the CFD-DSMC approach presented herein may be a suitable way to obtain a higher fidelity solution. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Glass, CE (reprint author), NASA, Langley Res Ctr, M-S 408A, Hampton, VA 23681 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0124-1 J9 AIP CONF PROC PY 2003 VL 663 BP 441 EP 448 PG 8 WC Physics, Fluids & Plasmas SC Physics GA BW84R UT WOS:000183372100055 ER PT B AU Singh, UN Yu, JR AF Singh, UN Yu, JR BE Ince, F Onbasioglu, S TI 2-micron laser development for space-based remote sensing applications SO RAST 2003: RECENT ADVANCES IN SPACE TECHNOLOGIES, PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Recent Advances in Space Technologies CY NOV 20-22, 2003 CL Istanbul, TURKEY SP Turish AF Acad, Bogazici Univ, Istanbul Tech Univ, Maltepe Univ, Old Domin Univ, Virginia Polytech Univ ID HO AB The design and performance of a diode pumped Tin sensitized Ho LuLiF4 (LuLF) laser oscillator and double-pass Tm:Ho:YLF laser amplifiers are described. The oscillator produced 135-mJ of Q-Switched output, which represents a slope efficiency of 0.09. To our knowledge this is the highest Q-Switched output for this material. The output energy of double-pass amplifier was improved by 75% compared to single-pass amplifier, and 380-mJ single pulse energy and 630-mJ double pulse energy have been achieved with high efficiency. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Singh, UN (reprint author), NASA, Langley Res Ctr, MS 468, Hampton, VA 23681 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8142-4 PY 2003 BP 485 EP 487 PG 3 WC Engineering, Aerospace; Remote Sensing SC Engineering; Remote Sensing GA BAH80 UT WOS:000222320100084 ER PT B AU Chamis, CC Minnetyan, L AF Chamis, CC Minnetyan, L BE Gdoutos, EE MarioliRiga, ZP TI Damage tolerant composite joint design SO RECENT ADVANCES IN COMPOSITE MATERIALS: IN HONOR OF S.A. PAIPETIS LA English DT Proceedings Paper CT International Symposium on Recent Advances in Composite Materials CY JUN 12-14, 2003 CL DEMOCRITUS UNIV THRACE, XANTHI, GREECE HO DEMOCRITUS UNIV THRACE ID PROGRESSIVE FRACTURE AB Damage initiation and progressive fracture of adhesively bonded graphite/epoxy composite joints are investigated under various loading conditions. Load induced damage in both the adhesive bond and the adjoining laminate is considered. An integrated computer code is utilized for the simulation of composite structural degradation. The damage progression sequence and structural fracture resistance during different degradation stages are evaluated in detail. Results indicate that adhesive properties have a significant effect on structural durability even when damage initiation/progression is not in the adhesive bond. Design implications with regard to damage tolerance of adhesively bonded joints are examined. Influence of the type of loading and the choice of adhesive on damage initiation and progression for adhesively bonded composite joints are investigated. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Clarkson Univ, Potsdam, NY 13699 USA. RP Chamis, CC (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-1299-3 PY 2003 BP 265 EP 278 PG 14 WC Materials Science, Composites SC Materials Science GA BX11R UT WOS:000184324000022 ER PT B AU Kazanas, D Nicolaidis, A AF Kazanas, D Nicolaidis, A BE Kokkotas, KD Stergioulas, N TI Cosmic rays and large extra dimensions SO RECENT DEVELOPMENTS IN GRAVITY LA English DT Proceedings Paper CT 10th Hellenic Relativity Conference on Recent Developments in Gravity CY MAY 30-JUN 02, 2002 CL UNIV THESSALONIKI, KALLITHEA, GREECE SP Aristotle Univ Thessaloniki, Aristotle Univ Thessaloniki, Dept Phys, Aristotle Univ Thessaloniki, Sect Astrophys, Astron & Mech, Aristotle Univ Thessaloniki, Res Comm, Minist Educ Hellas, Minist Culture Hellas, Minist Macedonia Thrace Hellas, Union Hellen Phys HO UNIV THESSALONIKI ID SPECTRUM; CONSTRAINTS; TEV AB We have proposed that the cosmic ray spectrum "knee", the steepening of the cosmic ray spectrum at energy E greater than or similar to 10(15.5) eV, is due to "new physics", namely new interactions at TeV cm energies which produce particles undetected by the experimental apparatus. In this letter we examine specifically the possibility that this interaction is low scale gravity. We consider that the graviton propagates, besides the usual four dimensions, into an additional delta, compactified, large dimensions and we estimate the graviton production in pp collisions in the high energy approximation where graviton emission is factorized. We find that the cross section for graviton production rises as fast as (roots/M-f)(2+delta), where M-f is the fundamental scale of gravity in 4+delta dimensions, and that the distribution of radiating a fraction y of the initial particle's energy into gravitational energy (which goes undetected) behaves as deltay(delta-1). The missing energy leads to an underestimate of the true energy and generates a break in the inferred cosmic ray spectrum (the "knee"). By fitting the cosmic ray spectrum data we deduce that the favorite values for the parameters of the theory are M similar to 8 TeV and delta = 4. C1 NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RP Nicolaidis, A (reprint author), NASA, Goddard Space Flight Ctr, LHEA, Code 661, Greenbelt, MD 20771 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-238-370-0 PY 2003 BP 108 EP 115 DI 10.1142/9789812791238_0011 PG 8 WC Physics, Multidisciplinary SC Physics GA BX79R UT WOS:000186472100011 ER PT S AU Leviton, DB Kirk, J Lobsinger, L AF Leviton, DB Kirk, J Lobsinger, L BE Decker, JE Brown, N TI Ultra-high resolution Cartesian absolute optical encoder SO RECENT DEVELOPMENTS IN TRACEABLE DIMENSIONAL MEASUREMENTS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Recent Developments in Traceable Dimensional Measurements II CY AUG 04-06, 2003 CL SAN DIEGO, CA SP SPIE DE optical encoder; Cartesian; absolute; two-dimensional; pattern recognition; sensitivity; linearity AB A new optical encoder which measures absolute, true-Cartesian displacement with ultra-high sensitivity and linearity has been developed at NASA's Goddard Space Flight Center. The device is the two-dimensional analog of recently developed linear and rotary encoders based on optical pattern recognition. In this encoder, a glass scale carrying absolute Cartesian position information travels with the payload in an X-Y motion system. Because the scale comprises the entire measurement coordinate system in a monolithic form, motion control axes can be skew to one another to an arbitrary degree and can exhibit substantial lateral drift with no effect on the correctness of X-Y readout, thus eliminating challenges of orthogonal mounting for motion axes and challenges of mounting independent encoders parallel to the directions of travel for each constituent X and Y axis. Prototype devices with ranges of 30 x 30 nun and 150 x 150 mm with 5 nm and 50 nm resolutions, respectively, have been built in the laboratory. Performance data from the Cartesian encoder in the Point Target Assembly for the optical calibration stimulus for Hubble Space Telescope's Wide Field Camera 3 are presented. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Leviton, DB (reprint author), NASA, Goddard Space Flight Ctr, Code 551, Greenbelt, MD 20771 USA. NR 5 TC 5 Z9 5 U1 1 U2 7 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5063-4 J9 P SOC PHOTO-OPT INS PY 2003 VL 5190 BP 111 EP 121 DI 10.1117/12.518376 PG 11 WC Instruments & Instrumentation SC Instruments & Instrumentation GA BY14C UT WOS:000187881400012 ER PT S AU Toland, RW AF Toland, RW BE Decker, JE Brown, N TI A precision metrology system for the Hubble Space Telescope Wide Field Camera 3 instrument SO RECENT DEVELOPMENTS IN TRACEABLE DIMENSIONAL MEASUREMENTS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Recent Developments in Traceable Dimensional Measurements II CY AUG 04-06, 2003 CL SAN DIEGO, CA SP SPIE DE cathetometer; optical metrology; calibration AB The Wide Field Camera 3 (WFC3) instrument for the Hubble Space Telescope (HST) will replace the current Wide Field and Planetary Camera 2 (WFPC2). By providing higher throughput and sensitivity than WFPC2, and operating from the near-IR to the near-UV, WFC3 will once again bring the performance of HST above that from ground-based observatories. Crucial to the integration of the WFC3 optical bench is a pair of 2-axis cathetometers used to view targets which cannot be seen by other means when the bench is loaded into its enclosure. The setup and calibration of these cathetometers is described, along with results from a comparison of the cathetometer system with other metrology techniques. C1 NASA, Goddard Space Flight Ctr, Opt Syst Alignment & Test Grp, Greenbelt, MD 20771 USA. RP Toland, RW (reprint author), NASA, Goddard Space Flight Ctr, Opt Syst Alignment & Test Grp, Code 551-1, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5063-4 J9 P SOC PHOTO-OPT INS PY 2003 VL 5190 BP 253 EP 264 DI 10.1117/12.502248 PG 12 WC Instruments & Instrumentation SC Instruments & Instrumentation GA BY14C UT WOS:000187881400027 ER PT S AU Lay, OP Dubovitsky, S Peters, RD Burger, J Ahn, SW Steier, WH Fetterman, HR Chang, Y AF Lay, OP Dubovitsky, S Peters, RD Burger, J Ahn, SW Steier, WH Fetterman, HR Chang, Y BE Decker, JE Brown, N TI Absolute distance measurement with the MSTAR sensor SO RECENT DEVELOPMENTS IN TRACEABLE DIMENSIONAL MEASUREMENTS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Recent Developments in Traceable Dimensional Measurements II CY AUG 04-06, 2003 CL SAN DIEGO, CA SP SPIE DE absolute metrology; distance measurement ID FREQUENCY STABILIZATION; LASER; INTERFEROMETRY; RESOLUTION; PRECISION AB The MSTAR sensor (Modulation Sideband Technology for Absolute Ranging) is a new system for measuring absolute distance, capable of resolving the integer cycle ambiguity of standard interferometers, and making it possible to measure distance with sub-nanometer accuracy. The sensor uses a single laser in coqjunction with fast phase modulators and low-frequency detectors. We describe the design of the system - the principle of operation, the metrology source, beam-launching optics, and signal processing - and show results for target distances up to 1 meter. We then demonstrate how the system can be scaled to kilometer-scale distances. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lay, OP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 18 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5063-4 J9 P SOC PHOTO-OPT INS PY 2003 VL 5190 BP 361 EP 372 DI 10.1117/12.503760 PG 12 WC Instruments & Instrumentation SC Instruments & Instrumentation GA BY14C UT WOS:000187881400038 ER PT S AU Leviton, DB AF Leviton, DB BE Decker, JE Brown, N TI Ultra-high resolution, absolute, Cartesian electronic autocollimator SO RECENT DEVELOPMENTS IN TRACEABLE DIMENSIONAL MEASUREMENTS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Recent Developments in Traceable Dimensional Measurements II CY AUG 04-06, 2003 CL SAN DIEGO, CA SP SPIE DE electronic autocollimator; absolute; Cartesian; pattern recognition; sensitivity; linearity AB The development of a compact, ultra-high resolution, electronic autocollimator with excellent readout stability, linearity, and coordinate orthogonality is presented. This optical metrology tool relies on new advances in Cartesian optical encoders based on pattern recognition technology. Readout instabilities characteristic of conventional electronic autocollimators whose lateral effect photodetectors and operational amplifiers exhibit temporal and thermal drifts, are absent in this new technology. An autocollimator with a form factor similar to conventional alignment telescopes has been demonstrated with an angular resolution of 0.02 arcseconds peak-to-peak and less than 0.01 arcseconds rms. Various optical metrology applications for the laboratory and for space flight., including cryostatic ones, are described. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Leviton, DB (reprint author), NASA, Goddard Space Flight Ctr, Code 551, Greenbelt, MD 20771 USA. NR 4 TC 4 Z9 4 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5063-4 J9 P SOC PHOTO-OPT INS PY 2003 VL 5190 BP 468 EP 475 DI 10.1117/12.518377 PG 8 WC Instruments & Instrumentation SC Instruments & Instrumentation GA BY14C UT WOS:000187881400050 ER PT S AU Middleton, E McMurtney, JE Campbell, PK Corp, LA Butcher, LM Chappelle, EW AF Middleton, E McMurtney, JE Campbell, PK Corp, LA Butcher, LM Chappelle, EW BE Owe, M DUrso, G Toulios, L TI Optical and fluorescence properties of corn leaves from different nitrogen regimes SO REMOTE SENSING FOR AGRICULTURE, ECOSYSTEMS, AND HYDROLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing for Agriculture, Ecosystems and Hydrology IV CY SEP 22-25, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE high spectral resolution reflectance and fluorescence; chlorophyll fluorescence; carbon/nitrogen ratio; chlorophyll b; red edge; nitrogen deficiency and excess ID PLANT STRESS AB The important role of nitrogen (N) in limiting or enhancing vegetation productivity is relatively well understood, although the interaction of N with other environmental variables in natural and agricultural ecosystems needs more study. In 2001, a suite of optical, fluorescence, and biophysical measurements were collected on leaves of corn (Zea Mays L.) from field plots provided four N fertilizer application rates: 20%, 50%, 100% and 150% of optimal N levels. Two complementary sets of high-resolution (< 2 nm) optical spectra were acquired for both adaxial and abaxial leaf surfaces. The first was comprised of leaf optical properties (350-2500 nm) for reflectance, transmittance, and absorptance. The second was comprised of reflectance spectra (500-1000 mn) acquired with and without a long pass 665 nm filter to determine the fluorescence contribution to "apparent reflectance" in the 670-750 mn spectrum that includes the 685 and 740 run chlorophyll fluorescence (Ch1F) peaks. Two types of fluorescence measurements were also made on adaxial and abaxial surfaces: 1) fluorescence images in four 10 nm bands (blue, green, red, far-red) resulting from broadband irradiance excitation; and 2) emission spectra at 5 mn resolution produced by three excitation wavelengths (280, 380, and 532 nm). The strongest relationships between optical properties and foliar chemistry were obtained for a "red-edge" optical parameter versus ON and chlorophyll b. Select optical indices and Ch1F parameters were correlated. A significant contribution of steady-state Ch1F to apparent reflectance was observed, averaging 10-25% at 685 nm and 2-6% at 740 mn over the range of N treatments. From all measurements assessing fluorescence, higher Ch1F was measured from the abaxial leaf surfaces. C1 NASA, Goddard Space Flight Ctr, Terr Phys Lab, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Middleton, E (reprint author), NASA, Goddard Space Flight Ctr, Terr Phys Lab, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. RI Campbell, Petya/G-4931-2013; Campbell, Petya/L-7486-2013 OI Campbell, Petya/0000-0002-0505-4951; Campbell, Petya/0000-0002-0505-4951 NR 23 TC 3 Z9 5 U1 1 U2 9 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4661-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4879 BP 72 EP 83 DI 10.1117/12.463087 PG 12 WC Ecology; Remote Sensing; Soil Science; Water Resources SC Environmental Sciences & Ecology; Remote Sensing; Agriculture; Water Resources GA BW50D UT WOS:000182227200007 ER PT S AU French, AN Schmugge, TJ Jacob, F Ogawa, K AF French, AN Schmugge, TJ Jacob, F Ogawa, K BE Owe, M DUrso, G Toulios, L TI Two surface temperature retrieval methods compared over agricultural lands SO REMOTE SENSING FOR AGRICULTURE, ECOSYSTEMS, AND HYDROLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing for Agriculture, Ecosystems and Hydrology IV CY SEP 22-25, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE ASTER; emiissivity; thermal infrared; MASTER; temperature-emissivity separation; TES; NEM ID EMISSIVITY SEPARATION; IMAGES AB Accurate, spatially distributed surface temperatures are required for modeling evapotranspiration (ET) over agricultural fields under wide ranging conditions, including stressed and unstressed vegetation. Modeling approaches that use surface temperature observations, however, have the burden of estimating surface emissivities. Emissivity estimation, the subject of much recent research, is facilitated by observations in multiple thermal infrared bands. But it is nevertheless a difficult task. Using observations from multiband thermal sensors, ASTER and MASTER, estimated surface emissivities and temperatures are retrieved in two different ways: the temperature emtissivity separation approach (TES), and the normalized emissivity approach (NEM). Both rely upon empirical relationships, but the assumed relationships are different. TES relies upon a relationship between the minimum spectral emissivity and the range of observed emissivities. NEM relies upon an assumption that at least one thermal band has a predetermined emissivity (close to 1.0). Experiments comparing TES and NEM were performed using simulated observations from spectral library data, and with actual data from two different landscapes- one in central Oklahoma, USA, and another in southern New Mexico, USA. The simulation results suggest that TES's empirical relationship is more realistic than NEM's assumed maximum emissivity, and therefore TES temperature estimates are more accurate than NEM estimates. But when using remote sensing data, TES estimates of maximum emissivities are lower than expected, thus causing overestimated temperatures. Work in progress will determine the significance of this overestimation by comparing ground level measurements against the remote sensing observations. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP French, AN (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RI Jacob, Frederic/A-5946-2011 OI Jacob, Frederic/0000-0002-2491-3096 NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4661-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4879 BP 194 EP 201 DI 10.1117/12.462452 PG 8 WC Ecology; Remote Sensing; Soil Science; Water Resources SC Environmental Sciences & Ecology; Remote Sensing; Agriculture; Water Resources GA BW50D UT WOS:000182227200020 ER PT S AU Owe, M De Jeu, R AF Owe, M De Jeu, R BE Owe, M DUrso, G Toulios, L TI Surface parameter retrieval at global scales by microwave remote sensing SO REMOTE SENSING FOR AGRICULTURE, ECOSYSTEMS, AND HYDROLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing for Agriculture, Ecosystems and Hydrology IV CY SEP 22-25, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE remote sensing; nricrowave; soil temperature ID POLARIZATION DIFFERENCE; SOIL-MOISTURE; GHZ AB Surface soil temperature is an important input parameter to a variety of environment models, such as global circulation models, radiative transfer, and land surface process models. Soil temperature is especially important for normalizing microwave radiobrightness temperatures in inverse radiative transfer modelling for soil moisture and vegetation optical depth retrieval. To ensure maximum accuracy of soil moisture retrieval models on a regional or global scale, spatially averaged temperature data are necessary. Since the variability of surface temperature in time and space is extremely high due to incoming solar radiation, air temperature, vegetation, soil physical properties, and topography, an aggregation of a few point measurements rarely provides a good spatial average. Remote sensing methods typically provide spatially averaged values-needed. Thermal infrared sensors (TIR) measure the skin temperature, but usually require some atmospheric correction, and during periods of cloud cover they become unusable. Microwave sensors also have the potential for providing reliable estimates of spatially averaged soil temperature. Microwave instruments are also much less affected by atmospheric conditions and thus require little or no correction. A technique to estimate the effective temperature with vertical polarized high-frequency microwave brightness temperatures is presented. Calibration procedures with field observations are discussed, and a technique to estimate the soil temperature at the soil moisture sampling depth for 6.6 GHz is shown. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Owe, M (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, 974, Greenbelt, MD 20771 USA. NR 9 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4661-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4879 BP 202 EP 210 DI 10.1117/12.466000 PG 9 WC Ecology; Remote Sensing; Soil Science; Water Resources SC Environmental Sciences & Ecology; Remote Sensing; Agriculture; Water Resources GA BW50D UT WOS:000182227200021 ER PT S AU Foster, JL Hall, DK Kelly, REJ Chang, ATC Chien, JYL AF Foster, JL Hall, DK Kelly, REJ Chang, ATC Chien, JYL BE Owe, M DUrso, G Toulios, L TI Comparison of relative errors in snow maps in north America and Eurasia in 2001-02 SO REMOTE SENSING FOR AGRICULTURE, ECOSYSTEMS, AND HYDROLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing for Agriculture, Ecosystems and Hydrology IV CY SEP 22-25, 2002 CL AGIA PELAGIA, GREECE SP SPIE ID SATELLITE DATA; COVER AB Results of this investigation confirm previous results by several other authors that correspondence between the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Scanning Sensor Microwave Instrument (SSMI) - derived snow maps improves as the winter progresses. Early in the season, the SSMI snow mapping algorithms are unable to identify shallow and wet snow as snow cover, while the MODIS snow maps perform well under those circumstances, but cannot map snow through clouds and cannot provide estimates of SWE. By mid winter when the snowpack is deeper, temperatures are colder, and liquid water in the snowpack is minimal, the agreement between MODIS- and SSMI-derived snow maps improves. For North America, the difference between MODIS and SSMI was approximately 35% for early December but averaged about 5% for the maps examined in February of 2002, and for Eurasia (eastern Asia), the difference between the MODIS and SSMI maps was less than about 10% in early January of 2001. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Foster, JL (reprint author), NASA, Goddard Space Flight Ctr, Code 974, Greenbelt, MD 20771 USA. RI Hall, Dorothy/D-5562-2012 NR 11 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4661-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4879 BP 428 EP 438 DI 10.1117/12.474411 PG 11 WC Ecology; Remote Sensing; Soil Science; Water Resources SC Environmental Sciences & Ecology; Remote Sensing; Agriculture; Water Resources GA BW50D UT WOS:000182227200045 ER PT S AU Pitts, MC Thomason, LW AF Pitts, MC Thomason, LW BE Schafer, KP LadoBordowsky, O Comeron, A Picard, RH TI SAGE III temperature and pressure retrievals: Initial results SO REMOTE SENSING OF CLOUDS AND THE ATMOSPHERE VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing of Clouds and the Atmosphere VII CY SEP 24-27, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE remote sensing; temperature retrievals; oxygen A-band; SAGE III AB The Stratospheric Aerosol and Gas Experiment (SAGE) III is the fourth generation of solar occultation satellite instruments designed by NASA to measure vertical profiles of aerosol extinction and the molecular densities of gaseous species in the atmosphere. With an expanded spectral range compared with its predecessors, SAGE III has the capability to retrieve profiles of atmospheric temperature and pressure utilizing multi-spectral measurements of the oxygen A-band absorption feature near 762 run. As part of NASA's Earth Science Enterprise, Earth Observing System, the first of two SAGE III instruments was successfully launched onboard the Meteor-3M satellite in December 2001. Given the inherent insensitivity of solar occultation experiments to long-term instrument degradation and the expected lifetime of the instruments (6+ years), the SAGE III instruments should provide a long-term record of self-calibrated, high vertical resolution temperature and pressure measurements. These measurements will be valuable for monitoring temperature trends in the stratosphere and mesosphere and for comparison studies with other temperature data sets. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Pitts, MC (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4664-5 J9 P SOC PHOTO-OPT INS PY 2003 VL 4882 BP 62 EP 70 DI 10.1117/12.463004 PG 9 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Remote Sensing SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Remote Sensing GA BW64U UT WOS:000182689200008 ER PT S AU Mertens, CJ Mlynczak, MG Lopez-Puertas, M Wintersteiner, PP Picard, RH Winick, JR Gordley, LL Russell, JM AF Mertens, CJ Mlynczak, MG Lopez-Puertas, M Wintersteiner, PP Picard, RH Winick, JR Gordley, LL Russell, JM BE Schafer, KP LadoBordowsky, O Comeron, A Picard, RH TI Retrieval of kinetic temperature and carbon dioxide abundance from non-local thermodynamic equilibrium limb emission measurements made by the SABER experiment on the TIMED satellite SO REMOTE SENSING OF CLOUDS AND THE ATMOSPHERE VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing of Clouds and the Atmosphere VII CY SEP 24-27, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE remote sensing; non-local thermodynamic equilibrium (non-LTE); thermal structure; carbon dioxide; mesosphere; lower thermosphere; middle atmosphere ID 4.6 MU-M; CO2; ATMOSPHERE; RADIANCE; MODEL AB The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) experiment was launched onboard the TIMED satellite in December, 2001. SABER is designed to provide measurements of temperature, constituents, and the key radiative and chemical sources and sinks of energy in the mesosphere and lower thermosphere (MLT). SABER measures Earth limb emission in 10 broadband radiometer channels ranging from 1.27 mum to 17 mum. Measurements are made both day and night over the latitude range from 52degreesS to 83degreesN with alternating hemisphere coverage every 60 days. In this paper we concentrate on retrieved profiles of kinetic temperature (T-k) and CO2 volume mixing ratio (vmr), inferred from observed 15 mum and 4.3 mum limb emissions. SABER-measured limb radiances are in non-local thermodynamic equilibrium (non-LTE) in the MLT region. The complexity of non-LTE radiation transfer combined with the large volume of data measured by SABER requires new retrieval approaches and radiative transfer techniques to accurately and efficiently retrieve the data products. In this paper we present the salient features of the coupled non-LTE T-k/CO2 retrieval algorithm, along with preliminary results. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Mertens, CJ (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. RI Lopez Puertas, Manuel/M-8219-2013 OI Lopez Puertas, Manuel/0000-0003-2941-7734 NR 21 TC 6 Z9 6 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4664-5 J9 P SOC PHOTO-OPT INS PY 2003 VL 4882 BP 162 EP 171 DI 10.1117/12.463358 PG 10 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Remote Sensing SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Remote Sensing GA BW64U UT WOS:000182689200018 ER PT S AU Pitts, M Hansen, G Lucker, P AF Pitts, M Hansen, G Lucker, P BE Schafer, KP LadoBordowsky, O Comeron, A Picard, RH TI An airborne A-band spectrometer for remote sensing of aerosol and cloud properties SO REMOTE SENSING OF CLOUDS AND THE ATMOSPHERE VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing of Clouds and the Atmosphere VII CY SEP 24-27, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE aerosols; clouds; A-band; remote sensing ID MOLECULAR LINE ABSORPTION; SCATTERING ATMOSPHERE; OXYGEN AB Recent theoretical studies have demonstrated the potential of spaceborne high spectral resolution 02 A-band spectrometers for retrieval of aerosol and cloud optical properties. High spectral resolution is the key to these retrievals because it permits a separation of the surface and atmospheric scattering components of the reflectance measurements. Although promising, this new approach poses numerous technical challenges related to instrument design, characterization, and calibration that have not been fully addressed by previous conceptual studies. To experimentally assess the capabilities of this promising new remote sensing application, the NASA Langley Research Center has developed the Langley Airborne A-Band Spectrometer (LAABS). This instrument will serve as a unique test bed to evaluate the impact of realistic instrument performance on A-band retrieval capabilities. After full characterization of the instrument through laboratory testing, a detailed forward model of the instrument's radiance measurements will be developed. The instrument model will be validated against actual measured spectra obtained from ground-based operations of the instrument. Airborne A-band spectra obtained during initial test flights of this instrument during the CLAMS field campaign in July 2001 will be analyzed to assess aerosol retrieval capability. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Pitts, M (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4664-5 J9 P SOC PHOTO-OPT INS PY 2003 VL 4882 BP 353 EP 362 DI 10.1117/12.463006 PG 10 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Remote Sensing SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Remote Sensing GA BW64U UT WOS:000182689200038 ER PT S AU Woods, DC Osborn, MT Lucker, PL AF Woods, DC Osborn, MT Lucker, PL BE Schafer, KP LadoBordowsky, O Comeron, A Picard, RH TI Lidar monitoring of stratospheric aerosol at Hampton, Virginia SO REMOTE SENSING OF CLOUDS AND THE ATMOSPHERE VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing of Clouds and the Atmosphere VII CY SEP 24-27, 2002 CL AGIA PELAGIA, GREECE SP SPIE ID EL-CHICHON; VOLCANIC CLOUD; PINATUBO; ERUPTION AB Recent lidar measurements at Hampton, Virginia (37. IN, 76.3W) indicate that the current mid-latitude stratospheric aerosol level, after recovery from the 1991 eruption of Mount Pinatubo, is lower than the background level measure during the vocanically quiescent period in 1979. This suggests that perhaps the natural stratospheric aerosol background may be lower than previously thought. Volcanically inactive periods, such as the periods after the 1982 El Chichon eruption and again after the 1991 Pinatubo eruption, provide opportunities to study long-term trends in volcanic aerosol decay. And, the present state of very low aerosol loading in the stratosphere, provides opportunities to study and gain a better understanding of the natural background aerosol. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Woods, DC (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4664-5 J9 P SOC PHOTO-OPT INS PY 2003 VL 4882 BP 474 EP 480 DI 10.1117/12.463021 PG 7 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Remote Sensing SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Remote Sensing GA BW64U UT WOS:000182689200050 ER PT J AU Pan, JY Yan, XH Zheng, QN Liu, WT Klemas, VV AF Pan, JY Yan, XH Zheng, QN Liu, WT Klemas, VV TI Interpretation of scatterometer ocean surface wind vector EOFs over the Northwestern Pacific SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID ERS-1 SCATTEROMETER; PRESSURE FIELDS; EAST-ASIA; VARIABILITY; CLIMATE; SATELLITE; SYSTEM; IMPACT; ENSO; ASSIMILATION AB Satellite scatterometer winds over the northwestern Pacific were analyzed with the vector empirical orthogonal function (VEOF) method. The Hilbert-Huang transform (HHT), a newly developed non-linear and non-stationary time series data processing method, was also employed in the analysis. A combination of European Remote Sensing Satellite (ERS) - 1/2 scatterometer, NASA Scatterometer (NSCAT) and NASA's Quick Scatterometer (QuikSCAT) winds covering the period from January 1992 to April 2000 and the area of 0-50degreesN, 100-148degreesE constitutes the baseline for this study. The results indicate that annual cycles dominate the two leading VEOF modes. The first VEOF shows the East Asian monsoon features and the second represents a spring-autumn oscillation. We removed the annual signal from the data set and calculated the interannual VEOFs. The first interannual VEOF represents the interannual variability existing in the spring-autumn oscillation. The temporal mode is correlated with the Southern Oscillation Index (Sol), but has a half-year lag with respect to the SOI. The spatial mode of the first interannual VEOF reflects the response of the tropical and extratropical winds to ENSO events. The second interannual VEOF is another ENSO related mode, and the temporal VEOF mode is correlated with the SOI with a correlation coefficient of 0.78, revealing the wind variability over mid-latitudes, which is associated with ENSO events. Further analysis indicated that the wind variability over the coast of East Asia represents anomalies of a Hadley cell. The quasi-biennial oscillation (QBO) was found in the temporal mode, indicating and verifying that the QBO in the wind fields is related to ENSO events. The third VEOF shows the interannaul variability in the winter-summer mode and displays the interannual variability of the East Asian monsoon. The three leading interannual VEOFs are statistically meaningful as confirmed by a significance test. (C) 2002 Elsevier Science Inc. All rights reserved. C1 Univ Delaware, Grad Coll Marine Studies, Ctr Remote Sensing, Newark, DE 19716 USA. Ocean Univ Qingdao, Ocean Remote Sensing Inst, Qingdao 266003, Peoples R China. CALTECH, Jet Prop Lab 300 323, Pasadena, CA 91109 USA. RP Pan, JY (reprint author), Univ Delaware, Grad Coll Marine Studies, Ctr Remote Sensing, Newark, DE 19716 USA. RI Zheng, Quanan/F-9025-2010 NR 39 TC 19 Z9 23 U1 1 U2 9 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD JAN PY 2003 VL 84 IS 1 BP 53 EP 68 AR PII S0034-4257(02)00073-1 DI 10.1016/S0034-4257(02)00073-1 PG 16 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 620DL UT WOS:000179518300005 ER PT B AU Howell, PA Winfree, WP AF Howell, PA Winfree, WP BE Thompson, DO Chimenti, DE TI Automated identification of intergranular corrosion in x-ray CT images SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 22A AND 22B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 29th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 14-19, 2002 CL WESTERN WASHINGTON UNIV, BELLINGHAM, WA HO WESTERN WASHINGTON UNIV AB Characterization of a material or structure by computed tomography results in the acquisition of large quantities of data that need to be tediously examined to determine the location and size of damage. Since the computed tomography images are digital, there is significant potential for reducing the human effort evolved in this process by digital processing of this data to enhance the signatures of flaws and perform automated identification of suspected flaws. Techniques are presented that enhance the contrast between corroded and uncorroded regions to simplify the analysis and improve quality of flaw identification. Algorithms developed in part for computer vision, such as anisotropic diffusion and edge detection techniques, are applied to the data. Anisotropic diffusion techniques are shown to significantly reduce image noise while maintaining the contrast between intergranular corrosion and uncorroded regions and preserving the important features of the flaw. Edge detection techniques are shown to enable a rapid location of regions requiring further analysis. In regions identified by the edge detection technique, neural network techniques are applied to automate defect detection of the intergranular corrosion. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Howell, PA (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 5 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0117-9 J9 REV PROG Q PY 2003 VL 20 BP 568 EP 574 PN A&B PG 7 WC Acoustics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Acoustics; Engineering; Instruments & Instrumentation; Materials Science; Optics GA BW52Z UT WOS:000182317500074 ER PT B AU Roth, DJ Martin, RE Harmon, LM Gyekenyesi, AL Kautz, HE AF Roth, DJ Martin, RE Harmon, LM Gyekenyesi, AL Kautz, HE BE Thompson, DO Chimenti, DE TI Development of a high performance acoustoultrasonic scan system SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 22A AND 22B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 29th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 14-19, 2002 CL WESTERN WASHINGTON UNIV, BELLINGHAM, WA HO WESTERN WASHINGTON UNIV ID COMPOSITE AB Acousto-ultrasonic (AU) interrogation is a single-sided nondestructive evaluation technique employing separated sending and receiving transducers. It is used for assessing the microstructural condition/distributed damage state of the material between the transducers. AU is complementary to more traditional NDE methods such as ultrasonic c-scan, x-ray radiography, and themographic inspection that tend to be used primarily for discrete flaw detection. Through its history, AU has been used to inspect polymer matrix composite, metal matrix composite, ceramic matrix composite, and even monolithic metallic materials. The development of a high-performance automated AU scan system for characterizing within-sample microstructural and property homogeneity is currently in a prototype stage at NASA. In this paper, a review of essential AU technology is given. Additionally, the basic hardware and software configuration, and preliminary results with the system, are described. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Roth, DJ (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 17 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0117-9 J9 REV PROG Q PY 2003 VL 20 BP 891 EP 898 PN A&B PG 8 WC Acoustics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Acoustics; Engineering; Instruments & Instrumentation; Materials Science; Optics GA BW52Z UT WOS:000182317500116 ER PT B AU Wincheski, B Simpson, J Namkung, M Percy, D Callahan, J AF Wincheski, B Simpson, J Namkung, M Percy, D Callahan, J BE Thompson, DO Chimenti, DE TI Development and testing of prototype Giant Magnetoresistive (GMR) rotating probe system SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 22A AND 22B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 29th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 14-19, 2002 CL WESTERN WASHINGTON UNIV, BELLINGHAM, WA HO WESTERN WASHINGTON UNIV AB Continued development of the giant magrietoresistive based rotating probe system has resulted in the fabrication of a fieldable prototype instrument. The system, designed for the detection of deeply buried flaws under installed fasteners, utilizes a giant magnetoresistive sensor within the self-nulling probe design for improved low frequency capabilities. The prototype unit incorporates a new probe design for deep penetration and reduced edge effects along with new electronics and system software. Testing of the prototype system has been performed at SANDIA National Laboratories Aging Aircraft NDI Validation Center. The complete system configuration along with field testing results are presented. C1 NASA, LaRC, Hampton, VA 23681 USA. RP Wincheski, B (reprint author), NASA, LaRC, MS 231, Hampton, VA 23681 USA. RI Namkung, Min/E-1533-2012 NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0117-9 J9 REV PROG Q PY 2003 VL 20 BP 947 EP 953 PN A&B PG 7 WC Acoustics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Acoustics; Engineering; Instruments & Instrumentation; Materials Science; Optics GA BW52Z UT WOS:000182317500123 ER PT B AU Winfree, WP Zalameda, JN AF Winfree, WP Zalameda, JN BE Thompson, DO Chimenti, DE TI Thermographic depth profiling of delaminations in composites SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 22A AND 22B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 29th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 14-19, 2002 CL WESTERN WASHINGTON UNIV, BELLINGHAM, WA HO WESTERN WASHINGTON UNIV ID DAMAGE; SYSTEM AB A method for determining the depth of delaminations in composite specimens is presented. The method is based on a one-dimensional model for a composite with a delamination that is represented as a contact resistance between the upper and lower regions of the specimen. To estimate the depth and contact resistance of a delamination in an efficient method, a method is used that makes use of a eigenvector representation of the measured and theoretical data. The technique is shown to give estimates of manufactured delamination depths that are in good agreement with the specified depths. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Winfree, WP (reprint author), NASA, Langley Res Ctr, MS 231, Hampton, VA 23681 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0117-9 J9 REV PROG Q PY 2003 VL 20 BP 981 EP 988 PN A&B PG 8 WC Acoustics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Acoustics; Engineering; Instruments & Instrumentation; Materials Science; Optics GA BW52Z UT WOS:000182317500127 ER PT B AU Madaras, EI Anastasi, RF AF Madaras, EI Anastasi, RF BE Thompson, DO Chimenti, DE TI Comparison of ultrasound with tensile testing of thermally damaged polyimide insulated wiring (MIL-W-81381) SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 22A AND 22B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 29th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 14-19, 2002 CL WESTERN WASHINGTON UNIV, BELLINGHAM, WA HO WESTERN WASHINGTON UNIV ID WAVES AB Ultrasonic measurements were performed on MIL-W-81381/7, /12, and /21 wire, a polyimide (Kapton(R)) insulated wire. The phase velocity for the 20-gauge MIL-W-81381/7 wire had a baseline value of 3023 +/- 78 m/s. After exposure to high temperatures, the wire's phase velocity rapidly increased, and reached an asymptotic value of 3598 +/- 20 m/s after 100 hours exposure. Similar responses were measured in other gauges. The baseline measurements of Young's moduli resulted in values of 5636 +/- 486, 7714 +/- 505, and 8767 +/- 292 KSI for the 20 ga, 16 ga, and 12 ga. wires respectively. C1 NASA, Langley Res Ctr, NESB, Hampton, VA 23681 USA. RP Madaras, EI (reprint author), NASA, Langley Res Ctr, NESB, MS231, Hampton, VA 23681 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0117-9 J9 REV PROG Q PY 2003 VL 20 BP 1407 EP 1414 PN A&B PG 8 WC Acoustics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Acoustics; Engineering; Instruments & Instrumentation; Materials Science; Optics GA BW52Z UT WOS:000182317500183 ER PT B AU Prosser, WH Brown, TL Woodard, SE Fleming, GA Cooper, EG AF Prosser, WH Brown, TL Woodard, SE Fleming, GA Cooper, EG BE Thompson, DO Chimenti, DE TI Sensor technology for integrated vehicle health management of aerospace vehicles SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 22A AND 22B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 29th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 14-19, 2002 CL WESTERN WASHINGTON UNIV, BELLINGHAM, WA HO WESTERN WASHINGTON UNIV ID STRAIN AB NASA is focusing considerable efforts on technology development for Integrated Vehicle Health Management systems. The research in this area is targeted toward increasing aerospace vehicle safety and reliability, while reducing vehicle operating and maintenance costs. On-board, real-time sensing technologies that can provide detailed information on structural integrity are central to such a health management system. This paper describes a number of sensor technologies currently under development for integrated vehicle health management. The capabilities, current limitations, and future research needs of these technologies are addressed. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Prosser, WH (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0117-9 J9 REV PROG Q PY 2003 VL 20 BP 1582 EP 1589 PN A&B PG 8 WC Acoustics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Acoustics; Engineering; Instruments & Instrumentation; Materials Science; Optics GA BW52Z UT WOS:000182317500206 ER PT S AU Dunphy, JR Salcedo, JJ Murphy, KS AF Dunphy, JR Salcedo, JJ Murphy, KS BE Wang, GY Liu, Q Yao, YY Skowron, A TI Intelligent generation of candidate sets for genetic algorithms in very large search spaces SO ROUGH SETS, FUZZY SETS, DATA MINING, AND GRANULAR COMPUTING SE Lecture Notes in Artificial Intelligence LA English DT Article; Proceedings Paper CT 9th International Conference on Rough Sets, Fuzzy Sets, Data Mining and Granular Computing (RSFDGrC 2003) CY MAY 26-29, 2003 CL CHONGQING, PEOPLES R CHINA SP Natl Nat Sci Fdn China, Chongqing Municipal Educ Comm, Chongqing Municipal Sci & Technol Comm, Chongqing Bur Informat Ind AB We have been working on how to select safety measures for space missions in an optimal way. The main limitation on the measures that can be performed is cost. There are often hundreds of possible measures and each measure has an associated cost and an effectiveness that describes its potential to reduce the risk to the mission goals. A computer search of such an enormous search space is not practical if every combination is evaluated. It was therefore decided to use an evolutionary algorithm to improve the efficiency of the search. A simple approach would lead to many sets of solutions which were wildly expensive and so unfeasible. Preselecting candidates which meet the cost goals reduces the problem to a manageable size. Preselection is based on rough set theory since cost goals are usually not rigid. This paper describes the methodology of ensuring every candidate is roughly comparable in cost. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. EM Julia.Dunphy@jpl.nasa.gov; Jose.Salcedo@jpl.nasa.gov; Keri.Murphy@jpl.nasa.gov NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-14040-9 J9 LECT NOTES ARTIF INT PY 2003 VL 2639 BP 453 EP 457 PG 5 WC Computer Science, Artificial Intelligence SC Computer Science GA BX12N UT WOS:000184350600076 ER PT B AU Henderson, EM Maggio, G Elrada, HA Yazdpour, SJ AF Henderson, EM Maggio, G Elrada, HA Yazdpour, SJ BE Bedford, T VanGelder, PHA TI A dynamic risk model for evaluation of space shuttle abort scenarios SO SAFETY AND RELIABILITY, VOLS 1 AND 2 LA English DT Proceedings Paper CT 14th European Safety and Reliability Conference (ESREL 2003) CY JUN 15-18, 2003 CL MAASTRICHT, NETHERLANDS SP European Safety & Reliabil Assoc, TNO Public Safety, Directorate Gen Public Works & Waste Management, Holland Railconsult, Techn Univ Eindhoven, HIV Consultants, Arteca Consultancy, Delta PI, NRG, Simtech Engn AB As the Space Shuttle ascends to orbit it transverses various intact abort regions evaluated and planned before the flight to ensure that the Space Shuttle Orbiter, along with its crew, may be returned intact either to the original launch site, a transoceanic landing site, or from orbit. An intact abort may be initiated due to a number of system failures but the highest likelihood and most challenging abort scenarios are initiated by a premature shutdown of a Space Shuttle Main Engine (SSME). The potential consequences of such a shutdown vary as a function of a number of mission parameters but all of them may be related to mission time for a specific mission profile. This paper focuses on the Dynamic Abort Risk Evaluation (DARE) model process, applications, and its capability to evaluate the risk of Loss Of Vehicle (LOV) due to the complex systems interactions that occur during Space Shuttle intact abort scenarios. In addition, the paper will examine which of the Space Shuttle subsystems are critical to ensuring a successful return of the Space Shuttle Orbiter and crew from such a situation. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Henderson, EM (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU A A BALKEMA PUBLISHERS PI LEIDEN PA SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS BN 90-5809-551-7 PY 2003 BP 801 EP 806 PG 6 WC Engineering, Multidisciplinary SC Engineering GA BX15H UT WOS:000184438400109 ER PT J AU Harris, CE AF Harris, CE TI Everything at once SO SCIENTIFIC AMERICAN LA English DT Letter C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Harris, CE (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SCI AMERICAN INC PI NEW YORK PA 415 MADISON AVE, NEW YORK, NY 10017 USA SN 0036-8733 J9 SCI AM JI Sci.Am. PD JAN PY 2003 VL 288 IS 1 BP 12 EP 12 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 624YJ UT WOS:000179789500004 ER PT B AU Pravdo, SH Shaklan, SB AF Pravdo, SH Shaklan, SB BE Deming, D Seager, S TI Stellar Planet Survey-STEPS SO SCIENTIFIC FRONTIERS IN RESEARCH ON EXTRASOLAR PLANETS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Scientific Frontiers in Research on Extrasolar Planets CY JUN 18-21, 2002 CL CARNEGIE INST, WASHINGTON, D.C. SP NASA Origins Solar Syst Program HO CARNEGIE INST ID TRIPLE SYSTEM; COMPANION; SEARCH; STARS AB The Stellar Planet Survey (STEPS) is an astrometric search for planets around nearby stars. The advantages of astrometry are (1) the technique is more sensitive to detecting planets with larger planet-to-star separations, i.e. stellar systems similar to ours; and (2) the planet-to-star mass ratios are measured directly, independent of the system inclination angles. Since, in contrast, radial velocity searches are more sensitive to systems with smaller separations, the majority of known planets are close to their stars: only 25% of planets known today have orbits beyond 1.5 AU, and none are as distant as Jupiter. Our search for solar-like systems now has a temporal baseline of 4 years, and has yielded preliminary evidence for low-mass companions to some of our targets. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91106 USA. RP Pravdo, SH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91106 USA. NR 14 TC 3 Z9 4 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-141-9 J9 ASTR SOC P PY 2003 VL 294 BP 107 EP 110 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX68A UT WOS:000186106100021 ER PT B AU Farrell, WM Desch, MD Lazio, TJ Bastian, T Zarka, P AF Farrell, WM Desch, MD Lazio, TJ Bastian, T Zarka, P BE Deming, D Seager, S TI Limits on the magnetosphere/stellar wind interactions for the extrasolar planet about tau bootes SO SCIENTIFIC FRONTIERS IN RESEARCH ON EXTRASOLAR PLANETS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Scientific Frontiers in Research on Extrasolar Planets CY JUN 18-21, 2002 CL CARNEGIE INST, WASHINGTON, D.C. SP NASA Origins Solar Syst Program HO CARNEGIE INST ID TERRESTRIAL KILOMETRIC RADIATION; EMISSION AB Among the most impressive astronomical discoveries in the past decade are the observations of Jupiter-like planets in orbit around stars similar to our sun (Mayor and Queloz 1995; Marcy 1998). These extrasolar planets are detected primarily from optical signatures of the star's orbital perturbation about the star/planet center of mass. To date, over 80 massive planets have been discovered about sun-like stars, these stars located in the near-vicinity of our own solar system (< 100 pc). By analogy with the sun's gas giant planets, it has been predicted that these extrasolar planets will have electrically -active stellar-wind driven planetary magnetospheres possibly capable of emitting long-wavelength radio emission (Burke 1992; Farrell et al. 1999; Bastian et al. 2000; Zarka et al. 200 1) consistent with radiometric Bode's laws known to apply in our solar system. In 1999 and in 2002, the Very Large Array (VLA) surveyed the region near Tau Bootes for long-wavelength radio emission from its extrasolar planet. This planet had been previously predicted to be a good candidate for coherent electron cyclotron radio emission in the 10's of MHz. While no obvious signal was detected at 74 MHz to a sensitivity of <0.12 Jy (1 Jy= 10(26) W/m(2) Hz(-1)), the results can be applied to place upper limits on the stellar winds and planetary magnetic field. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Farrell, WM (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Farrell, William/I-4865-2013 NR 15 TC 10 Z9 10 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-141-9 J9 ASTR SOC P PY 2003 VL 294 BP 151 EP 156 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX68A UT WOS:000186106100028 ER PT B AU Nagasawa, M Lin, DNC AF Nagasawa, M Lin, DNC BE Deming, D Seager, S TI Eccentricity evolution of multiple planetary systems due to the depletion of protostellar disks SO SCIENTIFIC FRONTIERS IN RESEARCH ON EXTRASOLAR PLANETS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Scientific Frontiers in Research on Extrasolar Planets CY JUN 18-21, 2002 CL CARNEGIE INST, WASHINGTON, D.C. SP NASA Origins Solar Syst Program HO CARNEGIE INST AB We investigate the eccentricity evolution of non-resonant multiple extrasolar planets during the epoch in which the Protostellar disk outside the planets is gradually cleared. We calculate the initial eccentricities of planets around Upsilon Andromeda, HD168443, HD74156, and 47 UMa and analyze their evolution during depletion of the disk. We find that the disk depletion could cause a change in the eccentricities. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Nagasawa, M (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-141-9 J9 ASTR SOC P PY 2003 VL 294 BP 201 EP 204 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX68A UT WOS:000186106100038 ER PT B AU Quintana, EV AF Quintana, EV BE Deming, D Seager, S TI Terrestrial planet formation around a Centauri B SO SCIENTIFIC FRONTIERS IN RESEARCH ON EXTRASOLAR PLANETS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Scientific Frontiers in Research on Extrasolar Planets CY JUN 18-21, 2002 CL CARNEGIE INST, WASHINGTON, D.C. SP NASA Origins Solar Syst Program HO CARNEGIE INST ID BINARY STAR SYSTEMS; SYMPLECTIC INTEGRATOR; ACCRETION AB The late stages of terrestrial planet formation around each star in the alpha Centauri AB binary system are modeled using a recently developed symplectic algorithm designed to follow N-body systems with two dominant masses. Each integration begins with a circumstellar disk consisting of fourteen large embryos embedded in a disk of smaller planetesimals orbiting one star, and we follow the evolution of the accreting bodies for 200 Myr - 1 Gyr. This paper describes simulations in which the circumstellar disk lies in the binary orbital plane and is centered around alpha Centauri B, and they are compared with recent simulations of terrestrial planet formation in the solar system. Simulations of terrestrial planet growth around a Cen A are discussed elsewhere (Quintana et al. 2002). In both cases, the binary companion has a similar effect on terrestrial planet formation around the central star as Jupiter and Saturn have around the sun; i.e., the companion determines an outer boundary for the terrestrial region but doesn't prevent the formation of terrestrial planets. C1 NASA, Ames Res Ctr, Div Space Sci 245 3, Moffett Field, CA 94035 USA. RP Quintana, EV (reprint author), NASA, Ames Res Ctr, Div Space Sci 245 3, Moffett Field, CA 94035 USA. NR 8 TC 6 Z9 6 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-141-9 J9 ASTR SOC P PY 2003 VL 294 BP 319 EP 322 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX68A UT WOS:000186106100065 ER PT B AU Ipatov, SI AF Ipatov, SI BE Deming, D Seager, S TI Formation and migration of trans-neptunian objects SO SCIENTIFIC FRONTIERS IN RESEARCH ON EXTRASOLAR PLANETS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Scientific Frontiers in Research on Extrasolar Planets CY JUN 18-21, 2002 CL CARNEGIE INST, WASHINGTON, D.C. SP NASA Origins Solar Syst Program HO CARNEGIE INST ID COMETS AB Some large trans-Neptunian objects could be formed by the compression of rarefied dust condensations, but not by the accumulation of smaller planetesimals. A considerable portion of near-Earth objects could have come from the trans-Neptunian region. Our runs of the evolution of thousands orbits of Jupiter-family comets under the gravitational influence of planets showed that former Jupiter-family comets collide with the terrestrial planets mostly from orbits with aphelia located deep inside Jupiter's orbit. The total mass of water delivered by planetesimals from beyond Jupiter's orbit to the Earth could exceed the mass of Earth's oceans. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ipatov, SI (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-141-9 J9 ASTR SOC P PY 2003 VL 294 BP 349 EP 354 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX68A UT WOS:000186106100071 ER PT B AU Borucki, WJ Koch, DG Basri, GB Caldwell, DA Caldwell, JF Cochran, WD DeVore, E Dunham, EW Geary, JC Gilliland, RL Gould, A Jenkins, JM Kondo, Y Latham, DW Lissauer, JJ AF Borucki, WJ Koch, DG Basri, GB Caldwell, DA Caldwell, JF Cochran, WD DeVore, E Dunham, EW Geary, JC Gilliland, RL Gould, A Jenkins, JM Kondo, Y Latham, DW Lissauer, JJ BE Deming, D Seager, S TI The Kepler mission: Finding the sizes, orbits and frequencies of earth-size and larger extrasolar planets SO SCIENTIFIC FRONTIERS IN RESEARCH ON EXTRASOLAR PLANETS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Scientific Frontiers in Research on Extrasolar Planets CY JUN 18-21, 2002 CL CARNEGIE INST, WASHINGTON, D.C. SP NASA Origins Solar Syst Program HO CARNEGIE INST ID GIANT PLANETS; PHOTOMETRY; SPECTRA AB The first step in discovering the extent of life in our galaxy is to determine the number of terrestrial planets in circumstellar habitable zones (HZ). The Kepler Mission is designed around a 0.95 m aperture Schmidt-type telescope with an array of 42 CCDs. The photometer is designed to continuously monitor the brightness of 100,000 solar-like stars to detect the transits of Earth-size and larger planets. It is scheduled to be launched into a heliocentric orbit in 2007. Measurements of the depth and repetition time of transits provide the size of the planet relative to the star and its orbital period. When combined with ground-based spectroscopy of these stars to fix the stellar parameters, the true planet radius and orbit, semi-major axis, hence the position relative to the HZ, are determined. The spectra are also used to discover the relationships between the characteristics of planets and the stars that they orbit. In particular, the association of planetary size and occurrence frequency with stellar mass and metallicity will be investigated. At the end of the four year mission, hundreds of terrestrial planets should be discovered in and near the HZ of their stars if such planets are common. Extending the mission to six years doubles the expected number of Earth-size planets in the HZ. A null result would imply that terrestrial planets in the HZ occur in less than 1% of the stars and that habitable planets might be quite rare. Based on the results of the current Doppler velocity discoveries, detection of the reflected light from several hundred short-period giant planets is also expected. Information on the albedos and densities of those giants showing transits will be obtained. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Borucki, WJ (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI Caldwell, Douglas/L-7911-2014 OI Caldwell, Douglas/0000-0003-1963-9616 NR 11 TC 25 Z9 25 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-141-9 J9 ASTR SOC P PY 2003 VL 294 BP 427 EP 440 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX68A UT WOS:000186106100087 ER PT B AU Espenak, F AF Espenak, F BE Deming, D Seager, S TI 2004 and 2012 transits of Venus SO SCIENTIFIC FRONTIERS IN RESEARCH ON EXTRASOLAR PLANETS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Scientific Frontiers in Research on Extrasolar Planets CY JUN 18-21, 2002 CL CARNEGIE INST, WASHINGTON, D.C. SP NASA Origins Solar Syst Program HO CARNEGIE INST AB Venus will transit the sun's disk in 2004 and 2012. Detailed predictions are presented and include maps showing the global visibility of these rare planetary alignments. C1 Goddard Space Flight Ctr, Planetary Syst Branch, Greenbelt, MD 20771 USA. RP Espenak, F (reprint author), Goddard Space Flight Ctr, Planetary Syst Branch, Cod 693, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-141-9 J9 ASTR SOC P PY 2003 VL 294 BP 445 EP 448 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX68A UT WOS:000186106100089 ER PT B AU Sandell, G Becklin, EE Dunham, EW AF Sandell, G Becklin, EE Dunham, EW BE Deming, D Seager, S TI SOFIA - Science potential for extrasolar planet research SO SCIENTIFIC FRONTIERS IN RESEARCH ON EXTRASOLAR PLANETS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Scientific Frontiers in Research on Extrasolar Planets CY JUN 18-21, 2002 CL CARNEGIE INST, WASHINGTON, D.C. SP NASA Origins Solar Syst Program HO CARNEGIE INST ID PHOTOMETRY; TRANSITS; MISSION; IMAGES; SYSTEM; STARS; DUST AB The joint U.S. and German Stratospheric Observatory For Infrared Astronomy (SOFIA) project to develop and operate a 2.5-meter infrared airborne telescope in a Boeing 747-SP is now well into development. The telescope was delivered to the U.S. in September 2002 and will be integrated into the aircraft in early 2003. First science flights will begin in late 2004. Once fully operational the observatory will do 960 observing hours/year, with an expected lifetime of over 20 years. We give an overview of the characteristics of the observatory and its first suite of nine instruments, three of which are facility instruments, five are principal investigator instruments and one is a specialty instrument. C1 NASA, Ames Res Ctr, Univ Space Res Assoc, Moffett Field, CA 94035 USA. RP Sandell, G (reprint author), NASA, Ames Res Ctr, Univ Space Res Assoc, MS 144-2, Moffett Field, CA 94035 USA. NR 14 TC 4 Z9 4 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-141-9 J9 ASTR SOC P PY 2003 VL 294 BP 591 EP 594 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX68A UT WOS:000186106100114 ER PT S AU Southward, RE Pevzner, M Thompson, DW AF Southward, RE Pevzner, M Thompson, DW BE Lu, Y Brinker, CJ Antonietti, M Bai, C TI Silver-polyimide nanocomposite membranes: Self-generated highly reflective flexible mirrored surfaces SO SELF-ASSEMBLED NANOSTRUCTURED MATERIALS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Self-Assembled Nanostructured Materials held at the 2003 MRS Spring Meeting CY APR 22-25, 2003 CL SAN FRANCISCO, CA SP Mat Res Soc ID FILMS AB The synthesis of reflective silvered polyimide films by a single-stage auto-metallization process entailing the (hexafluoroacetylacetonato)silver(I) complex dissolved in solutions of poly(amic acid)s and polyimides formed from 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane-dianhydride (6FDA) and 2,2-bis(4-(4-aminophenoxy)hexafluoropropane (4-BDAF) is described. Heating cast silver(I)-poly(amic acid)/polyimide films effects silver(I) reduction and nano-aggregation giving reflective films for Ag concentrations from 6-10 wt %. A 6% silver film gives specular reflectivies greater than 80%. Films prepared from the soluble fully imidized form of 6FDA/4-BDAF were less reflective. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Southward, RE (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 8 TC 4 Z9 4 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-712-1 J9 MATER RES SOC SYMP P PY 2003 VL 775 BP 193 EP 198 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA BY10P UT WOS:000187670700030 ER PT S AU Pain, B Hancock, B AF Pain, B Hancock, B BE Blouke, MM Sampat, N Motta, RJ TI Accurate estimation of conversion gain and quantum efficiency in CMOS imagers SO SENSORS AND CAMERA SYSTEMS FOR SCIENTIFIC, INDUSTRIAL, AND DIGITAL PHOTOGRAPHY APPLICATIONS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors and Camera Systems for Scientific, Industrial, and Digital Photography Applications IV CY 2003 CL SANTA CLARA, CA SP Soc Imaging Sci & Technol, SPIE DE mean-variance method; quantum efficiency; CMOS imager; imager measurement ID SENSORS AB We present a new technique for accurate estimation of quantum efficiency, conversion gain; and noise in imagers. The traditional mean-variance method provides an erroneous estimation of these parameters for a non-linear device. Quantum efficiency, estimated by the mean-variance method; changes with the illumination level, a result that is inconsistent with theory. The estimation error can be easily larger than 50%; at mid-level illumination, and results from incorrect modeling of the transfer function. This is corrected by using non-linear estimation methods that force the slope of the photon transfer function to-be proportional to the conversion gain. This results in accurate modeling of the signal.. dependence of the conversion gain; and in turn, accurate estimation of quantum efficiency and noise. By applying both methods to the measured data gathered from the same mega-pixel imager operated under different biasing. conditions; it is shown that the non-linear estimation method provides a reliable and accurate estimation of quantum efficiency and noise, while the mean-variance method over-estimates quantum efficiency and under-estimates noise. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Pain, B (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 5 TC 14 Z9 14 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4817-6 J9 P SOC PHOTO-OPT INS PY 2003 VL 5017 BP 94 EP 103 DI 10.1117/12.483900 PG 10 WC Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Engineering; Optics; Imaging Science & Photographic Technology GA BW93U UT WOS:000183702400012 ER PT S AU Neeck, SP Kakar, RK Adams, WJ Smith, EA AF Neeck, SP Kakar, RK Adams, WJ Smith, EA BE Fujisada, H Lurie, JB Aten, ML Weber, K TI Enabling global precipitation measurement (GPM) SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE AB Of all the water on the Earth, only 3% is drinkable and two thirds of that water is locked away in polar ice. Precipitation constantly renews our fresh water resources and the latent heat it releases is the principal source of energy that drives atmospheric circulation and weather disturbances. It is the principal indicator of the rate of global water cycle and can also be used effectively as input for numerical weather forecasting. The Global Precipitation Measurement (GPM), a cooperative effort of the National Aeronautics and Space Administration (NASA) and Japan's National Space Development Agency (NASDA), aims to gather precipitation and related data globally. It will build upon the legacy of the extremely successful Tropical Rainfall Measuring Mission (TRMM) and will extend the spatial and temporal coverage of precipitation measurement to identify trends in the Earth's global water cycle, further explore the structure of rainfall to improve efforts to predict climate, and provide high quality rainfall accumulation products. GPM envisions a core satellite, up to eight constellation satellites, local ground validation sites and regional high quality rain gauge networks, and a global precipitation data system. It is anticipated that NASDA will provide the core satellite's dual frequency precipitation radar, its launch vehicle, and a constellation satellite. GPM's flexible architecture enables other international and domestic participants to provide enhancements incrementally as plans permit. The European Space Agency (ESA) is currently studying contributing a constellation satellite, EGPM, as an Earth Explorer Opportunity Mission. GPM is now in the Formulation Phase and is one of the highest priorities among the new missions for which NASA's Earth Science Enterprise seeks final approval. GPM launches are targeted to begin in 2007. C1 NASA, Washington, DC 20546 USA. RP Neeck, SP (reprint author), NASA, Headquarters, Washington, DC 20546 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4881 BP 67 EP 76 DI 10.1117/12.462594 PG 10 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200009 ER PT S AU Stocker, EF Koblinsky, C AF Stocker, EF Koblinsky, C BE Fujisada, H Lurie, JB Aten, ML Weber, K TI Sea-surface salinity: the missing measurement SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE aquarius; sea-surface; salinity; radiometer,scatterometer; ocean-circulation; thermohaline-circulation ID OCEAN AB Even the youngest child knows that the sea is salty. Yet, routine, global information about the degree of saltiness and the distribution of the salinity is not available. Indeed, the sea surface salinity measurement is a key missing measurement in global change research. Salinity influences circulation and links the ocean to global change and the water-cycle. Space-based remote sensing of important global change ocean parameters such as sea-surface temperature and water-cycle parameters such as precipitation have been available to the research community but a space-based global sensing of salinity has been missing. In July 2002, the National Aeronautical and Space Administration (NASA) announced that the Aquarius mission, focused on the global measurement of sea surface salinity, is one of the missions approved under its ESSP-3 program. Aquarius will begin a risk-reduction phase during 2003. Aquarius will carry a multi-beam 1.4 GHz (L-band) radiometer used for retrieving salinity. It also will carry a 1.2 GHz (L-band) scatterometer used for measuring surface roughness. Aquarius is tentatively scheduled for a 2006 launch into an 8-day Sun-synchronous orbit. Aquarius' key science data product will be a monthly, global surface salinity map at 100 km resolution with an accuracy of 0.2 practical salinity units. Aquarius will have a 3 year operational period. Among other things, global salinity data will permit estimates of sea surface density, or buoyancy, that drives the ocean's three-dimensional circulation. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Stocker, EF (reprint author), NASA, Goddard Space Flight Ctr, Code 902, Greenbelt, MD 20771 USA. NR 6 TC 0 Z9 0 U1 2 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4881 BP 77 EP 85 DI 10.1117/12.463041 PG 9 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200010 ER PT S AU Leibee, JE Kronenwetter, JA AF Leibee, JE Kronenwetter, JA BE Fujisada, H Lurie, JB Aten, ML Weber, K TI NPP: NASA's continuity mission for earth observation SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE remote sensing; NPP; NPOESS; VIIRS; CrIS; ATMS AB The NASA NPOESS Preparatory Project (NPP) is designed to collect radiometric data to make comprehensive measurements of atmospheric temperature and humidity, and cloud and aerosol properties. NPP will provide NASA with continuation of global change parameters after the Earth Observing System Terra and Aqua missions. In addition, NPP will provide a pre-operational risk reduction demonstration and validation of three critical instruments for the National Polar-Orbiting Operational Environmental Satellite System (NPOESS). NPP is a joint mission with NASA, NOAA, and the Department of Defense. NPP will launch in 2006 and operate in a sun synchronous descending node orbit, with a 10:30 AM equator crossing time. This paper discusses the NPP mission and the design of the satellite. The key Earth System Science observations that are to be taken are highlighted, along with the key Environmental Data Records (EDRs) that NPP will provide. The Key EDRs for which NPP will provide data are vertical moisture profile, vertical temperature profile, imagery, sea surface temperature, and soil moisture. The mission concept, including the satellite and ground system architecture, combines elements provided by NASA, the DoD, and NOAH. One of the driving requirements is providing complete EDRs within 180 minutes of observation, with a goal of within 90 minutes or less. For the NPOESS spacecraft the goal is 15 minutes from time of observation. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Leibee, JE (reprint author), NASA, Goddard Space Flight Ctr, Code 429, Greenbelt, MD 20771 USA. EM Jack.E.Leibee.1@.gsfc.nasa.gov; Jeffrey.A.Kronenwetter.1@gsfc.nasa.gov NR 4 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 PROC SPIE PY 2003 VL 4881 BP 86 EP 94 DI 10.1117/12.462508 PG 9 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200011 ER PT S AU Johns, AT Sabelhaus, PA Krimchansky, A AF Johns, AT Sabelhaus, PA Krimchansky, A BE Fujisada, H Lurie, JB Aten, ML Weber, K TI Techniques and trends in sensor data processing: NASA experiences with Earth observing satellites SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE NASA; earth science enterprise; EOS; sensor data capture; sensor data delivery AB NASA's Earth Science Mission Operations and Systems (ESMOS) Project is responsible for developing and operating sensor data capture, processing and delivery systems on behalf of NASA's Earth Science Enterprise (ESE). As the volume of sensor data being collected by the next generation of Earth observing satellites continues to dramatically increase, the demand for timely data delivery has correspondingly increased. The ESMOS Project has utilized a variety of techniques and methodologies to provide sensor data to the end user, and has collected a series of lessons learned with regard to the most efficient implementations based on the needs of the end user. This paper discusses the successes achieved and the pitfalls encountered by NASA, NOAA and ESA and makes recommendations for changes and enhancements to maximize future mission sensor data processing. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Johns, AT (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4881 BP 95 EP 103 DI 10.1117/12.462506 PG 9 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200012 ER PT S AU Aumann, HH Pagano, T AF Aumann, HH Pagano, T BE Fujisada, H Lurie, JB Aten, ML Weber, K TI Early results from AIRS on the EOS SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE hyperspectral; infrared; climate; radiometric calibration; weather-forecasting ID SEA-SURFACE AB The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua spacecraft is an infrared spectrometer/radiometer which covers the 650 - 2700 cm(-1) region of the spectrum with 2378 spectral channels. The EOS Aqua was launched on 4 May 2002 from Vandenburg AFB, California, into a 705km high, sun synchronous orbit. First tests of the radiometric calibration using the analysis of (observed - calculated) for data from a single, relatively cloud free 2500 x 2500 km area of the subtropical Atlantic ocean confirm absolute radiometric accuracy of better than 0.5K. The spectral information in the data also suggests that the analyzed region contained more moisture than the NCEP analysis. Based on these results we expect that the assimilation of AIRS data into the forecast to result in major medium range weather forecast improvements and that the data set recorded by AIRS during its nominal seven year lifetime will be a major resource for climate studies. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Aumann, HH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4881 BP 131 EP 136 DI 10.1117/12.462605 PG 6 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200016 ER PT S AU Markham, BL Barker, JL Barsi, JA Kaita, E Thome, KJ Helder, DL Palluconi, FD Schott, JR Scaramuzza, P AF Markham, BL Barker, JL Barsi, JA Kaita, E Thome, KJ Helder, DL Palluconi, FD Schott, JR Scaramuzza, P BE Fujisada, H Lurie, JB Aten, ML Weber, K TI Landsat-7 ETM+ radiometric stability and absolute calibration SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE Landsat; ETM; absolute calibration; vicarious calibration AB Launched in April 1999, the Landsat-7 ETM+ instrument is in its fourth year of operation. The quality of the acquired calibrated imagery continues to be high, especially with respect to its three most important radiometric performance parameters: reflective band instrument stability to better than +/-1%, reflective band absolute calibration to better than +/-5%, and thermal band absolute calibration to better than +/-0.6 K. The ETM+ instrument has been the most stable of any of the Landsat instruments, in both the reflective and thermal channels. To date, the best on-board calibration source for the reflective bands has been the Full Aperture Solar Calibrator, which has indicated changes of at most -1.8% to -2.0% (95% C.I.) change per year in the ETM+ gain (band 4). However, this change is believed to be caused by changes in the solar diffuser panel, as opposed to a change in the instrument's gain. This belief is based partially on ground observations, which bound the changes in gain in band 4 at -0.7% to +1.5%. Also, ETM+ stability is indicated by the monitoring of desert targets. These image-based results for four Saharan and Arabian sites, for a collection of 35 scenes over the three years since launch, bound the gain change at -0.7% to +0.5% in band 4. Thermal calibration from ground observations revealed an offset error of +0.31 W/m(2) sr um soon after launch. This offset was corrected within the U. S. ground processing system at EROS Data Center on 21-Dec-00, and since then, the band 6 on-board calibration has indicated changes of at most +0.02% to +0.04% (95% C.I.) per year. The latest ground observations have detected no remaining offset error with an RMS error of +/-0.6 K. The stability and absolute calibration of the Landsat-7 ETM+ sensor make it an ideal candidate to be used as a reference source for radiometric cross-calibrating to other land remote sensing satellite systems. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Markham, BL (reprint author), NASA, Goddard Space Flight Ctr, Code 923, Greenbelt, MD 20771 USA. RI Thome, Kurtis/D-7251-2012; Markham, Brian/M-4842-2013 OI Markham, Brian/0000-0002-9612-8169 NR 6 TC 5 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4881 BP 308 EP 318 DI 10.1117/12.462998 PG 11 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200033 ER PT S AU Butler, JJ Park, H Barnes, PY Early, EA van Eijk-Olij, C Zoutman, AE van Buller-Leeuwen, S Schaarsberg, JG AF Butler, JJ Park, H Barnes, PY Early, EA van Eijk-Olij, C Zoutman, AE van Buller-Leeuwen, S Schaarsberg, JG BE Fujisada, H Lurie, JB Aten, ML Weber, K TI Comparison of ultraviolet Bi-directional Reflectance Distribution Function (BRDF) measurements of diffusers used in the calibration of the Total Ozone Mapping Spectrometer (TOMS) SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE ID RADIOMETRIC CALIBRATION AB The measurement and long-term monitoring of global total ozone by ultraviolet albedo measuring satellite instruments require accurate and precise determination of the Bi-directional Reflectance Distribution Function (BRDF) of laboratory-based diffusers used in the pre-launch calibration of those instruments. To assess the ability of laboratories to provide accurate UltraViolet (UV) diffuse BRDF measurements, a BRDF measurement comparison was initiated by the NASA Total Ozone Mapping Spectrometer (TOMS) Project. From December 1998 to September 1999, NASA's Goddard Space Flight Center (GSFC), TPD TNO (formerly the TNO Institute of Applied Physics), and the National Institute of Standards and Technology (NIST) made BRDF measurements on four Spectralon diffusers used in the pre-launch calibration of three TOMS instruments. The diffusers were measured at the six TOMS wavelengths and at the incident and scatter angles used in the TOMS pre-launch calibration. The participation of GSFC, TPD TNO, and NIST in the comparison establishes a link between the diffuser calibrations of the on-orbit TOMS instruments, the Ozone Monitoring Instrument (OMI), and a national standards laboratory. The results of the comparison show that all of the BRDF measurements on the four diffusers agreed within +0.85% to -1.10% of the average BRDF and were well within the combined measurement uncertainties of the participating laboratories. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Butler, JJ (reprint author), NASA, Goddard Space Flight Ctr, Code 920-1, Greenbelt, MD 20771 USA. RI Butler, James/D-4188-2013 NR 8 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4881 BP 345 EP 354 DI 10.1117/12.463013 PG 10 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200037 ER PT S AU Barnes, RA Zalewski, EF AF Barnes, RA Zalewski, EF BE Fujisada, H Lurie, JB Aten, ML Weber, K TI The reflectance-based calibration of SeaWiFS SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE SeaWiFS; calibration; reflectance; on-board diffuser ID DIFFUSE-REFLECTANCE; OCEANIC WATERS; IRRADIANCE AB We present a calibration approach for the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) based on the reflectance properties of the instrument's onboard diffuser. This technique uses SeaWiFS as a reflectometer, measuring the reflected solar irradiance from the Earth and from the onboard diffuser. Since the sun is the common source of light for both measurements, the ratio of the SeaWiFS-measured radiances from the Earth and the diffuser provide the ratio for the reflectances of the two samples. The reflectance characterization of the onboard diffuser is the calibration reference for this approach. The result of the ratioing technique is based on the linearity of the instrument's response to the intensity of the input light. The calibration requires knowledge of the reflectance of the onboard diffuser at the start of the SeaWiFS mission, the response of the instrument bands, in digital numbers (DN), for measurements of the diffuser at that time, and the change of the instrument's response over time after the start of the mission. C1 NASA, Goddard Space Flight Ctr, SeaWiFS Project, Greenbelt, MD 20771 USA. RP Barnes, RA (reprint author), NASA, Goddard Space Flight Ctr, SeaWiFS Project, Code 970-2, Greenbelt, MD 20771 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4881 BP 355 EP 368 DI 10.1117/12.462495 PG 14 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200038 ER PT S AU Smith, GL Lee, RB Paden, J AF Smith, GL Lee, RB Paden, J BE Fujisada, H Lurie, JB Aten, ML Weber, K TI Dome degradation pattern of the ERBE wide field-of-view shortwave radiometer SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE calibration; degradation; radiation budget; radiometers ID RADIATION BUDGET EXPERIMENT AB The Earth Radiation Budget Satellite carried a nonscanning radiometer package for the measurement of the solar radiative flux which is reflected by the Earth and the outgoing longwave radiation from the Earth. These fluxes are measured by wide field-of-view radiometers, which are active cavity radiometers (ACRs) having apertures which are open to radiation from the Earth from one limb to the other. The reflected shortwave radiative flux is measured by an ACR which has a quartz dome over the aperture to cut out the OLR component. The instrument has operated for over 15 years, producing an unbroken data record of Earth radiation budget from one instrument. However, the during this time the dome degraded due to direct solar radiation during sun rise and sunset at the spacecraft. The degradation is taken into account by rotating the instrument every 2 weeks so as to view the Sun, which serves as a calibration target. However, the solar dosage varies over the surface of the dome, so that its degradation is not uniform. Moreover, the spacecraft operates so as to always have one side to the Sun, so that one side of the dome gets more exposure than the other. The question then arises as to what is the pattern of solar dosage and the resulting non-uniform degradation on the measurements? This paper computes the pattern of solar exposure of the dome. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Smith, GL (reprint author), NASA, Langley Res Ctr, MS 420, Hampton, VA 23681 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4881 BP 369 EP 377 DI 10.1117/12.462516 PG 9 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200039 ER PT S AU Poole, LR Winker, DM Pelon, JR McCormick, MP AF Poole, LR Winker, DM Pelon, JR McCormick, MP BE Fujisada, H Lurie, JB Aten, ML Weber, K TI CALIPSO: Global aerosol and cloud observations from lidar and passive instruments SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE lidar; aerosol; cloud; radiative forcing; climate AB CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Spaceborne Observations) is an approved satellite mission being developed through collaboration between NASA and the French space agency CNES. The mission is scheduled for launch in 2004 and will operate for 3 years as part of a five-satellite formation called the Aqua constellation. This constellation will provide a unique data set on aerosol and cloud optical and physical properties and aerosol-cloud interactions that will substantially increase our understanding of the climate system and the potential for climate change. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Poole, LR (reprint author), NASA, Langley Res Ctr, MS 435, Hampton, VA 23681 USA. NR 2 TC 13 Z9 13 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4881 BP 419 EP 426 DI 10.1117/12.462519 PG 8 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200044 ER PT S AU Habib, S Hildebrand, P AF Habib, S Hildebrand, P BE Fujisada, H Lurie, JB Aten, ML Weber, K TI Sensor web architectural concepts and implementation challenges - An heuristic approach SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE AB There is a significant interest in the Earth Science remote sensing community in substantially increasing the number of observations relative to the current frequency of collection. The obvious reason for such a push is to improve the temporal and surface coverage of measurements. However, there is little analysis available in terms of benefits, costs and optimized set of sensors needed to make these necessary observations. This is a complex problem that should be carefully studied and balanced over many boundaries. For example, the question of technology maturity versus users' desire for obtaining additional measurements is noncongruent. This is further complicated by the limitations of the laws of physics and the economic conditions. With the advent of advanced technology, it is anticipated that developments in spacecraft technology will enable advanced capabilities to become more affordable. However, specialized detector subsystems, and precision flying techniques may still require substantial innovation, development time and cost. Additionally, the space deployment scheme should also be given careful attention because of the high associated expense. Nonetheless, it is important to carefully examine the science priorities and steer the development efforts that can commensurate with the tangible requirements. This paper outlines a possible set of architectural concepts, operational scenarios and potential benefits of one scheme versus another. It further makes some suggestions where one can draw boundary conditions to incrementally solve this predicament. C1 Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Habib, S (reprint author), Goddard Space Flight Ctr, Code 900, Greenbelt, MD 20771 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4881 BP 438 EP 447 DI 10.1117/12.462615 PG 10 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200046 ER PT S AU Heaps, WS AF Heaps, WS BE Fujisada, H Lurie, JB Aten, ML Weber, K TI Simple Fabry-Perot based instrument for surface pressure sensing from space SO SENSORS, SYSTEMS AND NEXT-GENERATION SATELLITES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems and Next-Generation Satellites VI CY SEP 23-26, 2002 CL AGIA PELAGIA, GREECE SP SPIE DE remote sensing; pressure; oxygen; A-band AB Mitchel and O'Bnen observed in 1989 that a passive satellite measurement using the oxygen A-band could exhibit a precision better than 1 % when used to make a surface pressure measurement. We will present a design and performance simulation for a Fabry-Perot interferometer based instrument which should exceed this level of performance. The design is small, inexpensive and rugged. C1 NASA, Goddard Space Flight Ctr, Instrument Syst & Technol Div, Greenbelt, MD 20771 USA. RP Heaps, WS (reprint author), NASA, Goddard Space Flight Ctr, Instrument Syst & Technol Div, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4663-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4881 BP 543 EP 548 DI 10.1117/12.462997 PG 6 WC Remote Sensing; Optics; Imaging Science & Photographic Technology SC Remote Sensing; Optics; Imaging Science & Photographic Technology GA BW68V UT WOS:000182828200056 ER PT J AU Mohamadinejad, H Knox, JC Smith, JE AF Mohamadinejad, H Knox, JC Smith, JE TI Experimental and numerical investigation of two-dimensional CO2 adsorption/desorption in packed sorption beds under non-ideal flows SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article ID HEAT-TRANSFER; FIXED-BED; DIFFUSION; SPHERES AB The experimental results Of CO2 adsorption and desorption in a packed column indicated that the concentration wave front at the center of the packed column differs from those close to the wall of column filled with adsorbent material even though the ratio of column diameter to the particle size is greater than 20([1]) The comparison of the experimental results with one-dimensional model of packed column shows that to simulate the average breakthrough in a packed column, a two-dimensional (radial and axial) model of packed column is needed.([2]) In this article, the mathematical model of a nonslip flow through a packed column 2 inches in diameter and 18 inches in length filled with 5A zeolite pellets is presented. The comparison of experimental results of CO2 adsorption and desorption for the mixed and central breakthrough of the packed column with numerical results is also presented. C1 Univ Alabama, Dept Chem Engn, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Smith, JE (reprint author), Univ Alabama, Dept Chem Engn, Huntsville, AL 35899 USA. NR 31 TC 6 Z9 7 U1 1 U2 10 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2003 VL 38 IS 16 BP 3875 EP 3904 DI 10.1081/SS-120024710 PG 30 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 736QB UT WOS:000186180700001 ER PT B AU Beaver, JM Schiavone, GA AF Beaver, JM Schiavone, GA BE AlAni, B Arabnia, HR Mun, Y TI A comparison of software quality modeling techniques SO SERP'03: PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING RESEARCH AND PRACTICE, VOLS 1 AND 2 LA English DT Proceedings Paper CT International Conference on Software Engineering Research and Practice CY JUN 23-26, 2003 CL LAS VEGAS, NV SP Comp Sci Res, Educ & Applicat Press, Int Technol Inst, Korean Soc Internet Informat, World Acad Sci Informat Technol DE error-prone software; predictive statistical models; software metrics; software quality ID DESIGN METRICS AB Accurately representing the quality of software under development remains a major challenge to the software engineering discipline. Many approaches have been offered that attempt to capture the complex relationships between metrics captured during design, and the final quality of the software product. Unfortunately, most of these approaches are either controversial in terms of their validity or simply not universally applicable. This study compares the effectiveness of three different estimation techniques: least square regression, relative least squares regression, and the iterative averaging algorithm Using the average relative error criterion, it is the iterative averaging algorithm, a very simple method of spatial data analysis, that is revealed to be superior in terms its ability to correctly represent a given data set, and its ability to provide accurate and valid predictions about whether or not a given software module will be error-prone. C1 NASA, Spaceport Proc Syst, Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. RP Beaver, JM (reprint author), NASA, Spaceport Proc Syst, Kennedy Space Ctr, Mail Code YA-D8, Kennedy Space Ctr, FL 32899 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU C S R E A PRESS PI ATHENS PA 115 AVALON DR, ATHENS, GA 30606 USA BN 1-932415-21-1 PY 2003 BP 263 EP 266 PG 4 WC Computer Science, Software Engineering SC Computer Science GA BY09H UT WOS:000187617100041 ER PT J AU Loncaric, J Tsynkov, SV AF Loncaric, J Tsynkov, SV TI Optimization of acoustic source strength in the problems of active noise control SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE noise cancellation; control sources; minimization of amplitude; volume velocity; surface monopoles ID ARTIFICIAL BOUNDARY-CONDITIONS; FLOW AB We consider a problem of eliminating the unwanted time-harmonic noise on a predetermined region of interest. The desired objective is achieved by active means, i.e., by introducing additional sources of sound called control sources, which generate the appropriate annihilating acoustic signal (antisound). A general solution for the control sources has been obtained previously in both continuous and discrete formulation of the problem. In the current paper, we focus on optimizing the overall absolute acoustic source strength of the control sources. Mathematically, this amounts to the minimization of multivariable complex-valued functions in the sense of L-1 with conical constraints, which are only "marginally" convex. The corresponding numerical optimization problem appears very challenging even for the most sophisticated state-of-the-art methodologies, and even when the dimension of the grid is small and the waves are long. Our central result is that the global L-1-optimal solution can, in fact, be obtained without solving the numerical optimization problem. This solution is given by a special layer of monopole sources on the perimeter of the protected region. We provide a rigorous proof of global L-1 minimality for both continuous and discrete optimization problems in the one-dimensional case. We also provide numerical evidence that corroborates our result in the two-dimensional case, when the protected domain is a cylinder. Even though we cannot fully justify it, we believe that the same result holds in the general case, i.e., for multidimensional settings and domains of arbitrary shape. We formulate this notion as a conjecture at the end of the paper. C1 NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. N Carolina State Univ, Dept Math, Raleigh, NC 27695 USA. Tel Aviv Univ, Sch Math Sci, IL-69978 Tel Aviv, Israel. RP Loncaric, J (reprint author), Natl Inst Aerosp, 144 Res Dr, Hampton, VA 23666 USA. NR 26 TC 21 Z9 22 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PY 2003 VL 63 IS 4 BP 1141 EP 1183 AR PII S0036139902404220 DI 10.1137/S0036139902404220 PG 43 WC Mathematics, Applied SC Mathematics GA 690BT UT WOS:000183528000003 ER PT J AU Bryson, S Levy, D AF Bryson, S Levy, D TI High-order central WENO schemes for multidimensional Hamilton-Jacobi equations SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE Hamilton-Jacobi equations; central schemes; high order; WENO; CWENO ID HYPERBOLIC CONSERVATION-LAWS; ESSENTIALLY NONOSCILLATORY SCHEMES; WEIGHTED ENO SCHEMES; VISCOSITY SOLUTIONS; EFFICIENT IMPLEMENTATION; TRIANGULAR MESHES; SYSTEMS; DISCRETIZATION AB We present new third- and fifth-order Godunov-type central schemes for approximating solutions of the Hamilton-Jacobi (HJ) equation in an arbitrary number of space dimensions. These are the first central schemes for approximating solutions of the HJ equations with an order of accuracy that is greater than two. In two space dimensions we present two versions for the third- order scheme: one scheme that is based on a genuinely two-dimensional central weighted ENO reconstruction, and another scheme that is based on a simpler dimension-by-dimension reconstruction. The simpler dimension-by-dimension variant is then extended to a multidimensional fifth-order scheme. Our numerical examples in one, two, and three space dimensions verify the expected order of accuracy of the schemes. C1 NASA, Ames Res Ctr, NASA Adv Supercomp Div, Moffett Field, CA 94035 USA. Stanford Univ, Program Sci Comp Computat Math, Stanford, CA 94305 USA. RP Bryson, S (reprint author), Stanford Univ, Program Sci Comp Computat Math, Stanford, CA 94305 USA. NR 40 TC 39 Z9 39 U1 0 U2 4 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1429 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PY 2003 VL 41 IS 4 BP 1339 EP 1369 DI 10.1137/S0036142902408404 PG 31 WC Mathematics, Applied SC Mathematics GA 730DJ UT WOS:000185813700009 ER PT J AU Dolan, ED Lewis, RM Torczon, V AF Dolan, ED Lewis, RM Torczon, V TI On the local convergence of pattern search SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE pattern search; local convergence analysis; global convergence analysis; stopping criteria; desultory rate of convergence ID CONSTRAINED MINIMIZATION; OPTIMIZATION; ALGORITHMS AB We examine the local convergence properties of pattern search methods, complementing the previously established global convergence properties for this class of algorithms. We show that the step-length control parameter which appears in the definition of pattern search algorithms provides a reliable asymptotic measure of first-order stationarity. This gives an analytical justification for a traditional stopping criterion for pattern search methods. Using this measure of first-order stationarity, we both revisit the global convergence properties of pattern search and analyze the behavior of pattern search in the neighborhood of an isolated local minimizer. C1 Northwestern Univ, Argonne, IL 60439 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Coll William & Mary, Dept Math, Williamsburg, VA 23187 USA. Coll William & Mary, Dept Comp Sci, Williamsburg, VA 23187 USA. NASA, Langley Res Ctr, ICASE, Hampton, VA 23665 USA. RP Dolan, ED (reprint author), Northwestern Univ, Argonne, IL 60439 USA. NR 18 TC 63 Z9 63 U1 0 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PY 2003 VL 14 IS 2 BP 567 EP 583 DI 10.1037/S1052623400374495 PG 17 WC Mathematics, Applied SC Mathematics GA 759MT UT WOS:000187742000015 ER PT J AU Diskin, B Thomas, JL AF Diskin, B Thomas, JL TI New factorizable discretizations for the Euler equations SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article; Proceedings Paper CT 7th Annual Copper Mountain Conference on Iterative Methods CY MAR 24-29, 2002 CL COPPER MT, COLORADO SP Univ Colorado, SIAM DE Euler equations; textbook multigrid efficiency; distributed relaxation; factorizable schemes ID TEXTBOOK MULTIGRID EFFICIENCY; NAVIER-STOKES EQUATIONS; RECIRCULATING-FLOWS; SOLVERS; CONVERGENCE AB A multigrid method is defined as having textbook multigrid efficiency (TME) if solutions to the governing system of equations are attained in a computational work that is a small ( less than 10) multiple of the operation count in one target-grid residual evaluation. A way to achieve TME for the Euler and Navier-Stokes equations is to apply the distributed relaxation method, thereby separating the elliptic and hyperbolic partitions of the equations. Design of a distributed relaxation scheme can be significantly simplified if the principal linearization of the target discretization possesses two properties: ( 1) factorizability and ( 2) consistent approximations for the separate factors. The first property implies that the discrete system determinant can be represented as a product of discrete factors, each of them approximating a corresponding factor of the determinant of the differential equations. The second property requires that the discrete factors reflect the physical anisotropies, be stable, and be easily solvable. This paper presents an approach to the derivation of discretization schemes for which TME can be achieved by multigrid solvers with distributed relaxation. In particular, discrete schemes for the nonconservative Euler equations possessing properties ( 1) and ( 2) have been derived and analyzed. The accuracy of these scheme has been tested for subsonic flow regimes and compared with accuracy of standard schemes. TME has been demonstrated in solving fully subsonic quasi-one-dimensional flow in a convergent/divergent channel. C1 Natl Inst Aerosp, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA. RP Diskin, B (reprint author), Natl Inst Aerosp, 144 Res Dr, Hampton, VA 23681 USA. NR 31 TC 2 Z9 2 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2003 VL 25 IS 2 BP 657 EP 681 DI 10.1137/S1064827502404787 PG 25 WC Mathematics, Applied SC Mathematics GA 752FG UT WOS:000187148900018 ER PT S AU Neudeck, PG Spry, DJ Trunek, AJ Powell, JA Beheim, GM AF Neudeck, PG Spry, DJ Trunek, AJ Powell, JA Beheim, GM BE Saddow, SE Larkin, DJ Saks, NS Schoner, A TI Confinement of screw dislocations to predetermined lateral positions in (0001) 4H-SiC epilayers using homoepitaxial web growth SO SILICON CARBIDE 2002-MATERIALS, PROCESSING AND DEVICES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Silicon Carbide-Materials, Processing and Devices held at the 2002 MRS Fall Meeting CY DEC 02-04, 2002 CL BOSTON, MA SP Mat Res Soc, Army Res Lab, NASA Glenn Res Ctr, Off Naval Res ID BREAKDOWN; SURFACES; DEFECTS; WAFERS AB This paper reports initial demonstration of a cantilevered homoepitaxial growth process that places screw dislocations at predetermined lateral positions in on-axis 4H-SiC mesa epilayers. Thin cantilevers were grown extending toward the interior of hollow pre-growth mesa shapes etched into an on-axis 4H-SiC wafer, eventually completely coalescing to form roofed cavities. Each completely coalesced cavity exhibited either: 1) a screw dislocation growth spiral located exactly where final cantilever coalescence occurred, or 2) no growth spiral. The fact that growth spirals are not observed at any other position except the central coalescence point suggests that substrate screw dislocations, initially surrounded by the hollow portion of the pre-growth mesa shape, are relocated to the final coalescence point of the webbed epilayer roof Molten potassium hydroxide etch studies revealed that properly grown webbed cantilevers exhibited no etch pits, confirming the superior crystal quality of the cantilevers. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Neudeck, PG (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 77-1, Cleveland, OH 44135 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-679-6 J9 MATER RES SOC SYMP P PY 2003 VL 742 BP 241 EP 246 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Characterization & Testing SC Engineering; Instruments & Instrumentation; Materials Science GA BW52N UT WOS:000182316400033 ER PT B AU Gentry, BM Chen, HL Li, SX Mathur, S Dobler, J Hasselbrack, W AF Gentry, BM Chen, HL Li, SX Mathur, S Dobler, J Hasselbrack, W BE Wandinger, U TI Tropospheric wind profiles obtained with the GLOW molecular Doppler lidar during the 2002 International H2O Project SO SIXTH INTERNATIONAL SYMPOSIUM ON TROPOSPHERIC PROFILING: NEEDS AND TECHNOLOGIES LA English DT Proceedings Paper CT 6th International Symposium on Tropospheric Profiling CY SEP 14-20, 2003 CL Leipzig, GERMANY SP Inst Tropospher Res, German Weather Serv, Meteorol Observ Lindenberg, IFT, DWD, DLR, Sachsen, DFG DE Doppler lidar; tropospheric wind; double edge technique; Fabry-Perot etalon ID VALIDATION AB The Goddard Lidar Observatory for Winds (GLOW) is a mobile direct detection Doppler lidar system which uses the double edge technique to measure the Doppler shift of the molecular backscattered laser signal at a wavelength of 355 nm. In the spring of 2002 GLOW was deployed to the western Oklahoma profiling site (36degrees 33.500' N, 100degrees 36.371' W) to participate in the International H2O Project (IHOP). During the IHOP campaign over 240 hours of wind profiles were obtained with the GLOW lidar in support of a variety of scientific investigations. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Gentry, BM (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 912, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU INST TROPICAL MEDICINE ROTTERDAM - LEIDEN PI LEIDEN PA WASSENAARSEWEG 62, POSTBUS 9605, 2300 LEIDEN, NETHERLANDS PY 2003 BP 6 EP 8 PG 3 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications GA BY76Y UT WOS:000189458700002 ER PT B AU Schwemmer, GK Miller, DO Wilkerson, TD AF Schwemmer, GK Miller, DO Wilkerson, TD BE Wandinger, U TI HARLIE aerosol and cloud structure and wind observations during HARGLO and IHOP SO SIXTH INTERNATIONAL SYMPOSIUM ON TROPOSPHERIC PROFILING: NEEDS AND TECHNOLOGIES LA English DT Proceedings Paper CT 6th International Symposium on Tropospheric Profiling CY SEP 14-20, 2003 CL Leipzig, GERMANY SP Inst Tropospher Res, German Weather Serv, Meteorol Observ Lindenberg, IFT, DWD, DLR, Sachsen, DFG DE scanning lidar; wind; aerosols; clouds; boundary layer AB The Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE) is a conical-scanning, 1-mum wavelength lidar that has been adapted for ground-based applications and used to infer horizontal wind information by tracking the motions of aerosol and cloud scattering structures. In addition, HARLIE's rapid continuous scanning enables boundary layer statistics and a new cloud lidar data product that gives cloud coverage as a function of altitude with high temporal resolution. HARLIE has been used in several field campaigns while developing the techniques for wind, boundary layer (BL), and cloud data products. These campaigns involved a variety of wind measuring instruments including rawindsondes, cloud-tracked winds from video imagery, Doppler lidars and Doppler radars. HARGLO-2 was one of these campaigns and was dedicated to wind profile intercomparisons over a 1-week period in November of 2001. The most recent of these campaigns was the International H2O Project (IHOP) located in the Southern Great Plains of the US during May and June of 2002. C1 Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Schwemmer, GK (reprint author), Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. NR 2 TC 2 Z9 2 U1 0 U2 0 PU INST TROPICAL MEDICINE ROTTERDAM - LEIDEN PI LEIDEN PA WASSENAARSEWEG 62, POSTBUS 9605, 2300 LEIDEN, NETHERLANDS PY 2003 BP 65 EP 67 PG 3 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications GA BY76Y UT WOS:000189458700020 ER PT B AU Shiue, JC AF Shiue, JC BE Wandinger, U TI The evolution of spaceborne microwave temperature and humidity sounders for operational polar-orbiting weather satellites SO SIXTH INTERNATIONAL SYMPOSIUM ON TROPOSPHERIC PROFILING: NEEDS AND TECHNOLOGIES LA English DT Proceedings Paper CT 6th International Symposium on Tropospheric Profiling CY SEP 14-20, 2003 CL Leipzig, GERMANY SP Inst Tropospher Res, German Weather Serv, Meteorol Observ Lindenberg, IFT, DWD, DLR, Sachsen, DFG DE microwave radiometry; temperature & humidity sounders C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Shiue, JC (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INST TROPICAL MEDICINE ROTTERDAM - LEIDEN PI LEIDEN PA WASSENAARSEWEG 62, POSTBUS 9605, 2300 LEIDEN, NETHERLANDS PY 2003 BP 131 EP 132 PG 2 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications GA BY76Y UT WOS:000189458700043 ER PT B AU Ferrare, RA Clayton, MB Feltz, W Ogren, JA Andrews, E Turner, DD AF Ferrare, RA Clayton, MB Feltz, W Ogren, JA Andrews, E Turner, DD BE Wandinger, U TI Measurements of water vapor and aerosol profiles over the ARM SGP site SO SIXTH INTERNATIONAL SYMPOSIUM ON TROPOSPHERIC PROFILING: NEEDS AND TECHNOLOGIES LA English DT Proceedings Paper CT 6th International Symposium on Tropospheric Profiling CY SEP 14-20, 2003 CL Leipzig, GERMANY SP Inst Tropospher Res, German Weather Serv, Meteorol Observ Lindenberg, IFT, DWD, DLR, Sachsen, DFG DE Aerosol extinction; optical thickness; water vapor; relative humidity ID EMITTED RADIANCE INTERFEROMETER; SOUTHERN GREAT-PLAINS; RAMAN LIDAR; TEMPERATURE; RETRIEVALS; EXTINCTION; ACCURACY; AERI AB We review the water vapor and aerosol profiling measurements acquired at the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site in northern Oklahoma (36.606 N, 97.50 W). We discuss examples of these measurements and show how they have been used to study the water vapor and aerosol variability over this site during the past several years. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Ferrare, RA (reprint author), NASA, Langley Res Ctr, MS 401A, Hampton, VA 23681 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU INST TROPICAL MEDICINE ROTTERDAM - LEIDEN PI LEIDEN PA WASSENAARSEWEG 62, POSTBUS 9605, 2300 LEIDEN, NETHERLANDS PY 2003 BP 203 EP 205 PG 3 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications GA BY76Y UT WOS:000189458700066 ER PT B AU Heaps, WS Kawa, SR Georgieva, E Wilson, E AF Heaps, WS Kawa, SR Georgieva, E Wilson, E BE Wandinger, U TI Progresson passive sensor for ultra-precise measurement Of CO2 SO SIXTH INTERNATIONAL SYMPOSIUM ON TROPOSPHERIC PROFILING: NEEDS AND TECHNOLOGIES LA English DT Proceedings Paper CT 6th International Symposium on Tropospheric Profiling CY SEP 14-20, 2003 CL Leipzig, GERMANY SP Inst Tropospher Res, German Weather Serv, Meteorol Observ Lindenberg, IFT, DWD, DLR, Sachsen, DFG DE carbon dioxide; carbon cycle; Fabry-Perot AB We will present results from a novel instrument employing a Fabry-Perot interferometer to measure column carbon dioxide with great precision. These measurements are very important for improving our understanding of the global warming phenomenon. The instrument technique can be extended to a number of other important trace gases in the atmosphere. C1 NASA, Goddard Space Flight Ctr, Instrument Syst & Technol Div, Greenbelt, MD 20771 USA. RP Heaps, WS (reprint author), NASA, Goddard Space Flight Ctr, Instrument Syst & Technol Div, Code 661, Greenbelt, MD 20771 USA. RI Wilson, Emily/C-9158-2012; Kawa, Stephan/E-9040-2012 OI Wilson, Emily/0000-0001-5634-3713; NR 0 TC 2 Z9 2 U1 0 U2 0 PU INST TROPICAL MEDICINE ROTTERDAM - LEIDEN PI LEIDEN PA WASSENAARSEWEG 62, POSTBUS 9605, 2300 LEIDEN, NETHERLANDS PY 2003 BP 252 EP 254 PG 3 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications GA BY76Y UT WOS:000189458700083 ER PT B AU Whiteman, D Demoz, B Di Girolamo, P Wang, Z Evans, K Lin, RF AF Whiteman, D Demoz, B Di Girolamo, P Wang, Z Evans, K Lin, RF BE Wandinger, U TI NASA/GSFC Scanning Raman Lidar measurements of water vapor and clouds during the International H2O Project (IHOP) field campaign SO SIXTH INTERNATIONAL SYMPOSIUM ON TROPOSPHERIC PROFILING: NEEDS AND TECHNOLOGIES LA English DT Proceedings Paper CT 6th International Symposium on Tropospheric Profiling CY SEP 14-20, 2003 CL Leipzig, GERMANY SP Inst Tropospher Res, German Weather Serv, Meteorol Observ Lindenberg, IFT, DWD, DLR, Sachsen, DFG AB The NASA/GSFC Scanning Raman Lidar (SRL) acquired approximately 200 hours of water vapor, aerosol and cloud measurements during the IHOP field campaign. The detailed water vapor structure of events such as a dryline passage and internal bores were revealed. We discuss the error characteristics of the instrument as well as the water vapor and cirrus cloud structure during the 19-20 June bore event. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Whiteman, D (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU INST TROPICAL MEDICINE ROTTERDAM - LEIDEN PI LEIDEN PA WASSENAARSEWEG 62, POSTBUS 9605, 2300 LEIDEN, NETHERLANDS PY 2003 BP 381 EP 383 PG 3 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications GA BY76Y UT WOS:000189458700125 ER PT B AU Browell, EV Ismail, S Ferrare, RA Kooi, SA Notari, A Butler, CF Brackett, VG Revercomb, HE Antonelli, P AF Browell, EV Ismail, S Ferrare, RA Kooi, SA Notari, A Butler, CF Brackett, VG Revercomb, HE Antonelli, P BE Wandinger, U TI Airborne remote measurements of water vapor, relative humidity, aerosol, and cloud distributions during the IHOP field experiment SO SIXTH INTERNATIONAL SYMPOSIUM ON TROPOSPHERIC PROFILING: NEEDS AND TECHNOLOGIES LA English DT Proceedings Paper CT 6th International Symposium on Tropospheric Profiling CY SEP 14-20, 2003 CL Leipzig, GERMANY SP Inst Tropospher Res, German Weather Serv, Meteorol Observ Lindenberg, IFT, DWD, DLR, Sachsen, DFG DE water vapor; aerosols; clouds; relative humidity; airborne lidar; LASE; scanning HIS AB The Lidar Atmospheric Sensing Experiment (LASE) was flown on the NASA DC-8 aircraft to investigate large-scale variations in water vapor (H,O-2), aerosols, and clouds during the International H2O Project (IHOP) conducted over the Southern Great Plains during May-June 2002. During IHOP, LASE data were used on several missions to examine the spatial and temporal characteristics of dry lines and fronts and the onset of convection along them and to map the spatial and temporal gradients in boundary layer H2O distributions under relatively quiescent conditions and in the presence of low level jets. This paper describes the LASE system and discusses LASE measurements of H2O, aerosols, and clouds during the IHOP field experiment and associated relative humidity (RH) distributions derived from average radiosonde temperature (T) profiles and from Scanning High-resolution Interferometer Sounder (S-HIS) T profiles measured along the DC-8 flight track. C1 NASA Langley Res Ctr, Hampton, VA 23681 USA. RP Browell, EV (reprint author), NASA Langley Res Ctr, MS-401A, Hampton, VA 23681 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU INST TROPICAL MEDICINE ROTTERDAM - LEIDEN PI LEIDEN PA WASSENAARSEWEG 62, POSTBUS 9605, 2300 LEIDEN, NETHERLANDS PY 2003 BP 384 EP 386 PG 3 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications GA BY76Y UT WOS:000189458700126 ER PT B AU Demoz, B Miller, D Evans, K Whiteman, D Di Girolamo, P Schwemmer, G Gentry, B Starr, D Wang, Z AF Demoz, B Miller, D Evans, K Whiteman, D Di Girolamo, P Schwemmer, G Gentry, B Starr, D Wang, Z BE Wandinger, U TI Moisture, wind, and boundary layer evolution during a dryline in IHOP-2002: 22 May 2002 SO SIXTH INTERNATIONAL SYMPOSIUM ON TROPOSPHERIC PROFILING: NEEDS AND TECHNOLOGIES LA English DT Proceedings Paper CT 6th International Symposium on Tropospheric Profiling CY SEP 14-20, 2003 CL Leipzig, GERMANY SP Inst Tropospher Res, German Weather Serv, Meteorol Observ Lindenberg, IFT, DWD, DLR, Sachsen, DFG DE dryline; wind lidar; Raman lidar; holographic lidar; boundary layer; IHOP_2002 ID LIDAR AB As part of the International H2O Project (IHOP_2002), three NASA/GSFC lidars acquired high-resolution clear air data of wind, CBL evolution, and water vapor mixing ratio profiles during a dryline event that occurred on 22 May 2002. Together with the anciliary suite of instruments deployed in IHOP_2002, these lidar data sets offer a unique look into the mesoscale evolution and convective scale dynamics in and around a dryline. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Demoz, B (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU INST TROPICAL MEDICINE ROTTERDAM - LEIDEN PI LEIDEN PA WASSENAARSEWEG 62, POSTBUS 9605, 2300 LEIDEN, NETHERLANDS PY 2003 BP 387 EP 389 PG 3 WC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications SC Instruments & Instrumentation; Meteorology & Atmospheric Sciences; Imaging Science & Photographic Technology; Telecommunications GA BY76Y UT WOS:000189458700127 ER PT S AU Lee, PU Klippel, A Tappe, H AF Lee, PU Klippel, A Tappe, H BE Butz, A Kruger, A Olivier, P TI The effect of motion in graphical user interfaces SO SMART GRAPHICS, PROCEEDINGS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 3rd International Symposium on Smart Graphics CY JUL 02-04, 2003 CL EUROPEAN MEDIA LAB, HEIDELBERG, GERMANY SP Klaus Tschira Fdn, Corel Corp HO EUROPEAN MEDIA LAB AB Motion can be an effective tool to focus user's attention and to support the parsing of complex information in. graphical user interfaces. Despite the ubiquitous use of motion in animated displays, its effectiveness has been marginal at best. The ineffectiveness of many animated displays may be due to a mismatch between the attributes of motion and the nature of the task at hand. To test this hypothesis, we examined different modes of route presentation that are commonly used today (e.g. internet maps, GPS maps, etc.) and their effects on the subsequent route memory. Participants learned a route from a map of a fictitious town. The route was presented to them either as a solid line (static) or as a moving dot.(dynamic). In a subsequent memory task, participants recalled fewer pertinent landmarks (i.e. landmarks at the turns) in the dynamic condition, likely due to the moving dot that focused equally on critical and less important parts of the route. A second study included a combined (i.e. both static and dynamic) presentation mode, which potentially had a better recall than either presentation mode alone. Additionally, verbalization data confirmed that the static presentation mode allocated the attention to the task relevant information better than the dynamic mode. These findings support the hypothesis that animated tasks are conceived of as sequences of discrete steps, and that the motion in animated displays inhibits the discretization process. The results also suggest that a combined presentation mode can unite the benefits of both static and dynamic modes. C1 San Jose State Univ, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Bremen, Cognit Syst Grp, Dept Math & Informat, Bremen, Germany. Humboldt Univ, Dept English & Amer Studies, D-10099 Berlin, Germany. RP Lee, PU (reprint author), San Jose State Univ, NASA, Ames Res Ctr, Mail Stop 262-4, Moffett Field, CA 94035 USA. NR 14 TC 7 Z9 7 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-40557-7 J9 LECT NOTES COMPUT SC PY 2003 VL 2733 BP 12 EP 21 PG 10 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BX36W UT WOS:000185075300002 ER PT S AU Milos, FS Karunaratne, KSG AF Milos, FS Karunaratne, KSG BE Kundu, T TI Active wireless temperature sensors for aerospace thermal protection systems SO SMART NONDESTRUCTIVE EVALUATION AND HEALTH MONITORING OF STRUCTURAL AND BIOLOGICAL SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Nondestructive Evaluation and Health Monitoring of Structural and Biological Systems II CY MAR 03-05, 2003 CL SAN DIEGO, CA SP SPIE DE damage detection; embedded sensor; structural health monitoring; RFID; thermal protection system AB Vehicle system health diagnostics is an area where major improvements have been identified for potential implementation into the design of new reusable launch vehicles in order to reduce life-cycle costs, to increase safety margins, and to improve mission reliability. NASA Ames is leading the effort to advance inspection and health management technologies for thermal protection systems. This paper summarizes a joint effort by NASA Ames and Korteks to develop active "wireless" sensors that can be embedded in the thermal protection system to monitor subsurface temperature histories. These devices are thermocouples integrated with radio-frequency identification circuits to enable non-contact communication of temperature data through aerospace thermal protection materials. Two generations of prototype sensors are discussed. The advanced prototype collects data from three type-k thermocouples attached to a 25-mm square integrated circuit and can communicate through 7 to 10 cm thickness of thermal protection materials. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Milos, FS (reprint author), NASA, Ames Res Ctr, MS 234-1, Moffett Field, CA 94035 USA. NR 6 TC 1 Z9 2 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4852-4 J9 P SOC PHOTO-OPT INS PY 2003 VL 5047 BP 120 EP 129 DI 10.1117/12.483813 PG 10 WC Engineering, Biomedical; Engineering, Mechanical; Materials Science, Characterization & Testing SC Engineering; Materials Science GA BX45E UT WOS:000185330600012 ER PT S AU George, T AF George, T BE Chiao, JC Varadan, VK Cane, C TI Overview of MEMS/NEMS technology development for space applications at NASA/JPL SO SMART SENSORS, ACTUATORS, AND MEMS, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Sensors, Actuators, and MEMS CY MAY 19-21, 2003 CL MASPALOMAS, SPAIN SP SPIE, Spanish Govt, Canary Govt, Canary Isl Special Zone, Res Inst Appl Microelect, Univ Las Palmas Gran Canaria, Sch Telecommun Engn, Univ Las Palmas Gran Canaria, Dept Elect Engn & Control DE MEMS; NEMS; space; sensor; NASA; JPL; inertial guidance; micro-propulsion; micro-electroplating; micro-instruments; TRL; PICOSAT ID MEMS; MICROACTUATOR; NANOWIRES; AEROGEL AB This paper highlights the current technology development activities of the MEMS Technology Group at JPL. A diverse range of MEMS/NEMS, technologies are under development, that are primarily applicable to NASA's needs in the area of robotic planetary exploration. MEMS/NEMS technologies have obvious advantages for space applications, since they offer the promise of highly capable devices with ultra low mass, size and power consumption. However, the key challenge appears to be in finding efficient means to transition these technologies into "customer" applications. A brief description of this problem is presented along with the Group's innovative approach to rapidly advance the maturity of technologies via insertion into space missions. Also described are some of the major capabilities of the MEMS Technology Group. A few important examples from among the broad classes of technologies being developed are discussed, these include the "Spider Web Bolometer", High-Performance Miniature Gyroscopes, an Electron Luminescence X-ray Spectrometer, a MEMS-based "Knudsen" Thermal Transpiration pump, MEMS Inchworm Actuators, and Nanowire-based Biological/Chemical Sensors. C1 CALTECH, Jet Prop Lab, MEMS Technol Grp, Situ Technol & Expt Syst Sect, Pasadena, CA 91109 USA. RP George, T (reprint author), CALTECH, Jet Prop Lab, MEMS Technol Grp, Situ Technol & Expt Syst Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 38 TC 15 Z9 17 U1 1 U2 9 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4976-8 J9 P SOC PHOTO-OPT INS PY 2003 VL 5116 BP 136 EP 148 DI 10.1117/12.497796 PG 13 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics; Physics, Condensed Matter SC Computer Science; Engineering; Instruments & Instrumentation; Optics; Physics GA BX04S UT WOS:000184053200017 ER PT S AU Ross, RG AF Ross, RG BE Agnes, GS Wang, KW TI Vibration suppression of advanced space cryocoolers - an overview SO SMART STRUCTURES AND MATERIALS 2003: DAMPING AND ISOLATION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2003 Conference CY MAR 02-06, 2003 CL SAN DIEGO, CA SP SPIE, ASME, SEM, Boeing Co, Rhombus Consultant Grp, CSA Engn Inc, ISIS Canada, USAF, Off Sci Res, DARPA, Ceram Soc Japan, Intelligent Mat Forum, USA Res Off, Jet Propuls Lab, USN, Off Res, Natl Sci Fdn, USN, Res Lab DE vibration suppression; cryocoolers; particle dampers; electrodynamic braking AB Mechanical cryocoolers represent a significant enabling technology for precision space instruments by providing cryogenic temperatures for sensitive infrared, gamma-ray, and x-ray detectors. However, the vibration generated by the cryocooler's refrigeration compressor has long been identified as a critical integration issue. The key sensitivity is the extent to which the cooler's vibration harmonics excite spacecraft resonances and prevent on-board sensors from achieving their operational goals with respect to resolution and pointing accuracy. To reduce the cryocooler's vibration signature to acceptable levels, a variety of active vibration suppression technologies have been developed and implemented over the past 15 years. At this point, nearly all space cryocoolers have active vibration suppression systems built into their drive electronics that reduce the peak unbalanced forces to less than 1% of their original levels. Typical systems of today individually control the vibration in each of the cryocoolers lowest drive harmonics, with some controlling as many as 16 harmonics. A second vibration issue associated with cryocoolers is surviving launch. Here the same pistons and coldfingers that generate vibration during operation are often the most critical elements in terms of surviving high input acceleration levels. Since electrical power is generally not available during launch, passive vibration suppression technologies have been developed. Common vibration damping techniques include electrodynamic braking via shorted motor coils and the use of particle dampers on sensitive cryogenic elements. This paper provides an overview of the vibration characteristics of typical linear-drive space cryocoolers, outlines their history of development, and presents typical performance of the various active and passive vibration suppression systems being used. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ross, RG (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 28 TC 10 Z9 10 U1 0 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4857-5 J9 P SOC PHOTO-OPT INS PY 2003 VL 5052 BP 1 EP 12 PG 12 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BX45H UT WOS:000185332000002 ER PT S AU McGowan, AMR Cox, DE Lazos, BS Waszak, MR Raney, DL Siochi, EJ Pao, SP AF McGowan, AMR Cox, DE Lazos, BS Waszak, MR Raney, DL Siochi, EJ Pao, SP BE BarCohen, Y TI Biologically-inspired technologies in NASA's Morphing Project SO SMART STRUCTURES AND MATERIALS 2003: ELECTROACTIVE POLYMER ACTUATORS AND DEVICES (EAPAD) SE Proceedings of SPIE LA English DT Proceedings Paper CT Smart Structures and Materials 2003 Conference CY MAR 02-06, 2003 CL SAN DIEGO, CA SP SPIE, ASME, SEM, Boeing Co, Rhombus Consultant Grp, CSA Engn Inc, ISIS Canada, USAF, Off Sci Res, DARPA, Ceram Soc Japan, Intelligent Mat Forum, USA Res Off, Jet Propuls Lab, USN, Off Res, Natl Sci Fdn, USN, Res Lab DE biomimetics; biological-inspiration; non-planar airfoils; micro air vehicles; autonomous control; collaborative control; dynamic soaring; nanotechnology; morphing AB For centuries, biology has provided fertile ground for hypothesis, discovery, and inspiration. Time-tested methods used in nature are being used as a basis for several research studies conducted at the NASA Langley Research Center as a part of Morphing Project, which develops and assesses breakthrough vehicle technologies. These studies range from low drag airfoil design guided by marine and avian morphologies to soaring techniques inspired by birds and the study of small flexible wing vehicles. Biology often suggests unconventional yet effective approaches such as non-planar wings, dynamic soaring, exploiting aeroelastic effects, collaborative control, flapping, and fibrous active materials. These approaches and other novel technologies for future flight vehicles are being studied in NASA's Morphing Project. This paper will discuss recent findings in the aeronautics-based, biologically-inspired research in the project. C1 NASA Langley Res Ctr, Hampton, VA 23681 USA. RP NASA Langley Res Ctr, Mail Stop 254, Hampton, VA 23681 USA. NR 24 TC 8 Z9 9 U1 0 U2 5 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4856-7 J9 PROC SPIE PY 2003 VL 5051 BP 1 EP 13 DI 10.1117/12.484714 PG 13 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Polymer Science SC Engineering; Materials Science; Polymer Science GA BX45G UT WOS:000185331100002 ER PT S AU Bar-Cohen, Y Breazeal, C AF Bar-Cohen, Y Breazeal, C BE BarCohen, Y TI Biologically inspired intelligent robotics SO SMART STRUCTURES AND MATERIALS 2003: ELECTROACTIVE POLYMER ACTUATORS AND DEVICES (EAPAD) SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2003 Conference CY MAR 02-06, 2003 CL SAN DIEGO, CA SP SPIE, ASME, SEM, Boeing Co, Rhombus Consultant Grp, CSA Engn Inc, ISIS Canada, USAF, Off Sci Res, DARPA, Ceram Soc Japan, Intelligent Mat Forum, USA Res Off, Jet Propuls Lab, USN, Off Res, Natl Sci Fdn, USN, Res Lab DE biomimetics; electroactive polymers; actuators; robotics; android head; EAP platforms AB Humans throughout history have always sought to mimic the appearance, mobility, functionality, intelligent operation, and thinking process of biological creatures. This field of biologically inspired technology, having the moniker biomimetics, has evolved from making static copies of human and animals in the form of statues to the emergence of robots that operate with realistic behavior. Imagine a person walking towards you where suddenly you notice something weird about him - he is not real but rather he is a robot. Your reaction would probably be "I can't believable it but this robot looks very real" just as you would react to an artificial flower that is a good imitation. You may even proceed and touch the robot to check if your assessment is correct but, as oppose to the flower case, the robot may be programmed to respond physical and verbally. This science fiction scenario could become a reality as the current trend continues in developing biologically inspired technologies. Technology evolution led to such fields as artificial muscles, artificial intelligence, and artificial vision as well as biomimetic capabilities in materials science, mechanics, electronics, computing science, information technology and many others. This paper will review the state of the art and challenges to biologically-inspired technologies and the role that EAP is expected to play as the technology evolves. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bar-Cohen, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 82-105, Pasadena, CA 91109 USA. NR 8 TC 6 Z9 6 U1 1 U2 9 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4856-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 5051 BP 14 EP 20 DI 10.1117/12.484379 PG 7 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Polymer Science SC Engineering; Materials Science; Polymer Science GA BX45G UT WOS:000185331100003 ER PT S AU Su, J Hales, K Xu, TB AF Su, J Hales, K Xu, TB BE BarCohen, Y TI Composition and annealing effects on the response of electrostrictive graft elastomers SO SMART STRUCTURES AND MATERIALS 2003: ELECTROACTIVE POLYMER ACTUATORS AND DEVICES (EAPAD) SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2003 Conference CY MAR 02-06, 2003 CL SAN DIEGO, CA SP SPIE, ASME, SEM, Boeing Co, Rhombus Consultant Grp, CSA Engn Inc, ISIS Canada, USAF, Off Sci Res, DARPA, Ceram Soc Japan, Intelligent Mat Forum, USA Res Off, Jet Propuls Lab, USN, Off Res, Natl Sci Fdn, USN, Res Lab DE electrostrictive; graft elastomer; morphological control; annealing AB The electrostrictive graft elastomer is a new type of electromechanically active polymer developed by NASA. The material has demonstrated promising electromechanical properties including large electrical field induced strain, high electromechanical output, and a relatively high mechanical modulus. As a two-component system, the elastomer contains flexible backbone chains and electro-responsive polar grafted crystal domains. The two-component material system enables optimization of the electrostriction by controlling the relative fraction of the two components and the molecular morphology. The present work is a systematic study on the effects of the relative fraction of the two components and morphology on the electrical field induced strain. The results show that the elastomer containing more polar grafted domains and higher crystallinity yields higher electric field-induced strains. C1 NASA Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. RP Su, J (reprint author), NASA Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. NR 5 TC 1 Z9 1 U1 2 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4856-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 5051 BP 191 EP 197 DI 10.1117/12.484404 PG 7 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Polymer Science SC Engineering; Materials Science; Polymer Science GA BX45G UT WOS:000185331100019 ER PT S AU Bao, XQ Bar-Cohen, Y Chang, Z Sherrit, S AF Bao, XQ Bar-Cohen, Y Chang, Z Sherrit, S BE BarCohen, Y TI Numerical modeling of single-layer electroactive polymer mirrors for space applications SO SMART STRUCTURES AND MATERIALS 2003: ELECTROACTIVE POLYMER ACTUATORS AND DEVICES (EAPAD) SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2003 Conference CY MAR 02-06, 2003 CL SAN DIEGO, CA SP SPIE, ASME, SEM, Boeing Co, Rhombus Consultant Grp, CSA Engn Inc, ISIS Canada, USAF, Off Sci Res, DARPA, Ceram Soc Japan, Intelligent Mat Forum, USA Res Off, Jet Propuls Lab, USN, Off Res, Natl Sci Fdn, USN, Res Lab DE electroactive polymer; thin film mirror; thin film antenna; reflector; controllable membranes ID ACTUATOR; IPMC AB Thin-film mirrors are attractive for large apertures, lightweight optical systems and microwave antennas operating in micro-gravity environments. The surface shape of these deployable thin film structures requires control to a precision range that depends on the specific applications. For optical systems, such surfaces need to be deployed and refined in the range of sub-microns. Electroactive polymers (EAP) are potential candidates for making such thin film materials. Generally, EAP materials are produced in thin film form with electrodes on their major surfaces. Depending on the reflectivity of the electrodes and surface roughness of the polymer they can also be produced with mirror finishes. The development of a controllable mirror made of single-layer EAP mirror was investigated and the results are described in this manuscript. The analytical solution for the required voltage/strain distribution to allow forming a parabolic mirror from a planar film is presented. Calculations show a single layer film made of currently available EAP has the capability to control the focal length of a 2-m diameter mirror from infinity to 1.25 m. The results are verified by FEM simulations. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bao, XQ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 5 Z9 5 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4856-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 5051 BP 381 EP 388 DI 10.1117/12.484399 PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Polymer Science SC Engineering; Materials Science; Polymer Science GA BX45G UT WOS:000185331100040 ER PT S AU Sherrit, S Bao, XQQ Bar-Cohen, Y Chang, ZS AF Sherrit, S Bao, XQQ Bar-Cohen, Y Chang, ZS BE Inaudi, D Udd, E TI BAW and SAW sensors for in-situ analysis SO SMART STRUCTURES AND MATERIALS 2003: SMART SENSOR TECHNOLOGY AND MEASUREMENT SYSTEMS SE Proceedings of SPIE LA English DT Proceedings Paper CT Smart Structures and Materials 2003 Conference CY MAR 02-06, 2003 CL SAN DIEGO, CA SP SPIE, ASME, SEM, Boeing Co, Rhombus Consultant Grp, CSA Engn Inc, ISIS Canada, USAF, Off Sci Res, DARPA, Ceram Soc Japan, Intelligent Mat Forum, USA Res Off, Jet Propuls Lab, USN, Off Res, Natl Sci Fdn, USN, Res Lab DE piezoelectric; ultrasonic; bulk acoustic waves; surface acoustic waves; RF interrogated sensors; microfluidics ID QUARTZ-CRYSTAL MICROBALANCE; CHEMICAL SENSORS; IMMUNOSENSOR; FREQUENCY; HUMIDITY; IDT AB In-situ planetary sample analysis is a major goal in current and future NASA exploration missions. In general in-situ analysis experiments are designed to investigate chemical, biological or geological markers or properties to determine the complex history of the body being studied or for use as a pre-screening measurement to increase the scientific value of samples selected for sample return. In order to expand the number of applicable sensor schemes and the available capability an investigation into piezoelectric bulk acoustic wave (BAW) and surface acoustic wave (SAW) resonators has been initiated with emphasis on applications to future NASA missions. In general, BAW and SAW sensors can be configured to directly measure mass, acoustic impedance, density and elastic property changes. Indirectly they can be designed to measure or monitor pressure, temperature, dew/melting point, curing, adsorption/desorption, and viscosity and be configured with the appropriate reaction layers as chemical sensors or as Immunosensors. The various models used to describe these sensors will be presented and the measurand sensitivity and importance of cross sensitivities will be discussed. Recent advances in passive wireless RF interrogated SAW technology has increased the scope of these sensor systems to remote sensing (10m) and to applications which may have been deemed previously inaccessible(1.2.3.4.) Examples include SAW stress sensors buried in large structures that once assembled are inaccessible for measurement that can be interrogated with wireless RF signals to determine the health of the structure. In addition, this technology has recently been coupled with other sensor technology allowing for an expansion of the possibilities for remote sensing. On the basis of the cost, range, versatility and ease of array fabrication, these sensors offer significant potential for future NASA missions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Sherrit, S (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 32 TC 3 Z9 3 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4855-9 J9 PROC SPIE PY 2003 VL 5050 BP 81 EP 91 DI 10.1117/12.484252 PG 11 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BX34H UT WOS:000184997000010 ER PT S AU Grant, J Kaul, R Taylor, S Myer, G Jackson, K Sharma, A AF Grant, J Kaul, R Taylor, S Myer, G Jackson, K Sharma, A BE Inaudi, D Udd, E TI Distributed sensing of carbon-epoxy composites and composite wound pressure vessels using Fiber-Bragg gratings SO SMART STRUCTURES AND MATERIALS 2003: SMART SENSOR TECHNOLOGY AND MEASUREMENT SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2003 Conference CY MAR 02-06, 2003 CL SAN DIEGO, CA SP SPIE, ASME, SEM, Boeing Co, Rhombus Consultant Grp, CSA Engn Inc, ISIS Canada, USAF, Off Sci Res, DARPA, Ceram Soc Japan, Intelligent Mat Forum, USA Res Off, Jet Propuls Lab, USN, Off Res, Natl Sci Fdn, USN, Res Lab DE Bragg sensor; carbon-epoxy; composite; embedded FBG; carbon laminate; pressure vessel AB Multiple Fiber Bragg-gratings are embedded in carbon-epoxy laminates as well as in composite wound pressure vessel. Structural properties of such composites are investigated. The measurements include stress-strain relation in laminates and Poisson's ratio in several specimens with varying orientation of the optical fiber Bragg-sensor with respect to the carbon fiber in an epoxy matrix. Additionally, fiber Bragg gratings are bonded on the surface of these laminates and cylinders fabricated out of carbon-epoxy composites and multiple points are monitored and compared for strain measurements at several locations. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Grant, J (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 5 TC 2 Z9 2 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4855-9 J9 P SOC PHOTO-OPT INS PY 2003 VL 5050 BP 187 EP 196 DI 10.1117/12.484236 PG 10 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BX34H UT WOS:000184997000022 ER PT S AU Bar-Cohen, Y Bao, X Chang, Z Sherrit, S AF Bar-Cohen, Y Bao, X Chang, Z Sherrit, S BE Baz, AM TI An ultrasonic sampler and sensor platform for in-situ astrobiological exploration SO SMART STRUCTURES AND MATERIALS 2003: SMART STRUCTURES AND INTEGRATED SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2003 Conference CY MAR 02-06, 2003 CL SAN DIEGO, CA SP SPIE, ASME, SEM, Boeing Co, Rhombus Consultant Grp, CSA Engn Inc, ISIS Canada, USAF, Off Sci Res, DARPA, Ceram Soc Japan, Intelligent Mat Forum, USA Res Off, Jet Propuls Lab, USN, Off Res, Natl Sci Fdn, USN, Res Lab DE USDC; lab-on-a-drill; sampler; sensor platform; in-situ analysis; ultrasonic drilling AB The search for existing or past life in the Universe is one of the most important objectives of NASA's mission. In support of this objective, ultrasonic based mechanisms are currently being developed at JPL to allow probing and sampling of rocks and to use the mechanisms as a sensor platform for in-situ astrobiological analysis. The technology is based on the novel Ultrasonic/Sonic Driller/Corer (USDC), which requires low axial force, thereby overcoming one of the major limitations of planetary sampling using conventional drills in low gravity environments. The USDC was demonstrated to: 1) drill ice and various rocks including granite, diorite, basalt and limestone, 2) not require bit sharpening, and 3) operate at high and low temperatures. The capabilities that are being investigated include probing the ground to select sampling sites, collecting various forms of samples, and hosting sensors for measuring various properties. A series of modifications of the USDC basic configuration were implemented leading to an ultrasonic abrasion tool (URAT), Ultrasonic Gopher for deep drilling, and the Lab-on-a-drill. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bar-Cohen, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 3 Z9 4 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4861-3 J9 P SOC PHOTO-OPT INS PY 2003 VL 5056 BP 457 EP 465 DI 10.1117/12.483391 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BX45J UT WOS:000185332300046 ER PT S AU Sokolowski, WM Hayashi, S AF Sokolowski, WM Hayashi, S BE Baz, AM TI Applications of cold hibernated elastic memory (CHEM) structures SO SMART STRUCTURES AND MATERIALS 2003: SMART STRUCTURES AND INTEGRATED SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2003 Conference CY MAR 02-06, 2003 CL SAN DIEGO, CA SP SPIE, ASME, SEM, Boeing Co, Rhombus Consultant Grp, CSA Engn Inc, ISIS Canada, USAF, Off Sci Res, DARPA, Ceram Soc Japan, Intelligent Mat Forum, USA Res Off, Jet Propuls Lab, USN, Off Res, Natl Sci Fdn, USN, Res Lab DE expandable structures; shape memory polymers; open cellular structures; glass transition temperature Tg; glassy and rubbery states AB Experiments and analyses have confirmed the feasibility of an innovative, new class of very simple, reliable, low mass; low packaging volume, and low-cost self-deployable structures for space and commercial applications. The material technology called "cold hibernated elastic memory" (CHEM) utilizes shape memory polymers in open cellular (foam) structures. The CHEM foams are self-deployable and are using the foam's elastic recovery plus their shape memory to erect structures. These structures are under development by the NASA's Jet Propulsion Laboratory (JPL) and Mitsubishi Heavy Industries (MHI). Currently, the CHEM structure concept is well formulated with clear space and commercial applications. The CHEM structures are described here and their major advantages are identified over other expandable/deployable structures. Previous experimental results were very encouraging and indicated that the CHEM foam technology can perform robustly in the Earth environment as well as in space. Some potential space applications were studied under various programs at JPL with promising results. Although the space community will be the major beneficiary, a lot of potential commercial and biomedical applications are also foreseen for the "earth environment" and are described in this paper as well. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sokolowski, WM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 TC 8 Z9 8 U1 3 U2 9 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4861-3 J9 P SOC PHOTO-OPT INS PY 2003 VL 5056 BP 534 EP 544 DI 10.1117/12.483480 PG 11 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BX45J UT WOS:000185332300054 ER PT S AU Chang, ZS Sherrit, S Bao, XQ Bar-Cohen, Y AF Chang, ZS Sherrit, S Bao, XQ Bar-Cohen, Y BE Baz, AM TI In-situ rock probing using the ultrasonic/sonic driller/corer (USDC) SO SMART STRUCTURES AND MATERIALS 2003: SMART STRUCTURES AND INTEGRATED SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2003 Conference CY MAR 02-06, 2003 CL SAN DIEGO, CA SP SPIE, ASME, SEM, Boeing Co, Rhombus Consultant Grp, CSA Engn Inc, ISIS Canada, USAF, Off Sci Res, DARPA, Ceram Soc Japan, Intelligent Mat Forum, USA Res Off, Jet Propuls Lab, USN, Off Res, Natl Sci Fdn, USN, Res Lab DE ultrasonic/sonic driller/corer (USDC); in-situ analysis; probing; planetary exploration AB In-situ sampling and analysis are important capabilities to allow meeting the major objectives of future NASA's planetary exploration missions. The development of an ultrasonic device that can serve as a probe, sampler and sensors platform for in-situ analysis is currently underway at JPL. The device is based on the novel Ultrasonic/Sonic Driller/Corer (USDC) technology, which was co-developed by the Non-Destructive Evaluation and Advanced Actuator laboratory (NDEAA, http://ndeaa.jpl.nasa.gov/), JPL, and Cybersonics. This sampling technology requires low axial force, thereby overcoming one of the major limitations of planetary sampling in low gravity using conventional drills. This device allows the design of an effective tool that is compact, low mass and uses low power. To assure effective use of power for drilling/coring rocks in-situ probing is needed to allow selecting rocks with the highest probability of containing information (biological markers, water, etc.). While the major function of the USDC is sampling, drilling and coring, it also has great potential to serve as a probing device. The USDC imparts elastic waves into the sampled medium offering a sounding method for geophysical analysis similar to the techniques used by the oil industry. Also, the characteristic of the piezoelectric actuator, which drives the USDC, is affected by the medium to which it is coupled. Using a variety of device configurations, a series of experiments were conducted to measure the elastic wave velocity, scattering, impedance and the shift in resonance frequency. Various rocks are being tested to determine their characteristics. Preliminary results are encouraging. Currently, investigation is conducted to find methods of minimizing the effect of surface roughness, geometry and sample dimensions on the data. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chang, ZS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 67-119, Pasadena, CA 91109 USA. NR 3 TC 1 Z9 1 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4861-3 J9 P SOC PHOTO-OPT INS PY 2003 VL 5056 BP 567 EP 573 DI 10.1117/12.483403 PG 7 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BX45J UT WOS:000185332300057 ER PT B AU Wheeler, KR AF Wheeler, KR BE Kercel, SW TI Device control using gestures sensed from EMG SO SMCIA/03: PROCEEDINGS OF THE 2003 IEEE INTERNATIONAL WORKSHOP ON SOFT COMPUTING IN INDUSTRIAL APPLICATIONS LA English DT Proceedings Paper CT IEEE International Workshop on Soft Computing in Industrial Applications CY JUN 23-25, 2003 CL BINGHAMTON, BINGHAMTON, NY SP IEEE Syst, Man & Cybernet Soc HO BINGHAMTON ID SPEECH RECOGNITION AB In this paper we present neuro-electric interfaces for virtual device control. The examples presented rely upon sampling Electromyogram data from a participants forearm. This data is then fed into pattern recognition software that has been trained to distinguish gestures from a given gesture set. The pattern recognition software consists of hidden Markov models which are used to recognize the gestures as they are being performed in real-time. Two experiments were conducted to examine the feasibility of this interface technology. The first replicated a virtual joystick interface, and the second replicated a keyboard. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM Kevin.R.Wheeler@nasa.gov NR 4 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7855-5 PY 2003 BP 21 EP 26 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BX49J UT WOS:000185467100005 ER PT S AU Barkstrom, BR AF Barkstrom, BR BE Westfechtel, B VanderHoek, A TI Data product configuration management and versioning in large-scale production of satellite scientific data SO SOFTWARE CONFIGURATION MANAGEMENT SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT ICSE Software Configuration Management Workshops 2001 and 2003 CY MAY 09-10, 2003 CL PORTLAND, OREGON SP ICSE AB This paper describes a formal structure for keeping track of files, source code, scripts, and related material for large-scale Earth science data production. We first describe the environment and processes that govern this configuration management problem. Then, we show that a graph with typed nodes and arcs can describe the derivation of production design and of the produced files and their metadata. The graph provides three useful by-products: a hierarchical data file inventory structure that can help system users find particular files, methods for creating production graphs that govern job scheduling and provenance graphs that track all of the sources and transformations between raw data input and a particular output file, a systematic relationship between different elements of the structure and development documentation. C1 NASA Langley Res Ctr, Atmospher Sci Data Ctr, Hampton, VA 23681 USA. RP Barkstrom, BR (reprint author), NASA Langley Res Ctr, Atmospher Sci Data Ctr, Hampton, VA 23681 USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-14036-0 J9 LECT NOTES COMPUT SC PY 2003 VL 2649 BP 118 EP 133 PG 16 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BW95U UT WOS:000183763100009 ER PT J AU Keenan, FP Katsiyannis, AC Aggarwal, KM Mathioudakis, M Brosius, JW Davila, JM Thomas, RJ AF Keenan, FP Katsiyannis, AC Aggarwal, KM Mathioudakis, M Brosius, JW Davila, JM Thomas, RJ TI SiIX emission lines in spectra obtained with the Solar EUV Research Telescope and Spectrograph (SERTS) SO SOLAR PHYSICS LA English DT Article ID EXTREME-ULTRAVIOLET SPECTRA; FINE-STRUCTURE TRANSITIONS; ACTIVE-REGION; RATE COEFFICIENTS; ATOMIC DATABASE; IX; EXCITATION; STRENGTHS; IONS; SUN AB Theoretical electron-density-sensitive emission line ratios involving 2s(2)2p(2)-2s2p(3) transitions in Si IX between 223 and 350 Angstrom are presented. A comparison of these with an extensive dataset of solar-active-region, quiet-Sun, subflare and off-limb observations, obtained during rocket flights by the Solar EUV Research Telescope and Spectrograph (SERTS), reveals generally very good agreement between theory and experiment. This provides support for the accuracy of the line-ratio diagnostics, and hence the atomic data on which they are based. In particular, the density-sensitive intensity ratio I (258.10 Angstrom)/ I (349.87 Angstrom) offers an especially promising diagnostic for studies of coronal plasmas, as it involves two reasonably strong emission lines and varies by more than an order of magnitude over the useful density range of 10(9)-10(11) cm(-3). The 2s(2)2p(2) S-1(0) - 2s2p(3) P-1(1) transition at 259.77 Angstrom is very marginally identified for the first time in the SERTS database, although it has previously been detected in solar flare observations. C1 Queens Univ Belfast, Dept Pure & Appl Phys, Belfast BT7 1NN, Antrim, North Ireland. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Keenan, FP (reprint author), Queens Univ Belfast, Dept Pure & Appl Phys, Belfast BT7 1NN, Antrim, North Ireland. RI Katsiyannis, Thanassis/L-8496-2013 NR 25 TC 4 Z9 4 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JAN PY 2003 VL 212 IS 1 BP 65 EP 79 DI 10.1023/A:1022944231493 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 659DD UT WOS:000181761500005 ER PT J AU Kucera, TA Tovar, M De Pontieu, B AF Kucera, TA Tovar, M De Pontieu, B TI Prominence motions observed at high cadences in temperatures from 10 000 to 250 000 K SO SOLAR PHYSICS LA English DT Article ID TRANSITION REGION; QUIESCENT PROMINENCES; SOLAR PROMINENCES; CORONAL EXPLORER; MAGNETIC-FIELDS; DYNAMICS; TRACE; FLOWS; SOHO AB We report here for the first time observations of prominence velocities over a wide range of temperatures and with a high time cadence. Our study of ultraviolet movies of prominences reveals that multi-thermal features with speeds of 5-70 km s(-1) perpendicular to the line of sight are common in the prominences which showed traceable motions. These speeds are noticeably higher than the typical speeds of 5-20 km s(-1) observed in Ha data from 'quiet' prominences and are more typical of 'activated' prominences in which speeds of up to 40 km s(-1) have been reported. The observations were performed using five separate datasets taken by the Solar and Heliospheric Observatory's Coronal Diagnostic Spectrometer (SOHO/CDS) in its wide slit overlappogram mode in lines from He I, O V, and Mg IX and a separate prominence observation taken with both the Transition Region and Coronal Explorer ( TRACE) in its 1216 and 1600 Angstrom bands and in Halpha by the Swedish Vacuum Solar Telescope (SVST) at La Palma. The movies were taken with cadences > 1 image per minute and were made simultaneously or near-simultaneously in spectral lines formed at two or more temperatures. We traced motion that lasted for 3 to 20 min and went distances up to 10(5) km. Most, but not all, of these were chiefly horizontal. In many cases we were able to observe the same motions over temperature ranges from 20 000 to 250 000 K or 10 000 to 100 000 K. Observations are compared with model predictions. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Calif State Univ Northridge, Northridge, CA 91330 USA. Lockheed Martin Solar & Astrophys, Palo Alto, CA USA. RP NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. EM terry.kucera@gsfc.nasa.gov RI Kucera, Therese/C-9558-2012; OI Kucera, Therese/0000-0001-9632-447X NR 29 TC 33 Z9 33 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 EI 1573-093X J9 SOL PHYS JI Sol. Phys. PD JAN PY 2003 VL 212 IS 1 BP 81 EP 97 DI 10.1023/A:1022900604972 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 659DD UT WOS:000181761500006 ER PT B AU Thomas, RJ AF Thomas, RJ BE Bueno, JT Almeida, JS TI SOHO/CDS measurements of coronal EUV polarization SO SOLAR POLARIZATION 3 SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 3rd International Workshop on Solar Polarization CY SEP 30-OCT 04, 2002 CL TENERIFE, SPAIN SP Minist Ciencia & Technol, Gobierno Canarias, Univ La Laguna AB Polarization in coronal EUV emission above the solar limb has been measured using the SOHO/CDS normal-incidence spectrometer. The instrument has a polarization sensitivity greater than 50%, causing variations in intensity response as a function of the spacecraft's roll angle for linearly polarized light. Such observations were made at heights up to 0.22 solar radii during two special roll-maneuvers of the SOHO spacecraft; above a modestly active equatorial region in 1997 and above a relatively cool polar region in 2001. The observed EUV emission lines cover a temperature range from 4.1 to 6.2 in logT. Near the disk, measured intensities of all lines fall off exponentially at different rates related to the hydrostatic density scale-heights of the emitting plasma, since this emission is dominated by collisional excitation with an N-e(2) dependence. Beyond a certain distance, however, intensity gradients of the cooler lines switch over to a flatter exponential slope, suggesting that this radiation is dominated by resonance scattering which varies as N-e to the first power. Such radiation should also be linearly polarized in the plane perpendicular to the line-of-sight and solar center. That signature has now been detected, strongly confirming this interpretation, although the measured modulations are actually much larger than expected from standard models. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Thomas, RJ (reprint author), NASA, Goddard Space Flight Ctr, Code 682, Greenbelt, MD 20771 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-156-7 J9 ASTR SOC P PY 2003 VL 307 BP 497 EP 502 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BY37D UT WOS:000189124000058 ER PT S AU Gopalswamy, N Lara, A Yashiro, S Nunes, S Howard, RA AF Gopalswamy, N Lara, A Yashiro, S Nunes, S Howard, RA BE Wilson, A TI Coronal mass ejection activity during solar cycle 23 SO SOLAR VARIABILITY AS AN INPUT TO THE EARTH'S ENVIRONMENT SE ESA Special Publications LA English DT Proceedings Paper CT International Solar Cycle Studies Symposium (ISCS 2003) CY JUN 23-28, 2003 CL TATRANSKA LOMNIC, SLOVAKIA SP Sci Comm Solar Terr Phys, Int Astron Union, European Space Agcy, Comm Space Res, US Natl Sci Fdn, Volksbank Ludova Bank, Grand Hotel Tatranska Lomnica, SAS, Astron Inst, SAS, Inst Exptl Phys, SAS, Geophys Inst DE CMEs; solar cycle variations ID SOLAR; ERUPTIONS; LASCO; EARTH; FLUX AB We studied the solar cycle variation of various properties of coronal mass ejections (CMEs), such as daily CME rate, mean and median speeds, and the latitude of solar sources for cycle 23 (1996-2002). We find that (1) there is an order of magnitude increase in CME rate from the solar minimum (0.5/day) to maximum (6/day), (2) the maximum rate is significantly higher than previous estimates, (3) the mean and median speeds of CMEs also increase from minimum to maximum by a factor of 2, (4) the number of metric type II bursts (summed over CR) tracks CME rate, but the CME speed seems to be only of secondary importance, (5) for type II bursts originating farther from the Sun the CME speed is important, (6) the latitude distribution of CMEs separate the prominence-associated (high-latitude) and active-region associated CMEs, and (7) the rate of high-latitude CMEs shows north-south asymmetry and the cessation eruptions in the north and south roughly mark the polarity reversals. We compared the rates of the fast-and-wide CMEs, major solar flares, interplanetary (IP) shocks, long-wavelength type II bursts and large SEP events. This comparison revealed that the number of major flares is generally too large compared to all the other numbers. In other words, fast-and-wide CMEs, long-wavelength type II bursts, large SEP events, and IP shocks have a close physical relationship. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Gopalswamy, N (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. EM gopals@fugee.gsfc.nasa.gov RI Gopalswamy, Nat/D-3659-2012; OI Lara, Alejandro/0000-0001-6336-5291 NR 29 TC 49 Z9 51 U1 0 U2 4 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-845-X J9 ESA SPEC PUBL PY 2003 VL 535 BP 403 EP 414 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BY20M UT WOS:000188242400075 ER PT S AU Burlaga, LF Ness, NF Wang, YM Sheeley, NR AF Burlaga, LF Ness, NF Wang, YM Sheeley, NR BE Velli, M Bruno, R Malara, F TI Voyager 1 studies of the HMF to 81 AU during the ascending phase of solar cycle 23 SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID HELIOSPHERIC MAGNETIC-FIELD; DISTANT HELIOSPHERE; SECTOR STRUCTURE; SOLAR MAXIMUM AB The paper analyzes the magnetic field strength B and polarity observed in the distant heliosphere from 1996 to early 2001 and will be discussed in relation to the variation of B from 1978 through 1996. The observations extend the results of Burlaga et al. [1]. The polarity of the heliospheric magnetic field (HMF) from 1997 to early 2001 is studied in relation to the extrapolated position of the heliospheric current sheet (HCS). These observations of polarity extend the earlier results of Burlaga et al. [2] and Burlaga and Ness [3]. The V1 observations of the heliospheric magnetic field strength B agree with Parker's model of the global heliospheric magnetic field from 1 to 81 AU and from 1978 to 2001, when one considers the solar cycle variations in the source magnetic field strength and the latitude/time variation in the solar wind speed. Parker's model, without adjustable parameters, describe the general tendency for B to decrease with increasing distance R from the Sun, and the solar cycle time variations causing the three broad increases of B around 1980, 1990, and 2000, and the minima of B in 1987 and 1997. The variation of magnetic polarity observed by V1 and V2 was caused by the increasing latitudinal width of the sector zone with increasing solar activity, which in turn was related to the increasing maximum latitudinal extent and the decreasing minimum latitudinal extent of the footpoints of the HCS. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Burlaga, LF (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. NR 13 TC 2 Z9 2 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 39 EP 42 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700006 ER PT S AU Liewer, PC Neugebauer, M Zurbuchen, T AF Liewer, PC Neugebauer, M Zurbuchen, T BE Velli, M Bruno, R Malara, F TI Active-region sources of solar wind near solar maximum SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF AB Previous studies of the source regions of solar wind sampled by ACE and Ulysses showed that some solar wind originates from open flux areas in active regions. These sources were labeled active region sources when there was no corresponding coronal hole in the He 10830 Angstrom synoptic maps. Here, we present results on an investigation of the magnetic topology of these active region sources and a search for corresponding features in EUV and soft X-ray images. In most, but not all, cases, a dark hole or lane is seen in the EUV and SXT image as for familiar coronal hole sources. However, in one case, the soft-X ray images and the magnetic model showed a coronal structure quite different from typical coronal hole structure. Using ACE data, we also find that the solar wind from these active region sources generally has a higher Oxygen charge state than wind from the Helium-10830Angstrom coronal hole sources, indicating a hotter source region, consistent with the active region source interpretation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Liewer, PC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 51 EP 54 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700009 ER PT S AU Woo, R Habbal, SR AF Woo, R Habbal, SR BE Velli, M Bruno, R Malara, F TI Ubiquitous open magnetic field lines in the inner corona SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID SOLAR-WIND; SUN AB The notion that density structure reflects magnetic field lines makes it possible to deduce information on coronal magnetic fields from density measurements. The purpose of this paper is to summarize the observational evidence for ubiquitous open magnetic field lines in the inner corona from density measurements. Based on both global and filamentary structures, these density measurements explain the unexpected predominance of the radial component of coronal magnetic field discovered in polarimetric observations over three decades ago. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Woo, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 17 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 55 EP 58 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700010 ER PT S AU Smith, EJ Balogh, A AF Smith, EJ Balogh, A BE Velli, M Bruno, R Malara, F TI Open magnetic flux: Variation with latitude and solar cycle SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID ULYSSES; FIELD; ORIGIN AB Recent Ulysses observations of the heliospheric magnetic field (HMF) reveal that the sun's open magnetic flux in the solar wind, as measured by r(2) Br, is independent of heliographic latitude at solar maximum and at solar minimum. It follows that 4pi r(2) Br at any latitude provides an accurate estimate of the total open flux from the sun. An additional Ulysses result is that long term averages of r(2) Br are very nearly the same at the recent solar maximum as at the preceding minimum. The model of the HMF developed by L. Fisk and his colleagues, which includes several features absent from the well-known Parker model, leads to the prediction that the open flux is relatively constant or perhaps invariant. Motivated by these considerations, Br has been analyzed over the longer interval of four sunspot cycles (20-23) using the archived OMNI field measurements obtained in the ecliptic at 1 AU. Averages of Br, after separation into inward and outward sectors as with Ulysses data, agree within a few percent with previous results based on \Br\, the modulus of the radial component. Averages of Br increase by a factor of about 2 from solar minimum to maximum in cycles 21 and 22 but change only slightly in cycles 20 and 23. The variations in open flux are better correlated with total unsigned flux in the photosphere than with sunspot number, both reaching peak values. after sunspot maximum. The open flux decreases at solar minima and secondary decreases occur when the polar cap fields vanish. It appears that the near equality of the open flux at minimum and maximum observed by Ulysses was, in fact, caused by a time variation with the measurements near maximum being obtained while a secondary decrease was occurring. Thus, the open flux is generally variable and only constant during shorter intervals when the solar field is stable. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Smith, EJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 25 Z9 25 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 67 EP 70 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700013 ER PT S AU Sittler, EC Ofman, L Gibson, S Guhathakurta, M Davila, J Skoug, R Fludra, A Holzer, T AF Sittler, EC Ofman, L Gibson, S Guhathakurta, M Davila, J Skoug, R Fludra, A Holzer, T BE Velli, M Bruno, R Malara, F TI Development of multidimensional MHD model for the solar corona and solar wind SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID HELMET-STREAMER; DISRUPTION AB We are developing a time stationary self-consistent 2D MHD model of the solar corona and solar wind that explicitly solves the energy equation, using a semi-empirical 2D MHD model of the corona to provide an empirically determined effective heat flux q(eff) (i.e., the term effective means the possible presence of wave contributions). But, as our preliminary results indicate, in order to achieve high speed winds over the poles we also need to include the empirically determined effective pressure P-eff as a constraint in the momentum equation, which means that momentum addition by waves above 2 R-S are required to produce high speed winds. At present our calculations do not include the P-eff constraint. The estimates of P-eff and q(eff) come from the semi-empirical 2D MHD model of the solar corona by Sittler and Guhathakurta (1999a,2002) which is based on Mk-III, Skylab and Ulysses observations. For future model development we plan to use SOHO LASCO, CDs, EIT, UVCS and Ulysses data as constraints for our model calculations. The model by Sittler and Guhathakurta (1999a, 2002) is not a self-consistent calculation. The calculations presented here is the first attempt at providing a self-consistent calculation based on empirical constraints. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sittler, EC (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 11 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 113 EP 116 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700024 ER PT S AU Roberts, DA Goldstein, ML Deane, A AF Roberts, DA Goldstein, ML Deane, A BE Velli, M Bruno, R Malara, F TI Three-dimensional MHD simulation of solar wind structure SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID HELIOSPHERIC CURRENT SHEET; TURBULENCE AB We examine the 3-D structure of field lines in the expanding solar wind using an MHD code that allows the imposition of streams, a current sheet, flux tubes, microstreams, waves, and quasi-2-D turbulence. We find the natural development of closed field lines and lines with more complex geometry in the current sheet region. We show that microstreams cause an increased divergence of the field lines. The various initially strange looking heliospheric field lines we find have observational support in early work by K. Schatten and others, who found very similar structures using simple projection methods, as well in more recent work examining the nature of current sheet crossings. Our simulations exhibit most of the solar wind field configurations suggested by Schatten in his Solar Wind Two review. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Roberts, DA (reprint author), NASA, Goddard Space Flight Ctr, Code 692, Greenbelt, MD 20771 USA. RI Goldstein, Melvyn/B-1724-2008 NR 8 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 133 EP 136 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700029 ER PT S AU Yamauchi, Y Suess, ST Sakurai, T AF Yamauchi, Y Suess, ST Sakurai, T BE Velli, M Bruno, R Malara, F TI Relation between polar plumes and fine structure in the solar wind from Ulysses high-latitude observations SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID PRESSURE-BALANCE STRUCTURES; CORONAL PLUMES; DISCONTINUITIES; STREAMS; HOLES AB Ulysses observations showed that pressure balance structures (PBSs) are a common feature in the high-latitude and high-speed solar winds near the solar minimum. PBSs have been hypothesized to be remnants of coronal plumes and to be related to network activity such as magnetic reconnection in the photosphere. This suggests that information on the magnetic structure of PBSs would help to study the relation between PBSs and polar plumes. We have investigated the magnetic structures of the 104 PBSs by applying a minimum variance analysis to Ulysses/Magnetometer data and by examining the pitch-angle distribution of energetic electrons measured with Ulysses/SWOOPS. We found that PBSs have relatively more tangential discontinuities rather than rotational from the minimum variance analysis and there is no difference between PBSs observed in north and south polar regions. From the analysis of energetic electron data, most PBSs also show local bidirectional electron flux or isotropic pitch-angle distribution expected in plasmoids or, less often, the distribution expected in association with current-sheet structures. This suggests the hypothesis that PBSs are generated due by network activity such as magnetic reconnection at the base of polar plumes. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Yamauchi, Y (reprint author), NASA, George C Marshall Space Flight Ctr, SD 50, Huntsville, AL 35812 USA. NR 14 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 255 EP 258 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700059 ER PT S AU Usmanov, AV Goldstein, ML AF Usmanov, AV Goldstein, ML BE Velli, M Bruno, R Malara, F TI Three-dimensional MHD modeling of the solar corona and solar wind SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID MAGNETIC-FIELD; ALFVEN WAVES; POLE AB A global MHD model is developed to reproduce Ulysses observations during its fast latitude transition in 1994-1995. The governing polytropic single-fluid MHD equations are solved for a steady coronal outflow. The model includes Alfven wave momentum and energy addition into open field regions. We combine a solution for a tilted dipole magnetic field in the inner computational region (1-20 R-circle dot) with a three-dimensional solution in the outer region which extends to 1 AU. The inner region solution is essentially the same as in [1], but obtained with a different numerical algorithm and rotated to match the inclination inferred for the solar dipole from observations during the Ulysses transversal. The steady solution in the outer region is constructed by a marching-along-radius method and accounts for solar rotation. We show that the simulated variations of plasma and magnetic field parameters and in particular the extension of slow wind belt agree fairly well with the Ulysses observations. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Usmanov, AV (reprint author), NASA, Goddard Space Flight Ctr, Code 692, Greenbelt, MD 20771 USA. RI Goldstein, Melvyn/B-1724-2008; Usmanov, Arcadi/A-9860-2013 NR 19 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 393 EP 398 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700090 ER PT S AU Goldstein, ML Roberts, DA Deane, A AF Goldstein, ML Roberts, DA Deane, A BE Velli, M Bruno, R Malara, F TI The effect of microstreams on Alfvenic fluctuations in the solar wind SO SOLAR WIND TEN, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID INTERPLANETARY MAGNETIC-FIELD; MAGNETOHYDRODYNAMIC TURBULENCE; VELOCITY SHEAR; WAVES; PLASMA; ANISOTROPY; EQUATIONS; DIFFUSION; SPECTRA AB Even in nominally uniform solar wind flows, such as over the solar poles near solar minimum, the wind velocity exhibits fluctuations of order 40 km/s. We have shown previously that such variations will shear planar parallel propagating magnetic fluctuations leading to the generation of transverse wave vectors. Here we extend our previous two-dimensional magnetohydrodynamic (MHD) simulations to three dimensions and describe how, starting from an initial spectrum of circularly polarized Alfven waves with radial wave vectors, such "microstreams" might produce fluctuations that could be described as "quasi-two-dimensional". Our goal is to elucidate the origin of the "two-component" nature of the correlation function of magnetic fluctuations. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Goldstein, ML (reprint author), NASA, Goddard Space Flight Ctr, Code 692, Greenbelt, MD 20771 USA. RI Goldstein, Melvyn/B-1724-2008 NR 32 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 405 EP 408 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700092 ER PT S AU Cane, HV AF Cane, HV BE Velli, M Bruno, R Malara, F TI Solar flares, type III radio bursts, CMEs, and energetic particles SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID EVENTS AB Despite the fact that it has been well known since the earliest observations that solar energetic particle events are well associated with solar flares it is often considered that the association is not physically significant. Instead, in large events, the particles are considered to be only accelerated at a shock driven by the coronal mass ejection (CME) that is also always present. If particles are accelerated in the associated flare, it is claimed that such particles do not find access to open field lines and therefore do not escape from the low corona. However recent work has established that long lasting type III radio bursts extending to low frequencies are associated with all prompt solar particle events. Such bursts establish the presence of open field lines. Furthermore, tracing the radio bursts to the lowest frequencies, generated near the observer, shows that the radio producing electrons gain access to a region of large angular extent. It is likely that the electrons undergo cross field transport and it seems reasonable that ions do also. Such observations indicate that particle propagation in the inner heliosphere is not yet fully understood. They also imply that the contribution of flare particles in major particle events needs to be properly addressed. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Cane, HV (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 589 EP 592 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700134 ER PT S AU Gopalswamy, N Yashiro, S Michalek, G Kaiser, ML Howard, RA Leske, R von Rosenvinge, T Reames, DV AF Gopalswamy, N Yashiro, S Michalek, G Kaiser, ML Howard, RA Leske, R von Rosenvinge, T Reames, DV BE Velli, M Bruno, R Malara, F TI Effect of CME interactions on the production of solar energetic particles SO SOLAR WIND TEN, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID CORONAL MASS EJECTIONS; SUN AB We analyzed a set of 52 fast and wide, frontside western hemispheric (FWFW) CMEs in conjunction with solar energetic particle (SEP) and radio burst data and found that 42 of these CMEs were associated with SEPs. All but two of the 42 SEP-associated FWFW CMEs (95%) were interacting with preceding CMEs or dense streamers. Most of the remaining 10 SEP-poor FWFW CMEs had either insignificant or no interaction with preceding CMEs or streamers, and were ejected into a tenuous corona. There is also a close association between type 11 radio bursts in the near-Sun interplanetary medium and SEP-associated FWFW CMEs suggesting that electron accelerators are also good proton accelerators. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gopalswamy, N (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Gopalswamy, Nat/D-3659-2012 NR 8 TC 8 Z9 8 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 608 EP 611 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700138 ER PT S AU Wiedenbeck, ME Mason, GM Christian, ER Cohen, CMS Cummings, AC Dwyer, JR Gold, RE Krimigis, SM Leske, RA Mazur, JE Mewaldt, RA Slocum, PL Stone, EC von Rosenvinge, TT AF Wiedenbeck, ME Mason, GM Christian, ER Cohen, CMS Cummings, AC Dwyer, JR Gold, RE Krimigis, SM Leske, RA Mazur, JE Mewaldt, RA Slocum, PL Stone, EC von Rosenvinge, TT BE Velli, M Bruno, R Malara, F TI How common is energetic He-3 in the inner heliosphere? SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID SOLAR PARTICLE EVENTS; ISOTOPE SPECTROMETER; ACCELERATION; ACE AB Using data from the SIS and ULEIS instruments on the Advanced Composition Explorer (ACE) we have identified periods during which energetic He-3 is present in near-Earth interplanetary space between November 1997 and May 2002. The data, which cover the energy intervals 0.2-1 MeV/nuc (ULEIS) and 4.5-16.3 MeV/nuc (SIS), show that He-3 is present a significant fraction of the time, as would be required if these suprathermal particles were the major source of the He-3 being accelerated by shocks in the interplanetary medium. Specifically, we find that energetic 3He is present at least similar to60% of the time, and perhaps significantly more often. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wiedenbeck, ME (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Christian, Eric/D-4974-2012 OI Christian, Eric/0000-0003-2134-3937 NR 12 TC 25 Z9 25 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 652 EP 655 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700149 ER PT S AU Richardson, IG Cane, HV Lepri, ST Zurbuchen, TH Gosling, JT AF Richardson, IG Cane, HV Lepri, ST Zurbuchen, TH Gosling, JT BE Velli, M Bruno, R Malara, F TI Spatial relationship of signatures of interplanetary coronal mass ejections SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF AB Interplanetary coronal mass ejections (ICMEs) are characterized by a number of signatures. In particular, we examine the relationship between Fe charge states and other signatures during ICMEs in solar cycle 23. Though enhanced Fe charge states characterize many ICMEs, average charge states vary from event to event, are more likely to be enhanced in faster or flare-related ICMEs, and do not appear to depend on whether the ICME is a magnetic cloud. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Richardson, IG (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RI Lepri, Susan/I-8611-2012 NR 7 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 681 EP 684 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700156 ER PT S AU Osherovich, VA Fainberg, J Vinas, A Fitzenreiter, R AF Osherovich, VA Fainberg, J Vinas, A Fitzenreiter, R BE Velli, M Bruno, R Malara, F TI Complexity of the 18 October 1995 magnetic cloud observed by wind and the multi-tube magnetic cloud model SO SOLAR WIND TEN, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF AB The notion that a magnetic cloud may consist not of one but of a few closely interacting magnetic tubes came from the analysis of the relation between the electron temperature T(e) and plasma density N(e) ((1)Fainberg et al. 1996). The log-log plot of T(e) versus N(e) of data in the 10-13 June 1993 Ulysses magnetic cloud revealed two polytropes (both with gamma(e) < 1) which have been attributed by (2)Osherovich, Fainberg and Stone (1999a) to two helices embedded in the same cylindrical flux rope. In contrast to configurations with cylindrical symmetry, magnetic configurations with helical symmetry allow a description of many helices which in cross section look like distorted flux ropes. We present elements of the magnetic and thermodynamic structure of the Oct 18-21, 1995 magnetic cloud observed by Wind. Our research is complementary to previous studies of this cloud by other authors ((3)Larson et al. 1997; (4)Lepping et al. 1997; (5)Janoo et al. 1998). The log-log plots of T(e) vs N(e) suggest that this cloud consists of eight magnetic tubes with polytropic indices below unity and a few non-coherent structures for which the polytropic relation is not valid. The solar wind quasi-invariant ((6)Osherovich et al., 1999b) for this cloud strongly anti-correlates with the Dst index for the resulting magnetic storm. C1 NASA, Goddard Space Flight Ctr, EER Syst Inc, Greenbelt, MD 20771 USA. RP Osherovich, VA (reprint author), NASA, Goddard Space Flight Ctr, EER Syst Inc, Greenbelt, MD 20771 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 733 EP 736 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700167 ER PT S AU Szabo, A Smith, CW Skoug, RM AF Szabo, A Smith, CW Skoug, RM BE Velli, M Bruno, R Malara, F TI The transition of interplanetary shocks through the magnetosheath SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID RANKINE-HUGONIOT PROBLEM; BOW SHOCK; MAGNETOPAUSE; SPACECRAFT AB WIND, ACE, IMP 8 and Geotail data shows that the magnetosheath signature of IP shocks is primarily a fast-mode shock or pressure pulse with a wide ramp. No model predicted secondary discontinuities could be identified above the magnetosheath background fluctuation level. Even though the interplanetary surface geometry of IP shocks could be significantly corrugated, this study suggests that there is no significant deceleration of the pressure front in the magnetosheath. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Szabo, A (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. NR 25 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 782 EP 785 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700179 ER PT S AU Collier, MR Moore, TE Ogilvie, K Chornay, DJ Keller, J Fuselier, S Quinn, J Wurz, P Wuest, M Hsieh, KC AF Collier, MR Moore, TE Ogilvie, K Chornay, DJ Keller, J Fuselier, S Quinn, J Wurz, P Wuest, M Hsieh, KC BE Velli, M Bruno, R Malara, F TI Dust in the wind: The dust geometric cross section at 1 AU based on neutral solar wind observations SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID ZODIACAL LIGHT; INTERSTELLAR DUST; HELIOSPHERE; ATOMS; HYDROGEN; PLASMA; RATES AB We report observations of the neutral component of the solar wind from the Low Energy Neutral Atom (LENA) imager on the NASA IMAGE spacecraft from year 2001. There is a pronounced annual modulation of the neutral solar wind, and the flux outside of the upstream region is used to place an upper limit on the dust geometric cross section in the sunward direction at 1 AU of Gamma(1AU) < 6x10(-19) cm(-1). This value agrees with inferences made from the zodiacal light. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Collier, MR (reprint author), NASA, Goddard Space Flight Ctr, Code 692, Greenbelt, MD 20771 USA. RI Moore, Thomas/D-4675-2012; Keller, John/I-5097-2013; Collier, Michael/I-4864-2013 OI Moore, Thomas/0000-0002-3150-1137; Collier, Michael/0000-0001-9658-6605 NR 27 TC 17 Z9 17 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 790 EP 793 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700181 ER PT S AU Ruzmaikin, A AF Ruzmaikin, A CA MASSE Sci Team BE Velli, M Bruno, R Malara, F TI Multi-angle viewing of the Sun and the inner Heliosphere SO SOLAR WIND TEN, PROCEEDINGS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 10th International Solar Wind Conference CY JUN 17-21, 2002 CL PISA, ITALY SP Univ Firenze, Univ Pisa, Univ Calabria, IFSI, ASI, European Space Agcy, INAF ID PARTICLE-ACCELERATION; MAGNETIC-FIELD; EMERGING FLUX; SOLAR-WIND; LONGITUDES; SHOCKS; WAVES; MODEL AB We describe the concept of a proposed mission, called Multi-Angle Solar Sources Explorer (MASSE), that would observe the Sun and the inner Heliosphere from an orbit at 0.72 AU over all solar longitudes. It would, in coordination with observations from Earth's side, investigate the sources of solar activity from their origin deep within the Sun, their emergence onto the photosphere, and their ejection into the Heliosphere. It carries a Doppler-magnetic imager, and in situ energetic particle, solar wind, and magnetic field detectors. Three-dimensional views of the convection zone, where solar activity originates, are reconstructed by correlating MASSE and earth-side Doppler signals from acoustic wave packets traversing deep solar layers. Magnetic images reveal the evolution of active regions over their life-time and allow the study of emerging fields from deep layers. Particle, plasma, and magnetic field data provide information on the sites and mechanisms of acceleration of hazardous high-energy particles produced by coronal mass ejections. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ruzmaikin, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0148-9 J9 AIP CONF PROC PY 2003 VL 679 BP 826 EP 829 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BX72B UT WOS:000186211700188 ER PT J AU Jin, ZR Cressler, JD Niu, GF Marshall, PW Kim, HS Reed, R Joseph, AJ AF Jin, ZR Cressler, JD Niu, GF Marshall, PW Kim, HS Reed, R Joseph, AJ TI Proton response of low-frequency noise in 0.20 mu m 90 GHz f(T) UHV/CVD SiGeHBTs SO SOLID-STATE ELECTRONICS LA English DT Article DE SiGeHBT; 1/f noise; proton irradiation ID BIPOLAR-TRANSISTORS AB The influence of proton exposure on the low-frequency noise of 0.20 mum UHV/CVD SiGe HBTs is presented. The noise degradation after irradiation shows a strong dependence on transistor geometry. Our previously developed noise theory is used to understand this behavior, and a comparison is made between these new results on third generation SiGe technology and our prior results on the first generation SiGe technology. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Auburn Univ, Dept Elect & Comp Engn, Alabama Microelect Sci & Technol Ctr, Auburn, AL 36849 USA. IBM Microelect, Essex Jct, VT 05401 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Jackson & Tull Chartered Engineers, Washington, DC 20018 USA. RP Jin, ZR (reprint author), Auburn Univ, Dept Elect & Comp Engn, Alabama Microelect Sci & Technol Ctr, 200 Brown Hall, Auburn, AL 36849 USA. NR 9 TC 10 Z9 10 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JAN PY 2003 VL 47 IS 1 BP 39 EP 44 AR PII S0038-1101(02)00251-4 DI 10.1016/S0038-1101(02)00251-4 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 628JQ UT WOS:000179990500006 ER PT J AU Nigam, S Kim, J Luo, B Ren, F Chung, GY Pearton, SJ Williams, JR Shenai, K Neudeck, P AF Nigam, S Kim, J Luo, B Ren, F Chung, GY Pearton, SJ Williams, JR Shenai, K Neudeck, P TI Effect of contact geometry on 4H-SiC rectifiers with junction termination extension SO SOLID-STATE ELECTRONICS LA English DT Article ID POWER DEVICES; DESIGN CONSIDERATIONS; EDGE TERMINATION; SIC DIODES; VOLTAGE AB SiC rectifiers with an on/off current ratio of 4 x 10(5) (at 1.5 V/-500 V) were fabricated using junction termination extension (JTE) and dielectric overlap. The reverse breakdown voltage was inversely dependent on contact area and was not a strong function of JTE length up to 40 mum. Similarly, for a given JTE length, the metal overlap did not have a strong influence on breakdown voltage. Oval- and circular-shaped contacts produced larger breakdown voltages than square rectifying contacts. The on-state resistance, R-ON, was 4.2 mOmega cm(2), which is close to the theoretical minimum of these rectifiers using Ni Schottky contacts. The figure-of-merit (V-B)(2)/R-ON was as high as 156 MW cm(-2). (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Sterling Semicond, Tampa, FL 33619 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Illinois, Dept Elect & Comp Engn, Chicago, IL 60607 USA. Auburn Univ, Dept Phys, Auburn, AL 36849 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Ren, F (reprint author), Univ Florida, Dept Chem Engn, POB 116005, Gainesville, FL 32611 USA. RI Kim, Jihyun/F-6940-2013 NR 22 TC 2 Z9 3 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JAN PY 2003 VL 47 IS 1 BP 57 EP 60 AR PII S0038-1101(02)00273-3 DI 10.1016/S0038-1101(02)00273-3 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 628JQ UT WOS:000179990500009 ER PT J AU Nigam, S Kim, J Luo, B Ren, F Chung, GY Pearton, SJ Williams, JR Shenai, K Neudeck, P AF Nigam, S Kim, J Luo, B Ren, F Chung, GY Pearton, SJ Williams, JR Shenai, K Neudeck, P TI Influence of edge termination geometry on performance of 4H-SiC p-i-n rectifiers SO SOLID-STATE ELECTRONICS LA English DT Article ID 4H SILICON-CARBIDE; DESIGN CONSIDERATIONS; DIODES AB P-i-n 4H-SiC rectifiers with SiO2 passivated mesa edge termination showed forward current characteristics dominated by recombination at low bias (n similar to 1.97) and diffusion at high voltages (n similar to 1.1). The forward turn-on voltage was similar to4 V, with a specific on-state resistance of 15 mOmega cm(2), on/off current ratio of 1.5 x 10(5) at 3 V/-450 V and figure-of-merit, V-B(2)/R-ON, of 13.5 MW cm(-2). The mesa extension distance did not have a strong impact on reverse breakdown voltage. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Illinois, Dept Elect & Comp Engn, Chicago, IL 60607 USA. Auburn Univ, Dept Phys, Auburn, AL 36849 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Sterling Semicond, Tampa, FL 33619 USA. RP Ren, F (reprint author), Univ Florida, Dept Chem Engn, POB 116005, Gainesville, FL 32611 USA. RI Kim, Jihyun/F-6940-2013 NR 17 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JAN PY 2003 VL 47 IS 1 BP 61 EP 64 AR PII S0038-1101(02)00272-1 DI 10.1016/S0038-1101(02)00272-1 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 628JQ UT WOS:000179990500010 ER PT S AU George, K Durante, M Wu, H Willingham, V Cucinotta, FA AF George, K Durante, M Wu, H Willingham, V Cucinotta, FA BE Hei, TK Wu, HL TI In vivo and in vitro measurements of complex-type chromosomal exchanges induced by heavy ions SO SPACE LIFE SCIENCES: BIODOSIMETRY, BIOMARKERS AND LATE STOCHASTIC EFFECTS OF SPACE RADIATION SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT World Space Congress CY OCT 10-19, 2002 CL HOUSTON, TEXAS SP Comm Space Res ID HUMAN-LYMPHOCYTES; HIGH-LET; BLOOD-LYMPHOCYTES; CHARGED-PARTICLES; SITU HYBRIDIZATION; ALPHA-PARTICLES; TIME-COURSE; ABERRATIONS; RADIATION; CELLS AB Heavy ions are more efficient in producing complex-type chromosome exchanges than sparsely ionizing radiation, and this can potentially be used as a biomarker of radiation quality. We measured the induction of complex-type chromosomal aberrations in human peripheral blood lymphocytes exposed in vitro to accelerated H-, He-, C-, Ar-, Fe- and Au-ions in the LET range of approximately 0.4-1400 keV/mum. Chromosomes were analyzed either at the first post-irradiation mitosis, or in interphase, following premature condensation by phosphatase inhibitors. Selected chromosomes were then visualized after FISH-painting. The dose-response curve for the induction of complex-type exchanges by heavy ions was linear in the dose-range 0.2-1.5 Gy, while gamma-rays did not produce a significant increase in the yield of complex rearrangements in this dose range. The yield of complex aberrations after 1 Gy of heavy ions increased up to an LET around 100 keV/mum, and then declined at higher LET values. When mitotic cells were analyzed, the frequency of complex rearrangements after I Gy was about 10 times higher for Ar- or Fe-ions (the most effective ions, with LET around 100 keV/mum) than for 250 MeV protons, and values were about 35 times higher in prematurely condensed chromosomes. These results suggest that complex rearrangements may be detected in astronauts' blood lymphocytes after long-term space flight, because crews are exposed to HZE particles from galactic cosmic radiation. However, in a cytogenetic study of ten astronauts after long-term missions on the Mir or International Space Station, we found a very low frequency of complex rearrangements, and a significant post-flight increase was detected in only one out of the ten crew members. It appears that the use of complex-type exchanges as biomarker of radiation quality in vivo after low-dose chronic exposure in mixed radiation fields is hampered by statistical uncertainties. (C) 2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Wyle Life Sci, Houston, TX 77058 USA. Univ Naples Federico II, Dept Phys, Naples, Italy. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP George, K (reprint author), Wyle Life Sci, Houston, TX 77058 USA. RI Durante, Marco/K-1315-2014; OI Durante, Marco/0000-0002-4615-553X NR 28 TC 21 Z9 24 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 6 BP 1525 EP 1535 DI 10.1016/S0273-1177(03)00088-7 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX38D UT WOS:000185090300005 PM 12971407 ER PT S AU Wu, H Durante, M Furusawa, Y George, K Kawata, T Cucinotta, FA AF Wu, H Durante, M Furusawa, Y George, K Kawata, T Cucinotta, FA BE Hei, TK Wu, HL TI M-fish analysis of chromosome aberrations in human fibroblasts exposed to energetic iron ions in vitro SO SPACE LIFE SCIENCES: BIODOSIMETRY, BIOMARKERS AND LATE STOCHASTIC EFFECTS OF SPACE RADIATION SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT World Space Congress CY OCT 10-19, 2002 CL HOUSTON, TEXAS SP Comm Space Res ID HUMAN-LYMPHOCYTES; EXCHANGE ABERRATIONS; IONIZING-RADIATION; SITU HYBRIDIZATION; TELOMERIC PNA; PARTICLES; PROBES AB Confluent human fibroblast cells were exposed to 6 Gy gamma-rays or 200 MeV/nucleon Fe ions at 0.7 or 3 Gy. The cells were allowed to repair for 24 hours after exposure and chromosomes were collected using a premature chromosome condensation technique with calyculin-A. Chromosome aberrations were analyzed using the multicolor FISH (mFISH) technique that allows identification of both complex and truly incomplete exchanges. Results showed that both doses of the Fe ions produced higher ratios of complex to simple exchanges and lower ratio of complete to incomplete exchanges than the 6 Gy gamma-exposure. The ratios of aberration yields were similar for the two doses of Fe ions. After 0.7 Gy of Fe ions, most complex aberrations were found to involve three or four chromosomes, indicating this is the maximum number of chromosome domains traversed by a single Fe ion track. Published by Elsevier Science Ltd on behalf of COSPAR. C1 Wyle Labs, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Naples Federico II, Dept Phys, Naples, Italy. Natl Inst Radiol Sci, Chiba 260, Japan. Chiba Univ, Dept Radiat Therapy, Chiba, Japan. RP Wu, H (reprint author), Wyle Labs, 1290 Hercules Dr, Houston, TX 77058 USA. RI Durante, Marco/K-1315-2014; OI Durante, Marco/0000-0002-4615-553X NR 14 TC 9 Z9 9 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 6 BP 1537 EP 1542 DI 10.1016/S0273-1177(03)00092-9 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX38D UT WOS:000185090300006 PM 12971408 ER PT S AU Katz, R Cucinotta, FA AF Katz, R Cucinotta, FA BE Hei, TK Wu, HL TI Low fluence SO SPACE LIFE SCIENCES: BIODOSIMETRY, BIOMARKERS AND LATE STOCHASTIC EFFECTS OF SPACE RADIATION SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT World Space Congress CY OCT 10-19, 2002 CL HOUSTON, TEXAS SP Comm Space Res ID SURVIVAL AB The question of the appropriate extrapolation to low dose has long been a subject of controversy. A linear no-threshold model is favored by regulatory bodies as the basis of RBE assignments and estimates of radiation hazards to the general population. This model is largely supported by extensive application of the linear-quadratic survival formula "fitted" statistically to a wide variety of experimental data obtained at doses typically exceeding 1 Gy, and then extrapolated to mGy for practical applications, and even to the prediction of hazards from single electrons. Such extrapolations are questionable at best, and may even prove hazardous for risk evaluations. Fluence and geometry rather than dose based data are proposed as a basis for a limiting "threshold" for a "low dose" extrapolation. The proposed threshold is one where the fluence of particles is one per square micron, where on average only 2/3 of the 1 mum(2) pixels covering an irradiated area are traversed by one or more particles. The corresponding dose threshold is determined by the LET of the bombarding radiation. For relativistic electrons this dose is about 0.032 Gy. (C) 2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Nebraska, Lincoln, NE 68588 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Katz, R (reprint author), Univ Nebraska, Lincoln, NE 68588 USA. NR 16 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 6 BP 1553 EP 1556 DI 10.1016/S0273-1177(03)00090-5 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX38D UT WOS:000185090300008 PM 12971410 ER PT S AU Rodriguez, LF Kang, S Ting, KC AF Rodriguez, LF Kang, S Ting, KC BE Nelson, M Pechurkin, NS Dempster, WF Somova, LA Shea, MA TI Top-level modeling of an ALS system utilizing object-oriented techniques SO SPACE LIFE SCIENCES: CLOSED ARTIFICIAL ECOSYSTEMS AND LIFE SUPPORT SYSTEMS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT Meeting of F4 1 Session of the 34th Scientific Assembly of COSPAR CY OCT, 2002 CL HOUSTON, TEXAS SP Comm Space Res AB The possible configuration of an Advanced Life Support (ALS) System capable of supporting human life for long-term space missions continues to evolve as researchers investigate potential technologies and configurations. To facilitate the decision process the development of acceptable, flexible, and dynamic mathematical computer modeling tools capable of system level analysis is desirable. Object-oriented techniques have been adopted to develop a dynamic top-level model of an ALS system. This approach has several advantages; among these, object-oriented abstractions of systems are inherently modular in architecture. Thus, models can initially be somewhat simplistic, while allowing for adjustments and improvements. In addition, by coding the model in Java, the model can be implemented via the World Wide Web, greatly encouraging the utilization of the model. Systems analysis is further enabled with the utilization of a readily available backend database containing information supporting the model. The subsystem models of the ALS system model include Crew, Biomass Production, Waste Processing and Resource Recovery, Food Processing and Nutrition, and the Interconnecting Space. Each subsystem model and an overall model have been developed. Presented here is the procedure utilized to develop the modeling tool, the vision of the modeling tool, and the current focus for each of the subsystem models. (C) 2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 NASA, Lyndon B Johnson Space Ctr, Natl Res Council, Houston, TX 77058 USA. Rural Dev Adm, Natl Agr Mechanizat Res Inst, Suwon 441100, South Korea. Ohio State Univ, Food Agr & Biol Engn Dept, Columbus, OH 43210 USA. RP Rodriguez, LF (reprint author), NASA, Lyndon B Johnson Space Ctr, Natl Res Council, EC2, Houston, TX 77058 USA. NR 35 TC 2 Z9 2 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 7 BP 1811 EP 1822 DI 10.1016/S0273-1177(03)00080-2 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics; Ecology; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA BX17V UT WOS:000184541200025 PM 14503522 ER PT S AU Ronca, AE AF Ronca, AE BE Bruce, LL Ijiri, K Perbal, G TI Studies toward birth and early mammalian development in space SO SPACE LIFE SCIENCES: GRAVITATIONAL BIOLOGY: 2002 SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT Conference on Animal Model System for Long-Term Spaceflight CY OCT 17, 2003 CL HOUSTON, TX ID RATS AB Sustaining life beyond Earth on either space stations or other planets will require a clear understanding of how the space environment affects key phases of mammalian reproduction and development. Pregnancy, parturition (birth) and the early development of offspring are complex processes essential for successful reproduction and the proliferation of mammalian species. While no mammal has yet undergone birth within the space environment, studies spanning the gravity continuum from 0- to 2-g are revealing startling insights into how reproduction and development may proceed under gravitational conditions deviating from those typically experienced on Earth. In this report, I review studies of pregnant Norway rats and their offspring flown in microgravity (mug) onboard the NASA Space Shuttle throughout the period corresponding to mid- to late gestation, and analogous studies of pregnant rats exposed to hypergravity (hg) onboard the NASA Ames Research Center 24-ft centrifuge. Studies of postnatal rats flown in space or exposed to centrifugation are reviewed. Although many important questions remain unanswered, the available data suggest that numerous aspects of pregnancy, birth and early mammalian development can proceed under altered gravity conditions. Published by Elsevier Ltd on behalf of COSPAR. C1 NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA. RP Ronca, AE (reprint author), NASA, Ames Res Ctr, Div Life Sci, MS 261-3, Moffett Field, CA 94035 USA. EM aronca@mail.arc.nasa.gov FU NASA [NIMH 46485] NR 15 TC 8 Z9 8 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES PY 2003 VL 32 IS 8 BP 1483 EP 1490 DI 10.1016/S0273-1177(03)00620-3 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Biology; Cell Biology; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Cell Biology; Geology; Meteorology & Atmospheric Sciences GA BY15C UT WOS:000187952900006 PM 15000095 ER PT S AU Levine, HG Anderson, K Boody, A Cox, D Kuznetsov, OA Hasenstein, KH AF Levine, HG Anderson, K Boody, A Cox, D Kuznetsov, OA Hasenstein, KH BE Kiss, JZ Kern, VD TI Germination and elongation of flax in microgravity SO SPACE LIFE SCIENCES: GRAVITY-RELATED PROCESSES IN PLANTS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT Meeting of F1 2 Session of the 34th Scientific Assembly of COSPAR CY 2002 CL HOUSTON, TEXAS SP Comm Space Res AB This experiment was conducted as part of a risk mitigation payload aboard the Space Shuttle Atlantis on STS-101. The objectives were to test, a newly developed water delivery system, and to determine the optimal combination of water volume and substrate. for the imbibition and germination of flax. (Linum usitatissimum) seeds in space. Two different combinations of germination paper were tested for their ability to absorb, distribute, and retain water in microgravity. A single layer of thick germination paper was compared with one layer of thin germination paper under a layer of thick paper. Paper strips were cut to fit snugly into seed cassettes, and seeds were glued to them with the micropyle ends pointing outward. Water was delivered in small increments that traveled through the paper via capillary action. Three water delivery volumes were tested, with the largest (480 muL) outperforming the 400 muL and 320 muL volumes for percent germination (90.6%) and root growth (mean = 4.1 mm) during the 34-hour spaceflight experiment. The ground control experiment yielded similar results, but with lower rates of germination (84.4%) and shorter root lengths (mean = 2.8 mm). It is not clear if the roots emerged more quickly in microgravity and/or grew faster than the ground controls. The single layer of thick germination paper generally exhibited better overall growth than the two layered option. Significant seed position effects were observed in both the flight and ground control experiments. Overall, the design of the water delivery system, seed cassettes and the germination paper strip concept was validated as an effective method for promoting seed germination and root growth under microgravity conditions. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 Dynam Corp, Kennedy Space Ctr, FL 32899 USA. Bionet Corp, Kennedy Space Ctr, FL 32899 USA. NASA, Kennedy Space Ctr, FL 32899 USA. Univ SW Louisiana, Dept Biol, Lafayette, LA 70504 USA. RP Levine, HG (reprint author), Dynam Corp, Mail Code DYN-3, Kennedy Space Ctr, FL 32899 USA. RI Hasenstein, Karl/B-2759-2015 NR 3 TC 4 Z9 5 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 10 BP 2261 EP 2268 DI 10.1016/S0273-1177(03)00253-9 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Plant Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Plant Sciences; Geology; Meteorology & Atmospheric Sciences GA BX44Z UT WOS:000185329600012 PM 14686441 ER PT S AU White, RJ Bassingthwaighte, JB Charles, JB Kushmerick, MJ Newman, DJ AF White, RJ Bassingthwaighte, JB Charles, JB Kushmerick, MJ Newman, DJ BE Horneck, G Vazquez, ME Porterfield, DM TI Issues of exploration: Human health and wellbeing during a mission to Mars SO SPACE LIFE SCIENCES: MISSIONS TO MARS, RADIATION BIOLOGY, AND PLANTS AS A FOUNDATION FOR LONG-TERM LIFE SUPPORT SYSTEMS IN SPACE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F0 1 and F1 3-F2 3 Symposia of COSPAR Scientific Commission F held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP CNES, Deutsch Zentrum Luft & Raumfahrt eV, European Space Sci Comm, Int Astronaut Federat, Int Soc Study Origin Life, NASA, Comm Space Res ID TRICARBOXYLIC-ACID CYCLE; CROSS-BRIDGE CYCLE; DICTYOSTELIUM-DISCOIDEUM; CREATINE-KINASE; PUBLIC-HEALTH; STEADY-STATE; MUSCLE; BEHAVIOR; MODEL; PREVENTION AB Today, the tools are in our hands to enable us to travel away from our home planet and become citizens of the solar system. Even now, we are seriously beginning to develop the robust infrastructure that will make the 21(st) century the Century of Space Travel. But this bold step must be taken with due concern for the health, safety and wellbeing of future space explorers. Our long experience with space biomedical research convinces us that, if we are to deal effectively with the medical and biomedical issues of exploration, then dramatic and bold steps are also necessary in this field. We can no longer treat the human body as if it were composed of muscles, bones, heart and brain acting independently. Instead, we must lead the effort to develop a fully integrated view of the body, with all parts connected and fully interacting in a realistic way. This paper will present the status of current (2000) plans by the National Space Biomedical Research Institute to initiate research in this area of integrative physiology and medicine. Specifically, three example projects are discussed as potential stepping stones towards the ultimate goal of producing a digital human. These projects relate to developing a functional model of the human musculoskeletal system and the heart. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Natl Space Biomed Res Inst, Houston, TX 77030 USA. Univ Washington, Dept Bioengn, Seattle, WA 98195 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Washington, Dept Radiol, Seattle, WA 98195 USA. MIT, Cambridge, MA 02139 USA. RP White, RJ (reprint author), Natl Space Biomed Res Inst, 1 Baylor Plaza,NA-425, Houston, TX 77030 USA. NR 25 TC 8 Z9 8 U1 2 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 1 BP 7 EP 16 AR PII S0273-1177(02)00652-X DI 10.1016/S0273-1177(02)00652-X PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98Q UT WOS:000180591400001 PM 12577893 ER PT S AU Schimmerling, W Cucinotta, FA Wilson, JW AF Schimmerling, W Cucinotta, FA Wilson, JW BE Horneck, G Vazquez, ME Porterfield, DM TI Radiation risk and human space exploration SO SPACE LIFE SCIENCES: MISSIONS TO MARS, RADIATION BIOLOGY, AND PLANTS AS A FOUNDATION FOR LONG-TERM LIFE SUPPORT SYSTEMS IN SPACE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F0 1 and F1 3-F2 3 Symposia of COSPAR Scientific Commission F held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP CNES, Deutsch Zentrum Luft & Raumfahrt eV, European Space Sci Comm, Int Astronaut Federat, Int Soc Study Origin Life, NASA, Comm Space Res AB Radiation protection is essential to enable humans to live and work safely in space. Predictions about the nature,and magnitude of the risks posed by space radiation are subject to very large uncertainties. Prudent use of worst-case scenarios may impose unacceptable constraints on shielding mass for spacecraft or habitats, tours of duty of crews on Space Station, and on the radius and duration of sorties on planetary surfaces. The NASA Space Radiation Health Program has been devised to develop the knowledge required to accurately predict and to efficiently manage radiation risk. The knowledge will be acquired by means of a peer-reviewed, largely ground-based and investigator-initiated, basic science research program. The NASA Strategic Plan to accomplish these objectives in a manner consistent with the high priority assigned to the protection and health maintenance of crews will be presented. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Washington, DC 20546 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Schimmerling, W (reprint author), NASA, Washington, DC 20546 USA. NR 14 TC 35 Z9 38 U1 3 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 1 BP 27 EP 34 AR PII S0273-1177(02)00653-1 DI 10.1016/S0273-1177(02)00653-1 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98Q UT WOS:000180591400004 PM 12577903 ER PT S AU Drysdale, AE Ewert, MK Hanford, AJ AF Drysdale, AE Ewert, MK Hanford, AJ BE Horneck, G Vazquez, ME Porterfield, DM TI Life support approaches for Mars missions SO SPACE LIFE SCIENCES: MISSIONS TO MARS, RADIATION BIOLOGY, AND PLANTS AS A FOUNDATION FOR LONG-TERM LIFE SUPPORT SYSTEMS IN SPACE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F0 1 and F1 3-F2 3 Symposia of COSPAR Scientific Commission F held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP CNES, Deutsch Zentrum Luft & Raumfahrt eV, European Space Sci Comm, Int Astronaut Federat, Int Soc Study Origin Life, NASA, Comm Space Res AB Life support approaches for Mars missions are evaluated using an equivalent system mass (ESM) approach, in which all significant costs are converted into mass units. The best approach, as defined by the lowest mission ESM, depends on several mission parameters, notably duration, environment and consequent infrastructure costs, and crew size, as well as the characteristics of the technologies which are available. Generally, for the missions under consideration, physicochemical regeneration is most cost effective. However, bioregeneration is likely to be of use for producing salad crops for any mission, for producing staple crops for medium duration missions, and for most food, air and water regeneration for long missions (durations of a decade). Potential applications of in situ resource utilization need to be considered further. (C) 2002 Published by Elsevier Science Ltd on behalf of COSPAR. C1 Boeing Co, Kennedy Space Ctr, FL 32815 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Lockheed Martin Space Operat, Houston, TX 77058 USA. RP Drysdale, AE (reprint author), Boeing Co, POB 21233, Kennedy Space Ctr, FL 32815 USA. NR 10 TC 25 Z9 25 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 1 BP 51 EP 61 AR PII S0273-1177(02)00658-0 DI 10.1016/S0273-1177(02)00658-0 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98Q UT WOS:000180591400008 PM 12577926 ER PT S AU Mancinelli, RL AF Mancinelli, RL BE Horneck, G Vazquez, ME Porterfield, DM TI Planetary protection and the search for life beneath the surface of Mars SO SPACE LIFE SCIENCES: MISSIONS TO MARS, RADIATION BIOLOGY, AND PLANTS AS A FOUNDATION FOR LONG-TERM LIFE SUPPORT SYSTEMS IN SPACE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F0 1 and F1 3-F2 3 Symposia of COSPAR Scientific Commission F held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP CNES, Deutsch Zentrum Luft & Raumfahrt eV, European Space Sci Comm, Int Astronaut Federat, Int Soc Study Origin Life, NASA, Comm Space Res AB The search for traces of extinct and extant life on Mars will be extended to beneath the surface of the planet. Current data from Mars missions suggesting the presence of liquid water early in Mars' history and mathematical modeling of the fate of water on Mars imply that liquid water may exist deep beneath the surface of Mars. This leads to the hypothesis that life may exist deep beneath the Martian surface. One possible scenario to look for life on Mars involves a series of unmanned missions culminating with a manned mission drilling deep into the Martian subsurface (similar to3Km), collecting samples, and conducting preliminary analyses to select samples for return to earth. This mission must address both forward and back contamination issues, and falls under planetary protection category V. Planetary protection issues to be addressed include provisions stating that the inevitable deposition of earth microbes by humans should be minimized and localized, and that earth microbes and organic material must not contaminate the Martian subsurface. This requires that the drilling equipment be sterilized prior to use. Further, the collection, containment and retrieval of the sample must be conducted such that the crew is protected and that any materials returning to earth are contained (i.e., physically and biologically isolated) and the chain of connection with Mars is broken (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Mancinelli, RL (reprint author), NASA, Ames Res Ctr, Mail Stop 239-4, Moffett Field, CA 94035 USA. RI Mancinelli, Rocco/L-8971-2016 NR 12 TC 14 Z9 15 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 1 BP 103 EP 107 AR PII S0273-1177(02)00663-4 DI 10.1016/S0273-1177(02)00663-4 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98Q UT WOS:000180591400014 PM 12577965 ER PT S AU Wheeler, RM AF Wheeler, RM BE Horneck, G Vazquez, ME Porterfield, DM TI Carbon balance in bioregenerative life support systems: Some effects of system closure, waste management, and crop harvest index SO SPACE LIFE SCIENCES: MISSIONS TO MARS, RADIATION BIOLOGY, AND PLANTS AS A FOUNDATION FOR LONG-TERM LIFE SUPPORT SYSTEMS IN SPACE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F0 1 and F1 3-F2 3 Symposia of COSPAR Scientific Commission F held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP CNES, Deutsch Zentrum Luft & Raumfahrt eV, European Space Sci Comm, Int Astronaut Federat, Int Soc Study Origin Life, NASA, Comm Space Res ID GROWTH; ENVIRONMENT; YIELD; SPACE AB In Advanced Life Support (ALS) systems with bioregenerative components, plant photosynthesis would be used to produce O-2 and food, while removing CO2. Much of the plant biomass would be inedible and hence must be considered in waste management. This waste could be oxidized (e.g., incinerated or aerobically digested) to resupply CO2 to the plants, but this would not be needed unless the system were highly closed with regard to food. For example, in a partially closed system where some of the food is grown and some is imported, CO2 from oxidized waste when combined with crew and microbial respiration could exceed the CO2 removal capability of the plants. Moreover, it would consume some O-2 Produced from photosynthesis that could have been used by the crew. For partially closed systems it would be more appropriate to store or find other uses for the inedible biomass and excess carbon, such as generating soils or growing woody plants (e.g., dwarf fruit trees). Regardless of system closure, high harvest crops (i.e., crops with a high edible to total biomass ratio) would increase food production per unit area and O-2 yields for systems where waste biomass is oxidized to recycle CO2. Such interlinking effects between the plants and waste treatment strategies point out the importance of oxidizing only that amount of waste needed to optimize system performance. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Biol Sci Branch, Kennedy Space Ctr, FL 32899 USA. RP Wheeler, RM (reprint author), NASA, Biol Sci Branch, Mail Code YA-D3, Kennedy Space Ctr, FL 32899 USA. NR 27 TC 17 Z9 17 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 1 BP 169 EP 175 AR PII S0273-1177(02)00742-1 DI 10.1016/S0273-1177(02)00742-1 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98Q UT WOS:000180591400022 PM 12578002 ER PT S AU Salisbury, FB Campbell, WF Carman, JG Bingham, GE Bubenheim, DL Yendler, B Sytchev, V Levinskikh, MA Ivanova, I Chernova, L Podolsky, I AF Salisbury, FB Campbell, WF Carman, JG Bingham, GE Bubenheim, DL Yendler, B Sytchev, V Levinskikh, MA Ivanova, I Chernova, L Podolsky, I BE Horneck, G Vazquez, ME Porterfield, DM TI Plant growth during the Greenhouse II experiment on the MIR orbital station SO SPACE LIFE SCIENCES: MISSIONS TO MARS, RADIATION BIOLOGY, AND PLANTS AS A FOUNDATION FOR LONG-TERM LIFE SUPPORT SYSTEMS IN SPACE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F0 1 and F1 3-F2 3 Symposia of COSPAR Scientific Commission F held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP CNES, Deutsch Zentrum Luft & Raumfahrt eV, European Space Sci Comm, Int Astronaut Federat, Int Soc Study Origin Life, NASA, Comm Space Res ID SUPER DWARF WHEAT; SPACE AB We carried out three experiments with Super Dwarf wheat in the Bulgarian/Russian growth chamber Svet (0.1 m(2) growing area) on the Space Station Mir. This paper mostly describes the first of these NASA-supported trials, began on Aug. 13, 1995. Plants were sampled five times and harvested on Nov. 9 after 90 days. Equipment failures led to low irradiance (3, then 4 of 6 lamp sets failed), instances of high temperatures (ca. 37 degreesC), and sometimes excessive substrate moisture. Although plants grew for the 90 d, no wheat heads were produced. Considering the low light levels, plants were surprisingly green, but of course biomass production was low. Plants were highly disoriented (low light, mirror walls?). Fixed and dried samples and the root module were returned on the U.S. Shuttle Atlantis on Nov. 20, 1995. Samples of the substrate, a nutrient-charged zeolite called Balkanine, were taken from the root module, carefully examined for roots, weighed, dried, and reweighed. The Svet control unit and the light bank were shipped to Moscow. An experiment validation test (EVT) of plant growth and experimental procedures, carried Out in MOSCOW, was highly successful. Equipment built in Utah to measure CO2, H2O vapor, irradiance, air and leaf (IR) temperature, O-2, pressure, and substrate moisture worked well in the EVT and in space. After this manuscript was first prepared, plants were grown in Mir with a new light bank and controller for 123 d in late 1996 and 39 days in 1996/1997. Plants grew exceptionally well with higher biomass production than in any previous space experiment, but the ca. 280 wheat heads that were produced in 1996 contained no seeds. Ethylene in the cabin atmosphere was responsible. (C) 2002 Published by Elsevier Science Ltd on behalf of COSPAR. C1 Utah State Univ, Dept Plants Soils & Biometeorol, Logan, UT 84322 USA. Utah State Univ, Space Dynam Lab, N Logan, UT 84341 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Inst Biomed Problems, Moscow 123007, Russia. RP Salisbury, FB (reprint author), Utah State Univ, Dept Plants Soils & Biometeorol, Logan, UT 84322 USA. NR 12 TC 13 Z9 14 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 1 BP 221 EP 227 AR PII S0273-1177(02)00744-5 DI 10.1016/S0273-1177(02)00744-5 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98Q UT WOS:000180591400029 PM 12580179 ER PT S AU Bubenheim, DL Stieber, J Campbell, WF Salisbury, FB Levinski, M Sytchev, V Pdolsky, I Chernova, L AF Bubenheim, DL Stieber, J Campbell, WF Salisbury, FB Levinski, M Sytchev, V Pdolsky, I Chernova, L BE Horneck, G Vazquez, ME Porterfield, DM TI Induced abnormality in MIR- and Earth grown Super Dwarf wheat SO SPACE LIFE SCIENCES: MISSIONS TO MARS, RADIATION BIOLOGY, AND PLANTS AS A FOUNDATION FOR LONG-TERM LIFE SUPPORT SYSTEMS IN SPACE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F0 1 and F1 3-F2 3 Symposia of COSPAR Scientific Commission F held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP CNES, Deutsch Zentrum Luft & Raumfahrt eV, European Space Sci Comm, Int Astronaut Federat, Int Soc Study Origin Life, NASA, Comm Space Res AB Super-dwarf wheat grown on the Mir space station using the Svet "Greenhouse" exhibited morphological, metabolic and reproductive abnormalities compared with Earth-grown wheat. Of prominent importance were the abnormalities associated with reproductive ontogeny and the total absence of seed formation on Mir. Changes in the apical meristem associated with transition from the vegetative phase to floral initiation and development of the reproductive spike were all typical of 'Super-Dwarf wheat up to the point of anthesis. Observation of ruptured anthers from the Mir-grown plants revealed what appeared to be normally developed pollen. These pollen gains, however, contained only one nuclei, while normal viable pollen is tri-nucleate. A potentially important difference in the flight experiment, compared with ground reference studies, was the presence of a high level of atmospheric ethylene (1,200 ppb). Ground studies conducted by exposing 'Super-Dwarf wheat to ethylene just prior to anthesis resulted in manifestation of the same abnormalities observed in the space flight samples. (C) 2002 Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. Utah State Univ, Dept Plant & Soil Sci, Logan, UT 84322 USA. Minist Publ Hlth Russia, Inst Biomed Problems, Moscow, Russia. RP Bubenheim, DL (reprint author), NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. NR 5 TC 6 Z9 9 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 1 BP 229 EP 234 AR PII S0273-1177(02)00745-7 DI 10.1016/S0273-1177(02)00745-7 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98Q UT WOS:000180591400030 PM 12580182 ER PT S AU Bubenheim, DL Schlick, G Wilson, D Bates, M AF Bubenheim, DL Schlick, G Wilson, D Bates, M BE Horneck, G Vazquez, ME Porterfield, DM TI Performance of the CELSS Antarctic Analog Project (CAAP) crop production system SO SPACE LIFE SCIENCES: MISSIONS TO MARS, RADIATION BIOLOGY, AND PLANTS AS A FOUNDATION FOR LONG-TERM LIFE SUPPORT SYSTEMS IN SPACE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F0 1 and F1 3-F2 3 Symposia of COSPAR Scientific Commission F held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP CNES, Deutsch Zentrum Luft & Raumfahrt eV, European Space Sci Comm, Int Astronaut Federat, Int Soc Study Origin Life, NASA, Comm Space Res AB Regenerative life support systems potentially offer a level of self-sufficiency and a decrease in logistics and associated costs in support of space exploration and habitation missions. Current state-of-the-art in plant-based, regenerative life support requires resources in excess of allocation proposed for candidate mission scenarios. Feasibility thresholds have been identified for candidate exploration missions. The goal of this paper is to review recent advances in performance achieved in the CELSS Antarctic Analog Project (CAAP) in light of the likely resource constraints. A prototype CAAP crop production chamber has been constructed and operated at the Ames Research Center. The chamber includes a number of unique hardware and software components focused on attempts to increase production efficiency, increase energy efficiency, and control the flow of energy and mass through the system. Both single crop, batch production and continuous cultivation of mixed crops production studies have been completed. The crop productivity as well as engineering performance of the chamber are described. For each scenario, energy required and partitioned for lighting, cooling, pumping, fans, etc. is quantified. Crop production and the resulting lighting efficiency and energy conversion efficiencies are presented. In the mixed-crop scenario, with 27 different crops under cultivation, 17 m(2) of crop area provided a mean of 515g edible biomass per day (85% of the approximate 620 g required for one person). Enhanced engineering and crop production performance achieved with the CAAP chamber, compared with current state-of-the-art, places plant-based life support systems at the threshold of feasibility. (C) 2002 Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. RP Bubenheim, DL (reprint author), NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. NR 17 TC 2 Z9 3 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 1 BP 255 EP 262 AR PII S0273-1177(02)00738-X DI 10.1016/S0273-1177(02)00738-X PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98Q UT WOS:000180591400035 PM 12580191 ER PT S AU Kliss, M Blackwell, C Zografos, A Drews, M MacElroy, R McKenna, R Heyenga, AG AF Kliss, M Blackwell, C Zografos, A Drews, M MacElroy, R McKenna, R Heyenga, AG BE Horneck, G Vazquez, ME Porterfield, DM TI Initial closed operation of the CELSS Test Facility Engineering Development Unit SO SPACE LIFE SCIENCES: MISSIONS TO MARS, RADIATION BIOLOGY, AND PLANTS AS A FOUNDATION FOR LONG-TERM LIFE SUPPORT SYSTEMS IN SPACE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F0 1 and F1 3-F2 3 Symposia of COSPAR Scientific Commission F held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP CNES, Deutsch Zentrum Luft & Raumfahrt eV, European Space Sci Comm, Int Astronaut Federat, Int Soc Study Origin Life, NASA, Comm Space Res AB As part of the NASA Advanced Life Support Flight Program, a Controlled Ecological Life Support System (CELSS) Test Facility Engineering Development Unit has been constructed and is undergoing initial operational testing at NASA Ames Research Center. The Engineering Development Unit (EDU) is a tightly closed, stringently controlled, ground-based testbed which provides a broad range of environmental conditions under which a variety of CELSS higher plant crops can be grown. Although the EDU was developed primarily to provide near-term engineering data and a realistic determination of the subsystem and system requirements necessary for the fabrication of a comparable flight unit, the EDU has also provided a means to evaluate plant crop productivity and physiology under controlled conditions. This paper describes the initial closed operational testing of the EDU, with emphasis on the hardware performance capabilities. Measured performance data during a 28-day closed operation period are compared with the specified functional requirements, and an example of inferring crop growth parameters from the test data is presented. Plans for future science and technology testing are also discussed. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Ames Res Ctr, Lockheed Martin Engn & Sci, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Natl Res Council, Moffett Field, CA 94035 USA. RP Kliss, M (reprint author), NASA, Ames Res Ctr, Lockheed Martin Engn & Sci, Mail Stop 239-15, Moffett Field, CA 94035 USA. NR 7 TC 2 Z9 2 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 1 BP 263 EP 270 AR PII S0273-1177(02)00753-6 DI 10.1016/S0273-1177(02)00753-6 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98Q UT WOS:000180591400036 PM 12580194 ER PT S AU De Angelis, G Clem, JM Goldhagen, PE Wilson, JW AF De Angelis, G Clem, JM Goldhagen, PE Wilson, JW BE Smart, DF TI A new dynamical Atmospheric Ionizing Radiation (AIR) model for epidemiological studies SO SPACE LIFE SCIENCES: STRUCTURE AND DYNAMICS OF THE GLOBAL SPACE RADIATION FIELD AT AIRCRAFT ALTITIUDES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TEXAS SP Comm Space Res ID COMMERCIAL AIRLINE PILOTS; CANCER INCIDENCE; SPACE RADIATION; COSMIC-RAYS; MORTALITY; ATTENDANTS; PARTICLES; PERSONNEL; EXPOSURE; COHORT AB A new Atmospheric Ionizing Radiation (AIR) model is currently being developed for use in radiation dose evaluation in epidemiological studies targeted to atmospheric flight personnel such as civilian airlines crewmembers. The model will allow computing values for biologically relevant parameters, e.g. dose equivalent and effective dose, for individual flights from 1945. Each flight is described by its actual three-dimensional flight profile, i.e. geographic coordinates and altitudes varying with time. Solar modulated primary particles are filtered with a new analytical fully angular dependent geomagnetic cutoff rigidity model, as a function of latitude, longitude, arrival direction, altitude and time. The particle transport results have been obtained with a technique based on the three-dimensional Monte Carlo transport code FLUKA, with a special procedure to deal with HZE particles. Particle fluxes are transformed into dose-related quantities and then integrated all along the flight path to obtain the overall flight dose. Preliminary validations of the particle transport technique using data from the AIR Project ER-2 flight campaign of measurements are encouraging. Future efforts will deal with modeling of the effects of the aircraft structure as well as inclusion of solar particle events. Published by Elsevier Ltd on behalf of COSPAR. C1 Old Dominion Univ, Norfolk, VA 23508 USA. Ist Super Sanita, I-00161 Rome, Italy. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. US Dept Homeland Secur, Environm Measurements Lab, New York, NY 10014 USA. RP De Angelis, G (reprint author), Old Dominion Univ, Norfolk, VA 23508 USA. NR 53 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 32 IS 1 BP 17 EP 26 DI 10.1016/S0273-1177(03)00508-8 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX64R UT WOS:000185946800002 PM 14727658 ER PT S AU Clem, JM De Angelis, G Goldhagen, P Wilson, JW AF Clem, JM De Angelis, G Goldhagen, P Wilson, JW BE Smart, DF TI Preliminary validation of computational procedures for a new Atmospheric Ionizing Radiation (AIR) model SO SPACE LIFE SCIENCES: STRUCTURE AND DYNAMICS OF THE GLOBAL SPACE RADIATION FIELD AT AIRCRAFT ALTITIUDES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TEXAS SP Comm Space Res ID GALACTIC COSMIC-RAYS; NEAR-EARTH ORBIT; HELIUM SPECTRA; PROTON; ENVIRONMENT; MODULATION; GV AB A new computational procedure to determine particle fluxes in the Earth's atmosphere is presented. The primary cosmic ray spectrum has been modeled through an analysis of simultaneous proton and helium measurements made on high altitude balloon flights and spacecraft. An improved global fit to the data was achieved through applying a unique technique utilizing the Fokker-Plank equation with a non-linear rigidity-dependent diffusion coefficient. The propagation of primary particles through the Earth's atmosphere is calculated with a three-dimensional Monte Carlo transport program called FLUKA. Primary protons and helium nuclei (alphas) are generated within the rigidity range of 0.5 GV - 20 TV uniform in cos(2)theta. For a given location, primaries above the effective cutoff rigidity are transported through the atmosphere. Alpha particles are initially transported with a separate package called HEAVY to simulate fragmentation. This package interfaces with FLUKA to provide interaction starting points for each nucleon originating from a helium nucleus. Results from this calculation are presented and compared to measurements. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Ist Super Sanita, I-00161 Rome, Italy. US Dept Homeland Secur, Environm Measurements Lab, New York, NY 10014 USA. RP Clem, JM (reprint author), Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. NR 28 TC 8 Z9 9 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 32 IS 1 BP 27 EP 33 DI 10.1016/S0273-1177(03)00509-X PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX64R UT WOS:000185946800003 PM 14727659 ER PT S AU Goldhagen, P Clem, JM Wilson, JW AF Goldhagen, P Clem, JM Wilson, JW BE Smart, DF TI Recent results from measurements of the energy spectrum of cosmic-ray induced neutrons aboard an ER-2 airplane and on the ground SO SPACE LIFE SCIENCES: STRUCTURE AND DYNAMICS OF THE GLOBAL SPACE RADIATION FIELD AT AIRCRAFT ALTITIUDES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TEXAS SP Comm Space Res ID EXPOSURE; FLUENCE AB Crews of future high-altitude commercial aircraft may be significantly exposed to atmospheric cosmic radiation from galactic cosmic rays (GCR). To help determine such exposures, the Atmospheric Ionizing Radiation Project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on a NASA ER-2 high-altitude aircraft. The primary instrument was a sensitive extended-energy multisphere neutron spectrometer, which was also used to make measurements on the ground. Its detector responses were calculated for neutrons and charged hadrons at energies up to 100 GeV using the radiation transport code MCNPX. We have now recalculated the detector responses including the effects of the airplane structure. We are also using new FLUKA calculations of GCR-induced hadron spectra in the atmosphere to correct for spectrometer counts produced by charged hadrons. Neutron spectra are unfolded from the corrected measured count rates. using the MAXED code. Results for the measured cosmic-ray neutron spectrum (thermal to >10 GeV), total neutron fluence rate, and neutron dose equivalent and effective dose rates, and their dependence on altitude and geomagnetic cutoff generally agree well with results from recent calculations of GCR-induced neutron spectra. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 US Dept Homeland Secur, Environm Measurements Lab, New York, NY 10014 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Goldhagen, P (reprint author), US Dept Homeland Secur, Environm Measurements Lab, New York, NY 10014 USA. NR 20 TC 21 Z9 21 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 32 IS 1 BP 35 EP 40 DI 10.1016/S0273-1177(03)00506-4 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX64R UT WOS:000185946800004 PM 14727660 ER PT S AU Uchihori, Y Benton, E Moeller, J Bendrick, G AF Uchihori, Y Benton, E Moeller, J Bendrick, G BE Smart, DF TI Radiation measurements aboard NASA ER-2 high altitude aircraft with the Liulin-4J portable spectrometer SO SPACE LIFE SCIENCES: STRUCTURE AND DYNAMICS OF THE GLOBAL SPACE RADIATION FIELD AT AIRCRAFT ALTITIUDES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TEXAS SP Comm Space Res AB The risks to aircrew health posed by prolonged exposure to low levels of ionizing radiation at aircraft altitudes have recently received renewed attention. Civil and military aircraft currently on the drawing board are expected to operate at higher altitudes (>12 km) and fly longer ranges than do existing aircraft, thereby exposing their crews to higher levels of ionizing radiation, for longer periods of time. We are currently carrying out dosimetric measurements of the ionizing radiation environment at similar to20 km altitude using portable Si detectors aboard NASA's two ER-2 high altitude research aircraft. The instruments, Liulin-4J, have been extensively calibrated at several particle accelerators. With these instruments, we can measure not only absorbed dose, but also variation of the absorbed dose as a function of time. We report radiation dose measurements as function of time, altitude, and latitude for several ER-2 missions. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 Natl Inst Radiol Sci, Chiba 2638555, Japan. Eril Res Inc, San Rafael, CA 94915 USA. USAF, McConnell Air Force Base, KS 67221 USA. NASA, Dryden Flight Res Ctr, Edwards AFB, CA 93523 USA. RP Uchihori, Y (reprint author), Natl Inst Radiol Sci, Anagawa 4-9-1, Chiba 2638555, Japan. NR 4 TC 0 Z9 0 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 32 IS 1 BP 41 EP 46 DI 10.1016/S0273-1177(03)00507-6 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX64R UT WOS:000185946800005 PM 14727661 ER PT S AU Dachev, TP Stassinopoulos, EG Tomov, BT Dimitrov, PG Matviichuk, YN Shurshakov, VA Petrov, VM AF Dachev, TP Stassinopoulos, EG Tomov, BT Dimitrov, PG Matviichuk, YN Shurshakov, VA Petrov, VM BE Smart, DF TI Analysis of the cyclotron facility calibration and aircraft dosimetry results from the LIULIN-3M instrument SO SPACE LIFE SCIENCES: STRUCTURE AND DYNAMICS OF THE GLOBAL SPACE RADIATION FIELD AT AIRCRAFT ALTITIUDES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TEXAS SP Comm Space Res AB The LIULIN-3M instrument is a further development of the LIULIN dosimeter-radiometer, used on the MIR space station during the 1988-1994 time period. The LIULIN-3M is designed for continuous monitoring of the radiation environment during the BION-12 satellite flight in 1999. A semiconductor detector with I mm thickness and I cm 2 area is contained in the instrument. Pulse high analysis technique is used to determine the energy losses in the detector. The final data from the instrument are the flux and the dose rate for the exposure time and 256 channels of absorbed dose spectra based on the assumption that the particle flux is normal to the detector. The LIULIN-3M instrument was calibrated by proton fluxes with different energies at the Indiana University Cyclotron Facility in June 1997 and had been used for radiation measurements during commercial aircraft flights. The calibration procedure and some flight results are presented in this paper. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 Acad G Bonchev St, Solar Terr Influences Lab, Sofia 1113, Bulgaria. NASA, Goddard Space Flight Ctr, Radiat Phys Off, Greenbelt, MD 20771 USA. Moscow Biomed Problems Inst, Moscow 123007, Russia. RP Dachev, TP (reprint author), Acad G Bonchev St, Solar Terr Influences Lab, Block 3, Sofia 1113, Bulgaria. NR 4 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 32 IS 1 BP 67 EP 71 DI 10.1016/S0273-1177(03)00511-8 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX64R UT WOS:000185946800009 PM 14727665 ER PT S AU Wilson, JW Goldhagen, P Rafnsson, V Clem, JM De Angelis, G Friedberg, W AF Wilson, JW Goldhagen, P Rafnsson, V Clem, JM De Angelis, G Friedberg, W BE Smart, DF TI Overview of Atmospheric Ionizing Radiation (AIR) research: SST-present SO SPACE LIFE SCIENCES: STRUCTURE AND DYNAMICS OF THE GLOBAL SPACE RADIATION FIELD AT AIRCRAFT ALTITUDES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TX SP Comm Space Res ID AIRLINE CABIN ATTENDANTS; CANCER INCIDENCE; FLIGHT ATTENDANTS; COSMIC-RADIATION; BREAST-CANCER; COMMERCIAL AVIATION; AIRCRAFT ALTITUDES; UNITED-STATES; HEALTH RISKS; COCKPIT CREW AB The Supersonic Transport (SST) program, proposed in 1961, first raised concern for the exposure of pregnant occupants by solar energetic particles (SEP), and neutrons were suspected to have a main role in particle propagation deep into the atmosphere. An eight-year flight program confirmed the role of SEP as a significant hazard and of the neutrons as contributing over half of the galactic cosmic ray exposures, with the largest contribution from neutrons above 10 MeV. The FAA Advisory Committee on the Radiobiological Aspects of the SST provided operational requirements. The more recent lowering of ICRP-recommended exposure limits (1990) with the classification of aircrew as "radiation workers" renewed interest in GCR background exposures at commercial flight altitudes and stimulated epidemiological studies in Europe, Japan, Canada and the USA. The proposed development of a High Speed Civil Transport (HSCT) required validation of the role of high-energy neutrons, and this resulted in ER-2 flights at solar minimum (June 1997) and studies on effects of aircraft materials on interior exposures. Recent evaluation of health outcomes of DOE nuclear workers resulted in legislation for health compensation in year 2000 and recent European aircrew epidemiological studies of health outcomes bring renewed interest in aircraft radiation exposures. As improved radiation models become available, it is imperative that a corresponding epidemiological program of US aircrew be implemented. Published by Elsevier Ltd on behalf of COSPAR. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. US Dept Homeland Secur, Environm Measurements Lab, New York, NY 10014 USA. Univ Iceland, IS-107 Reykjavik, Iceland. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. Old Dominion Univ, Norfolk, VA 23508 USA. Ist Super Sanita, I-00161 Rome, Italy. Civil Aerosp Med Inst, Oklahoma City, OK 73125 USA. RP Wilson, JW (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM john.w.wilson@larc.nasa.gov NR 86 TC 18 Z9 19 U1 2 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES PY 2003 VL 32 IS 1 BP 3 EP 16 DI 10.1016/S0273-1177(03)00499-X PG 14 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX64R UT WOS:000185946800001 PM 14727657 ER PT S AU Greenfield, MA AF Greenfield, MA BE Reid, MS Romero, M TI Faster, Better, Cheaper - NASA's lessons learned: Robust risk management SO SPACE SAFETY, RESCUE AND QUALITY 2001 SE SCIENCE AND TECHNOLOGY SERIES LA English DT Proceedings Paper CT 34th Symposium on Space Safety, Rescue and Quality CY OCT 01-05, 2001 CL TOULOUSE, FRANCE SP Int Acad Astronaut Comm Safety & Qual AB In January 200 1, NASA released the much-anticipated NASA Integrated Action Team (NIAT) report, "Enhancing Mission Success - A Framework for the Future." The NASA Chief Engineer chartered the NIAT in March 2000 with a twofold objective-to develop an integrated plan to address recommendations from failure board reports on the Mars program, Space Shuttle wiring issues, and a generic assessment of NASA's "Faster, Better, Cheaper" practices, and to formulate actions for improvement from an Agency perspective. The NIAT reviewed and assessed 165 findings from the four reports and generated a set of 17 actions divided into five "implementation themes." This paper focuses on the implementation theme entitled "Understanding and Controlling Risk." It explains the actions NASA plans to take to improve risk identification, assessment, and management. It discusses the definitions of acceptable risk and success criteria and explains NASA's increased emphasis on safety and mission assurance. C1 NASA, Washington, DC 20546 USA. RP Greenfield, MA (reprint author), NASA, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 0278-4017 BN 0-87703-500-8 J9 SCI TECH PY 2003 VL 106 BP 23 EP 28 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW51V UT WOS:000182255700003 ER PT S AU Newman, JS Wander, SM Vantine, W Benfield, P Winters, K AF Newman, JS Wander, SM Vantine, W Benfield, P Winters, K BE Reid, MS Romero, M TI Introducing the NASA process based Mission Assurance knowledge management system (PBMA-KMS) SO SPACE SAFETY, RESCUE AND QUALITY 2001 SE SCIENCE AND TECHNOLOGY SERIES LA English DT Proceedings Paper CT 34th Symposium on Space Safety, Rescue and Quality CY OCT 01-05, 2001 CL TOULOUSE, FRANCE SP Int Acad Astronaut Comm Safety & Qual AB Recurrent and costly aerospace system failures and the challenge to define knowledge-based approaches to the systems engineering assurance and control functions are two fundamental drivers behind the evolution of the PBMA-KMS. In response to these challenges, and taking advantage of advances in computer and information management technology, the NASA Office of Safety & Mission Assurance began development of the PBMA-KMS in mid 1999. The PBMA-KMS is a user-friendly, web-based resource designed to support life-cycle safety and mission success management. This paper describes the PBMA-KMS functionality, operation, and plans for future growth. C1 NASA, Headquarters, Washington, DC 20546 USA. RP Newman, JS (reprint author), NASA, Headquarters, Washington, DC 20546 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 0278-4017 BN 0-87703-500-8 J9 SCI TECH PY 2003 VL 106 BP 69 EP 81 PG 13 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW51V UT WOS:000182255700007 ER PT J AU Sandel, BR Goldstein, J Gallagher, DL Spasojevic, M AF Sandel, BR Goldstein, J Gallagher, DL Spasojevic, M TI Extreme Ultraviolet Imager observations of the structure and dynamics of the plasmasphere SO SPACE SCIENCE REVIEWS LA English DT Review ID RING CURRENT; MAGNETOSPHERIC CONVECTION; PLASMAPAUSE; MOTION; MODEL AB The IMAGE Extreme Ultraviolet Imager (EUV) provides our first global images of the plasmasphere by imaging the distribution of He+ in its 30.4-nm resonance line. The images reveal the details of a highly structured and dynamic entity. Comparing EUV images and selected in-situ observations has helped to validate the remote sensing measurements. The brightness in the EUV images is heavily weighted by the He+ density near the plane of the magnetic equator, but two lines of evidence emphasize that the features seen by EUV extend far from the equator, and in at least some cases reach the ionosphere. Certain features and behaviors, including shoulders, channels, notches, and plasma erosion events, appear frequently in the EUV images. These are keys to understanding the ways that electric fields in the inner magnetosphere affect the large and meso-scale distribution of plasma, and their study can elucidate the mechanisms by which the solar wind and interplanetary magnetic field couple to the inner magnetosphere. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. Stanford Univ, Star Lab, Stanford, CA 94305 USA. RP Sandel, BR (reprint author), Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. NR 27 TC 99 Z9 101 U1 1 U2 8 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 109 IS 1-4 BP 25 EP 46 DI 10.1023/B:SPAC.0000007511.47727.5b PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 752EA UT WOS:000187133000003 ER PT J AU Fok, MC Moore, TE Wilson, GR Perez, JD Zhang, XX Brandt, PC Mitchell, DG Roelof, EC Jahn, JM Pollock, CJ Wolf, RA AF Fok, MC Moore, TE Wilson, GR Perez, JD Zhang, XX Brandt, PC Mitchell, DG Roelof, EC Jahn, JM Pollock, CJ Wolf, RA TI Global ENA IMAGE simulations SO SPACE SCIENCE REVIEWS LA English DT Review ID NEUTRAL ATOM IMAGES; TIME RING CURRENT; MAGNETIC-FIELD; STORM-TIME; EARTHS MAGNETOSPHERE; ELECTRIC-FIELD; PLASMA SHEET; LARGE-SCALE; SUBSTORM; MODEL AB The energetic neutral atom (ENA) images obtained by the ISEE and POLAR satellites pointed the way toward global imaging of the magnetospheric plasmas. The Imager for Magnetopause to Aurora Global Exploration (IMAGE) is the first mission to dedicate multiple neutral atom imagers: HENA, MENA and LENA, to monitor the ion distributions in high-, medium- and low-energy ranges, respectively. Since the start of science operation, HENA, MENA and LENA have been continuously sending down images of the ring current, ionospheric outflow, and magnetosheath enhancements from high pressure solar wind. To unfold multiple-dimensional (equal or greater than 3) plasma distributions from 2-dimensional images is not a trivial task. Comparison with simulated ENA images from a modeled ion distribution provides an important basis for interpretation of features in the observed images. Another approach is to develop image inversion methods to extract ion information from ENA images. Simulation studies have successfully reproduced and explained energetic ion drift dynamics, the transition from open to closed drift paths, and the magnetosheath response to extreme solar wind conditions. On the other hand, HENA has observed storm-time ion enhancement on the nightside toward dawn that differs from simple concepts but can be explained using more sophisticated models. LENA images from perigee passes reveal unexpected characteristics that now can be interpreted as evidence for a transient superthermal exospheric component that is gravitationally-influenced if not bound. In this paper, we will report ENA simulations performed during several IMAGE observed events. These simulations provide insight and explanations to the ENA features that were not readily understandable previously. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Mission Res Corp, Nashua, NH 03062 USA. Auburn Univ, Dept Phys, Allison Lab 206, Auburn, AL 36849 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. SW Res Inst, San Antonio, TX 78238 USA. Rice Univ, Houston, TX 77005 USA. RP Fok, MC (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM mei-ching.h.fok@nasa.gov RI Moore, Thomas/D-4675-2012; Fok, Mei-Ching/D-1626-2012 OI Moore, Thomas/0000-0002-3150-1137; NR 50 TC 84 Z9 84 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 109 IS 1-4 BP 77 EP 103 DI 10.1023/B:SPAC.0000007514.56380.fd PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 752EA UT WOS:000187133000006 ER PT J AU Green, JL Reinisch, BW AF Green, JL Reinisch, BW TI An overview of results from RPI on IMAGE SO SPACE SCIENCE REVIEWS LA English DT Review ID RADIO PLASMA IMAGER; ELECTRON-DENSITY; MAGNETOSPHERE; FEASIBILITY; FIELD; CONTINUUM; MODEL; SCALE AB The Radio Plasma Imager (RPI) on the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft was designed as a long-range magnetospheric radio sounder, relaxation sounder, and a passive plasma wave instrument. The RPI is a highly flexible instrument that can be programmed to perform these types of measurements at times when IMAGE is located in key regions of the magnetosphere. RPI is the first radio sounder ever flown to large radial distances into the magnetosphere. The long-range sounder echoes from RPI allow remote sensing of a variety of plasmas structures and boundaries in the magnetosphere. A profile inversion technique for RPI echo traces has been developed and provides a method for determining the density distribution of the plasma from either direct or field-aligned echoes. This technique has enabled the determination of the evolving density structure of the polar cap and the plasmasphere under a variety of geomagnetic conditions. New results from RPI show that the plasmasphere refills in slightly greater than a day at L values of 2.8 and that ion heating is probably playing a major role in the overall density distribution along the field-line. In addition, RPI's plasma resonance observations at large radial distances over the polar cap provided in situ measurements of the plasma density with an accuracy of a few percent. For the first time in the magnetosphere, RPI has also observed the plasma D resonances. RPI's long antennas and its very low noise receivers provide excellent observations in the passive receive-only mode when the instrument measures the thermal plasma noise as well as natural emissions such as the continuum radiation and auroral kilometric radiation (AKR). Recent passive measurements from RPI have been compared extensively with images from the Extreme Ultraviolet (EUV) imager on IMAGE resulting in a number of new discoveries. For instance, these combined observations show that kilometric continuum can be generated at the plasmapause from sources in or very near the magnetic equator, within a bite-out region of the plasmasphere. The process by which plasmaspheric bite-out structures are produced is not completely understood at this time. Finally, RPI has been used to successfully test the feasibility of magnetospheric tomography. During perigee passages of the Wind spacecraft, RPI radio transmissions at one and two frequencies have been observed by the Waves instrument. The received electric field vector was observed to rotate with time due to the changing density of plasma, and thus Faraday rotation was measured. Many future multi-spacecraft missions propose to use Faraday rotation to obtain global density pictures of the magnetosphere. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Massachusetts, Ctr Atmospher Res, Lowell, MA USA. RP Green, JL (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 36 TC 15 Z9 16 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 109 IS 1-4 BP 183 EP 210 DI 10.1023/B:SPAC.0000007519.44362.65 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 752EA UT WOS:000187133000010 ER PT J AU Frey, HU Mende, SB Immel, TJ Gerard, JC Hubert, B Habraken, S Spann, J Gladstone, GR Bisikalo, DV Shematovich, VI AF Frey, HU Mende, SB Immel, TJ Gerard, JC Hubert, B Habraken, S Spann, J Gladstone, GR Bisikalo, DV Shematovich, VI TI Summary of quantitative interpretation of IMAGE far ultraviolet auroral data SO SPACE SCIENCE REVIEWS LA English DT Review DE IMAGE; Far Ultraviolet instrument; FUV; aurora; quantitative; proton; electron; flux and energy ID PROTON AURORA; ENERGY CHARACTERISTICS; STATISTICAL-MODEL; ION PRECIPITATION; FUV; ELECTRON; DAYGLOW; ATMOSPHERE; EMISSION; PROFILE AB Direct imaging of the magnetosphere by instruments on the IMAGE spacecraft is supplemented by simultaneous observations of the global aurora in three far ultraviolet (FUV) wavelength bands. The purpose of the multi-wavelength imaging is to study the global auroral particle and energy input from the magnetosphere into the atmosphere. This paper describes the method for quantitative interpretation of FUV measurements. The Wide-Band Imaging Camera (WIC) provides broad band ultraviolet images of the aurora with maximum spatial resolution by imaging the nitrogen lines and bands between 140 and 180 nm wavelength. The Spectrographic Imager (SI), a dual wavelength monochromatic instrument, images both Doppler-shifted Lyman-alpha emissions produced by precipitating protons, in the SI-12 channel and OI 135.6 nm emissions in the SI-13 channel. From the SI-12 Doppler shifted Lyman-alpha images it is possible to obtain the precipitating proton flux provided assumptions are made regarding the mean energy of the protons. Knowledge of the proton (flux and energy) component allows the calculation of the contribution produced by protons in the WIC and SI-13 instruments. Comparison of the corrected WIC and SI-13 signals provides a measure of the electron mean energy, which can then be used to determine the electron energy flux. To accomplish this, reliable emission modeling and instrument calibrations are required. In-flight calibration using early-type stars was used to validate the pre-flight laboratory calibrations and determine long-term trends in sensitivity. In general, very reasonable agreement is found between in-situ measurements and remote quantitative determinations. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Liege, B-4000 Liege, Belgium. Ctr Spatiale Liege, B-4031 Liege, Belgium. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. SW Res Inst, San Antonio, TX 78228 USA. Russian Acad Sci, Inst Astron, Moscow V71, Russia. RP Frey, HU (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. EM hfrey@ssl.berkeley.edu RI Shematovich, Valery/E-4670-2014; Bisikalo, Dmitry/E-5122-2014; OI Frey, Harald/0000-0001-8955-3282; GERARD, Jean-Claude/0000-0002-8565-8746 NR 35 TC 54 Z9 55 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 109 IS 1-4 BP 255 EP 283 DI 10.1023/B:SPAC.0000007521.39348.a5 PG 29 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 752EA UT WOS:000187133000012 ER PT J AU Fuselier, SA Mende, SB Moore, TE Frey, HU Petrinec, SM Claflin, ES Collier, MR AF Fuselier, SA Mende, SB Moore, TE Frey, HU Petrinec, SM Claflin, ES Collier, MR TI CUSP dynamics and ionospheric outflow SO SPACE SCIENCE REVIEWS LA English DT Review ID INTERPLANETARY MAGNETIC-FIELD; POLAR CUSP; MAGNETOSHEATH PLASMA; DAYSIDE IONOSPHERE; ION OUTFLOW; EARTHS MAGNETOPAUSE; ALTITUDE CUSP; PROTON AURORA; MAGNETOSPHERE; RECONNECTION AB One of the IMAGE mission science goals is to understand the dayside amoral oval and its dynamic relationship to the magnetosphere. Two ways the auroral oval is dynamically coupled to the magnetosphere are through the injection of magnetosheath plasma into the magnetospheric cusps and through the ejection of ionospheric plasma into the magnetosphere. The ionospheric footpoints of the Earth's magnetospheric cusps are relatively narrow regions in invariant latitude that map magnetically to the magnetopause. Monitoring the cusp reveals two important aspects of magnetic reconnection at the magnetopause. Continuous cusp observations reveal the relative contributions of quasi-steady versus impulsive reconnection to the overall transfer of mass, energy, and momentum across the magnetopause. The location of the cusp is used to determine where magnetic reconnection is occurring on the magnetopause. Of particular interest is the distinction between anti-parallel reconnection, where the magnetosheath and magnetospheric field lines are strictly anti-parallel, and component merging, where the magnetosheath and magnetospheric field lines have one component that is anti-parallel. IMAGE observations suggest that quasi-steady, anti-parallel reconnection is occurring in regions at the dayside magnetopause. However, it is difficult to rule out additional component reconnection using these observations. The ionospheric footpoint of the cusp is also a region of relatively intense ionospheric outflow. Since outflow also occurs in other regions of the amoral oval, one of the long-standing problems has been to determine the relative contributions of the cusp/cleft and the rest of the auroral oval to the overall ionospheric ion content in the Earth's magnetosphere. While the nature of ionospheric outflow has made it difficult to resolve this long-standing problem, the new neutral atom images from IMAGE have provided important evidence that ionospheric outflow is strongly controlled by solar wind input, is 'prompt' in response to changes in the solar wind, and may have very narrow and distinct pitch angle structures and charge exchange altitudes. C1 Lockheed Martin Adv Technol Ctr, Palo Alto, CA USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Fuselier, SA (reprint author), Lockheed Martin Adv Technol Ctr, Palo Alto, CA USA. RI Moore, Thomas/D-4675-2012; Collier, Michael/I-4864-2013; OI Moore, Thomas/0000-0002-3150-1137; Collier, Michael/0000-0001-9658-6605; Frey, Harald/0000-0001-8955-3282 NR 45 TC 16 Z9 16 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 109 IS 1-4 BP 285 EP 312 DI 10.1023/B:SPAC.0000007522.71147.b3 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 752EA UT WOS:000187133000013 ER PT J AU Moore, TE Collier, MR Fok, MC Fuselier, SA Khan, H Lennartsson, W Simpson, DG Wilson, GR Chandler, MO AF Moore, TE Collier, MR Fok, MC Fuselier, SA Khan, H Lennartsson, W Simpson, DG Wilson, GR Chandler, MO TI Heliosphere-geosphere interactions using Low Energy Neutral Atom imaging SO SPACE SCIENCE REVIEWS LA English DT Review ID ION OUTFLOW; MAGNETOSPHERE; GEOCORONA; ALTITUDES; HYDROGEN; SPACE AB Development of the low energy neutral atom (LENA) imager was originally motivated by a need to remotely sense plasma heating in the topside ionosphere, with the goal of greatly enhanced temporal resolution of an otherwise familiar phenomenon. During ground test and calibration, the LENA imager was found to respond to neutral atoms with energies well above its nominal energy range of 10-750 eV, up to at least 3-4 keV, owing to sputtering interactions with its conversion surface. On orbit, LENA has been found to respond to a ubiquitous neutral atom component of the solar wind, to the neutral atoms formed by magnetosheath interactions with the geocorona during periods of high solar wind pressure, and to the interstellar neutral atoms flowing through the heliosphere during the season of maximal relative wind velocity between spacecraft and interstellar medium. LENA imaging has thus emerged as a promising new tool for studying the interplanetary medium and its interaction with the magnetosphere, in addition to the ionospheric heating and outflow that result from this interaction. LENA emissions from the ionosphere consist of a fast component that can be observed at high altitudes, and slower components that evidently create a quasi-trapped extended superthermal exosphere. The more energetic emissions are responsive to solar wind energy inputs on time scales of a few minutes. C1 NASA, Goddard Space Flight Ctr, Interplanetary Phys Branch, Greenbelt, MD 20771 USA. Lockheed Martin Adv Technol Ctr, Dept H1 11, Palo Alto, CA 94304 USA. Mission Res Corp, Nashua, NH 03062 USA. NASA, George C Marshall Space Flight Ctr SD50, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. RP Moore, TE (reprint author), NASA, Goddard Space Flight Ctr, Interplanetary Phys Branch, Code 692, Greenbelt, MD 20771 USA. RI Moore, Thomas/D-4675-2012; Fok, Mei-Ching/D-1626-2012; Collier, Michael/I-4864-2013 OI Moore, Thomas/0000-0002-3150-1137; Collier, Michael/0000-0001-9658-6605 NR 26 TC 17 Z9 17 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 109 IS 1-4 BP 351 EP 371 DI 10.1023/B:SPAC.0000007524.11258.b4 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 752EA UT WOS:000187133000015 ER PT J AU Ray, RD Rowlands, DD Egbert, GD AF Ray, RD Rowlands, DD Egbert, GD TI Tidal models in a new era of satellite gravimetry SO SPACE SCIENCE REVIEWS LA English DT Review ID INTERSATELLITE TRACKING; OCEAN TIDE AB The high precision gravity measurements to be made by recently launched (and recently approved) satellites place new demands on models of Earth, atmospheric, and oceanic tides. The latter is the most problematic. The ocean tides induce variations in the Earth's geoid by amounts that far exceed the new satellite sensitivities, and tidal models must be used to correct for this. Two methods are used here to determine the standard errors in current ocean tide models. At long wavelengths these errors exceed the sensitivity of the GRACE mission. Tidal errors will not prevent the new satellite missions from improving our knowledge of the geopotential by orders of magnitude, but the errors may well contaminate GRACE estimates of temporal variations in gravity. Solar tides are especially problematic because of their long alias periods. The satellite data may be used to improve tidal models once a sufficiently long time series is obtained. Improvements in the long-wavelength components of lunar tides are especially promising. C1 NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. RP NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Code 926, Greenbelt, MD 20771 USA. EM richard.ray@gsfc.nasa.gov RI Ray, Richard/D-1034-2012; Rowlands, David/D-2751-2012; OI Egbert, Gary/0000-0003-1276-8538 NR 16 TC 43 Z9 44 U1 1 U2 6 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 108 IS 1-2 BP 271 EP 282 DI 10.1023/A:1026223308107 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 732AM UT WOS:000185918700024 ER PT J AU Bender, PL Hall, JL Ye, J Klipstein, WM AF Bender, PL Hall, JL Ye, J Klipstein, WM TI Satellite-satellite laser links for future gravity missions SO SPACE SCIENCE REVIEWS LA English DT Review ID LISA; NM AB A strong candidate for use in future missions to map time variations in the Earth's gravity field is laser heterodyne measurements between separate spacecraft. At the shortest wavelengths that can be measured in space, the main accuracy limitation for variations in the potential with latitude is expected to be the frequency stability of the laser. Thus the development of simple and reliable space-qualified lasers with high frequency stability appears to be an important goal for the near future. In the last few years, quite high stability has been achieved by locking the second harmonic of a Nd:YAG laser to a resonant absorption line of iodine molecules in an absorption cell. Such a laser system can be made quite robust, and temperature related frequency shifts can be controlled at a low value. Recent results from laboratory systems are described. The Allan standard deviation for the beat between two such lasers was 2 x 10(-14) at 10 s, and reached 7 x 10(-15) at 600 s. C1 Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Boulder, CO 80309 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Natl Inst Stand & Technol, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. EM pbender@jila.colorado.edu; jhall@jila.colorado.edu; ye@jila.colorado.edu; klipstein@jpl.nasa.gov RI Ye, Jun/C-3312-2011 NR 12 TC 29 Z9 33 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 108 IS 1-2 BP 377 EP 384 DI 10.1023/A:1026195913558 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 732AM UT WOS:000185918700033 ER PT J AU Valdivia, JA Klimas, A Vassiliadis, D Uritsky, V Takalo, J AF Valdivia, JA Klimas, A Vassiliadis, D Uritsky, V Takalo, J TI Self-organization in a current sheet model SO SPACE SCIENCE REVIEWS LA English DT Review DE self-organizations; space plasmas; substorms ID MAGNETOTAIL CURRENT SHEET; EARTHS PLASMA SHEET; MAGNETIC RECONNECTION; COUPLED-MAP; CRITICALITY; MAGNETOSPHERE; TURBULENCE; SUBSTORMS; DYNAMICS; SPECTRA AB Self-organization is a possible solution to the seemingly contradicting observation of the repeatable and coherent substorm phenomena with underlying complex behavior in the plasma sheet. Self-organization, through spatio-temporal chaos, emerges naturally in a plasma physics model with sporadic dissipation. C1 Univ Chile, Dept Fis, Santiago, Chile. Univ Adelaide, World Inst Space Environm Res, Adelaide, SA 5005, Australia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Univ Space Res Assoc, Greenbelt, MD USA. Univ Oulu, Dept Phys Sci, Oulu, Finland. RP Univ Chile, Dept Fis, Santiago, Chile. RI Valdivia, Juan/A-3631-2008 OI Valdivia, Juan/0000-0003-3381-9904 NR 28 TC 18 Z9 18 U1 1 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 107 IS 1-2 BP 515 EP 522 DI 10.1023/A:1025518527128 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 717PR UT WOS:000185099000052 ER PT J AU Burnett, DS Barraclough, BL Bennett, R Neugebauer, M Oldham, LP Sasaki, CN Sevilla, D Smith, N Stansbery, E Sweetnam, D Wiens, RC AF Burnett, DS Barraclough, BL Bennett, R Neugebauer, M Oldham, LP Sasaki, CN Sevilla, D Smith, N Stansbery, E Sweetnam, D Wiens, RC TI The Genesis Discovery mission: Return of solar matter to Earth SO SPACE SCIENCE REVIEWS LA English DT Review ID ISOTOPIC COMPOSITION; CARBONACEOUS CHONDRITES; QUASI-STATIONARY; WIND; OXYGEN; ABUNDANCES; NITROGEN; NEBULA; SOHO/CELIAS/MTOF; FRACTIONATION AB The Genesis Discovery mission will return samples of solar matter for analysis of isotopic and elemental compositions in terrestrial laboratories. This is accomplished by exposing ultra-pure materials to the solar wind at the L1 Lagrangian point and returning the materials to Earth. Solar wind collection will continue until April 2004 with Earth return in Sept. 2004. The general science objectives of Genesis are to ( 1) to obtain solar isotopic abundances to the level of precision required for the interpretation of planetary science data, ( 2) to significantly improve knowledge of solar elemental abundances, ( 3) to measure the composition of the different solar wind regimes, and ( 4) to provide a reservoir of solar matter to serve the needs of planetary science in the 21st century. The Genesis flight system is a sun-pointed spinner, consisting of a spacecraft deck and a sample return capsule ( SRC). The SRC houses a canister which contains the collector materials. The lid of the SRC and a cover to the canister were opened to begin solar wind collection on November 30, 2001. To obtain samples of O and N ions of higher fluence relative to background levels in the target materials, an electrostatic mirror ('concentrator') is used which focuses the incoming ions over a diameter of about 20 cm onto a 6 cm diameter set of target materials. Solar wind electron and ion monitors ( electrostatic analyzers) determine the solar wind regime present at the spacecraft and control the deployment of separate arrays of collector materials to provide the independent regime samples. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Lockheed Martin Astronaut, Denver, CO 80201 USA. RP Burnett, DS (reprint author), CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. EM burnett@gps.caltech.edu NR 32 TC 95 Z9 96 U1 0 U2 8 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 105 IS 3-4 BP 509 EP 534 DI 10.1023/A:1024425810605 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 693GA UT WOS:000183707700001 ER PT J AU Jurewicz, AJG Burnett, DS Wiens, RC Friedmann, TA Hays, CC Hohlfelder, RJ Nishiizumi, K Stone, JA Woolum, DS Becker, R Butterworth, AL Campbell, AJ Ebihara, M Franchi, IA Heber, V Hohenberg, CM Humayun, M McKeegan, KD McNamara, K Meshik, A Pepin, RO Schlutter, D Wieler, R AF Jurewicz, AJG Burnett, DS Wiens, RC Friedmann, TA Hays, CC Hohlfelder, RJ Nishiizumi, K Stone, JA Woolum, DS Becker, R Butterworth, AL Campbell, AJ Ebihara, M Franchi, IA Heber, V Hohenberg, CM Humayun, M McKeegan, KD McNamara, K Meshik, A Pepin, RO Schlutter, D Wieler, R TI The Genesis solar-wind collector materials SO SPACE SCIENCE REVIEWS LA English DT Review AB Genesis ( NASA Discovery Mission #5) is a sample return mission. Collectors comprised of ultra-high purity materials will be exposed to the solar wind and then returned to Earth for laboratory analysis. There is a suite of fifteen types of ultra-pure materials distributed among several locations. Most of the materials are mounted on deployable panels ('collector arrays'), with some as targets in the focal spot of an electrostatic mirror ( the 'concentrator'). Other materials are strategically placed on the spacecraft as additional targets of opportunity to maximize the area for solar-wind collection. Most of the collection area consists of hexagonal collectors in the arrays; approximately half are silicon, the rest are for solar-wind components not retained and/or not easily measured in silicon. There are a variety of materials both in collector arrays and elsewhere targeted for the analyses of specific solar-wind components. Engineering and science factors drove the selection process. Engineering required testing of physical properties such as the ability to withstand shaking on launch and thermal cycling during deployment. Science constraints included bulk purity, surface and interface cleanliness, retentiveness with respect to individual solar-wind components, and availability. A detailed report of material parameters planned as a resource for choosing materials for study will be published on a Genesis website, and will be updated as additional information is obtained. Some material is already linked to the Genesis plasma data website ( genesis. lanl. gov). Genesis should provide a reservoir of materials for allocation to the scientific community throughout the 21st Century. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. Los Alamos Natl Lab, Los Alamos, NM USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Calif State Univ Fullerton, Dept Phys, Fullerton, CA 92634 USA. Univ Minnesota, Dept Phys, Minneapolis, MN 55455 USA. Open Univ, Planetary Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Tokyo Metropolitan Univ, Dept Chem, Tokyo 158, Japan. Swiss Fed Inst Technol, Inst Isotope Geol & Mineral Resources, Zurich, Switzerland. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Jurewicz, AJG (reprint author), CALTECH, Jet Prop Lab, M-S 183-501,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Wieler, Rainer/A-1355-2010; McKeegan, Kevin/A-4107-2008; OI Wieler, Rainer/0000-0001-5666-7494; McKeegan, Kevin/0000-0002-1827-729X; Humayun, Munir/0000-0001-8516-9435 NR 22 TC 32 Z9 32 U1 2 U2 17 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 105 IS 3-4 BP 535 EP 560 DI 10.1023/A:1024469927444 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 693GA UT WOS:000183707700002 ER PT J AU Nordholt, JE Wiens, RC Abeyta, RA Baldonado, JR Burnett, DS Casey, P Everett, DT Kroesche, J Lockhart, WL MacNeal, P McComas, DJ Mietz, DE Moses, RW Neugebauer, M Poths, J Reisenfeld, DB Storms, SA Urdiales, C AF Nordholt, JE Wiens, RC Abeyta, RA Baldonado, JR Burnett, DS Casey, P Everett, DT Kroesche, J Lockhart, WL MacNeal, P McComas, DJ Mietz, DE Moses, RW Neugebauer, M Poths, J Reisenfeld, DB Storms, SA Urdiales, C TI The Genesis solar wind concentrator SO SPACE SCIENCE REVIEWS LA English DT Review ID ISOTOPIC COMPOSITION; BOARD SOHO; OXYGEN; CELIAS/MTOF; APOLLO-11 AB The primary goal of the Genesis Mission is to collect solar wind ions and, from their analysis, establish key isotopic ratios that will help constrain models of solar nebula formation and evolution. The ratios of primary interest include O-17/O-16 and O-18/O-16 to +/- 0.1%, N-15/N-14 to +/- 1%, and the Li, Be, and B elemental and isotopic abundances. The required accuracies in N and O ratios cannot be achieved without concentrating the solar wind and implanting it into low-background target materials that are returned to Earth for analysis. The Genesis Concentrator is designed to concentrate the heavy ion flux from the solar wind by an average factor of at least 20 and implant it into a target of ultra-pure, well-characterized materials. High-transparency grids held at high voltages are used near the aperture to reject > 90% of the protons, avoiding damage to the target. Another set of grids and applied voltages are used to accelerate and focus the remaining ions to implant into the target. The design uses an energy-independent parabolic ion mirror to focus ions onto a 6.2 cm diameter target of materials selected to contain levels of O and other elements of interest established and documented to be below 10% of the levels expected from the concentrated solar wind. To optimize the concentration of the ions, voltages are constantly adjusted based on realtime solar wind speed and temperature measurements from the Genesis ion monitor. Construction of the Concentrator required new developments in ion optics; materials; and instrument testing and handling. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. CALTECH, Pasadena, CA 91125 USA. SW Res Inst, San Antonio, TX USA. Mobius Syst, San Antonio, TX USA. Creat Circuitry, San Antonio, TX USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Nordholt, JE (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RI Reisenfeld, Daniel/F-7614-2015 NR 23 TC 9 Z9 9 U1 1 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 105 IS 3-4 BP 561 EP 599 DI 10.1023/A:1024422011514 PG 39 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 693GA UT WOS:000183707700003 ER PT J AU Wiens, RC Neugebauer, M Reisenfeld, DB Moses, RW Nordholt, JE Burnett, DS AF Wiens, RC Neugebauer, M Reisenfeld, DB Moses, RW Nordholt, JE Burnett, DS TI Genesis Solar Wind Concentrator: Computer simulations of performance under solar wind conditions SO SPACE SCIENCE REVIEWS LA English DT Review ID OXYGEN AB The design and operation of the Genesis Solar-Wind Concentrator relies heavily on computer simulations. The computer model is described here, as well as the solar wind conditions used as simulation inputs, including oxygen charge state, velocity, thermal, and angular distributions. The simulation included effects such as ion backscattering losses, which also affect the mass fractionation of the instrument. Calculations were performed for oxygen, the principal element of interest, as well as for H and He. Ion fluences and oxygen mass fractionation are determined as a function of radius on the target. The results were used to verify that the instrument was indeed meeting its requirements, and will help prepare for distribution of the target samples upon return of the instrument to earth. The actual instrumental fractionation will be determined at that time by comparing solar-wind neon isotope ratios measured in passive collectors with neon in the Concentrator target, and by using a model similar to the one described here to extrapolate the instrumental fractionation to oxygen isotopes. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. CALTECH, Pasadena, CA 91125 USA. RP Wiens, RC (reprint author), Los Alamos Natl Lab, NIS-1,MS D466, Los Alamos, NM 87545 USA. EM rwiens@lanl.gov RI Reisenfeld, Daniel/F-7614-2015 NR 10 TC 14 Z9 14 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 105 IS 3-4 BP 601 EP 625 DI 10.1023/A:1024474028352 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 693GA UT WOS:000183707700004 ER PT J AU Neugebauer, M Steinberg, JT Tokar, RL Barraclough, BL Dors, EE Wiens, RC Gingerich, DE Luckey, D Whiteaker, DB AF Neugebauer, M Steinberg, JT Tokar, RL Barraclough, BL Dors, EE Wiens, RC Gingerich, DE Luckey, D Whiteaker, DB TI Genesis on-board determination of the solar wind flow regime SO SPACE SCIENCE REVIEWS LA English DT Review ID TEMPERATURE; EVENTS AB Some of the objectives of the Genesis mission require the separate collection of solar wind originating in different types of solar sources. Measurements of the solar wind protons, alpha particles, and electrons are used on-board the spacecraft to determine whether the solar-wind source is most likely a coronal hole, interstream flow, or a coronal mass ejection. A simple fuzzy logic scheme operating on measurements of the proton temperature, the alpha-particle abundance, and the presence of bidirectional streaming of suprathermal electrons was developed for this purpose. Additional requirements on the algorithm include the ability to identify the passage of forward shocks, reasonable levels of hysteresis and persistence, and the ability to modify the algorithm by changes in stored constants rather than changes in the software. After a few minor adjustments, the algorithm performed well during the initial portion of the mission. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Los Alamos Natl Lab, Los Alamos, NM USA. Lockheed Martin Astronaut, Denver, CO USA. Raytheon Missile Syst, Tucson, AZ USA. RP Neugebauer, M (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 16 TC 38 Z9 38 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2003 VL 105 IS 3-4 BP 661 EP 679 DI 10.1023/A:1024478129261 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 693GA UT WOS:000183707700006 ER PT S AU Fredrickson, SE Abbott, LW Duran, S Jochim, JD Studak, JW Wagenknecht, JD Williams, NM AF Fredrickson, SE Abbott, LW Duran, S Jochim, JD Studak, JW Wagenknecht, JD Williams, NM BE Tchoryk, P Shoemaker, J TI Mini AERCam: Development of a free flying nanosatellite inspection robot SO SPACE SYSTEMS TECHNOLOGY AND OPERATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Systems Technology and Operations CY APR 24, 2003 CL ORLANDO, FL SP SPIE DE AERCam; free flyer; inspection; nanosatellite; spacecraft; servicing; autonomy AB The Engineering Directorate of NASA Johnson Space Center has developed a nanosatellite-class free-flyer intended for future external inspection and remote viewing of human spaceflight activities, including International Space Station (ISS) operations. The Miniature Autonomous Extravehicular Robotic Camera (Mini AERCam) technology demonstration unit has been integrated into the approximate form and function of a flight system. The spherical Mini AERCam free flyer is 7.5 inches in diameter and weighs approximately 10 pounds, yet it incorporates significant additional capabilities compared to the 35 pound, 14 inch AERCam Sprint that flew as a Shuttle flight experiment in 1997. Mini AERCam hosts a full suite of miniaturized avionics, instrumentation, communications, navigation, imaging, power. and propulsion subsystems, including two digital video cameras and a high resolution still image camera. The vehicle is designed for either remotely piloted operations or supervised autonomous operations including automatic stationkeeping and point-to-point maneuvering. Free-flyer testing has been conducted on an air-bearing table and in a six degree-of-freedom closed-loop orbital simulation. The orbital simulation models the three-dimensional dynamics of the free-flyer in proximity to the ISS, and produces corresponding God's eye views and simulated free-flyer camera views. A high-fidelity simulation is achieved by directly interfacing to free-flyer thruster driver signals, emulating the MEMS gyro responses in hardware, and using the "truth" state to drive a GPS signal generator connected to the free-flyer GPS receiver. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Fredrickson, SE (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 6 TC 7 Z9 7 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4948-2 J9 P SOC PHOTO-OPT INS PY 2003 VL 5088 BP 97 EP 111 DI 10.1117/12.498108 PG 15 WC Automation & Control Systems; Engineering, Aerospace SC Automation & Control Systems; Engineering GA BX58H UT WOS:000185758200010 ER PT S AU Ottenstein, L Ku, JT Feenan, D AF Ottenstein, L Ku, JT Feenan, D BE ElGenk, MS TI Thermal vacuum testing of a novel loop heat pipe design for the swift BAT instrument SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB An advanced thermal control system for the Burst Alert Telescope on the Swift satellite has been designed and an engineering test unit (ETU) has been built and tested in a thermal vacuum chamber. The ETU assembly consists of a propylene loop heat pipe, two constant conductance heat pipes, a variable conductance heat pipe (VCHP),which is used for rough temperature control of the system, and a radiator. The entire assembly was tested in a thermal vacuum chamber at NASA/GSFC in early 2002. Tests were performed with thermal mass to represent the instrument and with electrical resistance heaters providing the heat to be transferred Start-up and heat transfer of over 300 W was demonstrated with both steady and variable condenser sink temperatures. Radiator sink temperatures ranged from a high of approximately 273 K, to a low of approximately 83 K, and the system was held at a constant operating temperature of 278 K throughout most of the testing. A novel LHP temperature control methodology using both temperature-control led electrical resistance heaters and a small VCHP was demonstrated. This paper describes the system and the tests performed and includes a discussion of the test results. C1 NASA, Goddard Space Flight Ctr, Thermal Engn Branch, Greenbelt, MD 20771 USA. RP Ottenstein, L (reprint author), NASA, Goddard Space Flight Ctr, Thermal Engn Branch, Code 545, Greenbelt, MD 20771 USA. NR 2 TC 4 Z9 4 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 33 EP 41 PG 9 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400004 ER PT S AU Ottenstein, L Butler, D Ku, JT Cheung, K Baldauff, R Hoang, T AF Ottenstein, L Butler, D Ku, JT Cheung, K Baldauff, R Hoang, T BE ElGenk, MS TI Flight testing of the Capillary Pumped Loop 3 experiment SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The Capillary Pumped Loop 3 (CAPL 3) experiment was a multiple evaporator capillary pumped loop experiment that flew in the Space Shuttle payload bay in December 2001 (STS-108). ne main objective of CAPL 3 was to demonstrate in micro-gravity a multiple evaporator capillary pumped loop system, capable of reliable start-up, reliable continuous operation, and heat load sharing, with hardware for a deployable radiator. Tests performed on orbit included start-ups; power cycles, low power tests (100 W total), high power tests (up to 1447 W total), heat load sharing, variable/fixed conductance transition tests, and saturation temperature change tests. The majority of the tests were completed successfully, although the experiment did-exhibit an unexpected sensitivity to shuttle maneuvers. This paper describes the experiment, the tests performed during the. mission, and the test results. C1 NASA, Goddard Space Flight Ctr, Thermal Engn Branch, Greenbelt, MD 20771 USA. RP Ottenstein, L (reprint author), NASA, Goddard Space Flight Ctr, Thermal Engn Branch, Greenbelt, MD 20771 USA. NR 4 TC 3 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 55 EP 64 PG 10 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400007 ER PT S AU Jaworske, DA Shumway, DA AF Jaworske, DA Shumway, DA BE ElGenk, MS TI Solar selective coatings for high temperature applications SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Solar selective coatings are envisioned for use on minisatellites, for applications where solar energy is to be used to power heat engines or to provide thermal energy for remote regions in the interior of the spacecraft. These coatings are designed to have the combined properties of high solar absorptance and low infrared emittance. The coatings-must be durable at elevated temperatures. For thermal bus-applicaiions, the temperature during operation is likely to be near 100degreesC. For heat engine applications, the temperature is expected to be much greater. The objective of this work was to screen candidate solar selective coatings for their high temperature durability. Candidate solar selective coatings were composed of molecular mixtures of metal and dielectric, including: nickel and aluminum oxide, titanium and aluminum oxide, and platinum and aluminum oxide. To identify high temperature durability, the solar absorptance and infrared emittance of the candidate coatings were evaluated initially, and after heating to temperatures in the range of 400degreesC to 700degreesC. The titanium and aluminum oxide molecular mixture was found to be the most durable. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Jaworske, DA (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 7 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 65 EP 70 PG 6 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400008 ER PT S AU Salvail, PG Carter, RR AF Salvail, PG Carter, RR BE ElGenk, MS TI Alkali metal handling practices at NASA MSFC SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB NASA Marshall Space Flight Center (MSFC) is NASA's principle propulsion development center. Research and development is coordinated and carried out. on not only the existing transportation systems, but also those that may be flown in the near future. Heat pipe cooled fast fission cores are among several concepts being considered for the Nuclear Systems Initiative. Marshall Space Flight Center has developed a capability to handle high-purity alkali metals for use in heat pipes or liquid metal heat transfer loops. This capability. is a low budget prototype of an alkali metal handling system that would allow the production of flight qualified heat pipe modules or alkali metal loops. The processing approach used to introduce pure alkali metal into heat pipe, modules and other test articles are described in this paper. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Salvail, PG (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 101 EP 105 PG 5 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400013 ER PT S AU Kizito, JP Balasubramanaim, R Boggess, MJ Stebe, KJ AF Kizito, JP Balasubramanaim, R Boggess, MJ Stebe, KJ BE ElGenk, MS TI Effect of non-ionic Surfactants on nucleate pool boiling SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The ultimate aim of this project is to understand the influence of surfactants on boiling heat transfer in microgravity, and identify the regimes which promote improved heat flux and the mechanisms for it. The groundbased experiments we have performed examine boiling curves for a flat substrate that consists of a thin layer of platinum that is deposited on a smooth silicon wafer, in ultra-purified water. These experiments establish a 1g baseline, to which microgravity boiling curves can be compared. We use the non-ionic surfactants Triton X-100 and Surfynol 104 in this study. Boiling data are obtained for aqueous solutions of these surfactants at various concentrations and are compared to the data for pure water. C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. RP Kizito, JP (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Mail Stop 110-3, Cleveland, OH 44135 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 122 EP 131 PG 10 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400016 ER PT S AU Mosier, CL AF Mosier, CL BE ElGenk, MS TI MAP propulsion system-thermal design SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The propulsion system of the Microwave Anisotropy Probe (MAP) had stringent requirements that made the thermal design unique. To meet instrument stability requirements the system had to be designed to keep temperatures of 91 components within acceptable limits without heater cycling. Although the spacecraft remains at a fixed 22degrees sun angle at L2, the variations in solar constant, property degradation, and bus voltage range all significantly affect the temperature. Large portions of the fuel lines are external to the structure and all components are mounted to non-conductive composite structure. These two facts-made the sensitivity to the ML1 effective emissivity and bus temperature very high. Approximately two years prior to launch the propulsion system was redesigned to meet MAP requirements. The new design utilized hardware-that was already installed in order to meet schedule constraints. The spacecraft design and the thermal requirements were changed to compensate for inadequacies of the existing hardware. The propulsion system-consists of fuel lines, fill and drain lines/valve, eight thrusters; a RXCM, and a propulsion tank. A voltage regulator was added to keep critical components within limits. Software was developed to control the operational heaters. Trim resistors were put in series with each operational heater circuits and the tank survival heater. A highly sophisticated test program, which included "real time" model correlation, was developed to determine trim resistors sizes. These trim resistors were installed during a chamber break and verified during thermal balance testing. C1 NASA, Goddard Space Flight Ctr, Thermal Engn Branch, Greenbelt, MD 20771 USA. RP Mosier, CL (reprint author), NASA, Goddard Space Flight Ctr, Thermal Engn Branch, Code 545, Greenbelt, MD 20771 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 187 EP 193 PG 7 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400024 ER PT S AU Novak, KS Phillips, CJ Birur, GC Sunada, ET Pauken, MT AF Novak, KS Phillips, CJ Birur, GC Sunada, ET Pauken, MT BE ElGenk, MS TI Development of a thermal control architecture for the mars exploration rovers SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB In May and June of 2003, the National Aeronautics and Space Administration (NASA) will launch two roving science vehicles on their way to Mars. They will land on Mars in January and February of 2004 and carry out 90-Sol missions. This paper addresses the thermal design architecture of the Mars Exploration Rover (MER) developed for Mars surface operations. The surface atmosphere temperature on Mars can vary from 0degreesC in the heat of the day to -100degreesC in the early morning, prior to sunrise. Heater usage at night must be minimized in order to conserve battery energy. The desire to minimize nighttime heater energy led to a design in which all temperature sensitive electronics and the battery were placed inside a well-insulated (carbon-opacified aerogel lined) Warm Electronics Box (WEB). In addition, radioisotope heater units (RHU's, non-electric heat sources) were mounted on the battery and electronics inside the WEB. During the Martian day, the electronics inside the WEB dissipate a large amount of energy (over 710 W*hrs). This heat energy raises the internal temperatures inside the WEB. Hardware items that have similar temperature limits were conductively coupled together to share heat and concentrate thermal mass. Thermal mass helped to minimize temperature increases in the hot case (with maximum internal dissipation) and minimize temperature decreases in the cold case (with minimum internal dissipation). In order to prevent the battery from exceeding its maximum allowable flight temperature, wax-actuated passive thermal switches were placed between the battery and an external radiator. This paper discusses the design philosophies and system requirements that resulted in a successful Mars rover thermal design. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Novak, KS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 4 Z9 4 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 194 EP 205 PG 12 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400025 ER PT S AU Ganapathi, GB Birur, GC Tsuyuki, GT McGrath, PL Patzold, JD AF Ganapathi, GB Birur, GC Tsuyuki, GT McGrath, PL Patzold, JD BE ElGenk, MS TI Active Heat Rejection System on Mars Exploration Rover - Design changes from Mars Pathfinder SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The active Heat Rejection System designed for Mars Pathfinder was modified for the Mars Exploration Rover (Mars '03) mission and will be used to remove excess heat from the Rover electronics during the cruise part of the mission. The Integrated Pump Assembly design from MPF remained essentially intact; changes were primarily made to reduce weight. However, the cooling loop was significantly redesigned to service totally different requirements for the-MER rovers. In addition, the vent design was readdressed to alleviate potentially excessive nutation as was induced on the MPF spacecraft in the process of dumping the CFC-11 overboard prior to Entry/Descent/Landing. The current vent design was based on a better understanding of the flow characteristics during the blowdown process. This paper addresses some of the key design changes. This paper also addresses lessons learned from the performance testing, and potential changes to improve the HRS performance (e.g, temperature oscillations). C1 CALTECH, Jet Prop Lab, Thermal & Prop Sect, Pasadena, CA 91109 USA. RP Ganapathi, GB (reprint author), CALTECH, Jet Prop Lab, Thermal & Prop Sect, M-S 125-109,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 206 EP 217 PG 12 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400026 ER PT S AU Youngquist, RC AF Youngquist, RC BE ElGenk, MS TI Water detection and removal from shuttle tiles SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Current methods for detecting and removing water from the Space Shuttle tiles have proved inadequate incases of excessive water exposure. This paper describes two new tools that are currently being introduced to Shuttle processing to supplement the existing methods. A capacitive device has been developed to augment the IR camera method of detecting wafer in the tiles and a vacuum pump. systems being tested as a likely replacement to the heat lamps currently used to dry wet tiles. C1 NASA, Kennedy Space Ctr, Spacesport Engn & Technol Directorate, Kennedy Space Ctr, FL 32899 USA. RP Youngquist, RC (reprint author), NASA, Kennedy Space Ctr, Spacesport Engn & Technol Directorate, Kennedy Space Ctr, FL 32899 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 269 EP 275 PG 7 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400033 ER PT S AU Vu, BT Kandula, M Margasahayam, RN Ford, DA AF Vu, BT Kandula, M Margasahayam, RN Ford, DA BE ElGenk, MS TI Launch system testbed: An innovative approach for design and development of future launch structures SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc ID FINITE-DIFFERENCE SCHEMES; COMPUTATIONAL AEROACOUSTICS; BOUNDARY-CONDITIONS; NOISE AB The launch of space vehicles generates extreme conditions, such as vibrations and acoustics that can affect the launch pad, space vehicles, and their payloads. These acoustic loads are the results of intense acoustic environment generated by the interaction of the rocket-engine exhaust stream mixing with the ambient atmosphere. The primary source of structural vibrations and internal loads during launch is due to these acoustic loads. Therefore, being able to manage and suppress these undesirable conditions is critical to proper functioning of vehicle components, payloads, and launch support structures. The goal of the Launch System Testbed at NASA-Kennedy Space Center is to develop new methods to improve the performance of launch systems by reducing noise, vibration, and stress loads generated during launch. C1 NASA, Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. RP Vu, BT (reprint author), NASA, Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 276 EP 289 PG 14 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400034 ER PT S AU Landis, GA Denis, V AF Landis, GA Denis, V BE ElGenk, MS TI High altitude launch for a practical SSTO SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Existing engineering materials allow the constuction of towers to heights of many kilometers. Orbital launch from a high altitude has significant advantages over sea-level launch due to the reduced atmospheric pressure, resulting in lower atmospheric drag on the vehicle and allowing higher rocket engine performance. High-altitude launch sites are particularly advantageous for single-stage to orbit (SSTO) vehicles, where the payload is typically 2% of the initial launch mass. An earlier paper enumerated some of the advantages of high altitude launch of SSTO vehicles. In this paper, we calculate launch trajectories for a candidate SSTO vehicle, and calculate the advantage of launch at launch altitudes 5 to 25 kilometer altitudes above sea level. The performance increase can be directly translated into increased payload capability to orbit, ranging from 5 to 20% increase in the mass to orbit. For a candidate vehicle with an initial payload fraction of 2% of gross lift-off weight, this corresponds to 31% increase in payload (for 5-km launch altitude) to 122% additional payload (for 25-km launch altitude). C1 NASA, John Glenn Res Ctr, Cleveland, OH 44135 USA. RP Landis, GA (reprint author), NASA, John Glenn Res Ctr, Mailstop 302-1,21000 Brook Pk Rd, Cleveland, OH 44135 USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 290 EP 295 PG 6 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400035 ER PT S AU Calle, LM MacDowell, LG Vinje, RD AF Calle, LM MacDowell, LG Vinje, RD BE ElGenk, MS TI Electrochemical evaluation of alloys for spaceport design SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Corrosion studies began at the Kennedy Space Center (KSC) in 1966 during the Gemini/Apollo Programs with the evaluation of long-term protective coatings for the corrosion protection of carbon steel. NASA's KSC Beach Corrosion Test Site, which was established at that time, has been documented by the American Society of Materials (ASM) as one of the most corrosive naturally occurring environments in the world. With the introduction of the Space Shuttle in 1981, the already highly corrosive conditions at the launch pad were rendered even more severe by the acidic exhaust from the solid rocker boosters. In the years that followed, numerous studies have identified materials, coatings, and maintenance procedures for launch hardware and equipment exposed to the highly corrosive environment at the launch pad. The Corrosion Laboratory was established at KSC in 1985 and was outfitted with state-of-the-art electrochemistry equipment to conduct research and materials characterization in many different corrosive environments. This paper will describe the application of electrochemistry in combination with atmospheric exposure to the selection of alloys in a spaceport environment. C1 NASA, Kennedy Space Ctr, Corros Sci & Technol, Kennedy Space Ctr, FL 32899 USA. RP Calle, LM (reprint author), NASA, Kennedy Space Ctr, Corros Sci & Technol, Mail Code YA-C2-T, Kennedy Space Ctr, FL 32899 USA. NR 13 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 296 EP 303 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400036 ER PT S AU Roe, FD Howard, RT AF Roe, FD Howard, RT BE ElGenk, MS TI The successful development of an automated rendezvous and capture (AR&C) system for the National Aeronautics and Space Administration SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB During the 1990's, the Marshall Space Flight Center (MSFC) conducted pioneering research in the development of an automated rendezvous and capture/docking (AR&C) system for U.S.-space vehicles. Development and demonstration of a rendezvous sensor was identified early in the AR&C Program as the critical enabling technology that allows automated proximity operations and docking. A first generation rendezvous sensor, the Video Guidance Sensor (VGS), was developed and successfully flown on STS-87 and STS-95, proving the concept of a video based sensor. A ground demonstration of the entire-system and software. was successfully tested. Advances in both video and signal processing technologies and the-lessons learned from the two successful flight experiments provided a baseline for the development, by the MSFC, of a new generation of video based rendezvous sensor. The Advanced Video Guidance Sensor (AGS) has greatly increased performance and additional capability for longer-range operation with a new target designed as a direct replacement for existing ISS hemispherical reflectors. C1 NASA, George C Marshall Space Flight Ctr, Simulat Grp, Huntsville, AL 35812 USA. RP Roe, FD (reprint author), NASA, George C Marshall Space Flight Ctr, Simulat Grp, Huntsville, AL 35812 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 313 EP 319 PG 7 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400038 ER PT S AU Gill, PS Vaughan, WW AF Gill, PS Vaughan, WW BE ElGenk, MS TI Development of NASA technical standards program relative to enhancing engineering capabilities SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The enhancement of engineering capabilities is an important aspect of any organization; especially those engaged in aerospace development activities. Technical Standards are one of the key elements of this endeavor. The NASA Technical Standards Program was formed in 1997 in response to the NASA Administrator's directive to develop an Agencywide Technical Standards Program. The Program's principal objective involved the converting Center-unique technical standards into Agency wide standards and the adoption/endorsement of non-Government technical standards in lieu of government standards. In the process of these actions, the potential for further enhancement of the Agency's engineering capabilities was noted relative to value of being able to access Agencywide the necessary full-text technical standards, standards update notifications, and integration of lessons learned with technical standards, all available to the user from one Website. This was accomplished and is now being enhanced based on feedbacks from the Agency's engineering staff and supporting contractors. This paper addresses the development experiences with the NASA Technical Standards Program and the enhancement of the Agency's engineering capabilities provided by the Program's products. Metrics are provided on significant aspects of the Program. C1 NASA, George C Marshall Space Flight Ctr, NASA Tech Stand Program Off, Huntsville, AL 35812 USA. RP Gill, PS (reprint author), NASA, George C Marshall Space Flight Ctr, NASA Tech Stand Program Off, Huntsville, AL 35812 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 320 EP 324 PG 5 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400039 ER PT S AU Schuiling, RL AF Schuiling, RL BE ElGenk, MS TI Functions and requirements in the advanced environment SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB This paper describes the initial activity of the Advanced Spaceport Technology Working Group (ASTWG), a joint federal. government, state government, military, academia, and commercial working group, as it works to develop a technology planning process. This process will be used by the ASTWG to identify, coordinate, develop, and demonstrate technologies that will improve spaceport safety and reliability and lower the cost of access to space. The initial phases, of the process involve systems definition and performance gap identification by the ASTWG Vision Team. The output of this initiative will be the input for technical focus teams in developing concepts of spaceport technology gaps and technology development for future spaceports. C1 NASA, John F Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. RP Schuiling, RL (reprint author), NASA, John F Kennedy Space Ctr, Mail Code YA-E6, Kennedy Space Ctr, FL 32899 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 325 EP 332 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400040 ER PT S AU Elliott, JO Nakagawa, RY Spilker, TR Lipinski, RJ Poston, DI Moreland, DW AF Elliott, JO Nakagawa, RY Spilker, TR Lipinski, RJ Poston, DI Moreland, DW BE ElGenk, MS TI NEPTranS; A shuttle-tended NEP interplanetary transportation system SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Recently, a study was performed by a team from JPL and the DOE to develop a mission architecture for a reusable NEP Interplanetary Transfer Vehicle, a "Space Truck". This vehicle is designed to be used for delivery of payloads from Earth to a variety of destinations, including Mars and Venus, dependent on mission needs. In addition to delivering payloads to the target bodies, the vehicle is designed to perform autonomous rendezvous and capture of sample return capsules at the destination for return to Earth. In order to maximize the utility of the vehicle, its design is optimized for servicing between missions with the Space Shuttle. Fuel tanks, ion thrusters, and Power Management and Distribution electronics are all on-orbit replaceable units, located at the payload interface end of the spacecraft to ensure a minimal radiation dose to the Shuttle and crew during maintenance and. resupply operations. Operational flexibility is maximized through the use of replaceable fuel tanks and thrusters, allowing tailoring of fuel load to any given destination and payload mass. This paper discusses the preliminary design developed for the NEP Interplanetary Transfer Vehicle, including its configuration and design features, and outlines the concept for mission design, including discussion of unique requirements for launch, deployment and operations-with the Space Shuttle, and-rendezvous and servicing by the Shuttle in Earth orbit following a return from each target destination. C1 CALTECH, Jet Prop Lab, Mission & Syst Architecture Sect, Pasadena, CA 91109 USA. RP Elliott, JO (reprint author), CALTECH, Jet Prop Lab, Mission & Syst Architecture Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 339 EP 346 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400042 ER PT S AU Nilsen, EN AF Nilsen, EN BE ElGenk, MS TI A fission powered Mars telecommunications orbiter mission concept SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The Mars Program is perforrming ongoing studies to investigate concepts for high data rate telecommunications orbiters to support future Mars surface and orbital science missions. NASA recently completed a mission study to examine the use of a fission reactor powered telecommunications orbiter to enable high priority science at Mars and to validate key technologies in power, propulsion and telecommunications. This paper details the objectives of the mission, the key constraints that influenced the mission design, and the flight and ground system implementation. Issues that influenced the mission architecture are discussed, as well as the technology assumptions. Key mission and technology trades are listed and the decision, criteria are developed. This mission concept was developed to examine the science benefit of a reactor powered telecommunications orbiter. No decision on power sources would be made until after completion of an Environmental Impact Statement.. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nilsen, EN (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 347 EP 352 PG 6 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400043 ER PT S AU Elliott, JO Lipinski, RJ Poston, DI AF Elliott, JO Lipinski, RJ Poston, DI BE ElGenk, MS TI Mission concept for a nuclear reactor-powered Mars cryobot lander SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Recently, a team from JPL and the DOE carried out a study to investigate the utility of a 3 kWe surface fission power system for Mars landed missions. In the course of the study it became clear that the application of such a power system was, enabling to a wide variety of potential missions. Of these, two concepts were developed, one for a stationary lander and one for a reactor-powered rover. This paper discusses the design of the lander mission, which was developed around the concept of landing a cryobot on the Mars north polar ice cap. The cryobot is designed to bore through the entire 2-3 km thickness of the ice cap, Providing a picture of the Martian climate spanning more than a million years of Martian history. The high sustained-power available-from the reactor system proves to be an ideal match for this mission design, enabling a level of science return unavailable from any alternative power sources. lander design is based on a minimum extrapolation of. technology, drawing heavily on the existing concepts in development at JPL for the 2009. Mars Science Laboratory (MSL) lander and EDL systems. This paper describes the, unique design challenges, encountered in the development of this mission architecture and incorporation of the fission power system in the lander, and presents a detailed description of the final design of this trailblazing science mission. C1 CALTECH, Jet Prop Lab, Mission & Syst Architecture Sect, Pasadena, CA 91109 USA. RP Elliott, JO (reprint author), CALTECH, Jet Prop Lab, Mission & Syst Architecture Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 353 EP 360 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400044 ER PT S AU Elliott, JO Lipinski, RJ Poston, DI AF Elliott, JO Lipinski, RJ Poston, DI BE ElGenk, MS TI Design concept for a nuclear reactor-powered Mars rover SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB A study was recently carried out by a team from JPL and the DOE to investigate the utility of a DOE developed 3 kWe surface fission power system for Mars missions. The team was originally tasked to perform a study to evaluate the usefulness and feasibility of incorporation of such a power system into a landed mission. In the course of the study it became clear that the application of such a power system was enabling to a wide variety of potential missions. Of these, two missions were developed, one for a stationary lander and one for a reactor-powered rover. This paper discusses the design of the rover mission, which was developed around the concept of incorporating the fission power system directly into a large rover chassis to provide high power, long range traverse capability. The rover design is based on a minimum extrapolation of technology, and adapts existing concepts developed at JPL for the 2009 Mars Science Laboratory (MSL) rover, lander and EDL systems. The small size of the reactor allowed its incorporation directly into an existing large MSL rover chassis design, allowing direct use of MSL aeroshell and pallet lander elements, beefed up to support the significantly greater mass involved in the nuclear power system and its associated shielding. This paper describes the unique design challenges encountered in the development of this mission architecture and incorporation of the fission power system in the rover, and presents a detailed description of the final design of this innovative concept for providing long range, long duration mobility on Mars. C1 CALTECH, Jet Prop Lab, Mission & Syst Architecture Sect, Pasadena, CA 91109 USA. RP Elliott, JO (reprint author), CALTECH, Jet Prop Lab, Mission & Syst Architecture Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 376 EP 383 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400047 ER PT S AU Van Dyke, M Houts, M Godfroy, T Dickens, R Martin, JJ Salvail, P Carter, R AF Van Dyke, M Houts, M Godfroy, T Dickens, R Martin, JJ Salvail, P Carter, R BE ElGenk, MS TI Test facilities in support of high power electric propulsion systems SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Successful development of space fission systems requires an extensive program of affordable and realistic testing. In addition to tests related to design/development of the fission system, realistic testing of the actual flight unit must also be performed. If the system is designed to operate within established radiation damage and fuel burn up is while simultaneously being designed to allow close simulation of heat from fission using resistance heaters, high confidence in fission system performance and lifetime can be attained through non-nuclear testing. Through demonstration of systems concepts (designed by DOE National Laboratories) in relevant environments, this philosophy has been demonstrated through hardware testing in the High Power Propulsion Thermal Simulator (HPPTS). The HPPTS is, designed to enable very realistic non-nuclear testing of space fission systems. Ongoing research at the HPPTS is geared towards facilitating research, development, system integration,- and system utilization via cooperative efforts. with DOE, labs, industry, universities, and other NASA centers. Through hardware based design and testing, the HPPTS investigates High Power Electric Propulsion (HPEP) component, subsystem, and integrated system design and performance. C1 NASA, Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Van Dyke, M (reprint author), NASA, Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 1 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 451 EP 456 PG 6 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400055 ER PT S AU Emrich, WJ AF Emrich, WJ BE ElGenk, MS TI First results of the gasdynamic mirror fusion propulsion experiment SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB An experimental Gasdynamic Mirror or GDM device has been constructed at the NASA Marshall Space Flight Center to provide an initial assessment of the applicability of this technology for propulsion systems. This paper presents the first experimental results obtained from the machine and an analysis of the types of plasma instabilities likely to be encountered. It is intended that this device operate at higher plasma densities and with much larger L/D ratios than previous mirror machines. The high L/D ratio minimizes to a large extent certain, magnetic curvature effects which lead to plasma instabilities causing a loss of plasma confinement. The high plasma density results in the plasma behaving much more like a conventional fluid with a-mean-free path shorter than the length of the device. This characteristic helps reduce problems associated with "loss cone" microinstabilities. The device has been constructed to allow a considerable degree of flexibility in its configuration thus permitting the experiment to grow over time without necessitating a great deal of additional fabrication. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Emrich, WJ (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 483 EP 489 PG 7 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400059 ER PT S AU Williams, CH Mikellides, PG Mikellides, IG Gerwin, RA Dux, IJ AF Williams, CH Mikellides, PG Mikellides, IG Gerwin, RA Dux, IJ BE ElGenk, MS TI Fusion propulsion through a magnetic nozzle and open divertor SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB A revised magnetic nozzle and open poloidal bundle divertor concept is proposed for a small aspect ratio, spherical torus reactor to be used in direct nuclear fusion space propulsion. A preliminary analysis of convergent/divergent flow through a magnetic nozzle illustrated the importance of high efficiency, where a power conversion efficiency of only 75% could lead to a doubling of exit area ratio requirements over ideal conditions. Preliminary MHD simulations have shown that as much as 50% of the mass flow could penetrate into the plasma-magnetic field boundary layer, leading to a thermal-to-directed jet power loss of 30% and a spacecraft payload mass ratio loss of similar to60% of ideal. The importance of understanding the plasma-magnetic field interface and the inability of space/time dependent MHD simulations to resolve fine-scaled, gradient-driven micro-instabilities is currently under study. Preliminary plasma interface broadening mechanism studies have concluded that significant attachment of the plasma onto the magnetic field can occur at the nozzle inlet, that anomalous resistivity is likely to be a significant issue in the plasma regime of interest, that Rayleigh-Taylor instabilities may not be of immediate concern (but cannot be discounted), and that full Hall current effects must be incorporated into the ongoing simulations. C1 NASA, Glenn Res Ctr, Space Transportat Project Off, Cleveland, OH 44135 USA. RP Williams, CH (reprint author), NASA, Glenn Res Ctr, Space Transportat Project Off, Cleveland, OH 44135 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 510 EP 515 PG 6 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400063 ER PT S AU Gilland, J Johnston, G AF Gilland, J Johnston, G BE ElGenk, MS TI MPD thruster performance analytic models SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Magnetoplasmadynamic (MPD) thrusters are capable of accelerating quasi-neutral plasmas to high exhaust velocities using Megawatts (MW) of electric power. These characteristics make such devices worthy of consideration for demanding, far-term missions such as the human exploration of Mars or beyond. Assessment of MPD thrusters at the system and mission level is often difficult due to their status as ongoing experimental research topics rather than developed thrusters. However, in order to assess MPD thrusters' utility in later missions, some adequate characterization of performance, or more exactly, projected performance, and system level definition are required for use in analyses. The most recent physical models of self-field MPD thrusters have been examined, assessed, and reconfigured for use by systems and mission analysts. The physical models allow for rational projections of thruster performance based on physical parameters that can be measured in the laboratory. The models and their implications for the design of future MPD thrusters are presented. C1 NASA, OAI, Glenn Res Ctr, Cleveland, OH 44142 USA. RP Gilland, J (reprint author), NASA, OAI, Glenn Res Ctr, Cleveland, OH 44142 USA. NR 14 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 516 EP 524 PG 9 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400064 ER PT S AU Hrbud, I Goodfellow, K Van Dyke, M Houts, M AF Hrbud, I Goodfellow, K Van Dyke, M Houts, M BE ElGenk, MS TI Non-nuclear NEP system testing SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc ID DEVELOPMENT PROGRESS; FISSION AB The Safe Affordable Fission Engine (SAFE) test se ties Addresses Phase 1 Space Fission Systems issues in particular non-nuclear testing and system integration issues leading to the testing and non-nuclear demonstration of a 400-kW fully integrated flight unit. The first part of the SAFE 30 test series demonstrated operation of the simulated nuclear core and heat pipe system. Experimental data acquired in a number of different test scenarios will validate existing computational models, demonstrated system flexibility (fast start-ups, multiple start-ups/shut downs), simulate predictable failure modes and operating environments. The objective of the second part is to demonstrate an integrated propulsion system consisting of a core, conversion system and a thruster where the system converts thermal heat into jet power. This end-to-end system demonstration sets a precedent for ground testing of nuclear electric propulsion systems. The paper describes the SAFE 30 end-to-end system demonstration and its subsystems. C1 NASA, ERC Inc, MSFC Grp, Huntsville, AL 35812 USA. RP Hrbud, I (reprint author), NASA, ERC Inc, MSFC Grp, Huntsville, AL 35812 USA. NR 16 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 533 EP 539 PG 7 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400066 ER PT S AU Martin, J Lewis, R Chakrabarti, S Sims, WH Pearson, JB Fant, WE AF Martin, J Lewis, R Chakrabarti, S Sims, WH Pearson, JB Fant, WE BE ElGenk, MS TI Ion dynamic capture experiments with the high performance antiproton trap (HiPAT) SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc ID VACUUM AB To take the first step towards using the energy produced from the matt,er-antimatter annihilation for propulsion applications, the NASA Marshall Space Flight Center (MSFC) Propulsion Research Center (PRC) has initiated a research activity examining the storage of low energy antiprotons. The High Performance Antiproton Trap (HiPAT) is an electromagnetic system (Penning-Malmberg design) consisting of a 4 Tesla superconductor, a high voltage electrode confinement system, and an ultra high vacuum, test section. It has been designed with an ultimate goal of maintaining 10(12) charged particles with a half-life of 18 days. Currently, this system is being evaluated experimentally using normal matter ions that are cheap to produce, relatively easy to handle, and provide a good indication of overall trap behavior (with the exception of assessing annihilation losses). The ions are produced via a positive hydrogen ion source and transported to HiPAT in a beam line equipped with electrostatic optics. The optics serve to both focus and gate the incoming ions, providing microsecond-timed beam pulses that are dynamically captured by cycling the HiPAT forward containment field like a "trap door". Initial dynamic capture. experiments have been successfully performed with beam energy and currents set to 1.9 kV and 23 muamps, respectively. At these settings up to 2x10(9) ions have been trapped during a single dynamic cycle. C1 NASA, MSFC, Huntsville, AL 35812 USA. RP Martin, J (reprint author), NASA, MSFC, TD 40, Huntsville, AL 35812 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 563 EP 570 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400070 ER PT S AU Angirasa, D Mason, LS Shaltens, RK AF Angirasa, D Mason, LS Shaltens, RK BE ElGenk, MS TI Radiator concepts for nuclear powered Brayton conversion systems SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB This paper reviews the technical background for the development of Brayton power conversion system for Nuclear Electric Propulsion (NEP). The Brayton system is outlined in terms of its subsystems and their components. The heat rejection subsystem is examined. Some potential concepts are developed for the heat rejection subsystems. The requisite analyses for the design of radiators were developed. Theoretical and numerical aspects are discussed. Technological issues with reference to the radiators are highlighted. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Angirasa, D (reprint author), NASA, Glenn Res Ctr, MS 301-2,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 605 EP 612 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400075 ER PT S AU Thieme, LG Schreiber, JG AF Thieme, LG Schreiber, JG BE ElGenk, MS TI NASA GRC stirling technology development overview SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc ID CONVERTER AB The Department of Energy, Lockheed Martin (LM), Stirling, Technology Company, and NASA Glenn Research Center (GRC) are developing a high-efficiency Stirling. Radioisotope Generator (SRG) for potentials NASA Space Science missions. The SRG is being developed for multimission use, including providing spacecraft onboard electric power for NASA deep space missions and power for unmanned Mars rovers. NASA GRC is conducting an in-house supporting technology project to assist in developing the Stirling convertor for space qualification and mission implementation. Preparations are underway for a thermal/vacuum-system demonstration and unattended operation during endurance testing of the 55-We Technology. Demonstration Convertors. Heater head life assessment efforts continue, including verification of the heater head brazing and heat treatment schedules and evaluation of any potential regenerator oxidation. Long-term magnet aging tests are continuing to characterize any possible aging in the strength or demagnetization resistance of the permanent magnets used in the linear alternator. Testing of the magnet/lamination epoxy bond for performance and lifetime characteristics is now underway. These efforts are expected to provide key inputs. as the system integrator, LM, begins system development of the SRG. GRC is also developing advanced technology for Stirling convertors. Cleveland State University (CSU) is progressing toward a multi-dimensional Stirling computational fluid dynamics code, capable of modeling complete convertors. Validation efforts at both CSU and the University of Minnesota are complementing the code development. New efforts have been started this year on 4 lightweight convertor, advanced controllers, high-temperature materials, and an end-to-end system dynamics model. Performance and mass improvement goals have been established for second and third-generation Stirling radioisotope power systems. C1 NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Thieme, LG (reprint author), NASA, Glenn Res Ctr Lewis Field, MS 301-2,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 12 TC 5 Z9 5 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 613 EP 620 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400076 ER PT S AU Hervol, D Mason, LS Birchenough, A AF Hervol, D Mason, LS Birchenough, A BE ElGenk, MS TI Experimental results from a 2 kW Brayton power conversion unit SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB This paper presents experimental test results from operation of 6 2 kWe Brayton power conversion unit. The Brayton converter was developed for a solar dynamic power system flight experiment planned for the Mir Space Station in 1997. The flight experiment was cancelled, but the converter was tested at Glenn Research Center as part of them Solar Dynamic Ground Test Demonstration system which included a solar concentrator, heat receiver, and space radiator. In preparation for the current testing, the heat receiver was removed and replaced with an electrical resistance heater, simulating the thermal input of a steady-state nuclear source. The converter was operated over a full range of thermal input power levels and rotor speeds to generate an overall performance map. The converter unit will serve as the centerpiece of a Nuclear Electric Propulsion Testbed at Glenn. Future potential uses for the Testbed include high voltage electrical controller development integrated electric thruster testing and advanced radiator demonstration testing to help guide high power Brayton technology development for NEP. C1 NASA, Glenn Res Ctr, Mech Syst Branch, Glenn Engn & Sci Support Org,Analex Corp, Cleveland, OH 44135 USA. RP Hervol, D (reprint author), NASA, Glenn Res Ctr, Mech Syst Branch, Glenn Engn & Sci Support Org,Analex Corp, MS 301-5,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 621 EP 628 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400077 ER PT S AU Tew, RC Cairelli, JE Ibrahim, MB Simon, TW Gedeon, D AF Tew, RC Cairelli, JE Ibrahim, MB Simon, TW Gedeon, D BE ElGenk, MS TI Overview of NASA multi-dimensional Stirling convertor code development and validation effort SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB A NASA grant has been awarded to Cleveland State University (CSU) to develop a multi-dimensional (multi-D) Stirling computer code with the goals of improving loss predictions and identifying component areas for improvements. The University of Minnesota (UMN) and Gedeon Associates are teamed with CSU. Development of test rigs at UMN and CSU and validation of the code against test data are part of the effort. The one-dimensional (1-D) Stirling codes used for design and performance prediction do not rigorously model regions of the working space where abrupt changes in flow area occur (such as manifolds and other transitions between components). Certain hardware experiences have demonstrated large performance gains by varying manifolds and heat exchanger designs to improve flow distributions in the heat exchangers. I-D codes were not able to predict these performance gains. An accurate multi-D code should improve understanding of the effects of area changes along the main flow axis, sensitivity of performance to slight changes in internal geometry, and, in general, the understanding of various internal thermodynamic losses. The commercial CFD-ACE code has been chosen for development of the multi-D code. This 2-D/3-D code has highly developed pre- and post-processors, and moving boundary capability. Preliminary attempts at validation of CFD-ACE models of MIT gas. spring and "two space" test rigs were encouraging. Also, CSU's simulations of the UMN oscillating-flow rig compare well with flow visualization results from UMN. A complementary Department of Energy (DOE) Regenerator Research effort is aiding in development of regenerator matrix models that will be used in the multi-D Stirling code. This paper reports on the progress and challenges of this multi-D code development effort. C1 NASA, Glenn Res Ctr, Thermomech Branch, Cleveland, OH 44135 USA. RP Tew, RC (reprint author), NASA, Glenn Res Ctr, Thermomech Branch, Cleveland, OH 44135 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 668 EP 676 PG 9 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400084 ER PT S AU Calle, CI Buhler, CR Mantovani, JG Groop, EE Nowicki, AW AF Calle, CI Buhler, CR Mantovani, JG Groop, EE Nowicki, AW BE ElGenk, MS TI Application of electrometer technology to materials evaluation for future planetary spaceports SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc ID MARS ORBITER CAMERA; DUST; PATHFINDER AB Future spaceports on dusty and dry planetary environments; such as the Martian or lunar environments; may be hindered by the build-up of electrostatic charge that may generate unwanted electrostatic potentials. In an effort to, evaluate suitable materials for these environments, an electrometer sensor technology was developed. This technology and its associated environmental simulators. have made possible the characterization of the electrostatic response of possible spaceport materials exposed to planetary regolith simulants. A "triboelectric series" ranking of these materials according to their electrostatic response has been developed. Some material candidates with low electrostatic response when in contact with the regolith simulants have been identified. Candidate materials for future planetary spaceports can be characterized with this technology. C1 NASA, Electromagnet Phys Lab, Kennedy Space Ctr, FL 32899 USA. RP Calle, CI (reprint author), NASA, Electromagnet Phys Lab, Kennedy Space Ctr, FL 32899 USA. NR 22 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 751 EP 756 PG 6 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400093 ER PT S AU Houts, M Van Dyke, M Godfroy, T Martin, J Bragg-Sitton, S Dickens, R Salvail, P Williams, E Harper, R Hrbud, I Carter, R AF Houts, M Van Dyke, M Godfroy, T Martin, J Bragg-Sitton, S Dickens, R Salvail, P Williams, E Harper, R Hrbud, I Carter, R BE ElGenk, MS TI Hardware based technology assessment in support of near-term space fission missions SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Fission technology can enable rapid, affordable access to any point in the solar system. If fission propulsion systems are to be developed to their full potential; however, near-term customers must be identified and initial fission systems successfully developed, launched, and utilized. Successful utilization will most likely occur if frequent, significant hardware-based milestones can be achieved throughout the program. Achieving these milestones will depend on the capability to perform highly realistic non-nuclear testing of nuclear systems. This paper discusses ongoing and potential research that could help achieve these milestones. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Houts, M (reprint author), NASA, George C Marshall Space Flight Ctr, TD40, Huntsville, AL 35812 USA. EM michael.houts@msfc.nasa.gov NR 8 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 784 EP 789 PG 6 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400098 ER PT S AU Morgan, TH Niebur, SM AF Morgan, TH Niebur, SM BE ElGenk, MS TI Implementing a new line of medium-class, unmanned space exploration missions SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The NASA Office of Space Science will soon be releasing the first Announcement of Opportunity to propose new, medium-class, missions for Solar System Exploration. This new mission line, called New Frontiers, has been created in order to allow greater access to A larger variety of targets in our Solar System. Missions may be of larger scope than the current Discovery program missions; proposed costs for building, launching, operating, and analyzing data from the New Frontiers missions may be as large as $650M (Fiscal Year 2003 dollars) and proposed launch date may be up to 47 months after development is initiated. New Frontiers missions may use radioisotope power sources (e.g. RTGs) and larger launch vehicles than allowed for Discovery missions, due to the greater allowed cost. Each proposal opportunity will be focused on proposals for investigations that address most if not all of the science objectives of one or more of the "Medium Class" investigations identified in the recent National Academy Planetary Science Decadal Survey (National Research Council, 2002). The management of this program is to be similar to Discovery, with a few significant differences. Ibis paper describes the New Frontiers program, compares it to the successful Discovery program, and discusses the challenges involved in the selection and implementation of New Frontiers missions. C1 NASA, Headquarters, Off Space Sci, Solar Syst Explorat Div, Washington, DC 20546 USA. RP Morgan, TH (reprint author), NASA, Headquarters, Off Space Sci, Solar Syst Explorat Div, Washington, DC 20546 USA. RI Morgan, Thomas/I-5943-2013 NR 5 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 790 EP 797 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400099 ER PT S AU Perry, RB Pelacci, DG AF Perry, RB Pelacci, DG BE ElGenk, MS TI Considerations and lessons learned in implementing effective, low-cost, unmanned space exploration missions SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Since the early 1990s, NASA has implemented a number of low-cost, unmanned space exploration missions including the recent missions associated with the Mars Exploration Program, and also missions in the Discovery and Explorer Programs. This paper addresses a number of the system design and implementation considerations and lessons learned that must be addressed for these missions to be successful, and stresses that effective systems engineering practices must be adopted and applied consistently throughout all mission project phases. Emphasis is placed on highlighting effective approaches that have been successfully used in past programs. These considerations and lessons learned should be considered in formulating effective future technology demonstration and science exploration mission efforts for NASA's Nuclear Systems Initiative (NSI) and New Frontiers Program. C1 NASA, Langley Res Ctr, Earth & Space Sci Support Off, Hampton, VA 23681 USA. RP Perry, RB (reprint author), NASA, Langley Res Ctr, Earth & Space Sci Support Off, Hampton, VA 23681 USA. NR 8 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 798 EP 804 PG 7 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400100 ER PT S AU Troutman, PA Bethke, K Stillwagen, F Caldwell, DL Manvi, R Strickland, C Krizan, SA AF Troutman, PA Bethke, K Stillwagen, F Caldwell, DL Manvi, R Strickland, C Krizan, SA BE ElGenk, MS TI Revolutionary concepts for Human Outer Planet Exploration (HOPE) SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB This paper summarizes the content of a NASA-led study performed to identify revolutionary concepts and supporting technologies for Human-Outer Planet Exploration (HOPE). Callisto, the fourth of Jupiter's Galilean moons, was chosen as the destination for the HOPE study. Assumptions for the Callisto mission include a launch year of 2045 or later, a spacecraft capable of transporting humans to and from Callisto in less, than five years, and a requirement to support, three humans on the surface for a minimum of 30 days. Analyses performed in support of HOPE include identification of precursor science and technology demonstration missions and development of vehicle concepts for transporting crew and supplies. A complete surface architecture was developed to provide the human crew with a power system, a propellant production plant, a surface habitat and supporting robotic systems: An operational concept was defined that provides a surface layout for these architecture components, a list of surface-tasks, a 30-day timeline, a daily schedule, and a plan for communication from the surface. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Troutman, PA (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 0 TC 2 Z9 2 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 821 EP 828 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400103 ER PT S AU Borowski, SK McGuire, ML Mason, LS Gilland, JH Packard, TW AF Borowski, SK McGuire, ML Mason, LS Gilland, JH Packard, TW BE ElGenk, MS TI "Bimodal" nuclear thermal rocket (BNTR) propulsion for an artificial gravity HOPE mission to Callisto SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB This paper summarizes the results of a year long, multi-center NASA study which examined the viability of nuclear fission propulsion systems for Human Outer Planet Exploration (HOPE). The HOPE mission assumes a crew of six is sent to Callisto, Jupiter's outermost large moon, to establish a surface base and propellant production facility. The Asgard asteroid formation, a region potentially rich in water-ice, is selected as the landing site. High thrust BNTR propulsion is used to transport the crew from the Earth-Moon L I staging node to Callisto then back to Earth in less than 5 years. Cargo and LH2 "return" propellant for the piloted Callisto transfer vehicle (PCTV) is pre-deployed at the moon (before the crew's departure) using low thrust, high power, nuclear electric propulsion (NEP) cargo and tanker vehicles powered by hydrogen magnetoplasmadynamic (MPD) thrusters. The PCTV is powered by three 25 klb(f) BNTR engines which also produce 50 kW, of power for crew life support and spacecraft operational needs. To counter the debilitating effects of long duration space flight (similar to855 days out and similar to836 days back) under "0-g(E)" conditions, the PCTV-generates an artificial gravity environment of "1-g(E)" via rotation of the vehicle about its center-of-mass at a rate of similar to4 rpm. After similar to123 days at Callisto, the "refueled" PCTV leaves orbit for-the trip home. Direct capsule re-entry of the crew at mission end is assumed. Dynamic Brayton power conversion and high temperature uranium dioxide (UO2) in tungsten metal "cermet"-fuel is used in both the BNTR and NEP vehicles to maximize hardware commonality. Technology performance levels and vehicle characteristics are presented, and requirements for PCTV reusability are also discussed. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Borowski, SK (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 829 EP 836 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400104 ER PT S AU McGuire, ML Borowski, SK Masoni, LS Gilland, J AF McGuire, ML Borowski, SK Masoni, LS Gilland, J BE ElGenk, MS TI High, power MPD Nuclear Electric Proulsion (NEP) for artificial gravity HOPE missions to Callisto SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The following paper documents the results of a one-year multi-center NASA study on. the prospect of sending humans to Jupiter's moon, Callisto, using an all Nuclear Electric Propulsion (NEP) space transportation system architecture with magnetoplasmadynamic (MPD) thrusters. The fission reactor system utilizes high temperature uranium dioxide (UO2) in tungsten (W) metal matrix "cermet" fuel and electricity is generated using advanced dynamic Brayton power conversion technology. The mission timeframe assumes on-going human Moon and Mars missions and existing space infrastructure to support launch of cargo and crewed spacecraft to Jupiter in 2041 and 2045, respectively. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP McGuire, ML (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 3 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 837 EP 843 PG 7 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400105 ER PT S AU Falck, RD Borowski, SK AF Falck, RD Borowski, SK BE ElGenk, MS TI High power Nuclear Electric Propulsion (NEP) for cargo and propellant transfer missions in cislunar space SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The performance of Nuclear Electric Propulsion (NEP) in transporting cargo and propellant from Low Earth Orbit (LEO) to the first Earth-Moon Lagrange point (EML1) is examined. The baseline NEP vehicle utilizes a fission reactor system with Brayton power conversion for electric power generation to power multiple liquid hydrogen magnetoplasmadynamic (MPD) thrusters. Vehicle characteristics and performance levels are based on technology availability in a fifteen to twenty year timeframe. Results of numerical trajectory analyses are also provided. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Falck, RD (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 3 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 844 EP 849 PG 6 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400106 ER PT S AU Landis, GA AF Landis, GA BE ElGenk, MS TI Robots and humans: Synergy in planetary exploration SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc ID MARS AB How will humans and robots cooperate in future planetary exploration? Are humans and robots fundamentally separate modes of exploration, or can humans and robots,work together to synergistically explore the solar system? It is proposed that humans and robots can work together in exploring the planets by use of telerobotic operation to expand the function and usefulness of human explorers, and to extend the range of human exploration to hostile environments. C1 NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. RP Landis, GA (reprint author), NASA, John H Glenn Res Ctr, Mailstop 302-1,21000 Brook Pk Rd, Cleveland, OH 44135 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 853 EP 860 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400107 ER PT S AU Watson, PM Engle, M AF Watson, PM Engle, M BE ElGenk, MS TI The International Space Station habitat SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The International Space Station (ISS) is an engineering project unlike any other. The vehicle is inhabited and operational as it is constructed. The habitability resources available to the crew are the sleep quarters, the galley, the waste and hygiene compartment, and exercise equipment. These items-are mainly in the Russian Service Module and their placement is awkward for the crew to use and work around. ISS assembly will continue with the truss build and the addition of the International Partner Laboratories. Prior to the addition of the International Partner Laboratories, Node 2 will be added. The Node 2 module will provide additional stowage volume and room for more crew sleep quarters. The purpose of the ISS is to perform research and a major area of emphasis is on the effects of long duration space flight on humans, as result of this research the habitability requirements for the International Space Station crews will be determined. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Watson, PM (reprint author), NASA, Lyndon B Johnson Space Ctr, Mail Code OM, Houston, TX 77058 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 869 EP 873 PG 5 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400109 ER PT S AU Robbins, WW AF Robbins, WW BE ElGenk, MS TI Lessons learned in maintenance of the International Space Station SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The International Space Station (ISS) began development in 1984. On-orbit assembly and operations began in 1998, and ISS is now a 330,000-pound operational orbiting laboratory. The ISS Program still has several years of assembly ahead, with fifteen years of operations to follow. However, the experience to date has proven valuable in identifying lessons in developing a logistics support infrastructure, and maintaining a permanently orbiting facility. Understanding what has been successful in ISS, as well as not so successful, will help new space exploration programs. ISS lessons will help new programs effectively embed supportability in design and management, and control life cycle cost through effective programmatic requirements and prudent early design investments. These lessons can be grouped into three major areas. The first is the programmatic lessons in establishing and managing an acquisition logistics office. The second area is design strategies. The third area is lessons in operational maintenance. Human space exploration and colonization of space is dependent on the ability to sustain a long duration space-based vehicle that is funded, designed, built and operated by a consortium of international partners. The lessons that are emerging from the ISS program are of value to the next generation of space vehicle development managers. C1 NASA, Lyndon B Johnson Space Ctr, Space Stn Program Off, Houston, TX 77058 USA. RP Robbins, WW (reprint author), NASA, Lyndon B Johnson Space Ctr, Space Stn Program Off, Houston, TX 77058 USA. NR 1 TC 0 Z9 0 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 874 EP 881 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400110 ER PT S AU Tripathi, RK Wilson, JW AF Tripathi, RK Wilson, JW BE ElGenk, MS TI Reliability methods for shield design process SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc ID SPACE RADIATION PROTECTION; TRANSPORT; ISSUES AB Providing protection against. the hazards of space radiation is a major challenge to the exploration and development of space. The great cost of added radiation shielding is a potential limiting factor in deep space operations. In this enabling technology, we have developed methods for optimized shield design over multi-segmented missions involving multiple work and living areas in the transport and duty phase of space missions. The total shield mass over all pieces of equipment and habitats is optimized subject to career dose and dose rate constraints. An important component of this technology is the estimation of two most commonly identified uncertainties in radiation shield design, the shielding properties of materials used and the understanding of the biological response of the astronaut to the radiation leaking through the materials into the living space. The largest uncertainty, of course, is in the biological response to especially high charge and energy (HZE) ions of the galactic cosmic rays. These uncertainties are blended with the optimization design procedure to formulate reliability-based methods for shield design processes. The details of the methods will be discussed. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Tripathi, RK (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 898 EP 906 PG 9 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400113 ER PT S AU Singleterry, RC Johns, BD Fan, KY Cheatwood, FM Qualls, GD Wareing, TA McGhee, J Pautz, S Prinja, AK Gleicher, F Failla, G Sobieszczanski-Sobieski, J Wilson, JW AF Singleterry, RC Johns, BD Fan, KY Cheatwood, FM Qualls, GD Wareing, TA McGhee, J Pautz, S Prinja, AK Gleicher, F Failla, G Sobieszczanski-Sobieski, J Wilson, JW BE ElGenk, MS TI Development of collaborative engineering environments for spacecraft design SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The hazards of ionizing radiation in space continue-to be a limiting factor in the design of missions, spacecraft, and habitats. Shielding against such hazards is an enabling-technology in the human and robotic exploration and development of space. If the design of the radiation shielding is not optimal for the mission, then excess mass will be launched, mission costs will be higher than necessary, and useful payload will be reduced. This reduced mission capability scenario can be-repeated for other technical design disciplines. These other disciplines calf also effect each other's requirements. A collaborative engineering environment can optimize ALL design, parameters for cost (or another parameter) producing a spacecraft that will meet all mission requirements at the minimum cost. This paper describes two environments that include space radiation analyses and the inclusion within a larger optimization methodology. C1 NASA, Langley Res Ctr, Struct & Mat Competency, Hampton, VA 23681 USA. RP Singleterry, RC (reprint author), NASA, Langley Res Ctr, Struct & Mat Competency, Hampton, VA 23681 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 907 EP 916 PG 10 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400114 ER PT S AU Mazuruk, K Grugel, RN AF Mazuruk, K Grugel, RN BE ElGenk, MS TI New experiments with spinning metallic discs SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB A number of recent advanced theories related to torsion properties of the space-time matrix predict the existence of an interaction between classically spinning objects. Indeed, some experimental data suggest that spinning magnetic bodies discernibly interact with Earth's natural fields. If there are interactions between rotating bodies then nuclear spins could be used for detection. Thus, assuming a spinning body induces a hypothetical torsion field, a sensor based on the giant magnetoresistance effect would detect-local changes. Experimentally, spinning a brass wheel shielded from Earth's. magnetic field showed no measurable change in signals; with no shielding a Faraday disc phenomenon was observed. Unexpected experimental measurements from the non-axial Faraday disc configuration were recorded and a theoretical model was derived to explain them. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Mazuruk, K (reprint author), NASA, George C Marshall Space Flight Ctr, MS-SD46, Huntsville, AL 35812 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 947 EP 951 PG 5 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400119 ER PT S AU Wilson, JW Nealy, JE De Angelis, G Clowdsley, MS Badavi, FF AF Wilson, JW Nealy, JE De Angelis, G Clowdsley, MS Badavi, FF BE ElGenk, MS TI Deep space environment and shielding SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc ID GALACTIC COSMIC-RAYS; INTERPLANETARY SPACE; RADIATION PROTECTION; TARGET FRAGMENTATION; ISSUES; PROPAGATION; PREDICTIONS; QUALITY; SPECTRA AB Mission scenarios outside the Earth's protective magnetic shield are being studied. Included are high usage assets in the near-Earth environment for casual. trips, for research, for commercial and for operational platforms, in which career exposures will be multimission determined overt the astronaut's lifetime. In addition, the exploration beyond these near Earth operational platforms will include single missions of long duration to planets, asteroids, and planetary satellites. The interplanetary environment is evaluated using convective diffusion theory. Local induced environments for each celestial body are modeled by using results from recent targeted spacecraft studies, and integrated into the design environments. Design scenarios are then evaluated for these missions., The underlying assumptions in deriving the model environments and their impact on mission exposures with various shield materials will be discussed. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Wilson, JW (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM john.w.wilson@larc.nasa.gov NR 55 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 993 EP 1010 PG 18 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400125 ER PT S AU Hugger, CP Qualls, GD Wilson, JW Cuccinotta, FA Shavers, MR Zapp, N AF Hugger, CP Qualls, GD Wilson, JW Cuccinotta, FA Shavers, MR Zapp, N BE ElGenk, MS TI ISS as a platform for environmental model evaluation SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The International Space Station provides researchers with a unique opportunity to develop and test radiation environment models and computational procedures. Since having manned-missions into space is an ongoing part of NASA exploration of space, it has become necessary to conceive new methods to determine the safety of the astronauts in that environment. One of the major environmental hazards in space is the radiation an astronaut will be exposed to during their mission, NASA Langley Research Center, working in conjunction with Johnson Space Center, is developing a process that accurately simulates the radiation environment in the International Space Station. The environment includes the shielding provided by the ISS and the radiation environment surrounding the ISS. The radiation shielding is modeled using commercial CAD software. Ray-tracing software is used to calculate the shielding thicknesses for the model. A radiation environment is generated from data acquired from the NASA-GSFC National Space Science Data Center and transport codes for heavy ions and electrons. The radiation dose can then be calculated through combining the thickness files and the radiation environment. Various radiation dose experiments were and still are being performed on the International Space Station. Analysis of the radiation shielding environmental model. can be compared to data obtained from the ISS, enabling researchers to perfect their methods of predicting radiation environments and allowing them to create a tool that can be applied to future endeavors into space. C1 NASA Langley, Swales Aerosp, Hampton, VA 23681 USA. RP Hugger, CP (reprint author), NASA Langley, Swales Aerosp, Mail Stop 186A, Hampton, VA 23681 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 1011 EP 1017 PG 7 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400126 ER PT S AU Baird, RS Sanders, GB Simon, TM AF Baird, RS Sanders, GB Simon, TM BE ElGenk, MS TI ISRU development strategy and recent activities to support near and far term missions SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The practical: expansion of humans beyond low Earth orbit into. near-Earth. space and out into the solar system for exploration, commercialization, tourism, and colonization will require the effective utilization of whatever. indigenous resources are available to make these endeavors economically feasible-and capable of extended operations. This concept of, "living off the land" is called In-Situ Resource Utilization (ISRU). The, resources available for ISRU applications vary widely, depending upon the location. However, there are resources, technologies,. and processes that are common to multiple destinations and ISRU-related applications. These resources range from carbon dioxide (CO2) and water vapor found in human habitats. (surface,& spacecraft) and in the Martian atmosphere, to water (ice and hydrated minerals) and various oxygen, carbon, and metal-bearing resources found on comets and asteroids, and in planetary surface materials at numerous destinations of interest (Moon, Mars, Titan, and Europa). Many parties are-investigating the common technologies and processes to effectively extract and use these resources. This paper will discuss how ISRU is enabling for both near and far term human exploration missions, and present a summary of recent and on-going ISRU work sponsored by, the NASA/Johnson Space Center. Technology development activities that will be described in detail include an advanced CO2 freezer acquisition system, a multi-fluid common bulkhead cryogenic storage tank, and a variety of microchannel chemical reactor concepts. Recent advanced Sabatier reactor concept development activities in preparation for later, end-to-end system testing will be described as well. This paper will also discuss an ISRU-based strategy to enable extensive robotic and human surface exploration.,operations and a related on-going demonstration program for a fuel cell based power plant for rover applications. Technology, commonalities between ISRU, life support systems, and Extra Vehicular Activity (EVA),. applications will also be presented. C1 NASA, Lyndon B Johnson Space Ctr, Div Energy Syst, Houston, TX 77058 USA. RP Baird, RS (reprint author), NASA, Lyndon B Johnson Space Ctr, Div Energy Syst, Houston, TX 77058 USA. NR 4 TC 2 Z9 2 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 1087 EP 1094 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400135 ER PT S AU Lamassoure, ES Blair, BR Diaz, J Oderman, M Duke, MB Vaucher, M Manvi, R Easter, RW AF Lamassoure, ES Blair, BR Diaz, J Oderman, M Duke, MB Vaucher, M Manvi, R Easter, RW BE ElGenk, MS TI Evaluation of private sector roles in space resource development SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB An integrated engineering and financial modeling approach has been developed and used to evaluate the potential for private sector investment. in space resource development, and to assess possible roles of the public sector in fostering private interest. This paper presents the modeling approach and its results for a transportation service lising propellant extracted from lunar regolith. The analysis starts. with careful case study definition, including an analysis of the customer base and market requirements, which are, the basis' for design of a modular, scalable space architecture. The derived non-recurring, recurring and operations costs become inputs for a 'standard' financial model, as used in, any commercial business plan. This model generates pro forma financial statements, calculates the amount of capitalization required, and generates return on equity calculations using two valuation metrics of direct interest to private investors: market enterprise value and multiples of key financial measures. Use of this model on an architecture to sell transportation services in Earth orbit based on lunar propellants shows how to rapidly test various assumptions and identify interesting architectural options, key areas-for investment in exploration and technology; or innovative business approaches that could produce an economically viable industry. The same approach can be used to evaluate any other possible private ventures in space, and conclude on the respective roles. of NASA and the private sector in space resource development and solar system exploration. C1 Jet Prop Lab, Miss & Syst Architecture Sect, Pasadena, CA 91109 USA. RP Lamassoure, ES (reprint author), Jet Prop Lab, Miss & Syst Architecture Sect, Pasadena, CA 91109 USA. NR 9 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 1095 EP 1102 PG 8 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400136 ER PT S AU Baird, RS Sanders, G Simon, T McCurdy, K AF Baird, RS Sanders, G Simon, T McCurdy, K BE ElGenk, MS TI ISRU reactant, fuel cell based power plant for robotic and human mobile exploration applications SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Three basic power generation system concepts are generally considered for lander, rover, and Extra-Vehicular Activity (EVA) assistant applications for robotic and human Moon and Mars exploration missions. The most common-power system considered is the solar array and battery system. While relatively simple and successful, solar array/battery-systems have some serious limitations for mobile applications. For typical rover applications, these, limitations include relatively low total energy storage capabilities, daylight only operating times (6 to 8 hours on Mars), relatively short operating lives depending on the operating environment, and rover/lander size and surface use constraints. Radioisotope power systems are being reconsidered for long-range science missions. Unfortunately, the high cost, political controversy, and launch difficulties that are associated with nuclear-based power systems suggests that the use of radioisotope powered landers, rovers, and EVA assistants will be limited. The third power system concept now being considered are fuel cell based systems. Fuel cell power systems overcome many of the performance and surface exploration limitations of solar array/battery power systems and the prohibitive cost and other difficulties associated with nuclear power systems for mobile applications. In an effort to better understand the capabilities and limitations of fuel cell power systems for Moon-and Mars exploration applications, NASA,. is investigating the use of In-Situ Resource Utilization (ISRU) produced reactant, fuel cell based power plants to power robotic outpost rovers, science equipment, and, future, human Spacecraft, surface-excursion rovers, an d EVA assistant rovers. This paper will briefly compare the capabilities and limitations of fuel cell power systems relative to solar array/battery and nuclear systems, discuss-the unique and enhanced missions that fuel cell power systems enable, and discuss the common technology and system attributes possible for robotic and human exploration to maximize scientific return and minimize cost and risk to both. Progress made to. date at the Johnson Space Center on an ISRU producible reactant, Proton Exchange Membrane (PEM) fuel cell based power plant project for use in the first demonstration of this concept in conjunction with rover applications will be presented in detail. C1 NASA, Lyndon B Johnson Space Ctr, Div Energy Syst, Houston, TX 77062 USA. RP Baird, RS (reprint author), NASA, Lyndon B Johnson Space Ctr, Div Energy Syst, Houston, TX 77062 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 1157 EP 1162 PG 6 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400144 ER PT S AU Cassanova, RA Turner, RE Russell, PL AF Cassanova, RA Turner, RE Russell, PL BE ElGenk, MS TI Visions and possibilities for future exploration of space SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The NASA Institute for Advanced Concepts (NIAC) is sponsored by NASA Headquarters to inspire, solicit, select, fund and nurture revolutionary, advanced concepts for aeronautics-and space. NIAC has funded concepts that explore. the possibilities of significant breakthroughs and paradigm shifts applicable to the exploration of space. This paper summarizes NIAC-funded advanced concepts that directly relate to the colonization of planetary surfaces by humans and their agents. C1 NASA, Inst Adv Concepts, Atlanta, GA 30318 USA. RP Cassanova, RA (reprint author), NASA, Inst Adv Concepts, 555 14th St,NW,Suite A, Atlanta, GA 30318 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 1171 EP 1186 PG 16 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400146 ER PT S AU Landis, GA AF Landis, GA BE ElGenk, MS TI Colonization of Venus SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB Although the surface of Venus is an extremely hostile environment, at about 50 kilometers above the surface the atmosphere of Venus is the most earthlike environment (other than Earth itself) in the solar system. It is proposed here that in the near term, human exploration of Venus could take place from aerostat vehicles in the atmosphere, and that in, the long term, permanent settlements could be made in the form of cities designed to float at about fifty kilometer altitude in the atmosphere of Venus. C1 NASA, John Glenn Res Ctr, Cleveland, OH 44135 USA. RP Landis, GA (reprint author), NASA, John Glenn Res Ctr, Mailstop 302-1,21000 Brook Pk Rd, Cleveland, OH 44135 USA. NR 9 TC 3 Z9 3 U1 2 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 1193 EP 1198 PG 6 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400148 ER PT S AU Weinstein, LM AF Weinstein, LM BE ElGenk, MS TI Space colonization using space-elevators from phobos SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB A novel approach is examined for creating an industrial civilization beyond Earth. The approach would take advantage of the unique configuration of Mars and its moon. Phobos to make a transportation system capable of raising mass from the surface of Mars to space at a low cost. Mars would be used as the primary location for support personnel and infrastructure. Phobos would be used as a source of raw materials for space-based activity, and as an anchor for tethered carbon-nanotube-based space-elevators. One space-elevator would terminate at the upper edge of Mars' atmosphere. Small craft would be launched from Mars' surface to rendezvous With the moving elevator tip and their payloads detached and raised with solar powered loop elevators to Phobos. Another space-elevator would be extended outward from Phobos to launch craft toward the Earth/Moon system or the asteroid belt. The outward tip would also be used to catch arriving craft. This approach would allow Mars to be colonized, and allow transportation of people and supplies from Mars to support the space industry. In addition, large quantities of material obtained from Phobos could be used to construct space habitats and also supply propellant and material for space industry in the Earth/Moon system as well as around Mars. C1 NASA, Langley Res Ctr, Adv Measurement & Diagnost Branch, Hampton, VA 23681 USA. RP Weinstein, LM (reprint author), NASA, Langley Res Ctr, Adv Measurement & Diagnost Branch, Hampton, VA 23681 USA. NR 13 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 1227 EP 1235 PG 9 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400153 ER PT S AU Smitherman, DV AF Smitherman, DV BE ElGenk, MS TI Pathways to colonization SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM - STAIF 2003 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-2003) CY FEB 02-05, 2003 CL ALBUQUERQUE, NM SP US DOE, NASA, Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Inst Chem Engn, Amer Nucl Soc AB The steps required for space colonization are many to grow from our current 3-person International Space Station, now under construction, to an infrastructure that can support hundreds and eventually thousands of people in space. This paper will summarize the author's findings from numerous studies and workshops on related subjects and identify some of the critical next steps toward space colonization. Findings will be drawn from the author's previous work on space colony design, space infrastructure workshops, and various studies that addressed space policy. In conclusion, this paper will note that significant progress has been made on space facility construction through the International Space Station program, and that significant efforts are needed in the development of new reusable Earth to Orbit transportation systems. The next key steps will include reusable in space transportation systems supported by in space propellant depots, the continued development of inflatable habitat and space elevator technologies, and the resolution of policy issues that will establish a future vision for space development. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Smitherman, DV (reprint author), NASA, George C Marshall Space Flight Ctr, Mail Code FD02, Huntsville, AL 35812 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0114-4 J9 AIP CONF PROC PY 2003 VL 654 BP 1243 EP 1249 PG 7 WC Engineering, Aerospace; Thermodynamics; Energy & Fuels; Engineering, Electrical & Electronic SC Engineering; Thermodynamics; Energy & Fuels GA BW22Z UT WOS:000181267400155 ER PT S AU Pesnell, WD Goldberg, RA Chenette, DL Schulz, M Gaines, EE AF Pesnell, WD Goldberg, RA Chenette, DL Schulz, M Gaines, EE BE Onsager, TG FullerRowell, TJ Kamide, Y Shea, MA Thompson, R TI Evolution of relativistic electrons during a magnetic storm as seen in low-earth orbit SO SPACE WEATHER 2000 SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT PSW1/C0 1/D0 5/E2 5/F2 0 Symposium of the COSPAR Scientific Panel on Space Weather held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Amer Geophys Union, Int Space Environm Serv, Int Union Geodesy & Geophy, Int Assoc Geomagnetism & Aeron, Int Union Radio Sci, NOAA, Comm Space Res ID MIDDLE ATMOSPHERE; MESOSPHERIC OZONE; UARS AB Highly relativistic electron events (HREs) are periods of intense, long-lived, energetic electron fluxes in the outer radiation zone. We are using measurements from the High Energy Particle Spectrometer (HEPS) on the Upper Atmosphere Research Satellite (UARS) to develop a database of the pitch-angle and energy-resolved electron fluxes with energies between 30 keV and 5 MeV. The data acquired by HEPS have overlapped with the declining phase of solar cycle 22 making these data very important, since HREs are thought to peak in frequency and intensity during this phase of the solar cycle. We find a consistent scenario of electrons being injected into the radiation belts by a magnetic storm (deduced from Dst) and being slowly accelerated to ever higher energies over days to weeks. The energy dependence of the flux is an essential part of the analysis. Electrons with energies greater than 300 keV are the last to appear following an injection and also linger longer than electrons with lower energies. (C) 2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Nomad Res Inc, Arnold, MD 21012 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Lockheed Martin Adv Technol, Space Phys Dept, Palo Alto, CA 94304 USA. RP Pesnell, WD (reprint author), Nomad Res Inc, 795 Scarborough Court, Arnold, MD 21012 USA. RI Pesnell, William/D-1062-2012; Goldberg, Richard /E-1881-2012 OI Pesnell, William/0000-0002-8306-2500; NR 9 TC 0 Z9 0 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 4 BP 1059 EP 1062 DI 10.1016/S0273-1177(02)00788-3 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX17T UT WOS:000184540400037 ER PT S AU Tsurutani, BT Zhou, XY AF Tsurutani, BT Zhou, XY BE Onsager, TG FullerRowell, TJ Kamide, Y Shea, MA Thompson, R TI Interplanetary shock triggvering of substorms: Wind and polar SO SPACE WEATHER 2000 SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT PSW1/C0 1/D0 5/E2 5/F2 0 Symposium of the COSPAR Scientific Panel on Space Weather held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Amer Geophys Union, Int Space Environm Serv, Int Union Geodesy & Geophy, Int Assoc Geomagnetism & Aeron, Int Union Radio Sci, NOAA, Comm Space Res ID PLASMA SHEET; SOLAR-WIND; MAGNETOSPHERIC SUBSTORMS; RECONNECTION; DISRUPTION; DIVERSION; ONSET AB WIND solar wind data and POLAR UV imaging data are used to study magnetospheric responses to interplanetary shocks. It is found that the solar wind preconditions determine the different auroral responses. A similar to 1.5 hr "precondition" (upstream of the interplanetary shocks) gives good empirical results. If the upstream IMF B-z is strongly southward preceding interplanetary shocks, a substorm expansion phase results (44% of all events). If the IMF B-z is similar to 0, pseudobreakups occur. If B-z is northward, there is no obvious resultant nightside geomagnetic activity. (C) 2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tsurutani, BT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 18 TC 28 Z9 28 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 4 BP 1063 EP 1067 DI 10.1016/S0273-1177(02)00796-2 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX17T UT WOS:000184540400038 ER PT S AU Farrugia, CJ Gnavi, G Gratton, FT Oieroset, M Ogilvie, KW Lepping, RP Lin, RP AF Farrugia, CJ Gnavi, G Gratton, FT Oieroset, M Ogilvie, KW Lepping, RP Lin, RP BE Onsager, TG FullerRowell, TJ Kamide, Y Shea, MA Thompson, R TI Waves in the plasma depletion layer derived from three magnetosheath passes made by wind SO SPACE WEATHER 2000 SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT PSW1/C0 1/D0 5/E2 5/F2 0 Symposium of the COSPAR Scientific Panel on Space Weather held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Amer Geophys Union, Int Space Environm Serv, Int Union Geodesy & Geophy, Int Assoc Geomagnetism & Aeron, Int Union Radio Sci, NOAA, Comm Space Res ID ION-CYCLOTRON WAVES; SUBSOLAR MAGNETOSHEATH; DAYSIDE MAGNETOPAUSE; TERRESTRIAL; SPACECRAFT; PRESSURE AB We analyze theoretically wave activity in the plasma depletion layer (PDL) based on measurements made by the WIND spacecraft on 3 passes of the magnetosheath at low, southern magnetic latitudes and within 1 hour of noon. The passes occurred on November 30, December 12, and December 24, 1994. They were under moderate-to-low solar wind dynamic pressure, allowing a characterization of the near-subsolar PDL under typical solar wind conditions. Magnetic fluctuations transverse to the background field characteristic of electromagnetic ion cyclotron waves are present in all 3 PDLs and we illustrate this by the December 24, 1994 pass. We estimate numerically the electromagnetic ion cyclotron wave excitation, using measured parameters and supplementing these by average values for those other parameters which were not available. The activity increases as the magnetopause is approached, except for November 30. The interplay of the proton thermal anisotropy and the proton beta parallel to the magnetic field, quantities which are anticorrelated, may be used to explain the major similarities and differences of the theoretical results for the respective passes. These are the only 3 passes near the subsolar region for moderate-to-low dynamic pressure which have been examined to date, and the only ones made in this locale by Wind. (C) 2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ Buenos Aires, Fac Ciencias Exactas & Nat, CONICET, Inst Fis Plasma, RA-1428 Buenos Aires, DF, Argentina. Space Sci Labs, Berkeley, CA USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Farrugia, CJ (reprint author), Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 4 BP 1099 EP 1104 DI 10.1016/S0273-1177(02)00807-4 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX17T UT WOS:000184540400044 ER PT S AU Farrugia, CJ Gratton, FT Torbert, RB Bender, L Gnavi, G Ogilvie, KW Erkaev, NV Lepping, RP Stauning, P AF Farrugia, CJ Gratton, FT Torbert, RB Bender, L Gnavi, G Ogilvie, KW Erkaev, NV Lepping, RP Stauning, P BE Onsager, TG FullerRowell, TJ Kamide, Y Shea, MA Thompson, R TI On the dependence of dayside Kelvin-Helmholtz activity on IMF orientation SO SPACE WEATHER 2000 SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT PSW1/C0 1/D0 5/E2 5/F2 0 Symposium of the COSPAR Scientific Panel on Space Weather held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Amer Geophys Union, Int Space Environm Serv, Int Union Geodesy & Geophy, Int Assoc Geomagnetism & Aeron, Int Union Radio Sci, NOAA, Comm Space Res ID EARTHS MAGNETOPAUSE; MAGNETIC-FIELD; WAVES AB With its similar to12 h-long period of strongly northward magnetic field, the coronal mass ejection which passed Earth on April 11, 1997 affords an excellent opportunity of studying Kelvin-Helmholtz (KH) activity at the dayside magnetopause as a function of the clock angle, theta, of the interplanetary field (IMF). A correlation between the wavelength of the KH waves and theta may be expected on the basis of our recent model, where activity is generated in strips which broaden as theta decreases. We identify two 2-hour long intervals of small, but different, clock angles, and make a preliminary test of model predictions, using records from two ground magnetometer chains, both on the dayside. Taking into account the local time of the magnetometer arrays and the geometry of the KH-active strips, we show that the resonant stations measured considerably more spectral power density in the 3-4 mHz range during the phase with smaller theta. Moreover, as theta increases, the spectral power spectrum shifted to higher frequencies that were almost absent for smaller theta. (C) 2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ Buenos Aires, Fac Ciencias Exactas & Nat, CONICET, Inst Fis Plasma, RA-1428 Buenos Aires, DF, Argentina. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Russian Acad Sci, Inst Computat Modeling, Krasnoyarsk 660036, Russia. Danish Meteorol Inst, Copenhagen, Denmark. RP Farrugia, CJ (reprint author), Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. RI Erkaev, Nikolai/M-1608-2013 OI Erkaev, Nikolai/0000-0001-8993-6400 NR 16 TC 9 Z9 9 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES PY 2003 VL 31 IS 4 BP 1105 EP 1110 DI 10.1016/S0273-1177(02)00889-X PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX17T UT WOS:000184540400045 ER PT S AU Farrugia, CJ Burlaga, LF Jordanova, VK Freeman, MP Lawrence, G Matsui, H Cocheci, CC Arnoldy, RL Scudder, JD Ogilvie, KW Lepping, RP AF Farrugia, CJ Burlaga, LF Jordanova, VK Freeman, MP Lawrence, G Matsui, H Cocheci, CC Arnoldy, RL Scudder, JD Ogilvie, KW Lepping, RP BE Onsager, TG FullerRowell, TJ Kamide, Y Shea, MA Thompson, R TI Power to the magnetosphere: May 4, 1998 SO SPACE WEATHER 2000 SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT PSW1/C0 1/D0 5/E2 5/F2 0 Symposium of the COSPAR Scientific Panel on Space Weather held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Amer Geophys Union, Int Space Environm Serv, Int Union Geodesy & Geophy, Int Assoc Geomagnetism & Aeron, Int Union Radio Sci, NOAA, Comm Space Res ID MAGNETIC CLOUD; GEOMAGNETIC STORMS AB An extraordinary powering of the magnetosphere by the solar wind occurred in a 3-hour burst early on May 4 when the IMF was very intense and pointed south (similar to-35 nT; "erosion phase"). Examining solar wind streams over 3 months, we found that May 4 represented a very fast, hot, non-corotating stream overtaking an interplanetary coronal mass ejection (ICME), thus forming a compound stream. By integrating the ''epsilon" parameter over time, we find that the energy deposited in the magnetosphere during the erosion phase on May 4 (of order 7.5 J m(-2)) was higher to that deposited during the previous 3-day period, itself a very geoeffective interval. We compare the energy and power supply to the magnetosphere on May 4 with 13 other events, mainly ICMEs and magnetic clouds, during the period 1995-2000. Specifically, we examine (a) the total energy input over 3 days, and (b) the average power over a 3-hour period near maximum power of the respective configurations. As regards (a), we find the energy of the May 4 stream to be comparable to that of the strong events observed during the 6-year period. As regards (b), we find May 4 to represent a large fluctuation from the norm, exceeded only by the Bastille Day event (July 15, 2000). The ability to predict a concentration of electromagnetic power and energy such as that in the May 4 fast stream poses a challenge to our ability to predict space weather. (C) 2003 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. British Antarctic Survey, Cambridge CB3 0ET, England. Univ Birmingham, Dept Astrophys & Space Res, Birmingham B15 2TT, W Midlands, England. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. RP Farrugia, CJ (reprint author), Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. RI Scudder, Jack/D-8417-2013 OI Scudder, Jack/0000-0001-7975-5630 NR 11 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2003 VL 31 IS 4 BP 1117 EP 1122 DI 10.1016/S0273-1177(02)00891-8 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BX17T UT WOS:000184540400047 ER PT S AU Naasz, BJ Berry, MM Kim, HY Hall, CD AF Naasz, BJ Berry, MM Kim, HY Hall, CD BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Integrated orbit and attitude control for a nanosatellite with power constraints SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB Small satellites tend to be power-limited, so that actuators used to control the orbit and attitude must compete with each other as well as with other subsystems for limited electrical power. The Virginia Tech nanosatellite project, HokieSat, must use its limited power resources to operate pulsed-plasma thrusters for orbit control and magnetic torque coils for attitude control, while also providing power to a GPS receiver, a crosslink transceiver, and other subsystems. The orbit and attitude control strategies were developed independently. The attitude control system is based on an application of LQR to an averaged system of equations, whereas the orbit control is based on orbit element feedback. In this paper we describe the strategy for integrating these two control systems and present simulation results to verify the strategy. C1 NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 USA. RP Naasz, BJ (reprint author), NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Code 572, Greenbelt, MD 20771 USA. NR 19 TC 3 Z9 3 U1 0 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 9 EP 25 PN 1-3 PG 17 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100003 ER PT S AU Roithmayr, CM Karlgaard, CD Kumar, RR Bose, DM AF Roithmayr, CM Karlgaard, CD Kumar, RR Bose, DM BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Integrated power and attitude control for a spacecraft with flywheels and control moment gyroscopes SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm ID TRACKING AB A law is designed for simultaneous control of the orientation of an Earth-pointing spacecraft, the energy stored by counter-rotating flywheels, and the angular momentum of the flywheels and control moment gyroscopes used together as an integrated set of actuators for attitude control. General, nonlinear equations of motion are presented in vector-dyadic form, and used to obtain approximate expressions which are then linearized in preparation for design of control laws that include feedback of flywheel kinetic energy error as a means of compensating for damping exerted by rotor bearings. Two flywheel "steering laws" are developed such that torque commanded by an attitude control law is applied while energy is stored or discharged at the required rate. Using the International Space Station as an example, numerical simulations are performed to demonstrate control about a torque equilibrium attitude, and illustrate the benefits of kinetic energy error feedback. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Roithmayr, CM (reprint author), NASA, Langley Res Ctr, Mail Stop 328, Hampton, VA 23681 USA. NR 21 TC 0 Z9 0 U1 0 U2 2 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 385 EP 406 PN 1-3 PG 22 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100025 ER PT S AU Miller, JK AF Miller, JK BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Lunar transfer trajectory design and the four-body problem SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB The existence of a ballistic trajectory from the Earth to orbit about the Moon was long considered to be impossible based on analysis of the three-body problem. In 1990 a ballistic trajectory from the Earth to lunar orbit was discovered while analyzing a plan to salvage the Muses A (Hiten) spacecraft. This trajectory utilized the Sun's gravity in conjunction with the Earth's and Moon's gravity and was thus the first example of a practical four-body trajectory design. This paper presents a review of lunar transfer trajectories that go beyond three-body theory and the Jacobi integral. These include Hiten, Lunar A and the Genesis return trajectory from the vicinity of the Moon to Earth. It is shown that these trajectories may be analyzed by piecing together segments where three-body motion dominates. C1 CALTECH, Jet Prop Lab, Navigat Syst Sect, Pasadena, CA 91109 USA. RP Miller, JK (reprint author), CALTECH, Jet Prop Lab, Navigat Syst Sect, 4800 Oak Grove Dr,MS 301-125, Pasadena, CA 91109 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 685 EP 695 PN 1-3 PG 11 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100042 ER PT S AU Quadrelli, MB AF Quadrelli, MB BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Modeling and analysis for nutation time constant determination of on-axis diaphragm tanks on spinners: Application to the deep space one spacecraft SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB This paper describes the modeling, analysis, and testing done to determine the DS1 nutation time constant. The significance of this analysis and testing program is that Deep Space One was the first spacecraft flown by JPL with a diaphragm tank located on the spin axis. First, modeling considerations are made, and in order to simulate the nonlinear behavior of the spacecraft containing the liquid (Hydrazine), the dynamics of a rigid body coupled through a universal joint to a pendulum mass representing the liquid slosh has been analyzed. This nonlinear simulation is done in order to estimate the nutation time constant with a pendulum slosh model. Second, some considerations follow on the modeling of tanks with diaphragms in spinner tanks. Third, the actual spin drop tests are described. These tests also confirm a nutation time constant in excess of 1000 seconds, both in the case of tests done for the Xenon tank only and in the case of tests done for the Hydrazine tank only. The large value of the nutation time constant computed and verified by testing for this system ensured that it remained well above the required values of 150 seconds at ignition, and 50 seconds at burnout. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Quadrelli, MB (reprint author), CALTECH, Jet Prop Lab, Mail Stop 198-326,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 24 TC 0 Z9 0 U1 0 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 835 EP 854 PN 1-3 PG 20 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100051 ER PT S AU Mettler, E Quadrelli, MB AF Mettler, E Quadrelli, MB BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Modeling of MARSIS segmented booms and prediction of in-flight dynamics of the mars express spacecraft SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB In this paper we provide an independent modeling and dynamic analysis of the MARSIS Antenna segmented booms deployed on the Mars Express Spacecraft. The Mars Express Mission is a joint NASA/ESA Cooperative project. The Mars Express Spacecraft being built by ESA will be launched in June 2003 and arrive at Mars in December 2003 to begin a four year study of the planet's atmosphere, surface, and subsurface. The Mars Advanced Radar for Subsurface and Ionospheric Mapping (MARSIS), provided by NASA and managed by JPL, is a key instrument in the search for water on Mars. Our objective was to determine the antenna's dynamic interaction with the spacecraft bus (or central rigid body). Static and modal analyses make use of boom material parameters, mass properties, and laboratory test results provided by TRW Astro Aerospace, Goleta, California, in addition to data on spacecraft mass properties and orbital parameters from Astrium, Toulouse, France. Solutions are derived involving coupled equations of motion for vehicle orbital mechanics, rigid body spacecraft bus, and flexible-appendages dynamics. Numerical simulations were performed of a "flying model" of the spacecraft in the perigee phase of its elliptical Mars orbit, with all MARSIS booms fully deployed and Reaction Wheels used to both disturb and control the spacecraft attitude. The spacecraft's Reaction Wheel model and Attitude Controller were designed by the authors and is not optimized nor based on any specific information provided by Astrium. Realistic excitations of the bus and boom appendages were imposed by short reaction wheel torque-time profiles that were constructed to maximize excitation of the system fundamental vibration mode. To clearly identify only the MARSIS interaction with the bus, the solar panels were modeled as rigid elements, and the attitude sensors and reaction wheels were assumed to be free from noise and other errors. The simulation results verify the Antenna system modeling fidelity and provide data on proximate "worst case" dynamic interactions between the flexible booms and the spacecraft bus that demonstrate the MARSIS dynamic compatibility with the spacecraft. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mettler, E (reprint author), CALTECH, Jet Prop Lab, Mail Stop 198-138, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 0 U1 1 U2 3 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 855 EP 871 PN 1-3 PG 17 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100052 ER PT S AU Raiszadeh, B AF Raiszadeh, B BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Mutibody parachute flight simulations for planetary entry trajectories using "equilibrium points" SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB A method has been developed to reduce numerical stiffness and computer CPU requirements of high fidelity multibody flight simulations involving parachutes for planetary entry trajectories. Typical parachute entry configurations consist of entry bodies suspended from a parachute, connected by flexible lines. To accurately calculate line forces and moments, the simulations need to keep track of the point where the flexible lines meet (confluence point). In previous multibody parachute flight simulations, the confluence point has been modeled as a point mass. Using a point mass for the confluence point tends to make the simulation numerically stiff, because its mass is typically much less that than the main rigid body masses. One solution for stiff differential equations is to use a very small integration time step. However, this results in large computer CPU requirements. In the method described in the paper, the need for using a mass as the confluence point has been eliminated. Instead, the confluence point is modeled using an "equilibrium point". This point is calculated at every integration step as the point at which sum of all line forces is zero (static equilibrium). The use of this "equilibrium point" has the advantage of both reducing the numerical stiffness of the simulations, and eliminating the dynamical equations associated with vibration of a lumped mass on a high-tension string. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Raiszadeh, B (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 5 TC 0 Z9 1 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 913 EP 923 PN 1-3 PG 11 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100055 ER PT S AU Noreen, G Kerridge, S Diehl, R Neelon, J Ely, T Turner, AE AF Noreen, G Kerridge, S Diehl, R Neelon, J Ely, T Turner, AE BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Daily repeat-groundtrack mars orbits SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB This paper derives orbits at Mars with groundtracks that repeat at the same times every solar day (sol). A relay orbiter in such an orbit would pass over in-situ probes at the same times every sol, ensuring consistent coverage and simplifying mission design and operations. 42 orbits in five classes are characterized: 14 circular equatorial prograde orbits 14 circular equatorial retrograde orbits 11 circular sun synchronous orbits 2 eccentric equatorial orbits 1 eccentric critically inclined orbit The paper reports on the performance of a relay orbiter in some of these orbits. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Noreen, G (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 1143 EP 1155 PN 1-3 PG 13 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100069 ER PT S AU Roundhill, I Roth, D AF Roundhill, I Roth, D BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Satellite ephemerides update schedule for the Cassini mission SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB The Cassini mission will arrive at Saturn in July 2004 to explore the Saturnian system. The navigation team will update the ephemerides of 9 satellites to improve spacecraft navigation and provide information on satellite location for pointing of the spacecraft. This paper outlines the approach used to predict pointing uncertainty when pointing information is generated with a spacecraft prediction and older satellite ephemerides. This modeling is then used to choose times when the satellite ephemerides need to be updated to meet requirements. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Roundhill, I (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 1391 EP 1406 PN 1-3 PG 16 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100083 ER PT S AU Wilson, RS Williams, KE AF Wilson, RS Williams, KE BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Genesis trajectory and maneuver design strategies during early flight SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB As the fifth Discovery mission, the Genesis spacecraft was launched on August 8, 2001 with a science objective to collect solar wind samples for a period of approximately two and a half years while in orbit in the vicinity of the Sun-Earth L-1 libration point. These samples will eventually be delivered back to the Earth for analysis, posing a formidable challenge in terms of both mission design and navigation. This paper discusses trajectory and maneuver design strategies employed during the early phases of flight to accommodate spacecraft and instrument design constraints, while achieving the science objectives of the mission. Topics to be discussed include: mission overview, spacecraft design and constraints, maneuver analyses and trajectory re-optimization studies, and operational flight experience to date. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wilson, RS (reprint author), CALTECH, Jet Prop Lab, MS 301-140L,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 22 TC 2 Z9 2 U1 0 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 1439 EP 1456 PN 1-3 PG 18 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100086 ER PT S AU Truong, SH Cuevas, OO Slojkowski, S AF Truong, SH Cuevas, OO Slojkowski, S BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Orbit determination support for the Microwave Anisotropy Probe (MAP) SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB NASA's Microwave Anisotropy Probe (MAP) was launched from the Cape Canaveral Air Force Station Complex 17 aboard a Delta II 7425-10 expendable launch vehicle on June 30, 2001. The spacecraft received a nominal direct insertion by the Delta expendable launch vehicle into a 185-km circular orbit with a 28.7degrees inclination. MAP was then maneuvered into a sequence of phasing loops designed to set up a lunar swingby (gravity-assisted acceleration) of the spacecraft onto a transfer trajectory to a lissajous orbit about the Earth-Sun L2 Lagrange point, about 1.5 million km from Earth. Because of its complex orbital characteristics, the mission provided a unique challenge for orbit determination (OD) support in many orbital regimes. This paper summarizes the premission trajectory covariance error analysis, as well as actual OD results. The use and impact of the various tracking stations, systems, and measurements will be also discussed. Important lessons learned from the MAP OD support team will be presented. There will be a discussion of the challenges presented to OD support including the effects of delta-Vs at apogee as well as perigee, and the impact of the spacecraft attitude mode on the OD accuracy and covariance analysis. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Truong, SH (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 1457 EP 1471 PN 1-3 PG 15 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100087 ER PT S AU Boain, RJ AF Boain, RJ BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI The CloudSat mission: A virtual platform SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB CloudSat's Science Team decided from the beginning to capitalize on the synergy between CALIPSO's lidar measurements, Aquas MODIS measurements, and observations made by CloudSat's Cloud Profiling Radar in making the most comprehensive studies possible of clouds and their impact on climatological forecasting. The Science Team requested that CloudSat's mission design accommodate requirements on simultaneity and coincidence of measurements to form, in effect, a "virtual platform" of three satellites. This paper describes the mission design for CloudSat that enables and creates this virtual platform. It describes CloudSat's formations with CALIPSO separated by only 15-seconds and its formation with Aqua separated by no more than 90 seconds, and on average by about 61 seconds. It further describes how CloudSat will be controlled to ensure maintenance of the formations per the science requirements. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Boain, RJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 2121 EP 2138 PN 1-3 PG 18 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100125 ER PT S AU Burkhart, PD AF Burkhart, PD BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Approach navigation for the 2009 Mars large lander SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB The current Mars exploration plan envisions the launch of a large lander in the 2009 launch opportunity with a soft landing on Mars in the fall of 2010. The goal is to achieve a landed surface position within 10km of the target landing site. Current entry descent and landing (EDL) analysis shows that the largest contributor to the landed position error is uncertainty of the initial conditions, which are supplied by the ground-based navigation process. The focus of this paper is the performance of the approach navigation process using combinations of Deep Space Network (DSN) Doppler, ranging and delta differential one-way range (DeltaDOR) measurements along with optical navigation data collected by the spacecraft. Results for several combinations of data types will be included. C1 CALTECH, Jet Prop Lab, Navigat & Mission Design Sect, Pasadena, CA 91109 USA. RP Burkhart, PD (reprint author), CALTECH, Jet Prop Lab, Navigat & Mission Design Sect, 4800 Oak Grove Dr,MS 301-125L, Pasadena, CA 91109 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 2183 EP 2197 PN 1-3 PG 15 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100128 ER PT S AU Kennedy, BM Bhaskaran, SK Riedel, JE Wang, M AF Kennedy, BM Bhaskaran, SK Riedel, JE Wang, M BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI Radiometric orbit determination activities in support of navigating deep space 1 to comet Borrelly SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm ID DEEP-SPACE-1 EXTENDED MISSION AB Four months after its encounter with the asteroid Braille, Deep Space I lost the use of its only star tracker. After several months of planning, development and testing, new software was uploaded that allowed the spacecraft to restore celestial inertial reference and begin thrusting towards an encounter with comet Borrelly. The new mission plan would have to work within the constraints of the new software as well as minimize use of the dwindling supply of hydrazine, the fuel needed to maintain the spacecraft attitude. In the spring and summer of 2001, as it approached comet Borrelly, the spacecraft lost its celestial reference several times. As the mission plan required nearly continuous low-thrust, the resulting attitude drifts caused the spacecraft to push itself off course. Difficulty in restoring attitude information had a further impact on the spacecraft trajectory. Modeling these attitude drifts before and during attitude recovery periods was necessary in order to determine the new orbit. This allowed for the timely redevelopment of upcoming mission bums that put the spacecraft back on course for its encounter. Once back on course, an approach targeting strategy using only IPS TCMs enabled the spacecraft to start the encounter with Borrelly with high expectations of success. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kennedy, BM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 301-125J, Pasadena, CA 91109 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 2217 EP 2235 PN 1-3 PG 19 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100130 ER PT S AU Miller, JK Turyshev, SG AF Miller, JK Turyshev, SG BE Scheeres, DJ Pittelkau, ME Proulx, RJ Cangahuala, LA TI The trajectory of a photon: General relativity light time delay SO SPACEFLIGHT MECHANICS 2003, PTS 1-3 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 13th Annual Space Flight Mechanics Meeting CY FEB 09-13, 2003 CL PONCE, PR SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc Space Flight Mech Tech Comm, AIAA Astrodynam Tech Comm AB The transit time of a photon or electromagnetic wave between two points in space is a measurement that is used to determine the orbits of the planets and spacecraft for the purposes of navigation and science. Both the navigation of a spacecraft and science experiments, particularly associated with General Relativity, require precise measurements of the transit time. Since the Deep Space tracking stations can measure times to within 0.1 ns or about 3 cm, it is necessary to model the transit time to this accuracy. In this paper, a formula is developed for the total one-way transit time of a photon in the coordinate time of General Relativity. A bending term is identified that contributes about 10 ns to the transit time of a photon that grazes the Sun and is not generally included in other formula in the literature. The results are verified by performing numerical integration of the equations of motion for a photon. A numerical photon ephemeris is computed and compared with the analytic formula. C1 CALTECH, Jet Prop Lab, Navigat Syst Sect, Pasadena, CA 91109 USA. RP Miller, JK (reprint author), CALTECH, Jet Prop Lab, Navigat Syst Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 J9 ADV ASTRONAUT SCI PY 2003 VL 114 BP 2245 EP 2255 PN 1-3 PG 11 WC Automation & Control Systems; Engineering, Aerospace; Mechanics SC Automation & Control Systems; Engineering; Mechanics GA BX92J UT WOS:000186831100132 ER PT S AU Owe, M De Jeu, RAM AF Owe, M De Jeu, RAM BE Singhroy, V Hansen, DT Pierce, RR Johnson, AI TI The need for regular remote sensing observations of global soil moisture SO SPATIAL METHODS FOR SOLUTION OF ENVIRONMENTAL AND HYDROLOGIC PROBLEMS-SCIENCE, POLICY, AND STANDARDIZATION SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Spatial Methods for the Solution of Environmental and Hydrologic Problems CY JAN 25, 2001 CL RENO, NV DE soil moisture; global climate change; remote sensing; microwave ID VEGETATION OPTICAL DEPTH; MICROWAVE EMISSION; WATER-CONTENT; MODEL; SCATTERING; CANOPIES; BEHAVIOR; GHZ AB Soil moisture is an important component of the water and energy balance of the Earth's surface, and as such, is essential to many Earth science disciplines-Regular and accurate estimates of soil moisture are an important input to the study, of climate change, numerical weather, prediction models, drought forecasts, and agricultural predictions. Soil moisture has been identified as a parameter of significant potential for improving the accuracy of large-scale land surface-atmosphere interaction models. However, accurate estimates of surface soil, moisture are often difficult to make, especially at large spatial scales. Soil moisture is a highly variable land surface parameter, and while point measurements are usually accurate, they are typically representative only of the immediate sample location, and simple averaging of point values, in order to obtain large-area spatial means, often leads to substantial errors. In addition, ground sampling is labor intensive and costly, and consequently highly impractical for long-term and/or, large-scale monitoring. Since satellite remote sensing observations are already, a spatially averaged value, they are ideally suited for measuring land surface parameters such as soil moisture. Passive microwave remote sensing presents the greatest potential for providing regular spatially representative estimates of surface soil moisture at global scales. But, while the optimum wavelength such a sensor has yet for soil moisture sensing is in the L-band (1.4 GHz or lambda = 21 cm) to be deployed operationally. However, new and highly improved microwave retrieval techniques are being developed that maximize the information that c an be obtained from less optimum sensors, such as C-band and even X-band. Progress from one such study is presented, along with preliminary results of some validation studies and plans to develop a 20-year retrospective global database of surface soil moisture. This data product will be made available to the general public through the Goddard Space Flight Center Distributed Active Archive Center (DAAC). Improved real-time estimates of surface soil moisture should greatly improve the performance of real-time models, while the development of historical data sets will provide necessary information for simulation and validation of long-term climate and global change studies. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Owe, M (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Code 661, Greenbelt, MD 20771 USA. NR 30 TC 0 Z9 0 U1 0 U2 3 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-3455-X J9 AM SOC TEST MATER PY 2003 VL 1420 BP 92 EP 106 DI 10.1520/STP10916S PG 15 WC Computer Science, Interdisciplinary Applications; Environmental Sciences; Geography, Physical; Remote Sensing; Water Resources SC Computer Science; Environmental Sciences & Ecology; Physical Geography; Remote Sensing; Water Resources GA BW30Q UT WOS:000181492100007 ER PT S AU Leviton, DB Frey, BJ AF Leviton, DB Frey, BJ BE AtadEttedgui, E DOdorico, S TI Design of a cryogenic, high accuracy, absolute prism refractometer for infrared through far ultraviolet optical materials SO SPECIALIZED OPTICAL DEVELOPMENTS IN ASTRONOMY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Specialized Optical Developments in Astronomy CY AUG 25-26, 2002 CL WAIKOLOA, HI SP SPIE DE cryogenic; refractometer; infrared; optical properties; refractive index; optical encoder; air bearing; deviation AB The next generation of cryogenic, infrared (IR), space optical instrumentation (for NGST and other missions) will require a knowledge of refractive indices for constituent optical materials to a level of accuracy which is not currently attainable. The rationale for and design of a broadband, absolute, prism reftactometer for measuring refractive index at cryogenic temperatures to very high absolute accuracy is discussed. The refractometer design also permits similar measurements through the far ultraviolet where accurate refractive index data are scarce for most UV optical materials. The technical challenges in achieving high accuracy in these wavelength regions and at extremely cold temperatures are presented, along with novel solutions under development to meet those challenges. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Leviton, DB (reprint author), NASA, Goddard Space Flight Ctr, Code 551, Greenbelt, MD 20771 USA. NR 9 TC 8 Z9 8 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4621-1 J9 P SOC PHOTO-OPT INS PY 2003 VL 4842 BP 259 EP 269 DI 10.1117/12.459479 PG 11 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BW38Z UT WOS:000181846900026 ER PT S AU Raouf, NA Trauger, JT AF Raouf, NA Trauger, JT BE AtadEttedgui, E DOdorico, S TI Characterization of UV-visible filters for the wide field camera 3 of the Hubble Space Telescope SO SPECIALIZED OPTICAL DEVELOPMENTS IN ASTRONOMY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Specialized Optical Developments in Astronomy CY AUG 25-26, 2002 CL WAIKOLOA, HI SP SPIE DE WFC3; HST; UVIS filters; filter characterization AB A set of 48 ultraviolet-visible filters in the Wide Field Camera 3 will be deployed on the Hubble Space Telescope in 2004. We summarize the specifications for the filters, derived through interaction with the Science Oversight Committee. A detailed characterization of the 48 filters is presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Raouf, NA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4621-1 J9 P SOC PHOTO-OPT INS PY 2003 VL 4842 BP 301 EP 318 DI 10.1117/12.458102 PG 18 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BW38Z UT WOS:000181846900031 ER PT B AU Barnes, JC Barnes, NP Koch, G Edwards, WC Yu, J Petway, LP AF Barnes, JC Barnes, NP Koch, G Edwards, WC Yu, J Petway, LP BE DiBartolo, B TI NASA DIAL/lidar laser technology development program SO SPECTROSCOPY OF SYSTEMS WITH SPATIALLY CONFINED STRUCTURES SE NATO SCIENCE SERIES, SERIES II: MATHEMATICS, PHYSICS AND CHEMISTRY LA English DT Proceedings Paper CT Conference of the NATO-Advanced-Study-Institute on Spectroscopy of Systems with Spatially Confined Structures CY JUN 15-30, 2001 CL ERICE, ITALY SP NATO, Adv Study Inst, Int Sch Atom & Mol Spect Ettore Majorana, NASA, ENEA Org, Boston Coll, Italian Minist Univ & Sci Res & Technol, Natl Sci Fdn, Sicilian Reg Gov ID TM-YLF LASER AB This paper gives an overview of the Laser Systems Branch solid-state laser technology development program. Emphasis is placed on the unique advanced laser developments needed to meet measurement requirements for important future NASA remote sensing missions. C1 NASA, Langley Res Ctr, Laser Syst Branch, Hampton, VA 23681 USA. RP Barnes, JC (reprint author), NASA, Langley Res Ctr, Laser Syst Branch, Mail Stop 474, Hampton, VA 23681 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-1103-2 J9 NATO SCI SER II MATH PY 2003 VL 90 BP 653 EP 664 PG 12 WC Optics; Physics, Condensed Matter; Physics, Particles & Fields; Spectroscopy SC Optics; Physics; Spectroscopy GA BW96N UT WOS:000183787700020 ER PT B AU Bredekamp, JH Golombek, DA AF Bredekamp, JH Golombek, DA BE Feigelson, ED Babu, GJ TI NASA's astrophysics data environment SO STATISTICAL CHALLENGES IN ASTRONOMY LA English DT Proceedings Paper CT 3rd Statistical Challenges in Modern Astronomy Conference (SCMA III) CY JUL 18-21, 2001 CL PENN STATE UNIV, UNIVERSITY PK, PA SP Natl Sci Fdn, Div Math Sci, Natl Aeronaut & Space Adm, Appl Informat Syst Res Program HO PENN STATE UNIV AB NASA has a comprehensive space science data management program to assure that science data assets acquired from space missions are expediently available and utilized by scientists, educators, and the general public. This paper will discuss the guiding principles and approach for space science data archives, and describe the current landscape of astronomical data centers and services. It will conclude with prospects and opportunities to mine and exploit the emerging collective "digital sky" in all wavelengths for new scientific discoveries. C1 NASA, Off Space Sci, Washington, DC 20546 USA. RP Bredekamp, JH (reprint author), NASA, Off Space Sci, 300 E St SW, Washington, DC 20546 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 0-387-95546-1 PY 2003 BP 103 EP 112 DI 10.1007/0-387-21529-8_7 PG 10 WC Astronomy & Astrophysics; Statistics & Probability SC Astronomy & Astrophysics; Mathematics GA BW17K UT WOS:000181073200007 ER PT B AU Scargle, JD AF Scargle, JD BE Feigelson, ED Babu, GJ TI Advanced tools for astronomical time series and image analysis SO STATISTICAL CHALLENGES IN ASTRONOMY LA English DT Proceedings Paper CT 3rd Statistical Challenges in Modern Astronomy Conference (SCMA III) CY JUL 18-21, 2001 CL PENN STATE UNIV, UNIVERSITY PK, PA SP Natl Sci Fdn, Div Math Sci, Natl Aeronaut & Space Adm, Appl Informat Syst Res Program HO PENN STATE UNIV ID UNEVENLY SPACED DATA AB The algorithms described here, which I have developed for applications in X-ray and gamma-ray astronomy, will hopefully be of use in other ways, perhaps aiding in the exploration of modern astronomy's data cornucopia. The goal is to describe principled approaches to some ubiquitous problems, such as detection and characterization of periodic and aperiodic signals, estimation of time delays between multiple time series, and source detection in noisy images with noisy backgrounds. The latter problem is related to detection of clusters in data spaces of various dimensions. A goal of this work is to achieve a unifying view of several related topics: signal detection and characterization, cluster identification, classification, density estimation, and multivariate regression. In addition to being useful for analysis of data from space-based and ground-based missions, these algorithms may be a basis for a future automatic science discovery facility, and in turn provide analysis tools for the Virtual Observatory. This chapter has ties to those by Larry Bretthorst, Tom Loredo, Alanna Connors, Fionn Murtagh, Jim Berger, David van Dyk, Vicent Martinez & Enn Saar. The paper is followed by commentaries by Thomas J. Loredo and Peter E. Freeman. "The unconscious goal of the scientific philosopher is the automation of science." Irving John Good, The Estimation of Probabilities, 1965 "Automate or die." Silicon Valley Billboard, June, 2001. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Scargle, JD (reprint author), NASA, Ames Res Ctr, Mail Stop 245-3, Moffett Field, CA 94035 USA. NR 22 TC 4 Z9 4 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 0-387-95546-1 PY 2003 BP 293 EP 308 DI 10.1007/0-387-21529-8_20 PG 16 WC Astronomy & Astrophysics; Statistics & Probability SC Astronomy & Astrophysics; Mathematics GA BW17K UT WOS:000181073200020 ER PT B AU Phillips, NG Kogut, A AF Phillips, NG Kogut, A BE Feigelson, ED Babu, GJ TI Parameter estimation via neural networks SO STATISTICAL CHALLENGES IN ASTRONOMY LA English DT Proceedings Paper CT 3rd Statistical Challenges in Modern Astronomy Conference (SCMA III) CY JUL 18-21, 2001 CL PENN STATE UNIV, UNIVERSITY PK, PA SP Natl Sci Fdn, Div Math Sci, Natl Aeronaut & Space Adm, Appl Informat Syst Res Program HO PENN STATE UNIV AB We use neural networks for astrophysical parameter estimation in the context of models of the cosmic microwave background (CMB). Our method allows for a Bayesian analysis and recovers results comparable to standard maximum likelihood methods when tested on simulated CMB anisotropy maps. We find the computational cost for this method scales with the map size as N-CPU similar to N-pix(1.5). C1 NASA, Goddard Space Flight Ctr, RITSS, Greenbelt, MD 20771 USA. RP Phillips, NG (reprint author), NASA, Goddard Space Flight Ctr, RITSS, Code 685, Greenbelt, MD 20771 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 0-387-95546-1 PY 2003 BP 471 EP 473 DI 10.1007/0-387-21529-8_56 PG 3 WC Astronomy & Astrophysics; Statistics & Probability SC Astronomy & Astrophysics; Mathematics GA BW17K UT WOS:000181073200056 ER PT B AU Young, CA Connors, A Kolaczyk, E McConnell, M Rank, G Ryan, JM Schoenfelder, V AF Young, CA Connors, A Kolaczyk, E McConnell, M Rank, G Ryan, JM Schoenfelder, V BE Feigelson, ED Babu, GJ TI Bayesian multiscale deconvolution applied to gamma-ray spectroscopy SO STATISTICAL CHALLENGES IN ASTRONOMY LA English DT Proceedings Paper CT 3rd Statistical Challenges in Modern Astronomy Conference (SCMA III) CY JUL 18-21, 2001 CL PENN STATE UNIV, UNIVERSITY PK, PA SP Natl Sci Fdn, Div Math Sci, Natl Aeronaut & Space Adm, Appl Informat Syst Res Program HO PENN STATE UNIV AB A common task in gamma-ray astronomy is to extract spectral information, such as model constraints and incident photon spectrum estimates, given the measured energy deposited in a detector and the detector response. This is the classic problem of spectral "deconvolution" or spectral inversion [2]. The methods of forward folding (i.e. parameter fitting) and maximum entropy "deconvolution" (i.e. estimating independent input photon rates for each individual energy bin) have been used successfully for gamma-ray solar flares (e.g. [5]). Nowak and Kolaczyk [4] have developed a fast, robust, technique using a Bayesian multiscale framework that addresses many problems with added algorithmic advantages. We briefly mention this new approach and demonstrate its use with time resolved solar flare gamma-ray spectroscopy. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Young, CA (reprint author), NASA, Goddard Space Flight Ctr, Code 682-3, Greenbelt, MD 20771 USA. NR 5 TC 0 Z9 0 U1 1 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 0-387-95546-1 PY 2003 BP 503 EP 504 DI 10.1007/0-387-21529-8_67 PG 2 WC Astronomy & Astrophysics; Statistics & Probability SC Astronomy & Astrophysics; Mathematics GA BW17K UT WOS:000181073200067 ER PT B AU Rubinstein, R He, GW AF Rubinstein, R He, GW BE Kaneda, Y Gotoh, T TI The Eulerian time correlation function in homogeneous isotropic turbulence SO STATISTICAL THEORIES AND COMPUTATIONAL APPROACHES TO TURBULENCE: MODERN PERSPECTIVES AND APPLICATIONS TO GLOBAL-SCALE FLOWS LA English DT Proceedings Paper CT Workshop on Statistical Theories and Computational Approaches to Turbulence CY OCT 10-13, 2001 CL NAGOYA UNIV, NAGOYA, JAPAN SP Japanese Soc Promot Sci, Res Fdn Electrotechnol Chubu, Daiko Fdn HO NAGOYA UNIV AB Two general models axe proposed for the Eulerian time correlation function in homogeneous isotropic turbulence. The first is based on continued fraction approximations to its Laplace transform, and the second is based on random sweeping by a possibly non-Gaussian velocity field. Both models can give reasonable quantitative agreement with DNS data for moderate time separations over which the time correlation functions at different wavenumbers exhibit a common self-similar form. C1 NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA. RP Rubinstein, R (reprint author), NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Mail Stop 128, Hampton, VA 23681 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG TOKYO PI TOKYO PA 37-3, HONGO 3-CHOME BONKYO-KU, TOKYO, 113, JAPAN BN 4-431-70335-7 PY 2003 BP 229 EP 238 PG 10 WC Mechanics; Physics, Fluids & Plasmas; Physics, Mathematical SC Mechanics; Physics GA BV66L UT WOS:000179683500015 ER PT B AU Wachter, S Hoard, DW Hansen, KH Wilcox, RE Taylor, HM Finkelstein, SL AF Wachter, S Hoard, DW Hansen, KH Wilcox, RE Taylor, HM Finkelstein, SL BE Cheng, KS Leung, KC Li, TP TI Cool companions to white dwarfs from 2MASS SO STELLAR ASTROPHYSICS - A TRIBUTE TO HELMUT A. ABT SE ASTROPHYSICS AND SPACE SCIENCE LIBRARY LA English DT Proceedings Paper CT 6th Pacific Rim Stellar Conference on Stellar Astrophysics CY JUL 11-17, 2002 CL Xian, PEOPLES R CHINA SP Univ Hong Kong, Chinese Acad Sci, Inst High Energy Phys, Shaanxi Astron Observ DE white dwarfs; near-IR; surveys AB We present near-infrared magnitudes for white dwarfs selected from the catalog of McCook & Sion that are contained in the 2 Micron All Sky Survey Second Incremental Data Release. We show that the loci of single WDs and WD + red dwarf binaries occupy distinct regions of the near-IR color-color diagram. Using observational near-IR data for WDs and M-L dwarfs, we have compared a sample of simulated WD + red dwarf binaries with our 2MASS data. The colors of the simulated binaries are dominated by the low mass companion through the late-M to early-L spectral types. For later spectral types of the companion, however, the colors of unresolved binaries become progressively bluer. Binaries containing the lowest mass companions will be difficult to distinguish from single WDs solely on the basis of their near-IR colors. C1 CALTECH, Jet Prop Lab, SIRTF Sci Ctr, Pasadena, CA 91125 USA. RP Wachter, S (reprint author), CALTECH, Jet Prop Lab, SIRTF Sci Ctr, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-1683-2 J9 ASTROPHYS SPACE SC L PY 2003 VL 298 BP 267 EP 269 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BAA58 UT WOS:000221354700040 ER PT B AU Koesterke, L AF Koesterke, L BE Hubeny, I Mihalas, D Werner, K TI Rate equations with ALI and more SO STELLAR ATMOSPHERE MODELING SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT International Workshop on Stellar Atmosphere Modeling CY APR 08-12, 2002 CL UNIV TUBINGEN, TUBINGEN, GERMANY HO UNIV TUBINGEN ID MULTILEVEL RADIATIVE-TRANSFER; LAMBDA ITERATION METHOD; NON-LTE; CONTINUUM AB The construction of (stellar) atmospheres in non-LTE requires the application of iterative techniques in all aspects of the problem. One essential is the solution of non-linear systems of equations by applying the Newton-Raphson scheme. The properties of this method and its derivatives, namely the Broyden method and Kantorovich's method, are reviewed. Most important is the fact that fast methods, such as the Newt-on method, are particularly reliable, because they clearly indicate when the iteration can be stopped, i.e. when the iterative solution has approached proximity to the true solution. The second part deals with temperature-correction schemes. Because the, temperature equation is the major obstacle to splitting the equations of statistical equilibrium into independent blocks for different elements, temperature-correction schemes, such as the method by Unsold-Lucy, have regained the interest of several groups. However, the method by Unsold-Lucy turns out to be very slow, and it might give false convergence even far away from the solution. This is in agreement with the findings of the first part. In the third part, the convergence speed of the overall ALI method is investigated. Among other factors, the speed is set by the choice of the Lambda* operator. We know from both theoretical.,considerations, and numerical experiments with static atmospheres, that, the diagonal of the exact A operator is (nearly) optimal., However, if expanding atmospheres are calculated in the co-moving frame the situation is much more difficult, and,an optimal operator cannot be easily derived as a by-product of the radiation transfer. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Koesterke, L (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-131-1 J9 ASTR SOC P PY 2003 VL 288 BP 215 EP 226 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW53Y UT WOS:000182322800025 ER PT J AU Chen, SS Revoltella, RP Papini, S Michelini, M Fitzgerald, W Zimmerberg, J Margolis, L AF Chen, SS Revoltella, RP Papini, S Michelini, M Fitzgerald, W Zimmerberg, J Margolis, L TI Multilineage differentiation of rhesus monkey embryonic stem cells in three-dimensional culture systems SO STEM CELLS LA English DT Article DE embryonic stem cell; collagen matrix; three-dimensional structure ID COLONY-STIMULATING FACTOR; GRANULOCYTE-MACROPHAGE CSF; CENTRAL-NERVOUS-SYSTEM; IN-VITRO; NEURAL PRECURSORS; ES CELLS; DOPAMINERGIC-NEURONS; BETA-TUBULIN; TUMOR PROGRESSION; GM-CSF AB In the course of normal embryogenesis, embryonic stem (ES) cells differentiate along different lineages in the context of complex three-dimensional (3D) tissue structures. In order to study this phenomenon in vitro under controlled conditions, 3D culture systems are necessary. Here, we studied in vitro differentiation of rhesus monkey ES cells in 3D collagen matrixes (collagen gels and porous collagen sponges). Differentiation of ES cells in these 3D systems was different from that in monolayers. ES cells differentiated in collagen matrixes into neural, epithelial, and endothelial lineages. The abilities of ES cells to form various structures in two chemically similar but topologically different matrixes were different. In particular, in collagen gels ES cells formed gland-like circular structures, whereas in collagen sponges ES cells were scattered through the matrix or formed aggregates. Soluble factors produced by feeder cells or added to the culture medium facilitated ES cell differentiation into particular lineages. Coculture with fibroblasts in collagen gel facilitated ES cell differentiation into cells of a neural lineage expressing nestin, neural cell adhesion molecule, and class III beta-tubulin. In collagen sponges, keratinocytes facilitated ES cell differentiation into cells of an endothelial lineage expressing factor VIII. Exogenous granulocyte-macrophage colony-stimulating factor further enhanced endothelial differentiation. Thus, both soluble factors and the type of extracellular matrix seem to be critical in directing differentiation of ES cells and the formation of tissue-like structures. Three-dimensional culture systems are a valuable tool for studying the mechanisms of these phenomena. C1 NICHD, NASA, NIH, Ctr 3 Dimens Tissue Culture,Lab Cellular & Mol Bi, Bethesda, MD 20892 USA. CNR, Inst Biomed Technol, Unit Immunobiol & Cell Differentiat, I-56100 Pisa, Italy. RP Margolis, L (reprint author), NICHD, NASA, NIH, Ctr 3 Dimens Tissue Culture,Lab Cellular & Mol Bi, Bethesda, MD 20892 USA. NR 56 TC 58 Z9 65 U1 0 U2 6 PU ALPHAMED PRESS PI MIAMISBURG PA ONE PRESTIGE PLACE, STE 290, MIAMISBURG, OH 45342-3758 USA SN 1066-5099 J9 STEM CELLS JI Stem Cells PY 2003 VL 21 IS 3 BP 281 EP 295 DI 10.1634/stemcells.21-3-281 PG 15 WC Cell & Tissue Engineering; Biotechnology & Applied Microbiology; Oncology; Cell Biology; Hematology SC Cell Biology; Biotechnology & Applied Microbiology; Oncology; Hematology GA 683CK UT WOS:000183129600005 PM 12743323 ER PT J AU Andrews, RJ Mah, RW AF Andrews, RJ Mah, RW TI The NASA Smart Probe Project for real-time multiple microsensor tissue recognition SO STEREOTACTIC AND FUNCTIONAL NEUROSURGERY LA English DT Article; Proceedings Paper CT Meeting of the American-Society-for-Stereotactic-and-Functional-Neurosurgery CY MAY 18-21, 2003 CL NEW YORK, NEW YORK SP Amer Soc Stereotact & Funct Neurosurg DE brain biopsy; neural network; robotics; stereotaxy ID IDENTIFICATION AB Background: Remote surgery requires automated sensors, effectors and sensor-effector communication. The NASA Smart Probe Project has focused on the sensor aspect. Methods: The NASA Smart Probe uses neural networks and data from multiple microsensors for a unique tissue signature in real time. Animal and human trials use several probe configurations: (1) 8-microsensor probe (2.5 mm in diameter) for rodent studies ( normal and subcutaneous mammary tumor tissues), and (2) 21-gauge needle probe with 3 spectroscopic fibers and an impedance microelectrode for breast cancer diagnosis in humans. Multisensor data are collected in real time ( update 100 times/s) using PCs. Results: Human data ( collected by NASA licensee BioLuminate) from 15 women undergoing breast biopsy distinguished normal tissue from both benign tumors and breast carcinoma. Tumor margins and necrosis are rapidly detected. Conclusion: Real-time tissue identification is achievable. Potential applications, including probes incorporating nanoelectrode arrays, are presented. Copyright (C) 2003 S. Karger AG, Basel. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Andrews, RJ (reprint author), 555 Knowles Dr,Suite 112, Los Gatos, CA 95032 USA. EM rja@russelljandrews.org NR 10 TC 6 Z9 6 U1 0 U2 0 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 1011-6125 J9 STEREOT FUNCT NEUROS JI Stereotact. Funct. Neurosurg. PY 2003 VL 80 IS 1-4 BP 114 EP 119 DI 10.1159/000075170 PG 6 WC Neurosciences; Neuroimaging; Surgery SC Neurosciences & Neurology; Surgery GA 766PZ UT WOS:000188385900019 PM 14745219 ER PT S AU Pap, JM AF Pap, JM BE Rozelot, JP TI Total solar and spectral irradiance variations from near-UV to infrared SO SUN'S SURFACE AND SUBSURFACE: INVESTIGATING SHAPE AND IRRADIANCE SE Lecture Notes in Physics LA English DT Proceedings Paper CT 5th CNRS School of Solar Astrophysics CY MAY 22-26, 2000 CL ST PIERRE OLERON, FRANCE SP CNRS ID LYMAN-ALPHA-IRRADIANCE; CLIMATE-CHANGE; LUMINOSITY VARIATIONS; ACTIVE REGIONS; VARIABILITY; SUN; RADIUS; VIRGO; CYCLE; OSCILLATIONS AB Total solar and UV irradiances have been measured from various space platforms for more than two decades. These measurements established conclusively that solar irradiance changes on a wide range of time scales: from minutes to the 11 years solar cycle. The first results on the spectral distribution of total irradiance variations have been provided by the SunPhotometers on the SOHO/VIRGO experiment at 402, 500, and 862 nm, showing that spectral irradiance at these particular wavelengths changes in a fashion similar to total irradiance with amplitudes being higher at the shorter wavelengths. Although considerable information exist on irradiance variations, their physical origin is not yet fully understood. Current empirical models assume that most of the irradiance variations can be explained by the effect of surface magnetic activity features, and it is assumed that there is a linear relation between solar indices and irradiance changes. In contrast, current results show that both UV and total irradiances were higher at the maximum of solar cycle 23 than magnetic indices, such as the sunspot number and the full disk magnetic field strength. In addition, there is a growing evidence that global effects, like temperature changes, may also contribute to irradiance variations. In this paper we give an overview of the current results on total and spectral irradiance variations, their relation to magnetic activity using measurements from the National Solar Observatory an Kitt Peak and SOHO-MDI. Climate implications of irradiance variations are also discussed. C1 Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. RP Pap, JM (reprint author), Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. NR 92 TC 7 Z9 7 U1 1 U2 2 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0075-8450 BN 3-540-44188-3 J9 LECT NOTES PHYS PY 2003 VL 599 BP 129 EP 155 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW61J UT WOS:000182571000005 ER PT J AU Lazarenkova, OL Balandin, AA AF Lazarenkova, OL Balandin, AA TI Raman scattering from three-dimensionally regimented quantum dot superlattices SO SUPERLATTICES AND MICROSTRUCTURES LA English DT Article DE Raman spectroscopy; quantum dot superlattice; confined phonons; Ge/Si ID GLASS MATRIX AB We examine the low-energy part of Raman scattering spectrum from a three-dimensional regimented array of GexSi1-x quantum dots on Si. Our analysis is based on a numerical solution of the elasticity equation for the whole quantum dot superlattice. Three-dimensional acoustic phonon folding due to structure regimentation and small feature size leads to unique signatures in Raman spectra, which cannot be predicted using the Lamb-type models for quantum dots or the Rytov model for a quantum well superlattice. We found that symmetry breaking, which is achieved when the inter-dot distances are comparable to the dot dimensions, results in increased intensity of confined phonon modes. It is also shown that changes in dot material composition and alteration of the dot size lead to different Raman spectrum modification. The latter can be used as a tool to distinguish phonon confinement effects on Raman spectra from alloying and strain induced effects. (C) 2003 Elsevier Ltd. All rights reserved. C1 Univ Calif Riverside, Dept Elect Engn, Nano Device Lab, Riverside, CA 92521 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Balandin, AA (reprint author), Univ Calif Riverside, Dept Elect Engn, Nano Device Lab, Riverside, CA 92521 USA. NR 20 TC 6 Z9 6 U1 0 U2 4 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0749-6036 J9 SUPERLATTICE MICROST JI Superlattices Microstruct. PD JAN-FEB PY 2003 VL 33 IS 1-2 BP 95 EP 101 DI 10.1016/S0749-6036(03)00049-1 PG 7 WC Physics, Condensed Matter SC Physics GA 733TU UT WOS:000186017400010 ER PT B AU Bonner, JK Mehta, A AF Bonner, JK Mehta, A BE Mittal, KL TI Qualifying a cleaning system for space flight printed wiring assemblies SO SURFACE CONTAMINATION AND CLEANING, VOL 1 LA English DT Proceedings Paper CT International Symposium on Surface Contamination and Cleaning CY MAY 23-25, 2001 CL NEWARK, NJ SP MST Conf DE aqueous cleaning (AC); conformal coating; ionic contamination testing (ICT); greenhouse warming potential (GWP); multilayer board (MLB); ozone depletion potential (ODP); printed wiring assembly (PWA); printed wiring board (PWB); rosin mildly activated (RMA); semi-aqueous cleaning (SAC); surface mount technology (SMT); volatile organic compound (VOC) AB Cleaning critical and high reliability printed wiring assemblies (PWAs) continues to be important to ensure high reliability performance and to prevent premature failure. The necessary steps to qualifying both a cleaning system and an appropriate chemistry for cleaning such PWAs are set forth. This paper addresses a centrifugal cleaning system used in conjunction with a water-based cleaning medium to achieve optimally low levels of contaminants on PWAs. Ionograph data, ion chromatography profiling, residual rosin determination, and outgassing data are presented demonstrating the effectiveness of the centrifugal cleaning system and the aqueous cleaning agent for space flight printed wiring assemblies. It is concluded that a centrifugal cleaning system coupled with a suitable aqueous chemistry can be successfully employed to clean high reliability PWAs. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bonner, JK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU VSP BV-C/O BRILL ACAD PUBL PI LEIDEN PA PO BOX 9000, 2300 PA LEIDEN, NETHERLANDS BN 90-6764-376-9 PY 2003 BP 225 EP 239 PG 15 WC Engineering, Chemical; Engineering, Mechanical SC Engineering GA BY20Z UT WOS:000188246300015 ER PT S AU Elmustafa, AA Lou, J Adewoye, O Soboyejo, WO Stone, DS AF Elmustafa, AA Lou, J Adewoye, O Soboyejo, WO Stone, DS BE Kumar, A Meng, WJ Cheng, YT Zabinski, JS Doll, GL Veprek, S TI Bilinear behavior in the indentation size effect: A consequence of strain gradient plasticity SO SURFACE ENGINEERING 2002-SYNTHESIS, CHARACTERIZATION AND APPLICATIONS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Conference on Surface Engineering 2002 - Synthesis, Characterization and Applications held at the 2002 MRS Fall Meeting CY DEC 02-05, 2002 CL BOSTON, MA SP Mat Res Soc ID ELASTIC-MODULUS; HARDNESS; COPPER; DEPTH; LOAD AB This paper examines the effects of stacking fault energy on the micro- and nano-indentation behavior of face-centered-cubic thin films. These include: LIGA nickel MEMS structures, alpha brass, copper and high purity aluminum. The measured hardness are then fitted to a strain gradient plasticity model based on the Taylor dislocation hardening model. Hardness is shown to exhibit a size dependence with different characteristic slopes in the micron and nano-scale regimes. Deep indents are shown to exhibit classical linear behavior. However, shallow indents exhibit an abrupt decrease in slope (almost by a factor of 10), giving rise to a bi-linear behavior. Furthermore, as the gradients become less sharp, the trends in the nano-hardness data become similar to those of the microbardness data predicted by the strain gradient plasticity model. Finally, the effects of stacking fault energy are then discussed within the context of cross-slip and hardening associated with Shockly partials. C1 NASA, Langley Res Ctr, ConITS, Hampton, VA 23665 USA. RP Elmustafa, AA (reprint author), NASA, Langley Res Ctr, ConITS, Hampton, VA 23665 USA. RI Stone, Donald/A-7496-2016 NR 17 TC 0 Z9 0 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-687-7 J9 MATER RES SOC SYMP P PY 2003 VL 750 BP 27 EP 32 PG 6 WC Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Physics, Condensed Matter SC Metallurgy & Metallurgical Engineering; Materials Science; Physics GA BW91Y UT WOS:000183595500005 ER PT S AU Elmustafa, AA Tambwe, MF Stone, DS AF Elmustafa, AA Tambwe, MF Stone, DS BE Kumar, A Meng, WJ Cheng, YT Zabinski, JS Doll, GL Veprek, S TI Activation volume analysis of plastic deformation in fcc materials using nanoindentation SO SURFACE ENGINEERING 2002-SYNTHESIS, CHARACTERIZATION AND APPLICATIONS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Conference on Surface Engineering 2002 - Synthesis, Characterization and Applications held at the 2002 MRS Fall Meeting CY DEC 02-05, 2002 CL BOSTON, MA SP Mat Res Soc ID METALS; FLOW AB Activation volumes for plastic deformation of fee metals are measured using nanoindentation. Materials include bulk, polycrystalline aluminum and alpha-brass, and sputtered copper and nickel thin films on silicon substrates. From a hardness measurement, V * is defined as 9k(B)T/partial derivativeH/partial derivativeln epsilon(eff), where H is the hardness and epsilon(eff) is a representative strain rate beneath the indenter. Data obtained using nanoindentation are consistent with those obtained using more conventional experiments based on uniaxial loading. C1 NASA, Langley Res Ctr, ConITS, Hampton, VA 23665 USA. RP Elmustafa, AA (reprint author), NASA, Langley Res Ctr, ConITS, Hampton, VA 23665 USA. RI Stone, Donald/A-7496-2016 NR 15 TC 2 Z9 2 U1 1 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-687-7 J9 MATER RES SOC SYMP P PY 2003 VL 750 BP 77 EP 82 PG 6 WC Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Physics, Condensed Matter SC Metallurgy & Metallurgical Engineering; Materials Science; Physics GA BW91Y UT WOS:000183595500013 ER PT B AU Raj, SV Ghosn, LJ Agarwal, A Lachtrupp, TP AF Raj, SV Ghosn, LJ Agarwal, A Lachtrupp, TP BE Seal, S Dahotre, NB Moore, JJ Suryanarayana, C Agarwal, A TI An assessment of the residual stresses in low pressure plasma sprayed coatings on an advanced copper alloy SO SURFACE ENGINEERING: IN MATERIALS SCIENCE II LA English DT Proceedings Paper CT Symposium on Surface Engineering in Materials Science II CY MAR 02-06, 2003 CL SAN DIEGO, CA SP Univ Cent Florida, Adv Mat Proc & Analys Ctr, Univ Cent Florida, Mech, Mat & Aerosp Engn, Univ Tennessee, Univ Cent Florida, Off Res, Colorado Sch Mines, Adv Coatings & Surface Engn Lab, Florida Int Univ AB Modeling studies were conducted on low pressure plasma sprayed (LPPS) NiAl top coat applied to an advanced Cu-8(at.%)Cr-4%Nb alloy (GRCop-84) substrate using Ni as a bond coat. A thermal analysis suggested that the NiAl and Ni top and bond coats, respectively, would provide adequate thermal protection to the GRCop-84 substrate in a rocket engine operating under high heat flux conditions. Residual stress measurements were conducted at different depths from the free surface on coated and uncoated GRCop-84 specimens by x-ray diffraction. These data are compared with theoretically estimated values assessed by a finite element analysis simulating the development of these stresses as the coated substrate cools down from the plasma spraying temperature to room temperature. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Raj, SV (reprint author), NASA, Glenn Res Ctr, MS 24-1,21000 Brookpark Rd, Cleveland, OH 44135 USA. NR 10 TC 0 Z9 0 U1 1 U2 1 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-537-9 PY 2003 BP 49 EP 56 PG 8 WC Engineering, Manufacturing; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BW60F UT WOS:000182547600006 ER PT J AU Yang, JH Oh, WS Elder, IA Leventis, N Sotiriou-Leventis, C AF Yang, JH Oh, WS Elder, IA Leventis, N Sotiriou-Leventis, C TI Coupling of 3,8-dibromo-1,10-phenanthroline with 3,5-diethynylheptyloxybenzene: A Suzuki/Miyaura versus a Sonogashira perspective SO SYNTHETIC COMMUNICATIONS LA English DT Article DE Suzuki; Miyaura; Sonogashira; coupling; 3,8-dibromo-1,10-phenanthroline ID ARYL BROMIDES; ACETYLENE DERIVATIVES; ROOM-TEMPERATURE; TERMINAL ALKYNES; CHEMISTRY; COMPLEXES; CATALYST; ROUTE; SALT AB We report a new application of the Suzuki-Miyaura reaction whereas two bifunctional reactants, 3,8-dibromo-1,10-phenanthroline and 3,5-diethynylheptyloxylbenzene (9), yield 3,8-bis(3-ethynyl-5-heptyloxyphenylethynyl)-1,10-phenanthroline (2) efficiently (74% yield) without polymerization. This was achieved by reacting a stoichiometric amount of 9 and (Me3Si)(2)NLi to obtain quantitatively the monoacetylide anion of 9 (10). The latter was activated with B-methoxy-9-BBN and reacted in analogy to the alkynyl copper complex of a Sonogashira route. However, in the Sonogashira reaction, the alkynyl copper complex is present in small equilibrium concentrations and polymerization takes place even when reagents are mixed slowly. Actually the Sonogashira route gave no desired product 2, as the latter polymerizes easily via homo-coupling in the presence of air and Cu(I). C1 Univ Missouri, Dept Chem, Rolla, MO 65409 USA. NASA, Lewis Res Ctr, Div Mat, Cleveland, OH 44135 USA. RP Sotiriou-Leventis, C (reprint author), Univ Missouri, Dept Chem, 21000 Brookpk Rd, Rolla, MO 65409 USA. EM cslevent@umr.edu NR 22 TC 6 Z9 6 U1 1 U2 9 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0039-7911 J9 SYNTHETIC COMMUN JI Synth. Commun. PY 2003 VL 33 IS 19 BP 3317 EP 3325 DI 10.1081/SCC-120023989 PG 9 WC Chemistry, Organic SC Chemistry GA 721BR UT WOS:000185297600006 ER PT S AU Poll, S Iverson, D Patterson-Hine, A AF Poll, S Iverson, D Patterson-Hine, A BE Willett, PK Kirubarajan, T TI Characterization of model-based reasoning strategies for use in IVHM architectures SO SYSTEM DIAGNOSIS AND PROGNOSIS: SECURITY AND CONDITION MONITORING ISSUES III SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on System Diagnosis and Prognosis: Security and Condition Monitoring Issues III CY APR 21, 2003 CL ORLANDO, FL SP SPIE DE model-based reasoning; diagnostic reasoning; fault diagnosis; hybrid rockets AB Open architectures are gaining popularity for Integrated Vehicle Health Management (IVHM) applications due to the diversity of subsystem health monitoring strategies in use and the need to integrate a variety of techniques at the system health management level. The basic concept of an open architecture suggests that whatever monitoring or reasoning strategy a subsystem wishes to deploy, the system architecture will support the needs of that subsystem and will be capable of transmitting, subsystem health status across subsystem boundaries and up to the system level for system-wide fault identification and diagnosis. There is a need to understand the capabilities of various reasoning engines and how they, coupled with intelligent monitoring techniques, can support fault detection and system level fault management. Researchers in IVHM at NASA Ames Research Center are supporting the development of an IVHM system for liquefying-fuel hybrid rockets. In the initial stage of this project, a few readily available reasoning engines were studied to assess candidate technologies for application in next generation launch systems. Three tools representing the spectrum of model-based reasoning approaches, from a quantitative simulation based approach to a graph-based fault propagation technique, were applied to model the behavior of the Hybrid Combustion Facility testbed at Ames. This paper summarizes the characterization of the modeling process for each of the techniques. C1 NASA, Ames Res Ctr, Computat Sci Div, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, Computat Sci Div, Moffett Field, CA 94035 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4967-9 J9 PROC SPIE PY 2003 VL 5107 BP 94 EP 105 DI 10.1117/12.487219 PG 12 WC Automation & Control Systems SC Automation & Control Systems GA BX48M UT WOS:000185396000009 ER PT S AU Stoica, A AF Stoica, A BE MeloPinto, P Teodorescu, HN Fukuda, T TI Evolution of analog circuits for fuzzy systems SO SYSTEMATIC ORGANISATION OF INFORMATION IN FUZZY SYSTEMS SE NATO SCIENCE SERIES, SUB-SERIES III: COMPUTER AND SYSTEMS SCIENCES LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Systematic Organisation of Information in Fuzzy Systems CY OCT 24-26, 2001 CL Vila Real, PORTUGAL SP NATO Sci Affairs Div, Univ Trasosmotes Alto Douro/CETAV, Vila Real Comm, Minist Sci, Tech Univ Iasi, Fac Elect & Telecommun AB The paper presents several aspects related to the use of evolutionary algorithms (EA) for analog circuit design, and to the automatic circuit reconfiguration on programmable analog devices. It demonstrates the power of EA in the synthesis of circuits implementing circuits for specific fuzzy operators and for deriving very compact implementations of complete fuzzy systems. Uniquely, circuits with a totally new type of superimposed multifunctionality can be synthesized. It discusses the power of using programmable devices to do fuzzy configurable computing. To obtain circuits that work both in simulations and on real hardware a technique called mixtrinsic evolution has been developed, which expended becomes a model identification technique with larger applicability. Finally, it is shown how evolution can be accelerated by operating with "fuzzy" switches, with partial opening, and the concept of "fuzzy topologies" for electronic circuits is suggested as a model to characterize behaviors in those experiments. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Stoica, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU I O S PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 1387-6694 BN 1-58603-295-X J9 NATO SC S SS III C S PY 2003 VL 184 BP 277 EP 287 PG 11 WC Computer Science, Artificial Intelligence SC Computer Science GA BY81Y UT WOS:000189470700017 ER PT S AU Ford, VG Hull, A Shaklan, S Levine, M White, M Lowman, A Cohen, E AF Ford, VG Hull, A Shaklan, S Levine, M White, M Lowman, A Cohen, E BE Coulter, DR TI Terrestrial planet finder coronagraph SO TECHNIQUES AND INSTRUMENTATION FOR DETECTION OF EXOPLANETS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets CY AUG 05-07, 2003 CL SAN DIEGO, CA SP SPIE DE coronagraph; telescope; space; terrestrial planet finder AB This paper and oral presentation will describe the technology studies, the testbeds, and the architecture studies that will enhance the understanding and viability of a Terrestrial Planet Finder Coronagraph. Topics to be described fall in two categories: technology development and coronagraph mission design. The focus of the paper will be explanation of the tasks, their organization and current status. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ford, VG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 9 Z9 9 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5043-X J9 P SOC PHOTO-OPT INS PY 2003 VL 5170 BP 1 EP 12 DI 10.1117/12.512633 PG 12 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BY13C UT WOS:000187838700001 ER PT S AU Green, JJ Shaklan, SB AF Green, JJ Shaklan, SB BE Coulter, DR TI Optimizing coronagraph designs to minimize their contrast sensitivity to low-order optical aberrations SO TECHNIQUES AND INSTRUMENTATION FOR DETECTION OF EXOPLANETS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets CY AUG 05-07, 2003 CL SAN DIEGO, CA SP SPIE DE coronagraphic telescope; error modeling; optical aberrations; extrasolar planets AB The presence of optical aberrations in the entrance pupil of a coronagraph causes the stellar light to scatter about the occulting spot, reducing the effective contrast achievable. Even if these aberrations are sufficiently corrected with a deformable mirror to enable planet detection, small drifts in the optical alignment of the telescope introduce additional low-order aberrations. The design parameters of the coronagraph itself (e.g. occulting spot size, Lyot stop diameter, etc.) affect how these aberrations impact the contrast in the focal plane. In this study, we examine the sensitivity of contrast to low-order optical errors for several coronagraph concepts over their respective design parameters. By combining these sensitivities with the telescope throughput, we show that for each coronagraph concept there is an optimum selection of the design parameters that provides efficient, high-contrast imaging at the inner working distance in the presence of alignment errors. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Green, JJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 306-336, Pasadena, CA 91109 USA. NR 13 TC 15 Z9 15 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5043-X J9 P SOC PHOTO-OPT INS PY 2003 VL 5170 BP 25 EP 37 DI 10.1117/12.506485 PG 13 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BY13C UT WOS:000187838700003 ER PT S AU Green, JJ Basinger, SA Cohen, D Niessner, AF Redding, DC Shaklan, SB Trauger, JT AF Green, JJ Basinger, SA Cohen, D Niessner, AF Redding, DC Shaklan, SB Trauger, JT BE Coulter, DR TI Demonstration of extreme wavefront sensing performance on the TPF high contrast imaging testbed SO TECHNIQUES AND INSTRUMENTATION FOR DETECTION OF EXOPLANETS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets CY AUG 05-07, 2003 CL SAN DIEGO, CA SP SPIE DE coronagraph; wavefront sensing; phase-retrieval; focus-diversity; wavefront control AB The Terrestrial Planet Finder (TPF) high contrast imaging testbed (HCIT) facilitates the investigation into the diversity of engineering challenges presented by the goal of direct exo-planet detection. For instance, HCIT offers a high-density deformable mirror to control the optical wavefront errors, a configurable coronagraph to control the diffracted light, and translatable cameras for measuring the focal and pupil planes before and after the coronagraph. One of the principle challenges for a coronagraphic space telescope is the extreme level of wavefront control required to make the very faint planet signal reasonably detectable. A key component, the extremely accurate sensing of the wavefront aberrations, was recently shown to be achievable using a sufficiently constrained image-based approach. In this paper, we summarize the experimental performance a focus-diverse phase-retrieval method that uses symmetrically defocus point-spread function measurements that are obtained about the coronagraph occulter focal plane. Using the HCIT, we demonstrate the high level of wavefront sensing repeatability achieved with our particular choices of focus diversity, data fidelity and processing methodologies. We compare these results to traceable simulations to suggest a partitioning of the error sources that may be limiting the experimental results. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Green, JJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 306-336, Pasadena, CA 91109 USA. NR 13 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5043-X J9 P SOC PHOTO-OPT INS PY 2003 VL 5170 BP 38 EP 48 DI 10.1117/12.506513 PG 11 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BY13C UT WOS:000187838700004 ER PT S AU Lay, OP Jeganathan, M Peters, R AF Lay, OP Jeganathan, M Peters, R BE Coulter, DR TI Adaptive nulling: a new enabling technology for interferometric exoplanet detection SO TECHNIQUES AND INSTRUMENTATION FOR DETECTION OF EXOPLANETS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets CY AUG 05-07, 2003 CL SAN DIEGO, CA SP SPIE DE nulling interferometry; planet detection AB Deep, stable nulling of starlight requires careful control of the amplitudes and phases of the beams that are being combined. The detection of earth-like planets using the interferometer architectures currently being considered for the Terrestrial Planet Finder mission require that the E-field amplitudes are balanced at the level of similar to 0. 1%, and the phases are controlled at the level of 1 mrad (corresponding to similar to 1.5 nm for a wavelength of 10 mum). These conditions must be met simultaneously at all wavelengths across the science band, and for both polarization states, imposing unrealistic tolerances on the symmetry between the optical beamtrains. We introduce the concept of a compensator that is inserted into the beamtrain, which can adaptively correct for the mismatches across the spectrum, enabling deep nulls with realistic, imperfect optics. The design presented uses a deformable mirror to adjust the amplitude and phase of each beam as an arbitrary function of wavelength and polarization. A proof-of-concept experiment will be conducted at visible/near-IR wavelengths, followed by a system operating in the Mid-IR band. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lay, OP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 5 Z9 5 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5043-X J9 P SOC PHOTO-OPT INS PY 2003 VL 5170 BP 103 EP 112 DI 10.1117/12.503759 PG 10 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BY13C UT WOS:000187838700011 ER PT S AU Blackwood, G Serabyn, E Dubovitsky, S Aung, MM Gunter, SM Henry, C AF Blackwood, G Serabyn, E Dubovitsky, S Aung, MM Gunter, SM Henry, C BE Coulter, DR TI System design and technology development for the Terrestrial Planet Finder infrared interferometer SO TECHNIQUES AND INSTRUMENTATION FOR DETECTION OF EXOPLANETS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets CY AUG 05-07, 2003 CL SAN DIEGO, CA SP SPIE DE interferometry; terrestrial planets; nulling; formation-flying; cryogenic structures ID MISSION AB This paper describes the technical program that will demonstrate the viability of two mid-infrared nulling interferometer architectures for the Terrestrial Planet Finder (TPF) to support a mission concept downselect in 2006 between a nulling interferometer and a visible coronagraph. The TPF science objectives are to survey a statistically significant number of nearby solar-type stars for radiation from terrestrial planets, to characterize these planets and to perform spectroscopy for detection of biomarkers. A 4-telescope, 36-m Structurally-Connected Interferometer using a dual-chopped Bracewell nuller will meet the minimum science requirement to completely survey at least 30 nearby stars and partially survey 120 others. A Formation-Flying Interferometer is being designed to meet the full science requirement to completely survey at least 150 stars, and involves a trade between dual-chopped Bracewell, degenerate Angel Cross, and the Darwin bow-tie configuration. The system engineering trades for the connected structure and formation-flying architectures are described. The top technical concerns for these architectures are mapped to technology developments that will retire these concerns prior to the project downselect. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Blackwood, G (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 301-451, Pasadena, CA 91109 USA. NR 19 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5043-X J9 P SOC PHOTO-OPT INS PY 2003 VL 5170 BP 129 EP 143 DI 10.1117/12.521311 PG 15 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BY13C UT WOS:000187838700013 ER PT S AU Martin, SR Gappinger, RO Loya, FM Mennesson, BP Crawford, SL Serabyn, E AF Martin, SR Gappinger, RO Loya, FM Mennesson, BP Crawford, SL Serabyn, E BE Coulter, DR TI A mid-infrared nuller for Terrestrial Planet Finder: Design, progress and results. SO TECHNIQUES AND INSTRUMENTATION FOR DETECTION OF EXOPLANETS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets CY AUG 05-07, 2003 CL SAN DIEGO, CA SP SPIE DE nulling; interferometry; exo-planets; exo-zodiacal dust ID BROAD-BAND; LIGHT; DEEP AB Nulling interferometry shows promise as a technique enabling investigation of faint objects such as planets and exo-zodiacal dust around nearby stars. At Jet Propulsion Laboratory, a nulling beam combiner has been built for the Terrestrial Planet Finder project and has been used to pursue deep and stable narrowband nulls. We describe the design and layout of the modified Mach Zehnder TPF miller, and the results achieved in the laboratory to date. We report stabilized nulls at about the 10(-6) level achieved using a CO2 laser operating at 10.6 mum, and discuss the alignment steps needed to produce good performance. A pair of similar nullers has been built for the Keck Observatory, for planned observations of exo-zodiacal dust clouds(1). We also show briefly a result from the Keck breadboard experiments: passively stabilized nulls centered around 10.6 micron of about 2 10(-4) have been achieved at bandwidths of 29%. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Martin, SR (reprint author), CALTECH, Jet Prop Lab, M-S 306-388,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 10 Z9 10 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5043-X J9 P SOC PHOTO-OPT INS PY 2003 VL 5170 BP 144 EP 154 DI 10.1117/12.521312 PG 11 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BY13C UT WOS:000187838700014 ER PT S AU Levine, BM Shao, M Liu, D Wallace, JK Lane, B AF Levine, BM Shao, M Liu, D Wallace, JK Lane, B BE Coulter, DR TI Planet detection in visible light with a single aperture telescope and nulling coronagraph SO TECHNIQUES AND INSTRUMENTATION FOR DETECTION OF EXOPLANETS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets CY AUG 05-07, 2003 CL SAN DIEGO, CA SP SPIE DE planet detection; visible nulling interferometer; coronagraph; space telescope ID EXTRASOLAR PLANETS; INTERFEROMETER AB This paper describes the latest progress for visible direct detection of Earth like extrasolar planets using a nulling coronagraph instrument behind a 4m class telescope. Such a system is capable of satisfying the scientific objectives of the Terrestrial Planet Finder mission In our design, a 4 beam nulling interferometer is synthesized from the telescope pupil, producing a very deep null proportional to theta(4) which is then filtered by a coherent array of single mode fibers to suppress the residual scattered light. With diffraction limited telescope optics and similar quality components in the optical train (lambda/20), suppression of the starlight to 10(-1)0 is achievable. Such a telescope with this nulling interferometer as back-end instrument can image and detect planets, or provide the input to a low resolution spectrometer. Shown are key features of this system in a space mission, latest results of laboratory measurements demonstrating achievable null depth, and progress toward fabrication of coherent single mode fiber arrays. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Levine, BM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 15 TC 9 Z9 9 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5043-X J9 P SOC PHOTO-OPT INS PY 2003 VL 5170 BP 200 EP 208 DI 10.1117/12.507807 PG 9 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BY13C UT WOS:000187838700020 ER PT S AU Wallace, JK Shao, M Lane, B Levine, BM Loya, F Azizi, A Holmes, B Aguayo, F Negron, J Sanchez, G Gappinger, R AF Wallace, JK Shao, M Lane, B Levine, BM Loya, F Azizi, A Holmes, B Aguayo, F Negron, J Sanchez, G Gappinger, R BE Coulter, DR TI Experimental results from the optical planet detector interferometer SO TECHNIQUES AND INSTRUMENTATION FOR DETECTION OF EXOPLANETS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets CY AUG 05-07, 2003 CL SAN DIEGO, CA SP SPIE DE space-based stellar interferometry; coronography; milling interferometry; extrasolar planets AB Researches have suggested several techniques (ie.: pupil masking, coronography, nulling interferometry) for high contrast imaging that permit the direct detection and characterization of extrasolar planets. Our team at JPL, in previous papers(1,3), has described an instrument that will combine the best of several of these techniques: a single aperture visible nulling corograph. The elegant simplicity of this design enables a powerful planet-imaging instrument at modest cost. The heart of this instrument is the visible light nulling interferometer for producing deep, achromatic nulls over a wide optical band pass, and a coherent array of single mode optical fibers(2) that is key to suppressing the level of scattered light. Both of these key components are currently being developed and have produced intial results. This paper will review, in detail, the design of the nulling interferometer experiment and review the latest experimental results. These results illustrate that we are well on our way to developing the fundamental components necessary for planned mission. Likewise, our results demonstrate that the cur-rent nulling levels are already consistent with final requirements. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91105 USA. RP Wallace, JK (reprint author), CALTECH, Jet Propuls Lab, 4800 Oak Grove Dr, Pasadena, CA 91105 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5043-X J9 P SOC PHOTO-OPT INS PY 2003 VL 5170 BP 209 EP 216 DI 10.1117/12.506356 PG 8 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BY13C UT WOS:000187838700021 ER PT S AU Liu, DT Levine, BM Shao, M AF Liu, DT Levine, BM Shao, M BE Coulter, DR TI Design and fabrication of a coherent array of single-mode optical fibers for the nulling coronagraph SO TECHNIQUES AND INSTRUMENTATION FOR DETECTION OF EXOPLANETS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets CY AUG 05-07, 2003 CL SAN DIEGO, CA SP SPIE DE coherent fiber array; micro-lens array; step-index single-mode fiber; photonic crystal fiber; spatial filter; Zygo interferometer; nulling interferometer; coronagraph AB We present the development of a single-mode spatial filter array for the nulling coronagraph application. The development consists of two generations of fiber array designs and a Zygo-interferometer based lens array to fiber array alignment methodology. We discuss the use of large mode field diameter (MFD) fibers to relax fiber placement tolerance of the fiber array. The pros and cons of using the Photonic Crystal Fiber (PCF) for building the array are discussed. The future plan for implementing a 1000-channel class, single-mode spatial filter array is described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Liu, DT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 1 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5043-X J9 P SOC PHOTO-OPT INS PY 2003 VL 5170 BP 217 EP 228 DI 10.1117/12.508070 PG 12 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BY13C UT WOS:000187838700022 ER PT S AU Bowers, CW Woodgate, BE Lyon, RG AF Bowers, CW Woodgate, BE Lyon, RG BE Coulter, DR TI A novel method of high accuracy, wavefront phase and amplitude correction for coronagraphy SO TECHNIQUES AND INSTRUMENTATION FOR DETECTION OF EXOPLANETS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Techniques and Instrumentation for Detection of Exoplanets CY AUG 05-07, 2003 CL SAN DIEGO, CA SP SPIE DE coronagraphy AB Detection of extra-solar, and especially terrestrial-like planets, using coronagraphy requires an extremely high level of wavefront correction. For example, the study of Woodruff et al. (2002) has shown that phase uniformity of order 10(-4)lambda(rms) must be achieved over the critical range of spatial frequencies to produce the similar to10(10) contrast needed for the Terrestrial Planet Finder (TPF) mission. Correction of wavefront phase errors to this level may be accomplished by using a very high precision deformable mirror (DM). However, not only phase but also amplitude uniformity of the same scale (similar to10(-4)) and over the same spatial frequency range must be simultaneously obtained to remove all residual speckle in the image plane. We present a design for producing simultaneous wavefront phase and amplitude uniformity to high levels from an input wavefront of lower quality. The design uses a dual Michelson interferometer arrangement incorporating two DM and a single, fixed mirror (all at pupils) and two beamsplitters: one with unequal (asymmetric) beam splitting and one with symmetric beam splitting. This design allows high precision correction of both phase and amplitude using DM with relatively coarse steps and permits a simple correction algorithm. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bowers, CW (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. RI Woodgate, Bruce/D-2970-2012 NR 3 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5043-X J9 P SOC PHOTO-OPT INS PY 2003 VL 5170 BP 292 EP 306 DI 10.1117/12.532515 PG 15 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BY13C UT WOS:000187838700029 ER PT J AU Conway, E AF Conway, E TI First to fly: North Carolina and the beginnings of aviation. SO TECHNOLOGY AND CULTURE LA English DT Book Review C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Conway, E (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU JOHNS HOPKINS UNIV PRESS PI BALTIMORE PA JOURNALS PUBLISHING DIVISION, 2715 NORTH CHARLES ST, BALTIMORE, MD 21218-4319 USA SN 0040-165X J9 TECHNOL CULT JI Technol. Cult. PD JAN PY 2003 VL 44 IS 1 BP 180 EP 181 DI 10.1353/tech.2003.0008 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 652YJ UT WOS:000181408200021 ER PT S AU Hedges, SB AF Hedges, SB BE Donoghue, PCJ Smith, MP TI Molecular clocks and a biological trigger for Neoproterozoic Snowball Earth events and the Cambrian explosion SO TELLING THE EVOLUTIONARY TIME: MOLECULAR CLOCKS AND THE FOSSIL RECORD SE Systematics Association Special Volume Series LA English DT Proceedings Paper CT Joint Palaentological-Association/Systematic-Assocation Symposium held at the 3rd Biennial Meeting of the Systematic-Association CY SEP 05, 2001 CL Imperial Coll, London, ENGLAND HO Imperial Coll ID DETERMINING DIVERGENCE TIMES; ATMOSPHERIC OXYGEN; EARLY EVOLUTION; METAZOAN PHYLA; PROTEIN CLOCK; ANIMAL PHYLA; ORIGIN; LAND; MAMMALS; FOSSILS AB Two major events occurred in the history of the Earth and its biota during the late Precambrian and Cambrian (750-500 Ma; million years ago): a sequence of global glaciations (Snowball Earth events) followed by the sudden appearance in the fossil record of approximately half of the living animal phyla (the 'Cambrian explosion'). This has fuelled speculation that the two events were associated, perhaps through the generation of biological diversity during periods of isolation in glacial refugia, or in the period subsequent to isolation. However, recent molecular clock analyses have suggested that fungi and plants colonized land in the late Precambrian, considerably earlier than indicated by the fossil record, raising the possibility of a different connection between Snowball Earth events and the Cambrian explosion. These new data suggest a biological rather than geological trigger for the global glaciations, through increased rates of weathering by land fungi (e.g. lichens) and plants, and burial of decay-resistant carbon compounds of early land plants. The weathering and carbon burial would have lowered levels of carbon dioxide, possibly leading to the Snowball Earth events. A biological trigger can also explain the cyclic nature of the glaciations if they reflect cycles of extinction and recovery. Moreover, the fungal photobionts and early land plants may have generated sufficient oxygen in the latest Precambrian and Early Cambrian for animals to evolve larger body sizes and hard parts, explaining the Cambrian explosion. This model can be tested by increased precision of molecular clock estimates of divergence times and by searching for biomarkers and fossils of land fungi and plants in rocks of this time period. C1 NASA, Astrobiol Inst, Mueller Lab 208, University Pk, PA 16802 USA. RP Hedges, SB (reprint author), NASA, Astrobiol Inst, Mueller Lab 208, University Pk, PA 16802 USA. EM sbh1@psu.edu NR 83 TC 2 Z9 3 U1 1 U2 6 PU CRC PRESS-TAYLOR & FRANCIS GROUP PI BOCA RATON PA 6000 BROKEN SOUND PARKWAY NW, STE 300, BOCA RATON, FL 33487-2742 USA SN 0309-2593 BN 0-415-27524-5 J9 SYST ASSOC SPEC VOL JI Syst. Assoc. Spec. Vol. Ser. PY 2003 IS 66 BP 27 EP 40 PG 14 WC Biochemistry & Molecular Biology; Evolutionary Biology; Paleontology SC Biochemistry & Molecular Biology; Evolutionary Biology; Paleontology GA BY50X UT WOS:000189395500003 ER PT J AU Errico, RM Raeder, KD Fillion, L AF Errico, RM Raeder, KD Fillion, L TI Examination of the sensitivity of forecast precipitation rates to possible perturbations of initial conditions SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY LA English DT Article ID IDEALIZED EXTRATROPICAL CYCLONE; PRIMITIVE-EQUATION MODEL; ADJOINT SENSITIVITY; PHYSICAL PROCESSES; SINGULAR VECTORS; MESOSCALE MODEL; MOIST PHYSICS; PREDICTABILITY; ERRORS; SIMULATIONS AB An adjoint model that includes precipitation physics is applied to four synoptic cases in order to compare the sensitivities of both convective and non-convectivc precipitation rates with respect to initial perturbations of temperature, water vapor mixing ratio. vorticity or divergence. These are contrasted with sensitivities of barotropic vorticity. Forecast periods between 1 and 24 It are investigated. Root-mean-square values of the sensitivities as a function of vertical coordinate and field are presented as well as time series of impacts of optimal perturbations weighted by initial variances of uncertainties in the fields. For all the forecast aspects and cases considered. the greatest sensitivity and impacts are with regard to the temperature field. Precipitation is equally sensitive to vorticity and divergence, but when their relative uncertainties are considered. impacts of the vorticity dominate those of divergence. Precipitation is sensitive to initial specific humidity, but so is barotropic vorticity within a cyclone. The sensitivities of precipitation were not found to increase with forecast periods as much as the sensitivities to vorticity. suggesting that even within the same synoptic feature, different processes are responsible for the development of these distinct characteristics. Although comparison with corresponding impacts in the nonlinear model suggests that a 24 h period is too long for the adjoint-estimated precipitation impacts to be good approximations to the nonlinear results in some of the cases. 6-h adjoint-estimated results appear useful. C1 Canada Meteorol Ctr, Montreal, PQ, Canada. Natl Ctr Atmospher Res, Boulder, CO USA. RP Errico, RM (reprint author), NASA, Goddard Space Flight Ctr, Data Assimilat Off, Code 910-3, Greenbelt, MD 20771 USA. NR 27 TC 16 Z9 16 U1 0 U2 1 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6495 J9 TELLUS A JI Tellus Ser. A-Dyn. Meteorol. Oceanol. PD JAN PY 2003 VL 55 IS 1 BP 88 EP 105 DI 10.1034/j.1600-0870.2003.201394.x PG 18 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA 642NT UT WOS:000180811000006 ER PT S AU Nesbitt, JA Gleeson, B Sordelet, D Barrett, CA AF Nesbitt, JA Gleeson, B Sordelet, D Barrett, CA BE Chandra, T Torralba, JM Sakai, T TI Pt and Hf additions to NiAl bond coats and their effect on the lifetime of thermal barrier coatings SO THERMEC'2003, PTS 1-5 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 4th International Conference on Processing and Manufacturing of Advanced Materials CY JUL 07-11, 2003 CL UNIV CARLOS III MADRID, MADRID, SPAIN SP Minerals, Met & Mat Soc HO UNIV CARLOS III MADRID DE TBC's; thermal barrier coatings; Ni-aluminides; bond coats AB The lifetimes of thermal barrier coatings (TBC's) with various NiAlPt(HfZr) bond coats were determined by cyclic oxidation testing at 1163degreesC (2125degreesF). The bond coats were sprayed from powders by low pressure plasma spraying onto Rene N5 superalloy substrates. Yttria stabilized zirconia (8YSZ) top coats were applied by air plasma spraying. Surprisingly, there was not a strong correlation between TBC lifetime and Pt or Hf content although Zr additions decreased lifetimes. TBC failure morphologies and bond coat microstructures were examined and are discussed with respect to the bond coat compositions. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Nesbitt, JA (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 8 TC 13 Z9 13 U1 1 U2 7 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-919-9 J9 MATER SCI FORUM PY 2003 VL 426-4 BP 209 EP 214 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BW92N UT WOS:000183626400027 ER PT S AU Bonacuse, PJ Kalluri, S AF Bonacuse, PJ Kalluri, S BE McGaw, MA Kalluri, S Bressers, J Peteves, SD TI Cyclic deformation behavior of Haynes 188 superalloy under axial-torsional, thermomechanical loading SO THERMOMECHANICAL FATIGUE BEHAVIOR OF MATERIALS: 4TH VOLUME SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT 4th Symposium on Thermomechanical Fatigue Behavior of Materials CY NOV 07-08, 2001 CL DALLAS, TX SP ASTM Comm E08 DE thermomechanical; cyclic deformation; multiaxial; axial-torsional; and cobalt-base superalloy AB Four types of axial-torsional, thermomechanical fatigue experiments have been performed on Haynes 188 superalloy: mechanically in-phase and thermally in-phase, mechanically in-phase and thermally out-of-phase, mechanically out-of-phase and thermally inphase, and mechanically out-of-phase and thermally out-of-phase. In this study, representative cyclic deformation behavior of the axial-torsional, thermomechanical experiments is presented and compared with isothermal experiments performed at the two temperature extremes (316degreesC and 760degreesC) of the thermal cycle. The evolution of cyclic hardening under axial-torsional, thermomechanical conditions is also presented and compared with the corresponding isothermal data. C1 NASA, Glenn Res Ctr, Ohio Aerosp Inst, Brookpark, OH 44135 USA. NR 8 TC 0 Z9 0 U1 2 U2 11 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-3467-3 J9 AM SOC TEST MATER PY 2003 VL 1428 BP 65 EP 80 DI 10.1520/STP11427S PG 16 WC Thermodynamics; Mechanics; Materials Science, Characterization & Testing SC Thermodynamics; Mechanics; Materials Science GA BX89H UT WOS:000186758000005 ER PT S AU Good, BS Chubb, DL AF Good, BS Chubb, DL BE Coutts, TJ Guazzoni, G Luther, J TI Theoretical comparison of erbium, holmium and thulium aluminum garnet selective emitters SO THERMOPHOTOVOLTAIC GENERATION OF ELECTRICITY SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 5th Conference on Thermophotovoltaic Generation of Electricity CY SEP 16-19, 2002 CL ROME, ITALY SP USA, CECOM, USA, Off Res (European Off), Natl Renewable Energy Lab, US DOE, NASA Glenn Res Ctr AB Spectral control through the use of selective emitters is an important means of improving the efficiency of thermophotovoltaic (TPV) systems. The availability of PV cells having a wide range of bandgap energies, along with the development of selective emitters having a range of emission band energies, gives the developer of TPV power systems a wide range of options. The rare earth aluminum garnet selective emitters developed in our laboratory offer a number of advantages when used in such systems [1-3]. In this paper, we present results of a detailed computational study of the effects of a number of design and operating parameters, including emitter film thickness, scattering within the film, and the temperature gradient across the film thickness, on the performance of three rare-earth aluminum garnet selective emitters. Specifically, we present emitter efficiency, net emittance, wavelength-dependent emittance, total output power, and the useful output power, for Er3Al5O12, Ho3Al5O12, and Tm3Al5O12 emitters, as functions of the above parameters. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Good, BS (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 7 TC 0 Z9 0 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0113-6 J9 AIP CONF PROC PY 2003 VL 653 BP 142 EP 154 PG 13 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA BW21J UT WOS:000181203400014 ER PT S AU Chubb, DL Wolford, DS Meulenberg, A DiMatteo, RS AF Chubb, DL Wolford, DS Meulenberg, A DiMatteo, RS BE Coutts, TJ Guazzoni, G Luther, J TI Semiconductor silicon as a selective emitter SO THERMOPHOTOVOLTAIC GENERATION OF ELECTRICITY SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 5th Conference on Thermophotovoltaic Generation of Electricity CY SEP 16-19, 2002 CL ROME, ITALY SP USA, CECOM, USA, Off Res (European Off), Natl Renewable Energy Lab, US DOE, NASA Glenn Res Ctr ID TEMPERATURE; EMISSIVITY AB Silicon operating in a vacuum is a good candidate thermal emitter since it has a high melting point (1680 K). The semiconductor bandgap, which can provide selective emission, adds to the potential for high operating temperature and, therefore, high radiated power. We present the detailed emitter theory, along with both theoretical and experimental results for spectral emittance of thin (similar to1 mum) silicon films on sapphire substrates with a platinum backing. These results show the importance of temperature and film thickness in determining the selective spectral emittance and, with the proper material parameters, can be readily extended to other materials and systems. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Chubb, DL (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RI Meulenberg, Andrew/K-4194-2012 OI Meulenberg, Andrew/0000-0003-3570-4705 NR 14 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0113-6 J9 AIP CONF PROC PY 2003 VL 653 BP 174 EP 200 PG 27 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA BW21J UT WOS:000181203400017 ER PT S AU Winfree, WP Zalameda, JN AF Winfree, WP Zalameda, JN BE Cramer, KE Maldague, XP TI Thermographic determination of delamination depth in composites SO THERMOSENSE XXV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Thermosense XXV CY APR 22-24, 2003 CL ORLANDO, FL SP SPIE DE thermography; composite; delamination; nondestructive evaluation ID DAMAGE; SYSTEM AB The determination of the depth and size of delaminations is important for assessing their impact on structural integrity. A common technique for depth determination from thermal responses relies on a calibration of the technique based on flat bottom hole in a NDE standard. This assumes a delamination will effectively block all the heat diffusion from the region above the delamination to the region below the delamination. For graphite fiber reinforced composites, where a thin delamination has a contact resistance, which is comparable with the thermal resistance of the layer above it, this assumption is inaccurate. This paper discusses thermographic depth profiling based on an analytical model for heat diffusion representing two layers connected by a contact resistance. The model is shown to accurately represent the thermal response obtained for flash heating of composite specimens with known delaminations. Using the model to fit the thermal responses enables an estimation of the depth of the delamination. The accuracy of the technique is determined from measurements on composite specimens with delaminations at known depths. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Winfree, WP (reprint author), NASA, Langley Res Ctr, MS 231, Hampton, VA 23681 USA. NR 6 TC 17 Z9 17 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4932-6 J9 P SOC PHOTO-OPT INS PY 2003 VL 5073 BP 363 EP 373 DI 10.1117/12.485866 PG 11 WC Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Instruments & Instrumentation; Materials Science; Optics GA BW84B UT WOS:000183318500039 ER PT S AU Zalameda, JN Rajic, N Winfree, WP AF Zalameda, JN Rajic, N Winfree, WP BE Cramer, KE Maldague, XP TI A comparison of image processing algorithms for thermal nondestructive evaluation SO THERMOSENSE XXV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Thermosense XXV CY APR 22-24, 2003 CL ORLANDO, FL SP SPIE DE thermal nondestructive evaluation algorithms; defect contrast; corrosion; delamination and thermal diffusivity ID THERMOGRAPHY AB Thermography involves the application of heat to a structure and observation of surface temperature anomalies to reveal subsurface defects. Detection of subsurface defects can be greatly enhanced by the real time capture of a series of thermal images in time and the subsequent analysis of these images using various image processing algorithms. By applying image-processing algorithms, defects not readily observable can be detected and quantitatively characterized. The focus of this work is to investigate several of the numerous data reduction algorithms for thermal nondestructive evaluation by comparing results on a set of test samples. Some new types of data reduction algorithms have been recently developed with advantages such as noise reduction, file size compression, and material property measurements. By comparing various algorithms on factors such as computational speed, simplicity of use, robustness to noise, quantitative information, and optimum defect detection the most efficient algorithm may be chosen based on the user's needs. C1 NASA, Langley Res Ctr, USA,Nondestruct Evaluat Sci Branch,MS 231, Res Lab,Vehicle Technol Directorate, Hampton, VA 23661 USA. RP Zalameda, JN (reprint author), NASA, Langley Res Ctr, USA,Nondestruct Evaluat Sci Branch,MS 231, Res Lab,Vehicle Technol Directorate, Hampton, VA 23661 USA. NR 8 TC 14 Z9 14 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4932-6 J9 P SOC PHOTO-OPT INS PY 2003 VL 5073 BP 374 EP 385 DI 10.1117/12.485869 PG 12 WC Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Instruments & Instrumentation; Materials Science; Optics GA BW84B UT WOS:000183318500040 ER PT S AU Smits, J Wincheski, B Ingram, J Watkins, N Jordan, J AF Smits, J Wincheski, B Ingram, J Watkins, N Jordan, J BE Orlando, TM Merhari, L Taylor, DP Ikuta, K TI Controlled deposition and applied field alignment of single walled carbon nanotubes for CNT device fabrication. SO THREE-DIMENSIONAL NANOENGINEERED ASSEMBLIES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Three-Dimensional Nanoengineered Assemblies CY DEC 01-05, 2002 CL BOSTON, MA SP USA, Off Res, USAF, Off Sci Res, Natl Sci Fdn, USN, Off Naval Res AB Carbon nanotubes (CNTs) offer great potential for advanced sensing devices due to their unique electronic transport properties. However, a significant obstacle to the realization of practical CNT devices is the formation of controlled, reliable and reproducible CNT to metallic contacts. In this work, a procedure for the deposition and alignment of CNTs onto metallic electrodes using chemically functionalized lithographic patterns is reported. This method uses photo and electron beam lithography to pattern simple Cr/Au thin film circuits on oxidized Si substrates. The circuits are then re-patterned with a self-assembled monolayer (SAM) of 3-aminopropyltriethoxysilane (APTES) to specify desired CNT locations between electrodes. The application of an electric field to the metallic contacts during the deposition of solution suspended single walled CNTs causes alignment of the CNTs in the field direction. This method consistently produces aligned CNTs in the defined locations. C1 NASA, Langley Res Ctr, Lockheed Martin Space Operat, Hampton, VA 23665 USA. RP Smits, J (reprint author), NASA, Langley Res Ctr, Lockheed Martin Space Operat, Hampton, VA 23665 USA. NR 8 TC 0 Z9 0 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-676-1 J9 MATER RES SOC SYMP P PY 2003 VL 739 BP 205 EP 210 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA BX10V UT WOS:000184304600029 ER PT S AU Cobleigh, JM Giannakopoulu, D Pasareanu, CS AF Cobleigh, JM Giannakopoulu, D Pasareanu, CS BE Garavel, H Hatcliff, J TI Learning assumptions for compositional verification SO TOOLS AND ALGORITHMS FOR THE CONSTRUCTION AND ANALYSIS OF SYSTEMS, PROCEEDINGS SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT Joint European Conference on Theory and Practice of Software (ETAPS 2003) CY APR 05-13, 2003 CL WARSAW, POLAND SP Warsaw Univ, Inst Informat, Fdn Informat Technol Dev, European Assoc Theoret Comp Sci, European Assoc Programming Languages & Syst, European Assoc Software Sci & Technol, ACM SIGACT, ACM SIGSOFT, ACM SIGPLAN AB Compositional verification is a promising approach to addressing the state explosion problem associated with model checking. One compositional technique advocates proving properties of a system by checking properties of its components in an assume-guarantee style. However, the application of this technique is difficult because it involves non-trivial human input. This paper presents a novel framework for performing assume-guarantee reasoning in an-incremental and fully automated fashion. To check a component against a property, our approach generates assumptions that the environment needs to satisfy for the property to hold. These assumptions are then discharged on the rest of the system. Assumptions are computed by a learning algorithm. They are initially approximate, but become gradually more precise by means of counterexamples obtained by model checking the component and its environment, alternately. This iterative process may at any stage conclude that the property is either true or false in the system. We have implemented our approach in the LTSA tool and applied it to a NASA system. C1 Univ Massachusetts, Dept Comp Sci, Amherst, MA 01003 USA. Kestrel Technol LLC, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Univ Massachusetts, Dept Comp Sci, Amherst, MA 01003 USA. EM jcobleig@cs.umass.edu; dimitra@email.arc.nasa.gov; pcorina@email.arc.nasa.gov NR 24 TC 114 Z9 115 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-00898-5 J9 LECT NOTES COMPUT SC PY 2003 VL 2619 BP 331 EP 346 PG 16 WC Computer Science, Theory & Methods SC Computer Science GA BW74M UT WOS:000183012400023 ER PT S AU Khurshid, S Pasareanu, CS Visser, W AF Khurshid, S Pasareanu, CS Visser, W BE Garavel, H Hatcliff, J TI Generalized symbolic execution for model checking and testing SO TOOLS AND ALGORITHMS FOR THE CONSTRUCTION AND ANALYSIS OF SYSTEMS, PROCEEDINGS SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT Joint European Conference on Theory and Practice of Software (ETAPS 2003) CY APR 05-13, 2003 CL WARSAW, POLAND SP Warsaw Univ, Inst Informat, Fdn Informat Technol Dev, European Assoc Theoret Comp Sci, European Assoc Programming Languages & Syst, European Assoc Software Sci & Technol, ACM SIGACT, ACM SIGSOFT, ACM SIGPLAN AB Modern software systems, which often are concurrent and manipulate complex data structures must be extremely reliable. We present a novel framework based on symbolic execution, for automated checking of such systems. We provide a two-fold generalization of traditional symbolic execution based approaches. First, We define a source to source translation to instrument a program, which enables standard model checkers to perform symbolic execution of the program. Second, we give a novel symbolic execution algorithm that handles dynamically allocated structures (e.g., lists and trees), method preconditions (e.g., acyclicity), data (e.g., integers and strings) and concurrency. The program instrumentation enables a model checker to automatically explore different program heap configurations and manipulate logical formulae on program data (using a decision procedure). We illustrate two applications of our framework: checking correctness of multi-threaded programs that take inputs from unbounded domains with complex, structure and generation of non-isomorphic test inputs that satisfy a testing criterion. Our implementation for Java uses the Java PathFinder model checker. C1 MIT, Comp Sci Lab, Cambridge, MA 02139 USA. NASA, Ames Res Ctr, RIACS, USRA, Moffett Field, CA 94035 USA. RP MIT, Comp Sci Lab, 545 Technol Sq, Cambridge, MA 02139 USA. EM khurshid@lcs.mit.edu; pcorina@email.arc.nasa.gov; wvisser@email.arc.nasa.gov NR 20 TC 98 Z9 100 U1 0 U2 5 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-00898-5 J9 LECT NOTES COMPUT SC PY 2003 VL 2619 BP 553 EP 568 PG 16 WC Computer Science, Theory & Methods SC Computer Science GA BW74M UT WOS:000183012400039 ER PT S AU Coulter, DR AF Coulter, DR BE Lacoste, H TI NASA's Terrestrial Planet Finder mission: The search for habitable planets SO TOWARDS OTHER EARTHS: DARWIN/TPF AND THE SEARCH FOR EXTRASOLAR TERRESTRIAL PLANETS, PROCEEDINGS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Conference on Towards Other Earths - DARWIN/TPF and the Search for Extrasolar Terrestrial Planets CY APR 22-25, 2003 CL Heidelberg, GERMANY SP Max Planck Inst Astron, European Space Agcy, NASA ID COMPANION AB The Terrestrial Planet Finder (TPF) is one of the major missions in the NASA Office of Space Science Origins Theme, The primary science objective of the TPF mission is to search for, detect, and characterize planetary systems beyond our own Solar System, including specifically Earth-like planets. This paper describes the current status of TPF as well as outlines the plans for near term science investigations, mission studies and technology development leading to a mission architecture selection in the 2006 time frame in support of a launch by the middle of the next decade. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Coulter, DR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-849-2 J9 ESA SP PUBL PY 2003 VL 539 BP 47 EP 54 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BY94B UT WOS:000189500300006 ER PT S AU Grady, CA AF Grady, CA BE Lacoste, H TI High contrast imaging with HST/STIS: The current potential for planet finding SO TOWARDS OTHER EARTHS: DARWIN/TPF AND THE SEARCH FOR EXTRASOLAR TERRESTRIAL PLANETS, PROCEEDINGS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Conference on Towards Other Earths - DARWIN/TPF and the Search for Extrasolar Terrestrial Planets CY APR 22-25, 2003 CL Heidelberg, GERMANY SP Max Planck Inst Astron, European Space Agcy, NASA DE coronagraphic imaging; protoplanetary disks; debris disks ID HERBIG AE STAR; CORONAGRAPHIC OBSERVATIONS; CIRCUMSTELLAR DISK; BETA-PICTORIS; HD-100546; DUST; ASYMMETRIES; ENVIRONMENT; IMAGES; ORIGIN AB The Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope has a simple white-light coronagraph which has been used to image circumstellar envelopes, jets, disks, and to detect low-mass companions associated with pre-Main Sequence stars and the more IR-luminous debris disks. STIS has also been used to image near the millimeter bright knot associated with the candidate planetary system epsilon Eri. The STIS dataset has resulted in detections of circumstellar nebulosity with surface bright-ess ranging from 10(-3.5) to 10(-6.5) per HST resolution element relative to the occulted star, and limiting contrasts for nebulosity and point sources associated with e Eri down to 10(-9.5) per HST resolution element relative to the star. These data constitute some of the deepest coronagraphic imagery currently available for systems which will be of interest to future planet searches by Darwin/TPF. We summarize the lessons learned and the implications for the next generation of planet search programs. C1 NASA, Goddard Space Flight Ctr, Eureka Sci, Greenbelt, MD 20771 USA. RP Grady, CA (reprint author), NASA, Goddard Space Flight Ctr, Eureka Sci, Code 681, Greenbelt, MD 20771 USA. NR 38 TC 0 Z9 0 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-849-2 J9 ESA SP PUBL PY 2003 VL 539 BP 57 EP 67 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BY94B UT WOS:000189500300007 ER PT S AU Borucki, WJ Koch, D Basri, G Brown, T Caldwell, D DeVore, E Dunham, E Gautier, T Geary, J Gilliland, R Gould, A Howell, S Jenkins, J AF Borucki, WJ Koch, D Basri, G Brown, T Caldwell, D DeVore, E Dunham, E Gautier, T Geary, J Gilliland, R Gould, A Howell, S Jenkins, J BE Lacoste, H TI Kepler Mission: A mission to find Earth-size planets in the habitable zone SO TOWARDS OTHER EARTHS: DARWIN/TPF AND THE SEARCH FOR EXTRASOLAR TERRESTRIAL PLANETS, PROCEEDINGS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Conference on Towards Other Earths - DARWIN/TPF and the Search for Extrasolar Terrestrial Planets CY APR 22-25, 2003 CL Heidelberg, GERMANY SP Max Planck Inst Astron, European Space Agcy, NASA ID EXTRASOLAR GIANT PLANETS; STARS; SPECTRA AB The Kepler Mission is a NASA Discovery-class mission designed to continuously monitor the brightness of 100,000 main sequence stars to detect the transit of Earth-size and larger planets. It is a wide field of view photometer with a Schmidt-type telescope and an array of 42 CCDs covering the 100 sq. degree field-of-view (FOV). It has a 0.95 m aperture and a 1.4 m primary and is designed to attain a photometric precision of 20 parts per million (ppm) for 12(th) magnitude solar-like stars for a 6.5-hour transit duration. It will continuously observe 100,000 main sequence stars from 9(th) to 15(th) magnitude in the Cygnus constellation for a period of four years with a cadence of 4 measurements per hour. The photometer is scheduled to be launched in 2007 into heliocentric orbit. A ground-based program to classify all 450,000 stars brighter than 15(th) magnitude in the FOV and to conduct a detailed examination of a subset of the stars that show planetary companions is also planned. Hundreds of Earth-size planets should be detected if they are common around solar-like stars. Ground-based spectrometric observations of those stars with planetary companions will be made to determine the dependences of the frequency and size of terrestrial planets on stellar characteristics such as type and metallicity. A null result would imply that terrestrial planets are rare. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Borucki, WJ (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 11 TC 16 Z9 16 U1 0 U2 1 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-849-2 J9 ESA SP PUBL PY 2003 VL 539 BP 69 EP 81 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BY94B UT WOS:000189500300008 ER PT S AU Danchi, WC Allen, RJ Benford, DJ Deming, D Gezari, DY Kuchner, M Leisawitz, DT Linfield, R Millan-Gabet, R Monnier, JD Mumma, M Mundy, LG Noecker, C Rajagopal, J Seager, S Traub, WA AF Danchi, WC Allen, RJ Benford, DJ Deming, D Gezari, DY Kuchner, M Leisawitz, DT Linfield, R Millan-Gabet, R Monnier, JD Mumma, M Mundy, LG Noecker, C Rajagopal, J Seager, S Traub, WA BE Lacoste, H TI The Fourier-Kelvin stellar interferometer SO TOWARDS OTHER EARTHS: DARWIN/TPF AND THE SEARCH FOR EXTRASOLAR TERRESTRIAL PLANETS, PROCEEDINGS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Conference on Towards Other Earths - DARWIN/TPF and the Search for Extrasolar Terrestrial Planets CY APR 22-25, 2003 CL Heidelberg, GERMANY SP Max Planck Inst Astron, European Space Agcy, NASA AB The Fourier-Kelvin Stellar Interferometer (FKSI) is a mission concept for an imaging and nulling interferometer for the mid-infrared spectral region (528 microns). FKSI is conceived as a scientific and technological pathfinder to TPF/DARWIN as well as the NASA Vision Missions SAFIR and SPECS. It will also be a high angular resolution infrared space observatory complementary to JWST. The scientific emphasis of the mission is on detection and spectroscopy of the atmospheres of Extra-solar Giant Planets (EGPs), the search for Brown Dwarfs and other low mass stellar companions, and the evolution of protostellar systems. FKSI can observe these systems from just after the collapse of the precursor molecular cloud core, through the formation of the disk surrounding the protostar, the formation of planets in the disk, and eventual dispersal of the disk material. FKSI could also play a very powerful role in the investigation of the structure of active galactic nuclei and extra-galactic star formation. We present the major results of a set of detailed design studies for the FKSI mission that were performed as a method of understanding major trade-offs pertinent to schedule, cost, and risk in preparation for submission of a Discovery proposal. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Danchi, WC (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012; Kuchner, Marc/E-2288-2012; mumma, michael/I-2764-2013 OI Benford, Dominic/0000-0002-9884-4206; NR 12 TC 4 Z9 4 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-849-2 J9 ESA SP PUBL PY 2003 VL 539 BP 83 EP 90 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BY94B UT WOS:000189500300009 ER PT S AU Serabyrn, E AF Serabyrn, E BE Lacoste, H TI An overvew of the Keck interferomieter nuller SO TOWARDS OTHER EARTHS: DARWIN/TPF AND THE SEARCH FOR EXTRASOLAR TERRESTRIAL PLANETS, PROCEEDINGS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Conference on Towards Other Earths - DARWIN/TPF and the Search for Extrasolar Terrestrial Planets CY APR 22-25, 2003 CL Heidelberg, GERMANY SP Max Planck Inst Astron, European Space Agcy, NASA AB The first high dynamic range interferometry mode planned to come on line at the Keck Observatory is mid-infrared nulling interferometry. In this paper, an overview is given of the goals and experimental configuration of the Keck Interferometer Nuller (KIN). After an introduction to the science enabled by mid-infrared nulling interferometry on the Keck Interferometer's baseline, a system level overview of the experiment is provided, which includes a discussion of the optical path-length matching and stabilization approaches. This is followed by brief tours of both the nulling beam-combiner breadboard and the mid-infrared camera to be used in the experiment. The paper concludes with a discussion of the performance levels attained to date with the mid-infrared nullers built at the Jet Propulsion Laboratory. These symmetric millers, all based on the modified Mach-Zehnder beam-combiner configuration, have now experimentally verified the predicted dual-polarization nulling capability of a reversed beamsplitter pair arrangement. To date, the JPL nulling beamcombiners have nulled broadband thermal mid-infrared radiation to the 10(-4) level, and monochromatic (10.6 mum CO2 laser) radiation to the 10(-6) level. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Serabyrn, E (reprint author), CALTECH, Jet Prop Lab, 171-113, Pasadena, CA 91109 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-849-2 J9 ESA SP PUBL PY 2003 VL 539 BP 91 EP 98 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BY94B UT WOS:000189500300010 ER PT S AU Beichman, CA AF Beichman, CA BE Lacoste, H TI How many earths are enough? SO TOWARDS OTHER EARTHS: DARWIN/TPF AND THE SEARCH FOR EXTRASOLAR TERRESTRIAL PLANETS, PROCEEDINGS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Conference on Towards Other Earths - DARWIN/TPF and the Search for Extrasolar Terrestrial Planets CY APR 22-25, 2003 CL Heidelberg, GERMANY SP Max Planck Inst Astron, European Space Agcy, NASA AB The goals of NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin missions are to find and characterize terrestrial planets in the habitable zones of other stars, and to search for evidence of life in the atmospheres of any planets found. A key issue that must be addressed is the size of the sample of stars that must be searched before the scientific community, the funding agencies, and the public at large will be satisfied that an expensive space observatory will have a high probability of success. This question lies at the heart of the definition of TPF/Darwin. In this paper, I discuss some of the parameters that bound the size of the TPF/Darwin sample and outline a science program to improve our knowledge so that we can make timely decisions about the scope and expense of TPF/Darwin. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Beichman, CA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-849-2 J9 ESA SP PUBL PY 2003 VL 539 BP 271 EP 275 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BY94B UT WOS:000189500300029 ER PT S AU Lay, O Jeganathan, M Peters, R AF Lay, O Jeganathan, M Peters, R BE Lacoste, H TI Adaptive nulling: A new tool for interferometric exo-planet detection SO TOWARDS OTHER EARTHS: DARWIN/TPF AND THE SEARCH FOR EXTRASOLAR TERRESTRIAL PLANETS, PROCEEDINGS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Conference on Towards Other Earths - DARWIN/TPF and the Search for Extrasolar Terrestrial Planets CY APR 22-25, 2003 CL Heidelberg, GERMANY SP Max Planck Inst Astron, European Space Agcy, NASA AB Deep, stable nulling of starlight requires careful control of the amplitudes and phases of the beams that are being combined. The detection of earth-like planets using the interferometer architectures currently being considered require that the E-field amplitudes are balanced at the level of similar to 0.1%, and the phases are controlled at the level of 1 mrad (corresponding to similar to 1.5 nm for a wavelength of 10 mum). These conditions must be met simultaneously at all wavelengths across the science band, and for both polarization states, imposing unrealistic tolerances on the symmetry between the optical beamtrains. We introduce the concept of a compensator that is inserted into the beamtrain, which can adaptively correct for the mismatches across the spectrum, enabling deep nulls with realistic, imperfect optics. The design presented uses a deformable mirror to adjust the amplitude and phase of each beam as an arbitrary function of wavelength and polarization. A proof-of-concept experiment will be conducted at visible / near-IR wavelengths, followed by a system operating in the Mid-IR band. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Lay, O (reprint author), Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-849-2 J9 ESA SP PUBL PY 2003 VL 539 BP 503 EP 506 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BY94B UT WOS:000189500300071 ER PT S AU Mennesson, B Crawford, SL Serabyn, E Martin, S Creech-Eakman, M Hardy, G AF Mennesson, B Crawford, SL Serabyn, E Martin, S Creech-Eakman, M Hardy, G BE Lacoste, H TI Laboratory performance of the Keck interferometer nulling beam combiner SO TOWARDS OTHER EARTHS: DARWIN/TPF AND THE SEARCH FOR EXTRASOLAR TERRESTRIAL PLANETS, PROCEEDINGS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT Conference on Towards Other Earths - DARWIN/TPF and the Search for Extrasolar Terrestrial Planets CY APR 22-25, 2003 CL Heidelberg, GERMANY SP Max Planck Inst Astron, European Space Agcy, NASA DE nulling; interferometry; mid-infrared ID LIGHT; DEEP AB Now that regular visibility squared measurements are routinely achieved, mid-infrared nulling is the next observing mode to be implemented on the Keck Interferometer (KI). This mode's main objective is the characterization of exo-zodiacal dust disks around nearby main sequence stars (Kuchner & Serabyn, 2003) in support of the TPF space mission. Keck Nuller also shares numerous characteristics with an interferometric TPF, and will then serve as a technical precursor for this mission. We report here the results obtained in the laboratory with the KI mid-IR nulling beam combiner, which is based on a dual polarization Modified Mach Zender (MMZ) combiner (Serabyn & Colavita, 2001), and dispersion compensation and achromatic nulling through zinc-selenide (ZnSe) dielectric plates (Koresko et al., 2002). Best broad-band dual polarization transient rejection levels obtained so far on thermal sources ran-e from 7500:1 over a 29% bandwidth (FWHM from 9.20 to 12.35 microns) to 17000:1 with an 18% bandwidth (FWHM from 9.70 to 11.65 microns). These rejections are basically one order of magnitude better than the limit set by the stellar finite angular size, which is about 1000:1 at 10 microns for a 1 mas diameter star observed with KI 80 m baseline. These results then validate the optical concept chosen for the nulling back-end, which now needs to be properly integrated with the mid-IR nulling camera and the KI beam train. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mennesson, B (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-849-2 J9 ESA SP PUBL PY 2003 VL 539 BP 525 EP 528 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BY94B UT WOS:000189500300075 ER PT S AU Velusamy, T Angel, RP Eatchel, A Tenerelli, D Woolf, NJ AF Velusamy, T Angel, RP Eatchel, A Tenerelli, D Woolf, NJ BE Lacoste, H TI Single and double Bracewell nulling interferometer in space SO TOWARDS OTHER EARTHS: DARWIN/TPF AND THE SEARCH FOR EXTRASOLAR TERRESTRIAL PLANETS, PROCEEDINGS SE ESA Special Publications LA English DT Proceedings Paper CT Conference on Towards Other Earths - DARWIN/TPF and the Search for Extrasolar Terrestrial Planets CY APR 22-25, 2003 CL Heidelberg, GERMANY SP Max Planck Inst Astron, European Space Agcy, NASA ID GIANT PLANETS AB As part of a NASA NRA study we have examined the design and use of a small Bracewell nulling interferometer in space for observations of Jovian and terrestrial planets in the 4-12 mum spectral region. At these wavelengths, the contrast is typically 10(-7) for most planets while younger and/or more massive Jovian planets have a contrast 100 times better. For planets farther from their star than Earth, a short baseline can provide good null depth and still have adequate resolution. With the single Bracewell nulling interferometer described here, massive/young giant planets far from their star are not difficult to observe and young Jovian mass planetary systems as far as 100 pc can be probed. A program to study planetary systems like the solar system is much harder. In the case of older and smaller planets, distinguishing the planet signal from the star and local zodiacal background is much harder and requires both high stability of the gain for the IR detectors, and nulling over periods of hours. The difficulties of a 2-telescope, single Bracewell nuller are overcome using a dual Bracewell nuller consisting of four telescopes, and phase chopping between two null beams. Double Bracewell nulling described here will have the potential to detect Earth's around 20 nearby stars. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Velusamy, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Thangasamy.Velusamy@jpl.nasa.gov NR 9 TC 1 Z9 1 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-849-2 J9 ESA SPEC PUBL PY 2003 VL 539 BP 631 EP 636 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BY94B UT WOS:000189500300096 ER PT S AU Bar-Cohen, Y Sherrit, S Bao, XQ Chang, ZS AF Bar-Cohen, Y Sherrit, S Bao, XQ Chang, ZS BE BarCohen, Y TI Enabling novel space and terrestrial applications using transducing materials at JPL SO TRANSDUCING MATERIALS AND DEVICES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Transducing Materials and Devices CY OCT 30-NOV 01, 2002 CL BRUGGE, BELGIUM SP SPIE DE actuators; ultrasonic drill; Piezopump; artificial muscles; electroactive polymers; biomimetics; ferrosource; USM AB Transducing materials are being used in many aspects of our daily life serving as actuators, sensors, displays, communications and other components of commercial mechanisms.. At JPL, such materials are being used to enable novel space and terrestrial applications. This effort involves mostly the use of piezoelectric, electroactive polymers (EAP), and shape memory alloys (SMA). The piezoelectric based devices and mechanisms that were developed include ultrasonic motors, piezopump, ultrasonic/sonic driller/corer (USDC), and ferrosource. Further, the electroactive polymers were used to demonstrate a gripper, wiper, lifter and haptic interfaces. The research and develop tasks consists analytical modeling, experimental corroboration, material characterization as well as device and mechanisms design, construction and demonstration. This effort is multidisciplinary requiring expertise that is complemented through international cooperation. The research team activity will be reviewed in this paper. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bar-Cohen, Y (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 13 TC 0 Z9 0 U1 0 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4741-2 J9 P SOC PHOTO-OPT INS PY 2003 VL 4946 BP 8 EP 16 DI 10.1117/12.468370 PG 9 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BW51N UT WOS:000182252000002 ER PT S AU Dooley, JA Good, NR White, CV Leland, RS AF Dooley, JA Good, NR White, CV Leland, RS BE BarCohen, Y TI Magnetoelastic vibration damping properties of TbDy alloys SO TRANSDUCING MATERIALS AND DEVICES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Transducing Materials and Devices CY OCT 30-NOV 01, 2002 CL BRUGGE, BELGIUM SP SPIE ID MAGNETOSTRICTION AB Damping of axial and bending mode vibrations in giant magnetoelastic polycrystalline TbDy alloys was studied at cryogenic temperatures. All specimens of TbDy were arc-melted in the proper composition ratio and dropped into a chilled copper mold. Additional treatments consisted of cold plane-rolling to induce crystallographic texture and then heat-treating to relieve internal stress. Mechanical hysteretic losses were measured at various strains, frequencies, and loading configurations down to 77 K. Both as-cast and textured polycrystalline ThDy samples were tested along with an aluminum specimen for comparison. Loss factors at multiple natural vibration frequencies of the samples were measured for axial modes. Larger damping rates were measured for axial mode vibrations than for bending mode vibrations, possibly reflecting the larger specimen volume contributing to magnetoelastic damping. At LN2 temperatures TbDy materials demonstrated eta > 0.05 at 0.01 Hz and eta > 0.1 at higher frequencies from 0.6-1.5 kHz. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Dooley, JA (reprint author), Jet Prop Lab, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4741-2 J9 P SOC PHOTO-OPT INS PY 2003 VL 4946 BP 25 EP 34 DI 10.1117/12.468377 PG 10 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BW51N UT WOS:000182252000004 ER PT J AU Pepper, SV Kingsbury, EP AF Pepper, SV Kingsbury, EP TI Spiral orbit tribometry - Part I: Description of the tribometer SO TRIBOLOGY TRANSACTIONS LA English DT Article DE bearings; rolling element; ball; boundary lubrication; engineering analysis and computing; contact mechanics; friction testing; bench tests ID BEARING AB A new rolling contact tribometer based on a planar thrust bearing geometry is described. The bearing "races" are flat plates that drive a ball into a near-circular, spiral path. The spiraling ball is returned to its initial radius each revolution around the race by a "guide plate" backed by a force transducer. The motions of the ball are analyzed and the force exerted by the ball on the guide plate is related to the friction coefficient of the system. The experimental characteristics of the system are presented and the system is shown to exhibit the behavior expected for a tribometer. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Interesting Rolling Contact, Walpole, MA 02081 USA. RP Pepper, SV (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 9 TC 11 Z9 14 U1 3 U2 4 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD JAN PY 2003 VL 46 IS 1 BP 57 EP 64 DI 10.1080/10402000308982600 PG 8 WC Engineering, Mechanical SC Engineering GA 642TA UT WOS:000180819500009 ER PT J AU Pepper, SV Kingsbury, EP AF Pepper, SV Kingsbury, EP TI Spiral orbit tribometry - Part II: Evaluation of three liquid lubricants in vacuum SO TRIBOLOGY TRANSACTIONS LA English DT Article DE adverse environments tribology; vacuum and space; bearings; rolling element; ball; boundary lubrication; friction; bench tests; lubricant degradation; stability; chemical attack ID PERFLUOROPOLYETHERS; TEMPERATURES; CONTACT; FILMS AB The coefficients of friction and relative degradation rates Of three lubricants run in the boundary regime in vacuum are evaluated in a Spiral Orbit Tribometer. This tribometer subjected the lubricants to rolling contact conditions similar to those found in angular contact ball bearings. A multiply alkylated cyclopentane (MAC) hydrocarbon lubricant suffered degradation at a rate almost two orders of magnitude less than the degradation rate of two perfluoropolyalkylether (PFPE) lubricants. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Interesting Rolling Contact, Walpole, MA 02081 USA. RP Pepper, SV (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 12 TC 14 Z9 16 U1 2 U2 7 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD JAN PY 2003 VL 46 IS 1 BP 65 EP 69 DI 10.1080/10402000308982601 PG 5 WC Engineering, Mechanical SC Engineering GA 642TA UT WOS:000180819500010 ER PT J AU Vlcek, BL Hendricks, RC Zaretsky, EV Savage, M AF Vlcek, BL Hendricks, RC Zaretsky, EV Savage, M TI Comparative fatigue lives of rubber and PVC wiper cylindrical coatings SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 57th Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY MAY 19-23, 2002 CL HOUSTON, TEXAS SP Soc Tribologists Lubricat Engn DE coatings; fatigue; life prediction; Weibull analysis; printing AB Three coating materials for rotating, cylindrical, coated wiping rollers were fatigue tested in two Intaglio printing presses. The coatings were a hard, cross-linked, plasticized polyvinyl chloride (PVC) thermoset (P-series); a plasticized PVC (A-series); and a hard nitrile rubber (R-series). Both two- and three-parameter Weibull analyses and a cost-benefit analysis were performed. The mean value of life for the R-series coating is 24 and 9 times longer than that of the P- and A-series coatings, respectively. At a very high probability of survival, the R-series coating is approximately 2 and 6 times the lives of the P- and A-series, respectively, before the first failure occurs. The cost and replacement rate for the R-series coating is significantly less than those for the P- and A-series coatings. When all coatings are run to failure, using the mean (life) time between removal (MTBR) for each coating to calculate the number of replacements and costs provides qualitatively similar results to those using a Weibull analysis. For these coatings, at a given operating temperature, the higher that temperature above the glass transition temperature, the longer the fatigue life. C1 Georgia So Univ, Statesboro, GA 30460 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Akron, Akron, OH 44325 USA. RP Vlcek, BL (reprint author), Georgia So Univ, Statesboro, GA 30460 USA. NR 24 TC 1 Z9 1 U1 0 U2 0 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD JAN PY 2003 VL 46 IS 1 BP 101 EP 110 DI 10.1080/10402000308982606 PG 10 WC Engineering, Mechanical SC Engineering GA 642TA UT WOS:000180819500018 ER PT J AU Cioc, S Dimofte, F Keith, TG Fleming, DP AF Cioc, S Dimofte, F Keith, TG Fleming, DP TI Computation of pressurized gas bearings using the CE/SE method SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT 57th Annual Meeting of the Society-of-Tribologists-and-Lubrication-Engineers CY MAY 19-23, 2002 CL HOUSTON, TEXAS SP Soc Tribologists Lubricat Engn DE bearings; gas; hydrostatic lubrication; flow rate ID ELEMENT AB A numerical scheme that has been successfully used to solve a wide variety of compressible flow problems, including flows with large and small discontinuities, entitled the space-time conservation element and solution element (CE/SE) method, is extended to compute compressible viscous flows in pressurized thin fluid films. This method is applied to calculate the pressure distribution in a hybrid gas journal bearing. The formulation of the problem is presented, including the modeling of the feeding system. The numerical results obtained are compared with experimental data. Good agreement between the computed results and the test data were obtained, and thus, validate the CE/SE method to solve such problems. C1 Univ Toledo, Dept Mech Engn, Toledo, OH 43606 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. RP Cioc, S (reprint author), Univ Toledo, Dept Mech Engn, Toledo, OH 43606 USA. NR 13 TC 4 Z9 4 U1 1 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 1040-2004 J9 TRIBOL T JI Tribol. Trans. PD JAN PY 2003 VL 46 IS 1 BP 128 EP 133 DI 10.1080/10402000308982609 PG 6 WC Engineering, Mechanical SC Engineering GA 642TA UT WOS:000180819500021 ER PT B AU Gilliam, D AF Gilliam, D GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI WETICE 2003 Eighth Enterprise Security (ES) Workshop report SO TWELFTH IEEE INTERNATIONAL WORKSHOPS ON ENABLING TECHNOLOGIES: INFRASTRUCTURE FOR COLLABORATIVE ENTERPRISES, PROCEEDINGS LA English DT Proceedings Paper CT 12th IEEE International Workshop on Enabling Technologies - Infrastructure for Collaborative Enterprises CY JUN 09-11, 2003 CL JOHANNES KEPLER UNIV, LINZ, AUSTRIA SP IEEE Comp Soc Tech Comm Data Engn, Concurrent Engn Res Ctr, West Viginia Univ HO JOHANNES KEPLER UNIV C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Gilliam, D (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-1963-6 PY 2003 BP 179 EP 183 PG 5 WC Computer Science, Theory & Methods SC Computer Science GA BX71J UT WOS:000186183900032 ER PT B AU Chow, E Spence, MC Pell, B Stewart, H Korsmeyer, D Liu, J Chang, HP Viernes, C Goforth, A AF Chow, E Spence, MC Pell, B Stewart, H Korsmeyer, D Liu, J Chang, HP Viernes, C Goforth, A GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Secured Advanced Federated Environment (SAFE): A NASA solution for secure cross-organization collaboration SO TWELFTH IEEE INTERNATIONAL WORKSHOPS ON ENABLING TECHNOLOGIES: INFRASTRUCTURE FOR COLLABORATIVE ENTERPRISES, PROCEEDINGS LA English DT Proceedings Paper CT 12th IEEE International Workshop on Enabling Technologies - Infrastructure for Collaborative Enterprises CY JUN 09-11, 2003 CL JOHANNES KEPLER UNIV, LINZ, AUSTRIA SP IEEE Comp Soc Tech Comm Data Engn, Concurrent Engn Res Ctr, West Viginia Univ HO JOHANNES KEPLER UNIV AB This paper discusses the challenges and security issues inherent in building complex cross-organizational collaborative projects and software systems within NASA. By applying the design principles of compartmentalization, organizational hierarchy and inter-organizational federation, the Secured Advanced Federated Environment (SAFE) is laying the foundation for a collaborative virtual infrastructure for the NASA community. A key element of SAFE is the Micro Security Domain (MSD) concept, which balances the need to collaborate and the need to enforce enterprise and local security rules. With the SAFE approach, security is an integral component of enterprise software and network design, not an afterthought. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chow, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 1 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-1963-6 PY 2003 BP 214 EP 219 PG 6 WC Computer Science, Theory & Methods SC Computer Science GA BX71J UT WOS:000186183900038 ER PT B AU Gilliam, DP Wolfe, TL Sherif, JS Bishop, M AF Gilliam, DP Wolfe, TL Sherif, JS Bishop, M GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Software security checklist for the software life cycle SO TWELFTH IEEE INTERNATIONAL WORKSHOPS ON ENABLING TECHNOLOGIES: INFRASTRUCTURE FOR COLLABORATIVE ENTERPRISES, PROCEEDINGS LA English DT Proceedings Paper CT 12th IEEE International Workshop on Enabling Technologies - Infrastructure for Collaborative Enterprises CY JUN 09-11, 2003 CL JOHANNES KEPLER UNIV, LINZ, AUSTRIA SP IEEE Comp Soc Tech Comm Data Engn, Concurrent Engn Res Ctr, West Viginia Univ HO JOHANNES KEPLER UNIV AB A formal approach to security in the software life cycle is essential to protect corporate resources. However, little thought has been given to this aspect Of software development. Traditionally, software security has been treated as an afterthought leading to a cycle of 'penetrate and patch.' Due to its criticality, security should be integrated as a formal approach in the software life cycle. Both a software security checklist and assessment tools should be incorporated into this life cycle process. The current research at JPL addresses both of these areas through the development of a Software Security Assessment Instrument (SSAI). This paper focuses on the development of a Software Security Checklist (SSC)for the life cycle. It includes the critical areas of requirements gathering and specification, design and code issues, and maintenance and decommissioning of software and systems. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. EM david.p.gilliam@jpl.nasa.gov; thomas.l.wolfe@jpl.nasa.gov; josefs.sherif@jpl.nasa.gov; bishop@cs.ucdavis.edu NR 15 TC 13 Z9 13 U1 1 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-1963-6 PY 2003 BP 243 EP 248 PG 6 WC Computer Science, Theory & Methods SC Computer Science GA BX71J UT WOS:000186183900043 ER PT B AU Snyder, GJ AF Snyder, GJ GP IEEE TI Design and optimization of compatible, segmented thermoelectric generators SO TWENTY-SECOND INTERNATIONAL CONFERENCE ON THERMOELECTRICS, PROCEEDINGS ICT '03 LA English DT Proceedings Paper CT 22nd International Conference on Thermoelectrics (ICT 03) CY AUG 17-21, 2003 CL La Grande Motte, FRANCE SP Univ Montpellier 2, Lab Physicochim Matiere Condensee, Univ Nancy 1, Lab Phys Materiaux ID EFFICIENCY AB The thermoelectric compatibility factor is used to rationally select materials for a segmented thermoelectric generator. The thermoelectric potential is used for the exact analytic expressions for materials with temperature dependent thermoelectric properties. This calculation does not assume constant or averaged thermoelectric properties as is often done for analytic results. The calculations use the relative current density as the intensive independent variable. A method of optimizing the system configuration is outlined that allows a separation of the system level and thermoelectric level with only three interface parameters: thermoelectric hot side temperature, cold side temperature and the heat flux. The calculation of performance under non-optimal conditions is described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jsnyder@jpl.nasa.gov RI Snyder, G. Jeffrey/E-4453-2011; Snyder, G/I-2263-2015 OI Snyder, G. Jeffrey/0000-0003-1414-8682; NR 10 TC 6 Z9 6 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8301-X PY 2003 BP 443 EP 446 DI 10.1109/ICT.2003.1287543 PG 4 WC Thermodynamics; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Thermodynamics; Engineering; Materials Science; Physics GA BY60K UT WOS:000189419000107 ER PT S AU Ting, DZY AF Ting, DZY BE Tsen, KTF Song, JJ Jiang, HX TI Ultra-refractive and extended-range one-dimensional photonic crystal superprisms SO ULTRAFAST PHENOMENA IN SEMICONDUCTORS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultrafast Phenomena in Semiconductors VII CY JAN 28-30, 2003 CL SAN JOSE, CA SP SPIE DE photonic crystal; one-dimensional; superprism; ultra-refraction ID FLOQUET-BLOCH WAVES; LIGHT-PROPAGATION; BAND-GAP; CIRCUITS; GRATINGS; GUIDES AB We describe theoretical analysis and design of one-dimensional photonic crystal prisms. We find that inside the photonic crystal, for frequencies near the band edges, light propagation direction is extremely sensitive to the variations in wavelength and incident angle. Outside the photonic crystal, propagation direction of transmitted light is highly sensitive to changes in wavelength, but less so to incident angle. For transmitted light outside the photonic crystal, the superprism effect can be used for wavelength dispersion over entire photonic bands, rather than just near the band edges only. This extended-range superprism effect broadens the useful wavelength range, admits better optical transmission, and exhibits angular dependence on wavelength with greatly reduced non-linearity. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ting, DZY (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 302-231, Pasadena, CA 91109 USA. NR 27 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4792-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 4992 BP 43 EP 54 DI 10.1117/12.475711 PG 12 WC Optics; Physics, Applied; Physics, Condensed Matter SC Optics; Physics GA BX02E UT WOS:000183989700005 ER PT J AU Martin, DS South, DA Garcia, KM Arbeille, P AF Martin, DS South, DA Garcia, KM Arbeille, P TI Ultrasound in space SO ULTRASOUND IN MEDICINE AND BIOLOGY LA English DT Review DE space; microgravity; ultrasound ID SHORT-DURATION SPACEFLIGHT; CENTRAL VENOUS-PRESSURE; HEAD-DOWN; BED-REST; ORTHOSTATIC INTOLERANCE; ECHOCARDIOGRAPHIC EVALUATION; DECOMPRESSION-SICKNESS; ARTERIAL-PRESSURE; CARDIAC ATROPHY; THIGH CUFFS AB Physiology of the human body in space has been a major concern for space-faring nations since the beginning of the space era. Ultrasound (US) is one of the most cost effective and versatile forms of medical imaging. As such, its use in characterizing microgravity-induced changes in physiology is being realized. In addition to the use of US in related ground-based studies, equipment has also been modified to fly in space. This involves alteration to handle the stresses of launch and different power and cooling requirements. Study protocols also have been altered to accommodate the microgravity environment. Ultrasound studies to date have shown a pattern of adaptation to microgravity that includes changes in cardiac chamber sizes and vertebral spacing. Ultrasound has been and will continue to be an important component in the investigation of physiological and, possibly, pathologic changes occurring in space or as a result of spaceflight. (E-mail: dsmartin@ems.jsc.nasa.gov) Published by Elsevier Science Inc. on behalf of World Federation for Ultrasound in Medicine Biology. C1 NASA, Wyle Labs, Lyndon B Johnson Space Ctr, Cardiovasc Lab, Houston, TX 77058 USA. Univ Tours, Unit Med Physiol Spatiale, CHU, F-37041 Tours, France. RP Martin, DS (reprint author), NASA, Wyle Labs, Lyndon B Johnson Space Ctr, Cardiovasc Lab, 1290 Hercules Dr,Suite 120, Houston, TX 77058 USA. NR 53 TC 25 Z9 25 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0301-5629 J9 ULTRASOUND MED BIOL JI Ultrasound Med. Biol. PD JAN PY 2003 VL 29 IS 1 BP 1 EP 12 AR PII S0301-5629(02)00692-0 DI 10.1016/S0301-5629(02)00692-0 PG 12 WC Acoustics; Radiology, Nuclear Medicine & Medical Imaging SC Acoustics; Radiology, Nuclear Medicine & Medical Imaging GA 647YC UT WOS:000181120800001 PM 12604111 ER PT S AU Hsu, NC Herman, JR Holben, B AF Hsu, NC Herman, JR Holben, B BE Gao, W Herman, JR Shi, G Shibasaki, K Slusser, JR TI Effect of aerosol on UV radiation: An overview SO ULTRAVIOLET GROUND- AND SPACE-BASED MEASUREMENTS, MODELS, AND EFFECTS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultraviolet Ground- and Space-based Measurements, Models and Effects II CY OCT 25, 2002 CL HANGZHOU, PEOPLES R CHINA SP Chinese Soc Oceanog, SPIE, NASA Earth Sci Technol Off, Natl Polar Orbiting Operat Environm Satellite Syst, Commun Res Lab, NOAA, Minist Sci & Technol, China Assoc Sci & Technol, State Ocean Adm, Chinese Meteorol Adm, CNSA, Natl Nat Sci Fdn China, China Aerosp Cooperat Sci & Technol, Hangzhou City Govt, Michigan Aerosp Corp, NASDA Japan DE UV; aerosols; satellite; measurements ID ULTRAVIOLET-B RADIATION; OPTICAL-THICKNESS; MEXICO-CITY; OZONE; IRRADIANCE; ABSORPTION; SATELLITE; DEPTH AB One of the key components in understanding how global climate change effects the biological environment on Earth is determining how the amount of UV radiation reaching the surface has changed in response. In order to accurately quantify such changes, the role of tropospheric aerosols in both changing the amount of UV surface radiation and affecting the measurement of such radiation must be better understood. In this paper we will provide an overview on our current understanding of troposheric aerosols and their effect on UV radiation. We will also describe how such aerosols are taken into account when trying, to measure the UV surface radiation, and we will show how the diurnal variability of tropospheric aerosols lead to significant errors in determining UV surface radiation from space measurements. Finally, we will describe how measurement from future sensors launched into orbit other than those low to the Earth can reduce such errors. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hsu, NC (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Hsu, N. Christina/H-3420-2013 NR 20 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4682-3 J9 P SOC PHOTO-OPT INS PY 2003 VL 4896 BP 8 EP 19 DI 10.1117/12.466137 PG 12 WC Geosciences, Multidisciplinary; Remote Sensing; Physics, Applied SC Geology; Remote Sensing; Physics GA BX21C UT WOS:000184614300003 ER PT S AU Herman, JR AF Herman, JR BE Gao, W Herman, JR Shi, G Shibasaki, K Slusser, JR TI Possible changes in reflectivity of the Earth at 360 nm: 1980-2001 SO ULTRAVIOLET GROUND- AND SPACE-BASED MEASUREMENTS, MODELS, AND EFFECTS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultraviolet Ground- and Space-based Measurements, Models and Effects II CY OCT 25, 2002 CL HANGZHOU, PEOPLES R CHINA SP Chinese Soc Oceanog, SPIE, NASA Earth Sci Technol Off, Natl Polar Orbiting Operat Environm Satellite Syst, Commun Res Lab, NOAA, Minist Sci & Technol, China Assoc Sci & Technol, State Ocean Adm, Chinese Meteorol Adm, CNSA, Natl Nat Sci Fdn China, China Aerosp Cooperat Sci & Technol, Hangzhou City Govt, Michigan Aerosp Corp, NASDA Japan ID SURFACE UV IRRADIANCE; ULTRAVIOLET-RADIATION; SATELLITE ESTIMATION; OPTICAL-THICKNESS; OZONE CHANGE; TOMS DATA; AEROSOLS; CLOUDS; CLIMATOLOGY; ATLAS-1 AB The new Version 8 TOMS 360 nm reflectivity time series 1980 to 1992 and 1997 to 2001 have been combined to estimate changes that have occurred over a 21-year period. The observed changes are mostly related to changes in cloud cover and aerosols, since the Earthy appears dark (2 to 6% reflectivity) at 360 nm. The relative radiance calibration of the two TOMS (Nimbus-7, N7 and Earth-Probe, EP) has been adjusted using the measured minimum reflectivity over mid-latitude ocean and land locations (+/-50degrees). The result is that the previously published N7 minimum reflectivity decreased by 0.02 and now matches the better-calibrated Earth-Probe/TOMS. Most of the local trend features seen in the N7 time series (1980 to 1992) have been continued in the combined time series, but the overall zonal average and global trends have changed. The correlation of cloud cover with solar activity (measured by the 10.7 cm solar radiation) that was present during the Ninibus-7 period (1980 to 1992) is no longer evident for the period 1980 to 2001. The key results include a continuing decrease in cloud cover over Europe and North America and an increase in reflectivity near Antarctica. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Herman, JR (reprint author), NASA, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. OI Herman, Jay/0000-0002-9146-1632 NR 28 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4682-3 J9 P SOC PHOTO-OPT INS PY 2003 VL 4896 BP 20 EP 34 DI 10.1117/12.466130 PG 15 WC Geosciences, Multidisciplinary; Remote Sensing; Physics, Applied SC Geology; Remote Sensing; Physics GA BX21C UT WOS:000184614300004 ER PT S AU Huntsberger, T Sujan, VA Dubowsky, S Schenker, PS AF Huntsberger, T Sujan, VA Dubowsky, S Schenker, PS BE Gerhart, GR Shoemaker, CM Gage, DW TI Integrated system for sensing and traverse of cliff faces SO UNMANNED GROUND VEHICLE TECHNOLOGY V SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Unmanned Ground Vehicle Technology V CY APR 22-23, 2003 CL ORLANDO, FL SP SPIE DE cooperative robots; information theory; unstructured environments; cliff exploration ID CONTROL ARCHITECTURE; CAMPOUT AB A long duration robotic presence on lunar and planetary surfaces will allow the acquisition of scientifically interesting information from a diverse set of surface and sub-surface sites. The wide range of terrain types including plains, cliffs, sand dunes, and lava tubes will require the development of robotic systems that can adapt to possibly rapidly changing terrain. These systems include single as well as teams of robots. In this paper, we describe the development of an integrated suite of autonomous, adaptive hardware/software control methods called SMART (Systern for Mobility and Access to Rough Terrain) that enables mobile robots to explore potentially important science sites currently beyond the reach of conventional rover designs. SMART uses the behavior coordination mechanisms of CAMPOUT, a previously developed system for multi-agent control. For the specific application area of cliffside exploration, SMART consists of a distributed sensing system for cooperative map-making called MITSAF (Model-based Information Theoretic Sensing And Fusion), a mobility system for rappelling down a cliff and moving to a designated way-point, and science sample acquisition from the cliff face. We also report the results of some experimental studies on highly sloped cliff faces. C1 CALTECH, Jet Prop Lab, Mobil syst Concepts Dev Sect, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, Mobil syst Concepts Dev Sect, MS82-105,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Terry.Huntsberger@jpl.nasa.gov NR 18 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4942-3 J9 PROC SPIE PY 2003 VL 5083 BP 27 EP 37 DI 10.1117/12.497548 PG 11 WC Automation & Control Systems; Robotics SC Automation & Control Systems; Robotics GA BX80V UT WOS:000186496800003 ER PT S AU Matthies, L Bellutta, P McHenry, M AF Matthies, L Bellutta, P McHenry, M BE Gerhart, GR Shoemaker, CM Gage, DW TI Detecting water hazards for autonomous off-road navigation SO UNMANNED GROUND VEHICLE TECHNOLOGY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unmanned Ground Vehicle Technology V CY APR 22-23, 2003 CL ORLANDO, FL SP SPIE AB Detecting water hazards for autonomous, off-road navigation of unmanned ground vehicles is a largely unexplored problem. In this paper, we catalog environmental variables that affect the difficulty of this problem, including day vs. night operation, whether the water reflects sky or other terrain features, the size of the water body, and other factors. We briefly survey sensors that are applicable to detecting water hazards in each of these conditions. We then present analyses and results for water detection for four specific sensor cases: (1) using color image classification to recognize sky reflections in water during the day, (2) using ladar to detect the presence of water bodies and to measure their depth, (3) using short-wave infrared (SWIR) imagery to detect water bodies, as well as snow and ice, and (4) using mid-wave infrared (MWIR) imagery to recognize water bodies at night. For color imagery, we demonstrate solid results with a classifier that runs at nearly video rate on a 433 MHz processor. For ladar, we present a detailed propagation analysis that shows the limits of water body detection and depth estimation as a function of lookahead distance, water depth, and ladar wavelength. For SWIR and MWIR, we present sample imagery from a variety of data collections that illustrate the potential of these sensors. These results demonstrate significant progress on this problem. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Matthies, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 14 TC 13 Z9 15 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4942-3 J9 P SOC PHOTO-OPT INS PY 2003 VL 5083 BP 231 EP 242 DI 10.1117/12.496942 PG 12 WC Automation & Control Systems; Robotics SC Automation & Control Systems; Robotics GA BX80V UT WOS:000186496800022 ER PT S AU Ansar, A Matthies, L AF Ansar, A Matthies, L BE Gerhart, GR Shoemaker, CM Gage, DW TI Multibaseline stereo system for evaluation of binocular stereo SO UNMANNED GROUND VEHICLE TECHNOLOGY V SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Unmanned Ground Vehicle Technology V CY APR 22-23, 2003 CL ORLANDO, FL SP SPIE DE Multibaseline; stereo; navigation AB Binocular, correlation based stereo has been a key component in many efforts at autonomous vehicle navigation. However, estimation of ground truth range data, especially in field conditions, remains a challenge. We present a 5 camera, multibaseline stereo system and demonstrate its use as a passive ground truthing mechanism for binocular stereo. In this paper, we provide both a system description and a detailed overview of a novel depth-based multibaseline stereo algorithm. Our new algorithm avoids the need for pairwise camera rectification. We conclude with several simulations and real world experiments to verify our results. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Adnan.I.Ansar@jp.nasa.gov NR 12 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4942-3 J9 PROC SPIE PY 2003 VL 5083 BP 243 EP 252 DI 10.1117/12.487040 PG 10 WC Automation & Control Systems; Robotics SC Automation & Control Systems; Robotics GA BX80V UT WOS:000186496800023 ER PT S AU Nesnas, I Wright, A Bajracharya, M Simmons, R Estlin, T Kim, WS AF Nesnas, I Wright, A Bajracharya, M Simmons, R Estlin, T Kim, WS BE Gerhart, GR Shoemaker, CM Gage, DW TI CLARAty: An architecture for reusable robotic software SO UNMANNED GROUND VEHICLE TECHNOLOGY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unmanned Ground Vehicle Technology V CY APR 22-23, 2003 CL ORLANDO, FL SP SPIE DE robotic architecture; reusable robotic software; interoperable robotic software; standard robotic interfaces ID MOBILE ROBOT AB In this article, we will present an overview of the Coupled Layered Architecture for Robotic Autonomy. CLARAty develops a framework for generic and reusable robotic components that can be adapted to a number of heterogeneous robot platforms. It also provides a framework that will simplify the-integration of new technologies and enable the comparison of various elements. CLARAty consists of two distinct layers: a Functional Layer and a Decision Layer. The Functional Layer defines the various abstractions of the system and adapts the abstract components to real or simulated devices. It provides a framework and the algorithms for low- and rnid-level autonomy. The Decision Layer provides the system's high-level autonomy, which reasons about global resources and mission constraints. The Decision Layer accesses information from the Functional Layer at multiple levels of granularity. In this article, we will also present some of the challenges in developing interoperable software for various rover platforms. Examples will include challenges from the locomotion and manipulation domains. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nesnas, I (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Simmons, Reid/0000-0003-3153-0453 NR 23 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4942-3 J9 P SOC PHOTO-OPT INS PY 2003 VL 5083 BP 253 EP 264 DI 10.1117/12.497223 PG 12 WC Automation & Control Systems; Robotics SC Automation & Control Systems; Robotics GA BX80V UT WOS:000186496800024 ER PT B AU Gornitz, V Hartig, EK AF Gornitz, V Hartig, EK BE Ewing, L Herrington, T Magoon, O TI Vulnerable shores of the metropolitan New York area: Preparing for sea level rise SO URBAN BEACHES: BALANCING PUBLIC RIGHTS AND PRIVATE DEVELOPMENT LA English DT Proceedings Paper CT 4th Annual Northeast-Shore-and-Beach-Preservation-Association Conference CY OCT 24-26, 2001 CL Stevens Inst Technol, Hoboken, NJ SP NE Shore & Beach Preservat Assoc, NJ Marine Sci Consortium, Coastal Zone Fdn, COPRI HO Stevens Inst Technol C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Gornitz, V (reprint author), NASA, Goddard Inst Space Studies, New York, NY 10025 USA. NR 4 TC 0 Z9 0 U1 1 U2 3 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 USA BN 0-7844-0682-0 PY 2003 BP 82 EP 88 PG 7 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA BY60Z UT WOS:000189420400009 ER PT S AU Breckinridge, JB AF Breckinridge, JB BE MacEwen, HA TI Astronomical search for origins: Are we alone? SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes CY AUG 03-05, 2003 CL San Diego, CA SP SPIE AB Recent advances in astronomical research have led to a much-improved understanding of the evolution of the physical Universe. Recent advances in biology and genetics have led to a much-improved understanding of our biological Universe. Scientists now believe that we have the research tools to begin to answer one of man's two most compelling research questions: Are we alone? and How did we get here? This paper reviews the requirements and challenges we face to engineer and build the large space-based systems of interferometers and innovative single-aperture telescopes to detect and characterize in detail earth type planets around stars other than our sun. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Breckinridge, JB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5039-1 J9 P SOC PHOTO-OPT INS PY 2003 VL 5166 BP 8 EP 12 PG 5 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BY61H UT WOS:000189421200002 ER PT S AU Thronson, HA AF Thronson, HA BE MacEwen, HA TI Options for post-JWST space telescopes SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes CY AUG 03-05, 2003 CL San Diego, CA SP SPIE DE NASA; telescopes; space telescopes; human exploration; JWST; NASA Exploration Team AB With the selection completed of the industrial partners for the James Webb Space Telescope (JWST) and subsequent replanning concluded, several groups and NASA have begun to consider options for subsequent major space astronomy missions. Active interest includes scientific justification for even larger space observatories, the technologies necessary to enable such missions, supporting infrastructure and facilities, system designs, and the political environment that would be receptive to the sustained funding necessary for such major missions. This paper discusses each of these issues in turn and concludes similarly to the recommendations of the NASA Exploration Team (NEXT) that a human-occupied gateway at the Earth-Moon L1 point offers several attractive opportunities for NASA and the scientific community, including primarily the capability to support very large aperture science facilities, as well as a publicly appealing option for human exploration beyond low-Earth orbit.. C1 NASA, Off Space Sci, Washington, DC 20546 USA. RP Thronson, HA (reprint author), NASA, Off Space Sci, 300 E St SW, Washington, DC 20546 USA. RI Thronson, Harley/E-3382-2012 NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5039-1 J9 P SOC PHOTO-OPT INS PY 2003 VL 5166 BP 13 EP 18 PG 6 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BY61H UT WOS:000189421200003 ER PT S AU Hoppe, DJ Baron, RL Cwik, TA AF Hoppe, DJ Baron, RL Cwik, TA BE MacEwen, HA TI Application of a large space-based diffractive optical element telescope to the terrestrial planet-finder mission: Design and tolerance issues SO UV/OPTICAL/IR SPACE TELESCOPES: INNOVATIVE TECHNOLOGIES AND CONCEPTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV/Optical/IR Space Telescopes CY AUG 03-05, 2003 CL San Diego, CA SP SPIE DE diffractive optical element telescope; diffraction calculation; DOE; telescope; TPF; tolerance; scattered light AB An analytical description of the scattered light from a 10 meter diameter Diffractive Optical Element lens-based telescope operating at 1 micron wavelength has been formulated. The specifics of the grating and blaze as well as physical manufacturing constraints were made a part of the problem to be solved. A major simplifying approximation made is that a 1 dimensional lens was assumed for the calculations. This simplified model still serves to illustrate the important effects and limitations of a high performance lens used as a telescope. Focal plane light scattering has been rigorously determined for simplified cases. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hoppe, DJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5039-1 J9 P SOC PHOTO-OPT INS PY 2003 VL 5166 BP 281 EP 295 PG 15 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BY61H UT WOS:000189421200030 ER PT S AU Waldinger, R Jarvis, P Dungan, J AF Waldinger, R Jarvis, P Dungan, J BE Dershowitz, N TI Program synthesis for multi-agent question answering SO VERIFICATION: THEORY AND PRACTICE: ESSAYS DEDICATED TO ZHOAR MANNA ON THE OCCASION OF HIS 64TH BIRTHDAY SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT International Symposium on Verification - Theory and Practice in honor of the 64th Birthday of Zohar Manna CY JUN 29-JUL 04, 2003 CL Taormina, Italy SP Univ Pisa, Tel Aviv Univ, Sch Comp Sci, Catania Univ, Dipartimento Matemat & Informat AB Techniques that were developed for program synthesis are being applied to allow multiple agents to communicate with each other and cooperate to solve a single problem. We illustrate the use of program synthesis techniques in a system that answers questions about geography. C1 SRI Int, Artificial Intelligence, Menlo Pk, CA 94025 USA. NASA, Ames Res Ctr, Ecoyst Sci & Technol Branch, Moffett Field, CA USA. RP Waldinger, R (reprint author), SRI Int, Artificial Intelligence, Menlo Pk, CA 94025 USA. EM waldinger@ai.sri.com; jarvis@ai.sri.com; Jennifer.L.Dungan@nasa.gov RI Dungan, Jennifer/G-9921-2016 OI Dungan, Jennifer/0000-0002-4863-1616 NR 17 TC 0 Z9 0 U1 1 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-21002-4 J9 LECT NOTES COMPUT SC PY 2003 VL 2772 BP 747 EP 761 PG 15 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BAB26 UT WOS:000221438400032 ER PT S AU Jobson, DJ Rahman, ZU Woodell, GA AF Jobson, DJ Rahman, ZU Woodell, GA BE Rahman, ZU Schowengerdt, RA Reichenbach, SE TI Feature visibility limits in the non-linear enhancement of turbid images SO VISUAL INFORMATION PROCESSING XII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Information Processing XII CY APR 21, 2003 CL ORLANDO, FL SP SPIE ID RETINEX; RESTORATION; INFORMATION AB The advancement of non-linear processing methods for generic automatic clarification of turbid imagery has led us from extensions of entirely passive multiscale Retinex processing to a new framework of active measurement and control of the enhancement process called the Visual Servo. In the process of testing this new non-linear computational scheme, we have identified that feature visibility limits in the post-enhancement image now simplify to a single signal-to-noise figure of merit: a feature is visible if the feature-background signal difference is greater than the RMS noise level. In other words, a signal-to-noise limit of approximately unity constitutes a lower limit on feature visibility. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Jobson, DJ (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 9 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4968-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 5108 BP 24 EP 30 DI 10.1117/12.488842 PG 7 WC Computer Science, Software Engineering; Imaging Science & Photographic Technology SC Computer Science; Imaging Science & Photographic Technology GA BX48N UT WOS:000185396200003 ER PT S AU Xing, J AF Xing, J BE Rahman, ZU Schowengerdt, RA Reichenbach, SE TI An image compression model based on the human visual system SO VISUAL INFORMATION PROCESSING XII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Information Processing XII CY APR 21, 2003 CL ORLANDO, FL SP SPIE ID CORTICAL MAGNIFICATION; PERIPHERAL-VISION; CONTRAST; SENSITIVITY; ENHANCEMENT; RECOGNITION; SUPPRESSION; RESOLUTION AB Most algorithms of image processing treat an image homogeneously, while the human visual system processes a retinal image differently in the foveal and peripheral visual fields. It has been known that contrast sensitivity, spatial resolution and color discrimination of the visual system decrease from the fovea to the periphery. Moreover, recent psychophysical results showed that the spatial interactions between neighboring parts of a visual image are fundamentally different in the fovea and periphery. The perception of a visual stimulus can be suppressed or enhanced by the presence of other stimuli in its surround region. The spatial suppression in the periphery was much stronger than that in the fovea. In this report, we built an image processing model based on the neurophysiology of the human visual cortex to explore the possible impacts of the spatial interactions on image perception. We first adjusted model parameters to make the model have the same performance as human subjects had in perceiving foveal and peripheral images respectively. With those parameters, we simulated the image processing by the fovea and peripheral vision. We found that the strong spatial suppression in the periphery resulted in image boundary segmentation and salient target extraction. The response to a uniform image region was suppressed while the response to the boundary or salient regions remained. With this strategy, the visual information processed by the human cognition system is largely reduced. Based on these findings, we proposed a foveal-peripheral model for image compression and other possible applications. C1 San Jose State Univ Fdn, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Xing, J (reprint author), San Jose State Univ Fdn, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4968-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 5108 BP 63 EP 72 DI 10.1117/12.485820 PG 10 WC Computer Science, Software Engineering; Imaging Science & Photographic Technology SC Computer Science; Imaging Science & Photographic Technology GA BX48N UT WOS:000185396200007 ER PT S AU Hines, G Rahman, ZU Jobson, D Woodell, G AF Hines, G Rahman, ZU Jobson, D Woodell, G BE Rahman, ZU Schowengerdt, RA Reichenbach, SE TI Multi-image registration for an enhanced vision system SO VISUAL INFORMATION PROCESSING XII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Information Processing XII CY APR 21, 2003 CL ORLANDO, FL SP SPIE DE image registration; control points; resampling ID IMAGE REGISTRATION; RETINEX AB An Enhanced Vision System (EVS) utilizing multi-sensor image fusion is currently under development, at the NASA Langley Research Center. The EVS will provide enhanced images of the flight environment to assist pilots in poor visibility conditions. Multi-spectral images obtained from a short wave infrared (SWIR), a long wave infrared (LWIR), and a color visible band CCD camera, are enhanced and fused using the Retinex algorithm. The images from the different sensors do not have a uniform data structure: the three sensors not only operate at different wavelengths, but they also have different spatial resolutions, optical fields of view (FOV), and bore-sighting inaccuracies. Thus. in order to perform image fusion. the images must first be co-registered. Image registration is the task of aligning images taken at different times, from different sensors. or from different viewpoints, so that all corresponding points in the images match. In this paper, we present two methods for registering multiple multi-spectral images. The first method performs registration using sensor specifications to match the FOVs and resolutions directly through image resampling. In the second method, registration is obtained through geometric correction based on a spatial transformation defined by user selected control points and regression analysis. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Hines, G (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 24 TC 3 Z9 4 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4968-7 J9 P SOC PHOTO-OPT INS PY 2003 VL 5108 BP 231 EP 241 DI 10.1117/12.496917 PG 11 WC Computer Science, Software Engineering; Imaging Science & Photographic Technology SC Computer Science; Imaging Science & Photographic Technology GA BX48N UT WOS:000185396200024 ER PT S AU Spirkovska, L Lodha, SK AF Spirkovska, L Lodha, SK BE Erbacher, RF Chen, PC Roberts, JC Grohn, MT Borner, K TI Audio-visual situational awareness for general aviation pilots SO VISUALIZATION AND DATA ANALYSIS 2003 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 10th Annual Conference on Visualization and Data Analysis CY JAN 21-22, 2003 CL SANTA CLARA, CA SP Soc Imaging Sci & Technol, SPIE DE situational awareness; weather visualization; general aviation; speech user interface AB Weather is one of the major causes of general aviation accidents. One possible cause is that the pilot may not absorb and retain all the weather information she is required to review prior to flight. A second cause is the inadequacy of in-flight weather updates: pilots are limited to verbal updates via aircraft radio contact with a ground-based weather specialist. We propose weather visualization and interaction methods tailored for general aviation pilots to improve understanding of pre-flight weather data and improve in-flight weather updates. Our system, Aviation Weather Environment (AWE), utilizes information visualization techniques, a direct manipulation graphical interface, and a speech-based interface to improve a pilot's situational awareness of relevant weather data. The system design is based on a user study and feedback from pilots. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Spirkovska, L (reprint author), NASA, Ames Res Ctr, M-S 269-3, Moffett Field, CA 94035 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4809-5 J9 P SOC PHOTO-OPT INS PY 2003 VL 5009 BP 193 EP 202 DI 10.1117/12.473908 PG 10 WC Computer Science, Information Systems; Imaging Science & Photographic Technology SC Computer Science; Imaging Science & Photographic Technology GA BX07E UT WOS:000184179600020 ER PT S AU Carn, SA Krueger, AJ Bluth, GJS Schaefer, SJ Krotkov, NA Watson, IM Datta, S AF Carn, SA Krueger, AJ Bluth, GJS Schaefer, SJ Krotkov, NA Watson, IM Datta, S BE Oppenheimer, C Pyle, DM Barclay, J TI Volcanic eruption detection by the Total Ozone Mapping Spectrometer (TOMS) instruments: a 22-year record of sulphur dioxide and ash emissions SO VOLCANIC DEGASSING SE Geological Society Special Publication LA English DT Proceedings Paper CT Flagship Meeting of the Geological-Society-of-London on Origins, Emissions and Impacts of Volcanic Gases CY OCT, 2001 CL Geol Soc London, London, ENGLAND HO Geol Soc London ID NYAMURAGIRA VOLCANO; EXPLOSIVE VOLCANISM; REDOUBT VOLCANO; SOUFRIERE HILLS; CLOUDS; ULTRAVIOLET; ZAIRE; GALUNGGUNG; RETRIEVALS; MONTSERRAT AB Since their first deployment in November 1978, the Total Ozone Mapping Spectrometer (TOMS) instruments have provided a robust and near-continuous record of sulphur dioxide (SO(2)) and ash emissions from active volcanoes worldwide. Data from the four TOMS satellites that have flown to date have been analysed with the latest SO(2)/ash algorithms and incorporated into a TOMS volcanic emissions database that presently covers 22 years of SO(2) and ash emissions. The 1978-2001 record comprises 102 eruptions from 61 volcanoes, resulting in 784 days of volcanic cloud observations. Regular eruptions of Nyamuragira (DR Congo) since 1978, accompanied by copious SO(2) production, have contributed material on approximately 30% of the days on which clouds were observed. The latest SO(2) retrieval results from Earth Probe (EP) TOMS document a period (1996-2001) lacking large explosive eruptions, and also dominated by SO(2) emission from four eruptions of Nyamuragira. EP TOMS has detected the SO(2) and ash produced during 23 eruptions from 15 volcanoes to date, with volcanic clouds observed on 158 days. The EP TOMS instrument began to degrade in 2001, but has now stabilized, although its planned successor (QuikTOMS) recently failed to achieve orbit. New SO(2) algorithms are currently being developed for the Ozone Monitoring Instrument, which will continue the TOMS record of UV remote sensing of volcanic emissions from 2004 onwards. C1 Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, NASA, Baltimore, MD 21250 USA. RP Carn, SA (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, NASA, 1000 Hilltop Circle, Baltimore, MD 21250 USA. EM scarn@umbc.edu RI Watson, Matt/E-5236-2011; Krotkov, Nickolay/E-1541-2012 OI Watson, Matt/0000-0001-9198-2203; Krotkov, Nickolay/0000-0001-6170-6750 NR 72 TC 34 Z9 34 U1 1 U2 10 PU GEOLOGICAL SOC PUBLISHING HOUSE PI BATH PA UNIT 7, BRASSMILL ENTERPRISE CTR, BRASSMILL LANE, BATH BA1 3JN, AVON, ENGLAND SN 0305-8719 BN 1-86239-136-X J9 GEOL SOC SPEC PUBL PY 2003 VL 213 BP 177 EP 202 DI 10.1144/GSL.SP.2003.213.01.11 PG 26 WC Geochemistry & Geophysics; Environmental Sciences; Geography, Physical; Geology SC Geochemistry & Geophysics; Environmental Sciences & Ecology; Physical Geography; Geology GA BY57L UT WOS:000189411900010 ER PT S AU Jalobeanu, A Blanc-Feraud, L Zerubia, J AF Jalobeanu, A Blanc-Feraud, L Zerubia, J BE Unser, MA Aldroubi, A Laine, AF TI Natural image modeling using complex wavelets SO WAVELETS: APPLICATIONS IN SIGNAL AND IMAGE PROCESSING X, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Wavelets - Applications in Signal and Image Processing X Conference CY AUG 04-08, 2003 CL SAN DIEGO, CA SP SPIE DE complex wavelets; image modeling; hierarchical Bayesian inference; denoising; deblurring ID DECOMPOSITION AB We propose to model satellite and aerial images using a probabilistic approach. We show how the properties of these images, such as scale invariance, rotational invariance and spatial adaptivity lead to a new general model which aims to describe a broad range of natural images. The complex wavelet transform initially proposed by Kingsbury is a simple way of taking into account all these characteristics. We build a statistical model around this transform, by defining an adaptive Gaussian model with interscale dependencies, global parameters, and hyperpriors controlling the behavior of these parameters. This model has been successfully applied to denoising and deconvolution, for real images and simulations provided by the French Space Agency. C1 NASA, Ames Res Ctr, RIACS, USRA, Moffett Field, CA USA. RP Jalobeanu, A (reprint author), NASA, Ames Res Ctr, RIACS, USRA, Moffett Field, CA USA. NR 25 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5080-4 J9 P SOC PHOTO-OPT INS PY 2003 VL 5207 BP 480 EP 494 DI 10.1117/12.507945 PN 1&2 PG 15 WC Mathematics, Interdisciplinary Applications; Imaging Science & Photographic Technology SC Mathematics; Imaging Science & Photographic Technology GA BY23F UT WOS:000188360200047 ER PT S AU Zavorin, I Le Moigne, J AF Zavorin, I Le Moigne, J BE Unser, MA Aldroubi, A Laine, AF TI Application of multiresolution wavelet pyramids and gradient search based on mutual information to sub-pixel registration of multisensor satellite imagery SO WAVELETS: APPLICATIONS IN SIGNAL AND IMAGE PROCESSING X, PTS 1 AND 2 SE Proceedings of SPIE-The International Society for Optical Engineering LA English DT Proceedings Paper CT Wavelets - Applications in Signal and Image Processing X Conference CY AUG 04-08, 2003 CL SAN DIEGO, CA SP SPIE DE sub-pixel image registration; wavelets; mutual information; multi-sensor satellite imagery AB Accurate geometric registration is an important step that precedes various tasks of processing of remotely sensed imagery. Assuming that, after radiometric and systematic correction, images are registered to within a few pixels, our goal is to develop fast and reliable automatic registration methods for multi-sensor data that would yield sub-pixel accuracy. This paper compares two gradient-based algorithms for sub-pixel image registration developed by Thevenaz et al. One of them optimizes intensity difference while the other maximizes mutual information between two images. The algorithms were combined with three invariant wavelet pyramids, a centered cubic spline pyramid as well as both low-pass and band-pass Simoncelli Steerable pyramids. This paper compared the different variations of the two algorithms on both synthetic and real satellite imagery. We found that for single-sensor data, the intensity-based algorithm combined with a band-pass wavelet pyramid produces the best results, while for multi-sensor images, the best choice is the mutual-information-based method combined with a steerable low-pass pyramid. C1 NASA, Goddard Space Flight Ctr, UMBC GEST Ctr, Greenbelt, MD 20771 USA. RP Zavorin, I (reprint author), NASA, Goddard Space Flight Ctr, UMBC GEST Ctr, Code 661, Greenbelt, MD 20771 USA. EM zavorin@backserv.gsfc.nasa.gov NR 23 TC 0 Z9 0 U1 0 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5080-4 J9 P SOC PHOTO-OPT INS PY 2003 VL 5207 BP 666 EP 677 DI 10.1117/12.505883 PN 1&2 PG 12 WC Mathematics, Interdisciplinary Applications; Imaging Science & Photographic Technology SC Mathematics; Imaging Science & Photographic Technology GA BY23F UT WOS:000188360200063 ER PT B AU Menon, AS Barnes, B Mills, R Bruyns, CD Twombly, A Smith, J Montgomery, K Boyle, R AF Menon, AS Barnes, B Mills, R Bruyns, CD Twombly, A Smith, J Montgomery, K Boyle, R BE Skala, V TI Using registration, calibration, and robotics to build a more accurate virtual reality simulation for astronaut training and telemedicine SO WSCG 2003 SHORT PAPERS, PROCEEDINGS LA English DT Proceedings Paper CT 11th International Conference on Computer Graphics, Visualization and Computer Vision 2003 CY FEB 03-07, 2003 CL UNIV W BOHEMIA, PLZEN, CZECH REPUBLIC HO UNIV W BOHEMIA DE registration; robotics; virtual reality; astronaut training ID AUGMENTED REALITY AB Computer simulation of surgery and scientific experiments help in preparation, training, and assessment. These benefits can be further extended with the integration of robotics for teleoperation and assistance. We describe our efforts to build a realistic and useable simulation for astronaut training and experiment planning. Most of our development focused on user interaction with hand sensors, a necessary component for realism. For the hands, we developed a simulation and focused on aspects of fine tuning the registration and calibration to increase realism and functionality. This proved to be a necessary basis to integrate robotics and further the simulation's range of applications. Accurate registration, calibration, and robotic integration helped build a foundation for a useable simulation for astronaut training on ground and avenues of robotic assistance during flight. C1 NASA, Ames Res Ctr, BioVis Lab, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, BioVis Lab, Mail Stop 239-11, Moffett Field, CA 94035 USA. EM asmenon@stanford.edu; bbarnes@stanford.edu; rmills@stanford.edu; bruyns@mail.arc.nasa.gov; xtwombly@mail.arc.nasa.gov; jdsmith@mail.arc.nasa.gov; Kevin@biocomp.stanford.edu; rboyle@mail.arc.nasa.gov NR 32 TC 0 Z9 0 U1 0 U2 1 PU UNIV WEST BOHEMIA PI PLZEN PA PILSEN UNIVERZITNI 8, PLZEN 306 14, CZECH REPUBLIC BN 80-903100-1-X PY 2003 BP 87 EP 94 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BW43N UT WOS:000181978400013 ER PT S AU Weisskopf, MC AF Weisskopf, MC BE Trumper, JE Tananbaum, HD TI Three years of operation of the Chandra x-ray Observatory SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE x-ray imaging; grazing-incidence optics; x-ray astronomy ID DISCOVERY; EMISSION; CLUSTER; M87 AB The on-orbit performance of the Chandra X-Ray Observatory over its first three years of observations is reviewed. Operations are running smoothly and the scientific return continues to be exciting and outstanding. C1 NASA, Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. RP Weisskopf, MC (reprint author), NASA, Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. NR 19 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 PROC SPIE PY 2003 VL 4851 BP 1 EP 16 DI 10.1117/12.461425 PN 1&2 PG 16 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600001 ER PT S AU O'Dell, SL Blackwell, WC Cameron, RA Minow, JI Morris, DC Spitzbart, BJ Swartz, DA Virani, SN Wolk, SJ AF O'Dell, SL Blackwell, WC Cameron, RA Minow, JI Morris, DC Spitzbart, BJ Swartz, DA Virani, SN Wolk, SJ BE Trumper, JE Tananbaum, HD TI Managing radiation degradation of CCDs on the Chandra X-ray Observatory SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE ID ADVANCED-COMPOSITION-EXPLORER; FLIGHT CONTAMINATION MONITOR; HIGH-RESOLUTION CAMERA; ALPHA-MONITOR; AXAF; CALIBRATION; SPECTROMETER; ENVIRONMENT; DAMAGE AB The CCDs on the Chandra X-ray Observatory are sensitive to radiation damage, particularly from low-energy protons scattering off the telescope's mirrors onto the focal plane. In its highly elliptical orbit, Chandra passes through a spatially and temporally varying radiation environment, ranging from the radiation belts to the solar wind. Translating the Advanced CCD Imaging Spectrometer (ACIS) out of the focal position during radiation-belt passages has prevented loss of scientific utility. However, carefully managing the radiation damage during the remainder of the orbit, without unnecessarily sacrificing observing time, is essential to optimizing the scientific value of this exceptional observatory throughout its planned 10-year mission. In working toward this optimization, the Chandra team developed and applied a radiation-management strategy. This strategy includes autonomous instrument safing triggered by the on-board radiation monitor, as well as monitoring, alerts, and intervention based upon real-time space-environment data from NOAA and NASA spacecraft. Furthermore, because Chandra often spends much of its orbit out of the solar wind (in the Earth's outer magnetosphere and magnetosheath), the team developed the Chandra Radiation Model to describe the complete low-energy-proton environment. Management of the radiation damage has thus far succeeded in limiting degradation of the charge-transfer inefficiency (CTI) to less than 3.5 x 10(-6) and 1.3 x 10(-6) per year for the front-illuminated and back-illuminated CCDs, respectively. This rate of degradation is acceptable for maintaining the scientific viability of all ACIS CCDs for more than ten years. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP O'Dell, SL (reprint author), NASA, George C Marshall Space Flight Ctr, MSFC-SD50, Huntsville, AL 35812 USA. OI Wolk, Scott/0000-0002-0826-9261; O'Dell, Stephen/0000-0002-1868-8056 NR 31 TC 8 Z9 8 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 77 EP 88 DI 10.1117/12.461493 PN 1&2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600007 ER PT S AU White, NE Tananbaum, H AF White, NE Tananbaum, H BE Trumper, JE Tananbaum, HD TI Constellation-X mission: Science objectives and implementation plan SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE X-ray optics; X-ray detectors; X-ray astronomy; black holes; astrophysics AB The Constellation-X mission is a large collecting area X-ray facility, emphasizing observations at high spectral resolution (R similar to 300--3000) while covering a broad energy band (0.25-60 keV). By increasing the telescope aperture and utilizing efficient spectrometers the mission will achieve a factor of 25-100 increased sensitivity over current high resolution X-ray spectroscopy missions. Constellation-X is the X-ray astronomy equivalent of large ground-based optical telescopes such as the Keck and the VLT, complementing the high spatial resolution capabilities of Chandra. Key technologies under development for the mission include lightweight high throughput X-ray optics, multilayer coatings to enhance the hard X-ray performance of X-ray optics, micro-calorimeter spectrometer arrays, low power and low weight CCD arrays, lightweight gratings and hard X-ray detectors. Constellation-X will for the first time make high resolution X-ray spectroscopy of faint X-ray source populations a matter of routine. With its increased capabilities, Constellation-X will address many fundamental astrophysics questions such as observing the formation and evolution of clusters of galaxies, constraining the Baryon content of the Universe, observing the effects of strong gravity close to the event horizon of black holes and using these effects to determine the black hole rotation. The Constellation-X mission has received strong endorsements in two recent National Academy of Sciences reports: the Astronomy and Astrophysics Survey and the Committee on the Physics of the Universe. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP White, NE (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 660, Greenbelt, MD 20771 USA. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 0 TC 18 Z9 18 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 293 EP 303 DI 10.1117/12.461276 PN 1&2 PG 11 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600027 ER PT S AU Gendreau, KC Cash, WC Shipley, AF White, N AF Gendreau, KC Cash, WC Shipley, AF White, N BE Trumper, JE Tananbaum, HD TI The MAXIM pathfinder X-ray interferometry mission SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE AB The MAXIM Pathfinder (MP) mission is under study as a scientific and technical stepping stone for the full MAXIM X-ray interferometry mission. While full MAXIM will resolve the event horizons of black holes with 0.1 microarcsecond imaging, MP will address scientific and technical issues as a 100 microarcsecond imager with some capabilities to resolve microarcsecond structure. We will present the primary science goals of MP. These include resolving stellar coronae, distinguishing between jets and accretion disks in AGN. This paper will also present the baseline design of MP. We will over-view the challenging technical requirements and solutions for formation flying, target acquisition, and metrology. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Gendreau, KC (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 7 TC 18 Z9 18 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 353 EP 364 DI 10.1117/12.461316 PN 1&2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600033 ER PT S AU Petre, R Zhang, WW Content, DA Saha, TT Stewart, J Hair, JH Nguyen, D Podgorski, WA Davis, WR Freeman, MD Cohen, LBM Schattenburg, ML Heilmann, RK Sun, YX Forest, C AF Petre, R Zhang, WW Content, DA Saha, TT Stewart, J Hair, JH Nguyen, D Podgorski, WA Davis, WR Freeman, MD Cohen, LBM Schattenburg, ML Heilmann, RK Sun, YX Forest, C BE Trumper, JE Tananbaum, HD TI Constellation-X spectroscopy X-ray telescope (SXT) SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE X-ray optics; X-ray telescopes; constellation-X ID MIRRORS AB We provide an overview of the Constellation-X SXT development program. We describe the performance requirements and goals, and the status of the technology development program. The SXT has a 1.6-meter diameter, a 10-meter focal length, and is to have an angular resolution exceeding 15 arc seconds. It has a modular design, incorporating lightweight, multiply nested, segmented Wolter Type I X-ray mirrors. All aspects of the design lend themselves to mass-production. The reflecting surfaces are produced by epoxy replication off precision mandrels onto glass substrates that have been accurately formed by thermal slumping. Coalignment of groups of reflectors to the required sub-micron accuracy is assisted by precision silicon microstructures. Optical alignment is performed using the Centroid Detector Assembly (CDA) originally developed for aligning the Chandra mirror. Recent efforts have concentrated on the production of an Engineering Unit, incorporating the components for the first time into a flight-like configuration. We summarize the status of the development of the processes for the key components and the initial metrology results of the Engineering Unit. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Petre, R (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. RI Heilmann, Ralf/D-4680-2009 NR 8 TC 16 Z9 16 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 433 EP 440 DI 10.1117/12.461317 PN 1&2 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600041 ER PT S AU Chan, KW Soong, Y Serlemitsos, PJ AF Chan, KW Soong, Y Serlemitsos, PJ BE Trumper, JE Tananbaum, HD TI The X-Ray mirrors for the Astro-E2 mission SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE X-ray optics; X-ray telescopes; thin-foil mirrors; Astro-E2 ID FABRICATION AB The X-Ray telescopes (XRT) for the US/Japan collaborative mission Astro-E2 will be of the same basic design as those built for the original Astro-E mission which failed to reach orbit in Feb. 2000. The NASA/GSFC X-ray Astrophysics Branch will again provide the five lightweight, broad-band mirrors for the mission. X-ray calibrations of the mirrors delivered for the original Astro-E instrument showed spatial resolutions characterized by Half-Power Diameters (HPD) in the range of 1.8 - 2.2 minutes of arc, essentially independent of photon energy in the soft x-ray band. For the mission Astro-E2, both funding constraints and management decisions drastically limit any design modifications, so reflector fabrication and assembly procedures have remained largely unchanged. Nevertheless, in view of the importance in scientific return of attaining even a modest improvement in the spatial resolution of these mirrors, we have carefully considered the various sources of spatial error and, whenever possible, incorporated promising modifications. In this paper, we discuss our current understanding of the various error components as well as the small changes we have been able to implement. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Chan, KW (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 662, Greenbelt, MD 20771 USA. NR 5 TC 11 Z9 11 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 451 EP 458 DI 10.1117/12.461281 PN 1&2 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600043 ER PT S AU Zhang, W Chan, KW Content, D Owens, S Petre, R Serlemitsos, P Saha, T Soong, Y AF Zhang, W Chan, KW Content, D Owens, S Petre, R Serlemitsos, P Saha, T Soong, Y BE Trumper, JE Tananbaum, HD TI Development of mirror segments for the Constellation-X observatory SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE ID RAY AB As NASA's next major X-ray observatory, Constellation-X will have a photon collection area of 30,000 cm(2) at 1 keV, which, after folding other instrumental responses, translates into an effective area of 15,000 cm(2). The observatory consists of four identical satellites each of which carries a spectroscopic X-ray telescope mirror assembly (SXT) that is 1.6 in in diameter and has a focal length of 10 in and a collection area of 7,500 cm(2) at 1 keV and an angular resolution of 15" HPD (half-power diameter) at the system level. Each mirror assembly consists of a large number of mirror segments precisely assembled together. Our development of the mirror segments is divided into two steps. The first one is to develop the basic approach and fabricate segments within the constraints of existing infra-structure to meet the angular resolution requirement, but not mirror segment size requirement. We have all but successfully completed this part of the development. We are now on the verge of going into the second step, that is to fabricate mirror segments of larger sizes to reduce the number of segments that have to be aligned and integrated. In this paper, we report on the requirements and the development status of the mirror segments. These assembly and other requirements of the SXT are reported elsewhere (Podgorski et al. and Hair et al.). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Zhang, W (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 6 TC 13 Z9 13 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 503 EP 518 DI 10.1117/12.461421 PN 1&2 PG 16 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600048 ER PT S AU Leviton, DB Frey, BJ Madison, LE Parker, JA Sheinman, OE AF Leviton, DB Frey, BJ Madison, LE Parker, JA Sheinman, OE BE Trumper, JE Tananbaum, HD TI Sub-arcsecond, differential, deflectometry to measure thermally-induced distortions of the Swift optical bench SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE optical bench; distortion; deflectometry AB The Swift optical bench is a roughly 2.7 in diameter, 0.1 in thick composite structure carrying the Burst Alert Telescope (BAT), X-ray Telescope (XRT), and the Ultraviolet Optical Telescope (UVOT) as well as various attitude control instrumentation for the spacecraft. A high precision test of the optical bench using multi-aperture optical deflectometry was developed to verify that the relative boresights of the XRT and UVOT instruments would not change by more than several arcseconds when a worst case on-orbit temperature gradient is imposed through the thickness of the bench. Results of validation tests in a laminar flow cleanroom environment without vibration isolation demonstrated a differential measurement capability with 0.2 arcsecond sensitivity and 0.5 arcsecond accuracy per day. The technique is easily adaptable to similar deflection monitoring requirements for other large spacecraft structures. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Leviton, DB (reprint author), NASA, Goddard Space Flight Ctr, Code 551, Greenbelt, MD 20771 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 587 EP 598 DI 10.1117/12.474308 PN 1&2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600056 ER PT S AU Ramsey, B Elsner, R Engelhaupt, D O'Dell, S Speegle, C Weiskopf, M AF Ramsey, B Elsner, R Engelhaupt, D O'Dell, S Speegle, C Weiskopf, M BE Trumper, JE Tananbaum, HD TI The development of hard-x-ray optics at MSFC SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE electroform-nickel replication; x-ray imaging; grazing-incidence optics; x-ray astronomy AB We are fabricating optics for the hard-x-ray region using electroform nickel replication. The attraction of this process, which has been widely used elsewhere, is that the resulting full shell optics are inherently stable and thus can have very good angular resolution. The challenge with this process is to develop lightweight optics (nickel has a relatively high density of 8.9 g / cm(3)), and to keep down the costs of mandrel fabrication. We accomplished the former through the development of high-strength, low-stress nickel alloys that permit very thin, stable, shells without fabrication- and handling-induced deformations. For the latter, we have utilized inexpensive grinding and diamond turning to figure the mandrels and then purpose-built polishing machines to finish the surface. In-house plating tanks and a simple water-bath separation system complete the process. To date we have built shells ranging in size from 5 cm diameter to 50 cm, and with thickness down to 100 micron. For our HERO balloon program, we are fabricating over 200 iridium-coated shells, 250 microns thick, for hard-x-ray imaging up to 75 keV. Early test results on these have indicated half-power-diameters of 15 arcsec. The status of these developments will be reviewed. C1 NASA, Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. RP Ramsey, B (reprint author), NASA, Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. NR 3 TC 9 Z9 9 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 631 EP 638 DI 10.1117/12.461597 PN 1&2 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600060 ER PT S AU Hair, JH Stewart, JW Petre, R Zhang, WW Content, DA Saha, TT Podgorski, WA Glenn, P Schattenberg, ML Heilmann, RK Sun, YX Nanan, G AF Hair, JH Stewart, JW Petre, R Zhang, WW Content, DA Saha, TT Podgorski, WA Glenn, P Schattenberg, ML Heilmann, RK Sun, YX Nanan, G BE Trumper, JE Tananbaum, HD TI Constellation-X spectroscopy x-ray telescope segmented optic assembly and alignment implementation SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE segmented X-Ray optics; Centroid Detector Assembly; interferometry; optical alignment methods; optic support; precision adjustment; delicate assembly processes AB The Constellation-X mission will perform X-Ray science with improvements in energy resolution and effective area over its predecessor missions. The primary instrument on each of the four Constellation-X spacecraft is the Spectroscopy X-Ray Telescope (SXT). The SXT is a 1.6m diameter grazing incidence mirror assembly comprised of approximately 4000 optic elements. In order for the optic elements to work together to achieve the required 15 arcsec image resolution for the telescope, each optic must be aligned very precisely. To enable the alignment of the optic elements to the required tolerances, new technology must be developed through a series of technology demonstrators. The first step in this process is the production of the Optical Assembly Pathfinder (OAP). The OAP represents a small section, or module, of the complete SXT and has been designed to facilitate the evaluation and development of the optic element support, alignment, and adjustment concepts, processes, and procedures. To do this, one pair of optic elements, primary and secondary, will be aligned using optical alignment methods including the Centroid Detector Assembly (CDA) and Interferometry. Ten Optic Adjustment Arms will support the optic elements such that their position and figures can be adjusted. Currently, one section, the primary section, of the OAP has been assembled and is awaiting the installation of an optic element for testing. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hair, JH (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Heilmann, Ralf/D-4680-2009 NR 3 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 696 EP 707 DI 10.1117/12.461468 PN 1&2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600067 ER PT S AU Okajima, T Ogasaka, Y Tamura, K Furuzawa, A Tawara, Y Yamashita, K Kunieda, H AF Okajima, T Ogasaka, Y Tamura, K Furuzawa, A Tawara, Y Yamashita, K Kunieda, H BE Trumper, JE Tananbaum, HD TI Supermirror design for the XEUS X-ray telescope SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE multilayer; supermirror; X-ray telescope; hard X-ray; X-ray optics AB X-ray telescopes have been providing high sensitivity in X-ray observations in various missions. Recently XMM-Newton achieved an effective area of about 2000 cm(2) at 8 keV and a very high sensitivity. For X-ray telescopes in the future, one of the key technologies is to expand the energy band beyond 10 keV. In our previous work, we designed depth-graded multilayers, so called supermirror, for a hard X-ray telescope and it was successfully flown in a balloon flight. This technology is promising to extend the energy band up to 40 keV. We would like to propose supermirror coatings on the mirrors of the XEUS X-ray telescope, which has a focal length of 50 m, a diameter of 4.5 m and a mirror length of 1 m. In this configuration. incident angle is ranging from 0.17 to 0.65 degrees and a large effective area of 30000 cm 2 at 8 keV can be achieved. To extend the energy band up to 80 keV, platinum-carbon supermirrors are effective for the incident angle below 0.4 degrees. If the inner part of the XEUS mirrors are coated with multilayers, the, effective area will be enhanced above 10 keV and be kept over 100 cm 2 up to 80 keV. In this paper, we propose the supermirror design and discuss the performance, of the XEUS hard X-ray telescope with supermirrors. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM okajima@milkyway.gsfc.nasa.gov NR 8 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 PROC SPIE PY 2003 VL 4851 BP 716 EP 723 DI 10.1117/12.461409 PN 1&2 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600069 ER PT S AU Figueroa-Feliciano, E Boyce, K Chervenak, J Finkbeiner, F Kelley, R Li, M Lindeman, M Porter, S Stahle, CK AF Figueroa-Feliciano, E Boyce, K Chervenak, J Finkbeiner, F Kelley, R Li, M Lindeman, M Porter, S Stahle, CK BE Trumper, JE Tananbaum, HD TI Posit ion-sensitive microcalorimeters for large-field, high-energy-resolution astrophysics SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE x-ray; spectrometer; microcalorimeter; calorimeter; imaging; position-sensitive; distributed readout; Constellation-X ID TRANSITION-EDGE SENSORS AB We are developing a distributed-readout imaging spectrometer named Position-Sensitive Transition-Edge Sensor (PoST). A PoST is a microcalorimeter capable of one-dimensional imaging spectroscopy. It consists of two 'Ransition-Edge Sensors (TESs) at each end of a long x-ray absorber. The position of an x-ray absorption event in the PoST is determined from the rise time and relative signal sizes in the two sensors. The energy of the absorbed photon is inferred from the sum of the two pulses. We discuss the modeling, operation, and readout of PoSTs and their application to the Constellation-X mission. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Figueroa-Feliciano, E (reprint author), Code 662,Bld 2,Rm 251, Greenbelt, MD 20771 USA. RI Kelley, Richard/K-4474-2012 NR 18 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 913 EP 921 DI 10.1117/12.461424 PN 1&2 PG 9 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600090 ER PT S AU Baumgartner, WH Tueller, J Krimm, H Barthelmy, S Berendse, F Ryan, L Birsa, F Okajima, T Kunieda, H Ogasaka, Y Tawara, Y Tamura, K AF Baumgartner, WH Tueller, J Krimm, H Barthelmy, S Berendse, F Ryan, L Birsa, F Okajima, T Kunieda, H Ogasaka, Y Tawara, Y Tamura, K BE Trumper, JE Tananbaum, HD TI The InFOC/S-mu hard X-ray telescope: Pixellated CZT detector/shield performance and flight results SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE CZT; background; shielding; balloon flights; hard X-ray astronomy; instrumentation ID BALLOON FLIGHT AB The CZT detector on the InFOCmuS hard X-ray telescope is a pixellated solid-state device capable of imaging spectroscopy by measuring the position and energy of each incoming photon. The detector sits at the focal point of an 8m focal length multilayered grazing incidence X-ray mirror which has significant effective area between 20-40 keV. The detector has an energy resolution of 4.0keV at 32keV, and the InFOCmuS telescope has an angular resolution of 2.2 arcminute and a field of view of about 10 arcminutes. InFOCmuS flew on a balloon mission in July 2001 and observed Cygnus X-1. We present results from laboratory testing of the detector to measure the uniformity of response across the detector, to determine the spectral resolution, and to perform a simple noise decomposition. We also present a hard X-ray spectrum and image of Cygnus X-1, and measurements of the hard X-ray CZT background obtained with the SWIN detector on InFOCmuS. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Baumgartner, WH (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. RI Barthelmy, Scott/D-2943-2012; Tueller, Jack/D-5334-2012 NR 13 TC 8 Z9 8 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 945 EP 956 DI 10.1117/12.461491 PN 1&2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600093 ER PT S AU Lindeman, MA Bandler, S Brekosky, RP Chervenak, JA Figueroa-Feliciano, E Finkbeiner, FM Galeazzi, M Li, MJ Stahle, CK AF Lindeman, MA Bandler, S Brekosky, RP Chervenak, JA Figueroa-Feliciano, E Finkbeiner, FM Galeazzi, M Li, MJ Stahle, CK BE Trumper, JE Tananbaum, HD TI Probing the phase transition of Mo/Au TES microcalorimeters SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE transition edge sensor; calorimeter; impedance measurement; heat capacity; superconductor; energy dispersive spectrometer AB We present recent measurements obtained using a new method for characterizing transition edge sensor (TES) calorimeters: We measured the electrical impedance of a TES calorimeter throughout the superconducting to normal metal phase transition. The impedance method enables us to precisely measure how the resistance and heat capacity of the TES varies throughout the phase transition. These measurements probe the internal state of our Mo /Au TES. We also present recent results from measurements of noise in our TESs. Our measurements are instrumental toward understanding and optimizing our TES calorimeters. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lindeman, MA (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. RI Bandler, Simon/A-6258-2010 OI Bandler, Simon/0000-0002-5112-8106 NR 5 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 957 EP 964 DI 10.1117/12.461466 PN 1&2 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600094 ER PT S AU Sharma, DP Gaskin, JA Ramsey, BD Seller, P AF Sharma, DP Gaskin, JA Ramsey, BD Seller, P BE Trumper, JE Tananbaum, HD TI Characteristics of a 16x16 fine-pixel cadmium-zinc-telluride detector SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE CdZnTe; pixellated detectors; HERO; X-ray ID RAY AB Cadmium-Zinc-Telluride (CdZnTe) multi-pixel detectors are ideal for astrophysical application. As part of ongoing research at the Marshall Space Flight Center (MSFC), we are working to develop a 64x64 fine-pixel detector for use at the focus of high-resolution gazing-incidence optics. As a first step towards achieving this goal, we present results from a 16x 16 fine-pixel CdZnTe detector, 2mm thick, having a pixel pitch of 300mum and an inter-pixel gap of 50mum. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Sharma, DP (reprint author), NASA, George C Marshall Space Flight Ctr, SD 50, Huntsville, AL 35812 USA. NR 6 TC 3 Z9 3 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 1019 EP 1028 DI 10.1117/12.478479 PN 1&2 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600101 ER PT S AU Vigneau, DN Robinson, DW AF Vigneau, DN Robinson, DW BE Trumper, JE Tananbaum, HD TI Large coded aperture mask for spaceflight hard X-ray images SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE coded aperture mask; Swift; Burst Alert Telescope; hard X-rays AB The 2.6 square meter coded aperture mask is a vital part of the Burst Alert Telescope on the Swift mission. A random, but known pattern of more than 50,000 lead tiles, each 5 mm square, was bonded to a larg honeycomb panel which projects a shadow on the detector array during a gamma ray burst. A two-year development process was necessary to explore ideas, apply techniques, and finalize procedures to meet the strict requirements for the coded aperture mask. Challenges included finding a honeycomb substrate with minimal gamma ray attenuation, selecting an adhesive with adequate bond strength to hold the tiles in place but flexible enough to allow the tiles to expand and contract without distorting the panel under large temperature gradients, and eliminating excess adhesive from all untiled areas. Finding an efficient way to bond the > 50,000 lead tiles to the panel while maintaining positional tolerances within 0.1 min was no small task. In order to generate the desired bondline, adhesive was applied and allowed to cure to each tile. The "pre-cured" tiles were located in a tool to maintain positional accuracy, wet adhesive was applied to the panel, and the wetted substrate was lowered to the tile surface with synchronized actuators. Using this procedure, the entire tile pattern was transferred to the large honeycomb panel in a single bond. The pressure for the bond was achieved by enclosing the entire system in a vacuum bag. Thermal vacuum and acoustic tests validated this approach. This paper discusses the methods, materials, and techniques used to fabricate this very large and unique coded aperture mask for the Swift mission. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Vigneau, DN (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 1 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 1326 EP 1335 DI 10.1117/12.461162 PN 1&2 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600133 ER PT S AU Robinson, DW AF Robinson, DW BE Trumper, JE Tananbaum, HD TI Building a new kind of Graded-Z shield for Swift's Burst Alert Telescope SO X-RAY AND GAMMA-RAY TELESCOPES AND INSTRUMENTS FOR ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Telescopes and Instruments for Astronomy CY AUG 24-28, 2002 CL WAIKOLOA, HI SP SPIE DE Graded-Z Shield; Swift; BAT; Gamma-rays; X-rays AB The Burst Alert Telescope (BAT) on Swift has a graded-Z Shield that closes out the volume between the coded aperture mask and the Cadmium-Zinc-Telluride (CZT) detector array. The purpose of the 37-kilogram shield is to attenuate gamma rays that have not penetrated the coded aperture mask of the BAT instrument and are therefore a major source of noise on the detector array. Unlike previous shields made from plates and panels, this shield consists of multiple layers of thin metal foils (lead, tantalum, tin, and copper) that are stitched together much like standard multi-layer insulation blankets. The shield sections are fastened around BAT, forming a curtain around the instrument aperture. Strength tests were performed to validate and improve the design, and the shield will be vibration tested along with BAT in late 2002. Practical aspects such as the layup design, methods of manufacture, and testing of this new kind of graded-Z Shield are presented. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Robinson, DW (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 4 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4630-0 J9 P SOC PHOTO-OPT INS PY 2003 VL 4851 BP 1374 EP 1381 DI 10.1117/12.461133 PN 1&2 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BW45N UT WOS:000182073600138 ER PT S AU Palmeri, P Mendoza, C Kallman, T Bautista, M AF Palmeri, P Mendoza, C Kallman, T Bautista, M BE Bianconi, A Marcelli, A Saini, NL TI Photoionization of the Fe ions: Structure of the K-edge SO X-RAY AND INNER-SHELL PROCESSES SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 19th International Conference on X-Ray and Inner-Shell Processes CY JUN 24-28, 2002 CL ROME, ITALY SP Univ Roma La Sapienza, Lab Nazl Frascati, ENEA, INRM ID AUGER DECAY; RYDBERG SERIES; RESONANCES; ASCA AB X-ray absorption and emission features arising from the inner-shell transitions in iron are of practical importance in astrophysics due to the Fe cosmic abundance and to the absence of traits from other elements in the nearby spectrum. As a result, the strengths and energies of such features can constrain the ionization stage, elemental abundance, and column density of the gas in the vicinity of the exotic cosmic objects, e.g. active galactic nuclei (AGN) and galactic black hole candidates. Although the observational technology in X-ray astronomy is still evolving and currently lacks high spectroscopic resolution, the astrophysical models have been based on atomic calculations that predict a sudden and high step-like increase of the cross section, at the K-shell threshold (see for instance Ref. [1]). New Breit-Pauli R-matrix calculations of the photoionization cross section of the ground states of Fe XVII in the region near the K threshold are presented. They strongly support the view that the previously assumed sharp edge behaviour is not correct. The latter has been caused by the neglect of spectator Auger channels in the decay of the resonances converging to the K threshold. These decay channels include the dominant KLL channels and give rise to constant widths (independent of n). As a consequence, these series display damped Lorentzian components that rapidly blend to impose continuity at threshold, thus reformatting the previously held picture of the edge. Apparent broadened iron edges detected in the spectra of AGN and galactic black hole candidates seem [2, 3] to indicate that these quantum effects may be at least partially responsible for the observed broadening. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Palmeri, P (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0111-X J9 AIP CONF PROC PY 2003 VL 652 BP 159 EP 164 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Optics; Physics GA BW52R UT WOS:000182316700018 ER PT J AU Kanzawa, H Schiller, C Ovarlez, J Camy-Peyret, C Payan, S Jeseck, P Oelhaf, H Stowasser, M Traub, WA Jucks, KW Johnson, DG Toon, GC Sen, B Blavier, JF Park, JH Bodeker, GE Pan, LL Sugita, T Nakajima, H Yokota, T Suzuki, M Shiotani, M Sasano, Y AF Kanzawa, H Schiller, C Ovarlez, J Camy-Peyret, C Payan, S Jeseck, P Oelhaf, H Stowasser, M Traub, WA Jucks, KW Johnson, DG Toon, GC Sen, B Blavier, JF Park, JH Bodeker, GE Pan, LL Sugita, T Nakajima, H Yokota, T Suzuki, M Shiotani, M Sasano, Y TI Validation and data characteristics of water vapor profiles observed by the Improved Limb Atmospheric Spectrometer (ILAS) and processed with the version 5.20 algorithm SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE water vapor; polar stratosphere; validation; satellite sensor; Improved Limb Atmospheric Spectrometer (ILAS) ID POLAR STRATOSPHERIC CLOUDS; GAS EXPERIMENT-II; BALLOON-BORNE; TRACE GASES; SAGE II; OZONE; H2O; TROPOSPHERE; HYGROMETER; AEROSOL AB [1] Vertical profiles of water vapor concentration at high latitudes (57-72 degreesN; 64-89 degreesS) were observed by the Improved Limb Atmospheric Spectrometer (ILAS) solar occultation sensor aboard the Advanced Earth Observing Satellite (ADEOS). These measurements were made continuously from November 1996 through June 1997 with some additional periods in September to October 1996. A validation study of the water vapor data processed with the version 5.20 ILAS retrieval algorithm is presented in this paper. Uncertainty and general characteristics of the ILAS water vapor measurements are briefly reviewed. Comparisons are made with data obtained by (1) the ILAS validation balloon campaigns at Kiruna, Sweden and at Fairbanks, Alaska; (2) the aircraft measurements under the Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) campaign; and (3) available satellite measurements of the version 19 Halogen Occultation Experiment (HALOE) and the version 6 Stratospheric Aerosol and Gas Experiment II (SAGE II). The agreement between ILAS water vapor and all independent reliable correlative measurements in the altitude region of 15-60 km is better than 10% for the majority of cases and better than 20% for all comparisons, with the exception of some isolated cases detailed in this paper. Climatological comparisons of ILAS data with Upper Atmosphere Research Satellite (UARS) climatology and HALOE data show the overall consistency of ILAS water vapor data considering the known features of atmospheric circulation. The characteristics of ILAS measurements, i.e., high sampling frequency in polar latitudes with high vertical resolution along with the good data quality, make the ILAS water vapor data set valuable for various polar stratospheric research applications. C1 Natl Inst Environm Studies, Tsukuba, Ibaraki 3050053, Japan. Forschungszentrum Julich, Inst Stratosphaer Chem, D-52425 Julich, Germany. Ecole Polytech, CNRS, Meteorol Dynam Lab, F-91128 Palaiseau, France. Univ Paris 06, CNRS, Lab Phys Mol & Applicat, F-75252 Paris 05, France. Forschungszentrum Karlsruhe, Inst Meteorol & Klimaforsch, D-76021 Karlsruhe, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Natl Inst Water & Atmospher Res, Lauder, New Zealand. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Hokkaido Univ, Grad Sch Environm Earth Sci, Sapporo, Hokkaido 060, Japan. RP Kanzawa, H (reprint author), Natl Inst Environm Studies, 16-2 Onogawa, Tsukuba, Ibaraki 3050053, Japan. EM kanzawa@nies.go.jp; c.schiller@fz-juelich.de; Joelle.ovarlez@polytechnique.fr; camy@ccr.jussieu.fr; payan@ccr.jussieu.fr; jeseck@ccr.jussieu.fr; hermann.oelhaf@imk.fzk.de; markus.stowasser@imk.fzk.de; wtraub@cfa.harvard.edu; kjucks@cfa.harvard.edu; d.g.johnson@larc.nasa.gov; toon@mark4sun.jpl.nasa.gov; sen@mark4sun.jpl.nasa.gov; Jean.F.Blavier@jpl.nasa.gov; j.h.park@larc.nasa.gov; g.bodeker@niwa.cri.nz; liwen@ucar.edu; tsugita@nies.go.jp; hide@nies.go.jp; yoko@nies.go.jp; suzuki@eorc.nasda.go.jp; shiotani@kurasc.kyoto-u.ac.jp; sasano@nies.go.jp RI Pan, Laura/A-9296-2008; Sasano, Yasuhiro/C-2927-2009; Oelhaf, Hermann/A-7895-2013; Schiller, Cornelius/B-1004-2013; Johnson, David/F-2376-2015 OI Pan, Laura/0000-0001-7377-2114; Sasano, Yasuhiro/0000-0001-7470-5642; Johnson, David/0000-0003-4399-5653 NR 63 TC 16 Z9 16 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 31 PY 2002 VL 107 IS D24 AR 8217 DI 10.1029/2001JD000881 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650KF UT WOS:000181262000001 ER PT J AU Muscari, G Santee, ML de Zafra, RL AF Muscari, G Santee, ML de Zafra, RL TI Intercomparison of stratospheric HNO3 measurements over Antarctica: Ground-based millimeter-wave versus UARS/MLS Version 5 retrievals SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE intercomparison; nitric acid; polar stratosphere ID ATMOSPHERE RESEARCH SATELLITE; SPECTROSCOPIC MEASUREMENTS; SOUTH-POLE; WINTER; OZONE; TEMPERATURE; CHEMISTRY; EVOLUTION; NITROGEN; VORTEX AB [1] We present the first intercomparison between the two most comprehensive records of gas-phase HNO3 profiles in the Antarctic stratosphere, covering the greater part of 1993 and 1995. We compare measurements by the Stony Brook Ground-Based Millimeter-wave Spectrometer (GBMS) at the South Pole with Version 5 HNO3 data from the Microwave Limb Sounder (MLS) aboard the Upper Atmospheric Research Satellite. Trajectory tracing was used to select MLS measurements in the 70degrees-80degreesS latitude band that sampled air observed by the GBMS during passage over the Pole. When temperatures were near the HNO3 condensation range, additional screening was performed to select MLS measurements that sampled air parcels within 1.5 K of the temperature they experienced over the Pole. Quantitative comparisons are given at 7 different potential temperature levels spanning the range similar to19-30 km. Agreement between the data sets is quite good between 465 and 655 K ( similar to20-25 km) during a large fraction of the year. Agreement is best during winter and spring, when seasonally averaged differences are generally within 1 ppbv below similar to25 km. At higher altitudes, and during summer and fall, the agreement becomes worse, and GBMS measurements can exceed MLS values by more than 3 ppbv. We provide evidence that differences occurring in the lower stratosphere during fall are due to lack of colocation between the two data sets during a period of strong poleward gradients in HNO3. Remaining discrepancies between GBMS and MLS V5 HNO3 measurements are thought to be due to instrumental or retrieval biases. C1 SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Muscari, G (reprint author), Univ Roma La Sapienza, Dipartimento Fis, Ple Aldo Moro 5, Rome, Italy. EM muscari@g24ux.phys.uniroma1.it; michelle.l.santee@jpl.nasa.gov; rdezafra@notes.ce.sunysb.edu NR 30 TC 9 Z9 9 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 31 PY 2002 VL 107 IS D24 AR 4809 DI 10.1029/2002JD002546 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650KF UT WOS:000181262000010 ER PT J AU Carr, ME Strub, PT Thomas, AC Blanco, JL AF Carr, ME Strub, PT Thomas, AC Blanco, JL TI Evolution of 1996-1999 La Nina and El Nino conditions off the western coast of South America: A remote sensing perspective SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE Eastern boundary currents; Peru-Humboldt Current; remote sensing; El Nino-La Nina; coastal upwelling ID CALIFORNIA CURRENT; INTERANNUAL VARIABILITY; TEMPERATURE; TRANSITION; STATE; CHILE AB [1] We present the evolution of oceanographic conditions off the western coast of South America between 1996 and 1999, including the cold periods of 1996 and 1998-1999 and the 1997-1998 El Nino, using satellite observations of sea level, winds, sea surface temperature (SST), and chlorophyll concentration. Following a period of cold SST and low sea levels in 1996, both were anomalously high between March 1997 and May 1998. The anomalies were greatest between 5degreesS and 15degreesS, although they extended beyond 40degreesS. Two distinct peaks in sea level and SST occurred in June-July 1997 and December 1997 to January 1998, separated by a relaxation period (August-November) of weaker anomalies. Satellite winds were upwelling favorable throughout the time period for most of the region and in fact increased between November 1997 and March 1998 between 5degreesS and 25degreesS. Satellite-derived chlorophyll concentrations are available for November 1996 to June 1997 (Ocean Color and Temperature Sensor (OCTS)) and then from October 1997 to present (Sea-viewing Wide Field-of-view Sensor (SeaWiFS)). Near-surface chlorophyll concentrations fell from May to June 1997 and from December 1997 to March 1998. The decrease was more pronounced in northern Chile than off the coast of Peru or central Chile and was stronger for larger cross-shelf averaging bins since nearshore concentrations remained relatively high. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. Univ Maine, Sch Marine Sci, Orono, ME USA. Inst Fomento Pesquero, Valparaiso, Chile. RP Carr, ME (reprint author), CALTECH, Jet Prop Lab, MS 300-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 34 TC 25 Z9 26 U1 2 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 31 PY 2002 VL 107 IS C12 AR 3236 DI 10.1029/2001JC001183 PG 16 WC Oceanography SC Oceanography GA 649XR UT WOS:000181233700005 ER PT J AU Glaze, LS Stofan, ER Smrekar, SE Baloga, SM AF Glaze, LS Stofan, ER Smrekar, SE Baloga, SM TI Insights into corona formation through statistical analyses SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Venus; corona; statistics ID VENUS; ORIGIN; MORPHOLOGY; TECTONICS; EVOLUTION; BOUNDARY; HOTSPOTS; GRAVITY; MODELS; RISES AB [1] Statistical analysis of an expanded database of coronae on Venus indicates that the populations of Type 1 (with fracture annuli) and 2 (without fracture annuli) corona diameters are statistically indistinguishable, and therefore we have no basis for assuming different formation mechanisms. Analysis of the topography and diameters of coronae shows that coronae that are depressions, rimmed depressions, and domes tend to be significantly smaller than those that are plateaus, rimmed plateaus, or domes with surrounding rims. This is consistent with the model of Smrekar and Stofan [1997] and inconsistent with predictions of the spreading drop model of Koch and Manga [1996]. The diameter range for domes, the initial stage of corona formation, provides a broad constraint on the buoyancy of corona-forming plumes. Coronae are only slightly more likely to be topographically raised than depressions, with Type 1 coronae most frequently occurring as rimmed depressions and Type 2 coronae most frequently occurring with flat interiors and raised rims. Most Type 1 coronae are located along chasmata systems or fracture belts, while Type 2 coronae are found predominantly as isolated features in the plains. Coronae at hot spot rises tend to be significantly larger than coronae in other settings, consistent with a hotter upper mantle at hot spot rises and their active state. C1 Proxemy Res, Laytonsville, MD 20882 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Glaze, LS (reprint author), Proxemy Res, 20528 Farcroft Lane, Laytonsville, MD 20882 USA. RI Glaze, Lori/D-1314-2012 NR 28 TC 28 Z9 28 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 31 PY 2002 VL 107 IS E12 AR 5135 DI 10.1029/2002JE001904 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 649PX UT WOS:000181218100003 ER PT J AU McGovern, PJ Solomon, SC Smith, DE Zuber, MT Simons, M Wieczorek, MA Phillips, RJ Neumann, GA Aharonson, O Head, JW AF McGovern, PJ Solomon, SC Smith, DE Zuber, MT Simons, M Wieczorek, MA Phillips, RJ Neumann, GA Aharonson, O Head, JW TI Localized gravity/topography admittance and correlation spectra on Mars: Implications for regional and global evolution SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Mars; lithosphere; heat flux; thermal gradient; thermal evolution; admittance ID VALLES-MARINERIS; LARGE VOLCANOS; TERRESTRIAL PLANETS; INTERNAL STRUCTURE; THERMAL EVOLUTION; GRAVITY-FIELD; TOPOGRAPHY; SURVEYOR; MODELS; VENUS AB [1] From gravity and topography data collected by the Mars Global Surveyor spacecraft we calculate gravity/topography admittances and correlations in the spectral domain and compare them to those predicted from models of lithospheric flexure. On the basis of these comparisons we estimate the thickness of the Martian elastic lithosphere (T-e) required to support the observed topographic load since the time of loading. We convert T-e to estimates of heat flux and thermal gradient in the lithosphere through a consideration of the response of an elastic/plastic shell. In regions of high topography on Mars (e.g., the Tharsis rise and associated shield volcanoes), the mass-sheet (small-amplitude) approximation for the calculation of gravity from topography is inadequate. A correction that accounts for finite-amplitude topography tends to increase the amplitude of the predicted gravity signal at spacecraft altitudes. Proper implementation of this correction requires the use of radii from the center of mass (collectively known as the planetary "shape'') in lieu of "topography'' referenced to a gravitational equipotential. Anomalously dense surface layers or buried excess masses are not required to explain the observed admittances for the Tharsis Montes or Olympus Mons volcanoes when this correction is applied. Derived T-e values generally decrease with increasing age of the lithospheric load, in a manner consistent with a rapid decline of mantle heat flux during the Noachian and more modest rates of decline during subsequent epochs. C1 Lunar & Planetary Inst, Houston, TX 77058 USA. Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. CALTECH, Div Geol & Planetary Sci, Seismol Lab, Pasadena, CA 91125 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. RP McGovern, PJ (reprint author), Lunar & Planetary Inst, 3600 Bay Area Blvd, Houston, TX 77058 USA. RI Wieczorek, Mark/G-6427-2010; Neumann, Gregory/I-5591-2013; OI Wieczorek, Mark/0000-0001-7007-4222; Neumann, Gregory/0000-0003-0644-9944; McGovern, Patrick/0000-0001-9647-3096 NR 74 TC 166 Z9 168 U1 0 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 31 PY 2002 VL 107 IS E12 AR 5136 DI 10.1029/2002JE001854 PG 25 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 649PX UT WOS:000181218100002 ER PT J AU Waugh, DW Hall, TM AF Waugh, DW Hall, TM TI Age of stratospheric air: Theory, observations, and models SO REVIEWS OF GEOPHYSICS LA English DT Review DE stratosphere; transport; tracers; age ID MIDLATITUDE LOWER STRATOSPHERE; SEMI-LAGRANGIAN TRANSPORT; IN-SITU OBSERVATIONS; CARBON-DIOXIDE; 2-DIMENSIONAL MODEL; MIDDLE ATMOSPHERE; TRANSIT-TIME; WATER-VAPOR; TROPICAL STRATOSPHERE; SULFUR-HEXAFLUORIDE AB [1] We review the relationship between tracer distributions and transport timescales in the stratosphere and discuss the use of timescales to evaluate and constrain theories and numerical models of the stratosphere. The "age spectrum," the distribution of transit times since stratospheric air last made tropospheric contact, provides a way to understand the transport information of tracers, how sensitive different tracers are to various transport processes, and how to use tracers in combination to constrain transport rates. Trace gas observations can be used to infer aspects of the age spectrum, most commonly the "mean age," but also the shape of the spectrum. Observational inferences of transport timescales provide stringent tests of numerical models independent of photochemistry, and comparisons of these observations with chemical transport models have highlighted certain problems with transport in the models. Age simulations and comparisons with data can now be considered standard tests of stratospheric models. C1 Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Waugh, DW (reprint author), Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. RI Waugh, Darryn/K-3688-2016 OI Waugh, Darryn/0000-0001-7692-2798 NR 113 TC 167 Z9 167 U1 3 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 8755-1209 J9 REV GEOPHYS JI Rev. Geophys. PD DEC 31 PY 2002 VL 40 IS 4 AR 1010 DI 10.1029/2000RG000101 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 649MX UT WOS:000181213500002 ER PT J AU Khare, BN Meyyappan, M Kralj, J Wilhite, P Sisay, M Imanaka, H Koehne, J Baushchlicher, CW AF Khare, BN Meyyappan, M Kralj, J Wilhite, P Sisay, M Imanaka, H Koehne, J Baushchlicher, CW TI A glow-discharge approach for functionalization of carbon nanotubes SO APPLIED PHYSICS LETTERS LA English DT Article AB We demonstrate the functionalization of single-walled carbon nanotubes (SWNTs) using a glow discharge for generating atomic or molecular. radicals. A 30-s exposure to a cold plasma of H-2 results in near-saturation coverage of SWNT with atomic hydrogen. Functionalization of SWNTs with atomic hydrogen is confirmed by an infrared band at 2924 cm(-1), characteristic of C-H stretching mode. A corresponding decrease in:the ultraviolet absorption is also observed, which is due to a loss of some. conjugated C-C pi bonds in hydrogen covered SWNTs. (C) 2002 American Institute of Physics. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP SETI Inst, Mountain View, CA USA. EM meyya@orbit.arc.nasa.gov RI Imanaka, Hiroshi/E-7816-2012 NR 17 TC 56 Z9 56 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 30 PY 2002 VL 81 IS 27 BP 5237 EP 5239 DI 10.1063/1.1533859 PG 3 WC Physics, Applied SC Physics GA 631GY UT WOS:000180160800047 ER PT J AU Gingrich, RM Adami, C AF Gingrich, RM Adami, C TI Quantum entanglement of moving bodies SO PHYSICAL REVIEW LETTERS LA English DT Article ID RELATIVISTIC TEMPERATURE TRANSFORMATION; STATE AB We study the properties of quantum entanglement in moving frames, and show that, because spin and momentum become mixed when viewed by a moving observer, the entanglement between the spins of a pair of particles is not invariant. We give an example of a pair, fully spin entangled in the rest frame, which has its spin entanglement reduced in all other frames. Similarly, we show that there are pairs whose spin entanglement increases from zero to maximal entanglement when boosted. While spin and momentum entanglement separately are not Lorentz invariant, the joint entanglement of the wave function is. C1 CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, Pasadena, CA 91109 USA. RP Gingrich, RM (reprint author), CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, 126-347, Pasadena, CA 91109 USA. RI Adami, Christoph/A-5181-2009; Adami, Christoph/A-9675-2011 OI Adami, Christoph/0000-0002-2915-9504 NR 24 TC 162 Z9 163 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 30 PY 2002 VL 89 IS 27 AR 270402 DI 10.1103/PhysRevLett.89.270402 PG 4 WC Physics, Multidisciplinary SC Physics GA 627RX UT WOS:000179949600002 PM 12513186 ER PT J AU Hakkinen, S AF Hakkinen, S TI Freshening of the Labrador Sea surface waters in the 1990s: Another great salinity anomaly? SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NORTHERN NORTH-ATLANTIC; VARIABILITY AB [1] The observed Labrador Sea surface salinities for 1951-2001 in region [55W-40W, 45N-55N] show freshening in the 1990s which may rival the Great Salinity Anomaly (GSA) of the 1970s [Dickson et al., 1988]. The 1990s freshening is distinct in the lowest range of salinity values associated with the coastal waters. The variability of the highest salinity values, provided by the North Atlantic Current entering the Labrador Sea, shows that the high salinity Atlantic waters were not widely present in the 1970's and 1990s. This can be interpreted as weakened transport of saline waters to the area. This explanation is consistent with an Arctic-North Atlantic model results forced by NCEP/NCAR Reanalysis data (for 1958-2001) which suggest that these periods are associated with a reduced meridional overturning. The model also associates the coastal freshening with southward current anomalies which are well correlated with the number of icebergs crossing 48N. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hakkinen, S (reprint author), NASA, Goddard Space Flight Ctr, Code 971, Greenbelt, MD 20771 USA. RI Hakkinen, Sirpa/E-1461-2012 NR 10 TC 21 Z9 21 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 28 PY 2002 VL 29 IS 24 AR 2232 DI 10.1029/2002GL015243 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 649WT UT WOS:000181231500001 ER PT J AU Tsurutani, BT Dasgupta, B Galvan, C Neugebauer, M Lakhina, GS Arballo, JK Winterhalter, D Goldstein, BE Buti, B AF Tsurutani, BT Dasgupta, B Galvan, C Neugebauer, M Lakhina, GS Arballo, JK Winterhalter, D Goldstein, BE Buti, B TI Phase-steepened Alfven waves, proton perpendicular energization and the creation of magnetic holes and magnetic decreases: The ponderomotive force SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND; PLASMA; DISTRIBUTIONS; ACCELERATION; MECHANISM AB [1] Solar wind protons detected within Magnetic Holes (MHs) and Magnetic Decreases (MDs) are found to be preferentially heated perpendicular to (B) over right arrow (0). The MHs/MDs are associated with the phase-steepened edges of nonlinear Alfven waves. The proton anisotropies can lead to the proton cyclotron and mirror mode plasma instabilities. We examine the Ponderomotive Force (PF), a phenomenon due to wave pressure gradients, and show that for this plasma regime and for phase-steepened Alfven waves, the PF proton acceleration/energization will primarily be orthogonal to B-0. It is suggested that accelerated ions create the MHs/MDs by a diamagnetic effect. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Indian Natl Sci Acad, New Delhi, India. Indian Inst Geomagnetism, Bombay 400005, Maharashtra, India. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. RP Tsurutani, BT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Lakhina, Gurbax /C-9295-2012; OI Lakhina, Gurbax /0000-0002-8956-486X NR 24 TC 56 Z9 58 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 28 PY 2002 VL 29 IS 24 AR 2233 DI 10.1029/2002GL015652 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 649WT UT WOS:000181231500004 ER PT J AU Waugh, DW Vollmer, MK Weiss, RF Haine, TWN Hall, TM AF Waugh, DW Vollmer, MK Weiss, RF Haine, TWN Hall, TM TI Transit time distributions in Lake Issyk-Kul SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TRANSPORT; CFC-11; OCEAN; AGE; SF6 AB [1] Measurements of sulfur hexafluoride (SF6)and chlorofluorocarbons (CFCs) are used to constrain the timescales for deep-water renewal in Lake Issyk-Kul. As these tracers have different tropospheric histories their combination provides more transport information than one tracer alone. In particular, from these measurements the mean, Gamma, and standard deviation, sigma, of the distributions of transit times since water made last contact with the surface can be tightly constrained. Gamma is older than the age determined from SF6 and younger than the ages from the CFCs, and increases from around 4 yrs at 200 m to around 10.5 yrs at the deepest location (655 m). sigma also increases with depth and equals around 0.7 to 0.8 Gamma, which corresponds to large ranges of transit times, and implies mixing processes play a major role in the transport. The approach used can also be applied to similar tracer measurements in the oceans and groundwaters to constrain transport in these geophysical systems. C1 Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. Max Planck Inst Chem, D-55020 Mainz, Germany. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Waugh, DW (reprint author), Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. RI Waugh, Darryn/K-3688-2016 OI Waugh, Darryn/0000-0001-7692-2798 NR 14 TC 18 Z9 18 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 28 PY 2002 VL 29 IS 24 AR 2231 DI 10.1029/2002GL016201 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 649WT UT WOS:000181231500014 ER PT J AU Xie, SP Hafner, J Tanimoto, Y Liu, WT Tokinaga, H Xu, HM AF Xie, SP Hafner, J Tanimoto, Y Liu, WT Tokinaga, H Xu, HM TI Bathymetric effect on the winter sea surface temperature and climate of the Yellow and East China Seas SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PACIFIC; WIND AB [1] Whether and how the atmosphere reacts to changes in extratropical sea surface temperature (SST) is under intense debate and this lack of understanding has been a major obstacle in the study of non-El Nino climate variability. Using new satellite measurements, we detect clear ocean-to-atmospheric feedback in the Yellow and East China (YEC) Seas that is triggered by the submerged ocean bottom topography. Under intense surface cooling in winter, water properties are well mixed up to 100 m deep. Ocean depth thus has a strong influence on SST of the continental shelf, leading to a remarkable collocation of warm tongues and deep channels. High winds and increased cloudiness are found over these warm tongues; one such band of ocean-atmospheric co-variation meanders through the basin, following a deep channel for an amazing distance of 1000 km. In addition to these climatic effects, the Kuroshio Front-where the warm current meets the much colder shelf water-strengthens the growth of storms. C1 Univ Hawaii, Int Pacific Res Ctr, Honolulu, HI 96822 USA. Hokkaido Univ, Grad Sch Environm Earth Sci, Sapporo, Hokkaido 0600810, Japan. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Hawaii, Dept Meteorol, Honolulu, HI 96822 USA. Frontier Res Syst Global Change, Yokohama, Kanagawa, Japan. Nanjing Inst Meteorol, Dept Atmospher Sci, Nanjing, Peoples R China. RP Xie, SP (reprint author), Univ Hawaii, Int Pacific Res Ctr, 1680 E West Rd, Honolulu, HI 96822 USA. EM xie@hawaii.edu RI Xie, Shang-Ping/C-1254-2009; Tanimoto, Youichi/F-8819-2012; Tokinaga, Hiroki/K-6813-2012 OI Xie, Shang-Ping/0000-0002-3676-1325; NR 18 TC 115 Z9 129 U1 1 U2 24 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 28 PY 2002 VL 29 IS 24 AR 2228 DI 10.1029/2002GL015884 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 649WT UT WOS:000181231500009 ER PT J AU Gao, RS Popp, PJ Ray, EA Rosenlof, KH Northway, MJ Fahey, DW Tuck, AF Webster, CR Hurst, DF Schauffler, SM Jost, H Bui, TP AF Gao, RS Popp, PJ Ray, EA Rosenlof, KH Northway, MJ Fahey, DW Tuck, AF Webster, CR Hurst, DF Schauffler, SM Jost, H Bui, TP TI Role of NOy as a diagnostic of small-scale mixing in a denitrified polar vortex SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE small-scale mixing; NOy; polar vortex ID ARCTIC WINTER STRATOSPHERE; VERTICAL EDDY DIFFUSIVITY; OZONE LOSS; RADAR OBSERVATIONS; MIDDLE ATMOSPHERE; CLIMATOLOGY; TURBULENCE; ADVECTION AB [1] Observations of three stratospheric species (N2O, CH4, and NOy) are examined for their suitability as mixing tracers in the inner Arctic vortex region between late February and mid-March 2000. NOy is highly inhomogeneous on isentropic surfaces and has little systematic vertical gradient between the 420 and 470 K potential temperature surfaces due to severe and extensive denitrification. Probability distribution functions of NOy calculated from in situ measurements do not show systematic and significant change as a function of time, indicating that mixing was too slow to substantially homogenize NOy distribution and therefore to strongly affect photochemical O-3 destruction rates during the period. We propose that the NOy inhomogeneity is useful for diagnosing small-scale, irreversible mixing rates during the measurement period. A simple kinematic model is used to show that the NOy standard deviation on an isentropic level in the vortex has desirable properties for quantifying these rates. A practical method for deriving mixing rates for chemistry and transport models has been proposed for future studies. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Gao, RS (reprint author), NOAA, Aeron Lab, Boulder, CO 80305 USA. RI Tuck, Adrian/F-6024-2011; Gao, Ru-Shan/H-7455-2013; Ray, Eric/D-5941-2013; Rosenlof, Karen/B-5652-2008; Hurst, Dale/D-1554-2016; Fahey, David/G-4499-2013 OI Tuck, Adrian/0000-0002-2074-0538; Ray, Eric/0000-0001-8727-9849; Rosenlof, Karen/0000-0002-0903-8270; Hurst, Dale/0000-0002-6315-2322; Fahey, David/0000-0003-1720-0634 NR 36 TC 4 Z9 4 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 28 PY 2002 VL 107 IS D24 AR 4794 DI 10.1029/2002JD002332 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650JF UT WOS:000181259400011 ER PT J AU Jost, HJ Loewenstein, M Greenblatt, JB Podolske, JR Bui, TP Hurst, DF Elkins, JW Herman, RL Webster, CR Schauffler, SM Atlas, EL Newman, PA Lait, LR Wofsy, SC AF Jost, HJ Loewenstein, M Greenblatt, JB Podolske, JR Bui, TP Hurst, DF Elkins, JW Herman, RL Webster, CR Schauffler, SM Atlas, EL Newman, PA Lait, LR Wofsy, SC TI Mixing events revealed by anomalous tracer relationships in the Arctic vortex during winter 1999/2000 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE polar vortex; stratosphere; ozone layer; mixing; atmospheric dynamics ID POLAR VORTEX; LOWER STRATOSPHERE; OZONE DEPLETION; TRANSPORT; N2O; AIRCRAFT; DESCENT; PROFILE; GASES; EDGE AB [1] During the 1999/2000 Arctic winter SAGE III-Ozone Loss and Validation Experiment (SOLVE) campaign, high-resolution, in situ tracer data measured aboard the NASA ER-2 high-altitude aircraft revealed anomalous mixing events within the polar vortex. From January to March 2000 in the 350-500 K potential temperature range, we found mixing events during 15% of the flight time on average with significant maxima at potential temperatures of 450, 410, and 380 K. The events were spread throughout the vortex but showed a distinct minimum at 73degrees N and a peak at 85 degreesN equivalent latitude. About 60% of the observed mixing events were less than 13 km wide. Based on a case study of tracer-tracer relationships, an objective simple method is introduced to detect such events using the linear nitrous oxide (N2O): potential temperature relationship observed deep in the vortex. Rigorous analysis and supporting evidence from total water data corroborated the validity of the method. These results suggest mixing across the polar vortex edge occurred preferentially in layers at select altitudes in the Arctic winter 1999/2000. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Bay Area Environm Res Inst, Sonoma, CA USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. RP NASA, Ames Res Ctr, Mail Stop 245-5, Moffett Field, CA 94035 USA. EM hjost@mail.arc.nasa.gov; mloewenstein@mail.arc.nasa.gov; buygreen@splash.princeton.edu; dhurst@cmdl.noaa.gov; james.w.elkins@noaa.gov; cwebster@pop.jpl.nasa.gov; sues@acd.ucat.edu; atlas@acd.ucar.edu; newman@notus.gsfc.nasa.gov; scw@io.harvard.edu RI Newman, Paul/D-6208-2012; Herman, Robert/H-9389-2012; Atlas, Elliot/J-8171-2015; Hurst, Dale/D-1554-2016 OI Newman, Paul/0000-0003-1139-2508; Herman, Robert/0000-0001-7063-6424; Hurst, Dale/0000-0002-6315-2322 NR 33 TC 11 Z9 11 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 28 PY 2002 VL 107 IS D24 AR 4795 DI 10.1029/2002JD002380 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650JF UT WOS:000181259400012 ER PT J AU Rind, D Lerner, J Perlwitz, J McLinden, C Prather, M AF Rind, D Lerner, J Perlwitz, J McLinden, C Prather, M TI Sensitivity of tracer transports and stratospheric ozone to sea surface temperature patterns in the doubled CO2 climate SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE tracer transports and climate; stratosphere and climate change; climate change and ozone; future SSTs and tracer transports ID GENERAL-CIRCULATION MODEL; MIDDLE ATMOSPHERE; ARCTIC OSCILLATION; PROJECTED CHANGES; GREENHOUSE GASES; DIAGNOSTIC-TOOL; ONLINE TRACERS; VARIABILITY; TROPOSPHERE; DEPENDENCE AB [1] Two sets of sea surface temperature/sea ice changes are used to test the sensitivity of tracer transport to the pattern of warming in the doubled CO2 climate. One set (2CO2WT) has greater tropical and high latitude sea surface temperature changes than the other (2CO2), although both fall within the range of plausible response. Simulations were done both with and without interactive ozone. Results show that the SST pattern affects the circulation change throughout the troposphere and middle atmosphere; the ozone interaction affects primarily the upper stratosphere, but through wave-mean flow interaction has effects that extend down into the upper troposphere. Both experiments feature increased tropospheric/stratospheric exchange at low latitudes and greater vertical mixing within the troposphere; only the WT experiments result in increased interhemispheric transport and a more direct circulation in the high latitude stratosphere. Ozone increases in the upper stratosphere and decreases in the lower stratosphere in all the simulations, with greater transport of high latitude ozone into the troposphere in the WT runs. At sea level there is a more positive phase of the Arctic Oscillation (AO)-type oscillation, and this is also true at 100 mbar, but there is no significance in the middle troposphere and the sign is different in the middle stratosphere. Many of these results differ from those generated in older versions of the GISS GCMAM despite the same SST forcing due to differences in control run characteristics, which has implications for model intercomparison experiments. C1 Columbia Univ, Goddard Inst Space Studies, New York, NY 10025 USA. Meteorol Serv Canada, Air Qual Res Branch, Downsview, ON, Canada. Univ Calif Irvine, Earth Syst Sci Dept, Irvine, CA 92697 USA. RP Columbia Univ, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM drind@giss.nasa.gov; jlerner@giss.nasa.gov; judith@giss.nasa.gov; chris.mclinden@ec.gc.ca; mprather@uci.edu RI Perlwitz, Judith/B-7201-2008; McLinden, Chris/A-7710-2010 OI Perlwitz, Judith/0000-0003-4061-2442; McLinden, Chris/0000-0001-5054-1380 NR 31 TC 17 Z9 17 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 28 PY 2002 VL 107 IS D24 AR 4800 DI 10.1029/2002JD002483 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650JF UT WOS:000181259400013 ER PT J AU Neugebauer, M Liewer, PC Smith, EJ Skoug, RM Zurbuchen, TH AF Neugebauer, M Liewer, PC Smith, EJ Skoug, RM Zurbuchen, TH TI Sources of the solar wind at solar activity maximum SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE solar wind sources; solar active regions; coronal holes ID ION COMPOSITION SPECTROMETER; STREAM INTERFACES; MAGNETIC-FIELD; HELIOGRAPHIC LATITUDES; PLASMA OBSERVATIONS; ULYSSES PLASMA; REGIONS; MODELS; HOLES; CORONA AB The photospheric sources of solar wind observed by the Ulysses and ACE spacecraft from 1998 to early 2001 are determined through a two-step mapping process. Solar wind speed measured at the spacecraft is used in a ballistic model to determine a foot point on a source surface at a solar distance of 2.5 solar radii. A potential-field source-surface model is then used to trace the field and flow from the source surface to the photosphere. Comparison of the polarity of the measured interplanetary field with the polarity of the photospheric source region shows good agreement for spacecraft latitudes equatorward of 60degrees. At higher southern latitudes, the mapping predicts that Ulysses should have observed only outward directed magnetic fields, whereas both polarities were observed. A detailed analysis is performed on four of the solar rotations for which the mapped and observed polarities were in generally good agreement. For those rotations, the solar wind mapped to both coronal holes and active regions. These findings for a period of high solar activity differ from the findings of a similar study of the solar wind in 1994-1995 when solar activity was very low. At solar minimum the fastest wind mapped to the interior of large polar coronal holes while slower wind mapped to the boundaries of those holes or to smaller low-latitude coronal holes. For the data examined in the present study, neither spacecraft detected wind from the small polar coronal holes when they existed and the speed was never as high as that observed by Ulysses at solar minimum. The principal difference between the solar wind from coronal holes and from active regions is that the O7+/O6+ ion ratio is lower for the coronal hole flow, but not as low as in the polar coronal hole flow at solar minimum. Furthermore, the active-region flows appear to be organized into several substreams unlike the more monolithic structure of flows from coronal holes. The boundaries between plasma flows from neighboring sources are marked by large magnetic holes, plasma sheets, and low entropy, independent of whether the sources have the same or opposite magnetic polarities. The evolution of solar wind properties between 1 AU and the 1.6-5.4 AU solar distance of Ulysses is also briefly discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA. RP Neugebauer, M (reprint author), Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. NR 41 TC 76 Z9 77 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 28 PY 2002 VL 107 IS A12 AR 1488 DI 10.1029/JA000306 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 650BT UT WOS:000181243000001 ER PT J AU Omidi, N Blanco-Cano, X Russell, CT Karimabadi, H Acuna, M AF Omidi, N Blanco-Cano, X Russell, CT Karimabadi, H Acuna, M TI Hybrid simulations of solar wind interaction with magnetized asteroids: General characteristics SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE asteroids; solar wind interactions; whistler wake; hybrid simulations ID FIELD AB Using electromagnetic hybrid (kinetic ions, fluid electrons) simulations, the interaction between solar wind and a magnetized asteroid is investigated. At no or very low levels of asteroid magnetization the solar wind remains undisturbed. As the level of magnetization is increased, a phase standing whistler wake is generated which owing to its propagation characteristics remains confined to planes close to that containing the solar wind flow velocity and the interplanetary magnetic field (IMF). No density perturbations are associated with this wake. Further increase in asteroid magnetization results in the additional generation of fast and slow magnetosonic wakes, which fall behind the whistler wake and are associated with the formation of a plasma tail. Because of their propagation characteristics, these wakes are more symmetric than the whistler wake. At still higher levels of magnetization where plasma pileup occurs upstream of the asteroid, the fast magnetosonic wake becomes dominant and eventually exhibits shock-like behavior. In general, the size of the interaction region increases with the level of asteroid's magnetic field strength. This interaction region is highly structured and asymmetric owing to wave propagation characteristics and the IMF direction. In addition, once the fast magnetosonic wake is strong enough to result in ion reflection the subsequent E x B motion of these ions results in considerable asymmetry in the interaction region. This is a purely ion kinetic effect which comes about as a result of the overall interaction region being comparable to ion scale lengths. C1 Univ Calif San Diego, Dept Elect & Comp Engn, La Jolla, CA 92093 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City 04510, DF, Mexico. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. Univ Calif San Diego, Calif Space Inst, La Jolla, CA 92093 USA. RP Omidi, N (reprint author), Univ Calif San Diego, Dept Elect & Comp Engn, Mail Code 0407, La Jolla, CA 92093 USA. NR 14 TC 39 Z9 39 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 28 PY 2002 VL 107 IS A12 AR 1487 DI 10.1029/2002JA009441 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 650BT UT WOS:000181243000004 ER PT J AU Kar, J Trepte, CR Thomason, LW Zawodny, JM Cunnold, DM Wang, HJ AF Kar, J Trepte, CR Thomason, LW Zawodny, JM Cunnold, DM Wang, HJ TI On the tropospheric measurements of ozone by the Stratospheric Aerosol and Gas Experiment II (SAGE II, version 6.1) in the tropics SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAPPING SPECTROMETER; COLUMN OZONE; CLOUD; SATELLITE AB [1] Tropospheric measurements of ozone from SAGE II (version 6.1) in the tropics have been analyzed using 12 years of data (1985-1990, 1994-1999). The seasonally averaged vertical profiles of the ozone mixing ratio in the upper troposphere have been presented for the first time from satellite measurements. These profiles show qualitative similarities with corresponding seasonal mean ozonesonde profiles at northern and southern tropical stations and are about 40-50% less than the sonde values. Despite this systematic offset, the measurements appear to be consistent with a zonal wave one pattern in the upper tropospheric column ozone and with the recently predicted summertime ozone enhancement over the Middle East. These results thus affirm the usefulness of the occultation method in studying tropospheric ozone. C1 Univ Arizona, Inst Atmospher Phys, Tucson, AZ 85721 USA. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23665 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. RP Kar, J (reprint author), Univ Arizona, Inst Atmospher Phys, Tucson, AZ 85721 USA. NR 12 TC 13 Z9 13 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 27 PY 2002 VL 29 IS 24 AR 2208 DI 10.1029/2002GL016241 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 649WR UT WOS:000181231400017 ER PT J AU Wu, XP Argus, DF Heflin, MB Ivins, ER Webb, FH AF Wu, XP Argus, DF Heflin, MB Ivins, ER Webb, FH TI Site distribution and aliasing effects in the inversion for load coefficients and geocenter motion from GPS data SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GRAVITATIONAL-FIELD; EARTHS ROTATION; DEFORMATION; SYSTEM AB [1] Precise GPS measurements of elastic relative site displacements due to surface mass loading offer important constraints on global surface mass transport. We investigate effects of site distribution and aliasing by higher-degree (n greater than or equal to 2) loading terms on inversion of GPS data for n = 1 load coefficients and geocenter motion. Covariance and simulation analyses are conducted to assess the sensitivity of the inversion to aliasing and mismodeling errors and possible uncertainties in the n = 1 load coefficient determination. We found that the use of center-of-figure approximation in the inverse formulation could cause 10-15% errors in the inverted load coefficients. n = 1 load estimates may be contaminated significantly by unknown higher-degree terms, depending on the load scenario and the GPS site distribution. The uncertainty in n = 1 zonal load estimate is at the level of 80-95% for two load scenarios. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wu, XP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 238-600, Pasadena, CA 91109 USA. RI Argus, Donald/F-7704-2011 NR 10 TC 31 Z9 33 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 27 PY 2002 VL 29 IS 24 AR 2210 DI 10.1029/2002GL016324 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 649WR UT WOS:000181231400019 ER PT J AU Boy, JP Chao, BF AF Boy, JP Chao, BF TI Time-variable gravity signal during the water impoundment of China's Three-Gorges Reservoir SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID EARTH AB [1] Beginning in 2003, China's Three-Gorges Reservoir will start water impoundment in phases. By 2009, it will be holding 40 km 3 of water, flooding a stretch of middle Yangtze River about 600 km in length. The water impoundment process represents a geophysical "controlled experiment'' offering a unique opportunity for detailed studies of a classical forward/inverse modeling problem of surface loading. While Wang [2000] studied the large loading effects on a local scale, we aim for longer spatial scales upwards from several hundred km, specially on the time-variable gravity signals that can be detected by the newly-launched GRACE satellite mission, whose 5-year lifetime (until 2007) will span the major impoundment period. Our results using the Green's function method adopting the PREM elastic Earth model indicate that the per-year geoid height increase is above the GRACE observational sensitivity out to harmonic degree 20, and to degree 50 (corresponding to a wavelength of 800 km) when integrated over the 5-year period. C1 NASA, Goddard Space Flight Ctr, UMBC GEST, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. RP Boy, JP (reprint author), NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Code 926, Greenbelt, MD 20771 USA. RI Chao, Benjamin Fong/N-6156-2013; Boy, Jean-Paul/E-6677-2017 OI Boy, Jean-Paul/0000-0003-0259-209X NR 15 TC 3 Z9 3 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 26 PY 2002 VL 29 IS 24 AR 2200 DI 10.1029/2002GL016457 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 649WG UT WOS:000181230500014 ER PT J AU Le, G Lu, G Strangeway, RJ Pfaff, RF AF Le, G Lu, G Strangeway, RJ Pfaff, RF TI Strong interplanetary magnetic field B-y-related plasma convection in the ionosphere and cusp field-aligned currents under northward interplanetary magnetic field conditions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE field-aligned currents; ionosphere convection; polar cusp; northward IMF; large IMF B-y; FAST spacecraft ID POLAR-CAP CONVECTION; BIRKELAND CURRENTS; ELECTRIC-FIELDS; IMF CONDITIONS; LATITUDE; MAGNETOSPHERE; PATTERNS; MODELS; PRECIPITATION; ACCELERATION AB We present in this paper an investigation of interplanetary magnetic field (IMF) B-y-related plasma convection and cusp field-aligned currents using Fast Auroral Snapshot (FAST) data and the assimilative mapping of ionospheric electrodynamics (AMIE) model during a prolonged interval with large positive IMF B-y and northward B-z conditions (B-y/B(z)much greater than1). Using the FAST single trajectory observations to validate the global convection patterns at key times and key locations, we have demonstrated that the AMIE procedure provides a reasonably good description of plasma circulations in the ionosphere during this interval. Our results show that the plasma convection in the ionosphere is consistent with the antiparallel merging model. When the IMF has a strongly positive B-y component under northward conditions, we find that the global plasma convection forms two cells oriented nearly along the Sun-Earth line in the ionosphere. In the Northern Hemisphere, the dayside cell has clockwise convection, mainly circulating within the polar cap on open field lines. It appears to be the lobe cell convection. A second cell with counterclockwise convection is located in the nightside, circulating across the polar cap boundary. The lobe cell convection is driven by the reconnection along the antiparallel merging lines poleward of the cusp extending toward the duskside when IMF B-y/B(z)much greater than1. The field-aligned currents in the cusp region flow downward into the ionosphere. The return field-aligned currents extend into the polar cap in the center of the dayside lobe convection cell. The field-aligned currents are closed through the Peterson currents in the ionosphere, which flow poleward from the polar cap boundary along the electric field direction. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. RP Le, G (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Code 696, Greenbelt, MD 20771 USA. RI Lu, Gang/A-6669-2011; Le, Guan/C-9524-2012; Pfaff, Robert/F-5703-2012 OI Le, Guan/0000-0002-9504-5214; Pfaff, Robert/0000-0002-4881-9715 NR 43 TC 6 Z9 6 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 26 PY 2002 VL 107 IS A12 AR 1477 DI 10.1029/2001JA007546 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 650BM UT WOS:000181242500001 ER PT J AU Vander Wal, RL Hall, LJ Berger, GM AF Vander Wal, RL Hall, LJ Berger, GM TI Optimization of flame synthesis for carbon nanotubes using supported catalyst SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; CO-H2-H2O GAS-MIXTURES; LARGE-SCALE; CO FOILS; FILAMENTOUS CARBON; SINGLE; FE; NANOFIBERS; GROWTH; IRON AB A series of rich premixed flames are used to realize a post-flame gas mixture for optimum carbon nanotube (CNT) growth using inexpensive hydrocarbon fuels. The mixture of CO, CO2, H-2, and H2O is varied through use of hydrocarbon fuels with different H/C ratio in flames with different fuel/air ratios. Both SEM and HRTEM imaging are used to correlate the nanotube morphology and internal structure to the reaction gas composition. The variations observed are understood in light of the gas composition and the interaction of the reactive components with both the deposited Co catalyst particles and supporting metal substrate. Further comparisons between flames producing the same CO or H-2 Concentrations identify the roles of these gases in CNT synthesis. Optimal flame synthesis conditions, defined upon a H-2 and CO concentration map, are gauged on the basis of CNT length, relative surface density, and level of graphitic structure. C1 NASA, NCMR, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Vander Wal, RL (reprint author), NASA, NCMR, Glenn Res Ctr, MS 110-3,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 60 TC 46 Z9 46 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD DEC 26 PY 2002 VL 106 IS 51 BP 13122 EP 13132 DI 10.1021/jp020614l PG 11 WC Chemistry, Physical SC Chemistry GA 628GQ UT WOS:000179985100008 ER PT J AU Davies, S Chipperfield, MP Carslaw, KS Sinnhuber, BM Anderson, JG Stimpfle, RM Wilmouth, DM Fahey, DW Popp, PJ Richard, EC von der Gathen, P Jost, H Webster, CR AF Davies, S Chipperfield, MP Carslaw, KS Sinnhuber, BM Anderson, JG Stimpfle, RM Wilmouth, DM Fahey, DW Popp, PJ Richard, EC von der Gathen, P Jost, H Webster, CR TI Modeling the effect of denitrification on Arctic ozone depletion during winter 1999/2000 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE Arctic; stratosphere; denitrification; modeling; ozone; SOLVE/THESEO 2000 ID POLAR STRATOSPHERIC CLOUDS; NASA ER-2 AIRCRAFT; SULFURIC-ACID; INTERHEMISPHERIC DIFFERENCES; ANTARCTIC OZONE; NITRIC-ACID; VORTEX; HNO3; RECOVERY; SYSTEM AB We have used the SLIMCAT three-dimensional chemical transport model together with observations from the Stratospheric Aerosol and Gas Experiment (SAGE III) Ozone Loss and Validation Experiment (SOLVE) and the Third European Stratospheric Experiment on Ozone (THESEO 2000) to quantify the effect of denitrification on Arctic ozone loss. We have used two different denitrification schemes in the model: one based on the sedimentation of ice particles containing cocondensed nitric acid trihydrate (NAT) and the other based on large NAT particles. The model was forced using both UK Meteorological Office (UKMO) and European Centre for Medium-Range Weather Forecasts (ECMWF) analyses. In the Arctic lower stratosphere the UKMO analyzed temperatures are similar to the ECMWF, except at temperatures near the ice point where the UKMO analyses are colder by over 2 K. Consequently, the UKMO analyses predicted large regions of ice clouds, in contrast to the ECMWF. The denitrification scheme based on large NAT particles gives the best agreement with ER-2 NOy observations for both sets of meteorological analyses. Although the ice scheme and UKMO analyses also produce denitrification, the vertical extent of denitrification and renitrification does not agree as well with the observed NOy. Uncertainties in the budget of ClOy observations from the ER-2 prevent an indirect validation of the best model denitrification scheme based on these data. The denitrified model runs give the best agreement with the observed HCl and ClONO2 reservoirs in mid March. However, UKMO-forced runs generally overestimate the observed ClOx during the same period. The denitrified model runs indicate that by late March 56-74% O-3 loss had occurred at 460 K and that denitrification contributed 21-30% of this loss. The model runs showing the largest O-3 depletion (forced by UKMO analyses) agree well with ER-2 and ozone sonde data, although these runs overestimated ClOx. C1 Univ Leeds, Sch Environm, Leeds LS2 9JT, W Yorkshire, England. Harvard Univ, Dept Chem, Cambridge, MA 02138 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. AWI Polar & Marine Res, D-14401 Potsdam, Germany. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. RP Univ Leeds, Sch Environm, Woodhouse Lane, Leeds LS2 9JT, W Yorkshire, England. EM stewart@env.leeds.ac.uk; martyn@env.leeds.ac.uk; carslaw@env.leeds.ac.uk; bms@env.leeds.ac.uk; anderson@huarp.harvard.edu; stimpfle@huarp.harvard.edu; wilmouth@huarp.harvard.edu; fahey@al.noaa.gov; ppopp@al.noaa.gov; richard@al.noaa.gov; gathen@awi-potsdam.de; hjost@mail.arc.nasa.gov; Chris.R.Webster@jpl.nasa.gov RI Chipperfield, Martyn/H-6359-2013; Sinnhuber, Bjorn-Martin/A-7007-2013; Fahey, David/G-4499-2013; von der Gathen, Peter/B-8515-2009; Carslaw, Ken/C-8514-2009 OI Chipperfield, Martyn/0000-0002-6803-4149; Sinnhuber, Bjorn-Martin/0000-0001-9608-7320; Fahey, David/0000-0003-1720-0634; von der Gathen, Peter/0000-0001-7409-1556; Carslaw, Ken/0000-0002-6800-154X NR 60 TC 31 Z9 31 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 24 PY 2002 VL 108 IS D5 AR 8322 DI 10.1029/2001JD000445 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650JN UT WOS:000181260200001 ER PT J AU Ko, M Hu, WJ Rodriguez, JM Kondo, Y Koike, M Kita, K Kawakami, S Blake, D Liu, S Ogawa, T AF Ko, M Hu, WJ Rodriguez, JM Kondo, Y Koike, M Kita, K Kawakami, S Blake, D Liu, S Ogawa, T TI Photochemical ozone budget during the BIBLE A and B campaigns SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE tropospheric ozone; biomass burning; lightning ID WESTERN NORTH PACIFIC; UPPER TROPOSPHERE; GLOBAL DISTRIBUTION; TROPICAL PACIFIC; UNITED-STATES; PEM-WEST; CHEMISTRY; HOX; OH; RADICALS AB [1] Using the measured concentrations of NO, O-3,H2O, CO, CH4, and NMHCs along the flight tracks, a photochemical box model is used to calculate the concentrations of the Ox radicals, the HOx radicals, and the nitrogen species at the sampling points. The calculations make use of the measurements from radiometers to scale clear sky photolysis rates to account for cloud cover and ground albedo at the sampling time/point. The concentrations of the nitrogen species in each of the sampled air parcels are computed assuming they are in instantaneous equilibrium with the measured NO and O-3. The diurnally varying species concentrations are next calculated using the box model and used to estimate the diurnally averaged production and removal rates of ozone for the sampled air parcels. Clear sky photolysis rates are used in the diurnal calculations. The campaign also provided measured concentration of NOy. The observed NO/NOy ratio is usually larger than the model calculated equilibrium value. There are several possible explanations. It could be a result of recent injection of NO into the air parcel, recent removal of HNO3 from the parcel, recent rapid transport of an air parcel from another location, or a combination of all processes. Our analyses suggest that the local production rate of O-3 can be used as another indicator of recent NO injection. However, more direct studies using air trajectory analyses and other collaborative evidences are needed to ascertain the roles played by individual process. C1 Atmospher & Environm Res Inc, Lexington, MA USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan. Univ Tokyo, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. Natl Space Dev Agcy Japan, Earth Observat Res Ctr, Chuou Ku, Tokyo 1060032, Japan. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. Acad Sinica, Inst Earth Sci, Taipei 110, Taiwan. RP NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM m.k.ko@larc.nasa.gov; whu@deq.state.va.us; jrodriguez@rsmas.miami.edu; kondo@atmos.rcast.u-tokyo.ac.jp; koike@eps.s.u-tokyo.ac.jp; kita@sunepl.geoph.s.u-tokyo.ac.jp; kawakami@eorc.nasda.go.jp; dblake@orion.oac.uci.edu; shawliu@earth.sinica.edu.tw; t_ogawa@eorc.nasda.go.jp RI Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012; Rodriguez, Jose/G-3751-2013; Ko, Malcolm/D-5898-2015 OI Rodriguez, Jose/0000-0002-1902-4649; NR 29 TC 7 Z9 7 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 24 PY 2002 VL 108 IS D3 AR 8404 DI 10.1029/2001JD000800 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650JK UT WOS:000181259800001 ER PT J AU Tselioudis, G Jakob, C AF Tselioudis, G Jakob, C TI Evaluation of midlatitude cloud properties in a weather and a climate model: Dependence on dynamic regime and spatial resolution SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE clouds; model; evaluation; midlatitudes; weather; climate ID ECMWF MODEL; CIRCULATION SYSTEMS; SATELLITE; TEMPERATURE; RADIATION; ISCCP AB [1] In this study, the midlatitude cloud fields produced by a climate (GISS) and a weather (ECMWF) model are evaluated against satellite observations. Monthly ensembles of model cloud property distributions for the four seasons are compared with similar ensembles from satellite retrievals. The weather model is run in both forecast and "climate'' mode in order to evaluate the importance of the exact representation of the atmospheric conditions in these ensemble comparisons. The weather and climate models are evaluated at different resolutions that cover the range used in today's climate and weather prediction simulations. Cloud property evaluations are separated into broadly defined dynamic regimes that cover the range of large-scale midlatitude motions. Quantitative evaluation tables are produced that rank the performance of the different model versions used in the study. The evaluation analysis reveals several common features between the two models. Those are the overestimation of cloud optical depth in all dynamic regimes, the underestimation of cloud cover in the large-scale descent regime and the underestimation of cloud top height in the large-scale descent regime. It is also shown that, in the radiative balance calculations, the models compensate for the overestimation of cloud optical depth through the underprediction of cloud cover. The comparison of the forecast and "climate'' runs of the ECMWF model shows remarkably similar statistical properties of the clouds in the two runs. The analysis of runs with different resolutions reveals large improvement when going from a 4degrees x 5degrees 9-layer to a 2degrees x 2.5degrees 32-layer run with the GISS GCM, much of which is caused by the increase in vertical resolution. A comparison of a T42 and a T106 run of the same vertical resolution with the ECMWF GCM does not show considerable differences between the two model versions. C1 Columbia Univ, Goddard Inst Space Studies, NASA, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys, New York, NY 10027 USA. European Ctr Medium Range Weather Forecasts, Reading RG2 9AX, Berks, England. RP Tselioudis, G (reprint author), Columbia Univ, Goddard Inst Space Studies, NASA, 2880 Broadway, New York, NY 10025 USA. EM gtselioudis@giss.nasa.gov; c.jakob@bom.gov.au RI Jakob, Christian/A-1082-2010 OI Jakob, Christian/0000-0002-5012-3207 NR 22 TC 62 Z9 63 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 24 PY 2002 VL 107 IS D24 AR 4781 DI 10.1029/2002JD002259 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650HX UT WOS:000181258500001 ER PT J AU Chi, PJ Russell, CT Raeder, J Zesta, E Yumoto, K Kawano, H Kitamura, K Petrinec, SM Angelopoulos, V Le, G Moldwin, MB AF Chi, PJ Russell, CT Raeder, J Zesta, E Yumoto, K Kawano, H Kitamura, K Petrinec, SM Angelopoulos, V Le, G Moldwin, MB TI Reply to comment by T. Kikuchi and T. Araki on "Propagation of the preliminary reverse impulse of sudden commencements to low latitudes"' SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Editorial Material DE sudden impulses; preliminary reverse impulse; MHD waves; inhomogeneous magnetosphere; magnetic pulsations ID MAGNETIC PULSATIONS; IONOSPHERE; MAGNETOSPHERE; PRESSURE; WAVE C1 Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Atmospher Sci, Los Angeles, CA 90095 USA. Kyushu Univ, Dept Earth & Planetary Sci, Fukuoka 812, Japan. Lockheed Martin Adv Technol Ctr, Palo Alto, CA USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Chi, PJ (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Box 951567, Los Angeles, CA 90095 USA. RI Moldwin, Mark/F-8785-2011; Le, Guan/C-9524-2012 OI Moldwin, Mark/0000-0003-0954-1770; Le, Guan/0000-0002-9504-5214 NR 13 TC 5 Z9 5 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 24 PY 2002 VL 107 IS A12 AR 1474 DI 10.1029/2002JA009369 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 650BF UT WOS:000181241900007 ER PT J AU Picone, JM Hedin, AE Drob, DP Aikin, AC AF Picone, JM Hedin, AE Drob, DP Aikin, AC TI NRLMSISE-00 empirical model of the atmosphere: Statistical comparisons and scientific issues SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE empirical; atmosphere; model; composition; temperature; drag ID THERMOSPHERIC MODEL; HOT OXYGEN; MASS-SPECTROMETER; SATELLITE DRAG; MILLSTONE HILL; DENSITY; CLIMATOLOGY; TEMPERATURE; VARIABILITY; GEOCORONA AB [1] The new NRLMSISE-00 empirical atmospheric model extends from the ground to the exobase and is a major upgrade of the MSISE-90 model in the thermosphere. The new model and the associated NRLMSIS database now include the following data: (1) total mass density from satellite accelerometers and from orbit determination (including the Jacchia and Barlier data sets), (2) temperature from incoherent scatter radar covering 1981-1997, and (3) molecular oxygen number density, [O-2], from solar ultraviolet occultation aboard the Solar Maximum Mission. A new component, "anomalous oxygen,'' allows for appreciable O+ and hot atomic oxygen contributions to the total mass density at high altitudes and applies primarily to drag estimation above 500 km. Extensive tables compare our entire database to the NRLMSISE-00, MSISE-90, and Jacchia-70 models for different altitude bands and levels of geomagnetic activity. We also explore scientific issues related to the new data sets in the NRLMSIS database. Especially noteworthy is the solar activity dependence of the Jacchia data, with which we study a large O+ contribution to the total mass density under the combination of summer, low solar activity, high latitude, and high altitude. Under these conditions, except at very low solar activity, the Jacchia data and the Jacchia-70 model indeed show a significantly higher total mass density than does MSISE-90. However, under the corresponding winter conditions, the MSIS-class models represent a noticeable improvement relative to Jacchia-70 over a wide range of F-10.7. Considering the two regimes together, NRLMSISE-00 achieves an improvement over both MSISE-90 and Jacchia-70 by incorporating advantages of each. C1 USN, Res Lab, Div Space Sci, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Washington, DC USA. RP USN, Res Lab, Div Space Sci, EO Hulburt Ctr Space Res, Code 7643,Bldg 209,4555 Overlook Ave SW, Washington, DC 20375 USA. EM picone@nrl.navy.mil RI Drob, Douglas/G-4061-2014 OI Drob, Douglas/0000-0002-2045-7740 NR 36 TC 1094 Z9 1133 U1 12 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 24 PY 2002 VL 107 IS A12 AR 1468 DI 10.1029/2002JA009430 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 650BF UT WOS:000181241900010 ER PT J AU Drdla, K Schoeberl, MR AF Drdla, K Schoeberl, MR TI Microphysical modeling of the 1999-2000 Arctic winter 2. Chlorine activation and ozone depletion SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SULFURIC-ACID-SOLUTIONS; IN-SITU MEASUREMENTS; POLAR VORTEX; STRATOSPHERIC TEMPERATURES; HETEROGENEOUS REACTIONS; UPPER TROPOSPHERE; SULFATE AEROSOLS; LOSS RATES; POAM II; HCL AB [1] The effect of polar stratospheric clouds (PSCs) on ozone depletion during the 1999-2000 Arctic winter has been assessed using a coupled microphysical/ photochemical model. Scenarios spanned a large range of denitrification levels, with up to 80% vortex-averaged denitrification and localized dehydration. PSC composition was varied, exploring sensitivity to heterogeneous reaction rates. PSC formation during February was critical in causing severe ozone depletion below 500 K. Heterogeneous chemistry on these PSCs was able to continuously reactivate the newly produced ClONO2. Only 30-40% vortex-averaged ozone loss would have occurred without this chlorine reactivation; with it, 21-32% more ozone loss is possible. During February (unlike earlier in the winter), chlorine reactivation and ozone loss were sensitive to heterogeneous chemistry: varying the reactivities altered ozone loss by 11%. An analysis of the critical temperatures for heterogeneous chemistry demonstrates the importance of temperatures near the nitric acid trihydrate condensation point, where many uncertainties influence heterogeneous reaction rates. Chlorine reactivation during February also prevented denitrification from enhancing ozone loss until March: 70% vortex-averaged denitrification only enhanced ozone depletion by 3% on 10 March. The mid-March vortex breakup probably limited the extent of ozone depletion; if the vortex had remained stable until 15 April, 16% ozone loss (out of a total 68% ozone loss) could be caused by 70% denitrification. Ozone loss intensifies nonlinearly with enhanced denitrification: in individual air parcels with 90% denitrification, 40% ozone loss in mid-April can be attributed to denitrification alone. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM katja@aerosol.arc.nasa.gov NR 48 TC 2 Z9 2 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 21 PY 2002 VL 108 IS D5 AR 8319 DI 10.1029/2001JD001159 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650HB UT WOS:000181256500001 ER PT J AU Herman, RL Drdla, K Spackman, JR Hurst, DF Popp, PJ Webster, CR Romashkin, PA Elkins, JW Weinstock, EM Gandrud, BW Toon, GC Schoeberl, MR Jost, H Atlas, EL Bui, TP AF Herman, RL Drdla, K Spackman, JR Hurst, DF Popp, PJ Webster, CR Romashkin, PA Elkins, JW Weinstock, EM Gandrud, BW Toon, GC Schoeberl, MR Jost, H Atlas, EL Bui, TP TI Hydration, dehydration, and the total hydrogen budget of the 1999/2000 winter Arctic stratosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE hydration; dehydration; SOLVE; stratosphere; water; Arctic ID IN-SITU MEASUREMENTS; WATER-VAPOR; POLAR VORTEX; ANTARCTIC STRATOSPHERE; OZONE DEPLETION; DENITRIFICATION; H2O; TRENDS; CH4; SPECTROMETER AB [1] Stratospheric H2O, CH4, and H-2 measured during the 1999/2000 Arctic winter are used to examine the total hydrogen budget and to quantify hydration and dehydration within the Arctic polar vortex. The mean volume mixing ratio of equivalent water, H2Oeq =H2O + 2* CH4, was found to be 7.38 +/- 0.11 ppmv in the vortex and 7.35 +/- 0.10 ppmv in the extravortex and vortex edge regions, implying insignificant net loss of H2O from the 50-90 hPa layer of the Arctic stratosphere. However, isolated occurrences of hydration and dehydration were observed on several flights. In particular, an average dehydration of 0.31 ppmv was encountered for 440 km along the NASA ER-2 aircraft flight path on 27 January 2000 (0.63 ppmv maximum dehydration). Diabatic back-trajectory calculations indicate that this dehydrated air parcel may have encountered temperatures below the ice frost point two weeks earlier. In addition to these isolated events, measurements of equivalent water indicated a decrease with altitude throughout the lower stratospheric vortex and vortex edge. Potential causes of this altitude dependence are quantified. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. NOAA, Aeron Lab, Boulder, CO 80305 USA. Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Bay Area Environm Res Inst, Sonoma, CA 95476 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Robert.L.Herman@jpl.nasa.gov; katja@aerosol.arc.nasa.gov; ryan@huarp.harvard.edu; dale.hurst@noaa.gov; ppopp@al.noaa.gov; chris.webster@jpl.nasa.gov; pavel.romashkin@noaa.gov; James.W.Elkins@noaa.gov; weinstock@huarp.harvard.edu; gandrud@particlemetrics.com; toon@mark4sun.jpl.nasa.gov; schom@notus.gsfc.nasa.gov; hjost@mail.arc.nasa.gov; atlas@ucar.edu; pbui@mail.arc.nasa.gov RI Herman, Robert/H-9389-2012; Atlas, Elliot/J-8171-2015; Hurst, Dale/D-1554-2016 OI Herman, Robert/0000-0001-7063-6424; Hurst, Dale/0000-0002-6315-2322 NR 68 TC 8 Z9 8 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 21 PY 2002 VL 108 IS D5 AR 8320 DI 10.1029/2001JD001257 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650HB UT WOS:000181256500002 ER PT J AU Doran, PT McKay, CP Clow, GD Dana, GL Fountain, AG Nylen, T Lyons, WB AF Doran, PT McKay, CP Clow, GD Dana, GL Fountain, AG Nylen, T Lyons, WB TI Valley floor climate observations from the McMurdo dry valleys, Antarctica, 1986-2000 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE Antarctica; dry valleys; climate; katabatic wind ID EAST ANTARCTICA; KATABATIC FLOW; ADELIE LAND; MIOCENE; REGION; JUMPS; ICE AB Climate observations from the McMurdo dry valleys, East Antarctica are presented from a network of seven valley floor automatic meteorological stations during the period 1986 to 2000. Mean annual temperatures ranged from -14.8degreesC to -30.0degreesC, depending on the site and period of measurement. Mean annual relative humidity is generally highest near the coast. Mean annual wind speed increases with proximity to the polar plateau. Site-to-site variation in mean annual solar flux and PAR is due to exposure of each station and changes over time are likely related to changes in cloudiness. During the nonsummer months, strong katabatic winds are frequent at some sites and infrequent at others, creating large variation in mean annual temperature owing to the warming effect of the winds. Katabatic wind exposure appears to be controlled to a large degree by the presence of colder air in the region that collects at low points and keeps the warm less dense katabatic flow from the ground. The strong influence of katabatic winds makes prediction of relative mean annual temperature based on geographical position (elevation and distance from the coast) alone, not possible. During the summer months, onshore winds dominate and warm as they progress through the valleys creating a strong linear relationship (r(2)=0.992) of increasing potential temperature with distance from the coast (0.09degreesC km(-1)). In contrast to mean annual temperature, summer temperature lends itself quite well to model predictions, and is used to construct a statistical model for predicting summer dry valley temperatures at unmonitored sites. C1 Univ Illinois, Chicago, IL 60607 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA. Desert Res Inst, Water Resources Ctr, Reno, NV 89512 USA. Portland State Univ, Dept Geol, Portland, OR 97207 USA. Ohio State Univ, Byrd Polar Res Ctr, Columbus, OH 43210 USA. RP Doran, PT (reprint author), Univ Illinois, Chicago, IL 60607 USA. EM pdoran@uic.edu; mckay@gal.arc.nasa.gov; clow@usgs.gov; gdana@dri.edu; bjaf@odin.cc.pdx.edu; psu17038@odin.cc.pdx.edu; lyons.142@osu.edu NR 35 TC 208 Z9 208 U1 0 U2 21 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 21 PY 2002 VL 107 IS D24 AR 4772 DI 10.1029/2001JD002045 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650GE UT WOS:000181254300004 ER PT J AU Wu, DL Jiang, JH AF Wu, DL Jiang, JH TI MLS observations of atmospheric gravity waves over Antarctica SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE Gravity waves; Antarctica; polar stratospheric cloud; circulation; ozone depletion ID POLAR STRATOSPHERIC CLOUDS; OZONE DEPLETION; TEMPERATURES; VARIANCE; WINDS; HNO3 AB Stratospheric gravity waves over Antarctica are studied with the radiance variances observed by Upper Atmosphere Research Satellite Microwave Limb Sounder (UARS MLS). Strong wave activities are found during August and September in 1992-1994 over the Drake Passage region (290degrees-315degrees longitude and 50degreesS-70degreesS latitude), where the enhancement seems associated with the topography of both South America and Antarctic Peninsula tips. During the same period, significant gravity wave activities are also evident along the Antarctic coastal region. The vertical growth of the wave variance shows a scale height of similar to14 km at low altitudes for both Drake Passage and the coastal regions but reduces substantially at high altitudes. The growth rate transition occurs at a lower altitude in the Drake Passage region where the variance is larger. The gravity wave activities observed near the Antarctic may contribute significantly to the formation of polar stratospheric clouds (PSC) because of the overlapping with the vortex edge and with the PSC activities as observed by CLAES (Cryogenic Limb Array Etalon Spectrometer). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jiang, JH (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-701,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jonathan@mls.jpl.nasa.gov RI Wu, Dong/D-5375-2012 NR 23 TC 50 Z9 51 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 21 PY 2002 VL 107 IS D24 AR 4773 DI 10.1029/2002JD002390 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650GE UT WOS:000181254300006 ER PT J AU Chen, G Chapron, B Ezraty, R Vandemark, D AF Chen, G Chapron, B Ezraty, R Vandemark, D TI A dual-frequency approach for retrieving sea surface wind speed from TOPEX altimetry SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE sea surface wind speed; retrieval; TOPEX; altimeter; dual frequency ID WAVE HEIGHT; ALGORITHM; BUOYS AB More than a dozen of wind speed (U) algorithms have been proposed during the past 2 decades, as a result of a continuing effort to improve altimeter wind measurement. The progress in terms of accuracy, however, is seen to be rather slow. The reported root mean square (RMS) error of prevailing algorithms varies mostly between 1.6 and 2.0 m/s for the dominant wind regime. As far as the TOPEX altimeter is concerned, three measured quantities, namely, the radar cross sections from Ku and C band (sigma(Ku) and sigma(C)), as well as the significant wave height (H-s), have been used in previous algorithm developments, resulting in a variety of single-, dual-, and three-parameter model functions. On the basis of the finding of a banded dependency of the U-sigma(Ku) relationship on sigma(C) a new approach for retrieving altimeter wind speed, termed linear composite method (LCM), is proposed in this study. The LCM model function appears as a set of sigma(C)-dependent linear relations between U and sigma(Ku). A unique advantage of this approach is that it allows the algorithm to be tuned or expanded for a given range of wind speed without affecting the rest. Over 1.7 million coincident TOPEX/NASA scatterometer (NSCAT) and TOPEX/QuikSCAT data covering a period of 2.5 years are used to adjust the model. Validation against extensive buoy measurements indicates that the LCM algorithm is almost unbiased and has an overall RMS error of 1.56 m/s, which is 12% lower compared to the algorithm in operational use [Witter and Chelton, 1991]. In addition, a small (2.5-6%, depending on the reference data set) but significant improvement is found for the LCM when compared to the most recent dual- parameter algorithm [Gourrion et al., 2002]. C1 Ocean Univ China, Ocean Remote Sensing Inst, Qingdao 266003, Peoples R China. IFREMER, Ctr Brest, Dept Oceanog Phys & Spatiale, F-29280 Plouzane, France. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Flight Facil, Wallops Isl, VA 23337 USA. RP Chen, G (reprint author), Ocean Univ China, Ocean Remote Sensing Inst, 5 Yushan Rd, Qingdao 266003, Peoples R China. RI Chapron, Bertrand/O-6527-2015 NR 21 TC 11 Z9 16 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 21 PY 2002 VL 107 IS C12 AR 3226 DI 10.1029/2001JC001098 PG 10 WC Oceanography SC Oceanography GA 649XA UT WOS:000181232200001 ER PT J AU Ofman, L Gary, SP Vinas, A AF Ofman, L Gary, SP Vinas, A TI Resonant heating and acceleration of ions in coronal holes driven by cyclotron resonant spectra SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE ion cyclotron waves; heating; coronal holes; hybrid simulations; solar wind; minor ions ID SPEED SOLAR-WIND; MODEL; WAVES; CONSTRAINTS; ANISOTROPY; UVCS AB Recent observations and models suggest that the resonant absorption of ion cyclotron waves heats and accelerates the ions in the solar wind. Velocity distributions of minor ions derived from SOHO Ultraviolet Cronagraph Spectrometer (UVCS) observations in coronal holes indicate that the minor ion temperature anisotropy is T-perpendicular to/T-parallel to>10 and that outflow speeds are higher than those of the solar wind protons. Here one-dimensional hybrid simulations of initially homogeneous, collisionless plasmas are used to study a model of coronal plasmas including kinetic protons, a tenuous component of oxygen ions, and massless fluid electrons. Spectra of ion cyclotron resonant Alfven waves are imposed on the system to study the resultant heating of both ion species. We investigate the effects of various power spectra of the form f(-1) or f(-5/3) and vary the input frequency range. We find that the ion heating strongly depends on the power contained in the frequency range of the input spectrum that can resonate with the ions. The minor O5+ ions are easily heated and become anisotropic due to various forms of the spectra. The protons remain nearly isotropic and are weakly heated in most cases in this study. We investigate the self-consistent fluctuation spectrum generated by the response of the ions and the non-Maxwellian features in the velocity distribution. C1 Catholic Univ Amer, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Catholic Univ Amer, Washington, DC 20064 USA. EM Leon.Ofman@gsfc.nasa.gov; pgary@lanl.gov; vinas@unamuno.gsfc.nasa.gov NR 31 TC 37 Z9 38 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 21 PY 2002 VL 107 IS A12 AR 1461 DI 10.1029/2002JA009432 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 650AR UT WOS:000181240600002 ER PT J AU McDermid, IS Beyerle, G Haner, DA Leblanc, T AF McDermid, IS Beyerle, G Haner, DA Leblanc, T TI Redesign and improved performance of the tropospheric ozone lidar at the Jet Propulsion Laboratory Table Mountain Facility SO APPLIED OPTICS LA English DT Article ID STRATOSPHERIC OZONE; SYSTEM AB Improvements to the tropospheric ozone lidar at the Jet Propulsion Laboratory Table Mountain Facility for measurements of ozone profiles in the troposphere and lower stratosphere, between approximately 5-and 20-km altitude, are described. The changes were primarily related to the receiver optical subsystems and the data-acquisition system. The original 40-cm Cassegrain telescope was replaced with a faster (f/3) 91-cm Newtonian mirror. In the focal plane of this mirror, the lidar signal is divided into two parts by use of two separate optical fibers as field stops corresponding to different but neighboring 0.6-mrad fields of view. We then separate the two received wavelengths by aligning each transmitted beam to one of the fibers. In addition, two 50-mm telescopes are used for the collection of near-range returns. The four optical signals are brought to a chopper wheel for independent signal selection in the time and range domain. For each channel, an interference filter is used for skylight rejection and additional cross-talk prevention. The signals are detected with miniature photomultiplier tubes and input to a fast photon-counting system. The goals of these modifications were to increase the spatial and temporal resolution of the. lidar, to extend the altitude range covered, to improve the quality of the raw data, and to enable regular and routine operation of the system for long-term measurements. (C) 2002 Optical Society of America. C1 CALTECH, Jet Prop Lab, Table Mt Facil, Wrightwood, CA 92397 USA. EM mcdermid@tmf.jpl.nasa.gov NR 14 TC 29 Z9 29 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD DEC 20 PY 2002 VL 41 IS 36 BP 7550 EP 7555 DI 10.1364/AO.41.007550 PG 6 WC Optics SC Optics GA 627AE UT WOS:000179905300006 ER PT J AU Fixsen, DJ Mather, JC AF Fixsen, DJ Mather, JC TI The spectral results of the far-infrared absolute spectrophotometer instrument on COBE SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations ID CMBR SPECTRUM; FIRAS; DISTORTION; LIMITS; DESIGN; MAPS; GAS AB The cosmic microwave background (CMB) spectral results of the Far-Infrared Absolute Spectrophotometer (FIRAS) instrument are summarized. Some questions that have been raised about the calibration accuracy are also addressed. Finally, we comment on the potential for major improvements with new measurement approaches. The measurement of the deviation of the CMB spectrum from a 2.725 +/- 0.001 K blackbody form made by the COBE-FIRAS could be improved by nearly 2 orders of magnitude. C1 NASA, SSAI, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Infrared Astrophys Branch, Greenbelt, MD 20771 USA. RP Fixsen, DJ (reprint author), NASA, SSAI, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 33 TC 122 Z9 122 U1 0 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP 817 EP 822 DI 10.1086/344402 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DA UT WOS:000179914300005 ER PT J AU Clements, DL McDowell, JC Shaked, S Baker, AC Borne, K Colina, L Lamb, SA Mundell, C AF Clements, DL McDowell, JC Shaked, S Baker, AC Borne, K Colina, L Lamb, SA Mundell, C TI Chandra observations of ARP 220: The nuclear source SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (Arp 220); galaxies : interactions; galaxies : starburst; X-rays : galaxies ID ULTRALUMINOUS INFRARED GALAXIES; MU-M; ARP-220; STARBURST; EMISSION; ULIRGS; QUASAR; ISO AB We present the first results from 60 ks of observations of Arp 220 using the ACIS-S instrument on Chandra. We report the detection of several sources near the galaxy's nucleus, including a point source with a hard spectrum that is coincident with the western radio nucleus B. This point source is mildly absorbed (N-H similar to 3 x 10(22) cm(-2)) and has an estimated luminosity of 4 x 10(40) ergs s(-1). In addition, a fainter source may coincide with the eastern nucleus A. Extended hard X-ray emission in the vicinity raises the total estimated nuclear 2-10 keV X-ray luminosity to 1.2 x 10(41) ergs s(-1), but we cannot rule out a hidden active galactic nucleus behind columns exceeding 5 x 10(24) cm(-2). We also detect a peak of soft X-ray emission to the west of the nucleus and a hard point source 2.5 kpc from the nucleus with a luminosity of 6 x 10(39) ergs s(-1). C1 Univ London Imperial Coll Sci Technol & Med, Dept Phys, London SW7 2BW, England. Cardiff Univ, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. NASA, Raytheon Informat Technol & Sci Serv, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CSIC, Inst Estructura Mat, E-28006 Madrid, Spain. Univ Illinois, Loomis Lab Phys, Ctr Theoret Astrophys, Dept Phys, Urbana, IL 61801 USA. Liverpool John Moores Univ, Astrophys Res Inst, Wirral CH41 1LD, Cheshire, England. Univ Illinois, Loomis Lab Phys, Ctr Theoret Astrophys, Dept Astron, Urbana, IL 61801 USA. RP Clements, DL (reprint author), Univ London Imperial Coll Sci Technol & Med, Dept Phys, Prince Consort Rd, London SW7 2BW, England. NR 43 TC 53 Z9 53 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP 974 EP 980 DI 10.1086/344439 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DA UT WOS:000179914300017 ER PT J AU Berger, E Kulkarni, SR Bloom, JS Price, PA Fox, DW Frail, DA Axelrod, TS Chevalier, RA Colbert, E Costa, E Djorgovski, SG Frontera, F Galama, TJ Halpern, JP Harrison, FA Holtzman, J Hurley, K Kimble, RA McCarthy, PJ Piro, L Reichart, D Ricker, GR Sari, R Schmidt, BP Wheeler, JC Vanderppek, R Yost, SA AF Berger, E Kulkarni, SR Bloom, JS Price, PA Fox, DW Frail, DA Axelrod, TS Chevalier, RA Colbert, E Costa, E Djorgovski, SG Frontera, F Galama, TJ Halpern, JP Harrison, FA Holtzman, J Hurley, K Kimble, RA McCarthy, PJ Piro, L Reichart, D Ricker, GR Sari, R Schmidt, BP Wheeler, JC Vanderppek, R Yost, SA TI The faint optical afterglow and host galaxy of GRB 020124: Implications for the nature of dark gamma-ray bursts SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; dust, extinction; gamma rays : bursts ID ULTRAVIOLET EXTINCTION; STAR-FORMATION; EMISSION; CURVES; PROGENITORS; SYSTEM AB We present ground-based optical observations of GRB 020124 starting 1.6 hr after the burst, as well as subsequent Very Large Array and Hubble Space Telescope (HST) observations. The optical afterglow of GRB 020124 is one of the faintest afterglows detected to date, and it exhibits a relatively rapid decay, F-nu proportional to t(-1.60+/-0.04), followed by further steepening. In addition, a weak radio source was found coincident with the optical afterglow. The HST observations reveal that a positionally coincident host galaxy must be the faintest host to date, R greater than or similar to 29.5 mag. The afterglow observations can be explained by several models requiring little or no extinction within the host galaxy, A(V)(host) approximate to 0-0.9 mag. These observations have significant implications for the interpretation of the so-called dark bursts ( bursts for which no optical afterglow is detected), which are usually attributed to dust extinction within the host galaxy. The faintness and relatively rapid decay of the afterglow of GRB 020124, combined with the low inferred extinction, indicate that some dark bursts are intrinsically dim and not dust obscured. Thus, the diversity in the underlying properties of optical afterglows must be observationally determined before substantive inferences can be drawn from the statistics of dark bursts. C1 CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. Mt Stromlo & Siding Spring Observ, Res Sch Astron & Astrophys, Weston 2611, Australia. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. CNR, Ist Astrofis Spaziale, Area Tor Vergata, I-00133 Rome, Italy. CNR, Ist Astrofis Spaziale, I-40129 Bologna, Italy. Univ Ferrara, Dept Phys, I-44100 Ferrara, Italy. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. New Mexico State Univ, Dept Astron, MSC 4500, Las Cruces, NM 88003 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. RP Berger, E (reprint author), CALTECH, Div Phys Math & Astron, 105-24, Pasadena, CA 91125 USA. RI Kimble, Randy/D-5317-2012; Galama, Titus/D-1429-2014; PIRO, LUIGI/E-4954-2013; OI Galama, Titus/0000-0002-1036-396X; PIRO, LUIGI/0000-0003-4159-3984; Costa, Enrico/0000-0003-4925-8523; Schmidt, Brian/0000-0001-6589-1287 NR 37 TC 89 Z9 90 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP 981 EP 987 DI 10.1086/344262 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DA UT WOS:000179914300018 ER PT J AU Hwang, U Decourchelle, A Holt, SS Petre, R AF Hwang, U Decourchelle, A Holt, SS Petre, R TI Thermal and nonthermal X-ray emission from the forward shock in Tycho's supernova remnant SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (Tycho's supernova remnant); shock waves; supernova remnants; X-rays : general; X-rays : ISM ID CASSIOPEIA-A; PARTICLE-ACCELERATION; NONRADIATIVE SHOCKS; OPTICAL-EMISSION; NOVA REMNANTS; COSMIC-RAYS; EXPANSION; SN-1006; CHANDRA; EJECTA AB We present Chandra X-ray images of Tycho's supernova remnant that delineate its outer shock as a thin, smooth rim along the straight northeastern edge and most of the circular western half. The images also show that the Si and S ejecta are highly clumpy and have reached near the forward shock at numerous locations. Most of the X-ray spectra that we examine along the rim show evidence of line emission from Si and S ejecta, while the continuum is well represented by either a thermal or a nonthermal model. If the continuum is assumed to be thermal, the electron temperatures at the rim are all similar at about 2 keV, while the ionization ages are very low because of the overall weakness of the line emission. These electron temperatures are substantially below those expected for equilibration of the electron and ion temperatures, assuming shock velocities inferred from radio and X-ray expansion measurements; the electron-to-mean temperature ratios are less than or similar to0.1-0.2, indicating that collisionless heating of the electrons at the shock is modest. The nonthermal contribution to these spectra might be important, but cannot be strongly constrained by these data. It could account for as much as half of the flux in the 4-6 keV energy range, based on an extrapolation of the hard X-ray spectrum above 10 keV. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. CEA Saclay, Serv Astrophys, F-91191 Gif Sur Yvette, France. FW Olin Coll Engn, Needham, MA 02492 USA. RP Hwang, U (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 55 TC 96 Z9 98 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP 1101 EP 1115 DI 10.1086/344366 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DA UT WOS:000179914300029 ER PT J AU Verner, EM Gull, TR Bruhweiler, F Johansson, S Ishibashi, K Davidson, K AF Verner, EM Gull, TR Bruhweiler, F Johansson, S Ishibashi, K Davidson, K TI The origin of Fe II and [Fe II] emission lines in the 4000-10000 angstrom range in the BD Weigelt blobs of eta Carinae SO ASTROPHYSICAL JOURNAL LA English DT Article DE HII regions; ISM : individual (eta Carinae); line : formation; line : identification ID IRON-PROJECT; ATOMIC DATA; TRANSITION-PROBABILITIES; ORION NEBULA; EXCITATION; SPECTRA; SPECTROSCOPY; EJECTA; BINARY AB We present numerical simulations that reproduce the salient features of the amazingly strong [Fe II] and Fe II emission spectra in the B and D Weigelt blobs of Carinae. For our studies we have used spectra obtained during the 1998 epoch observations with the Hubble Space Telescope (HST). The spectrum of the B and D Weigelt blobs dominates in [Fe II] and Fe II emission lines. The same observations show no Fe I or Fe III We have compared our measurements of the strongest (greater than or equal to200) [Fe II] and Fe II lines and blends in the spectrum with theoretical predictions. Our predictions are based on non-LTE modeling of the Fe II atom, which includes the lowest 371 energy levels (all levels up to 11.6 eV). We have investigated the dependence of the spectrum on electron density, pumping by the blackbody-like stellar continuum, and intense Lyalpha emission. We find that radiative pumping is essential in explaining the observed spectrum. We have identified the main pumping routes responsible for the observed Fe II emission. Comparison between the model and observations reveals details of the radiation field. Pumping by the blackbody-like stellar radiation field from eta Carinae explains the numerous strong [Fe II] and Fe II lines in the range of 4000-6500 Angstrom. The strongest Fe II lines in a range of 8000-10000 Angstrom are pumped by intense Lyalpha radiation. C1 Catholic Univ Amer, Greenbelt, MD 20771 USA. NASA, Lab Astron & Space Sci, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lund Univ, Lund Observ, S-22100 Lund, Sweden. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA. RP Verner, EM (reprint author), Catholic Univ Amer, Greenbelt, MD 20771 USA. RI Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 NR 37 TC 32 Z9 32 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP 1154 EP 1167 DI 10.1086/344443 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DA UT WOS:000179914300033 ER PT J AU Wood, BE Redfield, S Linsky, JL Sahu, MS AF Wood, BE Redfield, S Linsky, JL Sahu, MS TI Elemental abundances and ionization states within the local interstellar cloud derived from Hubble Space Telescope and Far Ultraviolet Spectroscopic Explorer observations of the Capella line of sight SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ultraviolet : ISM ID EPSILON-CANIS-MAJORIS; ON-ORBIT PERFORMANCE; DEUTERIUM ABUNDANCE; FUSE MISSION; D/H RATIO; SPECTROGRAPH OBSERVATIONS; 3-DIMENSIONAL STRUCTURE; IMAGING SPECTROGRAPH; ALPHA ABSORPTION; ELECTRON-DENSITY AB We use ultraviolet spectra of Capella from the Hubble Space Telescope and Far Ultraviolet Spectroscopic Explorer satellites to study interstellar absorption lines from the Local Interstellar Cloud (LIC). Measurements of these lines are used to empirically determine the ionization states of carbon, nitrogen, and silicon in the LIC, for comparison with the predictions of theoretical photoionization models. We find that the observed ionization states are consistent with previously published photoionization predictions. Total abundances are determined for the elements mentioned above, and others, for comparison with solar abundances. Magnesium, aluminum, silicon, and iron are all depleted by at least a factor of 10 toward Capella. The abundances of carbon, nitrogen, and oxygen are essentially solar, although the error bars are large enough to also allow depletions of about a factor of 2 for these elements. C1 Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Inst Stand & Technol, Boulder, CO 80309 USA. RP Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. EM woodb@origins.colorado.edu; sredfiel@origins.colorado.edu; jlinsky@jila.colorado.edu; msahu@panke.gsfc.nasa.gov NR 66 TC 31 Z9 31 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP 1168 EP 1179 DI 10.1086/344407 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DA UT WOS:000179914300034 ER PT J AU Smale, AP Church, MJ Balucinska-Church, M AF Smale, AP Church, MJ Balucinska-Church, M TI Dip spectroscopy of the low-mass X-ray binary XB 1254-690 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : close; circumstellar matter; dust, extinction; scattering; stars : individual (XB 1254-690); X-rays : stars ID NEUTRON-STARS; ACCRETION; XB-1254-690; X1254-690 AB We observed the low-mass X-ray binary XB 1254-690 with the Rossi X-Ray Timing Explorer in 2001 May and December. During the first observation, strong dipping on the 3.9 hr orbital period and a high degree of variability were observed, along with "shoulders" similar to15% deep during extended intervals on each side of the main dips. The first observation also included pronounced flaring activity. The nondip spectrum obtained using the PCA instrument was well described by a two-component model consisting of a blackbody with kT = 1.30 +/- 0.10 keV plus a cutoff power-law representation of Comptonized emission with power-law photon index 1.10 +/- 0.46 and a cutoff energy of 5.9-1.4+3.0 keV. The intensity decrease in the shoulders of dipping is energy- independent, consistent with electron scattering in the outer ionized regions of the absorber. In deep dipping, the depth of dipping reached 100% in the energy band below 5 keV, indicating that all emitting regions were covered by absorber. Intensity- selected dip spectra were well tted by a model in which the pointlike blackbody is rapidly covered, while the extended Comptonized emission is progressively overlapped by the absorber, with the covering fraction rising to 95% in the deepest portion of the dip. The intensity of this component in the dip spectra could be modeled by a combination of electron scattering and photoelectric absorption. Dipping did not occur during the 2001 December observation, but remarkably, both bursting and aring were observed contemporaneously. C1 NASA, Univ Space Res Assoc, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England. Jagiellonian Univ, Astron Observ, PL-30244 Krakow, Poland. RP Smale, AP (reprint author), NASA, Univ Space Res Assoc, High Energy Astrophys Lab, Goddard Space Flight Ctr, Code 660-1, Greenbelt, MD 20771 USA. NR 28 TC 25 Z9 25 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP 1286 EP 1292 DI 10.1086/344339 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DA UT WOS:000179914300044 ER PT J AU Sekanina, Z Chodas, PW AF Sekanina, Z Chodas, PW TI Fragmentation origin of major sungrazing comets C/1970 K1, C/1880 C1, and C/1843 D1 SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : general; comets : individual (X/1106 C1, C/1843 D1, C/1880 C1, C/1882 R1, C/1887 B1, C/1945 X1, C/1963 R1, C/1965 S1, C/1970 K1, D/1993 F2) methods : data analysis AB Following our recent successful modeling of the common origin of two of the brightest members of the Kreutz system of sungrazing comets, we now examine three other objects: C/1970 K1 (White-Ortiz- Bolelli), the most recent sungrazer discovered from Earth, C/1880 C1 (Great Southern Comet), and C/1843 D1 (Great March Comet). For White-Ortiz- Bolelli, five possible origin and orbit evolution scenarios are explored. Wend that its parent was neither C/1965 S1 (Ikeya-Seki), nor C/1882 R1 (Great September Comet), nor the comet of 1106 (the presumed parent of Ikeya-Seki and the 1882 comet). The motion of C/1970 K1 is consistent with a scenario in which the parent was an unknown fragment that separated from the 1106 comet at the same time as, or shortly before, Ikeya-Seki and passed through perihelion in 1970 June July, shortly after White-Ortiz-Bolelli. The separation of White-Ortiz- Bolelli from this fragment is found to have occurred around the mid-eighteenth century, at a heliocentric distance of about 150 AU, with a relative velocity of 3-5 m s(-1) in the general direction of the Sun and to the north of the orbital plane. On the other hand, we conclude that the 1880 comet separated directly from C/1843 D1, the second brightest known sungrazer, some 100-150 days after the 1843 comet's previous perihelion passage in the eleventh century, at 2.5 3 AU from the Sun, with a relative velocity of slightly more than 7 m s(-1) in the generally antisolar direction and to the south of the orbital plane. The pattern of fragmentation of the Kreutz system's members discovered from Earth begins to resemble the evolution of the system's minor fragments detected coronagraphically from aboard the SOHO spacecraft, and there is significant qualitative similarity with fragmentation of comet D/1993 F2 (Shoemaker-Levy 9). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sekanina, Z (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 8 Z9 8 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP 1389 EP 1398 DI 10.1086/344261 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DA UT WOS:000179914300052 ER PT J AU Roe, HG de Pater, I Macintosh, BA McKay, CP AF Roe, HG de Pater, I Macintosh, BA McKay, CP TI Titan's clouds from Gemini and Keck adaptive optics imaging SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : solar system; instrumentation : adaptive optics; planets and satellites : individual (Titan) ID SATURN SYSTEM; FIRST LIGHT; ATMOSPHERE; IMAGES; HST; TROPOSPHERE; TELESCOPE; ASYMMETRY; SURFACE; MODELS AB Using adaptive optics on the Gemini and Keck II telescopes, we found a thin haze and discrete clouds in Titan's south polar troposphere. The discrete clouds vary on timescales of a few hours. We propose a seasonal mechanism to explain the formation of this spring polar tropospheric haze. Assuming that the clouds are located in or above the haze, we suggest that convection within this haze layer triggers methane condensation; subsequent latent heat release leads to vigorous convection and formation of transient clouds. Our results have significant implications for planning the Cassini mission flybys of Titan. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Roe, HG (reprint author), Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. NR 39 TC 93 Z9 93 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP 1399 EP 1406 DI 10.1086/344403 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DA UT WOS:000179914300053 ER PT J AU Stothers, RB AF Stothers, RB TI Thermodynamics of a homogeneous mixture of gas, radiation, and turbulence SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic processes; equation of state; plasmas; turbulence ID STARS; OSCILLATIONS; CONVECTION; MODEL AB Subject to certain constraints, the equilibrium thermodynamics of a mixture of ionizing gas, blackbody radiation, and homogeneous turbulence is worked out in some detail. Specific heats and adiabatic exponents (Chandrasekhar's gammas) are calculated. The adiabatic exponents show only a weak dependence on the turbulent pressure and the turbulent energy. This dependence is weakest under conditions of strong partial ionization of the gas, or when the relative pressure due to radiation is very high. Analytic expressions and numerical examples are both given, and possible astrophysical applications are briefly discussed. C1 NASA, Inst Space Studies, Goddard Space Flight Ctr, New York, NY 10025 USA. RP Stothers, RB (reprint author), NASA, Inst Space Studies, Goddard Space Flight Ctr, 2880 Broadway, New York, NY 10025 USA. NR 24 TC 1 Z9 1 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP 1407 EP 1412 DI 10.1086/344296 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DA UT WOS:000179914300054 ER PT J AU Brown, TM Heap, SR Hubeny, I Lanz, T Lindler, D AF Brown, TM Heap, SR Hubeny, I Lanz, T Lindler, D TI Isolating clusters with Wolf-Rayet stars in I Zw 18 (vol 579, pg L75, 2002) SO ASTROPHYSICAL JOURNAL LA English DT Correction C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Brown, TM (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. NR 1 TC 1 Z9 1 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP L129 EP L129 PN 2 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DB UT WOS:000179914500016 ER PT J AU Tylka, AJ Boberg, PR Cohen, CMS Dietrich, WF Maclennan, CG Mason, GM Ng, CK Reames, DV AF Tylka, AJ Boberg, PR Cohen, CMS Dietrich, WF Maclennan, CG Mason, GM Ng, CK Reames, DV TI Flare- and shock-accelerated energetic particles in the solar events of 2001 April 14 and 15 SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; shock waves; Sun : coronal mass ejections (CMEs); Sun : flares; Sun : particle emission ID ADVANCED-COMPOSITION-EXPLORER; ISOTOPE SPECTROMETER; SPACECRAFT; SPECTRA; WIND; ACE; ENHANCEMENTS; ABUNDANCES; EVOLUTION; IONS AB We report heavy-ion composition and spectra for the solar energetic particle (SEP) events of 2001 April 14 and 15, using the combined capabilities of the Advanced Composition Explorer (ACE), Wind, and the Interplanetary Monitoring Platform 8 (IMP-8) to cover the energy range from similar to30 keV nucleon to similar to400 MeV nucleon(-1). These two events are, respectively, the largest impulsive event and the largest ground- level event observed so far in solar cycle 23. These events arose from the same active region and launched into similar interplanetary conditions. Both were associated with large western flares and fast coronal mass ejections (CMEs). However, the two events are distinctly different, thereby providing useful reminders of the fundamental differences between flare- and shock-accelerated SEPs. The detailed observations present challenges for our theoretical understanding of SEP production. Of particular note is the fact that iron has a harder power-law energy spectrum than oxygen above similar to3 MeV nucleon(-1) in the shock-dominated April 15 event. This spectral difference, which is seen in many other gradual events of various sizes and heliolongitudes, leads to enhanced Fe/O at high energies. Simple shock acceleration models predict the same power-law index for all species. Thus, understanding the origin of this spectral difference will significantly contribute to the resolution of the ongoing debate about the relative roles of CME-driven shocks and flares in producing high-energy solar heavy ions. C1 USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. CALTECH, Pasadena, CA 91125 USA. Univ Chicago, Enrico Fermi Inst, Lab Astrophys & Space Res, Chicago, IL 60637 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Tylka, AJ (reprint author), USN, Res Lab, EO Hulburt Ctr Space Res, Code 7652, Washington, DC 20375 USA. RI Tylka, Allan/G-9592-2014 NR 32 TC 35 Z9 36 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 20 PY 2002 VL 581 IS 2 BP L119 EP L123 DI 10.1086/346033 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 627DB UT WOS:000179914500014 ER PT J AU Ricca, A Bauschlicher, CW AF Ricca, A Bauschlicher, CW TI Ab initio study of Eu3+-L (L = H2O, H2S, NH2CH3, S(CH3)(2), imidazole) complexes SO CHEMICAL PHYSICS LETTERS LA English DT Article ID GAUSSIAN-BASIS SETS; CORRELATED MOLECULAR CALCULATIONS; TRIVALENT LANTHANIDE CATIONS; ATOMS; PROTEINS; PROBES AB The ground states and binding energies of Eu3+-L (L = H2O, H2S, NH2CH3, S(CH3)(2), imidazole) complexes has been determined using ab initio techniques. The binding is mostly electrostatic as expected. The empty f orbital is different for the S compounds, being a pi-like orbital, while for the O and N containing ligands it is a sigma-like orbital. However, the range in the binding energies for the different f holes is small. (C) 2002 Elsevier Science B.V. All rights reserved. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Ricca, A (reprint author), NASA, Ames Res Ctr, Mail Stop 230-3, Moffett Field, CA 94035 USA. NR 21 TC 4 Z9 4 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD DEC 20 PY 2002 VL 366 IS 5-6 BP 623 EP 627 AR PII S0009-2614(02)01627-5 DI 10.1016/S0009-2614(02)01627-5 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 619PC UT WOS:000179484300028 ER PT J AU Randerson, JT Collatz, GJ Fessenden, JE Munoz, AD Still, CJ Berry, JA Fung, IY Suits, N Denning, AS AF Randerson, JT Collatz, GJ Fessenden, JE Munoz, AD Still, CJ Berry, JA Fung, IY Suits, N Denning, AS TI A possible global covariance between terrestrial gross primary production and C-13 discrimination: Consequences for the atmospheric C-13 budget and its response to ENSO SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article DE global drought stress; tropical ecosystems; interannual variability of atmospheric delta C-13; terrestrial carbon sinks; El Nino-Southern Oscillation ID CARBON-ISOTOPE DISCRIMINATION; INTERANNUAL CLIMATE VARIABILITY; SURFACE PARAMETERIZATION SIB2; LONG-TERM VARIABILITY; EL-NINO; SOUTHERN OSCILLATION; LAND PRECIPITATION; EQUATORIAL PACIFIC; AMAZONIAN FORESTS; AIR-TEMPERATURE AB It is well known that terrestrial photosynthesis and C-13 discrimination vary in response to a number of environmental and biological factors such as atmospheric humidity and genotypic differences in stomatal regulation. Small changes in the global balance between diffusive conductances to CO2 and photosynthesis in C3 vegetation have the potential to influence the C-13 budget of the atmosphere because these changes scale with the relatively large one-way gross primary production (GPP) flux. Over a period of days to years, this atmospheric isotopic forcing is damped by the return flux consisting mostly of respiration, Fire, and volatile organic carbon losses. Here we explore the magnitude of this class of isotopic disequilibria with an ecophysiological model (SiB2) and a double deconvolution inversion framework that includes time-varying discrimination for the period of 1981-1994. If the net land carbon sink and plant C-13 discrimination covary on interannual timescales at the global scale, consistent with El Nino-induced drought stress causing a decline in global GPP and C3 discrimination, then less interannual variability in ocean and land net carbon exchange is required to explain atmospheric trends in delta(13)C and CO2 as compared with previous studies that assumed discrimination was invariant. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Ctr Atmospher Sci, Berkeley, CA 94720 USA. Carnegie Inst Washington, Dept Plant Biol, Stanford, CA 94305 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. RP Randerson, JT (reprint author), CALTECH, Div Geol & Planetary Sci, Mail Stop 100-23, Pasadena, CA 91125 USA. RI Berry, Joseph/B-8211-2009; collatz, george/D-5381-2012; Denning, Scott/F-4974-2011 OI Berry, Joseph/0000-0002-5849-6438; Denning, Scott/0000-0003-3032-7875 NR 90 TC 50 Z9 52 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD DEC 20 PY 2002 VL 16 IS 4 AR 1136 DI 10.1029/2001GB001845 PG 16 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 649LC UT WOS:000181209000002 ER PT J AU Hopkins, D Halford, G Coroneos, R Patnaik, S AF Hopkins, D Halford, G Coroneos, R Patnaik, S TI Fidelity of the integrated force method solution SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Letter ID FINITE-ELEMENT ANALYSIS; STRUCTURAL-ANALYSIS; COMPATIBILITY CONDITIONS; DISPLACEMENT CONSTRAINTS; OPTIMIZATION; STRESS; FORMULATION; CONTINUUM; MECHANICS; BEHAVIOR C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Hopkins, D (reprint author), NASA, Glenn Res Ctr, Lewis Field,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 37 TC 2 Z9 2 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD DEC 20 PY 2002 VL 55 IS 11 BP 1367 EP 1371 DI 10.1002/nme.626 PG 5 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 617MZ UT WOS:000179366600005 ER PT J AU Fox-Rabinovitz, MS Takacs, LL Govindaraju, RC AF Fox-Rabinovitz, MS Takacs, LL Govindaraju, RC TI A variable-resolution stretched-grid general circulation model and data assimilation system with multiple areas of interest: Studying the anomalous regional climate events of 1998 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE regional; downscaling; drought; flood; precipitation; mesoscale ID SHALLOW-WATER EQUATIONS; NUMERICAL WEATHER PREDICTION; GCM DYNAMICAL CORE; PRIMITIVE EQUATIONS; GLOBAL-MODEL; SIMULATION; PARAMETERIZATIONS; CONVECTION; EUROPE; ENERGY AB [1] The new stretched-grid (SG) design with multiple (four) areas of interest, one at each global quadrant, is implemented into both a SG general circulation model (GCM) and a SG data assimilation system (DAS). The four areas of interest include the United States/northern Mexico, the El Nino area/central South America, India/China, and the eastern Indian Ocean/Australia. Both SG-GCM and SG-DAS annual (November 1997 to December 1998) integrations are performed with 50-km regional resolution. The efficient regional downscaling to mesoscales is obtained for each of the four areas of interest, while the consistent interactions between regional and global scales and the high quality of global circulation are preserved. This is the advantage of the SG approach. The global variable-resolution DAS incorporating the SG-GCM has been developed and tested as an efficient tool for producing regional analyses and diagnostics with enhanced mesoscale resolution. The anomalous regional climate events of 1998 that occurred over the United States, Mexico, South America, China, India, African Sahel, and Australia are investigated in both simulation and data assimilation modes. The assimilated products are also used, along with gauge precipitation data, for validating the simulation results. The obtained results show that the SG-GCM and SG-DAS are capable of producing realistic high-quality simulated and assimilated products at mesoscale resolution for regional climate studies and applications. C1 Univ Maryland, ESSIC, College Pk, MD 20742 USA. Sci Applicat Int Corp, Gen Sci Operat Div, Beltsville, MD 20705 USA. NASA, Goddard Space Flight Ctr, Data Assimilat Off, Greenbelt, MD 20771 USA. RP Fox-Rabinovitz, MS (reprint author), Univ Maryland, ESSIC, Room 2207,224 CSS Bldg, College Pk, MD 20742 USA. EM foxrab@atmos.umd.edu NR 57 TC 12 Z9 12 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 20 PY 2002 VL 107 IS D24 AR 4768 DI 10.1029/2002JD002177 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650GB UT WOS:000181253900003 ER PT J AU Heikes, BG Chang, WN Pilson, MEQ Swift, E Singh, HB Guenther, A Jacob, DJ Field, BD Fall, R Riemer, D Brand, L AF Heikes, BG Chang, WN Pilson, MEQ Swift, E Singh, HB Guenther, A Jacob, DJ Field, BD Fall, R Riemer, D Brand, L TI Atmospheric methanol budget and ocean implication SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article DE methanol; OVOC; oxygenated hydrocarbons; atmosphere; ocean ID VOLATILE ORGANIC-COMPOUNDS; TRANSFORM INFRARED-SPECTROSCOPY; GLYCINE BETAINE UPTAKE; AIR-SEA EXCHANGE; OXYGENATED HYDROCARBONS; CARBONYL-COMPOUNDS; NATURAL-WATERS; BIOLOGICAL TURNOVER; SEASONAL-VARIATIONS; TROPOSPHERIC OZONE AB [1] Methanol is a biogeochemically active compound and a significant component of the volatile organic carbon in the atmosphere. It influences background tropospheric photochemistry and may serve as a tracer for biogenic emissions. The mass of methanol in the atmospheric reservoir, the annual mass flux of methanol from sources to sinks, and the estimated atmospheric lifetime of methanol in the free troposphere, marine boundary layer, continental boundary layer, and in-cloud, are evaluated. The atmosphere contains approximately 4 Tg (terragrams, 10(12) g) of methanol. Estimates of global methanol sources and sinks total 340 and 270 Tg methanol yr(-1), respectively, and are in balance given their estimated precision. Sink terms were evaluated using observed methanol distributions; the total loss is approximately a factor of 5 larger than prior estimates. The adopted source is a factor of 3 larger than its prior estimate. Recent net flux observations and the magnitude of the estimated sink suggest biogenic methanol emissions to be near their current estimated upper limit, >280 Tg methanol yr(-1), and this value was adopted. The methanol source will be larger with the inclusion of an argued for oceanic gross emission of 30 Tg methanol yr(-1), but a major uncertainty concerns whether the oceans are a major net sink or source of methanol, an issue which will not be resolved without new measurements. Other large uncertainties are the estimates of primary biogenic emissions and gas surface deposition. The first loss estimates of methanol by in-cloud chemistry and precipitation are presented. They are approximately equal at 10 Tg methanol yr(-1), each. These are small in comparison to the surface loss and gas phase photochemical loss estimated here but would be significant additional losses in earlier budgets. Surface exchange processes dominate the atmospheric budget of methanol and its distribution. The atmospheric deposition of methanol and the argued for methanol produced in the upper ocean are ubiquitous sources of C-1 substrate capable of sustaining methylotrophic organisms throughout the surface ocean. C1 Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80305 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, CIRES, Boulder, CO 80309 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RP Heikes, BG (reprint author), Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. RI Guenther, Alex/B-1617-2008 OI Guenther, Alex/0000-0001-6283-8288 NR 97 TC 94 Z9 94 U1 8 U2 33 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD DEC 19 PY 2002 VL 16 IS 4 AR 1133 DI 10.1029/2002GB001895 PG 13 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 649KZ UT WOS:000181208700002 ER PT J AU Drdla, K Gandrud, BW Baumgardner, D Wilson, JC Bui, TP Hurst, D Schauffler, SM Jost, H Greenblatt, JB Webster, CR AF Drdla, K Gandrud, BW Baumgardner, D Wilson, JC Bui, TP Hurst, D Schauffler, SM Jost, H Greenblatt, JB Webster, CR TI Evidence for the widespread presence of liquid-phase particles during the 1999-2000 Arctic winter SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE sulfate aerosol; freezing; polar stratospheric clouds; stratosphere; Arctic ID POLAR STRATOSPHERIC CLOUDS; OBSERVED SANDWICH STRUCTURE; SULFURIC-ACID TETRAHYDRATE; NITRIC-ACID; LIDAR OBSERVATIONS; VAPOR-PRESSURES; INSITU MEASUREMENTS; SIZE DISTRIBUTIONS; SULFATE AEROSOLS; LOW-TEMPERATURES AB In situ Multiangle Spectrometer Probe (MASP) particle measurements have been analyzed to determine the typical behavior of sulfate particles during the SAGE III Ozone Loss and Validation Experiment (SOLVE) campaign. The study has explored variations in the total particle concentration measured by MASP. A new analysis method has been developed in which increases of the MASP concentration can be interpreted as growth of small particles (those which are smaller than 0.2 mum in radius at midlatitudes). The method also allows all of the MASP measurements made during the SOLVE campaign to be incorporated in a single analysis. At all levels of the stratosphere, the total MASP concentration (and therefore aerosol growth) varies continuously with temperature. This behavior is well-reproduced by assuming that the sulfate aerosols are liquid solutions, but cannot be reproduced if the aerosol is assumed to be frozen. At sufficiently cold temperatures, larger increases in the MASP concentration are consistently seen; the observed onset temperature for this growth is in good agreement with model expectations for liquid ternary solutions. Liquid-like behavior is apparent for all measurements made in the Arctic during SOLVE, both inside and outside the vortex, and even at the coldest temperatures sampled during the campaign. At the levels with the coldest measured temperatures, which cause maximum particle sizes and thus the greatest total MASP concentrations, 90% of the particles grow as liquids. Therefore, the freezing that occurred during the 1999-2000 Arctic winter was selective, with most of the particles remaining liquid even in the presence of a small number of frozen particles. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Nacl Autonoma Mexico, Mexico City 04510, DF, Mexico. Univ Denver, Denver, CO USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Bay Area Environm Res Inst, Sonoma, CA USA. Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 USA. NASA, Jet Propuls Lab, Pasadena, CA USA. RP Drdla, K (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM katja@aerosol.arc.nasa.gov RI Hurst, Dale/D-1554-2016 OI Hurst, Dale/0000-0002-6315-2322 NR 55 TC 3 Z9 3 U1 2 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 19 PY 2002 VL 108 IS D5 AR 8318 DI 10.1029/2001JD001127 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650GX UT WOS:000181256100001 ER PT J AU Brogniez, C Bazureau, A Lenoble, J Chu, WP AF Brogniez, C Bazureau, A Lenoble, J Chu, WP TI Stratospheric Aerosol and Gas Experiment (SAGE) III measurements: A study on the retrieval of ozone, nitrogen dioxide, and aerosol extinction coefficients SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE SAGE III; Earth's atmosphere; minor species; inversion algorithm; simulation ID ABSORPTION CROSS-SECTIONS; SENSING REFERENCE DATA; 231-794 NM RANGE; INVERSION ALGORITHM; GOME AB [1] This paper presents the inversion algorithms that we propose to apply to the Stratospheric Aerosol and Gas Experiment (SAGE) III measurements for retrieving the aerosol and gas components of the Earth atmosphere. SAGE III is an upgraded version of SAGE II: The main improvements are the larger number of channels, including several resolved channels and a channel centered near 1.55 mum, and a higher vertical resolution. The species retrieval from the transmission measurements can be achieved via the inversion algorithm that we developed at Laboratoire d'Optique Atmospherique for SAGE II with only minor changes, in which all the channels are handled altogether for species separation by using an iterative method. For SAGE III, ozone and nitrogen dioxide can also be retrieved independently from two specific resolved channels by using their spectral signature over a small wavelength range; this second inversion leads only to the ozone and nitrogen dioxide concentrations and to the aerosols at two wavelengths. Since these later O-3 and NO2 retrievals are shown to be of better quality, it is further possible to use them in the first algorithm, in a combined analysis, for aerosol separation in the other channels. The performances of these three inversions have been compared for various atmospheric models, accounting for some probable measurement errors. The three methods perform very well in the case of nominal data. When errors are added to the measurements, the combined analysis leads generally to better retrieval for O-3 and NO2, while there is almost no improvement for the aerosols. For random measurement error, the retrieved profiles exhibit no bias with respect to the input profiles, except at high altitude. The accuracy of the results is shown to be dependent on the species and on the atmospheric model. C1 Univ Sci & Technol Lille, CNRS, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. Interact Rayonnement Solaire Atmosphere, Grenoble, France. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Brogniez, C (reprint author), Univ Sci & Technol Lille, CNRS, Opt Atmospher Lab, Batiment P5, F-59655 Villeneuve Dascq, France. EM colette.brogniez@loa.univ-lille1.fr; ariane.bazureau@aerov.jussieu.fr; lenoble@univ-lille1.fr; w.p.chu@larc.nasa.gov NR 18 TC 6 Z9 6 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 19 PY 2002 VL 107 IS D24 AR 4758 DI 10.1029/2001JD001576 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650FZ UT WOS:000181253700011 ER PT J AU Robinson, WA Reudy, R Hansen, JE AF Robinson, WA Reudy, R Hansen, JE TI General circulation model simulations of recent cooling in the east-central United States SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE global warming; U. S. climate; global climate model (GCM); sea surface temperature; cloud cover; climate change ID SOUTHERN OSCILLATION; CLIMATE-CHANGE; WATER-VAPOR; EL-NINO; TEMPERATURE; ENSO; PRECIPITATION; TRENDS AB [1] In ensembles of retrospective general circulation model (GCM) simulations, surface temperatures in the east-central United States cool between 1951 and 1997. This cooling, which is broadly consistent with observed surface temperatures, is present in GCM experiments driven by observed time varying sea-surface temperatures (SSTs) in the tropical Pacific, whether or not increasing greenhouse gases and other time varying climate forcings are included. Here we focus on ensembles with fixed radiative forcing and with observed varying SST in different regions. In these experiments the trend and variability in east-central U. S. surface temperatures are tied to tropical Pacific SSTs. Warm tropical Pacific SSTs cool U. S. temperatures by diminishing solar heating through an increase in cloud cover. These associations are embedded within a year-round response to warm tropical Pacific SST that features tropospheric warming throughout the tropics and regions of tropospheric cooling in midlatitudes. Precipitable water vapor over the Gulf of Mexico and the Caribbean and the tropospheric thermal gradient across the Gulf Coast of the United States increase when the tropical Pacific is warm. In observations, recent warming in the tropical Pacific is also associated with increased precipitable water over the southeast United States. The observed cooling in the east-central United States, relative to the rest of the globe, is accompanied by increased cloud cover, though year-to-year variations in cloud cover, U. S. surface temperatures, and tropical Pacific SST are less tightly coupled in observations than in the GCM. C1 Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Robinson, WA (reprint author), Univ Illinois, Dept Atmospher Sci, 105 S Gregory St, Urbana, IL 61801 USA. EM robinson@atmos.uiuc.edu; cdrar@ipcc2.giss.nasa.gov; jhansen@giss.nasa.gov RI Robinson, Walter/I-3782-2012 OI Robinson, Walter/0000-0002-6669-7408 NR 21 TC 44 Z9 44 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 19 PY 2002 VL 107 IS D24 AR 4748 DI 10.1029/2001JD001577 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650FZ UT WOS:000181253700012 ER PT J AU Yokota, T Nakajima, H Sugita, T Tsubaki, H Itou, Y Kaji, M Suzuki, M Kanzawa, H Park, JH Sasano, Y AF Yokota, T Nakajima, H Sugita, T Tsubaki, H Itou, Y Kaji, M Suzuki, M Kanzawa, H Park, JH Sasano, Y TI Improved Limb Atmospheric Spectrometer (ILAS) data retrieval algorithm for Version 5.20 gas profile products SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC AEROSOL; ABSORPTION-SPECTRA; OPTICAL-CONSTANTS; POLAR OZONE; INSTRUMENT; REGION; WINTER; H2O; TEMPERATURES; PERFORMANCE AB [1] The Improved Limb Atmospheric Spectrometer (ILAS), a sensor for stratospheric ozone layer observation using a solar occultation technique, was mounted on the Advanced Earth Observing Satellite (ADEOS), which was put into a Sun-synchronous polar orbit in August 1996. Operational measurements were recorded over high-latitude regions from November 1996 to June 1997. This paper describes the data processing algorithm of Version 5.20 used to retrieve vertical profiles of gases such as ozone, nitric acid, nitrogen dioxide, nitrous oxide, methane, and water vapor from the infrared spectral measurements of ILAS. To simultaneously derive mixing ratios of individual gas species as a function of altitude, the nonlinear least squares method was utilized for spectral fitting, and the onion peeling method was applied to perform vertical profiling. This paper also discusses in detail estimation of errors (internal and external errors) associated with the derived gas profiles and compares the errors with repeatability. The internal error estimated from residuals in spectral fitting was generally larger than the repeatability, which suggests either that some unknown factors have not been incorporated into the forward model for simulating observed transmittance data or that some parameters in the model are inaccurate. The external error was almost comparable in magnitude to the repeatability. Numerical simulations were carried out to investigate performance of the nongaseous correction technique. The results showed that the background level of sulfuric acid aerosols has little effect on the retrieved profiles, while polar stratospheric clouds (PSCs) with extinction coefficients of the order of 10(-3) km(-1) at a wavelength of 780 nm have nonnegligible effects on the profiles of some gas species. Despite the problems that require further investigations, it is shown that the ILAS Version 5.20 algorithm generates scientifically useful products. C1 Natl Inst Environm Studies, Tsukuba, Ibaraki 3058506, Japan. Fujitsu FIP Corp, Tokyo, Japan. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Univ Tsukuba, Grad Sch Syst Management, Tokyo, Japan. RP Yokota, T (reprint author), Natl Inst Environm Studies, Tsukuba, Ibaraki 3058506, Japan. EM yoko@nies.go.jp RI Sasano, Yasuhiro/C-2927-2009 OI Sasano, Yasuhiro/0000-0001-7470-5642 NR 49 TC 44 Z9 44 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 19 PY 2002 VL 107 IS D24 AR 8216 DI 10.1029/2001JD000628 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650FZ UT WOS:000181253700002 ER PT J AU Zhang, JH Lohmann, U Lin, B AF Zhang, JH Lohmann, U Lin, B TI A new statistically based autoconversion rate parameterization for use in large-scale models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE autoconversion rate; statistical cloud scheme; subgrid-scale variability; cloud modeling; ARM; SHEBA ID GENERAL-CIRCULATION MODEL; SINGLE-COLUMN MODEL; 2ND-ORDER TURBULENCE CLOSURE; PHYSICALLY-BASED SCHEME; CLIMATE MODELS; MICROPHYSICAL PROCESSES; STRATIFORM CLOUDS; BOUNDARY-LAYER; PRECIPITATION; SIMULATIONS AB [1] The autoconversion rate is a key process for the formation of precipitation in warm clouds. In climate models, physical processes such as autoconversion rate, which are calculated from grid mean values, are biased, because they do not take subgrid variability into account. Recently, statistical cloud schemes have been introduced in large-scale models to account for partially cloud-covered grid boxes. However, these schemes do not include the in-cloud variability in their parameterizations. In this paper, a new statistically based autoconversion rate considering the in-cloud variability is introduced and tested in three cases using the Canadian Single Column Model (SCM) of the global climate model. The results show that the new autoconversion rate improves the model simulation, especially in terms of liquid water path in all three case studies. C1 Dalhousie Univ, Dept Phys & Atmospher Sci, Halifax, NS B3H 3J5, Canada. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Zhang, JH (reprint author), Dalhousie Univ, Dept Phys & Atmospher Sci, Halifax, NS B3H 3J5, Canada. EM zhang@mathstat.dal.ca RI Lohmann, Ulrike/B-6153-2009 OI Lohmann, Ulrike/0000-0001-8885-3785 NR 33 TC 16 Z9 16 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 19 PY 2002 VL 107 IS D24 AR 4750 DI 10.1029/2001JD001484 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650FZ UT WOS:000181253700010 ER PT J AU Fu, LL Qiu, B AF Fu, LL Qiu, B TI Low-frequency variability of the North Pacific Ocean: The roles of boundary- and wind-driven baroclinic Rossby waves SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE Rossby waves; satellite altimetry; El Nino; North Pacific; eastern boundary ID SEA-LEVEL VARIABILITY; EL-NINO; COAST; THERMOCLINE; ATLANTIC; AMERICA; MODEL AB The effects of the sea level variability along the eastern boundary of the North Pacific Ocean, including those associated with El Nino Southern Oscillation, have been considered an important factor in determining the low-frequency large-scale variability of the ocean interior through Rossby waves generated at the eastern boundary. This hypothesis is examined in this study using 8 years worth of the sea surface height observations made by the TOPEX/Poseidon satellite. The timescales of interest are longer than 90 days with the annual cycle removed. The results indicate that the influence of the eastern boundary of the North Pacific Ocean has limited offshore extent, varying from 3000-4000 km at 10degreesN to 200-300 km at 50degreesN. The variability in the ocean interior is primarily driven by wind with only a minor influence from the boundary. Simulations of a linear two-layer model of the ocean driven by wind stress curl are correlated with the observations. The effects of wind forcing accumulate along the characteristics of long nondispersive Rossby waves in the time-longitude domain. These wind-driven Rossby waves overwhelm the boundary-driven waves in the ocean interior, where there are only some small residual effects of the boundary-driven waves, however. These small effects become clearer after the simulated wind-driven variability is removed from the observations. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Hawaii Manoa, Dept Oceanog, Honolulu, HI 96822 USA. RP Fu, LL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Qiu, Bo/D-9569-2017 NR 28 TC 76 Z9 81 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 19 PY 2002 VL 107 IS C12 AR 3220 DI 10.1029/2001JC001131 PG 10 WC Oceanography SC Oceanography GA 649WV UT WOS:000181231700002 ER PT J AU Harada, E Kumagai, J Ozawa, K Imabayashi, S Tsapin, AS Nealson, KH Meyer, TE Cusanovich, MA Akutsu, H AF Harada, E Kumagai, J Ozawa, K Imabayashi, S Tsapin, AS Nealson, KH Meyer, TE Cusanovich, MA Akutsu, H TI A directional electron transfer regulator based on heme-chain architecture in the small tetraheme cytochrome c from Shewanella oneidensis SO FEBS LETTERS LA English DT Article DE redox potential; tetraheme cytochrome; heme architecture; cooperativity; NMR; polarography ID FLAVOCYTOCHROME-C; FUMARATE REDUCTASE; PUTREFACIENS MR-1; C(3); IDENTIFICATION; FRIGIDIMARINA; PURIFICATION; RESPIRATION; NCIMB400; ORDER AB The macroscopic and microscopic redox potentials of the four hemes of the small tetraheme cytochrome c from Shewanella oneidensis were determined. The microscopic redox potentials show that the order of reduction is from hemes in the C-terminal domain (hemes 3 and 4) to the N-terminal domain (heme 1), demonstrating the polarization of the tetraheme chain during reduction. This makes heme 4 the most efficient electron delivery site. Furthermore, multi-step reduction of other redox centers through either heme 4 or heme 3 is shown to be possible. This has provided new insights into the two-electron reduction of the flavin in the homologous flavocytochrome c-fumarate reductase. (C) 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved. C1 Osaka Univ, Inst Prot Res, Osaka 5650871, Japan. Yokohama Natl Univ, Fac Engn, Yokohama, Kanagawa 2408501, Japan. Japan Biol Informat Consortium, Chuo Ku, Tokyo 1040032, Japan. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Dept Biochem & Mol Biophys, Tucson, AZ 85721 USA. Okazaki Natl Resinst, Inst Mol Sci, Okazaki, Aichi 4448585, Japan. RP Akutsu, H (reprint author), Osaka Univ, Inst Prot Res, Osaka 5650871, Japan. FU NIGMS NIH HHS [GM21277] NR 20 TC 25 Z9 25 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0014-5793 J9 FEBS LETT JI FEBS Lett. PD DEC 18 PY 2002 VL 532 IS 3 BP 333 EP 337 AR PII S0014-5793(02)03696-7 DI 10.1016/S0014-5793(02)03696-7 PG 5 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 626QP UT WOS:000179884800013 PM 12482588 ER PT J AU Head, J Pappalardo, R Collins, G Belton, MJS Giese, B Wagner, R Breneman, H Spaun, N Nixon, B Neukum, G Moore, J AF Head, J Pappalardo, R Collins, G Belton, MJS Giese, B Wagner, R Breneman, H Spaun, N Nixon, B Neukum, G Moore, J TI Evidence for Europa-like tectonic resurfacing styles on Ganymede SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GROOVED TERRAIN; SEPARATION AB Very high-resolution imaging and stereo topographic data obtained during the Galileo G28 encounter with Ganymede show 1) evidence for Europa-like, crustal spreading and resurfacing to form portions of the bright terrain, and 2) bright terrain that appears smooth at Voyager resolution (and thus a strong candidate for cryovolcanism) but instead is tectonically deformed and lacks embayment relationships when viewed at high resolution. In contrast to previous views, these new data show that tectonism has been the dominant process in shaping some very smooth areas and that Ganymede appears to have experienced Europa-like crustal spreading during its previous history. C1 Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. Univ Colorado, Astrophys & Planetary Sci Dept, Boulder, CO 80309 USA. Wheaton Coll, Dept Phys & Astron, Norton, MA 02766 USA. Belton Space Explorat Initiat LLC, Tucson, AZ 85716 USA. DLR, Inst Planetary Explorat, Berlin, Germany. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Free Univ Berlin, D-12249 Berlin, Germany. RP Head, J (reprint author), Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. NR 25 TC 14 Z9 14 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 18 PY 2002 VL 29 IS 24 AR 2151 DI 10.1029/2002GL015961 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 649FR UT WOS:000181196900002 ER PT J AU Ponte, RM Ray, RD AF Ponte, RM Ray, RD TI Atmospheric pressure corrections in geodesy and oceanography: A strategy for handling air tides SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SURFACE PRESSURE AB Global pressure data are often needed for processing or interpreting modern geodetic and oceanographic measurements. The most common source of these data is the analysis or reanalysis products of various meteorological centers. Tidal signals in these products can be problematic for several reasons, including potentially aliased sampling of the semidiurnal solar tide as well as the presence of various modeling or timing errors. Building on the work of Van den Dool and colleagues, we lay out a strategy for handling atmospheric tides in (re) analysis data. The procedure also offers a method to account for ocean loading corrections in satellite altimeter data that are consistent with standard ocean-tide corrections. The proposed strategy has immediate application to the ongoing Jason-1 and GRACE satellite missions. C1 AER Inc, Lexington, MA 02421 USA. NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. RP Ponte, RM (reprint author), AER Inc, 131 Hartwell Ave, Lexington, MA 02421 USA. RI Ray, Richard/D-1034-2012; OI Ponte, Rui/0000-0001-7206-6461 NR 15 TC 31 Z9 31 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 18 PY 2002 VL 29 IS 24 AR 2153 DI 10.1029/2002GL016340 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 649FR UT WOS:000181196900003 ER PT J AU Pierce, RB Al-Saadi, J Fairlie, TD Natarajan, M Harvey, VL Grose, WL Russell, JM Bevilacqua, R Eckermann, SD Fahey, D Popp, P Richard, E Stimpfle, R Toon, GC Webster, CR Elkins, J AF Pierce, RB Al-Saadi, J Fairlie, TD Natarajan, M Harvey, VL Grose, WL Russell, JM Bevilacqua, R Eckermann, SD Fahey, D Popp, P Richard, E Stimpfle, R Toon, GC Webster, CR Elkins, J TI Large-scale chemical evolution of the Arctic vortex during the 1999/2000 winter: HALOE/POAM III Lagrangian photochemical modeling for the SAGE III-Ozone Loss and Validation Experiment (SOLVE) campaign SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE photochemical; Lagrangian; Arctic; ozone; HALOE; POAM; SOLVE ID IN-SITU MEASUREMENTS; POLAR VORTEX; STRATOSPHERIC OZONE; TROPOSPHERE; TRANSPORT; REMOVAL; HNO3 AB [1] The LaRC Lagrangian Chemical Transport Model (LaRC LCTM) is used to simulate the kinematic and chemical evolution of an ensemble of trajectories initialized from Halogen Occultation Experiment (HALOE) and Polar Ozone and Aerosol Measurement (POAM) III atmospheric soundings over the SAGE III-Ozone Loss and Validation Experiment (SOLVE) campaign period. Initial mixing ratios of species which are not measured by HALOE or POAM III are specified using sunrise and sunset constituent CH4 and constituent PV regressions obtained from the LaRC IMPACT model, a global three dimensional general circulation and photochemical model. Ensemble averaging of the trajectory chemical characteristics provides a vortex-average perspective of the photochemical state of the Arctic vortex. The vortex-averaged evolution of ozone, chlorine, nitrogen species, and ozone photochemical loss rates is presented. Enhanced chlorine catalyzed ozone loss begins in mid-January above 500 K, and the altitude of the peak loss gradually descends during the rest of the simulation. Peak vortex averaged loss rates of over 60 ppbv/day occur in early March at 450 K. Vortex averaged loss rates decline after mid-March. The accumulated photochemical ozone loss during the period from 1 December 1999 to 30 March 2000 peaks at 450 K with net losses of near 2.2 ppmv. The predicted distributions of CH4, O-3, denitrification, and chlorine activation are compared to the distributions obtained from in situ measurements to evaluate the accuracy of the simulations. The comparisons show best agreement when diffusive tendencies are included in the model calculations, highlighting the importance of this process in the Arctic vortex. Sensitivity tests examining the large-scale influence of orographically generated gravity-wave temperature anomalies are also presented. Results from this sensitivity study show that mountain-wave temperature perturbations contribute an additional 2-8% O-3 loss during the 1999/2000 winter. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Sci Applicat Int Corp, Hampton, VA 23665 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23669 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20032 USA. NOAA, Aeron Lab, Boulder, CO 80305 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20032 USA. RP NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM r.b.pierce@larc.nasa.gov; v.l.harvey@larc.nasa.gov; james.russell@hamptonu.edu; bevilacq@poamb.nrl.navy.mil; eckerman@map.nrl.navy.mil; fahey@al.noaa.gov; stimpfle@huarp.harvard.edu; toon@mark4sun.jpl.nasa.gov; chris.r.webster@jpl.nasa.gov; jelkins@cmdl.noaa.gov RI Fahey, David/G-4499-2013; Pierce, Robert Bradley/F-5609-2010 OI Fahey, David/0000-0003-1720-0634; Pierce, Robert Bradley/0000-0002-2767-1643 NR 49 TC 0 Z9 0 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 18 PY 2002 VL 108 IS D5 AR 8317 DI 10.1029/2001JD001063 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 650GW UT WOS:000181256000001 ER PT J AU Bingham, FM Howden, SD Koblinsky, CJ AF Bingham, FM Howden, SD Koblinsky, CJ TI Sea surface salinity measurements in the historical database SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE sea surface salinity; historical data; frequency histogram; probability density; world ocean database; skewness ID TROPICAL PACIFIC-OCEAN; NORTH-ATLANTIC; PRECIPITATION; TEMPERATURE AB We have examined historical distributions of sea surface salinity (SSS) observations in a data set consisting of a combination of the World Ocean Database 1998 (WOD98) and a thermosalinograph and bucket salinity database collected from volunteer observing ships. It is well known that SSS in much of the world's ocean is measured infrequently or not at all. We find that 27% of one-degree squares in the world ocean (open and coastal, excluding the Arctic Ocean) had no observations of SSS in the historical database, and 70% had 10 or fewer. Systematic sampling of SSS (more than 10,000 observations per year globally) did not start until after 1960. Most SSS observations in the WOD98 are concentrated in the North Sea and coast of northern Europe, the east and west coasts of North America, and around Japan. About 28% of SSS measurements are in coastal waters. We plotted frequency histograms of SSS for some selected well-sampled one-degree squares in the North Atlantic and tropical Pacific. We found most frequency histograms to be non-Gaussian. The main departure from normal distribution is due to anomalous low-salinity measurements creating a negative skewness. This conclusion is verified as a global phenomenon by examining statistics of mean-median SSS difference within one-degree squares. This quantity is found to be predominantly negative over the global ocean. These anomalous low-salinity values may be due to rainfall events, but there are other plausible physical mechanisms, like frontal movement and eddy activity. There were also areas where the distributions were bimodal due to the presence of meandering fronts with little cross-frontal mixing. Examples are shown where the non-Gaussian nature of the distributions in the areas examined is both a short-term and a long-term phenomenon. That is, the distributions are skewed on a nearly instantaneous (similar to1 month) basis and averaged over long time periods (1+years). This has important implications for climatologies because the differences between mean and modal SSS, for the analyzed one-degree squares, is of order 0.1. Furthermore, the implication for validation studies for remote sensing missions is that the studies must make enough measurements of SSS to determine the extent to which the probability density is not Gaussian. C1 Univ N Carolina, Ctr Marine Sci, Wilmington, NC 28409 USA. Univ So Mississippi, Dept Marine Sci, Stennis Space Ctr, MS 39529 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bingham, FM (reprint author), Univ N Carolina, Ctr Marine Sci, 5600 Marvin K Mass Lane, Wilmington, NC 28409 USA. NR 36 TC 19 Z9 21 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD DEC 18 PY 2002 VL 107 IS C12 AR 8019 DI 10.1029/2000jc000767 PG 10 WC Oceanography SC Oceanography GA 649WU UT WOS:000181231600002 ER PT J AU Araneda, JA Vinas, AF Astudillo, HF AF Araneda, JA Vinas, AF Astudillo, HF TI Proton core temperature effects on the relative drift and anisotropy evolution of the ion beam instability in the fast solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE fast solar wind; plasma waves; ion-beam instabilities; ion-cyclotron modes; temperature anisotropy; preferential heating ID ELECTROMAGNETIC PROTON/PROTON INSTABILITIES; MAGNETOSONIC INSTABILITY; STREAMS; DRIVEN; ACCELERATION; STABILITY; PLASMAS; 0.3-AU; CORONA; 1-AU AB Typical nonthermal features of ion velocity distributions observed in the fast solar wind are the relative streaming between two proton components, an alpha/proton relative flow, and anisotropic proton cores with T(perpendicular top)>T(parallel top), where the subscripts denote directions relative to the background magnetic field B(0). All these nonthermal features lead to the growth of the several electromagnetic instabilities. Here, linear Vlasov theory and one-dimensional hybrid simulations are used to study these instabilities in a homogeneous, magnetized, and collisionless plasma model. Under these conditions, both magnetosonic and Alfven/cyclotron modes become unstable. We show that for conditions typical of the fast solar wind and parallel propagation, the proton core temperature anisotropy plays a significant role in modifying the wave-particle scattering of each ion component as compared to the isotropic case. Such an effect leads to a reduction in both the heating and anisotropy enhancement of the proton beam and alpha component and to a decrease in the relative proton/proton and proton/alpha flow speeds below the corresponding isotropic instability thresholds. This result provides additional support to the physical scenario in which instability thresholds correspond to observable constraints on plasma species anisotropies and match closer recent solar wind observations. C1 Univ Concepcion, Fac Ciencias Fis & Matemat, Dept Fis, Concepcion, Chile. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Araneda, JA (reprint author), Univ Concepcion, Fac Ciencias Fis & Matemat, Dept Fis, Casilla 160-C, Concepcion, Chile. EM jaraned@udec.cl; adolfo.vinas@gsfc.nasa.gov; hastudil@udec.cl RI Araneda, Jaime/J-9245-2015 NR 37 TC 26 Z9 26 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 18 PY 2002 VL 107 IS A12 AR 1453 DI 10.1029/202JA009337 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 650AJ UT WOS:000181239900005 ER PT J AU Vandemark, D Tran, N Beckley, BD Chapron, B Gaspar, P AF Vandemark, D Tran, N Beckley, BD Chapron, B Gaspar, P TI Direct estimation of sea state impacts on radar altimeter sea level measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TOPEX; BIAS AB A new sea state bias modeling approach is presented that makes use of altimeter-derived marine geoid estimates. This method contrasts with previous models that require differencing between repeat altimeter passes for SSB isolation, along with complex bivariate inversion, to derive a relation between wind speed, wave height and SSB. Here one directly bin-averages sea height residuals over the wind and wave correlatives. Comparison with the most current nonparametric repeat-pass model shows close agreement and provides a first validation of this simpler and more direct technique. Success is attributed mainly to extensive space and time averaging. Ease in implementation and benefits in working with absolute levels provide much appeal. Further advantages and potential limitations, centered on the need to effectively randomize large sea level anomaly components to expose the bias, are also discussed. C1 Raytheon ITSS, Greenbelt, MD USA. IFREMER, Ctr Brest, Plouzane, France. Collecte Localisat Satellites, Ramonville St Agne, France. NASA, Goddard Space Flight Ctr, Wallops Isl, VA 23337 USA. RP Vandemark, D (reprint author), Univ New Hampshire, OPAL, Rm 142 Morse Hall, Durham, NH 03824 USA. RI Chapron, Bertrand/O-6527-2015 NR 9 TC 15 Z9 15 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 17 PY 2002 VL 29 IS 24 AR 2148 DI 10.1029/2002GL015776 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 649FN UT WOS:000181196500001 ER PT J AU Pralle, MU Moelders, N McNeal, MP Puscasu, I Greenwald, AC Daly, JT Johnson, EA George, T Choi, DS El-Kady, I Biswas, R AF Pralle, MU Moelders, N McNeal, MP Puscasu, I Greenwald, AC Daly, JT Johnson, EA George, T Choi, DS El-Kady, I Biswas, R TI Photonic crystal enhanced narrow-band infrared emitters SO APPLIED PHYSICS LETTERS LA English DT Article ID EXTRAORDINARY OPTICAL-TRANSMISSION; SUBWAVELENGTH HOLE ARRAYS AB We have experimentally and theoretically developed a unique thermally stimulated midinfrared source that emits radiation within a narrow range of wavelengths (deltalambda/lambdaless than or equal to0.2). The emission wavelengths are defined by the periodicity of a metal coated silicon-air photonic crystal etched into the emitter surface. The lattice of the holes in the metal mediate the coupling of light into discrete surface plasmon states. This yields surfaces with spectrally nonuniform infrared reflection properties where over much of the IR 90+% of photons are reflected yet, in a narrow spectral region, 90% absorption is observed. Transfer matrix calculations simulate well the position and strength of the absorption features. This technology will afford tunable infrared emitters with high power in a narrow spectral band that are critical for sensing, spectroscopy, and thermophotovoltaic applications. (C) 2002 American Institute of Physics. C1 Ion Opt Inc, Waltham, MA 02452 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Iowa State Univ, Ames Lab, Dept Phys, Ames, IA 50011 USA. Iowa State Univ, Microelect Res Ctr, Ames, IA 50011 USA. RP Pralle, MU (reprint author), Ion Opt Inc, Waltham, MA 02452 USA. RI El-Kady, Ihab/D-2886-2013; Choi, Daniel/A-8181-2017 OI El-Kady, Ihab/0000-0001-7417-9814; NR 23 TC 158 Z9 164 U1 5 U2 53 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 16 PY 2002 VL 81 IS 25 BP 4685 EP 4687 DI 10.1063/1.1526919 PG 3 WC Physics, Applied SC Physics GA 623YB UT WOS:000179731000001 ER PT J AU Okamoto, H Chen, DM Yamada, T AF Okamoto, H Chen, DM Yamada, T TI Competing classical and quantum effects in shape relaxation of a metallic island SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRON FRINGES; GROWTH; PB; SI(111); FILMS; INSTABILITY; OVERLAYERS; MORPHOLOGY; STABILITY; SURFACES AB Pb islands grown on a Si substrate transform at room temperature from a flattop facet geometry into an unusual ring shape. The volume-preserving mass transport is catalyzed by the electrical field from the tip of a scanning tunneling microscope. The ring morphology results from the competing classical and quantum effects in the shape relaxation. The latter is enhanced by the large anisotropy of the effective mass, and leads to a sequential strip-flow growth on alternating strips of the same facet defined by substrate steps, showing its dynamical impact on the stability of a nanostructure. C1 Harvard Univ, Rowland Inst Harvard, Cambridge, MA 02142 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Okamoto, H (reprint author), Harvard Univ, Rowland Inst Harvard, Cambridge, MA 02142 USA. EM chen@rowland.harvard.edu RI Yamada, Toshishige/E-7834-2012 OI Yamada, Toshishige/0000-0001-7145-9212 NR 29 TC 40 Z9 40 U1 1 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 16 PY 2002 VL 89 IS 25 AR 256101 DI 10.1103/PhysRevLett.89.256101 PG 4 WC Physics, Multidisciplinary SC Physics GA 622ZT UT WOS:000179678900036 PM 12484902 ER PT J AU Ord, GN Gualtieri, JA AF Ord, GN Gualtieri, JA TI The Feynman propagator from a single path SO PHYSICAL REVIEW LETTERS LA English DT Article ID HAUSDORFF DIMENSION; QUANTUM; CHESSBOARD; MODEL AB We show that it is possible to construct the Feynman propagator for a free particle in one dimension, without quantization, from a single continuous space-time path. C1 Ryerson Univ, MPCS, Toronto, ON, Canada. NASA, Goddard Space Flight Ctr, Appl Informat Sci Branch, Greenbelt, MD 20771 USA. RP Ord, GN (reprint author), Ryerson Univ, MPCS, Toronto, ON, Canada. NR 18 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 16 PY 2002 VL 89 IS 25 AR 250403 DI 10.1103/PhysRevLett.89.250403 PG 4 WC Physics, Multidisciplinary SC Physics GA 622ZT UT WOS:000179678900004 PM 12484870 ER PT J AU Segre, PN AF Segre, PN TI Origin of stability in sedimentation SO PHYSICAL REVIEW LETTERS LA English DT Article ID NON-BROWNIAN SPHERES; VELOCITY FLUCTUATIONS; SUSPENSIONS; DIFFUSION AB Velocity fluctuations and particle concentrations are studied in a liquid fluidized bed to investigate the origin of steady state sedimentation. Both the velocity fluctuations and the particle concentrations are found to strongly depend on height. A flux balance model shows why the bed is stable: velocity fluctuations drive a downward particle flux that is compensated by an upward particle flux stemming from an excess flow velocity due to the stratification in concentration. Our results show that in steady state the magnitudes of the fluctuations are related to the degree of stratification. C1 NASA, George C Marshall Space Flight Ctr, Biophys Grp, Huntsville, AL 35812 USA. RP Segre, PN (reprint author), NASA, George C Marshall Space Flight Ctr, Biophys Grp, Huntsville, AL 35812 USA. NR 17 TC 10 Z9 10 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD DEC 16 PY 2002 VL 89 IS 25 AR 254503 DI 10.1103/PhysRevLett.89.254503 PG 4 WC Physics, Multidisciplinary SC Physics GA 622ZT UT WOS:000179678900026 PM 12484892 ER PT J AU Treiman, AH Amundsen, HEF Blake, DF Bunch, T AF Treiman, AH Amundsen, HEF Blake, DF Bunch, T TI Hydrothermal origin for carbonate globules in Martian meteorite ALH84001: a terrestrial analogue from Spitsbergen (Norway) SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Mars; ALH84001; Spitsbergen; hydrothermal; siderite; magnesite; ankerite ID LOW-TEMPERATURE; NORTHWESTERN SPITSBERGEN; PERIDOTITE XENOLITHS; PETROLOGIC EVIDENCE; UPPER MANTLE; MARS; ALLAN-HILLS-84001; MAGNETITE; HISTORY; ISOTOPES AB Carbonate minerals in the ancient Martian meteorite ALH84001 are the only known solid phases that bear witness to the processing of volatile and biologically critical compounds (CO2, H2O) on early Mars. Similar carbonates have been found in xenoliths and their host basalts from Quaternary volcanic centers in northern Spitsbergen (Norway). These carbonates were deposited by hot (i.e., hydrothermal) waters associated with the volcanic activity. By analogy with the Spitsbergen carbonates, the ALH84001 carbonates were probably also deposited by hot water. Hydrothermal activity was probably common and widespread on Early Mars, which featured abundant basaltic rocks, water as ice or liquid, and heat from volcanos and asteroid impacts. On Earth, descendants of the earliest life forms still prefer hydrothermal environments, which are now shown to have been present on early Mars. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Lunar & Planetary Inst, Houston, TX 77058 USA. Univ Oslo, Dept Phys & Geol, N-0364 Oslo, Norway. NASA, Ames Res Ctr, Ecobiol Branch, Moffett Field, CA 94035 USA. No Arizona Univ, Dept Geol, Bilby Res Ctr, Flagstaff, AZ 86011 USA. Earth & Planetary Explorat Serv, N-0364 Oslo, Norway. ARC Dessert Res, Prescott, AZ 86301 USA. RP Treiman, AH (reprint author), Lunar & Planetary Inst, 3600 Bay Area Blvd, Houston, TX 77058 USA. NR 49 TC 44 Z9 44 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD DEC 15 PY 2002 VL 204 IS 3-4 BP 323 EP 332 AR PII S0012-821X(02)00998-6 DI 10.1016/S0012-821X(02)00998-6 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 621QB UT WOS:000179600000001 ER PT J AU Ma, Q Tipping, RH AF Ma, Q Tipping, RH TI Water vapor millimeter wave foreign continuum: A Lanczos calculation in the coordinate representation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID WING LINE-SHAPES; ATMOSPHERIC WINDOW; 239 GHZ; DENSITY-MATRIX; ABSORPTION; H2O; MIXTURES; H2O-N-2; C2H6 AB The water vapor foreign-continuum absorption has been calculated theoretically from first principles for the millimeter wave spectral region as a function of frequency f and temperature T. The calculations are made using the Lanczos algorithm by writing the resolvent operator (omega-L)(-1) as continued fractions. In order to guarantee the quick convergence of the continued fractions, the line space of H2O is divided into two subspaces: one consists of the positive resonance lines and the other the negative ones. By ignoring the coupling between them, (omega-L)(-1) is expressed as a sum of two continued fractions. The parameters appearing in each of the fractions are functions of the matrix elements of powers of the Liouville operator L between the starting vectors spanning the corresponding subspaces. In the present work, we have taken into account all powers of L up to 5. With the coordinate representation in which the orientations of the H2O-N-2 collision pair are chosen as the basis functions in Hilbert space, the anisotropic interaction potential is diagonal, and calculations of the matrix elements are transformed to multidimensional integrations. The latter are evaluated with the Monte Carlo method. In order to reduce the lengthy calculations, we assume that the anisotropic potential has rotational symmetry about the Z axis of H2O, and consists of the long-range dipole-quadrupole part and a short-range repulsive site-site model. Once the parameters of the continued fractions are known, one can calculate the poles and residues and then carry out the ensemble average over the translational motion. Within the quasistatic approximation, one can treat the latter classically and obtain contributions to the absorption coefficient at the poles. Finally, the absorption coefficient at frequency f can be derived by an interpolation method. The results are fitted to a simple function of f and T, and are compared with experimental data and with two different versions of Liebe's empirical model. In general, the theoretical results are in good agreement with the experiment. Meanwhile, the magnitudes of the theoretical absorption are between those of the 1989 and 1993 versions, but the temperature dependence is closer to the latter one. (C) 2002 American Institute of Physics. C1 Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys, New York, NY 10025 USA. Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. RP Ma, Q (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. NR 27 TC 17 Z9 17 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD DEC 15 PY 2002 VL 117 IS 23 BP 10581 EP 10596 DI 10.1063/1.1516792 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 619UC UT WOS:000179495000018 ER PT J AU Lee, S Kim, J Jonsson, L Wilkins, JW Bryant, GW Klimeck, G AF Lee, S Kim, J Jonsson, L Wilkins, JW Bryant, GW Klimeck, G TI Many-body levels of optically excited and multiply charged InAs nanocrystals modeled by semiempirical tight binding SO PHYSICAL REVIEW B LA English DT Article ID SEMICONDUCTOR QUANTUM DOTS; ELECTRON-HOLE CORRELATIONS; CDSE NANOCRYSTALS; ENERGIES AB Many-body levels of optically excited and multiply charged InAs nanocrystals are studied with the semiempirical tight-binding model. Single-particle levels of unstrained spherical InAs nanocrystals are described by the sp(3)d(5)s(*) nearest-neighbor tight-binding model including spin-orbit coupling. For optically excited InAs nanocrystals, first-order corrections of electron-hole Coulomb and exchange interaction to exciton levels and the oscillator strengths of the exciton levels determine several low-lying, bright-exciton levels. The origin of the large oscillator strengths of the bright exciton levels is explained by the analysis of dominant angular momenta of exciton envelope functions. Good agreement with photoluminescence excitation experiments is achieved for the size dependence of the three lowest bright-exciton energies of InAs nanocrystals with radius larger than 20 A. For multiply charged InAs nanocrystals, polarization of the nanocrystal environment is approximated by modeling the environment with a uniform dielectric medium. This polarization model incorporated into the tight-binding model provides a reasonable description of electron and hole addition energies in scanning tunneling spectroscopy experiments. C1 Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Illinois, Natl Ctr Supercomp Applicat, Urbana, IL 61801 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lee, S (reprint author), Ohio State Univ, Dept Phys, 174 W 18th Ave, Columbus, OH 43210 USA. RI Klimeck, Gerhard/A-1414-2012 OI Klimeck, Gerhard/0000-0001-7128-773X NR 39 TC 43 Z9 43 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 2002 VL 66 IS 23 AR 235307 DI 10.1103/PhysRevB.66.235307 PG 12 WC Physics, Condensed Matter SC Physics GA 633JL UT WOS:000180279400074 ER PT J AU Marcinkevicius, S Siegert, J Leon, R Cechavicius, B Magness, B Taylor, W Lobo, C AF Marcinkevicius, S Siegert, J Leon, R Cechavicius, B Magness, B Taylor, W Lobo, C TI Changes in luminescence intensities and carrier dynamics induced by proton irradiation in InxGa1-xAs/GaAs quantum dots SO PHYSICAL REVIEW B LA English DT Article ID ENHANCED RADIATION HARDNESS; ENERGY-RELAXATION; DEEP LEVELS; DAMAGE; LASERS; TEMPERATURE; DEPENDENCE; WELLS; GAAS; DEGRADATION AB The effects of proton irradiation (1.5 MeV) on photoluminescence intensities and carrier dynamics were compared between InGaAs/GaAs quantum dots and similar quantum well structures. A significant enhancement in radiation tolerance is seen with three-dimensional quantum confinement. Measurements were carried out in different quantum dot structures varying in dot surface density (4x10(8)-3x10(10) cm(-2)) and substrate orientation [(100) and (311)B]. Similar trends were observed for all quantum dot samples. A slight increase in photoluminescence emission intensity after low to intermediate proton doses is observed in InGaAs/GaAs (100) quantum dot structures. The latter is explained in terms of more efficient carrier transfer from the wetting layer via radiation-induced defects. C1 Royal Inst Technol, Dept Microelect & Informat Technol, S-16440 Kista, Sweden. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Lithuania Acad Sci, Inst Semicond Phys, LT-2600 Vilnius, Lithuania. Calif State Univ Los Angeles, Dept Phys & Astron, Los Angeles, CA 90032 USA. Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England. RP Marcinkevicius, S (reprint author), Royal Inst Technol, Dept Microelect & Informat Technol, Electrum 229, S-16440 Kista, Sweden. RI Schaff, William/B-5839-2009 NR 31 TC 27 Z9 27 U1 0 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD DEC 15 PY 2002 VL 66 IS 23 AR 235314 DI 10.1103/PhysRevB.66.235314 PG 6 WC Physics, Condensed Matter SC Physics GA 633JL UT WOS:000180279400081 ER PT J AU Prince, TA Tinto, M Larson, SL Armstrong, JW AF Prince, TA Tinto, M Larson, SL Armstrong, JW TI LISA optimal sensitivity SO PHYSICAL REVIEW D LA English DT Article ID GRAVITATIONAL-WAVE DATA AB The multiple Doppler readouts available on the Laser Interferometer Space Antenna (LISA) permit simultaneous formation of several interferometric observables. All these observables are independent of laser frequency fluctuations and have different couplings to gravitational waves and to the various LISA instrumental noises. Within the functional space of interferometric combinations LISA will be able to synthesize, we have identified a triplet of interferometric combinations that show optimally combined sensitivity. As an application of the method, we computed the sensitivity improvement for sinusoidal sources in the nominal, equal-arm LISA configuration. In the part of the Fourier band where the period of the wave is longer than the typical light travel-time across LISA, the sensitivity gain over a single Michelson interferometer is equal to root2. In the mid-band region, where the LISA Michelson combination has its best sensitivity, the improvement over the Michelson sensitivity is slightly better than root2, and the frequency band of best sensitivity is broadened. For frequencies greater than the reciprocal of the light travel-time, the sensitivity improvement is oscillatory and similar toroot3>, but can be greater than root3 near frequencies that are integer multiples of the inverse of the one-way light travel-time in the LISA arm. C1 CALTECH, Space Radiat lab, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Prince, TA (reprint author), CALTECH, Space Radiat lab, Pasadena, CA 91125 USA. RI Larson, Shane/E-8576-2010 NR 11 TC 89 Z9 89 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 15 PY 2002 VL 66 IS 12 AR 122002 DI 10.1103/PhysRevD.66.122002 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 634AL UT WOS:000180317800005 ER PT J AU Hall, TM Haine, TWN Waugh, DW AF Hall, TM Haine, TWN Waugh, DW TI Inferring the concentration of anthropogenic carbon in the ocean from tracers SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article DE carbon cycle; ocean carbon uptake; ocean tracers; ocean transport; transit-time distribution ID NORTHERN INDIAN-OCEAN; ATLANTIC-OCEAN; DISSOCIATION-CONSTANTS; CO2; SEAWATER; WATER; AGE; TETRACHLORIDE; DEEP; SECTION AB [1] We present a technique to infer concentrations of anthropogenic carbon in the ocean from observable tracers and illustrate the technique using synthetic data from a simple model. In contrast to several recent studies, the technique makes no assumptions about transport being dominated by bulk advection and does not require separation of the small anthropogenic signal from the large and variable natural carbon cycle. Mixing is included naturally and implicitly by using observable tracers in combination to estimate the distributions of transit times from the surface to interior points. The time-varying signal of anthropogenic carbon in surface waters is propagated directly into the interior by the transit time distributions (TTDs) without having to consider background natural carbon. The TTD technique provides estimates of anthropogenic carbon, as simulated directly in the model, that are more accurate than techniques relying on single tracer "ages'' (e.g., CFC age) to represent transport. In general, the TTD technique works best when at least two tracers are used in combination, and the tracers have significantly different timescales in either their surface temporal variation or radioactive decay. Possibilities are a CFC or CCl4 in combination with natural Delta(14)C or Ar-39. However, even for a CFC alone the TTD technique results in less bias for anthropogenic carbon estimates than use of a CFC age. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. RP Hall, TM (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. RI Waugh, Darryn/K-3688-2016 OI Waugh, Darryn/0000-0001-7692-2798 NR 48 TC 59 Z9 59 U1 1 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD DEC 14 PY 2002 VL 16 IS 4 AR 1131 DI 10.1029/2001GB001835 PG 15 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 647TJ UT WOS:000181109900002 ER PT J AU Lumpe, JD Fromm, M Hoppel, K Bevilacqua, RM Randall, CE Browell, EV Grant, WB McGee, T Burris, J Twigg, L Richard, EC Toon, GC Margitan, JJ Sen, B Pfeilsticker, K Boesch, H Fitzenberger, R Goutail, F Pommereau, JP AF Lumpe, JD Fromm, M Hoppel, K Bevilacqua, RM Randall, CE Browell, EV Grant, WB McGee, T Burris, J Twigg, L Richard, EC Toon, GC Margitan, JJ Sen, B Pfeilsticker, K Boesch, H Fitzenberger, R Goutail, F Pommereau, JP TI Comparison of POAM III ozone measurements with correlative aircraft and balloon data during SOLVE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOLAR OCCULTATION; POLAR OZONE; SAGE-II; LIDAR; VALIDATION; AEROSOL; STRATOSPHERE; INSTRUMENT; NITROGEN; HALOE AB [1] The Polar Ozone and Aerosol Measurement (POAM) III instrument operated continuously during the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) mission, making approximately 1400 ozone profile measurements at high latitudes both inside and outside the Arctic polar vortex. The wealth of ozone measurements obtained from a variety of instruments and platforms during SOLVE provided a unique opportunity to compare correlative measurements with the POAM III data set. In this paper, we validate the POAM III version 3.0 ozone against measurements from seven different instruments that operated as part of the combined SOLVE/THESEO 2000 campaign. These include the airborne UV Differential Absorption Lidar (UV DIAL) and the Airborne Raman Ozone and Temperature Lidar (AROTEL) instruments on the DC-8, the dual-beam UV-Absorption Ozone Photometer on the ER-2, the MkIV Interferometer balloon instrument, the Laboratoire de Physique Moleculaire et Applications and Differential Optical Absorption Spectroscopy (LPMA/DOAS) balloon gondola, the JPL in situ ozone instrument on the Observations of the Middle Stratosphere (OMS) balloon platform, and the Systeme D'Analyze par Observations Zenithales (SAOZ) balloon sonde. The resulting comparisons show a remarkable degree of consistency despite the very different measurement techniques inherent in the data sets and thus provide a strong validation of the POAM III version 3.0 ozone. This is particularly true in the primary 14-30 km region, where there are significant overlaps with all seven instruments. At these altitudes, POAM III agrees with all the data sets to within 7-10% with no detectable bias. The observed differences are within the combined errors of POAM III and the correlative measurements. Above 30 km, only a handful of SOLVE correlative measurements exist and the comparisons are highly variable. Therefore, the results are inconclusive. Below 14 km, the SOLVE comparisons also show a large amount of scatter and it is difficult to evaluate their consistency, although the number of correlative measurements is large. The UV DIAL, DOAS, and JPL/OMS comparisons show differences of up to 15% but no consistent bias. The ER-2, MkIV, and SAOZ comparisons, on the other hand, indicate a high POAM bias of 10-20% at the lower altitudes. In general, the SOLVE validation results presented here are consistent with the validation of the POAM III version 3.0 ozone using SAGE II and Halogen Occultation Experiment (HALOE) satellite data and in situ electrochemical cell (ECC) ozonesonde data. C1 Computat Phys Inc, Springfield, VA 22151 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Heidelberg Univ, Inst Umweltphys, D-6900 Heidelberg, Germany. CNRS, Serv Aeron, F-91371 Verrieres Le Buisson, France. RP Computat Phys Inc, 8001 Braddock Rd, Springfield, VA 22151 USA. EM lumpe@cpi.com RI Fromm, Michael/F-4639-2010; Grant, William/B-8311-2009; McGee, Thomas/G-4951-2013; Boesch, Hartmut/G-6021-2012; Randall, Cora/L-8760-2014 OI Grant, William/0000-0002-1439-3285; Randall, Cora/0000-0002-4313-4397 NR 24 TC 1 Z9 1 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 14 PY 2002 VL 108 IS D5 AR 8316 DI 10.1029/2001JD000472 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 648VR UT WOS:000181172000001 ER PT J AU Bowman, KW Worden, J Steck, T Worden, HM Clough, S Rodgers, C AF Bowman, KW Worden, J Steck, T Worden, HM Clough, S Rodgers, C TI Capturing time and vertical variability of tropospheric ozone: A study using TES nadir retrievals SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHEMISTRY; CLIMATOLOGY; SATELLITE; FUTURE; PAST AB [1] In this paper, the vertical resolution for Tropospheric Emission Spectrometer (TES) nadir ozone retrievals is established and is used to assess the ability of TES to capture time variations of ozone in the troposphere. This characterization is based on retrievals of ozone using simulated radiances generated from ozonesonde profiles taken over Bermuda from 14 April to 25 May 1993. To that end, a two-step retrieval strategy that includes an initial estimate of the "shape'' of the ozone followed by a finer-resolution estimate was developed to provide rapid and robust convergence against large deviations of ozone profiles in the troposphere and lower stratosphere relative to a climatology. An error analysis is derived that accurately accounts for representation errors of the profile, choices of regularization, and the dependence of the retrieval error on both the statistics of the profile and spectral measurement noise, as well as the sensitivity of these retrievals to errors in temperature. This analysis shows that TES should be able to retrieve ozone in the nadir with an approximately 6 km resolution in the troposphere. The root-mean square errors in estimates of the upper and lower tropospheric columns are about 1.35 Dobson units (DU) each. With this vertical resolution, TES would have the sensitivity to detect both the enhanced and reduced tropospheric ozone present in the Bermuda data set. Coupled with a 2-day near-repeat orbit and global coverage, TES retrievals of ozone could provide invaluable information to distinguish between anthropogenic and meteorological sources for the time variability of ozone in the troposphere. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91106 USA. Atmospher & Environm Res Inc, Cambridge, MA 02139 USA. Univ Oxford, Oxford, England. RP Bowman, KW (reprint author), CALTECH, Jet Prop Lab, MS 183-301,4800 Oak Grove Dr, Pasadena, CA 91106 USA. EM kevin.bowman@jpl.nasa.gov NR 30 TC 53 Z9 53 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 14 PY 2002 VL 107 IS D23 AR 4723 DI 10.1029/2002JD002150 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 648UN UT WOS:000181169100007 ER PT J AU Chepfer, H Minnis, P Young, D Nguyen, L Arduini, RF AF Chepfer, H Minnis, P Young, D Nguyen, L Arduini, RF TI Estimation of cirrus cloud effective ice crystal shapes using visible reflectances from dual-satellite measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ice clouds; crystal shape; geostationary satellites ID LIGHT-SCATTERING; RADIATIVE PROPERTIES; SINGLE-SCATTERING; TEMPERATURE; PARAMETERIZATION; AIRCRAFT; ISCCP AB [1] This study develops and examines a multiangle, multisatellite method for determining effective cloud particle shapes from reflectances observed at visible wavelengths. The technique exploits the significant differences in the various cloud particle shape phase functions near the backscatter direction to infer particle shape from a combination of views from a near-backscatter angle and a side scattering angle. Adding-doubling calculations confirm that the optimal viewing combinations include one near-backscatter angle and another between 60degrees and 150degrees. Sensitivity to shape increases with solar zenith angle. A total of 28 collocated, visible images from pairs of currently operating meteorological satellites with the desired viewing combinations were analyzed for particle shape. Matching reflectances from images with optimal viewing angles clearly separates water droplet from ice crystal clouds. Reflectance pairs from matched pixels containing ice crystals can be explained by the range of selected microphysical models. The most common retrieved shapes correspond to combinations of hexagonal compacts (aspect ratio of unity), hexagonal columns, and bullet rosettes. Although no single microphysical model can account for the observed variability, taken together, the models used for retrieving cloud particle size by the Clouds and the Earth's Radiant Energy System and the Moderate Resolution Imaging Spectroradiometer Projects can account for most of the reflectance variability observed in this limited data set. Additional studies are needed to assess the uncertainties in retrieved shapes due to temporal and spatial mismatches, anisotropic and bright background reflectances, and calibration errors and to validate the retrieved shapes. While applicable to a limited number of dual-satellite viewing combinations for current research and operational meteorological satellites, this approach could be used most extensively to derive effective particle size, shape, and optical depth from a combination of an imaging satellite in an L1 orbit, like Triana, and any other lower Earth orbiting satellites. C1 Ecole Polytech, Meteorol Dynam Lab, F-91128 Palaiseau, France. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Sci Applicat Int Corp, Hampton, VA USA. RP Chepfer, H (reprint author), Ecole Polytech, Meteorol Dynam Lab, F-91128 Palaiseau, France. EM chepfer@lmd.polytechnique.fr; p.minis@larc.nasa.gov; d.young@larc.nasa.gov; l.nguyen@larc.nasa.gov; r.f.arduini@larc.nasa.gov RI Minnis, Patrick/G-1902-2010 OI Minnis, Patrick/0000-0002-4733-6148 NR 36 TC 22 Z9 22 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 14 PY 2002 VL 107 IS D23 AR 4730 DI 10.1029/2000JD000240 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 648UN UT WOS:000181169100001 ER PT J AU Satheesh, SK Ramanathan, V Holben, BN Moorthy, KK Loeb, NG Maring, H Prospero, JM Savoie, D AF Satheesh, SK Ramanathan, V Holben, BN Moorthy, KK Loeb, NG Maring, H Prospero, JM Savoie, D TI Chemical, microphysical, and radiative effects of Indian Ocean aerosols SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosols; radiative forcing; climate; chemical composition ID PRE-INDOEX CRUISE; ARABIAN SEA; OPTICAL-PROPERTIES; ANTHROPOGENIC AEROSOLS; CARBONACEOUS AEROSOLS; ATMOSPHERIC AEROSOLS; SOLAR ABSORPTION; UNITED-STATES; EAST-COAST; CLIMATE AB [1] Extensive and long-term multistation measurements of aerosol properties and radiative fluxes were carried out in the haze plume off the South Asian continent. These experiments are carried out at Kaashidhoo Climate Observatory (KCO) (4.95 degreesN, 73.5 degreesE), Minicoy (8.5 degreesN, 73.0 degreesE), and Trivandrum (8.5 degreesN, 77.0 degreesE). In addition, the top of the atmosphere fluxes were measured simultaneously by the CERES radiation budget instrument. Long-term observations (more than 15 years) over Trivandrum show that there is a gradual increase in aerosol visible optical depth from similar to0.2 in 1986 to similar to0.4 in 1999. Pre- and post-monsoon aerosol characteristics are examined to study the seasonal variations. The impact of aerosols on short-wave radiation budget is estimated using direct observations of solar radiation using several independent ground-based radiometers and satellite data as well as from modeled aerosol properties. It was observed that "excess absorption'' is not needed to model diffuse fluxes. The lower atmospheric heating due to absorbing aerosols was as high as similar to20 W m(-2) which translates to a heating rate perturbation of similar to0.5degreesK/day. The effect of aerosol mixing state (internally and externally) on aerosol forcing appears to be negligible. A sensitivity study of the effect of aerosols over land in contrast to that over the ocean shows an enhancement in lower atmosphere heating by about 40% simultaneous with a reduction of similar to33% in surface cooling. Increasing sea-surface winds increase aerosol cooling due to increased sea salt aerosol concentrations, which can partly offset the heating effect due to absorbing aerosols. C1 Indian Inst Sci, Ctr Atmospher & Ocean Sci, Bangalore 560012, Karnataka, India. Univ Calif San Diego, Scripps Inst Oceanog, Ctr Clouds Chem & Climate, La Jolla, CA 92093 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Vikram Sarabhai Space Ctr, Space Phys Lab, Trivandrum 695022, Kerala, India. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RP Satheesh, SK (reprint author), Indian Inst Sci, Ctr Atmospher & Ocean Sci, Bangalore 560012, Karnataka, India. EM satheesh@caos.lisc.ernet.in; vram@fiji.ucsd.edu; brent@aeronet.gsfc.nasa.gov; k-k-moorthy@eth.net; n.g.loeb@larc.nasa.gov; hmaring@rsmas.miami.edu; jprospero@ramas.miami.edu; dsavoie@rsmas.miami.edu OI Prospero, Joseph/0000-0003-3608-6160; Moorthy, K. Krishna/0000-0002-7234-3868 NR 59 TC 71 Z9 72 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 14 PY 2002 VL 107 IS D23 AR 4725 DI 10.1029/2002JD002463 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 648UN UT WOS:000181169100012 ER PT J AU Wei, CF Kotamarthi, VR Ogunsola, OJ Horowitz, LW Walters, S Wuebbles, DJ Avery, MA Blake, DR Browell, EV Sachse, GW AF Wei, CF Kotamarthi, VR Ogunsola, OJ Horowitz, LW Walters, S Wuebbles, DJ Avery, MA Blake, DR Browell, EV Sachse, GW TI Seasonal variability of ozone mixing ratios and budgets in the tropical southern Pacific: A GCTM perspective SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHEMICAL-TRANSPORT MODEL; PEM-WEST-A; NONMETHANE HYDROCARBONS; EXPLORATORY MISSION; NORTH PACIFIC; CLIMATE-MODEL; PARAMETERIZATION; DISTRIBUTIONS; MOZART AB Significant seasonal variations in the concentrations of several trace gases were observed in the southern tropical Pacific during the Pacific Exploratory Mission (PEM) TROPICS-A (PT-A, September/October 1996) and PEM TROPICS-B (PT-B, March/April 1999) campaigns. The objective of this study is to evaluate the relationship between the measured and modeled seasonal variabilities through comparisons of these observations with model calculations. A three-dimensional (3-D) global-scale chemical transport model was employed to (1) evaluate the seasonal variations in ozone and CO mixing ratios; (2) calculate an ozone budget and identify its controlling factors; (3) evaluate the effectiveness of atmospheric transport barriers in the model, such as the Intertropical Convergence Zone (ITCZ); and (4) test the sensitivity of ozone over the tropical south Pacific to biomass-burning emissions. The model reproduces the main features of the observed seasonal variation in ozone and CO. According to the model calculation, the ozone burden during the PT-A was larger due to the transport of ozone into the central pacific middle troposphere from the west, whereas a net outflow of ozone from this region to the east resulted in a reduction of ozone burden during the PT-B period. Transport of ozone from the Northern Hemisphere into this region was found to be much larger during the PT-B period compared with the PT-A period. The in situ production and loss of ozone calculated in the model agreed with that derived from measurements. The gradients in the model for selected trace gases across the ITCZ were shown to be qualitatively similar to measurements. C1 Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. Argonne Natl Lab, Argonne, IL 60439 USA. GFDL, Princeton, NJ USA. NCAR, Boulder, CO USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Univ Calif Irvine, Irvine, CA USA. RP Wei, CF (reprint author), Univ Illinois, Dept Atmospher Sci, 105 S Gregory Ave, Urbana, IL 61801 USA. EM vrkotamarthi@anl.gov RI Horowitz, Larry/D-8048-2014 OI Horowitz, Larry/0000-0002-5886-3314 NR 40 TC 1 Z9 1 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 13 PY 2002 VL 108 IS D2 AR 8235 DI 10.1029/2001JD00772 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 648VG UT WOS:000181171000001 ER PT J AU Stothers, RB AF Stothers, RB TI Cloudy and clear stratospheres before AD 1000 inferred from written sources SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosol; historical sources; ice cores; lunar eclipses; solar observations; stratosphere ID GREENLAND ICE CORE; VOLCANIC DRY FOGS; TREE-RING RECORD; PLAGUE PANDEMICS; ELDGJA ERUPTION; MIDDLE-EAST; ICELAND; BC; PRECIPITATION; TEMPERATURES AB [1] How can observational information about stratospheric transparency in the preinstrumental era be acquired today? It may be reasonably assumed that a high turbidity in the stratosphere is almost always caused by light-scattering sulfate aerosols derived from large volcanic eruptions. Historical reports of a dimming of the Sun, red twilight glows, reddish solar haloes, and dark total eclipses of the Moon indicate a high turbidity; contrariwise, a ruddy disk shown by the eclipsed Moon betrays a clear stratosphere. On the basis of an extensive search of primary European and Middle Eastern written sources pertaining to the ancient and early medieval periods, seven stratospheric dry fogs, in addition to the four major ones already known, have been identified by using solar observations, and five smaller ones have been detected from dark total lunar eclipses. Seven of the eight most important dry fogs between 300 B.C. and A. D. 1000 can be either definitely or plausibly correlated with high levels of sulfate acidity observed in Greenland ice cores. An important conclusion is that this sample is probably very nearly complete for major dry fogs during this period. A second conclusion is that the ratio of dark to normal total lunar eclipses during early medieval times (A. D. 400-1000) appears to be equal, approximately, to the ratio that has prevailed for the past 40 years. These conclusions suggest that the frequency of volcanic eruptions, both large and moderate, throughout the world may have remained statistically constant (on a long timescale) since at least 300 B.C. C1 NASA, Goddard Space Flight Ctr, Inst Space Studies, New York, NY 10025 USA. RP Stothers, RB (reprint author), NASA, Goddard Space Flight Ctr, Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM rstothers@giss.nasa.gov NR 89 TC 9 Z9 9 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 13 PY 2002 VL 107 IS D23 AR 4718 DI 10.1029/2002JD002105 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 648UF UT WOS:000181168400005 ER PT J AU Patz, JA Hulme, M Rosenzweig, C Mitchell, TD Goldberg, RA Githeko, AK Lele, S McMichael, AJ Le Sueur, D AF Patz, JA Hulme, M Rosenzweig, C Mitchell, TD Goldberg, RA Githeko, AK Lele, S McMichael, AJ Le Sueur, D TI Climate change - Regional warming and malaria resurgence SO NATURE LA English DT Article ID VARIABILITY C1 Johns Hopkins Univ, Bloomberg Sch Publ Hlth, Dept Environm Hlth Sci, Baltimore, MD 21205 USA. Univ E Anglia, Sch Environm Sci, Tyndall Ctr Climate Change Res, Norwich NR4 7TJ, Norfolk, England. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, New York, NY 10025 USA. Kenya Govt Med Res Ctr, Ctr Vector Biol & Control Res, Climate & Human Hlth Res Unit, Kisumu, Kenya. Univ Alberta, Dept Math & Stat Sci, Edmonton, AB T6G 2G1, Canada. Australian Natl Univ, Natl Ctr Epidemiol & Populat Hlth, Canberra, ACT 0200, Australia. S Africa MRC, ZA-4013 Congella, Durban, South Africa. RP Patz, JA (reprint author), Johns Hopkins Univ, Bloomberg Sch Publ Hlth, Dept Environm Hlth Sci, Baltimore, MD 21205 USA. RI Hulme, Mike/F-9012-2010 OI Hulme, Mike/0000-0002-1273-7662 NR 9 TC 99 Z9 101 U1 1 U2 22 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD DEC 12 PY 2002 VL 420 IS 6916 BP 627 EP 628 DI 10.1038/420627a PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 624GK UT WOS:000179751800034 PM 12478282 ER PT J AU Kaufman, YJ Gobron, N Pinty, B Widlowski, JL Verstraete, MM AF Kaufman, YJ Gobron, N Pinty, B Widlowski, JL Verstraete, MM TI Relationship between surface reflectance in the visible and mid-IR used in MODIS aerosol algorithm - theory SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID NEAR-INFRARED REFLECTANCE; IMAGING SPECTRORADIOMETER; LAND; MODEL; VEGETATION; SPECTRA; MISR; EOS AB [1] Data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument that flies in polar orbit on the Terra and Aqua satellites, are used to derive the aerosol optical thickness and properties over land and ocean. The relationships between visible reflectance (at blue, rho(blue), and red, rho(red)), and mid-infrared (at 2.1 mum, rho(2.1)) are used in the MODIS aerosol retrieval algorithm to derive global distribution of aerosols over land. These relations have been established from a series of measurements indicating that rho(blue) similar to 0.5 rho(red) similar to 0.25 rho(2.1). Here we use a model to describe the transfer of radiation through a vegetation canopy composed of randomly oriented leaves to assess the theoretical foundations for these relationships. Calculations for a wide range of leaf area indices and vegetation fractions show that rho(blue) is consistently about 1/4 of rho(2.1) as used by MODIS for the whole range of analyzed cases, except for very dark soils, such as those found in burn scars. For its part, the ratio rho(red)/rho(2.1) varies from less than the empirically derived value of 1/2 for dense and dark vegetation, to more than 1/2 for bright mixture of soil and vegetation. This is in agreement with measurements over uniform dense vegetation, but not with measurements over mixed dark scenes. In the later case, the discrepancy could be probably mitigated by shadows due to uneven canopy and terrain on a large scale. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Joint Res Ctr, Inst Environm & Sustainabil, I-21020 Ispra, VA, Italy. RP Kaufman, YJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. OI Verstraete, Michel/0000-0003-0968-8721 NR 15 TC 43 Z9 45 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 11 PY 2002 VL 29 IS 23 AR 2116 DI 10.1029/2001GL014492 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 647MH UT WOS:000181096200001 ER PT J AU Danilin, MY Ko, MKW Bevilacqua, RM Lyjak, LV Froidevaux, L Santee, ML Zawodny, JM Hoppel, KW Richard, EC Spackman, JR Weinstock, EM Herman, RL McKinney, KA Wennberg, PO Eisele, FL Stimpfle, RM Scott, CJ Elkins, JW Bui, TV AF Danilin, MY Ko, MKW Bevilacqua, RM Lyjak, LV Froidevaux, L Santee, ML Zawodny, JM Hoppel, KW Richard, EC Spackman, JR Weinstock, EM Herman, RL McKinney, KA Wennberg, PO Eisele, FL Stimpfle, RM Scott, CJ Elkins, JW Bui, TV TI Comparison of ER-2 aircraft and POAM III, MLS, and SAGE II satellite measurements during SOLVE using traditional correlative analysis and trajectory hunting technique SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE measurement comparison; trajectory hunting; correactive analysis; SOLVE ID SOUNDER HNO3 OBSERVATIONS; ANTARCTIC OZONE HOLE; IN-SITU MEASUREMENTS; GAS EXPERIMENT II; LOWER STRATOSPHERE; POLAR OZONE; CHLORINE ACTIVATION; MIDDLE ATMOSPHERE; UPPER TROPOSPHERE; CLO MEASUREMENTS AB [1] We compared the version 5 Microwave Limb Sounder (MLS), version 3 Polar Ozone and Aerosol Measurement III (POAM III), version 6.0 Stratospheric Aerosol and Gas Experiment II (SAGE II), and NASA ER-2 aircraft measurements made in the Northern Hemisphere in January-February 2000 during the SAGE III Ozone Loss and Validation Experiment (SOLVE). This study addresses one of the key scientific objectives of the SOLVE campaign, namely, to validate multiplatform satellite measurements made in the polar stratosphere during winter. This intercomparison was performed by using a traditional correlative analysis (TCA) and a trajectory hunting technique (THT). TCA compares profiles colocated within a chosen spatial-temporal vicinity. Launching backward and forward trajectories from the points of measurement, the THT identifies air parcels sampled at least twice within a prescribed match criterion during the course of 5 days. We found that the ozone measurements made by these four instruments agree most of the time within +/-10% in the stratosphere up to 1400 K (similar to35 km). The water vapor measurements from POAM III and the ER-2 Harvard Lyman alpha hygrometer and Jet Propulsion Laboratory laser hygrometer agree to within +/-0.5 ppmv (or about +/-10%) in the lower stratosphere above 380 K. The MLS and ER-2 ClO measurements agree within their error bars for the TCA. The MLS and ER-2 nitric acid measurements near 17- to 20-km altitude agree within their uncertainties most of the time with a hint of a positive offset by MLS according to the TCA. We also applied the Atmospheric and Environmental Research, Inc. box model constrained by the ER-2 measurements for analysis of the ClO and HNO3 measurements using the THT. We found that: (1) the model values of ClO are smaller by about 0.3-0.4 (0.2) ppbv below (above) 400 K than those by MLS and (2) the HNO3 comparison shows a positive offset of MLS values by similar to1 and 1-2 ppbv below 400 K and near 450 K, respectively. Our study shows that, with some limitations (like HNO3 comparison under polar stratospheric cloud conditions), the THT is a more powerful tool for validation studies than the TCA, making conclusions of the comparison statistically more robust. C1 Atmospher & Environm Res Inc, Lexington, MA 02421 USA. USN, Res Lab, Washington, DC 20375 USA. Natl Ctr Atmospher Res, ACD, Boulder, CO 80303 USA. NASA, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02138 USA. RP Boeing Co, MS 0R-RC,POB 3707, Seattle, WA 98124 USA. EM danilin@h2o.ca.boeing.com RI Wennberg, Paul/A-5460-2012; Ko, Malcolm/D-5898-2015; Herman, Robert/H-9389-2012 OI Herman, Robert/0000-0001-7063-6424 NR 64 TC 10 Z9 10 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 11 PY 2002 VL 108 IS D5 AR 8315 DI 10.1029/2001JD000781 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 648VP UT WOS:000181171700001 ER PT J AU Koike, M Kondo, Y Kita, K Nishi, N Liu, SC Blake, D Ko, M Akutagawa, D Kawakami, S Takegawa, N Zhao, Y Ogawa, T AF Koike, M Kondo, Y Kita, K Nishi, N Liu, SC Blake, D Ko, M Akutagawa, D Kawakami, S Takegawa, N Zhao, Y Ogawa, T TI Reactive nitrogen over the tropical western Pacific: Influence from lightning and biomass burning during BIBLE A SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE reactive nitrogen; ozone; biomass burning; lightning; western Pacific ID ATLANTIC FLIGHT CORRIDOR; SOUTH ATLANTIC; TROPOSPHERIC OZONE; EMISSIONS; REGION; PHOTOCHEMISTRY; AUSTRALIA; INDONESIA; OCTOBER; ORIGIN AB The Biomass Burning and Lightning Experiment phase A (BIBLE A) aircraft campaign was carried out over the tropical western Pacific in September and October 1998. During this period, biomass burning activity in Indonesia was quite weak. Mixing ratios of NOx and NOy in air masses that had crossed over the Indonesian islands within 3 days prior to the measurement (Indonesian air masses) were systematically higher than those in air masses originating from the central Pacific (tropical air masses). Sixty percent of the Indonesian air masses at 9-13 km (upper troposphere, UT) originated from the central Pacific. The differences in NOy mixing ratio between these two types of air masses were likely due to processes that occurred while air masses were over the Islands. Evidence presented in this paper suggests convection carries material from the surface, and NO is produced from lightning. At altitudes below 3 km (lower troposphere, LT), typical gradient of NOx and NOy to CO (dNO(y)/dCO and dNO(x)/dCO) was smaller than that in the biomass burning plumes and in urban areas, suggesting that neither source has a dominant influence. When the CO-NOx and CO-NOy relationships in the UT are compared to the reference relationships chosen for the LT, the NOx and NOy values are higher by 40-60 pptv (80% of NOx) and 70-100 pptv (50% of NOy). This difference is attributed to in situ production of NO by lightning. Analyses using air mass trajectories and geostationary meteorological satellite (GMS) derived cloud height data show that convection over land, which could be accompanied by lightning activity, increases the NOx values, while convection over the ocean generally lowers the NOx level. These processes are found to have a significant impact on the O-3 production rate over the tropical western Pacific. C1 Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan. Ibaraki Univ, Fac Sci, Dept Environm Sci, Bunkyo Ku, Ibaraki 3108512, Japan. Kyoto Univ, Grad Sch Sci, Dept Earth & Planetary Sci, Sakyo Ku, Kyoto, Japan. Acad Sinica, Inst Earth Sci, Taipei 11529, Taiwan. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Nagoya Univ, Solar Terr Environm Lab, Aichi 4428507, Japan. NASDA, Earth Observ Res Ctr, Tokyo 1046023, Japan. Univ Calif Davis, Davis, CA 95616 USA. RP Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Bunkyo Ku, Hongo 7-3-1, Tokyo 1130033, Japan. EM koike@eps.s.u-tokyo.ac.jp; kondo@atmos.rcast.u-tokyo.ac.jp; kita@enu.sci.ibaraki.ac.jp; nishi@kugi.kyoto-u.ac.jp; shawliu@earth.sinica.edu.tw; dblake@orion.oac.uci.edu; m.k.ko@larc.nasa.gov; daisuke@stelab.nagoya-u.ac.jp; kawakami@eorc.nasda.go.jp; takegawa@atmos.rcast.u-tokyo.ac.jp; yzhao@mae.ucdavis.edu; t_ogawa@eorc.nasda.go.jp RI Ko, Malcolm/D-5898-2015; Kondo, Yutaka/D-1459-2012; Koike, Makoto/F-4366-2011 NR 30 TC 7 Z9 9 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 11 PY 2002 VL 108 IS D3 AR 8403 DI 10.1029/2001JD000823 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 648VK UT WOS:000181171300002 ER PT J AU Lane, MD Morris, RV Mertzman, SA Christensen, PR AF Lane, MD Morris, RV Mertzman, SA Christensen, PR TI Evidence for platy hematite grains in Sinus Meridiani, Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Mars; hematite; infrared; platy hematite; Sinus Meridiani; spectroscopy ID BANDED IRON-FORMATION; GOETHITE ALPHA-FEOOH; EMISSION-SPECTROSCOPY; WESTERN-AUSTRALIA; HYDROTHERMAL ORIGIN; SEDIMENTARY BASINS; PRESSURE SOLUTION; MARTIAN SURFACE; MINERALS; DEPOSITS AB Midinfrared (similar to1600-200 cm(-1)) spectral data received from the Mars Global Surveyor Thermal Emission Spectrometer (MGS TES) have provided evidence for a large hematite-bearing (alpha-Fe2O3) deposit in Sinus Meridiani, Mars. We report here the results of a laboratory spectroscopic investigation of 24 hematite samples, including polycrystalline hand samples (massive and schistose textures), single-crystal hand samples, and particle-size fractions (single-crystal and polycrystalline discrete particles). Laboratory midinfrared analyses of crystallographically oriented hematite samples suggest that the hematite emission in Sinus Meridiani (SM) is predominantly from the crystallographic c-face of hematite. This observation implies the presence of platy hematite particles, with the plate face being the crystallographic c-face. The observations are consistent with a formational model where the platy, gray hematite originated as an iron-oxide, chemically precipitated from Fe-rich aqueous and/or hydrothermal solutions on early Mars, that was buried, recrystallized to platy hematite, and subsequently reexposed as lenses of schistose hematite in a friable, consolidated stratigraphic unit. Unconsolidated platy hematite particles are also likely to be present as a physical-weathering product of the schistose hematite lenses. C1 Planetary Sci Inst, Tucson, AZ 85705 USA. Franklin & Marshall Coll, Dept Geosci, Lancaster, PA 17604 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. RP Lane, MD (reprint author), Planetary Sci Inst, 620 N 6th Ave, Tucson, AZ 85705 USA. NR 69 TC 45 Z9 45 U1 2 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD DEC 11 PY 2002 VL 107 IS E12 AR 5126 DI 10.1029/2001JE001832 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 648WJ UT WOS:000181173700002 ER PT J AU Wardzinski, G Zdziarski, AA Gierlinski, M Grove, JE Jahoda, K Johnson, WN AF Wardzinski, G Zdziarski, AA Gierlinski, M Grove, JE Jahoda, K Johnson, WN TI X-ray and gamma-ray spectra and variability of the black hole candidate GX 339-4 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; binaries : general; stars : individual : GX 339-4 gamma-rays : observations; gamma-rays : theory; X-rays : stars ID ADVECTION-DOMINATED ACCRETION; ACTIVE GALACTIC NUCLEI; LOW-HARD STATES; K-ALPHA LINE; CYGNUS X-1; MULTIWAVELENGTH OBSERVATIONS; OPTICAL SPECTROSCOPY; ASCA OBSERVATIONS; SOFT STATE; GX-339-4 AB We analyse five observations of the X-ray binary GX 339-4 by the soft gamma-ray OSSE detector on board CGRO simultaneous with either Ginga or RXTE observations. The source was bright during four of them, with the luminosity of L similar to 10(37) erg s(-1) and the spectrum typical for hard states of accreting black holes, and it was in an off state during the fifth one, with L 10(35) erg s(-1). Our broad-band spectral fits show the mean electron energy of electrons in the Comptonizing plasma decreasing with increasing luminosity within the hard (bright) state. For the observation with the best statistics at soft gamma-rays, similar to1/4 of energy in the Comptonizing plasma is probably carried by non-thermal electrons. Then, considering the efficiency of Comptonized hybrid synchrotron emission allows us to obtain an upper limit on the strength of the magnetic field in the X-ray source. Furthermore, this synchrotron emission is capable of producing the optical spectrum observed in an optically-high state of GX 339-4. In the off state, the hard X-ray spectrum is consistent with being dominated by bremsstrahlung. The unusually strong Fe Kalpha line observed by the RXTE/PCA during that state is found not to be intrinsic to the source but to originate mostly in the Galactic diffuse emission. C1 Nicholas Copernicus Astron Ctr, PL-00716 Warsaw, Poland. Univ Durham, Dept Phys, Durham DH1 3LE, England. Jagiellonian Univ, Astron Observ, PL-30244 Krakow, Poland. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Wardzinski, G (reprint author), Nicholas Copernicus Astron Ctr, Bartycka 18, PL-00716 Warsaw, Poland. RI Jahoda, Keith/D-5616-2012; Johnson, Neil/G-3309-2014; OI Gierlinski, Marek/0000-0001-9149-3514 NR 75 TC 47 Z9 47 U1 0 U2 0 PU BLACKWELL PUBLISHING LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD DEC 11 PY 2002 VL 337 IS 3 BP 829 EP 839 DI 10.1046/j.1365-8711.2002.05914.x PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 622LG UT WOS:000179648100011 ER PT J AU Su, WY Charlock, TP Rutledge, K AF Su, WY Charlock, TP Rutledge, K TI Observations of reflectance distribution around sunglint from a coastal ocean platform SO APPLIED OPTICS LA English DT Article ID SEA-SURFACE SLOPE; MEAN-SQUARE SLOPE; AEROSOL PROPERTIES; RADAR BACKSCATTER; SPECTRUM; WAVES; RETRIEVALS; MULTIANGLE; GLINT AB A scanning spectral photometer is deployed on a rigid coastal ocean platform to measure upwelling solar radiances from the sea surface at nine elevation angles spanning 150degrees of azimuth. Measured radiance distributions at 500 nm wavelength have been compared with traditional model simulations employing the Cox and Munk distribution of wave slopes. The model captures the general features of the observed angular reflectance distributions, but: (a) the observed peak value of sunglint near the specular direction is larger than simulated, except for a very calm sea; the model-measurement differences increase with wind speed and are largest for low solar elevation; (b) the observed sunglint is wider than simulated. In contrast to some previous studies, our results do not show a clear dependence of the mean square sea-surface slope on stability (air-sea temperature difference). (C) 2002 Optical Society of America. C1 Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Analyt Serv & Mat Inc, Hampton, VA 23666 USA. RP Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. NR 30 TC 25 Z9 27 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD DEC 10 PY 2002 VL 41 IS 35 BP 7369 EP 7383 DI 10.1364/AO.41.007369 PG 15 WC Optics SC Optics GA 625FC UT WOS:000179805400001 PM 12502292 ER PT J AU Dawson, KS Holzapfel, WL Carlstrom, JE Joy, M LaRoque, SJ Miller, AD Nagai, D AF Dawson, KS Holzapfel, WL Carlstrom, JE Joy, M LaRoque, SJ Miller, AD Nagai, D TI Measurement of arcminute-scale cosmic microwave background anisotropy with the Berkeley-Illinois-Maryland Association array SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations ID POWER SPECTRUM; FLUCTUATIONS; GALAXIES; REIONIZATION; SIMULATIONS; CLUSTERS; EMISSION AB We report the results of our continued study of arcminute-scale anisotropy in the cosmic microwave background (CMB) with the Berkeley-Illinois-Maryland Association array. The survey consists of 10 independent fields selected for low infrared dust emission and lack of bright radio point sources. With observations from the Very Large Array at 4.8 GHz, we have identified point sources that could act as contaminants in estimates of the CMB power spectrum and have removed them in the analysis. Modeling the observed power spectrum with a single at band power with an average multipole of l(eff)=6864, we find DeltaT=14.2(-6.0)(+4.8) muK at 68% confidence. The signal in the visibility data exceeds the expected contribution from instrumental noise with 96.5% confidence. We have also divided the data into two bins corresponding to different spatial resolutions in the power spectrum. We find DeltaT(1)=16.6(-5.9)(+5.3) muK at 68% confidence for CMB at band power described by an average multipole of l(eff)=5237 and DeltaT(2)<26.5 μK at 95% confidence for l(eff)=8748. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Dept Phys, Ctr Cosmol Phys, Chicago, IL 60637 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. RP Dawson, KS (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Holzapfel, William/I-4836-2015 NR 29 TC 51 Z9 51 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 86 EP 95 DI 10.1086/344226 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500005 ER PT J AU Bottcher, M Chiang, J AF Bottcher, M Chiang, J TI X-ray spectral variability signatures of flares in BL Lacertae objects SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : general; galaxies : active; galaxies : jets; radiation mechanisms : nonthermal ID HIGH-ENERGY EMISSION; EGRET OBSERVATIONS; BLAZAR 3C-279; GAMMA-RAYS; MODELS; JETS; MARKARIAN-421; EVOLUTION; DISTRIBUTIONS; PKS-2155-304 AB We present a detailed parameter study of the time-dependent electron injection and kinematics and the self-consistent radiation transport in jets of intermediate- and low-frequency peaked BL Lac objects. Using a time-dependent, combined synchrotron self-Compton (SSC) and external Compton jet model, we study the influence of variations of several essential model parameters, such as the electron injection compactness, the relative contribution of synchrotron to external soft photons to the soft photon compactness, the electron injection spectral index, and the details of the time profiles of the electron injection episodes giving rise to flaring activity. In the analysis of our results, we focus on the expected X-ray spectral variability signatures in a region of parameter space particularly well suited to reproduce the broadband spectral energy distributions of intermediate- and low-frequency peaked BL Lac objects. We demonstrate that SSC- and external Compton dominated models for the gamma-ray emission from blazars are producing significantly different signatures in the X-ray variability, in particular in the soft X-ray light curves and the spectral hysteresis at soft X-ray energies, which can be used as a powerful diagnostic to unveil the nature of the high-energy emission from BL Lac objects. C1 Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Joint Ctr Astrophys, Baltimore, MD 21250 USA. Univ Maryland, Dept Phys, Baltimore, MD 21250 USA. RP Bottcher, M (reprint author), Ohio Univ, Dept Phys & Astron, Athens, OH 45701 USA. NR 61 TC 111 Z9 111 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 127 EP 142 DI 10.1086/344155 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500008 ER PT J AU Chatzichristou, ET AF Chatzichristou, ET TI Multicolor optical imaging of infrared-warm Seyfert galaxies. V. Morphologies and interactions: Challenging the orientation model SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxies : active; galaxies : interactions; galaxies : photometry; galaxies : Seyfert ID ACTIVE GALACTIC NUCLEI; BROAD-LINE REGIONS; CIRCUMNUCLEAR STELLAR POPULATION; RESOLUTION RADIO OBSERVATIONS; POINT-SOURCE CATALOG; X-RAY-ABSORPTION; STAR-FORMATION; IRAS SOURCES; STARBURST CONNECTION; COMPOSITE GALAXIES AB This paper is the last in a series investigating the optical properties of a sample of mid-IR warm Seyfert galaxies and of a control sample of mid-IR cold galaxies. In the present paper I parametrize the morphologies and interaction properties of the host galaxies and combine these with the major conclusions in my previous papers. My results confirm that nuclear activity is linked to galactic interactions. I suggest an alternative view to the simple orientation-obscuration model postulated for Seyfert types 1 and 2 that takes into account the time evolution of their environmental and morphological properties. Within this view, the distinction between warm Seyfert 1 and 2 galaxies is not one of simple orientation; the latter might instead represent an earlier evolutionary stage, with properties intermediate between the (starburst-dominated) cold galaxies and the (AGN-dominated) warm Seyfert 1 galaxies. C1 Yale Univ, Dept Phys, New Haven, CT 06511 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Leiden Observ, NL-2300 RA Leiden, Netherlands. RP Yale Univ, Dept Phys, 260 Whitney Ave, New Haven, CT 06511 USA. NR 121 TC 6 Z9 6 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 161 EP 181 DI 10.1086/344086 PN 1 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500011 ER PT J AU Colbert, EJM Weaver, KA Krolik, JH Mulchaey, JS Mushotzky, RF AF Colbert, EJM Weaver, KA Krolik, JH Mulchaey, JS Mushotzky, RF TI The X-ray reflectors in the nucleus of the Seyfert galaxy NGC 1068 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : nuclei; galaxies : Seyfert; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; NARROW-LINE REGION; RESOLVED SPECTROSCOPY; PHYSICAL CONDITIONS; ASCA OBSERVATIONS; WARM ABSORBERS; NGC-1068; EMISSION; SPECTRUM; MATTER AB Based on observations of the Seyfert nucleus in NGC 1068 with ASCA, RXTE, and BeppoSAX, we report the discovery of a are (increase in flux by a factor of similar to1.6) in the 6.7 keV Fe K line component between observations obtained 4 months apart, with no significant change in the other (6.21, 6.4, and 6.97 keV) Fe Kalpha line components. During this time, the continuum flux decreased by similar to20%. The RXTE spectrum requires an Fe K absorption edge near 8.6 keV (Fe XXIII-XXV). The spectral data indicate that the 2-10 keV continuum emission is dominated (similar to2/3 of the luminosity) by reflection from a previously unidentified region of warm, ionized gas located less than or similar to0.2 pc from the AGN. The remaining similar to1/3 of the observed X-ray emission is reflected from optically thick, neutral gas. The coronal gas in the inner narrow-line region and/or the cold gas at the inner surface of the obscuring "torus" are possible cold reflectors. The inferred properties of the warm reflector are size (diameter) less than or similar to0.2 pc, gas density ngreater than or similar to10(5.5) cm(-3), ionization parameter xiapproximate to10(3.5) ergs cm s(-1), and covering fraction 0.003(L-0/10(43.5) ergs s(-1))(-1) <(&UOmega;/4π)<0.024(L-0/10(43.5) ergs s(-1))(-1), where L-0 is the intrinsic 2-10 keV X-ray luminosity of the AGN. We suggest that the warm reflector gas is the source of the ( variable) 6.7 keV Fe line emission and the 6.97 keV Fe line emission. The 6.7 keV line are is assumed to be due to an increase in the emissivity of the warm reflector gas from a decrease (by 20%-30%) in L-0. The properties of the warm reflector are most consistent with an intrinsically X-ray weak AGN with L(0)approximate to10(43.0) ergs s(-1). The optical and UV emission that scatters from the warm reflector into our line of sight is required to suffer strong extinction, which can be reconciled if the line of sight skims the outer surface of the torus. Thermal brems-strahlung radio emission from the warm reflector may be detectable in Very Long Baseline Array radio maps of the NGC 1068 nucleus. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, High Energy Phys Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, Laurel, MD 20723 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. RP Colbert, EJM (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Homewood Campus,3400 N Charles St, Baltimore, MD 21218 USA. NR 47 TC 22 Z9 22 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 182 EP 196 DI 10.1086/344100 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500012 ER PT J AU Hicks, EKS Malkan, MA Teplitz, HI McCarthy, PJ Yan, L AF Hicks, EKS Malkan, MA Teplitz, HI McCarthy, PJ Yan, L TI Star formation in emission-line galaxies between redshifts of 0.8 and 1.6 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : distances and redshifts; galaxies : Seyfert; galaxies : starburst; galaxies : statistics; infrared : galaxies; surveys ID ALPHA LUMINOSITY FUNCTION; LYMAN-BREAK GALAXIES; FIELD GALAXIES; SPECTRA; TELESCOPE; EVOLUTION; DENSITY; Z=1 AB Optical spectra of 14 emission-line galaxies representative of the 1999 NICMOS parallel grism Halpha survey of McCarthy et al. are presented. Of the 14, 9 have emission lines confirming the redshifts found in the grism survey. The higher resolution of our optical spectra improves the redshift accuracy by a factor of 5. The [O II]/Halpha values of our sample are found to be more than 2 times lower than expected from Jansen et al. This [O II]/Halpha ratio discrepancy is most likely explained by additional reddening in our Halpha-selected sample [on average, as much as an extra E(B-V)=0.6], as well as by a possible stronger dependence of the [O II]/Halpha ratio on galaxy luminosity than is found in local galaxies. The result is that star formation rates (SFRs) calculated from [O II]lambda3727 emission, uncorrected for extinction, are found to be on average 4+/-2 times lower than the SFRs calculated from Halpha emission. Classification of emission-line galaxies as starburst or Seyfert galaxies based on comparison of the ratios [O II]/Hbeta and [Ne III]lambda3869/Hbeta is discussed. New Seyfert 1 diagnostics using the Halpha line luminosity, H-band absolute magnitude, and Halpha equivalent widths are also presented. One galaxy is classified as a Seyfert 1 based on its broad emission lines, implying a comoving number density for Seyfert 1 galaxies of 2.5(-2.1)(+5.9)x10(-5) Mpc(-3). This comoving number density is a factor of 2.4(-2.0)(+5.5) times higher than estimated by other surveys. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Carnegie Inst Washington Observ, Pasadena, CA 91101 USA. CALTECH, SIRTF Sci Ctr, Pasadena, CA 91125 USA. RP Hicks, EKS (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. NR 36 TC 21 Z9 21 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 205 EP 222 DI 10.1086/344224 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500014 ER PT J AU Wiedner, MC Wilson, CD Harrison, A Hills, RE Lay, OP Carlstrom, JE AF Wiedner, MC Wilson, CD Harrison, A Hills, RE Lay, OP Carlstrom, JE TI Interferometric observations of the nuclear region of ARP 220 at submillimeter wavelengths SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (Arp 220); galaxies : ISM; galaxies : peculiar; galaxies : starburst; submillimeter; techniques : interferometric ID ULTRALUMINOUS INFRARED GALAXIES; MOLECULAR CLOUDS; LUMINOUS GALAXIES; STAR-FORMATION; IRAS GALAXIES; ARP-220; STARBURSTS; GAS; IC-4553; DISKS AB We report the first submillimeter interferometric observations of an ultraluminous infrared galaxy. We observed Arp 220 in the CO J=3-2 line and 342 GHz continuum with the single-baseline CSO-JCMT interferometer consisting of the Caltech Submillimeter Observatory (CSO) and the James Clerk Maxwell Telescope (JCMT). Models were fitted to the measured visibilities to constrain the structure of the source. The morphologies of the CO J=3-2 line and 342 GHz continuum emission are similar to those seen in published maps at 230 and 110 GHz. We clearly detect a binary source separated by similar to1" in the east-west direction in the 342 GHz continuum. The CO J=3-2 visibility amplitudes, however, indicate a more complicated structure, with evidence for a compact binary at some velocities and rather more extended structure at others. Less than 30% of the total CO J=3-2 emission is detected by the interferometer, which implies the presence of significant quantities of extended gas. We also obtained single-dish CO J=2-1, CO J=3-2, and HCN J=4-3 spectra. The HCN J=4-3 spectrum, unlike the CO spectra, is dominated by a single redshifted peak. The HCN J=4-3/CO J=3-2, HCN J=4-3/HCN J=10, and CO J=3-2/2-1 line ratios are larger in the redshifted (eastern) source, which suggests that the two sources may have different physical conditions. This result might be explained by the presence of an intense starburst that has begun to deplete or disperse the densest gas in the western source, while the eastern source harbors undispersed high-density gas. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. McMaster Univ, Hamilton, ON L8S 4M1, Canada. Univ Cambridge, Cavendish Lab, Mullard Radio Astron Observ, Cambridge CB3 0HE, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Wiedner, MC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St,MS 78, Cambridge, MA 02138 USA. NR 42 TC 15 Z9 15 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 229 EP 240 DI 10.1086/344106 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500016 ER PT J AU Figer, DF Najarro, F Gilmore, D Morris, M Kim, SS Serabyn, E McLean, IS Gilbert, AM Graham, JR Larkin, JE Levenson, NA Teplitz, HI AF Figer, DF Najarro, F Gilmore, D Morris, M Kim, SS Serabyn, E McLean, IS Gilbert, AM Graham, JR Larkin, JE Levenson, NA Teplitz, HI TI Massive stars in the Arches cluster SO ASTROPHYSICAL JOURNAL LA English DT Article DE Galaxy : center; infrared : stars; open clusters and associations : individual (Arches); stars : early-type; stars : formation; techniques : spectroscopic ID WOLF-RAYET STARS; COMPACT YOUNG CLUSTERS; GALACTIC-CENTER ARC; LOSS RATES; RADIO ARC; CONTINUUM OBSERVATIONS; SPECTRAL ATLAS; MILKY-WAY; HOT STARS; K-BAND AB We present and use new spectra and narrowband images, along with previously published broadband images, of stars in the Arches cluster to extract photometry, astrometry, equivalent width, and velocity information. The data are interpreted with a wind/atmosphere code to determine stellar temperatures, luminosities, mass-loss rates, and abundances. We have doubled the number of known emission-line stars, and we have also made the first spectroscopic identification of the main sequence for any population in the Galactic center. We conclude that the most massive stars are bona de Wolf-Rayet (W-R) stars; are some of the most massive stars known, having M-init>100 M-circle dot; and have prodigious winds, (M)over dot>10(-5) M-circle dot yr(-1), that are enriched with helium and nitrogen; with these identifications, the Arches cluster contains about 5% of all known W-R stars in the Galaxy. We find an upper limit to the velocity dispersion of 22 km s(-1), implying an upper limit to the cluster mass of 7x10(4) M-circle dot within a radius of 0.23 pc; we also estimate the bulk heliocentric velocity of the cluster to be v(cluster,circle dot)approximate to+95 km s(-1). Taken together, these results suggest that the Arches cluster was formed in a short, but massive, burst of star formation about 2.5+/-0.5 Myr ago, from a molecular cloud that is no longer present. The cluster happens to be approaching and ionizing the surface of a background molecular cloud, thus producing the thermal arched laments. We estimate that the cluster produces 4x10(51) ionizing photons s(-1), more than enough to account for the observed thermal radio flux from the nearby cloud, 3x10(49) ionizing photons s(-1). Commensurately, it produces 10(7.8) L-circle dot in total luminosity, providing the heating source for the nearby molecular cloud, L(cloud)approximate to 10(7) L-circle dot. These interactions between a cluster of hot stars and a wayward molecular cloud are similar to those seen in the "Quintuplet/Sickle" region. The small spread of formation times for the known young clusters in the Galactic center and the relative lack of intermediate-age stars (tau(age)=10(7.0)-10(7.3) yr) suggest that the Galactic center has recently been host to a burst of star formation. Finally, we have made new identifications of near-infrared sources that are counterparts to recently identified X-ray and radio sources. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. CSIC, Inst Estructura Mat, Madrid 29006, Spain. Univ Calif Los Angeles, Dept Phys & Astron, Div Astron, Los Angeles, CA 90095 USA. CALTECH, Pasadena, CA 91125 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. EM figer@stsci.edu; eserabyn@huey.jpl.nasa.gov RI Kim, Sungsoo/A-8601-2011; Najarro, Francisco/G-7288-2015; OI Kim, Sungsoo/0000-0002-5570-2160; Najarro, Francisco/0000-0002-9124-0039; Levenson, Nancy A./0000-0003-4209-639X NR 67 TC 188 Z9 189 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 258 EP 275 DI 10.1086/344154 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500018 ER PT J AU King, NL Nota, A Walsh, JR Panagia, N Gull, TR Pasquali, A Clampin, M Bergeron, LE AF King, NL Nota, A Walsh, JR Panagia, N Gull, TR Pasquali, A Clampin, M Bergeron, LE TI A Hubble Space Telescope polarization study of dust in the eta carinae homunculus SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; polarization; reflection nebulae; scattering; stars : individual (eta Carinae) ID IMAGING POLARIMETRY; NEBULA; ULTRAVIOLET; GRAINS AB New high-resolution polarization images of the eta Car Homunculus have been obtained with the Hubble Space Telescope (HST) at several wavelengths spanning the near-UV to the near-IR. With these images, taken with WFPC2 and NICMOS, we have been able to compare the polarization properties of the Homunculus at different wavelengths. We confirm that the Homunculus is primarily a reflection nebula and review the evidence that the inner region within 2" of eta Car has nonstellar hydrogen recombination emission. Additionally, we detect nebular [N II] emission in the inner 2" region. We confirm that the large-scale morphology of the polarization appears to be independent of wavelength from the near-UV to the near-IR. The smooth images of polarization and the very structured images of intensity show that there is no correlation between the surface brightness and polarization. We examine the polarization percentages and vector angles of small-scale features in the Homunculus, such as the paddle, the skirt, the spot, and the southern ridge, to speculate on whether the features are composed of scattering particles similar to those in the lobes as a whole. We construct three-dimensional radiative transfer models of the Homunculus. The models have a hollow "figure eight" with a central light source. Radiation from the central source is Mie-scattered off dust grains in the "figure eight" into our line of sight. Patchy extinction lining the outer shell of the "figure eight" is used to explain surface brightness inhomogeneities, but the patchy extinction is not modeled. We find that a combination of small and large silicate dust grains reproduces the high polarization and independence with wavelength of the data much better than a model with a single distribution of standard ISM-type silicate dust grains. Finally, two different geometrical forms of the Homunculus from the literature were used in the models and found to produce very similar polarization features. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. ST ECF ESO, D-85748 Garching, Germany. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP King, NL (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. RI Clampin, mark/D-2738-2012; Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 NR 38 TC 9 Z9 9 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 285 EP 306 DI 10.1086/344168 PN 1 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500020 ER PT J AU Bartel, N Bietenholz, MF Rupen, MP Beasley, AJ Graham, DA Altunin, VI Venturi, T Umana, G Cannon, WH Conway, JE AF Bartel, N Bietenholz, MF Rupen, MP Beasley, AJ Graham, DA Altunin, VI Venturi, T Umana, G Cannon, WH Conway, JE TI SN 1993J VLBI. II. Related changes of the deceleration, flux density decay, and spectrum SO ASTROPHYSICAL JOURNAL LA English DT Article DE supernovae : individual (SN 1993J); techniques : interferometric ID SYNCHROTRON SELF-ABSORPTION; SUPERNOVA 1993J; RADIO-EMISSION; LIGHT CURVES; SN-1993J; M81; EXPANSION; DISTANCE; MODEL; PROGENITOR AB Phase-referenced multifrequency VLBI observations of supernova 1993J in the nearby galaxy M81 at 34 epochs from t = 30 to similar to3000 days after shock breakout show the detailed characteristics of the non self-similar expansion. For the first year, the supernova expanded almost freely, with the outer radius of the radio shell r(o) proportional to t(m(t)) and m(t) = 0.919 +/- 0.019. During the following 4 years the deceleration grew to m(t) = 0.781 +/- 0.009, the expansion velocity slowed down by about half from originally v(0) similar to17,200 km s(-1) to just similar to8900 km s(-1), and the supernova swept up a mass of similar to0.3 M-.. Momentum conservation suggests that this mass is about equal to the mass of the shocked ejecta, likely composed of all the low-mass envelope of the progenitor left over after mass transfer to a purported binary companion, therefore supporting the binary scenario. Subsequently the deceleration changed again, this time decreasing to m(t) = 0.860 +/- 0.011 from t = 5 to 8 yr, consistent with hydrodynamic simulations. This late upturn of m(t) may be caused by the massive inner ejecta, which have reached the increasingly decelerated shocked ejecta, passing now through the reverse shock and pushing the low-mass envelope. This upturn of m(t) is mirrored by changes in the slope of the radio light curves and a flattening of the radio spectra, all consistent with power laws, with spectral indices changing from alpha = -0.85 +/- 0.03 to -0.64 +/- 0.03. The magnetic field in the radio shell region is inferred to decrease from originally proportional to r(o)(-0.99) to proportional to r(o)(-1.45) toward the end of our observations. After 7 years the radio light curves start to drop rapidly, suggesting that the supernova is now expanding into a zone of the circumstellar medium with a steep density profile. C1 York Univ, Dept Phys & Astron, N York, ON M3J 1P3, Canada. Natl Radio Astron Observ, Socorro, NM 87801 USA. Owens Valley Radio Observ, CARMA, Pig Pine, CA 93513 USA. Max Planck Inst Radioastron, D-53121 Bonn, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CNR, Inst Radioastron, I-40129 Bologna, Italy. CNR, Inst Radioastron, I-96017 Noto, Italy. CRESTech, Space Geodynam Lab, Toronto, ON M3J 3K1, Canada. Chalmers Univ Technol, Onsala Space Observ, S-43992 Onsala, Sweden. RP Bartel, N (reprint author), York Univ, Dept Phys & Astron, N York, ON M3J 1P3, Canada. OI Venturi, Tiziana/0000-0002-8476-6307 NR 47 TC 72 Z9 72 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 404 EP 426 DI 10.1086/344198 PN 1 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500029 ER PT J AU Splaver, EM Nice, DJ Arzoumanian, Z Camilo, F Lyne, AG Stairs, IH AF Splaver, EM Nice, DJ Arzoumanian, Z Camilo, F Lyne, AG Stairs, IH TI Probing the masses of the PSR J0621+1002 binary system through relativistic apsidal motion SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; ISM : structure; pulsars : individual (PSR J0621+1002); relativity; stars : neutron ID MILLISECOND PULSARS; TIMING FORMULA; RADIO PULSARS; DISPERSION; COMPANIONS; PLASMA AB Orbital, spin, and astrometric parameters of the millisecond pulsar PSR J0621+ 1002 have been determined through six years of timing observations at three radio telescopes. The chief result is a measurement of the rate of periastron advance, (omega) over dot 0.degrees0116 +/- 0.degrees0008 yr(-1). Interpreted as a general relativistic effect, this implies the sum of the pulsar mass, m(1), and the companion mass, m(2), to be M = m(1) + m(2) = 2.81 +/- 0.30 M-.. The Keplerian parameters rule out certain combinations of m(1) and m(2), as does the nondetection of Shapiro delay in the pulse arrival times. These constraints, together with the assumption that the companion is a white dwarf, lead to the 68% confidence maximum likelihood values of m(1) = 1.70(-0.29)(+0.32) M-. and m(2) = 0.97(-0.15)(+0.27) M-. and to the 95% confidence maximum likelihood values of m(1) = 1.70(-0.63)(+0.59) M-. and m(2) = 0.97(-0.24)(+0.43) M-.. The other major finding is that the pulsar experiences dramatic variability in its dispersion measure (DM), with gradients as steep as 0.013 pc cm(-3) yr(-1). A structure function analysis of the DM variations uncovers spatial fluctuations in the interstellar electron density that cannot be fitted to a single power law, unlike the Kolmogorov turbulent spectrum that has been seen in the direction of other pulsars. Other results from the timing analysis include the first measurements of the pulsar's proper motion, mu = 3.5 +/- 0.3 mas yr(-1), and of its spin-down rate, dP/dt = 4.7 10(-20), which, when corrected for kinematic biases and combined with the pulse period, P = 28.8 ms, gives a characteristic age of 1.1 x 10(10) yr and a surface magnetic field strength of 1.2 x 10(9) G. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. NASA, Goddard Space Flight Ctr, USRA, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Univ Manchester, Jodrell Bank Observ, Macclesfield SK11 9DL, Cheshire, England. Natl Radio Astron Observ, Green Bank, WV 24944 USA. RP Princeton Univ, Dept Phys, Box 708, Princeton, NJ 08544 USA. EM esplaver@princeton.edu; dnice@princeton.edu; zaven@milkyway.gsfc.nasa.gov; fernando@astro.columbia.edu; agl@jb.man.ac.uk; istairs@nrao.edu NR 29 TC 44 Z9 45 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 509 EP 518 DI 10.1086/344202 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500038 ER PT J AU Smith, RK Edgar, RJ Shafer, RA AF Smith, RK Edgar, RJ Shafer, RA TI The X-ray halo of GX 13+1 SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; scattering; X-rays : binaries; X-rays : ISM ID INTERSTELLAR GRAINS; ENERGY-SPECTRA; BINARIES; DUST; SCATTERING; GX-13+1; DISCOVERY; RADIO; LINE AB We present observations of the X-ray halo around the low-mass X-ray binary GX 13+1 from the Chandra X-ray telescope. The halo is caused by scattering in interstellar dust grains, and we use it to diagnose the line-of-sight position, size distribution, and density of the grains. Using the intrinsic energy resolution of Chandra's ACIS CCDs and the recent calibration observation of the Chandra point-spread function, we were able to extract the halo fraction as a function of energy and off-axis angle. We de ne a new quantity, the "halo coefficient", or the total halo intensity relative to the source extrapolated to 1 keV, and measure it to be 1.5(-0.1)(+0.5) for GX 13+1. We find a relationship between this value and the dust size, density, and hydrogen column density along the line of sight to GX 13+1. We also conclude that our data do not agree with "fluffy" dust models that earlier X-ray halo observations have supported and that models including an additional large dust grain population are not supported by these data. C1 Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Lab Astron & Space Phys, Greenbelt, MD 20771 USA. RP Smith, RK (reprint author), Smithsonian Astrophys Observ, 60 Garden St, Cambridge, MA 02138 USA. NR 28 TC 50 Z9 50 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 562 EP 569 DI 10.1086/344151 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500041 ER PT J AU Strohmayer, TE AF Strohmayer, TE TI Evidence for orbital decay of RX J1914.4+2456: Gravitational radiation and the nature of the X-ray emission SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; novae, cataclysmic variables; stars : individual (RX J1914.4+2456); white dwarfs; X-rays : binaries; X-rays : stars ID DOUBLE-DEGENERATE POLAR; CATACLYSMIC VARIABLES; BINARIES; PERIOD; SECONDARIES; POPULATION; SYSTEMS; STARS AB RX J1914.4+ 2456 is a candidate double-degenerate binary (AM CVn) with a putative 569 s orbital period. If this identification is correct, then it has one of the shortest binary orbital periods known, and gravitational radiation should drive the orbital evolution and mass transfer if the binary is semidetached. Here we report the results of a coherent timing study of the archival ROSAT and ASCA data for RX J1914.4+ 2456. We performed a phase-coherent timing analysis using all observations spanning a approximate to4.6 yr period. We demonstrate that all the data can be phase-connected, and we present evidence that the 1.756 mHz orbital frequency is increasing at a rate of (8 +/- 3) x 10(-18) Hz s(-1), consistent with the expected loss of angular momentum from the binary system via gravitational radiation. In addition to providing evidence for the emission of gravitational waves, measurement of the orbital (nu) over dot constrains models for the X-ray emission and the nature of the secondary. If stable mass accretion drives the X-ray flux, then a positive (nu) over dot is inconsistent with a degenerate donor. A helium-burning dwarf is compatible if indeed such systems can have periods as short as that of RX J1914.4+ 2456, an open theoretical question. Our measurement of a positive (nu) over dot is consistent with the unipolar induction model of Wu et al., which does not require accretion to drive the X-ray flux. We discuss how future timing measurements of RX J1914.4+ 2456 (and systems like it) with, for example, Chandra and XMM-Newton, can provide a unique probe of the interaction between mass loss and gravitational radiation. We also discuss the importance of such measurements in the context of gravitational wave detection from space, such as is expected in the future with the Laser Interferometer Space Antenna mission. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Strohmayer, TE (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. NR 32 TC 33 Z9 33 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 577 EP 584 DI 10.1086/344101 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500043 ER PT J AU Chae, J Poland, AI Aschwanden, MJ AF Chae, J Poland, AI Aschwanden, MJ TI Coronal loops heated by magnetohydrodynamic turbulence. I. A model of isobaric quiet-Sun loops with constant cross sections SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : corona; Sun : magnetic fields; Sun : transition region; turbulence ID TRANSITION REGION; THERMAL-STABILITY; HEATING MODELS; SOLAR CORONA; TRACE; DRIVEN; WAVES; SOHO AB Several recent papers have presented new observational results indicating that many coronal loops in active regions are nearly isothermal. It is expected that quiet-Sun loops may have similar thermal structures, since quiet-Sun differential emission measures look similar to those in active regions. In the quiet Sun, it is well known from observations that the nonthermal velocity inferred from the excess broadening of a line over thermal broadening reaches a peak of about 30 km s(-1) around 3 x 10(5) K and then decreases with temperature, having a value of about 20 km s(-1) at 1 x 10(6) K. In the present work, we make the assumption that the observed nonthermal velocities are a manifestation of magnetohydrodynamic (MHD) turbulence and present a model of static, isobaric coronal loops heated by turbulence. Instead of solving the MHD equations, we adopt simple energy spectra in MHD turbulence and infer the heating rate as a function of temperature from the observed nonthermal velocities. By solving the steady state energy equation of a loop in which temperature monotonically increases with height, we obtain the following results: (1) The heating rate is predominantly near the footpoints and decreases with the loop arc length. ( 2) There is a critical temperature above which the loop cannot be maintained in a steady state. ( 3) The loop is denser and is more isothermal than uniformly heated loops, being compatible with recent observations. (4) The theoretical differential emission measures are in good agreement with the empirical values at temperatures above 10 5 K. Below this temperature, we still have a large discrepancy. (5) It is possible to explain the observed strong correlation between intensity and nonthermal velocity of a spectral line in the quiet Sun. Our results support the idea that quasi-statically driven MHD turbulence of the direct current (DC) type in the stratified medium (transition region and corona) is a viable mechanism for coronal heating. C1 New Jersey Inst Technol, Big Bear Solar Observ, Big Bear City, CA 92314 USA. NASA, Goddard Space Flight Ctr, Solar Phys Branch, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Lockheed Martin Adv Technol Ctr, Solar & Astrophys Lab, Dept L9 41, Palo Alto, CA 94304 USA. EM chae@cnu.ac.kr NR 31 TC 12 Z9 12 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 726 EP 735 DI 10.1086/344103 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500054 ER PT J AU Sekanina, Z Chodas, PW AF Sekanina, Z Chodas, PW TI Common origin of two major sungrazing comets SO ASTROPHYSICAL JOURNAL LA English DT Article DE celestial mechanics; comets : general; comets : individual (X/1106 C1, C/1882 R1, C/1965 S1, D/1993 F2); methods : numerical ID SECONDARY FRAGMENTATION C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sekanina, Z (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 23 TC 12 Z9 12 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 760 EP 769 DI 10.1086/344216 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500057 ER PT J AU Oliversen, RJ Doane, N Scherb, F Harris, WM Morgenthaler, JP AF Oliversen, RJ Doane, N Scherb, F Harris, WM Morgenthaler, JP TI Measurements of [C I] emission from comet Hale-Bopp SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : individual (Hale-Bopp (C/1995 O1)) ID CARBON-MONOXIDE; 1P/HALLEY; C(D-1); RATES; H2O AB We present quantitative measurements of cometary [C I] 9850 Angstrom emission obtained during observations of comet Hale-Bopp (C/1995 O1) in 1997 March and April. The observations were carried out using a high-resolution (lambda/Deltalambda 40, 000) Fabry-Perot/CCD spectrometer at the McMath-Pierce Solar telescope on Kitt Peak. This forbidden line, the carbon analog of [O I] 6300 Angstrom, is emitted in the radiative decay of C(D-1) atoms. In the absence of other sources and sinks, [C I] 9850 Angstrom emission can be used as a direct tracer of CO photo-dissociation in comets. However, in Hale-Bopp's large, dense coma, other processes, such as collisional excitation of ground-state C(P-3), dissociative recombination of CO+, and collisional dissociation of CO and CO2 may produce significant amounts of C(D-1). The long C(D-1) radiative lifetime (similar to4000 s) makes collisional deexcitation (quenching) the primary loss mechanism in the inner coma. Thus, a detailed, self-consistent global model of collisional and photochemical interactions is necessary to fully account for [C I] 9850 Angstrom emission in comet Hale-Bopp. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Wisconsin, Space Astron Lab, Madison, WI 53706 USA. RP Oliversen, RJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 28 TC 11 Z9 11 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 10 PY 2002 VL 581 IS 1 BP 770 EP 775 DI 10.1086/344149 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 623AU UT WOS:000179681500058 ER PT J AU Smirnov, A Holben, BN Eck, TF Slutsker, I Chatenet, B Pinker, RT AF Smirnov, A Holben, BN Eck, TF Slutsker, I Chatenet, B Pinker, RT TI Diurnal variability of aerosol optical depth observed at AERONET (Aerosol Robotic Network) sites SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB [1] Diurnal variability of aerosol optical depth is important for various applications, including satellite aerosol data validation, radiative forcing computations, studies of aerosol interaction with humidity and clouds, and also public health. Aerosol optical depth measurements acquired through the ground-based Aerosol Robotic Network are analyzed. Analysis of the diurnal cycle over major urban/industrial areas within the network showed a prevailing pattern of the optical depth increase by 10-40% during the day at most sites. Diurnal variability range is <10% over various sites where dust aerosol is a major contributor to optical depth. Sites in southern Africa influenced by distant sources of biomass burning aerosol show no diurnal cycle, while the presence of local sources causes a diurnal trend with a maximum aerosol loading observed in the afternoon hours. Over oceans, because of the very low optical depth, even 20% departure from the daily average is practically within the measurement uncertainty. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Paris 07, Lab Interuniv Syst Atmospher, Creteil, France. Univ Paris 12, CNR, Creteil, France. Univ Maryland, College Pk, MD 20742 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. Sci Syst & Applicat Inc, Lanham, MD USA. RP Smirnov, A (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Pinker, Rachel/F-6565-2010; Smirnov, Alexander/C-2121-2009; ECK, THOMAS/D-7407-2012 OI Smirnov, Alexander/0000-0002-8208-1304; NR 16 TC 108 Z9 112 U1 6 U2 24 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD DEC 10 PY 2002 VL 29 IS 23 AR 2115 DI 10.1029/2002GL016305 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 647JV UT WOS:000181090400005 ER PT J AU Miller, AJ Nagatani, RM Flynn, LE Kondragunta, S Beach, E Stolarski, R McPeters, RD Bhartia, PK DeLand, MT Jackman, CH Wuebbles, DJ Patten, KO Cebula, RP AF Miller, AJ Nagatani, RM Flynn, LE Kondragunta, S Beach, E Stolarski, R McPeters, RD Bhartia, PK DeLand, MT Jackman, CH Wuebbles, DJ Patten, KO Cebula, RP TI A cohesive total ozone data set from the SBUV(/2) satellite system SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE total ozone; total ozone trends; SBUV ID TEMPERATURE; INSTRUMENT; TRENDS; STRATOSPHERE; CALIBRATION; VARIABILITY; DEPLETION; NIMBUS-4 AB [1] The long-term data collection of total ozone estimates from the Solar Backscatter Ultraviolet Ozone Sensors (SBUV and SBUV/2) began with the launch of SBUV on NASA's Nimbus-7 spacecraft in 1978. Following this successful demonstration, the National Oceanic and Atmospheric Administration (NOAA) adopted the slightly modified SBUV/2 instruments for placement on the afternoon Polar-Orbiting Operational Environmental Satellites (POES). The SBUV/2 instruments have flown on NOAA-9, -11, -14, and -16 in the POES series, with NOAA-16 launched in late 2000. Three more instruments are scheduled for launches in the next 6 years. While the absolute calibrations of individual instruments are good, they give total ozone accuracies of approximately 2%. However, without further adjustment, such interinstrument differences pose significant problems for atmospheric ozone trend analysis. In this paper we use the differences between total ozone estimates from the instruments during periods with overlapping coverage to account for these possible calibration biases. We use the NOAA-9 SBUV/2 record as the reference standard because of the length of its record and the amount of overlap with other instruments' records. By applying adjustments to the other data sets based on these differences, a complete, unified data set is created for use in analysis of long-term changes. The monthly-averaged total ozone time series for 50degreesS to 50degreesN and the hemispheric subsets are compared to the results from two 2-D chemistry models as a demonstration of the usefulness of the unified data sets. C1 NOAA, Natl Weather Serv, Climat Predict Ctr, Camp Springs, MD 20746 USA. NOAA, NESDIS, Res Off, Camp Springs, MD 20746 USA. Decis Syst Technol Inc, Rockville, MD USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syat & Applicat Inc, Lanham, MD USA. Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. RP Miller, AJ (reprint author), NOAA, Natl Weather Serv, Climat Predict Ctr, Camp Springs, MD 20746 USA. EM Alvin.Miller@noaa.gov; Ronald.Nagatani@noaa.gov; Lawrence.E.Flynn@noaa.gov; Shobha.Kondragunta@noaa.gov; Eric.Beach@noaa.gov; stolar@polska.gsfc.nasa.gov; mcpeters@wrabbit.gsfc.nasa.gov; bhartia@chapman.gsfc.nasa.gov; deland@sesda.com; jackman@assess.gsfc.nasa.gov; wuebbles@uiatma.atmos.uiuc.edu; kpatten@atmos.uiuc.edu; richardcebula@sesda.com RI Flynn, Lawrence/B-6321-2009; Beach, Eric/F-5576-2010; Stolarski, Richard/B-8499-2013; Jackman, Charles/D-4699-2012; McPeters, Richard/G-4955-2013; Kondragunta, Shobha/F-5601-2010 OI Flynn, Lawrence/0000-0001-6856-2614; Stolarski, Richard/0000-0001-8722-4012; McPeters, Richard/0000-0002-8926-8462; Kondragunta, Shobha/0000-0001-8593-8046 NR 31 TC 29 Z9 29 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 10 PY 2002 VL 107 IS D23 AR 4701 DI 10.1029/2001JD000853 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 647UH UT WOS:000181112100001 ER PT J AU Tabazadeh, A Djikaev, YS Reiss, H AF Tabazadeh, A Djikaev, YS Reiss, H TI Surface crystallization of supercooled water in clouds SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID HOMOGENEOUS ICE NUCLEATION; SULFURIC-ACID; CRYSTAL NUCLEATION; PHASE-TRANSITIONS; SOLUTION DROPLETS; LIQUID WATER; WAVE-CLOUDS; NITRIC-ACID; SIMULATIONS; PARTICLES AB The process by which liquid cloud droplets homogeneously crystallize into ice is still not well understood. The ice nucleation process based on the standard and classical theory of homogeneous freezing initiates within the interior volume of a cloud droplet. Current experimental data on homogeneous freezing rates of ice in droplets of supercooled water, both in air and emulsion oil samples, show considerable scatter. For example, at -33degreesC, the reported volume-based freezing rates of ice in supercooled water vary by as many as 5 orders of magnitude, which is well outside the range of measurement uncertainties. Here, we show that the process of ice nucleus formation at the air (or oil)-liquid water interface may help to explain why experimental results on ice nucleation rates yield different results in different ambient phases. Our results also suggest that surface crystallization of ice in cloud droplets can explain why low amounts of supercooled water have been observed in the atmosphere near -40degreesC. C1 NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. RP Tabazadeh, A (reprint author), NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. NR 42 TC 94 Z9 94 U1 1 U2 30 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD DEC 10 PY 2002 VL 99 IS 25 BP 15873 EP 15878 DI 10.1073/pnas.252640699 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 624VY UT WOS:000179783400011 PM 12456877 ER PT J AU Pfister, L Selkirk, HB Jensen, EJ Podolske, J Sachse, G Avery, M Schoeberl, MR Mahoney, MJ Richard, E AF Pfister, L Selkirk, HB Jensen, EJ Podolske, J Sachse, G Avery, M Schoeberl, MR Mahoney, MJ Richard, E TI Processes controlling water vapor in the winter Arctic tropopause region SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE tropopause; water vapor; stratosphere-troposphere exchange; dehydration ID STRATOSPHERE-TROPOSPHERE EXCHANGE; LOWERMOST STRATOSPHERE; OZONE; MECHANISMS; CHEMISTRY; AIRCRAFT; H2O; ICE AB [1] This work describes transport and thermodynamic processes that control water vapor near the tropopause during the SAGE III-Ozone Loss and Validation Experiment (SOLVE), held during the Arctic 1999/2000 winter season. Aircraft-based water vapor, carbon monoxide, and ozone measurements are analyzed so as to establish how deeply tropospheric air mixes into the Arctic lowermost stratosphere and what the implications are for cloud formation and water vapor removal in this region of the atmosphere. There are three major findings. First, troposphere-to-stratosphere exchange extends into the Arctic stratosphere to about 13 km. Penetration is to similar levels throughout the winter; however, because ozone increases with altitude most rapidly in the early spring, tropospheric air mixes with the highest values of ozone in that season. The effect of this upward mixing is to elevate water vapor mixing ratios significantly above their prevailing stratospheric values of about 5 ppmv. Second, the potential for cloud formation in the stratosphere is highest during early spring, with about 20% of the parcels which have ozone values of 300-350 ppbv experiencing ice saturation in a given 10 day period. Third, during early spring, temperatures at the tropopause are cold enough so that 5-10% of parcels experience relative humidities above 100%, even if the water content is as low as 5 ppmv. The implication is that during this period, dynamical processes near the Arctic tropopause can dehydrate air and keep the Arctic tropopause region very dry during early spring. C1 NASA, Ames Res Ctr, Atmospher Chem & Dynam Branch, Moffett Field, CA 94035 USA. Space Phys Res Inst, Sunnyvale, CA 94087 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Langley Res Ctr, Chem & Dynam Branch, Hampton, VA 23691 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Pfister, L (reprint author), NASA, Ames Res Ctr, Atmospher Chem & Dynam Branch, MS 245-5, Moffett Field, CA 94035 USA. EM pfister@telsci.arc.nasa.gov; hselkirk@mail.arc.nasa.gov; ejensen@mail.arca.nasa.gov; jpodolske@mail.arc.nasa.gov; G.Sachse@larc.nasa.gov; M.Avery@larc.nasa.gov; mmahoney@pop.jpl.nasa.gov; richard@al.noaa.gov RI Selkirk, Henry/H-2021-2012 NR 32 TC 2 Z9 2 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 7 PY 2002 VL 108 IS D5 AR 8314 DI 10.1029/2001JD001067 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 646WT UT WOS:000181059500002 ER PT J AU Ji, YM Stocker, E AF Ji, YM Stocker, E TI Seasonal, intraseasonal, and interannual variability of global land fires and their effects on atmospheric aerosol distribution SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE fire; aerosol; remote sensing ID DYNAMICS; TROPICS; SMOKE; TIME AB [1] In order to understand the variability of global land fires and their effects on the distribution of atmospheric aerosols, statistical methods were applied to the Tropical Rainfall Measuring Mission (TRMM) fire products as well as the Total Ozone Mapping Spectrometer (TOMS) aerosol index products for a period of 4 years from January 1998 to December 2001. The fire data in this period manifested a strong annual cycle of land fires in Southeast Asia with a peak in March and in Africa and North and South America with a peak in August. The data also indicated interannual variations in Indonesia and Central America associated with the 1998-1999 El Nino- Southern Oscillation cycle. The variability of global atmospheric aerosol is consistent with the fire variations over these regions. However, in southwestern Australia, intense fires were recorded in TRMM fire data, but no smoke was observed in the TOMS aerosol product. Excluding the Australian region, the correlation between fire count and TOMS aerosol index is about 0.55 for fire pixels. Empirical orthogonal function analysis (EOF) and singular spectrum analysis methods were used to analyze the TRMM Science Data and Information System pentad fire composite data and TOMS pentad aerosol index data for this 4 year period. The EOF analyses showed contrast between the Northern and Southern Hemispheres and also intercontinental transitions in Africa and America. These analyses also identified 25- 60 day intraseasonal oscillations that were superimposed on the annual cycles of both fire and aerosol data. The intraseasonal variability of fires showed a similarity of Madden- Julian oscillation mode. C1 George Mason Univ, Sch Computat Sci, Fairfax, VA 22030 USA. NASA, Goddard Space Flight Ctr, TRMM, TSDIS, Greenbelt, MD 20770 USA. RP Ji, YM (reprint author), George Mason Univ, Sch Computat Sci, Fairfax, VA 22030 USA. EM yji@tsdis.gsfc.nasa.gov; stocker@tsdis.gsfc.nasa.gov NR 16 TC 11 Z9 12 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 7 PY 2002 VL 107 IS D23 AR 4697 DI 10.1029/2002JD002331 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 646WM UT WOS:000181059000003 ER PT J AU Wang, HJ Cunnold, DM Thomason, LW Zawodny, JM Bodeker, GE AF Wang, HJ Cunnold, DM Thomason, LW Zawodny, JM Bodeker, GE TI Assessment of SAGE version 6.1 ozone data quality SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC WATER-VAPOR; TROPOSPHERIC OZONE; ANTHROPOGENIC CHLORINE; VERTICAL-DISTRIBUTION; OCCULTATION DATA; AEROSOL; TRENDS; MODEL; VARIABILITY; TEMPERATURE AB [1] The Stratospheric Aerosol and Gas Experiment (SAGE) II V6.1 ozone retrievals are shown to be of better precision at all levels and to be much more accurate than previous retrievals in the lower stratosphere below 20 km altitude. A filtering procedure for removing anomalous ozone profiles associated with volcanic aerosol/cloud effects and other identified artifacts in V6.1 ozone is described. The agreement between SAGE and ozonesondes in the mean is shown to be approximately 10% down to the tropopause. Relative to the sondes, SAGE tends to slightly overestimate ozone (less than 5%) between 15 and 20 km altitude and systematically underestimates ozone in the troposphere by approximately 30% in the regions between 8 km altitude and 2 km below the tropopause. The precisions (random errors) of SAGE ozone retrievals above 25 km altitude are estimated to be 4% or better; they are a factor of 10 worse below 16 km altitude. Linear trends in the differences between coincident SAGE and ozonesondes measurement are generally less than 0.3%/yr and not significantly different from zero in 95% confidence intervals. Compared to V5.96 retrievals, ozone trend differences between 20 and 50 km altitude are approximately 0.1%/yr; below 20 km altitude the SAGE II trends are more positive by approximately 0.2%/yr. For the 1984-1999 period, the SAGE II shows a localized ozone loss of -0.4 +/- 0.25%/yr (2) in the tropics at 20 km altitude. In the lower stratosphere, between 16 and 22 km altitudes, the SAGE shows significant ozone losses in the midlatitudes in both hemispheres during the 1979-1999 periods. The ozone trends range from -0.24 +/- 0.18%/yr to -0.77 +/- 0.46%/yr (2sigma). However, in the 1984-1999 period, the downward trends are smaller (-0.07%/yr to -0.25%/yr) in this altitude range, and the trends in the integrated column from 12 to 17 km altitude in midlatitudes (35degrees-60degrees) are not significantly different from zero (0.1 +/- 0.6%/yr (2sigma)). Averaged over the tropics (20degreesS-20degreesN), the ozone column above 15 km altitude exhibit a trend of -0.12 +/- 0.08%/yr (2sigma). C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Natl Inst Water & Atmospher Res, Lauder, Central Otago, New Zealand. RP Wang, HJ (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. EM raywang@eas.gatech.edu NR 48 TC 100 Z9 100 U1 2 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 6 PY 2002 VL 107 IS D23 AR 4691 DI 10.1029/2002JD002418 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 646WG UT WOS:000181058400003 ER PT J AU Dickey, JO Marcus, SL de Viron, O Fukumori, I AF Dickey, JO Marcus, SL de Viron, O Fukumori, I TI Recent Earth oblateness variations: Unraveling climate and postglacial rebound effects SO SCIENCE LA English DT Article ID REANALYSIS; GLACIERS; ROTATION AB Earth's dynamic oblateness (J(2)) has been decreasing due to postglacial rebound (PGR). However, J(2) began to increase in 1997, indicating a pronounced global-scale mass redistribution within Earth's system. We have determined that the observed increases in J(2) are caused primarily by a recent surge in subpolar glacial melting and by mass shifts in the Southern, Pacific, and Indian oceans. When these effects are removed, the residual trend in J(2) (-2.9 x 10(-11) year(-1)) becomes consistent with previous estimates of PGR from satellite and eclipse data. The climatic significance of these rapid shifts in glacial and oceanic mass, however, remains to be investigated. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Observ Royal Belgique, FNRS, B-1180 Brussels, Belgium. RP Dickey, JO (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI de Viron, Olivier/N-6647-2014; OI de Viron, Olivier/0000-0003-3112-9686; Marcus, Steven/0000-0002-5763-6961 NR 20 TC 65 Z9 70 U1 1 U2 7 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 6 PY 2002 VL 298 IS 5600 BP 1975 EP 1977 DI 10.1126/science.1077777 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 622CP UT WOS:000179629200040 PM 12471253 ER PT J AU Segura, TL Toon, OB Colaprete, A Zahnle, K AF Segura, TL Toon, OB Colaprete, A Zahnle, K TI Environmental effects of large impacts on Mars SO SCIENCE LA English DT Article ID CLIMATE AB The martian valley networks formed near the end of the period of heavy bombardment of the inner solar system, about 3.5 billion years ago. The largest impacts produced global blankets of very hot ejecta, ranging in thickness from meters to hundreds of meters. Our simulations indicated that the ejecta warmed the surface, keeping it above the freezing point of water for periods ranging from decades to millennia, depending on impactor size, and caused shallow subsurface or polar ice to evaporate or melt. Large impacts also injected steam into the atmosphere from the craters or from water innate to the impactors. From all sources, a typical 100-, 200-, or 250-kilometers asteroid injected about 2, 9, or 16 meters, respectively, of precipitable water into the atmosphere, which eventually rained out at a rate of about 2 meters per year. The rains from a large impact formed rivers and contributed to recharging aquifers. C1 Univ Colorado, Program Atmospher & Ocean Sci, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Segura, TL (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. NR 25 TC 165 Z9 169 U1 2 U2 12 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD DEC 6 PY 2002 VL 298 IS 5600 BP 1977 EP 1980 DI 10.1126/science.1073586 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 622CP UT WOS:000179629200041 PM 12471254 ER PT J AU Martin, BD Fuelberg, HE Blake, NJ Crawford, JH Logan, JA Blake, DR Sachse, GW AF Martin, BD Fuelberg, HE Blake, NJ Crawford, JH Logan, JA Blake, DR Sachse, GW TI Long-range transport of Asian outflow to the equatorial Pacific SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPICAL SOUTH-ATLANTIC; PEM-WEST-B; CHEMICAL CHARACTERISTICS; NONMETHANE HYDROCARBONS; CONTINENTAL OUTFLOW; TROPOSPHERIC OZONE; UNITED-STATES; AIR; EMISSIONS; OCEAN AB [1] The second Pacific Exploratory Mission to the Tropics (PEM T-B) was conducted as part of NASA's Global Tropospheric Experiment (GTE) from 25 February through 19 April 1999. Long-range pollution signatures are examined during four PEM T-B flights that ranged as far northeast as California and as far southwest as coastal New Guinea. The signatures are studied to determine their ages and chemical evolution during transport. The chemical species examined include nonmethane hydrocarbons, halocarbons, and carbon monoxide. Wind data from the European Centre for Medium Range Weather Forecasts (ECMWF) are used to calculate backward trajectories along the four flight tracks. Results show that some pollutants originating from the Asian continent, and even farther west, are transported across the Pacific by the middle latitude westerly winds and reach the subtropical Pacific anticyclone where they subside and turn southwestward under the influence of the low level trade winds. The parcels ultimately reach the western Pacific near coastal New Guinea after 20-25 days of transit. C1 Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Univ Calif Irvine, Irvine, CA USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Harvard Univ, Cambridge, MA 02138 USA. RP Martin, BD (reprint author), Florida State Univ, Dept Meteorol, 404 Love Bldg, Tallahassee, FL 32306 USA. EM fuelberg@met.fsu.edu RI Crawford, James/L-6632-2013 OI Crawford, James/0000-0002-6982-0934 NR 48 TC 3 Z9 3 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 5 PY 2002 VL 108 IS D2 AR 8322 DI 10.1029/2001JD001418 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 646WD UT WOS:000181058100002 ER PT J AU Wang, J Flagan, RC Seinfeld, JH Jonsson, HH Collins, DR Russell, PB Schmid, B Redemann, J Livingston, JM Gao, S Hegg, DA Welton, EJ Bates, D AF Wang, J Flagan, RC Seinfeld, JH Jonsson, HH Collins, DR Russell, PB Schmid, B Redemann, J Livingston, JM Gao, S Hegg, DA Welton, EJ Bates, D TI Clear-column radiative closure during ACE-Asia: Comparison of multiwavelength extinction derived from particle size and composition with results from Sun photometry SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosol optical depth; ACE-Asia; Sun photometer ID EFFECTIVE-MEDIUM APPROXIMATIONS; MID-ATLANTIC COAST; IN-SITU; CHEMICAL-COMPOSITION; OPTICAL-PROPERTIES; UNITED-STATES; WATER-VAPOR; AEROSOL; SCATTERING; BEHAVIOR AB [1] From March to May 2001, aerosol size distributions and chemical compositions were measured using differential mobility analyzers (DMA), an aerodynamic particle sizer (APS), Micro-Orifice Uniform Deposit Impactors (MOUDI), and denuder samplers onboard the Twin Otter aircraft as part of the Aerosol Characterization Experiment (ACE)-Asia campaign. Of the 19 research flights, measurements on four flights that represented different aerosol characteristics are analyzed in detail. Clear-column radiative closure is studied by comparing aerosol extinctions predicted using in situ aerosol size distribution and chemical composition measurements to those derived from the 14-wavelength NASA Ames Airborne Tracking Sun photometer (AATS-14). In the boundary layer, pollution layers, and free troposphere with no significant mineral dust present, aerosol extinction closure was achieved within the estimated uncertainties over the full range of wavelengths of AATS-14. Aerosol extinctions predicted based on measured size distributions also reproduce the wavelength dependence derived from AATS-14 data. Considering all four flights, the best fit lines yield Predicted/Observed ratios in boundary and pollution layers of 0.97 +/- 0.24 and 1.07 +/- 0.08 at lambda = 525 nm and 0.96 +/- 0.21 and 1.08 +/- 0.08 at lambda = 1059 nm, respectively. In free troposphere dust layers, aerosol extinctions predicted from the measured size distributions were generally smaller than those derived from the AATS-14 data, with Predicted/Observed ratios of 0.65 +/- 0.06 and 0.66 +/- 0.05 at 525 and 1059 nm, respectively. A detailed analysis suggests that the discrepancy is likely a result of the lack of the knowledge of mineral dust shape as well as variations in aerosol extinction derived from AATS-14 data when viewing through horizontally inhomogeneous layers. C1 CALTECH, Dept Chem Engn, Pasadena, CA 91125 USA. USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93933 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Bay Area Environm Res Inst, Sonoma, CA 94035 USA. SRI Int, Menlo Pk, CA 94035 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. NASA, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Greenbelt, MD 20771 USA. Univ Miami, Dept Phys, Coral Gables, FL 33124 USA. RP Wang, J (reprint author), Brookhaven Natl Lab, Dept Environm Sci, 75 Rutherford Dr, Upton, NY 11973 USA. EM seinfeld@caltech.edu RI Welton, Ellsworth/A-8362-2012; Collins, Don/F-9617-2012; Wang, Jian/G-9344-2011 NR 43 TC 52 Z9 52 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 5 PY 2002 VL 107 IS D23 AR 4688 DI 10.1029/2002JD002465 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 646VL UT WOS:000181056200005 ER PT J AU Uritsky, VM Klimas, AJ Vassiliadis, D Chua, D Parks, G AF Uritsky, VM Klimas, AJ Vassiliadis, D Chua, D Parks, G TI Scale-free statistics of spatiotemporal auroral emissions as depicted by POLAR UVI images: Dynamic magnetosphere is an avalanching system SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE multiscale turbulence; self-organized criticality; substorms; POLAR UVI experiment ID SELF-ORGANIZED CRITICALITY; EARTHWARD FLOW BURSTS; SPORADIC LOCALIZED RECONNECTIONS; NONLINEAR SURROGATE DATA; INDEX TIME-SERIES; PLASMA SHEET; AE-INDEX; INTERMITTENT TURBULENCE; ENERGY CHARACTERISTICS; ULTRAVIOLET IMAGER AB [1] We report first results from a spatiotemporal statistical analysis of ionospheric emissions as observed by the Ultraviolet Imager (UVI) onboard the POLAR spacecraft during 4 months of 1997 and 1998. Approximately 12,300 individual emission events near local midnight with durations exceeding the sampling time of the image sequences are investigated. The probability distributions of these events over the lifetime T, maximum area A, integrated area S, maximum power W, and integrated energy output are shown to obey distinct power law relations p similar to T-2.2, p similar to A(-1.8), p similar to S-1.6, p similar to W-1.7, p similar to E-1.5 over a wide range of scales. The observed behavior is consistent with the behavior of statistical -physical avalanche models near a stationary critical state. These results support the hypothesis of self- organized critical dynamics of the magnetosphere and suggest an important role for cross- scale coupling effects in the development of geomagnetic disturbances. C1 NASA, Magnetospher Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Univ Space Res Assoc, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Washington, Dept Earth & Space Sci, Seattle, WA 98195 USA. RP St Petersburg State Univ, Inst Phys, Magnetospher Phys Lab, St Petersburg, Russia. EM uritsky@geo.phys.spbu.ru NR 68 TC 85 Z9 85 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD DEC 5 PY 2002 VL 107 IS A12 AR 1426 DI 10.1029/2001JA000281 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 646GC UT WOS:000181026400001 ER PT J AU Sassi, F Salby, M Pumphrey, HC Read, WG AF Sassi, F Salby, M Pumphrey, HC Read, WG TI Influence of the Madden-Julian Oscillation on upper tropospheric humidity SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE Madden-Julian Oscillation; Upper Tropospheric Humidity; Tropical Convection ID MICROWAVE LIMB SOUNDER; TROPICAL UPPER TROPOSPHERE; GLOBAL CLOUD IMAGERY; WATER-VAPOR; MULTIPLE SATELLITES; LIFE-CYCLE; UARS MLS; CONVECTION; BEHAVIOR AB [1] Variations of upper tropospheric humidity (UTH) and cold cloud in the tropics reveal coherent changes that propagate eastward from the Indian Ocean into the Pacific. The coherence of UTH is high at periods of 30- 90 days along the equator. Near the tropical tropopause, UTH coherence is large over the equator in the Indian Ocean and over the subtropics in the central Pacific. A composite life cycle shows that enhanced UTH in the subtropics coincides with two anticyclonic gyres. They straddle anomalous cold cloud over the equator as it propagates eastward. The enhancement of UTH is consistent with anomalously- cold temperature, which mirrors the anticyclonic gyres. Those temperature anomalies cancel the height anomaly of the gyres overhead. The complex of anomalous UTH, cold cloud, and anticyclonic motion marches eastward across the western Pacific, until reaching the dateline. Anomalous convection over the equator then collapses, along with the subtropical gyres and enhanced UTH accompanying it. C1 Univ Colorado, Boulder, CO 80302 USA. Univ Edinburgh, Dept Meteorol, Edinburgh EH9 3JZ, Midlothian, Scotland. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sassi, F (reprint author), 1400 W 122nd Ave,101, Westminster, CO 80234 USA. EM sassi@thunder.asac.org; Murry.Salby@Colorado.EDU; hcp@met.ed.ac.uk; bill@mls.jpl.nasa.gov OI Sassi, Fabrizio/0000-0002-9492-7434 NR 22 TC 10 Z9 10 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 4 PY 2002 VL 107 IS D23 AR 4681 DI 10.1029/2001JD001331 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 646UY UT WOS:000181055000001 ER PT J AU Fleming, EL Jackman, CH Rosenfield, JE Considine, DB AF Fleming, EL Jackman, CH Rosenfield, JE Considine, DB TI Two-dimensional model simulations of the QBO in ozone and tracers in the tropical stratosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE interannual variability; stratospheric circulation; ozone ID QUASI-BIENNIAL OSCILLATION; EQUATORIAL LOWER STRATOSPHERE; GRAVITY-WAVE BREAKING; INTERANNUAL VARIABILITY; MIDDLE ATMOSPHERE; 2-DIMENSIONAL MODEL; SEMIANNUAL OSCILLATION; DIABATIC CIRCULATION; NUMERICAL-MODEL; GLOBAL QBO AB [1] Meteorological data from the United Kingdom Meteorological Office (UKMO) and constituent data from the Upper Atmospheric Research Satellite (UARS) are used to construct yearly zonal mean dynamical fields for the 1990s for use in the NASA/Goddard Space Flight Center (GSFC) two-dimensional (2-D) chemistry and transport model. This allows for interannual dynamical variability to be included in the model constituent simulations. In this study, we focus on the tropical stratosphere. We find that the phase of quasi-biennial oscillation (QBO) signals in equatorial CH4 and profile and total column O-3 data are resolved quite well using this empirically based 2-D model transport framework. However, the QBO amplitudes in the model constituents are systematically underestimated relative to the observations at most levels. This deficiency is probably due in part to the limited vertical resolutions of the 2-D model and the UKMO and UARS input data sets. We find that using different heating rate calculations in the model affects the interannual and QBO amplitudes in the constituent fields, but has little impact on the phase. Sensitivity tests reveal that the QBO in transport dominates the ozone interannual variability in the lower stratosphere, with the effect of the temperature QBO being dominant in the upper stratosphere via the strong temperature dependence of the ozone loss reaction rates. We also find that the QBO in odd nitrogen radicals, which is caused by the QBO modulated transport of NOy, plays a significant but not dominant role in determining the ozone QBO variability in the middle stratosphere. The model mean age of air is in good overall agreement with that determined from tropical lower-middle stratospheric OMS balloon observations of SF6 and CO2. The interannual variability of the equatorial mean age in the model increases with altitude and maximizes near 40 km, with a range of 4-5 years over the 1993-2000 time period. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Fleming, EL (reprint author), NASA, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. EM fleming@kahuna.gsfc.nasa.gov RI Jackman, Charles/D-4699-2012 NR 72 TC 19 Z9 19 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD DEC 3 PY 2002 VL 107 IS D23 AR 4665 DI 10.1029/2001JD001146 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 646UU UT WOS:000181054600001 ER PT J AU Loh, CY Zaman, KBMQ AF Loh, CY Zaman, KBMQ TI Numerical investigation of transonic resonance with a convergent-divergent nozzle SO AIAA JOURNAL LA English DT Article ID TIME CONSERVATION ELEMENT AB At pressure ratios lower than the design value, convergent-divergent nozzles often undergo a flow resonance accompanied by the emission of acoustic tones. The phenomenon, driven by the unsteady shock within the divergent section of the nozzle, has been studied experimentally previously. The space-time conservation element solution element method is employed to numerically investigate the phenomenon. The computations are performed for a given nozzle geometry for several different pressure ratios. Sustained limit-cycle oscillations are encountered in all cases. The oscillation frequencies and their variation with pressure ratio, including a stage jump, agree well with the experimental results. The unsteady flow data confirm that stage 1 of the resonance (fundamental) involves a one-quarter standing wave, whereas stage 2 (third harmonic) involves a three-quarter standing wave within the divergent section of the nozzle. Details of the shock motion, the How, and the near acoustic field are documented for one case each of stages 1 and 2. C1 Taitech Inc, Beavercreek, OH 45430 USA. NASA, John H Glenn Res Ctr, Turomachinery & Prop Syst Div, Cleveland, OH 44135 USA. RP Loh, CY (reprint author), Taitech Inc, 1430 Oak Court, Beavercreek, OH 45430 USA. NR 16 TC 23 Z9 23 U1 0 U2 7 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 2002 VL 40 IS 12 BP 2393 EP 2401 DI 10.2514/2.1607 PG 9 WC Engineering, Aerospace SC Engineering GA 622TA UT WOS:000179662000003 ER PT J AU Lazos, B AF Lazos, B TI Surface topology on the wheels of a generic four-wheel landing gear SO AIAA JOURNAL LA English DT Article ID VORTEX AB The analysis of shear stress lines in surface oil flow can provide attachment and separation characteristics on three-dimensional configurations about which flowfield data are often difficult or time consuming to acquire. This technique, in conjunction with mean surface pressure data, was utilized to determine the surface topology on a fore and aft wheel of a generic four-wheel landing gear model. Tests were performed at a Reynolds number of 6 x 10(5) based on wheel diameter. Because noise is produced when fluid attaches to or separates from a surface, the detailed analysis highlights regions on the wheels where further investigation may be warranted. The surface characteristics on the wheels determined in this study correlate well with the mean flowfield data acquired in a previous study. A relationship is hypothesized between observed changes in. the state of separation on the ground side of the fore wheel in the present study, with the changing streamwise location of a midwheel vortex discovered in a previous study. C1 NASA, Langley Res Ctr, Dept Flow Phys & Control, Hampton, VA 23681 USA. RP Lazos, B (reprint author), NASA, Langley Res Ctr, Dept Flow Phys & Control, Mail Stop 170, Hampton, VA 23681 USA. NR 19 TC 14 Z9 14 U1 1 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD DEC PY 2002 VL 40 IS 12 BP 2402 EP 2411 DI 10.2514/2.1608 PG 10 WC Engineering, Aerospace SC Engineering GA 622TA UT WOS:000179662000004 ER PT J AU Bandyopadhyay, S Boykin, PO Roychowdhury, V Vatan, F AF Bandyopadhyay, S Boykin, PO Roychowdhury, V Vatan, F TI A new proof for the existence of mutually unbiased bases SO ALGORITHMICA LA English DT Article DE quantum measurement; mutually unbiased bases; Hilbert space; quantum error-correcting codes ID QUANTUM-ERROR-CORRECTION; STATE DETERMINATION; SYSTEMS AB We develop a strong connection between maximally commuting bases of orthogonal unitary matrices and mutually unbiased bases. A necessary condition of the existence of mutually unbiased bases for any finite dimension is obtained. Then a constructive proof of the existence of mutually unbiased bases for dimensions that are powers of primes is presented. It is also proved that in any dimension d the number of mutually unbiased bases is at most d + 1. An explicit representation of mutually unbiased observables in terms of Pauli matrices are provided for d = 2(m). C1 Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA. Bose Inst, Dept Phys, Kolkata 700009, W Bengal, India. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA. EM som@ee.ucla.edu; boykin@ee.ucla.edu; vwani@ee.ucla.edu; Farrokh.Vatan@jpl.nasa.gov RI Bandyopadhyay, Somshubhro/A-1652-2015 NR 16 TC 271 Z9 273 U1 2 U2 6 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0178-4617 EI 1432-0541 J9 ALGORITHMICA JI Algorithmica PD DEC PY 2002 VL 34 IS 4 BP 512 EP 528 DI 10.1007/s00453-002-0980-7 PG 17 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 605AQ UT WOS:000178653600013 ER PT J AU Joubert, JM Latroche, M Bowman, RC Percheron-Guegan, A Bouree-Vigneron, F AF Joubert, JM Latroche, M Bowman, RC Percheron-Guegan, A Bouree-Vigneron, F TI Structural study of the LaNi46Ge0.4-D-2 system using X-ray and neutron powder diffraction SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article; Proceedings Paper CT International Conference on Neutron Scattering CY SEP 09-13, 2001 CL MUNICH, GERMANY ID DEGRADATION AB Intermetallic compounds that reversibly store hydrogen gas at room temperature and pressure are used in numerous devices including hydrogen gas storage units, fuel cells, hydrogen purification and heat-pump systems. LaNi5-xMx (M = Sn, Ge; 0 less than or equal to x less than or equal to 0.4), substitutional derivatives of LaNi5, are being used in sorption cryocoolers for applications in space. This study deals with structural characterizations of LaN4.6Ge0.4 and of its hydride (deuteride) including the hydrogen insertion sites in the metallic matrix and their occupancies. Results are compared to properties of Sn-substituted phases. C1 CNRS, ISCSA, LCMTR, F-94320 Thiais, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CE Saclay, CNRS, Leon Brillouin Lab, F-91191 Gif Sur Yvette, France. RP Latroche, M (reprint author), CNRS, ISCSA, LCMTR, 2 Rue H Dunant, F-94320 Thiais, France. RI Joubert, Jean-Marc/A-1259-2013; LATROCHE, MICHEL/L-6254-2014 OI LATROCHE, MICHEL/0000-0002-8677-8280 NR 10 TC 7 Z9 7 U1 0 U2 5 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD DEC PY 2002 VL 74 SU S BP S1037 EP S1039 DI 10.1007/s003390101189 PN 2 PG 3 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 649QN UT WOS:000181219600036 ER PT J AU Deamer, D Dworkin, JP Sandford, SA Bernstein, MP Allamandola, LJ AF Deamer, D Dworkin, JP Sandford, SA Bernstein, MP Allamandola, LJ TI The first cell membranes SO ASTROBIOLOGY LA English DT Review DE membranes; amphiphiles; self-assembly; prebiotic ID MURCHISON CARBONACEOUS CHONDRITE; SELF-REPRODUCING VESICLES; INTERSTELLAR ICE ANALOGS; MONOCARBOXYLIC ACIDS; AMINO-ACIDS; ULTRAVIOLET-IRRADIATION; PHOSPHOLIPID-BILAYERS; ENZYMATIC-SYNTHESIS; ORGANIC-MOLECULES; LIFE AB Organic compounds are synthesized in the interstellar medium and can be delivered to planetary surface's such as the early Earth, where they mix with endogenous species. Some of these compounds are. amphiphilic, having polar and nonpolar groups on the same molecule. Amphiphilic compounds spontaneously self-assemble into more complex structures such as bimolecular layers, which in turn form closed membranous vesicles. The first forms of cellular life required self-assembled membranes that were likely to have been produced from amphiphilic compounds on the prebiotic Earth. Laboratory simulations show that such vesicles readily encapsulate functional macromolecules, including nucleic acids and polymerases. The goal of future investigations will be to fabricate artificial cells as models of the origin of life. C1 Univ Calif Santa Cruz, Dept Chem & Biochem, Santa Cruz, CA 95064 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Ctr Study Life Universe, SETI Inst, Mountain View, CA USA. RP Deamer, D (reprint author), Univ Calif Santa Cruz, Dept Chem & Biochem, Santa Cruz, CA 95064 USA. EM deamer@hydrogen.ucsc.edu RI Dworkin, Jason/C-9417-2012 OI Dworkin, Jason/0000-0002-3961-8997 NR 73 TC 111 Z9 121 U1 3 U2 37 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD WIN PY 2002 VL 2 IS 4 BP 371 EP 381 DI 10.1089/153110702762470482 PG 11 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 671KT UT WOS:000182464500001 PM 12593777 ER PT J AU Bebout, BM Carpenter, SP Des Marais, DJ Discipulo, M Embaye, T Garcia-Pichel, F Hoehler, TM Hogan, M Jahnke, LL Keller, RM Miller, SR Prufert-Bebout, LE Raleigh, C Rothrock, M Turk, K AF Bebout, BM Carpenter, SP Des Marais, DJ Discipulo, M Embaye, T Garcia-Pichel, F Hoehler, TM Hogan, M Jahnke, LL Keller, RM Miller, SR Prufert-Bebout, LE Raleigh, C Rothrock, M Turk, K TI Long-term manipulations of intact microbial mat communities in a greenhouse collaboratory: Simulating Earth's present and past field environments SO ASTROBIOLOGY LA English DT Article DE microbial mat; biogeochemistry; biomarkers ID FATTY-ACIDS; CYANOBACTERIA; OXYGEN; SEDIMENTS; LIPIDS; MARINE; PHOTOSYNTHESIS; BACTERIA; CARBON; MICROGRADIENTS AB Photosynthetic microbial mat communities were obtained from marine hypersaline saltern ponds, maintained in a greenhouse facility, and examined for the effects of salinity variations. Because these microbial mats are considered to be useful analogs of ancient marine communities, they offer insights about evolutionary events during the >3 billion year time interval wherein mats co-evolved with Earth's lithosphere and atmosphere. Although photosynthetic mats can be highly dynamic and exhibit extremely high activity, the mats in the present study have been maintained for >1 year with relatively minor changes. The major groups of microorganisms, as assayed using microscopic, genetic, and biomarker methodologies, are essentially the same as those in the original field samples. Field and greenhouse mats were similar with respect to rates of exchange of oxygen and dissolved inorganic carbon across the mat-water interface, both during the day and at, night. Field and greenhouse mats exhibited similar rates of efflux of methane and hydrogen. Manipulations of salinity in the water overlying the mats produced changes in the community that strongly resemble those observed in the field. A collaboratory testbed and an array of automated features are being developed to support remote scientific experimentation with the assistance of intelligent software agents. This facility will permit teams of investigators the opportunity to explore ancient environmental conditions that are rare or absent today but that might have influenced the early evolution of these photosynthetic ecosystems. C1 NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Computat Sci Div, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA USA. Arizona State Univ, Dept Microbiol, Tempe, AZ 85287 USA. Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95064 USA. N Carolina State Univ, Dept Genet, Raleigh, NC 27695 USA. Montana State Univ, Bozeman, MT 59717 USA. RP Bebout, BM (reprint author), NASA, Ames Res Ctr, Exobiol Branch, Mail Stop 239-4, Moffett Field, CA 94035 USA. NR 57 TC 40 Z9 43 U1 0 U2 10 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD WIN PY 2002 VL 2 IS 4 BP 383 EP 402 DI 10.1089/153110702762470491 PG 20 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 671KT UT WOS:000182464500002 PM 12593778 ER PT J AU Noll, KS Stephens, DC Grundy, WM Millis, RL Spencer, J Buie, MW Tegler, SC Romanishin, W Cruikshank, DP AF Noll, KS Stephens, DC Grundy, WM Millis, RL Spencer, J Buie, MW Tegler, SC Romanishin, W Cruikshank, DP TI Detection of two binary trans-Neptunian objects, 1997 CQ(29) and 2000 CF105, with the Hubble Space Telescope SO ASTRONOMICAL JOURNAL LA English DT Article DE Kuiper belt; Oort cloud ID KUIPER-BELT OBJECTS; CHARGE-TRANSFER EFFICIENCY; PLUTO; SATELLITE; SPECTRA; WFPC2 AB Images of the trans-Neptunian objects 1997 CQ(29) and 2000 CF105 obtained with the Hubble Space Telescope WFPC2 camera show them to be binary. The two components of 1997 CQ29 were separated in our images by 0."20 +/- 0."03 in 2001 November and by 0."33 +/- 0."01 in 2002 June/July. The corresponding minimum physical distances are 6100 and 10,200 km. The companion to 2000 CF105 was 0."78 +/- 0."03 from the primary, at least 23,400 km. Six other objects in the trans-Neptunian region, including Pluto and its moon Charon, are known to be binaries; 1997 CQ29 and 2000 CF105 are the seventh and eighth known pair. Binarity appears to be a not uncommon characteristic in this region of the solar system, with detectable companions present in 4% +/- 2% of the objects we have examined. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Lowell Observ, Flagstaff, AZ 86001 USA. No Arizona Univ, Dept Phys & Astron, Flagstaff, AZ 86011 USA. Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Noll, KS (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. RI Noll, Keith/C-8447-2012 NR 27 TC 19 Z9 19 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD DEC PY 2002 VL 124 IS 6 BP 3424 EP 3429 DI 10.1086/344762 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 617KW UT WOS:000179361700035 ER PT J AU Popov, MV Bartel, N Cannon, WH Novikov, AY Kondratiev, VI Altunin, VI AF Popov, MV Bartel, N Cannon, WH Novikov, AY Kondratiev, VI Altunin, VI TI Pulsar microstructure and its quasi-periodicities with the S2VLBI system at a resolution of 62.5 nanoseconds SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : pulsars : general; radio continuum : stars; methods : data analysis; methods : observational ID NONRADIAL OSCILLATIONS; EMISSION MECHANISM; EMPIRICAL-THEORY; NEUTRON STARS; GIANT PULSES; CRAB PULSAR; RADIO; PSR-1133+16; FREQUENCIES; DISPERSION AB We report a study of microstructure and its quasi-periodicities of three pulsars at 1.65 GHz with the S2 VLBI system at a resolution of 62.5 ns, by far the highest for any such statistical study yet. For PSR B1929+10 we found in the average cross-correlation function (CCF) broad microstructure with a characteristic timescale of 95 +/- 10 mus and confirmed microstructure with characteristic timescales between 100 and 450 mus for PSRs B0950+08 and B1133+16. On a finer scale PSRs B0950+08, B1133+16 (component II) and B1929+10 show narrow microstructure with a characteristic timescale in the CCFs of similar to10 mus, the shortest found in the average CCF or autocorrelation function (ACF) for any pulsar, apart perhaps for the Crab pulsar. Histograms of microstructure widths are skewed heavily toward shorter timescales but display a sharp cutoff. The shortest micropulses have widths between 2 and 7 mus. There is some indication that the timescales of the broad, narrow, and shortest micropulses are, at least partly, related to the widths of the components of the integrated profiles and the subpulse widths. If the shortest micropulses observed are indeed due to beaming then the ratio,., of the relativistic energy of the emitting particles to the rest energy is about 20 000, independent of the pulsar period. We predict an observable lower limit for the width of micropulses from these pulsars at 1.65 GHz of 0.5 mus. If the short micropulses are instead interpreted as a radial modulation of the radiation pattern, then the associated emitting sources have dimensions of about 3 km in the observer's frame. For PSRs B0950+08 and B1133+16 ( both components) the micropulses had a residual dispersion delay over a 16-MHz frequency difference of similar to2 mus when compared to that of average pulse profiles over a much larger relative and absolute frequency range. This residual delay is likely the result of propagation effects in the pulsar magnetosphere that contribute to limiting the width of micropulses. No nanopulses or unresolved pulse spikes were detected. Cross-power spectra of single pulses show a large range of complexity with single spectral features representing classic quasi-periodicities and broad and overlapping features with essentially no periodicities at all. Significant differences were found for the two components of PSR B1133+16 in every aspect of our statistical analysis of micropulses and their quasi-periodicities. Asymmetries in the magnetosphere and the hollow cone of emission above the polar cap of the neutron star may be responsible for these differences. C1 PN Lebedev Phys Inst, Ctr Astro Space, Moscow 117997, Russia. York Univ, Dept Phys & Astron, N York, ON M3J 1P3, Canada. CRESTech, Space Geodynam Lab, Toronto, ON M3J 3K1, Canada. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Popov, MV (reprint author), PN Lebedev Phys Inst, Ctr Astro Space, Profsoyuznaya 84-32, Moscow 117997, Russia. RI Popov, Mikhail/M-6118-2015; Kondratiev, Vladislav/N-1105-2015 OI Kondratiev, Vladislav/0000-0001-8864-7471 NR 58 TC 20 Z9 20 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2002 VL 396 IS 1 BP 171 EP 187 DI 10.1051/0004-6361:20021402 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 617YB UT WOS:000179387600016 ER PT J AU Karachentsev, ID Mitronova, SN Karachentseva, VE Kudrya, YN Jarrett, TH AF Karachentsev, ID Mitronova, SN Karachentseva, VE Kudrya, YN Jarrett, TH TI The 2MASS Tully-Fisher relation for flat edge-on galaxies SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : spiral; galaxies : fundamental parameters ID SPIRAL GALAXIES; SC GALAXIES; EXTINCTION; SAMPLE AB The spiral edge-on galaxies from the "Revised Flat Galaxy Catalog" (RFGC) are identified with the Extended Source Catalog of the Two Micron All Sky Survey (2MASS). The relative number of 2MASS detected galaxies is 2996/4236 = 0.71. We consider the statistical properties of the Tully-Fisher relations for the edge-on galaxies in the B, I, J, H, and K-s bands. The slope of derived TF relations increases steadily from 4.9 in the B band to 9.3 in the K one. The effect is mainly due to the internal extinction, which is different in dwarf and giant spiral galaxies seen edge-on, that leads to the tight correlation between galaxy color and luminosity. The moderate scatter of the RFGC galaxies in the "color-luminosity" diagram, 0.(m)86, provides us with a "cheap" method of mass measurements of distances to galaxies on the basis of modern photometric sky surveys. C1 Russian Acad Sci, Special Astrophys Observ, N Arkhyz 369167, KChR, Russia. Isaac Newton Inst Chile, SAO Branch, St Petersburg, Russia. Kiev Natl Univ, Astron Observ, UA-04053 Kiev, Ukraine. CALTECH, Jet Prop Lab, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. RP Mitronova, SN (reprint author), Russian Acad Sci, Special Astrophys Observ, N Arkhyz 369167, KChR, Russia. NR 27 TC 34 Z9 38 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD DEC PY 2002 VL 396 IS 2 BP 431 EP 438 DI 10.1051/0004-6361:20021451 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 621DY UT WOS:000179574300010 ER PT J AU Xu, J Bock, JJ Ganga, KM Gorjian, V Uemizu, K Kawada, M Lange, AE Matsumoto, T Watabe, T AF Xu, J Bock, JJ Ganga, KM Gorjian, V Uemizu, K Kawada, M Lange, AE Matsumoto, T Watabe, T TI Measurement of sky surface brightness fluctuations at lambda=4 microns SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; diffuse radiation; galaxies : individual (NGC 4565, NGC 5907); galaxies : statistics; infrared : galaxies ID BACKGROUND EXPERIMENT SEARCH; GALAXY COUNTS; INFRARED-EMISSION; DARK-MATTER; LIGHT; ANISOTROPY; SPECTRUM; DIRBE; MODEL; HALO AB We present a measurement of faint-source confusion in deep, wide-field 4 mum images. The 1.degrees8 x 1.degrees8 images with 1700 resolution are centered about the nearby edge-on spiral galaxies NGC 4565 and NGC 5907. After removing statistical noise and gain fluctuations in the focal plane array, we measure spatial fluctuations in the sky brightness to be deltanuI(nu) = 2.74 +/- 0.14 nW m(-2) sr(-1), approximately 1% of the diffuse background level observed in a single pixel. The brightness fluctuations are confirmed to be associated with the sky by subtracting sequential images of the same region. An autocorrelation analysis shows the fluctuations are well described by unresolved point sources. We see no evidence for surface brightness fluctuations on larger angular scales (2' < theta < 280). The statistical distribution of brightness fluctuations allows us to estimate the density of sources below the detection limit. We present a Monte Carlo analysis of the undetected sources, which appear to be dominated by galaxies. Galaxies producing detected sky fluctuations contribute nuI(nu)(>S) = 1.04(-0.34)(+0.86) nW m(-2) sr(-1) to the cosmic infrared background, evaluated at S = 4.0 x 10(-8) nW m(-2). From the fluctuation data we can determine the integrated source counts N(>S) = 1.79(-0.40)(+0.26) x 10(7) sr(-1), evaluated at S = 4.0 x 10(-8) nW m(-2). The observed fluctuations are consistent with reddened K-band galaxy number counts. The number counts of extracted point sources with flux nuF(nu) > 6.3 x 10(-7) nW m(-2) are dominated by stars and agree well with the Galactic stellar model of Wright & Reese. Removing the stellar contribution from DIRBE maps with zodiacal subtraction results in a residual brightness of 14.0 +/- 2.6 (22.2 +/- 5.9) nW m(-2) sr(-1) at 3.5 (4.9) mum for the NGC 5907 field and 24.0 +/- 2.7 (36.8 +/- 6.0) nW m(-2) sr(-1) at 3.5 (4.9) mum for the NGC 4565 field. The NGC 5907 residuals are consistent with tentative detections of the infrared background reported by Dwek & Arendt, Wright & Reese, and Gorjian, Wright, Chary. C1 CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Infrared Proc & Anal Ctr, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Nagoya Univ, Chikusa Ku, Nagoya, Aichi 4648602, Japan. CALTECH, Pasadena, CA 91125 USA. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Nagoya Univ, Chikusa Ku, Nagoya, Aichi 4648602, Japan. RP Xu, J (reprint author), CALTECH, MS 59-33, Pasadena, CA 91125 USA. EM jingx@physics.ucsb.edu; jjb@astro.caltech.edu; kmg@ipac.caltech.edu; vg@jpl.nasa.gov; uemizu@ir.isas.ac.jp; kawada@u.phys.nagoya-u.ac.jp; ael@astro.caltech.edu; matsumo@ir.isas.ac.jp; watabe@u.phys.nagoya-u.ac.jp NR 33 TC 7 Z9 7 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2002 VL 580 IS 2 BP 653 EP 662 DI 10.1086/343854 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 619DG UT WOS:000179458300003 ER PT J AU Israel, GL Covino, S Stella, L Campana, S Marconi, G Mereghetti, S Mignani, R Negueruela, I Oosterbroek, T Parmar, AN Burderi, L Angelini, L AF Israel, GL Covino, S Stella, L Campana, S Marconi, G Mereghetti, S Mignani, R Negueruela, I Oosterbroek, T Parmar, AN Burderi, L Angelini, L TI The detection of variability from the candidate infrared counterpart to the anomalous X-ray pulsar 1E 1048.1-59371 SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : stars; pulsars : general; pulsars : individual (1E 1048.1-5937); stars : variables : other; X-rays : stars ID MAGNETIZED NEUTRON-STARS; FIELD; AXAF AB We report on the detection of variability from the proposed IR counterpart to the anomalous X-ray pulsar (AXP) 1E 1048.1-5937 based on Chandra and ESO optical/IR deep observations carried out in 2001-2002. Within the narrow Chandra uncertainty region for 1E 1048.1-5937, we found only one relatively faint (J = 22.1 +/- 0.3, J-K-s = 2.4) source, while the recently proposed IR counterpart was not detected down to a limiting K-s magnitude of similar to20.7 (3 sigma confidence level). This implies a remarkable IR brightening of this object, DeltaK(s) > 1.3, on a timescale of about 50 days. Although our knowledge of the IR properties of AXPs is rather limited (there is only one other source, 1E 2259+586, for which IR variability has been detected), the observed IR variability of the proposed counterpart strengthens its association with 1E 1048.1-5937. Our results make the IR (and presumably optical) variability a likely common characteristic of AXPs and provide new constraints on this class of objects. C1 Osserv Astron Brera, INAF, I-23807 Merate, Lc, Italy. European So Observ, Santiago 19, Chile. CNR, Ist Fis Cosm G Occhialini, I-20133 Milan, Italy. European So Observ, D-85748 Garching, Germany. Univ Alicante, Dept Fis Igegneria Sistemas & Teoria Senales, E-03080 Alicante, Spain. European Space Agcy, Estec, Res & Sci Support Dept, Astrophys Miss Div, NL-2200 AG Noordwijk, Netherlands. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Israel, GL (reprint author), Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy. RI Negueruela, Ignacio/L-5483-2014; OI Negueruela, Ignacio/0000-0003-1952-3680; Burderi, Luciano/0000-0001-5458-891X; Campana, Sergio/0000-0001-6278-1576; Parmar, Arvind/0000-0002-3307-6517; MEREGHETTI, SANDRO/0000-0003-3259-7801; Israel, GianLuca/0000-0001-5480-6438; Covino, Stefano/0000-0001-9078-5507 NR 24 TC 50 Z9 50 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2002 VL 580 IS 2 BP L143 EP L146 DI 10.1086/345612 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 619DL UT WOS:000179458700012 ER PT J AU Wang, HM Ji, HS Schmahl, EJ Qiu, J Liu, C Deng, N AF Wang, HM Ji, HS Schmahl, EJ Qiu, J Liu, C Deng, N TI Sudden disappearance of a small sunspot associated with the 2002 February 20 M2.4 flare SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : activity; Sun : flares; Sun : magnetic fields ID SOLAR-FLARE AB In this Letter, we present the evidence of rapid disappearance of a small sunspot associated with a M2.4 flare, which occurred in NOAA Active Region 9830, at 2106 UT, on 2002 February 20. The sunspot, in the size of about 45 arcsec(2), completely disappeared in about 60 minutes, coinciding with the onset of the flare. The magnetic flux of this sunspot disappeared in the similar timescale. Furthermore, we found that the disappearing sunspot is located near the edge of the main hard X-ray source observed by RHESSI. This hard X-ray source is located in the magnetic neutral line dividing the disappearing spot and the opposite polarity flux. Two possible explanations are offered: (1) the disappearing sunspot is due to the rapid magnetic reconnection and subsequent submergence; (2) the disappearing sunspot represents impulsive emergence and detachment of a magnetic "bubble." C1 New Jersey Inst Technol, Big Bear Solar Observ, Big Bear City, CA 92314 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. New Jersey Inst Technol, Ctr Solar Res, Newark, NJ 07102 USA. RP Wang, HM (reprint author), New Jersey Inst Technol, Big Bear Solar Observ, 40386 N Shore Lane, Big Bear City, CA 92314 USA. OI Deng, Na/0000-0001-8179-812X; Liu, Chang/0000-0002-6178-7471 NR 15 TC 21 Z9 21 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2002 VL 580 IS 2 BP L177 EP L180 DI 10.1086/345713 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 619DL UT WOS:000179458700019 ER PT J AU Wolff, CL AF Wolff, CL TI Rotational sequences of global oscillations inside the Sun SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : oscillations; Sun : activity; Sun : interior; Sun : oscillations ID SOLAR CORE; MODES; STAR AB A very simple mathematical sequence is detected in a half-century of thermal radio flux from the Sun. Since the only known solar source for the sequence is global oscillations trapped in the nonconvecting interior, g-modes and probably r-modes are active. If so, their rotation frequencies are detected and some previously reported difference frequencies are confirmed with high confidence. All angular harmonics for 2 less than or equal to l less than or equal to 7 are detected as well as some others up to the limit resolvable by the observations ( a Fourier spectrum of the 10.7 cm flux time series). The mean sidereal rotation rate of the nonconvecting interior is 428.2 nHz as averaged by g-modes and 429.8 nHz by the r-modes, indicating that g-mode energy is a bit more centrally concentrated. Helioseismology measures such rotation rates near 0.36R (R = solar radius), so the global modes would have about half their kinetic energy above and below that level. This, and the known log (r) energy dependence of most modes, implies that these oscillations are significantly reflected near 0.18R, the same level at which sound speed measurements display a maximum departure from theoretical models. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Wolff, CL (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. OI Wolff, Charles/0000-0001-8854-507X NR 20 TC 11 Z9 11 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD DEC 1 PY 2002 VL 580 IS 2 BP L181 EP L184 DI 10.1086/345712 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 619DL UT WOS:000179458700020 ER PT J AU Zingale, M Dursi, LJ ZuHone, J Calder, AC Fryxell, B Plewa, T Truran, JW Caceres, A Olson, K Ricker, PM Riley, K Rosner, R Siegel, A Timmes, FX Vladimirova, N AF Zingale, M Dursi, LJ ZuHone, J Calder, AC Fryxell, B Plewa, T Truran, JW Caceres, A Olson, K Ricker, PM Riley, K Rosner, R Siegel, A Timmes, FX Vladimirova, N TI Mapping initial hydrostatic models in Godunov codes SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE hydrodynamics; methods : numerical; stellar dynamics ID HYDRODYNAMICS; SIMULATIONS; EVOLUTION; STARS AB We look in detail at the process of mapping an astrophysical initial model from a stellar evolution code onto the computational grid of an explicit, Godunov-type code while maintaining hydrostatic equilibrium. This mapping process is common in astrophysical simulations, when it is necessary to follow short-timescale dynamics after a period of long-timescale buildup. We look at the effects of spatial resolution, boundary conditions, the treatment of the gravitational source terms in the hydrodynamics solver, and the initialization process itself. We conclude with a summary detailing the mapping process that yields the lowest ambient velocities in the mapped model. C1 Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Ctr Astrophys & Thermonucl Flashes, Chicago, IL 60637 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Nicholas Copernicus Astron Ctr, PL-87100 Torun, Poland. NASA, Goddard Space Flight Ctr, UMBC, GEST, Greenbelt, MD 20771 USA. RP Zingale, M (reprint author), Univ Calif Santa Cruz, Dept Astron & Astrophys, 477 Clark Kerr Hall, Santa Cruz, CA 95064 USA. RI Plewa, Tomasz/C-1470-2010; Calder, Alan/E-5348-2011; OI Plewa, Tomasz/0000-0002-1762-2565; Zingale, Michael/0000-0001-8401-030X; Dursi, Jonathan/0000-0002-4697-798X NR 22 TC 60 Z9 60 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD DEC PY 2002 VL 143 IS 2 BP 539 EP 565 DI 10.1086/342754 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 617KX UT WOS:000179361800011 ER PT J AU Hobbs, A Williamson, A AF Hobbs, A Williamson, A TI Human factor determinants of worker safety and work quality outcomes SO AUSTRALIAN JOURNAL OF PSYCHOLOGY LA English DT Article AB The circumstances leading up to 619 safety occurrences that occurred during aircraft maintenance were examined. Ninety-six per cent of the occurrences were at least partly attributable to human actions and in most cases, these actions took the form of errors. The most frequent errors were memory lapses, rule violations and skill-based slips. Worker safety occurrences tended to be preceded by skill-based slips, whereas work quality occurrences tended to be preceded by memory lapses. It is apparent that safety interventions must take into account the associations between error forms and outcomes. RP Hobbs, A (reprint author), San Jose State Univ, NASA, Ames Res Ctr, Mail Stop 262-4, Moffett Field, CA 94035 USA. NR 24 TC 2 Z9 2 U1 1 U2 4 PU AUSTRALIAN PSYCHOLOGICAL SOC PI CARLTON PA 1 GRATTAN STREET, CARLTON, VICTORIA 3053, AUSTRALIA SN 0004-9530 J9 AUST J PSYCHOL JI Aust. J. Psychol. PD DEC PY 2002 VL 54 IS 3 BP 157 EP 161 DI 10.1080/00049530412331312734 PG 5 WC Psychology, Multidisciplinary SC Psychology GA 635XZ UT WOS:000180426600006 ER PT J AU Gontcharov, IB Kovachevich, IV Pool, SL Navinkov, AL Barratt, MR AF Gontcharov, IB Kovachevich, IV Pool, SL Navinkov, AL Barratt, MR TI Medical care system for NASA-Mir spaceflights SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE space station; medical care systems; in-flight medical kits AB A fundamental goal of space medicine is to maintain the health and fitness of spacecrews. Meeting this goal requires reliable, effective, up-to-date medical support systems for use in microgravity. This article describes some of the factors considered in the design and assembly of Russian and U.S. in-flight medical care systems. The successful mutual use of U.S. and Russian medications and medical equipment under the NASA-Mir program conclusively demonstrated the importance and advantages of cooperation among participating space agencies. Continued progress toward the integration of U.S. and Russian flight medical systems will further increase the effectiveness of the medical support of joint missions aboard the International Space Station. C1 NASA, Lyndon B Johnson Space Ctr, Astronaut Off, Houston, TX 77058 USA. Russian Federat State Sci Ctr, Inst Biomed Problems, Moscow, Russia. Wyle Labs, Houston, TX USA. RP Pool, SL (reprint author), NASA, Lyndon B Johnson Space Ctr, Astronaut Off, Mail Code SA, Houston, TX 77058 USA. NR 9 TC 2 Z9 2 U1 1 U2 1 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD DEC PY 2002 VL 73 IS 12 BP 1219 EP 1223 PG 5 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 623UA UT WOS:000179720200011 PM 12498552 ER PT J AU Kuligowski, DR Winans, GA AF Kuligowski, DR Winans, GA TI Inorganic pyrophosphatase: A new polymorphic allozyme locus in Pacific salmon SO BIOCHEMICAL GENETICS LA English DT Article DE inorganic pyrophosphatase; genetic polymorphism; isolocus; electrophoresis; Pacific salmon ID VARIABILITY; NORTHWEST AB Genetic polymorphism of inorganic pyrophosphatase was investigated in 2799 individuals in four species of Pacific salmon: chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), kokanee (O. nerka), and steelhead (O. mykiss), using horizontal starch gel electrophoresis. This enzyme system appears to be an isolocus system with electrophoretically indistinguishable allozymes encoded by two loci (PP-1,2*) expressed in retinal tissue. Mendelian inheritance was observed with a breeding study in three family crosses. Population variability in four species was characterized in 44 populations from the U. S. Pacific coast. Three alleles were found in chinook salmon; two alleles each were found in coho salmon, kokanee, and steelhead. Chinook salmon and kokanee populations differed enough with respect to PP-1,2* frequencies that this isolocus is useful for genetic stock identification in these species. C1 Natl Marine Fisheries Serv, Manchester Res Stn, Manchester, WA 98353 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Conservat Biol Div, Seattle, WA 98112 USA. RP Kuligowski, DR (reprint author), Natl Marine Fisheries Serv, Manchester Res Stn, POB 130, Manchester, WA 98353 USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0006-2928 J9 BIOCHEM GENET JI Biochem. Genet. PD DEC PY 2002 VL 40 IS 11-12 BP 379 EP 385 DI 10.1023/A:1020773427693 PG 7 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA 607JT UT WOS:000178789000002 PM 12463346 ER PT J AU Adami, C AF Adami, C TI What is complexity? SO BIOESSAYS LA English DT Review ID DIGITAL ORGANISMS; EVOLUTION; SEQUENCES; TREND AB Arguments for or against a trend in the evolution of complexity are weakened by the lack of an unambiguous definition of complexity. Such definitions abound for both dynamical systems and biological organisms, but have drawbacks of either a conceptual or a practical nature. Physical complexity, a measure based on automata theory and information theory, is a simple and intuitive measure of the amount of information that an organism stores, in its genome, about the environment in which it evolves. It is argued that physical complexity must increase in molecular evolution of asexual organisms in a single niche if the environment does not change, due to natural selection. It is possible that complexity decreases in co-evolving systems as well as at high mutation rates, in sexual populations, and in time-dependent landscapes. However, it is reasoned that these factors usually help, rather than hinder, the evolution of complexity, and that a theory of physical complexity for co-evolving species will reveal an overall trend towards higher complexity in biological evolution. (C) 2002 Wiley Periodicals, Inc. C1 CALTECH, Digital Life Lab, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Adami, C (reprint author), CALTECH, Digital Life Lab, 136-93, Pasadena, CA 91125 USA. RI Adami, Christoph/A-5181-2009; Adami, Christoph/A-9675-2011 OI Adami, Christoph/0000-0002-2915-9504 NR 37 TC 131 Z9 135 U1 1 U2 31 PU COMPANY OF BIOLOGISTS LTD PI CAMBRIDGE PA BIDDER BUILDING CAMBRIDGE COMMERCIAL PARK COWLEY RD, CAMBRIDGE CB4 4DL, CAMBS, ENGLAND SN 0265-9247 J9 BIOESSAYS JI Bioessays PD DEC PY 2002 VL 24 IS 12 BP 1085 EP 1094 DI 10.1002/bies.10192 PG 10 WC Biochemistry & Molecular Biology; Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics GA 620DG UT WOS:000179517800002 PM 12447974 ER PT J AU Tou, J Ronca, A Grindeland, R Wade, C AF Tou, J Ronca, A Grindeland, R Wade, C TI Models to study gravitational biology of mammalian reproduction SO BIOLOGY OF REPRODUCTION LA English DT Review DE environment; female reproductive tract; fertilization; male reproductive tract; pituitary hormones ID DOWN BED REST; SPACE-FLIGHT; HORMONAL CHANGES; POSTPARTUM RATS; SPACEFLIGHT; PROLACTIN; WEIGHTLESSNESS; MICROGRAVITY; GESTATION; BODY AB Mammalian reproduction evolved within Earth's 1-g gravitational field. As we move closer to the reality of space habitation, there is growing scientific interest in how different gravitational states influence reproduction in mammals. Habitation of space and extended spaceflight missions require prolonged exposure to decreased gravity (hypogravity, i.e., weightlessness). Lift-off and re-entry of the spacecraft are associated with exposure to increased gravity (hypergravity). Existing data suggest that spaceflight is associated with a constellation of changes in reproductive physiology and function. However, limited spaceflight opportunities and confounding effects of various nongravitational factors associated with spaceflight (i.e., radiation, stress) have led to the development of ground-based models for studying the effects of altered gravity on biological systems. Human bed rest and rodent hindlimb unloading paradigms are used to study exposure to hypogravity. Centrifugation is used to study hypergravity. Here, we review the results of spaceflight and ground-based models of altered gravity on reproductive physiology. Studies utilizing ground-based models that simulate hyper- and hypogravity have produced reproductive results similar to those obtained from spaceflight and are contributing new information on biological responses across the gravity continuum, thereby confirming the appropriateness of these models for studying reproductive responses to altered gravity and the underlying mechanisms of these responses. Together, these unique tools are yielding new insights into the gravitational biology of reproduction in mammals. C1 NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA. RP Wade, C (reprint author), NASA, Ames Res Ctr, Div Life Sci, MS 239-11, Moffett Field, CA 94035 USA. FU PHS HHS [46485] NR 74 TC 16 Z9 17 U1 1 U2 8 PU SOC STUDY REPRODUCTION PI MADISON PA 1603 MONROE ST, MADISON, WI 53711-2021 USA SN 0006-3363 J9 BIOL REPROD JI Biol. Reprod. PD DEC PY 2002 VL 67 IS 6 BP 1681 EP 1687 DI 10.1095/biolreprod.102.007252 PG 7 WC Reproductive Biology SC Reproductive Biology GA 619JM UT WOS:000179472900004 PM 12444041 ER PT J AU Savary, CA Wirk, S Yetman, DL Tomasovic, SP Yu, D Pellis, NR AF Savary, CA Wirk, S Yetman, DL Tomasovic, SP Yu, D Pellis, NR TI Altered expression of heat shock proteins in breast cancer cells growing 3-dimensionally in a rotary cell culture system. SO BREAST CANCER RESEARCH AND TREATMENT LA English DT Meeting Abstract CT 25th San Antonio Breast Cancer Symposium CY DEC 11-14, 2002 CL SAN ANTONIO, TEXAS C1 Univ Texas, MD Anderson Canc Ctr, Houston, TX 77030 USA. Natl Aeronaut & Space Adm, Houston, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-6806 J9 BREAST CANCER RES TR JI Breast Cancer Res. Treat. PD DEC PY 2002 VL 76 SU 1 MA 585 BP S147 EP S147 PG 1 WC Oncology SC Oncology GA 624QA UT WOS:000179770100466 ER PT J AU Stephens, GL Vane, DG Boain, RJ Mace, GG Sassen, K Wang, ZE Illingworth, AJ O'Connor, EJ Rossow, WB Durden, SL Miller, SD Austin, RT Benedetti, A Mitrescu, C AF Stephens, GL Vane, DG Boain, RJ Mace, GG Sassen, K Wang, ZE Illingworth, AJ O'Connor, EJ Rossow, WB Durden, SL Miller, SD Austin, RT Benedetti, A Mitrescu, C CA CloudSat Sci Team TI The cloudsat mission and the a-train - A new dimension of space-based observations of clouds and precipitation SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID GENERAL-CIRCULATION MODEL; MILLIMETER-WAVE RADAR; LARGE-SCALE MODELS; MICROPHYSICAL PROCESSES; ATMOSPHERIC RADIATION; OPTICAL DEPTH; STRATUS CLOUD; ECMWF MODEL; CLIMATE; RETRIEVAL AB When launched in 2004, CloudSat-part of the new A-train constellation-will provide much needed measurements of the vertical structure of clouds from space. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. Univ Reading, Dept Meteorol, Reading, Berks, England. NASA, Goddard Inst Space Studies, Columbia, NY USA. USN, Res Lab, Monterey, CA USA. RP Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. EM stephens@atmos.colostate.edu RI Wang, Zhien/F-4857-2011; Rossow, William/F-3138-2015 NR 59 TC 1007 Z9 1039 U1 19 U2 90 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 EI 1520-0477 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD DEC PY 2002 VL 83 IS 12 BP 1771 EP 1790 DI 10.1175/BAMS-83-12-1771 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 637LP UT WOS:000180513300014 ER PT J AU Bishop, J Madejova, J Komadel, P Froschl, H AF Bishop, J Madejova, J Komadel, P Froschl, H TI The influence of structural Fe, Al and Mg on the infrared OH bands in spectra of dioctahedral smectites SO CLAY MINERALS LA English DT Article DE infrared spectroscopy; smectites; structural OH; montmorillonite; nontronite ID MOSSBAUER-SPECTROSCOPY; REFINED RELATIONSHIPS; CHEMICAL-COMPOSITION; STRETCHING REGION; MONTMORILLONITES; REFLECTANCE; MINERALS; IR; MARS AB Visible to near-infrared (NIR) reflectance spectra and mid-IR transmittance spectra are presented here for a collection of dioctahedral smectites. Analysis of the structural OH vibrations is performed by comparing the NIR combination and overtone bands with fundamental stretching and bending absorption features in the mid-IR region. Second derivatives are used to determine the actual band centres, which are often shifted slightly by a spectral continuum in the reflectance or transmittance spectra. New bands have been identified near 4170 and 4000 cm(-1) in the NIR spectra of nontronite with tetrahedral substitution. A related band is observed near 4100 cm(-1) for montmorillonites with substantial tetrahedral and/or octahedral substitution. These bands are correlated with the mid-IR bands near 680 cm(-1) for nontronite and near 630 cm(-1) for montmorillonite. Comparison of the OH overtone and combination bands with the fundamental stretching and bending vibrations gives consistent results. C1 NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. Slovak Acad Sci, Inst Inorgan Chem, SK-84236 Bratislava, Slovakia. Austrian Res Ctr Seiberdorf, A-2444 Seibersdorf, Austria. RP Bishop, J (reprint author), NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. EM jbishop@mail.arc.nasa.gov NR 23 TC 86 Z9 86 U1 3 U2 25 PU MINERALOGICAL SOC PI TWICKENHAM PA 12 BAYLIS MEWS, AMYAND PARK ROAD,, TWICKENHAM TW1 3HQ, MIDDLESEX, ENGLAND SN 0009-8558 J9 CLAY MINER JI Clay Min. PD DEC PY 2002 VL 37 IS 4 BP 607 EP 616 DI 10.1180/0009855023740063 PG 10 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy SC Chemistry; Geology; Mineralogy GA 629BT UT WOS:000180031100005 ER PT J AU Bishop, J Murad, E Dyar, MD AF Bishop, J Murad, E Dyar, MD TI The influence of octahedral and tetrahedral cation substitution on the structure of smectites and serpentines as observed through infrared spectroscopy SO CLAY MINERALS LA English DT Article DE infrared spectroscopy; smectites; serpentines; kaolinite; structural OH ID RESOLUTION REFLECTANCE SPECTROSCOPY; NONTRONITE; KAOLINITE; MONTMORILLONITES; DISSOLUTION; REDUCTION; LIZARDITE; MINERALS; SIZE; IRON AB Analysis of the near-infrared (NIR) spectral bands of phyllosilicates, together with the mid-infrared bands, enables testing and conformation of band assignments for the structural OH vibrations. Spectral analyses of selected smectites and serpentine-kaolin minerals are presented here. The results of this study indicate that dioctahedral smectites may contain both in-plane and out-of-plane OH-bending vibrations, as suggested by Farmer (1974). In-plane bands occur near 800-915 cm(-1), while the weaker out-of-plane vibrations occur near 600-700 cm(-1) and are enhanced in dioctahedral smectites when the structure is disrupted by substitutions. Analysis of the OH-stretching vibrations and their NIR overtone bands is also presented for both smectites and serpentine-kaolin minerals. These overtones are more straightforward for serpentines than for kaolinite, and a strong overtone associated with the kaolinite OH-stretching band at 3620 cm(-1) is found that supports its assignment as an OH-stretching band. C1 Bayer Geol Landesamt, D-95603 Markredwitz, Germany. Mt Holyoke Coll, Dept Earth & Environm, S Hadley, MA 01075 USA. NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. RP Bishop, J (reprint author), NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. NR 40 TC 79 Z9 79 U1 1 U2 10 PU MINERALOGICAL SOCIETY PI LONDON PA 41 QUEENS GATE, LONDON SW7 5HR, ENGLAND SN 0009-8558 J9 CLAY MINER JI Clay Min. PD DEC PY 2002 VL 37 IS 4 BP 617 EP 628 DI 10.1180/0009855023740064 PG 12 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy SC Chemistry; Geology; Mineralogy GA 629BT UT WOS:000180031100006 ER PT J AU Stroud, WJ Krishnamurthy, T Smith, SA AF Stroud, WJ Krishnamurthy, T Smith, SA TI Probabilistic and possibilistic analyses of the strength of a bonded joint SO CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES LA English DT Article DE bonded joint; probabilistic analysis; possibilistic analysis; fracture ID LAP-SHEAR SPECIMEN; ELEMENTS AB The effects of uncertainties on the predicted strength of a single lap shear joint are examined. Probabilistic and possibilistic methods are used to account for uncertainties. A total of ten variables are assumed to be random, with normal distributions. Both Monte Carlo Simulation and the First Order Reliability Method are used to determine the probability of failure. Triangular membership functions with upper and lower bounds located at plus or minus three standard deviations are used to model uncertainty in the possibilistic analysis. The alpha cut (or vertex) method is used to evaluate the possibility of failure. Linear and geometrically nonlinear finite element analyses are used calculate the response of the joint; fracture in the adhesive and material strength failure in the strap are used to evaluate its strength. Although probabilistic and possibilistic analyses provide significantly more information than do conventional deterministic analyses, they are computationally expensive. A novel scaling approach is-developed and used to substantially reduce the computational cost of the probabilistic and possibilistic analyses. The possibilistic approach for treating uncertainties appears to be viable during the conceptual and preliminary design stages when limited data are available and high accuracies are not needed. However, this viability is mixed with several cautions that are discussed herein. C1 USA, Res Lab, NASA,Langley Res ctr, Analyt & Computat Methods Branch,Vehicle Technol, Hampton, VA 23681 USA. RP Stroud, WJ (reprint author), USA, Res Lab, NASA,Langley Res ctr, Analyt & Computat Methods Branch,Vehicle Technol, Hampton, VA 23681 USA. NR 17 TC 10 Z9 10 U1 0 U2 1 PU TECH SCIENCE PRESS PI PALMDALE PA PO BOX 900486, PALMDALE, CA 93590-0486 USA SN 1526-1492 J9 CMES-COMP MODEL ENG JI CMES-Comp. Model. Eng. Sci. PD DEC PY 2002 VL 3 IS 6 BP 755 EP 772 PG 18 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 630AE UT WOS:000180084600006 ER PT J AU Barut, A Madenci, E Anderson, T Tessler, A AF Barut, A Madenci, E Anderson, T Tessler, A TI Equivalent single-layer theory for a complete stress field in sandwich panels under arbitrarily distributed loading SO COMPOSITE STRUCTURES LA English DT Article DE sandwich; single layer; virtual work; Fourier series; step loading ID PLATES; COMPOSITE AB In single-layer theory, the displacement components represent the weighted-average through the thickness of the sandwich panel. Although discrete-layer theories are more representative of sandwich construction than the single-layer theories, they suffer from an excessive number of field variables in proportion to the number of layers. In this study, utilizing Reissner's definitions for kinematics of thick plates, the displacement components at any point on the plate are approximated in terms of weighted-average quantities (displacements and rotations) that are functions of the in-plane coordinates. The equations of equilibrium and boundary conditions of the sandwich panel are derived by employing the principle of virtual displacements. The solution for an arbitrarily distributed load is obtained by employing Fourier series representations of the unknown field variables. This single-layer theory is validated against an analytical solution for simply supported square sandwich panels under pressure over a small region on the face sheet and is also compared with previous single-layer plate theories. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Arizona, Dept Aerosp & Mech Engn, Tucson, AZ 85721 USA. Univ Washington, Seattle, WA 98195 USA. NASA, Langley Res Ctr, Analyt & Computat Methods Branch, Hampton, VA 23681 USA. RP Madenci, E (reprint author), Univ Arizona, Dept Aerosp & Mech Engn, POB 210119, Tucson, AZ 85721 USA. EM madenci@email.arizona.edu RI Tessler, Alexander/A-4729-2009 NR 12 TC 13 Z9 13 U1 1 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0263-8223 EI 1879-1085 J9 COMPOS STRUCT JI Compos. Struct. PD DEC PY 2002 VL 58 IS 4 BP 483 EP 495 AR PII S0263-8223(02)00137-X DI 10.1016/S0263-8223(02)00137-X PG 13 WC Materials Science, Composites SC Materials Science GA 615NU UT WOS:000179253300008 ER PT J AU Popescu, SC Wynne, RH Nelson, RF AF Popescu, SC Wynne, RH Nelson, RF TI Estimating plot-level tree heights with lidar: local filtering with a canopy-height based variable window size SO COMPUTERS AND ELECTRONICS IN AGRICULTURE LA English DT Article; Proceedings Paper CT 2nd International Conference on Geospatial Information in Agriculture and Forestry CY JAN 10-12, 2000 CL FLORIDA DE lidar; forest inventory and analysis; tree height; interpolation; digital elevation model; variable window size ID LASER SCANNER DATA; FOREST STAND CHARACTERISTICS; AIRBORNE LIDAR; TERRAIN MODELS; TOPOGRAPHY; ALTIMETER; VOLUME; BIOMASS; SYSTEM AB In recent years, the use of airborne lidar technology to measure forest biophysical characteristics has been rapidly increasing. This paper discusses processing algorithms for deriving the terrain model and estimating tree heights by using a multiple return, highdensity, small-footprint lidar data set. The lidar data were acquired over deciduous, coniferous, and mixed stands of varying age classes and settings typical of the southeastern US. The specific objectives were: (1) to develop and test algorithms to estimate plot level tree height using lidar data, and (2) to investigate how ground measurements can help in the processing phase of lidar data for tree height assessment. The study area is located in the Piedmont physiographic province of Virginia, USA and includes a portion of the Appomattox-Buckingham State Forest (37degrees25'N, 78degrees41'W). Two lidar processing algorithms are discussed-the first based on single tree crown identification using a variable window size for local filtering, and the second based on the height of all laser pulses within the area covered by the ground truth data. Height estimates resulted from processing lidar data with both algorithms were compared to field measurements obtained with a plot design following the USDA Forest Service Forest Inventory and Analysis (FIA) field data layout. Linear regression was used to develop equations relating lidar-estimated parameters with field inventories for each of the FIA plots. As expected, the maximum height on each plot was predicted with the highest accuracy (R 2 values of 85 and 90%, for the first and the second algorithm, respectively). The variable window size algorithm performed better for predicting heights of dominant and co-dominant trees (R-2 values 84-85%), with a diameter at breast height (dbh) larger than 12.7 cm. (5 in), when compared with the algorithm based on all laserheights (R-2 values 57-73%). The use of field-based height thresholds when processing lidar data did not bring significant gains in explaining the total variation associated with tree height. The technique of local filtering with a variable window size considers fundamental forest bionietrics relationships and overall proved to give better results than the technique of all laser shots. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Virginia Tech, Dept Forestry, Blacksburg, VA 24061 USA. NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. RP Popescu, SC (reprint author), Virginia Tech, Dept Forestry, 319 Cheatham Hall, Blacksburg, VA 24061 USA. RI Popescu, Sorin/D-5981-2015 OI Popescu, Sorin/0000-0002-8155-8801 NR 37 TC 198 Z9 215 U1 3 U2 47 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0168-1699 J9 COMPUT ELECTRON AGR JI Comput. Electron. Agric. PD DEC PY 2002 VL 37 IS 1-3 SI SI BP 71 EP 95 AR PII S0168-1699(02)00121-7 DI 10.1016/S0168-1699(02)00121-7 PG 25 WC Agriculture, Multidisciplinary; Computer Science, Interdisciplinary Applications SC Agriculture; Computer Science GA 628UB UT WOS:000180014000007 ER PT J AU Schreckenghost, D Martin, C Bonasso, P Kortenkamp, D Milam, T Thronesbery, C AF Schreckenghost, D Martin, C Bonasso, P Kortenkamp, D Milam, T Thronesbery, C TI Supporting group interaction among humans and autonomous agents SO CONNECTION SCIENCE LA English DT Article; Proceedings Paper CT Workshop on Agent Autonomy in Group held in Conjunction with the AAAI 2002 Conference CY JUL, 2002 CL EDMONTON, CANADA DE multi-agent architecture; human-computer interaction; distributed collaboration; proxy agents; heterogeneous groups ID INTELLIGENT AB An important aspect of interaction among groups of humans and software agents is supporting collaboration among these heterogeneous agents while they operate remotely and communicate asynchronously. We are developing an architecture that supports multiple humans interacting with multiple automated control agents in such a manner. We are evaluating this architecture with a group consisting of the crew of a space-based vehicle and the automated software agents controlling the vehicle systems. Such agent interaction is modelled as a loosely co-ordinated group because this model minimizes agent commitment to group goals and constraints while addressing a significant portion of crew and control agent group behaviours. In this paper, we give background on human interaction with space-based automation. We identify related research in multi-agent autonomous architectures and single agent human-computer interaction systems, we describe our architecture design for human-software agent groups and we identify research issues in loosely co-ordinated human-software groups. C1 NASA, Lyndon B Johnson Space Ctr, TRACLabs, Houston, TX 77058 USA. RP Schreckenghost, D (reprint author), NASA, Lyndon B Johnson Space Ctr, TRACLabs, 1012 Hercules, Houston, TX 77058 USA. NR 28 TC 4 Z9 4 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0954-0091 J9 CONNECT SCI JI Connect. Sci. PD DEC PY 2002 VL 14 IS 4 BP 361 EP 369 DI 10.1080/0954009021000068709 PG 9 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA 667LB UT WOS:000182232600010 ER PT J AU Vercoutere, W Akeson, M AF Vercoutere, W Akeson, M TI Biosensors for DNA sequence detection SO CURRENT OPINION IN CHEMICAL BIOLOGY LA English DT Review ID SINGLE-NUCLEOTIDE POLYMORPHISMS; ACOUSTIC-WAVE SENSOR; MICROARRAYS; HYBRIDIZATION; DISCRIMINATION; AUTOMATION; MOLECULES; MUTATION; NANOPORE; GENOME AB DNA biosensors are being developed as alternatives to conventional DNA microarrays. These devices couple signal transduction directly to sequence recognition. Some of the most sensitive and functional technologies use fibre optics or electrochemical sensors in combination with DNA hybridization. In a shift from sequence recognition by hybridization, two emerging single-molecule techniques read sequence composition using zero-mode waveguides or electrical impedance in nanoscale pores. C1 NASA, Ames Res Ctr, Natl Space Grant Fdn, Bone Signaling Lab, Moffett Field, CA 94035 USA. Univ Calif Santa Cruz, Howard Hughes Med Inst, Dept Chem, Santa Cruz, CA 95064 USA. RP Vercoutere, W (reprint author), NASA, Ames Res Ctr, Natl Space Grant Fdn, Bone Signaling Lab, Mail Stop 236-7, Moffett Field, CA 94035 USA. NR 51 TC 108 Z9 110 U1 3 U2 33 PU CURRENT BIOLOGY LTD PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1367-5931 J9 CURR OPIN CHEM BIOL JI Curr. Opin. Chem. Biol. PD DEC PY 2002 VL 6 IS 6 BP 816 EP 822 DI 10.1016/S1367-5931(02)00395-2 PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 622GJ UT WOS:000179638400015 PM 12470736 ER PT J AU Hitzman, MW Redmond, PB Beaty, DW AF Hitzman, MW Redmond, PB Beaty, DW TI The carbonate-hosted Lisheen Zn-Pb-Ag deposit, County Tipperary, Ireland SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID FLUID-FLOW; GENESIS; FAULT AB The Lisheen Zn-Pb-Ag deposit, located in County Tipperary in southeast-central Ireland, consists of a group of strata-bound pyritic sulfide lenses containing 22 Mt of ore with an overall grade of 11.5 percent Zn, 1.9 percent Pb, 26 g/t Ag, and 16 percent Fe hosted in Lower Carboniferous (Early Mississippian) carbonate rocks. Sulfide bodies at Lisheen are restricted to the Waulsortian mudbank complex and the Lisduff oolite unit of the Ballysteen limestone, which compose the stratigraphically lowest, nonargillaceous carbonate horizons in the local Lower Carboniferous succession. The deposit is located within a major right-stepping relay zone of a segmented normal fault system. Sulfide bodies occur adjacent to the normal faults; thickest development of sulfides generally occurs at points of maximum throw Metal zoning is well developed relative to these structures. The Waulsortian mudbank complex and portions of the overlying succession were subjected to air early, pre-mineralization, regional-scale dolomitizing event that increased permeability. The regional dolostone produced by this event is cut and replaced by hydrothermal dolomite, referred to as black matrix breccia and white matrix breccia, associated with mineralization. Hydrothermal dolomitization was most intense in the Waulsortian mudbank complex, though it locally affected rocks from the Silurian basement to more than 200 in above the level of major sulfide precipitation. The majority of the Lisheen deposit consists of Fe-Zn-Pb-Ag sulfides hosted in the black matrix breccia, regional dolomite and, to a much lesser extent, undolomitized limestone of the Waulsortian complex, Sulfide bodies at Lisheen consist of pyrite-marcasite, sphalerite, and galena with subsidiary sulfosalt minerals, arsenopyrite, and copper sulfides. Sulfides replace carbonate minerals and infill dissolution cavities. Gangue minerals intergrown with sulfides include dolomite, calcite, barite, and quartz. Mineral textures indicate a regular paragenetic sequence of sulfide deposition from early precipitation of colloform iron sulfide containing minor sphalerite and galena through deposition of a complex assemblage of sphalerite, galena, iron sulfides, sulfosalt minerals, and copper sulfides. Distribution of alteration and sulfide zones indicates that the Lisheen deposit formed as a prograding hydrothermal system. Textural and mineralogic evidence suggests that the hydrothermal fluids were relatively acidic and that reaction with the carbonate host rocks was a primary reason for sulfide precipitation. On the basis of the probable age of faulting and crosscutting relationships of the regional and hydrothernial dolomite, the maximum age of mineralization at Lisheen was at least 10 m.y. after host-rock deposition. C1 Colorado Sch Mines, Dept Geol & Geol Engn, Golden, CO 80401 USA. Stanford Univ, Dept Earth & Environm Sci, Stanford, CA 94305 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hitzman, MW (reprint author), Colorado Sch Mines, Dept Geol & Geol Engn, Golden, CO 80401 USA. NR 81 TC 22 Z9 23 U1 3 U2 14 PU ECONOMIC GEOLOGY PUBL CO PI LITTLETON PA 5808 SOUTH RAPP ST, STE 209, LITTLETON, CO 80120-1942 USA SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD DEC PY 2002 VL 97 IS 8 BP 1627 EP 1655 DI 10.2113/97.8.1627 PG 29 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 648YH UT WOS:000181179000001 ER PT J AU Hill, MR Panontin, TL AF Hill, MR Panontin, TL TI Micromechanical modeling of fracture initiation in 7050 aluminum SO ENGINEERING FRACTURE MECHANICS LA English DT Article DE fracture; aluminum; micromechanical modeling; constraint ID HIGH-STRENGTH STEELS; TRIAXIALITY PARAMETER; DUCTILE FAILURE; STRESS; MECHANISMS; FAMILY; FIELDS; STATE AB Mechanical testing and finite element calculations have been carried out to characterize the fracture initiation behavior of the high-strength aluminum alloy 7050-T7451. Results show that fracture initiation is well predicted for two specimen types of differing constraint using the stress-modified, critical plastic strain micromechanical, model. The relation between stress triaxiality and critical plastic strain was found from a series of notched tensile specimens. Data from these tests are interpreted using both companion finite element modeling and common, semi-empirical relations, and these two approaches are compared. Multiple, interrupted tests of standard, highly constrained single edge notched bend specimens are used to obtain the J-R curve in 7050 for small amounts of tearing to experimentally identify initiation. Companion modeling and the stress-modified, critical plastic strain relation are used to find the length scale for fracture, l* needed for initiation predictions. The calibrated stress-modified, critical plastic strain relation and length scale are then used to predict fracture initiation of a low-constraint specimen. The prediction is within 5% of the experimental measurements. Finally, various aspects of the procedure followed in the present work are compared to previous efforts using similar approaches. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hill, MR (reprint author), Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. RI Hill, Michael/A-2525-2016 OI Hill, Michael/0000-0002-9168-211X NR 30 TC 14 Z9 14 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-7944 J9 ENG FRACT MECH JI Eng. Fract. Mech. PD DEC PY 2002 VL 69 IS 18 BP 2163 EP 2186 AR PII S0013-7944(01)00148-5 DI 10.1016/S0013-7944(01)00148-5 PG 24 WC Mechanics SC Mechanics GA 613KX UT WOS:000179132400007 ER PT J AU Tubiello, FN Ewert, F AF Tubiello, FN Ewert, F TI Simulating the effects of elevated CO2 on crops: approaches and applications for climate change SO EUROPEAN JOURNAL OF AGRONOMY LA English DT Article; Proceedings Paper CT 2nd International Symposium on Modeling Cropping Systems CY JUL 16-18, 2001 CL FLORENCE, ITALY DE elevated CO2; crops; agriculture; modeling; climate change ID CARBON-DIOXIDE CONCENTRATION; ENRICHMENT FACE EXPERIMENT; WINTER-WHEAT; CHANGE IMPACTS; UNITED-STATES; SPRING WHEAT; CANOPY PHOTOSYNTHESIS; INCREASED TEMPERATURE; AGRICULTURAL IMPACTS; PRESENT TECHNOLOGY AB Several crop models may be used to simulate the effects of elevated CO2 on crop productivity. Yet no summary exists in the literature attempting to describe differences among models and how simulations might differ under climate change conditions. We provide an introductory review focusing on simulating the impacts of elevated CO2 on crops. We describe and discuss modeling approaches, component modules, applications to climate change and model validation and inter-comparison studies. By searching the recent peer-reviewed literature from 1995 to present, we found that about 20% of published crop modeling studies have focused on climate change impacts. About half of these studies explicitly analyzed the effects of elevated CO2 on crop growth and yield. Our analysis further suggested that the crop models that have been used the most in climate change assessments are also those that have been evaluated the least using available data from elevated CO2 experiments. Based on our review, we identify a set of recommendations aimed at improving our confidence in predictions of crop production under elevated CO2 and climate change conditions. These include continued model evaluation with existing field experiment data; increased focus on limiting factors such as pest, weeds, and disease; and attention to temporal and spatial scaling issues. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Columbia Univ, Goddard Inst Space Studies, New York, NY 10025 USA. Royal Vet & Agr Univ, Dept Agr Sci, DK-2630 Taastrup, Denmark. RP Tubiello, FN (reprint author), Columbia Univ, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. NR 138 TC 134 Z9 136 U1 4 U2 38 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1161-0301 J9 EUR J AGRON JI Eur. J. Agron. PD DEC PY 2002 VL 18 IS 1-2 BP 57 EP 74 AR PII S1161-0301(02)00097-7 DI 10.1016/S1161-0301(02)00097-7 PG 18 WC Agronomy SC Agriculture GA 632FY UT WOS:000180214300005 ER PT J AU Stein, LY Jones, G Alexander, B Elmund, K Wright-Jones, C Nealson, KH AF Stein, LY Jones, G Alexander, B Elmund, K Wright-Jones, C Nealson, KH TI Intriguing microbial diversity associated with metal-rich particles from a freshwater reservoir SO FEMS MICROBIOLOGY ECOLOGY LA English DT Article DE Candidate Division OP10; Archaea; manganese; microbial diversity; freshwater ID RIBOSOMAL-RNA GENES; MICROORGANISM METALLOGENIUM; COMMUNITY STRUCTURE; SEQUENCE-ANALYSIS; LAKE WASHINGTON; MANGANESE; BACTERIAL; ARCHAEA; LEVEL; CONSORTIUM AB During the late summer to early fall, Horsetooth Reservoir in Fort Collins, CO, USA is fully stratified and exhibits seasonally high fluxes of iron, manganese, and metal-rich particles into the water column. Particles were collected from the mid-region of the hypolimnion and examined for metal content. Nucleic acids extracted from the particles were used to construct bacterial and archaeal 16S rDNA clone libraries. Surprisingly, 50% of cloned bacterial genes were closely related to a coherent cluster within Candidate Division OP10. To our knowledge, this is the first report of an environmental gene clone library that exhibits a dominance of OP10-related clones. Several other sequences, many with long branch lengths, clustered within eight separate bacterial divisions and the diatom chloroplasts. Most of these divisions are commonly found in freshwater environments. However, gene sequences from characterized metal-oxidizing or metal-reducing bacteria were not identified. The archaeal gene clone libraries contained diverse sequences, most with close homology to previously characterized gene clones of methanogens or uncultivated Crenarchaeota from soil and lacustrine environments. This study identified a unique environment where OP10 bacteria are potentially abundant. Furthermore, we demonstrated that the metal-rich particles from this reservoir support a diverse and interesting community of microorganisms. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91121 USA. City Ft Collins Util, Ft Collins, CO 80521 USA. NASA, Jet Prop Lab, Ctr Life Detect, Pasadena, CA 91109 USA. RP Stein, LY (reprint author), Univ Calif Riverside, Dept Environm Sci, Geol 2217, Riverside, CA 92521 USA. EM lisa.stein@ucr.edu RI Stein, Lisa/E-6374-2016 OI Stein, Lisa/0000-0001-5095-5022 NR 36 TC 50 Z9 55 U1 1 U2 10 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0168-6496 J9 FEMS MICROBIOL ECOL JI FEMS Microbiol. Ecol. PD DEC PY 2002 VL 42 IS 3 BP 431 EP 440 AR PII S0168-6496(02)00360-4 PG 10 WC Microbiology SC Microbiology GA 620QY UT WOS:000179545100011 PM 19709302 ER PT J AU Mulavara, AP Verstraete, MC Bloomberg, JJ AF Mulavara, AP Verstraete, MC Bloomberg, JJ TI Modulation of head movement control in humans during treadmill walking SO GAIT & POSTURE LA English DT Article DE gait; head-trunk coordination; gaze; angular displacement; neck moments ID SPACE-FLIGHT; GAZE STABILIZATION; RANDOM ROTATIONS; TARGET DISTANCE; LOCOMOTOR TASKS; TRUNK MOVEMENTS; VELOCITY; DYNAMICS; PLANE; BODY AB The purpose of this study was to investigate the coordination of the head relative to the trunk, within a gait cycle during gaze fixation. Nine normal subjects walked on a motorized treadmill driven at 1.79 m/s (20 s trials) while fixing their gaze on a centrally located earth-fixed target positioned at a distance of 2 m from their eyes. The net and relative angular motions of the head about the three axes of rotations, as well as the corresponding values for the moments acting on it relative to the trunk during the gait cycle were quantified and used as measures of coordination. The average net moment, as well as the average moments about the different axes were significantly different (P < 0.01) between the high impact and low/no impact phases of the gait cycle. However, the average net angular displacement as well as the average angular displacement about the axial rotation axis of the head relative to the trunk was maintained uniform (P > 0.01) throughout the gait cycle. The average angular displacement about the lateral bending axis was significantly increased (P < 0.01) during the high impact phase while that about the flexion-extension axis was significantly decreased (P <0.01) throughout the gait cycle. Thus, the coordination of the motion of the head relative to the trunk during walking is dynamically modulated depending on the behavioral events occurring in the gait cycle. This modulation may serve to aid stabilization of the head by counteracting the force variations acting on the upper body that may aid in the visual fixation of targets during walking. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Wyle Labs, Neurosci Labs, Houston, TX 77058 USA. Univ Akron, Dept Biomed Engn, Akron, OH 44325 USA. NASA, Lyndon B Johnson Space Ctr, Neurosci Labs, Houston, TX 77058 USA. RP Mulavara, AP (reprint author), Baylor Coll Med, Bobby R Alford Dept Otorhinolaryngol & Communucat, Natl Space Biomed Res Inst, Houston, TX 77030 USA. EM ajitkumar.mulavaral@jsc.nasa.gov NR 54 TC 25 Z9 25 U1 0 U2 12 PU ELSEVIER IRELAND LTD PI CLARE PA ELSEVIER HOUSE, BROOKVALE PLAZA, EAST PARK SHANNON, CO, CLARE, 00000, IRELAND SN 0966-6362 EI 1879-2219 J9 GAIT POSTURE JI Gait Posture PD DEC PY 2002 VL 16 IS 3 BP 271 EP 282 AR PII S0966-6362(02)00016-4 DI 10.1016/S0966-6362(02)00016-4 PG 12 WC Neurosciences; Orthopedics; Sport Sciences SC Neurosciences & Neurology; Orthopedics; Sport Sciences GA 630RR UT WOS:000180123100007 PM 12443952 ER PT J AU Miller, C Mulavara, A Bloomberg, J AF Miller, C Mulavara, A Bloomberg, J TI A quasi-static method for determining the characteristics of a motion capture camera system in a "split-volume" configuration SO GAIT & POSTURE LA English DT Article DE kinematics; measurement; split-volume; accuracy; resolution; repeatability ID ACCURACY; PERFORMANCE AB The purpose of this study was to determine the accuracy, repeatability and resolution of a six-camera Motion Analysis system in a vertical split-volume configuration using a unique quasi-static methodology. The position of a reflective marker was recorded while it was moved quasi-statically over a range of 2.54 mm (0.100 inches) via a linearly-translating table. The table was placed at five different heights to cover both sub-volumes and the overlapping region. Data analysis showed that accuracy, repeatability and resolution values were consistent across all regions of the split-volume. including the overlapping section. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Wyle Labs, Neurosci Labs, Houston, TX 77058 USA. Baylor Coll Med, Dept Otorhinolaryngol, Houston, TX USA. NASA, Johnson Space Ctr, Neurosci Lab, Houston, TX USA. RP Miller, C (reprint author), Wyle Labs, Neurosci Labs, Mail Code NL-37,1290 Nercules Dr,Suite 120, Houston, TX 77058 USA. NR 9 TC 17 Z9 17 U1 1 U2 2 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0966-6362 J9 GAIT POSTURE JI Gait Posture PD DEC PY 2002 VL 16 IS 3 BP 283 EP 287 AR PII S0966-6362(02)00019-X DI 10.1016/S0966-6362(02)00019-X PG 5 WC Neurosciences; Orthopedics; Sport Sciences SC Neurosciences & Neurology; Orthopedics; Sport Sciences GA 630RR UT WOS:000180123100008 PM 12443953 ER PT J AU Douglas, S Yang, HX AF Douglas, S Yang, HX TI Mineral biosignatures in evaporites: Presence of rosickyite in an endoevaporitic microbial community from Death Valley, California SO GEOLOGY LA English DT Article DE evaporites; geomicrobiology; Death Valley; rosickyite ID DEPOSITION; SULFUR; GULF; CARBONATES; BACTERIA; REGION; GYPSUM; EGYPT; LAKES; SUEZ AB Rosickyite is a rare form of sulfur (gamma-sulfur; monoclinic symmetry) that is not thermodynamically predicted to be stable at Earth's surface temperatures; instead, it reverts to the more common ot-sulfur form (orthorhombic symmetry). Here we show, for the first time, that rosickyite exists and is stably maintained within an endoevaporitic microbial community from the salt pan of Death Valley, California. We hypothesize that this mineral is formed by a cycle of microbial dissolution of gypsum (CaSO4.2H(2)O) to sulfide and reoxidation of the sulfide to elemental sulfur (rosickyite) within a stable oxygen-sulfide gradient maintained by the organisms. Furthermore, we report a microstratigraphic layering of mineral types that correlates with layering of the microbial community. Knowledge of how microbial communities can affect the mineral assemblages of evaporite deposits on Earth can help us to identify potential markers of the past or present existence of life on extraterrestrial bodies bearing evidence of ancient seas or lakes. C1 CALTECH, Jet Prop Lab, Ctr Life Detect, Pasadena, CA 91109 USA. RP Douglas, S (reprint author), CALTECH, Jet Prop Lab, Ctr Life Detect, 4800 Oak Grove Dr,MS 183-301, Pasadena, CA 91109 USA. NR 27 TC 31 Z9 33 U1 1 U2 5 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD DEC PY 2002 VL 30 IS 12 BP 1075 EP 1078 DI 10.1130/0091-7613(2002)030<1075:MBIEPO>2.0.CO;2 PG 4 WC Geology SC Geology GA 624AZ UT WOS:000179738400006 ER PT J AU Wang, GL Eltahir, EAB AF Wang, GL Eltahir, EAB TI Impact of CO2 concentration changes on the biosphere-atmosphere system of West Africa SO GLOBAL CHANGE BIOLOGY LA English DT Article DE CO2-induced climate changes; drought; plant-water relation; vegetation dynamics; water-use efficiency; West Africa; biosphere-atmosphere interactions ID TROPICAL NORTH-AFRICA; TALLGRASS PRAIRIE ECOSYSTEM; LAND-SURFACE PROPERTIES; CLIMATE-CHANGE; ELEVATED CO2; VEGETATION FEEDBACKS; BIOMASS PRODUCTION; SUMMER RAINFALL; SAHEL CLIMATE; CARBON-CYCLE AB Vegetation dynamics plays a critical role in causing the decadal variability of precipitation over the Sahel region of West Africa. However, the potential impact of changes in CO2 concentration on vegetation dynamics and precipitation variability of this region has not been addressed by previous studies. In this paper, we explore the role of CO2 concentration in the regional climate system of West Africa using a zonally symmetric, synchronously coupled biosphere-atmosphere model. We first document the response of precipitation and vegetation to incremental changes of CO2 concentration; the impact of CO2 concentration on the variability of the regional biosphere-atmosphere system is then addressed using the second half of the twentieth century as an example. An increase of CO2 concentration causes the regional biosphere-atmosphere system to become wetter and greener, with the radiative effect of CO2 and improved plant-water relation dominant in the Sahelian grassland region and the direct enhancement of leaf carbon assimilation dominant in the tree-covered region to the south. Driven by the observed sea surface temperature (SST) of the tropical Atlantic Ocean during the period 1950-97 and with CO2 concentration prescribed at a pre-industrial level 300ppmv, the model simulates a persistent Sahel drought during the period of 1960s-1990s. The simulated drought takes place in the form of a transition of the coupled biosphere-atmosphere system from a wet/green regime in the 1950s to a dry/barren regime after the 1960s. This climate transition is triggered by SST forcing and materialized through vegetation-climate interactions. The same SST forcing does not produce such a persistent drought when a constant modem CO2 concentration of 350ppmv is specified, indicating that the biosphere-atmosphere system at higher CO2 level is more resilient to drought-inducing external forcings. This finding suggests that the regional climate in Sahel, which tends to alternate between dry and wet spells, may experience longer (or more frequent) wet episodes and shorter (or less frequent) dry episodes in the future than in the past. Our study has significant implications regarding the impact of climate change on regional socio-economic development. C1 Goddard Earth Sci & Technol Ctr, UMBC & Data Assimilat Off, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. MIT, Dept Civil & Environm Engn, Cambridge, MA 02139 USA. RP Wang, GL (reprint author), Univ Connecticut, Dept Civil & Environm Engn, Storrs, CT 06269 USA. NR 54 TC 13 Z9 14 U1 1 U2 9 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1354-1013 J9 GLOBAL CHANGE BIOL JI Glob. Change Biol. PD DEC PY 2002 VL 8 IS 12 BP 1169 EP 1182 DI 10.1046/j.1365-2486.2002.00542.x PG 14 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 608KX UT WOS:000178846300002 ER PT J AU Konopliv, AS Miller, JK Owen, WM Yeomans, DK Giorgini, JD Garmier, R Barriot, JP AF Konopliv, AS Miller, JK Owen, WM Yeomans, DK Giorgini, JD Garmier, R Barriot, JP TI A global solution for the gravity field, rotation, landmarks, and Ephemeris of Eros SO ICARUS LA English DT Article DE asteroids, Eros; asteroids, Vesta; asteroids, rotation; surfaces, asteroids ID ORDER MODEL; LUNAR PROSPECTOR; ASTEROID MASSES AB As part of the NEAR Radio Science investigation, a global solution that includes both spherical and ellipsoidal harmonic gravity fields of Eros, Eros pole and rotation rate, Eros ephemeris, and landmark positions from the optical data was generated. This solution uses the entire one-year in orbit collection of X-band radiometric tracking (Doppler and range) from the Deep Space Network and landmark tracking observations generated from the NEAR spacecraft images of Eros. When compared to a constant density shape model, the gravity field shows a nearly homogeneous Eros. The Eros landmark solutions are in good agreement with the Eros shape model, and they reduce the center-of-mass and center-of-figure offset in the z direction to 13 m. Most of the NEAR spacecraft orbits are determined in all directions to an accuracy of several meters. The solution for the ephemeris of Eros constrains the mass of Vesta to 18.2 +/- 0.4 km(3)/s(2) and reduces the uncertainty in the Earth-Moon mass ratio. (C) 2002 Elsevier Science (USA). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Observ Midi Pyrenees, F-31400 Toulouse, France. RP Konopliv, AS (reprint author), CALTECH, Jet Prop Lab, MS 301-125J, Pasadena, CA 91109 USA. OI garmier, romain/0000-0002-3577-8117 NR 27 TC 36 Z9 37 U1 0 U2 0 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 2002 VL 160 IS 2 BP 289 EP 299 DI 10.1006/icar.2002.6975 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 628HR UT WOS:000179988000004 ER PT J AU Poulet, F Cuzzi, JN Cruikshank, DP Roush, T Dalle Ore, CM AF Poulet, F Cuzzi, JN Cruikshank, DP Roush, T Dalle Ore, CM TI Comparison between the Shkuratov and Hapke scattering theories for solid planetary surfaces: Application to the surface composition of two centaurs SO ICARUS LA English DT Article DE transfer; spectroscopy; centaurs ID BIDIRECTIONAL REFLECTANCE SPECTROSCOPY; KUIPER-BELT OBJECTS; WATER ICE; INFRARED-SPECTROSCOPY; ASYMMETRY PARAMETERS; MULTIPLE-SCATTERING; RADIATIVE-TRANSFER; OPTICAL-PROPERTIES; THERMAL EVOLUTION; PHASE FUNCTION AB This project examines the different approaches which deal with the theory of radiative transfer on atmosphereless bodies. We present the relative merits of two scattering theories based on the equivalent slab model: the extensively used Hapke theory (Hapke 1981, J. Geophys. Res. 86, 3039-3054) and the Shkuratov theory (Shkuratov et al. 1999, Icarus 141, 132-155). We found that their main difference is the role of the phase function of individual particles of regolith, which is predicted (and generally forward directed) in the case of the Shkuratov model instead of being a free parameter as formulated in the Hapke model. We also emphasize that different assumptions as to the manner in which different constituents are physically mixed in either model have a substantial effect on the synthetic spectra inferred. This leads to a significant extension of the validity of Hapke's or similar practical approaches to areas where these approaches are valid. We used two objects (the Centaurs 5145 Pholus and 8405 Asbolus) as examples. Previous modeling of the spectra of these two bodies with the Hapke approach gave suspect results in terms of the derived grain sizes, which were smaller than the wavelength, violating key assumptions of the model (Cruikshank et al. 1998, Icarus 135, 389-407 for Pholus; Barucci et al. 2000, Astron. Astrophys. 357, L53-56 for Asbolus). We considered several different types of powdered surfaces to interpret the surface composition of these two Centaurs. The effect of fine-scale contamination of water ice grains by small amounts of carbon and/or tholins is also explored. We can explain the strong red color and the rich near-infrared spectral signatures of Pholus using a five-component surface (contaminated water ice, amorphous carbon, Titan tholin, olivine, and methanol ice) where the grain sizes are consistent with the model assumptions. These components are similar to those inferred by Cruikshank et al. (1998), but we obtain very different grain sizes and relative abundances. For example, we obtain a relative abundance of water ice on the surface of Pholus of about 40% instead of 6% found with the Hapke model. Organic and carbonaceous components change by similar amounts. In the case of Asbolus, a tholin and amorphous carbon areal mixture can reproduce the spectrum, with water remaining at 9% or less. Using the albedo published by Fernandez et al. (2002, Astron. J. 123, 1050-1055) which is higher than most workers assume for Centaurs and Kuiper belt objects, a surface composition similar to that of Pholus is found. It appears that model-based uncertainties in relative compositions must be regarded with more attention. (C) 2002 Elsevier Science (USA). C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Poulet, F (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. NR 50 TC 86 Z9 87 U1 0 U2 8 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 2002 VL 160 IS 2 BP 313 EP 324 DI 10.1006/icar.2002.6970 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 628HR UT WOS:000179988000006 ER PT J AU Dyudina, UA Ingersoll, AP Vasavada, AR Ewald, SP AF Dyudina, UA Ingersoll, AP Vasavada, AR Ewald, SP CA Galileo SSI Team TI Monte Carlo radiative transfer modeling of lightning observed in Galileo images of Jupiter SO ICARUS LA English DT Article DE Jupiter, atmosphere; radiative transfer; image processing; atmospheres, structure ID MOIST CONVECTION; JOVIAN ATMOSPHERE; CLOUD STRUCTURE; IMAGING DATA; PLANETS; WATER; VOYAGER-1; BELT AB We study lightning on Jupiter and the clouds illuminated by the lightning using images taken by the Galileo orbiter. The Galileo images have a resolution of similar to25 km/pixel and are able to resolve the shape of single lightning spots, which have half widths (radii) at half the maximum intensity in the range 45-80 km. We compare the shape and width of lightning flashes in the images with simulated flashes produced by our 3D Monte Carlo light-scattering model. The model calculates Monte Carlo scattering of photons in a 3D opacity distribution. During each scattering event, light is partially absorbed. The new direction of the photon after scattering is chosen according to a Henyey-Greenstein phase function. An image from each direction is produced by accumulating photons emerging from the cloud in a small range (bins) of emission angles. The light source is modeled either as a point or a vertical line. A plane-parallel cloud layer does not always fit the data. In some cases the cloud over the light source appears to resemble cumulus clouds on Earth. Lightning is estimated to occur at least as deep as the bottom of the expected water cloud. For the six flashes studied, we find that the clouds above the lightning are optically thick (tau > 5). Jovian flashes are more regular and circular than the largest terrestrial flashes observed from space. On Jupiter there is nothing equivalent to the 30-40-km horizontal flashes that are seen on Earth. (C) 2002 Elsevier Science (USA). C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. CALTECH, Geol & Planetary Sci, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. RP Dyudina, UA (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. NR 40 TC 20 Z9 20 U1 0 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 2002 VL 160 IS 2 BP 336 EP 349 DI 10.1006/icar.2002.6977 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 628HR UT WOS:000179988000008 ER PT J AU Poulet, F Cuzzi, JN AF Poulet, F Cuzzi, JN TI The composition of Saturn's rings SO ICARUS LA English DT Article DE planetary rings, Saturn; spectroscopy; surfaces, planets ID OPTICAL-CONSTANTS; INFRARED-SPECTROSCOPY; H2O ICE; REFLECTANCE; SURFACES; SPECTRUM; SPECTROPHOTOMETRY; TEMPERATURES; WAVELENGTH; PHOTOMETRY AB A composite spectrum between 0.30 and 4.05 mum of Saturn's rings is analyzed using the Shkuratov scattering theory (Shkuratov et al. 1999, Icarus 137, 235-246). Several types of surface and composition are discussed. We demonstrate that both the strong reddening over the interval 0.3-0.7 mum and the water ice absorption features are well reproduced by an intimate ("salt-and-pepper") mixture of four coarse particles of two different materials: 93% are grains (typical sizes of 10, 200, and 2000 pm) of water ice containing a few percent of refractory organic solid (tholin) impurities within their bulk, and 7% are coarse grains of a dark material (amorphous carbon). The cosmogenic implications of the inferred composition are discussed. (C) 2002 Elsevier Science (USA). C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Poulet, F (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. EM poulet@despace.obspm.fr NR 41 TC 31 Z9 31 U1 1 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD DEC PY 2002 VL 160 IS 2 BP 350 EP 358 DI 10.1006/icar.2002.6967 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 628HR UT WOS:000179988000009 ER PT J AU Secor, DH Campana, SE Zdanowicz, VS Lam, JWH Yang, L Rooker, JR AF Secor, DH Campana, SE Zdanowicz, VS Lam, JWH Yang, L Rooker, JR TI Inter-laboratory comparison of Atlantic and Mediterranean bluefin tuna otolith microconstituents SO ICES JOURNAL OF MARINE SCIENCE LA English DT Article DE bluefin tuna; elemental fingerprint; migration; otolith microconstituents; stock structure ID PLASMA-MASS SPECTROMETRY; THUNNUS-THYNNUS; ELEMENTAL FINGERPRINTS; FISH OTOLITHS; PACIFIC-OCEAN; HUDSON RIVER; STRIPED BASS; STRONTIUM; MIGRATION; CHEMISTRY AB Elemental analysis of juvenile (age 0+ and 1 year) Atlantic bluefin tuna Thunnus thynnus otoliths by isotope dilution and conventional inductively coupled plasma mass spectrometry (ID ICP-MS and ICP-MS) indicated that the concentrations of certain elements varied among putative nursery grounds in the Atlantic Ocean. Further, trace element fingerprints of age-1 tuna from each nursery - the western Atlantic and Mediterranean Sea - were distinct and varied sufficiently to distinguish individuals from different regions with moderate confidence. Overall correct classification rates for a simulated test set of age-1 tuna were 68% (using ICP-MS) and 81% (using ID ICP-MS), despite a small sample size (9 Mediterranean vs. 19 western Atlantic tunas). Although ID ICP-MS was the more accurate of the two ICP-MS technologies, inter-laboratory precision was moderately high (3-18%) for individual elemental concentrations (Li, Na, Mg, K, Ca, Mn, Sr, and Ba), and multi-variate elemental fingerprints were similarly ordinated between laboratories (r=0.75). Age-0 tuna samples were too small to permit statistical classification tests, but showed similar levels of elemental concentrations between laboratories. Our results indicate that it should be possible to assign nursery ground origin to adult bluefin tuna based on the elemental composition of their extracted otolith core. (C) 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Maryland, Ctr Environm Sci, Chesapeake Biol Lab, Solomons, MD 20688 USA. Bedford Inst Oceanog, Marine Fis Div, Dartmouth, NS B2Y 4A2, Canada. Natl Marine Fisheries Serv, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. Natl Res Council Canada, Inst Natl Measurement Stand, Ottawa, ON K1A 0R6, Canada. Texas A&M Univ, Dept Marine Biol, Galveston, TX 77551 USA. RP Secor, DH (reprint author), Univ Maryland, Ctr Environm Sci, Chesapeake Biol Lab, Solomons, MD 20688 USA. RI Secor, D/D-4367-2012; Campana, Steven/C-3420-2013; Rooker, Jay/M-3197-2013; OI Secor, D/0000-0001-6007-4827; Campana, Steven/0000-0001-8802-3976; Rooker, Jay/0000-0002-5934-7688; Lam, Joseph/0000-0001-6402-0535; Yang, Lu/0000-0002-4351-2503 NR 33 TC 26 Z9 28 U1 0 U2 10 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 1054-3139 J9 ICES J MAR SCI JI ICES J. Mar. Sci. PD DEC PY 2002 VL 59 IS 6 BP 1294 EP 1304 DI 10.1006/jmsc.2002.1311 PG 11 WC Fisheries; Marine & Freshwater Biology; Oceanography SC Fisheries; Marine & Freshwater Biology; Oceanography GA 622BQ UT WOS:000179627000015 ER PT J AU Smart, MC Ratnakumar, BV Whitcanack, L Chin, K Rodriguez, M Surampudi, S AF Smart, MC Ratnakumar, BV Whitcanack, L Chin, K Rodriguez, M Surampudi, S TI Performance characteristics of lithium ion cells at low temperatures SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB The low temperature charge and discharge characteristics of experimental MCMB-LixNiyCo1-yO2 cells containing different electrolytes were investigated. The use of low ethylene carbonate (EC)-content electrolyte formulations has resulted in good discharge performance to temperatures as low as 40degreesC. The effect of charge voltage and charge current upon the individual electrode potentials at low temperature was investigated using the three electrode cells (containing lithium reference electrodes). In some cases, lithium plating was observed to occur upon low temperature charge, and found to be facilitated by high charge voltages, high charge currents, and poor anode kinetics. Electrochemical characterization of the cells has helped to establish the conditions under which lithium plating can occur by providing information regarding the polarization effects present at each electrode. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Smart, MC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 9 Z9 9 U1 1 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD DEC PY 2002 VL 17 IS 12 BP 16 EP 20 DI 10.1109/MAES.2002.1145732 PG 5 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 625BY UT WOS:000179798100006 ER PT J AU Gawronski, W Craparo, EM AF Gawronski, W Craparo, EM TI Antenna scanning techniques for estimation of spacecraft position SO IEEE ANTENNAS AND PROPAGATION MAGAZINE LA English DT Article DE antennas; scanning antennas; tracking; space vehicle tracking; satellite tracking; conical scan; Rosette scan; Lissajous scan; spacecraft position; antenna mechanical factors AB Scanning movements are added to a tracking antenna's trajectory to estimate the true spacecraft position. The scanning movements are composed of the harmonic axial movements of an antenna. This motion produces power variations of the received signal, which are used to estimate the spacecraft's position. Three different scanning patterns (conical scan, Lissajous scan, and rosette scan) are presented and analyzed in this paper. The analysis includes the evaluation of the estimation errors due to random or harmonic variation of the antenna's position, and due to random and harmonic variations of the power level. Typically, the estimation of the spacecraft's position is carried out after completing a full scanning cycle. Sliding-window scanning is introduced in this paper, wherein the spacecraft-position estimation is carried out in an almost-continuous manner, and it reduces the estimation time by half. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. MIT, Cambridge, MA 02139 USA. RP Gawronski, W (reprint author), CALTECH, Jet Prop Lab, MS 238-528,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Wadek.K.Gawronski@jpl.nasa.gov NR 7 TC 6 Z9 6 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1045-9243 EI 1558-4143 J9 IEEE ANTENN PROPAG M JI IEEE Antennas Propag. Mag. PD DEC PY 2002 VL 44 IS 6 BP 38 EP 45 DI 10.1109/MAP.2002.1167263 PG 8 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 637PE UT WOS:000180520600007 ER PT J AU Brenner, M Britcliffe, MJ Imbriale, WA AF Brenner, M Britcliffe, MJ Imbriale, WA TI Gravity deformation measurements of 70 m reflector surfaces SO IEEE ANTENNAS AND PROPAGATION MAGAZINE LA English DT Article DE reflector antennas; reflector antenna mechanical factors; strain; gravity deformation; surface fitting; antenna measurements; surface measurements AB Two of NASA's Deep Space Network (DSN) 70-meter reflectors were measured using a Leica TDM-5000 theodolite. The main reflector surface was measured at five elevation angles, so that a gravity-deformation model could be derived that described the main-reflector distortions over the entire range of elevation angles. The report describes the measurement equipment and accuracy, and the results derived from the data. C1 Engn Metrol Serv, Tucson, AZ 85704 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Brenner, M (reprint author), Engn Metrol Serv, Tucson, AZ 85704 USA. NR 2 TC 3 Z9 4 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1045-9243 EI 1558-4143 J9 IEEE ANTENN PROPAG M JI IEEE Antennas Propag. Mag. PD DEC PY 2002 VL 44 IS 6 BP 187 EP 192 DI 10.1109/MAP.2002.1167321 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 637PE UT WOS:000180520600023 ER PT J AU Castano, A Behar, A Will, PM AF Castano, A Behar, A Will, PM TI The Conro modules for reconfigurable robots SO IEEE-ASME TRANSACTIONS ON MECHATRONICS LA English DT Article DE autonomous; modular; reconfigurable; self-sufficient AB The goal of the Conro Project is to build deployable modular robots that can reconfigure into different shapes such as snakes or hexapods. Each Conro module is, itself, a robot and hence a, Conro robot is actually a multirobot system. In this paper we present an overview of the Conro modules, the design approach, an overview of the mechanical and electrical systems and a discussion on size versus power requirement of the module. Each module is self-contained; it has its own processor, power supply, communication system, sensors and actuators. The modules, although self-contained, were designed to work in groups, as part of a large modular robot. We conclude the paper by describing some of the robots that we have built using the Conro modules and describing the miniature custom-made Conro camera as an example of the type of sensors that can be carried as payload by these robots. C1 Univ So Calif, Inst Informat Sci, Marina Del Rey, CA 90292 USA. RP CALTECH, Jet Prop Lab, NASA, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM andres.castano@jpl.nasa.gov; alberto.behar@jpl.nasa.gov; will@isi.edu NR 20 TC 112 Z9 115 U1 0 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1083-4435 EI 1941-014X J9 IEEE-ASME T MECH JI IEEE-ASME Trans. Mechatron. PD DEC PY 2002 VL 7 IS 4 BP 403 EP 409 DI 10.1109/TMECH.2002.806233 PG 7 WC Automation & Control Systems; Engineering, Manufacturing; Engineering, Electrical & Electronic; Engineering, Mechanical SC Automation & Control Systems; Engineering GA 633QF UT WOS:000180293400002 ER PT J AU Simon, MK AF Simon, MK TI Single integral representations of certain integer powers of the Gaussian Q-function and their application SO IEEE COMMUNICATIONS LETTERS LA English DT Article AB Representations of the third and fourth powers of the Gaussian Q-function as a single integral with finite limits and an integrand that is Gaussian in the argument of the function are found. These representations are of the same form previously found for the first and second powers. of the Q-function And, therefore, allow extended application of the moment-generating function approach for evaluating the performance of digital communication systems over generalized fading channels. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Simon, MK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 22 Z9 22 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1089-7798 J9 IEEE COMMUN LETT JI IEEE Commun. Lett. PD DEC PY 2002 VL 6 IS 12 BP 532 EP 534 DI 10.1109/LCOMM.2002.806467 PG 3 WC Telecommunications SC Telecommunications GA 626WW UT WOS:000179897700006 ER PT J AU McSpadden, JO Mankins, JC AF McSpadden, James O. Mankins, John C. TI Space Solar Power Programs and Microwave Wireless Power Transmission Technology SO IEEE MICROWAVE MAGAZINE LA English DT Article C1 [McSpadden, James O.] Boeing Phantom Works, Seattle, WA 98124 USA. [Mankins, John C.] NASA, Washington, DC 20546 USA. RP McSpadden, JO (reprint author), Boeing Phantom Works, Seattle, WA 98124 USA. NR 48 TC 117 Z9 126 U1 3 U2 27 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1527-3342 EI 1557-9581 J9 IEEE MICROW MAG JI IEEE Microw. Mag. PD DEC PY 2002 VL 3 IS 4 BP 46 EP 57 DI 10.1109/MMW.2002.1145675 PG 12 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA V33AG UT WOS:000208991100006 ER PT J AU Alouini, MS Simon, MK AF Alouini, MS Simon, MK TI Dual diversity over correlated log-normal fading channels SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article; Proceedings Paper CT 5th Nordic Signal processing Symposium (NORSIG 2002) CY OCT, 2002 CL TROMSO TRONDHEIM, NORWAY DE amount of fading; diversity reception; equal-gain combining (EGC); fading correlation; log-normal fading; maximal-ratio combining (MRC); outage probability; selection combining (SC); switched combining ID SYSTEMS AB A great deal of attention has been devoted in the literature to studying the bit error rate (BER) performance of diversity combining systems in the presence of Rayleigh, Rice, and Nagakami-m fading. By comparison, the literature is relatively sparse in comparable analyses over log normal channels which typically characterize shadowing from indoor obstacles and moving human bodies. One reason for this disparity stems from the difficulty in evaluating the exact average BER when log-normal variates are involved, using, for example, the moment-generating function (AIGF) approach. due to the inability of expressing the MGF itself in a simple closed form. Since it is, possible to evaluate the marginal and joint statistical moments as well as the cumulative distribution function (edf) associated with a log-normal distribution in closed form, we rather focus here on other performance measures, namely, average combined output signal-to-noise ratio, amount of fading, and outage probability. The first two performance measures depend only on the moniems whereas the outage probability depends solely on the edf. Closed-form expressions (in terms of known functions), single-integral representations, or upper and lower bounds are obtained for these measures corresponding to maximal-ratio combining, selection combining, and switch-and-stay combining schemes, allowing for the possibility of correlation between the two branches. Numerical evaluations of these expressions illustrating the performances of each individual diversity type as well as comparisons among them are also presented. C1 Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Alouini, MS (reprint author), Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. NR 23 TC 70 Z9 70 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0090-6778 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD DEC PY 2002 VL 50 IS 12 BP 1946 EP 1959 DI 10.1109/TCOMM.2002.806552 PG 14 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 642AQ UT WOS:000180781200015 ER PT J AU Roy, S DeAnna, RG Zorman, CA Mehregany, M AF Roy, S DeAnna, RG Zorman, CA Mehregany, M TI Fabrication and characterization of polycrystalline SiC resonators SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE high temperature transducers; lateral resonant devices; microelectromechanical systems (MEMS); microsystems; polySiC; resonators; silicon carbide (SiC); surface micromachining ID CHEMICAL-VAPOR-DEPOSITION; FILMS; SILICON; THICK AB This paper presents the development of polycrystalline 3C silicon carbide (polySiC) lateral resonant devices, which are fabricated by a three-mask surface micromachining process using silicon dioxide (SiO2), polysilicon, and nickel (Ni) as the isolation, sacrificial, and contact metallization layers, respectively. The polySiC resonators are packaged for operation in high temperature environments using ceramic-based materials and nickel wirebonding procedures. Device operation is successfully demonstrated over <10(-5)-760 torr and 22-950 degreesC pressure and temperature ranges, respectively. Quality factors (Qs) of >100000 at <10(-5) torr and resonant frequency drifts of <18 ppm/h under continuous operation are achieved using an scanning electron microscope (SEM) setup. Device resonant frequency varies nonlinearly with increasing operating temperature. Finite element modeling reveals that this variation resulted from the interplay between the Young's modulus of polySiC and induced stresses, which occur due to mismatch in thermal expansion coefficients of the polySiC film and the underlying silicon (Si) substrate. C1 Cleveland Clin Fdn, Dept Biomed Engn, Cleveland, OH 44195 USA. NASA, Glenn Res Ctr Lewis Field, USA Res Lab, Vehicle Technol Ctr, Cleveland, OH 44135 USA. Case Western Reserve Univ, Dept Elect Engn & Comp Sci, Cleveland, OH 44106 USA. RP Cleveland Clin Fdn, Dept Biomed Engn, 9500 Euclid Ave, Cleveland, OH 44195 USA. EM roys@bme.ri.ccf.org OI Zorman, Christian/0000-0001-9773-9351 NR 22 TC 50 Z9 52 U1 0 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9383 EI 1557-9646 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD DEC PY 2002 VL 49 IS 12 BP 2323 EP 2332 DI 10.1109/TED.2002.807445 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 645MR UT WOS:000180982000029 ER PT J AU Njoku, EG Wilson, WJ Yueh, SH Dinardo, SJ Li, FK Jackson, TJ Lakshmi, V Bolten, J AF Njoku, EG Wilson, WJ Yueh, SH Dinardo, SJ Li, FK Jackson, TJ Lakshmi, V Bolten, J TI Observations of soil moisture using a passive and active low-frequency microwave airborne sensor during SGP99 SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE microwave; radar; radiometer; remote sensing; soil moisture ID L-BAND; SURFACE-ROUGHNESS; EMPIRICAL-MODEL; OCEAN SALINITY; WATER-CONTENT; SCATTEROMETER; IMPACT; FIFE AB Data were acquired by the Passive and Active Land S-band airborne sensor (PALS) during the 1999 Southern Great Plains (SGP99) experiment in Oklahoma to study remote sensing of soil moisture in vegetated terrain using low-frequency microwave radiometer and radar measurements. The PALS instrument measures radiometric brightness temperature and radar backscatter at L- and S-band frequencies with multiple polarizations and approximately equal spatial resolutions. The data acquired during SGP99 provide information on the sensitivities of multichannel low-frequency passive and active measurements to soil moisture for vegetation conditions including bare, pasture, and crop surface cover with field-averaged vegetation water contents mainly in the 0-2.5 kg m(-2) range. Precipitation occurring during the experiment provided an opportunity to observe wetting and drying surface conditions. Good correlations with soil moisture were observed in the radiometric channels. The 1.41-GHz horizontal-polarization channel showed the greatest sensitivity to soil moisture over the range of vegetation observed. For the fields sampled, a radiometric soil moisture retrieval accuracy of 2.3% volumetric was obtained. The radar channels showed significant correlation with soil moisture for some individual fields, with greatest sensitivity at 1.26-GHz vertical copolarized channel. However, variability in vegetation cover degraded the radar correlations for the combined field data. Images generated from data collected on a sequence of flight lines over the watershed region showed similar patterns of soil moisture change in the radiometer and radar responses. This indicates that under vegetated conditions for which soil moisture estimates may not be feasible using current radar algorithms, the radar measurements nevertheless show a response to soil moisture change, and they can provide useful information on the spatial and temporal variability of soil moisture. An illustration of the change detection approach is given. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA. Univ S Carolina, Dept Geol Sci, Columbia, SC 29208 USA. RP Njoku, EG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Bolten, John/F-9006-2012; Lakshmi, Venkat/I-3078-2016 OI Lakshmi, Venkat/0000-0001-7431-9004 NR 35 TC 101 Z9 108 U1 0 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD DEC PY 2002 VL 40 IS 12 BP 2659 EP 2673 DI 10.1109/TGRS.2002.807008 PG 15 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 643QE UT WOS:000180871300012 ER PT J AU Shi, JC Chen, KS Li, Q Jackson, TJ O'Neill, PE Tsang, L AF Shi, JC Chen, KS Li, Q Jackson, TJ O'Neill, PE Tsang, L TI A parameterized surface reflectivity model and estimation of bare-surface soil moisture with L-band radiometer SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE L-band radiometer; soil moisture; surface emission ID MICROWAVE EMISSION; OCEAN SALINITY; LAND SURFACES; SMOS MISSION; RETRIEVAL; ROUGHNESS; SCATTERING; ALGORITHM; SPACE AB Soil moisture is an important parameter for hydrological and climatic investigations. Future satellite missions with L-band passive microwave radiometers will significantly increase the capability of monitoring earth's soil moisture globally. Understanding the effects of surface roughness on microwave emission and developing quantitative bare-surface soil moisture retrieval algorithms is one of the essential components in many applications of geophysical properties in the complex earth terrain by microwave remote sensing. In this study, we explore the use of the integral equation model (IEM) for modeling microwave emission. This model was validated using a three-dimensional Monte Carlo model. The results indicate that the IEM model can be used to simulate the surface emission quite well for a wide range of surface roughness conditions with high confidence. Several important characteristics of the effects of surface roughness on radiometer emission signals at L-band 1.4 GHz that have not been adequately addressed in the current semiempirical surface effective reflectivity models are demonstrated by using IEM-simulated data. Using an IEM-simulated database for a wide range of surface soil moisture and roughness properties, we developed a parameterized surface effective reflectivity model with three typically used correlation functions and an inversion model that puts different weights on the polarization measurements to minimize surface roughness effects and to estimate the surface dielectric properties directly from dual-polarization measurements. The inversion technique was validated with four years (1979-1982) of ground microwave radiometer experiment data over several bare-surface test sites at Beltsville, MD. The accuracies in random-mean-square error are within or about 3% for incidence angles from 20degrees to 50degrees. C1 Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. Natl Cent Univ, Ctr Space & Remote Sensing Res, Chungli 32054, Taiwan. Univ Washington, Dept Elect Engn, Seattle, WA 98195 USA. USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Washington, Seattle, WA 98195 USA. RP Shi, JC (reprint author), Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. RI O'Neill, Peggy/D-2904-2013 NR 27 TC 73 Z9 93 U1 4 U2 25 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD DEC PY 2002 VL 40 IS 12 BP 2674 EP 2686 DI 10.1109/TGRS.2002.807003 PG 13 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 643QE UT WOS:000180871300013 ER PT J AU Liang, SL Fang, HL Morisette, JT Chen, MZ Shuey, CJ Walthall, CL Daughtry, CST AF Liang, SL Fang, HL Morisette, JT Chen, MZ Shuey, CJ Walthall, CL Daughtry, CST TI Atmospheric correction of landsat ETM plus land surface imagery - Part II: Validation and applications SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE atmospheric correction; broadband albedos; change detection; classification; validation ID AEROSOL AB This is the second paper of the series on atmospheric correction of Enhanced Thematic Mapper-Plus (ETM+) land surface imagery. In the first paper, a new algorithm that corrects heterogeneous aerosol scattering and surface adjacency effects was presented. In this study, our objectives are to 1) evaluate the accuracy of this new atmospheric correction algorithm using ground radiometric measurements, 2) apply this algorithm to correct Moderate-Resolution Imaging Spectroradiometer (MODIS) and SeaWiFS imagery, and 3) demonstrate how much atmospheric correction of ETM+ imagery can improve land cover classification, change detection, and broadband albedo calculations. Validation results indicate that this new algorithm can retrieve surface reflectance from ETM+ imagery accurately. All experimental cases demonstrate that this algorithm can be used for correcting both MODIS and SeaWiFS imagery. Although more tests and validation exercises are needed, it has been proven promising to correct different multispectral imagery operationally. We have also demonstrated that atmospheric correction does matter. C1 Univ Maryland, Dept Geog, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Toronto, Dept Geog & Urban Planning, Toronto, ON M5S 3G3, Canada. USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA. RP Liang, SL (reprint author), Univ Maryland, Dept Geog, College Pk, MD 20742 USA. RI liang, shunlin/C-2809-2015 NR 16 TC 54 Z9 71 U1 2 U2 12 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD DEC PY 2002 VL 40 IS 12 BP 2736 EP 2746 DI 10.1109/TGRS.2002.807579 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 643QE UT WOS:000180871300020 ER PT J AU Petkov, MP Lynn, KG Rodbell, KP Volksen, W Miller, RD AF Petkov, MP Lynn, KG Rodbell, KP Volksen, W Miller, RD TI Radiation effects in low dielectric constant methyl-silsesquioxane films SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE dielectric; electron radiation; ionizing radiation; low dielectric constant (low-k); polymer ID ANNIHILATION LIFETIME SPECTROSCOPY; MESOPOROUS THIN-FILMS; POSITRON-ANNIHILATION; ELECTRON-BEAM; SURFACES; SOLIDS AB The use of state-of-the-art microelectronic devices in space radiation environments faces new challenges with the adoption of low dielectric constant (low-k) materials as interlevel dielectrics. This is demonstrated in a preliminary study of methyl-silsesquioxane low-k films. We report radiation damage, induced by a 2-keV low- current-density (similar to2 x 10(6) s(-1) cm(-2)) positron beam, and observed by positron annihilation spectroscopy. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Washington State Univ, Dept Phys, Pullman, WA 99164 USA. IBM Corp, TJ Watson Res Ctr, Yorktown Hts, NY 10598 USA. IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. RP Petkov, MP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 26 TC 5 Z9 6 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 2724 EP 2728 DI 10.1109/TNS.2002.805353 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800018 ER PT J AU Fieseler, PD Ardalan, SM Frederickson, AR AF Fieseler, PD Ardalan, SM Frederickson, AR TI The radiation effects on Galileo spacecraft systems at Jupiter SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE anomaly; charging; dose; failure; Galileo; Jovian; Jupiter; radiation; spacecraft ID SPECTROMETER EXPERIMENT; DUST DETECTOR; MISSION; MAGNETOSPHERE; PARTICLES; ORBIT AB The Galileo spacecraft has been subjected to the harsh charged-particle environment around Jupiter since 1995. As the spacecraft has far exceeded the radiation dose for which it was designed, there have been a number of system failures attributable to radiation effects. This paper is a summary of those failures, the evidence for their connection to radiation related causes, and the associated fixes the Galileo flight team has implemented. C1 Jet Prop Lab, Mission Syst Engn, Pasadena, CA 91109 USA. Jet Prop Lab, Flight Syst Engn, Pasadena, CA 91109 USA. Jet Prop Lab, Reliabil Engn, Pasadena, CA 91109 USA. RP Fieseler, PD (reprint author), Jet Prop Lab, Mission Syst Engn, Pasadena, CA 91109 USA. NR 62 TC 16 Z9 17 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 2739 EP 2758 DI 10.1109/TNS.2002.805386 PN 1 PG 20 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800021 ER PT J AU Frederickson, AR Ratliff, JM Swift, GM AF Frederickson, AR Ratliff, JM Swift, GM TI On-orbit measurement of JFET leakage current and its annealing as functions of dose and bias at Jupiter SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE annealing; dose; JFET leakage current; radiation; space radiation AB Excessive source-pin leakage current was found to cause the Galileo Spacecraft gyroscope slew sensor to report incorrect spacecraft slew and thereby cause the computer to command inappropriate slewing. At normal bias, ground tests had found similar leakage to occur at dose levels similar to in-space levels. Controlled bias versus dose is used on-orbit in order to induce radiation-annealing and minimize growth of the leakage current in a DG181 JFET device. The growth of leakage current is minimized by turning the JFET power voltage off while it is in the radiation belts, thus, allowing for operation of the gyroscope attitude control system (ACS) when it is outside the radiation belts. During several 10- to 30-krad passes through the radiation belts, the leakage-associated damage was seen to slightly recover while power was turned off, but dramatically increase while turned on. The data provide perspective on the relations between ground test/design and optimization of performance in radiation and it suggests ways that procedures for ground testing could be improved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Frederickson, AR (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 13 TC 3 Z9 3 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 2759 EP 2764 DI 10.1109/TNS.2002.805976 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800022 ER PT J AU Ladbury, R Pickel, JC Gee, G Jordan, TM Bergeron, L Rauscher, B Reed, RA Marshall, PW Figer, D Fodness, B Kniffin, S AF Ladbury, R Pickel, JC Gee, G Jordan, TM Bergeron, L Rauscher, B Reed, RA Marshall, PW Figer, D Fodness, B Kniffin, S TI Characteristics of the Hubble Space Telescope's radiation environment inferred from charge-collection modeling of near-infrared camera and multi-object spectrometer darkframes SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE AB Dark frames from orbiting infrared detector arrays are analyzed using a charge-collection model to investigate the effects of secondary and primary particle environments in infrared detectors and related electronics. The effects of different components of the primary and secondary environments are assessed by examining trends with time and pixel-to-pixel charge correlations. C1 NASA, Goddard Space Flight Ctr, Orbital Sci Inc, Greenbelt, MD 20771 USA. PR&T Inc, Fallbrook, CA 92028 USA. NASA, Goddard Space Flight Ctr, SGT Inc, Greenbelt, MD 20771 USA. EMP Consultants, Gaithersburg, MD 20885 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. QSS Inc, Lanham, MD 20706 USA. RP Ladbury, R (reprint author), NASA, Goddard Space Flight Ctr, Orbital Sci Inc, Greenbelt, MD 20771 USA. NR 12 TC 4 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 2765 EP 2770 DI 10.1109/TNS.2002.805384 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800023 ER PT J AU Xapsos, MA Huston, SL Barth, JL Stassinopoulos, EG AF Xapsos, MA Huston, SL Barth, JL Stassinopoulos, EG TI Probabilistic model for low-altitude trapped-proton fluxes SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE AP8; low earth orbit (LEO); probabilistic model; TPM-1; trapped protons ID SOLAR MINIMUM AB A new approach is developed for the assessment of low-altitude trapped proton fluxes for future space missions. Low-altitude fluxes are dependent on solar activity levels due to the resulting heating and cooling of the upper atmosphere. However, solar activity levels cannot, be accurately predicted far enough into the future to accommodate typical spacecraft mission planning. Thus, the approach suggested here is to evaluate the trapped proton flux as a function of confidence level for a given mission time period. This is possible because of a recent advance in trapped proton modeling that uses the solar 10.7-cm radio flux, a measure of solar cycle activity, to calculate trapped proton fluxes as a continuous function of time throughout the solar cycle. This trapped proton model [1], [2] is combined with a new statistical description of the 10.7-cm flux to obtain the probabilistic model for low-altitude trapped proton fluxes. Results for proton energies ranging from 1.5 to 81.3 MeV are examined as a function of time throughout solar cycle 22 for various orbits. For altitudes below 1000 km, fluxes are significantly higher and energy spectra are significantly harder than those predicted by the AP8 model. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Boeing Co, Huntington Beach, CA 92647 USA. RP Xapsos, MA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 16 TC 12 Z9 13 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 2776 EP 2781 DI 10.1109/TNS.2002.805409 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800025 ER PT J AU Braley, GS Townsend, LW Cucinotta, FA Heilbronn, LH AF Braley, GS Townsend, LW Cucinotta, FA Heilbronn, LH TI Modeling of secondary neutron production from space radiation interactions SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, AZ SP IEEE DE neutrons; nuclear model; space radiator ID COLLISIONS; 0-DEGREES; NUCLEON; IONS AB A knockout-ablation-coalescence model capable of making quantitative predictions of neutron spectra produced in high-energy nucleon-nucleus and nucleus-nucleus collisions is presented. A Glauber model is used to describe neutrons produced in the knockout or abrasion stage of the reaction. In the ablation stage, a statistical evaporation model is used to calculate the neutron spectrum produced by the excited prefragment nucleus left over from the abrasion stage. The effects of,coalescence in reducing free neutron emission by composite particle formation are included. Typical results for predicted neutron energy and double-differential spectra are presented and compared with recently reported measurements for a variety of projectile and target nuclei of interest in space radiation protection. Except for differences resulting from the neglect of isobar production and decay in the model, predictions are in fairly good agreement with the measured data. C1 Armed Forces Radiobiol Res Inst, Bethesda, MD 20889 USA. Univ Tennessee, Dept Nucl Engn, Knoxville, TN 37996 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Armed Forces Radiobiol Res Inst, Bethesda, MD 20889 USA. EM braley@afrri.usuhs.mil; lTownsen@tennessee.edu; francis.a.cucinottal@jsc.nasa.gov; lhheilbronn@lbl.gov RI Heilbronn, Lawrence/J-6998-2013 OI Heilbronn, Lawrence/0000-0002-8226-1057 NR 11 TC 11 Z9 11 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 2800 EP 2804 DI 10.1109/TNS.2002.805343 PN 1 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800029 ER PT J AU Scheick, LZ Swift, GM AF Scheick, LZ Swift, GM TI Dose and microdose measurement based on threshold shifts in MOSFET arrays in commercial SRAMs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, AZ SP IEEE DE microdose; oxide damage; single event effect; single-hard error (SHE); SRAM; stuck bit ID RADIATION; SEU AB A new dosimetry method using an array of MOS transistors is described for a measuring dose absorbed from ionizing radiation. The method uses direct measurement of the number of cells that change state as a function of,applied-operating bias to a SRAM as a function of absorbed dose. Because the input and output of a SRAM are digital, the measurement of dose is easily accessible by a remote processing system. The devices show minimal response to total ionizing dose, but individual SRAM cells show strong microdose effects. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Scheick, LZ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM leif.scheick@jpl.nasa.gov NR 19 TC 13 Z9 13 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 2810 EP 2817 DI 10.1109/TNS.2002.805445 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800031 ER PT J AU Pickel, JC Reed, RA Ladbury, R Rauscher, B Marshall, PW Jordan, TM Fodness, B Gee, G AF Pickel, JC Reed, RA Ladbury, R Rauscher, B Marshall, PW Jordan, TM Fodness, B Gee, G TI Radiation-induced charge collection in infrared detector arrays SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, AZ SP IEEE DE cosmic rays; focal plane array; infrared detectors; infrared radiation effects; ion radiation effects; modeling; photodetectors ID PROTON AB A modeling approach is described for predicting charge collection in space-based infrared detector arrays due to ionizing particle radiation. The modeling uses a combination of analytical and Monte Carlo techniques to capture the essential features of energetic ion-induced charge collection to detector pixels in a two-dimensional array. The model addresses several aspects that are necessary for high-fidelity simulation of complex focal plane array structures including multiple layers, subregions within layers, variation of linear energy transfer with range, secondary electron scattering, free-field diffusion, and field-assisted diffusion. Example results are given and predictions are compared to experimental data. C1 PR&T Inc, Fallbrook, CA 92028 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Brookneal, VA 24528 USA. EMP Consultants, Gaithersburg, MD 20885 USA. SGT Inc, Greenbelt, MD 20771 USA. RP PR&T Inc, Fallbrook, CA 92028 USA. EM jim@pickel.net NR 13 TC 13 Z9 13 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9499 EI 1558-1578 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 2822 EP 2829 DI 10.1109/TNS.2002.805382 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800033 ER PT J AU Leon, R Marcinkevicius, S Siegert, J Cechavicius, B Magness, B Taylor, W Lobo, C AF Leon, R Marcinkevicius, S Siegert, J Cechavicius, B Magness, B Taylor, W Lobo, C TI Effects of proton irradiation on luminescence emission and carrier dynamics of self-assembled III-V quantum dots SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE carrier dynamics; compound semiconductors; displacement damage; photoluminescence; Stranski-Krastanow quantum dots ID ENHANCED RADIATION HARDNESS; LIGHT-EMITTING-DIODES; DEEP LEVELS; GAAS; DAMAGE; LASERS; TRANSFORMATION; DEPENDENCE; WELLS; DEGRADATION AB The effects of proton irradiation (1.5 MeV) on photoluminescence intensities and carrier dynamics were compared between III-V quantum dots and similar quantum well structures. A significant enhancement in radiation tolerance is seen with three-dimensional (3-D) quantum confinement.. Measurements were carried out in different quantum dot (QD) structures, varying in material (InGaAs/GaAs and InAlAS/AlGaAS), QD surface density (4 x 10(8) to 3 x 10(10) cm(-2)), and substrate orientation [(100) and (311) B]. Similar trends were observed for all QD samples. A slight increase in PL emission after low to intermediate proton doses, are also observed in InGaAs/GaAs (100) QD structures. The latter is explained in terms of more efficient carrier transfer from the wetting layer via radiation-induced defects. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Royal Inst Technol, Dept Microelect & Informat Technol, Electrum 229, S-16440 Kista, Sweden. Lithuania Acad Sci, Inst Semicond Phys, LT-2600 Vilnius, Lithuania. Calif State Univ Los Angeles, Dept Phys & Astron, Los Angeles, CA 90032 USA. Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England. RP Leon, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Schaff, William/B-5839-2009; Lobo, Charlene/B-3977-2013; Lobo, Charlene/G-5003-2011 OI Lobo, Charlene/0000-0002-2746-1363; Lobo, Charlene/0000-0002-2746-1363 NR 35 TC 19 Z9 19 U1 1 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 2844 EP 2851 DI 10.1109/TNS.2002.806018 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800036 ER PT J AU Miyahira, TF Johnston, AH AF Miyahira, TF Johnston, AH TI Trends in optocoupler radiation degradation SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE light-emitting diode (LED); optocoupler; proton radiation damage; radiation effects ID INDUCED TRANSIENTS; PROTON AB Proton-radiation test results for new optocoupler technologies are compared with those of older optocouplers. The new devices are far more resistant to displacement damage effects and have a much higher, current-transfer ratio (CTR). The improvements are due to improved optical-coupling efficiency in combination with light-emitting diode (LED) technologies that are inherently more resistant to lifetime degradation. Because of these changes, CTR degradation is no longer dominated by LED damage. LED degradation, gain degradation, and photoresponse degradation all contribute to the overall changes in CTR after irradiation in the newer device types. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Miyahira, TF (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 7 Z9 13 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 2868 EP 2873 DI 10.1109/TNS.2002.805350 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800039 ER PT J AU Li, Y Niu, G Cressler, JD Patel, J Marshall, PW Kim, HS Liu, MST Reed, RA Palmer, MJ AF Li, Y Niu, G Cressler, JD Patel, J Marshall, PW Kim, HS Liu, MST Reed, RA Palmer, MJ TI Proton radiation effects in 0.35-mu m partially depleted SOI MOSFETs fabricated on UNIBOND SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE interface states; MOSFETs; partially depleted; proton; radiation; SOI; UNIBOND ID SHALLOW-TRENCH ISOLATION; CMOS TECHNOLOGY; PERFORMANCE AB We investigate the proton radiation tolerance of a 0.35-mum SOI technology on UNIBOND material. The radiation response is characterized by threshold-voltage shifts of the front-gate and back-gate transistors. An increase of the front-gate threshold voltage is observed on the n-channel MOSFETs after irradiation and is attributed to radiation-induced interface states at the front-gate oxide/silicon interface. A double g(m) peak behavior is observed on the back-gate g(m)-V-GS curves for both n- and p-channel MOSFETs and is attributed to silicon/back-gate oxide interface traps with a delta-function-like distribution in the energy gap. The results suggest this 0.35-mum technology on UNIBOND material performs well in a proton-radiation environment. C1 Auburn Univ, Dept Elect & Comp Engn, Alabama Microelect Sci & Technol Ctr, Auburn, AL 36849 USA. Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Jackson & Tull Chartered Engineers, Washington, DC 20018 USA. Honeywell Solid State Elect Ctr, Plymouth, Devon, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Li, Y (reprint author), Auburn Univ, Dept Elect & Comp Engn, Alabama Microelect Sci & Technol Ctr, Auburn, AL 36849 USA. NR 19 TC 15 Z9 15 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 2930 EP 2936 DI 10.1109/TNS.2002.805428 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800049 ER PT J AU Becker, HN Miyahira, TF Johnston, AH AF Becker, HN Miyahira, TF Johnston, AH TI Latent damage in CMOS devices from single-event latchup SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE analog-digital conversion; CMOS integrated circuits; digital signal processors; electromigration; latent damage; oscillators; reliability; single-event latchup ID HIGH-CURRENT PULSE; METAL INTERCONNECT; FAILURE MODEL AB Evaluation of several types of CMOS devices after nondestructive latchup revealed structural changes in interconnects that appears to be due to localized ejection of part of the metallization due to melting. This is a potential reliability hazard for CMOS devices because it creates localized voids within interconnects that reduce the cross section by one to two orders of magnitude in the damaged region. These effects must be considered when testing devices for damage from latchup, as well as in establishing limits for current detection and shutdown as a means of latchup protection. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Becker, HN (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 17 TC 19 Z9 22 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 3009 EP 3015 DI 10.1109/TNS.2002.805332 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800060 ER PT J AU McNulty, PJ Yow, S Scheick, LZ Abdel-Kader, WG AF McNulty, PJ Yow, S Scheick, LZ Abdel-Kader, WG TI Charge removal from FGMOS floating gates SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE dosimetry; FGMOS transistors; ionizing radiation; trapped charge ID FAMOS AB Radiation effects on floating-gate-metal-oxide-semiconductor (FGMOS) devices in the passive or quiescent mode are due to a combination of the removal of negative charge from the floating gate and the generation and trapping of positive charge in the gate oxide. The latter is subject to room temperature annealing but not the former. No difference was observed between the effects of trapped charge on transistors in "0" and "1" logic states. The amount of negative charge per unit dose that is removed from the floating gates by heavy ions is less than that removed by 6 MeV electrons, which at least partially explains the sublinear dependence on linear energy transfer. C1 Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. CALTECH, Jet Prop Lab, Elect Parts Engn Off, Pasadena, CA 91109 USA. S Carolina State Univ, Dept Phys Sci, Orangeburg, SC 29117 USA. RP McNulty, PJ (reprint author), Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. NR 11 TC 15 Z9 15 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 3016 EP 3021 DI 10.1109/TNS.2002.805975 PN 1 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800061 ER PT J AU Reed, RA Marshall, PW Kim, HS McNulty, PJ Fodness, B Jordan, TM Reedy, R Tabbert, C Liu, MST Heikkila, W Buchner, S Ladbury, R LaBel, KA AF Reed, RA Marshall, PW Kim, HS McNulty, PJ Fodness, B Jordan, TM Reedy, R Tabbert, C Liu, MST Heikkila, W Buchner, S Ladbury, R LaBel, KA TI Evidence for angular effects in proton-induced single-event upsets SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE ID DEPENDENCE; SATELLITE; ANGLE AB Historically, proton-induced single-event effects (SEEs) ground test data are collected independent of the orientation of the microelectronic device to the proton beam direction. In this study, we present experimental and simulation evidence that shows an effect of over an order of magnitude on the proton-induced single-event upset (SEU) cross section when the angle of incidence of the proton beam is varied. The magnitude, of this effect is shown to depend on the incidence proton energy and the device critical charge. The angular effect is demonstrated for Silicon-On-Sapphire and Silicon-On-Insulator technologies, but would not necessarily be limited to these technologies. C1 NASA, Goddard Space Flight Ctr, Orbital Sci Inc, Greenbelt, MD 20771 USA. Jackson & Tull Chartered Engn, Washington, DC 20018 USA. Clemson Univ, Clemson, SC 29634 USA. SGT Inc, Greenbelt, MD 20770 USA. EMPC, Gaithersburg, MD 20885 USA. Peregrine Semicond, Melbourne, FL 32901 USA. Honeywell SSEC, Plymouth, MN 55441 USA. QSS Inc, Seabrook, MD 20706 USA. RP Reed, RA (reprint author), NASA, Goddard Space Flight Ctr, Orbital Sci Inc, Greenbelt, MD 20771 USA. NR 21 TC 47 Z9 49 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 3038 EP 3044 DI 10.1109/TNS.2002.805446 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800064 ER PT J AU Patterson, JD Edmonds, LD AF Patterson, JD Edmonds, LD TI Modeling the contribution of diffusion to device-upset cross sections SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE charge collection; DRAM; drift/diffusion; recombination; upset cross section ID CHARGE-COLLECTION; ION TRACKS; 3-DIMENSIONAL SIMULATION; SILICON DEVICES AB A novel technique for determining the diffusion-charge collection-efficiency function Omega(tau) ((x) over right arrow), which incorporates mixed-boundary conditions and carrier recombination, is presented and applied to a realistic, three-dimensional memory device to obtain the upset cross section or as a function of linear energy transfer (LET) and orientation of incidence. The model is able to reproduce experimental measurements and can be used to more accurately predict or across regimes where little data exists. This will allow for the determination of more precise errors rates while simultaneously requiring fewer experimental data points. RP Patterson, JD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 15 TC 4 Z9 4 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 3067 EP 3074 DI 10.1109/TNS.2002.805442 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800068 ER PT J AU Johnston, AH Miyahira, TF Edmonds, LD Irom, F AF Johnston, AH Miyahira, TF Edmonds, LD Irom, F TI Single-event transients in high-speed comparators SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE radiation effects; single-event transients (SETs); voltage comparators ID CIRCUITS AB Single-event transients are investigated in comparators with switching speed below 80 ns, including one BiCMOS device. Modeling results show that the collapse of internal junctions after an ion strike delays the onset of collector current because of transient currents in the substrate that are not shielded by the buried layer. Transients in high-speed comparators are strongly affected by differential input voltage, but are suppressed in the bipolar comparators when the differential input voltage exceeds 200 mV. The BiCMOS device behaves differently because of the CMOS circuitry in latter stages. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Johnston, AH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 TC 12 Z9 13 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 3082 EP 3089 DI 10.1109/TNS.2002.805397 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800070 ER PT J AU Boulghassoul, Y Massengill, LW Sternberg, AL Pease, RL Buchner, S Howard, JW McMorrow, D Savage, MW Poivey, C AF Boulghassoul, Y Massengill, LW Sternberg, AL Pease, RL Buchner, S Howard, JW McMorrow, D Savage, MW Poivey, C TI Circuit Modeling of the LM124 operational amplifier for analog single-event transient analysis SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 39th Annual International Nuclear and Space Radiation Effects Conference (NSREC) CY JUL 15-19, 2002 CL PHOENIX, ARIZONA SP IEEE DE analog single-event transients; circuit modeling; electrical calibration; laser calibration; LM124 operational amplifier; transistor parameter extraction ID PULSED-LASER AB This work presents the development of a transistor-level circuit model of the LM124 operational amplifier specifically engineered and calibrated for analog single-event transient (ASET) computer simulations. The techniques presented rely heavily on datasheet specifications for electrical parameterization and experimental laser probing for dc and transient calibration. The resulting circuit model proves to be suitable for broad-beam SET predictions and fault diagnostics for space applications. C1 Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. RLP Res, Albuquerque, NM 87122 USA. QSS, Seabrook, MD 20706 USA. Jackson & Tull, Greenbelt, MD 20771 USA. USN, Res Lab, Washington, DC 20375 USA. NAVSEA, Crane, IN 47522 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Boulghassoul, Y (reprint author), Vanderbilt Univ, Dept Elect Engn & Comp Sci, 221 Kirkland Hall, Nashville, TN 37235 USA. NR 17 TC 40 Z9 41 U1 2 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD DEC PY 2002 VL 49 IS 6 BP 3090 EP 3096 DI 10.1109/TNS.2002.805400 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 629NY UT WOS:000180056800071 ER EF