FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Datiles, MB Ansari, RR Reed, GF AF Datiles, MB Ansari, RR Reed, GF TI A clinical study of the human lens with a dynamic light scattering device SO EXPERIMENTAL EYE RESEARCH LA English DT Article DE cataract; lens; dynamic light scattering; corneal topography; clinical study ID PHOTON-CORRELATION SPECTROSCOPY; LIVING HUMAN LENS; CATARACT; SYSTEM; EYE; AGE AB A study was conducted to determine the potential usefulness and repeatability of a new dynamic light scattering (DLS) device for clinical studies of the human lens and early cataract. Studies using the cold cataract model showed this new device to be more sensitive than the Scheimpflug cataract imaging system in detecting the earliest cataractous changes. A miniaturized clinical DLS device developed by NASA using fiber optic probes was mounted on a Keratoscope (Optikon 2000), which has a 3-dimensional aiming system for accurate repeated sampling of the same area of the lens. A test/retest study was then conducted on the nuclear region of the lenses of 12 normal eyes. After a full, dilated eye examination, DLS data were obtained using the new device on the same eyes twice, 30-60 min apart. Particle size distributions and mean log particle size data were obtained. The mean percent differences between the larger and smaller of the test-retest pairs was 6.4 % (range 0.05-10.8 %); the between-test S.D. was 0.116. Actual numerical margin of error was +/-0.023. In addition, the mean coefficient of variation was 4.2 % (range 0.3-7.3 %), A useful clinical end point obtained from data produced by the device was the mean log particle size. These results suggest that the DLS will be useful in the detection and study of the beginning and earliest stages of cataract formation in humans. C1 NEI, Cataract Sect, Ophthalm Genet & Visual Funct Branch, NIH, Bethesda, MD 20892 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NEI, Biometry Branch, Div Epidemiol & Clin Res, Bethesda, MD 20892 USA. RP Datiles, MB (reprint author), NEI, Cataract Sect, Ophthalm Genet & Visual Funct Branch, NIH, Bldg 10,Rm 10N226,MSC 1860, Bethesda, MD 20892 USA. OI Datiles, Manuel III B./0000-0003-4660-1664 NR 23 TC 19 Z9 19 U1 1 U2 3 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0014-4835 J9 EXP EYE RES JI Exp. Eye Res. PD JAN PY 2002 VL 74 IS 1 BP 93 EP 102 DI 10.1006/exer.2001.1106 PG 10 WC Ophthalmology SC Ophthalmology GA 542JX UT WOS:000175040700010 PM 11878822 ER PT B AU Heap, SR Williger, GM Dave, R Weymann, RJ Jenkins, EB Tripp, TM AF Heap, SR Williger, GM Dave, R Weymann, RJ Jenkins, EB Tripp, TM BE Mulchaey, JS Stocke, JT TI HST/STIS spectroscopy of 3C 273 SO EXTRAGALACTIC GAS AT LOW REDSHIFT SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Extragalactic Gas at Low Redshift CY APR 04-06, 2001 CL CARNEGIE OBSERV, PASADENA, CA SP Univ Colorado, Cosm Orgins Spectrograph Project HO CARNEGIE OBSERV ID LY-ALPHA FOREST; HIGH-RESOLUTION SPECTROGRAPH; HUBBLE-SPACE-TELESCOPE; LOW-REDSHIFT; 3C-273; LINE; ABSORBERS; SIGHT AB We present preliminary results on the low-redshift Lyalpha forest as based on STIS spectra of 3C 273. A total of 121 intergalactic Lyalpha-absorbing systems were detected, of which 60 are above the 3.5sigma completeness limit, logN(HI) approximate to 12.3 cm(-2). The median line-width parameter, b = 27 km/s, is similar to that seen at high redshift. However the distribution of HI column densities has a steeper slope, beta = 2.02 +/- 0.21, than is seen at high redshift. Overall, the observed N-HI-b distribution is consistent with that derived from a ACDM hydrodynamic simulation. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Heap, SR (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. RI heap, sara/E-2237-2012 NR 20 TC 8 Z9 8 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-094-3 J9 ASTR SOC P PY 2002 VL 254 BP 63 EP 71 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU69Q UT WOS:000176731900007 ER PT B AU Williger, GM Campusano, LE Clowes, RG Graham, MJ AF Williger, GM Campusano, LE Clowes, RG Graham, MJ BE Mulchaey, JS Stocke, JT TI Large scale structure at z=1.2 from MgII absorbers SO EXTRAGALACTIC GAS AT LOW REDSHIFT SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Extragalactic Gas at Low Redshift CY APR 04-06, 2001 CL CARNEGIE OBSERV, PASADENA, CA SP Univ Colorado, Cosm Orgins Spectrograph Project HO CARNEGIE OBSERV ID LY-ALPHA FOREST; LOW-REDSHIFT; QUASARS; EVOLUTION; UNIVERSE AB The largest known structure in the high redshift universe consists of at least 18 quasars and spans similar to 5degrees x 2.5degrees on the sky, with a quasar spatial overdensity of 6-10 times above the mean. This large quasar group (LQG) provides an extraordinary laboratory similar to100 x 200 x 200h(-3) comoving Mpc(3) in size (q(0) = 0.5, A = 0, Ho = 100h km s(-1) Mpc(-1)) covering 1.20 < z < 1.38 in redshift. One approach to establishing how LQGs relate to mass (galaxy) enhancements is to probe their gas content and distribution via background quasars. We have found the LQG to be associated with 11 MgII absorption systems (an overdensity of similar to3), which appear to form a structure. In addition, we find a statistical tendency for MgII absorbers in general to correlate with field quasars (i.e. quasars both inside and outside of the LQG) at a projected scale length on the sky of 9h(-1) Mpc. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Williger, GM (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 23 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 1-58381-094-3 J9 ASTR SOC P PY 2002 VL 254 BP 132 EP 139 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU69Q UT WOS:000176731900015 ER PT S AU Catelan, M Bellazzini, M Ferraro, FR Pecci, FF Galleti, S Landsman, WB AF Catelan, M Bellazzini, M Ferraro, FR Pecci, FF Galleti, S Landsman, WB BE Geisler, D Grebel, EK Minniti, D TI Age as the second parameter in NGC 288/NGC 362? SO EXTRAGALACTIC STAR CLUSTERS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT Symposium on Extragalactic Star Clusters CY MAR 12-16, 2001 CL PUCON, CHILE SP Int Astronom Union ID GLOBULAR-CLUSTERS; METALLICITIES; ABUNDANCES; MODELS; GALAXY AB We derive the age difference between NGC 288 and NGC 362 using the bimodal horizontal branch (HB) of NGC 1851 as a "bridge" in the CMD analysis. Our results suggest that NGC 288 is older than both NGC 362 and NGC 1851 by similar or equal to 2 +/- 1 Gyr. A new grid of synthetic HBs discloses that age may be the second parameter (2ndP) for this pair provided that the Carretta & Gratton (1997) metallicity scale is to be preferred over the Zinn & West (1984) scale. In addition, the dispersion in ZAHB mass is found to be about twice as large in NGC 362 as in NGC 288, probably due to the much higher central density of the former. C1 Osservatorio Astron Bologna, I-40126 Bologna, Italy. NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. RI Bellazzini , Michele/O-9373-2015 OI Bellazzini , Michele/0000-0001-8200-810X NR 5 TC 0 Z9 0 U1 2 U2 2 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-115-X J9 IAU SYMP PY 2002 VL 207 BP 116 EP 118 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV57N UT WOS:000179397100016 ER PT S AU Lee, MG Park, HS Kim, SC Waller, WH Parker, JW Malumuth, EM Hodge, PW AF Lee, MG Park, HS Kim, SC Waller, WH Parker, JW Malumuth, EM Hodge, PW BE Geisler, D Grebel, EK Minniti, D TI HST-WFPC2 observations of the star clusters in the giant HII regions of M33 SO EXTRAGALACTIC STAR CLUSTERS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT Symposium on Extragalactic Star Clusters CY MAR 12-16, 2001 CL PUCON, CHILE SP Int Astronom Union AB We present a photometric study of the stars in ionizing star clusters embedded in several giant H II regions of M33 (CC93, IC 142, NGC 595, MA2, NGC 604 and NGC 588). Our photometry is based on the HST-WFPC2 images of these clusters. Color-magnitude diagrams and color-color diagrams of these clusters are obtained and are used for estimating the reddenings and ages of the clusters. The luminosity functions (LFs) and initial mass functions (IMFs) of the massive stars in these clusters are also derived. The slopes of the IMFs range from Gamma = -0.5 to -2.1. Interestingly, it is found that the IMFs get steeper with increasing galactocentric distance and with decreasing [O/H] abundance. C1 Seoul Natl Univ, SEES, Astron Program, Seoul 151742, South Korea. Tufts Univ, Dept Phys & Astron, Medford, MA 02155 USA. SW Res Inst, Boulder, CO 80302 USA. NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Lab Astron & Solar Phys, Greenbelt, MD 20771 USA. Univ Washington, Dept Astron, Seattle, WA 98195 USA. RP Seoul Natl Univ, SEES, Astron Program, Seoul 151742, South Korea. EM mglee@astrog.snu.ac.kr; sckim@astro.snu.ac.kr NR 5 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-115-X J9 IAU SYMP PY 2002 VL 207 BP 157 EP 159 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV57N UT WOS:000179397100030 ER PT S AU Borne, KD Keel, WC Appleton, PN Struck, C Lucas, RA Schultz, AB AF Borne, KD Keel, WC Appleton, PN Struck, C Lucas, RA Schultz, AB BE Geisler, D Grebel, EK Minniti, D TI HST observations of young star clusters in interacting galaxies SO EXTRAGALACTIC STAR CLUSTERS SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT Symposium on Extragalactic Star Clusters CY MAR 12-16, 2001 CL PUCON, CHILE SP Int Astronom Union ID TELESCOPE AB We present early results from the analysis of HST imaging observations for several pairs of interacting galaxies. We include two cases that were specifically chosen to represent a strong early (young) encounter and a weak late (old) encounter. The goals of the project include a determination of the timing, frequency, strength, and characteristics of the young star clusters formed in these two limiting cases of tidal encounters. C1 Raytheon ITSS, Astrophys Data Facil, Greenbelt, MD 20771 USA. NASA, GSFC, Astrophys Data Facil, Greenbelt, MD 20771 USA. Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. STScI, Baltimore, MD 21218 USA. RP Borne, KD (reprint author), Raytheon ITSS, Astrophys Data Facil, Code 631, Greenbelt, MD 20771 USA. NR 15 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-115-X J9 IAU SYMP PY 2002 VL 207 BP 474 EP 476 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV57N UT WOS:000179397100095 ER PT S AU James, MA Newman, JC Johnston, WM AF James, MA Newman, JC Johnston, WM BE Chona, R TI Three-dimensional analyses of crack-tip-opening angles and delta(5)-resistance curves for 2024-T351 aluminum alloy SO FATIGUE AND FRACTURE MECHANICS: 32ND VOLUME SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT 32nd Symposium on Fatigue and Fracture Mechanics CY JUN 14-16, 2000 CL CONSHOHOCKEN, PA SP ASTM Comm E 8 DE CTOA; CTOD; cracks; elastic-plastic fracture; delta(5); resistance curve AB The objective of this paper was to investigate the fracture behavior of compact and middle-crack tension specimens made of 6.35 mm thick 2024-T351 aluminum alloy. Tests were conducted on compact tension. C(T), specimens ranging in width from 51 to 152 mm and on middle-crack tension, M(T), specimens ranging in width from 76 to 1016 mm. Most of the M(T) specimens were allowed to buckle during the fracture tests. Three-dimensional, elastic-plastic, finite-element analyses (FEA) using the WARP3D code with straight-front cracks were used to show transferability of the critical crack-tip-opening angle (CTOA) fracture criterion from small laboratory specimens, such as the C(T) specimen to large M(T) specimens. A single value of critical CTOA (T, 6.35 degrees) was determined from the FEA (with a straight-crack front) by matching the average failure load for the 152 mm C(T) specimens. CTOA analyses were then conducted on the various width C(T) and M(T) specimens. The WARP3D analyses with the critical CTOA predicted the experimental failure loads within +/- 3% for all specimens. The delta (5)-resistance curves from the analyses of the C(T) and M(T) specimens were nearly identical up to the maximum load. Beyond maximum load, the delta (5)-resistance curves for the C(T) specimens began to deviate rapidly; whereas, the delta (5)-resistance curves for the M(T) specimens only deviated slightly. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP James, MA (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 23 TC 15 Z9 15 U1 0 U2 2 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2888-6 J9 AM SOC TEST MATER PY 2002 VL 1406 BP 279 EP 297 DI 10.1520/STP10592S PG 19 WC Engineering, Mechanical; Materials Science, Ceramics; Materials Science, Coatings & Films; Materials Science, Composites SC Engineering; Materials Science GA BT15L UT WOS:000172099700017 ER PT B AU Padula, SA Shyam, A Davidson, DL Milligan, WW AF Padula, SA Shyam, A Davidson, DL Milligan, WW BE Chan, KS Liaw, PK Bellows, RS Zogas, T Soboyejo, WO TI In situ study of high frequency fatigue crack propagation in a single crystal superalloy SO FATIGUE - DAVID L. DAVIDSON SYMPOSIUM LA English DT Proceedings Paper CT David L Davidson Symposium on High Cycle Fatigue held at the 2002 TMS Annual Meeting CY FEB 17-21, 2002 CL SEATTLE, WA SP Minerals Met & Mat Soc ID HIGH-CYCLE FATIGUE; BEHAVIOR; ALLOY AB High frequency fatigue crack propagation tests were conducted in situ, in a scanning electron microscope, on single crystals of the nickel-base superalloy Rene N5. The threshold was found to be around 2 MParootm, and the FCP curve appeared to be consistent with that of a similar polycrystalline alloy but with a lower threshold. Crack propagation was observed to occur on {111} as well as {001} planes at low DeltaK. Strain maps were measured ahead of the crack tip with the DISMAP stereo-imaging technique. SEM images of plasticity associated with the crack tip indicated plastic zone sizes mainly consistent with isotropic linear elastic fracture mechanics estimates, but the plasticity was concentrated in highly planar slip bands parallel to the crack, and the shape of the plastic zone and strain distribution were not isotropic. It is suggested that the threshold behavior may be related to the fracture surface roughness, since the threshold increased in from single crystal to fine-grain polycrystal to coarse-grain polycrystal, in the same order as the fracture surface roughness. C1 NASA Glenn Res Ctr, Cleveland, OH 44135 USA. RP Padula, SA (reprint author), NASA Glenn Res Ctr, Cleveland, OH 44135 USA. OI Shyam, Amit/0000-0002-6722-4709 NR 9 TC 0 Z9 0 U1 0 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-518-2 PY 2002 BP 183 EP 189 PG 7 WC Engineering, Mechanical; Materials Science, Coatings & Films SC Engineering; Materials Science GA BU50H UT WOS:000176155600013 ER PT J AU Forth, SC Keat, WD Favrow, LH AF Forth, SC Keat, WD Favrow, LH TI Experimental and computational investigation of three-dimensional mixed-mode fatigue SO FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES LA English DT Article DE boundary element; experiment; fatigue; fracture; mixed-mode; surface integral ID SURFACE INTEGRAL METHOD; CRACK-GROWTH AB Experimental and computational methods were developed to model three-dimensional (3-D) mixed-mode crack growth under fatigue loading with the objective of evaluating proposed 3-D fracture criteria. The experiments utilized 7075-T73 aluminium forgings cut into modified ASTM E740 surface crack specimens with pre-cracks orientated at angles of 30, 45 and 60 in separate tests. The progress of the evolving fatigue crack was monitored in real time using an automated visualization system. In addition, the amplitude of the loading was increased at prescribed intervals to mark the location of the 3-D crack front for post-test inspection. In order to evaluate proposed crack growth equations, computer simulations of the experiments were conducted using a 3-D fracture model based on the surface integral method. An automatic mesher advanced the crack front by adding a ring of elements consistent with local application of fracture criteria governing rate and direction of growth. Comparisons of the computational and experimental results showed that the best correlation was obtained when K-II and K-III were incorporated in the growth rate equations. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Union Coll, Dept Engn Mech, Schenectady, NY 12308 USA. United Technol Res Ctr, E Hartford, CT 06108 USA. RP Forth, SC (reprint author), NASA, Langley Res Ctr, MS 188E,2 W Reid St, Hampton, VA 23681 USA. NR 20 TC 10 Z9 11 U1 1 U2 2 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 8756-758X J9 FATIGUE FRACT ENG M JI Fatigue Fract. Eng. Mater. Struct. PD JAN PY 2002 VL 25 IS 1 BP 3 EP 15 DI 10.1046/j.1460-2695.2002.00413.x PG 13 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 513UL UT WOS:000173397800002 ER PT J AU Majumder, SB Jain, M Martinez, A Katiyar, RS Miranda, FA Van Keuls, FW Sahoo, PK Kulkarni, VN AF Majumder, SB Jain, M Martinez, A Katiyar, RS Miranda, FA Van Keuls, FW Sahoo, PK Kulkarni, VN TI Electrical characterists of sol-gel derived (100) oriented Ba0.5Sr0.5TiO3 thin films on LaAlO3 (100) substrates SO FERROELECTRICS LA English DT Article; Proceedings Paper CT 10th International Meeting on Ferroelectricity CY SEP 03-07, 2001 CL MADRID, SPAIN DE Mn doped BST films; dielectric transition; sol-gel; phase shifter; microwave dielectrics AB The nature of in-plane epitaxy and texture quality of highly oriented (100) Ba0.5Sr0.5TiO3 [BST (50/50)] thin films on (100) LaAlO3 (LAO) substrates were analyzed using X-ray pole figure analysis and RBS channeling measurements. The temperature dependent (100 to 325 K) electrical properties of the BST (50/50) films were characterized in terms of their low frequency (<1 MHz) dielectric behavior, ferroelectric properties and leakage current characteristics. Mn doping up to 3 at % was found to increase the phase shift from 260 degrees (undoped film) to 340 degrees (at 400 V). However, the insertion loss was also increased from 6.34 dB to 9.52 dB with Mn doping and as a result there was no appreciable improvement in the kappa factor (similar to 35 to 41 degrees/dB). The observed microwave properties are correlated in terms of the degree of texturing and surface morphology of these films. C1 Univ Puerto Rico, Dept Phys, San Juan, PR 00936 USA. NASA, GRC, Space Elect Div, Cleveland, OH 44135 USA. Indian Inst Technol, Dept Phys, Kanpur, Uttar Pradesh, India. RP Majumder, SB (reprint author), Univ Puerto Rico, Dept Phys, San Juan, PR 00936 USA. RI Sahoo, Pratap/B-1358-2008 NR 7 TC 0 Z9 0 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0015-0193 J9 FERROELECTRICS JI Ferroelectrics PY 2002 VL 267 BP 409 EP 414 DI 10.1080/00150190210991 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 573YR UT WOS:000176861100051 ER PT B AU Sayir, A Farmer, SC AF Sayir, A Farmer, SC BE Elices, M Llorca, J TI Fracture characteristics of single crystal and eutectic fibers SO FIBER FRACTURE LA English DT Proceedings Paper CT Fall Euroconference on Fiber Fracture CY 2000 CL MALLORCA, SPAIN SP European Union, European Sci Fdn, Spanish Minist Sci & Technol, USAF Off Sci Res, NASA, Glenn Res, Dupont Nemours Inc, Polytechnic Univ Madrid, Univ Balear Isl DE single-crystal fiber; Garnet fiber; perovskite; single-crystal Y2O3 (yttria); directional solidification; eutectic fiber; slow crack growth; creep resistance; coarsening ID MECHANICAL-PROPERTIES; CRACK GROWTH; BEHAVIOR; MODEL; YAG AB Single-crystal fibers are attractive for functional ceramic applications as active devices and are equally important for structural ceramic components as load bearing applications. The fracture characteristics of single-crystal fibers from a variety of crystal systems including the Al2O3/Y3Al5O12 eutectic were examined. The Young moduli of <0001> Al2O3, <111> Y3Al5O12 and <111> Y2O3 fibers were 453, 290, and 164 GPa, respectively, and agreed well with the literature. Single crystals of <111> Y2O3 were the weakest fibers and their strength did not exceed 700 MPa. The moderate tensile strength of single-crystal <111> Y3Al5O12 was controlled by the facet forming tendency of the cubic garnet structure and in some cases by the precipitation of cubic perovskite phase YAlO3. High-strength single-crystal <0001> Al2O3 fibers did not retain their strength at elevated temperatures. The data suggest that single-crystal <0001> Al2O3 failure is dependent on slow crack growth at elevated temperatures. The high-temperature tensile strength of Al2O3/Y3Al5O12 eutectic fibers is superior to sapphire (1.3 GPa at 1100degreesC) and demonstrably less prone to slow crack propagation. The Al2O3/Y3Al5O12 eutectic interphase boundary is of a coherent nature with strong bonding. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Sayir, A (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RI Elices, Manuel/F-7703-2016 OI Elices, Manuel/0000-0002-8204-1580 NR 23 TC 1 Z9 1 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-08-044104-1 PY 2002 BP 107 EP 123 DI 10.1016/B978-008044104-7/50007-1 PG 17 WC Materials Science, Multidisciplinary; Materials Science, Composites SC Materials Science GA BV98R UT WOS:000180591600007 ER PT S AU Okojie, RS Atwell, AR Kornegay, KT Roberson, SL Beliveau, A AF Okojie, RS Atwell, AR Kornegay, KT Roberson, SL Beliveau, A GP IEEE IEEE TI Design considerations for bulk micromachined 6H-SiC high-G Piezoresistive accelerometers SO FIFTEENTH IEEE INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS, TECHNICAL DIGEST SE PROCEEDINGS: IEEE MICRO ELECTRO MECHANICAL SYSTEMS WORKSHOP LA English DT Proceedings Paper CT 15th IEEE International Conference on Micro Electro Mechanical Systems (MEMS 2002) CY JAN 20-24, 2002 CL LAS VEGAS, NV SP IEEE, Robot & Automat Soc AB We report the utilization of key design parameters to simulate, batch-fabricate and evaluate first-generation single crystal 6H-SiC piezoresistive accelerometers for extreme impact, high electromagnetic fields (EM) and high temperature applications. The results from finite element analysis (FEA) of the selected design models were compared to evaluated prototypes. While FEA results predicted safe operation above 100,000-g's, preliminary experimental tests were performed up to 40,000-g's. Sensitivities ranging between 50 and 343 nV/g were measured. Non-linear behavior was observed over the shock range relative to the commercial accelerometer used as a benchmark. These initial results offer promise for the use of 6H-SiC accelerometers for extreme impact sensing in strong EM fields and temperature up to 600 degreesC that are beyond the capability of silicon. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Okojie, RS (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 77-1, Cleveland, OH 44135 USA. NR 10 TC 7 Z9 9 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1084-6999 BN 0-7803-7185-2 J9 PROC IEEE MICR ELECT PY 2002 BP 618 EP 622 DI 10.1109/MEMSYS.2002.984347 PG 5 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Robotics; Optics SC Engineering; Robotics; Optics GA BU07B UT WOS:000174908700151 ER PT B AU Araiza, R Xie, HJ Starks, SA Kreinovich, V AF Araiza, R Xie, HJ Starks, SA Kreinovich, V GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Automatic referencing of multi-spectral images SO FIFTH IEEE SOUTHWEST SYMPOSIUM ON IMAGE ANALYSIS AND INTERPRETATION, PROCEEDINGS LA English DT Proceedings Paper CT 5th IEEE Southwest Symposium on Image Analysis and Interpretation CY APR 07-09, 2002 CL SANTA FE, NM SP IEEE Comp Soc, IEEE Signal Processing Soc AB In order to adequately process satellite and radar information, it is necessary to find the exact correspondence between different types of images and between these images and the existing maps. In other words, we need to reference these images. In this paper we propose new methods for automatic referencing of satellite and radar images. C1 Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. RP Araiza, R (reprint author), Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. NR 3 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 0-7695-1537-1 PY 2002 BP 21 EP 25 DI 10.1109/IAI.2002.999882 PG 5 WC Imaging Science & Photographic Technology SC Imaging Science & Photographic Technology GA BU39F UT WOS:000175881800004 ER PT J AU Hshieh, FY Beeson, HD AF Hshieh, FY Beeson, HD TI Note: Measuring the effective heats of combustion of transformer-insulating fluids using a controlled-atmosphere cone calorimeter SO FIRE AND MATERIALS LA English DT Article AB The effective heats of combustion of two commonly used transformer-insulating fluids, a high molecular weight hydrocarbon fluid and a 50 cS silicone fluid, have been measured using a controlled-atmosphere cone calorimeter. The study shows that the cone calorimeter is a good tool to measure the effective heats of combustion of transformer-insulating fluids. Copyright (C) 2002 John Wiley Sons, Ltd. C1 Honeywell Tech Solut Inc, White Sands Test Facil, Las Cruces, NM 88004 USA. NASA, Lyndon B Johnson Space Ctr, White Sands Test Facil, Las Cruces, NM 88004 USA. RP Hshieh, FY (reprint author), Honeywell Tech Solut Inc, White Sands Test Facil, POB 20, Las Cruces, NM 88004 USA. NR 9 TC 3 Z9 3 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0308-0501 J9 FIRE MATER JI Fire Mater. PD JAN-FEB PY 2002 VL 26 IS 1 BP 47 EP 49 DI 10.1002/fam.778 PG 3 WC Materials Science, Multidisciplinary SC Materials Science GA 570XY UT WOS:000176686800005 ER PT B AU Johnson, AE Manduchi, R AF Johnson, AE Manduchi, R BE Cortelazzo, GM Guerra, C TI Probabilistic 3D data fusion for adaptive resolution surface generation SO FIRST INTERNATIONAL SYMPOSIUM ON 3D DATA PROCESSING VISUALIZATION AND TRANSMISSION LA English DT Proceedings Paper CT 1st International Symposium on 3D Data Processing Visualization and Transmission CY JUN 19-21, 2002 CL PADUA, ITALY SP Eurograph Assco, IEEE Soc Tech Comm Multimedia Signal Processing, Univ Padua, Dept Informat Engn, IBM T J Watson Lab, WIND, Veneto Reg ID OCTREE AB In this paper we present an algorithm for adaptive resolution integration of 3D data collected from multiple distributed sensors. The input to the algorithm is a set of 3D surface points and associated sensor models. Using a probabilistic rule, a surface probability function is generated that represents the probability that a particular volume of space contains the surface. The surface probability function is represented using an octree data structure; regions of space with samples of large covariance are stored at a coarser level than regions of space containing samples with smaller covariance. The algorithm outputs an adaptive resolution surface generated by connecting points that lie on the ridge of surface probability with triangles scaled to match the local discretization of space given by the octree. To demonstrate the performance of our algorithm, we present results from 3D data generated by scanning lidar and structure from motion. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. EM aej@jpl.nasa.gov; manduchi@seo.ucsc.edu NR 14 TC 2 Z9 2 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 0-7695-1521-5; 0-7695-1522-3 PY 2002 BP 578 EP 587 DI 10.1109/TDPVT.2002.1024121 PG 10 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology SC Computer Science; Engineering; Imaging Science & Photographic Technology GA BU79U UT WOS:000177028700084 ER PT J AU McBride, RS Fahay, MP Able, KW AF McBride, RS Fahay, MP Able, KW TI Larval and settlement periods of the northern searobin (Prionotus carolinus) and the striped searobin (P-evolans) SO FISHERY BULLETIN LA English DT Article ID NEW-YORK BIGHT; EARLY-LIFE-HISTORY; ATLANTIC BIGHT; ABUNDANCE; FISH; SEASONALITY; INDICATORS; BAY AB This study reports new information about searobin (Prionotus spp.) early life history from samples collected with a Tucker trawl (for planktonic stages) and a beam trawl (for newly settled fish) from the coastal waters of New Jersey. Northern searobin, Prionotus carolinus, were much more numerous than striped searobin, P. evolans, often by an order of magnitude. Larval Prionotus were collected during the period July-October and their densities peaked during September. For both species, notochord flexion was complete at 6-7 mm standard length (SL) and individuals settled at 8-9 mm SL. Flexion occurred as early as 13 days after hatching and settlement occurred as late as 25 days after hatching, according to ages estimated from sagittal microincrements. Both species settled directly in continental shelf habitats without evidence of delayed metamorphosis. Spawning, larval dispersal, or settlement may have occurred within certain estuaries, particularly for P. evolans; thus collections from shelf areas alone do not permit estimates of total larval production or settlement rates. Reproductive seasonality of P. carolinus and P. evolans may vary with respect to latitude and coastal depth. In this study, hatching dates and sizes of age-0 P. carolinus varied with respect to depth or distance from the New Jersey shore. Older and larger age-0 individuals were found in deeper waters. These variations in searobin age and size appear to be the combined result of intraspecific variations in searobin reproductive seasonality and the limited capability of searobin eggs and larvae to disperse. C1 Rutgers State Univ, Marine Field Stn, Inst Marine & Coastal Sci, Tuckerton, NJ 08087 USA. Natl Marine Fisheries Serv, Sandy Hook Lab, NE Fisheries Sci Ctr, NOAA, Highlands, NJ 07732 USA. RP McBride, RS (reprint author), Florida Marine Res Inst, 100 8th Ave SE, St Petersburg, FL 33701 USA. RI McBride, Richard/C-2818-2012 NR 46 TC 8 Z9 10 U1 0 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 2002 VL 100 IS 1 BP 63 EP 73 PG 11 WC Fisheries SC Fisheries GA 517UV UT WOS:000173629300007 ER PT J AU Zug, GR Balazs, GH Wetherall, JA Parker, DM Murakawa, SKK AF Zug, GR Balazs, GH Wetherall, JA Parker, DM Murakawa, SKK TI Age and growth of Hawaiian green seaturtles (Chelonia mydas): an analysis based on skeletochronology SO FISHERY BULLETIN LA English DT Article ID LOGGERHEAD SEA-TURTLES; CARETTA-CARETTA; RATES AB Skeletochronological data on growth changes in humerus diameter were used to estimate the age of Hawaiian green seaturtles ranging from 28.7 to 96.0 cm straight carapace length. Two age estimation methods, correction factor and spline integration, were compared, giving age estimates ranging from 4.1 to 34.6 and from 3.3 to 49.4 yr respectively, for the sample data. Mean growth rates of Hawaiian green seaturtles are 4-5 cm/yr in early juveniles, decline to a relatively constant rate of about 2 cm/yr by age 10 yr then decline again to less than 1 cm/yr as turtles near age 30 yr. On average, age estimates from the two techniques differed by just a few years for juvenile turtles, but by wider margins for mature turtles. The spline-integration method models the curvilinear relationship between humerus diameter and the width of periosteal growth increments within the humerus, and offers several advantages over the correction-factor approach. C1 Natl Museum Nat Hist, Div Amphibians & Reptiles, Dept Systemat Biol, Washington, DC 20560 USA. NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. Univ Hawaii, Joint Inst Marine & Atmospher Res, Honolulu, HI 96822 USA. RP Zug, GR (reprint author), Natl Museum Nat Hist, Div Amphibians & Reptiles, Dept Systemat Biol, Washington, DC 20560 USA. NR 24 TC 53 Z9 64 U1 0 U2 7 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 2002 VL 100 IS 1 BP 117 EP 127 PG 11 WC Fisheries SC Fisheries GA 517UV UT WOS:000173629300012 ER PT J AU DiNardo, GT DeMartini, EE Haight, WR AF DiNardo, GT DeMartini, EE Haight, WR TI Estimates of lobster-handling mortality associated with the Northwestern Hawaiian Islands lobster-trap fishery SO FISHERY BULLETIN LA English DT Article C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. Univ Hawaii, Joint Inst Marine & Atmospher Res, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. RP DiNardo, GT (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, 2570 Dole St, Honolulu, HI 96822 USA. NR 10 TC 16 Z9 16 U1 1 U2 1 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD JAN PY 2002 VL 100 IS 1 BP 128 EP 133 PG 6 WC Fisheries SC Fisheries GA 517UV UT WOS:000173629300013 ER PT S AU Giannakopoulou, D Lerda, F AF Giannakopoulou, D Lerda, F BE Peled, DA Vardi, MY TI From states to transitions: Improving translation of LTL formulae to Buchi automata SO FORMAL TECHNIQUE FOR NETWORKED AND DISTRIBUTED SYSTEMS - FORTE 2002, PROCEEDINGS SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 22nd International Conference on Formal Techniques for Networked and Distributed Systems CY NOV 11-14, 2002 CL RICE UNIV, HOUSTON, TX SP IFIP WG6 1 HO RICE UNIV AB Model checking is an automated technique for checking that a system satisfies a set of required properties. With explicit-state model checkers, properties are typically defined in linear-time temporal logic (LTL), and are translated into Buchi automata in order to be checked. This paper describes how, by labeling automata transitions rather than states, we significantly reduce the size of automata generated by existing tableau-based translation algorithms. Our optimizations apply to the core of the translation process, where generalized Buchi automata are constructed. These automata are subsequently transformed in a single efficient step into Buchi automata as used by model checkers. The tool that implements the work described here is released as part of the Java Path-Finder software (JPF), an explicit state model checker of Java programs under development at the NASA Ames Research Center. C1 NASA, Ames Res Ctr, RIACS USRA, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, RIACS USRA, Moffett Field, CA 94035 USA. EM dimitra@email.arc.nasa.gov; lerda@cmu.edu NR 11 TC 37 Z9 38 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-00141-7 J9 LECT NOTES COMPUT SC PY 2002 VL 2529 BP 308 EP 326 PG 19 WC Computer Science, Theory & Methods SC Computer Science GA BW68T UT WOS:000182827100020 ER PT J AU Batchelor, D AF Batchelor, D TI Semiclassical models for virtual antiparticle pairs, the unit of charge e, and the QCD coupling alpha(s) SO FOUNDATIONS OF PHYSICS LA English DT Article ID CLASSICAL ELECTRODYNAMICS AB New semiclassical models of virtual antiparticle pairs are used to compute the pair lifetimes, and good agreement with the Heisenberg lifetimes front quantum field theory (QFT) is found. The modeling method applies to both the electromagnetic and color forces. Evaluation of the action integral of potential field fluctuation for each interaction potential yields approximate to (h) over bar /2 for both electromagnetic and color fluctuations, in agreement with QFT. Thus each model is a quantized semiclassical representation for such virtual antiparticle pairs, to good approximation. When the results of the new models and QFT are combined, formulae for e and alpha(s)(q) are derived in terms of only (h) over bar and c. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Batchelor, D (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 46 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 0015-9018 J9 FOUND PHYS JI Found. Phys. PD JAN PY 2002 VL 32 IS 1 BP 51 EP 76 DI 10.1023/A:1013848830547 PG 26 WC Physics, Multidisciplinary SC Physics GA 527UW UT WOS:000174207200003 ER PT B AU Hoell, JM AF Hoell, JM GP AMS AMS TI Global Tropospheric Experiment: Tropospheric chemistry data spanning 18 years available from the NASA Langley atmospheric sciences data center. SO FOURTH CONFERENCE ON ATMOSPHERIC CHEMISTRY: URBAN, REGIONAL AND GLOBAL SCALE IMPACTS OF AIR POLLUTANTS LA English DT Proceedings Paper CT 4th Conference on Atmospheric Chemistry CY JAN 13-17, 2002 CL ORLANDO, FL SP Amer Meteorol Soc ID AIRBORNE INSTRUMENT INTERCOMPARISONS; HYDROXYL INSTRUMENTATION; CARBON-MONOXIDE; NITRIC-OXIDE C1 Langley Res Ctr, Hampton, VA 23681 USA. RP Hoell, JM (reprint author), Langley Res Ctr, MS 157-D, Hampton, VA 23681 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2002 BP 179 EP 180 PG 2 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BV53X UT WOS:000179290000037 ER PT S AU Powers, LM Salem, JA Weaver, AS AF Powers, LM Salem, JA Weaver, AS BE Salem, JA Quinn, GD Jenkins, MG TI Stresses in ceramic plates subjected to loading between concentric rings SO FRACTURE RESISTANCE TESTING OF MONOLITHIC AND COMPOSITE BRITTLE MATERIALS SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Fracture Resistance Testing of Monolithic and Composite Brittle Materials CY NOV 14, 2000 CL ORLANDO, FL SP ASTM Comm C28 Adv Ceram DE ceramics; multiaxial strength; stress; plates ID BRITTLE AB Plates of both square and round geometries are tested to determine the strength and fatigue properties of ceramics under multiaxial stresses. The necessary tolerances required for accurate testing are not well documented in published literature. The stresses in square and round plates subjected to loading between concentric rings were investigated via the finite element analysis method. In particular, the effects of load ring concentricity and the amount of the plate overhanging the support ring were investigated. Also, the errors generated by testing square plates between circular rings were investigated. The analyses were performed in support of an effort by the American Society for Testing and Materials Committee C28 on Advanced Ceramics to standardized multiaxial testing of ceramic plates. C1 Case Western Reserve Univ, NASA Glenn Res Ctr, Cleveland, OH 44135 USA. RP Powers, LM (reprint author), Case Western Reserve Univ, NASA Glenn Res Ctr, MS 49-7, Cleveland, OH 44135 USA. NR 13 TC 4 Z9 4 U1 0 U2 0 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2880-0 J9 AM SOC TEST MATER PY 2002 VL 1409 BP 30 EP 45 DI 10.1520/STP10470S PG 16 WC Materials Science, Ceramics SC Materials Science GA BT94R UT WOS:000174533300003 ER PT S AU Salem, JA Jenkins, MG AF Salem, JA Jenkins, MG BE Salem, JA Quinn, GD Jenkins, MG TI The effect of stress rate on slow crack growth parameter estimates SO FRACTURE RESISTANCE TESTING OF MONOLITHIC AND COMPOSITE BRITTLE MATERIALS SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Fracture Resistance Testing of Monolithic and Composite Brittle Materials CY NOV 14, 2000 CL ORLANDO, FL SP ASTM Comm C28 Adv Ceram DE dynamic fatigue; slow crack growth; ceramics; strength; life prediction; stress rate; stress corrosion; reliability AB Dynamic fatigue or constant stress-rate testing is a convenient method for generating SCG (slow crack growth) data on ceramics and glasses. The tests are simple, inexpensive, and accomplished quickly. However, the use of dynamic fatigue testing to generate slow crack growth data for SCG parameter estimation assumes that the test specimen lifetime is dominated by a single region of the SCG curve. This assumption breaks down when excessive stressing rates are used and significant portions of the crack growth occurs in all three regions of the SCG curve. The resultant averaging of data representing all three regions of the SCG curve results in an error in the estimated SCG parameters n and D, and such data may not be accurate for predicting the lifetime of industrial components. Dynamic fatigue tests covering five orders of magnitude well below the inert strength were performed on an alumina. The tests were performed using ASTM C 1161 "B" flexure specimens in accordance with ASTM Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress Rate Testing (C 1368-97). Statistical analysis of the experimental results indicates a statistically significant effect of stress rate on the SCG parameter n for stress rates above several MPa/s. The experimental results are in agreement with analytical results of Sudreau et al. [1] that show significant effects for rates greater than approximately one MPa/s. Recommendations for dynamic fatigue testing are given with regard to the current procedures in ASTM C 1368-97. C1 NASA, Glenn Res Ctr, Life Predict Branch, Cleveland, OH 44135 USA. RP Salem, JA (reprint author), NASA, Glenn Res Ctr, Life Predict Branch, 21000 Brookpk Rd,MS 49-7, Cleveland, OH 44135 USA. NR 9 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2880-0 J9 AM SOC TEST MATER PY 2002 VL 1409 BP 213 EP 227 DI 10.1520/STP10481S PG 15 WC Materials Science, Ceramics SC Materials Science GA BT94R UT WOS:000174533300014 ER PT S AU Lee, SH AF Lee, SH BE Mecherle, GS TI Pointing accuracy improvement using model-based noise reduction method SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES XIV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies XIV CY JAN 21-22, 2002 CL SAN JOSE, CA SP SPIE DE pointing; centroid estimation; optical communications ID ARRAYS AB A new method for improving centroid accuracy, thereby pointing accuracy, is proposed. Accurate centroid estimation is critical for free-space optical communications where the number of photons from the reference optical sources such as stars or an uplink beacon is limited. It is known that the centroid accuracy is proportional to the SNR. Presence of various noise sources during the exposure of CCD can lead to significant degradation of the centroid estimation. The noise sources include CCD read noise, background light, stray light, and CCD processing electronics. One of the most widely used methods to reduce the effects of the noise and background bias is the thresholding method, which subtracts a fixed threshold from the centroid window before centroid computation. The approach presented here, instead, utilizes the spot model to derive the signal boundary that is used to truncate the noise outside the signal boundary. This process effectively reduces both the bias and the noise. The effectiveness of the proposed method is demonstrated through simulations. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lee, SH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 5 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 0-8194-4374-3 J9 P SOC PHOTO-OPT INS PY 2002 VL 4635 BP 65 EP 71 DI 10.1117/12.464110 PG 7 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BU67M UT WOS:000176682900007 ER PT S AU Biswas, A Madden-Woods, B Srinivasan, M Vilnrotter, V Farr, W AF Biswas, A Madden-Woods, B Srinivasan, M Vilnrotter, V Farr, W BE Mecherle, GS TI Ground detectors for optical communications from deep space SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES XIV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies XIV CY JAN 21-22, 2002 CL SAN JOSE, CA SP SPIE DE avalanche photodiodes; pulse position modulation; bit-error rate AB A variety of avalanche photodiodes (APD's) were tested with pulse position modulated (PPM) Q-switched laser pulses incident on the detector, with varying amounts of attenuation. The detector output was recorded and postprocessed in order to determine the signal and noise slot statistics, as well as, to estimate bit-error-rates (BER). The probability distribution functions predicted by a Webb+Gaussian model were compared to the measured slot statistics, as were theoretical BER curves. Allowing noise equivalent temperature to be a free fitting parameter yielded good fits between measurements and theory. All the measurements used 256-ary PPM and 10-25 ns slot widths, with a Q-switched Nd: YVO4 laser modulated at 50K-100K pulses per second. A 3 mm diameter, silicon (Si) APD with 80% quantum efficiency (QE) at 532 nm displayed a sensitivity of 11-12 photons/bit for a BER of 10(-2) in the absence of background light. For this detector the sensitivity deteriorated to 18 photons/bit in the presence of 100 photons per 25 ns slot of background light. A 0.8 mm diameter near infrared (NIR) enhanced Si APD with QE of 0.38 displayed sensitivities of 23 - 32 photons/bit for a BER of 10(-2) at 1064 nm in the absence of background light. Backgrounds of 400 photons per 25 ns slot degraded the sensitivity to similar to 58 photons/slot. Finally a 3 mm 0 diameter NIR enhanced Si APD yielded a sensitivity of similar to 100 photons/bit @ 1064 nm for a BER of 10(-2) with no background present. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Biswas, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 16 TC 5 Z9 6 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 0-8194-4374-3 J9 P SOC PHOTO-OPT INS PY 2002 VL 4635 BP 72 EP 83 DI 10.1117/12.464111 PG 12 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BU67M UT WOS:000176682900008 ER PT S AU Vilnrotter, VA Lau, CW AF Vilnrotter, VA Lau, CW BE Mecherle, GS TI Quantum detection and channel capacity for communications applications SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES XIV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies XIV CY JAN 21-22, 2002 CL SAN JOSE, CA SP SPIE AB The fundamental performance limits and channel capacity of optical communications systems operating over the free space channel are examined using quantum detection theory. The performance of the optimum quantum receiver for on-off keying (OOK) and optical binary phase shift keying (BPSK) is first examined as a pure state (no noise) problem. The classical capacity of the binary symmetric channel for these two modulation schemes is then evaluated for the optimum quantum receiver by making use of the concept of quantum measurement states. The performance of M-ary pulse position modulation, which requires a product state representation, is evaluated along with the performance of certain "dense signal sets". Performance comparisons with classical techniques shows over 5 dB improvement in some cases when quantum detection is employed. As a further application of the quantum detection theory, the capacity of the binary channel with on-off keyed modulation and quantum detection is evaluated, and shown to exceed the capacity obtained with classical photon counting. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Vilnrotter, VA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. 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 0-8194-4374-3 J9 P SOC PHOTO-OPT INS PY 2002 VL 4635 BP 103 EP 115 DI 10.1117/12.464084 PG 13 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BU67M UT WOS:000176682900011 ER PT S AU Moision, B Hamkins, J AF Moision, B Hamkins, J BE Mecherle, GS TI Constrained coding for the deep-space optical channel SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES XIV SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies XIV CY JAN 21-22, 2002 CL SAN JOSE, CA SP SPIE DE constrained coding; error-correcting codes; convolutional codes; Reed-Solomon codes; concatenated codes; pulse position modulation; deep-space communications; optical communications ID CAPACITY AB We investigate methods of coding for a channel subject to a large dead-time constraint, i.e., a constraint on the minimum spacing between transmitted pulses, with the deep-space optical channel as the motivating example. Several constrained codes designed to satisfy the dead-time constraint are considered and compared on the basis of throughput, complexity, and decoded error-rate. The performance of an iteratively decoded serial concatenation of a modulation code with an outer code is evaluated and shown to provide significant gains over Reed-Solomon concatenated with Pulse Position Modulation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Moision, B (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM fbruce.moision@jpl.nasa.gov; jon.hamkins@jpl.nasa.gov NR 17 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 0-8194-4374-3 J9 PROC SPIE PY 2002 VL 4635 BP 127 EP 137 DI 10.1117/12.464086 PG 11 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BU67M UT WOS:000176682900013 ER PT S AU Biswas, A Vilnrotter, V Farr, W Fort, D Sigman, E AF Biswas, A Vilnrotter, V Farr, W Fort, D Sigman, E BE Mecherle, GS TI Pulse position modulated (PPM) ground receiver design for optical communications from deep space SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES XIV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies XIV CY JAN 21-22, 2002 CL SAN JOSE, CA SP SPIE DE pulse-position modulation; avalanche photodiodes; photomultiplier tube; slot synchronization AB Pulse position modulation (PPM) provides a means of using high peak power lasers for transmitting communications signals from planetary spacecraft to earth-based receiving stations. Large aperture (similar to10 m diameter) telescopes will be used to collect and focus the laser communications signal originating from a deep space transmitter on to a PPM receiver. Large area (1-3 mm diameter) sensitive detectors, preceded by appropriate narrow (0.1-0.2 nm) optical band-pass filters and followed by low-noise, high-gain, amplifiers will serve as the PPM receiver front end. A digital assembly will form the backbone of the receiver. The PPM receiver will achieve and maintain slot synchronization based on sub slot sums generated by a field programmable-gated array (FPGA). Spacecraft dynamics and timing issues between the ground-based receiver and the transmitter on board the spacecraft must be taken into account. In the present report, requirements and design of a prototype PPM receiver being developed over the next year will be elaborated. The design is driven by the need to demonstrate and validate PPM reception using a variety of detectors under simulated conditions representative of those to be encountered in a deep space optical communications link. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Biswas, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 6 Z9 6 U1 1 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 0-8194-4374-3 J9 P SOC PHOTO-OPT INS PY 2002 VL 4635 BP 224 EP 235 DI 10.1117/12.464093 PG 12 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BU67M UT WOS:000176682900022 ER PT S AU Hemmati, H Page, N AF Hemmati, H Page, N BE Mecherle, GS TI Approaches for efficient coupling of lasers to telescopes with secondary mirror and baffle obscuration SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES XIV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies XIV CY JAN 21-22, 2002 CL SAN JOSE, CA SP SPIE DE beam coupling; axicon; beam slicer; sub-aperture; and optical communications AB For free-space propagation, often laser sources with Gaussian intensity profile are utilized. A Cassegrainian telescope's central obstruction can block a significant amount of the transmitted beam energy. The previously known approaches to solve the problem include: use of an axicon optical element and or sub-aperture illumination of the telescope primary mirror. Two new approaches have been identified to eliminate all secondary mirror and baffle vignetting. These approaches include a beam-slicer and a beam-splitter/combiner optics. The new approaches eliminate the precise alignment required for axicon devices and are simple to fabricate. The beam-splitter/prism combiner approach results in a clean far field pattern and has transmission divergence that is limited to the diffraction limit for each of the sub-aperture transmission beams. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hemmati, H (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 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 0-8194-4374-3 J9 P SOC PHOTO-OPT INS PY 2002 VL 4635 BP 288 EP 294 DI 10.1117/12.464108 PG 7 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BU67M UT WOS:000176682900028 ER PT S AU Hemmati, H Wright, A Sanii, B Page, N Ortiz, GG Wilson, K AF Hemmati, H Wright, A Sanii, B Page, N Ortiz, GG Wilson, K BE Mecherle, GS TI Multi-gigabit data-rate optical communication depicting LEO-to-GEO and GEO-to-Ground links SO FREE-SPACE LASER COMMUNICATION TECHNOLOGIES XIV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Free-Space Laser Communication Technologies XIV CY JAN 21-22, 2002 CL SAN JOSE, CA SP SPIE AB Communication links with multi-giga-bits per sec (Gbps) data-rates depicting both LEO-GEO and GEO-to-Ground optical communications were characterized in the laboratory. A 5.4 Gbps link, with a capability of 7.5 Gbps, was demonstrated in the laboratory. The breadboard utilized a 13 cm diameter telescope as the transmit aperture that simulates the LEO terminal. The receiver is a 30-cm telescope that simulates the GEO terminal. The objective of the laboratory breadboard development is to validate the link analysis and to demonstrate a multi-gigabit link utilizing off-the-shelf or minimally modified commercially available components (optics and opto-electronics) and subsystems. For a bit-error-rate of 1E-7, the measured required received signal is within 1 to 2 dB of that predicted by the link analysis. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hemmati, H (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 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 0-8194-4374-3 J9 P SOC PHOTO-OPT INS PY 2002 VL 4635 BP 295 EP 301 DI 10.1117/12.464091 PG 7 WC Engineering, Aerospace; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BU67M UT WOS:000176682900029 ER PT S AU Anjali, T Scoglio, C de Oliveira, JC Chen, LC Akyildiz, IF Smith, JA Uhl, G Sciuto, A AF Anjali, T Scoglio, C de Oliveira, JC Chen, LC Akyildiz, IF Smith, JA Uhl, G Sciuto, A BE Stiller, B Smirnow, M Karsten, M Reichl, P TI A new path selection algorithm for MPLS networks based on available bandwidth estimation SO FROM QOS PROVISIONING TO QOS CHARGING, PROCEEDINGS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 3rd COST 263 International Workshop on Quality of Future Internet Services/2nd International Workshop on Internet Charging and QoS Technologies CY OCT 16-18, 2002 CL ZURICH, SWITZERLAND SP ETH Zurich, IBM Res, Zurich Res Lab, Siemens Schwiz AG, Swisscom AG, ETH Zurich, TIK, Comp Engn & Networks Lab DE QoS-aware path selection; passive measurement; available bandwidth ID ADMISSION CONTROL AB A network should deploy QoS-aware path selection algorithms for efficient routing. To this end, measurements of the various characteristics of the network can provide insight into the state and performance of the network. In this paper, we present a new QoS-aware path selection algorithm for flows requiring bandwidth guarantees based on an estimation algorithm for the available bandwidth on the links of the network. The estimation algorithm for the available bandwidth predicts the available bandwidth and also tells the duration for which the estimate is valid with a high degree of confidence. Thus, the path selection algorithm is adaptive and not very computationally intensive. C1 Georgia Inst Technol, Sch Elect & Comp Engn, Broadband & Wireless Networking Lab, Atlanta, GA 30332 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Anjali, T (reprint author), 250 14th St,Suite 556, Atlanta, GA 30318 USA. RI Akyildiz, Ian/G-7136-2011 OI Akyildiz, Ian/0000-0002-8099-3529 NR 15 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-44356-8 J9 LECT NOTES COMPUT SC PY 2002 VL 2511 BP 205 EP 214 PG 10 WC Computer Science, Information Systems; Computer Science, Theory & Methods; Telecommunications SC Computer Science; Telecommunications GA BY01Y UT WOS:000187254600020 ER PT S AU Beichman, C Coulter, D Lindensmith, C Lawson, P AF Beichman, C Coulter, D Lindensmith, C Lawson, P BE Dressler, AM TI Selected mission architectures for the terrestrial planet finder (TPF): Large, medium, and small SO FUTURE RESEARCH DIRECTION AND VISIONS FOR ASTRONOMY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Future Research Direction and Visions for Astronomy CY AUG 25-26, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE Terrestrial Planet Finder; planets; life; infrared; interferometer; coronagraph AB Four teams incorporating scientists and engineers from more than 50 universities and 20 engineering firms have assessed techniques for detecting and characterizing terrestrial planets orbiting nearby stars. The primary conclusion from the effort, of the past two years is that with suitable technology investment starting now, a mission to detect terrestrial planets around 150 nearby stars could be launched within a decade. Missions of smaller scale could carry out more modest programs capable of detecting and characterizing gas giant planets around tens of stars and of detecting terrestrial planets around the nearest stars. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Beichman, C (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 11 Z9 11 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 0-8194-4614-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4835 BP 115 EP 121 DI 10.1117/12.461532 PG 7 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BV95G UT WOS:000180513700013 ER PT S AU Mushotzky, R AF Mushotzky, R BE Dressler, AM TI Future x-ray missions - the extragalactic perspective SO FUTURE RESEARCH DIRECTION AND VISIONS FOR ASTRONOMY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Future Research Direction and Visions for Astronomy CY AUG 25-26, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE x-ray astronomy; spectroscopy; cosmology; active galaxies; space AB Recent results from XMM-Newton and Chandra show that sufficiently sensitive x-ray imaging and spectroscopic capabilities allow one to observe the, evolution of active galaxies out to z similar to 6, the x-ray signature of luminous star forming galaxies at z similar to 3, as well as the origin and evolution of cosmic structure. With the advent of new optical UV/IR and radio capabilities in the next decade, it is appropriate to evaluate the future capabilities of planned x-ray missions (e.g., Constellation-X and Astro-E2) as well as other missions being developed (e.g., Gen-X, XEUS, and Astro-G) or under advance planning (MAXIM and EXIST). I will present a summary of the present status of the field and the capabilities of these missions for extragalactic x-ray astronomy. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Mushotzky, R (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 662, Greenbelt, MD 20771 USA. NR 14 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 0-8194-4614-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4835 BP 164 EP 171 DI 10.1117/12.456506 PG 8 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BV95G UT WOS:000180513700018 ER PT S AU Ge, J Mahadevan, S van Eyken, J DeWitt, C Shaklan, S AF Ge, J Mahadevan, S van Eyken, J DeWitt, C Shaklan, S BE Dressler, AM TI All sky Doppler extra-solar planet surveys with a multi-object fixed-delay interferometer SO FUTURE RESEARCH DIRECTION AND VISIONS FOR ASTRONOMY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Future Research Direction and Visions for Astronomy CY AUG 25-26, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE interferometer; spectrometer; fringe; multi-object; Doppler; radial velocity; extra-solar planets ID RADIAL-VELOCITY MEASUREMENTS; SPECTROMETER; STAR; SPECTROGRAPH; PRECISION; COMPANION AB Characterization of extra-solar planetary systems requires surveying for planets around hundreds of thousands of nearby stars of all types, with different metalicities, environments (star cluster and multiple star systems), ages etc. Space missions such as SIM, NGST and TPF will identify many of these systems. However, these missions need ground-based surveys to find candidates to improve their efficiency and provide complementary work. Among these surveys, Doppler radial velocity (RV) surveys, which have detected almost all of similar to 100 known planetary systems, will continue to be the most efficient for detecting planets. Though the cross-dispersed echelle spectroscopy has demonstrated high sensitivity and good efficiency for observing thousands of stars, (limited to late F,G, K and M type), it would be tremendously challenging to search for hundreds of thousands of stars since this would require more than 2 orders of magnitude improvement in observing efficiency. New techniques with high throughput and multi- object capability for high precision RV surveys are crucial in solving this problem. Here we introduce a new technique based on a multi-object fixed-delay interferometer with a first order grating postdisperser which provides the potential for all sky radial velocity surveys for planets. This kind of instrument is a combination of a fixed-delay interferometer with a moderate resolution post-disperser. Doppler measurements are conducted by monitoring stellar interferometric fringe phase shifts instead of absorption line centroid shifts as in the echelle. High Doppler sensitivity is achieved by optimizing the optical delay in the interferometer and reducing photon noise by measuring multiple fringes over a broadband realized by the post-disperser. Since the resulting Doppler sensitivity is independent of the dispersion power of the post-disperser, the whole instrument can be designed for multiple objects, high throughput, and high Doppler sensitivity, while the instrument can be made very compact, thermally and mechanically rigid, and low-cost compared to the echelles. Its superior stability and simple instrument response allow its easy adaptation to other wavelengths such as UV and IR. Once a multi-object instrument of this type, with possible UV, visible and near-IR instrument channels, is coupled with a wide field telescope (a few degree, such as Sloan and WIYN), it will produce hundreds of fringing spectra to allow simultaneous searching for planets around late type F, G, and K stars in the visible, early type B and A-type stars, and white dwarfs in UV and late M-dwarfs in near-IR. The first light observations of our prototype interferometer at the Hobby-Eberly 9m and Palomar 5m telescopes in 2001 have demonstrated that this new technique can approach high Doppler precision mainly determined by photon statistics (Ge et al. 2001; van Eyken et al. 2001; Ge et al. 2002). For instance, a stellar intrinsic Doppler precision of similar to 3 m/s has been achieved with a wavelength coverage of similar to 140 Angstrom and S/N similar to 120 per pixel. The overall short-term Doppler measurement error is similar to 9 m/s. This is mainly caused by low fringe contrast (or visibility) of the iodine absorption lines 2.5% vs. similar to 7% in stellar lines for wavelength calibration. Recent observing at the KPNO 2.1-m telescope demonstrated good instrument throughput and increased wavelength coverage. The total detection efficiency including the sky, telescope and fiber transmission losses, the instrument and iodine transmission losses and detector quantum efficiency is 3.4% under 1.5 arcsec seeing conditions. This efficiency is already comparable to all of the echelle spectrometers for planet detection. C1 Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ge, J (reprint author), Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. NR 31 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 0-8194-4614-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4835 BP 180 EP 191 DI 10.1117/12.456507 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BV95G UT WOS:000180513700020 ER PT S AU Little, ME Kordesch, ME AF Little, ME Kordesch, ME BE Northrup, JE Neugebauer, J Look, DC Chichibu, SF Riechert, H TI Band-gap engineering in amorphous/microcrystalline ScxGa1-xN SO GAN AND RELATED ALLOYS-2001 SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on GaN and Related Alloys-2001 held at the 2001 MRS Fall Meeting CY NOV 26-30, 2001 CL BOSTON, MA SP Mat Res Soc ID AB-INITIO CALCULATIONS; ELECTRONIC-STRUCTURE; SCANDIUM NITRIDE; SCN; SEMICONDUCTORS; GROWTH AB Reactive sputtering was used to grow thin films of SexGa1-xN with scandium concentrations of 20%-70% on quartz substrates at temperatures of 300-675 K. X-ray diffraction (XRD) of the films showed either weak or no structure. suggesting the films are amorphous or microcrystalline, Optical absorption spectra were taken of each sample and the optical band gap was determined. The band gap varied linearly with increasing Ga concentration between 2.0 and 3.5 eV. Ellipsometry was used to confirm the band gap measurements and provide optical constants in the range 250-1200 nm. ScN and GaN have different crystal structures (rocksalt and wurzite, respectively), and thus may form a heterogeneous mixture as opposed to an alloy. Since the XRD data were inconclusive, bilayers of ScN/GaN were grown and optical absorption spectra taken. A fundamental difference in the spectra between the bilayer films and alloy films was seen, suggesting the films are alloys, not herterogeneous mixtures. C1 NASA Langley Res Ctr, ICASE, Hampton, VA 23666 USA. RP Little, ME (reprint author), NASA Langley Res Ctr, ICASE, Hampton, VA 23666 USA. NR 13 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 1-55899-629-X J9 MATER RES SOC SYMP P PY 2002 VL 693 BP 153 EP 157 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA BV02P UT WOS:000177647000025 ER PT J AU Ernstson, K Rampino, MR Hiltl, M AF Ernstson, K Rampino, MR Hiltl, M TI Cratered cobbles in Triassic Buntsandstein conglomerates in northeastern Spain: An indicator of shock deformation in the vicinity of large impacts: Reply SO GEOLOGY LA English DT Article ID GEOLOGICAL INVESTIGATIONS; INSIGHTS C1 Univ Wurzburg, Fak Geowissensch, D-97070 Wurzburg, Germany. NYU, Earth & Environm Sci Program, New York, NY 10003 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Lawrence Livermore Natl Lab, Phys Directorate, H Div, Livermore, CA 94551 USA. RP Ernstson, K (reprint author), Univ Wurzburg, Fak Geowissensch, D-97070 Wurzburg, Germany. NR 9 TC 0 Z9 0 U1 0 U2 0 PU GEOLOGICAL SOC AMERICA, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 J9 GEOLOGY JI Geology PD JAN PY 2002 VL 30 IS 1 BP 92 EP 92 DI 10.1130/0091-7613(2002)030<0092:>2.0.CO;2 PG 1 WC Geology SC Geology GA 515KR UT WOS:000173495200024 ER PT J AU Salmassi, TM Venkateswaren, K Satomi, M Nealson, KH Newman, DK Hering, JG AF Salmassi, TM Venkateswaren, K Satomi, M Nealson, KH Newman, DK Hering, JG TI Oxidation of arsenite by Agrobacterium albertimagni, AOL15, sp nov., isolated from Hot Creek, California SO GEOMICROBIOLOGY JOURNAL LA English DT Article DE arsenite-oxidation; Agrobacterium albertimagni strain AOL15; arsenite; arsenic; redox; microbial oxidation ID BACTERIA; WATER; HYBRIDIZATION; ARSENIC(III); ENVIRONMENT; RESPIRATION; REDUCTION; ARSENATE; OXIDASE; METALS AB An arsenite-oxidizing bacterium, Agrobacterium albertimagni strain AOL15 (ATCC BAA-24), was isolated from the surface of aquatic macrophytes collected in Hot Creek, California. Under laboratory conditions, whole cell suspensions of AOL15 oxidized arsenite with a K-s of 3.4 +/- 2.2 muM and a V-max of 1.81 +/- 0.58 x 10(12) mumole . cell(1) . min(1) (or 0.043 +/- 0.017 mumole . mg protein(1) . min-1). The K-s value for AOL15 is the lowest value to date reported for whole cell suspensions and is comparable to ambient concentrations of arsenic of 2.7 muM reported for Hot Creek, indicating that AOL15 can oxidize arsenite under ambient conditions. Previous studies at this site revealed a rapid in situ oxidation of geothermally-derived arsenite while field incubation studies demonstrated that this oxidation was bacterially mediated. The isolation of the arsenite oxidizer AOL15 from this environment supports these previous observations. Arsenite does not support chemolithoautotrophic growth of AOL15 and toxicity studies with AOL15 showed that arsenite (at 5 mM) is toxic to AOL15, yet arsenate concentrations as high as 50 mM do not show any toxic effects. These results suggest that the oxidation of arsenite by AOL15 is a detoxification mechanism. C1 CALTECH, Dept Environm Engn Sci, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Natl Res Inst Fisheries Sci, Kanagawa, Japan. CALTECH, Dept Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Hering, JG (reprint author), CALTECH, Dept Environm Engn Sci, 1200 E Calif Blvd,MSC 138-78, Pasadena, CA 91125 USA. NR 42 TC 85 Z9 87 U1 2 U2 17 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-0451 J9 GEOMICROBIOL J JI Geomicrobiol. J. PD JAN-FEB PY 2002 VL 19 IS 1 BP 53 EP 66 DI 10.1080/014904502317246165 PG 14 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 520PK UT WOS:000173790100005 ER PT J AU Juarez, MD Fisher, BM Orton, GS AF Juarez, MD Fisher, BM Orton, GS TI Large scale geostrophic winds with a full representation of the Coriolis force: Application to IR observations of the upper Jovian troposphere SO GEOPHYSICAL AND ASTROPHYSICAL FLUID DYNAMICS LA English DT Article DE geostrophy; atmospheric dynamics; infrared observations; Jupiter ID ZONAL FLOW; JUPITER; EQUATIONS; DYNAMICS; ATMOSPHERES; CONVECTION; TURBULENCE; STABILITY; VORTICES; PLANETS AB The diagnostics of large scale geostrophy in a stratified atmosphere are revisited in pressure coordinates using a full Coriolis force. This formulation of geostrophy includes the horizontal and vertical projections of the planetary rotation vector, is valid for shallow and deep atmospheres, accounts for the spherical geometry of the atmosphere, is not singular at the equator, and provides partial information about vertical velocities. The new expressions, although an improvement over the standard approach, are still only estimates because of the terms that are being neglected and because of the uncertainties in the observational data. The magnitudes of the errors are discussed. The accuracy of the standard hydrostatic approximation in the geostrophic regime is gauged and an alternative approach is discussed. The standard hydrostatic approximation predicts much smaller wind shears than those derived from the primitive equations. The observations are a set of global temperature maps of the upper Jovian troposphere at pressures, between 100 and 400 mbar, obtained from mid-infrared observations in June, 1996. Maps of the large-scale thermal winds show higher concentration of longitudinal structures and vertical velocities along two particular zonal bands at latitudes near 15degreesN and 15degreesS. Observational criteria are proposed to validate the standard versus the new diagnostic as well as the possible geostrophic regime of Jupiter's zonal jets. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Juarez, MD (reprint author), CALTECH, Jet Prop Lab, M-S 238-600, Pasadena, CA 91109 USA. NR 46 TC 4 Z9 4 U1 0 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0309-1929 J9 GEOPHYS ASTRO FLUID JI Geophys. Astrophys. Fluid Dyn. PY 2002 VL 96 IS 2 BP 87 EP 114 DI 10.1080/03091920290027943 PG 28 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Mechanics SC Astronomy & Astrophysics; Geochemistry & Geophysics; Mechanics GA 573VK UT WOS:000176852300001 ER PT J AU Juarez, MD AF Juarez, MD TI Geostrophic thermal winds with a full coriolis force: Response to "Thermal wind balance with full geostrophy" by J.-I. Yano SO GEOPHYSICAL AND ASTROPHYSICAL FLUID DYNAMICS LA English DT Editorial Material DE geostrophy; thermal wind; atmospheric dynamics; infrared observations; planetary atmospheres AB This paper gives the expressions for the synoptic scale thermal winds when a full Coriolis force is considered. The atmosphere is assumed stratified with a steady density profile. It is also argued that the resulting expressions can be applied to atmospheric temperature maps obtained by standard infrared methods only if approximations are made. This paper augments the interpretation of the results obtained in a previous paper by the author and addresses comments made by J.-I. Yano in another paper of this journal. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Juarez, MD (reprint author), CALTECH, Jet Prop Lab, M-S 238-600,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 1 Z9 1 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0309-1929 J9 GEOPHYS ASTRO FLUID JI Geophys. Astrophys. Fluid Dyn. PY 2002 VL 96 IS 5 BP 431 EP 434 DI 10.1080/0309192021000049956 PG 4 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Mechanics SC Astronomy & Astrophysics; Geochemistry & Geophysics; Mechanics GA 611WQ UT WOS:000179041100005 ER PT J AU Burr, DM McEwen, AS Sakimoto, SEH AF Burr, DM McEwen, AS Sakimoto, SEH TI Recent aqueous floods from the Cerberus Fossae, Mars SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GROUND ICE; REGION; LAVAS AB [1] Streamlined forms and longitudinal grooving seen in Mars Orbital Camera (MOC) images indicate recent aqueous flooding occurred downslope (south) of the southern-most Cerberus Fossae fissure. Topography from the Mars Orbital Laser Altimeter (MOLA), in conjunction with the absence of fluvial features in MOC images immediately to the north of the Fossa, substantiate the idea that floods emanated from this fissure. The floodwater flowed southward onto the western Cerberus Plains, where it probably percolated into existing lava flows. Thus, shallow ice may still be extant beneath young lava flows in this equatorial region. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. NASA, Goddard Space Flight Ctr, Goddard Earth Sci & Technol Ctr, Geodynam Branch, Greenbelt, MD 20771 USA. RP Burr, DM (reprint author), Univ Arizona, Lunar & Planetary Lab, 1629 E Univ Blvd, Tucson, AZ 85721 USA. NR 15 TC 61 Z9 61 U1 0 U2 3 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 JAN 1 PY 2002 VL 29 IS 1 AR 1013 DI 10.1029/2001GL013345 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 609CC UT WOS:000178884200001 ER PT S AU Kim, SS Carnes, SR Mysoor, NR Ulmer, CT Arvidson, R AF Kim, SS Carnes, SR Mysoor, NR Ulmer, CT Arvidson, R BE Koppenjan, SK Lee, H TI Miniature ground penetrating radar for planetary subsurface characterization: Preliminary field test results SO GPR 2002: NINTH INTERNATIONAL CONFERENCE ON GROUND PENETRATING RADAR SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 9th International Conference on Ground Penetrating Radar (GPR 2002) CY APR 29-MAY 02, 2002 CL SANTA BARBARA, CA SP Univ Calif, Santa Barbara, Bechtel Nevada, Special Technol Lab, GroundProbe, Sensors & Software Inc, Mala Geosci, Geophys Survey Syst DE GPR; miniature instrument; range gated step frequency radar AB We have developed a miniature range-gated step-frequency (RGSF) ground penetrating radar (GPR) for use in mapping subsurface structures from planetary rovers such as the rover associated with the Mars 2009 Smart Lander Mission. At each stepped frequency the antenna is used to both transmit and receive RF radiation. Radiation scattered back from the subsurface is amplified, mixed with a frequency reference, detected as an in-phase amplitude, and transformed from the frequency domain to the time/distance domain for interpretation. When fully developed, the frequency range will be from approximately 10 MHz to 500 MHz. Compared to conventional impulse GPRs, the RGSF system has a similar total operational bandwidth, but at any instant of operation, the transmitter/receiver system is tuned to a narrowband configuration. It can provide high average transmitter power per frequency and allow low sampling rate. This capability provides both significantly enhanced depth penetration and delineation of fine-scale interfaces. Our prototype GPR has miniaturized radar electronics (3 x 12 x 3 cm, 3W power, 30g), with a battery (14 V, 760 g) and a resistively loaded dipole antenna (2.3 m length, currently operating from 30 MHz - 150 MHz). Field testing of the prototype has been conducted over alluvium and a basaltic lava flow near the Lunar Crater Volcanic Field, Nevada, along a breakout channel north of the Silver Lake Playa, Mojave Desert, California, and over till and ash on Mauna Kea, Hawaii. Comparisons to known subsurface structures for the test sites demonstrate that the system is capable of resolving fine-scale variation in lava flow thickness, the depth to bedrock beneath the aeolian fill and alluvium in the break-out channel, and variations in till and ash thickness, from depths from meters to approximately 10 meters. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kim, SS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 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 0-8194-4522-3 J9 P SOC PHOTO-OPT INS PY 2002 VL 4758 BP 1 EP 6 DI 10.1117/12.462296 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Remote Sensing; Imaging Science & Photographic Technology GA BU70E UT WOS:000176734400001 ER PT S AU Dickey, JO AF Dickey, JO BE Sideris, MG TI Time variable gravity: An emerging frontier in interdisciplinary geodesy SO GRAVITY GEOID AND GEODYNAMICS 2000 SE International Association of Geodesy Symposia LA English DT Proceedings Paper CT IAG International Symposium on Gravity, Geoid and Geodynamics (GGG 2000) CY JUL 31-AUG 04, 2000 CL BANFF, CANADA SP Int Assoc Geodesy DE gravitational field; temporal variations of the potential; geodynamics; solid-Earth processes; sea level and glaciology; ocean dynamics; ocean bottom pressure; hydrology; water storage; and geodetic infrastructure AB The interdisciplinary potential of gravity is stressed with special emphasis on the synergistic use of gravity with other data types. Satellite gravity measurements expected from GRACE and CHAMP will provide unprecedented views of the Earth's gravity field and its changes with time. These measurements will be complementary with those of GOCE, which will provide unprecedented determination of the high-resolution static field. Gravity changes directly reflect changes in the masses of the ocean (thus allowing the separation of steric (heat induced) and non-steric contributions to sea level rise), the Greenland and Antarctic ice sheets, and the water stored in the continents. Not only can measurements of those changes provide a truly global integrated view of the Earth; they have, at the same time, sufficient spatial resolution to aid in the study of individual regions of the Earth. These data should yield information on water cycling previously unobtainable and be useful to both fundamental studies of the hydrologic cycle and practical assessments of water availability and distribution. Together with complementary geophysical data, satellite gravity data represent a new frontier in studies of the Earth and its fluid envelope. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jean.o.dickey@jpl.nasa.gov RI Symposia, IAG/K-2857-2012 NR 7 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0939-9585 BN 3-540-42469-5 J9 IAG SYMP PY 2002 VL 123 BP 1 EP 5 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BT80C UT WOS:000174088700001 ER PT S AU Gross, RS AF Gross, RS BE Sideris, MG TI Gravity, oceanic angular momentum, and the earth's rotation SO GRAVITY GEOID AND GEODYNAMICS 2000 SE INTERNATIONAL ASSOCIATION OF GEODESY SYMPOSIA LA English DT Proceedings Paper CT IAG International Symposium on Gravity, Geoid and Geodynamics (GGG 2000) CY JUL 31-AUG 04, 2000 CL BANFF, CANADA SP Int Assoc Geodesy DE oceanic angular momentum; ocean bottom pressure; Earth rotation; gravitational field ID ATMOSPHERIC MASS REDISTRIBUTION; GRAVITATIONAL-FIELD; POLAR MOTION; SEASONAL-VARIATIONS; TEMPORAL VARIATIONS; LAGEOS; VARIABILITY; EXCITATION; PRESSURE; SIGNALS AB The angular momentum of the oceans changes as both the distribution of mass within the oceans changes and as the direction and speed of oceanic currents change. Since, in the absence of external torques, the angular momentum of the solid Earth-atmosphere-ocean system is conserved, the changing oceanic angular momentum will cause the solid Earth's angular momentum to change, or, in other words, will cause the Earth's rotation to change. The changing distribution of mass within the oceans also causes the Earth's gravitational field to change, an effect that will soon be measured by the CHAMP and GRACE satellite missions. By measuring changes in the second-degree spherical harmonic coefficients of the Earth's gravitational field, which are related to the elements of the Earth's inertia tensor, CHAMP and GRACE will, in effect, be directly measuring changes in the Earth's rotation caused by mass redistribution. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gross, RS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 238-332, Pasadena, CA 91109 USA. RI Symposia, IAG/K-2857-2012 NR 33 TC 8 Z9 8 U1 1 U2 2 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0939-9585 BN 3-540-42469-5 J9 IAG SYMP PY 2002 VL 123 BP 153 EP 158 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BT80C UT WOS:000174088700026 ER PT S AU Gross, RS Chao, BF AF Gross, RS Chao, BF BE Sideris, MG TI The gravitational signature of earthquakes SO GRAVITY GEOID AND GEODYNAMICS 2000 SE INTERNATIONAL ASSOCIATION OF GEODESY SYMPOSIA LA English DT Proceedings Paper CT IAG International Symposium on Gravity, Geoid and Geodynamics (GGG 2000) CY JUL 31-AUG 04, 2000 CL BANFF, CANADA SP Int Assoc Geodesy DE earthquakes; gravitational field ID MOMENT TENSOR SOLUTIONS; VISCOELASTIC EARTH; CHANDLER-WOBBLE; GRAVITY CHANGES; EXCITATION; HARMONICS; ROTATION; FIELD; MODEL AB The static displacement field generated by an earthquake redistributes the Earth's mass and consequently causes the Earth's rotation and global gravitational field to change. Although the coseismic effect of earthquakes on the Earth's rotation and global gravitational field has been modeled in the past, no unambiguous observations of this effect have yet been made. However, the Gravity Recovery And Climate Experiment (GRACE) satellite, which is scheduled to be launched in 2001, will measure time variations of the Earth's gravitational field to high degree and order with unprecedented accuracy. Here, the coseismic effect of earthquakes on the Earth's global gravitational field will be modeled and compared with the expected accuracy of the GRACE measurements. It is shown that the coseismic effects of great earthquakes such as the 1960 Chilean or 1964 Alaskan events can cause global gravitational field changes that are large enough to be detected by GRACE. However, the coseismic effects of the largest earthquakes that have occurred during the past 35 years cause global gravitational field changes that are probably too small to be detected by GRACE. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gross, RS (reprint author), CALTECH, Jet Prop Lab, Mail Stop 238-332,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Symposia, IAG/K-2857-2012 NR 27 TC 22 Z9 22 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0939-9585 BN 3-540-42469-5 J9 IAG SYMP PY 2002 VL 123 BP 205 EP 210 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BT80C UT WOS:000174088700034 ER PT S AU Cox, CM Klosko, SM Chao, BF AF Cox, CM Klosko, SM Chao, BF BE Sideris, MG TI Changes in ice-mass balances inferred from time variations of the geopotential observed through SLR and DORIS tracking SO GRAVITY GEOID AND GEODYNAMICS 2000 SE INTERNATIONAL ASSOCIATION OF GEODESY SYMPOSIA LA English DT Proceedings Paper CT IAG International Symposium on Gravity, Geoid and Geodynamics (GGG 2000) CY JUL 31-AUG 04, 2000 CL BANFF, CANADA SP Int Assoc Geodesy DE time variable gravity; postglacial rebound; satellite laser tracking ID EARTHS ROTATION; SEA-LEVEL; GLACIERS; FIELD AB Analyses of Satellite Laser Ranging (SLR) tracking data have yielded estimates of rates for the low-degree zonal harmonics of the geopotential up through (J) over dot(6). Combined with observed changes in the Earth's rotation pole and global sea level rise, these observations provide a powerful constraint on aggregate mass transport within the Earth's systems. Inverse solutions, where these observed geodetic rates are used to constrain geophysical models, can yield estimates of the mantle viscosity contrast affecting postglacial rebound and ice sheet mass balance rates. In order to obtain the most accurate estimates, such analysis requires accounting for as many geophysical and environmental signals as possible that are contained in these observed trends. Analysis to date indicates that both the Antarctica and Greenland ice sheets are nearly in mass balance when the forward models are used without any accommodation for correction terms. These results are only somewhat dependent on the zonal rate solution used, despite the differences between these solutions. The ice mass balance results benefit from improved rate solutions; in particular, the Antarctic ice mass accumulation rate estimate will benefit from better separation of (J) over dot(3) and (J) overdot(5). The secular zonal rate solution can be improved using additional data. SLR and DORIS tracking of TOPEX/POSEIDON have been combined with the SLR tracking of LAGEOS, LAGEOS-2, Starlette, Stella, and Ajisai previously used to estimate the geopotential rates. Estimates of scale corrections to the forward models are also used to gain insight into the relative performance of these models and improve the estimate of the ice balances. C1 NASA, Goddard Space Flight Ctr, Raytheon Tech Serv Corp, Geodynam Dept, Greenbelt, MD 20771 USA. RP Cox, CM (reprint author), NASA, Goddard Space Flight Ctr, Raytheon Tech Serv Corp, Geodynam Dept, Code 661,Mailstop 926-0, Greenbelt, MD 20771 USA. RI Symposia, IAG/K-2857-2012 NR 19 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0939-9585 BN 3-540-42469-5 J9 IAG SYMP PY 2002 VL 123 BP 355 EP 360 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BT80C UT WOS:000174088700059 ER PT S AU Ivins, ER Wu, XP Raymond, CA Yoder, CF James, TS AF Ivins, ER Wu, XP Raymond, CA Yoder, CF James, TS BE Sideris, MG TI Temporal geoid of a rebounding Antarctica and potential measurement by the GRACE and GOCE satellites SO GRAVITY GEOID AND GEODYNAMICS 2000 SE INTERNATIONAL ASSOCIATION OF GEODESY SYMPOSIA LA English DT Proceedings Paper CT IAG International Symposium on Gravity, Geoid and Geodynamics (GGG 2000) CY JUL 31-AUG 04, 2000 CL BANFF, CANADA SP Int Assoc Geodesy DE satellite gravity; Antarctic glacial isostasy; mantle viscosity ID LAST GLACIAL MAXIMUM; ICE-SHEET; MASS-BALANCE; LATE PLEISTOCENE; SEA; INVERSION; ROTATION; MANTLE AB We model the present-day time-dependent gravity field of Antarctica driven by solid earth rebound response to deglaciation of a more extensive continental ice cover at Last Glacial Maximum (22-15 kyr BP). Among the various global components of late-Pleistocene and Holocene eustatic sea level rise, Antarctica's contribution has been most contentious. Using new geological inferences provided by marine sediment cores and ice-volcanic deposits within the Antarctic continental interior, we compute predictive maps of geoid secular variation and uplift. Competing forward models produce quite distinguishable signatures in terms of the resolution and accuracy of the GRACE and GOCE satellite missions. Both the timing and amplitude of the ice sheet paleotopography and the structure of mantle viscosity are crucial inputs to the predicted temporal gravity field in Antarctica. In general, our new predictions indicate that the rebound component of Antarctica's secularly varying geoid is at the 0.1 to 0.6 mm/yr level. These estimates may err on the conservative side if the ice sheet has been slowly deglaciating during the last two thousand years. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ivins, ER (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Symposia, IAG/K-2857-2012; James, Thomas/D-9301-2013 OI James, Thomas/0000-0001-7321-047X NR 30 TC 12 Z9 12 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0939-9585 BN 3-540-42469-5 J9 IAG SYMP PY 2002 VL 123 BP 361 EP 366 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BT80C UT WOS:000174088700060 ER PT S AU Williams, KE AF Williams, KE GP AAS AAS TI Prototype maneuver decomposition algorithm for Genesis SO GUIDANCE AND CONTROL 2002 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 25th Annual AAS Rocky Mountain Guidance and Control Conference CY FEB 06-10, 2002 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB This paper addresses a prototype of a maneuver decomposition algorithm developed by the Genesis Navigation Team at JPL. Genesis is the fifth mission selected as part of NASA's Discovery Program with the objective of collecting solar wind samples for a period of approximately two years while in orbit about the Earth-Sun L1 point. The algorithm described herein is an early prototype designed to support navigation analyses and to provide the basis for later development of operational software by the Spacecraft Team. The basic algorithm is applicable to any spin-stabilized spacecraft with axisymmetric thrusters. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Williams, KE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 301-125, 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 BN 0-87703-491-5 J9 ADV ASTRONAUT SCI PY 2002 VL 111 BP 3 EP 14 PG 12 WC Automation & Control Systems; Engineering, Aerospace SC Automation & Control Systems; Engineering GA BU98B UT WOS:000177552600001 ER PT S AU Moreau, MC Bauer, FH Carpenter, JR Davis, EP Davis, GW Jackson, LA AF Moreau, MC Bauer, FH Carpenter, JR Davis, EP Davis, GW Jackson, LA GP AAS AAS TI Preliminary results of the GPS flight experiment on the high earth orbit AMSAT-OSCAR 40 spacecraft SO GUIDANCE AND CONTROL 2002 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 25th Annual AAS Rocky Mountain Guidance and Control Conference CY FEB 06-10, 2002 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB The GPS flight experiment on the High Earth Orbit (HEO) AMSAT-OSCAR 40 (AO-40) spacecraft was activated for a period of approximately six weeks between 25 September and 2 November, 2001, and the initial results have exciting implications for using GPS as a low-cost orbit determination sensor for future HEO missions. AO-40, an amateur radio satellite launched November 16, 2000, is currently in a low inclination, 1000 by 58,800 km altitude orbit. Although the GPS receiver was not initialized in any way, it regularly returned GPS observations from points all around the orbit. Raw signal to noise levels as high as 12 AMUs (Trimble Amplitude Measurement Units) or approximately 48 dB-Hz have been recorded at apogee, when the spacecraft was close to 60,000 km in altitude. On several occasions when the receiver was below the GPS constellation (below 20,000 km altitude), observations were reported for GPS satellites tracked through side lobe transmissions. Although the receiver has not returned any point solutions, there has been at least one occasion when four satellites were tracked simultaneously, and this short arc of data was used to compute point solutions after the fact. These results are encouraging, especially considering the spacecraft is currently in a spin-stabilized attitude mode that narrows the effective field of view of the receiving antennas and adversely affects GPS tracking. Already AO-40 has demonstrated the feasibility of recording GPS observations in HEO using an unaided receiver. Furthermore, it is providing important information about the characteristics of GPS signals received by a spacecraft in a HEO, which has long been of interest to many in the GPS community. Based on the data returned so far, the tracking performance is expected to improve when the spacecraft is transitioned to a three axis stabilized, nadir pointing attitude in Summer, 2002. C1 NASA, Goddard Space Flight Ctr, Navigat & Control Ctr, Greenbelt, MD 20771 USA. RP Moreau, MC (reprint author), NASA, Goddard Space Flight Ctr, Navigat & Control Ctr, Greenbelt, MD 20771 USA. NR 15 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 BN 0-87703-491-5 J9 ADV ASTRONAUT SCI PY 2002 VL 111 BP 45 EP 59 PG 15 WC Automation & Control Systems; Engineering, Aerospace SC Automation & Control Systems; Engineering GA BU98B UT WOS:000177552600004 ER PT S AU Hughes, SP AF Hughes, SP GP AAS AAS TI Preliminary optimal orbit design for the Laser Interferometer Space Antenna (LISA) SO GUIDANCE AND CONTROL 2002 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 25th Annual AAS Rocky Mountain Guidance and Control Conference CY FEB 06-10, 2002 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB In this paper we present a preliminary optimal orbit analysis for the Laser Interferometer Space Antenna (LISA). LISA is a NASA/ESA mission to study gravitational waves and test predictions of general relativity. The nominal formation consists of three spacecraft in heliocentric orbits at 1 AU and trailing the Earth by twenty degrees. This configuration was chosen as a trade off to reduce the noise sources that will affect the instrument and to reduce the fuel to achieve the final orbit. We present equations for the nominal orbit design(1) and discuss several different measures of performance for the LISA formation. All of the measures directly relate the formation dynamics to science performance. Also, constraints on the formation dynamics due to spacecraft and instrument limitations are discussed. Using the nominal solution as an initial guess, the formation is optimized using Sequential Quadratic Programming to maximize the performance while satisfying a set of nonlinear constraints. Results are presented for each of the performance measures. C1 NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 USA. RP Hughes, SP (reprint author), NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 USA. NR 3 TC 9 Z9 9 U1 0 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-491-5 J9 ADV ASTRONAUT SCI PY 2002 VL 111 BP 61 EP 78 PG 18 WC Automation & Control Systems; Engineering, Aerospace SC Automation & Control Systems; Engineering GA BU98B UT WOS:000177552600005 ER PT S AU Barltrop, K Kan, E Levison, J Schira, C Epstein, K AF Barltrop, K Kan, E Levison, J Schira, C Epstein, K GP AAS AAS TI Deep Impact: ACS fault tolerance in a comet critical encounter SO GUIDANCE AND CONTROL 2002 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 25th Annual AAS Rocky Mountain Guidance and Control Conference CY FEB 06-10, 2002 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB The Deep Impact Project is a NASA Discovery mission to explore cometary science. A mother-daughter dual spacecraft, the Flyby and the Impactor, will launch in January 2004 to intercept comet Tempel-1 on July 4, 2005 as Tempel-1 swings around the Earth and the Sun in its 5.5-year heliocentric orbit.(2) The near comet environment is particularly hazardous and poses a strong challenge for spacecraft and navigation design.(3) Consequently, the mission objective and encounter scenario require a fault tolerant and autonomously recovering design for both spacecraft. This paper describes the overall fault protection architecture for the Flyby and Impactor with special attention to attitude determination and control fault protection design. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Barltrop, K (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 BN 0-87703-491-5 J9 ADV ASTRONAUT SCI PY 2002 VL 111 BP 111 EP 126 PG 16 WC Automation & Control Systems; Engineering, Aerospace SC Automation & Control Systems; Engineering GA BU98B UT WOS:000177552600008 ER PT S AU Gaskell, RW AF Gaskell, RW GP AAS AAS TI Determination of landmark topography from imaging data SO GUIDANCE AND CONTROL 2002 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 25th Annual AAS Rocky Mountain Guidance and Control Conference CY FEB 06-10, 2002 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB Viking, MOC and MOLA data are being used to construst high resolution topographic and albedo models of landmarks on Mars. These models can be reilluminated and correlated with in-flight images, acting as body-fixed navigation tie-points. A similar procedure, using sparse stereo points in place of MOLA data, is being used to map small bodies such as Phobos and Deimos. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gaskell, RW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 301-150, 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 BN 0-87703-491-5 J9 ADV ASTRONAUT SCI PY 2002 VL 111 BP 167 EP 179 PG 13 WC Automation & Control Systems; Engineering, Aerospace SC Automation & Control Systems; Engineering GA BU98B UT WOS:000177552600012 ER PT S AU Johnson, AE Skulsky, ED AF Johnson, AE Skulsky, ED GP AAS AAS TI Descent-speed testing of a hazard detection system for safe landing on Mars SO GUIDANCE AND CONTROL 2002 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 25th Annual AAS Rocky Mountain Guidance and Control Conference CY FEB 06-10, 2002 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB A prototype hazard detection system under development at JPL for the next generation of Martian landers consists of a scanning laser radar (LIDAR), inertial measurement unit (IMU), and hazard detection and avoidance algorithms. The hazard detection algorithms construct a topographic map of the landing area using the motion-corrected LIDAR data and subsequently generate estimates of surface slope and roughness. These estimates are used to identify areas that exceed landing constraints dictated by vehicle design. The hazard detection software then selects a safe landing site and this location is provided to the guidance algorithms, which then steer the vehicle to the selected location. A series of tests were performed to demonstrate the capabilities of the prototype hazard detection system at realistic terminal descent speeds. The test methodology was described in detail in a prior paper; in this paper we review the test methodology, describe the hazard detection algorithms, and provide preliminary results from the first hazard detection test. The ultimate goal of the hazard detection tests is to verify the performance of a LIDAR-based system for Mars landing. The performance of the system is characterized through post-test data processing as follows. First, the flight sensor data was processed to determine the vehicle trajectory, the shape of the imaged target and the detected hazards. These "flight products" were then compared to the truth trajectory generated from truth sensor measurements, the truth shape of the target, and hazards known to exist in the target. Differences between the flight and ground products were then used to determine the overall system performance as well as any weak links in the data collection system. Preliminary results indicate a shape reconstruction error of less than 0.1 m. Given correct trajectory data, the system was capable of detecting all hazards with radii greater than 0.5 m. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Johnson, AE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 125-209, 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 BN 0-87703-491-5 J9 ADV ASTRONAUT SCI PY 2002 VL 111 BP 193 EP 211 PG 19 WC Automation & Control Systems; Engineering, Aerospace SC Automation & Control Systems; Engineering GA BU98B UT WOS:000177552600014 ER PT S AU Gambino, J Dennehy, N AF Gambino, J Dennehy, N GP AAS AAS TI A multi-function guidance, navigation and control system for future earth and space science missions SO GUIDANCE AND CONTROL 2002 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 25th Annual AAS Rocky Mountain Guidance and Control Conference CY FEB 06-10, 2002 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB Over the past several years the Guidance, Navigation and Control Center (GNCC) at NASA's Goddard Space Flight Center (GSFC) has actively engaged in the development of advanced GN&C technology to enable future Earth and Space science missions. The Multi-Function GN&C System (MFGS) design presented in this paper represents the successful coalescence of several discrete GNCC hardware and software technology innovations into one single highly integrated, compact, low power and low cost unit that simultaneously provides autonomous real time on-board attitude determination solutions and navigation solutions with accuracies that satisfy many future GSFC mission requirements. The MFGS is intended to operate as a single self-contained multifunction unit combining the functions now typically performed by a number of hardware units on a spacecraft. However, recognizing the need to satisfy a variety of future mission requirements, design provisions have been included to permit the unit to interface with a number of external remotely mounted sensors and actuators such as magnetometers, sun sensors, star cameras, reaction wheels and thrusters. The result is a highly versatile MFGS that can be configured in multiple ways to suit a realm of mission-specific GN&C requirements. It is envisioned, that the MFGS will perform a mission enabling role by filling the Microsat GN&C technology gap. In addition, GSFC believes that the MFGS could be employed to significantly reduce volume, power and mass requirements on conventional satellites. C1 NASA, Goddard Space Flight Ctr, GNCC, Component & Hardware Syst Branch, Greenbelt, MD 20771 USA. RP Gambino, J (reprint author), NASA, Goddard Space Flight Ctr, GNCC, Component & Hardware Syst Branch, Code 573, Greenbelt, MD 20771 USA. NR 9 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 BN 0-87703-491-5 J9 ADV ASTRONAUT SCI PY 2002 VL 111 BP 349 EP 363 PG 15 WC Automation & Control Systems; Engineering, Aerospace SC Automation & Control Systems; Engineering GA BU98B UT WOS:000177552600025 ER PT S AU Collins, S Vanelli, CA Alexander, J Essmiller, J Rayman, M Sirlin, S AF Collins, S Vanelli, CA Alexander, J Essmiller, J Rayman, M Sirlin, S GP AAS AAS TI Deep space 1 flight experience: Adventures on an ion drive SO GUIDANCE AND CONTROL 2002 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 25th Annual AAS Rocky Mountain Guidance and Control Conference CY FEB 06-10, 2002 CL BRECKENRIDGE, CO SP Amer Astronaut Soc ID MISSION AB NASA/JPL's Deep Space 1 was launched in October of 1998 as a low-cost mission to flight-test solar electric propulsion, autonomous navigation and several other high-risk technologies that enable future planetary projects. This paper provides a brief overview of the DS1 attitude control subsystem, shares a few lessons-learned, and describes some of the many daunting challenges faced by our tiny flight team during the course of the mission. Special focus will be given to the nuances of flying a spacecraft with ion propulsion, our nick-of-time rewrite of the attitude determination software after the failure of the onboard star tracker in late 1999, and DS1's subsequent successful flyby of comet Borrelly on September 22, 2001. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Collins, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 230-207, Pasadena, CA 91109 USA. NR 5 TC 0 Z9 0 U1 2 U2 3 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-491-5 J9 ADV ASTRONAUT SCI PY 2002 VL 111 BP 415 EP 426 AR UNSP AAS02-072 PG 12 WC Automation & Control Systems; Engineering, Aerospace SC Automation & Control Systems; Engineering GA BU98B UT WOS:000177552600029 ER PT S AU O'Donnell, JR Andrews, SF Starin, SR Ward, DK AF O'Donnell, JR Andrews, SF Starin, SR Ward, DK GP AAS AAS TI Microwave anisotropy probe launch and early operations SO GUIDANCE AND CONTROL 2002 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 25th Annual AAS Rocky Mountain Guidance and Control Conference CY FEB 06-10, 2002 CL BRECKENRIDGE, CO SP Amer Astronaut Soc AB The Microwave Anisotropy Probe (MAP), a follow-on to the Differential Microwave Radiometer (DMR) instrument on the Cosmic Background Explorer (COBE), was launched from the Kennedy Space Center at 19:46:46 UTC on June 30, 2001. The powered flight and separation from the Delta II appeared to go as designed, with the launch placing MAP well within la launch dispersion and with less than 7 Nms of tip-off momentum. Because of this relatively low momentum, MAP was able to acquire the sun within only 15 minutes with a battery state of charge of 94%. After MAP's successful launch, a six week period of in-orbit checkout and orbit maneuvers followed. The dual purpose of the in-orbit checkout period was to validate the correct performance of all of MAP's systems and, from the attitude control system (ACS) point of view, to calibrate the performance of the spacecraft ACS sensors and actuators to maximize system performance. In addition to the checkout activities performed by the MAP team, the other critical activity taking place during the first six weeks after launch were a series of orbit maneuvers necessary to get the spacecraft from its launch orbit out to its desired orbit about L2, the second Earth-Sun Lagrange point. As MAP continues its standard operations, its ACS design is meeting all of its requirements to successfully complete the mission. This paper will describe the launch and early operations summarized above in greater detail, and show the performance of the attitude control and attitude determination system versus its requirements. Additionally, some of the unexpected events that occurred during this period will be discussed, including two events which dropped the spacecraft into its Safehold Mode and the presence of an "anomalous force" observed during each of the perigee orbit maneuvers that had the potential to cause these critical maneuvers to be prematurely aborted. C1 NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 USA. RP O'Donnell, JR (reprint author), NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 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 BN 0-87703-491-5 J9 ADV ASTRONAUT SCI PY 2002 VL 111 BP 447 EP 466 AR UNSP AAS02-074 PG 20 WC Automation & Control Systems; Engineering, Aerospace SC Automation & Control Systems; Engineering GA BU98B UT WOS:000177552600031 ER PT S AU Fredvik, T Kjeldseth-Moe, O Haugan, SVH Brekke, P Gurman, JB Wilhelm, K AF Fredvik, T Kjeldseth-Moe, O Haugan, SVH Brekke, P Gurman, JB Wilhelm, K BE BelyDubau, F TI Variability and dynamic state of active region loops SO HEATING AND ENERGETICS OF THE SOLAR CORONA AND SOLAR WIND SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT E2 1-D2 3 Symposium of COSPAR Scientific Commission E held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, MASSACHUSETTS SP CNES, European Space Agcy, Inst Space & Astronaut Sci, Comm Space Res ID SOHO; SUMER; SPECTROMETER; TELESCOPE AB A set of 218 consecutive CDS rasters taken at the solar limb on October 26-28 1999 has been used to investigate the variability and plasma dynamics of active region loops. Each raster contains simultaneous images in 6 different lines, covering the full temperature range of CDS, 10 000 K (He I) to 2.7 MK (Fe XVI). Activity is seen to go on without breaks at temperatures below 1 MK for the full 39 hours of the series. Transition region loops or extended sections of loops, 50-200 Mm long, appear and disappear in intervals as short as 11 minutes, the observing cadence. In the corona. the emission is less variable, but significant changes are seen. Measured Doppler shifts correspond to typical plasma velocities of 20 km s(-1) to 100 kin s(-1), at temperatures 10 000 K to 450 000 K, and siphon flows may occur in some of the loops. High velocities axe frequently seen where the emitted intensities are weak, often on the outer edges of loops as defined in that particular spectral line. At coronal temperatures, 1 MK and higher, systematic loop velocities occur only occasionally. Simultaneous observations with EIT and SUMER were made during part of the raster series and axe compared with the CDS result. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. NASA, Goddard Space Flight Ctr, ESA, Greenbelt, MD 20771 USA. Max Planck Inst Aeron, D-37189 Katlenburg Duhm, Germany. RP Fredvik, T (reprint author), Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. NR 9 TC 9 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 2002 VL 30 IS 3 BP 635 EP 640 AR PII S0273-1177(02)00355-1 DI 10.1016/S0273-1177(02)00355-1 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV25S UT WOS:000178339400037 ER PT S AU Al-Theneyan, A Mehrotra, P Zubair, M AF Al-Theneyan, A Mehrotra, P Zubair, M BE Sahni, S Prasanna, VK Shukla, U TI A resource brokering infrastructure for computational grids SO HIGH PERFORMANCE COMPUTING - HIPC 2002, PROCEEDINGS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 9th International Conference on High Performance Computing (HiPC 2002) CY DEC 18-21, 2002 CL BANGALORE, INDIA SP IFIP Working Grp Concurrent Syst, IEEE Comp Soc, ACM, European Assoc Theoret Comp Sci AB With the advances in the networking infrastructure in general, and the Internet in specific, we can build grid environments that allow users to utilize a diverse set of distributed and heterogeneous resources. Since the focus of such environments is the efficient usage of the underlying resources, a critical component is the brokering module that mediates the discovery, access and usage of these resources. One of the major tasks of the brokering module is brokering of resources. With the consumer's constraints, provider's rules, distributed heterogeneous resources and the large number of scheduling choices, the brokering module needs to decide where to place the user's jobs and when to start their execution in a way that yields the best performance to the user and the best utilization to the resource provider. In this paper we present the design and implementation of a flexible, extensible and generic policybased resource brokering infrastructure for computational grids following a layered facade design pattern and using XML as the underlying specification language. We also describe a testbed environment and our efforts at integrating it with several grid systems. C1 Old Dominion Univ, Dept Comp Sci, Norfolk, VA 23529 USA. NASA, Ames Res Ctr, NAS Div, Moffett Field, CA 94035 USA. RP Al-Theneyan, A (reprint author), Old Dominion Univ, Dept Comp Sci, Norfolk, VA 23529 USA. NR 13 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 3-540-00303-7 J9 LECT NOTES COMPUT SC PY 2002 VL 2552 BP 463 EP 473 PG 11 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BW58C UT WOS:000182489700044 ER PT S AU Luo, LS Qi, D Wang, LP AF Luo, LS Qi, D Wang, LP BE Breuer, M Durst, F Zenger, C TI Applications of the lattice Boltzmann method to complex and turbulent flows SO HIGH PERFORMANCE SCIENTIFIC AND ENGINEERING COMPUTING SE LECTURE NOTES IN COMPUTATIONAL SCIENCE AND ENGINEERING LA English DT Proceedings Paper CT 3rd International FORTWIHR Conference CY MAR 12-14, 2001 CL Univ Erlangen, Erlangen, GERMANY HO Univ Erlangen ID NAVIER-STOKES EQUATION; GAS AUTOMATA; BGK MODELS; SIMULATIONS; PROGRESS; SPACE AB We briefly review the method of the lattice Boltzmann equation (LBE). We show the three-dimensional LBE simulation results for a non-spherical particle in Couette flow and 16 particles in sedimentation in fluid. We compare the LBE simulation of the three-dimensional homogeneous isotropic turbulence flow in a periodic cubic box of the size 128 3 with the pseudo-spectral simulation, and find that the two results agree well with each other but the LBE method is more dissipative than the pseudo-spectral method in small scales, as expected. C1 NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. RP Luo, LS (reprint author), NASA, Langley Res Ctr, ICASE, MS 132C,3 W Reid St,Bldg 1152, Hampton, VA 23681 USA. RI Luo, Li-Shi/A-4561-2011 OI Luo, Li-Shi/0000-0003-1215-7892 NR 21 TC 15 Z9 15 U1 0 U2 6 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 1439-7358 BN 3-540-42946-8 J9 LECT NOTES COMP SCI PY 2002 VL 21 BP 123 EP 130 PG 8 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA BY81W UT WOS:000189470500014 ER PT S AU Campbell, J AF Campbell, J BE Phipps, CR TI STARSAT: A joint NASA/AF project for laser calibration of small objects in space SO HIGH-POWER LASER ABLATION IV, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on High-Power Laser Ablation IV CY APR 22-26, 2002 CL TAOS, NM SP SPIE, Los Alamos Natl Lab, USAF Windows Sci Program DE ladar; HI-CLASS; Space Shuttle; calibration; micro-satellites; Advanced Electro-Optical System; GPS AB The Air Force Research Laboratory/Directed Energy Directorate (AFRL/DE) and NASA/Marshall Space Flight Center (MSFC) are looking at a series of joint laser space calibration experiments using the 12J 15Hz CO2 HIgh Performance CO2 Ladar Surveillance Sensor (HI-CLASS) system on the 3.67 meter aperture Advanced Electro-Optics System (AEOS). The objectives of these experiments are to provide accurate range and signature measurements of calibration spheres, demonstrate high resolution tracking capability of small objects, and precision dray determination for LEO. Ancillary benefits include calibrating radar and optical sites, completing satellite conjunction analyses, supporting orbital perturbations analyses, and comparing radar and optical signatures. In the first experiment, a Global Positioning System (GPS)/laser beacon instrumented micro-satellite about 25 cm in diameter will be deployed from a Space Shuttle Hitchhiker canister or other suitable launch means. Orbiting in low earth orbit, the micro-satellite will pass over AEOS on the average of two times per 24-hour period. An onboard orbit propagator will activate the GPS unit and a visible laser beacon at the appropriate times. The HI-CLASS/AEOS system will detect the micro-satellite as it rises above the horizon, using GPS-generated acquisition vectors. The visible laser beacon will be used to fine-tune the tracking parameters for continuous ladar data measurements throughout the pass. This operational approach should maximize visibility to the ground-based laser while allowing battery life to be conserved, thus extending the lifetime of the satellite. GPS data will be transmitted to the ground providing independent location information for the micro-satellite down to submeter accuracies. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Campbell, J (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 8 TC 1 Z9 1 U1 1 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 0-8194-4524-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4760 BP 821 EP 832 DI 10.1117/12.482037 PN 1&2 PG 12 WC Optics; Physics, Applied SC Optics; Physics GA BV52U UT WOS:000179254400084 ER PT B AU Jacobson, NS Liu, ZK Kaufman, L Zhang, F AF Jacobson, NS Liu, ZK Kaufman, L Zhang, F BE Singhal, SC TI Calculation of phase equilibria in the Y2O3-Yb2O3-ZrO2 system SO HIGH TEMPERATURE MATERIALS, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Symposium on High Temperature Materials CY MAY 13-15, 2002 CL PHILADELPHIA, PA SP Electrochem Soc, High Temp Mat Div ID ZRO2-Y2O3 AB Rare earth oxide stabilized zirconias find a wide range of applications. An understanding of phase equilibria is essential to all applications. In this study, the available phase boundary data and the thermodynamic data are collected and assessed. Calphad-type databases are developed to completely describe the Y2O3-ZrO2, Yb2O3-ZrO2, and Y2O3-Yb2O3 systems. The oxide units are treated as components and regular and sub-regular solution models are used. The resultant calculated phase diagrams show good agreement with the experimental data. The binaries are combined to form the database for the Y2O3-Yb2O3-ZrO2 psuedo-ternary. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Jacobson, NS (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 29 TC 4 Z9 4 U1 1 U2 6 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-371-7 J9 ELEC SOC S PY 2002 VL 2002 IS 5 BP 1 EP 8 PG 8 WC Electrochemistry; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Electrochemistry; Materials Science; Metallurgy & Metallurgical Engineering GA BW03B UT WOS:000180671700001 ER PT S AU Jacobson, NS Copland, EH Mehrotra, GM Auping, J AF Jacobson, NS Copland, EH Mehrotra, GM Auping, J BE Singhal, SC TI Knudsen cell studies of Ti-Al thermodynamics SO HIGH TEMPERATURE MATERIALS, PROCEEDINGS SE Electrochemical Society Series LA English DT Proceedings Paper CT Symposium on High Temperature Materials CY MAY 13-15, 2002 CL PHILADELPHIA, PA SP Electrochem Soc, High Temp Mat Div AB In this paper, we describe the Knudsen cell technique for measurement of thermodynamic activities in alloys. Numerous experimental details must be adhered in order to obtain useful experimental data. These include introduction of an in-situ standard, precise temperature measurement, elimination of thermal gradients, and precise cell positioning. Our first design is discussed and some sample data on Ti-Al alloys is presented. The second modification and associated improvements are also discussed. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 10 TC 0 Z9 0 U1 1 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA SN 0275-0171 BN 1-56677-371-7 J9 ELEC SOC S PY 2002 VL 2002 IS 5 BP 226 EP 232 PG 7 WC Electrochemistry; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Electrochemistry; Materials Science; Metallurgy & Metallurgical Engineering GA BW03B UT WOS:000180671700025 ER PT B AU Lee, KN Opila, EJ AF Lee, KN Opila, EJ BE Singhal, SC TI Mullite plus CAS bond coat for environmental barrier coatings for Si-based ceramics SO HIGH TEMPERATURE MATERIALS, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Symposium on High Temperature Materials CY MAY 13-15, 2002 CL PHILADELPHIA, PA SP Electrochem Soc, High Temp Mat Div AB Current environmental barrier coatings (EBCs) for silicon-based ceramics consist of a bond coat and a top coat. Mullite bond coat modified by adding low CTE glass ceramics, such as BSAS (xBaO(.)1-xSrO.Al(2)O(3.)2SiO(2)) or CAS (CaO(.)Al(2)O(3.)2SiO(2)), was developed in the NASA Enabling Propulsion Materials (EPM) Program. EBCs based on mullite+CAS bond coat were characterized using high steam thermal cycling test and high steam isothermal thermogravemitry (TGA) at 1225degreesC - 1300degreesC. The Mullite+CAS bond coat showed far superior durability compared to mullite bond coat, due to enhanced crack resistance. A BSAS top coat provided further improved durability compared to EBCs with a yttria-stabilized zirconia (YSZ) top coat. Still further improvement in the durability was achieved by adding a silicon bond coat between the mullite and the substrate. However, the silicon/mullite+CAS/BSAS EBC showed inferior long-term durability compared to the current state-of-the-art EBC (silicon/mullite+BSAS/BSAS EBC), presumably due to the higher CAS-silica chemical reactivity. C1 Cleveland State Univ, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Lee, KN (reprint author), Cleveland State Univ, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 9 TC 1 Z9 1 U1 1 U2 2 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-371-7 J9 ELEC SOC S PY 2002 VL 2002 IS 5 BP 263 EP 273 PG 11 WC Electrochemistry; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Electrochemistry; Materials Science; Metallurgy & Metallurgical Engineering GA BW03B UT WOS:000180671700029 ER PT S AU Dehant V Feissel, M de Viron, O Yseboodt, M Bizouard, C AF Dehant, V Feissel, M de Viron, O Yseboodt, M Bizouard, C BE Rickman, H TI Analysis of the residuals between theoretical nutations and VLBI observations SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union C1 Observ Paris, F-75014 Paris, France. Jet Prop Lab, Pasadena, CA USA. RI de Viron, Olivier/N-6647-2014 OI de Viron, Olivier/0000-0003-3112-9686 NR 7 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 124 EP 125 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500030 ER PT S AU Taidakova, T Ozernoy, LM Gorkavyi, NN AF Taidakova, T Ozernoy, LM Gorkavyi, NN BE Rickman, H TI Resonant gaps in the scattered cometary population of the trans-Neptunian region SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union AB Our numerical simulations of the Edgeworth-Kuiper Belt objects gravitationally scattered by the four giant planets accounting for mean motion resonances reveal numerous resonant gaps in the distribution of the scattered population. C1 George Mason Univ, Sch Computat Sci, Fairfax, VA 22030 USA. George Mason Univ, Dept Phys & Astron, Fairfax, VA 22030 USA. NASA, Goddard Space Flight Ctr, NRC, NAS, 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 SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 251 EP 252 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500069 ER PT S AU Sweigart, AV AF Sweigart, AV BE Rickman, H TI Horizontal branch models as a test of mixing on the RGB SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union ID GLOBULAR-CLUSTERS AB We discuss the impact of mixing and rotation along the red-giant branch (RGB) on the properties of horizontal-branch (HB) stars with emphasis on two problems: the nature of the unexpected blue HB population in the metal-rich globular clusters (GCs) NGC 6388 and NGC 6441 and the cause of the low gravities in the blue HB stars. New stellar models indicate that the sloped HBs in NGC 6388 and NGC 6441 might arise from a spread in metallicity, implying that these GCs may be metal-rich analogues of omega Cen. The low gravity problem can be largely explained by the radiative levitation of Fe in the atmospheres of the blue HB stars. We show that the onset of radiative levitation and the drop in HB rotation velocities at T-eff approximate to 11,000 K coincide with the disappearance of surface convection. The low rotation velocities of the hotter HB stars may be due to the spin down of the surface layers by a weak stellar wind induced by the radiative levitation of Fe. We conclude that the impact of mixing and rotation on the HB remains to be clearly established. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sweigart, AV (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 5 TC 14 Z9 14 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 292 EP 294 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500082 ER PT S AU Canuto, VM AF Canuto, VM BE Rickman, H TI Mixing and transport in stars SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union ID TURBULENCE; CONVECTION; DIFFUSION; ROTATION; BOTTOM C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Pure & Appl Math, New York, NY 10027 USA. RP Canuto, VM (reprint author), NASA, Goddard Inst Space Studies, New York, NY 10025 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 295 EP 297 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500083 ER PT S AU Standish, EM AF Standish, EM BE Rickman, H TI Early observations and modern ephemerides SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union AB There is a great variety of planetary and lunar observations recorded throughout history. Even today, some of these are useful for the improvement of ephemerides, though one must use a lot of judgment and caution - for surprising reasons. Five different sets of observations are presented, each with a story and a lesson: Galileo's observations of Neptune, Lalande's observations of Neptune, Williams' measurements of the 1780 solar eclipse, Robertson's 1811 transit timings, and solar eclipses in general. C1 CALTECH, JPL, Pasadena, CA 91125 USA. RP Standish, EM (reprint author), CALTECH, JPL, Pasadena, CA 91125 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 326 EP 329 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500091 ER PT S AU Brekke, P AF Brekke, P BE Rickman, H TI Solar eruptions - the effects on the Earth's environment SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union AB The response of our space environment to the constantly changing Sun is known as "Space Weather". The Solar and Heliospheric Observatory (SOHO) has obtained significant new information about coronal mass ejections (CMEs), the source of the most severe disturbances in the Earth's environment. Most of the time space weather is of little concern in our everyday lives. However, when the space environment is disturbed by the variable outputs of the Sun, technologies that we depend on both in orbit and on the ground can be affected. The increasing deployment of radiation-, current-, and field-sensitive technological systems over the last few decades and the increasing presence of complex systems in space combine to make society more vulnerable to solar-terrestrial disturbances. Thus, our society is much more sensitive to space weather activity today compared to the last solar maximum. By observing the Sun 24 hours per day, SOHO has proved to be an important "space weather watchdog". The importance of real-time monitoring of the Sun will be pointed out and a number of enterprises affected by space weather will be discussed. C1 NASA, Goddard Space Flight Ctr, ESA Space Sci Dept, Greenbelt, MD 20771 USA. RP Brekke, P (reprint author), NASA, Goddard Space Flight Ctr, ESA Space Sci Dept, 682-3,G1, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 384 EP 388 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500106 ER PT S AU Sonneborn, G Moos, HW AF Sonneborn, G Moos, HW BE Rickman, H TI First results from the FUSE mission SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union ID LOCAL INTERSTELLAR-MEDIUM; SPECTROSCOPIC-EXPLORER OBSERVATIONS; HIGH-VELOCITY CLOUDS; HOPKINS-ULTRAVIOLET-TELESCOPE; HUBBLE-SPACE-TELESCOPE; ABSORPTION PROFILE SPECTROGRAPH; BIG-BANG NUCLEOSYNTHESIS; SEYFERT 1 GALAXIES; X-RAY; U-GEMINORUM AB The Far Ultraviolet Spectroscopic Explorer (FUSE) provides high-resolution spectroscopy at far ultraviolet (FUV) wavelengths (905-1187Angstrom) of many astronomical objects in order to address fundamental questions related to the origin of the universe. FUSE, a cooperative project of the United States, Canada, and France, was launched in June 1999 for a three-year primary mission. The instrument sensitivity permits studies of many extragalactic sources at high spectral resolution. The key science drivers for the mission design are absorption-line spectroscopy of the ISM and IGM to investigate D/H, O VI, and molecular hydrogen abundances and distribution in the Galaxy and beyond to z similar to 0.3. Most of the observing time is available to Guest Investigators. This Joint Discussion summarizes some of the scientific results determined primarily from the first several months of FUSE observations. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD USA. RP Sonneborn, G (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM george.sonneborn@gsfc.nasa.gov; hwm@pha.jhu.edu NR 193 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 545 EP 591 PG 47 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500153 ER PT S AU Atreya, SK Mahaffy, PR Niemann, HB Owen, TC AF Atreya, SK Mahaffy, PR Niemann, HB Owen, TC BE Rickman, H TI Composition and cloud structure of Jupiter's deep atmosphere SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union ID PROBE MASS-SPECTROMETER; MOIST CONVECTION; ABUNDANCE; SATURN; ORIGIN AB Abundances of ammonia, hydrogen sulfide, water, methane and other hydrocarbons, noble gases and their isotopes, etc. were measured for the first time to the 22 bar level. The ratios of the heavy elements to hydrogen were found to be enriched by a factor of 2-3 relative to solar, implying a large influx of cold planetesimals into Jupiter. C1 Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. RP Atreya, SK (reprint author), Univ Michigan, Dept Atmospher Ocean & Space Sci, 2455 Hayward St, Ann Arbor, MI 48109 USA. RI Mahaffy, Paul/E-4609-2012 NR 11 TC 1 Z9 1 U1 1 U2 2 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 597 EP 601 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500154 ER PT S AU Waite, JH Clarke, JT Walker, RJ Connerney, JEP McComas, D Riley, P Lewis, WS AF Waite, JH Clarke, JT Walker, RJ Connerney, JEP McComas, D Riley, P Lewis, WS BE Rickman, H TI Jupiter's aurora: Solar wind and rotational influences SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union C1 SW Res Inst, San Antonio, TX 78228 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Waite, JH (reprint author), SW Res Inst, 6220 Culebra Rd, San Antonio, TX 78228 USA. RI Clarke, John/C-8644-2013; connerney, john/I-5127-2013; OI connerney, jack/0000-0001-7478-6462 NR 0 TC 0 Z9 0 U1 0 U2 2 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 606 EP 606 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500156 ER PT S AU Davies, AG Doute, S AF Davies, AG Doute, S BE Rickman, H TI Galileo NIMS observations of Io SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union ID GLOBAL DISTRIBUTION; SULFUR-DIOXIDE; TEMPERATURE; VOLCANISM; STATE; SO2 AB The Near Infrared Mapping Spectometer (NIMS) on the Galileo spacecraft has been observing the volcanic Jovian satellite Io at regular intervals since June 1996. These infrared observations have allowed detailed mapping of the distribution and grain size of sulfur dioxide on Io's surface, identification of volcanic centers, mapping of the distribution of hot spots, and investigations into the style and evolution of individual volcanic Eruptions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, IGPP, Los Angeles, CA 90095 USA. RP Davies, AG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 614 EP 617 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500159 ER PT S AU Gibbard, SG Macintosh, BA Max, CE Roe, H de Pater, I Young, EF McKay, CP AF Gibbard, SG Macintosh, BA Max, CE Roe, H de Pater, I Young, EF McKay, CP BE Rickman, H TI The surface of Titan from adaptive optics observations SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. SW Res Inst, San Antonio, TX 78228 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Gibbard, SG (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 629 EP 629 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500164 ER PT S AU Ruff, SR Christensen, PR Bandfield, JL Hamilton, VE Kieffer, HH Morris, RV Lane, MD Malin, MC AF Ruff, SR Christensen, PR Bandfield, JL Hamilton, VE Kieffer, HH Morris, RV Lane, MD Malin, MC BE Rickman, H TI Martian surface composition as determined by the MGS thermal emission spectrometer SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union C1 Arizona State Univ, Tempe, AZ 85287 USA. US Geol Survey, Flagstaff, AZ 86001 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Malin Space Sci Syst, San Diego 92191, CA USA. RP Ruff, SR (reprint author), Arizona State Univ, Tempe, AZ 85287 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 636 EP 636 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500167 ER PT S AU Conrath, BJ Pearl, JC Smith, MD Christensen, PR AF Conrath, BJ Pearl, JC Smith, MD Christensen, PR BE Rickman, H TI MGS TES results: Atmospheric structure, aerosols, and dynamics SO HIGHLIGHTS OF ASTRONOMY, VOL 12 SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 24th General Assembly of the International-Astronomical-Union CY AUG 07-18, 2000 CL MANCHESTER, ENGLAND SP Int Astron Union ID THERMAL EMISSION SPECTROMETER; AEROBRAKING AB Thermal emission spectra from the MGS TES instrument permit retrieval of atmospheric properties that are of interest in the study of Martian meteorology, including temperature, dust, and water ice. Examples of analyses of zonal mean meridional thermal sructure for equinox and solstice conditions are presented. C1 Cornell Univ, Ithaca, NY 14853 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Arizona State Univ, Tempe, AZ USA. RP Conrath, BJ (reprint author), Cornell Univ, Ithaca, NY 14853 USA. RI Smith, Michael/C-8875-2012 NR 5 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-086-2 J9 IAU SYMP PY 2002 VL 12 BP 638 EP 641 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV30K UT WOS:000178493500169 ER PT S AU Hickey, GS Lih, SS Barbee, T AF Hickey, GS Lih, SS Barbee, T BE MacEwen, HA TI Development of nanolaminate thin shell mirrors SO HIGHLY INNOVATIVE SPACE TELESCOPE CONCEPTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Highly Innovative Space Telescope Concepts CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union ID PIEZOTHERMOELASTICITY AB The space science community has identified a need for ultra-light weight, large aperture optical systems that are capable of producing high-resolution images of low contrast. Current mirror technologies are limited due either to not being scalable to larger sizes at reasonable masses, or to lack of surface finish, dimensional stability in a space environment or long fabrication times. This paper will discuss the development of thin-shell, nano-laminate mirror substrates that are capable of being electro-actively figured. This technology has the potential to substantially reduce the cost of space based optics by allowing replication of ultra-lightweight primary mirrors from a master precision tool. Precision master tools have been shown to be used multiple times with repeatable surface quality results with less than one week fabrication times for the primary optical mirror substrate. Current development has developed a series of 0.25 and 0.5 meter spherical nanolaminate mirrors that are less than 0.5 kg/m(2) areal density before electroactive components are mounted, and a target of less than 2.0 kg/m with control elements. This paper will provide an overview of nanolaminate materials for optical mirrors, modeling of their behavior under figure control and experiments conducted to validate precision control. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Hickey, GS (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. NR 20 TC 13 Z9 13 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 0-8194-4628-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4849 BP 63 EP 76 DI 10.1117/12.460458 PG 14 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BV96Y UT WOS:000180549200008 ER PT S AU Jones, R Muntele, I Muntele, C Zimmerman, RL Ila, D AF Jones, R Muntele, I Muntele, C Zimmerman, RL Ila, D BE MacEwen, HA TI Study of lightweight Ni-Co alloy mirrors obtained by electroforming techniques SO HIGHLY INNOVATIVE SPACE TELESCOPE CONCEPTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Highly Innovative Space Telescope Concepts CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE lightweight mirrors; Ni-Co alloy; electroforming; normal incidence; replica mirror AB One contribution in reducing the costs of optics in space can be provided by production of ultralight mirrors. The decrease in the weight of the primary mirror of a telescope is anticipated to lead to the possibility of increasing the size of the telescopes, therefore increasing the amount and distance from which information is received. An electroplating process of ultralight replica mirrors from nickel sulfamate solution is described. Based on an experimental setup with cylindrical symmetry, flat mirrors with a diameter of 4 and 7 inches and thickness of I through 2 mm are made from a Ni-Co alloy. The composition of the resulting deposit is analyzed using Rutherford Backscattering Spectrometry (RBS) and Proton Induced X-ray Emission (PIXE). In order to isotopically resolve Ni and Co, 6 MeV nitrogen ions are used as projectiles in the RBS measurements. Solution parameters monitored during the deposition process using optical absorption spectrophotometry is correlated with the final concentration of Ni and Co in the deposit. Bath parameters like temperature; current density, agitation level and acidity are chosen at certain values and maintained constant from one sample to another throughout the deposition process. The purpose of the experiment is to obtain mirrors with near zero stress, and predetermined composition and hardness. This study is an intermediate step in obtaining through the same process, but with a larger scale setup, ultralight large aperture replica mirrors. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Jones, R (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 7 TC 2 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 0-8194-4628-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4849 BP 77 EP 85 DI 10.1117/12.460072 PG 9 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BV96Y UT WOS:000180549200009 ER PT S AU Cofield, RE Cwik, TA Raouf, NA AF Cofield, RE Cwik, TA Raouf, NA BE MacEwen, HA TI Toric offset three-reflector antenna for an advanced microwave limb sounder SO HIGHLY INNOVATIVE SPACE TELESCOPE CONCEPTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Highly Innovative Space Telescope Concepts CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE microwave limb sounding; wide FOV; toroidal reflectors; Gaussian beams; physical optics ID ATMOSPHERE RESEARCH SATELLITE AB An advanced Microwave Limb Sounder (MLS), now in concept development for a potential future mission, is a space-borne heterodyne instrument to measure pressure, temperature, and atmospheric constituents from thermal emission between 120 and 2400 GHz. Previous MLS instruments used pencil-beam antennas sized to resolve similar to 1 vertical scale height. Current atmospheric models need better horizontal resolution than orbit spacing provides. To meet these needs, a new antenna concept combines the wide scan range of the parabolic torus with unblocked offset Cassegrain optics. The resulting system is diffraction-limited in the vertical plane but extremely astigmatic, with beamwidths 0.13x2.5degrees. Nadir axis symmetry ensures that this Beam Aspect Ratio (BAR) is invariant over +/-33degrees of azimuth. The antenna can feed either an array of receivers or multiplexed low-noise receivers whose FOVs are swept by a small scanning mirror. We describe 3 stages of antenna design: First, using a paraxial-optics method, we choose conic profiles given vertical resolution orbit geometry, then develop the surfaces by nadir axis rotation, matching axisymmetric feeds to the BAR. A ray-trace program validates the design and generates alignment and deformation tolerances. Finally, a physical optics analysis verifies reflector surface currents and radiation patterns. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cofield, RE (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 SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4628-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4849 BP 235 EP 244 DI 10.1117/12.460463 PG 10 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BV96Y UT WOS:000180549200024 ER PT S AU de Weck, OL Miller, DW Mosier, GE AF de Weck, OL Miller, DW Mosier, GE BE MacEwen, HA TI Multidisciplinary analysis of the NEXUS precursor space telescope SO HIGHLY INNOVATIVE SPACE TELESCOPE CONCEPTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Highly Innovative Space Telescope Concepts CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE space telescopes; NEXUS; isoperformance; dynamics and controls; spacecraft design; optics; sensitivity analysis AB A multidisciplinary analysis is demonstrated for the NEXUS space telescope precursor mission. This mission was originally designed as an in-space technology testbed for the Next Generation Space Telescope (NGST). One of the main challenges is to achieve a very tight pointing accuracy with a sub-pixel line-of-sight (LOS) jitter budget and a root-mean-square (RMS) wavefront error smaller than lambda/50 despite the presence of electronic and mechanical disturbance sources. The analysis starts with the assessment of the performance for an initial design, which turns out not to meet the requirements. Twentyfive design parameters from structures, optics, dynamics and controls are then computed in a sensitivity and isoperformance analysis, in search of better designs. Isoperformance allows finding an acceptable design that is well "balanced" and does not place undue burden on a single subsystem. An error budget analysis shows the contributions of individual disturbance sources. This paper might be helpful in analyzing similar, innovative space telescope systems in the future. C1 MIT, ESD, Dept Aeronaut & Astronaut, Cambridge, MA 02139 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP de Weck, OL (reprint author), MIT, ESD, Dept Aeronaut & Astronaut, 77 Massachusetts Ave, Cambridge, MA 02139 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 0-8194-4628-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4849 BP 294 EP 304 DI 10.1117/12.460079 PG 11 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BV96Y UT WOS:000180549200030 ER PT S AU Chen, PC Oliversen, RJ Romeo, RC AF Chen, PC Oliversen, RJ Romeo, RC BE MacEwen, HA TI Fabrication and testing of ultra lightweight Gossamer class composite mirrors SO HIGHLY INNOVATIVE SPACE TELESCOPE CONCEPTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Highly Innovative Space Telescope Concepts CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE Gossamer; lightweight optics; ultra-smooth optics; composite mirrors ID TECHNOLOGY; OPTICS AB We report on the development of composite mirror technology under the NASA Gossamer Spacecraft Initiative program. The objectives are to produce moderate aperture, extremely low areal density mirrors with smooth surfaces and good optical figure. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Chen, PC (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 9 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 0-8194-4628-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4849 BP 339 EP 347 DI 10.1117/12.460460 PG 9 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BV96Y UT WOS:000180549200034 ER PT S AU Howard, JM AF Howard, JM BE MacEwen, HA TI Optical design tools for reflective optical systems SO HIGHLY INNOVATIVE SPACE TELESCOPE CONCEPTS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Highly Innovative Space Telescope Concepts CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union ID SPHERICAL MIRRORS; ASYMMETRIC SYSTEMS; FOUNDATIONS; LAYOUT; POINT AB Imaging constraints are applied in lens design software macros for automatic generation of Ritchey-Chretien, Three-Mirror-Anastigmat (TMA), and plane symmetric configurations of spherical, conic, and general aspheric mirrors. These tools provide rapid development of telescope and instrument designs by reducing the available degrees of freedom confronting the designer while maintaining the desired set of image properties (e.g. focal length and aberration control). A brief example of a Ritchey-Chretien telescope is presented. C1 NASA, Goddard Space Flight Ctr, Opt Branch, Greenbelt, MD 20771 USA. RP Howard, JM (reprint author), NASA, Goddard Space Flight Ctr, Opt Branch, Code 551, Greenbelt, MD 20771 USA. 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 0-8194-4628-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4849 BP 407 EP 412 DI 10.1117/12.478492 PG 6 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BV96Y UT WOS:000180549200042 ER PT B AU Kolb, EW AF Kolb, EW BE Martinez, VJ Trimble, V PonsBorderia, MJ TI Cosmology at the start of a new century SO HISTORICAL DEVELOPMENT OF MODERN COSMOLOGY SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT International Summer School on Historical Development of Modern Cosmology CY SEP 18-22, 2000 CL UNIV INT MENENDEZ PELAYO, VALENCIA, SPAIN SP Univ Valencia Cinc Segles, Gen Valenciana, Conselleria Cultura, Educ Ciencia, Minist Ciencia Tecnol HO UNIV INT MENENDEZ PELAYO ID DARK-MATTER; UNIVERSE; SUPERNOVAE AB Remarkable 20th-century cosmological discoveries and theoretical ideas led to the development of the present cosmological "standard model." In this lecture I will focus on one of the more recent ideas that may now be regarded as part of the framework of the standard big-bang model; namely, that structure in the universe results from the growth of small seed density fluctuations produced during the inflationary universe. In order to complete this picture, I will also discuss the idea that the present mass density is dominated by dark matter and that there is now a preponderance of dark energy. C1 Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. RP Kolb, EW (reprint author), Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, POB 500, Batavia, IL 60510 USA. NR 11 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 1-58381-092-7 J9 ASTR SOC P PY 2002 VL 252 BP 295 EP 307 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU65X UT WOS:000176629900019 ER PT B AU Pang, KD Yau, KK Chou, HH AF Pang, KD Yau, KK Chou, HH BE Ansari, SMR TI Astronomical dating and statistical analysis of ancient eclipse data SO HISTORY OF ORIENTAL ASTRONOMY SE ASTROPHYSICS AND SPACE SCIENCE LIBRARY LA English DT Proceedings Paper CT 23rd General Assembly of the International-Astronomical-Union CY AUG 22-23, 1997 CL KYOTO, JAPAN SP Int Astron Union ID MOTION AB All 13 Shang dynasty oracle bone eclipse records have been uniquely matched to six solar and seven lunar eclipses in the 14th to 12th centuries B.C. The King Zhong Kang fifth year autumnal (October 16, 1876 B.C.) and King Yu third year "double sunset" (September 24, 1912 B.C.) eclipses confirm the accuracy of the revised Bamboo Annals Xia dynasty chronology (Nivison and Pang, Early China 15, 1990, 87-95). The eclipse dates are plotted against the number of generations before 841 B.C. (the earliest accurate historical date), the respective kings ruled. The curve of bestfit has both the strengths of verified royal genealogy continuity - and eclipse dating - accuracy. It is 99% accurate, and can be confidently used as a foundation for building a detailed absolute chronology for the Xia, Shang and Zhou dynasties, an important project in China's current Five-Year Plan (Song Jian, Sci. Tech. Daily, May 17, 1996; Wehrfritz, Newsweek, July 7, 1997). C1 NASA, Planetary Explorat Program, Washington, DC 20546 USA. NR 57 TC 2 Z9 2 U1 2 U2 3 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-0657-8 J9 ASTROPHYS SPACE SC L PY 2002 VL 274 BP 95 EP 119 PG 25 WC History & Philosophy Of Science SC History & Philosophy of Science GA BW42C UT WOS:000181949900009 ER PT J AU McFarlane, DC Latorella, KA AF McFarlane, DC Latorella, KA TI The scope and importance of human interruption in human-computer interaction design SO HUMAN-COMPUTER INTERACTION LA English DT Review ID INDIVIDUAL-DIFFERENCES; MULTITASK SITUATIONS; SUPERVISORY CONTROL; TASKS; ATTENTION; BEHAVIOR; MODEL; PERFORMANCE; MANAGEMENT; SYSTEMS AB At first glance it seems absurd that busy people doing important jobs should want their computers to interrupt them. Interruptions are disruptive and people need to concentrate to make good decisions. However, successful job performance also frequently depends on people's abilities to (a) constantly monitor their dynamically changing information environments, (b) collaborate and communicate. with other people in the system, and (c) supervise background autonomous services. These critical abilities can require people to simultaneously query a large set of information sources, continuously monitor for important events, and respond to and communicate with other human operators. Automated monitoring and alerting systems minimize the need to constantly monitor, but they induce alerts that may interrupt other activities. Such interrupting technologies are already widespread and include concurrent multitasking; mixed-initiative interaction; support for delegation and supervisory control of automation, including intelligent agents; and other distributed, background services and technologies that increase human-human communication. People do not perform sustained, simultaneous, multichannel sampling well; however, they have great capacity to manage concurrent activities when given specific kinds of interface support. Literature from many domains shows deleterious consequences of human performance in interrupt-laden situations when interfaces do not support this aspect of the task environment. This article identifies why human interruption is an important human-computer interaction problem, and why it will continue to grow in ubiquity and importance. We provide examples of this problem in real-world systems, and we review theoretical tools for understanding human interruption. Based on interdisciplinary scientific results, we suggest potential approaches to user-interface design to help people effectively manage interruptions. C1 NASA, Langley Res Ctr, Crew Syst Branch, Hampton, VA 23665 USA. EM mcfarlane@acm.org; k.a.latorella@larc.nasa.gov NR 179 TC 147 Z9 150 U1 4 U2 34 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 0737-0024 EI 1532-7051 J9 HUM-COMPUT INTERACT JI Hum.-Comput. Interact. PY 2002 VL 17 IS 1 BP 1 EP 61 DI 10.1207/S15327051HCI1701_1 PG 61 WC Computer Science, Cybernetics; Computer Science, Theory & Methods SC Computer Science GA 606YG UT WOS:000178763100001 ER PT S AU Xing, J AF Xing, J BE Rogowitz, BE Pappas, TN TI The functional roles of center-surround interactions in visual image processing SO HUMAN VISION AND ELECTRONIC IMAGING VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Human Vision and Electronic Imaging VII CY JAN 21-24, 2002 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, SPIE ID CORTICAL MAGNIFICATION; CONTRAST; RECOGNITION; ENHANCEMENT; SUPPRESSION; RESOLUTION; VISION AB The perception of a visual stimulus is affected by the presence of other stimuli in its surround region. The perceived central contrast can be suppressed or enhanced by the surrounds. Our previous sychophysical results showed that both surround suppression and enhancement existed in the foveal vision while only suppression existed in the peripheral vision. Moreover, the suppression in the periphery was much stronger than that in the fovea. In this report, we built an image processing model for the vision system with lateral connections embedded. We first adjusted model parameters to make the model have the same performance as human subjects had in contrast perception experiments in fovea. and periphery respectively. With those parameters, we then analyzed the functions of lateral connections in image perception. We found that: 1) With foveal parameters, lateral interactions served the purpose of gain control and image regularization. The contrast response in the fovea was modulated by the global image through lateral connections. 2) With peripheral parameters, lateral interactions resulted in image boundary segmentation. The response to a uniform image region was suppressed while the response to the boundary regions remained. The results suggest that a visual image be encoded differently by foveal and peripheral vision. The possible impacts of this feature on image compression were discussed. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Xing, J (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 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 0-8194-4402-2 J9 P SOC PHOTO-OPT INS PY 2002 VL 4662 BP 96 EP 104 DI 10.1117/12.469506 PG 9 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Computer Science; Engineering; Optics; Imaging Science & Photographic Technology GA BU75J UT WOS:000176915500009 ER PT J AU Miller, JK Konopliv, AS Antreasian, PG Bordi, JJ Chesley, S Helfrich, CE Owen, WM Wang, TC Williams, BG Yeomans, DK AF Miller, JK Konopliv, AS Antreasian, PG Bordi, JJ Chesley, S Helfrich, CE Owen, WM Wang, TC Williams, BG Yeomans, DK TI Determination of shape, gravity, and rotational state of asteroid 433 Eros SO ICARUS LA English DT Article DE Eros; asteroid; shape; gravity harmonics; rotation state ID RENDEZVOUS MISSION; 433-EROS; FLYBY AB Prior to the Near Earth Asteroid Rendezvous (NEAR) mission, little was known about Eros except for its orbit, spin rate, and pole orientation, which could be determined from ground-based telescope observations. Radar bounce data provided a rough estimate of the shape of Eros. On December 23, 1998, after an engine misfire, the NEAR-Shoemaker spacecraft flew by Eros on a high-velocity trajectory that provided a brief glimpse of Eros and allowed for an estimate of the asteroid's pole, prime meridian, and mass. This new information, when combined with the ground-based observations, provided good a priori estimates for processing data in the orbit phase. After a one-year delay, NEAR orbit operations began when the spacecraft was successfully inserted into a 320 x 360 km orbit about Eros on February 14, 2000. Since that time, the NEAR spacecraft was in many different types of orbits where radiometric tracking data, optical images, and NEAR laser rangefinder (NLR) data allowed a determination of the shape, gravity, and rotational state of Eros. The NLR data, collected predominantly from the 5 orbit, together with landmark tracking from the optical data, have been processed to determine a 24th degree and order shape model. Radiometric tracking data and optical landmark data were used in a separate orbit determination process. As part of this latter process, the spherical harmonic gravity field of Eros was primarily determined from the 10 days in the 35-km orbit. Estimates for the gravity field of Eros were made as high as degree and order 15, but the coefficients are determined relative to their uncertainty only up to degree and order 10. The differences between the measured gravity field and one deter-mined from a constant density shape model are detected relative to their uncertainty only to degree and order 6. The offset between the center of figure and the center of mass is on about 30 m, indicating that Eros has a very uniform density (1% variation) on a large scale (35 km). Variations to degree and order 6 (about 6 km) may be partly explained by the existence of a 100-m, regolith or by small internal density variations. The best estimates for the J2000 right ascension and declination of the pole of Eros are alpha = 11.3692+/-0.003degrees and delta = 17.2273+/-0.006degrees. The rotation rate of Eros is 1639.38922+/-0.00015degrees/day, which gives a rotation period of 5.27025547 h. No wobble greater than 0.02 has been detected. Solar gravity gradient torques would introduce a wobble of at Most 0.001degrees. (C) 2002 Elsevier Science (USA). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. RP Miller, JK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 24 TC 98 Z9 108 U1 1 U2 9 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 JAN PY 2002 VL 155 IS 1 BP 3 EP 17 DI 10.1006/icar.2001.6753 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 544ML UT WOS:000175164100002 ER PT J AU Cheng, AF Barnouin-Jha, O Prockter, L Zuber, MT Neumann, G Smith, DE Garvin, J Robinson, M Veverka, J Thomas, P AF Cheng, AF Barnouin-Jha, O Prockter, L Zuber, MT Neumann, G Smith, DE Garvin, J Robinson, M Veverka, J Thomas, P TI Small-scale topography of 433 Eros from laser altimetry and imaging SO ICARUS LA English DT Article DE asteroid surfaces; asteroids; Eros; regoliths; tectonics ID MULTISPECTRAL IMAGER; SHAPE; ASTEROIDS; FLYBY; 253-MATHILDE; EVOLUTION; 433-EROS; MISSION; SURFACE; RADAR AB The NEAR laser rangefinder (NLR) obtained more than 16 million range returns from asteroid 433 Eros. We present the first results from analyses of topographic profiles interpreted with the aid of simultaneous, boresighted images obtained by the NEAR multispectral imager (MSI). The location of the NLR boresight relative to that of MSI is determined by detailed correlations of ranging data and simultaneous images, including cases where the laser boresight slewed off and on the limb of the asteroid and cases where the laser illuminated a boulder close to the time of an image. In the data presented, the precision of the range measurements is about I in, with the minimum spot diameter under 5 m, and successive spots are contiguous or overlapping. Elevation on the irregular object Eros is given with respect to the gravitational and centrifugal potential. Landslides in craters are characterized. Possible crater benches are identified. Examples of infilled craters are presented. These observations suggest a depth of unconsolidated regolith, which is subject to sliding, of typically a few tens of meters. An example of structurally controlled cratering is presented. Examples of tectonic features are described. Surface roughness on Eros is approximately self-affine from scales of a few meters to hundreds of meters. A comparison of fractal statistics shows that Eros is extremely rough on observed scales, when compared to terrestrial a'a lava on submeter scales and undisturbed lunar regolith on subcentimeter scales. (C) 2002 Elsevier Science (USA). C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. MIT, Cambridge, MA 02139 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Northwestern Univ, Evanston, IL 60208 USA. Cornell Univ, Ithaca, NY 14853 USA. RP Cheng, AF (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. RI Neumann, Gregory/I-5591-2013; Barnouin, Olivier/I-7475-2015 OI Neumann, Gregory/0000-0003-0644-9944; Barnouin, Olivier/0000-0002-3578-7750 NR 36 TC 35 Z9 35 U1 0 U2 2 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 JAN PY 2002 VL 155 IS 1 BP 51 EP 74 DI 10.1006/icar.2001.6750 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 544ML UT WOS:000175164100005 ER PT J AU Wilkison, SL Robinson, MS Thomas, PC Veverka, J McCoy, TJ Murchie, SL Prockter, LM Yeomans, DK AF Wilkison, SL Robinson, MS Thomas, PC Veverka, J McCoy, TJ Murchie, SL Prockter, LM Yeomans, DK TI An estimate of Eros's porosity and implications for internal structure SO ICARUS LA English DT Article DE Eros; meteorites; surfaces; asteroids; interiors ID CHONDRITE PARENT BODIES; ASTEROIDS; METEORITES; DISRUPTION; EVOLUTION; HISTORY; IMPACT; PHOBOS; GASPRA; SHAPE AB Earth-based spectral measurements and NEAR Shoemaker magnetometer, X-ray, and near-infrared spectrometer data are all consistent with Eros having a bulk composition and mineralogy similar to ordinary chondrite meteorites (OC). By comparing the bulk density of 433 Eros (2.67 +/- 0.03 g/cm(3)) with that of OCs (3.40 g/cm(3)), We estimate the total porosity of the asteroid to be 21-33%. Macro (or structural) porosity, best estimated to be similar to20%, is constrained to be between 6 and 33%. We conclude that Eros is a heavily fractured body, but we find no evidence that it was ever catastrophically disrupted and reaccumulated into a rubble pile. (C) 2002 Elsevier Science (USA). C1 Northwestern Univ, Dept Geol Sci, Evanston, IL 60208 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Smithsonian Inst, Natl Museum Nat Hist, Dept Mineral Sci, Washington, DC 20560 USA. Appl Phys Lab, Laurel, MD 20723 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Northwestern Univ, Dept Geol Sci, Evanston, IL 60208 USA. EM sarah@earth.nwu.edu RI Murchie, Scott/E-8030-2015 OI Murchie, Scott/0000-0002-1616-8751 NR 82 TC 41 Z9 42 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 EI 1090-2643 J9 ICARUS JI Icarus PD JAN PY 2002 VL 155 IS 1 BP 94 EP 103 DI 10.1006/icar.2001.6751 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 544ML UT WOS:000175164100007 ER PT J AU Lucey, PG Hinrichs, J Kelly, M Wellnitz, D Izenberg, N Murchie, S Robinson, M Clark, BE Bell, JF AF Lucey, PG Hinrichs, J Kelly, M Wellnitz, D Izenberg, N Murchie, S Robinson, M Clark, BE Bell, JF TI Detection of temperature-dependent spectral variation on the asteroid Eros and new evidence for the presence of an olivine-rich silicate assemblage SO ICARUS LA English DT Article ID REFLECTANCE SPECTRA; 433-EROS; MINERALS AB Data obtained by the near-infrared spectrometer carried by the NEAR-Shoemaker spacecraft show that the spectral properties of the asteroid Eros vary with temperature. The manner in which they vary demonstrates that the mineral olivine is a major constituent of the surface. The near-IR temperature-dependent spectral properties of Eros in the northern hemisphere, and for two individual regions on the surface, show clear evidence of the presence of the mineral olivine and are a close match to the temperature-spectral behavior of LL-type ordinary chondrite meteorites. While the presence of other olivine-rich meteorites cannot be excluded, H-type ordinary chondrites are clearly too pyroxene-rich to be permitted as a major surface component of Eros. The results of the thermal-spectral analysis are consistent with results from analysis of conventional reflectance spectra of the asteroid and contribute unambiguous detection of olivine to the understanding of the surface composition of Eros. (C) 2002 Elsevier Science (USA). C1 Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Maryland, College Pk, MD 20742 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Northwestern Univ, Evanston, IL 60208 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. RP Lucey, PG (reprint author), Hawaii Inst Geophys & Planetol, 2525 Correa Rd, Honolulu, HI 96822 USA. RI Wellnitz, Dennis/B-4080-2012; Murchie, Scott/E-8030-2015; Izenberg, Noam/F-3952-2015 OI Murchie, Scott/0000-0002-1616-8751; Izenberg, Noam/0000-0003-1629-6478 NR 24 TC 14 Z9 14 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 JAN PY 2002 VL 155 IS 1 BP 181 EP 188 DI 10.1006/icar.2001.6747 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 544ML UT WOS:000175164100012 ER PT J AU Acuna, MH Anderson, BJ Russell, CT Wasilewski, P Kletetschka, G Zanetti, L Omidi, N AF Acuna, MH Anderson, BJ Russell, CT Wasilewski, P Kletetschka, G Zanetti, L Omidi, N TI NEAR magnetic field observations at 433 Eros: First measurements from the surface of an asteroid SO ICARUS LA English DT Article DE asteroids; Eros; magnetic fields ID SHAPE AB The magnetometer investigation aboard the NEAR-Shoemaker spacecraft has obtained extensive magnetic field observations throughout the 433 Eros environment, from distances in excess of 100,000 km to those conducted after landing on 12 February 2001. We report the apparent absence of global scale magnetization at this asteroid (H < 0.005 A (.) m(-1); natural remanent magnetization per kilogram < 1.9 x 10(-6) A (.) m(2) (.) kg(-1)), orders of magnitude less than the intense magnetization attributed to S-class asteroids Gaspra and Braille. The extremely low magnetization state of 433 Eros places this object significantly below the levels generally associated with LL chondrites and undifferentiated primitive bodies, challenging our current understanding of the meteorite-asteroid connection. (C) 2002 Elsevier Science (USA). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Calif San Diego, Dept Elect & Comp Engn, La Jolla, CA 92093 USA. RP Anderson, BJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Kletetschka, Gunther/C-9996-2011; Anderson, Brian/I-8615-2012 OI Kletetschka, Gunther/0000-0002-0645-9037; NR 18 TC 25 Z9 26 U1 0 U2 10 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 JAN PY 2002 VL 155 IS 1 BP 220 EP 228 DI 10.1006/icar.2001.6772 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 544ML UT WOS:000175164100015 ER PT J AU Murchie, S Robinson, M Domingue, D Li, H Prockter, L Hawkins, SE Owen, W Clark, B Izenberg, N AF Murchie, S Robinson, M Domingue, D Li, H Prockter, L Hawkins, SE Owen, W Clark, B Izenberg, N TI Inflight calibration of the NEAR multispectral imager - II. Results from Eros approach and orbit SO ICARUS LA English DT Article DE asteroids; instrumentation; surfaces; Eros; NEAR ID MISSION; FLYBY AB During the Near-Earth Asteroid Rendezvous (NEAR) spacecraft's investigation of asteroid 433 Eros, inflight calibration measurements from the multispectral imager (MSI) have provided refined knowledge of the camera's radiometric performance, pointing, and light-scattering characteristics. Measurements while at Eros corroborate most earlier calibration results, although there appears to be a small, gradual change in instrument dark current and flat field due to effects of aging in the space environment. The most pronounced change in instrument behavior, however, is a dramatic increase in scattered light due to contaminants accumulated on the optics during unscheduled fuel usage in December 1998. Procedures to accurately quantify and to remediate the scattered light are described in a companion paper (Li et al. 2002, Icarus 155, 00-00). Acquisition of Eros measurements has clarified the relative, filter-to-filter, radiometric performance of the MSI. Absolute radiometric calibration appears very well constrained from flight measurements, with an accuracy of similar to5%. Pointing relative to the spacecraft coordinate system can be determined from the temperature of the spacecraft deck with an accuracy of similar to1 pixel. (C) 2002 Elsevier Science (USA). C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Northwestern Univ, Dept Geol Sci, Evanston, IL 60208 USA. Jet Prop Lab, Pasadena, CA 91109 USA. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. RP Murchie, S (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. RI Murchie, Scott/E-8030-2015; Izenberg, Noam/F-3952-2015 OI Murchie, Scott/0000-0002-1616-8751; Izenberg, Noam/0000-0003-1629-6478 NR 13 TC 14 Z9 14 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 JAN PY 2002 VL 155 IS 1 BP 229 EP 243 DI 10.1006/icar.2001.6746 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 544ML UT WOS:000175164100016 ER PT B AU Adessi, C Walch, S Anantram, MP AF Adessi, Ch. Walch, S. Anantram, M. P. BE Laudon, M Romanowicz, B TI Structure and environment influence in DNA conduction SO ICCN 2002: INTERNATIONAL CONFERENCE ON COMPUTATIONAL NANOSCIENCE AND NANOTECHNOLOGY LA English DT Proceedings Paper CT 2nd International Conference on Computational Nanoscience and Nanotechnology CY APR 21-25, 2002 CL San Juan, PR SP Appl Computat Res Soc, DARPA, Amer Phys Soc, Soc Ind & Appl Math, IEEE Electron Devices Soc, Swiss Fed Inst Technol Lausanne, TIMA CMP Lab, Univ Calif Davis, Dept Appl Sci, Coll Engn, Int Assoc Math & Comp Modeling, Accelrys Inc, Mintz Levin Cohn Ferris Glovsky & Popeo PC, Motorola, ANSYS Inc DE DNA; transmission; conduction; molecular devices ID ELECTRON-TRANSFER; TRANSPORT; MOLECULES; BASES AB Results for transmission throug poly(G) DNA molecule are presented. We show that a modification of the rise of a B-DNA form can induce a shift of the conduction channel toward the valence one. We clearly prove that deformation of the backbone of the molecule has a significant influence in hole transport. Finaly, we observe that the presence of ionic speices, such Na, in the close surrounding of the molecule can create new conduction channels. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Adessi, C (reprint author), NASA, Ames Res Ctr, Mail Stop T27A-1, Moffett Field, CA 94035 USA. EM adessi@nas.nasa.gov NR 16 TC 0 Z9 0 U1 1 U2 1 PU COMPUTATIONAL PUBLICATIONS PI CAMBRIDGE PA PUBISHING OFFICE, 308 ONE KENDALL SQ BLDG 600, CAMBRIDGE, MA 02139 USA BN 0-9708275-6-3 PY 2002 BP 56 EP 59 PG 4 WC Nanoscience & Nanotechnology SC Science & Technology - Other Topics GA BEY39 UT WOS:000240119600016 ER PT B AU Svizhenko, A Maiti, A Anantram, MP AF Svizhenko, Alexei Maiti, Amitesh Anantram, M. P. BE Laudon, M Romanowicz, B TI Effects of structural deformation and tube chirality on electronic conductance of carbon nanotubes SO ICCN 2002: INTERNATIONAL CONFERENCE ON COMPUTATIONAL NANOSCIENCE AND NANOTECHNOLOGY LA English DT Proceedings Paper CT 2nd International Conference on Computational Nanoscience and Nanotechnology CY APR 21-25, 2002 CL San Juan, PR SP Appl Computat Res Soc, DARPA, Amer Phys Soc, Soc Ind & Appl Math, IEEE Electron Devices Soc, Swiss Fed Inst Technol Lausanne, TIMA CMP Lab, Univ Calif Davis, Dept Appl Sci, Coll Engn, Int Assoc Math & Comp Modeling, Accelrys Inc, Mintz Levin Cohn Ferris Glovsky & Popeo PC, Motorola, ANSYS Inc DE nanotube; molecular dynamics; tight-binding; Green's function; sensor ID MOLECULES AB A combination of large scale classical force-field (UFF), density functional theory (DFT) and tight-binding Green's function transport calculations is used to study the electronic properties of carbon nanotubes under the twist, bending and AFM-tip deformation. We found that in agreement with experiment a significant change in electronic conductance can be induced by AFM-tip deformation of metallic zigzag tubes and by twist deformation of armchair tubes. The effect is explained in terms of bandstructure change under deformation. C1 NASA, Ames Res Ctr, MS, Moffett Field, CA 94035 USA. RP Svizhenko, A (reprint author), NASA, Ames Res Ctr, MS, T27A-1, Moffett Field, CA 94035 USA. EM svizhenk@nas.nasa.gov; amaiti@accelrys.com NR 12 TC 0 Z9 0 U1 0 U2 0 PU COMPUTATIONAL PUBLICATIONS PI CAMBRIDGE PA PUBISHING OFFICE, 308 ONE KENDALL SQ BLDG 600, CAMBRIDGE, MA 02139 USA BN 0-9708275-6-3 PY 2002 BP 314 EP 317 PG 4 WC Nanoscience & Nanotechnology SC Science & Technology - Other Topics GA BEY39 UT WOS:000240119600085 ER PT B AU Robinson, DC AF Robinson, Daryl C. BE Laudon, M Romanowicz, B TI Charge islands through tunneling SO ICCN 2002: INTERNATIONAL CONFERENCE ON COMPUTATIONAL NANOSCIENCE AND NANOTECHNOLOGY LA English DT Proceedings Paper CT 2nd International Conference on Computational Nanoscience and Nanotechnology CY APR 21-25, 2002 CL San Juan, PR SP Appl Computat Res Soc, DARPA, Amer Phys Soc, Soc Ind & Appl Math, IEEE Electron Devices Soc, Swiss Fed Inst Technol Lausanne, TIMA CMP Lab, Univ Calif Davis, Dept Appl Sci, Coll Engn, Int Assoc Math & Comp Modeling, Accelrys Inc, Mintz Levin Cohn Ferris Glovsky & Popeo PC, Motorola, ANSYS Inc DE nanotube; tunneling; discrete; trajectory; charge ID TRANSISTORS AB It has been recently reported that the electrical charge in semiconductive carbon nanotube is not evenly distributed, rather it is divided into charge "islands" [1,2]. This links the aforementioned phenomenon to tunneling provides further insight into the higher rate of tunneling processes, which makes tunneling devices attractive [3]. This per also provides a basis for calculating the charge over the length of the tube so that nanoscale devices' conductive properties may be fully exploited. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Robinson, DC (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM dcrobinson@grc.nasa.gov NR 7 TC 0 Z9 0 U1 0 U2 0 PU COMPUTATIONAL PUBLICATIONS PI CAMBRIDGE PA PUBISHING OFFICE, 308 ONE KENDALL SQ BLDG 600, CAMBRIDGE, MA 02139 USA BN 0-9708275-6-3 PY 2002 BP 494 EP 497 PG 4 WC Nanoscience & Nanotechnology SC Science & Technology - Other Topics GA BEY39 UT WOS:000240119600132 ER PT B AU Feather, MS Menzies, T AF Feather, MS Menzies, T GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Converging on the optimal attainment of requirements SO IEEE JOINT INTERNATIONAL CONFERENCE ON REQUIREMENTS ENGINEERING, PROCEEDINGS LA English DT Proceedings Paper CT IEEE Joint International Conference on Requirements Engineering CY SEP 09-13, 2002 CL ESSEN, GERMANY SP IEEE Comp Soc Tech Council Software Engn, CRP Henri Tudor, Univ Essen, PROMATIS AG, Rational Software Corp, T-Syst, ACM Sigsoft, GI, IFIP Working Grp 2 9, INCOSE AB Planning for the optimal attainment of requirements is an important early lifecycle activity. However, such planning is difficult when dealing with competing requirements, limited resources, and the incompleteness of information available at requirements time. A novel approach to requirements optimization is described. A requirements interaction model is executed to randomly sample the space of options. This produces a large amount of data, which is then condensed by a summarization tool. The result is a small list of critical decisions (i.e., those most influential in leading towards the desired optimum). This focuses human experts' attention on a relatively few decisions and makes them aware of major alternatives. This approach is iterative. Each iteration allows experts to select from among the major alternatives. In successive iterations the execution and summarization modules are run again, but each time further constrained by the decisions made in previous iteration. In the case study shown here, out of 99 yes/no decisions (approximately 10(30) possibilities), five iterations were sufficient to find and make the 30 key ones. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Martin.S.Feather@Jpl.Nasa.Gov; tim@menzies.com NR 18 TC 21 Z9 22 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 0-7695-1465-0; 0-7695-1466-9 PY 2002 BP 263 EP 270 DI 10.1109/ICRE.2002.1048537 PG 8 WC Computer Science, Software Engineering SC Computer Science GA BV24J UT WOS:000178310300041 ER PT J AU Scardelletti, MC Ponchak, GE Weller, TM AF Scardelletti, MC Ponchak, GE Weller, TM TI Miniaturized Wilkinson power dividers utilizing capacitive loading SO IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS LA English DT Article DE coplanar stripline; coplanar waveguide; power dividers; Wilkinson power dividers AB This letter reports the miniaturization of a planar Wilkinson power divider by capacitive loading of the quarter wave transmission lines employed in conventional Wilkinson power dividers. Reduction of the transmission line segments from lambda/4 to between lambda/5 and lambda/12 are reported here. The input and output lines at the three ports and the lines comprising the divider itself are coplanar waveguide (CPW) and asymmetric coplanar stripline (ACPS), respectively. The 10 GHz power dividers are fabricated on high resistivity silicon (HRS) and alumina wafers. These miniaturized dividers are 74% smaller than conventional Wilkinson power dividers, and have a return loss better than +30 dB and an insertion loss less than 0.55 dB. Design equations and a discussion about the effect of parasitic reactance on the isolation are presented for the first time. C1 NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Scardelletti, MC (reprint author), NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. NR 10 TC 124 Z9 125 U1 0 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1531-1309 J9 IEEE MICROW WIREL CO JI IEEE Microw. Wirel. Compon. Lett. PD JAN PY 2002 VL 12 IS 1 BP 6 EP 8 DI 10.1109/7260.975717 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 512RV UT WOS:000173338100003 ER PT J AU Kraft, CC AF Kraft, CC TI A New Course for NASA SO IEEE SPECTRUM LA English DT Editorial Material C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD JAN PY 2002 VL 39 IS 1 BP 14 EP 15 DI 10.1109/MSPEC.2002.975031 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 507AM UT WOS:000173004200006 ER PT J AU Garrison, JL Komjathy, A Zavorotny, VU Katzberg, SJ AF Garrison, JL Komjathy, A Zavorotny, VU Katzberg, SJ TI Wind speed measurement using forward scattered GPS signals SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE bistatic radar; global positioning system (GPS); oceanography; retrievals; scatterometry ID OCEAN; ALGORITHM; SYSTEM AB Instrumentation and retrieval algorithms are described which use the forward scattered range-coded signals from the global positioning system (GPS) radio navigation system for the measurement of sea surface roughness. This roughness has long been known to be dependent upon the surface wind speed. Experiments were conducted from aircraft along the TOPEX ground track and over experimental surface truth buoys. These flights used a receiver capable of recording the cross-correlation power in the reflected signal. The shape of this power distribution was then compared against analytical models, which employ a geometric optics approach. Two techniques for matching these functions were studied. The first recognized the most significant information content in the reflected signal is contained in the trailing edge slope of the waveform. The second attempted to match the complete shape of the waveform by approximating it as a series expansion and obtaining the nonlinear least squares estimate. Discussion is also presented on anomalies in the receiver operation and their identification and correction. C1 Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. Jet Prop Lab, Ionopher & Atmospher Remote Sensing Grp, Pasadena, CA 91109 USA. NOAA, Environm Technol Lab, Boulder, CO 80303 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Garrison, JL (reprint author), Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. NR 32 TC 147 Z9 160 U1 0 U2 16 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 JAN PY 2002 VL 40 IS 1 BP 50 EP 65 DI 10.1109/36.981349 PG 16 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 517VY UT WOS:000173632200006 ER PT J AU Stiles, BW Pollard, BD Dunbar, RS AF Stiles, BW Pollard, BD Dunbar, RS TI Direction interval retrieval with thresholded nudging: A method for improving the accuracy of QuikSCAT winds SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE algorithms; backscatter; ocean winds; scatterometry ID SET-THEORETIC ESTIMATION; MODEL FUNCTION; OCEAN; SCATTEROMETER; NSCAT; SATELLITE; SYSTEM; GHZ AB The SeaWinds scatterometer was developed by NASA JPL, Pasadena, CA, to measure the speed and direction of ocean surface winds. It was then launched onboard the QuikSCAT spacecraft. The accuracy of the majority of the swath and the size of the swath are such that the SeaWinds on QuikSCAT Mission (QSCAT) meets its science requirements despite shortcomings at certain cross-track positions. Nonetheless, it is desirable to modify the baseline processing in order to improve the quality of the less accurate portions of the swath, in particular near the far swath and nadir. Two disparate problems have been identified for these regions. At far swath, ambiguity removal skill is degraded due to the absence of inner beam measurements, limited azimuth diversity and boundary effects. Near nadir, due to nonoptimal measurement geometry, (measurement azimuths approximately 180degrees apart) there is a marked decrease in directional accuracy even when ambiguity removal works correctly. Two algorithms have been developed: direction interval retrieval (DIR) to address the nadir performance issue and thresholded nudging (TN) to improve ambiguity removal at far swath. We illustrate the impact of the two techniques by exhibiting prelaunch simulation results and postlaunch statistical performance metrics with respect to ECMWF wind fields and buoy data. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Stiles, BW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 17 TC 53 Z9 55 U1 1 U2 1 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 JAN PY 2002 VL 40 IS 1 BP 79 EP 89 DI 10.1109/36.981351 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 517VY UT WOS:000173632200008 ER PT J AU Acker, JG Shen, S Leptoukh, G Serafino, G Feldman, G McClain, C AF Acker, JG Shen, S Leptoukh, G Serafino, G Feldman, G McClain, C TI SeaWiFS ocean color data archive and distribution system: Assessment of system performance SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE data systems; ocean color; remote sensing ID CZCS AB The Sea-viewing Wide Field-of View Sensor (SeaWiFS) Mission has initiated a new era of ocean color remote sensing and has established performance benchmarks that will be emulated by subsequent missions. An integral element of the SeaWiFS mission is the data component, performed by the Goddard Earth Sciences Distributed Active Archive Center (GES DAAC), NASA Goddard Space Flight Center, Greenbelt, MD. Since the beginning of data distribution in September 1997, the GES DAAC has managed the data archive and improved data distribution capability. SeaWiFS data products are archived in a primary, secondary, and tertiary archive structure, ensuring data preservation. Data distribution utilizes a World Wide Web (WWW)-based ordering interface, allowing distribution either electronically or on magnetic tape media. Automatic data subscriptions, supplying user-tailored data product selections, have yielded a high archive-to-distribution ratio. System improvements have increased efficiency and redundancy. The user interface has added features designed to facilitate data access and data usage, enhanced by WWW information resources and comprehensive online dataset documentation. As SeaWiFS enters the latter half of its five-year mission, a system performance assessment provides useful information for other Earth remote sensing missions and allows consideration of future usage objectives for the SeaWiFS data archive. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. George Mason Univ, Fairfax, VA 22030 USA. RP Acker, JG (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. NR 6 TC 16 Z9 18 U1 0 U2 5 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 JAN PY 2002 VL 40 IS 1 BP 90 EP 103 DI 10.1109/36.981352 PG 14 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 517VY UT WOS:000173632200009 ER PT J AU Shabanov, NV Zhou, LM Knyazikhin, Y Myneni, RB Tucker, CJ AF Shabanov, NV Zhou, LM Knyazikhin, Y Myneni, RB Tucker, CJ TI Analysis of interannual changes in northern vegetation activity observed in AVHRR data from 1981 to 1994 SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE AVHRR; interannual variability; normalized difference; vegetation index (NDVI); vegetation dynamics ID HIGH-RESOLUTION RADIOMETER; LEAF-AREA INDEX; ATMOSPHERIC CO2; HIGH-LATITUDES; DATA SET; TEMPERATURE; CALIBRATION; RADIATION; CLIMATE; COVER AB This paper reports on the analysis of Pathfinder AVHRR land (PAL) data set that spans the period July 1981 to September 1994. The time series of normalized difference vegetation index (NDVI) data for land areas north of 45degrees N assembled by correcting the PAL data with spectral methods confirms the northerly greening trend and extension of the photosynthetically active growing season. Analysis of the channel reflectance data indicates that the interannual changes in red and near-infrared reflectances are similar to seasonal changes in the spring time period when green leaf area increases and photosynthetic activity ramps up. Model calculations and theoretical analysis of the sensitivity of NDVI to background reflectance variations confirm the hypothesis that warming driven reductions in snow cover extent and earlier onset of greening are responsible for the observed changes in spectral reflectances over vegetated land areas. C1 Boston Univ, Dept Geog, Boston, MA 02215 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Shabanov, NV (reprint author), Boston Univ, Dept Geog, Boston, MA 02215 USA. RI Zhou, Liming/A-2688-2012; Myneni, Ranga/F-5129-2012 NR 43 TC 96 Z9 119 U1 1 U2 20 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 JAN PY 2002 VL 40 IS 1 BP 115 EP 130 DI 10.1109/36.981354 PG 16 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 517VY UT WOS:000173632200011 ER PT J AU Guo, JJ Tsang, L Ding, KH Chang, ATC Chen, CT AF Guo, JJ Tsang, L Ding, KH Chang, ATC Chen, CT TI Frequency dependence of scattering by dense media of small particles based on Monte Carlo simulation of Maxwell equations SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE electromagnetic wave scattering; Monte Carlo method; passive microwave remote sensing ID SNOW WATER EQUIVALENT; QUASI-CRYSTALLINE APPROXIMATION; SENSOR MICROWAVE IMAGER; CLASSIFICATION; SPHERES; COVER; MODEL AB The frequency dependence of extinction and scattering by geophysical medium at microwave frequencies is an important scattering topic because multifrequency measurements are used in remote sensing applications. Classical independent scattering theory states that if the particles are small, scattering is proportional to the fourth power in three-dimensional (3-D) scattering and the third power in two-dimensional (2-D) scattering. In this paper, we present Monte Carlo simulation results of dense media scattering. The dense media consists of densely packed small particles. Solutions are based on rigorous methods of generating dense media and subsequent numerical solutions of Maxwell's equation. Numerical simulations indicate that the frequency dependence of densely packed sticky particles is weaker than independent scattering. C1 Univ Washington, Dept Elect Engn, Seattle, WA 98195 USA. USAF, Res Lab, Sensors Directorate, SNHE, Hanscom AFB, MA 01731 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Guo, JJ (reprint author), Univ Washington, Dept Elect Engn, Seattle, WA 98195 USA. NR 26 TC 7 Z9 8 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 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2002 VL 40 IS 1 BP 153 EP 161 DI 10.1109/36.981357 PG 9 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 517VY UT WOS:000173632200014 ER PT J AU Skofronick-Jackson, GM Gasiewski, AJ Wang, JR AF Skofronick-Jackson, GM Gasiewski, AJ Wang, JR TI Influence of microphysical cloud parameterizations on microwave brightness temperatures SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE clouds; electromagnetic scattering; millimeter wave radiometry; rain; remote sensing; snow ID WATER-VAPOR; PRECIPITATION; SIMULATIONS; ICE; RADIOMETER; RAINFALL; RETRIEVALS; MESOSCALE; SYSTEM; STORM AB The microphysical parameterization of clouds and rain cells plays a central role in atmospheric forward radiative transfer models used in calculating microwave brightness temperatures. The absorption and scattering properties of a hydrometeor-laden atmosphere are governed by particle phase, size distribution, aggregate density, shape, and dielectric constant. This study investigates the sensitivity of brightness temperatures with respect to the microphysical cloud parameterization. Calculated wideband (6-410 GHz) brightness temperatures were studied for four evolutionary stages of an oceanic convective storm using a five-phase hydrometeor model in a planar-stratified scattering-based radiative transfer model. Five other microphysical cloud parameterizations were compared to the baseline calculations to evaluate brightness temperature sensitivity to gross changes in the hydrometeor size distributions and the ice-air-water ratios in the frozen or partly frozen phase. The comparison shows that enlarging the raindrop size or adding water to the partly frozen hydrometeor mix warms brightness temperatures by as much as 55 K at 6 GHz. The cooling signature caused by ice scattering intensifies with increasing ice concentrations and at higher frequencies. An additional comparison to measured Convection and Moisture Experiment (CAMEX-3) brightness temperatures shows that in general all but two parameterizations produce calculated T(B)s that fall within the CAMEX-3 observed minima and maxima. The exceptions are for parameterizations that enhance the scattering characteristics of frozen hydrometeors. C1 Univ Maryland, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Microwave Sensors Branch, Greenbelt, MD 20771 USA. NOAA, Environm Technol Lab, Boulder, CO 80305 USA. RP Skofronick-Jackson, GM (reprint author), Univ Maryland, Baltimore, MD 21250 USA. RI Skofronick-Jackson, Gail/D-5354-2012 NR 36 TC 27 Z9 27 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 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2002 VL 40 IS 1 BP 187 EP 196 DI 10.1109/36.981360 PG 10 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 517VY UT WOS:000173632200017 ER PT J AU Garello, R Montorsi, G Benedetto, S Divsalar, D Pollara, F AF Garello, R Montorsi, G Benedetto, S Divsalar, D Pollara, F TI Labelings and encoders with the uniform bit error property with applications to serially concatenated trellis codes SO IEEE TRANSACTIONS ON INFORMATION THEORY LA English DT Article; Proceedings Paper CT IEEE International Symposium on Information Theory CY AUG 16-22, 1998 CL MIT, CAMBRIDGE, MA SP IEEE, Informat Theory Soc, Natl Sci Fdn, NASA, USN, Off Naval Res, AT&T, Motorola, Qualcomm, Lucent Technol, Bell Lab Innovat HO MIT DE coding; concatenated codes; constellations; encoding; labeling; trellis codes; uniform error property ID ROTATIONAL INVARIANCE; GAUSSIAN-CHANNEL; TURBO CODES; CONSTELLATIONS; CONSTRUCTION AB The well-known uniform error property for signal constellations and codes is extended to encompass information bits. We introduce a class of binary labelings for signal constellations, called bit geometrically uniform (BGU) labelings, for which the uniform bit error property holds, i.e., the bit error probability does not depend on the transmitted signal. Strong connections between the symmetries of constellations and binary Hamming spaces are involved. For block-coded modulation (BCM) and trellis-coded modulation (TCM) Euclidean-space codes, BGU encoders are introduced and studied. The properties of BGU encoders prove quite useful for the analysis and design of codes aimed at minimizing the bit, rather than symbol, error probability. Applications to the analysis and the design of serially concatenated trellis codes are presented, together with a case study which realizes a spectral efficiency of 2 b/s/Hz. C1 Univ Ancona, Dipartimento Elettron & Automat, I-60131 Ancona, Italy. Politecn Torino, Dipartimento Elettron, I-10129 Turin, Italy. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Univ Ancona, Dipartimento Elettron & Automat, I-60131 Ancona, Italy. EM roberto.garello@ieee.org; montorsi@polito.it; benedetto@polito.it; dariush@shannon.jpl.nasa.gov; fabrizio@shannon.jpl.nasa.gov RI Montorsi, Guido/D-4867-2012; OI benedetto, sergio/0000-0002-7648-5396; garello, roberto/0000-0003-0292-4648 NR 28 TC 17 Z9 17 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9448 EI 1557-9654 J9 IEEE T INFORM THEORY JI IEEE Trans. Inf. Theory PD JAN PY 2002 VL 48 IS 1 BP 123 EP 136 DI 10.1109/18.971743 PG 14 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 502CZ UT WOS:000172727300008 ER PT J AU Pogorzelski, RJ AF Pogorzelski, RJ TI Experimental confirmation of the dynamics of coupled-oscillator arrays and implications for angle-based modulation SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE modulation; phase-locked oscillators; phased arrays; voltage-controlled oscillators AB This paper describes a set of experimental measurements designed to test the predictions of the continuum theoretical model concerning the dynamics of a linear array of mutually in, jection-locked voltage-controlled oscillators. The model indicates that the phase distribution evolves according to a diffusion process, the diffusion rate being determined by the inter-oscillator locking range. The theoretical predictions are confirmed by the experimental results. In addition, a discussion of computational predictions of the characteristics of the signal received in the far zone when such an oscillator array excites a linear array of radiating elements is included. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Pogorzelski, RJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 9 Z9 9 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 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD JAN PY 2002 VL 50 IS 1 BP 143 EP 149 DI 10.1109/22.981258 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA 517NQ UT WOS:000173617100025 ER PT J AU Jones, PM Mitchell, CM AF Jones, PM Mitchell, CM TI Model-based cognitive engineering in complex systems - Part I SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART A-SYSTEMS AND HUMANS LA English DT Editorial Material C1 NASA, Ames Res Ctr, Human Factors Res & Technol Div, Moffett Field, CA 94035 USA. Georgia Inst Technol, Ctr Human Machine Syst Res, Atlanta, GA 30332 USA. RP Jones, PM (reprint author), NASA, Ames Res Ctr, Human Factors Res & Technol Div, Moffett Field, CA 94035 USA. OI Jones, Patricia/0000-0002-1519-5774 NR 12 TC 1 Z9 2 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 1083-4427 J9 IEEE T SYST MAN CY A JI IEEE Trans. Syst. Man Cybern. Paart A-Syst. Hum. PD JAN PY 2002 VL 32 IS 1 BP 2 EP 4 AR PII S1083-4427(02)02690-5 DI 10.1109/TSMCA.2002.995524 PG 3 WC Computer Science, Cybernetics; Computer Science, Theory & Methods SC Computer Science GA 541ZE UT WOS:000175016400001 ER PT J AU Ko, YC Alouini, MS Simon, MK AF Ko, YC Alouini, MS Simon, MK TI Analysis and optimization of switched diversity systems (vol 49, pg 1813, 2000) SO IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY LA English DT Correction C1 Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ko, YC (reprint author), Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. NR 1 TC 7 Z9 7 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9545 J9 IEEE T VEH TECHNOL JI IEEE Trans. Veh. Technol. PD JAN PY 2002 VL 51 IS 1 BP 216 EP 216 AR PII S0018-9545(02)00446-2 DI 10.1109/TVT.2002.992082 PG 1 WC Engineering, Electrical & Electronic; Telecommunications; Transportation Science & Technology SC Engineering; Telecommunications; Transportation GA 533EK UT WOS:000174516300020 ER PT B AU Thomas, SL Bodensteiner, NM AF Thomas, SL Bodensteiner, NM GP IEEE IEEE IEEE IEEE TI Managing complexity: The challenges of the International Space Station Program SO IEMC-2002: IEEE INTERNATIONAL ENGINEERING MANAGEMENT CONFERENCE, VOLS I AND II, PROCEEDINGS: MANAGING TECHNOLOGY FOR THE NEW ECONOMY LA English DT Proceedings Paper CT IEEE International Engineering Management Conference CY AUG 18-20, 2002 CL St Johns Coll, Cambridge, ENGLAND SP IEEE Engn Management Soc, IEE Reg 8, IEEE UKRI Sect, IEEE UKRI EMSIPC Chapter, Cambridge Ctr Technol Management HO St Johns Coll AB This study explores the varied challenges of managing complexity using the International Space Station (ISS) Program as an example of a complex, adaptive system. The paper begins by considering the program from the perspective of a evolutionary dialectic: with homoeostatic change as thesis, deterministic unpredictability as anti-thesis, and self-organization as the synthesis. The paper then examines the concept of self-organized criticality, considering the ISS Program's integrated and tiered team structure. The next section introduces bipolar variables confronted by employees adapting to and enacting this complex environment. Finally, we consider how organizational mindsets can entrench (or retrench) in this environment even in the face of dynamical change and how the ISS Program as a complex program has evolved and adapted to tolerate environmental ambiguity. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77059 USA. RP Thomas, SL (reprint author), NASA, Lyndon B Johnson Space Ctr, UHCL Box 234,2700 Bay Area Blvd, Houston, TX 77059 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7385-5 PY 2002 BP 649 EP 654 PG 6 WC Engineering, Industrial; Management; Operations Research & Management Science SC Engineering; Business & Economics; Operations Research & Management Science GA BV52F UT WOS:000179247300117 ER PT B AU Schnase, JL Smith, JA Stohlgren, TJ Graves, S Trees, C AF Schnase, JL Smith, JA Stohlgren, TJ Graves, S Trees, C GP IEEE IEEE IEEE TI Biological invasions: A challenge in ecological forecasting SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The spread of invasive species is one of the most daunting environmental, economic, and human-health problems facing the United States and the World today. It is one of several grand challenge environmental problems being considered by NASA's Earth Science Vision for 2025. The invasive species problem is complex and presents many challenges. Developing an invasive species predictive capability could significantly advance the science and technology of ecological forecasting. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Schnase, JL (reprint author), NASA, Goddard Space Flight Ctr, Code 930, Greenbelt, MD 20771 USA. NR 5 TC 4 Z9 4 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 122 EP 124 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800040 ER PT B AU Chao, BF Farr, T LaBrecque, J Bindschadler, R Douglas, B Rignot, E Shum, CK Wahr, J AF Chao, BF Farr, T LaBrecque, J Bindschadler, R Douglas, B Rignot, E Shum, CK Wahr, J GP IEEE IEEE IEEE TI Understanding sea level changes SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Sea level change occurs on all timescales, depending on the type of change in question. It also occurs with a continuous range of spatial scales--local, regional, and global. To understand and be able to eventually predict sea level changes is a truly interdisciplinary endeavor. It requires geodetic and non-geodetic measurements of various types from space as well as in situ, while various numerical models for a number of meteorological and geophysical processes or properties are essential or relevant. C1 NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. RP Chao, BF (reprint author), NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. RI Rignot, Eric/A-4560-2014 OI Rignot, Eric/0000-0002-3366-0481 NR 12 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 125 EP 127 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800041 ER PT B AU Raymond, CA Lundgren, PR Madsen, SN Rundle, JB AF Raymond, CA Lundgren, PR Madsen, SN Rundle, JB GP IEEE IEEE IEEE TI Understanding and responding to earthquake hazards SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Understanding the earthquake cycle and assessing earthquake hazards is a topic of both increasing potential for scientific advancement and social urgency. A large portion of the world's population inhabits seismically-active regions, including the megacities of Los Angeles and Mexico City, and heavily populated regions in Asia. Population growth will exacerbate the potential for huge earthquake-related casualties. However, powerful new tools to observe tectonic deformation have been developed and are being deployed with encouraging results for improving knowledge of fault system behavior and earthquake hazards. In the future, the coupling of complex numerical models and orders of magnitude increase in observing power promises to lead to accurate targeted, short-term earthquake forecasting. Dynamic earthquake hazard assessments resolved for a range of spatial scales (large and small fault systems) and time scales (months to decades) will allow a more systematic approach to prioritizing the retrofitting of vulnerable structures, relocating populations at risk, protecting lifelines preparing for disasters, and educating the public. The suite of spaceborne observations needed to achieve this vision has been studied, and the derived requirements have defined a set of mission architectures and enabling technologies that will accelerate progress in achieving the goal of improved earthquake hazard assessments. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Raymond, CA (reprint author), Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 128 EP 130 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800042 ER PT B AU Flaming, GM AF Flaming, GM GP IEEE IEEE IEEE TI Requirements for global precipitation measurement SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The measurement of precipitation on a global basis has many scientific and. societal benefits. The National Aeronautics and Space Administration's (NASA's) Tropical Rainfall Measuring Mission (TRMM), developed in cooperation with the National Space Development Agency (NASDA) of Japan, was launched in 1997, and is widely viewed as a highly successful mission. TRMM has successfully addressed many science issues, has identified areas relating to precipitation where additional research is required, and has also demonstrated the value of precipitation measurements to other disciplines, including hydrology and weather forecasting. In response to substantial interest in precipitation measurement, NASA has established a Project Office to begin planning for Global Precipitation Measurement (GPM). This paper will provide a brief overview of the needs for precipitation measurement, identify the top-level requirements, and provide details concerning the spacecraft and instruments that comprise the space segment of the concept mission. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Flaming, GM (reprint author), NASA, Goddard Space Flight Ctr, Code 420-2, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 269 EP 271 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800088 ER PT B AU Meneghini, R AF Meneghini, R GP IEEE IEEE IEEE TI Integral equations for a dual-wavelength radar SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci C1 NASA, GSFC, Greenbelt, MD 20071 USA. RP Meneghini, R (reprint author), NASA, GSFC, Code 975, Greenbelt, MD 20071 USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 272 EP 274 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800089 ER PT B AU Liao, L Meneghini, R Iguchi, T AF Liao, L Meneghini, R Iguchi, T GP IEEE IEEE IEEE TI Bright-band modeling of air/space-borne microwave radars SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci ID MELTING SNOWFLAKES AB In simulating the radar echo in the melting layer of stratiform rain, a melting snowflake is modeled as a spherical non-uniform mixture, prescribed as a stratified-sphere in that the fractional water content is given as a function of the radius of sphere. Combined with the melting layer model that depicts the melting fractions and fall velocities of hydrometeors, the radar profiles are produced and then compared with the measurements of TRMM PR and the dual-wavelength airborne radar. C1 Caelum Res Corp, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Liao, L (reprint author), Caelum Res Corp, NASA, Goddard Space Flight Ctr, Code 975, Greenbelt, MD 20771 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 278 EP 280 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800091 ER PT B AU Im, E Durden, SL Sadowy, G Li, L AF Im, E Durden, SL Sadowy, G Li, L GP IEEE IEEE IEEE TI Rainfall observations by the airborne dual-frequency precipitation radar during CAMEX-4 SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The 2(nd) Generation Precipitation Radar is a new design for a dual-frequency (13.4 and 35.6 GHz) spaceborne precipitation radar. An airborne PR-2 simulator has been developed to demonstrate key technologies. This airborne system was flown on the NASA DC-8 aircraft during the 4(th) Convection and Moisture Experiment in 2001. Data were acquired in Tropical Storms Chantal and Gabrielle, Hurricane Humberto, and in several more localized convective systems. The authors discuss the design of the PR-2 airborne radar and show observations from CAMEX-4. Overall, the observations validated the design of PR-2 and provide an extensive data set for scientific analyses. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Im, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 281 EP 283 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800092 ER PT B AU Torres-Martinez, E Schoeberl, M Kalb, MW AF Torres-Martinez, E Schoeberl, M Kalb, MW GP IEEE IEEE IEEE TI A web of sensors: Enabling the earth science vision SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Highly coordinated observations and autonomous decision-making are needed to improve our ability to detect, monitor, and predict weather; climate; and the onset of certain natural hazards. The 'sensorweb' concept has been proposed as a potential solution to this requirement. This paper presents two candidate uses for the concept, describes its capabilities and unique architectural properties, and outlines challenges to overcome for successful development of a sensorweb architecture. The conclusion proposes that the primary challenge to implementation of sensorwebs-beyond the obvious technical obstacles-will be our ability to develop and execute a long-term strategy that provides for the deployment of a series of compatible missions that deliver the full promise of envisioned sesnsorweb capabilities. C1 Goddard Space Flight Ctr, Earth Sci Technol Off, Greenbelt, MD 20771 USA. RP Torres-Martinez, E (reprint author), Goddard Space Flight Ctr, Earth Sci Technol Off, Greenbelt, MD 20771 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 351 EP 353 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800116 ER PT B AU Schoeberl, MR AF Schoeberl, MR GP IEEE IEEE IEEE TI The afternoon constellation: A formation of earth observing systems for the atmosphere and hydrosphere SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Two of the large EOS observatories, Aqua (formerly EOS-PM) and Aura (formerly EOS-CHEM) will fly is nearly the same inclination with 1:30 PM +/-15 min ascending node equatorial crossing times. Between Aura and Aqua a series of smaller satellites will be stationed: Cloudsat, CALIPSO (formerly PICASSO/CENA), and PARASOL. This constellation of low earth orbit satellites will provide an unprecedented opportunity to make atmospheric cloud observations. This paper will provide details of the science opportunity and describe the sensor types for the afternoon constellation. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Schoeberl, MR (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 354 EP 356 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800117 ER PT B AU Smith, WL Harrison, FW Hinton, DE Revercomb, HE Bingham, GE Petersen, R Dodge, JC AF Smith, WL Harrison, FW Hinton, DE Revercomb, HE Bingham, GE Petersen, R Dodge, JC GP IEEE IEEE IEEE TI GIFTS - The precursor geostationary satellite component of the future earth observing system SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The Geosynchronous Imaging Fourier Transform Spectrometer. (GIFTS) combines advanced technologies to observe surface thermal properties and atmospheric weather and chemistry variables in four dimensions. Large area format Focal Plane detector Arrays (LFPAs) provide near instantaneous large area coverage with high horizontal resolution. A Fourier Transform Spectrometer (FTS) enables atmospheric radiance spectra to be observed simultaneously for all LFPA detector elements thereby providing high vertical resolution temperature and moisture sounding information. The fourth dimension, time, is provided by the geosynchronous satellite platform, which enables near continuous imaging of the atmosphere's three-dimensional structure. The key advances that GIFTS achieves beyond current geosynchronous capabilities are: (1) the water-vapor winds will be altitude-resolved throughout the troposphere, (2) surface temperature and atmospheric soundings will be achieved with high spatial and temporal resolution, and (3) the transport of tropospheric pollutant gases (i.e., CO and 03) will be observed. GIFTS will be launched in 2005 as NASA's third New Millennium Program (NMP) Earth Observing (EO-3) satellite mission, and will serve as the prototype of sounding systems to fly on future operational geosynchronous satellites. After a one-year validation period in view of North America, the GIFTS will be repositioned to become the Navy's Indian Ocean METOC Imager (IOMI). In this presentation we describe the GIFTS technology and provide examples of the GIFTS remote sensing capabilities using aircraft interferometer data. The GIFTS is an important step in implementing the NASA Earth Science Enterprise vision of a sensor web for future Earth observations. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Smith, WL (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 0 TC 3 Z9 3 U1 1 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 357 EP 361 PG 5 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800118 ER PT B AU Wiscombe, W Herman, J Valero, F AF Wiscombe, W Herman, J Valero, F GP IEEE IEEE IEEE TI L-1 and L-2 observatories for Earth science in the post-2010 era SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Twin observatories 1.5 million km from Earth along the Earth-Sun line offer revolutionary possibilities for Earth observation and scientific progress. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Wiscombe, W (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Wiscombe, Warren/D-4665-2012; OI Wiscombe, Warren/0000-0001-6844-9849; Herman, Jay/0000-0002-9146-1632 NR 1 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 365 EP 367 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800120 ER PT B AU Peri, F Hagopian, M Lake, M AF Peri, F Hagopian, M Lake, M GP IEEE IEEE IEEE TI Lightweight deployable UV/Visible/IR telescopes SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The vision of the Earth Science Enterprise (ESE) of the National Aeronautics and Space Administration (NASA) established a variety of science challenges for the next 20 years, relating to predictions of weather, climate, and foreseeable changes in the Earth's environment. In this paper, we discuss the attendant needs for space-based, lightweight deployable telescopes for a variety of science challenges. In addition, we suggest some strategies for deploying the necessary assets. C1 NASA, Goddard Space Flight Ctr, Earth Sci Technol Off, Greenbelt, MD 20771 USA. RP Peri, F (reprint author), NASA, Goddard Space Flight Ctr, Earth Sci Technol Off, Code 711, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 368 EP 370 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800121 ER PT B AU Raymond, CA Bristow, JO Schoeberl, MR AF Raymond, CA Bristow, JO Schoeberl, MR GP IEEE IEEE IEEE TI Needs for an intelligent distributed spacecraft infrastructure SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Future Earth science observing systems will involve multiple space assets and capable models to advance understanding and enable prediction of Earth system variables. There are several types of distributed spacecraft architecture that contribute to an overall integrated sensor web future vision. Many technologies needed to enable the Vision essentially mimic commercial developments in the electronics, network and communications industry, suggesting that low-cost, capable micro-spacecraft will be realized in the near future. Spacecraft autonomy and capable compact sensor suites represent the most significant investments that will decrease cost and improve the capability and reliability of sensor webs. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Raymond, CA (reprint author), Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 371 EP 374 PG 4 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800122 ER PT B AU Lansing, F Lemmerman, L Walton, A Bothwell, G Bhasin, K Prescott, G AF Lansing, F Lemmerman, L Walton, A Bothwell, G Bhasin, K Prescott, G GP IEEE IEEE IEEE TI Needs for communications and onboard processing in the vision era SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The NASA New Millennium Program (NMP), in conjunction with the Earth Science Enterprise Technology Office, has examined the capability needs of future NASA Earth Science missions and defined a set of high priority technologies that offer broad benefits to future missions, which would benefit from validation in space before their use in a science mission. In the area of spacecraft communications, the need for high and ultra-high data rates is driving development of communications technologies. This paper describes the current vision and roadmaps of the NMP for the technology needed to support ultra-high data rates downlink to Earth. Hyperspectral land imaging, radar imaging and multi-instrument platforms represent the most demanding classes of instruments in which large data flows place limitations upon the performance of the instrument and systems. The existing and prospective Data Distribution (DD) modes employ various types of links, such as DD from low-earth-orbit (LEO) spacecraft direct to the ground, DD from geosynchronous (GEO) spacecraft, LEO to GEO relays, multi-spacecraft links, and sensor webs. Depending on the type of link, the current data rate requirements vary from 2 Mbps (LEO to GEO relay) to 150 Mbps (DD from LEO spacecraft). It is expected that in the 20-year timeframe, the link data rates may increase to 100 Gbps. To ensure such capabilities, the aggressive development of communication technologies in the optical frequency region is necessary. Current Technology Readiness Levels (TRL) of the technology components for space segment of communications hardware varies from 3 (proof of concept) to 5 (validation in relevant environment). Development of onboard processing represents another area driven by increasing data rates of spaceborne experiments. The technologies that need further development include data compression, event recognition and response, as well as specific hyperspectral and radar data processing. Aspects of onboard processing technologies requiring flight validation include: fault-tolerant computing and processor stability, autonomous event detection and response, situation-based data compression and processing. The required technology validation missions can be divided in two categories: hardware-related missions and software-related missions. Objectives of the first kind of missions include radiation-tolerant processors and radiation-tolerant package switching communications node/network interface. Objectives of the second kind of missions include autonomous spacecraft operations and payload (instrument-specific) system operations. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lansing, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 375 EP 377 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800123 ER PT B AU Duda, JL Mulligan, J Henegar, JM AF Duda, JL Mulligan, J Henegar, JM GP IEEE IEEE IEEE TI Evolving ground system architecture requirements for the National Polar-Orbiting Environmental Operational Satellite System (NPOESS) SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The Integrated Program Office (IPO) Is developing a ground system architecture for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) because requirements cannot be accommodated by current technology. Increased data rates, increased processing complexity, and more stringent latency requires another approach. In this paper, we discuss the rationale behind the challenging requirements, in which direction the requirements are evolving, and how the NPOESS ground system architecture might be related to the NASA Vision of a Web of Sensors. C1 NASA, Goddard Space Flight Ctr, Flight Program & Projects Directorate, Integrated Program Off, Greenbelt, MD 20771 USA. RP Duda, JL (reprint author), NASA, Goddard Space Flight Ctr, Flight Program & Projects Directorate, Integrated Program Off, Code 402, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 378 EP 380 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800124 ER PT B AU Racette, P Lang, R AF Racette, P Lang, R GP IEEE IEEE IEEE TI Comparative analysis of radiometer systems using non-stationary processes SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Radiometers require periodic calibration to correct for instabilities in the receiver response. Various calibration techniques exist that minimize the effect of instabilities in the receivers. The optimal technique depends upon many parameters. Some parameters are constrained by the particular application and others can be chosen in the system design. For example, the measurement uncertainty may be reduced to the limits of the resolution of the measurement (sensitivity) if periodic absolute calibration can be performed with sufficient frequency. However if the period between calibrations is long, a reference-differencing technique, i.e. Dicke-type design, can yield better performance. The measurement uncertainty not only depends upon the detection scheme but also on the number of pixels between calibrations, the integration time per pixel, integration time per calibration reference measurement, calibration reference temperature, and the brightness temperature of what is being measured. The best scheme for reducing the measurement uncertainty also depends, in large part, on the stability of the receiver electronics. In this presentation a framework for evaluating calibration schemes for a wide range of system architectures is presented. Two methods for treating receiver non-stationarity are compared with radiometer measurements. C1 NASA, Goddard Space Flight Ctr, Microwave Instrument Technol Branch, Greenbelt, MD 20771 USA. RP Racette, P (reprint author), NASA, Goddard Space Flight Ctr, Microwave Instrument Technol Branch, Greenbelt, MD 20771 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 565 EP 567 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800186 ER PT B AU Ungar, SG AF Ungar, SG GP IEEE IEEE IEEE TI Overview of the earth observing one (EO-1) mission SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB reported at the IGARSS-2001 Symposium, the first 120 days of the EO-1 mission, constituting the Accelerated Mission, far exceeded the goal of acquiring sufficient data to insure meeting minimal EO-1 valuation requirements. The strategy of using Southern Hemisphere test sites during the Northern Hemisphere winter solstice left EO-1 with data for a variety of ecosystems under varying conditions. These data, collected primarily in Argentina and Australia, have been extensively analyzed by the EO-1 Science Validation Team (SVT). Additionally, during the remainder of the first year of operation, EO-1 accumulated a rich legacy of data for a global variety of ecosystems under varying conditions to complete the Base Mission. The SVT will continue to analyze these data through September of 2002. EO-1 data became public in December of 2001 at the onset of the EO-1 Extended Mission. This Extended Mission opened opportunities for the public to commission EO-1 data collects. Data from both the Base Mission and Extended Mission are public ally available from the EROS Data Center. Results of both phases of the EO-1 Base Mission as well as early findings from the Extended Mission are summarized in this paper. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Ungar, SG (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 568 EP 571 PG 4 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800187 ER PT B AU Kim, Y van Zyl, J AF Kim, Y van Zyl, J GP IEEE IEEE IEEE TI On the relationship between polarimetric parameters and soil moisture SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Rough surface scattering depends on both roughness and dielectric constant of a surface. Therefore, a polarimetric measurement is useful for estimating soil moisture since we can remove the surface roughness effect using multiple scattering components from a polarimetric measurement. In this paper, we examine the relationship between polarimetric parameters and soil moisture. For example, the co-polarization ratio is independent of surface roughness to the first order of the small perturbation approximation. As surface roughness increases, it can be shown that both co- and cross-polarization ratios depend on the surface slope under the tilted Bragg approximation. The effects of the surface roughness to these ratios are theoretically investigated. An algorithm is proposed to estimate soil moisture from both co- and cross-polarization ratios. We will also study other polarimetric parameters such as the average alpha angle and eigenvalues to understand their relationship with soil moisture. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kim, Y (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 IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 644 EP 646 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800211 ER PT B AU Kelly, REJ Chang, ATC Tsang, L Chen, CT AF Kelly, REJ Chang, ATC Tsang, L Chen, CT GP IEEE IEEE IEEE TI Parameterization of snowpack grain size for global satellite microwave estimates of snow depth SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB For accurate estimation of global snow depth or snow water equivalent on the Earth's surface using passive microwave instruments, knowledge of the snow pack's physical properties is important. It is known that the bulk snow grain size distribution exerts an important control over the microwave response from snow between 3mm and 300 mm wavelengths. In the absence of high quality snowpack data at a global scale, we show how the grain size distribution can be estimated using a general empirical model of grain growth. This information is used to parameterize a dense media radiative transfer model (DMRT) to estimate the radiometric response from a snow pack as a function of changing grain size distribution. The DMRT equations are based on the quasi-crystalline approximation (QCA) for densely distributed moderate sized particles in a medium such as a snow pack. The model snow depth estimates from the DMRT are used to calibrate a Special Sensor Microwave Imager (SSM/I) snow depth retrieval algorithm which is based on the brightness temperature difference between 19 and 37 GHz with the SWE. The method is tested using meteorological data from the WMO global network. Results show that using the DMRT model coupled with a grain size model improved estimates of snow depth are obtained. C1 Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. RP Kelly, REJ (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 686 EP 688 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800225 ER PT B AU Dungan, JL Kao, D Pang, A AF Dungan, JL Kao, D Pang, A GP IEEE IEEE IEEE TI The uncertainty visualization problem in remote sensing analysis SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Remote sensing analyses usually result in maps of discrete or continuous variables. Ideally, each value in such a map should be accompanied by an uncertainty description, that is, a quantitative statement about the probability of error. A full description of uncertainty at each pixel is usefully represented using a probability distribution. Such a probability distribution may be based on an understanding of potential errors in position, spatial support (the area measured by the sensor's field of view), model parameters, the model structure, and the input variables to the model. Visualizing uncertainty in the products of remote sensing analysis presents the challenge that at least four dimensions are required. These are the spatial dimensions (x and y), the dimension of the variable being mapped and finally the probability dimension. Current visualization tools and techniques do not support these data sets directly. Even animation, a logical choice to represent other four dimensional problems, is not fully satisfactory for probability distribution data sets. We have first addressed the problem of visualizing uncertainty by creating interactive maps of first, second and third order statistics summarizing the distributions. Next, we have experimented with shaded surface rendering of distributions from a user-selectable profile (row or column) in the image. We demonstrate these methods using a data set generated by a geostatistical conditional simulation algorithm and a single band image and we discuss the future promise of visualizing all four dimensions at once. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Dungan, JL (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI Dungan, Jennifer/G-9921-2016 OI Dungan, Jennifer/0000-0002-4863-1616 NR 11 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 729 EP 731 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800239 ER PT B AU Li, L Im, E Connor, LN Chang, PS AF Li, L Im, E Connor, LN Chang, PS GP IEEE IEEE IEEE TI Detecting ocean surface winds using TRMM precipitation radar SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Although designed specifically for the measurement of precipitation in the atmosphere, the Precipitation Radar (PR) onboard the Tropical Rainfall Measuring Mission (TRMM) satellite also measures the normalized radar cross-section at the Earth's surface. As such, this instrument provides an interesting opportunity to explore an alternative radar configuration in the satellite remote sensing of ocean winds. In particular, it can measure the strength of the ocean winds in relatively higher spatial resolution as compared to the conventional scatterometer systems presently in use. The addition of wind sensing capability to precipitation radar also complements its rain profiling capability nicely and allows coincident wind and rain measurements. In this paper, we discuss a new ocean wind algorithm developed specifically for TRMM PR using maximum likelihood estimation. A unique feature of this wind algorithm is its capability to incorporate measurement sensitivity and noise information consistently in both the along-track and cross-track directions. This PR wind algorithm is then tested using data from the TRMM Microwave Imager (TMI) and NASA QuikSCAT scatterometer. Excellent agreement on the retrieved wind strengths is achieved among three sensors. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Li, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Chang, Paul/F-5580-2010 OI Chang, Paul/0000-0001-5113-0938 NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 748 EP 750 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800245 ER PT B AU Berkun, AC Fischman, MA Im, E AF Berkun, AC Fischman, MA Im, E GP IEEE IEEE IEEE TI An advanced FPGA-based processor and controller for the Next-Generation Precipitation Radar SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The Next-Generation Precipitation Radar (PR-2) prototyped by NASA/JPL will depend heavily on high-performance digital processing to collect meaningful rain echo data. Using field-programmable gate arrays (FPGAs), we have developed for the PR-2 a pulse-compression processor and adaptive timing controller that will enable full on-board processing capabilities in a 14 and 36 GHz spaceborne radar. This paper describes some of the new technologies for the on-board processor, including a 40 x 10(9) op/s bit-serial filter attaining -60 dB range sidelobe performance, and an adaptive scanning control and timing unit (CTU) which yields a 7-fold increase in the radar's dwell time over areas of precipitation. C1 CALTECH, Jet Prop Lab, Radar Sci & Engn Sect, Pasadena, CA 91109 USA. RP Berkun, AC (reprint author), CALTECH, Jet Prop Lab, Radar Sci & Engn Sect, 4800 Oak Grove Dr,M-S 300-241, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 780 EP 782 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800256 ER PT B AU Piepmeier, JR Racette, P Manning, W Wang, JR AF Piepmeier, JR Racette, P Manning, W Wang, JR GP IEEE IEEE IEEE TI The airborne Conical Scanning Millimeter-wave Imaging Radiometer (CoSMIR) SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Results of the first science flight of the airborne Conical Scanning Millimeter-wave Imaging Radiometer (CoSMIR) for high-altitude observations from the NASA ER-2 is discussed. Imagery collected from the flight demonstrates CoSMIR's unique conical/cross-track imaging mode and provides comparison of CoSMIR measurements to those of the SSM/T-2 satellite radiometer. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Piepmeier, JR (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 783 EP 785 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800257 ER PT B AU Le Vine, DM AF Le Vine, DM GP IEEE IEEE IEEE TI ESTAR experience with RFI at L-band and implications for future passive microwave remote sensing from space SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci ID RADIOMETER AB Although the spectral window at 1.413 GHz (L-band) is protected for passive use, radiometers for remote sensing commonly encounter problems with RIFT. Experience with the synthetic aperture radiometer, ESTAR, suggests that airports are one source of this RFI. The existence of RFI at L-band could be a problem for future remote sensing from space. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Le Vine, DM (reprint author), NASA, Goddard Space Flight Ctr, Code 975, Greenbelt, MD 20771 USA. NR 10 TC 6 Z9 6 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 847 EP 849 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800277 ER PT B AU Barnes, WL Xiong, X Salomonson, VV AF Barnes, WL Xiong, X Salomonson, VV GP IEEE IEEE IEEE TI Status of terra MODIS and aqua MODIS SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Launched on December 18, 1999, the MODIS ProtoFlight Model on-board the EOS Terra spacecraft (near sun-synchronous polar orbit, 10:30 am equator crossing time) has been providing the science community global data sets for over two years. The instrument has been performing well on-orbit in terms of its spatial and spectral characterization and radiometric calibration. Many science products have been developed and validated using the MODIS Level 1B calibrated data. To be launched in April 2002, the MODIS Flight Model 1 on the EOS Aqua spacecraft (1:30 pm equator crossing time) will enhance the MODIS products by providing afternoon observations. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Barnes, WL (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Xiong, Xiaoxiong (Jack)/J-9869-2012 NR 4 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 970 EP 972 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800318 ER PT S AU Tilton, JC Marchisio, G Koperski, K Datcu, M AF Tilton, JC Marchisio, G Koperski, K Datcu, M GP IEEE IEEE IEEE TI Image information mining utilizing Hierarchical Segmentation SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing IGARSS LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The Hierarchical Segmentation (HSEG) algorithm is an approach for producing high quality, hierarchically related image segmentations. The VisiMine image information mining system utilizes clustering and segmentation algorithms for reducing visual information in multispectral images to a manageable size. The project discussed herein seeks to enhance the VisiMine system through incorporating hierarchical segmentations from HSEG into the VisiMine system. C1 NASA, Goddard Space Flight Ctr, Flight Ctr, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Flight Ctr, Mail Code 935, Greenbelt, MD 20771 USA. EM James.C.Tilton.1@gsfc.nasa.gov; giovanni@insightful.com; krisk@insightful.com; mihai.datcu@dlr.de RI DATCU, Mihai/G-1655-2016 NR 5 TC 1 Z9 2 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2153-6996 BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1029 EP 1031 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800337 ER PT B AU Wilson, WJ Yueh, SH Dinardo, S Li, F AF Wilson, WJ Yueh, SH Dinardo, S Li, F GP IEEE IEEE IEEE TI L/S-band radiometer measurements of a saltwater pond SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci ID MICROWAVE AB L and S-band radiometer brightness temperature measurements from a salt-water pond were made of as a function of salinity and temperature. The L-band measurements are in excellent agreement with the Klein and Swift salinity model, and will provide accurate predictions for the L-band emission from the ocean for future ocean salinity satellite missions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wilson, WJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1120 EP 1122 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800367 ER PT B AU Salomonson, VV Barnes, W Xiong, J Kempler, S Masuoka, E AF Salomonson, VV Barnes, W Xiong, J Kempler, S Masuoka, E GP IEEE IEEE IEEE TI An overview of the earth observing system MODIS instrument and associated data systems performance SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The MODIS instrument on the EOS Terra Mission has completed over 2 years of successful operation. Excellent data products have been developed and a full year or more of these products are now available. Validation of these products is continuing and efforts to improve product availability and access are underway. The MODIS on the EOS Aqua satellite is projected to become operational in the late spring/early summer of 2002. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Salomonson, VV (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 2 TC 25 Z9 25 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1174 EP 1176 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800384 ER PT B AU Ichoku, C Kaufman, YJ Remer, LA Levy, R Chu, DA Li, RR Tanre, D Mattoo, S AF Ichoku, C Kaufman, YJ Remer, LA Levy, R Chu, DA Li, RR Tanre, D Mattoo, S GP IEEE IEEE IEEE TI MODIS aerosol products: Quality assessment and regional application case studies based on two years of operation SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Aerosol parameters are retrieved daily at 10-km spatial resolution from the MODerate resolution Imaging Spectro-radiometer (MODIS) daytime data. These aerosol parameters include: aerosol optical thickness (AOT) at 0.47, 0.55 and 0.66 mum wavelengths over land, and at 0.47, 0.55, 0.66, 0.87, 1.2, 1.6, and 2.1 mum over ocean; Angstrom exponent over land and ocean; and effective radii and the fraction of AOT contributed by the small size mode over ocean. The MODIS aerosol products have been largely validated globally and regionally, based on cross correlation with AErosol RObotic NETwork (AERONET) sun-photometer measurements. MODIS aerosol products are used to monitor aerosol global distributions both spatially and temporally. They are also operationally summarized on a global grid on a daily, weekly, and monthly basis, and used for radiative forcing calculations. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP Ichoku, C (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RI Ichoku, Charles/E-1857-2012; Levy, Robert/M-7764-2013 OI Ichoku, Charles/0000-0003-3244-4549; Levy, Robert/0000-0002-8933-5303 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 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1180 EP 1182 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800386 ER PT B AU Baum, BA Frey, RA Ackerman, S Menzel, WP AF Baum, BA Frey, RA Ackerman, S Menzel, WP GP IEEE IEEE IEEE TI Remote sensing of global cloud properties using MODIS data SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The algorithms currently employed by the Moderate Resolution Imaging Spectroradiometer (MODIS) atmospheres team to retrieve cloud height and cloud thermodynamic phase depend solely on infrared (IR) bands and operate independently of each other. Cloud heights are derived using bands located in the 15-mum CO2 band, i.e., the CO2 slicing method. Cloud thermodynamic phase is inferred using an IR bispectral technique using bands located at 8.5 and 11 mum. C1 NASA, CIMSS, Madison, WI 53706 USA. RP Baum, BA (reprint author), NASA, CIMSS, 1225 W Dayton St, Madison, WI 53706 USA. RI Menzel, W. Paul/B-8306-2011 OI Menzel, W. Paul/0000-0001-5690-1201 NR 4 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1183 EP 1184 PG 2 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800387 ER PT B AU Descloitres, J Sohlberg, R Owens, J Giglio, L Justice, C Carroll, M Seaton, J Crisologo, M Finco, M Lannom, K Bobbe, T AF Descloitres, J Sohlberg, R Owens, J Giglio, L Justice, C Carroll, M Seaton, J Crisologo, M Finco, M Lannom, K Bobbe, T GP IEEE IEEE IEEE TI The MODIS rapid response project SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The Moderate-resolution Imaging Spectroradiometer (MODIS) instrument on board the Terra satellite offers an unprecedented combination of daily spatial coverage, spatial resolution, and spectral characteristics. These capabilities make MODIS ideal to observe a variety of rapid events: active fires, floods, smoke transport, dust storms, severe storms, iceberg calving, and volcanic eruptions. A new processing system has been developed at NASA's Goddard Space Flight Center to provide a rapid response to those events, with initial emphasis on active fire detection and 250m-resolution imagery. MODIS data of most of the Earth's land surface is processed within a few hours of data acquisition. Collaboration between NASA, the University of Maryland and the U.S.D.A. Forest Service has been developed to provide fire information derived from MODIS to the fire managers. Active fire locations in the conterminous United States are produced by the MODIS Rapid Response System and communicated to the Forest Service within a few minutes of production. These active fire locations are used to generate regional fire maps, updated daily and provided to the fire managers to help them allocate adequate resources to firefighters. Active fire locations are also distributed to the Global Observation of Forest Cover (G.O.F.C.) user community through a web interface integrating MODIS active fire locations and Geographic Information System (G.I.S.) datasets. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP Descloitres, J (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. NR 0 TC 3 Z9 3 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1191 EP 1192 PG 2 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800390 ER PT B AU Bidwell, SW Yuter, S Adams, WJ Everett, DF Flaming, GM Smith, EA AF Bidwell, SW Yuter, S Adams, WJ Everett, DF Flaming, GM Smith, EA GP IEEE IEEE IEEE TI Plans for Global Precipitation Measurement ground validation SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB This paper introduces plans for ground validation (GV) for the Global Precipitation Measurement. At NASA's request, a Ground Validation Working Group, formed from the meteorological and hydrological communities, is recommending plans to guide the GV program. Ground validation efforts will commence as early as 2003 with the Spring 2003 Pilot Experiment and described herein. The Pilot Experiment is focused on mitigating engineering and scientific risk to the GPM program and, in particular, to the ground validation program. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bidwell, SW (reprint author), NASA, Goddard Space Flight Ctr, Code 420-2, Greenbelt, MD 20771 USA. RI Yuter, Sandra/E-8808-2015 OI Yuter, Sandra/0000-0002-3222-053X NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1370 EP 1372 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800447 ER PT B AU Hlavka, DL McGill, M Hart, WD Spinhirne, JD AF Hlavka, DL McGill, M Hart, WD Spinhirne, JD GP IEEE IEEE IEEE TI Cloud Physics Lidar optical measurements during the SAFARI-2000 field campaign SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci ID AEROSOL AB In this presentation, we will show new optical data processing results from the Cloud Physics Lidar during SAFARI-2000. Retrieved products include aerosol and cloud layer location and identification, layer optical depths, vertical extinction profiles, and extinction-to-backscatter (S) ratios for 532 and 1064 nm. The retrievals will focus on the persistent and smoky planetary boundary layer and occasional elevated aerosol layers found in southern Africa during August and September 2000. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP Hlavka, DL (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Code 912, Greenbelt, MD 20771 USA. RI McGill, Matthew/D-8176-2012 NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1373 EP 1375 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800448 ER PT B AU Palm, SP Hart, B Hlavka, D Spinhirne, J Mahesh, A Welton, EJ AF Palm, SP Hart, B Hlavka, D Spinhirne, J Mahesh, A Welton, EJ GP IEEE IEEE IEEE TI An overview of the GLAS real-time atmospheric processing algorithms and results from the analysis of simulated GLAS data sets SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB A new era in atmospheric remote sensing is about to begin. Global monitoring of clouds and aerosols from space using a backscatter lidar system will greatly add to our knowledge in areas such as polar cloud climatology, aerosol loading and transport, and the planetary boundary layer. The Geoscience Laser Altimeter System (GLAS) will produce nearly 5 GB of data per day. A challenge is to create autonomous algorithms that will analyze the data in near-real time. This paper briefly discusses the algorithms and presents results of testing with simulated GLAS data sets. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP Palm, SP (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Code 912, Greenbelt, MD 20771 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1376 EP 1378 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800449 ER PT B AU Spinhirne, J Berkoff, T Welton, E Campbell, J AF Spinhirne, J Berkoff, T Welton, E Campbell, J GP IEEE IEEE IEEE TI High pulse repetition rate, eye safe, visible wavelength lidar systems: Design, results and potential SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB In In 1993 the first of the eye safe visible wavelength lidar systems known now as Micro Pulse Lidar (MPL) became operational. Since that time there have been several dozen of these systems produced and applied for full time profiling of atmospheric cloud and aerosol structure. There is currently an observational network of MPL sites to support global climate research. In the course of application of these instruments there have been significant improvements in understanding, design and performance of the systems. There are addition potentiat and applications beyond current practice for the high repetition rate, eye safe designs. The MPL network and the current capability, design and future potential of MPL systems are described. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Spinhirne, J (reprint author), NASA, Goddard Space Flight Ctr, Code 912, Greenbelt, MD 20771 USA. NR 5 TC 1 Z9 1 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1382 EP 1383 PG 2 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800451 ER PT B AU Jambor, U Houser, PR Rodell, M Gottschalck, J Meng, CJ Cosgrove, B Entin, JK AF Jambor, U Houser, PR Rodell, M Gottschalck, J Meng, CJ Cosgrove, B Entin, JK GP IEEE IEEE IEEE TI Remotely sensed forcing data and the global land data assimilation system SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB A high-resolution, near-real-time Global Land Data Assimilation System (GLDAS) that integrates information from relevant satellite- and ground-based observations within a land data assimilation framework is being developed at NASA's Goddard Space Flight Center and NOAA's National Centers for Environmental Prediction (NCEP). The GLDAS framework enables it to serve as a powerful tool for various types of research and applications. Here, we examine the impact of replacing model-based forcing fields with observation-derived fields on Mosaic land surface model (LSM) simulations. Due to a paucity of recent land surface state observations over large domains, GLDAS-forced Mosaic LSM simulations will be evaluated against finer-resolution North American LDAS-forced results. C1 Univ Maryland Baltimore Cty, NASA, GSFC, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. RP Jambor, U (reprint author), Univ Maryland Baltimore Cty, NASA, GSFC, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. RI Rodell, Matthew/E-4946-2012; Houser, Paul/J-9515-2013 OI Rodell, Matthew/0000-0003-0106-7437; Houser, Paul/0000-0002-2991-0441 NR 9 TC 0 Z9 0 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1405 EP 1407 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800459 ER PT S AU Madsen, SN Chen, C Edelstein, W AF Madsen, SN Chen, C Edelstein, W GP IEEE IEEE IEEE TI Radar options for global earthquake monitoring SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing IGARSS LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Fine temporal sampling is essential for disaster management, e.g. of flooding, fires, landslides, hurricanes, and earthquakes. A powerful technique for mapping such natural hazards is synthetic aperture radar (SAR) interferometry, providing displacement measurements at the subwavelength scale and decorrelation estimates. Pre-seismic deformation, one of the most elusive aspects of earthquakes, will require much finer temporal sampling than present InSAR capabilities provide. Observations taken every few hours could provide time series data of rapidly evolving phenomena, such as pre-eruptive volcano dynamics, leading to major advances in predictive capability, improving the potential for modeling as well as for civil protection. Such radical performance improvements could be attained through large constellations of conventional low earth orbit (LEO) satellites or small constellations of geosynchronous SARs. The unique capability of a geosynchronous SAR in terms of instantaneously accessible area is contrasted with the requirements for huge electronically steered array (ESA) antennas. The optimal approach is very much dependant on technological developments, in particular geosynchronous SAR depends on the development of affordable very large ESA antennas, but also other technological developments will be required. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 1 TC 14 Z9 17 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2153-6996 BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1483 EP 1485 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800484 ER PT B AU Wright, CW Walsh, EJ Krabill, WB Vandemark, D Garcia, AW Black, PG Marks, FD Luettich, RA AF Wright, CW Walsh, EJ Krabill, WB Vandemark, D Garcia, AW Black, PG Marks, FD Luettich, RA GP IEEE IEEE IEEE TI Realtime storm surge measurement with a Scanning Radar Altimeter SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. RP Wright, CW (reprint author), NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Code 972, Wallops Isl, VA 23337 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1492 EP 1495 PG 4 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800487 ER PT B AU Lou, YL AF Lou, YL GP IEEE IEEE IEEE TI Review of the NASA/JPL airborne synthetic aperture radar system SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB AIRSAR has served as a test-bed for both imaging radar techniques and radar technologies for over a decade. In fact, the polarimetric, cross-track interferometric, and along-track interferometric radar techniques were all developed using AIRSAR. In this paper, we present the up-to-date system configuration, the expected performance and data accuracy in the standard radar modes. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lou, YL (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 IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1702 EP 1704 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800553 ER PT B AU Rincon, RF Lang, R Meneghini, R Bidwell, S Tokay, A AF Rincon, RF Lang, R Meneghini, R Bidwell, S Tokay, A GP IEEE IEEE IEEE TI Study of the variability in the rain drop size distribution over a 2.3 km path SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB In an effort to study the drop size distribution (DSD) a state-of-the-art instrument arrangement was deployed on Wallops Island, VA. The instrumentation consisted of a 2.3-km multi-frequency microwave link, three impact disdrometers, and a network of optical and tipping bucket raingauges. A dual-frequency inversion technique was implemented with the link measurements of attenuations at 25 GHz and 38 GHz to estimate the path-average DSD. Concurrently, an X-band, dual-polarization radar, located in the vicinity, collected polarization and reflectivity measurements over the link path. The evaluation of the estimates and measurements generated some preliminary results. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Rincon, RF (reprint author), NASA, Goddard Space Flight Ctr, 975,Bldg 33,Rm B409, Greenbelt, MD 20771 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1857 EP 1859 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800605 ER PT B AU Skofronick-Jackson, GM Weinman, JA Chang, DE AF Skofronick-Jackson, GM Weinman, JA Chang, DE GP IEEE IEEE IEEE TI Observation of snowfall over land by microwave radiometry from space SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci ID WATER-VAPOR; ICE AB High frequency (v > 100 GHz) observations from AMSU-B during the March 5-6, 2001 New England blizzard are used to investigate the detection of snowfall over land. The AMSU-B data are compared to NEXRAD reflectivities. The radiative effects of a snow model are compared with observations. Low altitude water vapor is shown to obscure emission from the underlying ground at high frequencies, but at high altitudes water vapor also reduces the impact of scattering by snow particles. C1 Univ Maryland Baltimore Cty, GEST Ctr, NASA Goddard, Greenbelt, MD 20771 USA. RP Skofronick-Jackson, GM (reprint author), Univ Maryland Baltimore Cty, GEST Ctr, NASA Goddard, Code 975, Greenbelt, MD 20771 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 1866 EP 1868 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800608 ER PT B AU Kelley, OA Stout, J Kwiatkowski, J Bacmeister, J AF Kelley, OA Stout, J Kwiatkowski, J Bacmeister, J GP IEEE IEEE IEEE TI Variations in the convective rain fraction observed by the tropical rainfall measuring mission (TRMM) Precipitation Radar (PR) SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci ID WARM POOL; CLOUDS AB Using a data clustering method, monthly statistics are calculated from rain rate estimates of the TRMM Precipitation Radar. The statistics show how the following variables change with the size of a rain event: convective rain rate, total rain rate, and convective rain fraction. On average, the convective rain fraction is found to be greatest for small mesoscale events covering 10(3) km(2), while rain rate increases monotonically with the size of the rain event. C1 NASA, Goddard Space Flight Ctr, TRMM Sci Data & Informat Syst, TSDIS, Greenbelt, MD 20771 USA. RP Kelley, OA (reprint author), NASA, Goddard Space Flight Ctr, TRMM Sci Data & Informat Syst, TSDIS, Greenbelt, MD 20771 USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 2012 EP 2016 PG 5 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800657 ER PT B AU Ranson, KJ Sun, G Kovacs, K Kharuk, VI AF Ranson, KJ Sun, G Kovacs, K Kharuk, VI GP IEEE IEEE IEEE TI Utility of SARs for mapping forest disturbance in Siberia SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB Radar backscatter data from multiple SAR satellites were acquired and analyzed for two sites subject to the forest disturbances in Western Siberia, Russia. The backscatter from disturbed and non-disturbed sites were analyzed and the individual and combined capabilities of ERS, JERS, and Radarsat evaluated. JERS was the single most useful radar for this analysis. The combination of radars improved the results. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ranson, KJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Ranson, Kenneth/G-2446-2012 OI Ranson, Kenneth/0000-0003-3806-7270 NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 2081 EP 2083 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800678 ER PT B AU Haldemann, AFC Jurgens, RF Slade, MA AF Haldemann, AFC Jurgens, RF Slade, MA GP IEEE IEEE IEEE TI Mars meter-scale roughness: Goldstone Solar System Radar Delay-Doppler database SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The entire fourtneen-year database of Goldstone Solar System Radar Mars near-nadir radar scattering model fits is being revised using the latest topography from the Mars Global Surveyor Mars Orbiter Laser Altimeter instrument. The improved radar dataset will better serve the Mars exploration community for landing site selection and characterization. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Haldemann, AFC (reprint author), CALTECH, Jet Prop Lab, Mail Stop 238-420,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 2169 EP 2169 PG 1 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800707 ER PT B AU Middleton, EM Campbell, PKE McMurtrey, JE Corp, LA Butcher, LM Chappelle, EW AF Middleton, EM Campbell, PKE McMurtrey, JE Corp, LA Butcher, LM Chappelle, EW GP IEEE IEEE IEEE TI "Red edge" optical properties of corn leaves from different nitrogen regimes SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB High resolution (< 2 nm) optical spectra and biophysical measurements were acquired from corn leaves from field plots having four nitrogen fertilizer application rates: 20%, 50%, 100% and 150% of optimal levels. Reflectance (R), transmittance (T), and absorptance (A) spectra were obtained for both adaxial and abaxial leaf surfaces. The strongest relationships between foliar chemistry and optical properties were demonstrated for C/N content and two optical parameters associated with the "red edge inflection point" (REIP):1) a normalized first derivative maximum (Dmax) occurring between 695 and 730 nm (Dmax/D744); and 2) the wavelength associated with Dmax (WL of REIP). A non-linear increase in the Dmax/D744 ratio as a function of ON content was observed for all optical properties (r(2) = 0.90-0.95). Similarly, a non-linear decrease in the WL of REIP as a function of C/N content was observed for all optical properties (RT, RB, TT, and AT) (r(2) = 0.85-0.96). The Dmax/D744 ratio increased as the WL of REIP declined from similar to730 to 700 nm, with curves per optical property expressing different degrees of non-linearity. C1 NASA, Goddard Space Flight Ctr, Terr Phys Lab, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Middleton, EM (reprint author), NASA, Goddard Space Flight Ctr, Terr Phys Lab, Biospher Sci Branch, 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 7 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 2208 EP 2210 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800721 ER PT B AU Ahmad, S Ouzounov, D Leptoukh, G Serafino, G Kempler, S AF Ahmad, S Ouzounov, D Leptoukh, G Serafino, G Kempler, S GP IEEE IEEE IEEE TI Highlights of MODIS products SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB A new collection of Earth science data is now publicly available for the understanding of the land, ocean, and atmospheric interactions and how they affect our climate system. Approximately 40 higher level science standard products are being produced from the Moderate Resolution Imaging Spectroradiometer (MODIS) high resolution radiances. MODIS data starting November 1, 2000 to the present have been processed with an improved calibration algorithm (version-3) and data products are available to the public and science user community. Nearly all of these products have been evaluated and found useful for science and various applications. Radiometric calibrated and geolocated radiance data and all derived atmospheric, land and ocean products are available free from NASA's Distributed Active Archive Centers (DAACs). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ahmad, S (reprint author), NASA, Goddard Space Flight Ctr, Code 902, Greenbelt, MD 20771 USA. RI Ouzounov, Dimitar/A-5929-2012 NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 2299 EP 2301 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800749 ER PT B AU de Colstoun, EB Hall, FG Meeson, B Los, SO Landis, D AF de Colstoun, EB Hall, FG Meeson, B Los, SO Landis, D GP IEEE IEEE IEEE TI The international satellite land surface climatology project (ISLSCP) initiative II data collection SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The International Satellite Land Surface Climatology Project (ISLSCP) Initiative 11 is compiling and producing a collection of high priority, global, interdisciplinary data sets that is responsive to the requirements of the International GEWEX Project Office (IGPO), and the International Geosphere Biosphere Programme Biospheric Aspects of the Hydrological Cycle (IGBP/BAHC) and ISLSCP scientific communities. The ISLSCP 11 activities, funded through NASA's Land Surface Hydrology Program, improve upon the original ISLSCP I collection by covering a longer period of time from 1986 to 1995, with at least a monthly time step, but also with many products being provided at spatial resolutions ranging from 1/4 to 1/2 and 1 degree. The satellite-derived vegetation data set that forms the core of the ISLSCP 11 collection covers the period from 1982 to 1998. The collection includes a variety of remotely-sensed data sets ranging from visible to microwave wavelengths. The data sets also include improved topography, surface radiation, near-surface meteorology, precipitation, runoff, and soils data sets that can be used in a variety of interdisciplinary research activities. Several data sets to support global carbon and biogeochemical studies are also provided. The final ISLSCP 11 collection is to be published in mid-2002 with any data sets currently available being accessible through the ISLSCP 11 web page (http://islscp2.gsfc.nasa.gov). C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP de Colstoun, EB (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Code 923, Greenbelt, MD 20771 USA. RI Los, Sietse/G-8985-2012; OI Los, Sietse/0000-0002-1325-3555 NR 5 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 2326 EP 2327 PG 2 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800757 ER PT B AU Campbell, PKE Middleton, EM Corp, LA McMurtney, JE Kim, MS Chappelle, EW Butcher, LM AF Campbell, PKE Middleton, EM Corp, LA McMurtney, JE Kim, MS Chappelle, EW Butcher, LM GP IEEE IEEE IEEE TI Contribution of chlorophyll fluorescence to the reflectance of corn foliage SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB To assess the contribution of chlorophyll fluorescence (ChIF) to apparent reflectance (Ra) in the red/far-red, spectra were collected on a C-4 agricultural species (corn, Zea Mays L.) under conditions ranging from nitrogen deficiency to excess. A significant contribution of ChIF to Ra was observed, with on average 10-25% at 685nm and 2-6% at 740mn of Ra being due to ChIF. Higher ChIF was consistently measured from the abaxial leaf surface as compared to the adaxial. Using 350-665nm excitation, the study confirms the trends in three ChIF ratios established previously by active F technology, suggesting that the ChIF utility this technology has developed for monitoring vegetation physiological status is likely applicable also under natural solar illumination. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Terr Phys Lab, Greenbelt, MD 20771 USA. RP Campbell, PKE (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Terr Phys Lab, 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 13 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 2775 EP 2777 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800903 ER PT B AU de Colstoun, EB Story, MH Thompson, C Smith, TG Irons, JR AF de Colstoun, EB Story, MH Thompson, C Smith, TG Irons, JR GP IEEE IEEE IEEE TI Vegetation mapping using multi-temporal ETM plus data and a decision tree classifier SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci ID RESOLUTION AB Decision tree classifiers have received much recent attention, particularly with regards to land cover classifications at continental to global scales. Their usage with high spatial resolution data, however, has not yet been fully explored. In support of the National Park Service Vegetation Mapping Program, we have examined the feasibility of using a commercially available decision tree classifier with multi-temporal satellite data from the Enhanced Thematic Mapper-Plus instrument to map 11 land cover types at the Delaware Water Gap National Recreation Area near Milford, PA. Using land cover classes as specified by the National Vegetation Classification Standard at the Formation level, the final land cover map has an overall accuracy of 83.6% when tested against a validation data set acquired on the ground. This same accuracy is 98.6% when considering only forest vs. non-forest classes. Usage of multiple dates improves the accuracy over the use of a single date, particularly for the different forest types. These results demonstrate the potential applicability of such an approach to the entire National Park system and to high spatial resolution land cover and forest mapping applications. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP de Colstoun, EB (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Code 923, Greenbelt, MD 20771 USA. RI Irons, James/D-8535-2012 NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 2890 EP 2892 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800940 ER PT B AU Corp, LA Middleton, EM McMurtney, JE Entcheva, PK Campbell, PKE Kim, MS Chappelle, EW Butcher, LM AF Corp, LA Middleton, EM McMurtney, JE Entcheva, PK Campbell, PKE Kim, MS Chappelle, EW Butcher, LM GP IEEE IEEE IEEE TI Fluorescence imaging techniques for monitoring vegetation SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci ID PLANTS; EMISSION; GREEN; REFLECTANCE; LEAVES; STATE; BLUE AB Fluorescence sensing systems for the remote assessment of vegetative parameters are currently being developed and tested for use from a variety of sensing platforms. Multi-spectral fluorescence imaging techniques are being applied to assess plant responses to changes in its growth environment. Fluorescence abaxial vs. adaxial spatial patterns of band emissions are discussed with respect to individual leaves excised from a field corn canopy supplied with four levels of nitrogen fertilization. Fluorescence emissions for adaxial leaf surfaces were found significantly lower in intensity and specific emission bands and band ratios were found sensitive to N fertilization level. C1 NASA, Goddard Space Flight Ctr, Lab Terrestrial Phys, Biosper Sci Branch, Greenbelt, MD 20771 USA. RP Corp, LA (reprint author), NASA, Goddard Space Flight Ctr, Lab Terrestrial Phys, Biosper Sci Branch, Code 661, 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 16 TC 0 Z9 0 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 3056 EP 3058 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116800994 ER PT B AU Leptoukh, G Ahmad, S Eaton, P Hegde, M Kempler, S Koziana, J Ostrenga, D Ouzounov, D Savtchenko, A Serafino, G Sharma, AK Zhou, B AF Leptoukh, G Ahmad, S Eaton, P Hegde, M Kempler, S Koziana, J Ostrenga, D Ouzounov, D Savtchenko, A Serafino, G Sharma, AK Zhou, B GP IEEE IEEE IEEE TI GES DAAC tools for accessing and visualizing MODIS data SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The NASA Goddard Earth Sciences Distributed Active Archive Center (GES DAAC) has the unique position of an intermediary between users and MODIS data. To help users accessing and manipulating MODIS data, various tools were developed the MODIS Data Support Team (MDST). Some of these tools are described below: WHOM. The Web based Hierarchical Ordering Mechanism (WHOM) for Terra data is a customized version of the larger DAAC web-based data gateway. WHOM offers enhanced graphic interfaces to identify temporal and spatial data coverage while searching and ordering MODIS data archived at the GES DAAC. An alternative "No Frills" page provide a quick access (by passing navigation) directly to WHOM pages for products users want to order. Browse images allow science data users to evaluate the data before ordering. MODIS Level 113 browse images are produced from the 1 km Calibrated Radiances product using channels 1, 4, 3 as true color during the day, and channel 32 as false color during the night. Subsampled at 5-km resolution products are generated at the GES DAAC so users can download smaller files. Subsetting Tools. Calibrated radiance (Level 1B) channel subsetting is being developed as an extension to the EOS Core System (ECS). The front end, a graphic user interface, is part of WHOM. The new Simple Scalable Script-Based Science Processor (S4P) that interacts with ECS drives the back end for data retrieval, archiving and distribution of the subsetted data. Visualization Tools. The MDST has developed two very simple IDL-based tools to map MODIS swath products. The first, geoview, has a simple, graphic interface, while the second, simap, is a command line utility. Modis_atmos was designed to work with atmospheric products. HDFLook for MODIS is a result of joint collaboration between the GES DAAC and the University of Lille, France. An RDF-EOS version of a popular MSPHINX program was developed to work with all MODIS and many other HDF-EOS data. Its main features include: geo-mapping, geo-projection conversion, interactive and batch mode processing, subsetting and subsampling, stitching of several granules, multi-granule processing, and conversion into GIS-compatible formats. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Leptoukh, G (reprint author), NASA, Goddard Space Flight Ctr, Code 902, Greenbelt, MD 20771 USA. RI Ouzounov, Dimitar/A-5929-2012 NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 3202 EP 3204 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116801040 ER PT B AU Qu, JJ Serafino, G Teng, B Ouzounov, D Pollack, N Chiu, L AF Qu, JJ Serafino, G Teng, B Ouzounov, D Pollack, N Chiu, L GP IEEE IEEE IEEE TI Responding to the challenge of producing and distributing MODIS data at the NASA/GES DISC via the remote sensing information partners (RSIP) program SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB With the Moderate Resolution Imaging Spectroradiometer (MODIS) provisional version (V003) data releasing, there is a new challenge of producing and distributing MODIS data to end users. However, for many prospective users of the data, the large file sizes and complex format of MODIS have posed difficulties, including insufficient bandwidth for downloading the data, insufficient storage on the users' platforms, and incompatibility of the format with visualization packages, including most Geographic Information System (GIS) packages. In respond to these issues, the NASA Goddard Earth Science (GES) Data and Information Service Center (DISC) has engaged in facilitating on new applications and distributions for Earth science remote sensing data through the Remote Sensing Information Partners (RSIP) program. This paper will discuss (1) designing the infrastructure for MODIS data production and distribution via the RSIP program; (2) constructing a system for customized RSIP MODIS data product development and distribution; (3) developing techniques and tools for MODIS processing; and (4) future plans to enhance the accessibility of MODIS applications through the RSIP program. C1 NASA, Goddard Space Flight Ctr, GES Data Informat Serv Ctr, DISC, Greenbelt, MD 20771 USA. RP Qu, JJ (reprint author), NASA, Goddard Space Flight Ctr, GES Data Informat Serv Ctr, DISC, Code 902-0, Greenbelt, MD 20771 USA. RI Ouzounov, Dimitar/A-5929-2012 NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 3208 EP 3210 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116801042 ER PT B AU Hul, YX Zhang, H Wielicki, B Stackhouse, P AF Hul, YX Zhang, H Wielicki, B Stackhouse, P GP IEEE IEEE IEEE TI A neural network MODIS-CERES narrowband to broadband conversion SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci C1 NASA, Langley Res Ctr, Radiat & Aerosol Branch, Hampton, VA 23665 USA. RP Hul, YX (reprint author), NASA, Langley Res Ctr, Radiat & Aerosol Branch, Hampton, VA 23665 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 3227 EP 3229 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116801048 ER PT B AU Rall, JAR Cavanaugh, J Campbell, J Abshire, JB Spinhirne, JD AF Rall, JAR Cavanaugh, J Campbell, J Abshire, JB Spinhirne, JD GP IEEE IEEE IEEE TI Automated geophysical observatory (AGO) lidar - Post Antarctic deployment performance SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB A ground based, autonomous, low-power atmospheric lidar instrument developed at NASA Goddard Space Flight Center was recently returned from an extended period on the Antarctic polar plateau. We report on the pre and post deployment performance of AGO Lidar, compare the instrument performance with lidar models, and compare results with with the anticipated performance of the new Automatic Weather Station (AWS) Lidar. C1 NASA, Goddard Space Flight Ctr, Laser Remote Sensing Branch, Greenbelt, MD 20771 USA. RP Rall, JAR (reprint author), NASA, Goddard Space Flight Ctr, Laser Remote Sensing Branch, Mail Code 924, Greenbelt, MD 20771 USA. RI Abshire, James/I-2800-2013 NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 3602 EP 3604 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116801172 ER PT B AU Nishihama, M Wolfe, RE Fleig, AJ Kuyper, J AF Nishihama, M Wolfe, RE Fleig, AJ Kuyper, J GP IEEE IEEE IEEE TI MODIS geolocation error analysis developments SO IGARSS 2002: IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM AND 24TH CANADIAN SYMPOSIUM ON REMOTE SENSING, VOLS I-VI, PROCEEDINGS: REMOTE SENSING: INTEGRATING OUR VIEW OF THE PLANET SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2002)/24th Canadian Symposium on Remote Sensing CY JUN 24-28, 2002 CL TORONTO, CANADA SP IEEE, IEEE, Geosci & Remote Sensing Soc, Canadian Remote Sensing Soc, Univ Waterloo, Natl Resouces Candad, Canadian Space Agcy, Environm Canada, Natl Aeronaut & Space Adm, Natl Ocean & Atmospher Adm, Off Naval Res, Natl Space Dev Agcy Japan, Natl Polar-Orbit Environm Satellite Syst, Ball Aerosp & Technol, Int Union Radio Sci AB The Moderate Resolution Imaging Spectroradiometer (MODIS) contains 36 bands from the visible to the thermal infrared with the nominal ground field of views of 250 m, 500m and 1 km. This paper summarizes the changes to the MODIS Earth location algorithm and geometric parameters since the launch of MODIS on the Terra spacecraft in December 1999. Detailed analysis of residuals from a global network of ground control point reveals biases in unexpected areas of the MODIS geometric model. For instance, systematic off-nadir along-track errors are best modeled by a tilt in the mirror coordinate system. Analysis also indicates that some along-track errors are possibly caused by uncertainty in spacecraft attitude estimates. We discuss how reducing these errors enable sub-pixel geolocation accuracy goals to be achieved. C1 NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. RP Nishihama, M (reprint author), NASA, Goddard Space Flight Ctr, Raytheon ITSS, Code 922,Bld 32,Rm S15D, Greenbelt, MD 20771 USA. RI Wolfe, Robert/E-1485-2012 OI Wolfe, Robert/0000-0002-0915-1855 NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7536-X J9 INT GEOSCI REMOTE SE PY 2002 BP 3661 EP 3663 PG 3 WC Computer Science, Artificial Intelligence; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Geology; Instruments & Instrumentation; Remote Sensing; Imaging Science & Photographic Technology GA BV48S UT WOS:000179116801192 ER PT S AU Le Moigne, J Laporte, N Netanyahu, NS AF Le Moigne, J Laporte, N Netanyahu, NS BE Serpico, SB TI Enhancement of tropical land cover mapping with wavelet-based fusion and unsupervised clustering of SAR and landsat image data SO IMAGE AND SIGNAL PROCESSING FOR REMOTE SENSING VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Image and Signal Processing for Remote Sensing VII CY SEP 18-21, 2001 CL TOULOUSE, FRANCE SP SPIE, European Opt Soc, Ctr Natl Etud Spatiales, NASA DE image fusion; land cover mapping; wavelet representation; unsupervised clustering; remote sensing imagery AB The characterization and the mapping of land cover/land use of forest areas, such as the Central African rainforest, is a very complex task. This complexity is mainly due to the extent of such areas and, as a consequence, to the lack of full and continuous cloud-free coverage of those large regions by one single remote sensing instrument. In order to provide improved vegetation maps of Central Africa and to develop forest monitoring techniques for applications at the local and regional scales, we propose to utilize multi-sensor remote sensing observations coupled with in-situ data. Fusion and clustering of multi-sensor data are the first steps towards the development of such a forest monitoring system. In this paper, we will describe some preliminary experiments involving the fusion of SAR and Landsat image data of the Lope Reserve in Gabon. Similarly to previous fusion studies, our fusion method is wavelet-based. The fusion provides a new image data set which contains more detailed texture features and preserves the large homogeneous regions that are observed by the Thematic Mapper sensor. The fusion step is followed by unsupervised clustering and provides a vegetation map of the area. C1 NASA, Goddard Space Flight Ctr, Appl Informat Sci Branch, Greenbelt, MD 20771 USA. RP Le Moigne, J (reprint author), NASA, Goddard Space Flight Ctr, Appl Informat Sci Branch, Greenbelt, MD 20771 USA. NR 17 TC 1 Z9 1 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 0-8194-4266-6 J9 P SOC PHOTO-OPT INS PY 2002 VL 4541 BP 190 EP 198 AR UNSP 4541-25 DI 10.1117/12.454153 PG 9 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BU16J UT WOS:000175179300018 ER PT S AU Le Moigne, J Cole-Rhodes, A Eastman, R Johnson, K Morisette, J Netanyahu, NS Stone, HS Zavorin, I AF Le Moigne, J Cole-Rhodes, A Eastman, R Johnson, K Morisette, J Netanyahu, NS Stone, HS Zavorin, I BE Serpico, SB TI Multi-sensor registration of earth remotely sensed imagery SO IMAGE AND SIGNAL PROCESSING FOR REMOTE SENSING VII SE Proceedings of SPIE-The International Society for Optical Engineering LA English DT Proceedings Paper CT Conference on Image and Signal Processing for Remote Sensing VII CY SEP 18-21, 2001 CL TOULOUSE, FRANCE SP SPIE, European Opt Soc, Ctr Natl Etud Spatiales, NASA DE image registration; multi-sensor; wavelet representation; optimization; Hausdorff distance; mutual information AB Assuming that approximate registration is given within a few pixels by a systematic correction system, we develop automatic image registration methods for multi-sensor data with the goal of achieving sub-pixel accuracy. Automatic image registration is usually defined by three steps; feature extraction, feature matching, and data resampling or fusion. Our previous work focused on image correlation methods based on the use of different features. In this paper, we study different feature matching techniques and present five algorithms where the features are either original gray levels or wavelet-like features, and the feature matching is based on gradient descent optimization, statistical robust matching, and mutual information. These algorithms are tested and compared on several multi-sensor datasets covering one of the EOS Core Sites, the Konza Prairie in Kansas, from four different sensors: IKONOS (4m), Landsat-7/ETM+ (30m), MODIS (500m), and SeaWIFS (1000m). C1 NASA, Goddard Space Flight Ctr, Appl Informat Sci Branch, Greenbelt, MD 20771 USA. RP Le Moigne, J (reprint author), NASA, Goddard Space Flight Ctr, Appl Informat Sci Branch, Greenbelt, MD 20771 USA. EM lemoigne@backserv.gsfc.nasa.gov; acrhodes@eng.morgan.edu; eastman@loyola.edu; kjohnson@eng.morgan.edu; jeff.morisette@gsfc.nasa.gov; nathan@cs.biu.ac.il; hstone@nerc.com; iaz@cs.umd.edu NR 24 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 0-8194-4266-6 J9 P SOC PHOTO-OPT INS PY 2002 VL 4541 AR UNSP 4541-01 DI 10.1117/12.454140 PG 10 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BU16J UT WOS:000175179300001 ER PT S AU Croll, A Schweizer, M Dold, P Kaiser, T Benz, KW Lichtensteiger, M AF Croll, A Schweizer, M Dold, P Kaiser, T Benz, KW Lichtensteiger, M BE Schwabe, D Kuhlmann, HC Croll, A Colinet, P TI Temperature and growth rate fluctuations in silicon floating zones SO IMPACT OF THE GRAVITY LEVEL ON MATERIALS PROCESSING AND FLUID DYNAMICS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT G0 1 Symposium of COSPAR Scientific Commission G held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Comm Space Res ID MAGNETIC-FIELDS; LIQUID BRIDGE; MICROGRAVITY AB Several earlier mug experiments have shown that time-dependent thermocapillary (Marangoni) convection is the major cause for the formation of dopant striations in floating-zone grown semiconductor crystals, at least in small-scale systems not employing RF heating. To quantify this correlation, a silicon floating-zone experiment was performed on the TEXUS36 flight (February 7, 1999) in a monoellipsoid mirror furnace to measure temperature fluctuations in the melt zone and the microscopic growth rate simultaneously. Fluctuations of 0.5K - 0.7K with main frequencies between 0.1Hz and 0.3Hz were detectable. The microscopic growth rate fluctuated considerably around the average growth rate of 1mm/min: rates from 4mm/min to negative values (backmelting) were observed. Dopant striations are clearly visible in the Sb-doped crystal. The frequencies associated with the dopant inhomogeneities correspond quite well with those of the temperature fluctuations and microscopic growth rates. 3D numerical simulations were performed to predict the optimum position of the temperature sensor, to evaluate characteristic temperature amplitudes and frequencies, and to give insight into the instability mechanisms of Marangoni convection in this configuration. The simulations were in good agreement with the experimental values, showing temperature fluctuations with frequencies f less than or equal to 0.25Hz and amplitudes up to 1.8K at a position equivalent to that of the sensor tip in the experiment. Future microgravity S-FZ experiments, currently scheduled for a MAXUS flight in 2001, will try to influence the formation of dopant striations by rotating magnetic fields or by vibrational convection. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Freiberg, Inst NE Met & Reinststoffe, D-09599 Freiberg, Germany. NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. Univ Freiburg, Inst Kristallog, D-79104 Freiburg, Germany. RP Croll, A (reprint author), Univ Freiberg, Inst NE Met & Reinststoffe, Leipziger Str 23, D-09599 Freiberg, Germany. RI Croell, Arne/A-2480-2013 OI Croell, Arne/0000-0002-8673-9994 NR 18 TC 4 Z9 4 U1 2 U2 7 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 2002 VL 29 IS 4 BP 527 EP 536 AR PII S0273-1177(01)00661-5 DI 10.1016/S0273-1177(01)00661-5 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BU17Q UT WOS:000175230700006 ER PT S AU Mazuruk, K AF Mazuruk, K BE Schwabe, D Kuhlmann, HC Croll, A Colinet, P TI Control of melt convection using traveling magnetic fields SO IMPACT OF THE GRAVITY LEVEL ON MATERIALS PROCESSING AND FLUID DYNAMICS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT G0 1 Symposium of COSPAR Scientific Commission G held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Comm Space Res ID FLUID-FLOW; CRYSTALS; GROWTH AB An axisymmetric traveling magnetic wave induces a meridional base flow in a cylindrical zone of an electrically conducting liquid. This remotely induced flow can be conveniently controlled, in magnitude and direction, and can have benefits for crystal growth applications. In particular, it can be used to significantly offset natural convection. Theoretical basics of this new technological method are presented. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Mazuruk, K (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 9 TC 16 Z9 17 U1 0 U2 5 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 2002 VL 29 IS 4 BP 541 EP 548 AR PII S0273-1177(01)00663-9 DI 10.1016/S0273-1177(01)00663-9 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BU17Q UT WOS:000175230700008 ER PT S AU Vann, L Hu, YX AF Vann, L Hu, YX GP IEEE IEEE TI A neural network inversion system for atmospheric remote-sensing measurements SO IMTC 2002: PROCEEDINGS OF THE 19TH IEEE INSTRUMENTATION AND MEASUREMENT TECHNOLOGY CONFERENCE, VOLS 1 & 2 SE IEEE INSTRUMENTATION & MEASUREMENT TECHNOLOGY CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT 19th IEEE Instrumentation and Measurement Technology Conference (IMTC/2002) CY MAY 21-23, 2002 CL ANCHORAGE, AK SP IEEE Instrumentat & Measurement Soc DE neural network; atmospheric remote sensing; cloud AB A neural network inversion system is being developed to retrieve physical properties of the atmosphere. The neural network is being trained with radiative transfer simulations, atmospheric measurements, and theoretical understandings about the physical properties and their signatures in satellite measurements. The learning and adjusting process will be very fast and automated. This study seeks to improve future remote-sensing algorithms by bridging visual understanding within the human brain and the retrieval techniques developed by researchers in scientific community. With the new inversion technique of remote-sensing measurements, we will greatly reduce the time and mass storage of conventional inversion methods. C1 NASA, Langley Res Ctr, Radiat & Aerosol Branch, Greenbelt, MD 20771 USA. RP Vann, L (reprint author), NASA, Langley Res Ctr, Radiat & Aerosol Branch, Greenbelt, MD 20771 USA. RI Hu, Yongxiang/K-4426-2012 NR 3 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1091-5281 BN 0-7803-7218-2 J9 IEEE IMTC P PY 2002 BP 1613 EP 1615 PG 3 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Computer Science; Engineering; Instruments & Instrumentation GA BV15Y UT WOS:000178011900282 ER PT S AU Gunapala, SD Bandara, SV Liu, JK Rafol, SB Shott, CA Jones, R Laband, S Woolaway, J Fastenau, JM Liu, AK AF Gunapala, SD Bandara, SV Liu, JK Rafol, SB Shott, CA Jones, R Laband, S Woolaway, J Fastenau, JM Liu, AK BE Dereniak, EL Sampson, RE TI 9 mu m cutoff 640x512 pixel GaAs/AlxGa1-xAs quantum well infrared photodetector hand-held camera SO INFRARED DETECTORS AND FOCAL PLANE ARRAYS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Infrared Detectors and Focal Plane Arrays VII CY APR 02-03, 2002 CL ORLANDO, FL SP SPIE DE focal plane arrays; QWIPs; long-wavelength infrared (LWIR); hand-held camera AB A 9 mum cutoff 640x512 pixel hand-held quantum well infrared photodetector (QWIP) camera has been demonstrated with excellent imagery. Based on the single pixel test data, a noise equivalent differential temperature (NETD) of 8 mK is expected at 65K operating temperature with f/2 optics at 300K background. This focal plane array has shown background limited performance (BPLI) at 72K operating temperature with the same optics and background conditions. In this paper, we discuss the development of this very sensitive long wavelength infrared (LWIR) camera based on a GaAS/AlGaAs QWIP focal plane array and its performance in quantum efficiency, NETD, uniformity, and operability. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gunapala, SD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 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 0-8194-4471-5 J9 P SOC PHOTO-OPT INS PY 2002 VL 4721 BP 144 EP 150 DI 10.1117/12.478841 PG 7 WC Engineering, Electrical & Electronic; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Engineering; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BV33A UT WOS:000178611900015 ER PT S AU Bandara, S Gunapala, S Rafol, S Ting, D Liu, J Mumolo, J Trinh, T AF Bandara, S Gunapala, S Rafol, S Ting, D Liu, J Mumolo, J Trinh, T BE Dereniak, EL Sampson, RE TI Quantum well infrared photodetectors for low background applications SO INFRARED DETECTORS AND FOCAL PLANE ARRAYS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Infrared Detectors and Focal Plane Arrays VII CY APR 02-03, 2002 CL ORLANDO, FL SP SPIE DE long wavelength infrared; detectors; quantum wells; imaging ID TEMPERATURE DARK CURRENT; MODEL; GAIN AB Quantum Well Infrared Photodetectors (QWIPs) afford greater flexibility than the usual extrinsically doped semiconductor IR detectors. The wavelength of the peak response and cutoff can be continuously tailored over any wavelength range between 6-20 mum. The spectral band width of these detectors can be tuned from narrow (Deltalambda/lambda similar to 10%) to wide (Deltalambda/lambda similar to 40%) allowing various applications. Also, QWIP device parameters can be optimized to achieve extremely high performances at high background at lower operating temperatures (similar to 30 K). However, for low-background irradiance levels at low operating temperatures, high resistivity of the active region could leads to non-linear responsivity behavior. A new structure with a photosensitive superlattice and a thick blocking barrier has been tested, and is expected to avoid anomalous behavior under low backgrounds at low temperatures. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bandara, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 14 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 0-8194-4471-5 J9 P SOC PHOTO-OPT INS PY 2002 VL 4721 BP 159 EP 164 DI 10.1117/12.478842 PG 6 WC Engineering, Electrical & Electronic; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Engineering; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BV33A UT WOS:000178611900017 ER PT S AU Bailin, SC Truszkowski, W AF Bailin, SC Truszkowski, W BE Truszkowski, W Rouff, C Hinchey, M TI Ontology negotiation: How agents can-really get to know each other SO INNOVATIVE CONCPTS FOR AGENT-BASED SYSTEMS SE LECTURE NOTES IN ARTIFICIAL INTELLIGENCE LA English DT Article; Proceedings Paper CT 1st International Workshop on Radical Agent Concepts CY JAN 16-18, 2002 CL MCLEAN, VIRGINIA SP GSFC, Jet Propuls Lab, Sci Applicat Int Corp C1 Knowledge Evolut Inc, Washington, DC 20036 USA. NASA, Goddard Space Flight Ctr, Adv Automat Technol Branch, Greenbelt, MD 20771 USA. RP Bailin, SC (reprint author), Knowledge Evolut Inc, 1215 17th St,NW,Suite 101, Washington, DC 20036 USA. NR 13 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 3-540-40725-1 J9 LECT NOTES ARTIF INT PY 2002 VL 2564 BP 320 EP 334 PG 15 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering SC Computer Science GA BX62U UT WOS:000185937000024 ER PT S AU Smid, J Obitko, M Truszkowski, W AF Smid, J Obitko, M Truszkowski, W BE Truszkowski, W Rouff, C Hinchey, M TI An approach to knowledge exchange and sharing between agents SO INNOVATIVE CONCPTS FOR AGENT-BASED SYSTEMS SE LECTURE NOTES IN ARTIFICIAL INTELLIGENCE LA English DT Article; Proceedings Paper CT 1st International Workshop on Radical Agent Concepts CY JAN 16-18, 2002 CL MCLEAN, VIRGINIA SP GSFC, Jet Propuls Lab, Sci Applicat Int Corp AB In this paper, we are interested in studying the communication of knowledge between abstract systems (agents). Finite state machines (FSM) are used both as the formalism of knowledge and communication. Some machines acquire procedural knowledge by evolving strategies using a protocol that communicates FSM fragments with other agents. The communication protocol is in the form of a dialogue automaton. The selected formalism can fully describe both the procedural knowledge in simple abstract systems and the dialogue between agents. Therefore we conclude that the FSM formalism is appropriate for describing a class of abstract game playing agents. C1 Morgan State Univ, Dept Comp Sci, Baltimore, MD 21239 USA. Czech Tech Univ, Dept Cybernet, CR-16635 Prague, Czech Republic. NASA, GSFC 588, Greenbelt, MD 20771 USA. RP Smid, J (reprint author), Morgan State Univ, Dept Comp Sci, Baltimore, MD 21239 USA. NR 8 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 3-540-40725-1 J9 LECT NOTES ARTIF INT PY 2002 VL 2564 BP 367 EP 376 PG 10 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering SC Computer Science GA BX62U UT WOS:000185937000028 ER PT S AU Lupisella, ML AF Lupisella, ML BE Truszkowski, W Rouff, C Hinchey, M TI Cooperative agents and the search for extraterrestrial life SO INNOVATIVE CONCPTS FOR AGENT-BASED SYSTEMS SE LECTURE NOTES IN ARTIFICIAL INTELLIGENCE LA English DT Article; Proceedings Paper CT 1st International Workshop on Radical Agent Concepts CY JAN 16-18, 2002 CL MCLEAN, VIRGINIA SP GSFC, Jet Propuls Lab, Sci Applicat Int Corp AB The primary purpose of this paper is to suggest how a cooperative agents exploratory approach could be useful in searching for extraterrestrial life. Certain features of cooperative agent approaches such as distribution of varied functions in space and time, and increased reliability and robustness through redundancy, map well to the requirements of searching for extraterrestrial life. This paper will outline the advantages of cooperative agent approaches and, more specifically, scenarios and architectures that might be used to leverage a cooperative agents approach to enable the effective and efficient search for extraterrestrial life. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Biol, College Pk, MD 20742 USA. RP Lupisella, ML (reprint author), NASA, Goddard Space Flight Ctr, Code 584,Greenbelt Rd, Greenbelt, MD 20771 USA. NR 20 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 3-540-40725-1 J9 LECT NOTES ARTIF INT PY 2002 VL 2564 BP 408 EP 416 PG 9 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering SC Computer Science GA BX62U UT WOS:000185937000031 ER PT S AU Riley, JT AF Riley, JT BE Truszkowski, W Rouff, C Hinchey, M TI Automatic code writing agent SO INNOVATIVE CONCPTS FOR AGENT-BASED SYSTEMS SE LECTURE NOTES IN ARTIFICIAL INTELLIGENCE LA English DT Article; Proceedings Paper CT 1st International Workshop on Radical Agent Concepts CY JAN 16-18, 2002 CL MCLEAN, VIRGINIA SP GSFC, Jet Propuls Lab, Sci Applicat Int Corp C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Riley, JT (reprint author), NASA, Goddard Space Flight Ctr, Code 740-3, Greenbelt, MD 20771 USA. NR 0 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 3-540-40725-1 J9 LECT NOTES ARTIF INT PY 2002 VL 2564 BP 451 EP 452 PG 2 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering SC Computer Science GA BX62U UT WOS:000185937000035 ER PT S AU Hoover, RB Jerman, G Rozanov, AY Davies, PCW AF Hoover, RB Jerman, G Rozanov, AY Davies, PCW BE Hoover, RB Rozanov, AY Paepe, RR TI Biomarkers and microfossils in the Murchison, Rainbow, and Tagish Lake meteorites SO INSTRUMENTS, METHODS, AND MISSIONS FOR ASTROBIOLOGY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instruments, Methods and Missions for Astrobiology V CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE DE astrobiology; Murchison; Rainbow; Tagish Lake; biomarkers; microfossils; meteorites ID EARLY SOLAR-SYSTEM; AMINO-ACIDS; CARBONACEOUS CHONDRITES; ORGANIC-MATTER; HYDROCARBONS; ORIGIN AB During the past six years, we have conducted extensive scanning electron and optical microscopy investigations and x-ray analysis to determine the morphology, life cycle processes, and elemental distributions in living and fossil cyanobacteria, bacteria, archaea, fungi, and algae sampled from terrestrial environments relevant to Astrobiology. Biominerals, pseudomorphs and microfossils have been studied for diverse microbial groups in various states of preservation in many types of rocks (e.g., oil shales, graphites, shungites, bauxites, limestones, pyrites, phosphorites, and hydrothermal vent chimneys). Results of these studies have beeen applied to the search for biosignatures in carbonaceous chondrites, stony, and nickel iron meteorites. We review important biomarkers found in terrestrial rocks and meteorites and present additional evidence for the existence of indigenous bacterial microfossils in-situ in freshly fractured surfaces of the Murchison, Rainbow and Tagish Lake carbonaceous meteorites. We provide secondary and backscatter electron images and spectral data obtained with Field Emission and Environmental Scanning Electron Microscopes of biominerals and microfossils. We discuss techniques for discriminating indigenous microfossils from recent terrestrial contaminants. Images are provided of framboidal magnetites in oil shales and meteorites and images and 2D x-ray maps are shown of bacterial microfossils embedded in the mineral matrix of the Murchison, Rainbow and Tagish Lake Carbonaceous Meteorites. These microfossils exhibit characteristics that preclude their interpretation as post-arrival contaminants and we interpret them as indigenous biogenic remains. C1 NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Astrobiol Grp, Huntsville, AL 35812 USA. RP Hoover, RB (reprint author), NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Astrobiol Grp, SD-50, Huntsville, AL 35812 USA. NR 66 TC 0 Z9 0 U1 2 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 0-8194-4638-6 J9 P SOC PHOTO-OPT INS PY 2002 VL 4859 BP 15 EP 31 PG 17 WC Biology; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing SC Life Sciences & Biomedicine - Other Topics; Geology; Instruments & Instrumentation; Remote Sensing GA BW51M UT WOS:000182251800002 ER PT S AU Warmflash, D McKay, DS Fox, GE Steele, A Maule, J Lynch, K Allen, CC AF Warmflash, D McKay, DS Fox, GE Steele, A Maule, J Lynch, K Allen, CC BE Hoover, RB Rozanov, AY Paepe, RR TI Detection of biomarkers of viable life in using immunoassay SO INSTRUMENTS, METHODS, AND MISSIONS FOR ASTROBIOLOGY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instruments, Methods and Missions for Astrobiology V CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE DE life detection; in situ; immunoassay; MASSE; ELISA; Mars; astrobiology; soil; regolith; biomarkers AB The Microarray Assay for Solar System Exploration (MASSE) will use a microarray of antibody tests to search for biomarkers in extraterrestrial environments. In order for this technology to be useful for in situ studies on any given planet, molecules present within the material examined must be extracted and recognizable to the antibodies used in the assays. Experiments are currently being conducted on the immunological detection of agents in environmental samples, including soils and JSC Mars - 1 Martian regolith simulant and progress and results of immunological testing of material containing biomarkers for viable life will be presented and discussed in the context of the development of the MASSE instrument. C1 NASA, Lyndon B Johnson Space Ctr, Astrobiol Inst, Houston, TX 77058 USA. RP Warmflash, D (reprint author), NASA, Lyndon B Johnson Space Ctr, Astrobiol Inst, Houston, TX 77058 USA. NR 5 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 0-8194-4638-6 J9 P SOC PHOTO-OPT INS PY 2002 VL 4859 BP 72 EP 77 PG 6 WC Biology; Geosciences, Multidisciplinary; Instruments & Instrumentation; Remote Sensing SC Life Sciences & Biomedicine - Other Topics; Geology; Instruments & Instrumentation; Remote Sensing GA BW51M UT WOS:000182251800006 ER PT S AU Hoover, RB Rozanov, AY AF Hoover, RB Rozanov, AY BE Hoover, RB Rozanov, AY Lipps, JH TI Microfossils, biominerals, and chemical biomarkers in meteorites SO INSTRUMENTS, METHODS, AND MISSIONS FOR ASTROBIOLOGY VI SE Proceedings of SPIE-The International Society for Optical Engineering LA English DT Proceedings Paper CT Conference on Instruments, Methods, and Missions for Astrobiology VI CY MAY 21-25, 2002 CL MOSCOW, RUSSIA SP Paleontol Inst, SPIE, Russian Fdn Basic Res, SPIE Russia Chapter DE astrobiology; biominerals; bioindicators; biomarkers; microfossils; carbonaceous meteorites ID MASSIVE SULFIDE DEPOSIT; EARLY SOLAR-SYSTEM; MURCHISON METEORITE; CARBONACEOUS CHONDRITES; ORGUEIL METEORITE; AMINO-ACIDS; MAGNETOTACTIC BACTERIA; ORGANIC COMPOUNDS; ALIPHATIC-HYDROCARBONS; AROMATIC HYDROCARBONS AB The discovery of biominerals, chemical biomarkers and evidence of microfossils in the Mars meteorite (ALH84001) stimulated research into biomarkers, microbial extremophiles and provided impetus to the newly emerging fields of Astrobiology and Bacterial Paleontology. The debate following the ALH84001 results has highlighted the importance of developing methodologies for recognition of mineral and elemental bioindicators, chemical biomarkers and microfossils in terrestrial rocks and meteorites prior to sample return missions to comets, asteroids, and Mars. Comparative studies of living and fossil microorganisms and biomarkers are vital to developing expertise needed to recognize indigenous biosignatures and recent contaminants. This paper reviews elemental and mineral bioindicators, chemical biomarkers and keropgen in terrestrial rocks and meteorites. Electron Microscopy images of hyperthermophilic nanobacteria, sulfur and sulfate reducing bacteria, and mineralized microfossils and kerogen found in-situ in carbonaceous meteorite rock matrix are presented. C1 NASA, George C Marshall Space Flight Ctr, Space Sci Dept SD50, Huntsville, AL 35812 USA. RP Hoover, RB (reprint author), NASA, George C Marshall Space Flight Ctr, Space Sci Dept SD50, Huntsville, AL 35812 USA. EM Richard.Hoover@msfc.nasa.gov; aroza@paleo.ru; Richard.Hoover@msfc.nasa.gov; aroza@paleo.ru NR 120 TC 0 Z9 0 U1 2 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 0-8194-4734-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4939 BP 10 EP 27 PG 18 WC Instruments & Instrumentation; Paleontology SC Instruments & Instrumentation; Paleontology GA BW40B UT WOS:000181863300002 ER PT J AU Miranda, FA Mueller, CH Van Keuls, FW Subramanyam, G Vignesparamoorthy, S AF Miranda, FA Mueller, CH Van Keuls, FW Subramanyam, G Vignesparamoorthy, S TI Performance enhancement of tunable bandpass filters using selective etched ferroelectric thin films SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT 14th International Symposium on Integrated Ferroelectrics/13th IEEE Int Symposium on the Applications of Ferroelectrics/19th Meeting on Ferroelectric Mat and their Applicat CY MAY 28-JUN 01, 2002 CL NARA, JAPAN DE BSTO; tunable filters; selective etching; insertion loss ID SRTIO3 AB The inclusion of voltage-tunable barium strontium titanate (BSTO) thin films into planar band pass filters offers tremendous potential to increase their versatility. The ability to tune the passband so as to correct for minor deviations in manufacturing tolerances, or to completely reconfigure the operating frequencies of a microwave communication system, are highly sought-after goals. However, use of ferroelectric films in these devices results in higher dielectric losses, which in turn increase the insertion loss and decrease the quality factors of the filters. This study explores the use of patterned ferroelectric layers to minimize dielectric losses without degrading tunability. Patterning the ferroelectric layers enables us to constrict the width of the ferroelectric layers between the coupled microstrip lines, and minimize losses due to ferroelectric layers. Coupled one-pole microstrip bandpass filters with fundamental resonaces at similar to7.2 GHz and well-defined harmonic resonances at similar to14.4 and similar to21.6 GHz, were designed, simulated and tested. For one of the filters, experimental results verified that its center frequency was tunable by 528 MHz at a center frequency of 21.957 GHz, with insertion losses varying from 4.3 to 2.5 dB, at 0 and 3.5 V/mum, respectively. These data demonstrate that the tuning-to-loss figure of merit of tunable microstrip filters can be greatly improved using patterned ferroelectric thin films as the tuning element, and tuning can be controlled by engineering the ferroelectric constriction in the coupled sections. C1 NASA, Glenn Res Ctr, Cleveland, OH USA. Analex Corp, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Cleveland, OH 44142 USA. Univ Dayton, Dept Elect & Comp Engn, Dayton, OH 45458 USA. RP Miranda, FA (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH USA. NR 10 TC 4 Z9 4 U1 1 U2 3 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK,, ABINGDON OX14 4RN, OXON, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2002 VL 50 BP 121 EP 131 DI 10.1080/10584580290172152 PG 11 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 625TL UT WOS:000179831600015 ER PT J AU MacLeod, TC Ho, FD AF MacLeod, TC Ho, FD TI Simulation model of a ferroelectric field effect transistor SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT 14th International Symposium on Integrated Ferroelectrics/13th IEEE Int Symposium on the Applications of Ferroelectrics/19th Meeting on Ferroelectric Mat and their Applicat CY MAY 28-JUN 01, 2002 CL NARA, JAPAN AB An electronic simulation model has been developed of a ferroelectric field effect transistor. This model can be used in standard electrical circuit simulation programs to simulate the main characteristics of the FFET. The model uses a previously developed algorithm as a basis for the design. The model has the main characteristics of the FFET, which are the current hysterisis with different gate voltages and decay of the drain current when the gate voltages is off. The drain current has values matching actual FFET's, which were measured experimentally. The input and output resistance in the model is similar to that of the FFET. The model is valid for all frequencies below RF levels. A variety of different ferroelectric material characteristics can be modeled. The model can be used to design circuits using FFET's with standard electrical simulation packages. The circuit can be used in designing non-volatile memory circuits and logic circuits and is compatible with all SPICE based circuit analysis programs. The model is a drop in library that integrates seamlessly into a SPICE simulation. A comparison is made between the model and experimental data measured from an actual FFET. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. RP MacLeod, TC (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 4 TC 3 Z9 3 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK,, ABINGDON OX14 4RN, OXON, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2002 VL 49 BP 51 EP 59 DI 10.1080/10584580290171766 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 625TC UT WOS:000179830800008 ER PT J AU Mueller, CH Van Keuls, FW Romanofksy, RR Alterovitz, SD Miranda, FA AF Mueller, CH Van Keuls, FW Romanofksy, RR Alterovitz, SD Miranda, FA TI Interplay between thin film ferroelectric composition, microstructure and microwave phase shifter performance SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT 14th International Symposium on Integrated Ferroelectrics/13th IEEE Int Symposium on the Applications of Ferroelectrics/19th Meeting on Ferroelectric Mat and their Applicat CY MAY 28-JUN 01, 2002 CL NARA, JAPAN DE BSTO; tunable phase shifter; insertion loss; microstructure ID SPECTROSCOPIC ELLIPSOMETRY; SRTIO3; SI AB One of the keys to successfully incorporating ferroelectric films into Ku-band (12-18 GHz) phase shifters is to establish the composition, microstructure and thickness required to meet the tuning needs, and tailor the film properties to meet these needs. Optimal performance is obtained when the film composition and device design are such that the device performance is limited by odd mode dielectric losses, and these losses are minimized as much as possible while still maintaining adequate tunability. The parameters required to maintain device performance will vary slightly depending on composition, but we can conclude that the best tuning-to-loss figures of merit (K-factor) are obtained when there is minimal variation between the in-plane and out-of-plane lattice parameters, and the full-width half maximum values of the BSTO (002) peaks are less than approximately 0.04. degrees. We have observed that for phase shifters in which the ferroelectric crystalline quality and thickness are almost identical, higher losses are observed in films with higher Ba/Sr ratios. The best performance was observed in phase shifters with Ba:Sr = 30:70. The superiority of this composition was attributed to several interacting factors: the Ba:Sr ratio was such that the Curie temperature (180 K) was far removed from room temperature, the crystalline quality of the film was excellent, and there was virtually no difference between the in-plane and out-of-plane lattice parameters of the film. C1 Analex Corp, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. Ohio Aerosp Inst, Cleveland, OH 44142 USA. RP Mueller, CH (reprint author), Analex Corp, Cleveland, OH 44135 USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK,, ABINGDON OX14 4RN, OXON, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2002 VL 49 BP 171 EP 180 DI 10.1080/10584580290171883 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 625TC UT WOS:000179830800020 ER PT J AU Katiyar, RS Miranda, FA Fernandez, FE AF Katiyar, RS Miranda, FA Fernandez, FE TI Proceedings of 2nd Ferroelectric Workshop in Puerto Rico (FWPR-2001) - San Juan, Puerto Rico, USA - June 1-2, 2001 - Guest Editorial SO INTEGRATED FERROELECTRICS LA English DT Editorial Material C1 Univ Puerto Rico, San Juan, PR 00936 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. Univ Puerto Rico, Mayaguez, PR USA. RP Katiyar, RS (reprint author), Univ Puerto Rico, San Juan, PR 00936 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2002 VL 42 BP VII EP X DI 10.1080/10584580210864 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 562JD UT WOS:000176192900001 ER PT J AU Jia, QX Groves, JR Arendt, PN Lu, P Miranda, FA AF Jia, QX Groves, JR Arendt, PN Lu, P Miranda, FA TI Monolithic integration of superconducting YBCO and dielectric SrTiO3 films on polycrystalline ferrites SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT 2nd Ferroelectric Workshop (FWPR-2001) CY JUN 01-02, 2001 CL SAN JUAN, PR DE ferrites; high-temperature superconductors; SrTiO3; thin films ID YTTRIUM-IRON-GARNET AB Monolithic integration of high-temperature superconducting YBCO and nonlinear dielectric SrTiO3 films on polycrystalline yttrium-irongarnet (YIG) substrates represents an advance of great technical significance for dual-tuning (both electrically and magnetically) microwave components. We have solved the problems of crystallographic incompatibility among these materials and the lack of a template for epitaxial growth of SrTiO3 and YBCO films on polycrystalline substrate. Using a template of biaxially oriented MgO, deposited by an ion-beam-assisted-deposition technique, we have produced device quality SrTiO3 and YBCO films on polycrystalline YIG substrates. Both SrTiO3 and YBCO films were c-axis oriented with an in-plane mosaic spread of 7degrees full width at half-maximum (FWHM) for SrTiO3 and less than 7degrees FWHM for YBCO. The YBCO films had transition temperatures above 87 K. C1 Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. New Mexico Inst Min & Technol, Dept Mat Sci & Engn, Socorro, NM 87801 USA. Glenn Res Ctr, Cleveland, OH 44135 USA. RP Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RI Jia, Q. X./C-5194-2008 NR 8 TC 0 Z9 0 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 1058-4587 EI 1607-8489 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2002 VL 42 BP 71 EP 78 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 562JD UT WOS:000176192900007 ER PT J AU Miranda, FA Van Keuls, FW Romanofsky, RR Mueller, CH Alterovitz, S Subramanyam, G AF Miranda, FA Van Keuls, FW Romanofsky, RR Mueller, CH Alterovitz, S Subramanyam, G TI Ferroelectric thin films-based technology for frequency- and phase-agile microwave communication applications SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT 2nd Ferroelectric Workshop (FWPR-2001) CY JUN 01-02, 2001 CL SAN JUAN, PUERTO RICO DE ferroelectric thin films; BaxSr1-xTiO3; phase shifters; K-factor; phased array antennas; K-band frequencies; XRD analysis; ellipsometry ID BAND; SHIFTER AB This paper deals with the current status of thin film ferroelectric-based frequency and phase agile microwave devices for communication applications. Researchers around the world have been active in this area for several years, and their results have been very relevant in determining the advantages and limitations of this technology when contrast with technology currently in use. The aforementioned results will be discussed in terms of device parameters such as RF losses, tunability, phase shift, frequency of operation, ease of fabrication, and projected cost, amongst others. Although the presentation will emphasize a NASA perspective, the information provided should offer a perspective of the attributes of this technology for other government agencies' electronically steerable electronics requirements, and for commercial communication applications. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Dayton, Dayton, OH 45469 USA. RP Miranda, FA (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 14 TC 30 Z9 31 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2002 VL 42 BP 131 EP 149 DI 10.1080/10584580210845 PG 19 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 562JD UT WOS:000176192900011 ER PT J AU Subramanyam, G Mohsina, N Zaman, A Van Keuls, FW Miranda, FA Romanofsky, RR Warner, JD Chen, CL AF Subramanyam, G Mohsina, N Zaman, A Van Keuls, FW Miranda, FA Romanofsky, RR Warner, JD Chen, CL TI Design and development of ferroelectric tunable coplanar waveguide components for Ku- and K-BAND applications SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT 2nd Ferroelectric Workshop (FWPR-2001) CY JUN 01-02, 2001 CL SAN JUAN, PUERTO RICO DE ferroelectric thin-films; coplanar waveguide transmission lines; filters ID THIN-FILM AB In the past several years, we have demonstrated electrically tunable microstrip components such as resonators, filters, diplexers, and couplers based on conductor/ferroelectrics/dielectric two-layered structure. Recently, we are focusing our efforts on tunable coplanar waveguide (CPW) components in collaboration with NASA Glenn Research Center, Cleveland, OH. The advantages of CPW components include higher dielectric tunability compared to microstrip structure, ease of shunt connections, and ease of testing. To date, we have modeled several CPW structures with ferroelectric thin-film to study the effect of inserting the ferroelectric thin-film on electric tunability, attenuation and dispersion. Also, we have designed and fabricated devices such as resonators, and filters. The ferroelectric tunable CPW filters were tunable by more than 3% at bias voltage levels of +/-100V. The BSTO based CPW filters offer higher sensitivity parameter as well as lower loss parameter compared to BSTO tunable 2-pole microstrip filters. C1 Univ Dayton, Dept ECE, Dayton, OH 45469 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. RP Subramanyam, G (reprint author), Univ Dayton, Dept ECE, Dayton, OH 45469 USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2002 VL 42 BP 151 EP 163 DI 10.1080/10584580210844 PG 13 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 562JD UT WOS:000176192900012 ER PT J AU Chen, CL Garrett, T Lin, Y Jiang, JC Meletis, EI Miranda, FA Zhang, Z Chu, WK AF Chen, CL Garrett, T Lin, Y Jiang, JC Meletis, EI Miranda, FA Zhang, Z Chu, WK TI Interface structures and epitaxial behavior of ferroelectric (Ba,Sr)TiO3 thin films SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT 2nd Ferroelectric Workshop (FWPR-2001) CY JUN 01-02, 2001 CL SAN JUAN, PUERTO RICO ID MICROWAVE PROPERTIES; PHASE SHIFTERS; TITANATE AB Perovskite Ba0.6Sr0.4TiO3 thin films were epitaxially grown on (001) LaAlO3 and (001) MgO by using pulsed laser ablation. The films are single crystal cubic structure with interface relationship of (001)BST // (001)(MgO) and <100>(BST) // <100>(MgO) for the films on (001) MgO and (001)(BST) // (001)(LAO) and <100>(BST) // <100>(LAO). High-resolution transmission electron microscopy studies indicated that the initially grown layer of the film on both (001) MgO and (001) LAO is TiO2 monolayer. Equally spaced misfit dislocations were found to form at the interface to release the lattice mismatch energy. Physical property measurements show that the films exhibit excellent room temperature dielectric behavior with very low dielectric loss of 0.007 and very large tenability of 45% at 1 MHz. The figure of merit of 60degrees/dB has been achieved for the microwave phase shifter operated at 24 GHz and room temperature. C1 Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. Louisiana State Univ, Dept Mech Engn, Baton Rouge, LA 70803 USA. Glenn Res Ctr, Commun Technol Div, Cleveland, OH 44135 USA. RP Chen, CL (reprint author), Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. RI lin, yuan/B-9955-2013 NR 14 TC 4 Z9 4 U1 0 U2 9 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2002 VL 42 BP 165 EP 172 DI 10.1080/10584580210843 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 562JD UT WOS:000176192900013 ER PT J AU Van Keuls, FW Mueller, CH Romanofsky, RR Warner, JD Miranda, FA Majumder, SB Jain, M Martinez, A Katiyar, RS Jiang, H AF Van Keuls, FW Mueller, CH Romanofsky, RR Warner, JD Miranda, FA Majumder, SB Jain, M Martinez, A Katiyar, RS Jiang, H TI Evaluation of chemical solution deposited BaxSr1-xTiO3 thin films on LaAlO3 in tunable microwave devices SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT 2nd Ferroelectric Workshop (FWPR-2001) CY JUN 01-02, 2001 CL SAN JUAN, PUERTO RICO DE ferroelectric; tunable; microwave; CSD ID PHASE; FERROELECTRICS; CAPACITORS AB Epitaxial BaxSr1-xTiO3 (BST) films grown on LaAlO3 by several deposition methods have been tested in coupled microstrip phase shifters (CMPS) at frequencies from 10 to 24 GHz. To date the best performance for the devices has been achieved using Pulsed Laser Deposition (PLD). However, recently chemical solution deposition (CSD) methods such as sot-gel and Metal-Organic Chemical Liquid Deposition (MOCLD) have shown advances in fabricating BST films for tunable microwave applications. CSD processes promise improvements in cost, speed and area covered during BST film deposition. This paper compares over 35 BST films used in identical CMPS circuits. In this study, the highest measured figures of merit of phase shift per dB of loss for PLD, MOCLD and sot-gel CMPS are 49, 47 and 41degrees/dB respectively. While other phase shifter designs using BST films have surpassed these values, these data base of identical circuits allows us to compare the BST films. X-ray diffraction characterization for many of the BST films is also given. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Puerto Rico, San Juan, PR 00931 USA. Corning Appl Technol, Woburn, MA 01801 USA. RP Van Keuls, FW (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. OI Jain, Menka/0000-0002-2264-6895 NR 9 TC 8 Z9 8 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2002 VL 42 BP 207 EP 217 DI 10.1080/10584580210851 PG 11 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 562JD UT WOS:000176192900016 ER PT J AU Jain, M Majumder, SB Martinez, A Katiyar, RS Van Keuls, FW Romanofsky, RR Miranda, FA AF Jain, M Majumder, SB Martinez, A Katiyar, RS Van Keuls, FW Romanofsky, RR Miranda, FA TI Highly textured chemical solution deposited Ba0.5Sr0.5Ti1-xMnxO3 (x similar to 0 to 5 at%) thin films for microwave dielectric applications SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT 2nd Ferroelectric Workshop (FWPR-2001) CY JUN 01-02, 2001 CL SAN JUAN, PUERTO RICO DE Mn doped BST thin film; epitaxy; phase shifter; sol-gel ID BARIUM STRONTIUM-TITANATE AB We have optimized the process methodology to grow highly (100) oriented barium strontium titanate (BaxSr1-xTiO3) (x = 0.5 and 0.6) thin films on lattice-matched (100) lanthanum aluminate (LAO) substrates by sol-gel technique. These films exhibited excellent phase shift and insertion loss characteristics at microwave frequencies. The work has been extended to study the effect of manganese (Mn) doping on the nature of epitaxial growth and electrical behavior of (100) oriented Ba0.5Sr0.5TiO3 (BST) thin films. The degree of texturing and quality of the in-plane epitaxy of BST thin films on lanthanum aluminate (LAO) was found to be improved for upto 3 at% Mn doping. These films were characterized in terms of their electrical properties and dielectric behavior at low (1kHz-1MHz) and microwave frequencies. We have fabricated eight-element coupled microstrip phase shifters (CMPS) and tested them in terms of their degree of phase shift and insertion loss characteristics. The phase shift increases from 239 degrees (undoped) to 337 degrees with 3 at% Mn doping. However, the insertion loss also increases (5.4 to 9.9 dB respectively) with the increase in dopant concentration so that effective kappa factor (defined as phase shift/insertion loss) does not improve significantly and remains in the range of 33-44 degrees/dB. The observed electrical properties are correlated with the structure and microstructure of the Mn doped BST films. C1 Univ Puerto Rico, Dept Phys, San Juan, PR 00931 USA. NASA, Glenn Res Ctr, Commun Technol Div, Cleveland, OH 44135 USA. RP Jain, M (reprint author), Univ Puerto Rico, Dept Phys, San Juan, PR 00931 USA. OI Jain, Menka/0000-0002-2264-6895 NR 14 TC 7 Z9 7 U1 0 U2 5 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2002 VL 42 BP 343 EP 355 DI 10.1080/10584580210848 PG 13 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 562JD UT WOS:000176192900025 ER PT J AU Jia, WY Monge, K Xu, WL Katiyar, R AF Jia, WY Monge, K Xu, WL Katiyar, R TI Spectroscopy of pure and Eu3+ doped ZnO SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT 2nd Ferroelectric Workshop (FWPR-2001) CY JUN 01-02, 2001 CL SAN JUAN, PUERTO RICO ID ZINC-OXIDE; PHOTOLUMINESCENCE; ELECTROLUMINESCENCE; LUMINESCENCE; IONS AB Pure and Eu3+ doped ZnO piezoelectric ceramics and thin films were prepared via solid state chemical reaction and by sol-gel method, respectively. Strong green emission band were observed from all samples. Both broad band emission from ZnO and line emission from Eu3+ were observed in the sample ZnO doped with Eu2O3. In contrast to the report in the literature, excitation spectrum showed that energy transfer from ZnO host to Eu ions in these samples was very weak and the transfer was through Eu3+ absorption of the green emission of ZnO. C1 Univ Puerto Rico, Dept Phys, NASA, Trop Ctr Earth & Space Studies, Mayaguez, PR 00681 USA. Univ Puerto Rico, Dept Phys, Rio Piedras, PR 00931 USA. RP Jia, WY (reprint author), Univ Puerto Rico, Dept Phys, NASA, Trop Ctr Earth & Space Studies, Mayaguez, PR 00681 USA. NR 14 TC 11 Z9 11 U1 0 U2 6 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2002 VL 42 BP 357 EP 363 DI 10.1080/10584580210836 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 562JD UT WOS:000176192900026 ER PT S AU Kim, Q Wrigley, CJ Cunningham, TJ Pain, B AF Kim, Q Wrigley, CJ Cunningham, TJ Pain, B BE Sidorin, YS Tervonen, A TI Space qualification of photonic devices SO INTEGRATED OPTICS: DEVICES, MATERIALS, AND TECHNOLOGIES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Integrated Optics - Devices, Materials, and Technologies VI CY FEB 21-23, 2002 CL SAN JOSE, CA SP SPIE DE space qualification; reliability; low power; InGaAsPIN array; InP JFETs array AB Key optical elements for space qualification plans of photonic devices are overviewed. Device parameters and qualifying procedures were discussed to assure the reliability of newly developed photonic devices needed for potential usage in space environments. The goal is to gradually establish enough data to develop a space qualification guideline for devices using empirical and numerical models to assess reliability including the lifetime degradation of devices for long-term space applications. Optical, electrical and mechanical device requirements of newly integrated photonic devices (diode lasers and detector arrays) were presented. Monolithically integrated active pixel InGaAs detector arrays were compared, as examples, with those hybridized with CMOS silicon multiplexers in terms of their performances and reliability. Adapting the existing fiber optical (1.55 mum) communication technology, this integration will be an ideal optoelectronic system for dual band (0.5-2.5 mum, Visible/IR) applications near room temperature for use in geological material research and in atmospheric gas sensing in space. For target identification on earth, however, there are concerns about the effectiveness of the device quality, reliability, and prevention of device failure in preparation for multifunctional, transportable shipboard surveillance, night vision, and emission spectroscopy in air and on Mars terrestrial applications. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kim, Q (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 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 0-8194-4379-4 J9 P SOC PHOTO-OPT INS PY 2002 VL 4640 BP 15 EP 21 DI 10.1117/12.433275 PG 7 WC Instruments & Instrumentation; Materials Science, Characterization & Testing; Optics SC Instruments & Instrumentation; Materials Science; Optics GA BU94S UT WOS:000177443600003 ER PT B AU Yang, G Cunningham, T Ortiz, M Heynssens, J Sun, C Hancock, B Seshadri, S Wrigley, C McCarty, K Pain, B AF Yang, G Cunningham, T Ortiz, M Heynssens, J Sun, C Hancock, B Seshadri, S Wrigley, C McCarty, K Pain, B BE Deen, MJ Misra, D Ruzyllo, J TI Integrated imaging sensor systems with CMOS active pixel sensor technology SO INTEGRATED OPTOELECTRONICS, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 1st International Symposium on Integrated Electronics CY MAY 12-17, 2002 CL PHILADELPHIA, PA SP Electrochem Soc, Electr Div, Electrochem Soc, Dielect Sci & Technol Div AB The availability of mature sub-micron CMOS technology has enabled the development of high performance active pixel sensor (APS) imagers and made possible the realization of drawing electronic imager technology into the mainstream of CMOS system-on-a-chip technology. The primary advantages of this CMOS APS imager technology are low-cost, low-power, simple digital interface, random access, simplicity of operation, high speed, miniaturization through system integration and improved functionality by incorporating on-chip signal processing circuits. This paper discusses common approaches to CMOS APS technology, as well as specific results on the five-wire programmable digital camera-on-a-chip developed at JPL. The paper also reports recent research in the design, operation, and performance of APS imagers for several imager applications. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yang, G (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-315, Pasadena, CA 91109 USA. NR 32 TC 0 Z9 0 U1 0 U2 1 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-370-9 J9 ELEC SOC S PY 2002 VL 2002 IS 4 BP 399 EP 430 PG 32 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BW03A UT WOS:000180671400023 ER PT B AU Tunstel, E Huntsberger, T Trebi-Ollennu, A Aghazarian, H Garrett, M Leger, C Kennedy, B Baumgartner, E Schenker, P AF Tunstel, E Huntsberger, T Trebi-Ollennu, A Aghazarian, H Garrett, M Leger, C Kennedy, B Baumgartner, E Schenker, P BE Gini, M Shen, WM Torras, C Yuasa, H TI FIDO rover system enhancements for high-fidelity mission Simulations SO INTELLIGENT AUTONOMOUS SYSTEMS 7 LA English DT Proceedings Paper CT 7th International Conference on Intelligent Autonomous Systems (IAS-7) CY 2001 CL MARINA DEL REY, CA SP Intelligent Autonomous Syst Soc AB The FIDO (Field Integrated Design & Operations) rover is an advanced mobility platform and research prototype for future Mars surface missions planned by NASA. It was used in a recent field trial aimed at realistic simulation of the 2003 NASA Mars Exploration Rovers (MER) mission. This paper reports the key system enhancements made to improve the utility of the FIDO rover as a platform for high-fidelity, physical simulation of Mars surface missions. We describe the approach taken to improve miss ion-relevant fidelity of the rover system in support of resource modeling, contingency sequencing, and added rover functionality as proposed for the actual mission. This is followed by a brief overview of autonomy technologies demonstrated in the field trial, infused into the flight mission, and advanced relative to the current mission baseline. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tunstel, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU I O S PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS BN 1-58603-239-9 PY 2002 BP 349 EP 356 PG 8 WC Computer Science, Artificial Intelligence; Robotics SC Computer Science; Robotics GA BU34L UT WOS:000175726200048 ER PT S AU Aist, G Kort, B Reilly, R Mostow, J Picard, R AF Aist, G Kort, B Reilly, R Mostow, J Picard, R BE Cerri, SA Gouarderes, G Paraguacu, F TI Adding human-provided emotional scaffolding to an automated reading tutor that listens increases student persistence SO INTELLIGENT TUTORING SYSTEMS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 6th International Conference on Intelligent Tutoring Systems CY JUN 02-07, 2002 CL SAN SEBASTIAN, SPAIN SP Assoc Comp Machinery, Int Federat Informat Processing, Artificial Intelligence Educ Soc, IEEE CS Learning Technol Task Force, French Direct Gen Armement, Asociac Espanola Inteligencia Artificial C1 MIT, Media Lab, Cambridge, MA 02139 USA. NASA, Ames Res Ctr, Adv Comp Sci Res Inst, Moffett Field, CA 94035 USA. Carnegie Mellon Univ, Project LISTEN, RINSH 4213, Pittsburgh, PA 15213 USA. RP Aist, G (reprint author), MIT, Media Lab, Bldg E15,77 Massachusetts Ave, Cambridge, MA 02139 USA. RI Picard, Rosalind/A-5095-2009 OI Picard, Rosalind/0000-0002-5661-0022 NR 0 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-43750-9 J9 LECT NOTES COMPUT SC PY 2002 VL 2363 BP 992 EP 992 PG 1 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA BV79M UT WOS:000180067900099 ER PT S AU Decker, AJ AF Decker, AJ BE Osten, W TI Interferometer control of optical tweezers SO INTERFEROMETRY XI: APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry XI Techniques, Analysis and Applications CY JUL 08-11, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington State Univ, Coll Engn & Architecture, Washington Technol Ctr, Univ Washington, Coll Engn DE interferometry; optical tweezers; nanotechnology ID PHASE AB This paper discusses progress in using spatial light modulators and interferometry to control the beam profile of an optical tweezers. The approach being developed is to use a spatial light modulator (SLM) to control the phase profile of the tweezers beam and to use a combination of the SLM and interferometry to control the intensity profile. The objective is to perform fine and calculable control of the moments and forces on a tip or tool to be used to manipulate and interrogate nanostructures. The performance of the SLM in generating multiple and independently controllable tweezers beams is also reported. Concurrent supporting research projects are mentioned and include tweezers beam scattering and neural-net processing of the interference patterns for control of the tweezers beams. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Decker, AJ (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 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 0-8194-4545-2 J9 P SOC PHOTO-OPT INS PY 2002 VL 4778 BP 142 EP 149 DI 10.1117/12.473537 PG 8 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA BV10H UT WOS:000177818000017 ER PT S AU Papalexandris, MV Waluschka, E AF Papalexandris, MV Waluschka, E BE Creath, K Schmit, J TI Numerical phase front propagation for the laser interferometer space antenna SO INTERFEROMETRY XI: TECHNIQUES AND ANALYSIS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry XI Techniques, Analysis and Applications CY JUL 08-11, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington State Univ, Coll Engn & Architecture, Washington Technol Ctr, Univ Washington, Coll Engn DE numerical beam propagation; tilt sensitivity; interferometry AB The present article reports on numerical studies of phase front propagation for the Laser Interferometer Space Antenna (LISA). The main objective is to determine the sensitivity of the average phase of the metrology beam with respect to fluctuations of the pointing of the beam. For this purpose, the metrology beam is propagated numerically along the interferometric arm of the instrument. The effects of the obscurations from the secondary mirror and its supporting struts axe studied in detail. Further, the effects of random wavefront distortions that occur due to imperfections of the optical elements are estimated through a series of Monte Carlo simulations. The results of this study can be used to determine design requirements for the instrument. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Papalexandris, MV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 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 0-8194-4544-4 J9 P SOC PHOTO-OPT INS PY 2002 VL 4777 BP 168 EP 176 DI 10.1117/12.472216 PG 9 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA BV10G UT WOS:000177817900019 ER PT S AU Nikora, AP AF Nikora, AP GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Maintenance issues for very long-lived robotic space systems SO INTERNATIONAL CONFERENCE ON SOFTWARE MAINTENANCE, PROCEEDINGS SE PROCEEDINGS - IEEE INTERNATIONAL CONFERENCE ON SOFTWARE MAINTENANCE LA English DT Proceedings Paper CT 18th International Conference on Software Maintenance CY OCT 03-06, 2002 CL MONTREAL, CANADA SP IEEE Comp Soc Tech Council Software Engn C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nikora, AP (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 IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 1063-6773 BN 0-7695-1819-2 J9 PROC IEEE INT CONF S PY 2002 BP 471 EP 471 DI 10.1109/ICSM.2002.1167805 PG 1 WC Computer Science, Software Engineering SC Computer Science GA BV44N UT WOS:000178983800058 ER PT S AU Hoover, RB Rozanov, AY AF Hoover, RB Rozanov, AY BE Kumakhov, MA TI Astrobiology: Traces of life in the cosmos SO INTERNATIONAL CONFERENCE ON X-RAY AND NEUTRON CAPILLARY OPTICS SE Proceedings of SPIE-The International Society for Optical Engineering LA English DT Proceedings Paper CT International Conference on X-ray and Neutron Capillary Optics CY SEP 08-12, 2001 CL ZVENIGOROD, RUSSIA SP Inst Roentgen Ipt, Russian Federat, Minist Ind, Sci & Technologies, Russian Fdn Basic Res, SPIE, SPIE Russia Chapter DE astrobiology; biomarkers; microfossils; meteorites; microbial extremophiles; Mars; Io; Europa ID MASSIVE SULFIDE DEPOSIT; EARLY SOLAR-SYSTEM; MURCHISON METEORITE; CARBONACEOUS CHONDRITES; ORGUEIL METEORITE; AMINO-ACIDS; MAGNETOTACTIC BACTERIA; ORGANIC COMPOUNDS; ALIPHATIC-HYDROCARBONS; AROMATIC HYDROCARBONS AB The discovery of traces of life (chemical, mineral, and morphological biomarkers/microfossils) in the ancient Mars meteorite (ALH84001) triggered the development of the rapidly emerging field of Astrobiology. Astrobiologists are seeking to develop conclusive methods to recognize biosignatures and microfossils of bacteria and other microbiota as well as to understand the spatial, temporal, environmental and chemical limitations of microbial extremophiles. Recent discoveries have revealed the great distribution and diversity of microbial extremophiles on Earth and profoundly increased the probability that life may exist elsewhere in the Cosmos. The rapidly emerging science of Bacterial Paleontology has provided important new information critical to the recognition of fossil bacteria on Earth and in Astromaterials. We have recently conducted independent scanning electron microscopy and x-ray analysis investigations in the United States and Russia in order to better understand the morphology and chemical composition of microfossils in ancient terrestrial rocks and carbonaceous meteorites. In this paper, we review some aspects of microbial extremophiles of Earth as modals for life on other bodies of the Solar System. We consider several of the important chemical, mineral and morphological biomarkers that provide definitive evidence of biogenic activity in ancient rocks and meteorites. We present Environmental Scanning Electron Microscope (ESEM) images of microfossils found in-situ in freshly fractured meteorite surfaces and describe Energy Dispersive Spectroscopy (EDS) and Link microprobe analysis of the chemical elements in the mineralized and/or kerogenous microfossils and meteorite rock matrix. We also discuss techniques and methods that may be used to help discriminate indigenous microfossils from recent terrestrial contaminants. We will also present new data from our in-situ investigations of living cyanobacteria and bacteria and freshly broken surfaces of terrestrial rocks and meteorites. Comparative analysis of these images are interpreted as providing dramatic evidence of indigenous microfossils of magnetotactic bacteria, cyanobacteria, and acritarchs in the Nogoya, Efremovka, Orgueil, Murchison and Tagish Lake Meteorites. Many of the forms in carbonaceous meteorites are large and complex providing strong evidence of biogenicity. Many of the forms found in carbonaceous meteorites are strikingly similar to microfossils of bacteria, cyanobacteria and fungi we know from the Cambrian phosphorites of Khubsugul, Mongolia and high carbon Phanerozoic and Precambrian rocks of the Siberian and Russian Platforms. Some meteorite microfossil assemblages are consistent with known characteristics of distinct microbial life cycles and reproductive stages of Nostocacean cyanobacteria (including trichomes, spores, and hormogonia). We also recognize assemblages consistent with microbial ecosystems we studied in permafrost and cryoconite communities of Antarctica, Alaska and Siberia and microfossil ecosystems from the Cambrian of Mongolia. C1 NASA, George C Marshall Space Flight Ctr, Space Sci Dept SD50, Huntsville, AL 35812 USA. RP Hoover, RB (reprint author), NASA, George C Marshall Space Flight Ctr, Space Sci Dept SD50, Huntsville, AL 35812 USA. EM Richard.Hoover@msfc.nasa.gov; aroza@paleo.ru NR 131 TC 2 Z9 2 U1 4 U2 13 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4532-0 J9 P SOC PHOTO-OPT INS PY 2002 VL 4765 BP 1 EP 19 DI 10.1117/12.454756 PG 19 WC Optics; Physics, Applied; Imaging Science & Photographic Technology SC Optics; Physics; Imaging Science & Photographic Technology GA BV34M UT WOS:000178619800001 ER PT B AU Pain, B Cunningham, TJ Hancock, B Yang, G Seshadri, S Ortiz, A AF Pain, B Cunningham, TJ Hancock, B Yang, G Seshadri, S Ortiz, A GP ELECTRONIC DEVICES SOCIETY OF IEEE ELECTRONIC DEVICES SOCIETY OF IEEE TI Reset noise suppression in two-dimensional CMOS photodiode pixels through column-based feedback-reset SO INTERNATIONAL ELECTRON DEVICES 2002 MEETING, TECHNICAL DIGEST LA English DT Proceedings Paper CT IEEE International Electron Devices Meeting CY DEC 08-11, 2002 CL SAN FRANCISCO, CA SP IEEE Elect Devices Soc AB We present a new CMOS photodiode imager pixel with ultra-low read noise through on-chip suppression of reset noise via column-based feedback circuitry. In a 0.5 mum CMOS process, the pixel occupies only 10x10mum(2) area. Data from a 256(2) CMOS imager indicates imager operation with read noise as low as 6 electrons without employing on- or off-chip correlated double sampling. The noise reduction is achieved without introducing any image lag, and with insignificant reduction in quantum efficiency and full-well. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM bpain@jpl.nasa.gov NR 7 TC 14 Z9 14 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7462-2 PY 2002 BP 809 EP 812 PG 4 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic; Physics, Applied SC Computer Science; Engineering; Physics GA BX39L UT WOS:000185143400186 ER PT J AU Prinzel, LJ Pope, AT Freeman, FG AF Prinzel, LJ Pope, AT Freeman, FG TI Physiological self-regulation and adaptive automation SO INTERNATIONAL JOURNAL OF AVIATION PSYCHOLOGY LA English DT Article ID PILOT PERFORMANCE; MOTION SICKNESS; TASK ALLOCATION; TRACKING TASK; EEG ACTIVITY; SYSTEM; VIGILANCE; INDEXES; ISSUES AB Adaptive automation has been proposed as a solution to Current problems of human-automation interaction. Past research has shown the potential of this advanced form of automation to enhance pilot engagement and lower cognitive workload. However, there have been concerns voiced regarding issues, such as automation surprises, associated with the use of adaptive automation. This study examined the use of psychophysiological self-regulation training with adaptive automation that may help pilots deal with these problems through the enhancement;of cognitive resource management skills. Eighteen participants were assigned to 3 3 groups (self-regulation training, false feedback, and control) and performed resource management, monitoring, and tracking tasks from the Multiple Attribute Task Battery. The tracking task was cycled between 3 levels of task difficulty (automatic, adaptive aiding, manual) on the basis of the electroencephalogram-derived engagement index. The other two tasks remained in automatic mode that had a single automation failure. Those participants who had received self-regulation training performed significantly better and reported lower National Aeronautics and Space Administration Task Load Index scores than participants in the false feedback and control groups. The theoretical and practical implications of these results for adaptive automation are discussed. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Old Dominion Univ, Norfolk, VA 23529 USA. RP Prinzel, LJ (reprint author), NASA, Langley Res Ctr, MS152, Hampton, VA 23681 USA. NR 49 TC 10 Z9 10 U1 1 U2 9 PU LAWRENCE ERLBAUM ASSOC INC PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430-2262 USA SN 1050-8414 J9 INT J AVIAT PSYCHOL JI Int. J. Aviat. Psychol. PY 2002 VL 12 IS 2 BP 179 EP 196 DI 10.1207/S15327108IJAP1202_5 PG 18 WC Psychology, Applied SC Psychology GA 589JA UT WOS:000177754100004 ER PT J AU Baker, DP Dismukes, RK AF Baker, DP Dismukes, RK TI Special issue on training instructors to evaluate aircrew performance SO INTERNATIONAL JOURNAL OF AVIATION PSYCHOLOGY LA English DT Editorial Material C1 Amer Inst Res, Washington, DC 20007 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Baker, DP (reprint author), Amer Inst Res, 100 Thomas Jefferson St NW, Washington, DC 20007 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU LAWRENCE ERLBAUM ASSOC INC PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430-2262 USA SN 1050-8414 J9 INT J AVIAT PSYCHOL JI Int. J. Aviat. Psychol. PY 2002 VL 12 IS 3 BP 203 EP 204 DI 10.1207/S15327108IJAP1203_1 PG 2 WC Psychology, Applied SC Psychology GA 613DP UT WOS:000179116700001 ER PT J AU Baker, DP Dismukes, RK AF Baker, DP Dismukes, RK TI A framework for understanding crew performance assessment issues SO INTERNATIONAL JOURNAL OF AVIATION PSYCHOLOGY LA English DT Article ID APPRAISAL AB The focus of this special issue is on training pilot instructors to assess crew performance. In this opening article we attempt to set the stage for the other articles in this issue by introducing a framework for understanding crew-performance assessment. We use this framework to outline issues that should be addressed when training pilot instructors, and we point to specific articles in the special issue that begin to answer these questions. We also look to literature from domains outside aviation psychology for guidance. Research on performance appraisal in the field of industrial psychology provides techniques and knowledge relevant to training instructors to evaluate crews reliably and validly. We conclude with a series of research questions that should be addressed. C1 Amer Inst Res, Washington, DC 20007 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Baker, DP (reprint author), Amer Inst Res, 1000 Thomas Jefferson St NW, Washington, DC 20007 USA. NR 19 TC 7 Z9 8 U1 1 U2 1 PU LAWRENCE ERLBAUM ASSOC INC PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430-2262 USA SN 1050-8414 J9 INT J AVIAT PSYCHOL JI Int. J. Aviat. Psychol. PY 2002 VL 12 IS 3 BP 205 EP 222 DI 10.1207/S15327108IJAP1203_2 PG 18 WC Psychology, Applied SC Psychology GA 613DP UT WOS:000179116700002 ER PT J AU Mulqueen, C Baker, DP Dismukes, RK AF Mulqueen, C Baker, DP Dismukes, RK TI Pilot instructor rater training: The utility of the multifacet item response theory model SO INTERNATIONAL JOURNAL OF AVIATION PSYCHOLOGY LA English DT Article ID RELIABILITY AB A multifacet 1-parameter item response theory (i.e., Rasch) model was used to examine interrater reliability training for pilot instructors. This model provides a means for examining individual instructor leniency or severity in ratings, difficulty of grade-sheet items, skill levels of flight crews, and interactions among these components. It was found that pilot instructor trainees differed in their levels of rating severity, and that higher crew resource management scores were easier to achieve than technical scores. Interaction analyses identified several pilot instructors who were evaluating crews in an unexpected manner, which is useful when providing feedback during training. C1 Amer Inst Res, Washington, DC 20007 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Mulqueen, C (reprint author), Amer Inst Res, 1000 Thomas Jefferson St NW, Washington, DC 20007 USA. NR 17 TC 3 Z9 3 U1 1 U2 2 PU LAWRENCE ERLBAUM ASSOC INC PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430-2262 USA SN 1050-8414 J9 INT J AVIAT PSYCHOL JI Int. J. Aviat. Psychol. PY 2002 VL 12 IS 3 BP 287 EP 303 DI 10.1207/S15327108IJAP1203_6 PG 17 WC Psychology, Applied SC Psychology GA 613DP UT WOS:000179116700006 ER PT J AU Corless, M Swei, SM Rotea, MA AF Corless, M Swei, SM Rotea, MA TI System order reduction in the stabilization of multi-block uncertain systems SO INTERNATIONAL JOURNAL OF CONTROL LA English DT Article ID LINEAR-SYSTEMS; QUADRATIC STABILIZABILITY; ROBUST STABILIZATION AB We consider the problem of robust stabilization of a class of systems which contain several uncertain/non-linear terms. We present two order reduction procedures which permit one to reduce the stabilization problem for the original system to a stabilization problem for a system containing fewer state variables and possibly fewer uncertain terms. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. RP Swei, SM (reprint author), NASA, Ames Res Ctr, Mail Stop 210-5, Moffett Field, CA 94035 USA. RI Corless, Martin/F-2299-2011 NR 14 TC 0 Z9 0 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK,, ABINGDON OX14 4RN, OXON, ENGLAND SN 0020-7179 J9 INT J CONTROL JI Int. J. Control PD JAN PY 2002 VL 75 IS 2 BP 69 EP 79 DI 10.1080/00207170110067099 PG 11 WC Automation & Control Systems SC Automation & Control Systems GA 512BK UT WOS:000173301100001 ER PT J AU Pan, B Shang, DY Li, BQ de Groh, HC AF Pan, B Shang, DY Li, BQ de Groh, HC TI Magnetic field effects on g-jitter induced flow and solute transport SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID SEMICONDUCTOR CRYSTAL-GROWTH; CONVECTION; MICROGRAVITY AB Numerical modeling and analyses are presented of magnetic damping of g-jitter driven fluid flow and its effect on the solutal striation in a simplified Bridgman-Stockbarger crystal growth system under microgravity. The model development is based on the finite element solution of the momentum, energy and solute transport equations under g-jitter conditions in the presence of an external magnetic field. The numerical model is verified by comparison with analytical solutions obtained for a simple parallel plate channel flow driven by g-jitter in a transverse magnetic field. Simulations are carried out to study the behavior of convective flow and solutal transport induced by the combined g-fitter and magneto hydrodynamic forces. Both the idealized single frequency g-jitter force and the real g-jitter perturbation taken during space flight are considered. Results indicate that an applied magnetic field can effectively damp the velocity caused by g-jitter and help to reduce the time variation of solute redistribution. A stronger applied field is more effective in suppressing the convective flows and hence reducing concentration variation. It is found that g-jitter driven flows have the same oscillation period as the driving force with or without the applied field. However, an applied magnetic field shortens the transient period over which the flow field evolves into a quasi-steady state time harmonic oscillation after g-jitter sets in. The flow intensity increases with an increase in g-jitter magnitude but decreases with an increase in the applied field strength. The reduced convection in the liquid pool by the applied magnetic field results in a reduction of the concentration oscillation. The magnetic field is very useful in suppressing the spiking velocities that are induced by the spikes in the real g-jitter data. The damping effect is more pronounced if the magnetic field is switched on before the onset of g-jitter disturbances. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Washington State Univ, Sch Management & Mat Engn, Pullman, WA 99164 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Li, BQ (reprint author), Washington State Univ, Sch Management & Mat Engn, POB 642920, Pullman, WA 99164 USA. NR 20 TC 13 Z9 14 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD JAN PY 2002 VL 45 IS 1 BP 125 EP 144 DI 10.1016/S0017-9310(01)00137-5 PG 20 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 490WF UT WOS:000172076200012 ER PT J AU Jacko, JA Salvendy, G Sainfort, F Emery, VK Akoumianakis, D Duffy, VG Ellison, J Gant, DB Gill, Z Ji, YG Jones, PM Karsh, BT Karshmer, AI Lazar, J Peacock, B Resnick, ML Sears, A Smith, MJ Stephanidis, C Ziegler, J AF Jacko, JA Salvendy, G Sainfort, F Emery, VK Akoumianakis, D Duffy, VG Ellison, J Gant, DB Gill, Z Ji, YG Jones, PM Karsh, BT Karshmer, AI Lazar, J Peacock, B Resnick, ML Sears, A Smith, MJ Stephanidis, C Ziegler, J TI Intranets and organizational learning: A research and development agenda SO INTERNATIONAL JOURNAL OF HUMAN-COMPUTER INTERACTION LA English DT Article ID PERCEPTIONS; FUTURES; IMPACT AB This article presents the outcomes of a technical symposium on the topic of the use of intranets as a tool for organizational learning, which was conducted at the 9th International Conference on Human-Computer Interaction, held in New Orleans, Louisiana, August 5 through 10, 2001. The objective of the symposium was to derive, based on the collective intelligence of experts, an agenda for research and development (R&D) concerning the use of intranet for organizational learning for the short, medium, and long term. Expert knowledge of this research area was acquired and assimilated through the symposium, which was composed of technical paper presentations and a full-day "white paper" session, as well as pre- and post-symposium survey dissemination and analysis. The current state of knowledge and resulting agenda for R&D are reported, and 4 critical areas are emphasized: organizational rules, norms and structures; changes in the nature of work; knowledge manipulation; and technology issues. C1 Georgia Inst Technol, Atlanta, GA 30332 USA. Purdue Univ, W Lafayette, IN 47907 USA. Natl Tsing Hua Univ, Hsinchu, Taiwan. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Wisconsin, Madison, WI USA. Univ S Florida, Tampa, FL 33620 USA. Towson Univ, Towson, MD USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Florida Int Univ, Miami, FL 33199 USA. Mississippi State Univ, Mississippi State, MS 39762 USA. Indiana Univ, Bloomington, IN 47405 USA. RP Georgia Inst Technol, 765 Ferst Dr, Atlanta, GA 30332 USA. OI Jones, Patricia/0000-0002-1519-5774 NR 79 TC 8 Z9 8 U1 1 U2 7 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 1044-7318 EI 1532-7590 J9 INT J HUM-COMPUT INT JI Int. J. Hum.-Comput. Interact. PY 2002 VL 14 IS 1 BP 93 EP 130 DI 10.1207/S15327590IJHC1401_3 PG 38 WC Computer Science, Cybernetics; Ergonomics SC Computer Science; Engineering GA 551UD UT WOS:000175579400003 ER PT J AU Lesuer, DR Syn, CK Whittenberger, JD Sherby, OD AF Lesuer, DR Syn, CK Whittenberger, JD Sherby, OD TI Flow stresses in metal laminates and pure metals during high temperature extrusion SO INTERNATIONAL JOURNAL OF PLASTICITY LA English DT Article DE thermomechanical processing; extrusion; layered material; coefficient of friction; constitutive behavior; creep; strengthening mechanisms ID ULTRAHIGH-CARBON-STEELS; STRAIN-RATE SUPERPLASTICITY; SOLID-SOLUTION ALLOYS; INTERMEDIATE TEMPERATURES; ELEVATED-TEMPERATURE; STAINLESS-STEEL; CREEP; AL; MICROSTRUCTURE; DEPENDENCE AB The flow stresses developed during elevated temperature extrusion in laminated metal composites are analyzed. The laminates consist either of ultrahigh carbon steels (UHCSs) or NiAl jacketed in a mild steel can. Flow stresses in the individual components of the laminate were determined by utilizing an isostrain model and by establishing the true coefficient of friction during extrusion. The average coefficient of friction was found equal to about 0.38 for UHCSs and 0.32 for NiAl. The results reveal that plastic flow of the UHCSs is a diffusion-controlled dislocation creep process. An increase in carbon content leads to a decrease in the flow stress because iron atom mobility is increased. An increase in substitutional solid solution alloy additions leads to an increase in the flow stress because of a decrease in the stacking fault energy. The influence of strain rate sensitivity of each component on the extrusion of laminated composites is modeled. It is shown that striking differences in extrusion response are achieved by altering the volume fraction and strain rate sensitivity of the component materials. The analysis of extrusion is extended to interpret Pearson and Smythe's 1931 data on extrusion of lead, tin and cadmium. These data are also shown to be well characterized by a diffusion-controlled dislocation creep process. Coefficients of friction for extrusion were determined for these three metals. These results, together with those for the UHCSs and NiAl, indicate that the friction coefficient is a function of the flow stress of the metal during extrusion, increasing in value as the flow stress decreases. It is proposed that this trend is principally related to microstructural changes that are unique to the process of extrusion. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. RP Syn, CK (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 62 TC 3 Z9 3 U1 2 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0749-6419 J9 INT J PLASTICITY JI Int. J. Plast. PY 2002 VL 18 IS 2 BP 155 EP 184 DI 10.1016/S0749-6419(00)00074-7 PG 30 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA 521EL UT WOS:000173826200002 ER PT J AU Vicente, GA Davenport, JC Scofield, RA AF Vicente, GA Davenport, JC Scofield, RA TI The role of orographic and parallax corrections on real time high resolution satellite rainfall rate distribution SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID PRECIPITATION AB This research presents a step by step description of the procedure to correct high resolution satellite rainfall estimation for parallax error and orographic effects, and shows how these adjustments can be performed on any satellite rainfall estimation technique. The procedure is tested on the experimental automatic rainfall estimation technique currently in use by the National Environment Satellite Data, and Information Service (NESDIS), at the National and Oceanic Administration (NOAA). C1 NASA, Raytheon ITSS, GSFC, DAAC, Greenbelt, MD 20771 USA. NOAA, NESDIS, Off Res & Applicat, WWB, Camp Springs, MD 20746 USA. RP Vicente, GA (reprint author), NASA, Raytheon ITSS, GSFC, DAAC, Code 902, Greenbelt, MD 20771 USA. NR 11 TC 56 Z9 56 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD JAN PY 2002 VL 23 IS 2 BP 221 EP 230 DI 10.1080/01431160010006935 PG 10 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 496XZ UT WOS:000172424800002 ER PT J AU Wunenburger, R Garrabos, Y Lecoutre, C Beysens, D Hegseth, J Zhong, F Barmatz, M AF Wunenburger, R Garrabos, Y Lecoutre, C Beysens, D Hegseth, J Zhong, F Barmatz, M TI Thermal response of a two-phase near-critical fluid in low gravity: Strong gas overheating as due to a particular phase distribution SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Chem Sci & Technol Lab, Phys & Chem Properties Div, Amer Soc Mech Engineers, Div Heat Transfer, Comm Thermophys Properties, Phys & Chem Properties Div HO UNIV COLORADO DE adiabatic compression; low gravity; near-critical fluid; two-phase heat and mass transfer ID VAPOR CRITICAL-POINT; THAN-T-C; PURE FLUID; DENSITY EQUILIBRATION; HEAT-TRANSPORT; MICROGRAVITY; RELAXATION; REGION; PROPAGATION; DYNAMICS AB Am experimental study of the thermal response to a stepwise rise of the wall temperature of two-phase near-critical SF6 in low gravity for an initial temperature ranging from 0.1 to 10.1 K from the critical temperature is described. The change in the vapor temperature with time considerably exceeds the change in the wall temperature (overheating by up to 23% of the wall temperature rise). This strong vapor overheating phenomenon results from the inhomogeneous adiabatic heating process occurring in the two-phase near-critical fluid while the vapor bubble is thermally isolated from the thermostated walls by the liquid. One-dimensional numerical simulations of heat transfer in near-critical two-phase He-3 confirm this explanation. The influence of heat and mass transfer between.-as and liquid occurring at short time scales on the thermal behavior is analyzed. A model for adiabatic heat transfer, which neglects phase change but accounts for the difference between the thermophysical. properties of the vapor and those of the liquid, is presented. A new characteristic time scale of adiabatic heat transfer is derived, which is found to be larger than that in a one-phase liquid and vapor. C1 Univ Bordeaux 1, UPR CNRS 9048, Inst Chim Mat Condensee Bordeaux, Equipe Supercrit Environm Mat & Espace, F-33608 Pessac, France. CEA, Serv Basses Temp, Equipe Supercrit Environm Mat & Espace, F-38054 Grenoble 9, France. Univ New Orleans, Dept Phys, New Orleans, LA 70148 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wunenburger, R (reprint author), Univ Bordeaux 1, UPR CNRS 9048, Inst Chim Mat Condensee Bordeaux, Equipe Supercrit Environm Mat & Espace, Ave Dr A Schweitzer, F-33608 Pessac, France. RI Lecoutre, Carole/H-3367-2013; Garrabos, Yves/H-5404-2013 NR 22 TC 6 Z9 6 U1 0 U2 2 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD JAN PY 2002 VL 23 IS 1 BP 103 EP 115 DI 10.1023/A:1013948925906 PG 13 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 527MX UT WOS:000174190800008 ER PT J AU Dorney, DJ Croft, RR Sondak, DL Stang, UE Twardochleb, CZ AF Dorney, DJ Croft, RR Sondak, DL Stang, UE Twardochleb, CZ TI Computational study of clocking an embedded stage in a 4-stage industrial turbine SO INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES LA English DT Article ID LOW-PRESSURE TURBINE; AXIAL COMPRESSOR; PERFORMANCE IMPROVEMENT; AIRFOIL CLOCKING; BLADE AB Multi-stage turbines have inherently unsteady flow fields because of relative motion between rotating and stationary airfoil rows. This relative motion leads to viscous and inviscid interactions between blade rows. As the number of stages increases in a turbomachine, the buildup of convected wakes can lead to progressively more complex wake/wake and wake/airfoil interactions. Variations in the relative circumferential positions of air-foils in adjacent rotating or non-rotating blade rows can alter these interactions, leading to different time-averaged losses and stage efficiencies. In addition, interaction between blade rows can intensify with increasing Mach number due to potential effects. It has been shown in previous studies, both experimental and computational, that airfoil clocking can be used to improve the efficiency and reduce the unsteadiness in multiple-stage axial turbomachines with equal blade counts. While previous investigations have for the most part focused on two-stage turbines, the goal of the current research is to evaluate the effects of clocking an embedded stage within a larger turbine system. Quasi-three-dimensional simulations of airfoil clocking have been performed for a four-stage industrial turbine. Time-averaged and unsteady data (including performance quantities) are presented. The results show a 0.5% efficiency variation in the stage where the vanes were clocked, and smaller efficiency variations in the upstream and downstream stages. The overall efficiency of the turbine system varies with the efficiency of the clocked stage, although by a smaller amount. C1 Virginia Commonwealth Univ, Richmond, VA 23298 USA. Boston Univ, Boston, MA 02215 USA. Solar Turbines, San Diego, CA USA. RP Dorney, DJ (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-0082 J9 INT J TURBO JET ENG JI Int. J. Turbo. Jet-Engines PY 2002 VL 19 IS 1-2 BP 21 EP 31 PG 11 WC Engineering, Aerospace SC Engineering GA 572YL UT WOS:000176802500003 ER PT J AU Dorney, DJ Sondak, DL AF Dorney, DJ Sondak, DL TI Three-dimensional Simulations of airfoil clocking in a 1-1/2 stage turbine SO INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES LA English DT Article ID AXIAL COMPRESSOR; PERFORMANCE AB Axial turbines have inherently unsteady flow fields because of the relative motion between rotor and stator airfoils. This relative motion leads to viscous and inviscid interactions between blade rows. As the number of stages increases in a turbomachine, the buildup of convected wakes can lead to progressively more complex wake/wake and wake/airfoil interactions, Variations in the relative circumferential positions of airfoils in adjacent rotating or non-rotating blade rows can change these interactions, leading to different unsteady forcing functions on airfoils and different turbine efficiencies. In addition, as the Mach number increases the interaction between blade rows can be intensified due to potential effects. It has been shown, both experimentally and computationally, that airfoil clocking can be used to improve the efficiency and reduce the unsteadiness in multiple-stage axial turbomachines with equal blade counts. While previous investigations have provided an improved understanding of the physics associated with air-foil clocking, most of the work focused on two-dimensional effects. More research is needed to determine how airfoil clocking can be incorporated in the design of three-dimensional airfoils. In the current study three-dimensional simulations of airfoil clocking have been performed for a 1 (1)/(2) stage high-pressure turbine operating at subsonic flow conditions. Comparisons have been made with the available time-averaged experimental data at a single clocking position. The predicted results indicate approximately a 1% efficiency variation as the second-stage airfoils are clocked with respect to the first-stage stator airfoils. C1 Virginia Commonwealth Univ, Richmond, VA 23284 USA. Boston Univ, Boston, MA 02215 USA. RP Dorney, DJ (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-0082 J9 INT J TURBO JET ENG JI Int. J. Turbo. Jet-Engines PY 2002 VL 19 IS 1-2 BP 33 EP 45 PG 13 WC Engineering, Aerospace SC Engineering GA 572YL UT WOS:000176802500004 ER PT J AU Dorney, DJ Merz, LF Sondak, DL Damle, SV Stringham, J AF Dorney, DJ Merz, LF Sondak, DL Damle, SV Stringham, J TI Performance improvements in an industrial compressor through airfoil clocking SO INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES LA English DT Article ID AXIAL COMPRESSOR; TURBINE AIRFOILS; SIMULATIONS AB Axial compressors have inherently unsteady flow fields because of relative motion between rotating and stationary airfoil rows. This relative motion leads to viscous and inviscid interactions between blade rows. As the number of stages increases in a turbomachine, the buildup of convected wakes can lead to progressively more complex wake/wake and wake/airfoil interactions. Variations in the relative circumferential positions of airfoils in adjacent rotating or non-rotating blade rows can change these interactions, leading to different time-averaged losses and stage efficiencies. As the Mach number increases the interaction between blade rows can be intensified due to potential effects. It has been shown, both experimentally and computationally, that airfoil clocking can be used to improve the efficiency and reduce the unsteadiness in multiple-stage axial turbomachines with equal blade counts. While previous investigations have focused on idealized geometries, the goal of the current research is to improve the performance of a compressor used in a production industrial gas turbine. Quasi three-dimensional simulations have been performed using both simplified and actual blade counts. Time-averaged and unsteady data (including performance quantities) are presented. In addition, a technique is introduced for determining the optimum clocking position during the early stages of the design process. C1 Virginia Commonwealth Univ, Richmond, VA 23284 USA. Boston Univ, Boston, MA 02215 USA. Solar Turbines, San Diego, CA USA. RP Dorney, DJ (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-0082 J9 INT J TURBO JET ENG JI Int. J. Turbo. Jet-Engines PY 2002 VL 19 IS 1-2 BP 47 EP 56 PG 10 WC Engineering, Aerospace SC Engineering GA 572YL UT WOS:000176802500005 ER PT S AU Howard, JM Stone, BD AF Howard, JM Stone, BD BE Manhart, PK Sasian, JM TI Nonanamorphic imaging with three conic mirrors SO INTERNATIONAL OPTICAL DESIGN CONFERENCE 2002 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT International Optical Design Conference CY JUN 03-05, 2002 CL TUCSON, AZ SP Opt Soc Amer, SPIE ID 3 SPHERICAL MIRRORS; ASYMMETRIC SYSTEMS; 1ST-ORDER LAYOUT; FOUNDATIONS AB Design methods are described for unobstructed. plane-symmetric systems composed of three conic mirrors. Low order imaging constraints. (including the requirement of nonanamorphism) are used to reduce the dimensionality of the configuration space. Examples are presented. C1 NASA, Goddard Space Flight Ctr, Opt Branch, Greenbelt, MD 20771 USA. RP Howard, JM (reprint author), NASA, Goddard Space Flight Ctr, Opt Branch, Code 551, Greenbelt, MD 20771 USA. NR 9 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 0-8194-4608-4 J9 P SOC PHOTO-OPT INS PY 2002 VL 4832 BP 25 EP 32 DI 10.1117/12.486489 PG 8 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BW30X UT WOS:000181494100003 ER PT S AU Mouroulis, P AF Mouroulis, P BE Manhart, PK Sasian, JM TI Beyond spot diagrams: End-user oriented optical design SO INTERNATIONAL OPTICAL DESIGN CONFERENCE 2002 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT International Optical Design Conference CY JUN 03-05, 2002 CL TUCSON, AZ SP Opt Soc Amer, SPIE DE optical systems design; image quality assessment; imaging spectroscopy ID PUSHBROOM IMAGING SPECTROMETERS AB In this talk, two examples are given of the process of translating user requirements into optimization and assessment tools: In the first place, recent work on the effects of aberrations on the perceived image quality of visual instruments is reviewed. This allows the assessment of a visual system in terms of expected loss of contrast and resolution as a function of aberration, and also the formulation of an image quality metric suitable for automatic optimization. The second example concerns the extraction of accurate spectroscopic information from pushbroom, imaging spectrometers. It is shown how the user requirements for calibration translate into spectral and spatial uniformity of response, and further to the complete absence of spectral and spatial distortion, as well as to the minimization of the variation of the LSF width in both directions, spatial and spectral. Techniques for accomplishing this in practice, both in terms of merit function and in terms of fabrication and assembly, are also discussed. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Mouroulis, P (reprint author), 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 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 0-8194-4608-4 J9 P SOC PHOTO-OPT INS PY 2002 VL 4832 BP 181 EP 185 DI 10.1117/12.486474 PG 5 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BW30X UT WOS:000181494100021 ER PT S AU Floyd, L Tobiska, WK Cebula, RP AF Floyd, L Tobiska, WK Cebula, RP BE Shea, MA TI Solar UV irradiance, its variation, and its relevance to the Earth SO INTERNATIONAL SOLAR CYCLE STUDY (ISCS) SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 1st International Solar Cycle Study Workshop CY JUL, 1998 CL NAGOYA, JAPAN SP Sci Comm Solar Terrestial Phys, Comm Solar Terrestial Res Japan, Comm Space Res ID LYMAN-ALPHA-IRRADIANCE; ULTRAVIOLET IRRADIANCE; K-LINE; BACKSCATTERED ULTRAVIOLET; CHROMOSPHERIC VARIABILITY; TIME-SERIES; CLIMATE; INDEXES; SOLAR-CYCLE-22; SBUV/2 AB Originating in the sun's upper photosphere, chromosphere, transition zone, and corona, solar UV (including EUV) emissions have a profound effect on Earth's ionosphere, thermosphere, mesosphere, and stratosphere. Through ionization, dissociation and excitation processes, solar UV is the primary source of energy input to the atmosphere and, as a result, it plays a central role in the atmosphere's vertical, thermal, and electronic structure. Further, the solar UV irradiance is a principal driver of the strong dynamics in the atmosphere and its cycles of chemical species, especially those of nitrogen and oxygen. Over the past three decades, numerous space-based measurements of solar UV light have been made in order to better understand its nature and effects. They show that the UV irradiance does varies through time, primarily on 27-day solar rotation and 11-year solar cycle time scales, and that this wavelength-dependent variation is primarily associated with the emergence, growth, and decay of active regions on the solar disk. Numerous models and proxies have been developed with some success to better understand and predict solar UV variations and their wavelength dependence. However, in spite of considerable progress, the present estimates of solar variability together with atmospheric models still do not provide complete and accurate descriptions of atmospheric phenomena. Acordingly, we cannot be sure that the accuracy of current measurements is sufficient. Moreover, in some cases, correlation studies of both atmosphere and climate, imply that solar variations are more important than physics-based models would indicate. We discuss the current international UV irradiance measurement and modeling program and make recommendations about its continuation. Also, we outline some evidence for and possible causes of a solar connection in the evolution of atmosphere and climate. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Interfreometr Inc, Chantilly, VA 20151 USA. Fed Data Corp, Jet Propuls Lab, Pasadena, CA 91109 USA. Raytheon STX Corp, Lanham, MD 20706 USA. RP Floyd, L (reprint author), Interfreometr Inc, 14120 Pk Long Ct, Chantilly, VA 20151 USA. NR 55 TC 21 Z9 21 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 2002 VL 29 IS 10 BP 1427 EP 1440 AR PII S0273-1177(02)00202-8 DI 10.1016/S0273-1177(02)00202-8 PG 14 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BU82U UT WOS:000177134900003 ER PT S AU Schmieder, B van Driel-Gesztelyi, L Aulanier, G Demoulin, P Thompson, B De Forest, C Wiik, JE Saint Cyr, C Vial, JC AF Schmieder, B van Driel-Gesztelyi, L Aulanier, G Demoulin, P Thompson, B De Forest, C Wiik, JE Saint Cyr, C Vial, JC BE Shea, MA TI Relationships between CME's and prominences SO INTERNATIONAL SOLAR CYCLE STUDY (ISCS) SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 1st International Solar Cycle Study Workshop CY JUL, 1998 CL NAGOYA, JAPAN SP Sci Comm Solar Terrestial Phys, Comm Solar Terrestial Res Japan, Comm Space Res ID CONFIGURATIONS SUPPORTING PROMINENCES; CORONAL MASS EJECTIONS; MAGNETIC-FIELD; ERUPTIVE PROMINENCE; LATERAL FEET; EVOLUTION; ENERGY; SUMER; LASCO; CDS AB We have studied the erupting prominences which were associated with coronal mass ejections during a series of campaigns involving both spacecraft, and ground-based observatories. The evolution of the physical conditions within the prominences was established from Halpha and magnetic field observations. Particular attention ahs been paid to the presence of mixed amgnetic polarity in the filament, channel, the evolution of the shear of the large-scale magnetic field, and the existence of multiple magnetic inversion lines. We conclude that reconnection of large-scale coronal magnetic fields is responsible for both the CME and filament, eruption. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 DASOP, Observ Paris, F-92195 Meudon, France. Univ Oslo, N-0315 Oslo, Norway. Konkoly Observ Budapest, H-1525 Budapest, Hungary. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Campus Uni, Orsay, France. RP Schmieder, B (reprint author), DASOP, Observ Paris, F-92195 Meudon, France. RI Thompson, Barbara/C-9429-2012; OI Demoulin, Pascal/0000-0001-8215-6532 NR 23 TC 11 Z9 11 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 2002 VL 29 IS 10 BP 1451 EP 1460 AR PII S0273-1177(02)00211-9 DI 10.1016/S0273-1177(02)00211-9 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BU82U UT WOS:000177134900006 ER PT S AU Plunkett, SP Michels, DJ Howard, RA Brueckner, GE Cyr, OCS Thompson, BJ Simnett, GM Schwenn, R Lamy, P AF Plunkett, SP Michels, DJ Howard, RA Brueckner, GE Cyr, OCS Thompson, BJ Simnett, GM Schwenn, R Lamy, P BE Shea, MA TI New insights on the onsets of coronal mass ejections from SOHO SO INTERNATIONAL SOLAR CYCLE STUDY (ISCS) SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 1st International Solar Cycle Study Workshop CY JUL, 1998 CL NAGOYA, JAPAN SP Sci Comm Solar Terrestial Phys, Comm Solar Terrestial Res Japan, Comm Space Res ID EARTH CONNECTION EVENT; SOLAR-ACTIVITY; LASCO OBSERVATIONS; SMM OBSERVATIONS; MAGNETIC CLOUD; JANUARY 1997; FLUX ROPE; STREAMER; TRANSIENTS; EVOLUTION AB Coronal mass ejections (CMES) are among the most dramatic forms of transient activity occurring in the solar atmosphere. Despite over twenty years of research, many basic questions related to the physics of CMEs have remained unanswered. Observations with the LASCO and EIT experiments on SOHO, combined with recent theoretical modeling, have provided new insights on some of these outstanding questions and have also raised many new ones that need to be addressed in the future. In this paper, we present some of the new results from SOHO pertaining to the source regions and onsets of CMEs, and their evolution in the corona. We emphasize the important role that studies of CMEs will play in the International Solar Cycle Studies program. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 USN, Res Lab, Space Res Assoc, Washington, DC 20375 USA. USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Computat Phys Inc, Greenbelt, MD 20771 USA. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Max Planck Inst Aeron, Lindau, Germany. Astron Spatiale Lab, Marseille, France. RP Plunkett, SP (reprint author), USN, Res Lab, Space Res Assoc, Washington, DC 20375 USA. RI Thompson, Barbara/C-9429-2012 NR 40 TC 13 Z9 13 U1 2 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 2002 VL 29 IS 10 BP 1473 EP 1488 AR PII S0273-1177(02)00207-7 DI 10.1016/S0273-1177(02)00207-7 PG 16 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BU82U UT WOS:000177134900009 ER PT S AU Sharber, JR Winningham, JD Frahm, RA Crowley, G Ridley, AJ Link, R AF Sharber, JR Winningham, JD Frahm, RA Crowley, G Ridley, AJ Link, R BE Shea, MA TI Construction of a particle climatology for the study of the effects of solar particle fluxes on the atmosphere SO INTERNATIONAL SOLAR CYCLE STUDY (ISCS) SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 1st International Solar Cycle Study Workshop CY JUL, 1998 CL NAGOYA, JAPAN SP Sci Comm Solar Terrestial Phys, Comm Solar Terrestial Res Japan, Comm Space Res ID AURORAL ION PRECIPITATION; GEOMAGNETIC STORMS; STATISTICAL-MODEL; 2-DIMENSIONAL MODEL; ENVIRONMENT MONITOR; MIDDLE ATMOSPHERE; THERMOSPHERE; IONOSPHERE; CONDUCTIVITY; SIMULATIONS AB In an investigation of the atmospheric effects of particle input, we are currently developing a particle climatology built using the UARS (Upper Atmosphere Research Satellite) particle database. UARS operates in a circular 585 km orbit and makes differential energy per unit charge measurements of electrons and positive ions in the range of a few eV to several MeV. The climatology is an empirical model that enables the user to obtain average spectral characteristics, precipitating particle fluxes, and ionization rate profiles as functions of latitude, local time, and activity level. To further the goals of Working Group I of the International Solar Cycle Study (ISCS), we propose the construction of such a particle climatology. We suggest the UARS particle climatology as a starting point, to be augmented by additional low-altitude particle data. In this paper we describe the development of the current climatology, show how it will be augmented to produce an improved ISCS climatology, and illustrate how this climatology will be used to carry out the objectives of the ISCS. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 NASA Headquarters, Washington, DC 20546 USA. SW Res Inst, San Antonio, TX 78238 USA. Univ Michigan, Ann Arbor, MI 48109 USA. RP Sharber, JR (reprint author), NASA Headquarters, 300 E St SW, Washington, DC 20546 USA. RI Ridley, Aaron/F-3943-2011 OI Ridley, Aaron/0000-0001-6933-8534 NR 26 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 0273-1177 J9 ADV SPACE RES PY 2002 VL 29 IS 10 BP 1513 EP 1522 AR PII S0273-1177(02)00212-0 DI 10.1016/S0273-1177(02)00212-0 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BU82U UT WOS:000177134900013 ER PT S AU Schmidtke, G Tobiska, WK Winningham, D AF Schmidtke, G Tobiska, WK Winningham, D BE Shea, MA TI Tiger-program for thermospheric-ionospheric geospheric research - Long-term measurement of solar EUV/UV fluxes for thermospheric-ionospheric (T/I) modelling and for space weather investigations SO INTERNATIONAL SOLAR CYCLE STUDY (ISCS) SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 1st International Solar Cycle Study Workshop CY JUL, 1998 CL NAGOYA, JAPAN SP Sci Comm Solar Terrestial Phys, Comm Solar Terrestial Res Japan, Comm Space Res ID IRRADIANCE AB On 18/19 June 1998 the 1st TIGER Symposium was held in Freiburg/Germany. After presentation and discussion of 28 invited and contributed talks, the symposium agreed to establish a longterm TIGER Program within the framework of the SCOSTEP International Solar Cycle Study Working Group 1, Panel 2. This decision is based on the general agreement that, for thermospheric-ionosphenic research as well as for a broad range of commercial applications in space, the improvement of existing thermosphenic-ionospheric (T/I) models is absolutely necessary to meet scientific goals. There are a number of scientific questions underlying the goal of understanding solar EUV/UV variability such as what are the primary mechanisms by which solar ultraviolet (UV), extreme ultraviolet (EUV), and soft X-ray (XUV) irradiance variations affect terrestrial global climate change and/or weather and what is their significance? How does solar forcing compare with that from other sources such as increasing concentrations of radiatively-active gases and atmospheric aerosols? How sensitive is the Earth's climate to changes in solar radiation? What time scales of solar variability are significant to climate? How might solar variability in these wavelengths affect global warming projections? Are there signatures of solar influences in the upper atmosphere that are distinct from anthropogenic effects? To meet these goals, coordinated work on the following topics is required and is discussed in detail below: 1. Measurement and modelling of solar EUV/UV radiation 2. Measurement and modelling of the solar wind (particles) originated energy T/I influx 3. Measurement of relevant thermospheric-ionospheric parameters 4. Modelling of the thermosphere/ionosphere 5. Fundamental physical investigations of photoenergetic atomic and molecular processes To make substantial progress in developing a complete understanding of the T/I processes, it is necessary to envisage solar cycle and longer timescales. This can be done in the global change context by making use of a broad range of worldwide existing resources with respect to manpower, experience, hardware, methods, flight opportunities, and funding resources. The TIGER Program alms to facilitate the coordination of these existing and planned activities and to help define missing links for achieving the scientific goals. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 IPM Freiburg, D-79110 Freiburg, Germany. Jet Propuls Lab, Fed Data Corp, Pasadena, CA 91109 USA. SW Res Inst, San Antonio, TX 78238 USA. RP Schmidtke, G (reprint author), IPM Freiburg, Heidenhofstr 8, D-79110 Freiburg, Germany. NR 5 TC 3 Z9 3 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 2002 VL 29 IS 10 BP 1553 EP 1559 AR PII S0273-1177(02)00210-7 DI 10.1016/S0273-1177(02)00210-7 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BU82U UT WOS:000177134900018 ER PT B AU Dunbar, BJ Korb, L AF Dunbar, BJ Korb, L BE Clark, DE Folz, DC McGee, TD TI Thermal protection design considerations for human-rated reusable space vehicles SO INTRODUCTION TO CERAMIC ENGINEERING DESIGN LA English DT Proceedings Paper CT Workshop on Designing with Engineering Ceramics CY JAN, 2001 CL COCOA BEACH, FL SP Natl Inst Ceram Engineers, Amer Ceram Soc, Engn Ceram Div AB The Space Shuffle Transportation System (STS) was developed to provide a reusable method for placing payloads and crew members into a low earth orbit in a single vehicle. Payloads consist of the following: experiments that take advantage of the microgravity environment in low earth orbit (e.g., Spacelab, Spacehab laboratories in the payload bay), instruments that study the earth (e.g., Side Imaging Radar), telescopes that study the university, and components of the International Space Station which are assembled in low earth orbit. One of the critical problems in developing this "revolutionary" concept in the 1060s was the design of a reusable thermal protection system (TPS) capable of surviving, not only the re-entry heating, but also the launch and landing mechanical loads. The major portion of the TPS consists of several thousands of pure silica fiber tiles covered with a ceramic coating and bonded onto the aluminum substructure. The design and manufacture of this system was not an easy process. Difficulties were encountered in achieving the aerodynamically smooth surface, structurally sound bonds and reduced mass. This chapter provides an overview of the rationale and thought processes that were instrumental in the design of the Shape Shuttle TPS from the late, 1960s until its first launch on April 12, 1981. The authors have accessed a number of original studies and papers within NSASA and Rockwell International Space Division that described the design trades and rational involved in the development of the system. Additional improvements have been implemented in the last 20 years, but he design content and rational remains largely unchanged as one of the four shuttles is prepared for the 110(th) launch. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Dunbar, BJ (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 NASA Rd 1, Houston, TX 77058 USA. NR 18 TC 2 Z9 2 U1 1 U2 6 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA BN 1-57498-131-5 PY 2002 BP 200 EP 231 PG 32 WC Materials Science, Ceramics SC Materials Science GA BW66M UT WOS:000182719500009 ER PT S AU Yorke, HW Richling, S AF Yorke, HW Richling, S BE Henney, WJ Franco, J Martos, M Pena, M TI The effects of winds and photoionization on the evolution of protostellar disks SO IONIZED GASEOUS NEBULAE: A CONFERENCE TO CELEBRATE THE 60TH BIRTHDAY OF SILVIA TORRES-PEIMBERT AND MANUEL PEIMBERT SE REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA, SERIE DE CONFERENCIAS LA English DT Proceedings Paper CT Symposium on Ionized Gaseous Nebulae CY NOV 21-24, 2000 CL UNAM, INST ASTRONOMIA, MEXICO CITY, MEXICO HO UNAM, INST ASTRONOMIA C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Yorke, HW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 3 TC 4 Z9 4 U1 0 U2 0 PU UNIVERSIDAD NACIONAL AUTONOMA MEXICO INSTITUTO ASTRONOMIA PI MEXICO CITY PA APARTADO POSTAL 70-264, MEXICO CITY 04510, MEXICO SN 1405-2059 J9 REV MEX AST ASTR PY 2002 VL 12 BP 92 EP 92 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU47Y UT WOS:000176123000028 ER PT S AU Rubin, RH Dufour, RJ Colgan, SWJ Liao, A Harrington, JP Levine, DA Lord, SD AF Rubin, RH Dufour, RJ Colgan, SWJ Liao, A Harrington, JP Levine, DA Lord, SD BE Henney, WJ Franco, J Martos, M Pena, M TI Planetary nebulae results from the infrared space observatory SO IONIZED GASEOUS NEBULAE: A CONFERENCE TO CELEBRATE THE 60TH BIRTHDAY OF SILVIA TORRES-PEIMBERT AND MANUEL PEIMBERT SE REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA, SERIE DE CONFERENCIAS LA English DT Proceedings Paper CT Symposium on Ionized Gaseous Nebulae CY NOV 21-24, 2000 CL UNAM, INST ASTRONOMIA, MEXICO CITY, MEXICO HO UNAM, INST ASTRONOMIA DE ISM : structure; planetary nebulae : general ID ATOMIC DATA; SPECTROSCOPY; TEMPERATURE; NGC-7009; LINES AB Observations with the Infrared Space Observatory (ISO) provide a means to assess important properties of the plasma in gaseous nebulae, including planetary nebulae (PNs). We present some results for average electron densities that have been determined from the flux ratios of several fine-structure, infrared emission lines. Because the ISO spectroscopic aperture was always at least as large as 14" x 20", these represent macroscopic measurements for our sample of PNs. We find some instances of the observed line flux ratio being clearly out of range of the theoretical predictions using current atomic data. In these cases, the ISO data cannot presently be used with these atomic data to derive electron density, but rather provide direction for needed improvements in the atomic collision strengths. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Rubin, RH (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. RI Colgan, Sean/M-4742-2014 NR 18 TC 2 Z9 2 U1 0 U2 0 PU UNIVERSIDAD NACIONAL AUTONOMA MEXICO INSTITUTO ASTRONOMIA PI MEXICO CITY PA APARTADO POSTAL 70-264, MEXICO CITY 04510, MEXICO SN 1405-2059 J9 REV MEX AST ASTR PY 2002 VL 12 BP 106 EP 111 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU47Y UT WOS:000176123000033 ER PT B AU Andrews, K Dolinar, S Pollara, F AF Andrews, K Dolinar, S Pollara, F GP IEEE IEEE TI LDPC decoding using multiple representations SO ISIT: 2002 IEEE INTERNATIONAL SYMPOSIUM ON INFORMATION THEORY, PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Symposium on Information Theory CY JUN 30-JUL 05, 2002 CL LAUSANNE, SWITZERLAND SP IEEE, Informat Theory Soc, QUALCOMM, Nokia, BROADCOM, IBM, Texas Instruments, Swisscom, DARPA, NSF, ONR, Dept Navy Sci & Technol, Swiss Natl Sci Fdn, Sun Microsyst, Haslerstiftung, EPFL, IEEE AB For a particular block code, a multitude of different parity check matrices could be chosen to represent the code constraints. We demonstrate that belief propagation decoders based on different parity check matrices often respond in different ways, and that for a given complexity, it may be preferable to use several decoders for fewer iterations, than to run a single decoder for many iterations. We also propose some additional decoder architectures that use multiple representations of the parity constraints. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Andrews, K (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7501-7 PY 2002 BP 456 EP 456 DI 10.1109/ISIT.2002.1023728 PG 1 WC Computer Science, Information Systems; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BV13N UT WOS:000177912700455 ER PT B AU Okong'o, N Bellan, J AF Okong'o, N Bellan, J BE Pollard, A Candel, S TI Characteristics of supercritical transitional temporal mixing layers SO IUTAM SYMPOSIUM ON TURBULENT MIXING AND COMBUSTION SE FLUID MECHANICS AND ITS APPLICATIONS LA English DT Proceedings Paper CT IUTAM Symposium on Turbulent Mixing and Combustion CY JUN 03-06, 2001 CL KINGSTON, CANADA SP IUTAM, Natl Res Council Canada, Natl Resources Canada, Queens Univ, CAGCT, Canadian Gas Assoc DE supercritical; transitional; mixing layer ID NITROGEN; HEPTANE AB Several Direct Numerical Simulation realizations of supercritical, three-dimensional, temporal mixing layers are used to investigate aspects of interest to turbulent combustion. The realizations are based on a model previously developed that accounts for the enlarged transport matrix at supercritical conditions (Soret and Dufour effects), for real gas equations of state, and for variable Schmidt and Prandtl numbers. This model is exercised for two very different sets of binary species, heptane/nitrogen and oxygen/hydrogen, to obtain transitional states for mixing layers excited at different perturbation wavelengths. Visualizations of the transitional states show that all layers develop convoluted regions of high density gradient magnitude (HDGM), which result both from the distortion of the initial density stratification boundary and from mixing. The species mass fraction in these HDGM regions is very weakly dependent of the perturbation wavelength. The existence of the HDGM regions, independent of the perturbation wavelength, indicates that they may be a feature of spatial mixing layers, and furthermore have a similar mass fraction composition. Evaluations of the applicability of the assumed PDF method for describing supercritical transitional flows shows that neither the beta density nor the Gaussian are appropriate representations of the conserved scalar, and that the PDFs of the partial densities and the temperature are correlated, invalidating the typical model of the reaction rate as the product of the marginal PDFs. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Okong'o, N (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-0747-7 J9 FLUID MEC A PY 2002 VL 70 BP 59 EP 71 PG 13 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BV68L UT WOS:000179768300006 ER PT B AU Talukder, A Manduchi, R Rankin, A Matthies, L AF Talukder, A Manduchi, R Rankin, A Matthies, L GP INRIA INRIA TI Fast and reliable obstacle detection and segmentation for cross-country navigation SO IV'2002: IEEE INTELLIGENT VEHICLE SYMPOSIUM, PROCEEDINGS LA English DT Proceedings Paper CT IEEE Intelligent Vehicle Symposium CY JUN 17-21, 2002 CL VERSAILLES, FRANCE SP IEEE, ITSC, INRIA DE autonomous navigation; obstacle detection; terrain perception; 3-D vision; classification; geometrical reasoning AB Obstacle detection (OD) is one of the main components of the control system of autonomous vehicles. In the case of indoor/urban navigation, obstacles are typically defined as surface points that are higher than the ground plane. This characterisation, however, cannot be used in cross-country and unstructured environments, where the notion of "ground plane" is often not meaningful. A previous OD technique for cross-counny navigation (adopted by the DEMO III experimental unmanned vehicle) computes obstacle by analysing the columns of a range image independently, looking for steps or slopes along the range profile. This procedure, however, is prone to missing obstacles with surface normal pointing away from the line of sight. We introduce a fast, fully 3-D OD technique that overcomes such a problem, reducing the risk of false-negatives while keeping the same rate of false-positives. A simple addition to our algorithm allows one to segment obstacle points into clusters, where each cluster identifies an isolated obstacle in 3-D space. Obstacle segmentation corresponds to finding the connected components of a suitable graph, an operation that can be performed at a minimal additional cost during the computation of obstacle points. Rule-based classification using 3-D geometrical measures derived for each segmented obstacle is then used to reject false-obstacles (for example, objects that are small in volume, or of low height). Results for a number of scenes of natural terrain are presented, and compared with a pre-existing obstacle detection algorithm. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ashit.talukder@jpl.nasa.gov; manduchi@soe.ucsc.edu; art.rankin@jpl.nasa.gov; larry.matthies@jpl.nasa.gov NR 13 TC 13 Z9 13 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7346-4 PY 2002 BP 610 EP 618 PG 9 WC Computer Science, Artificial Intelligence; Transportation Science & Technology SC Computer Science; Transportation GA BW26X UT WOS:000181392800093 ER PT J AU Williams, BG AF Williams, BG TI Technical challenges and results for navigation of NEAR shoemaker SO JOHNS HOPKINS APL TECHNICAL DIGEST LA English DT Article ID MISSION; EROS AB When the NEAR Shoemaker spacecraft began its orbit about the asteroid 433 Eros on 14 February 2000, it marked the beginning of many firsts for deep space navigation. Among these were the design and estimation techniques that were necessary to plan and execute navigation of the first spacecraft to orbit and land on an irregularly shaped small body. This article describes the navigation strategy and results for the rendezvous, orbit, and landing phases of the NEAR mission. Included are descriptions of the new techniques developed to deal with navigation challenges encountered during rendezvous and the year-long orbit phase. The orbit phase included circular orbits down to a 35-km radius and elliptical orbits that targeted overflights to within 2.7 km above the surface. The orbit phase ended on 12 February 2001, when NEAR Shoemaker was guided to a soft landing on the surface of Eros. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Williams, BG (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 16 TC 6 Z9 8 U1 0 U2 0 PU JOHNS HOPKINS UNIV PI LAUREL PA APPLIED PHYSICS LABORATORY ATTN: MANAGING EDITOR JOHN HOPKINS RD, BLDG 1-E254, LAUREL, MD 20723-6099 USA SN 0270-5214 J9 J HOPKINS APL TECH D JI Johns Hopkins APL Tech. Dig. PD JAN-MAR PY 2002 VL 23 IS 1 BP 34 EP 45 PG 12 WC Engineering, Multidisciplinary SC Engineering GA 598AW UT WOS:000178253800004 ER PT J AU Aglan, HA Gan, YX Wang, QY Kehoe, M AF Aglan, HA Gan, YX Wang, QY Kehoe, M TI Design guidelines for composite patches bonded to cracked aluminum substrates SO JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY LA English DT Article DE design guidelines; composite patches; structural repairs ID LABORATORY-EVALUATION; SURFACE TREATMENTS; FATIGUE BEHAVIOR; ADHESIVE JOINTS; REPAIR AB Design guidelines are proposed for boron fiber-reinforced epoxy composite patches bonded to cracked aluminum substrates. Stress analysis was performed on the composite patch bonded to an uncracked aluminum substrate. The load transfer via the adhesive and the stress levels in the aluminum substrate and the patch were determined. The local stress and stress distribution in the repaired V-shape side cracked substrates were obtained. The effects of crack length and patch geometries including the length and number of plies on the failure behavior of the repair were identified. The results were validated by static tensile tests. It was found that the theoretical calculations were in agreement with the experimental results. This indicates that the proposed analysis can be used as design guidelines for composite repairs of cracked structures. These guidelines coupled with a simple surface preparation technique developed in this work might aid composite patch installation in service. C1 Tuskegee Univ, Dept Mech Engn, Tuskegee, AL 36088 USA. NASA, Dryden Flight Res Ctr, Edwards AFB, CA 93523 USA. RP Aglan, HA (reprint author), Tuskegee Univ, Dept Mech Engn, Tuskegee, AL 36088 USA. RI WANG, Qing Yuan/G-5024-2010 NR 32 TC 2 Z9 2 U1 0 U2 2 PU VSP BV PI ZEIST PA PO BOX 346, 3700 AH ZEIST, NETHERLANDS SN 0169-4243 J9 J ADHES SCI TECHNOL JI J. Adhes. Sci. Technol. PY 2002 VL 16 IS 2 BP 197 EP 211 DI 10.1163/156856102317293704 PG 15 WC Engineering, Chemical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA 531FA UT WOS:000174404300006 ER PT J AU Lind, R AF Lind, R TI Match-point solutions for robust flutter analysis SO JOURNAL OF AIRCRAFT LA English DT Article ID MARGINS AB The computation of robust flutter speeds presents a significant advancement over traditional types of flutter analysis. In particular, mu-method analysis is able to generate robust flutter speeds that represent worst-case flight conditions with respect to potential modeling errors. Robust flutter speeds may be computed using a model formulation that has been previously presented; however, that formulation has limitations in its ability to generate a match-point solution. A model formulation is introduced for which mu-method analysis is guaranteed to compute a match-point solution. The match-point solution is immediately realized by analyzing a single model so the computation time is reduced from the previous approach that required iterations. Also, the solution is able to consider parametric uncertainty in any element, whereas the previous formulation did not consider mass uncertainty. The match-point formulation is derived by properly treating the nonlinear perturbations and uncertainties that affect the equation of motion. The Aerostructures Test Wing is used to demonstrate that the mu-method analysis computes match-point flutter speeds using this new formulation. C1 NASA, Dryden Flight Res Ctr, Edwards AFB, CA 93523 USA. RP Lind, R (reprint author), NASA, Dryden Flight Res Ctr, MS 4840 D-RS, Edwards AFB, CA 93523 USA. NR 18 TC 35 Z9 40 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 2002 VL 39 IS 1 BP 91 EP 99 DI 10.2514/2.2900 PG 9 WC Engineering, Aerospace SC Engineering GA 520BH UT WOS:000173759700012 ER PT J AU Lyle, KH Jackson, KE Fasanella, EL AF Lyle, KH Jackson, KE Fasanella, EL TI Simulation of aircraft landing gears with a nonlinear dynamic finite element code SO JOURNAL OF AIRCRAFT LA English DT Article AB Recent advances in computational speed have made aircraft and spacecraft crash simulations using an explicit, nonlinear. transient-dynamic, finite element analysis code more feasible. This paper describes the development of a simple landing-gear model, which accurately simulates the energy absorbed by the gear without adding substantial complexity to the model. For a crash model the landing gear response is approximated with a spring where the force applied to the fuselage is computed in a user-written subroutine. Helicopter crash simulations using this approach are compared with previously acquired experimental data from a full-scale crash test of a composite helicopter. C1 NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. RP Lyle, KH (reprint author), NASA, Langley Res Ctr, Struct Dynam Branch, MS 495, Hampton, VA 23681 USA. NR 8 TC 9 Z9 10 U1 0 U2 7 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 2002 VL 39 IS 1 BP 142 EP 147 DI 10.2514/2.2908 PG 6 WC Engineering, Aerospace SC Engineering GA 520BH UT WOS:000173759700019 ER PT J AU Vitali, R Park, O Haftka, RT Sankar, BV Rose, CA AF Vitali, R Park, O Haftka, RT Sankar, BV Rose, CA TI Structural optimization of a hat-stiffened panel using response surfaces SO JOURNAL OF AIRCRAFT LA English DT Article ID COMPOSITE; DESIGN AB A design study for structural optimization of a hat-stiffened laminated composite panel concept for an upper cover panel of a typical passenger bay of a blended wing-body transport airplane configuration is described. The feasibility of a hat-stiffened composite panel concept for an upper cover panel is investigated and is compared on the basis of weight to a thick sandwich panel concept that has been selected by designers as the baseline concept for the upper cover panel. The upper cover panel is designed for two load cases: internal pressure only and combined internal pressure and spanwise compression due to wing bending. The structural optimization problem is formulated using the panel weight as the objective function, with constraints on stress and buckling. The spacing of the hat stiffeners, the thickness of the skin, and the thickness of the components of the hat stiffener are used as design variables. The initial geometry of the hat-stiffened panel design is determined using the PANDA2 program by restricting the design to have uniform cross section in the spanwise direction. Because of the pressure loading, a more efficient design has variable cross section. Such designs are obtained by combining the STAGS finite element program with the optimization program in the Microsoft EXCEL spreadsheet program using response surfaces. Buckling and stress response surfaces are constructed from multiple STAGS analyses and are used as constraints in the optimization. The optimization conducted with the response surfaces results in considerable weight savings compared to the uniform cross section design, albeit a more complex design. Initial optimization cycles identify a design space where simple approximate analyses, such as Euler-Bernoulli beam theory and Kirchhoff plate theory applied to laminated composites, can be used to predict the behavior of the structure. C1 Univ Florida, Dept Aerosp Engn Mech & Engn Sci, Gainesville, FL 32611 USA. NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA. RP Vitali, R (reprint author), Univ Florida, Dept Aerosp Engn Mech & Engn Sci, 231 Aerosp Bldg, Gainesville, FL 32611 USA. OI Sankar, Bhavani/0000-0002-4556-1982 NR 10 TC 20 Z9 20 U1 2 U2 5 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 2002 VL 39 IS 1 BP 158 EP 166 DI 10.2514/2.2910 PG 9 WC Engineering, Aerospace SC Engineering GA 520BH UT WOS:000173759700021 ER PT J AU Aires, F Chedin, A Scott, NA Rossow, WB AF Aires, F Chedin, A Scott, NA Rossow, WB TI A regularized neural net approach for retrieval of atmospheric and surface temperatures with the IASI instrument SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID NETWORKS; STABILIZATION; PERFORMANCE; MODELS AB In this paper, a fast atmospheric and surface temperature retrieval algorithm is developed for the high-resolution Infrared Atmospheric Sounding Interferometer (IASI) spaceborne instrument. This algorithm is constructed on the basis of a neural network technique that has been regularized by introduction of information about the solution of the problem that is in addition to the information contained in the problem (a priori information). The performance of the resulting fast and accurate inverse radiative transfer model is presented for a large diversified dataset of radiosonde atmospheres that includes rare events. Two configurations are considered: a tropical-airmass specialized scheme and an all-airmasses scheme. The surface temperature for tropical situations yields an rms error of 0.4 K for instantaneous retrievals. Results for atmospheric temperature profile retrievals are close to the specifications of the World Meteorological Organization, namely, 1-K rms error for the instantaneous temperature retrieval with 1-km vertical resolution. C1 Columbia Univ, Dept Appl Phys, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Ecole Polytech, CNRS, Meteorol Dynam Lab, F-91128 Palaiseau, France. RP Aires, F (reprint author), Columbia Univ, Dept Appl Phys, NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. RI Rossow, William/F-3138-2015 NR 34 TC 74 Z9 77 U1 3 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2002 VL 41 IS 2 BP 144 EP 159 DI 10.1175/1520-0450(2002)041<0144:ARNNAF>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 512GK UT WOS:000173316500004 ER PT J AU Ulbrich, CW Atlas, D AF Ulbrich, CW Atlas, D TI On the separation of tropical convective and stratiform rains SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID RAINFALL MEASUREMENTS; AREA INTEGRALS; TOGA COARE; RADAR; CLOUDS; CLASSIFICATION; DISTRIBUTIONS; SIZE AB This work resolves an apparent conflict between the results of Yuter and Houze and Atlas et al. concerning relations between radar reflectivity factor Z and rainfall rate R derived from essentially the same drop size data observed aloft during the Tropical Ocean and Global Atmosphere program's (TOGA) Coupled Ocean-Atmosphere Response Experiment (COARE). It is shown that the single relation found by Yuter and Houze is founded upon distinct underlying Z-R relations for stratiform and convective rains. This result occurs despite the fact that errors in rain types classified by different methods and the variability of the effective drop sizes within each type tend to obscure the distinction. This newly found agreement between the two distinctly different methods of analysis also suggests the essential equivalence of the classification methods of Steiner et al. (based upon the existence of a maximum in the observed reflectivity field) and of Atlas et al. (based upon the magnitude of the drafts). However, further trials are necessary to demonstrate the generality of this equivalence. C1 Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Ulbrich, CW (reprint author), Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. NR 20 TC 24 Z9 24 U1 2 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PY 2002 VL 41 IS 2 BP 188 EP 195 DI 10.1175/1520-0450(2002)041<0188:OTSOTC>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 512GK UT WOS:000173316500007 ER PT J AU Walsh, BM Murray, KE Barnes, NP AF Walsh, BM Murray, KE Barnes, NP TI Cr : Er : Tm : Ho : yttrium aluminum garnet laser exhibiting dual wavelength lasing at 2.1 and 2.9 mu m: Spectroscopy and laser performance SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID YAG-ER; ENERGY; LUMINESCENCE; MANIFOLDS; CRYSTALS; YLF AB Over 1.0 J of 2.1 mum laser energy and over 0.5 J of 2.9 mum laser energy have been demonstrated in a single flashlamp pumped solid state laser material, specifically Cr:Er:Tm:Ho:YAG. Flashlamp pumped laser operation of Ho:YAG at 2.1 mum and Er:YAG at 2.9 mum in various host materials is well known. We have developed an innovative laser system that operates at each of these wavelengths independently or simultaneously in a single solid state laser material with performance comparable to single wavelength systems Er:YAG and Cr:Tm:Ho:YAG. Variation of the flashlamp pump pulse length provides a method to discriminate between lasing at 2.1 and 2.9 mum. This effect results from Er-->Tm-->Ho energy transfer, the short lifetime of the upper lasing manifold in Er, the I-4(11/2) manifold, and the relatively long upper laser level lifetime in Ho, the I-5(7) manifold. This simple tuning method of achieving two widely separated wavelengths without the use of optical tuning elements has potential applications in remote sensing and medical lasers. (C) 2002 American Institute of Physics. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Boston Coll, Dept Phys, Chestnut Hill, MA 02167 USA. RP NASA, Langley Res Ctr, MS 474, Hampton, VA 23681 USA. EM b.m.walsh@larc.nasa.gov NR 17 TC 8 Z9 8 U1 0 U2 15 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 1 PY 2002 VL 91 IS 1 BP 11 EP 17 DI 10.1063/1.1419211 PG 7 WC Physics, Applied SC Physics GA 504AX UT WOS:000172835600003 ER PT J AU Wolpert, DH Tumer, K AF Wolpert, DH Tumer, K TI Collective intelligence, data routing and Braess' paradox SO JOURNAL OF ARTIFICIAL INTELLIGENCE RESEARCH LA English DT Article ID NONCOOPERATIVE NETWORKS; CONGESTION; CAPACITY; TRAGEDY; COMMONS AB We consider the problem of designing the the utility functions of the utility-maximizing agents in a multi-agent system (MAS) so that they work synergistically to maximize a global utility. The particular problem domain we explore is the control of network routing by placing agents on all the routers in the network. Conventional approaches to this task have the agents all use the Ideal Shortest Path routing Algorithm (ISPA). We demonstrate that in many cases, due to the side-effects of one agent's actions on another agent's performance, having agents use ISPA's is suboptimal as far as global aggregate cost is concerned, even when they are only used to route infinitesimally small amounts of traffic. The utility functions of the individual agents are not "aligned" with the global utility, intuitively speaking. As a particular example of this we present an instance of Braess' paradox in which adding new links to a network whose agents all use the ISPA results in a decrease in overall throughput. We also demonstrate that load-balancing, in which the agents' decisions are collectively made to optimize the global cost incurred by all traffic currently being routed, is suboptimal as far as global cost averaged across time is concerned. This is also due to "side-effects", in this case of current routing decision on future traffic. The mathematics of Collective Intelligence (COIN) is concerned precisely with the issue of avoiding such deleterious side-effects in multi-agent systems, both over time and space. We present key concepts from that mathematics and use them to derive an algorithm whose ideal version should have better performance than that of having all agents use the ISPA, even in the infinitesimal limit. We present experiments verifying this, and also showing that a machine-learning-based version of this COIN algorithm in which costs are only imprecisely estimated via empirical means (a version potentially applicable in the real world) also outperforms the ISPA, despite having access to less information than does the ISPA. In particular, this COIN algorithm almost always avoids Braess' paradox. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, Mailstop 269-2, Moffett Field, CA 94035 USA. EM DHW@PTOLEMY.ARC.NASA.GOV; KAGAN@PTOLEMY.ARC.NASA.GOV NR 55 TC 20 Z9 20 U1 0 U2 3 PU AI ACCESS FOUNDATION PI MARINA DEL REY PA USC INFORMATION SCIENCES INST, 4676 ADMIRALITY WAY, MARINA DEL REY, CA 90292-6695 USA SN 1076-9757 EI 1943-5037 J9 J ARTIF INTELL RES JI J. Artif. Intell. Res. PY 2002 VL 16 BP 359 EP 387 PG 29 WC Computer Science, Artificial Intelligence SC Computer Science GA 564WP UT WOS:000176336800001 ER PT J AU Blaisdell, CJ Weiss, SR Kimes, DS Levine, ER Myers, M Timmins, S Bollinger, ME AF Blaisdell, CJ Weiss, SR Kimes, DS Levine, ER Myers, M Timmins, S Bollinger, ME TI Using seasonal variations in asthma hospitalizations in children to predict hospitalization frequency SO JOURNAL OF ASTHMA LA English DT Article ID AIR-POLLUTION; CHILDHOOD ASTHMA; NEURAL NETWORKS; RISK-FACTORS; INNER-CITY; ADMISSIONS; ALLERGENS; MORTALITY; EXACERBATIONS; POLLUTANTS AB Asthma hospitalization rates have increased in the United States since 1980. The exposure risk of many environmental factors, which contribute to respiratory disease, vary throughout the year. The objective of this study was to investigate the seasonal variation of pediatric asthma hospitalizations and predict hospitalization frequency. This was a longitudinal analysis of all pediatric asthma hospitalizations in the state of Maryland by age, gender, race, and residence using non-confidential discharge data sets from 1986 to 1999. Of the 631,422 pediatric hospitalizations in the state of Maryland during the years 1986-1999, 45,924 (7%) had a primary admission diagnosis of asthma. Frequency of hospitalization for asthma was lowest in the summer in all age groups, and highest in the fall. Seasonal variation in severe asthma episodes was least striking in children aged 15 - 18. This was in contrast to non-asthma admissions, which were highest in winter in preschool children, but relatively flat in school- and teenaged children. Using neural network modeling, weekly asthma hospitalizations could be predicted with an R-2 between 0.71 and 0.8. Temporal trends in asthma hospitalizations were seen in each age group, gender, race, and location. The seasonal variability in asthma hospitalizations suggests that acute asthma is influenced by variables beyond socioeconomic factors and adherence to medical regimens. Strategies to combat exacerbations of asthma should take into consideration seasonal effects on a population. In addition, temporal trends examined over many years can be used to predict frequency of severe asthma episodes in a population. C1 Univ Maryland, Med Ctr, Dept Pediat, Div Pulmonol Allergy, Baltimore, MD 21201 USA. Univ Maryland, Sch Pharm, Ctr Drugs & Publ Policy, Baltimore, MD 21201 USA. Univ Maryland, Sch Med, Dept Epidemiol & Prevent Med, Baltimore, MD 21201 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Blaisdell, CJ (reprint author), Univ Maryland, Med Ctr, Dept Pediat, Div Pulmonol Allergy, Bressler 10-019,655 W Baltimore St, Baltimore, MD 21201 USA. NR 39 TC 30 Z9 30 U1 1 U2 2 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0277-0903 J9 J ASTHMA JI J. Asthma PY 2002 VL 39 IS 7 BP 567 EP 575 DI 10.1081/JAS-120014921 PG 9 WC Allergy; Respiratory System SC Allergy; Respiratory System GA 613JU UT WOS:000179129800002 PM 12442946 ER PT J AU Turner, DD Ferrare, RA Brasseur, LAH Feltz, WF AF Turner, DD Ferrare, RA Brasseur, LAH Feltz, WF TI Automated retrievals of water vapor and aerosol profiles from an operational Raman lidar SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ELASTIC-BACKSCATTER LIDAR; SPECTRAL RESOLUTION LIDAR; ATMOSPHERIC-TEMPERATURE; RADIANCE MEASUREMENTS; OPTICAL-PROPERTIES; BOUNDARY-LAYER; EXTINCTION; CLOUDS; RADIATION; INTERFEROMETER AB Automated routines have been developed to derive water vapor mixing ratio, relative humidity, aerosol extinction and backscatter coefficient, and linear depolarization profiles, as well as total precipitable water vapor and aerosol optical thickness, from the operational Raman lidar at the Atmospheric Radiation Measurement (ARM) program's site in north-central Oklahoma. These routines have been devised to maintain the calibration of these data products, which have proven sensitive to the automatic alignment adjustments that are made periodically by the instrument. Since this Raman lidar does not scan, aerosol extinction cannot be directly computed below approximately 800 m due to the incomplete overlap of the outgoing laser beam with the detector's field of view. Therefore, the extinction-to-backscatter ratio at 1 km is used with the aerosol backscatter coefficient profile to compute aerosol extinction from 60 m to the level of complete overlap. Comparisons of aerosol optical depth derived using these algorithms with a collocated CIMEL sun photometer for clear-sky days over an approximate 2-yr period show a slope of 0.90 with a correlation coefficient of 0.884. Furthermore, comparing the aerosol extinction profile retrieved from this system with that from the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center's scanning Raman lidar agrees within 10% for the single available case. C1 Pacific NW Natl Lab, Climate Dynam Grp, Richland, WA 99352 USA. NASA, Langley Res Ctr, SAIC, Hampton, VA 23665 USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI USA. Sandia Natl Labs, Livermore, CA USA. RP Turner, DD (reprint author), Pacific NW Natl Lab, Climate Dynam Grp, MS K9-24,POB 999, Richland, WA 99352 USA. NR 54 TC 87 Z9 87 U1 0 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PY 2002 VL 19 IS 1 BP 37 EP 50 DI 10.1175/1520-0426(2002)019<0037:AROWVA>2.0.CO;2 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 504XR UT WOS:000172881900003 ER PT J AU Smith, GL Pandey, DK Lee, RB Barkstrom, BR Priestley, KJ AF Smith, GL Pandey, DK Lee, RB Barkstrom, BR Priestley, KJ TI Numerical filtering of spurious transients in a satellite scanning radiometer: Application to CERES SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ENERGY SYSTEM CERES; RAINFALL MEASURING MISSION; CLOUDS; SENSORS AB The Clouds and Earth Radiant Energy System (CERES) scanning radiometer was designed to provide high accuracy measurements of the radiances from the earth. Calibration testing of the instruments showed the presence of an undesired slow transient in the measurements of all channels at 1% to 2% of the signal. Analysis of the data showed that the transient consists of a single linear mode. The characteristic time of this mode is 0.3 to 0.4 s and is much greater than that the 8-10-ms response time of the detector, so that it is well separated from the detector response. A numerical filter was designed for the removal of this transient from the measurements. Results show no trace remaining of the transient after application of the numerical filter. The characterization of the slow mode on the basis of ground calibration data is discussed and flight results are shown for the CERES instruments aboard the Tropical Rainfall Measurement Mission and Terra spacecraft. The primary influence of the slow mode is in the calibration of the instrument and the in-flight validation of the calibration. This method may be applicable to other radiometers that are striving for high accuracy and encounter a slow spurious mode, regardless of the underlying physics. C1 NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. Virginia Polytech Inst & State Univ, Hampton, VA USA. Sci Applicat Int Corp, Hampton, VA USA. RP Smith, GL (reprint author), NASA, Langley Res Ctr, Div Atmospher Sci, Mail Stop 420, Hampton, VA 23681 USA. NR 14 TC 4 Z9 4 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PY 2002 VL 19 IS 2 BP 172 EP 182 DI 10.1175/1520-0426(2002)019<0172:NFOSTI>2.0.CO;2 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 514CC UT WOS:000173418200003 ER PT J AU Gonzalez, WD Tsurutani, BT Lepping, RP Schwenn, R AF Gonzalez, WD Tsurutani, BT Lepping, RP Schwenn, R TI Interplanetary phenomena associated with very intense geomagnetic storms SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article; Proceedings Paper CT 1st STEP-Results, Applications and Modeling Phase Conference (S-RAMP) CY OCT, 2000 CL SAPPPORO, JAPAN SP Int Council Sci Unions, Sci Comm Solar Terrestrial Phys DE solar activity; interplanetary magnetic fields; geomagnetic storms ID MAGNETIC CLOUDS; COMPOUND STREAMS; CURRENT SHEET; SOLAR-CYCLE; MAGNETOSPHERE; DISTURBANCES; REGIONS; MODELS; SHOCK; FIELD AB The dominant interplanetary phenomena that are frequently associated with intense magnetic storms are the interplanetary manifestations of fast coronal mass ejections (CMEs). Two such interplanetary structures, involving an intense and long duration B-s component of the IMF are: the sheath region behind a fast forward interplanetary shock, and the CME ejecta itself. Frequently, these structures lead to the development of intense storms with two-step growth in their main phases. These structures, when combined, lead sometimes to the development of very intense storms, especially when an additional interplanetary shock is found in the sheath plasma of the primary structure accompanying another stream. The second stream can also compress the primary cloud, intensifying the B-s field, and bringing with it an additional B, structure. Thus, at times very intense storms are associated with three or more B-s structures. Another aspect that can contribute to the development of very intense storms refers to the recent finding that magnetic clouds with very intense core magnetic fields tend to have large velocities, thus implying large amplitude interplanetary electric fields that can drive very intense magnetospheric energization. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Inst Nacl Pesquisas Espaciais, BR-12201970 Sao Jose Dos Campos, SP, Brazil. CALTECH, Jet Prop Lab, Pasadena, CA USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Max Planck Inst Aeron, Lindau, Germany. RP Gonzalez, WD (reprint author), Inst Nacl Pesquisas Espaciais, BR-12201970 Sao Jose Dos Campos, SP, Brazil. NR 55 TC 60 Z9 60 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD JAN PY 2002 VL 64 IS 2 BP 173 EP 181 AR PII S1364-6826(01)00082-7 DI 10.1016/S1364-6826(01)00082-7 PG 9 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 523NZ UT WOS:000173963100006 ER PT J AU Hartmann, JM Brodbeck, C Flaud, PM Tipping, RH Brown, A Ma, Q Lievin, J AF Hartmann, JM Brodbeck, C Flaud, PM Tipping, RH Brown, A Ma, Q Lievin, J TI Collision-induced absorption in the nu(2) fundamental band of CH4. II. Dependence on the perturber gas SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID METHANE SPECTRA; N2-N2 PAIRS; TEMPERATURES; MOLECULES; 300-K; 50-K AB The integrated intensities of the collision-induced enhancement spectra of the nu (2) band of CH4 perturbed by rare gases and linear molecules (N-2, H-2, and CO2) are calculated theoretically using the quadrupole transition moment obtained from an analysis of CH4-Ar spectra. In addition to the isotropic quadrupole mechanism responsible for the enhancement in CH4-rare gases, there is additional absorption arising from the anisotropic quadrupole mechanism in the case of molecular perturbers. This latter effect involves the matrix element of the anisotropic polarizability for the nu (2) transition in CH4 that is available from the analysis of the depolarized Raman intensity measurements. Overall, the theoretical values for the slope of the enhancement spectra with respect to the perturber density are in reasonably good agreement with the experimental results, thus confirming that the collision-induced absorption arises primarily through the quadrupolar induction mechanism. (C) 2002 American Institute of Physics. C1 Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Univ Paris 11, CNRS, Photophys Mol Lab, F-91405 Orsay, France. Columbia Univ, Dept Appl Phys, New York, NY 10025 USA. NASA, Inst Space Studies, Goddard Space Flight Ctr, New York, NY 10025 USA. Free Univ Brussels, Lab Chim Phys Mol, B-1050 Brussels, Belgium. RP Tipping, RH (reprint author), Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. NR 22 TC 8 Z9 8 U1 0 U2 0 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 JAN 1 PY 2002 VL 116 IS 1 BP 123 EP 127 DI 10.1063/1.1424311 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 503EC UT WOS:000172784700015 ER PT J AU Lin, B Wielicki, BA Chambers, LH Hu, YX Xu, KM AF Lin, B Wielicki, BA Chambers, LH Hu, YX Xu, KM TI The iris hypothesis: A negative or positive cloud feedback? SO JOURNAL OF CLIMATE LA English DT Article ID EARTH AB Using the Tropical Rainfall Measuring Mission (TRMM) satellite measurements over tropical oceans, this study evaluates the iris hypothesis recently proposed by Lindzen et al. that tropical upper-tropospheric anvils act as a strong negative feedback in the global climate system. The modeled radiative fluxes of Lindzen et al. are replaced by the Clouds and the Earth's Radiant Energy System (CERES) directly observed broadband radiation fields. The observations show that the clouds have much higher albedos and moderately larger longwave fluxes than those assumed by Lindzen et al. As a result, decreases in these clouds would cause a significant but weak positive feedback to the climate system, instead of providing a strong negative feedback. C1 NASA, Langley Res Ctr, Atmospher Sci Res, Hampton, VA 23681 USA. RP Lin, B (reprint author), NASA, Langley Res Ctr, Atmospher Sci Res, MS 420, Hampton, VA 23681 USA. RI Xu, Kuan-Man/B-7557-2013; Hu, Yongxiang/K-4426-2012 OI Xu, Kuan-Man/0000-0001-7851-2629; NR 10 TC 67 Z9 73 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2002 VL 15 IS 1 BP 3 EP 7 DI 10.1175/1520-0442(2002)015<0003:TIHANO>2.0.CO;2 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 504XG UT WOS:000172881000001 ER PT J AU Hakkinen, S Mo, KC AF Hakkinen, S Mo, KC TI The low-frequency variability of the tropical Atlantic Ocean SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; NORTH-ATLANTIC; CLIMATE VARIABILITY; SST VARIABILITY; CIRCULATION; ANOMALIES; OSCILLATION; MODEL; RAINFALL; PACIFIC AB Upper-ocean temperature variability in the tropical Atlantic is examined from the Comprehensive Ocean-Atmosphere Data Set (COADS) as well as from an ocean model simulation forced by COADS anomalies appended to a monthly climatology. The findings are as follows: Only the sea surface temperatures (SST) in the northern Tropics are driven by heat fluxes, while the southern tropical variability arises from wind-driven ocean circulation changes. The subsurface temperatures in the northern and southern Tropics are found to have a strong linkage to buoyancy forcing changes in the northern North Atlantic. Evidence for Kelvin-like boundary wave propagation from the high latitudes is presented from the model simulation. This extratropical influence is associated with wintertime North Atlantic oscillation (NAO) forcing and manifests itself in the northern and southern tropical temperature anomalies of the same sign at depths of 100-200 m as result of a Rossby wave propagation away from the eastern boundary in the wake of the boundary wave passage. The most apparent association of the southern tropical sea surface temperature anomalies (SSTA) arises with the anomalous cross-equatorial winds that can be related to both NAO and the remote influence from the Pacific equatorial region. These teleconnections are seasonal, so that the NAO impact on the tropical SST is the largest at midwinter but in spring and early summer the Pacific remote influence competes with NAO. However, NAO appears to have a more substantial role than the Pacific influence at low frequencies during the last 50 years. The dynamic origin of SSTA is indirectly confirmed from the SST-heat flux relationship using ocean model experiments that remove either anomalous wind stress forcing or atmospheric forcing anomalies contributing to heat exchange. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, Climate Predict Ctr, NWS, NCEP, Camp Springs, MD USA. RP Hakkinen, S (reprint author), NASA, Goddard Space Flight Ctr, Code 971, Greenbelt, MD 20771 USA. RI Hakkinen, Sirpa/E-1461-2012 NR 39 TC 13 Z9 13 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2002 VL 15 IS 3 BP 237 EP 250 DI 10.1175/1520-0442(2002)015<0237:TLFVOT>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 511GQ UT WOS:000173256600001 ER PT J AU Dickinson, RE Berry, JA Bonan, GB Collatz, GJ Field, CB Fung, IY Goulden, M Hoffmann, WA Jackson, RB Myneni, R Sellers, PJ Shaikh, M AF Dickinson, RE Berry, JA Bonan, GB Collatz, GJ Field, CB Fung, IY Goulden, M Hoffmann, WA Jackson, RB Myneni, R Sellers, PJ Shaikh, M TI Nitrogen controls on climate model evapotranspiration SO JOURNAL OF CLIMATE LA English DT Article ID LEAF LIFE-SPAN; CARBON-DIOXIDE; USE EFFICIENCY; EMISSIONS; CANOPY; PLANTS; PHOTOSYNTHESIS; NITRIFICATION; ECOSYSTEMS; FIXATION AB Most evapotranspiration over land occurs through vegetation. The fraction of net radiation balanced by evapotranspiration depends on stomatal controls. Stomates transpire water for the leaf to assimilate carbon, depending on the canopy carbon demand, and on root uptake, if it is limiting. Canopy carbon demand in turn depends on the balancing between visible photon-driven and enzyme-driven steps in the leaf carbon physiology. The enzyme-driven component is here represented by a Rubisco-related nitrogen reservoir that interacts with plant-soil nitrogen cycling and other components of a climate model. Previous canopy carbon models included in GCMs have assumed either fixed leaf nitrogen, that is, prescribed photosynthetic capacities, or an optimization between leaf nitrogen and light levels so that in either case stomatal conductance varied only with light levels and temperature. A nitrogen model is coupled to a previously derived but here modified carbon model and includes, besides the enzyme reservoir, additional plant stores for leaf structure and roots. It also includes organic and mineral reservoirs in the soil; the latter are generated, exchanged, and lost by biological fixation, deposition and fertilization, mineralization, nitrification, root uptake, denitrification, and leaching. The root nutrient uptake model is a novel and simple, but rigorous, treatment of soil transport and root physiological uptake. The other soil components are largely derived from previously published parameterizations and global budget constraints. The feasibility of applying the derived biogeochemical cycling model to climate model calculations of evapotranspiration is demonstrated through its incorporation in the Biosphere-Atmosphere Transfer Scheme land model and a 17-yr Atmospheric Model Inter comparison Project II integration with the NCAR CCM3 GCM. The derived global budgets show land net primary production (NPP), fine root carbon, and various aspects of the nitrogen cycling are reasonably consistent with past studies. Time series for monthly statistics averaged over model grid points for the Amazon evergreen forest and lower Colorado basin demonstrate the coupled interannual variability of modeled precipitation, evapotranspiration, NPP, and canopy Rubisco enzymes. C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Carnegie Inst Washington, Dept Plant Biol, Stanford, CA 94305 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Ctr Atmospher Sci, Berkeley, CA 94720 USA. Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA USA. Univ Brasilia, Dept Bot, Brasilia, DF, Brazil. Duke Univ, Dept Bot, Durham, NC 27706 USA. Boston Univ, Dept Geog, Boston, MA 02215 USA. NASA, Johnson Space Flight Ctr, Houston, TX USA. RP Dickinson, RE (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, 221 Bobby Dodd Way, Atlanta, GA 30332 USA. RI Hoffmann, William/E-8894-2010; Goulden, Michael/B-9934-2008; collatz, george/D-5381-2012; Myneni, Ranga/F-5129-2012 OI Hoffmann, William/0000-0002-1926-823X; NR 59 TC 53 Z9 62 U1 1 U2 24 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2002 VL 15 IS 3 BP 278 EP 295 DI 10.1175/1520-0442(2002)015<0278:NCOCME>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 511GQ UT WOS:000173256600004 ER PT J AU Yang, S Lau, KM Kim, KM AF Yang, S Lau, KM Kim, KM TI Variations of the East Asian jet stream and Asian-Pacific-American winter climate anomalies SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE-TEMPERATURE; EXTRATROPICAL SST ANOMALIES; GENERAL-CIRCULATION MODEL; SUMMER MONSOON; NORTH PACIFIC; ATMOSPHERIC RESPONSE; EL-NINO; TROPICAL PACIFIC; STATIONARY WAVES; 3-DIMENSIONAL PROPAGATION AB In this study, the authors apply the NCEP-NCAR reanalysis and other observations to depict the association of the Asian-Pacific-American climate with the East Asian jet stream (EAJS). With an emphasis on boreal winter seasons and on interannual timescales, they analyze the variations of the EAJS and their relationships with El Nino-Southern Oscillation (ENSO) and extratropical North Pacific sea surface temperature (SST), and assess the relative connections of the EAJS and ENSO to the anomalies of atmospheric circulation, surface temperature, and precipitation in the Asian-Pacific-American region. It is found that the EAJS is coupled to a teleconnection pattern spanning the entire Asian-Pacific-American region with the strongest signals over east Asia and the western Pacific. This pattern differs significantly from that associated with ENSO, which influences the earth's climate extensively with a strongest impact on the climate over the central Pacific and east. A strong EAJS is associated with an intensification of the weather and climate systems in Asia and over the Pacific such as deepening of the east Asian trough and the Aleutian low and strengthening of the east Asian winter monsoon. It is linked to colder and drier conditions in east Asia and stronger convection over the tropical Asia-Australia sector. Compared with ENSO, the EAJS seems to link to the climate signals of Asia and the Pacific more strongly. An intensified EAJS is also associated with anomalies of temperature and precipitation in North America due to the related changes in stationary wave patterns. While the EAJS does not strongly link to the tropical central-eastern Pacific SST, it is significantly associated with the extratropical North Pacific SST, more specifically the second most dominant mode of the empirical orthogonal function analysis of the SST. In addition, a strong (weak) EAJS seems to follow a large (small) meridional gradient of the western Pacific SST associated with warming (cooling) in the Tropics-subtropics and cooling (warming) in the extratropics. C1 NOAA, NWS, NCEP Climate Predict Ctr, Camp Springs, MD 20746 USA. NASA, Atmospheres Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. RP Yang, S (reprint author), NOAA, NWS, NCEP Climate Predict Ctr, 5200 Auth Rd,Room 605, Camp Springs, MD 20746 USA. EM song.yang@noaa.gov RI Yang, Song/B-4952-2009; Kim, Kyu-Myong/G-5398-2014; Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 95 TC 255 Z9 335 U1 7 U2 59 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 EI 1520-0442 J9 J CLIMATE JI J. Clim. PY 2002 VL 15 IS 3 BP 306 EP 325 DI 10.1175/1520-0442(2002)015<0306:VOTEAJ>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 511GQ UT WOS:000173256600006 ER PT J AU Takemura, T Nakajima, T Dubovik, O Holben, BN Kinne, S AF Takemura, T Nakajima, T Dubovik, O Holben, BN Kinne, S TI Single-scattering albedo and radiative forcing of various aerosol species with a global three-dimensional model SO JOURNAL OF CLIMATE LA English DT Article ID GENERAL-CIRCULATION MODEL; SKY RADIANCE MEASUREMENTS; OPTICAL-PROPERTIES; SULFATE AEROSOLS; SULFUR CYCLE; ANTHROPOGENIC SULFATE; TRANSPORT SCHEMES; HEATING RATES; CLIMATE; AERONET AB Global distributions of the aerosol optical thickness, Angstromngstrom exponent, and single-scattering albedo are simulated using an aerosol transport model coupled with an atmospheric general circulation model. All the main tropospheric aerosols are treated, that is, carbonaceous (organic and black carbons), sulfate, soil dust, and sea salt aerosols. The simulated total aerosol optical thickness, Angstromngstrom exponent, and single-scattering albedo for mixtures of four aerosol species are compared with observed values from both optical ground-based measurements and satellite remote sensing retrievals at dozens of locations including seasonal variations. The mean difference between the simulation and observations is found to be less than 30% for the optical thickness and less than 0.05 for the single-scattering albedo in most regions. The simulated single-scattering albedo over the Saharan region is, however, substantially smaller than the observation, though the standard optical constant of soil dust is used in this study. The radiative forcing by the direct effect of the main tropospheric aerosols is then estimated. The global annual mean values of the total direct radiative forcing of anthropogenic carbonaceous plus sulfate aerosols are calculated to be -0.19 and -0.75 W m(-2) under whole-sky and clear-sky conditions at the tropopause, respectively. C1 Univ Tokyo, Ctr Climate Syst Res, Meguro Ku, Tokyo 1538904, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Nakajima, T (reprint author), Univ Tokyo, Ctr Climate Syst Res, Meguro Ku, 4-6-1 Komaba, Tokyo 1538904, Japan. EM teruyuki@ccsr.u-tokyo.ac.jp RI Dubovik, Oleg/A-8235-2009; Takemura, Toshihiko/C-2822-2009; Nakajima, Teruyuki/H-2370-2013 OI Dubovik, Oleg/0000-0003-3482-6460; Takemura, Toshihiko/0000-0002-2859-6067; Nakajima, Teruyuki/0000-0002-9042-504X NR 48 TC 259 Z9 269 U1 5 U2 28 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2002 VL 15 IS 4 BP 333 EP 352 DI 10.1175/1520-0442(2002)015<0333:SSAARF>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 516PF UT WOS:000173561600001 ER PT J AU Schubert, SD Suarez, MJ Pegion, PJ Kistler, MA Kumar, A AF Schubert, SD Suarez, MJ Pegion, PJ Kistler, MA Kumar, A TI Predictability of zonal means during boreal summer SO JOURNAL OF CLIMATE LA English DT Article ID NORTHERN HEMISPHERE WINTER; SEA-SURFACE TEMPERATURE; UNITED-STATES; PRECIPITATION VARIABILITY; SOIL-MOISTURE; 1988 DROUGHT; EL-NINO; CIRCULATION; ANOMALIES; GCM AB This study examines the predictability of seasonal means during boreal summer. The results are based on ensembles of June-July-August (JJA) simulations (started in mid-May) carried out with the NASA Seasonal-to-Interannual Prediction Project (NSIPP-1) atmospheric general circulation model (AGCM) forced with observed sea surface temperatures (SSTs) and sea ice for the years 1980-99. It is found that the predictability of the JJA extratropical height field is primarily in the zonal-mean component of the response to the SST anomalies. This contrasts with the cold season (January-February-March) when the predictability of seasonal means in the boreal extratropics is primarily in the wave component of the El Nino-Southern Oscillation (ENSO) response. Two patterns dominate the interannual variability of the ensemble mean JJA zonal-mean height field. One has maximum variance in the tropical/subtropical upper troposphere, while the other has substantial variance in the midlatitudes of both hemispheres. Both are symmetric with respect to the equator. A regression analysis shows that the tropical/subtropical pattern is associated with SST anomalies in the far eastern tropical Pacific and the Indian Ocean, while the midlatitude pattern is associated with SST anomalies in the tropical Pacific just east of the date line. The two leading zonal height patterns are reproduced in model runs forced with the two leading JJA SST patterns of variability. A comparison with observations shows a signature of the midlatitude pattern that is consistent with the occurrence of dry and wet summers over the United States. It is hypothesized that both patterns, while imposing only weak constraints on extratropical warm season continental-scale climates, may play a role in the predilection for drought or pluvial conditions. C1 NASA, Goddard Space Flight Ctr, Goddard Lab Atmospheres, Greenbelt, MD 20771 USA. NOAA, Climate Modeling Branch, EMC, NWS,NCEP, Washington, DC USA. Gen Sci Corp, Beltsville, MD USA. RP Schubert, SD (reprint author), NASA, Goddard Space Flight Ctr, Goddard Lab Atmospheres, Code 910-3, Greenbelt, MD 20771 USA. RI Pegion, Philip/E-5247-2012 NR 43 TC 37 Z9 39 U1 1 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2002 VL 15 IS 4 BP 420 EP 434 DI 10.1175/1520-0442(2002)015<0420:POZMDB>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 516PF UT WOS:000173561600006 ER PT J AU Murtugudde, R Beauchamp, J McClain, CR Lewis, M Busalacchi, AJ AF Murtugudde, R Beauchamp, J McClain, CR Lewis, M Busalacchi, AJ TI Effects of penetrative radiation on the upper tropical ocean circulation SO JOURNAL OF CLIMATE LA English DT Article ID WESTERN EQUATORIAL PACIFIC; SEA-SURFACE TEMPERATURE; SOLAR-RADIATION; ARABIAN SEA; MIXED-LAYER; WARM POOL; EL-NINO; SEASONAL CYCLE; INDIAN-OCEAN; WIND STRESS AB The effects of penetrative radiation on the upper tropical ocean circulation have been investigated with an ocean general circulation model (OGCM) with attenuation depths derived from remotely sensed ocean color data. The OGCM is a reduced gravity, primitive equation, sigma coordinate model coupled to an advective atmospheric mixed layer model. These simulations use a single exponential profile for radiation attenuation in the water column, which is quite accurate for OGCMs with fairly coarse vertical resolution. The control runs use an attenuation depth of 17 m while the simulations use spatially variable attenuation depths. When a variable depth oceanic mixed layer is explicitly represented with interactive surface heat fluxes, the results can be counterintuitive. In the eastern equatorial Pacific, a tropical ocean region with one of the strongest biological activity, the realistic attenuation depths result in increased loss of radiation to the subsurface, but result in increased sea surface temperatures (SSTs) compared to the control run. Enhanced subsurface heating leads to weaker stratification, deeper mixed layers, reduced surface divergence, and hence less upwelling and entrainment. Thus, some of the systematic deficiencies in the present-day climate models, such as the colder than observed cold tongue in the equatorial Pacific may simply be related to inaccurate representation of the penetrative radiation and can be improved by the formulation presented here. The differences in ecosystems in each of the tropical oceans are clearly manifested in the manner in which biological heat trapping affects the upper ocean. While the tropical Atlantic has many similarities to the Pacific, the Amazon, Congo, and Niger Rivers' discharges dominate the attenuation of radiation. In the Indian Ocean, elevated biological activity and heat trapping are away from the equator in the Arabian Sea and the southern Tropics. For climate models, in view of their sensitivity to the zonal distribution of SST, using a basin mean of the ocean color-derived attenuation depth reduces the SST errors significantly in the Pacific although they occur in regions of high mean SST and may have potential feedbacks in coupled climate models. On the other hand, the spatial variations of attenuation depths in the Atlantic are crucial since using the basin mean produces significant errors. Thus the simplest and the most economic formulation is to simply employ the annual mean spatially variable attenuation depths derived from ocean color. C1 Univ Maryland, ESSIC, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, SeaWiFS Project Off, Greenbelt, MD 20771 USA. Dalhousie Univ, Dept Oceanog, Halifax, NS, Canada. RP Murtugudde, R (reprint author), Univ Maryland, ESSIC, CSS Bldg, College Pk, MD 20742 USA. NR 49 TC 133 Z9 136 U1 5 U2 13 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2002 VL 15 IS 5 BP 470 EP 486 DI 10.1175/1520-0442(2002)015<0470:EOPROT>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 519QX UT WOS:000173737900002 ER PT J AU Kwok, R Comiso, JC AF Kwok, R Comiso, JC TI Southern Ocean climate and sea ice anomalies associated with the Southern Oscillation SO JOURNAL OF CLIMATE LA English DT Article ID ANTARCTIC CIRCUMPOLAR WAVE; INTERANNUAL VARIABILITY; EL-NINO; TELECONNECTIONS; TEMPERATURE; HEMISPHERE; EVENTS; MODEL AB The anomalies in the climate and sea ice cover of the Southern Ocean and their relationships with the Southern Oscillation (SO) are investigated using a 17-yr dataset from 1982 to 1998. The polar climate anomalies are correlated with the Southern Oscillation index (SOI) and the composites of these anomalies are examined under the positive (SOI > 0), neutral (0 > SOI > -1), and negative (SOI < -1) phases of SOI. The climate dataset consists of sea level pressure, wind, surface air temperature, and sea surface temperature fields, while the sea ice dataset describes its extent, concentration, motion, and surface temperature. The analysis depicts, for the first time, the spatial variability in the relationship of the above variables with the SOI. The strongest correlation between the SOI and the polar climate anomalies are found in the Bellingshausen, Amundsen, and Ross Seas. The composite fields reveal anomalies that are organized in distinct large-scale spatial patterns with opposing polarities at the two extremes of SOI, and suggest oscillations that are closely linked to the SO. Within these sectors, positive (negative) phases of the SOI are generally associated with lower (higher) sea level pressure, cooler (warmer) surface air temperature, and cooler (warmer) sea surface temperature in these sectors. Associations between these climate anomalies and the behavior of the Antarctic sea ice cover are evident. Recent anomalies in the sea ice cover that are clearly associated with the SOI include the following: the record decrease in the sea ice extent in the Bellingshausen Sea from mid-1988 to early 1991; the relationship between Ross Sea SST and the ENSO signal, and reduced sea ice concentration in the Ross Sea; and the shortening of the ice season in the eastern Ross Sea, Amundsen Sea, far western Weddell Sea and lengthening of the ice season in the western Ross Sea, Bellinghausen Sea, and central Weddell Sea gyre during the period 1988-94. Four ENSO episodes over the last 17 years contributed to a negative mean in the SOI (-0.5). In each of these episodes, significant retreats in ice cover of the Bellingshausen and Amundsen Seas were observed showing a unique association of this region of the Antarctic with the Southern Oscillation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kwok, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 24 TC 193 Z9 206 U1 1 U2 33 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2002 VL 15 IS 5 BP 487 EP 501 DI 10.1175/1520-0442(2002)015<0487:SOCASI>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 519QX UT WOS:000173737900003 ER PT J AU Rossow, WB Delo, C Cairns, B AF Rossow, WB Delo, C Cairns, B TI Implications of the observed mesoscale variations of clouds for the Earth's radiation budget SO JOURNAL OF CLIMATE LA English DT Article ID BOUNDARY-LAYER CLOUDS; AVERAGED SOLAR FLUXES; GENERAL-CIRCULATION MODEL; PARALLEL ALBEDO BIASES; SHAPED OPTICAL MEDIA; HIGH-LEVEL CLOUDS; HORIZONTAL VARIABILITY; SATELLITE-OBSERVATIONS; DROPLET CONCENTRATION; AIRCRAFT MEASUREMENTS AB The effect of small spatial-scale cloud variations on radiative transfer in cloudy atmospheres currently receives a lot of research attention, but the available studies are not very clear about which spatial scales are important and report a very large range of estimates of the magnitude of the effects. Also, there have been no systematic investigations of how to measure and represent these cloud variations. The cloud climatology produced by the International Satellite Cloud Climatology Project (ISCCP) is exploited to 1) define and test different methods of representing cloud variation statistics; 2) investigate the range of spatial scales that should be included; 3) characterize cloud variations over a range of time- and space scales covering mesoscale (30-300 km, 3-12 h) into part of the lower part of the synoptic scale (300-3000 km, 1-30 days); 4) obtain a climatology of the optical thickness, emissivity, and cloud-top temperature variability of clouds that can be used in weather and climate GCMs, together with the parameterization proposed by Cairns et al., to account for the effects of small-scale cloud variations on radiative fluxes; and 5) evaluate the effect of observed cloud variations on the earth's radiation budget. These results lead to the formulation of a revised conceptual model of clouds for use in radiative transfer calculations in GCMs. The complete variability climatology can be obtained from the ISCCP Web site at http://isccp.giss. nasa. gov. C1 NASA, Goddard Inst Space Studies, Columbia Univ, New York, NY 10025 USA. RP Rossow, WB (reprint author), NASA, Goddard Inst Space Studies, Columbia Univ, 2880 Broadway, New York, NY 10025 USA. RI Rossow, William/F-3138-2015; OI Cairns, Brian/0000-0002-1980-1022 NR 80 TC 58 Z9 65 U1 2 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2002 VL 15 IS 6 BP 557 EP 585 DI 10.1175/1520-0442(2002)015<0557:IOTOMV>2.0.CO;2 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 524NR UT WOS:000174020200001 ER PT J AU Colon, E Lindesay, J Suarez, MJ AF Colon, E Lindesay, J Suarez, MJ TI The impact of surface flux- and circulation-driven feedbacks on simulated Madden-Julian oscillations SO JOURNAL OF CLIMATE LA English DT Article ID 40-50 DAY OSCILLATION; AQUA PLANET MODEL; OUTGOING LONGWAVE RADIATION; LOW-FREQUENCY OSCILLATIONS; EVAPORATION-WIND FEEDBACK; AIR-SEA INTERACTION; PACIFIC WARM POOL; INTRASEASONAL OSCILLATIONS; WESTERN PACIFIC; TROPICAL ATMOSPHERE AB The intent of this study is to measure the total contribution of individual wind- and moist flux-induced feedback mechanisms on the generation and maintenance of simulated Madden-Julian oscillations (MJOs). This task is accomplished through the use of an idealized GCM that is also employed to examine the impact of sea surface temperatures on the robustness of the MJO signal. Among the mechanisms investigated are Conditional Instability of the Second Kind (CISK), Wind Induced Surface Heat Exchange (WISHE), and the feedback due to specific humidity differences between the surface and the boundary layer. A series of numerical experiments was conducted in which one or more of these feedbacks were suppressed. The resulting structure and periodicity of the simulated mode was analyzed using eigenvector and spectral analysis methods. The relative phases of surface wind, turbulent flux, and boundary layer moisture anomaly fields were then contrasted. It was found that the model produced a far stronger signal when the turbulent surface flux contributions were unsuppressed. However, the inclusion of turbulent surface fluxes yielded simulated modes possessing unrealistic frequencies of 16.79-28.83 cycles yr(-1) compared with values in other studies ranging from 6.08 to 12.16 cycles yr(-1) (30-60 days). Overall, the modes appeared to be most sensitive to the model sea surface temperatures and the availability of moisture modulated by wind-driven feedbacks. C1 Howard Univ, Dept Phys & Astron, Washington, DC 20059 USA. NASA, Goddard Space Flight Ctr, Climat & Radiat Branch, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Colon, E (reprint author), Computat Phys Inc, 8001 Braddock Rd,Suite 210, Springfield, VA 22151 USA. NR 70 TC 5 Z9 5 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2002 VL 15 IS 6 BP 624 EP 641 DI 10.1175/1520-0442(2002)015<0624:TIOSFA>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 524NR UT WOS:000174020200004 ER PT J AU Goldberg, RK Stouffer, DC AF Goldberg, RK Stouffer, DC TI Strain rate dependent analysis of a polymer matrix composite utilizing a micromechanics approach SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE polymer matrix composites; micromechanics; viscoplasticity; strength; constitutive equations; impact ID FIBER-REINFORCED COMPOSITES; FAILURE; MODEL AB A research program is in progress to develop strain rate dependent deformation and failure models for the analysis of polymer matrix composites subject to high strain rate impact loads. The Ramaswamy-Stouffer viscoplastic constitutive equations for metals have been modified to model the strain rate dependent inelastic deformation of ductile polymers, including hydrostatic stress effects. These equations have been incorporated into a mechanics of materials based micromechanics model that was developed to analyze uniaxial composites at various fiber orientation angles. The Hashin failure criteria have been implemented into the micromechanics to predict ply failure strengths. The deformation response and ply failure strengths for the representative composite AS4/PEEK have been successfully predicted for a variety of fiber orientations and strain rates. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Cincinnati, Dept Aerosp Engn & Engn Mech, Cincinnati, OH 45221 USA. RP Goldberg, RK (reprint author), NASA, Glenn Res Ctr, Mail Stop 49-7,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 30 TC 25 Z9 26 U1 2 U2 9 PU SAGE PUBLICATIONS LTD PI LONDON PA 6 BONHILL STREET, LONDON EC2A 4PU, ENGLAND SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2002 VL 36 IS 7 BP 773 EP 793 DI 10.1106/002199802024613 PG 21 WC Materials Science, Composites SC Materials Science GA 562MR UT WOS:000176201900001 ER PT J AU Lee, DG Mitrovic, M Friedman, A Carman, GP AF Lee, DG Mitrovic, M Friedman, A Carman, GP TI Characterization of fiber optic sensors for structural health monitoring SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE EFPI fiber optic strain sensor; fatigue; composites ID SMART COMPOSITE STRUCTURES AB This paper presents experimental results on thermomechanical behavior of Extrinsic Fabry-Perot Interferometric fiber optic strain sensors (EFPI-FOSS). The objective of this study was to determine the accuracy, strength characteristics, and durability properties of both bare (nonembedded) EFPI sensors, and embedded optical fiber sensors in either a neat resin or aerospace grade composite laminate, Experimental results suggest that the embedded EFPI sensors provide reliable strain measurements for values exceeding 10,000 muepsilon under static loading conditions. A major portion of this study focused on evaluating the long term tension-tension fatigue behavior of optical Fiber sensors. Test data suggest the EFPI sensors provide reliable data up to I million cycles at fatigue strain levels below 3,000 muepsilon. For fatigue strain levels above this value, failure of the fiber optic sensor was observed. While the sensor failed it did not influence the strength and fatigue life of the composite coupons. Considering the design strains used in aerospace components, these results provide evidence that the EFPI sensors will survive during the life of typical aerospace structures. C1 Univ Calif Los Angeles, Dept Mech & Aerosp Engn, Los Angeles, CA 90095 USA. NASA, Dryden Flight Res Ctr, Washington, DC USA. RP Lee, DG (reprint author), Univ Calif Los Angeles, Dept Mech & Aerosp Engn, 32-135 Engn 4, Los Angeles, CA 90095 USA. NR 17 TC 23 Z9 23 U1 1 U2 1 PU SAGE PUBLICATIONS LTD PI LONDON PA 6 BONHILL STREET, LONDON EC2A 4PU, ENGLAND SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2002 VL 36 IS 11 BP 1349 EP 1366 DI 10.1106/002199802023166 PG 18 WC Materials Science, Composites SC Materials Science GA 564PF UT WOS:000176322200005 ER PT J AU Smith, JG Connell, JW Hergenrother, PM Criss, JM AF Smith, JG Connell, JW Hergenrother, PM Criss, JM TI Resin transfer moldable phenylethynyl containing imide oligomers SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE resin transfer molding; high temperature polymers; polyimides; phenylethynyl containing imides; carbon fiber composites; oligomeric thermosetting imides ID COMPOSITE PROPERTIES; POLYIMIDE OLIGOMERS; MOLECULAR-WEIGHT; ADHESIVE; PENDENT AB As part of an effort to develop high performance/high temperature materials for composite fabrication via resin transfer molding (RTM) and resin infusion (RI), phenylethynyl-containing imide oligomers (PEIs) have been investigated. Uncured resins with low and stable melt viscosities and when cured, high glass transition temperatures (T(g)s) and acceptable mechanical properties, are needed for RTM and RI processes. High performance/high temperature composites from these materials are potentially useful in advanced aerospace vehicles such as reuseable launch vehicles (RLVs). Several PEIs were prepared and evaluated for melt flow behavior and mechanical properties after thermal curing. Candidate materials exhibited the combination of properties required for RTM with melt viscosities of 0.4-1.0 Pa s at 280degreesC and melt stability for > 2 h at 280degreesC. Flat, void-free composites fabricated by RTM gave cured Tgs as high as 350degreesC, high mechanical properties, and excellent stability at 288degreesC. The chemical, physical, and mechanical properties of these resins and their composites are discussed. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Lockheed Martin Aeronaut Syst, Marietta, GA 30063 USA. RP Smith, JG (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 36 TC 28 Z9 31 U1 3 U2 8 PU SAGE PUBLICATIONS LTD PI LONDON PA 6 BONHILL STREET, LONDON EC2A 4PU, ENGLAND SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2002 VL 36 IS 19 BP 2255 EP 2265 DI 10.1106/002199802027293 PG 11 WC Materials Science, Composites SC Materials Science GA 602TM UT WOS:000178520600003 ER PT J AU Glaessgen, EH Raju, IS Poe, CC AF Glaessgen, EH Raju, IS Poe, CC TI Analytical and experimental studies of the debonding of stitched and unstitched composite joints SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE stitching; delamination; lap joints; finite element analysis ID FAILURE CRITERION; LAP JOINTS; ELEMENTS; DELAMINATION; BEARING AB The effect of stitches on the failure of a single lap joint configuration was determined in a combined experimental and finite element study. The experimental program was conducted to determine debond growth under static monotonic loading. The stitches were shown to delay the initiation of the debond and provide load transfer after total debonding of the lap joint. The experimentally determined debond length versus applied load was used as an input parameter in the finite element analysis of both stitched and unstitched configurations. The strain energy release rates at the debond front were calculated using plate elements. Discrete nonlinear spring elements were used to model the stitches and multipoint constraints were used to model the contact problem. Models of the unstitched configuration showed significant values of mode I and II strain energy release rates across the width of the joint and showed that mode III is zero at the centerline but increases near the free edge. Models of the stitched configuration showed that the stitches were effective in reducing the mode I component to zero, but had less effect on modes II and III. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Glaessgen, EH (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 42 TC 11 Z9 12 U1 0 U2 1 PU SAGE PUBLICATIONS LTD PI LONDON PA 6 BONHILL STREET, LONDON EC2A 4PU, ENGLAND SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2002 VL 36 IS 23 BP 2599 EP 2622 DI 10.1106/002199802028683 PG 24 WC Materials Science, Composites SC Materials Science GA 628PX UT WOS:000180006100001 ER PT J AU Walker, SP AF Walker, SP TI Thermal effects on the pin-bearing behavior of IM7/PETI5 composite joints SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE composite joints; pin-bearing; thermal effects; 3D finite element stress analysis; thermal residual stresses; cure stresses ID BOLTED JOINTS; STRESSES; TEMPERATURE; STRENGTH AB Thermal effects on the pin-bearing behavior of an IM7/PETI5 composite laminate are studied comprehensively within this paper. Pin-bearing tests of several lay-ups at the operating temperatures of - 129, 21, and 177degreesC are conducted to generate data on the effect of temperature changes on the pin-bearing behavior of the IM7/PETI5 material. A unique computational study investigating the factors influencing pin-bearing strength is performed for the [90,0](8s) lay-up. A detailed three-dimensional finite element model is developed including the modeling of resin layers between plies in the laminate with a pin hole. Using a previously established technique, the pin-bearing problem was modeled assuming a rigid frictionless pin and restraining only radial displacements at the hole boundary. An original three-dimensional solution, where thermal residual stresses were combined with the state of stress due to pin-bearing loads was evaluated. The presence of thermal residual stresses were observed to intensify the interlaminar stresses predicted at the hole boundary in the pin-bearing problem. Furthermore, the research shows that changes in material properties drives pin-bearing strength degradation with increasing temperature. The thermal residual cure stresses then somewhat affect the extent that the pin-bearing strength changes with temperature. In general, thermal residual stresses were determined to be significant in affecting pin-bearing strength. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Walker, SP (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 44 TC 8 Z9 8 U1 0 U2 5 PU SAGE PUBLICATIONS LTD PI LONDON PA 6 BONHILL STREET, LONDON EC2A 4PU, ENGLAND SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2002 VL 36 IS 23 BP 2623 EP 2651 DI 10.1106/002199802027873 PG 29 WC Materials Science, Composites SC Materials Science GA 628PX UT WOS:000180006100002 ER PT J AU Kumosa, M Odegard, G Armentrout, D Kumosa, L Searles, K Sutter, JK AF Kumosa, M Odegard, G Armentrout, D Kumosa, L Searles, K Sutter, JK TI Comparison of the +/- 45 degrees tensile and Iosipescu shear tests for woven fabric composite materials SO JOURNAL OF COMPOSITES TECHNOLOGY & RESEARCH LA English DT Article DE woven carbon/PMR-15 composite; Iosipescu test; +/- 45 degrees tensile test AB The mechanical response of a woven eight-harness satin graphite/polyimide composite has been investigated by performing +/-45degrees tensile and Iosipescu shear tests at room temperature. Nonlinear finite element simulations of the tests have been conducted to determine internal stress distributions in the +/-45degrees tensile and Iosipescu fabric specimens as a function of load. In the experimental part of this study, a series of tensile and Iosipescu shear tests have been performed. Acoustic emission techniques have been employed to monitor damage initiation and progression in the composite. The Finite element computations have shown that the internal stress distributions in the Iosipescu and tensile fabric specimens are significantly different. In the gage sections of Iosipescu specimens, the state of stress is essentially pure shear, whereas the tensile tests generate biaxial stress conditions. It has been shown in this research that the shear strength of the composite determined from the maximum loads obtained from the Iosipescu shear tests is significantly higher than the shear strength obtained from the +/-45degrees tensile tests. Moreover, the initiation of intralaminar damage in the tensile specimens occurs at much lower loads than in the Iosipescu specimens. It appear,; that the +/-45degrees tensile test significantly underestimates the shear strength of the composite evaluated from the onset of intralaminar damage and the maximum loads. C1 Univ Denver, Dept Engn, Ctr Adv Mat & Struct, Denver, CO 80208 USA. Oregon Grad Inst Sci & Technol, Dept Mat Sci & Engn, Portland, OR 97291 USA. NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Kumosa, M (reprint author), Univ Denver, Dept Engn, Ctr Adv Mat & Struct, 2390 S York St, Denver, CO 80208 USA. NR 9 TC 17 Z9 17 U1 2 U2 4 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0884-6804 J9 J COMPOS TECH RES JI J. Compos. Technol. Res. PD JAN PY 2002 VL 24 IS 1 BP 3 EP 16 PG 14 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA 554AK UT WOS:000175710500001 ER PT J AU Milano, M Koumoutsakos, P AF Milano, M Koumoutsakos, P TI A clustering genetic algorithm for cylinder drag optimization SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE flow control; optimization; genetic algorithm; bluff body flow ID REDUCTION; DESIGN AB A real coded genetic algorithm is implemented for the optimization of actuator parameters for cylinder drag minimization. We consider two types of idealized actuators that are allowed either to move steadily and tangentially to the cylinder surface ("belts") or to steadily blow/suck with a zero net mass constraint. The genetic algorithm we implement has the property of identifying minima basins,rather than single optimum points. The knowledge of the shape of the minimum basin enables further insights into the system properties and provides a sensitivity analysis in a fully automated way. The drag minimization problem is formulated as an optimal regulation problem. By means of the clustering property of the present genetic algorithm, a set of solutions producing drag reduction of up to 50% is identified. A comparison between the two types of actuators, based on the clustering property of the algorithm, indicates that blowing/suction actuation parameters are associated with larger tolerances when compared to optimal parameters for the belt actuators. The possibility of using a few strategically placed actuators to obtain a significant drag reduction is explored using the clustering diagnostics of this method. The optimal belt-actuator parameters obtained by optimizing the two-dimensional case is employed in three-dimensional simulations, by extending the actuators across the span of the cylinder surface. The three-dimensional controlled flow exhibits a strong two-dimensional character near the cylinder surface, resulting in significant drag reduction. (C) 2002 Elsevier Science. C1 ETH Zentrum, Inst Computat Sci, CH-8092 Zurich, Switzerland. NASA, Ames Res Ctr, CTR, Moffett Field, CA 94035 USA. RP Milano, M (reprint author), ETH Zentrum, Inst Computat Sci, CH-8092 Zurich, Switzerland. RI Koumoutsakos, Petros/A-2846-2008 OI Koumoutsakos, Petros/0000-0001-8337-2122 NR 28 TC 28 Z9 29 U1 3 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JAN 1 PY 2002 VL 175 IS 1 BP 79 EP 107 DI 10.1006/jcph.2001.6882 PG 29 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 511TC UT WOS:000173280800004 ER PT J AU Zhang, ZC Yu, STJ Chang, SC AF Zhang, ZC Yu, STJ Chang, SC TI A space-time conservation element and solution element method for solving the two- and three-dimensional unsteady Euler equations using quadrilateral and hexahedral meshes SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE the Eular equations; conservation laws; CE/SE method ID LAWS AB In this paper, we report a version of the space-time conservation element and solution element (CE/SE) method in which the 2D and 3D unsteady Euler equations are simulated using structured or, unstructured quadrilateral and hexahedral meshes, respectively. In the present method, mesh values of flow variables and their spatial derivatives are treated as independent unknowns to be solved for. At each mesh point, the value of a flow variable is obtained by imposing a flux conservation condition. On the other hand, the spatial derivatives are evaluated using a finite-difference/weighted-average procedure. Note that the present extension retains many key advantages of the original CE/SE method which uses triangular and tetrahedral meshes, respectively, for its 2D and 3D applications. These advantages include efficient parallel computing, ease of implementing nonreflecting boundary conditions, high-fidelity resolution of shocks and waves, and a genuinely multidimensional formulation without the need to use a dimensional-splitting approach. In particular, because Riemann solvers-the cornerstones of the Godunov-type upwind schemes-are not needed to capture shocks, the computational logic of the present method is considerably simpler. To demonstrate the capability of the present method, numerical results are presented for several benchmark problems including oblique shock reflection, supersonic flow over a wedge, and a 3D detonation flow. (C) 2002 Elsevier Science. C1 Wayne State Univ, Dept Mech Engn, Detroit, MI 48202 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Zhang, ZC (reprint author), Wayne State Univ, Dept Mech Engn, Detroit, MI 48202 USA. NR 29 TC 73 Z9 81 U1 4 U2 10 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JAN 1 PY 2002 VL 175 IS 1 BP 168 EP 199 DI 10.1006/jcph.2001.6934 PG 32 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 511TC UT WOS:000173280800007 ER PT J AU Mavriplis, DJ AF Mavriplis, DJ TI An assessment of linear versus nonlinear multigrid methods for unstructured mesh solvers SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE multigrid; unstructured; Krylov ID NONEQUILIBRIUM RADIATION DIFFUSION; EULER EQUATIONS; AGGLOMERATION; FLOWS AB The relative performance of a nonlinear fall approximation storage multigrid algorithm and an equivalent linear multigrid algorithm for solving two different nonlinear problems is investigated. The first case consists of a transient radiation diffusion problem for which an exact linearization is available, while the second problem involves the solution of the steady-state Navier-Stokes equations, where a first-order discrete Jacobian is employed as an approximation to the Jacobian of a second-order-accurate discretization. When an exact linearization is employed, the linear and nonlinear multigrid methods asymptotically converge at identical rates and the linear method is found to be more efficient due to its lower cost per cycle. When an approximate linearization is employed, as in the Navier-Stokes cases, the relative efficiency of the linear approach versus the nonlinear approach depends both on the degree to which the linear system approximates the full Jacobian as wen as on the relative cost of linear versus nonlinear multigrid cycles. For cases where convergence is limited by a poor Jacobian. approximation, substantial speedup can be obtained using either multigrid method as a preconditioner to a Newton-Krylov method. (C) 2002 Elsevier Science. C1 NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. RP Mavriplis, DJ (reprint author), NASA, Langley Res Ctr, ICASE, MS 132C, Hampton, VA 23681 USA. NR 31 TC 39 Z9 39 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JAN 1 PY 2002 VL 175 IS 1 BP 302 EP 325 DI 10.1006/jcph.2001.6948 PG 24 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 511TC UT WOS:000173280800012 ER PT J AU Dold, P Szofran, FR Benza, KW AF Dold, P Szofran, FR Benza, KW TI Detached growth of gallium doped germanium SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE Bridgman technique; detached Bridgman; de-wetting; semiconducting germanium ID BRIDGMAN GROWTH; SURFACE-TENSION; CRYSTAL-GROWTH; CONTACT-ANGLE; ZERO-GRAVITY; SOLIDIFICATION; MICROGRAVITY; CRUCIBLES; MELTS; INSB AB Detached Bridgman growth of gallium-doped germanium itself as well as the transition from detached to attached growth was observed in-situ for the first time, using a quartz-glass ampoule in a mirror furnace. Crystal diameter was 9 mm, the growth length 41 mm, and the growth velocity 0.5 mm/min. Undoped 111-oriented germanium served as seed material; the melt was doped with gallium (C-0 = 8.2 x 10(18) at/cm(3)). Detachment took place after a growth length of 7 mm and continued for 27 mm; the remaining 7 mm. grew with wall contact again. The wall-free growth could be observed around the entire circumference except for some small bridges (width: a few tens of micrometers, length: some hundreds of micrometers), where the crystal grew in contact with the wall. In the detached-grown part of the crystal, the 111-related growth lines are clearly visible. The transition from attached to detached growth and vice versa did not take place along a straight fine but transitioned as islands over a length of about I mm. The gap between the growing crystal and the container wall varied between 10 and 80 mum, as measured by a profilometer. The etch pit density is greatly reduced in the part of the crystal that grew free of the wall. An increase in the EPD is seen in the area where the crystal had contact with the ampoule wall by the bridges described above. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Univ Freiburg, Inst Kristallog, D-79104 Freiburg, Germany. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Dold, P (reprint author), Univ Freiburg, Inst Kristallog, Hebelstr 25, D-79104 Freiburg, Germany. NR 33 TC 20 Z9 20 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JAN PY 2002 VL 234 IS 1 BP 91 EP 98 DI 10.1016/S0022-0248(01)01659-1 PG 8 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 490DD UT WOS:000172034400012 ER PT J AU Su, CH Sha, YG Lehoczky, SL Szofran, FR Gillies, DC Scripa, RN Cobb, SD Wang, JC AF Su, CH Sha, YG Lehoczky, SL Szofran, FR Gillies, DC Scripa, RN Cobb, SD Wang, JC TI Crystal growth of HgZnTe alloy by directional solidification in low gravity environment SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE characterization; defects; dendrites; directional solidification; solid solutions; Bridgman technique; growth from melt; microgravity conditions; zinc compounds; semiconducting II-VI materials; semiconducting mercury compounds ID PSEUDOBINARY; MELTS AB An Hg0.84Zn0.16 Te alloy crystal was back-melted and partially resolidified during the first United States Microgravity Laboratory mission in the Marshall Space Flight Center's Crystal Growth Furnace. The experiment was inadvertently terminated at about 30% of planned completion. Nonetheless, it was successfully demonstrated that a HgZnTe alloy ingot partially grown and quenched on the ground can be back-melted and regrown in space under nearly steady-state growth conditions. An identical "ground-truth" experiment was performed following the mission and a comparison between the properties of the crystals is described. The results indicate the importance of residual microgravity acceleration (less than or similar to 0.4 mug) even in the submicrogravity range for the slow solidification velocities and large density gradients. Published by Elsevier Science B.V. C1 NASA, George C Marshall Space Flight Ctr, Micrograv Sci & Applicat Dept, Sci Directorate, Huntsville, AL 35812 USA. Univ Alabama, Birmingham, AL 35294 USA. Alabama A&M Univ, Normal, AL 35762 USA. RP Su, CH (reprint author), NASA, George C Marshall Space Flight Ctr, Micrograv Sci & Applicat Dept, Sci Directorate, SD46, Huntsville, AL 35812 USA. NR 11 TC 2 Z9 2 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JAN PY 2002 VL 234 IS 2-3 BP 487 EP 497 DI 10.1016/S0022-0248(01)01735-3 PG 11 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 507XX UT WOS:000173057500035 ER PT J AU Zhu, S Su, CH Cochrane, JC Lehoczky, S Cui, Y Burger, A AF Zhu, S Su, CH Cochrane, JC Lehoczky, S Cui, Y Burger, A TI Growth orientation of carbon nanotubes by thermal chemical vapor deposition SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE low dimensional structure; growth from vapor; nanomaterials ID DIAMETER; ARRAYS AB Carbon nanotubes (CNT) were synthesized using thermal chemical vapor deposition. The diameters of these CNT were quite uniform with the length of the CNT up to several tens of micrometers, With the substrate surface normal either along or against the gravity vector, different growth orientations or CNT were observed by scanning electron microscopy. The Raman spectra were similar for samples synthesized at different locations. These results suggest that gravity affects the growth of long CNT with small diameters. (C) 2002 Elsevier Science B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. NASA, George C Marshall Space Flight Ctr, Micrograv Sci & Applicat Dept, Sci Directorate, Huntsville, AL 35812 USA. Fisk Univ, Ctr Photon Mat, Nashville, TN 37208 USA. RP Zhu, S (reprint author), NASA, George C Marshall Space Flight Ctr, Space Sci Lab, USRA-SD47, Huntsville, AL 35812 USA. NR 19 TC 18 Z9 21 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JAN PY 2002 VL 234 IS 2-3 BP 584 EP 588 DI 10.1016/S0022-0248(01)01709-2 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 507XX UT WOS:000173057500048 ER PT J AU Arakere, NK Swanson, G AF Arakere, NK Swanson, G TI Effect of crystal orientation on fatigue failure of single crystal nickel base turbine blade superalloys SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT 45th International Gas Turbine and Aeroengine Congress and Exhibition CY MAY 08-11, 2000 CL MUNICH, GERMANY ID STRESS AB High cycle fatigue (HCF) induced failures in aircraft gas turbine and rocket engine turbopump blades is a pervasive problem. Single crystal nickel turbine blades are being utilized in rocket engine turbopumps and jet engines throughout industry because of their superior creep, stress rupture, melt resistance, and thermomechanical fatigue capabilities over polycrystalline alloys. Currently the most widely used single crystal turbine blade superalloys are PWA 1480/1493, PWA 1484, RENE' N-5 and CMSX-4. These alloys play an important role in commercial, military and space propulsion systems. Single crystal materials have highly, orthotropic properties making the position of the crystal lattice relative to the part geometry a significant factor in the overall analysis. The failure modes of single crystal turbine blades are complicated to predict due to the material orthotropy and variations in crystal orientations. Fatigue life estimation of single crystal turbine blades represents an important aspect of durability assessment. It is therefore of practical interest to develop effective fatigue failure criteria for single crystal nickel alloys and to investigate the effects of variation of primary and secondary crystal orientation on fatigue life. A fatigue failure criterion based on the maximum shear stress amplitude [Deltatau(max)] on the 24 octahedral and 6 cube slip systems, is presented for single crystal nickel superalloys (FCC crystal). This criterion reduces the scatter in uniaxial LCF test data considerably for PWA 1493 at 1200degreesF in air. Additionally, single crystal turbine blades used in the alternate advanced high-pressure fuel turbopump (AHPFTP/AT) are modeled using a large-scale three-dimensional finite element model This finite element model is capable of accounting for material orthotrophy and variation in primary and secondary crystal orientation. Effects of variation in crystal orientation on blade stress response are studied based on 297 finite element model runs. Fatigue lives at critical points in the blade are computed using finite element stress results and the failure criterion developed. Stress analysis results in the blade attachment region are also presented. Results presented demonstrates that control of secondary and primary crystallographic orientation has the potential to significantly increase a component's resistance to fatigue crack growth without adding additional weight or cost. C1 Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. NASA, George C Marshall Space Flight Ctr, Strength Anal Grp ED33, Huntsville, AL 35812 USA. RP Arakere, NK (reprint author), Univ Florida, Dept Mech Engn, Gainesville, FL 32611 USA. NR 15 TC 55 Z9 64 U1 5 U2 38 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 2002 VL 124 IS 1 BP 161 EP 176 DI 10.1115/1.1413767 PG 16 WC Engineering, Mechanical SC Engineering GA 547ML UT WOS:000175336100022 ER PT J AU Cooper, CD Clausen, CA Pettey, L Collins, MM de Fernandez, MP AF Cooper, CD Clausen, CA Pettey, L Collins, MM de Fernandez, MP TI Investigation of ultraviolet light-enhanced H2O2 oxidation of NOx emissions SO JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE LA English DT Article DE hydrogen peroxide; oxidation; nitrogen oxide; emissions ID HYDROGEN-PEROXIDE AB Injecting aqueous solutions of hydrogen peroxide (14202) into hot flue gases can convert nitric oxide (NO) to higher oxidation states (NO2, HNO2, and HNO3), which can then be removed in a wet scrubber. The optimum temperature for such conversion is 500degreesC (930degreesF), at which H2O2 is thermally "activated" (split into free radicals). At lower temperatures ultraviolet (UV) light can be used to activate the peroxide molecules. In this pilot plant study at Kennedy Space Center, experiments were done with none, one, or two UV lamps on, with and without SO2 present in the flue gases, at various temperatures, and with various injection rates of peroxide. Temperatures ranged from 117 to 350degreesC (243 to 660degreesF), and the molar ratios (peroxide to NO,) ranged from 0.68 to 5.02. Conversions of NO varied from below 10 to above 70%, with the highest conversions occurring with higher temperatures, higher dosages of hydrogen peroxide, and with both UV lamps turned on. Conversions of NOx (NO+ NO2) varied from below 5 to above 40%. The presence of SO2 did not inhibit NO or NOx conversion. C1 Univ Cent Florida, Dept Civil & Environm Engn, Orlando, FL 32816 USA. Univ Cent Florida, Dept Chem, Orlando, FL 32816 USA. NASA, Kennedy Space Ctr, Cape Canaveral, FL USA. Florida Inst Technol, Melbourne, FL 32901 USA. RP Cooper, CD (reprint author), Univ Cent Florida, Dept Civil & Environm Engn, POB 162450, Orlando, FL 32816 USA. OI Pozo de Fernandez, Maria/0000-0002-1663-5858 NR 8 TC 23 Z9 26 U1 6 U2 19 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 0733-9372 J9 J ENVIRON ENG-ASCE JI J. Environ. Eng.-ASCE PD JAN PY 2002 VL 128 IS 1 BP 68 EP 72 DI 10.1061/(ASCE)0733-9372(2002)128:1(68) PG 5 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 512EN UT WOS:000173308300010 ER PT J AU Olsen, N Moretto, T Friis-Christensen, E AF Olsen, N Moretto, T Friis-Christensen, E TI New approaches to explore the Earth's magnetic field SO JOURNAL OF GEODYNAMICS LA English DT Article AB New strategies are presented for the analysis of the high-precision geomagnetic data that are currently obtained by the low-orbiting satellites Orsted, CHAMP and Orsted-2/SAC-C. The measured magnetic field is the sum of contributions from various sources in the core, crust, ionosphere and magnetosphere, and the accuracy of core and crustal field models is affected by ionospheric and magnetospheric source contributions. A proper parameterization of these external sources, together with a careful data pre-selection, is necessary to avoid spurious effects. In addition, the advantage of having multiple satellite missions measuring simultaneously over different regions of the Earth is discussed, and swarm, a proposed constellation consisting of 6 satellites in two different orbit planes, is presented. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Danish Space Res Inst, DK-2100 Copenhagen, Denmark. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Olsen, N (reprint author), Danish Space Res Inst, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark. RI Olsen, Nils/H-1822-2011; Moretto, Therese/B-6846-2013 OI Olsen, Nils/0000-0003-1132-6113; Moretto, Therese/0000-0002-2403-5561 NR 7 TC 6 Z9 7 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0264-3707 J9 J GEODYN JI J. Geodyn. PD JAN-MAR PY 2002 VL 33 IS 1-2 BP 29 EP 41 AR PII S0264-3707(01)00052-7 DI 10.1016/S0264-3707(01)00052-7 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 539RZ UT WOS:000174885700006 ER PT J AU Ravat, D Wang, B Wildermuth, E Taylor, PT AF Ravat, D Wang, B Wildermuth, E Taylor, PT TI Gradients in the interpretation of satellite-altitude magnetic data: an example from central Africa SO JOURNAL OF GEODYNAMICS LA English DT Article ID POLYGONAL CROSS-SECTION; ANALYTIC SIGNAL; ORIGIN; ANOMALIES; BODIES; SHOCK; ROCKS; EARTH; DEPTH; FIELD AB The Euler and the analytic signal methods have been implemented in spherical coordinates to facilitate the interpretation of spherically- registered potential-field anomaly data collected by satellites. Model studies show that the methods are able to delineate the edges of idealized models even from 400 km altitude; the depth resolution is, however, not adequate from this altitude. A very large magnetic anomaly, the Bangui anomaly in central Africa, was studied using these methods. These results, from Magsat data, suggest that impact related remagnetization (Girdler, R.W.,Taylor, P.T., Frawley, J.J., 1992, A possible impact origin for the Bangui magnetic anomaly (Central Africa), Tectonophysics, 212, 45-58) and presence of a highly magnetic source (Ravat, D., Hinze, W.J., von Frese, R.R.B., 1992, Analysis of Magsat magnetic contrasts across Africa and South America. Tectonophysics 212, 59-76) near the center of the impact structure are likely contributors to the anomaly. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 So Illinois Univ, Dept Geol, Carbondale, IL 62901 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ravat, D (reprint author), So Illinois Univ, Dept Geol, MS 4324, Carbondale, IL 62901 USA. RI Taylor, Patrick/D-4707-2012; OI Taylor, Patrick/0000-0002-1212-9384; Ravat, Dhananjay/0000-0003-1962-4422 NR 32 TC 12 Z9 15 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0264-3707 J9 J GEODYN JI J. Geodyn. PD JAN-MAR PY 2002 VL 33 IS 1-2 BP 131 EP 142 AR PII S0264-3707(01)00059-X DI 10.1016/S0264-3707(01)00059-X PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 539RZ UT WOS:000174885700013 ER PT J AU Atlas, D Ulbrich, CW Marks, FD AF Atlas, D Ulbrich, CW Marks, FD TI Potential for estimating cloud liquid water path over sea ice from airborne passive microwave measurements - Reply SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material DE tropical rain types ID RAINDROP SPECTRA; STRATIFORM; RADAR C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Hurricane Res Div, Miami, FL 33149 USA. RP Atlas, D (reprint author), 7420 Westlake Terrace, Bethesda, MD 20817 USA. EM datlas@trmm.gsfc.nasa.gov; cwulbr@hubcap.clemson.edu; frank.marks@noaa.gov RI Marks, Frank/A-5733-2011 OI Marks, Frank/0000-0003-0371-5514 NR 10 TC 1 Z9 1 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 JAN PY 2002 VL 107 IS D1-D2 AR 4006 DI 10.1029/2001JD000658 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 609EC UT WOS:000178889800016 ER PT J AU Hidalgo, MA Cid, C Vinas, AF Sequeiros, J AF Hidalgo, MA Cid, C Vinas, AF Sequeiros, J TI A non-force-free approach to the topology of magnetic clouds in the solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE magnetic clouds; interplanetary magnetic fields ID CORONAL MASS EJECTIONS; SPACECRAFT; EVENTS AB [1] We present a new model for the topology of magnetic clouds at 1 AU that relates the magnetic field vector with the current density of the cloud without assuming the force-free condition. In addition, the model is formulated in such a way that it can be fitted directly to the data without the need of initially determining the flux rope axis by minimum variance. The model provides both the magnetic field strength and the direction in just one fitting procedure. In addition to the orientation of its axis and the relative closest-approach distance between the spacecraft and the cloud axis, the fit of the model to the experimental data allows an estimation of the current density of plasma inside the magnetic cloud. From our study on several clouds we conclude that this has values of the order of 10(-12) C m(-2) s(-1). Compared with the force-free model, although the improvement gained in the chi(2) values is not very great, the fitting procedure is shorter and easier, and the number of parameters involved has been reduced from seven to five. Our model also lets us check the validity of force-free approximation by the calculation of the value of the current density perpendicular to the flux rope, j(perpendicular to) = j x B/\B\. This component is assumed to be zero in the force-free model, but for all analyzed cases we obtain a nonzero value. This finite value implies the existence of pressure gradients inside the cloud that cannot be explained with a force-free approximation. In this paper, four cases are presented that have already been analyzed in the literature. We show that our model can explain the profiles of the magnetic field as a magnetic cloud passes a spacecraft. C1 Univ Alcala de Henares, Dept Fis, E-28871 Alcala De Henares, Madrid, Spain. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Hidalgo, MA (reprint author), Univ Alcala de Henares, Dept Fis, E-28871 Alcala De Henares, Madrid, Spain. NR 23 TC 46 Z9 47 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 JAN PY 2002 VL 107 IS A1 AR 1002 DI 10.1029/2001JA900100 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 609MD UT WOS:000178907300014 ER PT J AU Yang, YH Chao, JK Lin, CH Shue, JH Wang, XY Song, P Russell, CT Lepping, RP Lazarus, AJ AF Yang, YH Chao, JK Lin, CH Shue, JH Wang, XY Song, P Russell, CT Lepping, RP Lazarus, AJ TI Comparison of three magnetopause prediction models under extreme solar wind conditions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NEAR-EARTH MAGNETOTAIL; GEOSYNCHRONOUS ORBIT; MAGNETIC-FIELD; FLARING ANGLE; 6.6 RE; SHAPE; CROSSINGS; SIZE; PRESSURE; LOCATION AB [1] A database, the largest one to date, of magnetosheath encounters by geosynchronous satellites during 1986-1992 and 1999-2000 and upstream observations by Wind, IMP 8, or Geotail in the solar wind are used to estimate the forecasting capability of the models of Chao et al. [2001], Shue et al. [1998], and Petrinec and Russell [1996]. For each of the 1-min resolution data points obtained by GOES spacecraft, we check the following two things: if the magnetosheath was observed by the spacecraft, and if each of the three models predicted a magnetosheath encounter by the spacecraft. Three parameters are defined to quantify the models' forecasting capability: probability of prediction (PoP), probability of detection (PoD), and false alarm rate (FAR). A higher PoP and PoD with a lower FAR imply a better forecasting model. In the 1986-1992 period we found that most of the magnetosheath encounters observed at 6.6 R(E) are detected. In particular, the Chao et al. [2001] model predicts the lowest FAR compared with those of the other two models. We have also studied the magnetosheath encounters made by GOES spacecraft for the period from 1999 to 2000 using Wind and Geotail as the solar wind monitor. This independent database of magnetosheath encounters during 1999-2000 confirms our previous anticipations. The PoD of Petrinec and Russell [1996] model (94%) is much higher than those of Shue et al. [1998] (74%) and Chao et al. [2001] (84%) models. The Chao et al. [2001] model has a higher PoP than the other two models. The values of FAR for Chao et al. [2001], Shue et al. [1998], and Petrinec and Russell [1996] models are 25, 27, and 40%, respectively. C1 Natl Cent Univ, Inst Space Sci, Chungli 32054, Taiwan. Nan Jeon Inst Technol, Dept Elect Engn, Yenshui, Taiwan. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Acad Sinica, Ctr Space Sci & Appl Res, Beijing, Peoples R China. Univ Massachusetts, Ctr Atmospher Res, Lowell, MA 01854 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. RP Yang, YH (reprint author), Natl Cent Univ, Inst Space Sci, Chungli 32054, Taiwan. EM hyyang@jupiter.ss.ncu.edu.tw NR 25 TC 21 Z9 22 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-SPACE JI J. Geophys. Res-Space Phys. PD JAN PY 2002 VL 107 IS A1 AR 1008 DI 10.1029/2001JA000079 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 609MD UT WOS:000178907300008 ER PT J AU Price, SF Bindschadler, RA Hulbe, CL Blankenship, DD AF Price, SF Bindschadler, RA Hulbe, CL Blankenship, DD TI Force balance along an inland tributary and onset to Ice Stream D, West Antarctica SO JOURNAL OF GLACIOLOGY LA English DT Article ID SUBGLACIAL GEOLOGY; LATERAL DRAG; MASS-BALANCE; FLOW; SHEET; BUDGET; RADAR; CONFIGURATION; PATTERNS; GLACIER AB The transition from inland- to streaming-style ice flow near to and upstream from the onset to Ice Stream D, West Antarctica, is investigated using the force-balance technique. Basal drag provides the majority of the flow resistance over the study area but is substantially modified by non-local stress gradients. Lateral drag increases with distance downstream, balancing similar to 50-100% of the driving stress at the onset. Longitudinal stress gradients (LSG) are also found to be significant, an observation that distinguishes ice flow in this region from the inland- and streaming-flow regimes that bound it, in which LSG are usually negligible. LSG decrease the spatial variability in basal drag and sliding speed and increase the area of the bed over which frictional melting occurs. Overall, LSG decrease the resistive influence of basal stress concentrations and increase the spatial uniformity of basal sliding. These observations suggest that streaming flow develops as ail integrated response to the physical interaction between the Ice and its bed over all extended region upstream from the onset, rather than being solely due to changes in basal characteristics at the onset. An implication is that non-steady-flow behavior upstream from the onset may ultimately propagate downstream and result in non-steady behavior at the onset. C1 SAIC Gen Sci Corp, Beltsville, MD 20705 USA. NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. Univ Maryland, Baltimore Cty GEST Ctr, NASA, Goddard Space Flight Ctr,Oceans & Ice Branch, Greenbelt, MD 20771 USA. Univ Texas, Inst Geophys, Austin, TX 78759 USA. RP Price, SF (reprint author), Univ Washington, Dept Earth & Space Sci, Seattle, WA 98195 USA. EM sprice@geophys.washington.edu RI Blankenship, Donald/G-5935-2010; Price, Stephen /E-1568-2013 OI Price, Stephen /0000-0001-6878-2553 NR 44 TC 31 Z9 31 U1 1 U2 2 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2002 VL 48 IS 160 BP 20 EP 30 DI 10.3189/172756502781831539 PG 11 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 585PX UT WOS:000177534700003 ER PT J AU Zwally, HJ Jun, L AF Zwally, HJ Jun, L TI Seasonal and interannual variations of firn densification and ice-sheet surface elevation at the Greenland summit SO JOURNAL OF GLACIOLOGY LA English DT Article ID MASS-BALANCE; SNOW-ACCUMULATION; ANTARCTICA; DENSITY; MODEL; CORE; FLUCTUATIONS; VARIABILITY; ISLAND; CREEP AB Seasonal and interannual variations in surface elevation at the Greenland summit are modeled using a new temperature-dependent formulation of firn densification and are compared with elevations from European Remote-sensing Satellite (ERS-1/-2) radar altimetry. The rate constant and activation energy, usually set as constants in the Arrhenius-type relation, are strongly temperature-dependent, based on measurements of crystal-growth rates. A multiplicative factor in the densification rate accounts for differences between densification and grain-growth rates and is chosen to match the modeled and measured density profiles from 0 to 40 in. The stronger temperature dependence produces a significant seasonal cycle in the densification rate in the upper firn. Much of the densification and consequent surface lowering occur within 3 months in late spring/early summer, followed by a build-up from accumulation. Modeled elevation changes, using automatic weather station measurements of temperature and accumulation and modeled precipitation, agree well with observations. The respective seasonal amplitudes are 18 and 25 cm peak-to-peak with minima in mid-summer. The minimum elevation in 1995 is driven mainly by a temporary accumulation decrease and secondarily by warmer temperatures. Increased compaction driven by a summer warming trend decreases the modeled elevation (1992-99) by 20 cm, but accumulation increases in latter years dominate the overall 4.2 cm a(-1) trend. C1 NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. RP Zwally, HJ (reprint author), NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Code 971, Greenbelt, MD 20771 USA. NR 41 TC 71 Z9 72 U1 1 U2 14 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2002 VL 48 IS 161 BP 199 EP 207 DI 10.3189/172756502781831403 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 627PP UT WOS:000179941700003 ER PT J AU Bamber, J Rignot, E AF Bamber, J Rignot, E TI Unsteady flow inferred for Thwaites Glacier, and comparison with Pine Island Glacier, West Antarctica SO JOURNAL OF GLACIOLOGY LA English DT Article ID GREENLAND ICE-SHEET; RADAR INTERFEROMETRY; BALANCE VELOCITIES; ALTIMETER DATA; MODEL AB We present a comparison of surface velocities in 1996, derived from interferometric synthetic aperture radar, with an estimate of the long-term, depth-averaged velocity based on the assumption of steady-state flow for both Pine Island Glacier and its neighbour, Thwaites Glacier, West Antarctica. The results show that the former was close to balance conditions in 1996 (within 9%). The ice flux and velocity of the latter is significantly different in magnitude and distribution from that required to maintain the basin in a state of mass balance over the long term. The balance flux was found to be 32 +/- 19% less than the measured outgoing flux. We conclude that the mass imbalance and dramatic difference in the pattern of flow is most likely due to a substantial change in the flow regime of Thwaites Glacier in the recent past. C1 Univ Bristol, Bristol Glaciol Ctr, Ctr Polar Observat & Modelling, Bristol BS8 1SS, Avon, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bamber, J (reprint author), Univ Bristol, Bristol Glaciol Ctr, Ctr Polar Observat & Modelling, Univ Rd, Bristol BS8 1SS, Avon, England. RI Bamber, Jonathan/C-7608-2011; Rignot, Eric/A-4560-2014 OI Bamber, Jonathan/0000-0002-2280-2819; Rignot, Eric/0000-0002-3366-0481 NR 23 TC 9 Z9 9 U1 1 U2 8 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2002 VL 48 IS 161 BP 237 EP 246 DI 10.3189/172756502781831395 PG 10 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 627PP UT WOS:000179941700007 ER PT J AU Rignot, E AF Rignot, E TI Ice-shelf changes in Pine Island Bay, Antarctica, 1947-2000 SO JOURNAL OF GLACIOLOGY LA English DT Article ID BOTTOM CREVASSES; WEST ANTARCTICA; AMUNDSEN SEA; MELT RATES; GLACIER; CLIMATE; SHEET AB Aerial photographs from 1947 and 1966, satellite optical imagery from 1973 and 1980, and interferometric synthetic aperture radar (InSAR) data from 1992, 1996 and 2000 are employed to detect ice-shelf changes in Pine Island Bay, Antarctica. The front position of the fast-flowing central ice shelf did not migrate discernibly over the past 50 years. New cracks and rifts appeared in the 1990s, however, that reveal a major weakening of the ice shelf. At the grounding-line center, the ice shelf thinned 21 in in 8 years. The northern, slow-moving ice shelf also shows signs of decay: (1) its calving front is retreating at an accelerating rate; and (2) the ice shelf is slowly unpinning from its bedrock anchors. These changes are taking place in a region well beyond the temperature-dependent limit of viability of ice shelves, and hence differ from those observed along the Antarctica Peninsula. They are likely due to a change in oceanic forcing, not to a change in air temperature. One possibility is that the documented intrusion of warm circumpolar deep water on the continental shelf has increased basal melting compared to that required to maintain the ice shelf in a state of mass balance, and that this has triggered a general retreat of ice in this sector. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Rignot, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Rignot, Eric/A-4560-2014 OI Rignot, Eric/0000-0002-3366-0481 NR 32 TC 48 Z9 48 U1 0 U2 7 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2002 VL 48 IS 161 BP 247 EP 256 DI 10.3189/172756502781831386 PG 10 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 627PP UT WOS:000179941700008 ER PT J AU Bindschadler, RA AF Bindschadler, RA TI History of lower Pine Island Glacier, West Antarctica, from Landsat imagery SO JOURNAL OF GLACIOLOGY LA English DT Article ID ICE AB A 28 year record of lower Pine Island Glacier, West Antarctica, constructed from 15 Landsat images, shows changes at the terminus, grounding zone and both margins. The north margin has expanded 5 km into the adjacent ice shelf in a sustained event that was underway in 1973 and may have begun in 1957. Between 1991 and 1997, this expansion ceased and a new region of rifting was created associated with an ice rise on the glacier's floating tongue. Changes in the topography of a nearby ice rise are used to deduce an upper-bound estimate of a 134 in thinning of the adjacent ice shelf On the south margin, widening was limited to 1 km over the observation period and is seen propagating downstream in an intermediate-dated image. New areas of crevassing are also evident in the grounding zone of the glacier. Ice loss by the calving of large tabular bergs vastly exceeds mass loss by calving of many small bergs. These observations are consistent with reported changes of the 1990s and indicate that changes in the flow of Pine Island Glacier have occurred over the full period of satellite observations. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Oceans & Ice Branch, Greenbelt, MD 20771 USA. RP Bindschadler, RA (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Oceans & Ice Branch, Code 971, Greenbelt, MD 20771 USA. NR 10 TC 16 Z9 16 U1 0 U2 1 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2002 VL 48 IS 163 BP 536 EP 544 DI 10.3189/172756502781831052 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 692AL UT WOS:000183638100006 ER PT J AU Schmeltz, M Rignot, E Dupont, TK MacAyeal, DR AF Schmeltz, M Rignot, E Dupont, TK MacAyeal, DR TI Sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions: a model study SO JOURNAL OF GLACIOLOGY LA English DT Article ID STREAM-B; DYNAMICS; SHEET; FLOW AB We use a finite-element model of coupled ice-stream/ice-shelf flow to study the sensitivity of Pine Island Glacier, West Antarctica, to changes in ice-shelf and basal conditions. By tuning a softening coefficient of the ice along the glacier margins, and a basal friction coefficient controlling the distribution of basal shear stress underneath the ice stream, we are able to match model velocity to that observed with interferometric synthetic aperture radar (InSAR). We use the model to investigate the effect of small perturbations on ice flow. We find that a 5.5-13% reduction in our initial ice-shelf area increases the glacier velocity by 3.5-10% at the grounding line. The removal of the entire ice shelf increases the grounding-line velocity by >70%. The changes in velocity associated with ice-shelf reduction are felt several tens of km inland. Alternatively, a 5% reduction in basal shear stress increases the glacier velocity by 13% at the grounding line. By contrast, softening of the glacier side margins would have to be increased a lot more to produce a comparable change in ice velocity. Hence, both the ice-shelf buttressing and the basal shear stress contribute significant resistance to the flow of Pine Island Glacier. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. RP Schmeltz, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Rignot, Eric/A-4560-2014; OI Rignot, Eric/0000-0002-3366-0481; MacAyeal, Douglas/0000-0003-0647-6176 NR 23 TC 37 Z9 38 U1 0 U2 11 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2002 VL 48 IS 163 BP 552 EP 558 DI 10.3189/172756502781831061 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 692AL UT WOS:000183638100008 ER PT J AU Carsey, F Behar, A Lane, AL Realmuto, V Engelhardt, H AF Carsey, F Behar, A Lane, AL Realmuto, V Engelhardt, H TI A borehole camera system for imaging the deep interior of ice sheets SO JOURNAL OF GLACIOLOGY LA English DT Article AB The design and first deployment is described for the Jet Propulsion Laboratory-California Institute of Technology ice borehole camera system for acquisition of down-looking and side-looking images in a borehole made by a hot-water drill. The objective of the system is to acquire images in support of studies of the basal dynamics and thermodynamics of West Antarctic ice streams. A few sample images, obtained during the 2000/01 Antarctic field season, are shown from the basal layers of Ice Stream C. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Carsey, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 15 TC 27 Z9 27 U1 2 U2 3 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2002 VL 48 IS 163 BP 622 EP 628 DI 10.3189/172756502781831124 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 692AL UT WOS:000183638100016 ER PT J AU Bar-Itzhack, IY Harman, RR AF Bar-Itzhack, IY Harman, RR TI Optimal fusion of a given quaternion with vector measurements SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article C1 NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Guidance Navigat & Control Ctr, Greenbelt, MD 20771 USA. RP Bar-Itzhack, IY (reprint author), NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Guidance Navigat & Control Ctr, Code 572, Greenbelt, MD 20771 USA. NR 3 TC 1 Z9 2 U1 1 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD JAN-FEB PY 2002 VL 25 IS 1 BP 188 EP 190 DI 10.2514/2.4868 PG 3 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 513XH UT WOS:000173405800025 ER PT J AU Bhatt, RT Hull, DR Eldridge, JI Babuder, R AF Bhatt, RT Hull, DR Eldridge, JI Babuder, R TI Effects of interface coating and nitride enhancing additive on properties of Hi-Nicalon SiC Fiber reinforced reaction-bonded silicon nitride composites SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID OXIDATION AB Strong and tough Hi-Nicalon SiC fiber reinforced reaction-bonded silicon nitride matrix composites (SiC/RBSN) have been fabricated by the fiber lay-up approach. Commercially available uncoated and PBN, PBN/Si-rich PBN, and BN/SiC coated SiC Hi-Nicalon fiber tows were used as reinforcement. The composites contained similar to 24 vol% of aligned 14 mum diameter SiC fibers in a porous RBSN matrix. Both one- and two-dimensional composites were characterized. The effects of interface coating composition, and the nitridation enhancing additive, NiO, on the room temperature physical, tensile, and interfacial shear strength properties of SiC/RBSN matrix composites were evaluated. Results indicate that for all three coated fibers, the thickness of the coatings decreased from the outer periphery to the interior of the tows, and that from 10 to 30 percent of the fibers were not covered with the interface coating. In the uncoated regions, chemical reaction between the NiO additive and the SiC fiber occurs causing degradation of tensile properties of the composites. Among the three interface coating combinations investigated, the BN/SiC coated Hi-Nicalon SiC fiber reinforced RBSN matrix composite showed the least amount of uncoated regions and reasonably uniform interface coating thickness. The matrix cracking stress in SiC/RBSN composites was predicted using a fracture mechanics based crack bridging model. (C) 2002 Kluwer Academic Publishers. C1 USA, Res Lab, Glenn Res Ctr, Cleveland, OH 44135 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. RP Bhatt, RT (reprint author), USA, Res Lab, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 17 TC 5 Z9 6 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD JAN PY 2002 VL 37 IS 1 BP 141 EP 150 DI 10.1023/A:1013118514195 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 500XT UT WOS:000172654500016 ER PT J AU Castellani, OC de Oliveira, HP AF Castellani, OC de Oliveira, HP TI On solitons with nonminimally coupled scalar fields SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID BLACK-HOLES; KINK SOLUTION; HAIR THEOREM; INFLATION AB A nonsingular static and spherically symmetric space-time endowed with nonminimally coupled scalar field described by the action S=integrald(4) x (root -g/2)(R-g(alpha beta)phi (,alpha) phi (,beta)-xi R phi (2)) is presented for the case in which the coupling parameter xi >1/6. This solitonlike space-time is obtained using the technique of conformal transformation that associates solutions produced by ordinary scalar fields in general relativity with those with nonminimally coupled scalar fields. The dynamical stability of the solution is examined through the Galerkin method. (C) 2002 American Institute of Physics. C1 Univ Estado Rio de Janeiro, Inst Fis, Dept Fis Teor, BR-20550013 Rio De Janeiro, Brazil. Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. RP Univ Estado Rio de Janeiro, Inst Fis, Dept Fis Teor, BR-20550013 Rio De Janeiro, Brazil. EM otavio@dft.if.uerj.br; henrique@fnal.gov NR 28 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0022-2488 EI 1089-7658 J9 J MATH PHYS JI J. Math. Phys. PD JAN PY 2002 VL 43 IS 1 BP 508 EP 518 DI 10.1063/1.1421060 PG 11 WC Physics, Mathematical SC Physics GA 503GF UT WOS:000172790200032 ER PT J AU West, WC Whitacre, JF White, V Ratnakumar, BV AF West, WC Whitacre, JF White, V Ratnakumar, BV TI Fabrication and testing of all solid-state microscale lithium batteries for microspacecraft applications SO JOURNAL OF MICROMECHANICS AND MICROENGINEERING LA English DT Article AB A microfabrication process has been developed to prepare thin film solid-state lithium batteries as small as 50 mum x 50 mu m. Individual cells operate nominally at 3.9 V with 10 muA h cm(-2) for a 0.25 mum thick cathode film. The cells are easily fabricated in series and parallel arrangement to yield batteries with higher voltage and/or capacity. Multiple charge/discharge cycles are possible, though an apparent reaction of the in situ plated Li film with water or oxygen decreases cycle life several orders of magnitude from expected results. Further optimization of an encapsulating him will likely extend the cell cyclability. These microbattery arrays will be useful for providing on-chip power for low current. high voltage applications for microspacecraft and other miniaturized systems. C1 CALTECH, Jet Prop Lab, Ctr Integrated Space Microsyst, Electrochem Technol Grp,Micro Device Labs, Pasadena, CA 91109 USA. RP West, WC (reprint author), CALTECH, Jet Prop Lab, Ctr Integrated Space Microsyst, Electrochem Technol Grp,Micro Device Labs, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 72 Z9 72 U1 2 U2 26 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0960-1317 J9 J MICROMECH MICROENG JI J. Micromech. Microeng. PD JAN PY 2002 VL 12 IS 1 BP 58 EP 62 DI 10.1088/0960-1317/12/1/309 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Instruments & Instrumentation; Physics, Applied SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation; Physics GA 517UK UT WOS:000173628400009 ER PT J AU Zheng, JP Huang, CK AF Zheng, JP Huang, CK TI Electrochemical behavior of amorphous and crystalline ruthenium oxide electrodes SO JOURNAL OF NEW MATERIALS FOR ELECTROCHEMICAL SYSTEMS LA English DT Article DE ruthenium oxide; electrochemical capacitors; crystalline structure; and cyclic voltammetry ID CAPACITORS; RUO2; DENSITY; CHARGE; ENERGY AB The electrochemical behaviors of amorphous and crystalline ruthenium oxide materials were studied by cyclic voltammetry (CV) in the electrolyte of sulfuric acid solution. The CV scans were performed both in one whole-range and two half-ranges within the electrochemical stability windows of the systems. It was found that the amorphous materials, as compared to the crystalline ones, had higher specific capacitance, wider operating potential range, and more symmetrical current distribution in these ranges. The possible implications of electrochemical behaviors to the performance of capacitors made with these materials as electrodes were discussed. C1 Florida A&M Univ, Dept Elect & Comp Engn, Tallahassee, FL 32310 USA. Florida State Univ, Tallahassee, FL 32310 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Zheng, JP (reprint author), Florida A&M Univ, Dept Elect & Comp Engn, Tallahassee, FL 32310 USA. NR 18 TC 13 Z9 14 U1 0 U2 4 PU ECOLE POLYTECHNIQUE MONTREAL PI MONTREAL PA C P 6079, SUCC CENTRE-VILLE, MONTREAL, QC H3C 3A7, CANADA SN 1480-2422 J9 J NEW MAT ELECTR SYS JI J. New Mat.Electrochem. Syst. PD JAN PY 2002 VL 5 IS 1 BP 41 EP 46 PG 6 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 525TA UT WOS:000174086000007 ER PT J AU Kelton, KF Gangopadhyay, AK Lee, GW Hannet, L Hyers, RW Krishnan, S Robinson, MB Rogers, J Rathz, TJ AF Kelton, KF Gangopadhyay, AK Lee, GW Hannet, L Hyers, RW Krishnan, S Robinson, MB Rogers, J Rathz, TJ TI X-ray and electrostatic levitation undercooling studies in Ti-Zr-Ni quasicrystal forming alloys SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 55th Yamada Conference/11th International Conference on Liquid and Amorphous Metals (LAM 11) CY SEP 09-14, 2001 CL YOKOHAMA, JAPAN SP Yamada Sci Fdn, Keio Univ, Fac Sci & Technol, Yokohama Convent & Visitors Bur ID RANGE ORDER; LIQUIDS; NUCLEATION; CRYSTAL; GLASSES AB The first undercooling measurements on electrostatic-levitated droplets of TiZrNi alloys that form the icosahedral quasicrystal phase are presented. The reduced undercooling for crystallization decreases with an increasing polytetrahedral order of the primary solidifying phase, suggesting the development of icosahedral short-range order in the undercooled liquid. X-ray diffraction measurements made at the advanced photon source on liquid droplets of these alloys, aerodynamically levitated and heated to near their liquidus temperature, however, show only weak evidence for increased icosahedral order. This suggests that significant ordering occurs below the melting temperature. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Washington Univ, Dept Phys, St Louis, MO 63130 USA. CNRS, CRMHT, F-45071 Orleans 2, France. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. KLA Tencor Film & Surface Technol, San Jose, CA 95134 USA. RP Kelton, KF (reprint author), Washington Univ, Dept Phys, Campus Box 1105,1 Brookings Dr, St Louis, MO 63130 USA. EM kfk@wuphys.wustl.edu RI Hyers, Robert/G-3755-2010 NR 11 TC 36 Z9 37 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 EI 1873-4812 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PY 2002 VL 312-14 BP 305 EP 308 AR PII S0022-3093(02)01691-5 DI 10.1016/S0022-3093(02)01691-5 PG 4 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 607UT UT WOS:000178809700058 ER PT J AU Zhang, NL Chao, DF Yang, WJ AF Zhang, NL Chao, DF Yang, WJ TI Convective instability in transient evaporating thin liquid layers SO JOURNAL OF NON-EQUILIBRIUM THERMODYNAMICS LA English DT Article ID DRIVEN BENARD-CONVECTION AB Experimental results on the convective instability of a transient evaporating thin liquid layer are reported. Evaporation is identified as an agent causing Rayleigh-Benard convection and/or Marangoni-Benard convection. Convective flow occurs in the evaporating liquid layer as long as the evaporation is strong enough, regardless of whether the layer is heated or cooled from below. The wavelength of the cells maintains a preference value in steady evaporation. When an evaporating thin layer is strongly cooled from below, both the nonlinear temperature profile of the layer and the flow pattern change rapidly during the transient evaporation process. The wavelength of convection cells increases with time and tends towards the preference value with the approach of a steady evaporation stage. A modified Marangoni number and a modified Rayleigh number serve as the dimensionless control parameters for this system. C1 NASA, Glemm Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. Univ Michigan, Dept Mech Engn & Engn Sci, Ann Arbor, MI 48109 USA. RP Zhang, NL (reprint author), NASA, Glemm Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. NR 27 TC 0 Z9 0 U1 0 U2 1 PU WALTER DE GRUYTER & CO PI BERLIN PA GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY SN 0340-0204 J9 J NON-EQUIL THERMODY JI J. Non-Equilib. Thermodyn. PY 2002 VL 27 IS 1 BP 71 EP 89 DI 10.1515/JNETDY.2002.005 PG 19 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA 556YZ UT WOS:000175878800005 ER PT J AU Canuto, VM Howard, A Cheng, Y Dubovikov, MS AF Canuto, VM Howard, A Cheng, Y Dubovikov, MS TI Ocean turbulence. Part II: Vertical diffusivities of momentum, heat, salt, mass, and passive scalars SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID TRACER-RELEASE EXPERIMENT; ANNUAL-MEAN CLIMATOLOGY; WAVE-WAVE INTERACTIONS; THERMOHALINE CIRCULATION; BOUNDARY-LAYER; INTERNAL WAVES; RICHARDSON-NUMBER; DYNAMICAL MODEL; STRATIFIED FLOWS; ABYSSAL OCEAN AB A Reynolds stress-based model is used to derive algebraic expressions for the vertical diffusivities K-alpha (alpha = m, h, s) for momentum, heat, and salt. The diffusivities are expressed as K-alpha(R-rho, N, Ri(T), epsilon) in terms of the density ratio R-rho = alpha(s)partial derivativeS/partial derivativez(alpha(T)partial derivativeT/partial derivativez)(-1), the Brunt-Vaisala frequency N-2 = -grho(o)(-1)partial derivativerho/partial derivativez, the Richardson number Ri(T) = N-2/Sigma(2) (Sigma is the shear), and the dissipation rate of kinetic energy epsilon. The model is valid both in the mixed layer (ML) and below it. Here R-rho and N are computed everywhere using the large-scale fields from an ocean general circulation model while Ri(T) is contributed by resolved and unresolved shear. In the ML, the wind-generated large-scale shear dominates and can be computed within an OGCM. Below the ML, the wind is no longer felt and small-scale shear dominates. In this region, the model provides a new relation Ri(T) = cf (R-rho) with c approximate to 1 in lieu of Munk's suggestion Ri(T) approximate to c. Thus, below the ML, the K-alpha become functions of R-rho, N, and epsilon. The dissipation epsilon representing the physical processes responsible for the mixing, which are different in different parts of the ocean, must also be expressed in terms of the large-scale fields. In the ML, the main source of stirring is the wind but below the ML there is more than one possible source of stirring. For regions away from topography, one can compute epsilon using a model for internal waves. On the other hand, near topography, one must employ different expressions for epsilon. In agreement with the data, the resulting diffusivities are location dependent rather than universal values. Using North Atlantic Tracer Release Experiment (NATRE) data, the authors test the new diffusivities with and without an OGCM. The measured diffusivities are well reproduced. Also, a set of global T and S profiles is computed using this model and the KPP model. The profiles are compared with Levitus data. In the North Atlantic, at 24degreesN, the meridional overturning is close to the measured values of 17 +/- 4 Sv and 16 +/- 5 Sv (Sv = 10(6) m(3) s(-1)). The polar heat transport for the North Atlantic Ocean, the Indo-Pacific Ocean, and the global ocean are generally lowered by double diffusion. The freshwater budget is computed and compared with available data. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys, New York, NY 10027 USA. RP Canuto, VM (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM acvmc@giss.nasa.gov NR 84 TC 81 Z9 87 U1 1 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PY 2002 VL 32 IS 1 BP 240 EP 264 DI 10.1175/1520-0485(2002)032<0240:OTPIVD>2.0.CO;2 PG 25 WC Oceanography SC Oceanography GA 511HC UT WOS:000173257700013 ER PT J AU Heaton, AF Strange, NJ Longuski, JM Bonfiglio, EP AF Heaton, AF Strange, NJ Longuski, JM Bonfiglio, EP TI Automated design of the europa orbiter tour SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB Before the Europa Orbiter can be placed in orbit about Europa, it will be placed into a 200-day Jovian orbit and targeted for Ganymede. After a series of gravity-assist flybys of the Galilean satellites, the orbital energy is reduced to lower the arrival hyperbolic excess velocity at Europa. These energy-saving techniques reduce the propellant cost for Europa orbit insertion to a minimum. Key constraints during the tour include total time of flight and radiation dosage. Tours may employ 10 or more encounters with the Jovian satellites; hence, there is an enormous number of possible sequences of these satellites. A graphical method based on Tisserand's criterion is presented that greatly aids the design process. The Tisserand graph method facilitates the study of a wide range of arrival conditions, arrival dates, and satellite tours. C1 Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Heaton, AF (reprint author), NASA, George C Marshall Space Flight Ctr, Miss Design Sect, Huntsville, AL 35812 USA. NR 12 TC 32 Z9 32 U1 1 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2002 VL 39 IS 1 BP 17 EP 22 DI 10.2514/2.3801 PG 6 WC Engineering, Aerospace SC Engineering GA 523AE UT WOS:000173928500003 ER PT J AU Penzo, PA AF Penzo, PA TI To the far side of the sun using Venus gravity assist SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/AAS Astrodynamics Specialist Conference CY AUG 14-17, 2000 CL DENVER, COLORADO SP Amer Inst Aeronaut & Astronaut, AAS AB The recent NASA initiative to investigate our sun in depth, called "Living with a Star," includes consideration of several possible deep-space missions, one of which is placing a satellite on the far side of the sun. This satellite, together with Earth, can then observe the full evolution of solar phenomena as the sun rotates. Unfortunately, in using a direct approach celestial mechanics does not permit satellite placement to be done efficiently and in a timely manner. Here, the direct approach for satellite placement is shown to be costly compared with the use of Venus gravity assist. This paper investigates specifically the insertion of a far-side sentinel satellite in the year 2009 into the third quadrant (180 to 270 deg ahead of Earth) using single and double Venus gravity assists. Options for other possible missions, including a distributed set of solar observers, are briefly analyzed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Penzo, PA (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 AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2002 VL 39 IS 1 BP 37 EP 40 DI 10.2514/2.3779 PG 4 WC Engineering, Aerospace SC Engineering GA 523AE UT WOS:000173928500006 ER PT J AU Lee, AY Wertz, JA AF Lee, AY Wertz, JA TI In-flight estimation of the cassini spacecraft's inertia tensor SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID MASS C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. MIT, Space Syst Lab, Cambridge, MA 02139 USA. RP Lee, AY (reprint author), CALTECH, Jet Prop Lab, Mail Stop 230-104,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 25 Z9 27 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2002 VL 39 IS 1 BP 153 EP 155 DI 10.2514/2.3795 PG 3 WC Engineering, Aerospace SC Engineering GA 523AE UT WOS:000173928500022 ER PT J AU Leatherwood, JD Sullivan, BM Shepherd, KP McCurdy, DA Brown, SA AF Leatherwood, JD Sullivan, BM Shepherd, KP McCurdy, DA Brown, SA TI Summary of recent NASA studies of human response to sonic booms SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article; Proceedings Paper CT Acoustical-Society-of-America-Sonic-Boom Symposium held at the ASA 136th Meeting CY OCT 15-16, 1998 CL NORFOLK, VIRGINIA SP Acoust Soc Amer Son Boom, ASA, Phys Acous Noise & Anim Bioacoust Tech Comm ID VIBRATION; NOISE AB NASA Langley Research Center has conducted three groups of studies on human response to sonic booms: laboratory, "inhome," and field. The laboratory studies were designed to: (1) quantify loudness and annoyance response to a wide range of shaped sonic boom signatures and (2) assess several noise descriptors as estimators of sonic boom subjective effects. The studies were conducted using a sonic boom simulator capable of generating and playing, with high fidelity, both user-prescribed and recorded boom waveforms to test subjects. Results showed that sonic boom waveform shaping provided substantial reductions in loudness and annoyance and that perceived level was the best estimator of subjective effects. Booms having asymmetrical waveforms were found to be less loud than symmetrical waveforms of equivalent perceived level. Subjective responses to simulated ground-reflected waveforms were fully accounted for by perceived level. The inhome study presented participants with simulated sonic booms played within their normal home environment. The results showed that the equal energy theory of annoyance applied to a variety of multiple sonic boom exposures. The field studies concluded that sonic boom annoyance is greater than that in a conventional aircraft noise environment with the same continuous equivalent noise exposure. (C) 2002 Acoustical Society of America. C1 NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA. NR 27 TC 21 Z9 21 U1 0 U2 1 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JAN PY 2002 VL 111 IS 1 BP 586 EP 598 DI 10.1121/1.1371767 PN 2 PG 13 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 513TC UT WOS:000173394500014 PM 11837964 ER PT J AU Carlson, RM AF Carlson, RM TI Helicopter performance - Transportation's latest chromosome: The 21st Annual Alexander A. Nikolsky Lecture SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article; Proceedings Paper CT 57th Annual Forum of the American-Helicopter-Society CY 2001 CL WASHINGTON, D.C. SP Amer Helicopter Soc C1 USA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 15 TC 2 Z9 3 U1 0 U2 0 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD JAN PY 2002 VL 47 IS 1 BP 3 EP 17 PG 15 WC Engineering, Aerospace SC Engineering GA 517YP UT WOS:000173638500001 ER PT J AU Tischler, MB Tomashofski, CA AF Tischler, MB Tomashofski, CA TI Flight test identification of SH-2G flapped-rotor helicopter flight mechanics models SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article ID SYSTEM-IDENTIFICATION; DESIGN AB A flight testing and system identification program was conducted on the SH-2G helicopter to support the development of a new digital flight control system and piloted simulation. Higher-order state-space models, which include the coupled rotor/fuselage/engine/inflow dynamics, were determined using CIFER(R) (Comprehensive Identification from Frequency Responses) at three airspeeds that span the flight envelope: hover, 60 knots, and 100 knots. This paper discusses the flight testing techniques, the development of a physics-based identification model structure, and identification techniques that are suitable across the flight envelope. The frequency-domain system identification methods commonly used on conventional helicopters are seen to be well suited to flap-controlled rotor configurations. While key SH-2G response characteristics are not well modeled by existing analytical simulations, the flight-identified models for the SH-2G closely match the frequency response flight test database and accurately predict the time-domain response to control doublet inputs. The identified models are characterized by highly coupled fuselage-rotor dynamics, a high degree of pitch-roll inter-axis control coupling, and important effects of engine dynamics. The identified derivatives vary smoothly with airspeed and are consistent with theoretical predictions for standard hinge-offset rotors. C1 Aeroflightdynam Directorate AMRDEC, Ames Res Ctr, Moffett Field, CA 94035 USA. Kaman Aerosp Corp, Bloomfield, CT USA. RP Tischler, MB (reprint author), Aeroflightdynam Directorate AMRDEC, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 31 TC 2 Z9 2 U1 0 U2 2 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD JAN PY 2002 VL 47 IS 1 BP 18 EP 32 PG 15 WC Engineering, Aerospace SC Engineering GA 517YP UT WOS:000173638500002 ER PT J AU Kottapalli, S AF Kottapalli, S TI Neural network based representation of UH-60A pilot and hub accelerations SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article; Proceedings Paper CT American-Helicopter-Society-Aeromechanics-Specialists Meeting CY NOV 13-14, 2000 CL ATLANTA, GEORGIA SP Amer Helicopter Soc Aeromech Specialists AB Neural network relationships between the full-scale, experimental hub accelerations and the corresponding pilot floor vertical vibration are studied. The present quantitative effort represents an initial, systematic study on the UH-60A Black Hawk hub accelerations. The NASA/Army UH-60A Airloads Program flight test database is used. A physics-based "maneuver-effect-factor (MEF)," derived from the roll-angle and the pitch-rate, is used as well. Three neural network based representation-cases are considered. The pilot floor vertical vibration is considered in the first case and the hub accelerations are separately considered in the second case. The third case considers both the hub accelerations and the pilot floor vertical vibration. Neither the advance ratio nor the gross weight alone can be used to predict the pilot floor vertical vibration. However, the advance ratio and the gross weight together can be used to predict the pilot floor vertical vibration over the entire flight envelope. The hub accelerations data are modeled and found to be of acceptable quality. The hub accelerations alone cannot represent the pilot floor vertical vibration. The hub accelerations and the advance ratio can be used to represent the pilot floor vertical vibration. Also, the hub accelerations along with the advance ratio and the gross weight can be used to represent the pilot floor vertical vibration. Thus, the hub accelerations are clearly a factor in determining the pilot floor vertical vibration. C1 NASA, Ames Res Ctr, Army NASA Rotorcraft Div, Aeromech Branch, Moffett Field, CA 94035 USA. RP Kottapalli, S (reprint author), NASA, Ames Res Ctr, Army NASA Rotorcraft Div, Aeromech Branch, Moffett Field, CA 94035 USA. NR 12 TC 3 Z9 3 U1 0 U2 0 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD JAN PY 2002 VL 47 IS 1 BP 33 EP 41 PG 9 WC Engineering, Aerospace SC Engineering GA 517YP UT WOS:000173638500003 ER PT J AU Huff, EM Tumer, IY Barszcz, E Dzwonczyk, M McNames, J AF Huff, EM Tumer, IY Barszcz, E Dzwonczyk, M McNames, J TI An analysis of maneuvering effects on transmission vibrations in an AH-1 Cobra helicopter SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article AB During the past several years, an AH-1 Cobra aircraft at the NASA Ames Research Center has been instrumented with tri-axial accelerometers and a data acquisition system to support an experimental study of in-flight transmission vibration patterns. This paper describes the on-board HealthWatch system and presents important statistical analyses of the collected data sets. These analyses provide insight into how transmission vibration responds to several factors typically related to health and usage monitoring systems (HUMS), such as maneuver condition, order of execution, and pilot differences. Although a large database of flight recordings has been collected, these results focus on an overall analysis of planetary ring gear data that were recorded in two sets of flights. It is shown that variability due to torque is a major factor to be considered in real-time HUMS design and that certain steady state maneuvers yield a dramatically higher percentage of stationary recordings. Finally, it is conjectured that multi-axis recording may have previously unrecognized advantages for signal conditioning or analysis. C1 NASA, Ames Res Ctr, Computat Sci Div, Moffett Field, CA 94035 USA. Sigpro, Mt View, CA 94041 USA. RP Huff, EM (reprint author), NASA, Ames Res Ctr, Computat Sci Div, Moffett Field, CA 94035 USA. NR 17 TC 6 Z9 6 U1 1 U2 5 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD JAN PY 2002 VL 47 IS 1 BP 42 EP 49 PG 8 WC Engineering, Aerospace SC Engineering GA 517YP UT WOS:000173638500004 ER PT J AU Mettler, B Tischler, MB Kanade, T AF Mettler, B Tischler, MB Kanade, T TI System identification Modeling of a small-scale unmanned rotorcraft for flight control design SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article AB This paper describes the development of a parameterized model for a small-scale unmanned helicopter (Yamaha R-50 with 10 ft rotor diameter) and its identification using a frequency domain identification technique. The model explicitly accounts for the stabilizer bar, which has a strong influence on the flight dynamics characteristics. The accuracy of the identified model is verified by comparing the model-predicted responses with the responses collected during flight experiments. Furthermore, the values of key identified parameters are compared with the values predicted by helicopter theory to show that the model has a physically meaningful parameterization. Both hover and cruise flight conditions are examined. C1 Carnegie Mellon Univ, Inst Robot, Pittsburgh, PA 15213 USA. USA Aviat & Missile Command, Ames Res Ctr, Aeriflightdynam AMRDEC, Moffett Field, CA 94035 USA. RP Mettler, B (reprint author), Carnegie Mellon Univ, Inst Robot, Pittsburgh, PA 15213 USA. NR 15 TC 79 Z9 93 U1 0 U2 14 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD JAN PY 2002 VL 47 IS 1 BP 50 EP 63 PG 14 WC Engineering, Aerospace SC Engineering GA 517YP UT WOS:000173638500005 ER PT J AU Lewicki, DG AF Lewicki, DG TI Gear crack propagation path studies-guidelines for ultra-safe design SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article ID STRESS INTENSITY FACTORS; FATIGUE-CRACK; NUMERICAL-METHODS; TOOTH; TEETH; GROWTH AB Design guidelines are established to prevent catastrophic rim fracture failure modes when considering gear tooth bending fatigue. Analysis is performed using the finite element method with principles of linear elastic fracture mechanics. Crack propagation paths are predicted for a variety of gear tooth and rim configurations. The effects of rim and web thicknesses, initial crack locations, and gear tooth geometry factors such as diametral pitch, number of teeth, pitch radius, and tooth pressure angle are considered. Design maps of tooth/rim fracture modes including effects of gear geometry, applied load, crack size and material properties are developed. The occurrence of rim fractures significantly increases as the backup ratio (rim thickness divided by tooth height) decreases. The occurrence of rim fractures also increases as the initial crack location is moved down the root of the tooth. Increased rim and web compliance increases the occurrence of rim fractures. For gears with constant pitch radii, coarser-pitch teeth increases the occurrence of tooth fractures over rim fractures. Also, 25 pressure angle teeth has an increased occurrence of tooth fractures over rim fractures when compared to 20 pressure angle teeth. When comparing gears with the same number of teeth or for gears with constant diametral pitch, varying size has little or no effect on crack propagation paths. C1 USA, Res Lab, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Lewicki, DG (reprint author), USA, Res Lab, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 30 TC 18 Z9 21 U1 0 U2 6 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD JAN PY 2002 VL 47 IS 1 BP 64 EP 72 PG 9 WC Engineering, Aerospace SC Engineering GA 517YP UT WOS:000173638500006 ER PT J AU Desai, PN Mitcheltree, RA Cheatwood, FM AF Desai, PN Mitcheltree, RA Cheatwood, FM TI Sample return missions in the coming decades: A comparison of entry, descent, and landing scenarios SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article; Proceedings Paper CT 51st International Astronautical Congress CY OCT 02-06, 2000 CL RIO JANEIRO, BRAZIL ID DISPERSION ANALYSIS; CAPSULE; AERODYNAMICS AB In the coming decades, several missions will attempt to return samples to Earth from varying parts of the solar system. These samples will provide invaluable insight into the conditions present during the early formation of the solar system, and possibly give clues to how life began on Earth. A description of five sample return missions is presented (Stardust, Genesis, Muses-C, Mars Sample Return, and Comet Nucleus Sample Return). An overview of each sample return mission is given, concentrating particularly on the technical challenges posed during the Earth entry, descent, and landing phase of the missions. Each mission faces unique challenges in the design of an Earth entry capsule. The design of the entry capsule must address the aerodynamic, heating, deceleration, landing, and recovery requirements for the safe return of samples to Earth. C1 NASA, Langley Res Ctr, Aerosp Syst Concepts & Anal Competency, Hampton, VA 23665 USA. NASA, Langley Res Ctr, Explorat Programs Off, Hampton, VA 23665 USA. RP Desai, PN (reprint author), NASA, Langley Res Ctr, Aerosp Syst Concepts & Anal Competency, Hampton, VA 23665 USA. NR 21 TC 1 Z9 1 U1 0 U2 1 PU AMER ASTRONAUTICAL SOC PI SPRINGFIELD PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 USA SN 0021-9142 J9 J ASTRONAUT SCI JI J. Astronaut. Sci. PD JAN-MAR PY 2002 VL 50 IS 1 BP 17 EP 33 PG 17 WC Engineering, Aerospace SC Engineering GA 639KK UT WOS:000180627400002 ER PT J AU Aires, F Rossow, WB Chedin, A AF Aires, F Rossow, WB Chedin, A TI Rotation of EOFs by the independent component analysis: Toward a solution of the mixing problem in the decomposition of geophysical time series SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID PRINCIPAL COMPONENTS; BLIND SEPARATION; VARIABILITY; PREDICTION; ALGORITHM; SEA AB The Independent Component Analysis (ICA) is a recently developed technique for component extraction. This new method requires the statistical independence of the extracted components - a stronger constraint that uses higher-order statistics-instead of the classical decorrelation (in the sense of "no correlation''), which is a weaker constraint that uses only second-order statistics. This technique has been used recently for the analysis of geophysical time series with the goal of investigating the causes of variability in observed data (i.e., exploratory approach). The authors demonstrate with a data simulation experiment that, if initialized with a Principal Component Analysis (PCA), the ICA performs a rotation of the classical PCA (or EOF) solution. This experiment is conducted using a synthetic dataset, where the correct answer is known, to more clearly illustrate and understand the behavior of the more familiar PCA and less familiar ICA. This rotation uses no localization criterion like other rotation techniques; only the generalization of decorrelation into full statistical independence is used. This rotation of the PCA solution seems to be able to avoid the tendency of PCA to mix several components, even when the signal is just their linear sum. C1 Columbia Univ, Dept Appl Phys, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. CNRS, Meteorol Dynam Lab, Palaiseau, France. RP Aires, F (reprint author), Columbia Univ, Dept Appl Phys, NASA, Goddard Inst Space Studies, 2880 Broadway & 112th St, New York, NY 10025 USA. EM faires@giss.nasa.gov RI Rossow, William/F-3138-2015 NR 36 TC 25 Z9 26 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 1 BP 111 EP 123 DI 10.1175/1520-0469(2002)059<0111:ROEBTI>2.0.CO;2 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 500ZF UT WOS:000172658000007 ER PT J AU Geogdzhayev, IV Mishchenko, MI Rossow, WB Cairns, B Lacis, AA AF Geogdzhayev, IV Mishchenko, MI Rossow, WB Cairns, B Lacis, AA TI Global two-channel AVHRR retrievals of aerosol properties over the ocean for the period of NOAA-9 observations and preliminary retrievals using NOAA-7 and NOAA-11 data SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID HIGH-RESOLUTION RADIOMETER; TROPOSPHERIC AEROSOLS; OPTICAL DEPTH; SPECTRAL REFLECTANCE; CLOSURE EXPERIMENT; LIGHT-SCATTERING; CALIBRATION; SATELLITE; ALGORITHM; ACE-2 AB Described is an improved algorithm that uses channel 1 and 2 radiances of the Advanced Very High Resolution Radiometer (AVHRR) to retrieve the aerosol optical thickness and Angstromngstrom exponent over the ocean. Specifically discussed are recent changes in the algorithm as well as the results of a sensitivity study analyzing the effect of several sources of retrieval errors not addressed previously. Uncertainties in the AVHRR radiance calibration (particularly in the deep-space count value) may be among the major factors potentially limiting the retrieval accuracy. A change by one digital count may lead to a 50% change in the aerosol optical thickness and a change of 0.4 in the Angstromngstrom exponent. On the other hand, the performance of two-channel algorithms weakly depends on a specific choice of the aerosol size distribution function with less than 10% changes in the optical thickness resulting from replacing a power law with a bimodal modified lognormal distribution. The updated algorithm is applied to a 10-yr period of observations (Jul 1983-Aug 1994), which includes data from NOAA-7, NOAA-9 (Feb 1985-Nov 1988), and NOAA-11 satellites. (The results are posted online at http://gacp.giss.nasa.gov/retrievals.) The NOAA-9 record reveals a seasonal cycle with maxima occurring around January-February and minima in June-July in the globally averaged aerosol optical thickness. The NOAA-7 data appear to show a residual effect of the El Chichon eruption (Mar 1982) as increased optical thickness values in the beginning of the record. The June 1991 eruption of Mt. Pinatubo resulted in a sharp increase in the aerosol load to more than double its normal value. The NOAA-9 record shows no discernible long-term trends in the global and hemisphere averages of the optical thickness and Angstromngstrom exponent. On the other hand, there is a discontinuity in the Angstromngstrom exponent values derived from NOAA-9 and NOAA-11 data and a significant temporal trend in the NOAA-11 record. The latter is unlikely to be related to the Mt. Pinatubo eruption and may be indicative of a serious calibration problem. The NOAA-9 record shows that the Northern Hemisphere mean optical thickness systematically exceeds that averaged over the Southern Hemisphere. Zonal means of the optical thickness exhibit an increase in the tropical regions of the Northern Hemisphere associated with annual desert dust outbursts and a springtime increase at middle latitudes of the Northern Hemisphere. Increased aerosol loads observed at middle latitudes of the Southern Hemisphere are probably associated with higher sea salt particle concentrations. Reliable extension of the retrieval record beyond the NOAA-9 lifetime will help to corroborate these findings. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, New York, NY USA. RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. RI Lacis, Andrew/D-4658-2012; Rossow, William/F-3138-2015; Mishchenko, Michael/D-4426-2012; OI Cairns, Brian/0000-0002-1980-1022 NR 71 TC 56 Z9 56 U1 1 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 262 EP 278 DI 10.1175/1520-0469(2002)059<0262:GTCARO>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300003 ER PT J AU Zhao, TXP Stowe, LL Smirnov, A Crosby, D Sapper, J McClain, CR AF Zhao, TXP Stowe, LL Smirnov, A Crosby, D Sapper, J McClain, CR TI Development of a global validation package for satellite oceanic aerosol optical thickness retrieval based on AERONET observations and its application to NOAA/NESDIS operational aerosol retrievals SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INDIVIDUAL AVHRR CHANNELS; SKY RADIANCE MEASUREMENTS; SPECTRAL RADIANCES; CONSISTENCY CHECKS; QUALITY-CONTROL; ALGORITHM; SUN; INFORMATION; SENSITIVITY; NETWORK AB In this paper, a global validation package for satellite aerosol optical thickness retrieval using the Aerosol Robotic Network (AERONET) observations as ground truth is described. To standardize the validation procedure, the optimum time-space match-up window, the ensemble statistical analysis method, the best selection of AERONET channels, and the numerical scheme used to interpolate/extrapolate these observations to satellite channels have been identified through sensitivity studies. The package is shown to be a unique tool for more objective validation and intercomparison of satellite aerosol retrievals, helping to satisfy an increasingly important requirement of the satellite aerosol remote sensing community. Results of applying the package to the second-generation operational aerosol observational data (AEROBS) from the NOAA-14 Advanced Very High Resolution Radiometer (AVHRR) in 1998 and to the same year aerosol observation data [Clouds and the Earth's Radiant Energy System-Single Scanner Foodprint version 4 (CERES-SSF4)] from the Tropical Rainfall Measuring Mission (TRMM) Visible Infrared Scanner (VIRS) are presented as examples of global validation. The usefulness of the package for identifying improvements to the aerosol optical thickness tau retrieval algorithm is also demonstrated. The principal causes of systematic errors in the current National Oceanic and Atmospheric Administration (NOAA)/National Environmental Satellite, Data, and Information Service (NESDIS) operational aerosol optical thickness retrieval algorithm have been identified and can be reduced significantly, if the correction and adjustment suggested from the global validation are adopted. Random error in the tau retrieval is identified to be a major source of error on deriving the effective Angstromngstrom wavelength exponent alpha and may be associated with regional differences in aerosol particles, which are not accounted for in the current second-generation operational algorithm. Adjustments to the nonaerosol and aerosol radiative transfer model parameters that reduce systematic errors in tau retrievals are suggested for consideration in the next-generation algorithm. Basic features that should be included in the next-generation algorithm to reduce random error in tau retrievals and the resulting error in the effective Angstromngstrom wavelength exponent have also been discussed. Compared to the AERONET observation, the NOAA-14 AVHRR (AEROBS) tau values for mean conditions are biased high by 0.05 and 0.08, with random errors of 0.08 and 0.05, at 0.63 and 0.83 mum, respectively. Correspondingly, the TRMM VIRS (CERES-SSF4) values for mean conditions are biased high by 0.06 and 0.02, with random errors of 0.06 and 0.04 at 0.63 and 1.61 mum, respectively. After corrections and adjustments to the retrieval algorithm, the biases in both channels of AVHRR and VIRS are reduced significantly to values close to zero, although random error is almost unchanged. The alpha exponent derived directly from the aerosol optical thicknesses (taus) has been shown to be poorly correlated both before and after adjustments, indicating that random error in the tau measurement (possibly related to aerosol model parameter variations or cloud-surface reflectance contamination) needs to be reduced. C1 NOAA, NESDIS, ORA, E RAI,RM 711 C,WWBG, Camp Springs, MD 20746 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. Sci Syst & Applicat Inc, Greenbelt, MD USA. NOAA, NESDIS, OSDPD, Suitland, MD USA. RP Zhao, TXP (reprint author), NOAA, NESDIS, ORA, E RAI,RM 711 C,WWBG, 5200 Auth Rd, Camp Springs, MD 20746 USA. EM xuepeng.zhao@noaa.gov RI Smirnov, Alexander/C-2121-2009 OI Smirnov, Alexander/0000-0002-8208-1304 NR 37 TC 53 Z9 55 U1 0 U2 12 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 294 EP 312 DI 10.1175/1520-0469(2002)059<0294:DOAGVP>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300005 ER PT J AU Chowdhary, J Cairns, B Travis, LD AF Chowdhary, J Cairns, B Travis, LD TI Case studies of aerosol Retrievals over the ocean from multiangle, multispectral photopolarimetric remote sensing data SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID RESEARCH SCANNING POLARIMETER; REFLECTED SUNLIGHT; LIGHT-SCATTERING; TROPOSPHERIC AEROSOLS; SATELLITE RETRIEVAL; NITROGEN-DIOXIDE; ABSORPTION; ALGORITHM; WATERS; DISTRIBUTIONS AB To evaluate the global effects of aerosols on the direct radiative balance, tropospheric chemistry, and cloud properties of the earth's atmosphere requires high-precision remote sensing that is sensitive to the aerosol optical thickness, size distribution, refractive index, and number density. This study uses the multiangle 0.41-, 0.55-, 0.865-, and 2.25-mum channel data from the airborne Research Scanning Polarimeter to retrieve aerosol properties over the Pacific Ocean. It is shown that such photopolarimetric data are highly sensitive to the size distribution and refractive index of aerosol particles, which reduces the nonuniqueness in aerosol retrievals using such data as compared with less comprehensive datasets. Moreover, it is found that polarized reflectances obtained at the shorter wavelengths (0.41 and 0.55 mum) are significantly less sensitive to the contribution of the ocean's upwelling light than total reflectance measurements, providing a natural tool for the separation between the estimation of oceanic and atmospheric scattering properties. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA. RP Cairns, B (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM bc25@columbia.edu OI Cairns, Brian/0000-0002-1980-1022 NR 55 TC 63 Z9 64 U1 0 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 383 EP 397 DI 10.1175/1520-0469(2002)059<0383:CSOARO>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300009 ER PT J AU Torres, O Bhartia, PK Herman, JR Sinyuk, A Ginoux, P Holben, B AF Torres, O Bhartia, PK Herman, JR Sinyuk, A Ginoux, P Holben, B TI A long-term record of aerosol optical depth from TOMS observations and comparison to AERONET measurements SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID BACKSCATTERED ULTRAVIOLET-RADIATION; SOIL DUST AEROSOLS; INTERANNUAL VARIABILITY; TROPOSPHERIC AEROSOLS; EARTHS SURFACE; SATELLITE; ABSORPTION; OCEAN; RETRIEVALS; RADIANCES AB Observations of backscattered near-ultraviolet radiation from the Total Ozone Mapping Spectrometer (TOMS) on board the Nimbus-7 (1979-92) and the Earth Probe (mid-1996 to present) satellites have been used to derive a long-term record of aerosol optical depth over oceans and continents. The retrieval technique applied to the TOMS data makes use of two unique advantages of near-UV remote sensing not available in the visible or near-IR: 1) low reflectivity of all land surface types (including the normally bright deserts in the visible), which makes possible aerosol retrieval over the continents; and 2) large sensitivity to aerosol types that absorb in the UV, allowing the clear separation of carbonaceous and mineral aerosols from purely scattering particles such as sulfate and sea salt aerosols. The near-UV method of aerosol characterization is validated by comparison with Aerosol Robotic Network (AERONET) ground-based observations. TOMS retrievals of aerosol optical depth over land areas (1996-2000) are shown to agree reasonably well with AERONET sun photometer observations for a variety of environments characterized by different aerosol types, such as carbonaceous aerosols from biomass burning, desert dust aerosols, and sulfate aerosols. In most cases the TOMS-derived optical depths of UV-absorbing aerosols are within 30% of the AERONET observations, while nonabsorbing optical depths agree to within 20%. The results presented here constitute the first long-term nearly global climatology of aerosol optical depth over both land and water surfaces, extending the observations of aerosol optical depth to regions and times (1979 to present) not accessible to ground-based observations. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. RP Torres, O (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 916, Greenbelt, MD 20771 USA. RI Ginoux, Paul/C-2326-2008; Torres, Omar/G-4929-2013; Bhartia, Pawan/A-4209-2016; OI Ginoux, Paul/0000-0003-3642-2988; Bhartia, Pawan/0000-0001-8307-9137; Herman, Jay/0000-0002-9146-1632 NR 32 TC 350 Z9 357 U1 1 U2 25 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 398 EP 413 DI 10.1175/1520-0469(2002)059<0398:ALTROA>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300010 ER PT J AU Pitari, G Mancini, E Rizi, V Shindell, DT AF Pitari, G Mancini, E Rizi, V Shindell, DT TI Impact of future climate and emission changes on stratospheric aerosols and ozone SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article; Proceedings Paper CT European Workshop on Aviation, Aerosols, Contrails and Cirrus Cloud (A 2C3) CY JUL 10-12, 2000 CL SEEHEIM, GERMANY ID TROPOSPHERIC SULFUR CYCLE; GENERAL-CIRCULATION MODEL; II MEASUREMENTS; MOUNT-PINATUBO; SAGE-II; TEMPERATURE; SIMULATION; ERUPTION; CLOUD; CHEMISTRY AB Global climatological distributions of key aerosol quantities (extinction, optical depth, mass, and surface area density) are shown in comparison with results from a three-dimensional global model including stratospheric and tropospheric aerosol components. It is shown that future trends in global and regional anthropogenic emissions of sulfur dioxide may induce substantial changes in the lower stratospheric budget of sulfate aerosols: with the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios' (SRES) upper limit, "A2'' scenario, the integrated stratospheric sulfate mass is predicted to increase from 0.15 Tg-S to 0.20 Tg-S in the year 2030, and the 1.02-mum average optical depth from 1.5 X 10(-3) to 2.2 X 10(-3) with a 50% increase in shortwave radiative forcing. The latter, in turn, is found to be about 23% of the total forcing by sulfate aerosols (tropospheric 1 stratospheric). Convective upward transport of sulfur dioxide to the tropical tropopause is found to be a key point for understanding the global distribution of sulfate in the lower stratosphere. Large increases of anthropogenic sulfur production at tropical latitudes by developing countries may explain these rather large predicted changes of stratospheric sulfate. Effects of future climate changes on stratospheric aerosols are also discussed: it is shown that the largest perturbation is on the probability of polar stratospheric cloud (PSC) formation, and that is driven primarily by greenhouse gas-induced temperature changes. In particular, the model-calculated wintertime Arctic increase of total aerosol optical depth is close to a factor of 2, with PSC optical depth and surface area density increasing by a factor of 5. This is mainly due to the predicted decrease of sudden stratospheric warming frequency in the Northern Hemisphere and the associated higher stability of the polar vortex. Enhanced ozone losses result from faster heterogeneous chemical reactions on both sulfate and PSC aerosol surfaces. The chemically driven total ozone recovery in 2030 relative to 2000 is predicted to decrease from +4.5% to +3.7% when taking into account both climate and surface emission changes: effects related to climate changes (perturbed stratospheric circulation, water vapor distribution, PSC frequency, etc.) account for about 2/3 of the calculated slow down of the O-3 recovery rate. C1 Univ Aquila, Dipartimento Fis, I-67010 Laquila, Italy. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Pitari, G (reprint author), Univ Aquila, Dipartimento Fis, Via Vetoio, I-67010 Laquila, Italy. RI Shindell, Drew/D-4636-2012; Pitari, Giovanni/O-7458-2016; OI Pitari, Giovanni/0000-0001-7051-9578; Mancini, Eva/0000-0001-7071-0292; Rizi, Vincenzo/0000-0002-5277-6527 NR 61 TC 93 Z9 94 U1 1 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 414 EP 440 DI 10.1175/1520-0469(2002)059<0414:IOFCAE>2.0.CO;2 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300011 ER PT J AU Penner, JE Zhang, SY Chin, M Chuang, CC Feichter, J Feng, Y Geogdzhayev, IV Ginoux, P Herzog, M Higurashi, A Koch, D Land, C Lohmann, U Mishchenko, M Nakajima, T Pitari, G Soden, B Tegen, I Stowe, L AF Penner, JE Zhang, SY Chin, M Chuang, CC Feichter, J Feng, Y Geogdzhayev, IV Ginoux, P Herzog, M Higurashi, A Koch, D Land, C Lohmann, U Mishchenko, M Nakajima, T Pitari, G Soden, B Tegen, I Stowe, L TI A comparison of model- and satellite-derived aerosol optical depth and reflectivity SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GENERAL-CIRCULATION MODEL; 3-DIMENSIONAL MODEL; SULFUR CYCLE; GLOBAL-MODEL; EMISSIONS; SULFATE; OCEAN; CLIMATOLOGY; SENSITIVITY; SIMULATION AB The determination of an accurate quantitative understanding of the role of tropospheric aerosols in the earth's radiation budget is extremely important because forcing by anthropogenic aerosols presently represents one of the most uncertain aspects of climate models. Here the authors present a systematic comparison of three different analyses of satellite-retrieved aerosol optical depth based on the Advanced Very High Resolution Radiometer (AVHRR)-measured radiances with optical depths derived from six different models. Also compared are the model-derived clear-sky reflected shortwave radiation with satellite-measured reflectivities derived from the Earth Radiation Budget Experiment (ERBE) satellite. The three different satellite-derived optical depths differ by between -0.10 and 0.07 optical depth units in comparison to the average of the three analyses depending on latitude and month, but the general features of the retrievals are similar. The models differ by between -0.09 and +0.16 optical depth units from the average of the models. Differences between the average of the models and the average of the satellite analyses range over -0.11 to +0.05 optical depth units. These differences are significant since the annual average clear-sky radiative forcing associated with the difference between the average of the models and the average of the satellite analyses ranges between -3.9 and 0.7 W m(-2) depending on latitude and is -1.7 W m(-2) on a global average annual basis. Variations in the source strengths of dimethylsulfide-derived aerosols and sea salt aerosols can explain differences between the models, and between the models and satellite retrievals of up to 0.2 optical depth units. The comparison of model-generated reflected shortwave radiation and ERBE-measured shortwave radiation is similar in character as a function of latitude to the analysis of modeled and satellite-retrieved optical depths, but the differences between the modeled clear-sky reflected flux and the ERBE clear-sky reflected flux is generally larger than that inferred from the difference between the models and the AVHRR optical depths, especially at high latitudes. The difference between the mean of the models and the ERBE-analyzed clear-sky flux is 1.6 W m(-2). The overall comparison indicates that the model-generated aerosol optical depth is systematically lower than that inferred from measurements between the latitudes of 10degrees and 30degreesS. It is not likely that the shortfall is due to small values of the sea salt optical depth because increases in this component would create modeled optical depths that are larger than those from satellites in the region north of 30degreesN and near 50degreesS. Instead, the source strengths for DMS and biomass aerosols in the models may be too low. Firm conclusions, however, will require better retrieval procedures for the satellites, including better cloud screening procedures, further improvement of the model's treatment of aerosol transport and removal, and a better determination of aerosol source strengths. C1 Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lawrence Livermore Natl Lab, Div Atmospher Sci, Livermore, CA USA. Max Planck Inst Meteorol, Hamburg, Germany. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Natl Inst Environm Studies, Ibaraki, Japan. Dalhousie Univ, Halifax, NS, Canada. Univ Tokyo, Ctr Climate Syst Res, Tokyo, Japan. Univ Aquila, Dipartimento Fis, I-67100 Laquila, Italy. Princeton Univ, Geophys Fluid Dynam Lab, Princeton, NJ 08544 USA. Max Planck Inst Biogeochem, Jena, Germany. NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Satellite Res Lab, Washington, DC 20233 USA. RP Penner, JE (reprint author), Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. EM penner@umich.edu RI Herzog, Michael/B-4722-2010; Ginoux, Paul/C-2326-2008; Chin, Mian/J-8354-2012; Nakajima, Teruyuki/H-2370-2013; Penner, Joyce/J-1719-2012; chuang, cathy/H-4814-2012; Mishchenko, Michael/D-4426-2012; Lohmann, Ulrike/B-6153-2009; Pitari, Giovanni/O-7458-2016 OI Ginoux, Paul/0000-0003-3642-2988; Nakajima, Teruyuki/0000-0002-9042-504X; Lohmann, Ulrike/0000-0001-8885-3785; Pitari, Giovanni/0000-0001-7051-9578 NR 39 TC 77 Z9 77 U1 1 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 441 EP 460 DI 10.1175/1520-0469(2002)059<0441:ACOMAS>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300012 ER PT J AU Chin, M Ginoux, P Kinne, S Torres, O Holben, BN Duncan, BN Martin, RV Logan, JA Higurashi, A Nakajima, T AF Chin, M Ginoux, P Kinne, S Torres, O Holben, BN Duncan, BN Martin, RV Logan, JA Higurashi, A Nakajima, T TI Tropospheric aerosol optical thickness from the GOCART model and comparisons with satellite and Sun photometer measurements SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GLOBAL 3-DIMENSIONAL SIMULATION; GENERAL-CIRCULATION MODEL; MINERAL DUST AEROSOL; RADIATIVE PROPERTIES; SULFUR EMISSIONS; LIGHT-SCATTERING; TRANSPORT MODEL; AERONET; INVENTORY; DEPTH AB The Georgia Institute of Technology-Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model is used to simulate the aerosol optical thickness tau for major types of tropospheric aerosols including sulfate, dust, organic carbon (OC), black carbon (BC), and sea salt. The GOCART model uses a dust emission algorithm that quantifies the dust source as a function of the degree of topographic depression, and a biomass burning emission source that includes seasonal and interannual variability based on satellite observations. Results presented here show that on global average, dust aerosol has the highest tau at 500 nm (0.051), followed by sulfate (0.040), sea salt (0.027), OC (0.017), and BC (0.007). There are large geographical and seasonal variations of tau, controlled mainly by emission, transport, and hygroscopic properties of aerosols. The model calculated total taus at 500 nm have been compared with the satellite retrieval products from the Total Ozone Mapping Spectrometer (TOMS) over both land and ocean and from the Advanced Very High Resolution Radiometer (AVHRR) over the ocean. The model reproduces most of the prominent features in the satellite data, with an overall agreement within a factor of 2 over the aerosol source areas and outflow regions. While there are clear differences among the satellite products, a major discrepancy between the model and the satellite data is that the model shows a stronger variation of tau from source to remote regions. Quantitative comparison of model and satellite data is still difficult, due to the large uncertainties involved in deriving the tau values by both the model and satellite retrieval, and by the inconsistency in physical and optical parameters used between the model and the satellite retrieval. The comparison of monthly averaged model results with the sun photometer network [Aerosol Robotics Network (AERONET)] measurements shows that the model reproduces the seasonal variations at most of the sites, especially the places where biomass burning or dust aerosol dominates. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Maryland Baltimore Cty, JCET, Baltimore, MD USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Natl Inst Environm Studies, Tsukuba, Ibaraki, Japan. Univ Tokyo, Ctr Climate Syst Res, Tokyo, Japan. RP Chin, M (reprint author), NASA, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. EM chin@rondo.gsfc.nasa.gov RI Martin, Randall/A-2051-2008; Duncan, Bryan/A-5962-2011; Ginoux, Paul/C-2326-2008; Chin, Mian/J-8354-2012; Nakajima, Teruyuki/H-2370-2013; Martin, Randall/C-1205-2014; Torres, Omar/G-4929-2013 OI Ginoux, Paul/0000-0003-3642-2988; Nakajima, Teruyuki/0000-0002-9042-504X; Martin, Randall/0000-0003-2632-8402; NR 65 TC 592 Z9 596 U1 8 U2 44 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 461 EP 483 DI 10.1175/1520-0469(2002)059<0461:TAOTFT>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300013 ER PT J AU Smirnov, A Holben, BN Kaufman, YJ Dubovik, O Eck, TF Slutsker, I Pietras, C Halthore, RN AF Smirnov, A Holben, BN Kaufman, YJ Dubovik, O Eck, TF Slutsker, I Pietras, C Halthore, RN TI Optical properties of atmospheric aerosol in maritime environments SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Review ID MARINE BOUNDARY-LAYER; CHARACTERIZATION EXPERIMENT ACE-1; SKY RADIANCE MEASUREMENTS; TROPICAL INDIAN-OCEAN; SIZE DISTRIBUTIONS; ANTHROPOGENIC AEROSOLS; SAHARAN DUST; ARABIAN-SEA; WESTERN PACIFIC; ATLANTIC-OCEAN AB Systematic characterization of aerosol over the oceans is needed to understand the aerosol effect on climate and on transport of pollutants between continents. Reported are the results of a comprehensive optical and physical characterization of ambient aerosol in five key island locations of the Aerosol Robotic Network (AERONET) of sun and sky radiometers, spanning over 2-5 yr. The results are compared with aerosol optical depths and size distributions reported in the literature over the last 30 yr. Aerosol found over the tropical Pacific Ocean (at three sites between 20degreesS and 20degreesN) still resembles mostly clean background conditions dominated by maritime aerosol. The optical thickness is remarkably stable with mean value of tau(a) (500 nm) = 0.07, mode value at tau(am) = 0.06, and standard deviation of 0.02-0.05. The average Angstrom exponent range, from 0.3 to 0.7, characterizes the wavelength dependence of the optical thickness. Over the tropical to subtropical Atlantic (two stations at 7degreesS and 32degreesN) the optical thickness is significantly higher: taua (500 nm) = 0.14 and tau(am) = 0.10 due to the frequent presence of dust, smoke, and urban-industrial aerosol. For both oceans the atmospheric column aerosol is characterized by a bimodal lognormal size distribution with a fine mode at effective radius R-eff = 0.11 +/- 0.01 mum and coarse mode at R-eff = 2.1 +/- 0.3 mum. A review of the published 150 historical ship measurements from the last three decades shows that tau(am) was around 0.07 to 0.12 in general agreement with the present finding. The information should be useful as a test bed for aerosol global models and aerosol representation in global climate models. With global human population expansion and industrialization, these measurements can serve in the twenty-first century as a basis to assess decadal changes in the aerosol concentration, properties, and radiative forcing of climate. C1 NASA, Goddard Space Flight Ctr, Biosper Sci Branch, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Environm Sci & Technol Ctr, Baltimore, MD 21228 USA. Sci Applicat Int Corp, Greenbelt, MD USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP Smirnov, A (reprint author), NASA, Goddard Space Flight Ctr, Biosper Sci Branch, Code 923, Greenbelt, MD 20771 USA. RI Dubovik, Oleg/A-8235-2009; Smirnov, Alexander/C-2121-2009; ECK, THOMAS/D-7407-2012 OI Dubovik, Oleg/0000-0003-3482-6460; Smirnov, Alexander/0000-0002-8208-1304; NR 145 TC 224 Z9 234 U1 3 U2 22 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 501 EP 523 DI 10.1175/1520-0469(2002)059<0501:OPOAAI>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300015 ER PT J AU Alexandrov, MD Lacis, AA Carlson, BE Cairns, B AF Alexandrov, MD Lacis, AA Carlson, BE Cairns, B TI Remote sensing of atmospheric aerosols and trace gases by means of multifilter rotating shadowband radiometer. Part I: Retrieval algorithm SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID ABSORPTION CROSS-SECTIONS; 231-794 NM RANGE; OPTICAL DEPTH; TOTAL OZONE; NITROGEN-DIOXIDE; BAND RADIOMETER; GROUND ALBEDO; CHAPPUIS-BAND; SOLAR; RADIATION AB A retrieval algorithm for processing multifilter rotating shadowband radiometer (MFRSR) data from clear and partially cloudy days is described and validated. This method, while complementary to the Langley approach, uses consistency between the direct normal and diffuse horizontal measurements combined with a regression technique to simultaneously retrieve daily time series of column mean aerosol particle size, aerosol optical depth, NO(2), and ozone amounts along with the instrument's calibration constants. Comparison with the traditional Langley calibration method demonstrates two advantages of the approach described here: greater calibration stability and a decreased sensitivity of retrievals to calibration errors. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA. RP Alexandrov, MD (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM malexandrov@giss.nasa.gov RI Lacis, Andrew/D-4658-2012; Carlson, Barbara/D-8319-2012; OI Cairns, Brian/0000-0002-1980-1022 NR 61 TC 51 Z9 52 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 524 EP 543 DI 10.1175/1520-0469(2002)059<0524:RSOAAA>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300016 ER PT J AU Alexandrov, MD Lacis, AA Carlson, BE Cairns, B AF Alexandrov, MD Lacis, AA Carlson, BE Cairns, B TI Remote sensing of atmospheric aerosols and trace gases by means of multifilter rotating shadowband radiometer. Part II: Climatological applications SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID OPTICAL DEPTH; UNITED-STATES; NITROGEN-DIOXIDE; BAND RADIOMETER; INSTRUMENT; EXTINCTION; OZONE; MODEL; DUST AB Measurements from ground-based sun photometer networks can be used both to provide ground-truth validation of satellite aerosol retrievals and to produce a land-based aerosol climatology that is complementary to satellite retrievals that are currently performed mostly over ocean. The multifilter rotating shadowband radiometer (MFRSR) has become a popular network instrument in recent years. Several networks operate about a hundred instruments providing good geographical coverage of the United States. In addition, international use of the MFRSR has continued to increase, allowing MFRSR measurements to significantly contribute to aerosol climatologies. This study investigates the feasibility of creating a ground-based aerosol climatology using MFRSR measurements. Additionally, this analysis allows for testing of the performance of the retrieval algorithm under a variety of conditions. The retrieval algorithm is used for processing MFRSR data from clear and partially cloudy days to simultaneously retrieve daily time series of column mean aerosol particle size, aerosol optical depth, NO2, and ozone column amounts together with the instrument's calibration constants directly from the MFRSR measurements for a variety of sites covering a range of atmospheric and surface conditions. This analysis provides a description of seasonal changes in aerosol parameters and in column amounts of ozone and NO2 as a function of geographical location. In addition, the relationship between NO2 column amount and aerosol optical depth as a potential indicator of tropospheric pollution is investigated. Application of this analysis method to the measurements from growing numbers of MFRSRs will allow for expansion on this developing climatology. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA. RP Alexandrov, MD (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. RI Lacis, Andrew/D-4658-2012; Carlson, Barbara/D-8319-2012; OI Cairns, Brian/0000-0002-1980-1022 NR 34 TC 29 Z9 29 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 544 EP 566 DI 10.1175/1520-0469(2002)059<0544:RSOAAA>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300017 ER PT J AU Bergstrom, RW Russell, PB Hignett, P AF Bergstrom, RW Russell, PB Hignett, P TI Wavelength dependence of the absorption of black carbon particles: Predictions and results from the TARFOX experiment and implications for the aerosol single scattering albedo SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID LIGHT-ABSORPTION; REFRACTIVE-INDEXES; FRACTAL CLUSTERS; NUCLEAR WINTER; FLAME SOOT; SMOKE; COEFFICIENT; RADIATION; OPTICS; ACE-2 AB Measurements are presented of the wavelength dependence of the aerosol absorption coefficient taken during the Tropical Aerosol Radiative Forcing Observational Experiment (TARFOX) over the northern Atlantic. The data show an approximate lambda(-1) variation between 0.40 and 1.0 mum. The theoretical basis of the wavelength variation of the absorption of solar radiation by elemental carbon [or black carbon (BC)] is explored. For a wavelength independent refractive index the small particle absorption limit simplifies to a lambda(-1) variation in relatively good agreement with the data. This result implies that the refractive indices of BC were relatively constant in this wavelength region, in agreement with much of the data on refractive indices of BC. However, the result does not indicate the magnitude of the refractive indices. The implications of the wavelength dependence of BC absorption for the spectral behavior of the aerosol single scattering albedo are discussed. It is shown that the single scattering albedo for a mixture of BC and nonabsorbing material decreases with wavelength in the solar spectrum (i.e., the percentage amount of absorption increases). This decease in the single scattering albedo with wavelength for black carbon mixtures is different from the increase in single scattering albedo for most mineral aerosols (dusts). This indicates that, if generally true, the spectral variation of the single scattering albedo can be used to distinguish aerosol types. It also highlights the importance of measurements of the spectral variation of the aerosol absorption coefficient and single scattering albedo. C1 Bay Area Environm Res Inst, Sonoma, CA 95476 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Minist Def, Meteorol Support Grp, London, England. RP Bergstrom, RW (reprint author), Bay Area Environm Res Inst, Sonoma, CA 95476 USA. NR 57 TC 188 Z9 197 U1 1 U2 35 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 567 EP 577 DI 10.1175/1520-0469(2002)059<0567:WDOTAO>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300018 ER PT J AU Dubovik, O Holben, B Eck, TF Smirnov, A Kaufman, YJ King, MD Tanre, D Slutsker, I AF Dubovik, O Holben, B Eck, TF Smirnov, A Kaufman, YJ King, MD Tanre, D Slutsker, I TI Variability of absorption and optical properties of key aerosol types observed in worldwide locations SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Review ID MID-ATLANTIC COAST; PARTICLE-SIZE DISTRIBUTION; AIRBORNE MINERAL AEROSOLS; SKY RADIANCE MEASUREMENTS; ECLATS FIELD EXPERIMENT; ATMOSPHERIC DUST; SAHARAN AEROSOLS; UNITED-STATES; MEXICO-CITY; IN-SITU AB Aerosol radiative forcing is a critical, though variable and uncertain, component of the global climate. Yet climate models rely on sparse information of the aerosol optical properties. In situ measurements, though important in many respects, seldom provide measurements of the undisturbed aerosol in the entire atmospheric column. Here, 8 yr of worldwide distributed data from the AERONET network of ground-based radiometers were used to remotely sense the aerosol absorption and other optical properties in several key locations. Established procedures for maintaining and calibrating the global network of radiometers, cloud screening, and inversion techniques allow for a consistent retrieval of the optical properties of aerosol in locations with varying emission sources and conditions. The multiyear, multi-instrument observations show robust differentiation in both the magnitude and spectral dependence of the absorption-a property driving aerosol climate forcing, for desert dust, biomass burning, urban-industrial, and marine aerosols. Moreover, significant variability of the absorption for the same aerosol type appearing due to different meteorological and source characteristics as well as different emission characteristics are observed. It is expected that this aerosol characterization will help refine aerosol optical models and reduce uncertainties in satellite observations of the global aerosol and in modeling aerosol impacts on climate. C1 NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Earth Sci Directorate, Greenbelt, MD 20771 USA. Univ Sci & Tech Lille, Lille, France. RP Dubovik, O (reprint author), NASA, Goddard Space Flight Ctr, Terr Phys Lab, Code 923, Greenbelt, MD 20771 USA. RI Dubovik, Oleg/A-8235-2009; Smirnov, Alexander/C-2121-2009; King, Michael/C-7153-2011; ECK, THOMAS/D-7407-2012 OI Dubovik, Oleg/0000-0003-3482-6460; Smirnov, Alexander/0000-0002-8208-1304; King, Michael/0000-0003-2645-7298; NR 101 TC 1407 Z9 1481 U1 18 U2 228 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 590 EP 608 DI 10.1175/1520-0469(2002)059<0590:VOAAOP>2.0.CO;2 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300020 ER PT J AU Russell, PB Redemann, J Schmid, B Bergstrom, RW Livingston, JM McIntosh, DM Ramirez, SA Hartley, S Hobbs, PV Quinn, PK Carrico, CM Rood, MJ Ostrom, E Noone, KJ von Hoyningen-Huene, W Remer, L AF Russell, PB Redemann, J Schmid, B Bergstrom, RW Livingston, JM McIntosh, DM Ramirez, SA Hartley, S Hobbs, PV Quinn, PK Carrico, CM Rood, MJ Ostrom, E Noone, KJ von Hoyningen-Huene, W Remer, L TI Comparison of aerosol single scattering albedos derived by diverse techniques in two North Atlantic experiments SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID CHARACTERIZATION EXPERIMENT ACE-2; UNITED-STATES; IN-SITU; OPTICAL-PROPERTIES; VERTICAL STRUCTURE; LIGHT-ABSORPTION; RADIATION BUDGET; SOLAR IRRADIANCE; WATER-VAPOR; TARFOX AB Aerosol single scattering albedo omega (the ratio of scattering to extinction) is important in determining aerosol climatic effects, in explaining relationships between calculated and measured radiative fluxes, and in retrieving aerosol optical depths from satellite radiances. Recently, two experiments in the North Atlantic region, the Tropospheric Aerosol Radiative Forcing Observational Experiment (TARFOX) and the Second Aerosol Characterization Experiment (ACE- 2), determined aerosol omega by a variety of techniques. The techniques included fitting of calculated to measured radiative fluxes; retrievals of omega from skylight radiances; best fits of complex refractive index to profiles of backscatter, extinction, and size distribution; and in situ measurements of scattering and absorption at the surface and aloft. Both TARFOX and ACE- 2 found a fairly wide range of values for omega at midvisible wavelengths (similar to550 nm), with 0.85 less than or equal to omega(midvis) less than or equal to 0.99 for the marine aerosol impacted by continental pollution. Frequency distributions of omega could usually be approximated by lognormals in omega(max) - omega, with some occurrence of bimodality, suggesting the influence of different aerosol sources or processing. In both TARFOX and ACE-2, closure tests between measured and calculated radiative fluxes yielded best-fit values of omega(midvis) of 0.90 +/- 0.04 for the polluted boundary layer. Although these results have the virtue of describing the column aerosol unperturbed by sampling, they are subject to questions about representativeness and other uncertainties (e. g., thermal offsets, unknown gas absorption). The other techniques gave larger values for omega(midvis) for the polluted boundary layer, with a typical result of omega(midvis) = 0.95 +/- 0.04. Current uncertainties in omega are large in terms of climate effects. More tests are needed of the consistency among different methods and of humidification effects on omega. C1 NASA, Ames Res Ctr, Atmospher Chem & Dynam Branch, Moffett Field, CA 94035 USA. Bay Area Environm Res Inst, San Francisco, CA USA. SRI Int, Menlo Pk, CA 94025 USA. Symtech Corp, Moffett Field, CA USA. Univ Washington, Seattle, WA 98195 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Illinois, Urbana, IL 61801 USA. Stockholm Univ, S-10691 Stockholm, Sweden. Univ Bremen, Bremen, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Russell, PB (reprint author), NASA, Ames Res Ctr, Atmospher Chem & Dynam Branch, MS 245-5, Moffett Field, CA 94035 USA. RI Quinn, Patricia/R-1493-2016 OI Quinn, Patricia/0000-0003-0337-4895 NR 48 TC 60 Z9 60 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 609 EP 619 DI 10.1175/1520-0469(2002)059<0609:COASSA>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300021 ER PT J AU Smirnov, A Holben, BN Dubovik, O O'Neill, NT Eck, TF Westphal, DL Goroch, AK Pietras, C Slutsker, I AF Smirnov, A Holben, BN Dubovik, O O'Neill, NT Eck, TF Westphal, DL Goroch, AK Pietras, C Slutsker, I TI Atmospheric aerosol optical properties in the Persian Gulf SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SKY RADIANCE MEASUREMENTS; NORTH-ATLANTIC; UNITED-STATES; MINERAL DUST; AERONET; RADIATION; PARTICLES; TURBIDITY; CLIMATE; NETWORK AB Aerosol optical depth measurements over Bahrain acquired through the ground-based Aerosol Robotic Network (AERONET) are analyzed. Optical depths obtained from ground-based sun/sky radiometers showed a pronounced temporal trend, with a maximum dust aerosol loading observed during the March-July period. The aerosol optical depth probability distribution is rather narrow with a modal value of about 0.25. The Angstrom parameter frequency distribution has two peaks. One peak around 0.7 characterizes a situation when dust aerosol is more dominant, the second peak around 1.2 corresponds to relatively dust-free cases. The correlation between aerosol optical depth and water vapor content in the total atmospheric column is strong (correlation coefficient of 0.82) when dust aerosol is almost absent (Angstrom parameter is greater than 0.7), suggesting possible hygroscopic growth of fine mode particles or source region correlation, and much weaker (correlation coefficient of 0.45) in the presence of dust (Angstrom parameter is less than 0.7). Diurnal variations of the aerosol optical depth and precipitable water were insignificant. Angstrom parameter diurnal variability (similar to20%-25%) is evident during the April-May period, when dust dominated the atmospheric optical conditions. Variations in the aerosol volume size distributions retrieved from spectral sun and sky radiance data are mainly associated with the changes in the concentration of the coarse aerosol fraction (variation coefficient of 61%). Geometric mean radii for the fine and coarse aerosol fractions are 0.14 mum (std dev = 0.02) and 2.57 mum (std dev = 0.27), respectively. The geometric standard deviation of each fraction is 0.41 and 0.73, respectively. In dust-free conditions the single scattering albedo (SSA) decreases with wavelength, while in the presence of dust the SSA either stays neutral or increases slightly with wavelength. The changes in the Angstrom parameter derived from a ground-based nephelometer and a collocated sun photometer during the initial checkout period were quite similar. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Greenbelt, MD USA. Univ Sherbrooke, Ctr Applicat & Rech Teledetect, Sherbrooke, PQ J1K 2R1, Canada. Univ Maryland Baltimore Cty, Goddard Environm Sci & Technol Ctr, Baltimore, MD 21228 USA. Naval Res Lab, Monterey, CA USA. Sci Applicat Int Corp, Greenbelt, MD USA. RP Smirnov, A (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. RI Dubovik, Oleg/A-8235-2009; Smirnov, Alexander/C-2121-2009; ECK, THOMAS/D-7407-2012 OI Dubovik, Oleg/0000-0003-3482-6460; Smirnov, Alexander/0000-0002-8208-1304; NR 35 TC 115 Z9 115 U1 0 U2 11 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 620 EP 634 DI 10.1175/1520-0469(2002)059<0620:AAOPIT>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300022 ER PT J AU Kaufman, YJ Tanre, D Holben, BN Mattoo, S Remer, LA Eck, TF Vaughan, J Chatenet, B AF Kaufman, YJ Tanre, D Holben, BN Mattoo, S Remer, LA Eck, TF Vaughan, J Chatenet, B TI Aerosol radiative impact on spectral solar flux at the surface, derived from principal-plane sky measurements SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID TROPOSPHERIC AEROSOL; OPTICAL-PROPERTIES; EARTHS SURFACE; GLOBAL-SCALE; ABSORPTION; ATMOSPHERE; IRRADIANCE; RADIANCE; CLOUDS; SIMULATIONS AB Accurate measurements of the spectral solar flux reaching the surface in cloud-free conditions are required to determine the aerosol radiative impact and to test aerosol models that are used to calculate radiative forcing of climate. Spectral flux measurements are hampered in many locations by persistent broken cloud fields. Here a new technique is developed to derive the diffuse solar spectral flux reaching the surface from principal-plane measurements conducted in the last six years by the Aerosol Robotic Network (AERONET). This 50-100 instrument global network measures the principal-plane radiances in four spectral bands (0.44-1.02 mum) approximately every hour every day. These instruments also measure the spectral optical thickness and derive the aerosol size distribution and other properties from sky measurements. The advantage of the AERONET measurements is that collimated sky radiance is measured for each 1degrees x 1degrees field of view. Clouds and cloud shadows are rejected before the total sky brightness is reconstructed and the flux is derived. The results compare favorably with shadow band measurements and with aerosol models. Studied are smoke aerosol in Brazil; Saharan dust in Cape Verde; and urban-industrial pollution in Creteil, near Paris, France, and near Washington, D. C. The spectral attenuation of total (diffuse+direct) solar flux reaching the surface is given by f(lambda) = exp(-a(lambda) - b(lambda)tau(lambda)), where a(lambda) is attenuation by an atmosphere with no aerosol and b(lambda) is the aerosol attenuation coefficient. Remarkably, it is found that for these sites except for the Washington, D. C., site, the spectrally averaged value of b(lambda) does not vary significantly from one aerosol type to another: {b(lambda)} = 0.35 +/- 0.03 (for solar zenith angle of 50degrees). The measured 24-h average aerosol impact on the solar flux at the surface per unit optical thickness is DeltaF/Deltatau = -80 W m(-2) in these sites, almost independent of the aerosol type: smoke, dust, or urban-industrial pollution. In Washington, D. C., it is suspected, and demonstrated in a back of the envelope calculation, that the high amount of broken cloudiness and its correlation with the aerosol optical thickness are responsible for the apparent small aerosol forcing at the surface of DeltaF/Deltatau = -50 W m(-2). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Sci & Tech Lille, CNRS, Opt Atmospher Lab, Villeneuve Dascq, France. SM&A Corp, Vienna, VA USA. Raytheon ITSS, Lanham, MD USA. Washington State Univ, Dept Civil & Environm Engn, Pullman, WA 99164 USA. Univ Paris 07, Lab Interuniv Syst Atmospher, Creteil, France. Univ Paris 12, CNRS, Creteil, France. RP Kaufman, YJ (reprint author), NASA, Goddard Space Flight Ctr, Code 913, Greenbelt, MD 20771 USA. RI ECK, THOMAS/D-7407-2012 NR 43 TC 39 Z9 41 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 635 EP 646 DI 10.1175/1520-0469(2002)059<0635:ARIOSS>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300023 ER PT J AU Remer, LA Kaufman, YJ Levin, Z Ghan, S AF Remer, LA Kaufman, YJ Levin, Z Ghan, S TI Model assessment of the ability of MODIS to measure top-of-atmosphere direct radiative forcing from smoke aerosols SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GLOBAL 3-DIMENSIONAL MODEL; OPTICAL-THICKNESS; ANTHROPOGENIC AEROSOLS; SIZE DISTRIBUTION; TROPOSPHERIC AEROSOLS; AIRBORNE SIMULATOR; SCAR-B; TRANSPORT; SULFATE; SURFACE AB The new generation of satellite sensors such as the moderate resolution imaging spectroradiometer (MODIS) will be able to detect and characterize global aerosols with an unprecedented accuracy. The question remains whether this accuracy will be sufficient to narrow the uncertainties in estimates of aerosol radiative forcing at the top of the atmosphere. The discussion is narrowed to cloud-free direct forcing. Satellite remote sensing detects aerosol with the least amount of relative error when aerosol loading is high. Satellites are less effective when aerosol loading is low. The monthly mean results of two global aerosol transport models are used to simulate the spatial distribution of smoke aerosol in the Southern Hemisphere during the tropical biomass burning season. This spatial distribution allows us to determine that 87%-94% of the smoke aerosol forcing at the top of the atmosphere occurs in grid squares with sufficient signal-to-noise ratio to be detectable from space. The uncertainty of quantifying the smoke aerosol forcing in the Southern Hemisphere depends on the uncertainty introduced by errors in estimating the background aerosol, errors resulting from uncertainties in surface properties, and errors resulting from uncertainties in assumptions of aerosol properties. These three errors combine to give overall uncertainties of 1.2 to 2.2 W m(-2) (16%-60%) in determining the Southern Hemisphere smoke aerosol forcing at the top of the atmosphere. Residual cloud contamination uncertainty is not included in these estimates. Strategies that use the satellite data to derive flux directly or use the data in conjunction with ground-based remote sensing and aerosol transport models can reduce these uncertainties. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Tel Aviv Univ, Dept Geophys & Planetary Sci, Ramat Aviv, Israel. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Remer, LA (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 913, Greenbelt, MD 20771 USA. EM remer@climate.gsfc.nasa.gov RI Ghan, Steven/H-4301-2011 OI Ghan, Steven/0000-0001-8355-8699 NR 40 TC 7 Z9 10 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 657 EP 667 DI 10.1175/1520-0469(2002)059<0657:MAOTAO>2.0.CO;2 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300025 ER PT J AU Menon, S Del Genio, AD Koch, D Tselioudis, G AF Menon, S Del Genio, AD Koch, D Tselioudis, G TI GCM Simulations of the aerosol indirect effect: Sensitivity to cloud parameterization and aerosol burden SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID ANTHROPOGENIC SULFATE AEROSOLS; ATLANTIC REGIONAL EXPERIMENT; MARINE STRATOCUMULUS CLOUDS; GENERAL-CIRCULATION MODEL; SENSOR MICROWAVE IMAGER; NEAR-GLOBAL SURVEY; CONDENSATION NUCLEI; DROPLET CONCENTRATION; NORTH-ATLANTIC; BOUNDARY-LAYER AB In this paper the coupling of the Goddard Institute for Space Studies (GISS) general circulation model (GCM) to an online sulfur chemistry model and source models for organic matter and sea salt that is used to estimate the aerosol indirect effect is described. The cloud droplet number concentration is diagnosed empirically from field experiment datasets over land and ocean that observe droplet number and all three aerosol types simultaneously; corrections are made for implied variations in cloud turbulence levels. The resulting cloud droplet number is used to calculate variations in droplet effective radius, which in turn allows one to predict aerosol effects on cloud optical thickness and microphysical process rates. The aerosol indirect effect is calculated by differencing the top-of-the-atmosphere net cloud radiative forcing for simulations with present-day versus preindustrial emissions. Both the first and second indirect effects are explored. The sensitivity of the results presented here to cloud parameterization assumptions that control the vertical distribution of cloud occurrence, the autoconversion rate, and the aerosol scavenging rate, each of which feeds back significantly on the model aerosol burden, are tested. The global mean aerosol indirect effect for all three aerosol types ranges from -1.55 to -4.36 W m(-2) in the simulations. The results are quite sensitive to the preindustrial background aerosol burden, with low preindustrial burdens giving strong indirect effects, and to a lesser extent to the anthropogenic aerosol burden, with large burdens giving somewhat larger indirect effects. Because of this dependence on the background aerosol, model diagnostics such as albedo-particle size correlations and column cloud susceptibility, for which satellite validation products are available, are not good predictors of the resulting indirect effect. C1 Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY USA. Columbia Univ, Dept Appl Phys, New York, NY 10027 USA. RP Menon, S (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM smenon@giss.nasa.gov RI Del Genio, Anthony/D-4663-2012 OI Del Genio, Anthony/0000-0001-7450-1359 NR 82 TC 137 Z9 149 U1 1 U2 20 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 692 EP 713 DI 10.1175/1520-0469(2002)059<0692:GSOTAI>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300028 ER PT J AU Han, QY Rossow, WB Zeng, J Welch, R AF Han, QY Rossow, WB Zeng, J Welch, R TI Three different behaviors of liquid water path of water clouds in aerosol-cloud interactions SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID DROPLET-SIZE DISTRIBUTIONS; GENERAL-CIRCULATION MODEL; MARINE STRATIFORM CLOUDS; NEAR-GLOBAL SURVEY; SHIP TRACKS; CONDENSATION NUCLEI; EFFECTIVE-RADIUS; STRATOCUMULUS CLOUDS; SULFATE AEROSOLS; BOUNDARY-LAYER AB Estimates of the indirect aerosol effect in GCMs assume that either cloud liquid water path is constant (Twomey effect) or increases with increased droplet number concentration (drizzle-suppression or Albrecht effect). On the other hand, if cloud thermodynamics and dynamics are considered, cloud liquid water path may also decrease with increasing droplet number concentration, which has been predicted by model calculations and observed in ship track and urban influence studies. This study examines the different changes of cloud liquid water path associated with changes of cloud droplet number concentration. Satellite data (January, April, July, and October 1987) are used to determine the cloud liquid water sensitivity, defined as the ratio of changes of liquid water path and changes of column droplet number concentration. The results of a global survey for water clouds (cloud-top temperature >273 K, optical thickness 1 less than or equal to tau < 15) reveal all three behaviors of cloud liquid water path with aerosol changes: increasing, approximately constant, or decreasing as cloud column number concentration increases. The authors find that 1) in about one-third of the cases, predominantly in warmer locations or seasons, the cloud liquid water sensitivity is negative, and the regional and seasonal variations of the negative liquid water sensitivity are consistent with other observations; 2) in about one-third of the cases, a minus one-third (-1/3) power-law relation between effective droplet radius and column number concentration is found, consistent with a nearly constant cloud water path; and 3) in the remaining one-third of the cases, the cloud liquid water sensitivity is positive. These results support the suggestion that it is possible for an increase of cloud droplet number concentration to both reduce cloud droplet size and enhance evaporation just below cloud base, which decouples the cloud from the boundary layer in warmer locations, decreasing water supply from surface and reducing cloud liquid water. Results of this study also suggest that the current evaluations of the negative aerosol indirect forcing by GCMs, which are based on either the Twomey or Albrecht effects, may be overestimated in magnitude. C1 Univ Alabama, Huntsville, AL 35805 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Han, QY (reprint author), Univ Alabama, 320 Sparkman Dr, Huntsville, AL 35805 USA. RI Rossow, William/F-3138-2015 NR 52 TC 39 Z9 43 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 726 EP 735 DI 10.1175/1520-0469(2002)059<0726:TDBOLW>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300030 ER PT J AU Weaver, CJ Ginoux, P Hsu, NC Chou, MD Joiner, J AF Weaver, CJ Ginoux, P Hsu, NC Chou, MD Joiner, J TI Radiative forcing of Saharan dust: GOCART model simulations compared with ERBE data SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID MINERAL DUST; OPTICAL-THICKNESS; AEROSOL; TRANSPORT; INDEX; TOMS AB This study uses information on Saharan aerosol from a dust transport model to calculate radiative forcing values. The transport model is driven by assimilated meteorological fields from the Goddard Earth Observing System Data Assimilation System. The model produces global three-dimensional dust spatial information for four different mineral aerosol sizes. These dust fields are input to an offline radiative transfer calculation to obtain the direct radiative forcing due to the dust fields. These estimates of the shortwave reduction of radiation at the top of the atmosphere (TOA) compare reasonably well with the TOA reductions derived from Earth Radiation Budget Experiment (ERBE) and Total Ozone Mapping Spectrometer (TOMS) satellite data. The longwave radiation also agrees with the observations; however, potential errors in the assimilated temperatures complicate the comparison. Depending on the assumptions used in the calculation and the dust loading, the summertime forcing ranges from 0 to -18 W m(-2) over ocean and from 0 to +20 W m(-2) over land. Increments are terms in the assimilation general circulation model (GCM) equations that force the model toward observations. They are differences between the observed analyses and the GCM forecasts. Off west Africa the analysis temperature increments produced by the assimilation system show patterns that are consistent with the dust spatial distribution. It is not believed that radiative heating of dust is influencing the increments. Instead, it is suspected that dust is affecting the Television Infrared Observational Satellite (TIROS) Operational Vertical Sounder (TOVS) satellite temperature retrievals that provide the basis of the assimilated temperatures used by the model. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. GEST Inst, Rockville, MD USA. Georgia Inst Technol, Atlanta, GA 30332 USA. Univ Maryland Baltimore Cty, GEST, Baltimore, MD 21228 USA. RP Weaver, CJ (reprint author), NASA, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. RI Joiner, Joanna/D-6264-2012; Ginoux, Paul/C-2326-2008; Hsu, N. Christina/H-3420-2013 OI Ginoux, Paul/0000-0003-3642-2988; NR 24 TC 34 Z9 34 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 736 EP 747 DI 10.1175/1520-0469(2002)059<0736:RFOSDG>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300031 ER PT J AU Chou, MD Chan, PK Wang, MH AF Chou, MD Chan, PK Wang, MH TI Aerosol radiative forcing derived from SeaWiFS-retrieved aerosol optical properties SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID WATER-LEAVING RADIANCE; OCEAN-COLOR SENSORS; ATMOSPHERIC CORRECTION; INDIAN-OCEAN; CLIMATE; SENSITIVITY; POLDER AB To understand climatic implications of aerosols over global oceans, the aerosol optical properties retrieved from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) are analyzed, and the effects of the aerosols on the earth's radiation budgets [aerosol radiative forcing (ARF)] are computed using a radiative transfer model. It is found that the distribution of the SeaWiFS-retrieved aerosol optical thickness is distinctively zonal. The maximum in the equatorial region coincides with the intertropical convergence zone, and the maximum in the Southern Hemispheric high latitudes coincides with the region of prevailing westerlies. The minimum aerosol optical thickness is found in the subtropical high pressure regions, especially in the Southern Hemisphere. These zonal patterns clearly demonstrate the influence of atmospheric circulation on the oceanic aerosol distribution. Over global oceans, aerosols reduce the annual-mean net downward solar flux by 5.4 W m(-2) at the top of the atmosphere, and by 5.9 W m(-2) at the surface. The largest ARF is found in the tropical Atlantic, Arabian Sea, Bay of Bengal, the coastal regions of Southeast and East Asia, and the Southern Hemispheric high latitudes. During the period of the big Indonesian fires (September-December 1997), the cooling due to aerosols is more than 10 W m(-2) at the top of the atmosphere, and more than 25 W m(-2) at the surface in the vicinity of Indonesia. The atmosphere receives extra solar radiation by more than 15 W m(-2) over a large area. These large changes in radiative fluxes are expected to have enhanced the atmospheric stability, weakened the atmospheric circulation, and augmented the drought condition during that period. It would be very instructive to simulate the regional climatic impact of the big Indonesian fires during the 1987-88 El Nino event using a general circulation model. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA. RP Chou, MD (reprint author), NASA, Goddard Space Flight Ctr, Code 913, Greenbelt, MD 20771 USA. RI Wang, Menghua/F-5631-2010 OI Wang, Menghua/0000-0001-7019-3125 NR 30 TC 66 Z9 68 U1 1 U2 9 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PY 2002 VL 59 IS 3 BP 748 EP 757 DI 10.1175/1520-0469(2002)059<0748:ARFDFS>2.0.CO;2 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 514CD UT WOS:000173418300032 ER PT J AU Singh, M Salem, JA AF Singh, M Salem, JA TI Mechanical properties and microstructure of biomorphic silicon carbide ceramics fabricated from wood precursors SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Conference on Structural Ceramics and Ceramic Composites for High Temperature Applications CY OCT 07-12, 2001 CL SEVILLE, SPAIN SP Soc Espanola Ceram & Vidrio, European Ceram Soc, Amer Ceram Soc, Ceram Soc Japan, European Commiss Res DG, United Engn Fdn, USA Res Off, Natl Sci Fdn, Off Ind Technol, US DOE, Oak Ridge Natl Lab, European Off Aerosp Res & Dev, USAF Off Sci Res, Minist Ciencia & Technol, Junta Andalucia, Univ Sevilla DE mechanical properties; precursors-organic; microstructure ID COMPOSITES AB Silicon carbide-based, environment friendly, biomorphic ceramics have been fabricated by the pyrolysis and infiltration of natural wood (maple and mahogany) precursors. This technology provides an eco-friendly route to advanced ceramic materials. These biomorphic silicon carbide ceramics have tailorable properties and behave like silicon carbide based materials manufactured by conventional approaches. The elastic moduli and fracture toughness of biomorphic ceramics strongly depend on the properties of starting wood preforms and the degree of molten silicon infiltration. Mechanical properties of silicon carbide ceramics fabricated from maple wood precursors indicate flexural strengths of 344+/-58 MPa at room temperature and 230 36 MPa at 1350 degreesC. Room temperature fracture toughness of the maple based material is 2.6+/-0.2 MParootm while the mahogany precursor derived ceramics show a fracture toughness of 2.0+/-0.2 MParootm. The fracture toughness and the strength increase as the density of final material increases. Fractographic characterization indicates the failure origins to be pores and chipped pockets of silicon. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 NASA, Glenn Res Ctr, QSS Grp Inc, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Struct Div, Cleveland, OH 44135 USA. RP Singh, M (reprint author), NASA, Glenn Res Ctr, QSS Grp Inc, Cleveland, OH 44135 USA. NR 21 TC 93 Z9 102 U1 2 U2 22 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 2002 VL 22 IS 14-15 BP 2709 EP 2717 AR PII S0955-2219(02)00136-X DI 10.1016/S0955-2219(02)00136-X PG 9 WC Materials Science, Ceramics SC Materials Science GA 597ZZ UT WOS:000178251800036 ER PT J AU Varela-Feria, FM Martinez-Fernandez, J de Arellano-Lopez, AR Singh, M AF Varela-Feria, FM Martinez-Fernandez, J de Arellano-Lopez, AR Singh, M TI Low density biomorphic silicon carbide: microstructure and mechanical properties SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Conference on Structural Ceramics and Ceramic Composites for High Temperature Applications CY OCT 07-12, 2001 CL SEVILLE, SPAIN SP Soc Espanola Ceram & Vidrio, European Ceram Soc, Amer Ceram Soc, Ceram Soc Japan, European Commiss Res DG, United Engn Fdn, USA Res Off, Natl Sci Fdn, Off Ind Technol, US DOE, Oak Ridge Natl Lab, European Off Aerosp Res & Dev, USAF Off Sci Res, Minist Ciencia & Technol, Junta Andalucia, Univ Sevilla DE mechanical properties; microstructure; porosity; SiC ID CERAMICS; COMPOSITES AB Low density biomorphic SiC ceramics have been fabricated by melt infiltration of pine carbon templates. The resulting porous microstructure is anisotropic and presents a high level of connectivity. Some templates have been partially infiltrated to document the details of the infiltration process. The material has been tested at a constant compression with a strain rate of 2x10(-5) s(-1) at high temperatures between 1150 and 1350 degreesC. The materials showed high compressive strengths relative to the density, with values up to 241 MPa in the axial direction. The compressive strengths relative to those of fully dense SiC are a good extrapolation of previous studies with denser samples, and present qualitative agreement with the model by Gibson and Ashby for plastic collapse of cellular solids. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Sevilla, Dept Fis Mat Condensada, Seville, Spain. NASA, Glenn Res Ctr, QSS Grp Inc, Cleveland, OH 44135 USA. RP de Arellano-Lopez, AR (reprint author), Univ Sevilla, Dept Fis Mat Condensada, POB 1065, Seville, Spain. RI MARTINEZ FERNANDEZ, JULIAN/K-1826-2012; OI MARTINEZ FERNANDEZ, JULIAN/0000-0002-1199-6638; R. de Arellano Lopez, Antonio/0000-0002-7443-0244 NR 25 TC 81 Z9 83 U1 1 U2 10 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 2002 VL 22 IS 14-15 BP 2719 EP 2725 AR PII S0955-2219(02)00137-1 DI 10.1016/S0955-2219(02)00137-1 PG 7 WC Materials Science, Ceramics SC Materials Science GA 597ZZ UT WOS:000178251800037 ER PT J AU Munoz, A Fernandez, JM Singh, M AF Munoz, A Fernandez, JM Singh, M TI High temperature compressive mechanical behavior of joined biomorphic silicon carbide ceramics SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Conference on Structural Ceramics and Ceramic Composites for High Temperature Applications CY OCT 07-12, 2001 CL SEVILLE, SPAIN SP Soc Espanola Ceram & Vidrio, European Ceram Soc, Amer Ceram Soc, Ceram Soc Japan, European Commiss Res DG, United Engn Fdn, USA Res Off, Natl Sci Fdn, Off Ind Technol, US DOE, Oak Ridge Natl Lab, European Off Aerosp Res & Dev, USAF Off Sci Res, Minist Ciencia & Technol, Junta Andalucia, Univ Sevilla DE biomorphic; high temperature; joining; SiC; strength ID REACTION-FORMED JOINTS; WOOD; MICROSTRUCTURE; COMPOSITES AB Silicon carbide-based, environmentally conscious, biomorphic ceramics were fabricated by the reactive infiltration of molten silicon into porous, carbonaceous preforms derived from pyrolysis of African Bubinga wood. The bulk microstructure and high temperature mechanical properties of these ceramics were studied. These biomorphic ceramics mimic the fibrous microstructure of the wood resulting in high strength and anisotropy. The compressive strength parallel to fiber direction, which is the growth direction of the tree, was 750 MPa at 1100 degreesC and 300 MPa at 1350 degreesC. The compressive strength perpendicular to fiber direction was 215 MPa at 1100 degreesC and 120 MPa at 1350 C. These materials were joined using the ARCJoinT approach. The microstructure of the joints was studied by scanning electron microscopy and the high temperature strength was measured in compression, with the joint oriented 45 to the compression axis. The joined specimens had strengths from 615 MPa at 1100 C to 250 MPa at 1350 C when the fibers were parallel to the compression axis (forming 45 with the joint plane), which are about 20% lower than the strength of the bulk material in the same orientation. The strengths ranged from 373 MPa at 1100 C to 175 MPa at 1350 degreesC when the fibers were forming 45 with the compression axis (perpendicular to the joint plane), which are lower than the average strength of the bulk material compressed axially and in the perpendicular direction. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Univ Sevilla, Dept Fis Mat Condensada, Seville 41080, Spain. NASA, Glenn Res Ctr, QSS Grp Inc, Cleveland, OH 44135 USA. RP Fernandez, JM (reprint author), Univ Sevilla, Dept Fis Mat Condensada, Apdo 1065, Seville 41080, Spain. RI MARTINEZ FERNANDEZ, JULIAN/K-1826-2012 OI MARTINEZ FERNANDEZ, JULIAN/0000-0002-1199-6638 NR 26 TC 30 Z9 32 U1 0 U2 10 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 2002 VL 22 IS 14-15 BP 2727 EP 2733 AR PII S0955-2219(02)00138-3 DI 10.1016/S0955-2219(02)00138-3 PG 7 WC Materials Science, Ceramics SC Materials Science GA 597ZZ UT WOS:000178251800038 ER PT J AU Levine, SR Opila, EJ Halbig, MC Kiser, JD Singh, M Salem, JA AF Levine, SR Opila, EJ Halbig, MC Kiser, JD Singh, M Salem, JA TI Evaluation of ultra-high temperature ceramics for aeropropulsion use SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Conference on Structural Ceramics and Ceramic Composites for High Temperature Applications CY OCT 07-12, 2001 CL SEVILLE, SPAIN SP Soc Espanola Ceram & Vidrio, European Ceram Soc, Amer Ceram Soc, Ceram Soc Japan, European Commiss Res DG, United Engn Fdn, USA Res Off, Natl Sci Fdn, Off Ind Technol, US DOE, Oak Ridge Natl Lab, European Off Aerosp Res & Dev, USAF Off Sci Res, Minist Ciencia & Technol, Junta Andalucia, Univ Sevilla DE borides; composites; corrosion; engine components; thermal shock resistance ID OXIDATION AB Among the ultra-high temperature ceramics (UHTC) are a group of materials consisting of zirconium diboride or hafnium diboride plus silicon carbide, and in some instances, carbon. These materials offer a good combination of properties that make them candidates for airframe leading edges on sharp-bodied reentry vehicles. These UHTC perform well in the environment for such applications, i.e. air at low pressure. The purpose of this study was to examine three of these materials under conditions more representative of a propulsion environment, i.e. higher oxygen partial pressure and total pressure. Results of strength and fracture toughness measurements, furnace oxidation, and high velocity thermal shock exposures are presented for ZrB2 plus 20 vol.% SiC, ZrB2 plus 14 vol.% SiC plus 30 vol.% C, and SCS-9a SiC fiber reinforced ZrB2 plus 20 vol.% SiC. The poor oxidation resistance of UHTCs is the predominant factor limiting their applicability to propulsion applications. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Cleveland State Univ, Cleveland, OH 44135 USA. USA, Prop Directorate, Washington, DC 20310 USA. RP Levine, SR (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 106-5, Cleveland, OH 44135 USA. NR 12 TC 396 Z9 412 U1 19 U2 170 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 2002 VL 22 IS 14-15 BP 2757 EP 2767 AR PII S0955-2219(02)00140-1 DI 10.1016/S0955-2219(02)00140-1 PG 11 WC Materials Science, Ceramics SC Materials Science GA 597ZZ UT WOS:000178251800042 ER PT J AU Morscher, GN Cawley, JD AF Morscher, GN Cawley, JD TI Intermediate temperature strength degradation in SiC/SiC composites SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Conference on Structural Ceramics and Ceramic Composites for High Temperature Applications CY OCT 07-12, 2001 CL SEVILLE, SPAIN SP Soc Espanola Ceram & Vidrio, European Ceram Soc, Amer Ceram Soc, Ceram Soc Japan, European Commiss Res DG, United Engn Fdn, USA Res Off, Natl Sci Fdn, Off Ind Technol, US DOE, Oak Ridge Natl Lab, European Off Aerosp Res & Dev, USAF Off Sci Res, Minist Ciencia & Technol, Junta Andalucia, Univ Sevilla DE BN interfaces; mechanical properties; oxidation; SiC/SiC composites ID CERAMIC-MATRIX COMPOSITES; FIBER-REINFORCED COMPOSITES; STRESS-RUPTURE; BORON-NITRIDE; OXIDATION; AIR; CARBON; EMBRITTLEMENT; KINETICS; BRITTLE AB Woven silicon carbide fiber-reinforced, silicon carbide matrix composites are leading candidate materials for an advanced jet engine combustor liner application. Although the use temperature in the hot region for this application is expected to exceed 1200 degreesC, a potential life-limiting concern for this composite system exists at intermediate temperatures (800 200 C), where significant time-dependent strength degradation has been observed under stress-rupture loading. A number of factors control the degree of stress-rupture strength degradation, the major factor being the nature of the interphase separating the fiber and the matrix. BN interphases are superior to carbon interphases due to the slower oxidation kinetics of BN. A model for the intermediate temperature stress-rupture of SiC/BN/SiC composites is presented based on the observed mechanistic process that leads to strength degradation for the simple case of through-thickness matrix cracks. The approach taken has much in common with that used by Curtin and coworkers, for two different composite systems. The predictions of the model are in good agreement with the rupture data for stress-rupture of both precracked and as-produced composites. Also, three approaches that dramatically improve the intermediate temperature stress-rupture properties are described: Si-doped BN, fiber spreading, and "outside debonding". (C) 2002 Elsevier Science Ltd. All rights reserved. C1 NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. Case Western Reserve Univ, Dept Mat Sci & Engn, Cleveland, OH 44106 USA. RP Morscher, GN (reprint author), NASA, Glenn Res Ctr, Ohio Aerosp Inst, MS 106-5, Cleveland, OH 44135 USA. NR 32 TC 46 Z9 50 U1 0 U2 19 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. European Ceram. Soc. PY 2002 VL 22 IS 14-15 BP 2777 EP 2787 AR PII S0955-2219(02)00144-9 DI 10.1016/S0955-2219(02)00144-9 PG 11 WC Materials Science, Ceramics SC Materials Science GA 597ZZ UT WOS:000178251800044 ER PT J AU Yamazaki, Y Kaneda, Y Rubinstein, R AF Yamazaki, Y Kaneda, Y Rubinstein, R TI Dynamics of inviscid truncated model of rotating turbulence SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE inviscid truncated model; rotating turbulence; two-dimensionalization; equilibrium state ID STATISTICAL-MECHANICS; EQUILIBRIUM; FLOW AB The dynamics of the inviscid truncated system of rotating turbulence is studied by numerical simulations under various initial conditions and rotation rates. The simulations suggest that the rotating inviscid truncated system ultimately relaxes towards an equipartition state with energy isotropically distributed at all scales of motion regardless of the initial conditions. Rotation delays relaxation to equipartition in a strongly scale-dependent and anisotropic manner. There is some transient tendency to two-dimensionalize an initially isotropic non-equilibrium state and to maintain initially quasi-two-dimensional initial conditions. Both trends are enhanced by increasing the rotation rate. C1 Nagoya Univ, Grad Sch Engn, Dept Computat Sci & Engn, Chikusa Ku, Nagoya, Aichi 4648603, Japan. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Nagoya Univ, Grad Sch Engn, Dept Computat Sci & Engn, Chikusa Ku, Nagoya, Aichi 4648603, Japan. NR 18 TC 9 Z9 9 U1 0 U2 1 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD JAN PY 2002 VL 71 IS 1 BP 81 EP 92 DI 10.1143/JPSJ.71.81 PG 12 WC Physics, Multidisciplinary SC Physics GA 514NU UT WOS:000173448600017 ER PT J AU Cruden, BA Rao, MVVS Sharma, SP Meyyappan, M AF Cruden, BA Rao, MVVS Sharma, SP Meyyappan, M TI Detection of chamber conditioning by CF4 plasmas in an inductively coupled plasma reactor SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID LASER-INDUCED FLUORESCENCE; RADIOFREQUENCY DISCHARGES; REFERENCE CELL; RADICALS; CHF3; DIAGNOSTICS AB During oxide etch processes, buildup of fluorocarbon residues on reactor sidewalls can cause run-to-run drift and will necessitate time for conditioning and cleaning of the reactor. Various measurements in CF4 and Ar plasmas are made in an attempt to identify a metric useable to indicate the chamber condition. Mass spectrometry and Langmuir probe data show that the buildup of fluorocarbon films on the reactor surface causes a decrease in plasma floating potential, plasma potential, and ion energy in argon plasmas. This change in floating potential is also observed in CF4 plasma operation, and occurs primarily during the first hour and a half of plasma operation. A slight rise in electron density is also observed in the argon plasmas. Because the change is seen in an argon plasma, it is indicative of altered physical, not chemical, plasma-surface interactions. Specifically, the insulating films deposited on metal surfaces alter the electromagnetic fields seen by the plasma, affecting various parameters including the floating potential and electron density. An impedance probe placed on the inductive coil shows a slight reduction in plasma impedance due to this rising electron density. The optical emission of several species, including CF, C-2, Si, and C, is also monitored for changes in density resulting from the buildup of film on the chamber wall. Changes in the optical emission spectrum are comparable to the noise levels in these measurements. (C) 2002 American Vacuum Society. C1 NASA, Ames Res Ctr, Eloret Corp, Moffett Field, CA 94035 USA. RP Cruden, BA (reprint author), NASA, Ames Res Ctr, Eloret Corp, Moffett Field, CA 94035 USA. NR 30 TC 16 Z9 16 U1 2 U2 3 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE,, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD JAN-FEB PY 2002 VL 20 IS 1 BP 353 EP 363 DI 10.1116/1.1447246 PG 11 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 523YQ UT WOS:000173985500064 ER PT J AU Lewis, RF Gong, WS Ramsey, M Minor, L Boyle, R Merfeld, DM AF Lewis, RF Gong, WS Ramsey, M Minor, L Boyle, R Merfeld, DM TI Vestibular adaptation studied with a prosthetic semicircular canal SO JOURNAL OF VESTIBULAR RESEARCH-EQUILIBRIUM & ORIENTATION LA English DT Article; Proceedings Paper CT Symposium on Electrical Stimulation of the Vestibular System CY 2001 CL ST PETERSBURG, FLORIDA SP Assoc Res Otolaryngol DE vestibular; adaptation; prosthesis; monkey ID ELECTRICAL-STIMULATION; VESTIBULOOCULAR REFLEX; SQUIRREL-MONKEY; RECOVERY AB We have developed and tested a prosthetic semicircular canal that senses angular head velocity and uses this information to modulate the rate of current pulses applied to the vestibular nerve via a stimulating electrode. In one squirrel monkey, the lateral canals were plugged bilaterally and the prosthesis was secured to the animal's head with the angular velocity sensor parallel to the axis of the lateral canals. In the first experiment, the stimulating electrode was placed near the ampullary nerve of one lateral canal. Over a period of two weeks, the gain of the horizontal VOR during yaw axis rotation gradually increased, although the response magnitude remained relatively small. In the second experiment, the stimulating electrode was placed near the ampullary nerve of the posterior canal, but the orientation of the velocity sensor remained parallel to the axis of the lateral canals. Over a one-week period, the axis of the VOR response gradually shifted towards alignment with the (yaw) axis of head rotation. Chronic patterned stimulation of the eighth nerve can therefore provide adequate information to the brain to generate a measurable VOR response, and this can occur even if the prosthetic yaw rotation cue is provided via a branch of the VIIIth nerve that doesn't normally carry yaw rotational cues. The results provided by this pilot study suggest that it may be feasible to study central adaptation by chronically modifying the afferent vestibular cue with a prosthetic semicircular canal. C1 Massachusetts Eye & Ear Infirm, Jenks Vestibular Physiol Lab, Boston, MA 02114 USA. Harvard Univ, Sch Med, Dept Otol & Laryngol, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Neurol, Boston, MA 02115 USA. Johns Hopkins Sch Med, Dept Otolaryngol, Baltimore, MD USA. NASA, Ames Res Ctr, Ctr Bioinformat, Moffett Field, CA 94035 USA. RP Lewis, RF (reprint author), Massachusetts Eye & Ear Infirm, Jenks Vestibular Physiol Lab, 243 Charles St, Boston, MA 02114 USA. FU NIDCD NIH HHS [DC03066]; NINDS NIH HHS [NS27050] NR 14 TC 39 Z9 39 U1 1 U2 3 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0957-4271 J9 J VESTIBUL RES-EQUIL JI J. Vestib. Res.-Equilib. Orientat. PY 2002 VL 12 IS 2-3 BP 87 EP 94 PG 8 WC Neurosciences; Otorhinolaryngology SC Neurosciences & Neurology; Otorhinolaryngology GA 734LT UT WOS:000186058000004 PM 12867667 ER PT J AU Mulavara, AP Bloomberg, JJ AF Mulavara, AP Bloomberg, JJ TI Identifying head-trunk and lower limb contributions to gaze stabilization during locomotion SO JOURNAL OF VESTIBULAR RESEARCH-EQUILIBRIUM & ORIENTATION LA English DT Article; Proceedings Paper CT 6th Symposium on the Role of the Vestibular Organs in the Exploration of Space CY OCT, 2002 CL PORTLAND, OREGON SP NASA ID NEUROMUSCULAR ACTIVATION PATTERNS; VISUAL-VESTIBULAR INTERACTION; NECK MUSCLE RESPONSES; SPACE-FLIGHT; TREADMILL WALKING; MOVEMENT CONTROL; RANDOM ROTATIONS; POSTURAL CONTROL; VERTICAL HEAD; DYNAMICS AB The goal of the present study was to determine how the multiple, interdependent full-body sensorimotor subsystems respond to a change in gaze stabilization task constraints during locomotion. Nine subjects performed two gaze stabilization tasks while walking at 6.4 km/hr on a motorized treadmill: 1) focusing on a central point target; 2) reading numeral characters; both presented at 2 m in front at the level of their eyes. While subjects performed the tasks we measured: temporal parameters of gait, full body sagittal plane segmental kinematics of the head, trunk, thigh, tibia and foot, accelerations along the vertical axis at the head and the tibia, and the vertical forces acting on the support surface. We tested the hypothesis that with the increased demands placed on visual acuity during the number recognition task, subjects would modify full-body segmental kinematics in order to reduce perturbations to the head in order to successfully perform the task. We found that while reading numeral characters as compared to the central point target: 1) compensatory head pitch movement was on average 22% greater despite the fact that the trunk pitch and trunk vertical translation movement control were not significantly changed; 2) coordination patterns between head and trunk as reflected by the peak cross correlation between the head pitch and trunk pitch motion as well as the peak cross correlation between the head pitch and vertical trunk translation motion were not significantly changed; 3) knee joint total movement was on average 11% greater during the period from the heel strike event to the peak knee flexion event in stance phase of the gait cycle; 4) peak acceleration measured at the head was significantly reduced by an average of 13% in four of the six subjects. This was so even when the peak acceleration at the tibia and the transmission of the shock wave at heel strike (measured by the peak acceleration ratio of the head/tibia and the time lag between the tibial and head peak accelerations) remained unchanged. Taken together these results provide further evidence that the full body contributes to gaze stabilization during locomotion, and that its different functional elements can be modified online to contribute to gaze stabilization for different visual task constraints. C1 NASA, Lyndon B Johnson Space Ctr, Neurosci Labs, Houston, TX 77058 USA. Baylor Coll Med, Bobby R Alford Dept Otorhinolaryngol & Communicat, Natl Space Biomed Res Inst, Houston, TX 77030 USA. RP Mulavara, AP (reprint author), NASA, Lyndon B Johnson Space Ctr, Neurosci Labs, 2101 NASA Rd 1,MC SK2723, Houston, TX 77058 USA. NR 56 TC 23 Z9 23 U1 1 U2 6 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0957-4271 J9 J VESTIBUL RES-EQUIL JI J. Vestib. Res.-Equilib. Orientat. PY 2002 VL 12 IS 5-6 BP 255 EP 269 PG 15 WC Neurosciences; Otorhinolaryngology SC Neurosciences & Neurology; Otorhinolaryngology GA 733AY UT WOS:000185978800006 PM 14501102 ER PT J AU Eckstein, MP Ahumada, AJ AF Eckstein, Miguel P. Ahumada, Albert J., Jr. TI Classification images: A tool to analyze visual strategies Introduction SO JOURNAL OF VISION LA English DT Editorial Material ID RECEPTIVE-FIELDS; CORTEX; FEATURES; NOISE C1 [Eckstein, Miguel P.] Univ Calif Santa Barbara, Dept Psychol, Santa Barbara, CA 93106 USA. [Ahumada, Albert J., Jr.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Eckstein, MP (reprint author), Univ Calif Santa Barbara, Dept Psychol, Santa Barbara, CA 93106 USA. NR 12 TC 30 Z9 30 U1 0 U2 4 PU ASSOC RESEARCH VISION OPHTHALMOLOGY INC PI ROCKVILLE PA 12300 TWINBROOK PARKWAY, ROCKVILLE, MD 20852-1606 USA SN 1534-7362 J9 J VISION JI J. Vision PY 2002 VL 2 IS 1 BP I EP III AR i DI 10.1167/2.1.i PG 3 WC Ophthalmology SC Ophthalmology GA V02EW UT WOS:000206907500001 ER PT J AU Ahumada, AJ AF Ahumada, Albert J., Jr. TI Classification image weights and internal noise level estimation SO JOURNAL OF VISION LA English DT Article DE discrimination; detection; vision; noise AB For the linear discrimination of two stimuli in white Gaussian noise in the presence of internal noise, a method is described for estimating linear classification weights from the sum of noise images segregated by stimulus and response. The recommended method for combining the two response images for the same stimulus is to difference the average images. Weights are derived for combining images over stimuli and observers. Methods for estimating the level of internal noise are described with emphasis on the case of repeated presentations of the same noise sample. Simple tests for particular hypotheses about the weights are shown based on observer agreement with a noiseless version of the hypothesis. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Ahumada, AJ (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. FU NASA [RTOP 548-51-12] FX I am grateful to Bettina L. Beard and Andrew B. Watson for their support. The paper was greatly improved by thoughtful anonymous reviewers. This research was supported by NASA RTOP 548-51-12. Commercial relationships: None. NR 24 TC 79 Z9 79 U1 2 U2 7 PU ASSOC RESEARCH VISION OPHTHALMOLOGY INC PI ROCKVILLE PA 12300 TWINBROOK PARKWAY, ROCKVILLE, MD 20852-1606 USA SN 1534-7362 J9 J VISION JI J. Vision PY 2002 VL 2 IS 1 BP 121 EP 131 AR 8 DI 10.1167/2.1.8 PG 11 WC Ophthalmology SC Ophthalmology GA V02EW UT WOS:000206907500009 PM 12678600 ER PT J AU Scharff, LFV Ahumada, AJ AF Scharff, Lauren F. V. Ahumada, Albert J., Jr. TI Predicting the readability of transparent text SO JOURNAL OF VISION LA English DT Article DE vision models; luminance contrast; contrast gain; masking; text contrast; word search; transparent displays AB Will a simple global masking model based on image detection be successful at predicting the readability of transparent text? Text readability was measured for two types of transparent text: additive (as occurs in head-up displays) and multiplicative (which occurs in see-through liquid crystal display virtual reality displays). Text contrast and background texture were manipulated. Data from two previous experiments were also included (one using very low contrasts on plain backgrounds, and the other using higher-contrast opaque text on both plain and textured backgrounds). All variables influenced readability in at least an interactive manner. When there were background textures, the global masking index (that combines text contrast and background root mean square contrast) was a good predictor of search times (r = 0.89). When the masking was adjusted to include the text pixels as well as the background pixels in computations of mean luminance and contrast variability, predictability improved further (r = 0.91). C1 [Scharff, Lauren F. V.] Stephen F Austin State Univ, Dept Psychol, Nacogdoches, TX 75962 USA. [Ahumada, Albert J., Jr.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Scharff, LFV (reprint author), Stephen F Austin State Univ, Dept Psychol, Nacogdoches, TX 75962 USA. FU irspace Operations Systems (AOS) Project of NASA's Airspace Systems Program; NASA RTOP [711-51-12]; San Jose State University Foundation, San Jose, CA [NCC2-1095] FX We would like to thank Lori Shird for her assistance in the data collection process. Funding for this work was provided by the Airspace Operations Systems (AOS) Project of NASA's Airspace Systems Program and supported by NASA RTOP 711-51-12 through the Cooperative Agreement NCC2-1095 with the San Jose State University Foundation, San Jose, CA. Commercial Relationships: None. NR 25 TC 12 Z9 12 U1 0 U2 1 PU ASSOC RESEARCH VISION OPHTHALMOLOGY INC PI ROCKVILLE PA 12300 TWINBROOK PARKWAY, ROCKVILLE, MD 20852-1606 USA SN 1534-7362 J9 J VISION JI J. Vision PY 2002 VL 2 IS 9 BP 653 EP 666 DI 10.1167/2.9.7 PG 14 WC Ophthalmology SC Ophthalmology GA V02FD UT WOS:000206908200007 PM 12678636 ER PT J AU Heineck, JT Schultz, PH Anderson, JLB AF Heineck, JT Schultz, PH Anderson, JLB TI Application of three-component PIV to the measurement of hypervelocity impact ejecta SO JOURNAL OF VISUALIZATION LA English DT Article DE hypervelocity impacts; PIV; ballistic ejecta; meteor impact; Ames Vertical Gun Range ID EMPLACEMENT AB Three-component Particle Image Velocimetry has been applied to the measurement of hypervelocity ejecta from meteoritic impact experiments. This work represents the first attempt at measuring ejecta from a ballistic event using the PIN technique. The ejecta particles are measured directly, within a plane, at any controlled instant after the impact. The particle trajectories are observed at all azimuthal positions relative to the impact point thus revealing both the shape of the curtain and the distribution of velocities at a given instance. By seeding the target with 10 mum hollow spheres, the fluid flow associated with the impact in an atmosphere is simultaneously observed with the ejecta. 3C PIV is demonstrated to be an ideally suited technique for investigations on ejecta trajectories, ejecta curtain morphology and the fluid mechanics in the presence of an atmosphere. Sample results are presented. C1 NASA, Ames Res Ctr, Aerosp Projects Div, Expt Phys Grp, Moffett Field, CA 94035 USA. Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. RP Heineck, JT (reprint author), NASA, Ames Res Ctr, Aerosp Projects Div, Expt Phys Grp, Moffett Field, CA 94035 USA. NR 15 TC 7 Z9 7 U1 0 U2 1 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 1343-8875 J9 J VISUAL-JAPAN JI J. Vis. PY 2002 VL 5 IS 3 BP 233 EP 241 PG 9 WC Computer Science, Interdisciplinary Applications; Imaging Science & Photographic Technology SC Computer Science; Imaging Science & Photographic Technology GA 593KE UT WOS:000177989800010 ER PT S AU Degnan, J McGarry, J Zagwodzki, T Dabney, P Geiger, J Chabot, R Steggerda, C Marzouk, J Chu, A AF Degnan, J McGarry, J Zagwodzki, T Dabney, P Geiger, J Chabot, R Steggerda, C Marzouk, J Chu, A BE Schreiber, U Werner, CH Kamerman, GW Singh, UN TI Design and performance of a 3-D imaging, photon-counting, microlaser altimeter operating from aircraft cruise altitudes under day or night conditions SO LASER RADAR: RANGING AND ATMOSPHERIC LIDAR TECHNIQUES III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Radar - Ranging and Atmospheric Lidar Techniques III CY SEP 17-18, 2001 CL TOULOUSE, FRANCE SP SPIE, European Opt Soc, CNES, NASA DE laser altimetry; photon-counting; microchip lasers; subnanosecond pulse; multi-kilohertz ranging AB The present paper reports on the design and performance of a scanning, photon-counting laser altimeter, capable of daylight operations from aircraft cruise altitudes. In test flights, the system has successfully recorded high repetition rate returns from clouds, soils, man-made objects, vegetation, and water surfaces under full solar illumination. Following the flights, the signal was reliably extracted from the solar noise back-ground using a Post-Detection Poisson Filtering technique. The passively Q-switched microchip Nd:YAG laser measures only 2.25 mm in length and is pumped by a single 1.2 Watt GaAs laser diode. The output is frequency-doubled to take advantage of higher detector counting efficiencies and narrower spectral filters available at 532 nm. The transmitter produces several microjoules of green energy in a subnanosecond pulse at rates approaching 10 kHz. The illuminated ground area is imaged by a 14 cm diameter, diffraction-limited, off-axis telescope onto a segmented anode photomultiplier. Each anode segment is input to one channel of "fine" rangre receiver (5 cm resolution), which records the times-of-flight of individual photons. A parallel "coarse" receiver provides a lower resolution (>75 cm) histogram of all scatterers between the aircraft and ground and centers the "fine" receiver gate on the last set of returns. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Degnan, J (reprint author), NASA, Goddard Space Flight Ctr, Code 920-3, Greenbelt, MD 20771 USA. RI Dabney, Philip/C-9976-2013 NR 10 TC 6 Z9 6 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 0-8194-4271-2 J9 P SOC PHOTO-OPT INS PY 2002 VL 4546 BP 1 EP 10 DI 10.1117/12.453978 PG 10 WC Optics; Physics, Applied; Imaging Science & Photographic Technology SC Optics; Physics; Imaging Science & Photographic Technology GA BU20V UT WOS:000175314100001 ER PT S AU Ilchenko, VS Matsko, AB Savchenkov, AA Maleki, L AF Ilchenko, VS Matsko, AB Savchenkov, AA Maleki, L BE Kudryashov, AV TI High efficiency microwave and millimeter-wave electro-optical modulation with whispering-gallery resonators SO LASER RESONATORS AND BEAM CONTROL V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Resonators and Beam Control V CY JAN 22-23, 2002 CL SAN JOSE, CA SP SPIE DE Microsphere; microcavity; photonics; electrooptic modulator ID Q MICROSPHERE CAVITY; MODES; LASER AB We present an electro-optic modulator based on a toroidal lithium niobate cavity superimposed with a stripline resonator. We achieve modulator controlling power of about 1 mW with the microwave resonance (quality-factor Q similar to 10(2)) tuned to the 9 GHz free spectral range of optical whispering-gallery modes (Q similar to 5X10(6)). Operated as a photonic receiver, the device has a sensitivity of about 2.5 nW. Preliminary results with a 33 GHz prototype are also reported. Further efficiency improvement will enable various applications of the device in microwave photonics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ilchenko, VS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 298-100, Pasadena, CA 91109 USA. NR 12 TC 7 Z9 7 U1 0 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 0-8194-4368-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4629 BP 158 EP 163 DI 10.1117/12.469484 PG 6 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BU92V UT WOS:000177419900021 ER PT S AU Nadeau, JL Iltchenko, VS Kossakovski, D Bearman, GH Maleki, L AF Nadeau, JL Iltchenko, VS Kossakovski, D Bearman, GH Maleki, L BE Kudryashov, AV TI High-Q whispering-gallery mode sensor in liquids SO LASER RESONATORS AND BEAM CONTROL V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Laser Resonators and Beam Control V CY JAN 22-23, 2002 CL SAN JOSE, CA SP SPIE DE whispering-gallery mode; microresonator; streptavidin-biotin; Q factor; evanescent wave; biosensor AB Optical sensing of biomolecules on microfabricated glass surfaces requires surface coatings that minimize nonspecific binding while preserving the optical properties of the sensor. Microspheres with whispering-gallery (WG) modes can achieve quality factor (Q) levels many orders of magnitude greater than those of other WG-based microsensors: greater than 10(10) in air, and greater than 10(9) in a variety of solvents, including methanol, H2O and phosphate buffered saline (PBS). The presence of dyes that absorb in the wavelength of the WG excitation in the evanescent zone can cause this Q value to drop by almost 3 orders of magnitude. Silanization of the surface with mercapto-terminal silanes is compatible with high Q (>10(9)), but chemical cross-linking of streptavidin reduces the Q to 10(5)-10(6) due to build-up of a thick, irregular layer of protein. However, linkage of biotin to the silane terminus preserves the Q at a similar to2x10(7) and yields a reactive surface sensitive to avidin-containing ligands in a concentration-dependent manner. Improvements in the reliability of the surface chemistry show promise for construction of an ultrasensitive biosensor. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nadeau, JL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 183-301, Pasadena, CA 91109 USA. NR 11 TC 57 Z9 57 U1 1 U2 11 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4368-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4629 BP 172 EP 180 DI 10.1117/12.469488 PG 9 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BU92V UT WOS:000177419900023 ER PT J AU Lanzafame, RJ Stadler, I Whelan, HT AF Lanzafame, RJ Stadler, I Whelan, HT TI NASA LED photoradiation influences nitric oxide and collagen production in wounded rats SO LASERS IN SURGERY AND MEDICINE LA English DT Meeting Abstract C1 Rochester Gen Hosp, Ctr Laser, Rochester, NY 14621 USA. Med Coll Wisconsin, Dept Neurol, Milwaukee, WI 53226 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0196-8092 J9 LASER SURG MED JI Lasers Surg. Med. PY 2002 SU 14 MA 40 BP 12 EP 12 PG 1 WC Dermatology; Surgery SC Dermatology; Surgery GA 536XE UT WOS:000174726500039 ER PT J AU Stadler, I Ellie Lanzafame, RJ Oskuoi, P Whelan, HT AF Stadler, I Ellie Lanzafame, RJ Oskuoi, P Whelan, HT TI Alteration of osmotic fragility of red cells after near-infrared NASA led photoradiation is not ATP dependent SO LASERS IN SURGERY AND MEDICINE LA English DT Meeting Abstract C1 Rochester Gen Hosp, Ctr Laser, Rochester, NY 14621 USA. Med Coll Wisconsin, Dept Neurol, Milwaukee, WI 53226 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0196-8092 J9 LASER SURG MED JI Lasers Surg. Med. PY 2002 SU 14 MA 308 BP 83 EP 83 PG 1 WC Dermatology; Surgery SC Dermatology; Surgery GA 536XE UT WOS:000174726500286 ER PT S AU Peri, F Komar, GJ AF Peri, F Komar, GJ BE Singh, UN TI Active remote sensing technology development plans for NASA's Earth Science Enterprise SO LIDAR REMOTE SENSING FOR INDUSTRY AND ENVIRONMENT MONITORING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 2nd Conference on Lidar Remote Sensing for Industry and Environment Monitoring CY JUL 30-31, 2001 CL SAN DIEGO, CA SP SPIE, NASA Langley Res Ctr DE lasers; active remote sensing; Earth science; NASA; technology AB Future remote sensing instruments for the National Aeronautic and Space Administration (NASA) Earth Science Enterprise (ESE) will depend heavily upon lidars as active sources. Applications will include measurement of the chemical composition of the atmosphere, including global atmospheric CO2, tropospheric wind velocity and surface altimetry. In many cases, the technology requirements for these measurements exceed the state of the art in commercially available laser systems. Consequently, considerable research will be necessary in laser technologies in order to enable the future measurement needs of the ESE. In this paper we will describe the strategy that NASA's ESE will use to develop the necessary laser and supporting technologies. We will illustrate roadmaps of the various measurement needs detailing specific technology investments. In particular we will review the findings from workshops recently conducted by NASA to determine the technology drivers for these measurements. The Earth Science Technology Office is responsible for developing advanced technologies for the ESE, as such, this information is presented in order to communicate the relevancy of, and the need for investments in these technologies to the broadest technical audience. C1 NASA, Goddard Space Flight Ctr, Earth Sci Technol Off, Greenbelt, MD 20771 USA. RP Peri, F (reprint author), NASA, Goddard Space Flight Ctr, Earth Sci Technol Off, Code 711, Greenbelt, MD 20771 USA. NR 0 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 0-8194-4198-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4484 BP 1 EP 7 AR UNSP 4484-01 DI 10.1117/12.452767 PG 7 WC Environmental Sciences; Instruments & Instrumentation; Remote Sensing; Optics SC Environmental Sciences & Ecology; Instruments & Instrumentation; Remote Sensing; Optics GA BU15H UT WOS:000175162400001 ER PT S AU Schwemmer, GK Miller, DO Wilkerson, TD Andrus, I AF Schwemmer, GK Miller, DO Wilkerson, TD Andrus, I BE Singh, UN TI Time resolved 3-D mapping of atmospheric aerosols and clouds during the recent Atmospheric Radiation Measurement water vapor Intensive Operating Period SO LIDAR REMOTE SENSING FOR INDUSTRY AND ENVIRONMENT MONITORING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 2nd Conference on Lidar Remote Sensing for Industry and Environment Monitoring CY JUL 30-31, 2001 CL SAN DIEGO, CA SP SPIE, NASA Langley Res Ctr DE lidar; backscatter; atmospheric aerosols; clouds; holographic optical element; scanning; atmospheric dynamics; Doppler; wind profiles AB We have developed simplified conical scanning telescopes using Holographic Optical Elements (HOEs) to reduce the size, mass, angular momentum, and cost of scanning lidar systems. This technology enables wide-angle scanning and three-dimensional measurements of atmospheric backscatter when used in airborne instruments, and high temporal and spatial resolution observations of atmospheric dynamic structure, including wind profiles from ground-based facilities. We deployed the Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE) on the ground at the Department Of Energy's (DOE) central site in northern Oklahoma during their most recent Atmospheric Radiation Measurement (ARM) program Water Vapor Intensive Operating Period (WVIOP) in September-October 2000, in order to take advantage of the many coincident atmospheric measurements taking place at that time while collecting data with which to develop data reduction algorithms. We are evaluating the HARLIE technology and scanning techniques with an eye toward their application into other types of lidar systems, including Raman and Doppler lidar systems. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Schwemmer, GK (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 912, Greenbelt, MD 20771 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 0-8194-4198-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4484 BP 58 EP 63 AR UNSP 4484-07 DI 10.1117/12.452800 PG 6 WC Environmental Sciences; Instruments & Instrumentation; Remote Sensing; Optics SC Environmental Sciences & Ecology; Instruments & Instrumentation; Remote Sensing; Optics GA BU15H UT WOS:000175162400007 ER PT S AU Gentry, BM Chen, HL AF Gentry, BM Chen, HL BE Singh, UN TI Tropospheric wind measurements obtained with the Goddard Lidar Observatory for Winds (GLOW): Validation and performance SO LIDAR REMOTE SENSING FOR INDUSTRY AND ENVIRONMENT MONITORING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 2nd Conference on Lidar Remote Sensing for Industry and Environment Monitoring CY JUL 30-31, 2001 CL SAN DIEGO, CA SP SPIE, NASA Langley Res Ctr DE Doppler lidar; tropospheric wind; Fabry-Perot etalon ID DOPPLER LIDAR; EDGE TECHNIQUE AB The Goddard Lidar Observatory for Winds (GLOW) is a mobile Doppler lidar system which uses direct detection Doppler lidar techniques to measure wind profiles from the surface into the lower stratosphere. GLOW is intended to be used as a field deployable system for studying atmospheric dynamics and transport and can also serve as a testbed to evaluate candidate technologies developed for use in future spaceborne systems. In September of 2000 GLOW particpated in a three week intercomparison experiment at the GroundWinds facility in North Glen, NH. More than 50 hours of line-of-sight wind profile data were obtained in a wide variety of conditions including both day and night operation. Typical clear air lidar wind profiles extended to altitudes of 20 kin with a I km. vertical resolution and 1 minute averaging. A description of the mobile system is presented along with the examples of lidar wind profiles obtained with the Goddard system during the New Hampshire experiment. 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 14 TC 7 Z9 7 U1 0 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 0-8194-4198-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4484 BP 74 EP 81 AR UNSP 4484-09 DI 10.1117/12.452802 PG 8 WC Environmental Sciences; Instruments & Instrumentation; Remote Sensing; Optics SC Environmental Sciences & Ecology; Instruments & Instrumentation; Remote Sensing; Optics GA BU15H UT WOS:000175162400009 ER PT S AU Riishojgaard, LP Atlas, R Emmitt, GD AF Riishojgaard, LP Atlas, R Emmitt, GD BE Singh, UN TI The impact of Doppler lidar wind observations on a single-level meteorological analysis SO LIDAR REMOTE SENSING FOR INDUSTRY AND ENVIRONMENT MONITORING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 2nd Conference on Lidar Remote Sensing for Industry and Environment Monitoring CY JUL 30-31, 2001 CL SAN DIEGO, CA SP SPIE, NASA Langley Res Ctr DE satellite observations; Doppler Lidar; meteorology; data assimilation AB Through the use of observation operators, modern data assimilation systems have the capability to ingest observations of quantities that are not themselves model variables, but are mathematically related to those variables. An example of this are the so-called LOS (line of sight) winds that a Doppler wind Lidar can provide. The model - or data assimilation system - needs information about both components of the horizontal wind vectors, whereas the observations in this case only provide the projection of the wind vector onto a given direction. The analyzed value is then calculated essentially based on a comparison between the observation itself and the model-simulated value of the observed quantity. However, in order to assess the expected impact of such an observing system, it is important to examine the extent to which a meteorological analysis can be constrained by the LOS winds. The answer to this question depends on the fundamental character of the atmospheric flow fields that are analyzed, but more importantly it also depends on the real and assumed error covariance characteristics of these fields. A single-level wind analysis system designed to explore these issues has been built at the NASA Data Assimilation Office. In this system, simulated wind observations can be evaluated in terms of their impact on the analysis quality under various assumptions about their spatial distribution and error characteristics and about the error covariance of the background fields. The basic design of the system will be presented along with experimental results obtained with it. In particular, the value of simultaneously measuring LOS winds along two different directions for a given location will be discussed. C1 NASA, Goddard Space Flight Ctr, Data Assimilat Off, Greenbelt, MD 20771 USA. RP Riishojgaard, LP (reprint author), NASA, Goddard Space Flight Ctr, Data Assimilat Off, Greenbelt, MD 20771 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 0-8194-4198-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4484 BP 93 EP 102 AR UNSP 4484-39 DI 10.1117/12.452789 PG 10 WC Environmental Sciences; Instruments & Instrumentation; Remote Sensing; Optics SC Environmental Sciences & Ecology; Instruments & Instrumentation; Remote Sensing; Optics GA BU15H UT WOS:000175162400011 ER PT B AU Williger, GM Heap, SR Weymann, RJ Dave, R Carswell, RF AF Williger, GM Heap, SR Weymann, RJ Dave, R Carswell, RF BE Gilfanov, M Sunyaev, R Churazov, E TI STIS spectroscopy of the Ly alpha forest toward 3C 273 and PKS 0405-123 SO LIGHTHOUSES OF THE UNIVERSE: THE MOST LUMINOUS CELESTIAL OBJECTS AND THEIR USE FOR COSMOLOGY SE ESO ASTROPHYSICS SYMPOSIA LA English DT Proceedings Paper CT MPA/ESO/MPE/USM Joint Astronomy Conference on Lighthouses of the Universe CY AUG 06-10, 2001 CL GARCHING, GERMANY AB We present on-going results from similar to 7 km s(-1) resolution STIS spectra for two bright low z QSOs, 3C 273 (z = 0.158) and PKS 0405=123 (z = 0.574), as part of a STIS Investigation Definition Team (IDT) key project to determine the redshift density, H I column density and Doppler parameter distributions of weak Lyalpha forest systems at low redshift. In a preliminary analysis of features at the 4sigma level, our samples are complete to log N-HI similar to 12.5, 13.2 for 3C 273 and PKS 0405-123 respectively, with sample sizes of 36 and 169 Lyalpha lines at velocities Deltaupsilon greater than or equal to 5000 km s(-1) from their background QSOs. Our ultimate goal is to compare results with simulations of cosmological evolution, in order to make constraints on the physical characteristics of the intergalactic medium and UV background flux. We also find a variety of Galactic and intergalactic metal absorption lines, including O VI from intervening systems, which will be useful in studies of gas from the halo of the Galaxy and galaxies out to z similar to 0.6. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Williger, GM (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-43769-X J9 ESO ASTROPHY SYMP PY 2002 BP 544 EP 546 DI 10.1007/10856495_85 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV62R UT WOS:000179560500085 ER PT S AU Karasik, BS Sergeev, AV Gershenson, ME AF Karasik, BS Sergeev, AV Gershenson, ME BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI Electron-phonon relaxation in hot-electron detectors below 1 K SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN ID FILMS; METALS AB Recently proposed submillimeter hot-electron direct detectors rely on a weak thermal coupling between electrons and phonons. According to the theory, this should occur in impure films. So far, the experimental situation has been somewhat confusing. A number of works have shown a cubic temperature dependence of the electron-phonon relaxation rate below I K. In contrast to the traditional explanation, we show that it was not a clean limit behavior but rather an intermediate temperature asymptotics. In this case, an electron scattering from transversal phonons mediated by vibrating impurities/boundaries dominates. In our recent experiments we reached the dirty limit predicted by the theory in Hf and Ti films. A measured electron-phonon relaxation time followed the T-4 dependence and was a record-long (25 ms) at 40 mK. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Karasik, BS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 75 EP 78 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300018 ER PT S AU Moseley, H McCammon, D AF Moseley, H McCammon, D BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI High performance silicon hot electron bolometers SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN ID DOPED SILICON AB High performance Si bolometers can be made using the electron-phonon conductance in the heavily doped Si to provide thermal isolation from the cryogenic bath. Thermal conductance, response time, noise, and signal frequency resistance are predicted based on laboratory measurements of larger samples. The predictions show that such detectors can be built with thermal conductances suitable for a wide range of applications, ranging from the low backgrounds of cryogenic space telescopes to ground based imaging and spectroscopy. Their noise performance is expected to be near thermodynamic limits, allowing background limited performance for many far infrared and submillimeter photometric and spectroscopic applications. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Moseley, H (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Moseley, Harvey/D-5069-2012 NR 3 TC 4 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 103 EP 106 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300025 ER PT S AU Lindeman, MA Brekosky, RP Figueroa-Feliciano, E Finkbeiner, FM Li, M Stahle, CK Stahle, CM Tralshawala, N AF Lindeman, MA Brekosky, RP Figueroa-Feliciano, E Finkbeiner, FM Li, M Stahle, CK Stahle, CM Tralshawala, N BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI Performance of Mo/Au TES microcalorimeters SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN ID TRANSITION-EDGE SENSORS; NOISE AB We are developing X-ray calorimeters to meet the specifications of the Constellation-X mission. Each calorimeter consists of a transition-edge-sensor (TES) thermometer, which is suspended on a silicon-nitride membrane. Our TES thermometers are Mo/Au bilayer films that are biased in the sharp phase transition between the superconducting and normal-metal states. These calorimeters have demonstrated very good energy resolutions: 2.4 eV at 1.5 keV and 3.7 eV at 3.3 keV. The energy resolutions are limited by thermal noise and Johnson noise (which are intrinsic to any resistive calorimeter) plus excess noise. The excess noise, which is several times larger than the Johnson noise, is consistent with frequency-independent voltage noise in the TES. Detailed measurements of one Mo/Au TES demonstrate that the excess noise is independent of the voltage applied to the TES over a range of biases at the same TES resistance. The magnitude of the excess noise is smallest at the high-resistance end of the phase transition. We also compared noise in square Mo/Au TES's ranging in size from 300 microns to 600 microns to learn how the excess noise is affected by the geometry of the TES. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lindeman, MA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 5 TC 14 Z9 14 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 203 EP 206 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300047 ER PT S AU Finkbeiner, FM Brekosky, RP Chervenak, JA Figueroa-Feliciano, E Li, MJ Lindeman, MA Stahle, CK Stahle, CM Tralshawala, N AF Finkbeiner, FM Brekosky, RP Chervenak, JA Figueroa-Feliciano, E Li, MJ Lindeman, MA Stahle, CK Stahle, CM Tralshawala, N BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI Fabrication of close-packed TES microcalorimeter arrays using superconducting molybdenum/gold transition-edge sensors SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN AB We present an overview of our efforts in fabricating Transition-Edge Sensor (TES) microcalorimeter arrays for use in astronomical x-ray spectroscopy. Two distinct types of array schemes are currently pursued: 5x5 single pixel TES array where each pixel is a TES microcalorimeter, and Position-Sensing TES (PoST) array. In the latter, a row of 7 or 15 thermally-linked absorber pixels is read out by two TES at its ends. Both schemes employ superconducting Mo/Au bilayers as the TES. The TES are placed on silicon nitride membranes for thermal isolation from the structural frame. The silicon nitride membranes are prepared by a Deep Reactive Ion Etch (DRIE) process into a silicon wafer. In order to achieve the concept of closely packed arrays without decreasing its structural and functional integrity, we have already developed the technology to fabricate arrays of cantilevered pixel-sized absorbers and slit membranes in silicon nitride films. Furthermore, we have started to investigate ultra-low resistance through-wafer micro-vias to bring the electrical contact out to the back of a wafer. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Finkbeiner, FM (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. NR 4 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 215 EP 218 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300050 ER PT S AU Lindeman, MA Brekosky, RP Figueroa-Feliciano, E Finkbeiner, FM Li, M Stahle, CK Stahle, CM Tralshawala, N AF Lindeman, MA Brekosky, RP Figueroa-Feliciano, E Finkbeiner, FM Li, M Stahle, CK Stahle, CM Tralshawala, N BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI Detailed characterization of Mo/Au TES microcalorimeters SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN AB We are optimizing Mo/Au transition-edge-sensor (TES) calorimeters to meet the specifications of NASA's Constellation-X mission. Our calorimeters have already demonstrated very good energy resolution of X rays (2.4 eV at 1.5 keV). We wish to further improve the energy resolution by reducing excess noise in the calorimeters. Development of a detailed model and understanding of the noise is instrumental to reaching this goal. Towards that end, we employ a linear model that describes the response of a calorimeter to signal and various sources of noise. The model is based on detailed measurements of the parameters that affect the calorimeter's performance, such as current-voltage characteristics of the TES, thermal conductance of our silicon-nitride membranes, and inductance in the electronic circuit used to bias the TES. We determine the sharpness of the superconducting phase transition by fitting the model to the measured responsivity of the calorimeter. The model relates sources of noise, such as phonon noise, Johnson noise, and hypothetical sources of excess noise, to measurements of noise in the TES. Based on this analysis, we find that the excess noise is consistent with frequency-independent voltage noise in the TES. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lindeman, MA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 5 TC 7 Z9 7 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 219 EP 222 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300051 ER PT S AU Stahle, CK Lindeman, MA Figueroa-Feliciano, E Li, MJ Tralshawa, N Finkbeiner, FM Brekosky, RP Chervenak, JA AF Stahle, CK Lindeman, MA Figueroa-Feliciano, E Li, MJ Tralshawa, N Finkbeiner, FM Brekosky, RP Chervenak, JA BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI Arraying compact pixels of transition-edge microcalorimeters for imaging x-ray spectroscopy SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN ID TEMPERATURES; MEMBRANES AB We are developing superconducting transition-edge sensor (TES) microcalorimeters for astronomical x-ray spectroscopy. We have obtained very high energy resolution (2.4 eV at 1.5 keV and 3.7 eV at 3.3 keV) in large, isolated TES pixels using Mo/Au proximity-effect bilayers on silicon-nitride membranes several mm wide. In order to be truly suitable for use behind an x-ray telescope, however, such devices need to be arrayed with a pixel size and focal-plane coverage matched to the telescope focal length and spatial resolution. For the Constellation-X mission, this requires fitting the TES, its thermal link, and contact wiring into a 0.25 mm square, a far more compact geometry than has previously been investigated. We have demonstrated that the weak thermal link can be restricted to a narrow (similar to10 micron) perimeter of membrane around the TES and still provide a thermal conductance in the acceptable range. Varying the size and placement of slits in that nitride perimeter, we can tune that value. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Stahle, CK (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 5 TC 13 Z9 13 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 223 EP 226 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300052 ER PT S AU Figueroa-Feliciano, E Chervenak, J Finkbeiner, FM Li, M Lindeman, MA Stahle, CK Stahle, CM AF Figueroa-Feliciano, E Chervenak, J Finkbeiner, FM Li, M Lindeman, MA Stahle, CK Stahle, CM BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI First results from position-sensitive quantum calorimeters using Mo/Au transition-edge sensors SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN AB We report the first results from a high-energy-resolution imaging spectrometer called a Position-Sensitive Transition-Edge Sensor (POST). A POST is a quantum calorimeter consisting of two Transition Edge Sensors (TESs) on the ends of a long absorber to do one dimensional imaging spectroscopy. Comparing rise time and energy information, the position of the event in the POST is determined. Energy is inferred from the sum of the two pulses. We have fabricated 7- and 15-pixel PoSTs using Mo-Au TESs and Au absorbers. We have achieved 32 eV FWHM energy resolution at 1.5 keV with a 7-pixel PoST calorimeter. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Figueroa-Feliciano, E (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 1 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 239 EP 242 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300056 ER PT S AU Bock, JJ Goldin, A Hunt, C Lange, AE LeDuc, HG Day, PK Vayonakis, A Zmuidzinas, J AF Bock, JJ Goldin, A Hunt, C Lange, AE LeDuc, HG Day, PK Vayonakis, A Zmuidzinas, J BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI Integrated focal plane arrays for millimeter-wave astronomy SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN AB We are developing focal plane arrays of bolometric detectors for sub-millimeter and millimeter-wave astrophysics. We propose a flexible array architecture using arrays of slot antennae coupled via low-loss superconducting Nb transmission line to microstrip filters and antenna-coupled bolometers. By combining imaging and filtering functions with transmission line, we are able to realize unique structures such as a multi-band polarimeter and a planar, dispersive spectrometer, Micro-strip bolometers have significantly smaller active volume than standard detectors with extended absorbers, and can realize higher sensitivity and speed of response. The integrated array has natural immunity to stray radiation or spectral leaks, and minimizes the suspended mass operating at 0.1 - 0.3 K. We also discuss future space-borne spectroscopy and polarimetry applications. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bock, JJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 243 EP 246 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300057 ER PT S AU Goldin, A Bock, JJ Hunt, C Lange, AE LeDuc, H Vayonakis, A Zmuidzinas, J AF Goldin, A Bock, JJ Hunt, C Lange, AE LeDuc, H Vayonakis, A Zmuidzinas, J BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI SAMBA: Superconducting antenna-coupled, multi-frequency, bolometric array SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN AB We present a design for a multipixel, multiband (100 GHz, 200 GHz and 400 GHz) submillimeter instrument: SAMBA (Superconducting Antenna-coupled, Multi-frequency, Bolometric Array). SAMBA uses slot antenna coupled bolometers and microstrip filters. The concept allows for a much more compact, multiband imager compared to a comparable feedhorn-coupled bolometric system. SAMBA incorporates an array of slot antennas, superconducting transmission lines, a wide band multiplexer and superconducting transition edge bolometers. The transition-edge film measures the millimeter-wave power deposited in the resistor that terminates the transmission line. C1 JPL, Pasadena, CA 91109 USA. RP Goldin, A (reprint author), JPL, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 9 Z9 9 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 251 EP 254 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300059 ER PT S AU Stevenson, TR Pellerano, FA Stahle, CM Aidala, K Schoelkopf, RJ AF Stevenson, TR Pellerano, FA Stahle, CM Aidala, K Schoelkopf, RJ BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI Wavelength division multiplexing scheme for radio-frequency single electron transistors SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN ID X-RAY; READOUT; SENSORS; ARRAYS AB We describe work on a wavelength division multiplexing scheme for radio-frequency single electron transistors. We use a network of resonant impedance matching circuits to direct applied rf carrier waves to different transistors depending on carrier frequency. Using discrete components, we made a two-channel demonstration of this concept and successfully reconstructed input signals with small levels of cross coupling. A lithographic version of the rf circuits had measured parameters in agreement with electromagnetic modeling, with reduced cross capacitance and inductance, and should allow 20 to 50 channels to be multiplexed. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Stevenson, TR (reprint author), NASA, Goddard Space Flight Ctr, Code 553, Greenbelt, MD 20771 USA. RI Schoelkopf, Robert/J-8178-2012 NR 13 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 289 EP 292 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300067 ER PT S AU Staguhn, JG Allen, CA Benford, DJ Chervenak, JA Freund, MM Khan, SA Kutyrev, AS Moseley, SH Shafer, RA Deiker, S Grossman, EN Hilton, GC Irwin, KD Martinis, JM Nam, SW Rudman, DA Wollman, DA AF Staguhn, JG Allen, CA Benford, DJ Chervenak, JA Freund, MM Khan, SA Kutyrev, AS Moseley, SH Shafer, RA Deiker, S Grossman, EN Hilton, GC Irwin, KD Martinis, JM Nam, SW Rudman, DA Wollman, DA BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI TES detector noise limited readout using SQUID multiplexers SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN AB The availability of superconducting Transition Edge Sensors (TES) with large numbers of individual detector pixels requires multiplexers for efficient readout. The use of multiplexers reduces the number of wires needed between the cryogenic electronics and the room temperature electronics and cuts the number of required cryogenic amplifiers. We are using an 8 channel SQUID multiplexer to read out one-dimensional TES arrays which are used for submillimeter astronomical observations. We present results from test measurements which show that the low noise level of the SQUID multiplexers allows accurate measurements of the TES Johnson noise, and that in operation, the readout noise is dominated by the detector noise. Multiplexers for large number of channels require a large bandwidth for the multiplexed readout signal, We discuss the resulting implications for the noise performance of these multiplexers which will be used for the readout of two dimensional TES arrays in next generation instruments. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Staguhn, JG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012; Moseley, Harvey/D-5069-2012 OI Benford, Dominic/0000-0002-9884-4206; NR 1 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 321 EP 324 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300074 ER PT S AU Boyce, KR Figueroa-Feliciano, E Finkbeiner, FM Gendreau, KC Kelley, RL Lindeman, MA Porter, FS Stahle, CK Szymkowiak, AE AF Boyce, KR Figueroa-Feliciano, E Finkbeiner, FM Gendreau, KC Kelley, RL Lindeman, MA Porter, FS Stahle, CK Szymkowiak, AE BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI Data processing for large fast microcalorimeter arrays SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN AB Future missions such as Constellation-X plan to use arrays of 1000 or more microcalorimeters with peak count rates of 1000 per second on a single pixel and 10,000 per second C across the array. These requirements put severe constraints on the data processing system. Raw data from the array will exceed 3 Gbits/second. In addition, the limited power available on space-flight missions requires a highly efficient processing system. We discuss a possible data processing architecture that will fit within the constraints of Constellation-X C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Boyce, KR (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Porter, Frederick/0000-0002-6374-1119; 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 343 EP 346 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300079 ER PT S AU Shirron, PJ Canavan, ER DiPirro, MJ Jackson, M Panek, J Tuttle, JG AF Shirron, PJ Canavan, ER DiPirro, MJ Jackson, M Panek, J Tuttle, JG BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI A continuous low-temperature magnetic refrigerator SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN AB We report on recent progress in the development of a continuous adiabatic demagnetization refrigerator (ADR). Continuous operation avoids the constraints of long hold times and short recycle times that lead to the generally large mass of single-shot ADRs, allowing us to achieve an order of magnitude larger cooling power per unit mass. Our current design goal is 10 muW of cooling at 50 mK using a 6-10 K heat sink. The estimated mass is less than 10 kg, including magnetic shielding of each stage, The relatively high heat rejection capability allows it to operate with a mechanical cryocooler as part of a cryogen-free, low temperature cooling system. This has the advantages of long mission life and reduced complexity and cost. We have assembled a three-stage ADR and have demonstrated continuous cooling using a superfluid helium bath as the heat sink. The temperature stability is 8 muK rms or better over the entire cycle, and the cooling power is 2.5 muW at 60 mK rising to 10 muW at 100 mK. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Shirron, PJ (reprint author), NASA, Goddard Space Flight Ctr, Code 552, Greenbelt, MD 20771 USA. NR 5 TC 0 Z9 0 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 379 EP 382 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300086 ER PT S AU Brown, GV Behar, E Beiersdorfer, P Boyce, KR Chen, H Gendreau, KC Gygax, J Kahn, SM Kelley, RL Porter, FS Stahle, CK Szymkowiak, AE AF Brown, GV Behar, E Beiersdorfer, P Boyce, KR Chen, H Gendreau, KC Gygax, J Kahn, SM Kelley, RL Porter, FS Stahle, CK Szymkowiak, AE BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI Recent results from the spare low temperature Astro-E microcalorimeter used at the LLNL EBIT-I and EBIT-II SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN ID EXCITATION AB In the past year a spare NASA/GSFC Astro-E microcalorimeter has been installed, tested, and run successfully on the electron beam ions traps EBIT-I and EBIT-II at the Lawrence Livermore National Laboratory. The microcalorimeter complements crystal and grating spectrometers already part of the LLNL ebit program making it possible to measure a broad bandwidth (similar to0.3-10 keV) with moderate resolution while simultaneously measuring a narrow bandwidth (similar to0.7-1.3 keV) with high resolution. An overview of recent work is presented including measurements by the microcalorimeter of absolute excitation cross sections. These results continue our effort to provide atomic data of high quality to be used as benchmarks for theoretical calculations and to be included in atomic data bases employed by spectral fitting packages used to interpret spectra obtained by XMM-Newton and the Chandra X-Ray Observatory. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Brown, GV (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Porter, Frederick/0000-0002-6374-1119; 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 413 EP 416 AR UNSP CP605 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300094 ER PT S AU Porter, FS Beiersdorfer, P Boyce, KR Brown, GV Chen, H Gendreau, KC Gygax, J Kahn, S Kelley, RL Stahle, CK Szymkowiak, AE AF Porter, FS Beiersdorfer, P Boyce, KR Brown, GV Chen, H Gendreau, KC Gygax, J Kahn, S Kelley, RL Stahle, CK Szymkowiak, AE BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI Laboratory astrophysics using an XRS engineering model microcalorimeter SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN AB We have recently deployed an XRS (the X-ray Spectrometer on the Astro-E mission) engineering model microcalorimeter at the electron beam ion traps (EBIT I/II) at Lawrence Livermore National Laboratory. The EBIT I/II can produce well defined astrophysically interesting plasmas for a wide range of plasma conditions. The XRS engineering model was mated with a 32 element XRS 6x6 microcalorimeter array and integrated into a laboratory cryostat. The system was then transported to the EBIT I/II and operated over the last year. The microcalorimeter array has a composite resolution of 8 eV at I keV and I I eV at 6 keV. During the campaign, we performed a number of high resolution, broad band observations including: K and L shell Fe with single ionization energies from I - 8 keV, Maxwellian distributions of Fe with = 0.5-3 keV, non-equilibrium states of Fe with very fine time resolution for eta = 10(9) - 10(12) s cm(-3). The total observation time for the campaign was over 10 Ms and the analysis is ongoing. We will present here an overview of the instrument and a few of the preliminary results. The results of these experiments show the power and promise of the XRS microcalorimeter and give a detailed picture of how the instrument would have performed in orbit on Astro-E, and will perform in the future on the Astro-E2 mission. C1 NASA, GSFC, Greenbelt, MD 20771 USA. RP Porter, FS (reprint author), NASA, GSFC, Greenbelt, MD 20771 USA. RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Porter, Frederick/0000-0002-6374-1119; NR 3 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 421 EP 424 AR UNSP CP605 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300096 ER PT S AU Benford, DJ Ames, TA Chervenak, JA Grossman, EN Irwin, KD Khan, SA Maffei, B Moseley, SH Pajot, F Phillips, TG Renault, JC Reintsema, CD Rioux, C Shafer, RA Staguhn, JG Vastel, C Voellmer, GM AF Benford, DJ Ames, TA Chervenak, JA Grossman, EN Irwin, KD Khan, SA Maffei, B Moseley, SH Pajot, F Phillips, TG Renault, JC Reintsema, CD Rioux, C Shafer, RA Staguhn, JG Vastel, C Voellmer, GM BE Porter, FS McCammon, D Galeazzi, M Stahle, CK TI First astronomical use of multiplexed transition edge bolometers SO LOW TEMPERATURE DETECTORS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 9th International Workshop on Low Temperature Detectors CY JUL 22-27, 2001 CL UNIV WISCONSIN, MADISON, WI SP NASA Gooddard Space Flight Ctr HO UNIV WISCONSIN AB We present performance results based on the first astronomical use of multiplexed superconducting bolometers. The Fabry-Perot Interferometer Bolometer Research Experiment (FIBRE) is a broadband submillimeter spectrometer that achieved first light in June 2001 at the Caltech Submillimeter Observatory (CSO). FIBRE's detectors are superconducting transition edge sensor (TES) bolometers read out by a SQUID multiplexer. The Fabry-Perot uses a low resolution grating to order sort the incoming light. A linear bolometer array consisting of 16 elements detects this dispersed light, capturing 5 orders simultaneously from one position on the sky. With tuning of the Fabry-Perot over one free spectral range, a spectrum covering Deltalambda/lambda = 1/7 at a resolution of 8lambda/lambda approximate to 1/1200 can be acquired. This spectral resolution is sufficient to resolve Doppler-broadened line emission from external galaxies. FIBRE operates in the 350 pin and 450 gm bands. These bands cover line emission from the important star formation tracers neutral carbon [CI] and carbon monoxide (CO). We have verified that the multiplexed bolometers are photon noise limited even with the low power present in moderate resolution spectrometry. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Benford, DJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012; Moseley, Harvey/D-5069-2012 OI Benford, Dominic/0000-0002-9884-4206; NR 6 TC 7 Z9 7 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 0-7354-0049-0 J9 AIP CONF PROC PY 2002 VL 605 BP 589 EP 592 PG 4 WC Astronomy & Astrophysics; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Astronomy & Astrophysics; Engineering; Instruments & Instrumentation; Physics GA BU53Q UT WOS:000176260300134 ER PT J AU DellaCorte, C AF DellaCorte, C TI Another year older, more experienced and wiser SO LUBRICATION ENGINEERING LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 0024-7154 J9 LUBR ENG JI Lubric. Eng. PD JAN PY 2002 VL 58 IS 1 BP 3 EP + PG 2 WC Engineering, Mechanical SC Engineering GA 512ED UT WOS:000173307400001 ER PT S AU Crider, DH Vondrak, RR AF Crider, DH Vondrak, RR BE Foing, BH Heather, DJ TI Hydrogen migration to the lunar poles by solar wind bombardment of the moon SO LUNAR EXPLORATION 2000 SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT B0 2 Symposium of COSPAR Scientific Commission B held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP European Space Agcy, Comm Space Res AB We investigate the deposition of hydrogen at the lunar poles from the incident solar wind proton flux. We follow an incident solar wind proton as it interacts with the lunar surface, is emitted into the atmosphere, and migrate through a series of ballistic hops across the surface of. the Moon: We trace the path of the particle until it is removed from the system by photo-processes such as ionization or dissociation, by thermal escape, by,surface chemistry, or by reaching a cold trap. Iterating with various compounds formed through surface chemistry, we follow all hydrogen atoms input into the system, regardless of their molecular composition. Accumulating statistics on the outcomes for various input particles, we determine that .6 of the hydrogen forms H-2 through chemical sputtering. Most of the remaining H thermally desorbs as atomic in a fraction of .27. Although the amount converted to OH is small (10%), most hydrogen reaches the pole through OH migration,.008 OH/H+. Finally, we calculate the amount of time required for the solar wind to supply the amount of hydrogen detected at the poles by the Lunar Prospector Neutron Spectrometer to be 7 Myr. If the poles only retain water due to the low freezing points of the other molecules, the time required is 100 Myr. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Crider, DH (reprint author), NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Hurley, Dana/F-4488-2015 OI Hurley, Dana/0000-0003-1052-1494 NR 26 TC 46 Z9 48 U1 1 U2 4 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 2002 VL 30 IS 8 BP 1869 EP 1874 AR PII S0273-1177(02)00493-3 DI 10.1016/S0273-1177(02)00493-3 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98N UT WOS:000180590600001 ER PT S AU Bellucci, G Brown, RH Formisano, V Baines, KH Bibring, JP Buratti, BJ Capaccioni, F Cerroni, P Clark, RN Coradini, A Cruikshank, DP Drossart, P Jaumann, R Langevin, Y Matson, DL McCord, TB Mennella, V Miller, E Nelson, RM Nicholson, PD Sicardy, B Sotin, C AF Bellucci, G Brown, RH Formisano, V Baines, KH Bibring, JP Buratti, BJ Capaccioni, F Cerroni, P Clark, RN Coradini, A Cruikshank, DP Drossart, P Jaumann, R Langevin, Y Matson, DL McCord, TB Mennella, V Miller, E Nelson, RM Nicholson, PD Sicardy, B Sotin, C BE Foing, BH Heather, DJ TI Cassini/VIMS observations of the moon SO LUNAR EXPLORATION 2000 SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT B0 2 Symposium of COSPAR Scientific Commission B held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP European Space Agcy, Comm Space Res AB In this paper, we present preliminary scientific results obtained from the analysis of VIMS (Visible and Infrared Mapping Spectrometer) lunar images and spectra. These data were obtained during the Cassini Earth flyby in August 1999. Spectral ratios have been produced in order to derive lunar mineralogical maps. Some spectra observed at the north-east lunar limb, show few unusual absorption features located at 0.357, 0.430 and 0.452 mum, the origin of which is presently unknown. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 CNR, Ist Fis Spazio Interplanetario, I-00133 Rome, Italy. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CNRS, Inst Astrophys Spatiale, F-91405 Orsay, France. CNR, Ist Astrofis Spaziale, I-00133 Rome, Italy. US Geol Survey, Denver, CO 80225 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Observ Paris, F-92195 Meudon, France. DLR, Inst Weltraumsensor & Planetenerkundung, D-12489 Berlin, Germany. Univ Hawaii, Sch Ocean & Earth Sci & Technol, HIGP, Honolulu, HI 96822 USA. Osserv Astron Capodimonte, I-80131 Naples, Italy. Cornell Univ, Ithaca, NY 14853 USA. Univ Nantes, F-44322 Nantes 3, France. RP Bellucci, G (reprint author), CNR, Ist Fis Spazio Interplanetario, I-00133 Rome, Italy. OI Bellucci, Giancarlo/0000-0003-0867-8679; Capaccioni, Fabrizio/0000-0003-1631-4314 NR 4 TC 0 Z9 0 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 2002 VL 30 IS 8 BP 1889 EP 1894 AR PII S0273-1177(02)00484-2 DI 10.1016/S0273-1177(02)00484-2 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98N UT WOS:000180590600004 ER PT S AU Grande, M Dunkin, S Heather, D Kellett, B Perry, CH Browning, R Waltham, N Parker, D Kent, B Swinyard, B Fereday, J Howe, C Huovelin, J Muhli, P Hakala, PJ Vilhu, O Thomas, N Hughes, D Alleyne, H Grady, M Russell, S Lundin, R Barabash, S Baker, D Clark, PE Murray, CD Christou, A Guest, J Casanova, I d'Uston, LC Maurice, S Foing, B Kato, M AF Grande, M Dunkin, S Heather, D Kellett, B Perry, CH Browning, R Waltham, N Parker, D Kent, B Swinyard, B Fereday, J Howe, C Huovelin, J Muhli, P Hakala, PJ Vilhu, O Thomas, N Hughes, D Alleyne, H Grady, M Russell, S Lundin, R Barabash, S Baker, D Clark, PE Murray, CD Christou, A Guest, J Casanova, I d'Uston, LC Maurice, S Foing, B Kato, M BE Foing, BH Heather, DJ TI The D-CIXS X-ray spectrometer, and its capabilities for lunar science SO LUNAR EXPLORATION 2000 SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT B0 2 Symposium of COSPAR Scientific Commission B held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP European Space Agcy, Comm Space Res ID ABUNDANCE; SURFACE; MOON; IRON AB The purpose of the D-CIXS (Demonstration of a Compact Imaging X-ray Spectrometer) instrument on the ESA SMART-1 mission is to provide high quality spectroscopic mapping of the Moon by imaging fluorescence Xrays emitted from the lunar surface. In order to obtain adequate statistics for what can be very weak sources, it is essential to have a large effective area, while maintaining a low mass. The solution is to make a thin, low profile detector, essentially a modern version of "X-ray detecting paper". D-CIXS will achieve a spatial resolution on the ground of 42km from a spacecraft at 300 km altitude, with a spectral resolution of 200 eV or better. The instrument is based around the use of advanced dual microstructure collimator and Swept Charge Device X-ray detector technologies. Swept Charge Device X-ray detectors, a novel architecture based on proven CCD technology; have the virtue of providing superior X-ray detection and spectroscopic measurement capabilities, while also operating at room temperature. Thus we avoid the need for the large passive cooling radiator that was previously required to cool large X-ray focal plane CCDs. The advanced low profile microstructure collimation and filter design builds on expertise developed in solid state and microwave technology to enable us to dramatically reduce the instrument mass. The total mass of D-CIXS, including an X-ray solar monitor is similar to4.6 kg. D-CIXS will provide the first global map of the Moon in X-rays. During normal solar conditions, it will be able to detect absolute elemental abundances of Fe, Mg, Al and Si on the lunar surface, using the on-board solar monitor to obtain a continuous measurement of the input solar spectrum. During solar flare events, it will also be possible to detect other elements such as Ca, Ti, V, Cr, Mn, Co, K, P and Na. The global mapping of Mg, AI and Si, and in particular deriving Mg#, the magnesium number (MgO/[MgO+FeO]), represents the prime goal of the D-CIXS experiment. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Rutherford Appleton Lab, Planets & Space Plasma Grp, Didcot OX11 0QX, Oxon, England. UCL, Dept Geol Sci, London WC1E 6BT, England. ESTEC, Res & Sci Support Dept, NL-2200 AG Noordwijk, Netherlands. Univ Helsinki, Univ Helsinki Observ, FIN-00014 Helsinki, Finland. Tuorla Observ, FIN-21500 Piikkio, Finland. MPAe, D-37191 Katlenburg Lindau, Germany. Univ Sheffield, Dept Phys & Astron, Sheffield S10 2TN, S Yorkshire, England. Univ Sheffield, Dept Automat Control & Syst Engn, Sheffield S10 2TN, S Yorkshire, England. Nat Hist Museum, Dept Mineral, London SW7 5BD, England. IRF, SE-98128 Kiruna, Sweden. Univ Colorado, LASP, Boulder, CO 80303 USA. NASA, Goddard Spaceflight Ctr, Greenbelt, MD 20771 USA. Univ London Queen Mary Coll, London E1 4NS, England. Armagh Observ, Armagh BT61 9DG, North Ireland. UPC, Barcelona 08034, Spain. CESR, F-31028 Toulouse 4, France. Observ Midi Pyrenees, F-31400 Toulouse, France. ISAS, Kanagawa 2298510, Japan. RP Grande, M (reprint author), Rutherford Appleton Lab, Planets & Space Plasma Grp, Didcot OX11 0QX, Oxon, England. RI Grande, Manuel/C-2242-2013 OI Casanova, Ignasi/0000-0003-0462-4147; Grady, Monica/0000-0002-4055-533X; Grande, Manuel/0000-0002-2233-2618 NR 24 TC 9 Z9 9 U1 1 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-SERIES PY 2002 VL 30 IS 8 BP 1901 EP 1907 AR PII S0273-1177(02)00486-6 DI 10.1016/S0273-1177(02)00486-6 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98N UT WOS:000180590600006 ER PT J AU Decoste, D Scholkopf, B AF Decoste, D Scholkopf, B TI Training invariant support vector machines SO MACHINE LEARNING LA English DT Article DE support vector machines; invariance; prior knowledge; image classification; pattern recognition ID KERNELS AB Practical experience has shown that in order to obtain the best possible performance, prior knowledge about invariances of a classification problem at hand ought to be incorporated into the training procedure. We describe and review all known methods for doing so in support vector machines, provide experimental results, and discuss their respective merits. One of the significant new results reported in this work is our recent achievement of the lowest reported test error on the well-known MNIST digit recognition benchmark task, with SVM training times that are also significantly faster than previous SVM methods. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Max Planck Inst Biol Cybernet, D-72076 Tubingen, Germany. RP Decoste, D (reprint author), CALTECH, Jet Prop Lab, MS 126-347,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Scholkopf, Bernhard/A-7570-2013 NR 42 TC 209 Z9 214 U1 1 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0885-6125 J9 MACH LEARN JI Mach. Learn. PY 2002 VL 46 IS 1-3 BP 161 EP 190 DI 10.1023/A:1012454411458 PG 30 WC Computer Science, Artificial Intelligence SC Computer Science GA 481CF UT WOS:000171501800008 ER PT S AU Wincheski, B Namkung, M Paik, SM Smits, J AF Wincheski, B Namkung, M Paik, SM Smits, J BE DeHaven, PW Field, DP Harkness, SD Sutliff, JA Szpunar, JA Tang, L Thomson, T Vaudin, MD TI Carbon nanotube based magnetic tunnel junctions for electromagnetic nondestructive evaluation SO MAGNETIC AND ELECTRONIC FILMS-MICROSTRUCTURE, TEXTURE AND APPLICATION TO DATA STORAGE SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposia on Texture and Microstructure in Electronic and Magnetic Films/Nanostructural Magnetic Materials For Data Storage CY APR 01-04, 2002 CL SAN FRANCISCO, CA SP Mat Res Soc AB Spin coherent transport in carbon nanotubes enables single-nanotube devices for magnetic field sensing. This unique transport property of single walled carbon nanotubes (SWCNTs) has been studied for development into advanced sensors for nondestructive evaluation (NDE). Coupling of a single walled carbon nanotube to ferromagnetic electrodes is predicted to form a carbon nanotube magnetic tunnel junction. Fabrication of such devices has been performed through scanning probe and electron beam lithography. Purified single walled carbon nanotubes are deposited across electrodes to complete device fabrication. A spin-coherent quantum transport theory based on a nonequilibrium Green's function method has been established to predict conductance and magnetoconductance across junctions. Experimental measurements of the room temperature conductance of Cobalt/SWCNT/Cobalt junctions have been performed. C1 NASA, LaRC, Hampton, VA 23681 USA. RP Wincheski, B (reprint author), NASA, LaRC, Hampton, VA 23681 USA. RI Namkung, Min/E-1533-2012 NR 7 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 1-55899-657-5 J9 MATER RES SOC SYMP P PY 2002 VL 721 BP 271 EP 275 PG 5 WC Materials Science, Characterization & Testing; Physics, Condensed Matter SC Materials Science; Physics GA BV34R UT WOS:000178622900039 ER PT S AU Zhu, S Su, CH Cochrane, JC Gorti, S Lehoczky, S Cui, Y Burger, A AF Zhu, S Su, CH Cochrane, JC Gorti, S Lehoczky, S Cui, Y Burger, A BE Bernier, P Ajayan, P Iwasa, Y Nikolaev, P TI Orientational growth of carbon nanotube by thermal CVD SO MAKING FUNCTIONAL MATERIALS WITH NANOTUBES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Making Functional Materials with Nanotubes held at the 2001 MRS Fall Meeting CY NOV 26-29, 2001 CL BOSTON, MA SP Mat Res Soc ID CHEMICAL-VAPOR-DEPOSITION; DIAMETER AB Carbon nanotubes are synthesized using thermal chemical vapor deposition. Various temperature and pressure are used to fabricate carbon nanotubes. It is found that the nanotube-diameter distribution mainly depends on the growth-temperature. With the substrate surface normal either along or against the gravity vector, different growth orientations of multi-walled carbon nanotubes are observed by scanning electron microscopy although the Raman spectra are similar for samples synthesized at different locations. The sizes of these carbon nanotubes in each sample are quite uniform and the length of the tube is up to hundreds of micrometers. These results suggest the gravitation effects in the growth of long and small diameter CNT. C1 NASA, George C Marshall Space Flight Ctr, USRA, Huntsville, AL 35812 USA. RP Zhu, S (reprint author), NASA, George C Marshall Space Flight Ctr, USRA, Huntsville, AL 35812 USA. NR 13 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 1-55899-642-7 J9 MATER RES SOC SYMP P PY 2002 VL 706 BP 79 EP 84 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Materials Science, Composites; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA BU87T UT WOS:000177282900012 ER PT S AU Park, C Ounaies, Z Watson, KA Pawlowski, K Lowther, SE Connell, JW Siochi, EJ Harrison, JS Clair, TLS AF Park, C Ounaies, Z Watson, KA Pawlowski, K Lowther, SE Connell, JW Siochi, EJ Harrison, JS Clair, TLS BE Bernier, P Ajayan, P Iwasa, Y Nikolaev, P TI Polymer-single wall carbon nanotube composites for potential spacecraft applications SO MAKING FUNCTIONAL MATERIALS WITH NANOTUBES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Making Functional Materials with Nanotubes held at the 2001 MRS Fall Meeting CY NOV 26-29, 2001 CL BOSTON, MA SP Mat Res Soc AB Polymer-single wall carbon nanotube (SWNT) composite films were prepared and characterized as part of an effort to develop polymeric materials with improved combinations of properties for potential use on future spacecraft. Next generation spacecraft will require ultra-lightweight materials that possess specific and unique combinations of properties such as radiation and atomic oxygen resistance, low solar absorptivity, high thermal emissitivity, electrical conductivity, tear resistance, ability to be folded and seamed, and good mechanical properties. The objective of this work is to incorporate sufficient electrical conductivity into space durable polyimides to mitigate static charge build-up. The challenge is to obtain this level of conductivity (10(-8) S/cm) without degrading other properties of importance, particularly optical transparency. Several different approaches were attempted to fully disperse the SWNTs into the polymer matrix. These included high shear mixing, sonication, and synthesizing the polymers in the presence of pre-dispersed SWNTs. Acceptable levels of conductivity were obtained at loading levels less than one tenth weight percent SWNT without significantly sacrificing optical properties, Characterization of the nanocomposite films and the effect of SWNT concentration and dispersion on the conductivity, solar absorptivity, thermal emissivity, mechanical and thermal properties were discussed. Fibers and non-woven porous mats of SWNT reinforced polymer nanocomposite were produced using electrospinning. C1 NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA USA. RP Park, C (reprint author), ICASE, MS-226, Hampton, VA 23681 USA. NR 9 TC 19 Z9 20 U1 1 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-642-7 J9 MATER RES SOC SYMP P PY 2002 VL 706 BP 91 EP 96 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Materials Science, Composites; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA BU87T UT WOS:000177282900014 ER PT J AU Sogard, SM Olla, BL AF Sogard, SM Olla, BL TI Contrasts in the capacity and underlying mechanisms for compensatory growth in two pelagic marine fishes SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE ecological trade-offs; swimming performance; behavior; walleye pollock; sablefish ID JUVENILE ATLANTIC SALMON; TROUT ONCORHYNCHUS-MYKISS; ENERGY ACQUISITION RATES; COD GADUS-MORHUA; SWIMMING PERFORMANCE; INTRINSIC GROWTH; MENIDIA-MENIDIA; RAINBOW-TROUT; INDIVIDUAL VARIATION; POMATOMUS SALTATRIX AB The widespread capacity for teleost fishes to engage in compensatory growth suggests there are costs or trade-offs that constrain normal growth to sub-maximal rates. Some potential trade-offs include behavioral conflicts between foraging and avoiding predators, and physiological aspects of energy allocation between synthesis of new tissue and functional demands of metabolism and maintenance. We examined the capacity for compensation and some potential underlying mechanisms in juveniles of 2 northern Pacific fish species, walleye pollock Theragra chalcogramma and sablefish Anoplopoma fimbria. Fish were deprived of food for 2 to 3 wk, then returned to ad libitum rations. Growth rates were subsequently compared to those for continually fed fish for up to 16 wk, and potential trade-offs in behavior (food consumption, routine swimming speeds, and response to a predator) and physiology (indexed by critical swimming speeds) were examined during 3 time periods: immediately after deprivation, after 4 wk of ad libitum rations, and after 9 wk. We distinguished between routine swimming speeds, which indicate volitional motor activity, and critical swimming speeds, which estimate physiological capacity by forcing fish to swim to exhaustion against an increasing current. Previously deprived walleye Pollock exhibited a clear, sustained capacity for accelerated growth, allowing them to quickly catch up in size to continually fed fish, Sablefish, however, exhibited only a minor level of growth compensation. Underlying mechanisms of compensatory growth also differed between the 2 species. Previously deprived walleye Pollock increased food consumption to levels 3 to 4x greater than those of control fish and reduced energy expenditure by lowering routine swimming speeds. Compensating sablefish did not differ from control fish in consumption rates or routine swimming, but had lower critical swimming speeds than control fish, suggesting a trade-off in energy allocation. Responses to a simulated predator threat did not differ between previously deprived and continually fed fish of either species. The experimental results are suggestive of different mechanisms, behaviorally based for walleye pollock and physiologically based for sablefish, associated with accelerated growth. The differences between the 2 species in integrated processes of growth, behavior, and physiology are likely to be a function of their contrasting life history strategies and different baseline growth rates. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. RP Sogard, SM (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. EM susan.sogard@noaa.gov NR 33 TC 36 Z9 36 U1 1 U2 12 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2002 VL 243 BP 165 EP 177 DI 10.3354/meps243165 PG 13 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 623DZ UT WOS:000179689200015 ER PT J AU Bodkin, JL Ballachey, BE Dean, TA Fukuyama, AK Jewett, SC McDonald, L Monson, DH O'Clair, CE VanBlaricom, GR AF Bodkin, JL Ballachey, BE Dean, TA Fukuyama, AK Jewett, SC McDonald, L Monson, DH O'Clair, CE VanBlaricom, GR TI Sea otter population status and the process of recovery from the 1989 'Exxon Valdez' oil spill SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE abundance; biomarker; Enhydra lutris; food; mortality; P450; reproduction; survival ID PRINCE-WILLIAM-SOUND; ENHYDRA-LUTRIS; MUSSEL BEDS; INTERTIDAL BIOTA; KODIAK ISLAND; RIVER OTTERS; CRUDE-OIL; ALASKA; MORTALITY; HYDROCARBONS AB Sea otter Enhydra lutris populations were severely affected by the 1989 'Exxon Valdez' oil spill in western Prince William Sound, AK, and had not fully recovered by 2000. Here we present results of population surveys and incorporate findings from related studies to identify current population status and factors affecting recovery. Between 1993 and 2000, the number of sea otters in the spill-area of Prince William Sound increased by about 600 to nearly 2700. However, at Knight Island, where oil exposure and sea otter mortality in 1989 was most severe, no increase has been observed. Sea otter reproduction was not impaired, and the age and sex composition of captured otters are consistent with both intrinsic reproduction and immigration contributing to recovery. However, low resighting rates of marked otters at Knight Island compared to an unoiled reference area, and high proportions of young otters in beach cast carcasses through 1998, suggest that the lack of recovery was caused by relatively poor survival or emigration of potential recruits. Significantly higher levels of cytochrome P4501A (CYP1A), a biomarker of hydrocarbons, were found in sea otters at Knight Island from 1996 to 1998 compared to unoiled Montague Island, implicating oil effects in the lack of recovery at Knight Island. Delayed recovery does not appear to be directly related to food limitation. Although food availability was relatively low at both oiled and unoiled areas, we detected significant increases in sea otter abundance only at Montague Island, a finding inconsistent with food as a principal limiting factor. Persistent oil in habitats and prey provides a source of continued oil exposure and, combined with relatively low prey densities, suggests a potential interaction between oil and food. However, sea otters foraged more successfully at Knight Island and young females were in better condition than those at Montague Island. We conclude that progress toward recovery of sea otters in Prince William Sound is evident, but that in areas where initial oil effects were greatest, recovery may be constrained by residual spill effects, resulting from elevated mortality and emigration. It is evident that internal reproduction and immigration of juveniles has been the primary means of population recovery, as opposed to broad scale redistribution of adults from outside affected areas. The result is a recovery period protracted by long-term spill effects on survival and emigration and intrinsic limits to population growth. C1 US Geol Survey, Alaska Sci Ctr, Anchorage, AK 99503 USA. Coastal Resources Associates, La Jolla, CA 92093 USA. Univ Washington, US Geol Survey, Washington Cooperat Fish & Wildlife Res Unit, Sch Aquat & Fishery Sci, Seattle, WA 98195 USA. Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. Western Ecosyst Technol, Cheyenne, WY 82001 USA. Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. RP Bodkin, JL (reprint author), US Geol Survey, Alaska Sci Ctr, 1011 E Tudor Rd, Anchorage, AK 99503 USA. EM james_bodkin@usgs.gov RI Monson, Daniel/N-4469-2013 OI Monson, Daniel/0000-0002-4593-5673 NR 85 TC 73 Z9 73 U1 11 U2 58 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2002 VL 241 BP 237 EP 253 DI 10.3354/meps241237 PG 17 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 613RU UT WOS:000179145900022 ER PT J AU Dean, TA Bodkin, JL Fukuyama, AK Jewett, SC Monson, DH O'Clair, CE VanBlaricom, GR AF Dean, TA Bodkin, JL Fukuyama, AK Jewett, SC Monson, DH O'Clair, CE VanBlaricom, GR TI Food limitation and the recovery of sea otters following the 'Exxon Valdez' oil spill SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE Prince William Sound; Alaska; predator-prey interaction; prey availability; prey consumption rate; condition indices ID PRINCE-WILLIAM-SOUND; ENHYDRA-LUTRIS; POPULATION REGULATION; SHORELINE TREATMENTS; NORTHERN AUSTRALIA; FERAL DONKEYS; WILD REINDEER; TIME BUDGETS; ALASKA; MORTALITY AB We examined the potential role of food limitation in constraining the recovery of sea otters Enhydra lutris in Prince William Sound, Alaska, following the 'Exxon Valdez' oil spill. The spill resulted in the removal of a large number of sea otters in 1989, and as of 1998, the portion of the population in the heavily oiled northern Knight Island region had not fully recovered. Between 1996 and 1998, prey consumption rate was higher and the condition of sea otters was better at northern Knight Island than in an unoiled area of the sound (Montague Island). Estimates of prey energy available per unit mass of sea otter were about 4 times higher at Knight than Montague Island, albeit not significantly different between the 2 areas. Over this, same period, the number of sea otters remained constant at northern Knight Island but increased at Montague Island. These data suggest that food was at least as abundant at Knight than at Montague Island, and that recovery of sea otters via intrinsic population growth was limited by factors other than food. However, the availability of food, the prey consumption rate, and the condition of sea otters were all much lower at both Knight and Montague Islands than in areas newly occupied by sea otters where the population growth rate was near the theoretical maximum. It is possible that the relatively short supply of food (compared to areas where sea otter population growth rate was high) may have inhibited immigration or interacted with other factors (e.g. oil-induced mortality or predation) to restrict sea otter population growth. Nonetheless, these data suggest that impacts of anthropogenic disturbances on large, often food-limited vertebrate predators can persist in spite of the availability of food resources that are sufficient for intrinsic population growth. C1 Coastal Resources Associates, Carlsbad, CA 92008 USA. US Geol Survey, Alaska Biol Sci Ctr, Biol Res Div, Anchorage, AK 99503 USA. Univ Washington, US Geol Survey, Sch Aquat & Fishery Sci,Biol Resource Div, Washington Cooperat Fish & Wildlife Res Unit, Seattle, WA 98195 USA. Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. RP Dean, TA (reprint author), Coastal Resources Associates, 5674 El Camino Real,Suite M, Carlsbad, CA 92008 USA. EM coastal_resources@sbcglobal.net RI Monson, Daniel/N-4469-2013 OI Monson, Daniel/0000-0002-4593-5673 NR 81 TC 31 Z9 31 U1 4 U2 28 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2002 VL 241 BP 255 EP 270 DI 10.3354/meps241255 PG 16 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 613RU UT WOS:000179145900023 ER PT J AU Stunz, GW Minello, TJ Levin, PS AF Stunz, GW Minello, TJ Levin, PS TI Growth of newly settled red drum Sciaenops ocellatus in different estuarine habitat types SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE growth; habitat; habitat comparisons; red drum; estuaries; Sciaenops ocellatus ID FLOUNDER PSEUDOPLEURONECTES-AMERICANUS; WEAKFISH CYNOSCION REGALIS; OTOLITH INCREMENT WIDTHS; JUVENILE CHINOOK SALMON; CHESAPEAKE BAY; GALVESTON BAY; LARVAL FISH; SALT-MARSH; ONCORHYNCHUS-TSHAWYTSCHA; SEAGRASS MEADOWS AB We examined growth of recently settled juvenile red drum in salt marsh, seagrass, oyster reef, and on nonvegetated bottom areas in the Galveston Bay system of Texas (USA). We estimated growth using otolith microstructure from free-ranging fish collected in different habitat types and also measured growth of red drum in experimental enclosures where fish movement was restricted. Otolith growth was closely related to somatic growth in fish of 13 to 33 mm SL, and we used daily otolith increments from the last 10 d before capture as an indicator of growth following settlement into estuarine habitats. Growth rates of red drum captured at marsh, nonvegetated, and seagrass sites were not significantly different; no fish were collected on oyster reef. While reducing potential problems of a lagged response between otolith growth and somatic growth, the use of a 10 d growth period may have increased the likelihood of fish movement among habitats affecting our comparisons. The overall post-settlement growth rate of 0.45 mm d(-1) was similar to rates reported in the literature. Movement among habitat types was eliminated in experiments employing 24 solid-walled enclosures (60 cm diameter). Growth rates in enclosures over the 7 d experiment were 0.12 mm d(-1) in oyster reef, 0.21 mm d(-1) on nonvegetated bottom, 0.40 mm d(-1) in salt marsh, and 0.42 mm d(-1) in seagrass; rates in vegetated enclosures approximated natural growth rates. Significantly higher growth in marsh and seagrass enclosures suggests that growth potential for red drum may be highest in these vegetated areas. However, growth results in enclosures need to be evaluated carefully, because fish movement among habitat types may be important in these shallow estuarine systems. C1 SE Fisheries Sci Ctr, Galveston Lab, Fishery Ecol Branch, Natl Marine Fisheries Serv, Galveston, TX 77551 USA. NW Fisheries Sci Ctr, Seattle, WA 98112 USA. RP Stunz, GW (reprint author), SE Fisheries Sci Ctr, Galveston Lab, Fishery Ecol Branch, Natl Marine Fisheries Serv, 4700 Ave U, Galveston, TX 77551 USA. EM greg.stunz@noaa.gov NR 94 TC 45 Z9 48 U1 4 U2 19 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2002 VL 238 BP 227 EP 236 DI 10.3354/meps238227 PG 10 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 589YB UT WOS:000177788200020 ER PT J AU Bosley, KL Witting, DA Chambers, RC Wainright, SC AF Bosley, KL Witting, DA Chambers, RC Wainright, SC TI Estimating turnover rates of carbon and nitrogen in recently metamorphosed winter flounder Pseudopleuronectes americanus with stable isotopes SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE stable isotopes; diet shifts; Pseudopleuronectes americanus; winter-flounder habitat; temperature ID FOOD-WEB STRUCTURE; TROPHIC LEVEL; GEORGES BANK; FRACTIONATION; LARVAE; DIET; DELTA-C-13; GROWTH; ZOOPLANKTON; SETTLEMENT AB Stable-isotope ratios of carbon (C-13/C-12) and nitrogen (N-15/N-14) are widely used in the analysis of animal diets. However, using these stable-isotope ratios to infer dietary changes depends on precise knowledge of turnover rates of carbon and nitrogen. In the present study, carbon and nitrogen turnover rates were determined for recently settled juvenile winter flounder Pseudopleuronectes americanus in the laboratory using naturally occurring stable isotopes as dietary tracers. Flounder were reared at 13degreesC on a diet of rotifers Brachionus plicatilis of known isotopic composition from the time that the larvae began feeding until they reached metamorphosis and began to settle to the benthic habitat. At settlement, the fish were assigned to 1 of 2 temperature treatments (13 and 18degreesC). A subset of fish at each temperature was maintained on rotifers to serve as controls. The remaining fish were switched to a diet of brine shrimp Artemia sp. (known to be isotopically distinct from rotifers) and then sampled systematically over a 16 d period. Temperature had a significant effect on both carbon and nitrogen turnover rates. At 13degreesC, the half-life of carbon was 4.1 d (+/-0.6), and of nitrogen, 3.9 d (+/-0.7). At 18degreesC, the half-life of carbon was 2.2 d (+/-0.3), and of nitrogen, 3.1 d (+/-0.3). The change in isotopic composition closely followed predictions based entirely on the production of new tissue. C1 NW Fisheries Sci Ctr, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Fishery Resource Anal & Monitoring Div, Newport, OR 97365 USA. Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08901 USA. NE Fisheries Sci Ctr, Natl Marine Fisheries Serv, Coastal Ecol Branch, Highlands, NJ 07732 USA. RP Bosley, KL (reprint author), NW Fisheries Sci Ctr, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Fishery Resource Anal & Monitoring Div, 2030 SE Marine Sci Dr, Newport, OR 97365 USA. EM keith.bosley@noaa.gov NR 45 TC 101 Z9 103 U1 7 U2 25 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2002 VL 236 BP 233 EP 240 DI 10.3354/meps236233 PG 8 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 576LQ UT WOS:000177007100021 ER PT J AU Brodeur, RD Sugisaki, H Hunt, GL AF Brodeur, RD Sugisaki, H Hunt, GL TI Increases in jellyfish biomass in the Bering Sea: implications for the ecosystem SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE jellyfish; distribution; food consumption; ecosystem changes; Bering Sea ID AURELIA-AURITA MEDUSAE; PORT-PHILLIP BAY; GELATINOUS ZOOPLANKTON; CHRYSAORA-QUINQUECIRRHA; PELAGIC CNIDARIANS; CHESAPEAKE BAY; BLACK-SEA; ANOMALOUS CONDITIONS; AEQUOREA-VICTORIA; PREDATORY IMPACT AB There has been a dramatic increase in jellyfish biomass over the eastern Bering Sea shelf since the early 1990s, which was previously hypothesized to have been triggered by changing climate and ocean conditions. We examine the hypothesis that the presence of these large carnivores has affected fisheries resources, either through direct predation on larval stages, or through competition for zooplankton prey, In this paper, we explore the impact of this jellyfish increase on zooplankton and fish communities based on field data on the composition of the jellyfish community, and the abundance, size, stable isotopic signatures, and feeding habits of the principal scyphomedusae in the region. These data, together with those on zooplankton biomass, are used to estimate the ecosystem impacts of this increase. The center of jellyfish biomass has shifted from the SE Middle Shelf Domain in the early 1980s to the NW in the late 1990s. In recent years, the species composition of large medusae caught in trawls was dominated (>80% by number and >95% by weight) by the scyphozoan Chrysaora melanaster, Dense aggregations of this species occupied the water column in daytime between 10 and 40 in. Their food habits consisted mainly of pelagic crustaceans (euphausiids, copepods, amphipods), although other jellyfish and juvenile pollock were also consumed, Based on stable isotope ratios, the trophic level of this scyphozoan is equivalent to, or higher than, that of Age 0 pollock. Preliminary estimates showed that medusae have a moderate grazing impact on zooplankton in the area around the Pribilof Islands; C, melanaster was estimated on average to consume seasonally about one-third of the standing stock and 4.7% of the annual production of zooplankton in this region, Daily consumption of Age 0 pollock was estimated to be 2.8% of the standing stock around the Pribilof Islands during 1999. A hypothesis for the increase in jellyfishes observed in the eastern Bering Sea, based on release from competition from planktivorous forage fishes, is proposed. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Newport, OR 97365 USA. Tohoku Natl Fisheries Res Inst, Tagajo, Miyagi 985, Japan. Univ Calif Irvine, Dept Ecol & Evolutionary Biol, Irvine, CA 92697 USA. RP Brodeur, RD (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Newport, OR 97365 USA. EM rick.brodeur@noaa.gov OI Hunt, George/0000-0001-8709-2697 NR 69 TC 196 Z9 217 U1 7 U2 85 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2002 VL 233 BP 89 EP 103 DI 10.3354/meps233089 PG 15 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 563XL UT WOS:000176283200008 ER PT J AU Ryer, CH AF Ryer, CH TI Trawl stress and escapee vulnerability to predation in juvenile walleye pollock: Is there an unobserved bycatch of behaviorally impaired escapees? SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE bycatch; predation; stress; trawl; walleye pollock; behavior ID REDUCTION DEVICES; CHINOOK SALMON; RAINBOW-TROUT; DIAMOND-MESH; COHO SALMON; COD-ENDS; AVOIDANCE; SURVIVAL; FISH; DISTURBANCE AB Recent studies suggest that mortality of undersized fishes escaping through trawl codends may range from 0 to 100%, with mortalities of 10 to 30% being common. These values may be low, as they do not account for fishes which become behaviorally compromised by their passage through the trawl and ultimately succumb to predators. The goal of this study was to simulate in the laboratory the stressors associated with trawl passage and determine if they degrade the behavioral capabilities of juvenile walleye pollock Theragra chalcogramma to avoid predation. In the first of 2 experiments, groups of Age 1 yr+ walleye pollock were subjected to 3 treatments: (1) controls: no stressor; (2) swim/escape: forced swimming for 90 min at 0.33 m s(-1) in a towed net, followed by escape through 8 cm square mesh; (3) swim/crowd/escape: forced swimming followed by 3 min of crowding, followed by escape. To evaluate the effect of these treatments on pollock behavior, a sable-fish Anoplopoma fimbria (48 to 53 cm) was placed in an observation arena with the group and pollock anti-predator behavior was quantified. Beginning immediately after simulated trawling and for up to 24 h afterwards, pollock exposed to both trawl-stressor treatments were less likely to avoid the predator than controls, allowing it to approach closer. They were also less able to form a cohesive shoal, and in the case of the swim/crowd/escape treatment, swam more slowly than control fish. To determine if trawl-stressed fish are more vulnerable to predation, in a second experiment I mixed control and swim/crowd/escape pollock together and then subjected them to predation by a 48 to 60 cm lingcod Ophiodon elongatus, observing the behavior and enumerating the number of pollock consumed in each treatment, Lingcod concentrated attacks upon solitary individuals or those straggling behind the shoal, were more likely to lunge at pollock that did not move away when approached, and were more successful the closer the pollock at lunge initiation. As a result, trawl-stressed pollock were consumed in greater numbers than controls. On the basis of these results, it is reasonable to expect that juvenile walleye pollock passing through trawls suffer behavioral deficits, subjecting them to elevated predation risk, If this is a generic effect, these results suggest that there may be a significant bycatch associated with many commercial trawl fisheries which is generally unrecognized, unmeasured, and unaccounted for in current stock-assessment models. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Fisheries Behav Ecol Program,Hatfield Marine Sci, Newport, OR 97365 USA. RP Ryer, CH (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Fisheries Behav Ecol Program,Hatfield Marine Sci, Newport, OR 97365 USA. EM cliff.ryer@hmsc.orst.edu NR 59 TC 32 Z9 32 U1 7 U2 8 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2002 VL 232 BP 269 EP 279 DI 10.3354/meps232269 PG 11 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 561DT UT WOS:000176123900022 ER PT J AU Friedlander, AM DeMartini, EE AF Friedlander, AM DeMartini, EE TI Contrasts in density, size, and biomass of reef fishes between the northwestern and the main Hawaiian islands: the effects of fishing down apex predators SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE apex predators; overfishing; Hawaiian archipelago; fish assemblage ID BOTTOM KELP FOREST; MARINE ECOSYSTEMS; COMMUNITIES; RESERVES; POPULATIONS; MANAGEMENT; ABUNDANCE; ECOLOGY; STOCK AB A comparison between the northwestern Hawaiian islands (NWHI), a large, remote, and lightly fished area, and the main Hawaiian islands (MHI), an urbanized, heavily fished area, revealed dramatic differences in the numerical density, size, and biomass of the shallow reef fish assemblages. Grand mean fish standing stock in the NWHI was more than 260% greater than in the MHI. The most striking difference was the abundance and size of large apex predators (primarily sharks and jacks) in the NWHI compared to the MHI. More than 54% of the total fish biomass in the NWHI consisted of apex predators, whereas this trophic level accounted for less than 3% of the fish biomass in the MHI. In contrast, fish biomass in the MHI was dominated by herbivores (55%) and small-bodied lower-level carnivores (42%). Most of the dominant species by weight in the NWHI were either rare or absent in the MHI and the target species that were present, regardless of trophic level, were nearly always larger in the NWHI, These differences represent both near-extirpation of apex predators and heavy exploitation of lower trophic levels in the MHI compared to the largely unfished NWHI. The reefs in the NWHI are among the few remaining large-scale, intact, predator-dominated reef ecosystems left in the world and offer an opportunity to understand how unaltered ecosystems are structured, how they function, and how they can most effectively be preserved. The differences in fish assemblage structure in this study are evidence of the high level of exploitation in the MHI and the pressing need for ecosystem-level management of reef systems in the MHI as well as the NWHI. C1 Ocean Inst, Waimanalo, HI 96795 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. RP Friedlander, AM (reprint author), Ocean Inst, Makapuu Point 41-202,Kalanianaole Highway, Waimanalo, HI 96795 USA. EM afriedlander@oceanicinstitute.org NR 63 TC 306 Z9 325 U1 14 U2 115 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2002 VL 230 BP 253 EP 264 DI 10.3354/meps230253 PG 12 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 551XE UT WOS:000175588600022 ER PT J AU Kuropat, C Mercaldo-Allen, R Caldarone, E Goldberg, R Phelan, B Thurberg, F AF Kuropat, C Mercaldo-Allen, R Caldarone, E Goldberg, R Phelan, B Thurberg, F TI Evaluation of RNA concentration as an indicator of growth in young-of-the-year winter flounder Pseudopleuronectes americanus and tautog Tautoga onitis SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE RNA; winter flounder; tautog; estuary; habitat ID TROUT SALVELINUS-FONTINALIS; JUVENILE SUMMER FLOUNDER; DRUM SCIAENOPS-OCELLATUS; NUCLEIC-ACID; MUSCLE-TISSUE; DNA RATIOS; PROTEIN; LARVAL; RATES; TEMPERATURE AB White muscle tissue RNA concentration was evaluated as an indirect measure of fish growth. Young-of-the-year winter flounder Pseudopleuronectes americanus and tautog Tautoga onitis were grown in short-term caging experiments conducted during 1994 and 1995 within 3 geographically distinct estuarine systems in the NE of the USA: the Hammonasset River along the Connecticut coast of Long Island Sound, the Navesink River located in the Hudson-Raritan Bay estuary in northern New Jersey, and Great Bay-Little Egg Harbor estuary in southern New Jersey, Fish were caged in each of 5 habitat types including: eelgrass, macroalgae, unvegetated areas adjacent to eelgrass, unvegetated areas adjacent to macroalgae, and tidal marsh creeks. White muscle tissue RNA concentration (mug per mg wet tissue wt) was measured in winter flounder and tautog recovered from the cages and compared to instantaneous growth rate measurements of these same fish. RNA concentration was significantly correlated with growth rate measured as length (r = 0.83) and weight (r = 0.79) in winter flounder and length (r = 0.69) and weight (r = 0.73) in tautog. In most cases, estuary- and habitat-specific differences in growth rate, as determined by RNA concentration, were similar to those determined by measuring instantaneous growth. These results validate the use of RNA concentration as an indirect measure of growth in young-of-the-year winter flounder and tautog. C1 Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Milford Lab, Milford, CT 06460 USA. Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Narragansett Lab, Narragansett, RI 02882 USA. Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA. RP Kuropat, C (reprint author), Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Milford Lab, 212 Rogers Ave, Milford, CT 06460 USA. EM catherine.kuropat@noaa.gov NR 27 TC 29 Z9 33 U1 1 U2 10 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2002 VL 230 BP 265 EP 274 DI 10.3354/meps230265 PG 10 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 551XE UT WOS:000175588600023 ER PT J AU Behrenfeld, MJ Maranon, E Siegel, DA Hooker, SB AF Behrenfeld, MJ Maranon, E Siegel, DA Hooker, SB TI Photoacclimation and nutrient-based model of light-saturated photosynthesis for quantifying oceanic primary production SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE photosynthesis; modeling; primary production ID SKELETONEMA-COSTATUM BACILLARIOPHYCEAE; DIATOM PHAEODACTYLUM-TRICORNUTUM; MARINE-PHYTOPLANKTON; ELECTRON-TRANSPORT; ATLANTIC-OCEAN; CHEMICAL-COMPOSITION; IRON LIMITATION; TRANSITION ZONE; NORTH-ATLANTIC; LIMITED GROWTH AB Availability of remotely sensed phytoplankton biomass fields has greatly advanced primary production modeling efforts. However, conversion of near-surface chlorophyll concentrations to carbon fixation rates has been hindered by uncertainties in modeling light-saturated photosynthesis (P-max(b)). Here, we introduce a physiologically-based model for p(max)(b) that focuses on the effects of photoacclimation and nutrient limitation on relative changes in cellular chlorophyll and CO2 fixation capacities. This 'PhotoAcc' model describes P-max(b) as a function of light level at the bottom of the mixed layer or at the depth of interest below the mixed layer. Nutrient status is assessed from the relationship between mixed layer and nutricline depths. Temperature is assumed to have no direct influence on p(max)(b) above 5degreesC. The PhotoAcc model was parameterized using photosynthesis-irradiance observations made from extended transects across the Atlantic Ocean. Model performance was validated independently using time-series observations from the Sargasso Sea, The PhotoAcc model accounted for 70 to 80 % of the variance in light-saturated photosynthesis. Previously described temperature-dependent models did not account for a significant fraction of the variance in P-max(b) for our test data sets. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Vigo, Dept Ecol & Biol Anim, Vigo 36200, Spain. Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. RP Behrenfeld, MJ (reprint author), NASA, Goddard Space Flight Ctr, Code 971,Bldg 33, Greenbelt, MD 20771 USA. EM mjb@neptune.gsfc.nasa.gov RI Hooker, Stanford/E-2162-2012; Siegel, David/C-5587-2008; Maranon, Emilio/F-3013-2013 NR 92 TC 96 Z9 100 U1 2 U2 25 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2002 VL 228 BP 103 EP 117 DI 10.3354/meps228103 PG 15 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 535QK UT WOS:000174655000010 ER PT J AU Parrish, FA Abernathy, K Marshall, GJ Buhleier, BM AF Parrish, FA Abernathy, K Marshall, GJ Buhleier, BM TI Hawaiian monk seals (Monachus schauinslandi) foraging in deep-water coral beds SO MARINE MAMMAL SCIENCE LA English DT Article DE Hawaiian monk seal; Monachus schauinslandi; precious corals; deep-water corals; forage habitat; subphotic; CRITTERAM; endangered species AB Plans to harvest deep-water corals in the remote Northwestern Hawaiian Islands, close to populations of endangered Hawaiian monk seals (Monachus schauinslandi), have raised concerns about the seals' use of deep-water habitats. Movements and diving patterns of Seals Studied at French Frigate Shoals (FFS) Atoll indicated two areas where five males out of 33 instrumented seals dove deep enough (300-500 m) to encounter commercially sought deep-water corals. Submarine surveys conducted at each location found beds of gold (Gerardia sp.) and pink (Corallium sp,) precious coral suggesting an overlap between the foraging habitat of some seals and the target of the coral fishery. Areas adjacent to the coral beds that were visually censused using submersibles showed significantly fewer precious corals. Precious coral beds were not found on previous submarine Surveys at other regions around FFS, supporting the notion that seals were selecting the areas with corals as forage habitat. Five male seals were fitted with back-mounted video cameras to document feeding among precious corals. None of the five seals dove deep enough to encounter precious corals (>300 m). However, three of the seals visited beds of black coral (Cirrhipathes sp.) at shallower depths (similar to80 m). One seal was observed revisiting the black coral beds on three successive nights to feed on fish hiding among the coral stems. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. Natl Geog Televis, Washington, DC 20036 USA. RP Parrish, FA (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, 2570 Dole St, Honolulu, HI 96822 USA. NR 16 TC 44 Z9 50 U1 1 U2 11 PU SOC MARINE MAMMALOGY PI LAWRENCE PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA SN 0824-0469 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JAN PY 2002 VL 18 IS 1 BP 244 EP 258 DI 10.1111/j.1748-7692.2002.tb01031.x PG 15 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA 512KL UT WOS:000173323500018 ER PT B AU Proga, D AF Proga, D BE Crenshaw, DM Karemer, SB George, IM TI Dynamics of line-driven disk winds SO MASS OUTFLOW IN ACTIVE GALACTIC NUCLEI: NEW PERSPECTIVES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Mass Outflow in Active Galactic Nuclei: New Perspectives CY MAR 08-10, 2001 CL CATHOLIC UNIV AMER, WASHINGTON, D.C. HO CATHOLIC UNIV AMER AB I review the main results from recent 2-D, time-dependent hydrodynamic models of radiation-driven winds from accretion disks in active galactic nuclei (AGN). I also discuss the physical conditions needed for a disk wind to be shielded from the strong X-rays and to be accelerated to hypersonic velocities. I conclude with a few remarks on winds in hot stars, low mass young stellar objects, cataclysmic variables, low mass X-ray binaries, and galactic black holes and future work. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Proga, D (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 662, Greenbelt, MD 20771 USA. NR 6 TC 7 Z9 7 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-095-1 J9 ASTR SOC P PY 2002 VL 255 BP 309 EP 314 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU68L UT WOS:000176705100054 ER PT S AU Romanofsky, RR Varaljay, NC Alterovitz, SA Miranda, FA Mueller, CM VanKeuls, MW Kim, J Harshavardhan, KS AF Romanofsky, RR Varaljay, NC Alterovitz, SA Miranda, FA Mueller, CM VanKeuls, MW Kim, J Harshavardhan, KS BE Tidrow, SC Horwitz, JS Xi, XX Levy, J TI A statistical analysis of laser ablated Ba0.50Sr0.50TiO3 /LaAlO3 films for microwave applications SO MATERIALS ISSUES FOR TUNABLE RF AND MICROWAVE DEVICES III SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Issues for Tunable RF and Microwave Devices III held at the 2002 MRS Spring Meeting CY APR 02-03, 2002 CL SAN FRANCISCO, CA SP Mat Res Soc ID PHASE SHIFTERS AB The NASA Glenn Research Center is constructing a 616 element scanning phased array antenna using thin film BaxSr1-xTiO3 based phase shifters. A critical milestone is the production of 616 identical phase shifters at 19 GHz with approximate to4 dB insertion loss and at least 337.5degrees phase shift with 3 percent bandwidth. It is well known that there is a direct relationship between dielectric tuning and loss due to the Kramers-Kronig relationship and that film crystallinity and strain, affected by the substrate template, play an important role. Ba0.50Sr0.50TiO3 films, nominally 400 nm thick, were deposited on 48 0.25 mm thick, 5 cm diameter LaAlO3 wafers. Although previous results suggested that Mn-doped films on MgO were intrinsically superior in terms of phase shift per unit loss, for this application phase shift per unit length was more important. The composition was selected as a compromise between tuning and loss for room temperature operation (e.g. crystallinity progressively degrades for Ba concentrations in excess of 30 percent). As a prelude to fabricating the array, it was necessary to process, screen, and inventory a large number of samples. Variable angle ellipsometry was used to characterize refractive index and film thickness across each wafer. Microstructural properties of the thin films were characterized using high resolution X-ray diffractometry. Finally, prototype phase shifters and resonators were patterned on each wafer and RF probed to measure tuning as a function of dc bias voltage as well as peak (0 field) permittivity and unloaded Q. The relationship among film quality and uniformity and performance is analyzed. This work presents the first statistically relevant study of film quality and microwave performance and represents a milestone towards commercialization of thin ferroelectric films for microwave applications. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Romanofsky, RR (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 8 TC 3 Z9 3 U1 1 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-656-7 J9 MATER RES SOC SYMP P PY 2002 VL 720 BP 111 EP 122 PG 12 WC Physics, Condensed Matter SC Physics GA BV34Q UT WOS:000178622400017 ER PT S AU Miller, SKR Banks, BA Tollis, G AF Miller, SKR Banks, BA Tollis, G BE Vandiver, PB Goodway, M Mass, JL TI Treatment and analysis of a paint chip from "water lilies" a fire damaged Monet SO MATERIALS ISSUES IN ART AND ARCHAEOLOGY VI SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 6th Symposium on Materials Issues in Art and Archaeology held at the 2001 MRS Fall Meeting CY NOV 26-30, 2001 CL BOSTON, MA SP Mat Res Soc AB A museum fire in 1958 severely damaged a Monet "Water Lilies" (1916-1926) painting that was on display. The surface of the painting is very dark with areas of blistering and charring. Over the years, traditional techniques have been found to be ineffective at removal of the soot and char from the surface. The painting, which is now in the care of the New York University (NYU) Conservation Center of the Institute of Fine Arts, was the subject of a study to determine if atomic oxygen treatment could remove the soot and char without damaging the fragile painting underneath. For test purposes, a small chip of paint was removed from the edge of the painting by a conservator at NYU and supplied to NASA Glenn Research Center for atomic oxygen treatment and analysis. The diffuse spectral reflectance, at three locations on the paint chip, was monitored at intervals during the atomic oxygen treatment process. Photo documentation of the chip during treatment was also performed. The color contrast was calculated from the spectral reflectance data as a function of treatment duration. Results of the testing indicated that the contrast improved as a result of the treatment, and the differentiation of colors on the surface was significantly improved. Soot and char could be removed without visibly affecting the gross surface features such as impasto areas. These results indicate the feasibility for the treatment of the "Water Lilies" painting. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Miller, SKR (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 309-2, Cleveland, OH 44135 USA. NR 8 TC 0 Z9 0 U1 1 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-648-6 J9 MATER RES SOC SYMP P PY 2002 VL 712 BP 35 EP 40 PG 6 WC Archaeology; Art; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Archaeology; Art; Materials Science GA BV74A UT WOS:000179917500005 ER PT J AU Walker, S AF Walker, S TI Two-axes Scheimpflug focusing for particle image velocimetry SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE fluid flow velocity; particle image velocimetry; three-dimensional velocity; wind tunnel ID LIQUID FLOWS AB The objective of this work is to demonstrate the capabilities of a two-axes, three-dimensional particle image velocimetry (PIV) system for future use as a large-scale wind tunnel research tool. A two-axes PIV system provides the capability for camera placement virtually anywhere within three-dimensional space relative to the laser sheet plane of measurement. The Scheimpflug focusing method is applied in two orthogonal axes to achieve off-axis focusing. The two-axes, three-dimensional PIV system uses off-axis stereoscopic viewing to determine two perspective measurements of a three-dimensional velocity field within the laser sheet. A unique calibration procedure is used to determine the optical parameters that describe the position of the camera systems and which are necessary to perform the three-dimensional reconstruction of the displacements. This paper presents the calibration procedure as well as a method for reconstructing the three-dimensional particle displacements for this two-axes, three-dimensional PIV system. This two-axes, three-dimensional PIV system was demonstrated by measuring three-dimensional displacements of a target. Maximum instantaneous errors are estimated as 2% or less for all velocity components. These error estimates are for instantaneous displacements and include all error sources. The two-axes, three-dimensional PIV system was also used to make measurements of the freestream velocity within a wind tunnel. The out-of-plane freestream component of velocity measured by the PIV system differed from the expected value by less than 1.1 %. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, MS 260-1, Moffett Field, CA 94035 USA. EM swalker@mail.arc.nasa.gov NR 11 TC 22 Z9 23 U1 1 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD JAN PY 2002 VL 13 IS 1 BP 1 EP 12 DI 10.1088/0957-0233/13/1/301 PG 12 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 521JW UT WOS:000173837700004 ER PT S AU Bruyns, C Ottensmeyer, M AF Bruyns, C Ottensmeyer, M BE Dohi, T Kikinis, R TI Measurements of soft-tissue mechanical properties to support development of a physically based virtual animal model SO MEDICAL IMAGE COMPUTING AND COMPUTER-ASSISTED INTERVENTION-MICCAI 2002, PT 1 SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 5th International Conference on Medical Image Computing and Computer-Assisted Intervention CY SEP 25-28, 2002 CL TOKYO, JAPAN AB Though the course of ongoing development of a dynamic "Virtual Rat", the need for physically based simulation has been established. To support such physical modeling, data regarding the material properties of various tissues is required. We present the results of in vitro testing of rat organ tissues and discuss preliminary comparisons of the results with a Finite Element simulation of the test scenario and a method to extract parameters from test data. C1 NASA, Ames Res Ctr, BioVis Technol Ctr, Moffett Field, CA 94035 USA. Stanford Univ, Natl Biocomputat Ctr, Stanford, CA 94305 USA. RP Bruyns, C (reprint author), NASA, Ames Res Ctr, BioVis Technol Ctr, Moffett Field, CA 94035 USA. EM cbruyns@mail.arc.nasa.gov; mpo@alumni.mit.edu NR 12 TC 8 Z9 8 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-44224-3 J9 LECT NOTES COMPUT SC PY 2002 VL 2488 BP 282 EP 289 PG 8 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods; Engineering, Biomedical; Robotics SC Computer Science; Engineering; Robotics GA BY57N UT WOS:000189412100035 ER PT S AU Bruyns, CD Montgomery, K AF Bruyns, CD Montgomery, K BE Westwood, JD Hoffman, HM Robb, RA Stredney, D TI Generalized interactions using virtual tools within the Spring framework: Probing, piercing, cauterizing and ablating SO MEDICINE MEETS VIRTUAL REALITY 02/10: DIGITAL UPGRADES: APPLYING MOORES LAW TO HEALTH SE Studies in Health Technology and Informatics LA English DT Proceedings Paper CT 10th Annual Medicine Meets Virtual Reality Conference CY JAN 23, 2002 CL NEWPORT BEACH, CA AB We present schemes for real-time generalized interactions such as probing, piercing, cauterizing and ablating virtual tissues. These methods have been implemented in a robust, real-time (haptic rate) surgical simulation environment allowing us to model procedures including animal dissection, microsurgery, hysteroscopy, and cleft lip repair. C1 NASA, Ames Res Ctr, Ctr Bioinformat, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, Ctr Bioinformat, Moffett Field, CA 94035 USA. NR 11 TC 4 Z9 4 U1 0 U2 0 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0926-9630 BN 1-58603-203-8 J9 STUD HEALTH TECHNOL PY 2002 VL 85 BP 74 EP 78 PG 5 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications; Engineering, Biomedical SC Computer Science; Engineering GA BU64M UT WOS:000176591900013 ER PT S AU Bruyns, CD Montgomery, K AF Bruyns, CD Montgomery, K BE Westwood, JD Hoffman, HM Robb, RA Stredney, D TI Generalized interactions using virtual tools within the Spring framework: Cuttingi SO MEDICINE MEETS VIRTUAL REALITY 02/10: DIGITAL UPGRADES: APPLYING MOORES LAW TO HEALTH SE Studies in Health Technology and Informatics LA English DT Proceedings Paper CT 10th Annual Medicine Meets Virtual Reality Conference CY JAN 23, 2002 CL NEWPORT BEACH, CA AB We present schemes for real-time generalized mesh cutting. Starting with the a basic example, we describe the details of implementing cutting on single and multiple surface objects as well as hybrid and volumetric meshes using virtual tools with single and multiple cutting surfaces. These methods have been implemented in a robust surgical simulation environment allowing us to model procedures ranging from animal dissection to cleft lip correction. C1 NASA, Ames Res Ctr, Ctr Bioinformat, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, Ctr Bioinformat, Moffett Field, CA 94035 USA. NR 26 TC 2 Z9 2 U1 0 U2 0 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0926-9630 BN 1-58603-203-8 J9 STUD HEALTH TECHNOL PY 2002 VL 85 BP 79 EP 85 PG 7 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications; Engineering, Biomedical SC Computer Science; Engineering GA BU64M UT WOS:000176591900014 ER PT S AU Clark, N Singh, UN AF Clark, N Singh, UN BE Jin, GF McKillop, JS Hane, KH TI Intelligent vision systems SO MEMS/MOEMS TECHNOLOGIES AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on MEMS/MOEMS Technologies and Applications CY OCT 17-18, 2002 CL SHANGHAI, PEOPLES R CHINA SP SPIE, Chinese Opt Soc AB NASA's pursuit of reducing the size, weight, and cost of satellite systems, for advanced space systems, is providing a vital thrust to the development of systems-on-a-chip. Novel smart vision systems that incorporate active pixel photo-detectors, MEMs tunable etalons, electro-optical information processors, and applications of the novel smart vision system, including remote sensing, hyperspectral imaging, biomedical imaging and adaptive optics are discussed. C1 NASA, Langley Res Ctr, Laser & Electroopt Branch, Syst Engn Competency, Hampton, VA 23681 USA. RP Clark, N (reprint author), NASA, Langley Res Ctr, Laser & Electroopt Branch, Syst Engn Competency, MS 468, Hampton, VA 23681 USA. NR 12 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 0-8194-4717-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4928 BP 15 EP 26 DI 10.1117/12.483175 PG 12 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BV65P UT WOS:000179659300003 ER PT J AU Rubin, AE Zolensky, ME Bodnar, RJ AF Rubin, AE Zolensky, ME Bodnar, RJ TI The halite-bearing Zag and Monahans (1998) meteorite breccias: Shock metamorphism, thermal metamorphism and aqueous alteration on the H-chondrite parent body SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID REGOLITH BRECCIAS; SOLAR NEBULA; MAGNETITE; ASTEROIDS; HISTORY; GASES; MODEL AB Zag and Monahans (1998) are H-chondrite regolith breccias comprised mainly of light-colored metamorphosed clasts, dark clasts that exhibit extensive silicate darkening, and a halite-bearing clastic matrix. These meteorites reflect a complex set of modification processes that occurred on the H-chondrite parent body. The light-colored clasts are thermally metamorphosed H5 and H6 rocks that were fragmented and deposited in the regolith. The dark clasts formed from light-colored clasts during shock events that melted and mobilized a significant fraction of their metallic Fe-Ni and troilite grains. The clastic matrices of these meteorites are rich in solar-wind gases. Parent-body water was required to cause leaching of chondritic minerals and chondrule glass; the fluids became enriched in Na, K, Cl, Br, Al, Ca, Mg and Fe. Evaporation of the fluids caused them to become brines as halides and alkalies became supersaturated; grains of halite (and, in the case of Monahans (1998), halite with sylvite inclusions) precipitated at low temperatures (less than or equal to100 degreesC) in the porous regolith. In both meteorites fluid inclusions were trapped inside the halite crystals. Primary fluid inclusions were trapped in the growing crystals; secondary inclusions formed subsequently from fluid trapped within healed fractures. C1 Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Virginia Polytech Inst & State Univ, Dept Geol Sci, Blacksburg, VA 24061 USA. RP Rubin, AE (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. RI Bodnar, Robert/A-1916-2009 NR 60 TC 34 Z9 35 U1 4 U2 10 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JAN PY 2002 VL 37 IS 1 BP 125 EP 141 AR UNSP MS#4549 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 545XG UT WOS:000175242400009 ER PT J AU Czekala, H Simmer, C AF Czekala, H Simmer, C TI On precipitation induced polarization of microwave radiation measured from space SO METEOROLOGISCHE ZEITSCHRIFT LA English DT Article ID SHAPED ICE CRYSTALS; CLOUDS; RAINFALL; PARTICLE; HYDROMETEORS; ORIENTATION; SCATTERING; RAINDROPS; SYSTEMS; MODEL AB The polarization effects caused by horizontally aligned oblate hydrometeors show significant differences compared to the effect of spherical particles. Even in the presence of a thick ice cloud above the precipitation layer the oblate raindrops may still have an impact on the polarization differences (T-B,T-v - T-B,T-h) observed from space. For large oblate ice particles with aspect ratios as high as 3.3 the polarization difference is strongest for 85 GHz (more than 40 K). Other reasonable choices of ice particle shape above a layer of nonspherical rain drops can alter the results such that the polarization difference at 37 GHz exceeds the 85 GHz polarization signal, reaching +15 K for 37 GHz at a rain rate of 50 min/h. The scattering signal at 85 GHz is very sensitive to ice mass, but also depends very much on the ice particle shape. By choosing different ice shapes we demonstrate the large range of polarization signatures that can be expected and which include the results reported in the literature. Since different rain events are probably associated with different kinds of ice particles, the 85 GHz scattering signature is a very ambiguous source of information if it is used without additional information. At low frequencies (below 37 GHz) there is hardly any sensitivity to the ice particle shape. The information is directly linked to the water mass and raindrop shape which is known to a much better extent than the ice particle shape. C1 Columbia Univ, NASA Goddard Inst Space Studies, Dept Appl Phys & Appl Math, New York, NY 10025 USA. Univ Bonn, Meteorol Inst, D-5300 Bonn, Germany. RP Czekala, H (reprint author), Columbia Univ, NASA Goddard Inst Space Studies, Dept Appl Phys & Appl Math, 2880 Broadway, New York, NY 10025 USA. EM hczekala@giss.nasa.gov RI Simmer, Clemens/M-4949-2013 OI Simmer, Clemens/0000-0003-3001-8642 NR 31 TC 8 Z9 8 U1 0 U2 0 PU E SCHWEIZERBARTSCHE VERLAGS PI STUTTGART PA NAEGELE U OBERMILLER, SCIENCE PUBLISHERS, JOHANNESSTRASSE 3A, D 70176 STUTTGART, GERMANY SN 0941-2948 J9 METEOROL Z JI Meteorol. Z. PY 2002 VL 11 IS 1 BP 49 EP 60 DI 10.1127/0941-2948/2002/0011-0049 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 541WB UT WOS:000175007500006 ER PT J AU Oh, HJ Sohn, BJ Smith, EA Turk, FJ Seo, AS Chung, HS AF Oh, HJ Sohn, BJ Smith, EA Turk, FJ Seo, AS Chung, HS TI Validating infrared-based rainfall retrieval algorithms with 1-minute spatially dense raingage measurements over Korean peninsula SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID SATELLITE; CLOUD; REFLECTIVITY AB This study compares and contrasts six infrared-based satellite rain estimation techniques and their validation during a 2-month period from June 20-August 20, 1998 over the Korean peninsula. Two probability matching techniques (PMM1, PMM2), a look-up table technique (LUT), a convective-stratiform technique (CST), the Negri-Adler-Wetzel technique (NAWT), and the Arkin technique (ARKT) are applied to hourly infrared GMS imagery. Retrieved rainrates are compared against one-minute reporting raingage observations from the dense Automated Weather Station (AWS) network of Korea. The high spatial resolution and fine temporal resolution of the AWS measurements provide a unique and effective means to validate rain estimates derived from instantaneous space measurements, which is a main scientific focus of this study. Validation results indicate that all techniques exhibit better performance for more evenly spread rain events while exhibiting lesser performance for weak and sporadic rains for which validation sampling becomes more of a problem. Validation statistics show that climatologically-local techniques such as the PMM and LUT algorithms perform better than techniques developed in climatologically different regimes, indicating the well-known dependence of rain physics on the immediate environment. Nevertheless, the validation results suggest how the rain determination parameters including attributed rain and threshold brightness temperature could be optimized locally before application. As others have found, the most difficult problem with satellite infrared techniques is in the detection and quantification of heavy rainfall events arising from uncertainties in discriminating non-precipitating anvil clouds from convective clouds. However, for the set of algorithms under examination here, given the sharp resolution of the validation measurements, it is evident that the CST algorithm exhibits superior performance in differentiating between non-precipitating anvil and heavy rain. C1 Seoul Natl Univ, Sch Earth & Environm Sci, Seoul 151742, South Korea. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, Marine Meteorol Div, Monterey, CA USA. Korean Meteorol Adm, Meteorol Res Inst, Seoul, South Korea. RP Sohn, BJ (reprint author), Seoul Natl Univ, Sch Earth & Environm Sci, Seoul 151742, South Korea. RI Kim, Bo-Ra/E-6100-2013 NR 25 TC 15 Z9 15 U1 0 U2 0 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0177-7971 J9 METEOROL ATMOS PHYS JI Meteorol. Atmos. Phys. PY 2002 VL 81 IS 3-4 BP 273 EP 287 DI 10.1007/s00703-002-0552-z PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 636FF UT WOS:000180443400009 ER PT J AU Bosilovich, MG AF Bosilovich, MG TI On the vertical distribution of local and remote sources of water for precipitation SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID CENTRAL UNITED-STATES; SOIL-MOISTURE; GREAT-PLAINS; PARAMETERIZATION; DROUGHT; MODELS; SENSITIVITY; CONVECTION; ANOMALIES; BOUNDARY AB The vertical distribution of local and remote sources of water for precipitation and total column water over the United States are evaluated in a general circulation model simulation. The Goddard Earth Observing System (GEOS) general circulation model (GCM) includes passive constituent tracers to determine the geographical sources of the water in the column. Results show that the local percentage of precipitable water and local percentage of precipitation can be very different. The transport of water vapor from remote oceanic sources at mid and upper levels is important to the total water in the column over the central United States, while the access of locally evaporated water in convective precipitation processes is important to the local precipitation ratio. This result resembles the conceptual formulation of the convective parameterization. However, the formulations of simple models of precipitation recycling include the assumption that the ratio of the local water in the column is equal to the ratio of the local precipitation. The present results demonstrate the uncertainty in that assumption, as locally evaporated water is more concentrated near the surface. C1 NASA, Goddard Space Flight Ctr, Data Assimilat Off, Greenbelt, MD 20771 USA. RP Bosilovich, MG (reprint author), NASA, Goddard Space Flight Ctr, Data Assimilat Off, Code 910 3, Greenbelt, MD 20771 USA. EM mikeb@dao.gsfc.nasa.gov RI Bosilovich, Michael/F-8175-2012 NR 28 TC 27 Z9 27 U1 0 U2 2 PU SPRINGER WIEN PI WIEN PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 WIEN, AUSTRIA SN 0177-7971 J9 METEOROL ATMOS PHYS JI Meteorol. Atmos. Phys. PY 2002 VL 80 IS 1-4 BP 31 EP 41 DI 10.1007/s007030200012 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 577YL UT WOS:000177090600004 ER PT J AU Fulakeza, M Druyan, LM Krishnamurti, TN AF Fulakeza, M Druyan, LM Krishnamurti, TN TI A simple soil moisture scheme for regional climate simulations in the tropics SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID DIFFERENCE VEGETATION INDEX; BIOSPHERE MODEL SIB; CUMULUS PARAMETERIZATION; SURFACE-TEMPERATURE; EASTERN AFRICA; SHORT RAINS; RAINFALL; PRECIPITATION; SENSITIVITY; SKILL AB A regional climate model (RCM) is described which incorporates an improved scheme for soil moisture availability (SMA) compared to an earlier version. The improvement introduces a sensitivity of SMA to soil type, vegetation cover and ground albedo, making the model more adaptable to divers regions. In addition, the interactive SMA depends on past precipitation, ground temperature and terrain relief. Six RCM simulations of the monthly mean climate over southern Africa are performed at 0.5degrees grid spacing. Improvements in the RCM climate simulations compared to control runs are attributed to the newer SMA scheme. Only a slight improvement in skill results from driving the RCM with observational analyses as opposed to GCM "predicted" lateral boundary conditions. The high spatial resolution of the RCM provides a distinct advantage in the simulated spatial distribution of precipitation compared with a global model run at an effective grid spacing of 2.8degrees. The mesoscale precipitation signal in the RCM simulations is more dominant during the rather dry December 1982 than during December 1988. The improved SMA scheme contributed to a realistic partition between latent and sensible heat fluxes at the ground-atmosphere boundary and consequently a realistic diurnal cycle of ground temperature. Simulated differences in the spatial distribution of rainfall between December 1982 and December 1988 are more realistic with the improved scheme. C1 NASA, Goddard Inst Space Studies, Ctr Climate Syst Res, New York, NY 10025 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. RP Fulakeza, M (reprint author), NASA, Goddard Inst Space Studies, Ctr Climate Syst Res, New York, NY 10025 USA. NR 54 TC 6 Z9 6 U1 0 U2 1 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0177-7971 J9 METEOROL ATMOS PHYS JI Meteorol. Atmos. Phys. PY 2002 VL 79 IS 1-2 BP 105 EP 126 DI 10.1007/s703-002-8231-7 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 524WX UT WOS:000174036800007 ER PT B AU Liu, CC O'Connor, E Strohl, KP Klann, KP Ghiurcan, GA Hunter, G Dudik, L Shao, MJ AF Liu, CC O'Connor, E Strohl, KP Klann, KP Ghiurcan, GA Hunter, G Dudik, L Shao, MJ BE Hesketh, P Ang, SS Davidson, JL Hughes, HG Misra, D TI An assessment of microfabrication to sensor development and the integration of the sensor microsystem SO MICROFABRICATED SYSTEMS AND MEMS VI, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 6th Symposium on Microfabricated Systems and MEMS CY MAY 12-17, 2002 CL PHILADELPHIA, PA SP Electrochem Soc, Sensor Div AB Silicon-based microfabrication and micromachining techniques have been applied to produce various chemical and biological sensors. Some of these sensors have had scientific and commercial success. There are, however, limitations. A microfabricated sensor in itself does not constitute a microsystem for practical applications. Packaging of the sensor and interfacing connections between the sensors and external instruments, as well as providing appropriate energy to operate the sensor and its interfacing system, are important. The integration of these elements into a microsystem is a technical challenge. There are various approaches to develop each element in this microsystem. We will describe our own research efforts as a means of illustrating approaches in this endeavor. Specifically, a microfabricated telemetry system as a platform technology for interfacing application will be discussed. Also, the potential of producing planar structure thick film primary batteries for sensor application will be assessed. C1 Case Western Reserve Univ, Ctr Elect Design, Cleveland, OH 44106 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. RP Liu, CC (reprint author), Case Western Reserve Univ, Ctr Elect Design, 10900 Euclid Ave, Cleveland, OH 44106 USA. NR 11 TC 33 Z9 33 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-372-5 J9 ELEC SOC S PY 2002 VL 2002 IS 6 BP 1 EP 12 PG 12 WC Electrochemistry; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Electrochemistry; Engineering; Instruments & Instrumentation GA BW03C UT WOS:000180672200001 ER PT S AU Rashidnia, N Balasubramaniam, R AF Rashidnia, N Balasubramaniam, R BE Sadhal, SS TI Optical measurement of concentration gradient near miscible interfaces SO MICROGRAVITY TRANSPORT PROCESSES IN FLUID, THERMAL, BIOLOGICAL, AND MATERIALS SCIENCES SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Microgravity Transport Processes in Fluid, Thermal, Biological and Materials Sciences CY SEP 30-OCT 05, 2001 CL BANFF, CANADA SP NASA, Natl Sci Fdn, United Engn Fdn DE diffusivity; interferometry ID DIFFUSION-COEFFICIENT; CAPILLARY TUBES; INTERFEROMETER; DISPLACEMENTS; LIQUIDS AB A common path interferometer (CPI) system was developed to measure the diffusivity of transparent liquid pairs. The CPI is an optical technique that can be used to measure changes in the gradient of refractive index of transparent materials. The CPI is a shearing interferometer that shares the same optical path from a laser light source to the final imaging plane. Molecular diffusivity of liquids can be determined by using physical relations between changes in optical path length and liquid phase properties. In this paper, we present results obtained when the diffusivity depends on the local concentration of the miscible fluids. C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Cleveland, OH 44135 USA. RP Rashidnia, N (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Mail Stop 110-3, Cleveland, OH 44135 USA. NR 13 TC 3 Z9 3 U1 0 U2 3 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-423-4 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2002 VL 974 BP 193 EP 200 PG 8 WC Engineering, Chemical; Engineering, Mechanical; Multidisciplinary Sciences SC Engineering; Science & Technology - Other Topics GA BV61L UT WOS:000179509600017 PM 12446325 ER PT S AU Qiu, D Son, G Dhir, VK Chao, D Logsdon, K AF Qiu, D Son, G Dhir, VK Chao, D Logsdon, K BE Sadhal, SS TI Dynamics of single and multiple bubbles and associated heat transfer in nucleate boiling under low gravity conditions SO MICROGRAVITY TRANSPORT PROCESSES IN FLUID, THERMAL, BIOLOGICAL, AND MATERIALS SCIENCES SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Microgravity Transport Processes in Fluid, Thermal, Biological and Materials Sciences CY SEP 30-OCT 05, 2001 CL BANFF, CANADA SP NASA, Natl Sci Fdn, United Engn Fdn DE dynamics; single bubble; multiple bubbles; heat transfer; nucleate boiling; low gravity ID SURFACE AB Experimental studies and numerical simulation of growth and liftoff processes of single bubbles formed on designed nucleation sites have been conducted under low-gravity conditions. Merging of multiple bubbles and liftoff processes during boiling of water in the parabola flights of KC-135 aircraft were also experimentally studied. The heating area of the flat beater surface was discretized and equipped with a number of small heating elements that were separately powered in the temperature-control mode. As such, the wall superheat remained nearly constant during the growth and departure of the bubbles, whereas the local heat flux varied during the boiling process. From numerical calculation it is found that peak of heat flux occurs locally at the contact line of bubble and heater surface. Dry conditions exist inside the bubble base area, which is characterized through a zero heat flux region in the numerical calculation and a lower heat flux period in the experimental results. During the merger of multiple bubbles, dry-out continues. In both the numerical calculations and experimental results, the bubble lift-off is associated with an apparent increase in heat flux. Wall heat flux variation with time and spatial distribution during the growth of a single bubble from numerical simulations are compared with experimental data. C1 Univ Calif Los Angeles, Sch Engn, Dept Mech & Aerosp Engn, Los Angeles, CA 90095 USA. Sugang Univ, Dept Mech Engn, Seoul, South Korea. NASA, Glenn Res Ctr, Micrograv Div, Cleveland, OH USA. RP Dhir, VK (reprint author), Univ Calif Los Angeles, Sch Engn, Dept Mech & Aerosp Engn, 48-121 Engn, Los Angeles, CA 90095 USA. NR 11 TC 4 Z9 5 U1 1 U2 5 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-422-6 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2002 VL 974 BP 378 EP 397 PG 20 WC Engineering, Chemical; Engineering, Mechanical; Multidisciplinary Sciences SC Engineering; Science & Technology - Other Topics GA BV61L UT WOS:000179509600029 PM 12446337 ER PT S AU Gupta, NR Balasubramaniam, R Stebe, KJ AF Gupta, NR Balasubramaniam, R Stebe, KJ BE Sadhal, SS TI Rapidly expanding viscous drop from a submerged orifice at finite Reynolds numbers SO MICROGRAVITY TRANSPORT PROCESSES IN FLUID, THERMAL, BIOLOGICAL, AND MATERIALS SCIENCES SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Microgravity Transport Processes in Fluid, Thermal, Biological and Materials Sciences CY SEP 30-OCT 05, 2001 CL BANFF, CANADA SP NASA, Natl Sci Fdn, United Engn Fdn DE nonlinear dynamics; viscous drops; submerged orifice; drop expansion; finite Reynolds number; VOF; front tracking ID DYNAMICS; FLOWS; TUBE AB The rapid expansion and subsequent detachment of a drop or bubble are examined in this paper-Establishing the hydrodynamics of the drop growth and detachment process has applications ranging from improving insight into nucleate pool boiling, to improving techniques used to characterize dynamic surface tension. Here, the growth and detachment dynamics of viscous drops are studied numerically to establish an accurate description of the hydrodynamics. The full two-dimensional axisymmetric Navier-Stokes equations are solved using a single fluid volume-of-fluid (VOF) formulation on a fixed Eulerian grid. The interface is represented by marker particles that are convected in a Lagrangian manner on the underlying Eulerian grid. Results for surfactant-free, isothermal droplets from hemispherical caps to near detachment are presented. C1 Johns Hopkins Univ, Dept Chem Engn, Baltimore, MD 21218 USA. NASA, Glenn Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Cleveland, OH USA. RP Stebe, KJ (reprint author), Johns Hopkins Univ, Dept Chem Engn, 221 Maryland Hall,3400 N Charles St, Baltimore, MD 21218 USA. OI Gupta, Nivedita/0000-0002-6742-8445 NR 10 TC 1 Z9 1 U1 1 U2 3 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-422-6 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2002 VL 974 BP 398 EP 409 PG 12 WC Engineering, Chemical; Engineering, Mechanical; Multidisciplinary Sciences SC Engineering; Science & Technology - Other Topics GA BV61L UT WOS:000179509600030 PM 12446338 ER PT S AU Vunjak-Novakovic, G Searby, N De Luis, J Freed, LE AF Vunjak-Novakovic, G Searby, N De Luis, J Freed, LE BE Sadhal, SS TI Microgravity studies of cells and tissues SO MICROGRAVITY TRANSPORT PROCESSES IN FLUID, THERMAL, BIOLOGICAL, AND MATERIALS SCIENCES SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Microgravity Transport Processes in Fluid, Thermal, Biological and Materials Sciences CY SEP 30-OCT 05, 2001 CL BANFF, CANADA SP NASA, Natl Sci Fdn, United Engn Fdn DE microgravity; cell culture; tissue engineering; bioreactor; ground studies; flight studies ID ENGINEERED CARTILAGE; CARDIAC-MUSCLE; CULTIVATION; GROWTH; SPACE AB Controlled in vitro studies of cells and tissues under the conditions of microgravity (simulated on Earth, or actual in space) can improve our understanding of gravity sensing, transduction, and responses in living cells and tissues. This paper discusses the scientific results and practical implications of three NASA-related biotechnology projects: ground and space studies of microgravity tissue engineering (JSC-Houston), and the development of the cell culture unit for use aboard the International Space Station (ARC-Ames). C1 MIT, Cambridge, MA 02139 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Payload Syst Inc, Cambridge, MA USA. RP Vunjak-Novakovic, G (reprint author), MIT, 77 Massachusetts Ave E25-330, Cambridge, MA 02139 USA. OI Vunjak-Novakovic, Gordana/0000-0002-9382-1574 NR 25 TC 27 Z9 30 U1 0 U2 10 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-422-6 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2002 VL 974 BP 504 EP 517 PG 14 WC Engineering, Chemical; Engineering, Mechanical; Multidisciplinary Sciences SC Engineering; Science & Technology - Other Topics GA BV61L UT WOS:000179509600036 PM 12446344 ER PT S AU Walker, S Wilder, M Dimanlig, A Jagger, J Searby, N AF Walker, S Wilder, M Dimanlig, A Jagger, J Searby, N BE Sadhal, SS TI Flow field measurements in the cell culture unit SO MICROGRAVITY TRANSPORT PROCESSES IN FLUID, THERMAL, BIOLOGICAL, AND MATERIALS SCIENCES SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Microgravity Transport Processes in Fluid, Thermal, Biological and Materials Sciences CY SEP 30-OCT 05, 2001 CL BANFF, CANADA SP NASA, Natl Sci Fdn, United Engn Fdn DE international space station; life science; cell growth; PIV; cell specimen chamber; cell culture unit; CFD; flow visualization AB The cell culture unit (CCU) is being designed to support cell growth for long-duration life science experiments on the International Space Station (ISS). The CCU is a perfused loop system that provides a fluid environment for controlled cell growth experiments within cell specimen chambers (CSCs), and is intended to accommodate diverse cell specimen types. Many of the functional requirements depend on the fluid flow field within the CSC (e.g., feeding and gas management). A design goal of the CCU is to match, within experimental limits, all environmental conditions, other than the effects of gravity on the cells, whether the hardware is in microgravity (mug), normal Earth gravity, or up to 2g on the ISS centrifuge. In order to achieve this goal, two steps are being taken. The first step is to characterize the environmental conditions of current 1g cell biology experiments being performed in laboratories using ground-based hardware. The second step is to ensure that the design of the CCU allows the fluid flow conditions found in 1g to be replicated from microgravity up to 2g. The techniques that are being used to take these steps include flow visualization, particle image velocimetry (PIV), and computational fluid dynamics (CFD). Flow visualization using the injection of dye has been used to gain a global perspective of the characteristics of the CSC flow field. To characterize laboratory cell culture conditions, PIV is being used to determine the flow field parameters of cell suspension cultures grown in Erlenmeyer flasks on orbital shakers. These measured parameters will be compared to PIV measurements in the CSCs to ensure that the flow field that cells encounter in CSCs is within the bounds determined for typical laboratory experiments. Using CFD, a detailed simulation is being developed to predict the flow field within the CSC for a wide variety of flow conditions, including microgravity environments. Results from all these measurements and analyses of the CSC flow environment are presented and discussed. The final configuration of the CSC employs magnetic stir bars with angled paddles to achieve the necessary flow requirements within the CSC. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Walker, S (reprint author), NASA, Ames Res Ctr, MS-260-1, Moffett Field, CA 94035 USA. NR 7 TC 3 Z9 3 U1 0 U2 3 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-422-6 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2002 VL 974 BP 518 EP 540 PG 23 WC Engineering, Chemical; Engineering, Mechanical; Multidisciplinary Sciences SC Engineering; Science & Technology - Other Topics GA BV61L UT WOS:000179509600037 PM 12446345 ER PT J AU Zhang, YG Wolfson, O AF Zhang, YG Wolfson, O TI Untitled SO MOBILE NETWORKS & APPLICATIONS LA English DT Editorial Material C1 Univ Texas, Dept Comp Sci, Austin, TX 78712 USA. Argonne Natl Lab, Argonne, IL 60439 USA. USA, Res Labs, Washington, DC 20310 USA. NASA, Ctr Excellence Space Data & Informat Sci, Greenbelt, MD 20771 USA. Technion Israel Inst Technol, Fac Comp Sci, IL-32000 Haifa, Israel. Columbia Univ, New York, NY 10027 USA. NR 0 TC 31 Z9 32 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1383-469X J9 MOBILE NETW APPL JI Mobile Netw. Appl. PD JAN PY 2002 VL 7 IS 1 BP 7 EP 8 PG 2 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Telecommunications SC Computer Science; Telecommunications GA 512MJ UT WOS:000173327900001 ER PT J AU Xu, B Wolfson, O Chamberlain, S Rishe, N AF Xu, B Wolfson, O Chamberlain, S Rishe, N TI Cost based data dissemination in satellite networks SO MOBILE NETWORKS & APPLICATIONS LA English DT Article DE data replication; distributed databases; satellite networks AB We consider the problem of data dissemination in a broadcast network. In contrast to previously studied models, broadcasting is among peers, rather than client server. Such a model represents, for example, satellite communication among widely distributed nodes, sensor networks, and mobile ad hoc networks. We introduce a cost model for data dissemination in peer to peer broadcast networks. The model quantifies the tradeoff between the inconsistency of the data, and its transmission cost; the transmission cost may be given in terms of dollars, energy, or bandwidth. Using the model we first determine the parameters for which eager (i.e. consistent) replication has a lower cost than lazy (i.e. inconsistent) replication. Then we introduce a lazy broadcast policy and compare it with several naive or traditional approaches to solving the problem. C1 Univ Illinois, Dept Elect Engn & Comp Sci, Databases & Mobile Comp Lab, Chicago, IL 60680 USA. USA, Res Lab, Computat & Informat Sci Directorate, Washington, DC 20310 USA. Florida Int Univ, Sch Comp Sci, Miami, FL 33199 USA. Univ Illinois, Dept Elect Engn & Comp Sci, Mobile Informat Syst Ctr, Chicago, IL 60680 USA. Argonne Natl Lab, Argonne, IL 60439 USA. NASA, Ctr Excellence Space Data & Informat Sci, Greenbelt, MD 20771 USA. RP Univ Illinois, Dept Elect Engn & Comp Sci, Databases & Mobile Comp Lab, Chicago, IL 60680 USA. NR 33 TC 4 Z9 4 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1383-469X EI 1572-8153 J9 MOBILE NETW APPL JI Mobile Netw. Appl. PD JAN PY 2002 VL 7 IS 1 BP 49 EP 66 DI 10.1023/A:1013277313373 PG 18 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Telecommunications SC Computer Science; Telecommunications GA 512MJ UT WOS:000173327900005 ER PT S AU Ambrose, RO Savely, RT AF Ambrose, RO Savely, RT BE Gage, DW Choset, HM TI Synergy in the design of mobile manipulation SO MOBILE ROBOTS XVI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Mobile Robots XVI CY OCT 29-30, 2001 CL NEWTON, MA SP SPIE DE robot; design; mobile; manipulation; kinematics; control; perception; dexterity AB As our mobile robots develop greater range, autonomy, and sensor payloads, the desire to more fully interact with the environment has led researchers to the obvious integration of manipulators on their machines. This paper explores the integration of locomotion and manipulation in diverse forms, defining and then testing seven general design rules. This kinematics study reports on system level choices for integrating limbs on robot bodies, with a critique using seven metrics that include workspace, strength, occlusion and view factors for perception systems and the relative proportions of the robot to its work site. These design axioms were tested with three cases of radically different mobile robots, spanning the spectrum from gantries, to wheeled vehicles, to free climbers in space. In all cases, the robot design is considered as an anatomical study, comparing relative proportions of the limbs and the robot's body. For the wheeled vehicles in particular, sub categories were considered to identify the impact of multiple arms, and the interplay of manipulation and perception requirements. The study is completed with a look at actual robot prototypes built by the authors, and sub types, The design axioms were tested and found to be both valid and useful as governing principles in each case. These design cases include a gantry-arm combination built for an IVA habitat, multiple wheeled vehicles with arms, and the Robonaut system tested as a free climber moving across the exterior of a space craft mockup designed to emulate 0g dynamics. C1 NASA, Lyndon B Johnson Space Ctr, Automat Robot & Simulat Div, Houston, TX 77058 USA. RP Ambrose, RO (reprint author), NASA, Lyndon B Johnson Space Ctr, Automat Robot & Simulat Div, Houston, TX 77058 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 0-8194-4301-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4573 BP 10 EP 21 DI 10.1117/12.457444 PG 12 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics; Optics SC Automation & Control Systems; Engineering; Robotics; Optics GA BU21U UT WOS:000175367000002 ER PT S AU Gaines, DM Wilkes, M Kusumalnukool, K Thongchai, S Kawamura, K White, J AF Gaines, DM Wilkes, M Kusumalnukool, K Thongchai, S Kawamura, K White, J BE Gage, DW Choset, HM TI SAN-RL: Combining spreading activation networks and reinforcement learning to learn configurable behaviors SO MOBILE ROBOTS XVI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Mobile Robots XVI CY OCT 29-30, 2001 CL NEWTON, MA SP SPIE AB Reinforcement learning techniques have been successful in allowing an agent to learn a policy for achieving tasks. The overall behavior of the agent can be controlled with an appropriate reward function. However, the policy that is learned will be fixed to this reward function. If the user wishes to change his or her preference about how the task is achieved the agent must be retrained with this new reward function. We address this challenge by combining Spreading Activation Networks and Reinforcement Learning in an approach we call SAN-RL. This approach provides the agent with a causal structure, the spreading activation network, relating goals to the actions that can achieve those goals. This enables the agent, to select actions relative to the goal priorities. We combine this with reinforcement. learning to enable the agent to learn a policy. Together, these approaches enable the learning of a configurable behaviors, a policy that can be adapted to meet the current preferences. We compare the approach with Q-learning on a robot navigation task. We demonstrate that SAN-RL exhibits goal-directed behavior before learning, exploits the causal structure of the network to focus its search during learning and results in configurable behaviors after learning. C1 Jet Prop Lab, Pasadena, CA USA. RP Gaines, DM (reprint author), Jet Prop Lab, Pasadena, CA 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 0-8194-4301-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4573 BP 80 EP 91 DI 10.1117/12.457458 PG 12 WC Automation & Control Systems; Engineering, Electrical & Electronic; Robotics; Optics SC Automation & Control Systems; Engineering; Robotics; Optics GA BU21U UT WOS:000175367000008 ER PT S AU Groce, A Visser, W AF Groce, A Visser, W BE Boesnaecki, D Leue, S TI Heuristic model checking for Java programs SO MODEL CHECKING SOFTWARE, PROCEEDINGS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 9th International SPIN Workshop CY APR 11-13, 2002 CL GRENOBLE, FRANCE C1 Carnegie Mellon Univ, Sch Comp Sci, Pittsburgh, PA 15213 USA. NASA, Ames Res Ctr, RIACS, Ames, IA USA. RP Groce, A (reprint author), Carnegie Mellon Univ, Sch Comp Sci, Pittsburgh, PA 15213 USA. NR 5 TC 8 Z9 8 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-43477-1 J9 LECT NOTES COMPUT SC PY 2002 VL 2318 BP 242 EP 245 PG 4 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BW25X UT WOS:000181349100021 ER PT S AU Petkov, MP AF Petkov, MP BE Zavaliangos, A Tikare, V Olevsky, EA TI Model for comprehensive studies of porosity in mesoporous low-k dielectrics SO MODELING AND NUMERICAL SIMULATION OF MATERIALS BEHAVIOR AND EVOLUTION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Modeling and Numerical Simulation of Materials Behavior and Evolution held at the 2002 MRS Spring Meeting CY APR 02-05, 2002 CL SAN FRANCISCO, CA SP Mat Res Soc ID PERCOLATION AB The successful integration of a porous low dielectric constant (k) material as an interlevel dielectric depends on the morphology of the embedded porosity. Simple site percolation models are utilized here to investigate porosity properties of low-k dielectrics with respect to the current technology trends. Significant differences between two generations of porous dielectrics, k < 2.4 and k < 2.1, are found. The porosity fraction in the latter is above the percolation threshold, which may have serious impact on the materials physical properties and its compatibility with production steps. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Petkov, MP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 1-55899-667-2 J9 MATER RES SOC SYMP P PY 2002 VL 731 BP 285 EP 290 PG 6 WC Mathematics, Applied; Materials Science, Characterization & Testing SC Mathematics; Materials Science GA BV34T UT WOS:000178623800044 ER PT S AU Hernandez-Pajares, M Juan, JM Sanz, J Bilitza, D AF Hernandez-Pajares, M Juan, JM Sanz, J Bilitza, D BE Rawer, K Bilitza, D Reinisch, BW TI Combining GPS measurements and IRI model values for space weather specification SO MODELLING THE TOPSIDE IONOSPHERE AND PLASMASPHERE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C4 1-D3 9 Symposium of COSPAR Scientific Commission C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Int Union Radio Sci, Comm Space Res ID GLOBAL POSITIONING SYSTEM; ELECTRON-CONTENT; IONOSPHERE; RESOLUTION; TOMOGRAPHY AB We will discuss various ways in which the International Reference Ionosphere (IRI) model and ionospheric data deduced from GPS measurements can be combined to improve ionospheric determinations. A number of research groups are analyzing GPS data products and providing global maps of vertical Total Electron Content (TEC) oil a regular basis. IRI predictions can guide the interpolation of regional TEC estimations, computed from GPS data, to obtain global TEC maps. GPS measurements, oil the other hand, can be used to update the IRI monthly averages to actual conditions. This can be done by using the GPS-derived TEC maps or by using the actual GPS measurements of the electron content along the signal path from satellite to ground receiver. We will discuss the updating results using the actual GPS measurements. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Politecn Catalunya, E-08034 Barcelona, Spain. NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. RP Hernandez-Pajares, M (reprint author), Univ Politecn Catalunya, Campus Nord Mod C-3,Jordi Girona 1, E-08034 Barcelona, Spain. RI Sanz Subirana, Jaume/C-1265-2014; Juan Zornoza, Jose Miguel/S-6224-2016 OI Sanz Subirana, Jaume/0000-0001-8880-7084; Juan Zornoza, Jose Miguel/0000-0003-1126-2367 NR 15 TC 25 Z9 26 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 2002 VL 29 IS 6 BP 949 EP 958 DI 10.1016/S0273-1177(02)00051-0 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BU64Q UT WOS:000176593100021 ER PT S AU Zhao, C Bilitza, D Shum, C Schaer, S Beutler, G Ge, S AF Zhao, C Bilitza, D Shum, C Schaer, S Beutler, G Ge, S BE Rawer, K Bilitza, D Reinisch, BW TI Evaluation of IRI95 ionosphere model for radar altimeter applications SO MODELLING THE TOPSIDE IONOSPHERE AND PLASMASPHERE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C4 1-D3 9 Symposium of COSPAR Scientific Commission C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Int Union Radio Sci, Comm Space Res ID TOMOGRAPHY AB Using the TOPEX dual-frequency (Ku- and C-band) radar altimeter measured nadir total electron contents (TECs) from an orbital altitude of 1354 kin, the fidelity of the IRI95 ionosphere model and GPS-derived Global Ionosphere Map (GIM) have been evaluated. In particular, the models have been evaluated over the ocean for the time period 1993-1999, representing low, medium and high solar activity periods. In addition, the evaluation is also focused on the model performance for TEC variations due to local solar time, geographical locations, and long-term trend, or drift. The major spatial and temporal features of ionosphere depicted by IRI95 model agrees reasonably well when comparing with TOPEX ground-truth, except during high solar activity period in 1999. The error in IRI95 would translate into an apparent sea level change of 0.3-0.6 mm/yr for the majority (70%) of the global ocean. During high solar activities in 1999, the error reaches 1 mm/yr, Results indicate that GIM provides more accurate ionosphere delays during high solar activities. For the use of single-frequency altimeters (e.g., GFO) for sea level studies during high solar activity period, ionosphere models need further improvement. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA. Goddard Space Flight Ctr, Natl Space Sci Data Ctr, Greenbelt, MD 20895 USA. Univ Bern, Inst Astron, CH-3012 Bern, Switzerland. RP Zhao, C (reprint author), Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, 470 Hitchchcok Hall,2070 Neil Ave, Columbus, OH 43210 USA. NR 15 TC 5 Z9 5 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 2002 VL 29 IS 6 BP 967 EP 973 DI 10.1016/S0273-1177(02)00062-5 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BU64Q UT WOS:000176593100023 ER PT S AU Kilifarska, NA Ouzounov, DP AF Kilifarska, NA Ouzounov, DP BE Rawer, K Bilitza, D Reinisch, BW TI Spatial-time simulation of the upper ionosphere reaction on geomagnetic disturbances SO MODELLING THE TOPSIDE IONOSPHERE AND PLASMASPHERE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C4 1-D3 9 Symposium of COSPAR Scientific Commission C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Int Union Radio Sci, Comm Space Res ID MODELS; STORM AB The response of the ionosphere on two geomagnetic storms, as appearing in the ionosonde network in the Northern hemisphere, is examined and compared with ionospheric storm simulations provided by the theoretical data assimilative model of the ionosphere (TDAMI)). This is a first principles analytical theoretical ionospheric model that updates its input parameters (neutral species O, N-2, O-2 and vertical plasma drift) by real measurements of foF2 and hmF2 (Kilifarska, Ouzounov, 2001). It is concluded that TDAMI model successfully describes the ionospheric disturbances and might even be used as a prognostic tool. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Bulgarian Acad Sci, Inst Geophys, BU-1113 Sofia, Bulgaria. NASA, Goddard SFC, SSAI, Greenbelt, MD 20771 USA. RP Kilifarska, NA (reprint author), Bulgarian Acad Sci, Inst Geophys, 3 Acad G Bonchev, BU-1113 Sofia, Bulgaria. RI Ouzounov, Dimitar/A-5929-2012; OI Kilifarska, Natalya/0000-0002-1874-8610 NR 9 TC 0 Z9 0 U1 0 U2 1 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 2002 VL 29 IS 6 BP 1011 EP 1015 DI 10.1016/S0273-1177(02)00047-9 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BU64Q UT WOS:000176593100028 ER PT J AU Darve, E Wilson, MA Pohorille, A AF Darve, E Wilson, MA Pohorille, A TI Calculating free energies using a scaled-force molecular dynamics algorithm SO MOLECULAR SIMULATION LA English DT Article DE free energy; molecular dynamics; force of constraint; adaptive force; quasi-static approximation ID MONTE-CARLO SIMULATIONS; CANONICAL ENSEMBLE; AQUEOUS-SOLUTION; PHASE-SPACE; J-WALKING; 1,2-DICHLOROETHANE; WATER; EQUILIBRIUM; DISTRIBUTIONS; PROTEIN AB We propose and test a family of methods to calculate the free energy along a generalized coordinate, xi, based on computing the force acting on this coordinate. First, we derive a formula that connects the free energy in unconstrained simulations with the force of constraint that can be readily calculated numerically. Then, we consider two methods, which improve the efficiency of the free energy calculation by yielding uniform or nearly uniform sampling of xi. Both rely on modifying the force acting on xi. In one method, this force is replaced by a force with zero mean and xi is advanced quasistatically. In the second method, the force is augmented adaptively by a biasing force. We provide formulas for calculating the free energy of the unmodified system from the forces acting in these modified, non-Hamiltonian systems. Using conformational transitions in 1,2-dichloroethane as a test case, we show that both methods perform very well. C1 NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA 94035 USA. Stanford Univ, Ctr Turbulence Res, Stanford, CA 94305 USA. Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. RP NASA, Ames Res Ctr, Exobiol Branch, MS 239-4,Moffett Field, Moffett Field, CA 94035 USA. NR 41 TC 80 Z9 82 U1 1 U2 17 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0892-7022 EI 1029-0435 J9 MOL SIMULAT JI Mol. Simul. PD JAN-FEB PY 2002 VL 28 IS 1-2 BP 113 EP 144 DI 10.1080/08927020290004412 PG 32 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 561DH UT WOS:000176122400009 ER PT J AU Troccoli, A Balmaseda, MA Segschneider, J Vialard, J Anderson, DLT Haines, K Stockdale, T Vitart, F Fox, AD AF Troccoli, A Balmaseda, MA Segschneider, J Vialard, J Anderson, DLT Haines, K Stockdale, T Vitart, F Fox, AD TI Salinity adjustments in the presence of temperature data assimilation SO MONTHLY WEATHER REVIEW LA English DT Article ID EQUATORIAL PACIFIC; ENSO PREDICTION; TROPICAL OCEANS; COUPLED MODEL; VARIABILITY; IMPACT AB This paper is an evaluation of the role of salinity in the framework of temperature data assimilation in a global ocean model that is used to initialize seasonal climate forecasts. It is shown that the univariate assimilation of temperature profiles, without attempting to correct salinity, can induce first-order errors in the subsurface temperature and salinity fields. A recently developed scheme by A. Troccoli and K. Haines is used to improve the salinity field. In this scheme, salinity increments are derived from the observed temperature, by using the model temperature and salinity profiles, assuming that the temperature-salinity relationship in the model profiles is preserved. In addition, the temperature and salinity fields are matched below the observed temperature profile by vertically displacing the original model profiles. Two data assimilation experiments were performed for the 6-yr period 1993-98. These show that the salinity scheme is effective at maintaining the haline and thermal structures at and below thermocline level, especially in tropical regions, by avoiding spurious convection. In addition to improvements in the mean state, the scheme allows more temporal variability than simply controlling the salinity field by relaxation to climatological data. Some comparisons with sparse salinity observations are also made, which suggest that the subsurface salinity variability in the western Pacific is better reproduced in the experiment in which the salinity scheme is used. The salinity analyses might be improved further by use of altimeter sea level or sea surface salinity observations from satellite. C1 European Ctr Medium Range Weather Forecasts, Reading RG2 9AX, Berks, England. Univ Edinburgh, Dept Meteorol, Edinburgh, Midlothian, Scotland. RP Troccoli, A (reprint author), NASA, NSIPP, GEST, Code 971,Bldg 33, Greenbelt, MD 20771 USA. RI Vialard, Jerome/C-2809-2008; Troccoli, Alberto/A-1477-2012; OI Vialard, Jerome/0000-0001-6876-3766; Haines, Keith/0000-0003-2768-2374; Fox, Alan/0000-0002-9047-1986 NR 24 TC 47 Z9 54 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PY 2002 VL 130 IS 1 BP 89 EP 102 DI 10.1175/1520-0493(2002)130<0089:SAITPO>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 502AU UT WOS:000172721600006 ER PT J AU Reichle, RH McLaughlin, DB Entekhabi, D AF Reichle, RH McLaughlin, DB Entekhabi, D TI Hydrologic data assimilation with the ensemble Kalman filter SO MONTHLY WEATHER REVIEW LA English DT Article ID SUBSPACE STATISTICAL ESTIMATION; VARIATIONAL DATA ASSIMILATION; QUASI-GEOSTROPHIC MODEL; SOIL-MOISTURE; ANALYSIS SCHEME; PARAMETERS; IMPLEMENTATION; PRECIPITATION; SIMULATION AB Soil moisture controls the partitioning of moisture and energy fluxes at the land surface and is a key variable in weather and climate prediction. The performance of the ensemble Kalman filter (EnKF) for soil moisture estimation is assessed by assimilating L-band (1.4 GHz) microwave radiobrightness observations into a land surface model. An optimal smoother (a dynamic variational method) is used as a benchmark for evaluating the filter's performance. In a series of synthetic experiments the effect of ensemble size and non-Gaussian forecast errors on the estimation accuracy of the EnKF is investigated. With a state vector dimension of 4608 and a relatively small ensemble size of 30 (or 100; or 500), the actual errors in surface soil moisture at the final update time are reduced by 55% (or 70%; or 80%) from the value obtained without assimilation (as compared to 84% for the optimal smoother). For robust error variance estimates, an ensemble of at least 500 members is needed. The dynamic evolution of the estimation error variances is dominated by wetting and drying events with high variances during drydown and low variances when the soil is either very wet or very dry. Furthermore, the ensemble distribution of soil moisture is typically symmetric except under very dry or wet conditions when the effects of the nonlinearities in the model become significant. As a result, the actual errors are consistently larger than ensemble-derived forecast and analysis error variances. This suggests that the update is suboptimal. However, the degree of suboptimality is relatively small and results presented here indicate that the EnKF is a flexible and robust data assimilation option that gives satisfactory estimates even for moderate ensemble sizes. C1 MIT, Ralph M Parsons Lab, Dept Civil & Environm Engn, Cambridge, MA 02139 USA. RP Reichle, RH (reprint author), NASA, Goddard Space Flight Ctr, Bldg 33,A-110,Code 974, Greenbelt, MD 20771 USA. EM reichle@janus.gsfc.nasa.gov RI Reichle, Rolf/E-1419-2012 NR 32 TC 378 Z9 403 U1 7 U2 54 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PY 2002 VL 130 IS 1 BP 103 EP 114 DI 10.1175/1520-0493(2002)130<0103:HDAWTE>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 502AU UT WOS:000172721600007 ER PT B AU Wilcox, BH AF Wilcox, BH BE Schultz, AC Parker, LE TI Snow White and the 700 Dwarves - A cooperating robotic system SO MULTI-ROBOT SYSTEMS: FROM SWARMS TO INTELLIGENT AUTOMATA LA English DT Proceedings Paper CT Workshop on Multi-Robot Systems CY MAR, 2002 CL WASHINGTON, D.C. SP Naval Res Lab DE co-operating robots; excavation robots AB Detailed scientific study of possible sites on Mars such as extinct hot springs may require robotic excavation of the sort generally associated with archaeological "digs" on Earth. This paper describes a system developed to explore the feasibility of building such a robotic network. A scaling analysis shows that, for a given landed mass, it is better to break the payload into as many small vehicles as possible, due to the surface-to-volume implications on the power-to-weight ratio for the system using solar power. Each small vehicle must be equipped with a shovel and hopper to move loose material, and a provision for a percussive hammer to break up hard soils and rocks. A central mast rising from the nearby lander supports stereo imaging and a computer providing central co-ordination of activities. Each vehicle has limited sensing (e.g. no vision) but is designed to follow simple commands (goto(x,y)) and rules (keep to the right of oncoming traffic). The outer surface of each vehicle is arranged to capture solar energy, and the lander mast can be configured with a foil reflector to bounce sunlight down into the excavation to keep the vehicles powered most of the day. Thus we have a system consisting of a single tall mast with a pair of stereo cameras at the top and a large, silver reflector hanging down, together with a large number of small robots, each having a pick and shovel. This system has been dubbed "Snow White and the 700 Dwarves". C1 CALTECH, Jet Prop Lab, Robot Vehicles Grp, Pasadena, CA 91125 USA. RP Wilcox, BH (reprint author), CALTECH, Jet Prop Lab, Robot Vehicles Grp, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 4 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-0679-9 PY 2002 BP 123 EP 130 PG 8 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Robotics SC Automation & Control Systems; Computer Science; Robotics GA BV23S UT WOS:000178302300013 ER PT B AU Kortenkamp, D Schreckenghost, D Martin, C AF Kortenkamp, D Schreckenghost, D Martin, C BE Schultz, AC Parker, LE TI User interaction with multi-robot systems SO MULTI-ROBOT SYSTEMS: FROM SWARMS TO INTELLIGENT AUTOMATA LA English DT Proceedings Paper CT Workshop on Multi-Robot Systems CY MAR, 2002 CL WASHINGTON, D.C. SP Naval Res Lab DE multi-robot systems; human-robot interaction AB There has been very little research on multiple human users interacting with multiple autonomous robots. In this paper we present some of the requirements of such user interaction. We present a prototype architecture for collaborative interaction. This architecture is put into the context of multiple space robots monitoring a space structure to assist human crew members. C1 NASA, Lyndon B Johnson Space Ctr, Metr Inc, TRACLabs, Houston, TX 77058 USA. RP Kortenkamp, D (reprint author), NASA, Lyndon B Johnson Space Ctr, Metr Inc, TRACLabs, ER2, Houston, TX 77058 USA. NR 13 TC 4 Z9 4 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-0679-9 PY 2002 BP 213 EP 220 PG 8 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Robotics SC Automation & Control Systems; Computer Science; Robotics GA BV23S UT WOS:000178302300023 ER PT B AU Moore, RL Falconer, DA Sterling, AC AF Moore, RL Falconer, DA Sterling, AC BE Martens, PCH Cauffman, DP TI Contagious coronal heating from recurring emergence of magnetic flux SO MULTI-WAVELENGTH OBSERVATIONS OF CORONAL STRUCTURE AND DYNAMICS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT Yohkoh 10th Anniversary Meeting on Multi-Wavelength Observations of Coronal Structure and Dynamics CY JAN 20-24, 2002 CL KONA, HI SP Comm Space Res, NASA, Natl Sci Fdn, Inst Space & Astronaut Sci, Montana State Univ Solar Phys Grp, Lockheed Solar & Astrophys Lab, Solar Phys Res Corp, Elsevier Sci ID SOLAR CORONA; FIELD; SUN C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Moore, RL (reprint author), NASA, George C Marshall Space Flight Ctr, SD 50, Huntsville, AL 35812 USA. NR 9 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 BN 0-08-044060-6 J9 COSPAR COLL PY 2002 VL 13 BP 39 EP 42 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV60A UT WOS:000179468700008 ER PT B AU Saba, JLR Gaeng, T Tarbell, TD AF Saba, JLR Gaeng, T Tarbell, TD BE Martens, PCH Cauffman, DP TI A study of magnetic reconnection using simultaneous SOHO/MDI and trace data SO MULTI-WAVELENGTH OBSERVATIONS OF CORONAL STRUCTURE AND DYNAMICS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT Yohkoh 10th Anniversary Meeting on Multi-Wavelength Observations of Coronal Structure and Dynamics CY JAN 20-24, 2002 CL KONA, HI SP Comm Space Res, NASA, Natl Sci Fdn, Inst Space & Astronaut Sci, Montana State Univ Solar Phys Grp, Lockheed Solar & Astrophys Lab, Solar Phys Res Corp, Elsevier Sci AB High resolution, high cadence images from the Transition Region and Coronal Explorer (TRACE) together with high quality magnetograms from the Michelson Doppler Imager (MDI) on the Solar and Heliospheric Observatory (SOHO) let us examine signatures of magnetic reconnection and attempt to infer associated physical parameters such as the electric field strength in the solar corona. We analyzed TRACE UV and MDI magnetogram. data for a two-ribbon, GOES M1 class flare from NOAA active region 9236 at 2000 Nov 23 23:28 UT, with emphasis on dynamical development of the 1600 Angstrom band flare ribbons in the TRACE images; we estimated the magnetic reconnection rate from the change in photospheric magnetic flux swept out by the evolving ribbons. For simple assumptions with standard coronal parameters, the reconnection appears to be fast, with the inferred inflow velocity a significant fraction of the Alfven velocity. Some guidance from coronal imaging of the reconnection region or Doppler measurement of inflow is needed to sharpen the constraints on the length of the reconnecting current sheet and the coronal electric field. C1 NASA, Goddard Space Flight Ctr, Lockheed Martin Solar & Astrophys Lab, Greenbelt, MD 20771 USA. RP Saba, JLR (reprint author), NASA, Goddard Space Flight Ctr, Lockheed Martin Solar & Astrophys Lab, Code 682-3, Greenbelt, MD 20771 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND BN 0-08-044060-6 J9 COSPAR COLL PY 2002 VL 13 BP 175 EP 176 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV60A UT WOS:000179468700045 ER PT B AU Brosius, JW AF Brosius, JW BE Martens, PCH Cauffman, DP TI Search for evidence of alpha particle beams during a solar flare SO MULTI-WAVELENGTH OBSERVATIONS OF CORONAL STRUCTURE AND DYNAMICS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT Yohkoh 10th Anniversary Meeting on Multi-Wavelength Observations of Coronal Structure and Dynamics CY JAN 20-24, 2002 CL KONA, HI SP Comm Space Res, NASA, Natl Sci Fdn, Inst Space & Astronaut Sci, Montana State Univ Solar Phys Grp, Lockheed Solar & Astrophys Lab, Solar Phys Res Corp, Elsevier Sci C1 NASA, Goddard Space Flight Ctr, CUA, Greenbelt, MD 20771 USA. RP Brosius, JW (reprint author), NASA, Goddard Space Flight Ctr, CUA, Code 682, Greenbelt, MD 20771 USA. NR 0 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 BN 0-08-044060-6 J9 COSPAR COLL PY 2002 VL 13 BP 283 EP 284 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV60A UT WOS:000179468700067 ER PT B AU Falconer, DA Moore, RL Gary, GA AF Falconer, DA Moore, RL Gary, GA BE Martens, PCH Cauffman, DP TI Use of Yohkoh SXT in measuring net current and CME productivity of active regions SO MULTI-WAVELENGTH OBSERVATIONS OF CORONAL STRUCTURE AND DYNAMICS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT Yohkoh 10th Anniversary Meeting on Multi-Wavelength Observations of Coronal Structure and Dynamics CY JAN 20-24, 2002 CL KONA, HI SP Comm Space Res, NASA, Natl Sci Fdn, Inst Space & Astronaut Sci, Montana State Univ Solar Phys Grp, Lockheed Solar & Astrophys Lab, Solar Phys Res Corp, Elsevier Sci ID VECTOR C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Falconer, DA (reprint author), NASA, George C Marshall Space Flight Ctr, SD 50, Huntsville, AL 35812 USA. NR 4 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 BN 0-08-044060-6 J9 COSPAR COLL PY 2002 VL 13 BP 303 EP 304 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV60A UT WOS:000179468700076 ER PT B AU Holman, GD Sui, L McTiernan, JM Petrosian, V AF Holman, GD Sui, L McTiernan, JM Petrosian, V BE Martens, PCH Cauffman, DP TI Theoretical model images and spectra for comparison with, rhessi and microwave observations of solar flares SO MULTI-WAVELENGTH OBSERVATIONS OF CORONAL STRUCTURE AND DYNAMICS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT Yohkoh 10th Anniversary Meeting on Multi-Wavelength Observations of Coronal Structure and Dynamics CY JAN 20-24, 2002 CL KONA, HI SP Comm Space Res, NASA, Natl Sci Fdn, Inst Space & Astronaut Sci, Montana State Univ Solar Phys Grp, Lockheed Solar & Astrophys Lab, Solar Phys Res Corp, Elsevier Sci AB We have computed bremsstrahlung and gyrosynchrotron images and spectra from a model flare loop. Electrons with a power-law energy distribution are continuously injected at the top of a semicircular magnetic loop. The Fokker-Planck equation is integrated to obtain the steady-state electron distribution throughout the loop. Coulomb scattering and energy losses and magnetic mirroring are included in the model. The resulting electron distributions are used to compute the radiative emissions. Sample images and spectra are presented here. We are developing these models for the interpretation of RHESSI x-ray/gamma-ray data and coordinated microwave observations. The Fokker-Planck and radiation codes are available on the Web at: http://hesperia.gsfc.nasa.gov/hessi/modelware.htm. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Holman, GD (reprint author), NASA, Goddard Space Flight Ctr, Code 682, Greenbelt, MD 20771 USA. RI Holman, Gordon/C-9548-2012 NR 0 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 BN 0-08-044060-6 J9 COSPAR COLL PY 2002 VL 13 BP 405 EP 406 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV60A UT WOS:000179468700103 ER PT B AU Branch, EL Bikdash, M Homaifar, A AF Branch, EL Bikdash, M Homaifar, A BE Jamshidi, M Hata, Y Fathi, M Homaifar, A Jamshidi, JS TI Fuzzy and time-suboptimal control for dual track following and seeking of the magnetic hard disk drive SO MULTIMEDIA, IMAGE PROCESSING AND SOFT COMPUTING: TRENDS, PRINCIPLES AND APPLICATIONS SE TSI PRESS SERIES LA English DT Proceedings Paper CT 5th Biannual World Automation Congress CY JUN 09-13, 2002 CL ORLANDO, FL SP Univ Cent Florida, Florida Atlantic Univ DE fuzzy logic control; time sub-optimal control; magnetic disk drive; pole placement; bang-bang control; extended pontryagin's minimum principle (EPMP) AB Track-seeking for a magnetic hard drive is a time optimal control problem where the objective is to move the R/W head from the current track to a specified destination track in minimum time using a bounded control effort. One difficulty is due to the nonlinear saturation and hysterisis behavior of the voice coil actuator. Therefore a dual fuzzy logic controller (FLC) for track seeking and track following is designed and implemented. The controller uses position and velocity to decide on the commanded electrical current. Once the reading head gets within a small distance of the target track, a linear pole placement design is implemented. We compare the performance of this controller with a time-suboptimal design obtained for the linearized version of the dynamics. C1 N Carolina Agr & Tech State Univ, Dept Elect Engn, NASA, Autonomous Control Engn Ctr, Greensboro, NC 27411 USA. RP Branch, EL (reprint author), N Carolina Agr & Tech State Univ, Dept Elect Engn, NASA, Autonomous Control Engn Ctr, Greensboro, NC 27411 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU TSI PRESS PI ALBUQUERQUE PA PO BOX 14126, ALBUQUERQUE, NM 87191-4126 USA BN 1-889335-18-5 J9 TSI PRESS S PY 2002 VL 13 BP 37 EP 42 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Automation & Control Systems; Computer Science; Engineering; Telecommunications GA BV86P UT WOS:000180264900006 ER PT B AU Kreinovich, V Starks, SA Kosheleva, O AF Kreinovich, V Starks, SA Kosheleva, O BE Jamshidi, M Hata, Y Fathi, M Homaifar, A Jamshidi, JS TI Open-ended configurations of radio telescopes: Towards optimal design SO MULTIMEDIA, IMAGE PROCESSING AND SOFT COMPUTING: TRENDS, PRINCIPLES AND APPLICATIONS SE TSI PRESS SERIES LA English DT Proceedings Paper CT 5th Biannual World Automation Congress CY JUN 09-13, 2002 CL ORLANDO, FL SP Univ Cent Florida, Florida Atlantic Univ DE radio telescopes; very large array; optimization under uncertainty ID LARGE ARRAY AB The quality of radio astronomical images drastically depends on where we place the radio telescopes. During the design of the Very Large Array, it was empirically shown that the power lam, design, in which n-th antenna is placed at a distance n(beta) from the center, leads to the best image quality. In this paper, we provide a theoretical justification for this empirical fact. C1 Univ Texas, NASA, Panamer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. RP Kreinovich, V (reprint author), Univ Texas, NASA, Panamer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU TSI PRESS PI ALBUQUERQUE PA PO BOX 14126, ALBUQUERQUE, NM 87191-4126 USA BN 1-889335-18-5 J9 TSI PRESS S PY 2002 VL 13 BP 101 EP 106 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Automation & Control Systems; Computer Science; Engineering; Telecommunications GA BV86P UT WOS:000180264900016 ER PT B AU Iourinski, D Starks, SA Kreinovich, V AF Iourinski, D Starks, SA Kreinovich, V BE Jamshidi, M Hata, Y Fathi, M Homaifar, A Jamshidi, JS TI Swarm intelligence: Theoretical proof that empirical techniques are optimal SO MULTIMEDIA, IMAGE PROCESSING AND SOFT COMPUTING: TRENDS, PRINCIPLES AND APPLICATIONS SE TSI PRESS SERIES LA English DT Proceedings Paper CT 5th Biannual World Automation Congress CY JUN 09-13, 2002 CL ORLANDO, FL SP Univ Cent Florida, Florida Atlantic Univ DE swarm intelligence; autonomous agents; optimality proof AB A natural way to distribute tasks between autonomous agents is to use swarm intelligence techniques, which simulate the way social insects (such as wasps) distribute tasks between themselves. In this paper, we theoretically prove that the corresponding successful biologically inspired formulas are indeed statistically optimal (in some reasonable sense). C1 Univ Texas, NASA, Panamer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. RP Iourinski, D (reprint author), Univ Texas, NASA, Panamer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU TSI PRESS PI ALBUQUERQUE PA PO BOX 14126, ALBUQUERQUE, NM 87191-4126 USA BN 1-889335-18-5 J9 TSI PRESS S PY 2002 VL 13 BP 107 EP 112 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Automation & Control Systems; Computer Science; Engineering; Telecommunications GA BV86P UT WOS:000180264900017 ER PT B AU Finkleman, D Santiago, J Alfano, S Vallado, D AF Finkleman, D Santiago, J Alfano, S Vallado, D BE Hyder, AK Shahbazian, E Waltz, E TI Introduction to data fusion and applications in astrodynamics SO MULTISENSOR FUSION SE NATO SCIENCE SERIES, SERIES II: MATHEMATICS, PHYSICS AND CHEMISTRY LA English DT Proceedings Paper CT Conference of the NATO-Advanced-Study-Institute on Multisensor Data Fusion CY JUN 25-JUL 07, 2000 CL PITOCHRY, SCOTLAND SP NATO Adv Stud Inst C1 US Space Command, Colorado Springs, CO USA. RP Finkleman, D (reprint author), US Space Command, Colorado Springs, CO USA. NR 6 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-0722-1 J9 NATO SCI SER II MATH PY 2002 VL 70 BP 657 EP 671 PG 15 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA BV25Q UT WOS:000178338700033 ER PT S AU Hartley, FT Kanik, I AF Hartley, FT Kanik, I BE Sood, DK Malshe, AP Maeda, R TI A nanoscale soft-ionization membrane: A novel ionizer for ion mobility spectrometers for space applications SO NANO- AND MICROTECHNOLOGY: MATERIALS, PROCESSES, PACKAGING, AND SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT International Symposium on Smart Materials, Nano-, and Micro-Smart Systems CY DEC 16-18, 2002 CL RMIT UNIV, MELBOURNE, AUSTRALIA SP SPIE, Univ Arkansas, Natl Inst Adv Ind Sci & Technol, Cooperat Res Ctr Microtechnol, Dept Def, Australia, Swinburne Univ Technol, Adelaide Univ, Japanese Soc Electr Packaging, New Energy & Ind Technol Dev Org HO RMIT UNIV DE soft ionization; ion mobility spectrometers; Mars AB The Jet Propulsion Laboratory (JPL) has developed a novel nanometer-thick "Soft Ionization Membrane" (SIM) which is capable of ionizing nearly 100% of the gases that pass through it. Both sides of the membrane are coated with a metallic conducting film. A modest potential of less than 10 Volts across the membrane produces an electric field in excess of 107 V/cm over a region that is smaller than the mean free path of gas molecules which ionizes the neutral molecules that passing through. Because the region of high electric field is smaller than the mean free path of gas molecules, there are virtually no high energy collisions and the system does not suffer from the fatal problem of avalanche breakdown. The soft ionization mechanism does not fracture the medium or cause any secondary ionization. Thus, a truly new ionization technique is enabled by a simple nanoscale micromachined device. The SIM is tiny, rugged and wen suited for a wide variety of applications ranging from space micropropulsion systems to miniature analytical separation devices. In this paper we focus our attention on ion mobility spectrometers (IMSs) as a potential candidate to be incorporated with SIM. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hartley, FT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 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 0-8194-4731-5 J9 P SOC PHOTO-OPT INS PY 2002 VL 4936 BP 43 EP 49 DI 10.1117/12.484271 PG 7 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BW31A UT WOS:000181495200006 ER PT J AU Khare, BN Meyyappan, M Cassell, AM Nguyen, CV Han, J AF Khare, BN Meyyappan, M Cassell, AM Nguyen, CV Han, J TI Functionalization of carbon nanotubes using atomic hydrogen from a glow discharge SO NANO LETTERS LA English DT Article AB We have functionalized single walled carbon nanotubes (SWNTs) with atomic hydrogen generated in a cold plasma. A band at 2924 cm(-1) (3.4 mum), characteristic of the C-H stretching mode, is observed using Fourier transform infrared spectroscopy. Additional confirmation of functionalization is provided by irradiating with atomic deuterium. A band in the region 1940 cm-1 (5.2 mum) to 2450 cm(-1) (4.1 mum) corresponding to the C-D stretching mode is confirmed and another weak band in the region 1050 cm(-1) (9.5 mum) to 1300 cm(-1) (7.7 mum) corresponding to C-D bending mode is also seen. Our approach using a glow discharge provides a clean gas-phase process to functionalize SWNTs for further application development. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 21 TC 145 Z9 148 U1 1 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1530-6984 EI 1530-6992 J9 NANO LETT JI Nano Lett. PD JAN PY 2002 VL 2 IS 1 BP 73 EP 77 DI 10.1021/nl015646j PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 525NQ UT WOS:000174078200016 ER PT S AU Banks, B Miller, S de Groh, K Chan, A Sahota, M AF Banks, B Miller, S de Groh, K Chan, A Sahota, M BE Merhari, L Gonsalves, KE Dobisz, EA Angelopoulos, M Herr, D TI The development of surface roughness and implications for cellular attachment in biomedical applications SO NANOPATTERNING-FROM ULTRALARGE-SCALE INTERGRATION TO BIOTECHNOLOGY SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanopatterning - From Ultralarge-Scale Integration to Biotechnology held at the 2001 MRS Fall Meeting CY NOV 25-29, 2001 CL BOSTON, MA SP CERAMEC France, Motorola France, Res Ctr, Nanoresist Technologies Inc, Natl Sci Fdn, Whitaker Fdn, Mat Res Soc AB The application of a microscopic surface texture produced by ion beam sputter texturing to the surfaces of polymer implants has been shown to result in significant increases in cellular attachment compared to smooth surface implants in animal studies. A collaborative program between NASA Glenn Research Center and the Cleveland Clinic Foundation has been established to evaluate the potential for improving osteoblast attachment to surfaces that have been microscopically roughened by atomic oxygen texturing. The range of surface textures that is feasible depends upon both the texturing process and the duration of treatment. To determine whether surface texture saturates or continues to increase with treatment duration, an effort was conducted to examine the development of surface textures produced by various physical and chemical erosion processes. Both experimental tests and computational modeling were performed to explore the growth of surface texture with treatment time. Surface texturing by means of abrasive grit blasting of glass, stainless steel and polymethylmethacrylate surfaces was examined to measure the growth in roughness with grit blasting duration by surface profilometry measurements. Laboratory tests and computational modeling was also conducted to examine the development of texture on Aclar(R) (chlorotrifluoroethylene) and Kapton(R) polyimide, respectively. For the atomic oxygen texturing tests of Aclar(R), atomic force microscopy was used to measure the development of texture with atomic oxygen fluence. The results of all the testing and computational modeling support the premise that development of surface roughness obeys Poisson statistics. The results indicate that surface roughness does not saturate but increases as the square root of the treatment time. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Banks, B (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-641-9 J9 MATER RES SOC SYMP P PY 2002 VL 705 BP 253 EP 258 PG 6 WC Biotechnology & Applied Microbiology; Engineering, Multidisciplinary; Materials Science, Multidisciplinary; Physics, Applied SC Biotechnology & Applied Microbiology; Engineering; Materials Science; Physics GA BU87A UT WOS:000177252400032 ER PT S AU Campbell, S Scheiman, D AF Campbell, S Scheiman, D BE Komarneni, S Parker, JC Vaia, RA Lu, GQ Matsushita, JI TI Orientation of aromatic ion exchange diamines and the effect on melt viscosity and thermal stability of PMR-15 silicate nanocomposites SO NANOPHASE AND NANOCOMPOSITE MATERIALS IV SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanophase and Nanocomposite Materials IV held at the 2001 MRS Fall Meeting CY NOV 26-29, 2001 CL BOSTON, MA SP Mat Res Soc ID ORGANOCLAY AB Nanocomposites of PMR-15 polyimide and a diamine modified silicate were prepared by addition of the silicate to the PMR-15 resin. The orientation of the ion exchange diamine within the silicate gallery was determined by x-ray diffraction and found to depend on the clay cation exchange capacity. The oligomer melt viscosity exhibited a dependence on the orientation of the diamine in the silicate interlayer, and in some cases, on the length of the diamine. A correlation was observed between the oligomer melt viscosity and the crosslinking enthalpy, where nanocomposites with an increased melt viscosity exhibited a decrease in enthalpy on crosslinking. After crosslinking, those nanocomposites with a high melt viscosity had poorer thermal oxidative stability compared to the less viscous systems. The melt viscosity was tailored by co-exchange of an aromatic diamine and an aliphatic amine into the silicate. Nanocomposites prepared with this silicate exhibited an increase in thermal oxidative stability compared to the neat resin. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Campbell, S (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 14 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 1-55899-639-7 J9 MATER RES SOC SYMP P PY 2002 VL 703 BP 215 EP 221 PG 7 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA BU86Z UT WOS:000177252100031 ER PT S AU Southward, RE Dean, CJ Scott, JL Broadwater, ST Thompson, DW AF Southward, RE Dean, CJ Scott, JL Broadwater, ST Thompson, DW BE Komarneni, S Parker, JC Vaia, RA Lu, GQ Matsushita, JI TI Silver-polyimide nanocomposite films yielding highly reflective surfaces SO NANOPHASE AND NANOCOMPOSITE MATERIALS IV SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Nanophase and Nanocomposite Materials IV held at the 2001 MRS Fall Meeting CY NOV 26-29, 2001 CL BOSTON, MA SP Mat Res Soc AB Highly reflective surface-metallized flexible polyimide films have been prepared by the incorporation of the soluble silver ion complex (1,1,1-trifluoroacetylacetonato)silver(1) into dimethylacetamide solutions of the poly(amic acid) prepared from 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 2,2-bis[4-(4-aminophenoxy)phenyl] hexafluoropropane (4-BDAF). Thermal curing of solution cast silver(1)-poly(amic acid) films leads to cycloimidization of the amic acid with concommitant silver(1) reduction and formation of a reflective surface-silvered film at 8 and 13 weight percent silver. The metallized films are thermally stable and flexible with mechanical properties similar to those of the parent polyimide. TEM reveals that the bulk (interior) of the polyimide composite films have 5-20 manometer-sized silver particles with a surface layer of silver metal ca. 80 nm thick. Neither the bulk nor the surface of the films is electrically conductive. Adhesion of the surface metal to polyimide is excellent. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Southward, RE (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 13 TC 3 Z9 3 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-639-7 J9 MATER RES SOC SYMP P PY 2002 VL 703 BP 421 EP 426 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA BU86Z UT WOS:000177252100063 ER PT J AU Roller, CA Cohen, HS Kimball, KT Bloomberg, JJ AF Roller, CA Cohen, HS Kimball, KT Bloomberg, JJ TI Effects of normal aging on visuo-motor plasticity SO NEUROBIOLOGY OF AGING LA English DT Article DE aging; neural plasticity; sensorimotor adaptation; visuo-motor plasticity; visual-motor rearrangement; multilevel analysis; prisms ID CONTEXTUAL INTERFERENCE; VESTIBULAR INTERACTIONS; CEREBRAL-CORTEX; ADAPTATION; ACQUISITION; EXPERIENCE; SENESCENCE; RESPONSES; EXPOSURE; SKILL AB Normal aging is associated with declines in neurologic function. Uncompensated visual and vestibular problems may have dire consequences including dangerous falls. Visuo-motor plasticity is a form of behavioral neural plasticity, which is important in the process of adapting to visual or vestibular alteration, including those changes due to pathology, pharmacotherapy, surgery or even entry into microgravity or an underwater environment. To determine the effects of aging on visuo-motor plasticity, we chose the simple and easily measured paradigm of visual-motor rearrangement created by using visual displacement prisms while throwing, small balls at a target. Subjects threw balls before, during and after wearing a set of prisms which displace the visual scene by twenty degrees to the right. Data obtained during adaptation were modeled using multilevel modeling techniques for 73 subjects, aged 20 to 80 years. We found no statistically significant difference in measures of visuo-motor plasticity with advancing age. Further studies are underway examining variable practice training as a potential mechanism for enhancing this form of behavioral neural plasticity. (C) 2002 Elsevier Science Inc. All rights reserved. C1 Baylor Coll Med, Bobby R Alford Dept Otorhinolaryngol & Communicat, Houston, TX 77030 USA. Baylor Coll Med, Dept Med, Design & Anal Unit, Houston, TX 77030 USA. NASA, Neurosci Labs, Lyndon B Johnson Space Ctr, Houston, TX 77030 USA. RP Roller, CA (reprint author), Baylor Coll Med, Bobby R Alford Dept Otorhinolaryngol & Communicat, Houston, TX 77030 USA. FU NIDCD NIH HHS [R01 DC004167, DC04167] NR 38 TC 23 Z9 24 U1 2 U2 7 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0197-4580 J9 NEUROBIOL AGING JI Neurobiol. Aging PD JAN-FEB PY 2002 VL 23 IS 1 BP 117 EP 123 DI 10.1016/S0197-4580(01)00264-0 PG 7 WC Geriatrics & Gerontology; Neurosciences SC Geriatrics & Gerontology; Neurosciences & Neurology GA 506UY UT WOS:000172991200017 PM 11755026 ER PT S AU Somers, JT Reschke, MF Berthoz, A Taylor, LC AF Somers, JT Reschke, MF Berthoz, A Taylor, LC BE Kaminski, HJ Leigh, RJ TI Smooth pursuit tracking Saccade amplitude modulation during exposure to microgravity SO NEUROBIOLOGY OF EYE MOVEMENTS: FROM MOLECULES TO BEHAVIOR SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Neurobiology of Eye Movement - From Molecules to Behavior CY OCT 04-06, 2001 CL CASE WESTERN RESERVE UNIV, CLEVELAND, OHIO SP NY Acad Sci, Univ Hosp Cleveland, Evenor Armington Fund HO CASE WESTERN RESERVE UNIV DE saccade; smooth pursuit; space flight; main sequence ID CORRECTIVE SACCADES C1 Wyle Life Sci, Houston, TX 77058 USA. Lyndon B Johnson Space Ctr, SK3, Houston, TX 77058 USA. Coll France, F-75231 Paris, France. RP Somers, JT (reprint author), 1290 Hercules Dr,Suite 120, Houston, TX 77058 USA. NR 10 TC 3 Z9 3 U1 0 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-394-7 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2002 VL 956 BP 426 EP 429 PG 4 WC Multidisciplinary Sciences; Ophthalmology SC Science & Technology - Other Topics; Ophthalmology GA BU36T UT WOS:000175781500044 PM 11960831 ER PT S AU Swartz, BE Burmeister, M Somers, JT Rottach, KG Bespalova, IN Leigh, RJ AF Swartz, BE Burmeister, M Somers, JT Rottach, KG Bespalova, IN Leigh, RJ BE Kaminski, HJ Leigh, RJ TI A form of inherited cerebellar ataxia with saccadic intrusions, increased saccadic speed, sensory neuropathy, and myoclonus SO NEUROBIOLOGY OF EYE MOVEMENTS: FROM MOLECULES TO BEHAVIOR SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Neurobiology of Eye Movement - From Molecules to Behavior CY OCT 04-06, 2001 CL CASE WESTERN RESERVE UNIV, CLEVELAND, OHIO SP NY Acad Sci, Univ Hosp Cleveland, Evenor Armington Fund HO CASE WESTERN RESERVE UNIV DE cerebellum; ataxia; saccades ID FIXATION C1 Vet Affairs Med Ctr, Cleveland, OH 44106 USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Lyndon B Johnson Space Ctr, Houston, TX USA. RP Swartz, BE (reprint author), Univ Hosp Cleveland, Dept Neurol, 11100 Euclid Ave, Cleveland, OH 44106 USA. RI Burmeister, Margit/A-3157-2013 OI Burmeister, Margit/0000-0002-1914-2434 FU NEI NIH HHS [EY06717] NR 6 TC 20 Z9 20 U1 0 U2 2 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-394-7 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2002 VL 956 BP 441 EP 444 PG 4 WC Multidisciplinary Sciences; Ophthalmology SC Science & Technology - Other Topics; Ophthalmology GA BU36T UT WOS:000175781500048 PM 11960835 ER PT S AU Mulligan, JB AF Mulligan, JB BE Kaminski, HJ Leigh, RJ TI Sensory processing delays measured with the eye-movement correlogram SO NEUROBIOLOGY OF EYE MOVEMENTS: FROM MOLECULES TO BEHAVIOR SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Neurobiology of Eye Movement - From Molecules to Behavior CY OCT 04-06, 2001 CL CASE WESTERN RESERVE UNIV, CLEVELAND, OHIO SP NY Acad Sci, Univ Hosp Cleveland, Evenor Armington Fund HO CASE WESTERN RESERVE UNIV DE smooth pursuit system; eye-movement correlogram; saccades C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Mulligan, JB (reprint author), NASA, Ames Res Ctr, Mail Stop 262-2, Moffett Field, CA 94035 USA. NR 7 TC 4 Z9 4 U1 0 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-394-7 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2002 VL 956 BP 476 EP 478 PG 3 WC Multidisciplinary Sciences; Ophthalmology SC Science & Technology - Other Topics; Ophthalmology GA BU36T UT WOS:000175781500057 PM 11960844 ER PT S AU Han, Y Kumar, A Somers, J Kim, JI Leigh, RJ AF Han, Y Kumar, A Somers, J Kim, JI Leigh, RJ BE Kaminski, HJ Leigh, RJ TI Vestibulo-ocular responses during mirror-viewing SO NEUROBIOLOGY OF EYE MOVEMENTS: FROM MOLECULES TO BEHAVIOR SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Neurobiology of Eye Movement - From Molecules to Behavior CY OCT 04-06, 2001 CL CASE WESTERN RESERVE UNIV, CLEVELAND, OHIO SP NY Acad Sci, Univ Hosp Cleveland, Evenor Armington Fund HO CASE WESTERN RESERVE UNIV DE vestibulo-ocular responses; mirror-viewing; compensatory eye movements C1 Dankook Univ Hosp, Dept Neurol, Cheonan, South Korea. Lyndon B Johnson Space Ctr, Houston, TX USA. Case Western Reserve Univ, Cleveland, OH 44106 USA. Vet Affairs Med Ctr, Dept Biomed Engn, Cleveland, OH USA. Vet Affairs Med Ctr, Dept Neurol, Cleveland, OH USA. RP Leigh, RJ (reprint author), Univ Hosp Cleveland, Dept Neurol, 11100 Euclid Ave, Cleveland, OH 44106 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-394-7 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2002 VL 956 BP 527 EP 529 PG 3 WC Multidisciplinary Sciences; Ophthalmology SC Science & Technology - Other Topics; Ophthalmology GA BU36T UT WOS:000175781500071 PM 11960858 ER PT B AU Thompson, DJ Digel, SW Nolan, PL Reimer, O AF Thompson, DJ Digel, SW Nolan, PL Reimer, O BE Slane, PO Gaensler, BM TI High-energy gamma rays from neutron stars in supernova remnants: From EGRET to GLAST SO NEUTRON STARS IN SUPERNOVA REMNANTS SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT Workshop on Neutron Stars in Supernova Remnants CY AUG 14-17, 2001 CL BOSTON, MA SP NASA, NSF, MIT Ctr Space Res, Chandra X ray Ctr ID PULSARS; IC-443; NEBULA AB At least three pulsars in supernova remnants were detected E > 100 MeV by EGRET on the Compton Gamma Ray Observatory. Efforts to search for additional pulsars in the EGRET data have been unsuccessful due to limited statistics. An example is the recently-discovered radio pulsar J2229+6114, where efforts to search the EGRET data using several different methods failed to find significant evidence of pulsation. The GLAST Large Area Telescope (LAT) will have a much greater effective area and a narrower point-spread function than EGRET. In addition, the field of view will be more than four times larger than EGRET's, and the LAT will scan to avoid occultation by the earth, increasing by a large factor the total number of photons detected. The greater rates of photons from pulsar candidates and better discrimination of diffuse interstellar emission will enhance the sensitivity of pulsation searches. These improvements also offer the prospect of resolving point sources from extended emission in some SNRs to define the nature of the associations of EGRET sources with SNRs. Further, work with the GLAST LAT will benefit from ongoing multiwavelength studies (e.g. for RX J1836.2+5925) that provide specific candidate targets for gamma-ray studies. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Thompson, DJ (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. RI Thompson, David/D-2939-2012; Reimer, Olaf/A-3117-2013 OI Thompson, David/0000-0001-5217-9135; Reimer, Olaf/0000-0001-6953-1385 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 1-58381-111-7 J9 ASTR SOC P PY 2002 VL 271 BP 65 EP 68 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV48G UT WOS:000179110700012 ER PT B AU Harding, AK Gonthier, PL Ouellette, MS O'Brien, S Berrier, J AF Harding, AK Gonthier, PL Ouellette, MS O'Brien, S Berrier, J BE Slane, PO Gaensler, BM TI Galactic populations of radio-loud and radio-quiet gamma-ray pulsars SO NEUTRON STARS IN SUPERNOVA REMNANTS SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT Workshop on Neutron Stars in Supernova Remnants CY AUG 14-17, 2001 CL BOSTON, MA SP NASA, NSF, MIT Ctr Space Res, Chandra X ray Ctr AB We present Monte Carlo simulations of the Galactic population of radio and gamma-ray pulsars using the predicted luminosities of the polar cap emission model. Assuming an emission solid angle of 1 steradian and alignment of the radio and gamma-ray beams, we explore cases with and without magnetic field decay. For the case of field decay on a timescale of 5 Myr, our model predicts that EGRET should have seen 9 radio loud and 2 radio quiet, gamma-ray pulsars. GLAST, on the other hand, is expected to observe 90 radio-loud and 101 radio-quiet, gamma-ray pulsars of which 9 are expected to be identified as pulsed sources. These results differ significantly from gamma-ray pulsar population studies using outer gap emission models. Although both models predict large numbers of radio-quiet gamma-ray pulsars in the Galaxy, the ratios of radio-quiet to radio-loud pulsars detected by GLAST will be a key discriminant. C1 NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RP Harding, AK (reprint author), NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RI Harding, Alice/D-3160-2012 NR 9 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-111-7 J9 ASTR SOC P PY 2002 VL 271 BP 335 EP 338 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV48G UT WOS:000179110700066 ER PT J AU Kondo, Y McCluskey, GE Guinan, EF AF Kondo, Y McCluskey, GE Guinan, EF TI Problems in modeling evolutionary processes in close binaries SO NEW ASTRONOMY REVIEWS LA English DT Article DE accretion, accretion disks/clouds; binaries : close; celestial mechanics; hydrodynamics; mass flow; mass loss; Roche model; stars : evolution ID ANGULAR-MOMENTUM LOSS; ALGOL-TYPE BINARIES; POSSIBLE MASS; LIGHT CURVES; WHITE-DWARFS; HERCULIS; IUE AB In modeling the evolutionary processes of interacting binaries, a number of assumptions are invoked by many workers concerning the manner of the mass flow between the two stars. This article reviews the validity of the four assumptions most commonly used. namely, assumptions concerning (A) the critical Roche equipotential surface (the so-called Roche lobe), (B) accretion of matter from one star to its companion. (C) mass loss from the binary system, and (D), which is related to the last two items, whether the mass flow in a binary system is conservative or not. A large number of workers in this field appear to assume that the critical Roche equipotential surfaces (Roche lobes, in their lexicon) control the mass flow with the Lagrangian 1 point acting like a nozzle, channeling a rather well collimated jet of gas. Similarly, they also assume that accretion 'disks' are formed in this process and those 'disks' have properties very similar to solid disks with well defined surfaces and with precession, nutation etc. Finally. they assume, except in the most extreme case of rapid mass flow. conservative mass flow in which all mass lost by one star is completely accreted by the companion. These commonly invoked assumptions are critically examined from both observational data and relevant physics and are shown to be lacking realistic justification. We show what the concept of Roche equipotential surfaces actually tells us, and examine the manners of actual mass flow observed in selected binaries. (C) 2002 Elsevier Science B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lehigh Univ, Bethlehem, PA 18015 USA. Villanova Univ, Villanova, PA 19085 USA. RP Kondo, Y (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 23 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD JAN PY 2002 VL 46 IS 1 BP 1 EP 12 DI 10.1016/S1387-6473(01)00152-X PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 516XG UT WOS:000173581600001 ER PT S AU Becklin, EE Moon, LJ AF Becklin, EE Moon, LJ BE Szczerba, R TI Stratospheric Observatory For Infrared Astronomy (SOFIA) SO NEW RESULTS IN FAR IR AND SUB-MM ASTRONOMY SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT E1 4 Symposium of COSPAR Scientific Commission E held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP European Space Agcy, Int Astron Union, SPIE, Comm Space Res AB The joint U.S. and German SOFIA project to develop and operate a 2.5-meter infrared airborne telescope in a Boeing 747-SP is now well into development. First science flights will begin in 2004 with 20% of the observing time assigned to German investigators. The observatory is expected to operate for over 20 years. The sensitivity, characteristics and science instrument complement are discussed. SOFIA will have instrumentation that will allow astronomical surveys that were not possible on the KAO. A future SOFIA survey project related to astrochemistry is discussed. (C) 2002 Published by Elsevier Science Ltd on behalf of COSPAR. C1 Univ Calif Los Angeles, Div Astron & Astrophys, Los Angeles, CA 90095 USA. NASA, Ames Res Ctr, Univ Space Res Assoc, Moffett Field, CA 94035 USA. RP Becklin, EE (reprint author), Univ Calif Los Angeles, Div Astron & Astrophys, 405 Hilgard Ave, Los Angeles, CA 90095 USA. NR 7 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-SERIES PY 2002 VL 30 IS 9 BP 2083 EP 2088 AR PII S0273-1177(02)00591-4 DI 10.1016/S0273-1177(02)00591-4 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV98P UT WOS:000180590800015 ER PT S AU Pearlman, MR Degnan, JJ Bosworth, JM AF Pearlman, MR Degnan, JJ Bosworth, JM BE Drewes, H Dow, JM TI The international laser ranging service SO NEW TRENDS IN SPACE GEODESY SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT B2 1-PSD1 Symposium of COSPAR Scientific Commission B held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Agenzia Spatiale Italiana, CNES, European Space Agcy, Int Union Geodesy & Geophys, Int Assoc Geodesy AB The International Laser Ranging Service (ILRS) was established in September 1998 to support programs in geodetic, geophysical, and lunar research activities and to provide the International Earth Rotation Service (IERS) with products important to the maintenance of an accurate International Terrestrial Reference Frame (ITRF). Now in operation for nearly two years, the ILRS develops (1) the standards and specifications necessary for product consistency, and (2) the priorities and tracking strategies required to maximize network efficiency. The Service collects, merges, analyzes, archives and distributes satellite and lunar laser ranging data to satisfy a variety of scientific, engineering, and operational needs and encourages the application of new technologies to enhance the quality, quantity, and cost effectiveness of its data products. The ILRS works with (1) new satellite missions in the design and building of retroreflector targets to maximize data quality and quantity, and (2) science programs to optimize scientific data yield. The ILRS is organized into permanent components: (1) a Governing Board, (2) a Central Bureau, (3) Tracking Stations and Subnetworks, (4) Operations Centers, (5) Global and Regional Data Centers, and (6) Analysis, Lunar Analysis, and Associate Analysis Centers. The Governing Board, with broad representation from the international Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR) community, provides overall guidance and defines service policies, while the Central Bureau oversees and coordinates the daily service activities, maintains scientific and technological data bases, and facilitates communications. Active Working Groups in (1) Missions, (2) Networks and Engineering, (3) Data Formats and Procedures, (4) Analysis, and (5) Signal Processing provide key operational and technical expertise to better exploit current capabilities and to challenge the ILRS participants to keep pace with evolving user needs. The ILRS currently includes more than 40 SLR stations, routinely tracking about 20 retroreflector-equipped satellites and,the Moon in support of user needs. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Pearlman, MR (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 0 TC 335 Z9 346 U1 1 U2 9 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 2002 VL 30 IS 2 BP 135 EP 143 DI 10.1016/S0273-1177(02)00277-6 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV11T UT WOS:000177857000002 ER PT S AU Schluter, W Himwich, E Nothnagel, A Vandenberg, N Whitney, A AF Schluter, W Himwich, E Nothnagel, A Vandenberg, N Whitney, A BE Drewes, H Dow, JM TI IVS and its important role in the maintenance of the global reference systems SO NEW TRENDS IN SPACE GEODESY SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT B2 1-PSD1 Symposium of COSPAR Scientific Commission B held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Agenzia Spatiale Italiana, CNES, European Space Agcy, Int Union Geodesy & Geophys, Int Assoc Geodesy AB VLBI technique plays a primary role in the maintenance of global reference frames. The International VLBI Service for Geodesy and Astrometry (IVS) was established in February 1999 in order to support VLBI programs for geodetic, geophysical and astrometric research and operational activities. IVS coordinates the observations, the data flow, the correlation, the data analysis and the technology developments. Today not only science, research and development are making use of the results but also practical applications are dependent on IVS products. Thus, acting within the frame of International Association of Geodesy (IAG) and the International Astronomical Union (IAU), IVS has to guarantee provision of the required results on a regular, timely basis including Earth orientation parameters, position and velocity vectors. The paper will summarize the activities of the service and will give a prospective for the next few years, based on the experiences of the first IVS General Meeting. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 FS Wettzell, Bundesamt Lartog & Geodasie, D-93444 Kotzting, Germany. NASA, Goddard Space Flight Ctr, NVI Inc, Greenbelt, MD 20771 USA. Univ Bonn, Geodat Inc, D-53115 Bonn, Germany. MIT, Haystack Observ, Westford, MA 01886 USA. RP Schluter, W (reprint author), FS Wettzell, Bundesamt Lartog & Geodasie, D-93444 Kotzting, Germany. NR 7 TC 34 Z9 34 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 2002 VL 30 IS 2 BP 145 EP 150 DI 10.1016/S0273-1177(02)00278-8 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV11T UT WOS:000177857000003 ER PT S AU Tavernier, G Soudarin, L Larson, K Noll, C Ries, J Willis, P AF Tavernier, G Soudarin, L Larson, K Noll, C Ries, J Willis, P BE Drewes, H Dow, JM TI Current status of the DORIS Pilot Experiment and the future international DORIS Service SO NEW TRENDS IN SPACE GEODESY SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT B2 1-PSD1 Symposium of COSPAR Scientific Commission B held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Agenzia Spatiale Italiana, CNES, European Space Agcy, Int Union Geodesy & Geophys, Int Assoc Geodesy AB The aim of the DORIS Pilot Experiment is to assess the need and feasibility of an International DORIS Service. A Call for Proposals was broadcasted in September 1999 to prompt qualified organizations to submit proposals for components of the future IDS. DORIS Days were held in Toulouse (May 2-3, 2000). This second version of these Doris days was in particular devoted to a review of the start-up of the Doris Pilot Experiment. This paper recalls the objectives of the future IDS, points out its components and structure, and gives information on the current and future activities. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Ctr Natl Etud Spatiales, CNES, F-31401 Toulouse 4, France. CLS, F-31526 Ramonville St Agne, France. Univ Colorado, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Texas, Space Res Ctr, Austin, TX 78759 USA. LAREG, IGN, F-77455 Marne La Vallee, France. RP Tavernier, G (reprint author), Ctr Natl Etud Spatiales, CNES, 18 Ave Edouard Belin, F-31401 Toulouse 4, France. RI Willis, Pascal/A-8046-2008; Noll, Carey/D-8884-2012 OI Willis, Pascal/0000-0002-3257-0679; NR 0 TC 26 Z9 26 U1 0 U2 1 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 2002 VL 30 IS 2 BP 151 EP 156 DI 10.1016/S0273-1177(02)00279-X PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV11T UT WOS:000177857000004 ER PT S AU Dehant V de Viron, O AF Dehant, V de Viron, O BE Drewes, H Dow, JM TI Earth rotation as an interdisciplinary topic shared by astronomers, geodesists and geophysicists SO NEW TRENDS IN SPACE GEODESY SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT B2 1-PSD1 Symposium of COSPAR Scientific Commission B held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Agenzia Spatiale Italiana, CNES, European Space Agcy, Int Union Geodesy & Geophys, Int Assoc Geodesy ID ATMOSPHERIC ANGULAR-MOMENTUM; RIGID-EARTH; POLAR MOTION; FORCED NUTATIONS; SURFACE MOTIONS; TORQUE APPROACH; CORE; MANTLE; OCEAN; LENGTH AB Earth rotation is characterized by its angular speed and by the position of the rotation axis both in space and in a frame tied to the Earth. The changes of the angular velocity induce changes in the length-of-day, and the variation of the position of the rotation axis is associated with polar motion (in the reference frame tied to the Earth) and with precession-nutation (in the space-fixed reference frame). These effects can be decomposed into components varying at different time scales. The study of their causes involves in different fields of physics, from astronomy for the rigid Earth nutation, through internal geophysics for the length-of-day variation at the decadal time scale, to external geophysics for seasonal polar motion. In this paper, we show how each discipline brings its own light into the observation, understanding and modeling of the Earth's rotation. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Observ Royal Belgique, B-1180 Brussels, Belgium. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Dehant V (reprint author), Observ Royal Belgique, 3 Ave Circulaire, B-1180 Brussels, Belgium. RI de Viron, Olivier/N-6647-2014 OI de Viron, Olivier/0000-0003-3112-9686 NR 48 TC 7 Z9 10 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-SERIES PY 2002 VL 30 IS 2 BP 163 EP 173 DI 10.1016/S0273-1177(02)00281-8 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV11T UT WOS:000177857000006 ER PT S AU Gontier, AM Ma, C Arias, EF Eubanks, TM Fey, AL Jacobs, CS Sovers, OJ Archinal, BA Charlot, P AF Gontier, AM Ma, C Arias, EF Eubanks, TM Fey, AL Jacobs, CS Sovers, OJ Archinal, BA Charlot, P BE Drewes, H Dow, JM TI Establishment of the ICRF SO NEW TRENDS IN SPACE GEODESY SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT B2 1-PSD1 Symposium of COSPAR Scientific Commission B held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Agenzia Spatiale Italiana, CNES, European Space Agcy, Int Union Geodesy & Geophys, Int Assoc Geodesy ID REFERENCE FRAME SOURCES; ASTROMETRIC SUITABILITY; VLBA OBSERVATIONS; SYSTEM AB The International Celestial Reference Frame, is the basis for measurements from space geodesy and astrometry. It is defined by the positions of compact extragalactic radio sources measured by Very Long Baseline Interferometry and became the fundamental celestial reference frame as of 1 Jan 1998 after a lengthy, carefully conceived process of the International Astronomical Union. The construction of the International Celestial Reference Frame is discussed as well as its first extension issued in 1999. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Observ Paris, F-75014 Paris, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Bur Int Poids & Mesures, F-92312 Sevres, France. USN Observ, Washington, DC 20392 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RSA Syst, Florence, OR 97439 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Observ Bordeaux, CNRS, UMR 5804, F-33270 Floirac, France. RP Gontier, AM (reprint author), Observ Paris, 61 Ave Observ, F-75014 Paris, France. OI Eubanks, Thomas Marshall/0000-0001-9543-0414 NR 21 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-SERIES PY 2002 VL 30 IS 2 BP 185 EP 193 DI 10.1016/S0273-1177(02)00283-1 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BV11T UT WOS:000177857000008 ER PT S AU Abdul-Aziz, A Baaklini, G Bhatt, R AF Abdul-Aziz, A Baaklini, G Bhatt, R BE Gyekenyesi, AL Shepard, SM Huston, DR Aktan, AE Shull, PJ TI Non destructive evaluation of ceramic matrix composites coupled with finite element analyses SO NONDESTRUCTIVE EVALUATION AND HEALTH MONITORING OF AEROSPACE MATERIALS AND CIVIL INFRASTRUCTURES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Nondestructive Evaluation and Health Monitoring of Aerospace Materials and Civil Infrastructures CY MAR 18-19, 2002 CL NEWPORT BEACH, CA SP SPIE DE finite element analysis; computed topography; ceramic matrix composites; stress analysis; non destructive evaluation AB Ceramic matrix composites (CMC) are engineered materials filled with manufacturing anomalies, such as voids, delamination, or fiber cracking. In this paper, a non-destructive evaluation (NDE) of a CMC tensile specimen is coupled with a finite element analysis to locate the failure location prior to the actual testing. The tensile CMC specimen is scanned with computed tomography (CT) along various planes. The majority of the observed anomalies are porosities in the matrix. The CT images are then used to reconstruct a 3-D volume of the specimen's gage section using velocity(2) (an image processing software). Subsequently, a three dimensional finite element analysis (FEA) is carried out to include the scanned porosities. The stress variations along the scanned CT planes are determined, comparison of the FEA results with those extracted via NDE, and the test data are reported. C1 Cleveland State Univ, NASA, Glenn Res Ctr, Dept Civil Engn, Cleveland, OH 44135 USA. RP Abdul-Aziz, A (reprint author), Cleveland State Univ, NASA, Glenn Res Ctr, Dept Civil Engn, 2100 Brookpk Rd MS 6-1, Cleveland, OH 44135 USA. NR 11 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 0-8194-4452-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4704 BP 32 EP 39 DI 10.1117/12.470733 PG 8 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BV06M UT WOS:000177733400005 ER PT S AU Martin, RE Gyekenyesi, A AF Martin, RE Gyekenyesi, A BE Gyekenyesi, AL Shepard, SM Huston, DR Aktan, AE Shull, PJ TI Pulsed thermography of ceramic matrix composites SO NONDESTRUCTIVE EVALUATION AND HEALTH MONITORING OF AEROSPACE MATERIALS AND CIVIL INFRASTRUCTURES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Nondestructive Evaluation and Health Monitoring of Aerospace Materials and Civil Infrastructures CY MAR 18-19, 2002 CL NEWPORT BEACH, CA SP SPIE AB Pulsed thermography is a powerful method for the nondestructive evaluation (NDE) of composite materials since it provides a large field means for detecting subsurface material defects and material variations. The main difficulty in the use of this technique, however, is the processing and interpretation of the acquired thermal image data. This paper examines three methods for processing pulsed thermography results concerning a composite plate with material inserts that simulate delamination type defects. Using the same temporal data set, a specimen is analyzed utilizing peak contrast, peak slope and a newly developed thermal image reconstruction technique. Comparisons are made on a composite panel with differing defect sizes and depths. In addition, results are compared to images gathered using through transmission ultrasonics and microfocus radiography. With subjective manipulation, pulsed thermography was able to show the defects more clearly than either the ultrasonic or radiographic techniques. A discussion of this subjectivity and future directions for automation are provided in an effort to better understand the potential of the method. C1 Cleveland State Univ, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Martin, RE (reprint author), Cleveland State Univ, NASA, Glenn Res Ctr, 21000 Brookpk Rd MS 6-1, Cleveland, OH 44135 USA. NR 6 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 0-8194-4452-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4704 BP 82 EP 92 DI 10.1117/12.470713 PG 11 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BV06M UT WOS:000177733400012 ER PT S AU Sawicki, JT Gyekenyesi, AL Baaklinil, GY AF Sawicki, JT Gyekenyesi, AL Baaklinil, GY BE Gyekenyesi, AL Shepard, SM Huston, DR Aktan, AE Shull, PJ TI Modal-based diagnostics of cracked rotors SO NONDESTRUCTIVE EVALUATION AND HEALTH MONITORING OF AEROSPACE MATERIALS AND CIVIL INFRASTRUCTURES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Nondestructive Evaluation and Health Monitoring of Aerospace Materials and Civil Infrastructures CY MAR 18-19, 2002 CL NEWPORT BEACH, CA SP SPIE DE modal approach; damage detection; turbine disks ID STRUCTURAL DAMAGE DETECTION AB Different approaches are used to sense and to localize a damage of rotating structures. Most of the methods take advantage of the dynamic behavior of the structural model [1-7]. This paper uses the modal and sensor norms, as defined in [8], to determine damage locations. The proposed approach allows localization of damaged elements within a structure, and provides information concerning the impact of the damage on the structure's natural modes of vibration. C1 Cleveland State Univ, Dept Engn Mech, Cleveland, OH 44115 USA. NASA, Glenn Res Ctr, OAI, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Sawicki, JT (reprint author), Cleveland State Univ, Dept Engn Mech, Cleveland, OH 44115 USA. NR 12 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 0-8194-4452-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4704 BP 133 EP 138 DI 10.1117/12.470718 PG 6 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BV06M UT WOS:000177733400017 ER PT S AU Gyekenyesi, AL Harmon, LM Kautz, HE AF Gyekenyesi, AL Harmon, LM Kautz, HE BE Gyekenyesi, AL Shepard, SM Huston, DR Aktan, AE Shull, PJ TI The effect of experimental conditions on acousto-ultrasonic reproducibility SO NONDESTRUCTIVE EVALUATION AND HEALTH MONITORING OF AEROSPACE MATERIALS AND CIVIL INFRASTRUCTURES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Nondestructive Evaluation and Health Monitoring of Aerospace Materials and Civil Infrastructures CY MAR 18-19, 2002 CL NEWPORT BEACH, CA SP SPIE AB Acousto-ultrasonics (AU) is a nondestructive evaluation (NDE) technique that utilizes two ultrasonic transducers to interrogate the condition of a test specimen. The sending transducer introduces an ultrasonic pulse at a point on the surface of the specimen while a receiving transducer detects the signal after it has passed through the material. The aim of the method is to correlate certain parameters of the detected waveform to characteristics of the material between the two transducers. The waveform parameter of interest is the attenuation due to internal damping for which information is being garnered from the frequency domain. The parameters utilized to indirectly quantify the attenuation are the ultrasonic decay rate as well as various moments of the frequency power spectrum. Here, the sensitivity for each of the parameters was assessed in respect to changing boundary conditions during the experiments. Three conditions were controlled during the ultrasonic characterization of the specimens. First, issues concerning the contact force of the transducer were studied. Second, the support structure of the specimen was addressed. Lastly, the damage state of the material itself was considered. After analyzing the various AU parameters, the overall sensitivity of the AU technique to material change or damage were quantified and compared to changes in the AU values resulting from the experimental boundary conditions. This investigation showed that certain AU parameters could be utilized to gauge damage in composites, although, the experimental boundary conditions may slightly influence the results. The results of this study are important due to the fact that at this point AU is an empirical method. C1 NASA, Glenn Res Ctr, OAI, Cleveland, OH 44135 USA. RP Gyekenyesi, AL (reprint author), NASA, Glenn Res Ctr, OAI, 21000 Brookpk Rd,MS 6-1, Cleveland, OH 44135 USA. NR 12 TC 7 Z9 7 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 0-8194-4452-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4704 BP 177 EP 186 DI 10.1117/12.470723 PG 10 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BV06M UT WOS:000177733400022 ER PT J AU Able, KW Fahay, MP Heck, KL Roman, CT Lazzari, MA Kaiser, SC AF Able, KW Fahay, MP Heck, KL Roman, CT Lazzari, MA Kaiser, SC TI Seasonal distribution and abundance of fishes and decapod crustaceans in a Cape Cod estuary SO NORTHEASTERN NATURALIST LA English DT Article ID NEW-ENGLAND ESTUARY; SALT-MARSH; NEW-JERSEY; ATLANTIC SILVERSIDE; EELGRASS MEADOWS; MENIDIA-MENIDIA; HABITAT USE; PATTERNS; BIOMASS; MASSACHUSETTS AB Sampling in several habitat types (sand/mud, eelgrass, sand, gravel, macroalgae/mud) during all seasons with a variety of gears in Nauset Marsh, Massachusetts during 1985-1987 found a fauna consisting of 35 fish and 10 decapod crustacean species. Although most of the abundant species were found in several habitat types, species richness and habitat use appeared to be highest for vegetated habitats (eelgrass, macroalgae). The fishes and decapods were numerically dominated by cold-water taxa; however, numerous fish species, represented by rare individuals of predominantly southern forms, enriched the fauna. Species composition of Nauset Marsh could be distinguished from estuaries south of Cape Cod and even from the south shore of the cape. Both fishes and decapods were most abundant during the summer, apparently due to the contributions from spring and summer spawning in the estuary and the adjacent Atlantic Ocean. The location of Nauset Marsh and other estuaries on Cape Cod provide a unique opportunity to evaluate the importance of this region as a faunal boundary to estuarine species. C1 Rutgers State Univ, Inst Marine & Coastal Sci, Marine Field Stn, Tuckerton, NJ 08087 USA. NOAA, Natl Marine Fisheries Serv, Highlands, NJ 07732 USA. Marine Environm Sci Consortium, Dauphin Isl, AL 36528 USA. Univ S Alabama, Dauphin Isl, AL 36528 USA. Univ Rhode Isl, USGS Patuxent Wildlife Res Ctr, Narragansett, RI 02882 USA. Dept Marine Resources, Boothbay Harbor, ME 04575 USA. RP Able, KW (reprint author), Rutgers State Univ, Inst Marine & Coastal Sci, Marine Field Stn, Tuckerton, NJ 08087 USA. EM able@imcs.rutgers.edu; mike.fahay@noaa.gov; kheck@jaguar1.usouthal.edu; charles_roman@usgs.gov; mark_lazzari@state.me.us NR 50 TC 13 Z9 13 U1 1 U2 5 PU HUMBOLDT FIELD RESEARCH INST PI STEUBEN PA PO BOX 9, STEUBEN, ME 04680-0009 USA SN 1092-6194 EI 1938-5307 J9 NORTHEAST NAT JI Northeast. Nat PY 2002 VL 9 IS 3 BP 285 EP 302 DI 10.2307/3858472 PG 18 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 601WZ UT WOS:000178472900003 ER PT S AU Howard, JM AF Howard, JM BE Sasian, JM Koshel, RJ TI Unobstructed afocal systems of spherical mirrors SO NOVEL OPTICAL SYSTEMS DESIGN AND OPTIMIZATION V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th Conference on Novel Optical Systems Design and Optimization CY JUL 09, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington Technol Ctr, Univ Washington, Coll Engn, Washington State Univ, Coll Engn & Architecture, Univ Washington, Ctr Nanotechnol DE geometrical optics; optical design; lens design; spherical mirrors ID ASYMMETRIC SYSTEMS; FOUNDATIONS; LAYOUT; POINT AB Design methods are presented to facilitate studies of unobstructed afocal systems composed of two and three spherical mirrors. Only unobstructed systems with a plane of symmetry are considered. Low order imaging constraints are determined to eliminate available degrees of freedom and reduce the dimensionality of the configuration space. Example systems are presented. C1 NASA, Goddard Space Flight Ctr, Opt Branch, Greenbelt, MD 20771 USA. RP Howard, JM (reprint author), NASA, Goddard Space Flight Ctr, Opt Branch, Code 551, Greenbelt, MD 20771 USA. NR 9 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 0-8194-4535-5 J9 P SOC PHOTO-OPT INS PY 2002 VL 4768 BP 41 EP 47 DI 10.1117/12.482194 PG 7 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BV29S UT WOS:000178480200005 ER PT J AU Goldhagen, P Reginatto, M Kniss, T Wilson, JW Singleterry, RC Jones, IW Van Steveninck, W AF Goldhagen, P Reginatto, M Kniss, T Wilson, JW Singleterry, RC Jones, IW Van Steveninck, W TI Measurement of the energy spectrum of cosmic-ray induced neutrons aboard an ER-2 high-altitude airplane SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT International Workshop on Neutron Field Spectrometry in Science, Technology and Radiation Protection (NEUSPEC 2000) CY JUN 04-08, 2000 CL PISA, ITALY DE neutron spectrometry; cosmic rays; Bonner spheres; neutron dosimetry; radiation protection ID MAXIMUM-ENTROPY DECONVOLUTION; BONNER-SPHERE SET; RADIATION ENVIRONMENT; SPECTROMETER; ACCELERATOR; ATMOSPHERE; ZUGSPITZE; EXPOSURE; FLUENCE; COUNTER AB Crews working on present-day jet aircraft are a large occupationally exposed group with a relatively high average effective dose from galactic cosmic radiation. Crews of future high-speed commercial aircraft flying at higher altitudes would be even more exposed. To help reduce the significant uncertainties in calculations of such exposures, the atmospheric ionizing radiation (AIR) project, an international collaboration of 15 laboratories, made simultaneous radiation measurements with 14 instruments on five flights of a NASA ER-2 high-altitude aircraft. The primary AIR instrument was a highly sensitive extended-energy multisphere neutron spectrometer with lead and steel shells placed within the moderators of two of its 14 detectors to enhance response at high energies. Detector responses were calculated for neutrons and charged hadrons at energies up to 100 GeV using MCNPX. Neutron spectra were unfolded from the measured count rates using the new MAXED code. We have measured the cosmic-ray neutron spectrum (thermal to > 10 Gev), total neutron fluence rate, and neutron effective dose and dose equivalent rates and their dependence on altitude and geomagnetic cutoff. The measured cosmic-ray neutron spectra have almost no thermal neutrons, a large "evaporation" peak near 1 MeV and a second broad peak near 100 MeV which contributes about 69,% of the neutron effective dose. At high altitude, geomagnetic latitude has very little effect on the shape of the spectrum, but it is the dominant variable affecting neutron fluence rate, which was eight times higher at the northernmost measurement location than it was at the southernmost. The shape of the spectrum varied only slightly with altitude from 21 km down to 12 km (56-201 g cm(-2) atmospheric depth), but was significantly different on the ground. In all cases, ambient dose equivalent was greater than effective dose for cosmic-ray neutrons. (C) 2002 Elsevier Science B.V. All rights reserved. C1 US DOE, Environm Measurements Lab, New York, NY 10014 USA. Keithley Instruments Inc, Cleveland, OH 44139 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Goldhagen, P (reprint author), US DOE, Environm Measurements Lab, 201 Varick St,5th Floor, New York, NY 10014 USA. EM goldhagn@eml.doe.gov NR 37 TC 103 Z9 108 U1 2 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 1 PY 2002 VL 476 IS 1-2 BP 42 EP 51 AR PII S0168-9002(01)01386-9 DI 10.1016/S0168-9002(01)01386-9 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 522FT UT WOS:000173885900008 PM 12033224 ER PT S AU Tripathi, RK Wilson, JW Cucinotta, FA AF Tripathi, RK Wilson, JW Cucinotta, FA BE Norman, E Schroeder, L Wozniak, G TI Importance of nuclear physics to NASA's space missions SO NUCLEAR PHYSICS IN THE 21ST CENTURY SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT International Nuclear Physics Conference CY JUL 30-AUG 03, 2001 CL UNIV CALIF BERKELEY, BERKELEY, CA SP Int Union Pure & Appl Phys, Lawrence Berkeley Natl Lab, Argonne Natl Lab, Brookhaven Natl Lab, US DOE, Thomas Jefferson Natl Lab, Natl Sci Fdn, Los Alamos Natl Lab, Lawrence Livermore Natl Lab, JM Nitschke Fund E Bay Community Fdn HO UNIV CALIF BERKELEY ID CROSS-SECTIONS AB We show that nuclear physics is extremely important for accurate risk assessments for space missions. Due to paucity of experimental input radiation interaction information it is imperative to develop reliable accurate models for the interaction of radiation with matter. State-of-the-art nuclear cross sections models have been developed at the NASA Langley Research center and are discussed. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Tripathi, RK (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 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 0-7354-0056-3 J9 AIP CONF PROC PY 2002 VL 610 BP 295 EP 299 PG 5 WC Physics, Nuclear SC Physics GA BV19Q UT WOS:000178112600027 ER PT S AU Jul, E Black, A Lea, D Filman, R Welch, I AF Jul, E Black, A Lea, D Filman, R Welch, I BE Frohner, A TI Panel: The Next 700 Distributed Object Systems SO OBJECT-ORIENTED TECHNOLOGY, PROCEEDINGS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT ECOOP 2001 Workshop CY JUN 18-22, 2001 CL BUDAPEST, HUNGARY SP Univ Eotvos Lorand, Informat Dept, Assic Int Technol Objects, ACM/SIGPLAN AB The primary goal of the ECOOP 2001 Panel on The Next 700 Distributed Object Systems was to present a number of the essential characteristics of the next generation of distributed object systems as identified by participants in the ECOOP 2001 Workshop on The Next 700 Distributed Object Systems. Among many other topics, participants explored issues surrounding Peer-to-Peer computing, Failure handling, Context. C1 Univ Copenhagen, DIKU, DK-1168 Copenhagen, Denmark. Oregon Grad Inst, Beaverton, OR 97006 USA. SUNY Coll Oswego, Oswego, NY 13126 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Newcastle Upon Tyne, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England. RP Jul, E (reprint author), Univ Copenhagen, DIKU, DK-1168 Copenhagen, Denmark. NR 0 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 3-540-43675-8 J9 LECT NOTES COMPUT SC PY 2002 VL 2323 BP 208 EP 212 PG 5 WC Computer Science, Theory & Methods SC Computer Science GA BW25Z UT WOS:000181349900018 ER PT S AU Maks, L Koratkar, A Kerbel, U Pell, V AF Maks, L Koratkar, A Kerbel, U Pell, V BE Quinn, PJ TI Automation of coordinated planning between observatories: The visual observation layout tool (VOLT) SO OBSERVATORY OPERATIONS TO OPTIMIZE SCIENTIFIC RETURN III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Observatory Operations to Optimize Scientific Return CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE coordinated observations; space-based observatory; coordinated planning tool; multi-observatory scheduling; planning and scheduling AB Fulfilling the promise of the era of great observatories, NASA now has more than three space-based astronomical telescopes operating in different wavebands. This situation provides astronomers with the unique opportunity of simultaneously observing a target in multiple wavebands with these observatories. Currently scheduling multiple observatories simultaneously, for coordinated observations, is highly inefficient. Coordinated observations require painstaking manual collaboration among the observatory staff at each observatory. Because they are time-consuming and expensive to schedule, observatories often limit the number of coordinated observations that can be conducted. In order to exploit new paradigms for observatory operation, the Advanced Architectures and Automation Branch of NASA's Goddard Space Flight Center has developed a tool called the Visual Observation Layout Tool (VOLT). The main objective of VOLT is to provide a visual tool to automate the planning of coordinated observations by multiple astronomical observatories. Four of NASA's space-based astronomical observatories - the Hubble Space Telescope (HST), Far Ultraviolet Spectroscopic Explorer (FUSE), Rossi X-ray Timing Explorer (RXTE) and Chandra - are. enthusiastically pursuing the use of VOLT. This paper will focus on the purpose for developing VOLT, as well as the lessons learned during the infusion of VOLT into the planning and scheduling operations of these observatories. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Maks, L (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 0-8194-4623-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4844 BP 273 EP 283 DI 10.1117/12.459512 PG 11 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BW25B UT WOS:000181335200031 ER PT S AU Gal-Edd, J Fatig, C Steck, J Zepp, R AF Gal-Edd, J Fatig, C Steck, J Zepp, R BE Quinn, PJ TI Ground systems - Maximize science downlink to reduce costs SO OBSERVATORY OPERATIONS TO OPTIMIZE SCIENTIFIC RETURN III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Observatory Operations to Optimize Scientific Return CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE ground systems; operations; tradeoffs; cost savings; bandwidth AB Selections and tradeoffs during mission concept development and ground system architecture definition determine the cost-effectiveness of the spacecraft operations. The Next Generation Space Telescope (NGST) makes this difficult due to its unique mission requirements. Experience has shown a greater savings can be achieved at the ground station and it's interfaces with the spacecraft. Since a majority of the bandwidth is used for science data, this is one of the major areas to explore. This paper will address problems and experiences with the various approaches to accommodate the ground station interfaces with the spacecraft. As a team we have explored several approaches: - Antenna size, frequency, and transmit power on the spacecraft is a big driver in determining the ground station cost, - Data guarantee verses data loss risk, - Down-linking all data verses putting more logic for science processing on board. This includes discussions on guaranteed data delivery protocols and downlink change only data, - Evaluation of recording the data at the ground station for a reduced rate playback later, and - Transmitters at different frequencies for simultaneous downlinks. Many of these topics and how they are applied, change over the course of time as projects implement their requirements. To achieve the goal of 'low cost', innovated approaches have to be taken into consideration. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gal-Edd, J (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 0-8194-4623-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4844 BP 351 EP 357 DI 10.1117/12.472712 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BW25B UT WOS:000181335200039 ER PT S AU Walyus, KD Reis, J Bradley, A AF Walyus, KD Reis, J Bradley, A BE Quinn, PJ TI A contrast in low-cost operational concepts for orbiting satellites SO OBSERVATORY OPERATIONS TO OPTIMIZE SCIENTIFIC RETURN III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Observatory Operations to Optimize Scientific Return CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union AB Older spacecraft missions, especially those in low Earth orbit with telemetry intensive requirements, required round-the-clock control center staffing. The state of technology relied on control center personnel to continually examine data, make decisions, resolve anomalies, and file reports. Hubble Space Telescope (HST) is a prime example of this description. Technological advancements in hardware and software over the last decade have yielded increases in productivity and operational efficiency, which result in lower cost. The re-engineering effort of HST, which has recently concluded, utilized emerging technology to reduce cost and increase productivity. New missions, of which NASA's Transition Region and Coronal Explorer Satellite (TRACE) is an example, have benefited from recent technological advancements and are more cost-effective than when HST was first launched. During its launch (1998) and early orbit phase, the TRACE Flight Operations Team (FOT) employed continually staffed operations. Yet once the mission entered its nominal phase, the FOT reduced their staffing to standard weekday business hours. Operations were still conducted at night and during the weekends, but these operations occurred autonomously without compromising their high standards for data collections. For the HST, which launched in 1990, reduced cost operations will employ a different operational concept, when the spacecraft enters its low-cost phase after its final servicing mission in 2004. Primarily due to the spacecraft's design, the HST Project has determined that single-shift operations will introduce unacceptable risks for the amount of dollars saved. More importantly, significant cost-savings can still be achieved by changing the operational concept for the FOT, while still maintaining round-the-clock staffing. It's important to note that the low-cost solutions obtained for one satellite may not be applicable for other satellites. This paper will contrast the differences between low-cost operational concepts for a satellite launched in 1998 versus a satellite launched in 1990. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Walyus, KD (reprint author), NASA, Goddard Space Flight Ctr, Code 440-8, 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 0-8194-4623-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4844 BP 438 EP 445 DI 10.1117/12.460728 PG 8 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BW25B UT WOS:000181335200048 ER PT S AU Lychenheim, DE Pepe, J Knapp, D AF Lychenheim, DE Pepe, J Knapp, D BE Quinn, PJ TI Hubble Space Telescope on-line operations coordination SO OBSERVATORY OPERATIONS TO OPTIMIZE SCIENTIFIC RETURN III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Observatory Operations to Optimize Scientific Return CY AUG 22-23, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union AB An important aspect of the Hubble Space Telescope (HST) operations is the ability to quickly disseminate and coordinate spacecraft commanding and ground system information for both routine spacecraft operations and Space Shuttle Servicing Missions. When deviating from preplanned activities all new spacecraft commanding, ground system and space system configurations must be reviewed, authorized and executed in an efficient manner. The information describing the changes must be disseminated to and coordinated by a large group of users. In the early years of the HST mission a paper-based Operational Request System was used. The system worked, but was cumbersome to efficiently coordinate with a large geographically dispersed group of users in a timely manner. As network and server technology matured, the HST Project developed an on-line interactive Operations Request System. This Operations Request System is a server-based system (access via HST Net) that provides immediate access to command and ground system information to both local and remotely based Instrument Engineers, Flight Operations Team Controllers, Subsystem Engineers and Project Management. This paper describes the various aspects of the system's submission, review, authorization and implementation processes. Also described is the methodology used to arrive at the current system design and the Graphical User Interface (GUI). This system has been used successfully for all routine and special HST operations for the last five years. This approach to operations coordination is adaptable to spacecraft of any complexity. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lychenheim, DE (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 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 0-8194-4623-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4844 BP 446 EP 453 DI 10.1117/12.459510 PG 8 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BW25B UT WOS:000181335200049 ER PT B AU Workman, IK Foster, DG AF Workman, IK Foster, DG GP IEEE IEEE IEEE TI The webbing reef: A tool used in the study of juvenile red snapper (Lutjanus campechanus) SO OCEANS 2002 MTS/IEEE CONFERENCE & EXHIBITION, VOLS 1-4, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT MTS/IEEE Oceans 2002 Conference CY OCT 29-31, 2002 CL BILOXI, MS SP Marine Technol Soc, IEEE, OES AB The primary purpose for requiring shrimp trawlers to use bycatch reduction gear in the U. S. Gulf of Mexico is to reduce the incidental capture and mortality of juvenile red snapper (Lutjanus campechanus). Developing effective bycatch reduction devices (BRDs) for this purpose requires a good understanding of juvenile snapper behavior and their reaction to different trawl components, which is being accomplished through diver observations on shrimp trawls and with trawl attached cameras. Early BIRD development was dependent on chance encounters with juvenile snapper, but that changed in the mid-1990s with the invention of the trawlable webbing reef. The webbing reef proved to be ideally suited for attracting and concentrating juvenile red snapper for BRD studies, and its design was perfected to the point that it is now a simple, easily deployed, self-anchoring system. From habitat studies, we learned that we could selectively attract either age-0 or age-1 snapper by adjusting reef height and applied this in the design of the latest webbing reef. In the process of studying BRD escapement and site fidelity, we determined that juvenile red snapper have homing capabilities. Young snapper were observed residing at a webbing reef for almost four months, and displaced snapper were able to return to their original habitat from a distance of almost 2 km. Our study on spatial and temporal recruitment patterns indicates greater recruitment and longer residence time on reefs off Mississippi than off Alabama or Florida. A major factor affecting recruitment off Mississippi in 2001 was the occurrence of hypoxia which caused the loss of all red snapper and most of the invertebrates on and around the reefs. While the webbing reef has been an invaluable tool for increasing our knowledge of juvenile red snapper, its use is not limited to snapper studies. The webbing reef attracts and provides habitat for other species of fish, invertebrates and plants and, because of its simplicity and portability, can be used for long or short term projects in almost any marine environment. C1 Natl Marine Fisheries Serv, Pascagoula, MS 39568 USA. RP Workman, IK (reprint author), Natl Marine Fisheries Serv, PO Drawer 1207, Pascagoula, MS 39568 USA. NR 15 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7534-3 PY 2002 BP 146 EP 150 PG 5 WC Acoustics; Engineering, Ocean; Engineering, Electrical & Electronic; Instruments & Instrumentation; Imaging Science & Photographic Technology SC Acoustics; Engineering; Instruments & Instrumentation; Imaging Science & Photographic Technology GA BW53J UT WOS:000182293200024 ER PT S AU Ansari, RR Misra, AK Leung, AB King, JF Datiles, MB AF Ansari, RR Misra, AK Leung, AB King, JF Datiles, MB BE Manns, F Soderberg, PG Ho, A TI Non-invasive evaluation of corneal abnormalities using static and dynamic light scattering SO OPHTHALMIC TECHNOLOGIES XII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 12th Conference on Ophthalmic Technologies CY JAN 19-20, 2002 CL SAN JOSE, CA SP SPIE AB A preliminary study of corneal abnormalities in intact bovine eyes is presented. Twenty-one eyes were treated with chemicals, cotton swabs, and radial and photo-refractive surgeries. Dynamic and static light scattering was performed as a function of the penetration depth into the corneal tissue. Topographical maps of corneal refractive power from untreated and treated corneas were also obtained using videokeratoscopy and results compared. The ultimate aim is to develop the technique of dynamic light scattering (DLS) for clinical applications in early evaluation of corneal complications after laser-assisted in situ keratomileusis (LASIK) surgeries and other corneal abnormalities. Keywords: LASIK, Dynamic Light Scattering, Photo Refractive Surgery, Photon Correlation Spectroscopy, Cornea. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Ansari, RR (reprint author), NASA, Glenn Res Ctr, Mail Stop 333-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. OI Datiles, Manuel III B./0000-0003-4660-1664 NR 12 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 0-8194-4350-6 J9 P SOC PHOTO-OPT INS PY 2002 VL 4611 BP 220 EP 229 DI 10.1117/12.470598 PG 10 WC Engineering, Biomedical; Ophthalmology; Optics; Physics, Applied SC Engineering; Ophthalmology; Optics; Physics GA BU92M UT WOS:000177417400030 ER PT S AU Bockle, SB Rovati, L Ansari, RR AF Bockle, SB Rovati, L Ansari, RR BE Priezzhev, AV Cote, GL TI Polarimetric glucose sensing using Brewster-reflection off of eye lens: Theoretical analysis SO OPTICAL DIAGNOSTICS AND SENSING OF BIOLOGICAL FLUIDS AND GLUCOSE AND CHOLESTEROL MONITORING II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Diagnostics and Sensing of Biological Fluids and Glucose and Cholesterol Monitoring II CY JAN 23-24, 2002 CL SAN JOSE, CA SP SPIE DE non-invasive glucose sensor; polarimetry; diabetes AB An important task of in vivo polarimetric glucose sensing is to find an appropriate way to optically access the aqueous humor of the human eye. In this paper two different approaches are analyzed theoretically and applied to the eye model of Le Grand. First approach is the tangential path of Cote et al., and the second is a new scheme of this paper of applying Brewster reflection off the eye lens. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Ansari, RR (reprint author), NASA, Glenn Res Ctr, Mail Stop 333-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. RI Rovati, Luigi/K-3445-2015 OI Rovati, Luigi/0000-0002-1743-3043 NR 7 TC 6 Z9 6 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 0-8194-4363-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4624 BP 160 EP 164 PG 5 WC Engineering, Biomedical; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BU73G UT WOS:000176856000020 ER PT S AU Chao, TH Zhou, HY Reyes, G AF Chao, TH Zhou, HY Reyes, G BE Mu, GG Yu, FTS Jutamulia, S TI High-speed optical object recognition processor with massive holographic memory SO OPTICAL INFORMATION PROCESSING TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Information Processing Technology CY OCT 16-18, 2002 CL SHANGHAI, PEOPLES R CHINA SP SPIE, Chinese Opt Soc DE 512 x 512 grayscale optical correlator; high-density; high-speed holographic memory; real-time object recognition; agriculture pest control AB Real-time object recognition using a compact grayscale optical correlator will be introduced. A holographic memory module for storing a large bank of optimum correlation filters to accommodate large data throughput rate needed for many real-world applications has also been developed. System architecture of the optical processor and the holographic memory will be presented. Application examples of this object recognition technology will also be demonstrated. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91355 USA. RP Chao, TH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91355 USA. NR 6 TC 4 Z9 4 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 0-8194-4718-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4929 BP 237 EP 243 DI 10.1117/12.483219 PG 7 WC Computer Science, Artificial Intelligence; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Computer Science; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BV65Q UT WOS:000179659400030 ER PT J AU Orlovskii, YV Basiev, TT Vorob'ev, IN Orlovskaya, EO Barnes, NP Mirov, SB AF Orlovskii, YV Basiev, TT Vorob'ev, IN Orlovskaya, EO Barnes, NP Mirov, SB TI Temperature dependencies of excited states lifetimes and relaxation rates of 3-5 phonon (4-6 mu m) transitions in the YAG, LuAG and YLF crystals doped with trivalent holmium, thulium, and erbium SO OPTICAL MATERIALS LA English DT Article DE laser crystals; rare-earth ions; lifetimes; multiphonon relaxation; Mid-IR transitions; temperature dependence ID RARE-EARTH IONS; NONRADIATIVE RELAXATION; MULTIPHONON RELAXATION; ELECTRONIC EXCITATION; FLUORIDE SCHEELITES; LATTICE-DYNAMICS; ENERGY; MODEL; LIYF4 AB The temperature dependencies of the nanosecond multiphonon relaxation (MR) rates of the F-3(3) state of Tm3+ in the YLF crystal and of the F-5(5) state of Ho3+ ion in the YAG and LuAG crystals and of the microsecond MR rates of the F-4(9/2) (H-2(9/2)) state of Er3+ ions in YLF were measured in the wide temperature range using direct laser excitation and selective fluorescence kinetics decay registration. For YLF the observed relations are explained by 4-phonon process in the frame of a single-frequency model with homega(eff) = 450 +/- 30 cm(-1) for the F-3(3) state of Tm3+ and by 5-phonon process with homega(eff) = 445 cm(-1) for the F-4(9/2) (H-2(9/2)) state of Er3+. For YAG and LuAG crystals these dependencies are explained by the 3-phonon process with homega(eff) = 630 cm(-1). The decrease of the relaxation rate with the temperature in the ran-e from 13 to 80 K was observed for the F-4(9/2) (H-2(9/2)) state of Er3+ in the YLF crystal. It is explained by the redistribution of excited electronic states population of erbium ions over the higher lying Stark levels with different MR probabilities. A good fit of experimental temperature dependence (including the dropping part of the experimental curve) was obtained for single-frequency model (homega(eff) = 450 cm(-1)) with W-01 = 8.0 x 10(4) s(-1) and W-02 = 4.7 x 10(4) s(-1) accounting Boltzmann distribution of population over two excited Stark levels of the excited state of erbium ions. Employment of this model improves the fit between the experiment and the theory for the 5175 state of Ho3+ ion in YAG as well. Strong influence of the parameters of the non-linear theory of MR, i.e. the reduced matrix elements U-(k) of electronic transitions and the phonon factor of crystal matrix;I on the spontaneous MR rates was observed experimentally. The smaller these parameters the slower the spontaneous MR W-0. This fact can be used for searching new active crystal laser media for the mid-IR generation. (C) 2002 Elsevier Science B.V. All rights reserved. C1 RAS, Inst Gen Phys, Laser Mat & Technol Res Ctr, Moscow 119991, Russia. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Alabama, Birmingham, AL 35294 USA. RP Orlovskii, YV (reprint author), RAS, Inst Gen Phys, Laser Mat & Technol Res Ctr, 38 Vavilov St,Bld D,GSP-1, Moscow 119991, Russia. RI Orlovskii, Yurii/A-9639-2009 OI Orlovskii, Yurii/0000-0001-7234-8530 NR 30 TC 9 Z9 9 U1 0 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-3467 J9 OPT MATER JI Opt. Mater. PD JAN PY 2002 VL 18 IS 4 BP 355 EP 365 DI 10.1016/S0925-3467(01)00174-4 PG 11 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA 510HM UT WOS:000173202700001 ER PT S AU Chao, TH Zhou, HY Reyes, G AF Chao, TH Zhou, HY Reyes, G BE Casasent, DP TI Compact 512 x 512 grayscale optical correlator SO OPTICAL PATTERN RECOGNITION XIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Pattern Recognition XIII CY APR 02, 2002 CL ORLANDO, FL SP SPIE DE 512 x 512 grayscale optical correlator; 7-mu m pixel pitch FLC SLM; compact architecture; automatic target recognition ID CORRELATION FILTERS AB Jet Propulsion Laboratory (JPL) has developed, for the first time, a matchbox-size 512 x 512 grayscale optical correlator (GOC) with the volume of 2" x 2" x 1". This compact 512 x 512 GOC consists of a pair of newly developed ferroelectric liquid crystal spatial light modulator (FLC SLM) with a 7-mum pixel pitch, the smallest feature size developed to date. New system architecture has been designed that has go-read simplified the system alignment and elaxed the tolerance of the Fourier transform lenses. An experimental result of automatic target recognition (ATR) applications using this GOC has been accomplished. The high-quality correlation output has validated the superior quality of the FLC SLM and new GOC architecture. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chao, TH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 11 Z9 11 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 0-8194-4484-7 J9 P SOC PHOTO-OPT INS PY 2002 VL 4734 BP 9 EP 12 DI 10.1117/12.458412 PG 4 WC Computer Science, Artificial Intelligence; Optics; Imaging Science & Photographic Technology SC Computer Science; Optics; Imaging Science & Photographic Technology GA BU57W UT WOS:000176405800002 ER PT S AU Juday, RD Monroe, SE Rollins, JM AF Juday, RD Monroe, SE Rollins, JM BE Casasent, DP TI In situ characterization of a correlator's filter SLM SO OPTICAL PATTERN RECOGNITION XIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Pattern Recognition XIII CY APR 02, 2002 CL ORLANDO, FL SP SPIE DE optical correlators; pattern recognition AB Patterns written to input and filter of an optical correlator permit inferring complex action of the filter SLM. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Juday, RD (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 4 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 0-8194-4484-7 J9 P SOC PHOTO-OPT INS PY 2002 VL 4734 BP 44 EP 57 DI 10.1117/12.458419 PG 14 WC Computer Science, Artificial Intelligence; Optics; Imaging Science & Photographic Technology SC Computer Science; Optics; Imaging Science & Photographic Technology GA BU57W UT WOS:000176405800006 ER PT S AU Chao, TH Zhou, HY Reyes, G AF Chao, TH Zhou, HY Reyes, G BE Casasent, DP TI Spacecraft navigation using a grayscale optical correlator SO OPTICAL PATTERN RECOGNITION XIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Pattern Recognition XIII CY APR 02, 2002 CL ORLANDO, FL SP SPIE DE spacecraft navigation; landmark tracking; precision landing; grayscale optical correlator; high-speed target recognition; optical parallel processing AB In this paper, recent technical progress in developing a compact high-speed Grayscale Optical Correlator (GOC) for real-time pattern recognition at the Jet Propulsion Laboratory (JPL) will be presented. This GOC, under partial sponsorship by the Telecommunication and Mission Operation Directorate (TMOD) program at JPL, is being investigated for spacecraft navigation applications. All up-to-date hardware development, soft simulation and experimental demonstration of real-time landmark tracking during a lander descent sequence will be reported. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chao, TH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 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 0-8194-4484-7 J9 P SOC PHOTO-OPT INS PY 2002 VL 4734 BP 108 EP 112 DI 10.1117/12.458405 PG 5 WC Computer Science, Artificial Intelligence; Optics; Imaging Science & Photographic Technology SC Computer Science; Optics; Imaging Science & Photographic Technology GA BU57W UT WOS:000176405800013 ER PT S AU Walker, SM AF Walker, SM BE Shen, GX Cha, SS Chiang, FP Mercer, CR TI Particle image velocimetry study of the flow field within an Erlenmeyer flask on an orbital shaker table SO OPTICAL TECHNOLOGY AND IMAGE PROCESSING FOR FLUIDS AND SOLIDS DIAGNOSTICS 2002 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Technology and Image Processing for Fluids and Solids Diagnostics 2002 CY SEP 03-06, 2002 CL BEIJING, PEOPLES R CHINA SP Beijing Univ Aeronaut & Astronaut, KC Wong Educ Fdn, SPIE, Chinese Soc Theoret & Appl Mech, Chinese Aerodynam Res Soc, Visualizat Soc Japan AB Cell growth experiments are used to determine the effects that various environmental factors have on the development and life cycles of cells. For current earth-based testing, the experiments are conducted in Erlenmeyer flasks on orbital shaker tables. This method has been used for several decades and serves as the baseline-testing configuration. In the future, cell growth experiments will be conducted on the International Space Station (ISS), which will permit long duration testing of the effects of gravity on the development and life cycle of cells. Particle Image Velocimetry (PIV) has been used to measure the three-dimensional velocity field within the flasks. The high-resolution PIV data have been used to calculate accelerations and shear stresses that the cells typically encounter during testing. The PIV data will be used to verify that the fluid environment during testing on the ISS is comparable to that encountered during earth-based testing. C1 NASA, Ames Res Ctr, Syst Anal Branch, Expt Phys Grp, Moffett Field, CA 94035 USA. RP Walker, SM (reprint author), NASA, Ames Res Ctr, Syst Anal Branch, Expt Phys Grp, MS 260-1, Moffett Field, CA 94035 USA. NR 7 TC 0 Z9 0 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 0-8194-4864-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 5058 BP 34 EP 50 PG 17 WC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BX54Q UT WOS:000185646300005 ER PT S AU Burner, AW Yu, EX Cha, SS AF Burner, AW Yu, EX Cha, SS BE Shen, GX Cha, SS Chiang, FP Mercer, CR TI Phase-stepping interferometric system for capturing instantaneous flow fields under harsh environments SO OPTICAL TECHNOLOGY AND IMAGE PROCESSING FOR FLUIDS AND SOLIDS DIAGNOSTICS 2002 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Technology and Image Processing for Fluids and Solids Diagnostics 2002 CY SEP 03-06, 2002 CL BEIJING, PEOPLES R CHINA SP Beijing Univ Aeronaut & Astronaut, KC Wong Educ Fdn, SPIE, Chinese Soc Theoret & Appl Mech, Chinese Aerodynam Res Soc, Visualizat Soc Japan DE flow reconstruction; interferometry; phase-stepping; three-dimensional AB Interferometric reconstruction of a flow field usually consists of three steps. The first is to record interferograms, the second is to extract phase information from interferograms and the final is for numerical inversion of the phase data. In interferometric flow recording, test section enclosures and opaque models are frequently present, blocking a portion of the probing rays or restricting the view angle of the field to produce a partial data set especially for interferometric tomography. It also involves very harsh environments with external vibrations and disturbances of the ambient air. The ill-posed problem is susceptible to experimental noise and can produce serious distortions in reconstruction. Interferometric reconstruction of flow fields thus needs accurate phase information extraction. The major problem encountered in interferometry is that it extremely sensitive to external disturbances including the vibration of the optical setup. This is true especially for aerodynamic wind tunnel testing. For successful application of interferometry to experimental fluid mechanics and heat/mass transfer, efficient mechanisms for accurate flow-field recording and information extraction are thus very necessary. In interferometric recording, use of the phase stepping techniques is desirable whenever possible, since they provide the most accuracy. However, they are not applicable under disturbing conditions: that is, under harsh environments. In an effort to provide accurate interferometric data, we devise interferogram. recording and reduction techniques. They are based on a phase-stepping method: however, applicable to harsh environments including wind tunnel testing. Here we present the governing concepts, investigation results, and application demonstration of our approaches for practical flow measurements. The developed approaches are tested through phase extraction and 3-D reconstruction of an experimental flow field, which is designed for future wind tunnel testing. The test conditions are very harsh, involving building vibrations and ambient air disturbances especially during the interferometric data acquisition in the phase stepping process. The results of the thermocouple readings agree fairly well with those from the experiment when compared. The acceptable error in the entire interferometric reconstruction process is believed to be mainly due to the ill-posed nature of the tomographic reconstruction but not from the phase extraction of the employed phase-stepping technique. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Cha, SS (reprint author), 842 W Taylor St MC-251 2039 ERF, Chicago, IL 60607 USA. NR 7 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 0-8194-4864-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 5058 BP 591 EP 602 PG 12 WC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BX54Q UT WOS:000185646300080 ER PT B AU Mishchenko, M Tishkovets, V Litvinov, P AF Mishchenko, M Tishkovets, V Litvinov, P BE Videen, G Kocifaj, M TI Exact results of the vector theory of coherent backscattering from discrete random media: An overview SO OPTICS OF COSMIC DUST SE NATO SCIENCE SERIES, SERIES II: MATHEMATICS, PHYSICS AND CHEMISTRY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Optics of Cosmic Dust CY NOV 16-19, 2001 CL BRATISLAVA, SLOVAKIA SP NATO ID OUTER PLANET SATELLITES; MULTIPLE-SCATTERING; WEAK LOCALIZATION; POLARIZED-LIGHT; ENHANCED BACKSCATTERING; SPHERICAL-PARTICLES; ANISOTROPY; SURFACES; CLUSTERS AB Coherent backscattering of light by discrete random media, otherwise known as weak photon localization, is a remarkable optical phenomenon caused by constructive interference of waves propagating along the same light-scattering paths but in opposite directions. A well-known manifestation of coherent backscattering is an intensity peak centered at exactly the backscattering direction. It also has been established that when the incident beam is unpolarized then the coherent backscattering intensity peak can be accompanied by a sharp asymmetric peak of negative polarization with a minimum centered at a very small phase angle. It has been suggested that coherent backscattering could be a contributor to some effects observed for solar system bodies in visible light and at radiowave frequencies [1-4]. However, accurate theoretical computations of weak photon localization based on first physical principles are difficult and have been used in analyses of planetary observations in only a handful of publications: This chapter briefly discusses manifestations of coherent backscattering and reviews the exact theory of this phenomenon and its applications to analyses of laboratory data and remote-sensing observations. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Mishchenko, M (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. RI Mishchenko, Michael/D-4426-2012 NR 56 TC 21 Z9 21 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-0819-8 J9 NATO SCI SER II MATH PY 2002 VL 79 BP 239 EP 260 PG 22 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BV67E UT WOS:000179729200015 ER PT S AU Ford, V Karlmann, P Hagerott, E Scherr, L AF Ford, V Karlmann, P Hagerott, E Scherr, L BE Hatheway, AE TI Optomechanical design of ten modular cameras for the Mars exploration Rovers SO OPTOMECHANICAL DESIGN AND ENGINEERING 2002 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optomechanical Design and Engineering CY JUL 07-09, 2002 CL SEATTLE, WA SP Opt Res Associates, SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ Coll Sci, Washington State Univ Coll Engn, Washington Technol Ctr, Univ Washington Coll Engn, Univ Washington Ctr Nanotechnol, Washington State Univ Coll Architecture AB The 2003 mission to Mars includes two Rovers, which will land on the Martian surface. Each Rover carries 9 cameras of 4 different designs. In addition, one similar camera is mounted to each lander assembly to monitor the descent and provide information for firing the control jets during landing. This paper will discuss the mechanical systems design of the cameras, including fabrication tolerances of the lenses, thermal issues, radiation shielding, planetary protection, detector mounting, electronics, the modularity achieved, and how the 10 different locations were accommodated on the very tight real estate of the Rovers and Landers. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Ford, V (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. NR 0 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 0-8194-4538-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4771 BP 214 EP 221 DI 10.1117/12.482162 PG 8 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Optics SC Engineering; Optics GA BV35F UT WOS:000178662000022 ER PT B AU Greene, T AF Greene, T BE Alves, JF McCaughrean, MJ TI High-resolution near-IR spectroscopy of protostars with large telescope's SO ORIGINS OF STARS AND PLANETS: THE VLT VIEW SE ESO ASTROPHYSICS SYMPOSIA LA English DT Proceedings Paper CT European-Southern-Observatory Workshop CY APR 24-27, 2001 CL GARCHING, GERMANY SP European SO Observ ID YOUNG STELLAR OBJECTS; INFRARED SPECTRA; ACCRETION DISKS; STAR-FORMATION; CLUSTER; AGES AB It is now possible to measure absorption spectra of flat-spectrum and Class 1 protostars using D greater than or equal to 8m telescopes equipped with sensitive cryogenic IR spectrographs. For the first time ever, our latest high-resolution (R similar to 20, 000) Keck NIRSPEC data reveal that Class I protostars are indeed low-mass stars with pre-main-sequence or dwarf-like features. However, Class I and flat-spectrum protostars differ from T Tauri stars in that protostars have much higher IR veilings (r(k) greater than or equal to 1 - 3+) and they are rotating quickly, v sin i > 20 km s(-1). Interestingly, absorption spectra of low-mass protostars show stellar - not disk - absorption features. Our observations should also be able to probe whether protostellar photospheres have different physical structures than T Tauri stars, as predicted by theoretical models which account for accretion effects. There is much work to be done in this field, and the VLT can contribute immensely. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Greene, T (reprint author), NASA, Ames Res Ctr, Ms 245-6, Moffett Field, CA 94035 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-43541-7 J9 ESO ASTROPHY SYMP PY 2002 BP 283 EP 288 DI 10.1007/10856518_36 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV31X UT WOS:000178581700036 ER PT J AU Wang, P Liu, KY Cwik, T Green, R AF Wang, P Liu, KY Cwik, T Green, R TI MODTRAN on supercomputers and parallel computers SO PARALLEL COMPUTING LA English DT Article DE domain decomposition; parallelization; MODTRAN; radiance; transmission AB To enable efficient reduction of large data sets such as is done in the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) project at the Jet Propulsion Laboratory (JPL), a high performance version of MODTRAN is essential. One means to accomplish this is to apply the computational resources of parallel computer systems. In our present work, a flexible, parallel version of MODTRAN has been implemented on the Cray T3E, the HP SPP2000, and a Beowulf-class cluster computer using domain decomposition techniques and the Message Passing Interface (MPI) library. In this paper, porting the sequential MODTRAN to various platforms is discussed; strategies of designing a parallel version of MODTRAN are developed; detailed implementation for a parallel MODTRAN is reported, and performance data of the parallel code on various computers are presented. Near linear scaling performance of parallel MODTRAN has been obtained, and comparisons of wallclock time are made among various supercomputers and parallel computers. The parallel version of MODTRAN gives excellent speedup, which dramatically reduces total data processing time for many applications such as the AVIRIS project at JPL. (C) 2002 Elsevier Science B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wang, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 168-522, Pasadena, CA 91109 USA. NR 3 TC 23 Z9 26 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8191 J9 PARALLEL COMPUT JI Parallel Comput. PD JAN PY 2002 VL 28 IS 1 BP 53 EP 64 DI 10.1016/S0167-8191(01)00128-4 PG 12 WC Computer Science, Theory & Methods SC Computer Science GA 508AY UT WOS:000173066100004 ER PT S AU Norton, CD Cwik, TA AF Norton, CD Cwik, TA BE Wyrzykowski, R Dongarra, J Paprzycki, M Wasniewski, J TI Parallel unstructured AMR and Gigabit networking for Beowulf-Class clusters SO PARALLEL PROCESSING APPLIED MATHEMATICS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 4th International Conference on Parallel Processing and Applied Mathematics CY SEP 09-12, 2001 CL NALECZOW, POLAND SP Compaq Comp Corp, Intel Corp, Myricom Inc, Sun Microsyst Inc, Tech Univ Czestochowa AB The impact of Gigabit networking with Myrinet 2000 hardware and MPICH-GM software on a 2-way SMP Beowulf-Class cluster for parallel unstructured adaptive mesh refinement using the PYRAMID library is described. Network performance measurements show that approximately 225 Mbytes/s (1.8 Gbits/s) with 9.3mu seconds latency can be achieved for large messages in ping-pong tests. The performance varies depending on how processors communicate; either within an SMP node or across nodes. When applied to parallel unstructured AMR of 3D tetrahedral meshes noticeable improvement is observed when compared to 100BaseT (100 Mbits/s) Ethernet. Furthermore, when compared to traditional systems, such as the SGI Origin 2000, one realizes that Beowulf-Clusters with fast networks and high performance SMP processors compare favorably with such systems-even for communication intensive applications. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Norton, CD (reprint author), CALTECH, Jet Prop Lab, MS 169-315,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-43792-4 J9 LECT NOTES COMPUT SC PY 2002 VL 2328 BP 552 EP 563 PG 12 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA BV79H UT WOS:000180067200061 ER PT B AU Meier, DL AF Meier, DL BE Laing, RA Blundell, KM TI Simulations of relativistic jet formation in radio sources SO PARTICLES AND FIELDS IN RADIO GALAXIES SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT Oxford Radio Galaxy Workshop CY AUG 03-05, 2000 CL UNIV OXFORD, DEPT ASTROPHY, OXFORD, ENGLAND HO UNIV OXFORD, DEPT ASTROPHY ID BLACK-HOLES; ACCRETION DISKS; ASTROPHYSICAL JETS; MAGNETOHYDRODYNAMIC SIMULATIONS; BRIGHTNESS TEMPERATURE; SURFACE PHOTOMETRY; SPACE VLBI; GALAXIES; MECHANISM; ENERGY AB Radio galaxies and quasars produce collimated, relativistic flows with. Lorentz factors of at least 15. It is generally believed that such flow Velocities indicate that jet acceleration and collimation occurs in the relativistic environment of a supermassive black hole. Recently, several groups around the world have begun to test theories of jet formation using magnetohydrodynamic (MHD) simulations of magnetized gas flow around black holes. This paper reviews the field of simulations of MHD jet formation, with an emphasis on producing the observed jet speeds and on the role that black hole angular momentum might play. Jet speeds are expected to be of order the escape velocity in the jet-formation region (bulk Lorentz factor similar to 2.4 if in the ergosphere of a rotating black hole), but could be potentially much higher if rapid acceleration can occur near the hole in less than a dynamical time. Transient simulations often produce tightly-collimated jets, but in a steady state jet collimation is generally quite slow and broad. Regardless of the source of the rotational energy powering the jet (accretion disc or black hole spin), the total jet power should be proportional to the black hole mass and the accretion rate. When the type of accretion disc is taken into account, it is shown that the most powerful jets should occur when the black hole is rotating rapidly and when the accretion disc is geometrically. thick and hot. The implications of this modified spin paradigm for explaining phenomenological properties of both supermassive and stellar mass black hole systems is discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Meier, DL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM dlm@sgra.jpl.nasa.gov NR 37 TC 0 Z9 0 U1 1 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-090-0 J9 ASTR SOC P PY 2002 VL 250 BP 10 EP 21 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA BV27K UT WOS:000178405600002 ER PT J AU Ahumada, AJ AF Ahumada, AJ TI Planning classification image experiments SO PERCEPTION LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 2002 VL 31 SU S BP 106 EP 106 PG 1 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA 594MZ UT WOS:000178055500327 ER PT J AU Brooks, KR Stone, LS AF Brooks, KR Stone, LS TI Stereomotion speed discrimination at multiple disparity pedestals SO PERCEPTION LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Human Informat Proc Res Branch, Moffett Field, CA 94035 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 2002 VL 31 IS 3 BP 375 EP 375 PG 1 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA 533RD UT WOS:000174543300010 ER PT S AU Ott, M Macmurphy, S Friedberg, P AF Ott, M Macmurphy, S Friedberg, P BE Donkor, E Hayduk, MJ Pirich, AR Taylor, EW TI Characterization of a twelve channel optical fiber, ribbon cable and MTP array connector assembly for space flight environments SO PHOTONIC AND QUANTUM TECHNOLOGIES FOR AEROSPACE APPLICATIONS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Photonic and Quantum Technologies for Aerospace Applications IV CY APR 01-02, 2002 CL ORLANDO, FL SP SPIE AB Presented here is the second set of testing conducted by the Technology Validation Laboratory for Photonics at NASA Goddard Space Flight Center on the twelve optical fiber ribbon cable with MTP array connector for space flight environments. In the first set of testing the commercial 62.5/125 cable assembly was characterized using space flight parameters (published in SPIE Vol. 3440).[1] The testing showed that the cable assembly would survive a typical space flight mission with the exception of a vacuum environment. Two enhancements were conducted to the existing technology to better suit the vacuum environment as well as the existing optoelectronics and increase the reliability of the assembly during vibration. The MTP assembly characterized here has a 100/140 optical commercial fiber and non outgassing connector and cable components. The characterization for this enhanced fiber optic cable assembly involved vibration, thermal and radiation testing. The data and results of this characterization study are presented which include optical in-situ testing. C1 NASA, Goddard Space Flight Ctr, Sigma Res & Engn, Greenbelt, MD 20771 USA. RP Ott, M (reprint author), NASA, Goddard Space Flight Ctr, Sigma Res & Engn, Code 562, Greenbelt, MD 20771 USA. NR 4 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 0-8194-4482-0 J9 P SOC PHOTO-OPT INS PY 2002 VL 4732 BP 79 EP 88 DI 10.1117/12.477419 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BV29Q UT WOS:000178478300011 ER PT S AU Edwards, D Hubbs, W Stanaland, T Hollerman, A Altstatt, R AF Edwards, D Hubbs, W Stanaland, T Hollerman, A Altstatt, R BE Taylor, EW TI Characterization of space environmental effects on candidate solar sail material SO PHOTONICS FOR SPACE ENVIRONMENTS VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 8th Conference on Photonics for Space Environments VIII CY JUL 09-10, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington State Univ, Coll Engn & Architecture, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol DE solar sail; space environmental effects; radiation; material; ultralight weight AB The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) is concentrating research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A sail operates on the principle that photons, originating from the sun, impart pressure and provide a source of spacecraft propulsion. The pressure can be increased, by a factor of two if the sun-facing surface is perfectly reflective. Solar sails are generally composed of a highly reflective metallic front layer, a thin polymeric substrate, and occasionally a highly emissive back surface. The Space Environmental Effects Team at MSFC is actively characterizing candidate solar sail materials to evaluate the thereto-optical and mechanical properties after exposure to a simulated Geosynchronous Transfer Orbit (GTO) radiation environment. This study is the first known characterization of solar sail materials exposed to space simulated environments. The technique of radiation dose verses material depth profiling was used to determine the orbital equivalent exposure doses. The solar sail exposure procedures and results of the material characterization will be discussed. C1 NASA, George C Marshall Space Flight Ctr, MSFC, AL 35812 USA. RP Edwards, D (reprint author), NASA, George C Marshall Space Flight Ctr, Mail Stop ED31, MSFC, AL 35812 USA. NR 6 TC 6 Z9 6 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 0-8194-4591-6 J9 P SOC PHOTO-OPT INS PY 2002 VL 4823 BP 67 EP 74 DI 10.1117/12.451455 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BV91N UT WOS:000180378800007 ER PT S AU Gunapala, S Bandara, S Bock, J Ressler, M Liu, J Mumolo, J Rafol, S Werner, M Cardimona, D AF Gunapala, S Bandara, S Bock, J Ressler, M Liu, J Mumolo, J Rafol, S Werner, M Cardimona, D BE Taylor, EW TI GaAs/AlGaAs based multi-quantum well infrared detector arrays for low-background applications SO PHOTONICS FOR SPACE ENVIRONMENTS VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 8th Conference on Photonics for Space Environments VIII CY JUL 09-10, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington State Univ, Coll Engn & Architecture, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol ID TEMPERATURE DARK CURRENT; PHOTODETECTORS; CAMERA; MODEL; GAIN AB A long-wavelength large format Quantum Well Infrared Photodetector (QWIP) focal plane array has been successfully used in a ground based astronomy experiment. QWIP arrays afford greater flexibility than the usual extrinsically doped semiconductor infrared (IR) arrays. Recently, we operated an infrared camera with a 256x256 QWIP array sensitive at 8.5 mum at the prime focus of the 5-m Hale telescope, obtaining the images. The remarkable noise stability - and low l/f noise - of QWIP focal plane arrays enable camera to operate by modulating the optical signal with a nod period up to 100 s. A 500 s observation on dark sky renders a flat image with little indication of the low spatial frequency structures associated with imperfect sky subtraction or detector drifts. At low operating temperatures for low-background irradiance levels, high resistivity of thick barriers in the active region of QWIPs impedes electrons from entering the detector from the opposite electrode. This could lead to a delay in refilling the space-charge buildup, and result in a lower responsitivity at high optical modulation frequencies. In order to overcome this problem we have designed a new detector structure, the blocked intersubband detector (BID) with separate active quantum well region and blocking barrier. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gunapala, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 0-8194-4591-6 J9 P SOC PHOTO-OPT INS PY 2002 VL 4823 BP 80 EP 87 DI 10.1117/12.453511 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BV91N UT WOS:000180378800009 ER PT S AU Barnes, C Ott, M Johnston, A LaBel, K Reed, R Marshall, C Miyahira, T AF Barnes, C Ott, M Johnston, A LaBel, K Reed, R Marshall, C Miyahira, T BE Taylor, EW TI Recent photonics activities under the NASA Electronic Parts and Packaging (NEPP) Program SO PHOTONICS FOR SPACE ENVIRONMENTS VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 8th Conference on Photonics for Space Environments VIII CY JUL 09-10, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington State Univ, Coll Engn & Architecture, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol ID LIGHT-EMITTING-DIODES; PROTON DAMAGE; ENERGY-DEPENDENCE; OPTOCOUPLERS AB With the rapidly increasing insertion of photonic devices, circuits and subsystems into NASA spacecraft, a variety of issues associated with reliability and radiation tolerance have arisen. In this paper, we discuss these issues from the perspective of the work currently ongoing in the NASA Electronic Parts and Packaging (NEPP) Program. This Program is focused on evaluating the reliability and radiation response of advanced and emerging microelectronics and photonics technologies of interest to NASA spacecraft system designers. Examples to be discussed include radiation studies of various optoelectronic devices and reliability of photonic components. These studies have been motivated in part by problems observed in space that include the failure of optocouplers on TOPEX/Poseidon, and the observation of single event-induced transients in the Hubble Space Telescope. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Barnes, C (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 303-202, Pasadena, CA 91109 USA. NR 23 TC 3 Z9 3 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 0-8194-4591-6 J9 P SOC PHOTO-OPT INS PY 2002 VL 4823 BP 189 EP 204 DI 10.1117/12.452226 PG 16 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BV91N UT WOS:000180378800022 ER PT S AU Johnson, SD Waczynski, A Polidan, E Marshall, P Reed, R AF Johnson, SD Waczynski, A Polidan, E Marshall, P Reed, R BE Taylor, EW TI An analysis of charge transfer efficiency noise on proton-damaged CCDs for the Hubble Space Telescope Wide Field Camera 3 SO PHOTONICS FOR SPACE ENVIRONMENTS VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 8th Conference on Photonics for Space Environments VIII CY JUL 09-10, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington State Univ, Coll Engn & Architecture, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol DE CCD; proton damaged CCD; CTE; CTE noise; scientific CCD; WFC3; HST AB Proton induced charge transfer efficiency (CTE) degradation has been studied in the large format charge-coupled device (CCD) flight-like candidates for Wide Field Camera 3 for the Hubble Space Telescope. These detectors were irradiated with different proton fluences. This paper focuses on the statistical nature of CTE degradation due to damage on one of the irradiated devices with exceptional initial CTE characteristics. In radiation damaged CCDs, CTE noise can be the dominant noise component. In contrast to other noise sources, CTE noise has a component of fixed pattern noise that can be removed by the appropriate calibration technique. A large set of data was acquired and analysis of it confirms the expectation that CTE damage is a local phenomenon and it varies widely across the CCD surface. Possible mitigation solutions and their practicality are discussed in some detail. C1 NASA, Goddard Space Flight Ctr, Global Sci & Technol, Greenbelt, MD 20771 USA. RP Johnson, SD (reprint author), NASA, Goddard Space Flight Ctr, Global Sci & Technol, Greenbelt, MD 20771 USA. NR 4 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 0-8194-4591-6 J9 P SOC PHOTO-OPT INS PY 2002 VL 4823 BP 245 EP 253 DI 10.1117/12.452223 PG 9 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BV91N UT WOS:000180378800027 ER PT S AU Chao, TH Zhou, HY Reyes, G Dragoi, D Hanan, J AF Chao, TH Zhou, HY Reyes, G Dragoi, D Hanan, J BE Yu, FTS Guo, R TI High-speed high density holographic memory using electro-optic beam steering devices SO PHOTOREFRACTIVE FIBER AND CRYSTAL DEVICES: MATERIALS, OPTICAL PROPERTIES, AND APPLICATIONS VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Photorefractive Fiber and Crystal Devices - Materials, Optical Properties and Applications VIII CY JUL 09-11, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington State Univ, Coll Engn & Architecture, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol DE High-density; high-speed; compact holographic memory; liquid crystal beam steering device AB An innovative compact holographic memory system will be presented. This system utilizes a new electro-optic (E-O) beam steering technology to achieve high-speed, high-density holographic data storage. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91355 USA. RP Chao, TH (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91355 USA. NR 4 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 0-8194-4571-1 J9 P SOC PHOTO-OPT INS PY 2002 VL 4803 BP 70 EP 73 DI 10.1117/12.452712 PG 4 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA BV78J UT WOS:000179999400009 ER PT J AU Johansson, S Derkatch, A Donnelly, MP Hartman, H Hibbert, A Karlsson, H Kock, M Li, ZS Leckrone, DS Litzen, U Lundberg, H Mannervik, S Norlin, LO Nilsson, H Pickering, J Raassen, T Rostohar, D Royen, P Schmitt, A Johanning, M Sikstrom, CM Smith, PL Svanberg, S Wahlgren, GM AF Johansson, S Derkatch, A Donnelly, MP Hartman, H Hibbert, A Karlsson, H Kock, M Li, ZS Leckrone, DS Litzen, U Lundberg, H Mannervik, S Norlin, LO Nilsson, H Pickering, J Raassen, T Rostohar, D Royen, P Schmitt, A Johanning, M Sikstrom, CM Smith, PL Svanberg, S Wahlgren, GM TI The FERRUM Project: New f-value data for FeII and astrophysical applications SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 7th International Colloquium on Atomic Spectra and Oscillator Strengths (ASOS 7) CY AUG 05-09, 2001 CL QUEENS UNIV, BELFAST, NORTH IRELAND HO QUEENS UNIV ID SINGLY IONIZED IRON; TRANSITION-PROBABILITIES; OSCILLATOR-STRENGTHS; RADIATIVE LIFETIMES; ATOMIC DATA; SPECTRA; STATES; SPECTROSCOPY; MULTIPLET; LINES AB We present the FERRUM Project, an international collaboration aiming at a production and evaluation of oscillator strengths (transition probabilities) of selected spectral lines of singly ionized iron group elements, that are of astrophysical relevance. The results obtained include measurements and calculations of permitted and forbidden lines of Fe II. The data have been applied to both emission and absorption lines in astrophysical spectra. We make comparisons between experimental. theoretical and astrophysical f-values. We Live a general review of the various measurements, and discuss the UV8 multiplet of Fe II around 1610 Angstrom in detail. C1 Lund Observ, SE-22100 Lund, Sweden. Stockholm Univ, Dept Phys, S-10691 Stockholm, Sweden. Queens Univ Belfast, Dept Appl Math & Theoret Phys, Belfast, Antrim, North Ireland. Univ Hannover, Inst Atom & Mol Phys, Hannover, Germany. Lund Inst Technol, Dept Phys, S-22100 Lund, Sweden. NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. Royal Inst Technol, Dept Phys, Stockholm, Sweden. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Dept Phys, London, England. Univ Amsterdam, Astron Inst Anton Pannekoek, Amsterdam, Netherlands. Univ Kaiserslautern, Fachbereich Phys, D-6750 Kaiserslautern, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Johansson, S (reprint author), Lund Observ, Box 43, SE-22100 Lund, Sweden. RI Hartman, Henrik/K-3113-2013; Rostohar, Danijela/G-9994-2014; OI Li, Zhongshan/0000-0002-0447-2748 NR 29 TC 32 Z9 32 U1 0 U2 3 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 2002 VL T100 BP 71 EP 80 DI 10.1238/Physica.Topical.100a00071 PG 10 WC Physics, Multidisciplinary SC Physics GA 579EB UT WOS:000177162500009 ER PT J AU Abbas, MM Craven, PD Spann, JF West, E Pratico, J Tankosic, D Venturini, CC AF Abbas, MM Craven, PD Spann, JF West, E Pratico, J Tankosic, D Venturini, CC TI Photoemission experiments for charge characteristics of individual dust grains SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT International Topical Conference on Plasma Pysics CY SEP 03-07, 2001 CL UNIV ALGARVE, FARO, PORTUGAL HO UNIV ALGARVE ID SOLAR-SYSTEM; GAS; DYNAMICS; PLASMA; MASS AB Photoemission experiments with UV radiation have been performed to investigate the microphysics and charge characteristics of individual isolated dust grains of various compositions and sizes by using the electrodynamic balance facility at NASA Marshall Space Flight Center. Dust particles of 2-10 mum diameter are levitated in a vacuum chamber at pressures similar to10(-5) torr and exposed to a collimated beam of UV radiation in the 120-200 nm spectral range from a deuterium lamp source with a MgF2 window. A monochromator is used to select the UV wavelength with a spectral resolution of 8 urn, The electrodynamic facility permits measurements of the charge and diameters of particles of known composition, and monitoring of photoemission rates with the incident UV radiation. Experiments have been conducted on test particles of silica and polystyrene to determine the photoelectric yields and surface equilibrium potentials when exposed to UV radiation. A brief description of an experimental procedure for photoemission studies is given and some preliminary laboratory measurements of the photoelectric yields of individual dust particles are presented. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Alabama, Huntsville, AL 35899 USA. RP Abbas, MM (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 30 TC 14 Z9 14 U1 0 U2 3 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 2002 VL T98 BP 99 EP 103 PG 5 WC Physics, Multidisciplinary SC Physics GA 549AZ UT WOS:000175423500021 ER PT J AU Rietmeijer, FJM Nuth, JA Karner, JM Hallenbeck, SL AF Rietmeijer, FJM Nuth, JA Karner, JM Hallenbeck, SL TI Gas-to-solid condensation in a Mg-SiO-H(2)-O(2) vapor: metastable eutectics in the MgO-SiO(2) phase diagram SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID SYSTEM; DUST AB Kinetically controlled gas-to-solid condensation in Mg-SiO-H(2)-O(2) vapors resulted in the formation of amorphous, chemically ordered, solid compositions at 26 +/- 7, 46.5 +/- 2 and 87 +/- 3.5 wt.% MgO. The first two solid compositions match those of metastable eutectics in existing MgO-SiO(2) phase diagrams. An explanation for the highest-MgO metastable solid compositions requires a revision of this phase diagram to include a eutectic at similar to95 wt.% MgO. C1 Univ New Mexico, Inst Meteorit, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. Dupont Co Inc, Cent Res & Dev, Expt Stn, Wilmington, DE 19880 USA. RP Rietmeijer, FJM (reprint author), Univ New Mexico, Inst Meteorit, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. EM fransjmr@unm.edu; uljan@lepvax.gsfc.nasa.gov; Susan.Hallenbeck@usa.dupont.com RI Nuth, Joseph/E-7085-2012 NR 22 TC 33 Z9 33 U1 0 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PY 2002 VL 4 IS 3 BP 546 EP 551 DI 10.1039/b103421a PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 514MY UT WOS:000173445200022 ER PT J AU Adolphi, NL Badola, S Browder, LA Bowman, RC AF Adolphi, NL Badola, S Browder, LA Bowman, RC TI Magic-angle spinning NMR study of deuterium site occupancy and dynamics in ZrNiD1.0 and ZrNiD3.0 SO PHYSICAL REVIEW B LA English DT Article ID INTERMETALLIC COMPOUNDS; SORPTION CRYOCOOLERS; H SYSTEM; HYDROGEN; OCCUPATION; KINETICS; SPECTRA; ZRNIHX AB Both static and magic-angle spinning (MAS) H-2 nuclear magnetic resonance spectroscopy indicate that two inequivalent sites are occupied in ZrNMD3.0, in a 2:1 ratio, in agreement with previous work. The sites occupied in the trihydride phase have been previously identified as Zr3Ni and Zr3Ni2. In ZrNiD1.0, two well-resolved lines of equal intensity are observed in the MAS spectrum at temperatures<220 K, indicating that two other inequivalent sites are occupied in a 1:1 ratio, in contrast with previous reports that only one type of site (Zr4Ni2) is occupied in the monohydride (β) phase at room temperature and above. The temperature dependences of both MAS and static ZrNiD1.0 spectra indicate that no phase transitions occur over the entire temperature range studied, 160-500 K. The deuterium hopping rate in ZrNiD1.0 is determined from characteristic changes in the MAS spectra as a function of temperature, the motion is consistent with an activation energy E-a &CONG; 0.44 eV assuming a rate prefactor 1/τ(0) &SIM; 10(13)s(-1). In ZrNiD3.0, the rate of deuterium motion is determined from signatures of motion in the static and MAS spectra. The motion in ZrNiD3.0 is consistent with an activation energy E-a &CONG; 0.62 eV assuming a rate prefactor of &SIM;10(13) s(-1). C1 Knox Coll, Dept Phys, Galesburg, IL 61401 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Adolphi, NL (reprint author), Knox Coll, Dept Phys, Box 74, Galesburg, IL 61401 USA. NR 48 TC 2 Z9 2 U1 0 U2 0 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 JAN 1 PY 2002 VL 65 IS 2 AR 024301 DI 10.1103/PhysRevB.65.024301 PG 9 WC Physics, Condensed Matter SC Physics GA 510NA UT WOS:000173213100043 ER PT J AU Kriplani, U Lin, JYY Regehr, MW Fultz, B AF Kriplani, U Lin, JYY Regehr, MW Fultz, B TI Intensities of Mossbauer diffractions from polycrystalline bcc Fe-57 SO PHYSICAL REVIEW B LA English DT Article ID SYNCHROTRON RADIATION; ELECTRONIC SCATTERING; SUPPRESSION AB Diffraction patterns were measured on a polycrystalline bcc Fe-57 foil using a Mossbauer powder diffractometer with high sensitivity. Measurements with and without a magnetic field normal to the scattering plane showed large differences in the diffracted intensities of the different nuclear resonances. These magnetic effects on diffraction intensities were interpreted successfully with a single scattering theory developed to handle isotropic and anisotropic orientation distributions of hyperfine magnetic fields. When there is coherent interference between nuclear scattering and x-ray Rayleigh scattering, an asymmetry in the coherent intensity of the three pairs of diffractions for the Fe-57 magnetic sextet (1,6), (2,5), (3,4) is predicted. This is largest in the presence of a uniaxial magnetic field, and the calculated and measured asymmetries were in good agreement. A reduced diffraction intensity for lines (2,5) and (3,4) caused by spin-flip incoherence was also measured. The effects of dynamical diffraction, if present, are shown to be small. C1 CALTECH, WM Keck Lab, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Kriplani, U (reprint author), CALTECH, WM Keck Lab, Mail 138-78, Pasadena, CA 91125 USA. RI Lin, Jiao/A-2529-2016 OI Lin, Jiao/0000-0001-9233-0100 NR 30 TC 3 Z9 3 U1 0 U2 4 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 JAN 1 PY 2002 VL 65 IS 2 AR 024405 DI 10.1103/PhysRevB.65.024405 PG 9 WC Physics, Condensed Matter SC Physics GA 510NA UT WOS:000173213100050 ER PT J AU Seneor, P Chen, CT Yeh, NC Vasquez, RP Bell, LD Jung, CU Park, MS Kim, HJ Kang, WN Lee, SI AF Seneor, P Chen, CT Yeh, NC Vasquez, RP Bell, LD Jung, CU Park, MS Kim, HJ Kang, WN Lee, SI TI Spectroscopic evidence for anisotropic s-wave pairing symmetry in MgB2 SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTORS AB Scanning tunneling spectroscopy of superconducting MgB2 (T-c = 39 K) were studied on high-density pellets and c-axis oriented films. The sample surfaces were chemically etched to remove surface carbonated, and hydroxides, and the data were compared with calculated spectra for all symmetry-allowed pairing channels. The pairing potential (Delta(k)) is best described by an anisotropic s-wave pairing model, with Delta(k) = Delta(xy) sin(2)theta(k) +Delta(z) cos(2)theta(k), where theta(k) is the angle relative to the crystalline c-axis, Delta(z) similar to 8.0 meV, and Delta(xy) similar to 5.0 meV. C1 CALTECH, Dept Phys, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. Pohang Univ Sci & Technol, Natl Creat Res Initiat Ctr Superconduct, Pohang 790784, South Korea. Pohang Univ Sci & Technol, Dept Phys, Pohang 790784, South Korea. RP CALTECH, Dept Phys, Pasadena, CA 91125 USA. NR 32 TC 50 Z9 50 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JAN 1 PY 2002 VL 65 IS 1 AR 012505 DI 10.1103/PhysRevB.65.012505 PG 4 WC Physics, Condensed Matter SC Physics GA 510AF UT WOS:000173186000039 ER PT J AU Sitnov, MI Sharma, AS Papadopoulos, K Vassiliadis, D AF Sitnov, MI Sharma, AS Papadopoulos, K Vassiliadis, D TI Modeling substorm dynamics of the magnetosphere: From self-organization and self-organized criticality to nonequilibrium phase transitions SO PHYSICAL REVIEW E LA English DT Article ID TIME-SERIES; PLASMA SHEET; GEOMAGNETIC-ACTIVITY; MAGNETIC FLUCTUATIONS; GEOTAIL OBSERVATIONS; SPURIOUS DIMENSION; CURRENT DISRUPTION; ION DISTRIBUTIONS; BICOLORED NOISE; AE DATA AB Earth's magnetosphere during substorms exhibits a number of characteristic features such as the signatures of low effective dimension, hysteresis, and power-law spectra of fluctuations on different scales. The largest substorm phenomena are in reasonable agreement with low-dimensional magnetospheric models and in particular those of inverse bifurcation. However, deviations from the low-dimensional picture are also quite considerable, making the nonequilibrium phase transition more appropriate as a dynamical analog of the substorm activity. On the other hand, the multiscale magnetospheric dynamics cannot be limited to the features of self-organized criticality (SOC), which is based on a class of mathematical analogs of sandpiles. Like real sandpiles, during substorms the magnetosphere demonstrates features. that are distinct from SOC and are closer to those of conventional phase transitions, While the multiscale substorm activity resembles second-order phase transitions, the largest substorm avalanches are shown to reveal the features of first-order nonequilibrium transitions including hysteresis phenomena and a global structure of the type of a temperature-pressure-density diagram. Moreover, this diagram allows one to find a critical exponent, that reflects the multiscale aspect of the substorm activity, different from the power-law frequency and scale spectra of autonomous systems, although quite consistent with second-order phase transitions. In contrast to SOC exponents. this exponent relates input and output parameters of the magnetosphere. Using an analogy to the dynamical Ising model in the mean-field approximation, we show the connection between the data-derived exponent of nonequilibrium transitions in the magnetosphere and the standard critical exponent beta of equilibrium second-order phase transitions. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. RP Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RI Sitnov, Mikhail/H-2316-2016 NR 90 TC 51 Z9 51 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD JAN PY 2002 VL 65 IS 1 AR 016116 DI 10.1103/PhysRevE.65.016116 PN 2 PG 11 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 513YB UT WOS:000173407500027 PM 11800745 ER PT J AU Wolpert, DH AF Wolpert, DH TI Computational capabilities of physical systems SO PHYSICAL REVIEW E LA English DT Article ID UNDECIDABILITY; THERMODYNAMICS AB In this paper strong limits on the accuracy of real-world physical computation are established. To derive these results a non-Turing machine formulation of physical computation is used. First it is proven that there cannot be a physical computer C to which one can pose any and all computational tasks concerning the physical universe. Next it is proven that no physical computer C can correctly carry out every computational task in the subset of such tasks that could potentially be posed to C. This means in particular that there cannot be a physical computer that can be assured of correctly "processing information faster than the universe does." Because this result holds independent of how or if the computer is physically coupled to the rest of the universe, it also means that there cannot exist an infallible, general-purpose observation apparatus, nor an infallible, general-purpose control apparatus, These results do not rely on systems that are infinite, and/or nonclassical, and/or obey chaotic dynamics. They also hold even if one could use an infinitely fast, infinitely dense computer, with computational powers greater than that of a Turing machine (TM). After deriving these results analogs of the TM Halting theorem are derived for the novel kind of computer considered in this paper, as are results concerning the (im)possibility of certain kinds of error-correcting codes. In addition, an analog of algorithmic information complexity, "prediction complexity," is elaborated. A task-independent bound is derived on how much the prediction complexity of a computational task can differ for two different reference universal physical computers used to solve that task. This is analogous to the "encoding" bound governing how much the algorithm information complexity of a TM calculation can differ for two reference universal TMs. It is proven that either the Hamiltonian of our universe proscribes a certain type of computation, or prediction complexity is unique (unlike algorithmic information complexity). Finally, the implications of this analysis for the issue of whether the universe "is" a computer are briefly discussed. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Wolpert, DH (reprint author), NASA, Ames Res Ctr, N269-1, Moffett Field, CA 94035 USA. EM dhw@ptolemy.arc.nasa.gov NR 39 TC 0 Z9 0 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD JAN PY 2002 VL 65 IS 1 AR 016128 DI 10.1103/PhysRevE.65.016128 PN 2 PG 27 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 513YB UT WOS:000173407500039 ER PT J AU Behrend, D Haas, R Pino, D Gradinarsky, LP Keihm, SJ Schwarz, W Cucurull, L Rius, A AF Behrend, D Haas, R Pino, D Gradinarsky, LP Keihm, SJ Schwarz, W Cucurull, L Rius, A TI MM5 derived ZWDs compared to observational results from VLBI, GPS and WVR SO PHYSICS AND CHEMISTRY OF THE EARTH LA English DT Article ID MICROWAVE RADIOMETER; MESOSCALE MODEL; DELAY AB Modelled values of zenith wet delay (ZWD) from the non-hydrostatic numerical weather prediction (NWP) model MM5 are compared to estimated values retrieved from observations by geodetic very long baseline interferometry (VLBI), global positioning system (GPS) receivers, and water vapour radiometers (WVRs). In addition, sparse radiosonde (RS) data are used to augment the available data sets. The comparison is done for three stations of the European geodetic VLBI network for six observing sessions during the year 1999. The stations (Madrid, Onsala, and Wettzell) were primarily chosen to have the maximum number of collocated measuring techniques. In general, the time series for the different techniques show a good agreement. The correlation values between the techniques amount to 75-95%. The RMS differences of MM5 with respect to the other techniques obtain values of +/-1.3-1.6 cm. The bias between MM5 and VLBI lies at about 1.0 cm, the bias between MM5 and GPS varies in the range of 0.0-0.6 cm and appears to be station dependent. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 CSIC, Res Unit, IEEC, ES-08034 Barcelona, Spain. Chalmers Univ Technol, Onsala Space Observ, S-41296 Gothenburg, Sweden. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Fundamentalstn Wettzell, Bundesanstalt Kartog & Geodasie, Kotzting, Germany. RP Behrend, D (reprint author), Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd Ms 21, Menlo Pk, CA 94025 USA. RI Haas, Rudiger/G-1286-2010; Pino, David/F-7940-2014; Antonio, Rius/A-4873-2012; Cucurull, Lidia/E-8900-2015 OI Haas, Rudiger/0000-0003-2681-9228; Pino, David/0000-0002-4512-0175; Antonio, Rius/0000-0002-5947-2649; NR 17 TC 7 Z9 7 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1474-7065 J9 PHYS CHEM EARTH JI Phys. Chem. Earth PY 2002 VL 27 IS 4-5 BP 301 EP 308 AR PII S1474-7065(02)00004-9 DI 10.1016/S1474-7065(02)00004-9 PG 8 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA 571GR UT WOS:000176710100003 ER PT J AU Andersen, OB Knudsen, P Beckley, B AF Andersen, OB Knudsen, P Beckley, B TI Monitoring sea level and sea surface temperature trends from ERS satellites SO PHYSICS AND CHEMISTRY OF THE EARTH LA English DT Article; Proceedings Paper CT 26th General Assembly of the European-Geophysical-Society CY MAR 26-30, 2001 CL NICE, FRANCE SP European Geophys Soc DE ERS; altimetry; AVHRR; sea level changes; sea surface temperature changes AB Data from the two ESA satellites ERS-1 and ERS-2 are used in global and regional analysis of sea level and sea surface temperature trends over the last, 7.8 years. T he ERS satellites and in the future the ENVISAT satellite provide unique opportunity for monitoring both changes in sea level and sea surface temperature as these satellites are equipped with an altimeter to measure sea level height as well as an along track scanning radiometer (ATSR) to measure the sea surface temperature. Consistent increase in both sea level and sea surface temperatures are found in most parts of the Atlantic Ocean over this period. In the Indian Ocean and particularly the Pacific Ocean the trends in both sea level and temperature are still dominated by the large changes associated with the El Nino Southern Oscillation. In terms of contribution to the total global sea level change, the contribution of the central Pacific Ocean is as large as the contribution of the whole North Atlantic. The regional changes detected by ERS sea level and sea surface temperature observations are highly correlated with independent finding from TOPEX/POSEIDON (T/P) sea level observations and the Reynolds advanced very high resolution radiometer (AV-HRR) sea surface temperature observations. Global averaged spatial correlations between the 50degrees parallels are 0.87 between the ATSR and AVHRR based sea surface temperature trends-values, and 0.85 between the UP and ERS altimetric sea level trends. The spatial correlation between the ERS derived sea level change and sea surface temperature is 0.42 for both the ATSR and AVHRR derived data. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Kort Og Matrikelstyrelsen, Geodet Div, DK-2400 Copenhagen NV, Denmark. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Andersen, OB (reprint author), Kort Og Matrikelstyrelsen, Geodet Div, Rentemestervej 8, DK-2400 Copenhagen NV, Denmark. RI Andersen, Ole /H-7481-2016 OI Andersen, Ole /0000-0002-6685-3415 NR 9 TC 11 Z9 12 U1 0 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1474-7065 J9 PHYS CHEM EARTH JI Phys. Chem. Earth PY 2002 VL 27 IS 32-34 BP 1413 EP 1417 AR PII S1474-7065(02)00081-5 DI 10.1016/S1474-7065(02)00081-5 PG 5 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA 631JR UT WOS:000180164900006 ER PT S AU Li, JZ Cheung, SH Ning, CZ AF Li, JZ Cheung, SH Ning, CZ BE Blood, P Osinski, M Arakawa, Y TI Static and dynamic effects of lateral carrier diffusion in semiconductor lasers SO PHYSICS AND SIMULATION OF OPTOELECTRONIC DEVICES X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Physics and Simulation of Optoelectronic Devices X CY JAN 21-25, 2002 CL SAN JOSE, CA SP SPIE DE semiconductor laser; carrier diffusion; nonlinearity; current modulation ID SURFACE-EMITTING LASERS; MODE; SIMULATION; DENSITY AB Electron and hole diffusions in the plane of semiconductor quantum wells play an important. part in the static and dynamic operations of semiconductor lasers. It is well known that the value of diffusion coefficients affects the threshold pumping current of a semiconductor laser. At the same time, the strength of carrier diffusion process is expected to affect the modulation bandwidth of an AC-modulated laser. It is important not only to investigate the combined DC and AC effects due to carrier diffusion, but also to separate the AC effects from that of the combined effects in order to provide design insights for high speed modulation. In this presentation, we apply a hydrodynamic model developed by the present authors recently from the semiconductor Bloch equations. The model allows microscopic calculation of the lateral carrier diffusion coefficient, which is a nonlinear function of the carrier density and plasma temperature. We first studied combined AC and DC effects of lateral carrier diffusion by studying the bandwidth dependence on diffusion coefficient at a given DC current under small signal modulation. The results show an increase of modulation bandwidth with decrease in the diffusion coefficient. We simultaneously studied the effects of nonlinearity in the diffusion coefficient. To clearly identify how much of the bandwidth increase is a result of decrease in the threshold pumping current for smaller diffusion coefficient, thus an effective increase of DC pumping, we study the bandwidth dependence on diffusion coefficient at a given relative pumping. A detailed comparison of the two cases will be presented. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Li, JZ (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, MC T27A-1, Moffett Field, CA 94035 USA. NR 16 TC 0 Z9 0 U1 1 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 0-8194-4385-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4646 BP 293 EP 301 DI 10.1117/12.470528 PG 9 WC Engineering, Electrical & Electronic; Optics; Physics, Applied; Physics, Multidisciplinary SC Engineering; Optics; Physics GA BU90D UT WOS:000177343700032 ER PT J AU Kletetschka, G Wasilewski, PJ AF Kletetschka, G Wasilewski, PJ TI Grain size limit for SD hematite SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article DE hematite; grain size; domains; magnetic properties; Morin transition; susceptibility; hysteresis ID NRM-IRM(S) DEMAGNETIZATION PLOTS; MAGNETIC-ANOMALIES; FIELD-DEPENDENCE; SUSCEPTIBILITY; PYRRHOTITE; PARTICLES; BEHAVIOR; ROCKS AB Grain sizes in the range (10(-4) to 10(-1) mm) are common in some rocks. Because thermal and/or chemical remanent magnetization of hematite in this range approaches intensities of single domain (SD) magnetite, careful exploration of this transition, may serve to develop new applications in rock magnetism that relate to magnetic anomaly source identification, and various paleomagnetic and grain size-dependent investigations. Grain size-dependent magnetic behavior of hematite reveals a SD-multidomain (MD) transition at 0.1 mm. This transition is recognized by variation in magnetic coercivity and susceptibility and is related to an anomaly in remanence recovery when cycling through the Morin transition. The coercivity decrease with increasing grain size occurs much more gradually above 0.1 mm than below this value. Magnetic susceptibility of the grains smaller than 0.1 mm has negligible dependence on the amplitude of the applied alternating magnetic field. For the larger grains a new amplitude-dependent susceptibility component is observed. The grain size of 0.1 tran is also associated with loss of most of the remanence when cycling through the Morin transition. This behavior is ascribed to a transition from the metastable SD to the MD magnetic state. The increase in magnetized volume causes the demagnetizing energy to destabilize the SD state, resulting in a transition where the demagnetizing energy is reduced by nucleation of the domain wail for grains larger than 0.1 mm. The 0.1 mm transition has no significant effect on shape of the temperature-dependent coercivity and saturation magnetization. (C) 2002 Elsevier Science B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kletetschka, G (reprint author), NASA, Goddard Space Flight Ctr, Code 691, Greenbelt, MD 20771 USA. RI Kletetschka, Gunther/C-9996-2011 OI Kletetschka, Gunther/0000-0002-0645-9037 NR 23 TC 37 Z9 38 U1 2 U2 23 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD JAN 1 PY 2002 VL 129 IS 1-2 BP 173 EP 179 DI 10.1016/S0031-9201(01)00271-0 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 515JP UT WOS:000173492200012 ER PT J AU Donohue, MJ Costa, DP Goebel, E Antonelis, GA Baker, JD AF Donohue, MJ Costa, DP Goebel, E Antonelis, GA Baker, JD TI Milk intake and energy expenditure of free-ranging northern fur seal, Callorhinus ursinus, pups SO PHYSIOLOGICAL AND BIOCHEMICAL ZOOLOGY LA English DT Article ID TOTAL-BODY WATER; ELEPHANT SEAL; MIROUNGA-ANGUSTIROSTRIS; ARCTOCEPHALUS-GAZELLA; FORAGING ENERGETICS; HALICHOERUS-GRYPUS; ISOTOPE-DILUTION; LABELED WATER; GROWTH; EFFICIENCY AB Milk ingested by mammalian offspring, coupled with offspring's utilization of this energetic investment, influences survival and growth. A number of studies have examined milk intake in otariids, but few have examined milk intake over the entire lactation period, and none has independently measured energy expenditure concurrent with milk intake. We concurrently examined milk intake, field metabolic rate (FMR), and body composition of 41 pups over the entire lactation interval in 1995 and 1996 on St. Paul Island, Alaska. One hundred two metabolic measurements were obtained with isotope dilution methods. Mean milk intake did not differ annually but increased with age and mass, ranging from 3,400 +/- 239 to 6,780 +/- 449 (+/-SE) mL per suckling bout. Milk energy consumption did not vary with age on a mass-specific basis. No differences were detected in milk volume consumed by male and female pups, either absolutely or on a mass-specific basis. Mass-specific FMR peaked during molting, was lowest postmolt, and did not vary by sex. Pups in 1995 had lower FMR than pups in 1996 and were also fatter. Mean milk energy utilized for maintenance metabolism decreased over time from 77% to 43% in 1995 and remained at 71% in 1996. Pup body mass was negatively correlated with the percentage of total body water and positively correlated with the percentage of total body lipid (TBL). Pups increased the percentage of TBL from 16% to 37%. Northern fur seal pups increased energy intake over lactation, while concurrent changes in body composition and pelage condition resulted in mass-specific metabolic savings after the molt. C1 Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Natl Marine Mammal Lab, Seattle, WA 98115 USA. RP Donohue, MJ (reprint author), Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. NR 77 TC 33 Z9 33 U1 1 U2 9 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 1522-2152 J9 PHYSIOL BIOCHEM ZOOL JI Physiol. Biochem. Zool. PD JAN-FEB PY 2002 VL 75 IS 1 BP 3 EP 18 DI 10.1086/338284 PG 16 WC Physiology; Zoology SC Physiology; Zoology GA 530NB UT WOS:000174362800002 PM 11880973 ER PT B AU Mulligan, JB AF Mulligan, JB GP IS&T IS&T TI Vision-based approaches to digital halftoning SO PICS 2002: IMAGE PROCESSING, IMAGE QUALITY, IMAGE CAPTURE, SYSTEMS CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT Image Processing, Image Quality, Image Capture and Systems Conference (PICS2002) CY APR 07-10, 2002 CL PORTLAND, OR SP Agta Geraert Grp, Appl Sci Fict, Eastman Kodak Co, Hewlett Packard, Konica Corp, Lexmark Int Inc, Polaroid Corp, Xerox Corp ID ERROR DIFFUSION; DISCRIMINATION; ORIENTATION; PERCEPTION; GRATINGS; JPEG AB One way to describe the problem of digital halftoning is as a search for the quantized image that minimizes the visibility of artifacts. To apply this approach in practice, it is first necessary to specify a computational model for computing visible error that can be used to rank candidate images automatically. The model may be incorporated directly into a search algorithm, or used after-the-fact to rank images produced by algorithms that are more heuristic. These approaches have been quite successful when applied to achromatic images, even when using a relatively simple visual model accounting for high-frequency contrast sensitivity but with no masking. This approach can be directly generalized to additional dimensions such as time and color. Visual models based on threshold measures may not be optimal for low bit rate conditions where quantization noise is visible. Instead, the degree to which the noise is effortlessly segmented through perceptual scission may influence the utility of the final image. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Mulligan, JB (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 25 TC 1 Z9 1 U1 1 U2 1 PU SOC IMAGING SCIENCE & TECHNOLOGY PI SPRINGFIELD PA 7003 KILWORTH LANE, SPRINGFIELD, VA 22151 USA BN 0-89208-238-0 PY 2002 BP 1 EP 4 PG 4 WC Imaging Science & Photographic Technology SC Imaging Science & Photographic Technology GA BX03V UT WOS:000184031300001 ER PT J AU Bishop, JL Banin, A Mancinelli, RL Klovstad, MR AF Bishop, JL Banin, A Mancinelli, RL Klovstad, MR TI Detection of soluble and fixed NH4+ in clay minerals by DTA and IR reflectance spectroscopy: a potential tool for planetary surface exploration SO PLANETARY AND SPACE SCIENCE LA English DT Article ID SPECTRAL PROPERTIES; SPECTROMETER DATA; MARTIAN SURFACE; VOLCANIC-ROCKS; LAYER CHARGE; MARS; IDENTIFICATION AB Nitrogen is an essential element for life. It is the only element among the six major biogenic elements, C, N, S, O, P, H, whose presence in the Martian soil has not been positively and directly established. We describe here a study assessing the ability to detect NH4+ in soils using two methods: differential thermal analysis (DTA) and infrared (IR) reflectance spectroscopy. Four standard clay minerals (kaolinite, montmorillonite, illite and attapulgite) and an altered tephra sample from Mauna Kea were treated with NH4+ in this study, then leached in order to remove the non-chemically bound ammonium species. Aliquots of these NH4+-treated and then leached samples were analyzed by DTA and IR reflectance spectroscopy to quantify the detectability of soluble and sorbed/fixed NH4+. An exotherm at 270-280degreesC was clearly detected in the DTA curves of NH4+-treated (non-leached) samples. This feature is assigned to the thermal decomposition reaction of NH4+. Spectral bands observed at 1.56, 2.05, 2.12, 3.06, 3.25, 3.55, 4.2, 5.7 and 7.0 mum in the reflectance spectra of NH4+-treated and leached samples are assigned to the sorbed/fixed ammonium in the clays. The montmorillonite spectra have shown the most intense absorption features due to fixed ammonium among the leached samples in this study, as a result of its high cation sorption capacity. It is concluded that the presence of fixed NH4+ in clays may be detected by IR reflectance or emission spectroscopy. Distinction between soluble and fixed NH4+ may be achieved through the presence or absence of several spectral features assigned to the fixed NH4+ moiety and, specifically, by use of the 4.2 mum feature assigned to solution NH4+. Thermal analyses furnish supporting evidence of ammonium in the clays/soil through detection of N released at temperatures of 270-330degreesC. Based on the results of this study, it is estimated that IR spectra measured from a rover should be able to detect ammonium if present above a few mg NH4+ per g sample in the surface layers. Orbital IR spectra and thermal evolved-gas analyses measured on a rover may be able to detect ammonium in soils as well, but only if present at higher abundances. The spectral features at 3.06 and 7.0 mum due to bound NH4+ in clays and altered volcanic tephra appear to be the most promising for detection by orbital spectrometers. If N species are present in a solid phase on the Mars surface, sedimentary deposits may be the best regions to look for them. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. Hebrew Univ Jerusalem, Dept Soil & Water Sci, IL-76100 Rehovot, Israel. RP Bishop, JL (reprint author), NASA, Ames Res Ctr, SETI Inst, MS 239-4, Moffett Field, CA 94035 USA. RI Mancinelli, Rocco/L-8971-2016 NR 37 TC 18 Z9 18 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JAN PY 2002 VL 50 IS 1 BP 11 EP 19 AR PII S0032-0633(01)00077-0 DI 10.1016/S0032-0633(01)00077-0 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 533WJ UT WOS:000174553000003 ER PT S AU Justus, CG James, BF Bougher, SW Bridger, AFC Haberle, RM Murphy, JR Engel, S AF Justus, CG James, BF Bougher, SW Bridger, AFC Haberle, RM Murphy, JR Engel, S BE Zasova, LV Esposito, LW TI Mars-GRAM 2000: A Mars atmospheric model for engineering applications SO PLANETARY ATMOSPHERES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C3 1 Symposium of COSPAR Scientific Commission C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Agenzia Spaziale Italiana, Ctr Natl Etud Spatiales, Comm Space Res ID GENERAL-CIRCULATION MODEL; GLOBAL SURVEYOR; DYNAMICS AB This paper presents Mars Global Reference Atmospheric Model 2000 Version (Mars-GRAM 2000) and its new features. All parameterizations for temperature, pressure, density, and winds versus height, latitude, longitude, time of day, and Ls have been replaced by input data tables from NASA Ames Mars General Circulation Model, for the surface through 80-km altitude, and the University of Arizona Mars Thermospheric General Circulation Model for 80 to 170 km. A modified Stewart thermospheric model is still used for higher altitudes and for dependence on solar activity. "Climate factors" to tune for agreement with general circulation model data are no longer needed. Adjustment of exospheric temperature is still an option. Consistent with observations from Mars Global Surveyor, a new longitude-dependent wave model is included, with user input to specify waves having one to three wavelengths around the planet. A simplified perturbation model has been substituted for the earlier one. An input switch allows users to select either East or West longitude positive. The paper includes instructions on obtaining Mars-GRAM source code, data files, and a users guide for running the program. The Mars-GRAM users guide provides sample input and output and gives an example for incorporating Mars-GRAM as an atmospheric subroutine in a trajectory code. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Comp Sci Corp, Huntsville, AL 35824 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. San Jose State Univ, Dept Meteorol, San Jose, CA 95192 USA. NASA, Ames Res Ctr, Moffett Federal Airfield, CA 94035 USA. New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. RP Justus, CG (reprint author), Comp Sci Corp, POB 240005, Huntsville, AL 35824 USA. RI Bougher, Stephen/C-1913-2013 OI Bougher, Stephen/0000-0002-4178-2729 NR 16 TC 26 Z9 28 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 2002 VL 29 IS 2 SI 2002 BP 193 EP 202 AR PII S0273-1177(01)005569-5 DI 10.1016/S0273-1177(01)00569-5 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BT86G UT WOS:000174270200011 ER PT S AU Irwin, PGJ Calcutt, SB Weir, AL Taylor, FW Carlson, RW AF Irwin, PGJ Calcutt, SB Weir, AL Taylor, FW Carlson, RW BE Zasova, LV Esposito, LW TI Correlation of near-infrared albedo and 5-micron brightness variations in Jupiter's atmosphere SO PLANETARY ATMOSPHERES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C3 1 Symposium of COSPAR Scientific Commission C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Agenzia Spaziale Italiana, Ctr Natl Etud Spatiales, Comm Space Res ID CLOUD STRUCTURE; BROADENED METHANE; SPECTRA; CM(-1); BAND; COEFFICIENTS; PARAMETERS; AMMONIA; PLANETS AB The Galileo Near Infrared Mapping Spectrometer (NIMS) has returned many spectra of the Jovian atmosphere in the range 0.7-5.2 mum. Although communications restrictions have limited the data return, several wide-area maps have been recorded at near full NIMS resolution. Using these data it is possible to determine both the average shape of the near-infrared (NIR) spectra with very thick clouds (and zero 5-mum brightness) and how these spectra vary as the 5-mum brightness increases. In most of the cases studied, we find that the variable part of the reflectivity has a very different shape to the mean part and may best be explained by variable reflectivity in the cloud layers at pressures greater than 1 bar. In these cases it would thus appear that a variable opacity in a cloud deck based between 1 and 2 bars is mainly responsible for the NIR albedo variations, and not a higher ammonia cloud based above 1 bar as has often been previously suggested. While the composition of this main variable cloud deck could well be ammonium hydrosulphide, other candidates include ammonia (should the much higher estimate of its deep gaseous fractional abundance resulting from the Galileo probe mission be correct), and perhaps even the upper reaches of a deeper water cloud. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Oxford, Oxford OX1 3PU, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Irwin, PGJ (reprint author), Univ Oxford, Parks Rd, Oxford OX1 3PU, England. OI Calcutt, Simon/0000-0002-0102-3170; Irwin, Patrick/0000-0002-6772-384X NR 17 TC 2 Z9 2 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 2002 VL 29 IS 2 SI 2002 BP 285 EP 290 AR PII S0273-1177(01)00579-8 DI 10.1016/S0273-1177(01)00579-8 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BT86G UT WOS:000174270200022 ER PT S AU West, EA Porter, JG Davis, JM Gary, GA Adams, M AF West, EA Porter, JG Davis, JM Gary, GA Adams, M BE Goldstein, DH Chenault, DB Egan, WG Duggin, MJ TI Development of a polarimeter for magnetic field measurements in the ultraviolet SO POLARIZATION ANALYSIS, MEASUREMENT, AND REMOTE SENSING IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Polarization Analysis, Measurement and Remote Sensing IV CY JUL 29-31, 2001 CL SAN DIEGO, CA SP SPIE ID SOLAR MAXIMUM MISSION; REGION AB The polarizing optics that are being developed for the Solar Ultraviolet Magnetograph Investigation (SUMI) are described. This polarimeter is being designed for a sounding rocket payload which will make simultaneous measurements of two magnetically sensitive lines CIV (1550 A) and MgII (2800 A). With a limited observing program, the polarizing optics will be optimized for circular (V) and linear (Q) polarization measurements in active regions. The Q polarization will represent exploratory measurements of the transverse field in strong sunspots. This paper will give a brief overview of the SUMI instrument and its scientific goals, will describe the polarimeter that will be used in the sounding rocket program, and will present some of the measurements that have been made on the SUMI polarization optics. C1 NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35812 USA. RP West, EA (reprint author), NASA, George C Marshall Space Flight Ctr, NSSTC, SD50, Huntsville, AL 35812 USA. NR 7 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 0-8194-4195-3 J9 P SOC PHOTO-OPT INS PY 2002 VL 4481 BP 109 EP 117 AR UNSP 4481-17 DI 10.1117/12.452879 PG 3 WC Instruments & Instrumentation; Remote Sensing SC Instruments & Instrumentation; Remote Sensing GA BU15E UT WOS:000175162100014 ER PT S AU West, EA Hagyard, MJ Gary, GA Smith, JE Adams, M Cloyd, R AF West, EA Hagyard, MJ Gary, GA Smith, JE Adams, M Cloyd, R BE Goldstein, DH Chenault, DB Egan, WG Duggin, MJ TI Development of a NEW vector magnetograph at Marshall Space Flight Center (MSFC) SO POLARIZATION ANALYSIS, MEASUREMENT, AND REMOTE SENSING IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Polarization Analysis, Measurement and Remote Sensing IV CY JUL 29-31, 2001 CL SAN DIEGO, CA SP SPIE AB This paper will describe a new vector magnetograph (the Dome Vector Magnetograph) that has been developed at Marshall Space Flight Center. This magnetograph was a test bed for space flight concepts. One of those concepts that is currently being tested is the increased sensitivity to linear polarization by replacing electro-optical and rotating waveplates with a rotating linear analyzer. Our paper will describe the motivation for developing this magnetograph, compare this instrument with traditional magnetograph designs. C1 NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35812 USA. RP West, EA (reprint author), NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35812 USA. NR 6 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 0-8194-4195-3 J9 P SOC PHOTO-OPT INS PY 2002 VL 4481 BP 270 EP 280 AR UNSP 4481-37 DI 10.1117/12.452897 PG 5 WC Instruments & Instrumentation; Remote Sensing SC Instruments & Instrumentation; Remote Sensing GA BU15E UT WOS:000175162100031 ER PT J AU Hudgins, DM AF Hudgins, DM TI Interstellar polycyclic aromatic compounds and astrophysics SO POLYCYCLIC AROMATIC COMPOUNDS LA English DT Article; Proceedings Paper CT 18th International Symposium on Polycyclic Aromatic Compounds CY SEP 09-13, 2001 CL UNIV CINCINNATI, CINCINNATI, OHIO SP Int Soc Polycycl Aromat Compounds HO UNIV CINCINNATI DE infrared spectroscopy; interstellar molecules; matrix-isolation; polycyclic aromatic molecules and ions ID INFRARED-EMISSION BANDS; MATRIX-ISOLATED NAPHTHALENE; HYDROCARBON CATIONS; VIBRATIONAL-SPECTRA; ELECTRONIC-SPECTRA; MICRON EMISSION; RADICAL CATIONS; CARBON DUST; IR EMISSION; MODEL PAHS AB Over the past 15 years, thanks to significant, parallel advancements in observational, experimental, and theoretical techniques, tremendous strides have been made in our understanding of the role polycyclic aromatic compounds (PACs) in the interstellar medium (ISM). Twenty years ago, the notion of an abundant population of large, carbon-rich molecules in the ISM was considered preposterous. Today, the unmistakable spectroscopic signatures of PACs-shockingly large molecules by previous interstellar chemistry standards-are recognized throughout the universe. In this article, we will examine the interstellar PAC model and its importance to astrophysics, including: (a) the evidence which led to inception of the model, (b) the ensuing laboratory and theoretical studies of the fundamental spectroscopic properties of PAC by which the model has been refined and extended, and (c) a few examples of how the model is being exploited to derive insight into the nature of the interstellar PAC population. C1 NASA, Ames Res Ctr, Astrochem Lab, Mt View, CA 94035 USA. RP Hudgins, DM (reprint author), NASA, Ames Res Ctr, Astrochem Lab, MS 245-6, Mt View, CA 94035 USA. NR 70 TC 9 Z9 9 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 1040-6638 J9 POLYCYCL AROMAT COMP JI Polycycl. Aromat. Compd. PY 2002 VL 22 IS 3-4 BP 469 EP 488 DI 10.1080/10406630290103852 PG 20 WC Chemistry, Organic SC Chemistry GA 592QX UT WOS:000177949300027 ER PT B AU Hsu, F Vesely, WE AF Hsu, F Vesely, WE BE Bonano, EJ Camp, AL Majors, MJ Thompson, RA TI Comparisons of differences and commonalities of nuclear power plant PRAs and the space shuttle PRA SO PROBABILISTIC SAFETY ASSESSMENT AND MANAGEMENT, VOL I AND II, PROCEEDINGS LA English DT Proceedings Paper CT 6th International Conference on Probabilistic Assessment and Management (PSAM6) CY JUN 23-28, 2002 CL SAN JUAN, PR DE probabilistic risk assessment; space shuttle & nuclear plant safety AB This paper presents comparisons of the scope, conceptual framework, and essential elements of nuclear power plant Probabilistic Risk Assessments (PRAs) and the Space Shuttle PRA being conducted by NASA. Discussions are focused on various lessons learned in nuclear power plant PRA applications and their potential applicability to the Space Shuttle PRA. Based on insights gained from PRA projects for nuclear power plants and from the current Space Shuttle PRA effort, the paper explores the commonalities and the differences between the conduct of the different PRAs. C1 NASA, Lyndon B Johnson Space Ctr, SAIC, Houston, TX 77058 USA. RP Hsu, F (reprint author), NASA, Lyndon B Johnson Space Ctr, SAIC, SAIC-NC 62, Houston, TX 77058 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-08-044122-X PY 2002 BP 567 EP 574 PG 8 WC Engineering, Multidisciplinary; Operations Research & Management Science; Nuclear Science & Technology; Transportation SC Engineering; Operations Research & Management Science; Nuclear Science & Technology; Transportation GA BV86L UT WOS:000180264500086 ER PT S AU Okino, CM Corr, MG AF Okino, CM Corr, MG GP IEEE IEEE TI Best effort adaptive routing in statistically accurate sensor networks SO PROCEEDING OF THE 2002 INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOLS 1-3 SE IEEE International Joint Conference on Neural Networks (IJCNN) LA English DT Proceedings Paper CT International Joint Conference on Neural Networks (IJCNN 02) CY MAY 12-17, 2002 CL HONOLULU, HI SP IEEE, IEEE Neural Networks Soc, Int Neural Network Soc AB In this paper, we present some new results in statistically accurate sensor networks. In particular, we re-examine the adaptive routing sensor protocol called the Best Effort multi-Hop Geographical Routing protocol, and provide some new analysis for well known topologies. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM cokino@ipl.nasa.gov; corr@erg.sri.com NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2161-4393 BN 0-7803-7278-6 J9 IEEE IJCNN PY 2002 BP 345 EP 350 DI 10.1109/IJCNN.2002.1005495 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU92F UT WOS:000177402800063 ER PT S AU Okino, CM AF Okino, CM GP IEEE IEEE TI On the performance of swarm routing utilizing light-weight agents SO PROCEEDING OF THE 2002 INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOLS 1-3 SE IEEE International Joint Conference on Neural Networks (IJCNN) LA English DT Proceedings Paper CT International Joint Conference on Neural Networks (IJCNN 02) CY MAY 12-17, 2002 CL HONOLULU, HI SP IEEE, IEEE Neural Networks Soc, Int Neural Network Soc AB In this work, we present a relaxed swarm-routing algorithm in the spirit of AntNet and Agent Based Control (ABC). Our approach reduces the utilization of route tables by allowing for pure random route path searches similar to ABC while utilizing the current path diameter for updates as oppose to the commonly used link delay metrics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. EM cokino@jpl.nasa.gov NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2161-4393 BN 0-7803-7278-6 J9 IEEE IJCNN PY 2002 BP 361 EP 364 DI 10.1109/IJCNN.2002.1005498 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU92F UT WOS:000177402800066 ER PT S AU Pappa, RS Woods-Vedeler, JA Jones, TW AF Pappa, RS Woods-Vedeler, JA Jones, TW GP SPIE SPIE TI In-space structural validation plan for a stretched-lens solar array flight experiment SO PROCEEDINGS OF IMAC-XX: STRUCTURAL DYNAMICS VOLS I AND II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 20th IMAC Conference on Structural Dynamics CY FEB 04-07, 2002 CL LOS ANGELES, CA SP Soc Exptl Mech Inc ID IDENTIFICATION AB This paper summarizes in-space structural validation plans for a proposed Space Shuttle-based flight experiment. The test article is an innovative, lightweight solar array concept that uses pop-up, refractive stretched-lens concentrators to achieve a power/mass density of at least 175 W/kg, which is more than three times greater than current capabilities. The flight experiment will validate this new technology to retire the risk associated with its first use in space. The experiment includes structural diagnostic instrumentation to measure the deployment dynamics, static shape, and modes of vibration of the 8m-long solar array and several of its lenses. These data will be obtained by photogrammetry using the Shuttle payload-bay video cameras and miniature video cameras on the array. Six accelerometers are also included in the experiment to measure base excitations and small-amplitude tip motions. C1 NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. RP Pappa, RS (reprint author), NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-77-1 J9 P SOC PHOTO-OPT INS PY 2002 VL 4753 BP 461 EP 471 PG 5 WC Engineering, Aerospace; Engineering, Civil; Engineering, Mechanical SC Engineering GA BU66N UT WOS:000176646000067 ER PT S AU Kappus, KO Driskill, TC Parks, RA AF Kappus, KO Driskill, TC Parks, RA GP SPIE SPIE TI Modal testing of seven shuttle cargo elements for space station SO PROCEEDINGS OF IMAC-XX: STRUCTURAL DYNAMICS VOLS I AND II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 20th IMAC Conference on Structural Dynamics CY FEB 04-07, 2002 CL LOS ANGELES, CA SP Soc Exptl Mech Inc AB From December 1996 to May 2001, the Modal and Control Dynamics Team at NASA's Marshall Space Flight Center (MSFC) conducted modal tests on seven large elements of the International Space Station. Each of these elements has been or will be launched as a Space Shuttle payload for transport to the International Space Station (ISS). Like other Shuttle payloads, modal testing of these elements was required for verification of the finite element models used in coupled loads analyses for launch and landing. The seven modal tests included three modules - Node, Laboratory, and Airlock, and four truss segments - P6, P3/P4, S1/P1, and P5. Each element was installed and tested in the Shuttle Payload Modal Test Bed at MSFC. This unique facility can accommodate any Shuttle cargo element for modal test qualification. Flexure assemblies were utilized at each Shuttle-to-payload interface to simulate a constrained boundary in the load carrying degrees of freedom. For each element, multiple-input, multiple-output burst random modal testing was the primary approach with controlled input sine sweeps for linearity assessments. The accelerometer channel counts ranged from 252 channels to 1251 channels. An overview of these tests, as well as some lessons learned, will be provided in this paper. C1 NASA, George C Marshall Space Flight Ctr, Modal & Control Dynam Team, Huntsville, AL 35812 USA. RP Kappus, KO (reprint author), NASA, George C Marshall Space Flight Ctr, Modal & Control Dynam Team, ED27,MSFC, Huntsville, AL 35812 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-77-1 J9 P SOC PHOTO-OPT INS PY 2002 VL 4753 BP 703 EP 708 PG 4 WC Engineering, Aerospace; Engineering, Civil; Engineering, Mechanical SC Engineering GA BU66N UT WOS:000176646000106 ER PT S AU Peng, CY Tsuha, W AF Peng, CY Tsuha, W GP SPIE SPIE TI Dynamic simulation of Mars-03 entry, descent and landing system SO PROCEEDINGS OF IMAC-XX: STRUCTURAL DYNAMICS VOLS I AND II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 20th IMAC Conference on Structural Dynamics CY FEB 04-07, 2002 CL LOS ANGELES, CA SP Soc Exptl Mech Inc AB NASA's Mars Exploration Rover mission will place two landers on the surface of Mars using an innovative approach to entry, descent, and landing. Since it is difficult, expensive, and in some cases impossible to test the entry, descent, and landing system in Mars-like environment, an extensive simulation effort has been undertaken to validate the concept and to predict the performance of the system. A critical concern is the dynamical behavior of the system under winds as it descends through the Martian atmosphere. This paper summarizes multi-body dynamic simulations of the terminal phase of the entry and descent. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Peng, CY (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-77-1 J9 P SOC PHOTO-OPT INS PY 2002 VL 4753 BP 1123 EP 1129 PG 3 WC Engineering, Aerospace; Engineering, Civil; Engineering, Mechanical SC Engineering GA BU66N UT WOS:000176646000171 ER PT S AU Pritchard, J Buehrle, R Pappa, R Grosveld, F AF Pritchard, J Buehrle, R Pappa, R Grosveld, F GP SPIE SPIE TI Comparison of modal analysis methods applied to a vibro-acoustic test article SO PROCEEDINGS OF IMAC-XX: STRUCTURAL DYNAMICS VOLS I AND II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 20th IMAC Conference on Structural Dynamics CY FEB 04-07, 2002 CL LOS ANGELES, CA SP Soc Exptl Mech Inc AB Modal testing of a vibro-acoustic test article referred to as the Aluminum Testbed Cylinder (ATC) has provided frequency response data for the development of validated numerical models of complex structures for interior noise prediction and control. The ATC is an all aluminum, ring and stringer stiffened cylinder, 12 feet in length and 4 feet in diameter. The cylinder was designed to represent typical aircraft construction. Modal tests were conducted for several different configurations of the cylinder assembly under ambient and pressurized conditions. The purpose of this paper is to present results from dynamic testing of different ATC configurations using two modal analysis software methods: Eigensystem Realization Algorithm (ERA) and MTS IDEAS Polyreference method. The paper compares results from the two analysis methods as well as the results from various test configurations. The effects of pressurization on the modal characteristics are discussed. C1 NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. RP Pritchard, J (reprint author), NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. NR 10 TC 1 Z9 1 U1 0 U2 2 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-77-1 J9 P SOC PHOTO-OPT INS PY 2002 VL 4753 BP 1144 EP 1152 PG 3 WC Engineering, Aerospace; Engineering, Civil; Engineering, Mechanical SC Engineering GA BU66N UT WOS:000176646000174 ER PT S AU Gaspar, JL Solter, MJ Pappa, RS AF Gaspar, JL Solter, MJ Pappa, RS GP SPIE SPIE TI Membrane vibration studies using a scanning laser vibrometer SO PROCEEDINGS OF IMAC-XX: STRUCTURAL DYNAMICS VOLS I AND II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 20th IMAC Conference on Structural Dynamics CY FEB 04-07, 2002 CL LOS ANGELES, CA SP Soc Exptl Mech Inc AB This paper summarizes on-going experimental work at NASA Langley Research Center to measure the dynamics of a 1.016 m (40 in) square polyimide film Kapton membrane. A fixed fully automated impact hammer and Polytec PSV-300-H scanning laser vibrometer were used for non-contact modal testing of the membrane with zero-mass-loading. The paper discusses the results obtained by testing the membrane at various tension levels and at various excitation locations. Results obtained by direct shaker excitation to the membrane are also discussed. C1 NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. RP Gaspar, JL (reprint author), NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. NR 7 TC 0 Z9 0 U1 1 U2 1 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-77-1 J9 P SOC PHOTO-OPT INS PY 2002 VL 4753 BP 1532 EP 1538 PG 3 WC Engineering, Aerospace; Engineering, Civil; Engineering, Mechanical SC Engineering GA BU66N UT WOS:000176646000234 ER PT S AU Shin, JY AF Shin, JY GP ACC ACC TI Analysis of linear parameter varying system models based on reachable sets SO PROCEEDINGS OF THE 2002 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE Proceedings of the American Control Conference LA English DT Proceedings Paper CT 20th Annual American Control Conference (ACC) CY MAY 08-10, 2002 CL ANCHORAGE, AK SP Amer Automat Control Council, IFAC, SICE ID MISSILE AB This paper presents the analysis method of quasi-LPV models, comparing the ellipsoid set which contains the reachable set of a nonlinear system to determine which quasi-LPV model is less conservative to present the nonlinear dynamics. Quasi-LPV models are constructed from a nonlinear model using different methods, to facilitate synthesis of an LPV controller for the nonlinear system. The comparison results of the closed-loop system performance with the synthesized LPV controllers correspond to the analysis results of quasi-LPV models. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP NASA, Langley Res Ctr, ICASE MS132C, Hampton, VA 23681 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-7298-0 J9 P AMER CONTR CONF PY 2002 VL 1-6 BP 35 EP 40 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BV44D UT WOS:000178974700007 ER PT S AU Shin, JY Balas, GJ AF Shin, JY Balas, GJ GP ACC ACC TI Optimal blending functions in linear parameter varying control synthesis for F-16 aircraft SO PROCEEDINGS OF THE 2002 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE Proceedings of the American Control Conference LA English DT Proceedings Paper CT 20th Annual American Control Conference (ACC) CY MAY 08-10, 2002 CL ANCHORAGE, AK SP Amer Automat Control Council, IFAC, SICE ID LATERAL-DIRECTIONAL AXIS; POWERED APPROACH; MISSILE; DESIGN AB This paper presents a methodology of blending two linear parameter varying (LPV) controllers, over the entire parameter spaces. Optimal blending matrix functions are calculated to preserve each performance level of the LPV controller synthesized over each parameter subspace. The design of an LPV controller for the F-16 longitudinal axes over the entire flight envelope is demonstrated using this blending approach. The nonlinear simulations of the blended LPV controller show that the desired performance and robustness objectives are achieved across all altitude variations. C1 NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. RP NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-7298-0 J9 P AMER CONTR CONF PY 2002 VL 1-6 BP 41 EP 46 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BV44D UT WOS:000178974700008 ER PT S AU Whorton, MS AF Whorton, MS GP ACC ACC TI Robust control for microgravity vibration isolation with parametric uncertainty SO PROCEEDINGS OF THE 2002 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE Proceedings of the American Control Conference LA English DT Proceedings Paper CT 20th Annual American Control Conference (ACC) CY MAY 08-10, 2002 CL ANCHORAGE, AK SP Amer Automat Control Council, IFAC, SICE AB Many space-science experiments. need an active isolation system to provide a sufficiently quiescent microgravity environment. Modern control methods provide the potential for both high-performance and robust stability in the presence of parametric uncertainties that are characteristic of microgravity vibration isolation systems. This paper compares microgravity vibration isolation control system designs using H-2 and H-infinity methods on the basis of nominal performance and robustness to parametric uncertainties. C1 NASA, George C Marshall Space Flight Ctr, Control Syst Grp, Huntsville, AL 35812 USA. RP NASA, George C Marshall Space Flight Ctr, Control Syst Grp, TD55, Huntsville, AL 35812 USA. NR 9 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-7298-0 J9 P AMER CONTR CONF PY 2002 VL 1-6 BP 256 EP 261 DI 10.1109/ACC.2002.1024813 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BV44D UT WOS:000178974700044 ER EF