FN Thomson Reuters Web of Science™ VR 1.0 PT B AU Teng, W Serafino, G Chiu, L Rui, HL Bonk, J Hrubiak, P Yang, RH Ahmad, S Liu, Z Zhang, B Pollack, N Vicente, G Sharma, AK Lu, L AF Teng, W Serafino, G Chiu, L Rui, HL Bonk, J Hrubiak, P Yang, RH Ahmad, S Liu, Z Zhang, B Pollack, N Vicente, G Sharma, AK Lu, L GP AMS AMS TI Anatomy of TRMM science data support at the GES DAAC SO 18TH INTERNATIONAL CONFERENCE ON INTERACTIVE INFORMATION AND PROCESSING SYSTEMS (IIPS) FOR METEOROLOGY, OCEANOGRAPHY, AND HYDROLOGY LA English DT Proceedings Paper CT 18th International Conference on Interactive Information and Processing Systems (IIPS) for Meteorology, Oceanography and Hydrology CY JAN 13-17, 2002 CL ORLANDO, FL SP Amer Meteorol Soc C1 NASA, Goddard Space Flight Ctr, GSFC Earth Sci, SSAI,DAAC,DISC,GES, Greenbelt, MD 20771 USA. RP Teng, W (reprint author), NASA, Goddard Space Flight Ctr, GSFC Earth Sci, SSAI,DAAC,DISC,GES, Code 902-2, Greenbelt, MD 20771 USA. NR 6 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 228 EP 231 PG 4 WC Computer Science, Information Systems; Computer Science, Software Engineering; Meteorology & Atmospheric Sciences SC Computer Science; Meteorology & Atmospheric Sciences GA BV55B UT WOS:000179335200087 ER PT B AU Reed, RA Roth, DR Ladbury, R Kniffin, S LaBel, K AF Reed, RA Roth, DR Ladbury, R Kniffin, S LaBel, K GP IEEE IEEE TI In situ measurement of the particle linear energy transfer using the sensitive junctions of the device under test SO 2001 6TH EUROPEAN CONFERENCE ON RADIATION AND ITS EFFECTS ON COMPONENTS AND SYSTEMS LA English DT Proceedings Paper CT 6th European Conference on Radiation and Its Effects on Components and Systems CY SEP 10-14, 2001 CL GRENOBLE, FRANCE SP Techn Informat & Microelectr Comp Architecture Lab, RADECS Assoc, IEEE Nucl & Plasma Sci Soc AB We describe an approach for using charge collection measurement techniques to determine the LET of a particle that reaches the sensitive region with an unknown energy. The method requires that a calibration of the response of the sensitive region to particle LET be established. Then from this calibration, the unknown LET can be determined. We also give recommendation on how to use complex charge collection data to determine the distribution of particle LET reaching the sensitive region and how to correct the particle fluence for this distribution. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Reed, RA (reprint author), NASA, Goddard Space Flight Ctr, Code 561, 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 0-7803-7313-8 PY 2002 BP 18 EP 23 DI 10.1109/RADECS.2001.1159252 PG 6 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BV99V UT WOS:000180627900004 ER PT B AU Johnston, AH Miyahira, TF AF Johnston, AH Miyahira, TF GP IEEE IEEE TI Energy dependence of proton damage in optical emitters SO 2001 6TH EUROPEAN CONFERENCE ON RADIATION AND ITS EFFECTS ON COMPONENTS AND SYSTEMS LA English DT Proceedings Paper CT 6th European Conference on Radiation and Its Effects on Components and Systems CY SEP 10-14, 2001 CL GRENOBLE, FRANCE SP Techn Informat & Microelectr Comp Architecture Lab, RADECS Assoc, IEEE Nucl & Plasma Sci Soc ID LIGHT-EMITTING-DIODES AB The energy dependence of proton displacement damage effects is investigated for light-emitting diodes and laser diodes. Injection-enhanced annealing occurs more rapidly when devices are irradiated with protons below 50 MeV compared with annealing from 200 MeV protons. A different interpretation of damage in amphoterically doped LEDs is used to show that the dependence of damage on energy is relatively flat for energies above 50 MeV in contrast to older results in the literature that show a continued decrease in damage at higher energies. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Johnston, AH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7313-8 PY 2002 BP 172 EP 178 DI 10.1109/RADECS.2001.1159276 PG 7 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BV99V UT WOS:000180627900027 ER PT B AU Swift, GM Millward, DG Clark, HL AF Swift, GM Millward, DG Clark, HL GP IEEE IEEE TI Single-event testing using heavy ion irradiation through thick layers of material SO 2001 6TH EUROPEAN CONFERENCE ON RADIATION AND ITS EFFECTS ON COMPONENTS AND SYSTEMS LA English DT Proceedings Paper CT 6th European Conference on Radiation and Its Effects on Components and Systems CY SEP 10-14, 2001 CL GRENOBLE, FRANCE SP Techn Informat & Microelectr Comp Architecture Lab, RADECS Assoc, IEEE Nucl & Plasma Sci Soc AB Upset results for backside irradiated PowerPC750s (thin epi) and SDRAMs (deep charge collection from diffusion) illustrate the validity of single event test data when irradiating through a layer of silicon substrate. However, heavy-ion LET assignments require accurate material and thickness determination. Taking irradiating through materials further, the Texas A&M cyclotron uses adjustable degraders to offer a continuous range of heavy ion LETs as well as an optional in-air test fixture. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Swift, GM (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 0-7803-7313-8 PY 2002 BP 438 EP 442 DI 10.1109/RADECS.2001.1159319 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BV99V UT WOS:000180627900069 ER PT B AU Wilkins, R Huff, H Badhwar, GD Moore, J Zhou, J Singleterry, RC Wender, SA Fogarty, TN AF Wilkins, R Huff, H Badhwar, GD Moore, J Zhou, J Singleterry, RC Wender, SA Fogarty, TN GP IEEE IEEE TI Observation of changes in the single event upset rate in 4MB SRAM due to intervening materials in a neutron environment SO 2001 6TH EUROPEAN CONFERENCE ON RADIATION AND ITS EFFECTS ON COMPONENTS AND SYSTEMS LA English DT Proceedings Paper CT 6th European Conference on Radiation and Its Effects on Components and Systems CY SEP 10-14, 2001 CL GRENOBLE, FRANCE SP Techn Informat & Microelectr Comp Architecture Lab, RADECS Assoc, IEEE Nucl & Plasma Sci Soc ID SPECTRA AB We observe a significant increase (by a factor of approximately three) in the single event upset (SEU) rate in 4MB SRAM by modifying the incident high-energy neutron field with polyethylene of thickness between 20.5g/cm(2)-25.5g/cm(2). In comparison, these thicknesses of the same intervening materials greatly reduce the tissue equivalent dose as measured with a tissue equivalent proportional counter (TEPC). These results indicate intervening materials that may provide a measure of radiation shielding for humans may be detrimental to electronic systems. C1 Prairie View A&M Univ, NASA, Ctr Appl Radiat Res, Prairie View, TX 77446 USA. RP Wilkins, R (reprint author), Prairie View A&M Univ, NASA, Ctr Appl Radiat Res, Prairie View, TX 77446 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7313-8 PY 2002 BP 469 EP 473 DI 10.1109/RADECS.2001.1159325 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Engineering; Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BV99V UT WOS:000180627900075 ER PT S AU Callantine, TJ AF Callantine, TJ GP IEEE IEEE IEEE IEEE TI Agents for analysis and design of complex systems SO 2001 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: E-SYSTEMS AND E-MAN FOR CYBERNETICS IN CYBERSPACE SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man and Cybernetics (SMC) CY OCT 07-10, 2001 CL TUCSON, AZ SP IEEE, Raytheon DE agents; analysis and design; air traffic control; aviation; human performance models AB This paper describes how intelligent agents can simulate human operators to aid in the analysis and design of complex systems. The paper presents two examples of adapting the Crew Activity Tracking System (CATS) to function as an intelligent agent. The first is a model-based design application, in which CATS agents perform the task of air traffic controllers in order to test a new operational concept. The second concerns human error analysis, in which a coordinated team of CATS agents represents a flight crew and aircraft destroyed due to controlled flight into terrain. The paper also discusses issues regarding the development of task model-based agents that make plausible, human-like errors and the use of such agents. C1 San Jose State Univ, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Callantine, TJ (reprint author), San Jose State Univ, NASA, Ames Res Ctr, Mail Stop 262-4 Moffett Field, Moffett Field, CA 94035 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-7087-2 J9 IEEE SYS MAN CYBERN PY 2002 BP 567 EP 573 PG 7 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU92K UT WOS:000177404200097 ER PT S AU Wen, Q Gates, AQ Beck, J Kreinovich, V Keller, GR AF Wen, Q Gates, AQ Beck, J Kreinovich, V Keller, GR GP IEEE IEEE IEEE IEEE TI Towards automatic detection of erroneous measurement results in a gravity database SO 2001 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: E-SYSTEMS AND E-MAN FOR CYBERNETICS IN CYBERSPACE SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man and Cybernetics (SMC) CY OCT 07-10, 2001 CL TUCSON, AZ SP IEEE, Raytheon DE gravity database; erroneous measurement; automatic detection AB Geospatial databases often contain erroneous measurements. For some such databases such as gravity databases, the known methods of detecting erroneous measurements - based on regression analysis - do not work well. As a result, to clean such databases, experts use manual methods which are very time-consuming. In this paper, we propose a (natural) "localized" version of regression analysis as a technique for automatic cleaning. We illustrate the efficiency of this technique on the example of the gravity database. C1 Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. RP Wen, Q (reprint author), Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 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 SN 1062-922X BN 0-7803-7087-2 J9 IEEE SYS MAN CYBERN PY 2002 BP 2170 EP 2175 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU92K UT WOS:000177404200378 ER PT S AU Srikrishnan, S Araiza, R Xie, HJ Starks, SA Kreinovich, V AF Srikrishnan, S Araiza, R Xie, HJ Starks, SA Kreinovich, V GP IEEE IEEE IEEE IEEE TI Automatic referencing of satellite and radar images SO 2001 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: E-SYSTEMS AND E-MAN FOR CYBERNETICS IN CYBERSPACE SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man and Cybernetics (SMC) CY OCT 07-10, 2001 CL TUCSON, AZ SP IEEE, Raytheon DE satellite image; radar image; automatic image referencing 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 Srikrishnan, S (reprint author), Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 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 SN 1062-922X BN 0-7803-7087-2 J9 IEEE SYS MAN CYBERN PY 2002 BP 2176 EP 2181 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU92K UT WOS:000177404200379 ER PT S AU Starks, SA Iourinski, D Kreinovich, V AF Starks, SA Iourinski, D Kreinovich, V GP IEEE IEEE IEEE IEEE TI 2-D analogues of Allen interval algebra for image analysis: Towards justification SO 2001 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: E-SYSTEMS AND E-MAN FOR CYBERNETICS IN CYBERSPACE SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man and Cybernetics (SMC) CY OCT 07-10, 2001 CL TUCSON, AZ SP IEEE, Raytheon DE image analysis; relation between images AB In reasoning about time and duration, researchers often use Allen's Interval Algebra. This algebra describes possible relations between 1D intervals. An interval can precede the other one, follow the other one, start the other one, etc. This algebra describes the relationship befween different intervals in terms of words from natural language. To give a natural language description of 2D images, it is desirable to develop a similar approach for describing the relationship between 2-D objects in a picture. In their recent papers, Jim Keller and his collaborators proposed a new approach based on a simulation of a "force" between these objects. In this paper, we show that their force formula is theoretically optimal. C1 Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. RP Starks, SA (reprint author), Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. 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 1062-922X BN 0-7803-7087-2 J9 IEEE SYS MAN CYBERN PY 2002 BP 2182 EP 2186 PG 5 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU92K UT WOS:000177404200380 ER PT S AU Martinez, J Macias, L Esper, A Chaparro, J Alvarado, V Starks, SA Kreinovich, V AF Martinez, J Macias, L Esper, A Chaparro, J Alvarado, V Starks, SA Kreinovich, V GP IEEE IEEE IEEE IEEE TI Towards more realistic (e.g., non-associative) and- and or-operations in fuzzy logic SO 2001 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: E-SYSTEMS AND E-MAN FOR CYBERNETICS IN CYBERSPACE SE IEEE International Conference on Systems Man and Cybernetics Conference Proceedings LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man and Cybernetics (SMC) CY OCT 07-10, 2001 CL TUCSON, AZ SP IEEE, Raytheon DE fuzzy logic; non-associative operations AB How is fuzzy logic usually formalized? There are many seemingly reasonable requirements that a logic should satisfy: e.g., since A&B and B&A are the same, the corresponding and-operation should be commutative. Similarly, since A&A means the same as A, we should expect that the and-operation should also satisfy this property, etc. It turns out to be impossible to satisfy all these seemingly natural requirements, so usually, some requirements are picked as absolutely true (like commutativity or associativity), and others are ignored if they contradict to the picked ones. This idea leads to a neat mathematical theory, but the analysis of real-life expert reasoning shows that all the requirements are only approximately satisfied. we should require all of these requirements to be satisfied to some extent. In this paper, we show the preliminary results of analyzing such operations. In particular, we show that non-associative operations explain the empirical 7 +/- 2 law in psychology according to which a person can normally distinguish between no more than 7 plus minus 2 classes. C1 Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. RP Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. EM vladik@cs.utep.edu NR 13 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-7087-2 J9 IEEE SYS MAN CYBERN PY 2002 BP 2187 EP 2192 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU92K UT WOS:000177404200381 ER PT S AU Fathi, M Wawro, M AF Fathi, M Wawro, M GP IEEE IEEE IEEE IEEE TI A scheduling strategy for problems of finite element analysis on computational grids SO 2001 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: E-SYSTEMS AND E-MAN FOR CYBERNETICS IN CYBERSPACE SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man and Cybernetics (SMC) CY OCT 07-10, 2001 CL TUCSON, AZ SP IEEE, Raytheon AB The demand for high-performance computing grows with the increasing number of applications within this field. A generalized grid-computing concept may not be restricted to a single facility or a country, but may rather feature a world-wide network of distributed supercomputing clusters that are to the disposal of many research groups around the world [1],[2]. Each individual cluster may differ a lot from the other participating clusters in terms of computing power. Also the computational tasks which are to be assigned to different clusters may also differ in demand of computing power. Therefore an accurate scheduling of the diverse computational tasks to the different clusters improves the cost-effective utilization of the network resources. C1 Univ New Mexico, NASA, ACE Ctr, Albuquerque, NM 87131 USA. RP Fathi, M (reprint author), Univ New Mexico, NASA, ACE Ctr, EECE Bldg, Albuquerque, NM 87131 USA. 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 1062-922X BN 0-7803-7087-2 J9 IEEE SYS MAN CYBERN PY 2002 BP 2623 EP 2626 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU92K UT WOS:000177404200459 ER PT S AU Thompson, DJ Hartman, RC Kelly, H Kotani, T Krizmanic, J Moiseev, A Ormes, JF Ritz, S Schaefer, R Sheppard, D Singh, S Godfrey, G Silva, EDE Dubois, R Giebels, B Haller, G Handa, T Kamae, T Kavelaars, A Linder, T Ozaki, M Rochester, LS Roterman, FM Russell, JJ Sjogren, M Usher, T Valtersson, P Waite, AP Williams, SM Lauben, D Michelson, P Nolan, PL Wallace, J Mizuno, T Fukazawa, Y Hirano, K Mizushima, H Ogata, S Grove, JE Ampe, J Johnson, WN Lovellette, M Phlips, B Wood, D Sadrozinski, HFW Briber, S Dann, J Hirayama, M Johnson, RP Kliewer, S Kroger, W Manildi, J Paliaga, G Rowe, WA Schalk, T Webster, A Kuss, M Lumb, N Spandre, G AF Thompson, DJ Hartman, RC Kelly, H Kotani, T Krizmanic, J Moiseev, A Ormes, JF Ritz, S Schaefer, R Sheppard, D Singh, S Godfrey, G Silva, EDE Dubois, R Giebels, B Haller, G Handa, T Kamae, T Kavelaars, A Linder, T Ozaki, M Rochester, LS Roterman, FM Russell, JJ Sjogren, M Usher, T Valtersson, P Waite, AP Williams, SM Lauben, D Michelson, P Nolan, PL Wallace, J Mizuno, T Fukazawa, Y Hirano, K Mizushima, H Ogata, S Grove, JE Ampe, J Johnson, WN Lovellette, M Phlips, B Wood, D Sadrozinski, HFW Briber, S Dann, J Hirayama, M Johnson, RP Kliewer, S Kroger, W Manildi, J Paliaga, G Rowe, WA Schalk, T Webster, A Kuss, M Lumb, N Spandre, G BE Seibert, JA TI Gamma ray large area space telescope balloon flight engineering model: Overview SO 2001 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORDS, VOLS 1-4 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium CY NOV 04-10, 2001 CL SAN DIEGO, CA SP IEEE, Nucl Plasma Sci Soc ID BEAM TEST; GLAST AB The Gamma Ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) is a pair-production high-energy (>20 MeV) gamma-ray telescope being built by an international partnership of astrophysicists and particle physicists for a satellite launch in 2006, designed to study a wide variety of high-energy astrophysical phenomena. As part of the development effort, the collaboration has built a Balloon Flight Engineering Model (BFEM) for flight on a high-altitude scientific balloon. The BFEM is approximately the size of one of the 16 GLAST-LAT towers and contains all the components of the full instrument: plastic scintillator anticoincidence system (ACD), high-Z foil/Si strip pair-conversion tracker (TKR), CsI hodoscopic calorimeter (CAL), triggering and data acquisition electronics (DAQ), commanding system, power distribution, telemetry, real-time data display, and ground data processing system. The principal goal of the balloon flight was to demonstrate the performance of this instrument configuration under conditions similar to those expected in orbit. Results from a balloon flight from Palestine, Texas, on August 4, 2001, show that the BFEM successfully obtained gamma-ray data in this high-background environment. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Thompson, DJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Thompson, David/D-2939-2012; Kuss, Michael/H-8959-2012; Schaefer, Robert/C-2119-2016 OI Thompson, David/0000-0001-5217-9135; Schaefer, Robert/0000-0003-3692-0223 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 SN 1082-3654 BN 0-7803-7324-3 J9 IEEE NUCL SCI CONF R PY 2002 BP 447 EP 451 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Nuclear Science & Technology; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA BV30L UT WOS:000178495800100 ER PT S AU Thompson, DJ Hartman, RC Kelly, H Kotani, T Krizmanic, J Moiseev, A Ormes, JF Ritz, S Schaefer, R Sheppard, D Singh, S Godfrey, G Silva, EDE Dubois, R Giebels, B Haller, G Handa, T Kamae, T Kavelaars, A Linder, T Ozaki, M Rochester, LS Roterman, FM Russell, JJ Sjogren, M Usher, T Valtersson, P Waite, AP Williams, SM Lauben, D Michelson, P Nolan, PL Wallace, J Mizuno, T Fukazawa, Y Hirano, K Mizushima, H Ogata, S Grove, JE Ampe, J Johnson, WN Lovellette, M Phlips, B Wood, D Sadrozinski, HFW Briber, SW Dann, J Hirayama, M Johnson, RP Kliewer, S Kroger, W Manildi, J Paliaga, G Rowe, WA Schalk, T Webster, A Kuss, M Lumb, N Spandre, G AF Thompson, DJ Hartman, RC Kelly, H Kotani, T Krizmanic, J Moiseev, A Ormes, JF Ritz, S Schaefer, R Sheppard, D Singh, S Godfrey, G Silva, EDE Dubois, R Giebels, B Haller, G Handa, T Kamae, T Kavelaars, A Linder, T Ozaki, M Rochester, LS Roterman, FM Russell, JJ Sjogren, M Usher, T Valtersson, P Waite, AP Williams, SM Lauben, D Michelson, P Nolan, PL Wallace, J Mizuno, T Fukazawa, Y Hirano, K Mizushima, H Ogata, S Grove, JE Ampe, J Johnson, WN Lovellette, M Phlips, B Wood, D Sadrozinski, HFW Briber, SW Dann, J Hirayama, M Johnson, RP Kliewer, S Kroger, W Manildi, J Paliaga, G Rowe, WA Schalk, T Webster, A Kuss, M Lumb, N Spandre, G CA GLAST Large Area Telescope Collabo BE Seibert, JA TI Gamma Ray Large Area Space Telescope Balloon Flight Engineering Model: Overview SO 2001 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORDS, VOLS 1-4 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium CY NOV 04-10, 2001 CL SAN DIEGO, CA SP IEEE, Nucl Plasma Sci Soc ID BEAM TEST; GLAST AB The Gamma Ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) is a pair-production high-energy (>20 MeV) gamma-ray telescope being built by an international partnership of astrophysicists and particle physicists for a satellite launch in 2006, designed to study a wide variety of high-energy astrophyslical phenomena. As part of the development effort, the collaboration has built a Balloon Flight Engineering Model (BFEM) for flight on a high-altitude scientific balloon. The BFEM is approximately the size of one of the 16 GLAST-LAT towers and contains all the components of the full instrument: plastic scinitillator anticoincidence system (ACD), high-Z foil/Si strip pair-conversion tracker (TKR), CsI hodoscopic calorimeter (CAL), triggering and data acquisition electronics (DAQ), commanding system, power distribution, telemetry, real-time data display, and ground data processing system. The principal goal of the balloon flight was to demonstrate the performance of this instrument configuration under conditions similar to those expected in orbit. Results from a balloon flight from Palestine, Texas, on August 4, 2001, show that the BFEM successfully obtained gamma-ray data in this high-background environment. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Thompson, DJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Thompson, David/D-2939-2012; Kuss, Michael/H-8959-2012; Schaefer, Robert/C-2119-2016 OI Thompson, David/0000-0001-5217-9135; Schaefer, Robert/0000-0003-3692-0223 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 SN 1082-3654 BN 0-7803-7324-3 J9 IEEE NUCL SCI CONF R PY 2002 BP 487 EP 491 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Nuclear Science & Technology; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA BV30L UT WOS:000178495800108 ER PT S AU Sharma, DP Ramsey, BD Seller, P Tumer, T AF Sharma, DP Ramsey, BD Seller, P Tumer, T BE Seibert, JA TI A study of charge sharing in pixellated cadmium-zinc-telluride detectors SO 2001 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORDS, VOLS 1-4 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium CY NOV 04-10, 2001 CL SAN DIEGO, CA SP IEEE, Nucl Plasma Sci Soc AB In this paper we present the status and preliminary results from a CZT development program of fine pixel detectors. These are to be used at the focus of high-energy grazing-incidence optics (20-75 keV) of the HERO-Experiment under construction at the Marshal Space Flight Center. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Sharma, DP (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 3 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-7324-3 J9 IEEE NUCL SCI CONF R PY 2002 BP 991 EP 994 DI 10.1109/NSSMIC.2001.1009720 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Nuclear Science & Technology; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA BV30L UT WOS:000178495800216 ER PT S AU Ramsey, BD AF Ramsey, BD BE Seibert, JA TI (Fine-Pixel) Imaging CdZnTe Arrays for space applications SO 2001 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORDS, VOLS 1-4 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium CY NOV 04-10, 2001 CL SAN DIEGO, CA SP IEEE, Nucl Plasma Sci Soc ID X-RAY ASTRONOMY; RADIATION-DAMAGE; DETECTORS AB The compound Cadmium-Zinc-Telluride (CdZnTe) offers great promise for astrophysics. As crystal quality improves, the challenge for imaging array development is to derive electrode geometries and readout electronics to satisfy particular applications and to understand how the material will perform in the space environment. An overview of the requirements for CdZnTe imaging detectors at the focus of hard-x-ray grazing-incidence telescopes will be given together with the status of current array developments. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Ramsey, BD (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 13 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1082-3654 BN 0-7803-7324-3 J9 IEEE NUCL SCI CONF R PY 2002 BP 2377 EP 2381 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Nuclear Science & Technology; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA BV30L UT WOS:000178495800519 ER PT S AU Parsons, AM AF Parsons, AM CA Swift BAT Instrument Team BE Seibert, JA TI The Swift Gamma-Ray Burst Explorer burst alert telescope (BAT) SO 2001 IEEE NUCLEAR SCIENCE SYMPOSIUM, CONFERENCE RECORDS, VOLS 1-4 SE IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium CY NOV 04-10, 2001 CL SAN DIEGO, CA SP IEEE, Nucl Plasma Sci Soc AB The Swift Gamma Ray Burst Explorer, to be launched in late September 2003, will observe hundreds of gamma ray bursts per year and study their X-ray and optical afterglow with its multiwavelength complement of three instruments: a large gamma ray telescope called the Burst Alert Telescope (BAT), an X-Ray Telescope (XRT), and a UV/Optical Telescope (UVOT). The BAT is a large coded aperture gamma ray telescope with a wide field-of-view that provides the gamma ray burst triggers for the Swift Mission. BAT will observe and locate hundreds of bursts per year to better than 4 arc minutes accuracy. Using this prompt burst location information, Swift will slew quickly (within 20 - 70 s) and autonomously to point the on-board narrow field-of-view XRT and UVOT instruments at the burst for continued afterglow studies. A full description of the BAT instrument, including its 32,768-element CdZnTe detector array are presented and performance results from initial tests of BAT detector modules will also be discussed. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Parsons, AM (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Parsons, Ann/I-6604-2012 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 SN 1082-3654 BN 0-7803-7324-3 J9 IEEE NUCL SCI CONF R PY 2002 BP 2382 EP 2386 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Nuclear Science & Technology; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA BV30L UT WOS:000178495800520 ER PT B AU Truong, LV Wolff, FJ Dravid, NV AF Truong, LV Wolff, FJ Dravid, NV BE Pierson, E Jackson, WD TI Simulation of energy sharing among flywheels in parallel configuration SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB Flywheel Express Pallet Experiment (FEPE) has been proposed on the International Space Station to study flywheel energy storage application for Space Power Systems. In support of that effort, simulation of two independent, coaxially rotating flywheels, supplied from a common do bus, was performed. The simulation procedure was divided into three simple steps. First, both flywheels are charged approximately to half way of the speed range. Then, charging of one flywheel is continued to fully charged state while discharging the other to minimum charge state. Finally, charge/discharge process is reversed to switch the energy storage states of the two flywheels. System description, scope of simulation, discussion of simulation results, and conclusions will be presented. C1 NASA, Glenn Res Ctr, Cleveland, OH USA. RP Truong, LV (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 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 0-7803-7296-4 PY 2002 BP 15 EP 20 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700004 ER PT B AU Hoffman, DJ AF Hoffman, DJ BE Pierson, E Jackson, WD TI A systems model for power technology assessment SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB A computer model is under continuing development at NASA Glenn Research Center that enables first-order assessments of space power technology. The model, an evolution of NASA Glenn's Array Design Assessment Model (ADAM), is an Excel workbook that consists of numerous spreadsheets containing power technology performance data and sizing algorithms. Underlying the model is a number of databases that contain default values for various power generation, energy storage and power management and distribution component parameters. These databases are actively maintained by a team of systems analysts so that they contain state-of-art data as well as the most recent technology performance projections. Sizing of the power subsystems can be accomplished either by using an assumed mass specific power (W/kg) or energy (Wh/kg) or by a bottoms-up calculation that accounts for individual component performance and masses. The power generation, energy storage and power management and distribution subsystems are sized for given mission requirements for a baseline case and up to three alternatives. This allows four different power systems to be sized and compared using consistent assumptions and sizing algorithms. The component sizing models contained in the workbook are modular so that they can be easily maintained and updated. All significant input values have default values loaded from the databases that can be over-written by the user. The default data and sizing algorithms for each of the power subsystems are described in some detail. The user interface and workbook navigational features are also discussed. Finally, an example study case that illustrates the model's capability is presented. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Hoffman, DJ (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 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 0-7803-7296-4 PY 2002 BP 21 EP 26 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700005 ER PT B AU Michaelis, TD AF Michaelis, TD BE Pierson, E Jackson, WD TI Energy fundamentals SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Michaelis, TD (reprint author), NASA, Goddard Space Flight Ctr, 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 0-7803-7296-4 PY 2002 BP 27 EP 27 PG 1 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700006 ER PT B AU Delleur, AM Kerslake, TW AF Delleur, AM Kerslake, TW BE Pierson, E Jackson, WD TI Electrical performance of the International Space Station US photovoltaic array during bifacial illumination SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB With the first United States (US) photovoltaic array (PVA) activated on International Space Station (ISS) in December 2000, on-orbit data can now be compared to analytical predictions. Due to ISS operational constraints, it is not always possible to point the front side of the arrays at the Sun. Thus, in many cases, sunlight directly illuminates the backside of the PVA as well as albedo illumination on either the front or the back. During this time, appreciable power is produced since the solar cells are mounted on a thin, solar transparent substrate. It is important to present accurate predictions for both front and backside power generation for mission planning, certification of flight readiness for a given mission, and on-orbit mission support. To provide a more detailed assessment of the ISS power production capability, the authors developed a PVA electrical performance model applicable to generalized bifacial illumination conditions. On-orbit PVA performance data were also collected and analyzed. This paper describes the ISS PVA performance model, and the methods used to reduce orbital performance data. Analyses were performed using SPACE, a NASA-GRC developed computer code for the ISS program office. Results showed a excellent comparison of on-orbit performance data and analytical results. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Delleur, AM (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. 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 0-7803-7296-4 PY 2002 BP 39 EP 44 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700009 ER PT B AU Savoy, M Miller, T AF Savoy, M Miller, T BE Pierson, E Jackson, WD TI International Space Station electrical power system performance and operational lessons learned SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Savoy, M (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. 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 0-7803-7296-4 PY 2002 BP 93 EP 93 PG 1 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700022 ER PT B AU Fincannon, HJ AF Fincannon, HJ BE Pierson, E Jackson, WD TI Comparison of ISS power system telemetry with analytically derived data for shadowed cases SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB Accurate International Space Station (ISS) power prediction requires the quantification of solar array shadowing. Prior papers have discussed the NASA Glenn Research Center (GRC) ISS power system tool (SPACE: System Power Analysis for Capability Evaluation) and its integrated shadowing algorithms. On-orbit telemetry has become available that permits the correlation of theoretical shadowing predictions with actual data. This paper documents the comparison of a shadowing metric (total solar array current) as derived from SPACE predictions and on-orbit flight telemetry data for representative significant shadowing cases. Images from flight video recordings and the SPACE computer program graphical output are used to illustrate the comparison. The accuracy of the SPACE shadowing capability is demonstrated for the cases examined. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Fincannon, HJ (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS-500-103, Cleveland, OH 44135 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 0-7803-7296-4 PY 2002 BP 100 EP 105 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700024 ER PT B AU Dalton, P Cohen, F AF Dalton, P Cohen, F BE Pierson, E Jackson, WD TI International Space Station nickel-hydrogen battery on-orbit performance SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB International Space Station (ISS) Electric Power System (EPS) utilizes Nickel-Hydrogen (Ni-H-2) batteries as part of its power system to store electrical energy. The batteries are charged during insolation and discharged during eclipse. The batteries are designed to operate at a 35% depth of discharge (DOD) maximum during normal operation. Thirty-eight individual pressure vessel (IPV) Ni-H-2 battery cells are series-connected and packaged in an Orbital Replacement Unit (ORU). Two ORUs are series-connected utilizing a total of 76 cells, to form one battery. The ISS is the first application for low earth orbit (LEO) cycling of this quantity of series-connected cells. The P6 (Port) Integrated Equipment Assembly (IEA) containing the initial ISS high-power components was successfully launched on November 30, 2000. The IEA contains 12 Battery Subassembly ORUs (6 batteries) that provide station power during eclipse periods. This paper will discuss the battery performance data after eighteen months of cycling. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Dalton, P (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS500-103, Cleveland, OH 44135 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 0-7803-7296-4 PY 2002 BP 106 EP 113 PG 8 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700025 ER PT B AU Mason, LS AF Mason, LS BE Pierson, E Jackson, WD TI Power technology options for nuclear electric propulsion SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB On-going studies being conducted under the Office of Space Science (Code S) In-Space Propulsion Program have identified high power (100 kWe) NEP as an enabling technology for space science missions. The benefits of NEP include larger payload fractions, faster and more direct trajectories, and increased power at destination as compared to other propulsion technologies. In order to realize these benefits, a critical first-step is the development of a lightweight, long-lived reactor power system. This paper presents a historical review of relevant space reactor power programs, describes the operational characteristics of candidate power conversion technology options, and proposes a reactor power system concept with appealing near term performance and long term growth potential. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Mason, LS (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 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 BN 0-7803-7296-4 PY 2002 BP 114 EP 121 PG 8 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700026 ER PT B AU Choi, SH Golembiewski, W Chu, SH Song, KD King, G AF Choi, SH Golembiewski, W Chu, SH Song, KD King, G BE Pierson, E Jackson, WD TI Microwave power for smart membrane actuators SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Choi, SH (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 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 0-7803-7296-4 PY 2002 BP 122 EP 122 PG 1 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700027 ER PT B AU Wagner, RC Boyle, DR Decker, K AF Wagner, RC Boyle, DR Decker, K BE Pierson, E Jackson, WD TI Commercialization of flywheel energy storage technology on the international space station SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB An important mission of the International Space Station (ISS) is to provide a platform for engineering research and development of commercial technology in Low Earth Orbit (LEO). Flywheel energy storage technology is an ideal candidate for this mission because, in addition to benefiting the commercial and military satellite industries, it offers significant operating cost savings to the ISS. This paper describes a proposed flight experiment using the ISS EXpedite the PRocessing of Experiments to Space Station (EXPRESS) Pallet as a test platform to demonstrate the feasibility of operating high speed, composite flywheels in LEO for energy storage applications. The proposed ISS payload, the Flywheel Express Pallet Experiment (FEPE), will build upon the legacy of an earlier technology development effort for ISS, the Flywheel Energy Storage System (FESS) program. FESS was specifically designed to replace the Nickel Hydrogen (NiH2) Battery orbital replacement units in the ISS Electric Power System. In contrast, FEPE will incorporate two counter-rotating flywheels, on the ISS Express Pallet, exchanging energy with each other. The ISS will provide the small amount of power needed to make up for losses. From a technology perspective, FEPE is being proposed to validate flywheel systems in the combined LEO environment, which cannot be fully simulated in a ground facility. FEPE is also a necessary step in the commercialization of flywheel technology for satellites. C1 Univ Toledo, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Wagner, RC (reprint author), Univ Toledo, NASA, Glenn Res Ctr, 21000 Brookpk Rd,Mail Stop 301-5, Cleveland, OH 44135 USA. 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 0-7803-7296-4 PY 2002 BP 146 EP 150 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700032 ER PT B AU McLallin, KL AF McLallin, KL BE Pierson, E Jackson, WD TI IECEC 2002 abstract submission form SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP McLallin, KL (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,Mail Stop 500-103, Cleveland, OH 44135 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 0-7803-7296-4 PY 2002 BP 167 EP 167 PG 1 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700037 ER PT B AU Mason, P Beaman, BG AF Mason, P Beaman, BG BE Pierson, E Jackson, WD TI NASA/Goddard Space Flight Center (GSFC) integrated mission design center (IMDC) - Flywheel application survey 2002 SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE C1 NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Greenbelt, MD 20771 USA. RP Mason, P (reprint author), NASA, Goddard Space Flight Ctr, Flight Dynam Anal Branch, Code 572, 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 0-7803-7296-4 PY 2002 BP 179 EP 180 PG 2 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700040 ER PT B AU Bailey, SG Harris, JD Hepp, AF Anglin, EJ Raffaelle, RP Clark, HR Gardner, STP Sun, SS AF Bailey, SG Harris, JD Hepp, AF Anglin, EJ Raffaelle, RP Clark, HR Gardner, STP Sun, SS BE Pierson, E Jackson, WD TI Thin-film organic-based solar cells for space power SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE ID DONOR-ACCEPTOR HETEROJUNCTIONS; STABILITY; CONVERSION; POLYMER; EFFICIENCIES; SENSITIZERS AB Recent advances in dye-sensitized and organic polymer solar cells have lead NASA to investigate the potential of these devices for space power generation. Dye-sensitaized solar cells were exposed to simulated low-earth orbit conditions and their performance evaluated. All cells were characterized under simulated air mass zero (AM0) illumination. Complete cells were exposed to pressures less than 1 x 10(-7) torr for over a month, with no sign of sealant failure or electrolyte leakage. Cells from Solaronix SA were rapid thermal cycled under simulated low-earth orbit conditions. The cells were cycled 100 times from -80 C to 80 C, which is equivalent to 6 days in orbit. The best cell had a 4.6% loss in efficiency as a result of the thermal cycling. In a separate project, novel -Bridge-Donor-Bridge-Acceptor- (-BDBA-) type conjugated block copolymer systems have been synthesized and characterized by photoluminescence (PL). In comparison to pristine donor or acceptor, the PL emissions of final -B-D-B-A- block copolymer films were quenched over 99%. Effective and efficient photo induced electron transfer and charge separation occurs due to the interfaces of micro phase separated donor and acceptor blocks. The system is very promising for a variety high efficiency light harvesting applications. Under an SBIR contract, fullerene-doped polymer-based photovoltaic devices were fabricated and characterized. The best devices showed overall power efficiencies of similar to0.14% under white light. Devices fabricated from 2% solids content solutions in chlorobenzene gave the best results. Presently, device lifetimes are too short to be practical for space applications. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Bailey, SG (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 15 TC 0 Z9 0 U1 1 U2 8 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7296-4 PY 2002 BP 191 EP 196 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700043 ER PT B AU Hepp, AF AF Hepp, AF BE Pierson, E Jackson, WD TI IECEC 2002 abstract submission SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Hepp, AF (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,M-S 302-1, Cleveland, OH 44135 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 0-7803-7296-4 PY 2002 BP 197 EP 197 PG 1 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700044 ER PT B AU Hepp, AF Raffaelle, RP Banger, KK Jin, MH Lau, JE Harris, JD Cowen, JE Duraj, SA AF Hepp, AF Raffaelle, RP Banger, KK Jin, MH Lau, JE Harris, JD Cowen, JE Duraj, SA BE Pierson, E Jackson, WD TI Chemical vapor deposition for ULTR-lightweight thin-film solar arrays for space SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE ID SINGLE-SOURCE PRECURSORS AB The development of thin-film solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution to fabricating solar arrays with high specific power, (W/kg). The use of a polycrystalline chalcopyrite absorber layer for thin film solar cells is considered as the next generation photovoltaic devices. A key technical issues outlined in the 2001 US Photovoltaic Roadmap, is the need to develop low cost, high throughput manufacturing for high-efficiency thin film solar cells. At NASA GRC we have focused on the development of new single-source-precursors (SSP's) and their utility to deposit the chalcopyrite semi-conducting layer (CIS) onto flexible substrates for solar cell fabrication. The syntheses and thermal modulation of SSP's via molecular engineering is described. Thin-film fabrication studies demonstrate the SSP's can be used in a spray CVD process, for depositing CIS at reduced temperatures, which display good electrical properties, suitable for PV devices. C1 NASA, Glenn Res Ctr, Photovolta & Space Environm Branch, Cleveland, OH 44135 USA. RP Hepp, AF (reprint author), NASA, Glenn Res Ctr, Photovolta & Space Environm Branch, 2100 Brookpk Rd,M-S 302-1, Cleveland, OH 44135 USA. EM a.f.hepp@grc.nasa.gov; ryne.p.raffaelle@grc.nasa.gov; KulbinderBanger@oai.org; michael.h.jin@grc.nasa.gov; janice.e.lau@grc.nasa.gov; jerry.harris@grc.nasa.gov; J.Cowen@grc.nasa.gov; s.duraj@csuohio.edu NR 14 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7296-4 PY 2002 BP 198 EP 203 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700045 ER PT B AU Lyons, JW AF Lyons, JW BE Pierson, E Jackson, WD TI SMEX-lite modular solar array architecture SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB The NASA Small Explorer (SMEX) missions have typically had three years between mission definition and launch. This short schedule has posed significant challenges with respect to solar array design and procurement. Typically, the solar panel geometry is frozen prior to going out with a procurement. However, with the SMEX schedule, it has been virtually impossible to freeze the geometry in time to avoid scheduling problems with integrating the solar panels to the spacecraft. A modular solar array architecture was developed to alleviate this problem. This approach involves procuring sufficient modules for multiple missions and assembling the modules onto a solar array framework that is unique to each mission. The modular approach removes the solar array from the critical path of the SMEX integration and testing schedule. It also reduces the cost per unit area of the solar arrays and facilitates the inclusion of experiments involving new solar cell or panel technologies in the SMEX missions. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lyons, JW (reprint author), NASA, Goddard Space Flight Ctr, Code 563, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7296-4 PY 2002 BP 204 EP 208 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700046 ER PT B AU Kascak, PE Jansen, RH Kenny, BH Dever, TP AF Kascak, PE Jansen, RH Kenny, BH Dever, TP BE Pierson, E Jackson, WD TI Single axis attitutude control and DC bus regulation with two flywheels SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB A computer simulation of a flywheel energy storage single axis attitude control system is described. The simulation models hardware which will be experimentally tested in the future. This hardware consists of two counter rotating flywheels mounted to an airtable. The airtable allows one axis of rotational motion. An inertia DC bus coordinator is set forth that allows the two control problems, bus regulation and attitude control, to be separated. Simulation results are presented with a previously derived flywheel bus regulator (Kascak, 2001) and a simple PID attitude controller. C1 Univ Toledo, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Kascak, PE (reprint author), Univ Toledo, NASA, Glenn Res Ctr, MS301-5,21000 Brookpk Rd, Cleveland, OH 44135 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 0-7803-7296-4 PY 2002 BP 214 EP 221 PG 8 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700048 ER PT B AU Dever, TP Jansen, RH Brown, GV AF Dever, TP Jansen, RH Brown, GV BE Pierson, E Jackson, WD TI Estimator based controller for high speed flywheel magnetic bearing system SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB A flywheel system and its operator interface are described. Measurements of magnetic bearing negative stiffness are performed. Two digital magnetic bearing control algorithms (PD and estimator based) are defined, and their implementations are described. Tuning of each controller is discussed. Comparison of the two controllers' stability, damping noise and operating current are described. Results describing the superiority of the estimator-based controller are presented and discussed. C1 NASA, Glenn Res Ctr, QSS Grp Inc, Cleveland, OH 44135 USA. RP Dever, TP (reprint author), NASA, Glenn Res Ctr, QSS Grp Inc, MS 5-11,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 2 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7296-4 PY 2002 BP 227 EP 232 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700051 ER PT B AU Trase, LM AF Trase, LM BE Pierson, E Jackson, WD TI The evaluation and implementation of a water containment system to support aerospace flywheel testing SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB High-energy flywheel systems for aerospace power storage and attitude control applications are being developed because of the potential for increasing the energy density and reducing operational costs. A significant challenge facing the development of the test hardware is containment of the rotating elements in the event of a failure during the development and qualification stages of testing. This containment is critical in order to ensure the safety of the test personnel and the facility. A containment system utilizing water as the containment media is presented. Water containment was found to be a low cost, flexible, and highly effective containment system. Ballistic test results and analytical results are discussed along with a description of a flywheel test facility that was designed and built utilizing the water containment system at the NASA Glenn Research Center at Lewis Field in Cleveland, Ohio. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Trase, LM (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 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 0-7803-7296-4 PY 2002 BP 234 EP 238 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700052 ER PT B AU Keys, DJ Rao, GM AF Keys, DJ Rao, GM BE Pierson, E Jackson, WD TI Effective resistive drain design considerations for Ni-H-2 batteries and related battery support equipment SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE AB wThis paper will discuss some fundamental design parameters associated with both spacecraft batteries and commonly used battery cell resistive drain techniques as well as recommended methods to minimize the possibility of imposing excessive inadvertent and/or intentional reversal voltages across cells within the battery. Often overlooked, or at least not adequately considered, in the battery design and development phase is the effect of the battery design on the ability to efficiently discharge and remove the hydrogen in nickel pre-charged Nickel-Hydrogen (Ni-H-2) battery cells during routine, or planned, reconditioning. Coupled with the battery design considerations are also those concerns associated with the support equipment used to perform the resistive drain of the batteries. Attention paid to the design details associated with the effective resistive draining of the battery cells will lower the damage risk that may potentially be associated with this procedure. One of the most serious concerns often encountered in practice during resistive drain is the inadvertent, or excessive, voltage reversal of Ni-H-2 battery cells. Also, there is significant evidence that when Ni-H-2 battery cells are reversed for a prolonged period and/or for consecutive operations, a subsequent permanent loss of useable storage capacity as well as the potential for a shortened onorbit life span could be experienced. This paper is primarily aimed at battery designs utilizing either individual pressure vessels (IPV) or common pressure vessels (CPV) and is not intended to examine single pressure vessel (SPV) Ni-H-2 battery designs (although the basic design principles discussed in this paper are still applicable). In addition to the design considerations, an overview of the potential detrimental effects that can be caused by excessive battery cell reversal is also addressed in this paper. Experience has taught us that under certain circumstances (e.g., in preparation for Nickel precharged battery cell storage where removal of residual hydrogen is normally a requirement) undesirable battery cell reversals can be imposed within a battery during battery cell resistive drain. This experience has also resulted in the identification of good engineering practices designed to avoid potential damage to the batteries when performing routine procedures like those associated with battery reconditioning. The development of design guidelines in this paper are intended to help the spacecraft battery design engineer avoid problems associated with inadvertent or excessive battery cell reversal during reconditioning of spacecraft batteries. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Keys, DJ (reprint author), NASA, Goddard Space Flight Ctr, Code 563, 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 0-7803-7296-4 PY 2002 BP 290 EP 294 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700063 ER PT B AU Rao, GM Wajsgras, H Krol, SJ AF Rao, GM Wajsgras, H Krol, SJ BE Pierson, E Jackson, WD TI Intersociety Energy Conversion Engineering Conference 2002 - Rubble space telescope on-orbit NiH2 battery capacity performance (1990 to 2002) SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE C1 NASA, Goddard Space Flight Ctr, Space Power Applicat Branch, Greenbelt, MD 20771 USA. RP Rao, GM (reprint author), NASA, Goddard Space Flight Ctr, Space Power Applicat Branch, Code 661, 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 0-7803-7296-4 PY 2002 BP 295 EP 295 PG 1 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700064 ER PT B AU Smart, MC Ratnakumar, BV Chin, KB Whitcanack, LD Davies, ED Surampudi, S Manzo, MA Dalton, PJ AF Smart, MC Ratnakumar, BV Chin, KB Whitcanack, LD Davies, ED Surampudi, S Manzo, MA Dalton, PJ BE Pierson, E Jackson, WD TI Lithium-ion cell technology demonstration for future NASA applications SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE ID BATTERIES AB NASA requires lightweight rechargeable batteries for future missions to Mars and the outer planets that are capable of operating over a wide range of temperatures, with high specific energy and energy densities. Due to their attractive performance characteristics, lithium-ion batteries have been identified as the battery chemistry of choice for a number of future applications, including planetary orbiters, rovers and landers. For example, under the Mars Surveyor Program MSP 01 lithium-ion batteries were developed by Lithion (each being 28 V, 25 Ah, 8-cells, and 9 kg) and fully qualified prior to mission cancellation. In addition to the requirement of being able to supply at least 90 cycles on the surface of Mars, the battery demonstrated operational capability (both charge and discharge) over a large temperature range (-20 degreesC to +40 degreesC), with tolerance to nonoperational excursions to-30 degreesC and 50 degreesC. Currently, JPL is implementing lithium-ion technology on the 2003 Mars Exploration Rover (MER), which will be coupled with a solar array. This mission has similar performance requirements to that of the 2001 Lander in that high energy density and a wide operating temperature range are necessitated. In addition to planetary rover and lander applications, we are also engaged in determining the viability of using lithium-ion technology for orbiter applications that require exceptionally long life (>20,000 cycles at partial depth of discharge). To assess the viability of lithium-ion cells for these applications, a number of performance characterization tests have been performed (at the cell and battery level) on state-of-art prototype lithium-ion cells, including: assessing the cycle life performance (at varying DODs), life characteristics at extreme temperatures (<-10 degreesC and >+40 C), rate capability as a function of temperature (-30degrees to 40 degreesC), pulse capability, self-discharge and storage characteristics, as well as, mission profile capability. This paper will describe the current and future NASA missions that are considering lithium ion batteries and will contain results of the cell testing conducted to-date to validate the technology for these missions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Smart, MC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 0 Z9 0 U1 2 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7296-4 PY 2002 BP 297 EP 304 PG 8 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700066 ER PT B AU Choi, MK AF Choi, MK BE Pierson, E Jackson, WD TI Method of generating orbital transient equivalent sink temperatures and thermal vacuum test target temperatures for swift instruments SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Choi, MK (reprint author), NASA, Goddard Space Flight Ctr, Code 545, 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 0-7803-7296-4 PY 2002 BP 355 EP 356 PG 2 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700081 ER PT B AU Choi, MK AF Choi, MK BE Pierson, E Jackson, WD TI SWIFT burst alert telescope loop heat pipe thermal system characteristics and flight operation procedure SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Choi, MK (reprint author), NASA, Goddard Space Flight Ctr, Code 545, Greenbelt, MD 20771 USA. 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 0-7803-7296-4 PY 2002 BP 357 EP 360 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700082 ER PT B AU Choi, MK AF Choi, MK BE Pierson, E Jackson, WD TI AZW-LA-II white paint on swift BAT and XRT radiators: First time this paint is flown on an operational spacecraft SO 2002 37TH INTERSOCIETY ENERGY CONVERSION ENGINEERING CONFERENCE (IECEC) LA English DT Proceedings Paper CT 37th Intersociety Energy Conversion Engineering Conference (IECEC) CY JUL 29-31, 2002 CL Washington, DC SP IEEE, AIAA, ASME, ANS, AIChe, SAE C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Choi, MK (reprint author), NASA, Goddard Space Flight Ctr, Code 545, 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 0-7803-7296-4 PY 2002 BP 361 EP 363 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BBC67 UT WOS:000224865700083 ER PT B AU Wilson, E Lages, C Mah, R AF Wilson, E Lages, C Mah, R GP IEEE IEEE TI On-line, gyro-based, mass-property identification for thruster-controlled spacecraft using recursive least squares SO 2002 45TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL II, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 45th Midwest Symposium on Circuits and Systems (MWSCAS 2002) CY AUG 04-07, 2002 CL TULSA, OK SP IEEE, Circuits & Syst Soc, Oklahoma State Univ, Sch Elect & Comp Engn AB Spacecraft control, state estimation, and fault-detection-and-isolation systems are affected by unknown variations in the vehicle mass properties. It is often difficult to accurately measure inertia terms on the ground, and mass properties can change on-orbit as fuel is expended, the configuration changes, or payloads are added or removed. Recursive least squares-based algorithms that use gyro signals to identify the center of mass and inverse inertia matrix are presented. They are applied in simulation to 3 thruster-controlled vehicles: the X-38 and Mini-AERCam under development at NASA-JSC, and the S4, an air-bearing spacecraft simulator at the NASA-Ames Smart Systems Research Lab (SSRL). C1 NASA, Ames Res Ctr, Smart Syst Res Lab, Moffett Field, CA 94035 USA. RP Wilson, E (reprint author), NASA, Ames Res Ctr, Smart Syst Res Lab, MS 269-1, Moffett Field, CA 94035 USA. NR 12 TC 0 Z9 0 U1 1 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA PY 2002 BP 334 EP 337 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology SC Computer Science; Engineering; Imaging Science & Photographic Technology GA BW25K UT WOS:000181336800085 ER PT B AU Lee, M Weidner, RJ Soderblom, LA AF Lee, M Weidner, RJ Soderblom, LA GP IEEE IEEE TI Deep space 1 mission and observation of comet Borrellly SO 2002 45TH MIDWEST SYMPOSIUM ON CIRCUITS AND SYSTEMS, VOL II, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 45th Midwest Symposium on Circuits and Systems (MWSCAS 2002) CY AUG 04-07, 2002 CL TULSA, OK SP IEEE, Circuits & Syst Soc, Oklahoma State Univ, Sch Elect & Comp Engn C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lee, M (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 PY 2002 BP 367 EP 370 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology SC Computer Science; Engineering; Imaging Science & Photographic Technology GA BW25K UT WOS:000181336800093 ER PT B AU Kirkham, H AF Kirkham, H GP IEEE IEEE TI On the measurement of stationary electric fields in air SO 2002 CONFERENCE ON PRECISION ELECTROMAGNETIC MEASUREMENTS, CONFERENCE DIGEST LA English DT Proceedings Paper CT Conference on Precision Electromagnetic Measurements (CPEM 2002) CY JUN 16-21, 2002 CL OTTAWA, CANADA SP Bureau Int Poids Measures, IEEE Instrumentat & Measurement Soc, Natl Inst Stand & Technol, Int Union Pure & Appl Phys, Measurements Int Ltd, Natl Conf Stand Lab Int, Natl Res Council Canada, Union Radio Sci Int AB Applications and measurement methods for field measurements are reviewed. Recent developments using optical technology are examined. The various methods are compared. It is concluded that the best general purpose instrument is the isolated cylindrical field mill, but MEMS technology could famish better instruments in the future. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kirkham, H (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Kirkham, Harold/0000-0003-2893-7586 NR 6 TC 5 Z9 5 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7242-5 PY 2002 BP 524 EP 525 DI 10.1109/CPEM.2002.1034953 PG 2 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Engineering; Instruments & Instrumentation; Physics GA BV29Y UT WOS:000178482400255 ER PT B AU Woerner, DF AF Woerner, DF GP IEEE IEEE TI The selection and infusion of autonomy for Mars rovers SO 2002 FIRST INTERNATIONAL IEEE SYMPOSIUM INTELLIGENT SYSTEMS, VOL 1, PROCEEDINGS LA English DT Proceedings Paper CT 1st International IEEE Symposium on Intelligent Systems CY SEP 10-12, 2002 CL VARNA, BULGARIA SP IEEE Control Syst Soc, IEEE Instrumentat & Measurement Soc, IEEE Reg 8, Auckland Univ Technol, Knowledge Engn & Discovery Res Inst, IEE IM CS SMC Joint Chapter Bulgaria, IEEE Sect Bulgaria, ICT Dev Agcy, EUNITE DE autonomy; rovers; Mars; reliability AB How do you select autonomy, insure that it meets your needs, and arrives for launch in a reliable form? How do you ensure autonomy providers around the country meet these goals compliant with institutional practices and policies at the Jet Propulsion Laboratory for building space qualified reliable systems? Answers to these questions have resulted in a process we call autonomy infusion. This paper describes the process MSL is using to infuse autonomy into a rover, and describes attributes, and evaluation criteria and their use pertinent to autonomy technologies for Mars rovers in general. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Woerner, DF (reprint author), CALTECH, Jet Prop Lab, Mail Stop 301-422,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM david.f.woerner@jpl.nasa.gov NR 10 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7601-3 PY 2002 BP 86 EP 91 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BW08J UT WOS:000180818600015 ER PT S AU Larson, M Chui, T Croonquist, A Holmes, W Langford, D Liu, FC Pensinger, J AF Larson, M Chui, T Croonquist, A Holmes, W Langford, D Liu, FC Pensinger, J GP IEEE IEEE TI A low temperature facility for experiments on the international space station SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID HEAT-CAPACITY; LAMBDA-POINT; HELIUM; HE-4 AB The Jet Propulsion Laboratory (JPL) is currently developing the Low Temperature Microgravity Physics Experiments Facility (LTMPEF), a multiple user and multiple flight facility that will provide a long duration low temperature environment on board the International Space Station. The LTMPEF will be attached to the Japanese Experiment Module (KIBO) Exposed Facility of the International Space Station with an initial flight starting in late 2005. The LTMPF is a self contained, reusable, cryogenic facility containing a 180-liter superfluid helium tank, two experiment packages, and electronics to provide experiment control and telemetry. Two distinct primary experiments will be accommodated during each mission, and secondary experiments requiring no additional hardware beyond that built for the primary experiments will also be accommodated during each mission. Detailed technical capabilities of the Facility will be presented, along with a brief description of the six science investigations currently selected to fly on the first two missions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Larson, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 15 EP 21 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800001 ER PT S AU Klipstein, WM Maleki, L Prestage, JD Seidel, DJ Thompson, RJ AF Klipstein, WM Maleki, L Prestage, JD Seidel, DJ Thompson, RJ GP IEEE IEEE TI Laser-cooled atomic clocks as science payloads on the International Space Station SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB In this paper we present an overview of two flight-definition experiments to develop space-based ultrahigh performance atomic clocks for performing precision tests of Einstein's theories of Special and General Relativity. These experiments rely on laser-cooling of gases of atoms to near absolute zero to realize extremely long interaction times, enabling their performance. We focus on the role played by the Jet Propulsion Laboratory in developing the core technologies to support these and future missions. We also discuss the various science platforms available on the International Space Station (ISS) and the challenges of performing a laser cooled atomic clock experiment in this environment. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Klipstein, WM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 298-100, Pasadena, CA 91109 USA. NR 2 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 41 EP 46 PG 6 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800004 ER PT S AU Grasso, CA AF Grasso, CA GP IEEE IEEE TI The fully programmable spacecraft: Procedural sequencing for JPL deep space missions using VML (Virtual Machine Language) SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB VML (Virtual Machine Language) is an advanced procedural sequencing language which simplifies spacecraft operations, minimizes uplink product size, and allows autonomous operations aboard a mission without the development of autonomous flight software. The language is a mission-independent, high level, human readable script. It features a rich set of data types (including integers, doubles, and strings), named functions, parameters, IF and WHILE control structures, polymorphism, and on-the-fly creation of spacecraft commands from calculated values. VML has been used on six JPL deep space missions. It is currently in use on Mars Odyssey, Stardust, Genesis, and the Space Infrared Telescope Facility (SIRTF). It is slated for use on the 2005 Mars Reconnaissance Orbiter. The language and associated Right code has allowed spacecraft operations teams to place autonomy aboard deep space missions, implemented as operations products (blocks and sequences). The flight component of VML is implemented in C. This flight code interprets binaries produced by the ground component. It runs on a scheduled basis (typically 10 Hz) within the flight code, providing a configurable number of parallel threads of execution (typically eight, up to 65,533). The flight component responds to commands to load files, begin and end execution, save and restore global variable values, and set error responses. The VML flight component can issue spacecraft commands using parameter values and local variables within blocks and sequences. Hooks can invoke special-purpose mission-specific flight code from sequences. This paper lays out language constructs and capabilities, code features, and VML operations development concepts. The ability to migrate to the spacecraft functionality which is more traditionally implemented on the ground is examined. The implications for implementing spacecraft autonomy without the need for expensive flight software agent development is also discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Grasso, CA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 301-250D, 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 75 EP 81 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800007 ER PT S AU Traylor, M Hall, R Chau, S Whitfield, A AF Traylor, M Hall, R Chau, S Whitfield, A GP IEEE IEEE TI Modeling the Europa Pathfinder avionics system with a model based avionics architecture tool SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB In order to decrease avionics architecture development time, the Jet Propulsion Laboratory has developed a model-based architecture simulation tool called the Avionics System Architecture Tool (ASAT). ASAT consists of a library of reusable avionics component models, an avionics architecture development environment, and a set of scenario scripts embodying important sequences of system operation. ASAT users build avionics architecture models using components from the library, run scenarios through the architectures, and analyze simulation run results to verify the architecture meets system requirements. In this way, architecture level design problems are unconvered early in the design process. In addition, since the component models can easily be added, changed, or removed from the system model, ASAT supports rapid trade studies among architecture options. This paper reports on ASAT development and its application to model alternate avionics architectures of a Europa lander mission study project called Europa Pathfinder. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Traylor, M (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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 83 EP 91 PG 9 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800008 ER PT S AU Maldague, PF Alkalai, L Chau, S Cheung, KM Tong, D Ko, AY AF Maldague, PF Alkalai, L Chau, S Cheung, KM Tong, D Ko, AY GP IEEE IEEE TI Distributed computing for autonomous on board planning and sequence validation SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE Aerospace Conference Proceedings LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB We propose a new conceptual approach to system-level autonomy that exploits in a synergistic way recent breakthroughs in three specific areas: 1. Automatic generation of embeddable planning an validation software An existing Activity Plan Generation Tool (APGEN) will be modified into an embeddable, lightweight version (APGEN-lite) that is suitable for insertion into the Command and Data Handler (C&DH) subsystem of an autonomous Spacecraft (S/C). APGEN-lite will generate and validate science opportunities activities in real time onboard the S/C. As a result, it will optimize the automatic delivery of science data to the ground, and dramatically reduce the operational costs. 2. Integration of telecommunications forecaster and planning tools. To integrate a ground based telecom. link analysis tool known as the telecommunications forecaster predictor (TFP) to S/C environment by taking advantage of APGEN-lite, that will make use of advanced telecom technologies such adaptive compression schemes. 3. Fault-tolerant assignment of computing tasks to multiple processors. Because it is responsible for its own planning and validation tasks, an autonomous S/C has much higher computing requirements than a conventional S/C. Therefore, the avionics architecture for autonomy has to be much more fault-tolerant than the traditional flight system design. The breakthrough that we exploit in our approach is a recently developed high-speed scalable fault tolerant distributed avionics architecture, which consists of two or more processors connected to multiple sensors, actuators, and science instruments by a high-speed, fault tolerant bus network. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM adans.y.ko@jpl.nasa.gov 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 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 93 EP 104 PG 12 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800009 ER PT S AU Gluck, PR Holzmann, GJ AF Gluck, PR Holzmann, GJ GP IEEE IEEE TI Using SPIN model checking for flight software verification SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE Aerospace Conference Proceedings LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Flight software is the central nervous system of modem spacecraft. Verifying spacecraft flight software to assure that it operates correctly and safely is presently an intensive and costly process. A multitude of scenarios and tests must be devised, executed and reviewed to provide reasonable confidence that the software will perform as intended and not endanger the spacecraft. Undetected software defects on spacecraft and launch vehicles have caused embarrassing and costly failures in recent years. Model checking is a technique for software verification that can detect concurrency defects that are otherwise difficult to discover. Within appropriate constraints, a model checker can perform an exhaustive state-space search on a software design or implementation and alert the implementing organization to potential design deficiencies. Unfortunately, model checking of large software systems requires an often-too-substantial effort in developing and maintaining the software functional models. A recent development in this area, however, promises to enable software-implementing organizations to take advantage of the usefulness of model checking without hand-built functional models. This development is the appearance of "model extractors." A model extractor permits the automated and repeated testing of code as built rather than of separate design models. This allows model checking to be used without the overhead and perils involved in maintaining separate models. We have attempted to apply model checking to legacy flight software from NASA's Deep Space One (DS1) mission. This software was implemented in C and contained some known defects at launch that are detectable with a model checker. We will describe the model checking process, the tools used, and the methods and conditions necessary to successfully perform model checking on the DS1 flight software. C1 NASA, Jet Prop Lab, Pasadena, CA 91109 USA. RP NASA, Jet Prop Lab, Pasadena, CA 91109 USA. EM peter.r.gluck@jpl.nasa.gov; gerard@research.bell-labs.com NR 14 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 105 EP 113 PG 9 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800010 ER PT S AU Manvi, R Zimmerman, W Weisbin, C Rodriguez, G AF Manvi, R Zimmerman, W Weisbin, C Rodriguez, G GP IEEE IEEE TI Technology portfolio options for NASA missions using decision trees SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The portfolio allocation problem is pervasive to all R&D endeavors (i.e. all basic research sponsors need to be able to justify the anticipated incremental benefit/cost/ratios). The approach suggested is to utilize decision tree(s) that capitalize on past experience of probabilistic fault/event tree analysis developed in nuclear industry. A mission concept is formalized in terms of a sequence of event trees linkages and alternatives with probabilities/figures of merit of success and associated R&D costs ascribed at each link. For example, a search for life mission on Europa would involve site reconnaissance, site selection, landing, deep drilling through ice, small autonomous submersibles traversing the purported sea under ice, and in-situ life detection. Many advanced technologies not currently available would be required including long duration survivable systems (power, thermal, radiation), minimal mass autonomous systems (systems-on-a-chip, autonomous safe precision landing), life detection (including planetary protection) and communication of science data (ocean/ice/surface/orbiter/earth). For the Europa case, as an example, an event tree has been prepared in software (which means it is easily manipulated) with a variety of alternative technologies expressed. Mission objectives have been iterated with science teams; technology probabilities and costs at each link have been deduced and documented using information from Office of Space Science databases. These numbers are assumed to be the best estimates at present, which need to be reviewed and updated by NASA domain experts. Once the decision tree has been formulated with associated probabilities/figures of merit and costs at each link, it is easy to show that the proper metric for prioritization per dollar is the derivative which represents the relative change in probability of success at a given link, per change in investment dollar at that link, then divided by the current probability/figure of merit of that link. This is intuitively plausible since one seeks to maximize the change in probability for a unit change in R&D investment, and the smaller the probability of a given link, the more room there is to improve. In this model wherein the mission probability is multiplicative of the probability of all links (i.e. uncorrelated events), the percentage change in any one link propagates linearly to the percentage change in the overall mission probability. Using this metric, one can then prioritize and explain the technology investment strategy to potential R&D sponsors, and have a systematic method for continuing to improve the overall database and gain community consensus. The decision tree approach described, developed for an example long term (e.g. 2025) mission, is amenable to the introduction of time dependence if one is to consider investment strategies for nearer term endeavors, or Programs comprised of time sequences of several projects. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Manvi, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 179-224, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 115 EP 126 PG 12 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800011 ER PT S AU Wright, MR AF Wright, MR GP IEEE IEEE TI Integration and test for small shuttle payloads SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Recommended approaches for small space shuttle payload integration and test (I&T) are presented. The paper is intended for consideration by developers of small shuttle payloads, including I&T managers, project managers, and system engineers. Examples and lessons learned are presented based on the extensive history of NASA's Hitchhiker project. All aspects of I&T are presented, including: I&T team responsibilities, coordination, and communication Flight hardware handling practices Documentation and configuration management I&T considerations for payload development I&T at the development facility Prelaunch operations, transfer, orbiter integration and interface testing Postflight operations. This paper is of special interest to those payload projects that have small budgets and few resources: that is, the truly "faster, cheaper, better" projects. All shuttle small payload developers are strongly encouraged to apply these guidelines during I&T planning and ground operations to take full advantage of today's limited resources and to help ensure mission success. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Wright, MR (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 6 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 127 EP 146 PG 20 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800012 ER PT S AU Muirhead, BK AF Muirhead, BK GP IEEE IEEE TI Deep impact, the mission SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Deep Impact, The Mission This paper discusses the Deep Impact (DI) mission (the 8(th) Discovery Mission) objectives and potential discoveries derived from impacting a comet nucleus at ten times the speed of a bullet and simultaneously observing the results of that impact. The scientific return from this mission centers on 13 minutes of critical operations while flying through a comet's coma on July 4, 2005. A detailed mission and spacecraft description is provided including science instruments. The overall implementation approach is discussed including the special shared development and operations responsibilities among JPL, Ball Aerospace and University of Maryland. This paper also discusses the unique challenges of this mission especially the unknowns and potential hazards of flying deep into the comet environment (e.g. dust, surface topography, structure and composition). The design for robustness in the face of significant unknowns is discussed including autonomous navigation to track and hit a target, at a relative speed of 10 km/s. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Muirhead, BK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 147 EP 155 PG 9 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800013 ER PT S AU Kloss, C Girard, TJ Heinsohn, G Schulz, CK AF Kloss, C Girard, TJ Heinsohn, G Schulz, CK GP IEEE IEEE TI 2001 Mars Odyssey payload suite - The long, arduous journey to launch SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The 2001 Mars Odyssey spacecraft was successfully launched from the Cape Canaveral Air Force Station (CCAFS) on April 7, 2001. The payload suite consists of a Gamma-Ray Spectrometer, a Thermal Emission Imaging System, a Martian Radiation Environment Experiment, and a High Energy Neutron Spectrometer. The payload development model was based on the "faster, better, cheaper" Mars 98 Project (an orbiter and lander for $96M). Development of the payloads and assembly, test, and launch operations (ATLO) had significant challenges due to the low-cost nature of the project. Prior to payload deliveries, NASA imposed Red Team payload reviews to mitigate risk. Final payload integration occurred just two months before launch. Post-launch checkout was successfully completed three months after launch. This paper discusses the payload objectives, designs, procurement costs/philosophy, development and test challenges, lessons learned, and reports on the in-flight checkout. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Kloss, C (reprint author), Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 157 EP 170 PG 14 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800014 ER PT S AU Graf, J Zurek, R Jones, R Eisen, H Johnston, MD Jai, B Mateer, B AF Graf, J Zurek, R Jones, R Eisen, H Johnston, MD Jai, B Mateer, B GP IEEE IEEE TI An overview of the Mars Reconnaissance Orbiter mission SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The Mars Reconnaissance Orbiter (MRO) will be launched in August 2005 by an intermediate-class, expendable launch vehicle from Cape Canaveral Air Station, USA. It will deliver to Mars orbit a payload to conduct remote sensing science observations, characterize sites for future landers, and provide critical telecom/navigation relay capability for follow-on missions. The mission is designed to provide both global and targeted observations from a low 200 by 400 kin Mars orbit with a 3:00 P.M. local mean solar time (ascending node). During the one Martian year (687 Earth days) primary science phase, the orbiter will acquire visual and infrared high-resolution images of the planet's surface. After this science phase is completed, the orbiter will provide telecommunications support for spacecraft launched to Mars in the 2007 and 2009 opportunities. The primary mission ends on December 31, 2010,, approximately 5.5 years after launch. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Graf, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 171 EP 180 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800015 ER PT S AU Randolph, J Maleki, L Miyake, R Mettler, E Nesmith, B Prestage, J Tenerelli, D Chan, K Putnam, D Swanson, D AF Randolph, J Maleki, L Miyake, R Mettler, E Nesmith, B Prestage, J Tenerelli, D Chan, K Putnam, D Swanson, D GP IEEE IEEE TI SpaceTime: A mission with profound science at low cost SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB This is a AMEX [1] class mission that will carry a high precision clock to the vicinity of the Sun to measure relativistic effects related to time dilation in the immense gravity field. The results are expected to revolutionize our understanding of fundamental physics by this significant test of Einstein's Equivalence Principal. The architecture of the mission considers a low cost spacecraft that will be launched on a Solar Probe-like trajectory to the Sun. The simplicity of the instrument accommodation allows a very low cost and lightweight spacecraft configuration that can be launched on a low cost launch vehicle. This combination promises to yield profound new science at the very reasonable cost of a MIDEX mission. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Randolph, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 181 EP 188 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800016 ER PT S AU Johnson, WTK Jordan, R Safaeinili, A AF Johnson, WTK Jordan, R Safaeinili, A GP IEEE IEEE TI The Europa Orbiter radar sounder: Innovative radar design for a challenging mission SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Recent observations of the surface of the Jovian moon Europa indicates the possibility of the presence of a vast ocean beneath the icy surface. Currently the NASA mission Europa Orbiter plans to place several instruments, including a radar sounder, in a 150 kin circular orbit around this moon. The science objectives of the EO Mission are: Understand the surface composition, especially compounds of interest to prebiotic chemistry. Map the distribution of important constituents of the surface and characterize subsurface interfaces. Characterize the radiation environment in order to reduce the uncertainties for future missions, especially landers. To support these science objectives, the Europa Orbiter will have the following instruments: An ice-penetrating radar A laser altimeter An IR-visual imager. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Johnson, WTK (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 IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 189 EP 194 PG 6 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800017 ER PT S AU Dvorak, D Rasmussen, R Starbird, T AF Dvorak, D Rasmussen, R Starbird, T GP IEEE IEEE TI State knowledge representation in the mission data system SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The possible states of a system, be it a spacecraft, rover or ground station, are what system engineers identify and specify, what software engineers design for, and what operators monitor and control. Many activities inside mission software are directly concerned with state, whether planning it, estimating it, controlling it, reporting it or simulating it. The cause of several mission failures can be traced to inadequate or inconsistent representations of state. Consequently, the concept of 'state' and its representation occupy a prominent role in mission software architecture. The Mission Data System (NOS), presently under development by NASA to provide multi-mission flight and ground software for the next generation of deep space systems, addresses this fundamental need. This paper describes the MDS approach to state knowledge representation, covering state variables, state functions, state estimates and state constraints, emphasizing design patterns that reduce sources of human error. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Dvorak, D (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 195 EP 204 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800018 ER PT S AU Zimmerman, W Anderson, FS Carsey, F Conrad, P Englehardt, H French, L Hecht, M AF Zimmerman, W Anderson, FS Carsey, F Conrad, P Englehardt, H French, L Hecht, M GP IEEE IEEE TI The Mars '07 North Polar Cap Deep Penetration Cryo-Scout Mission SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB A 2007 Mars North Polar Cap penetration mission is being proposed under the Mars Scout Discovery Program. The Cryobot robotic mole vehicle being developed by a team of JPL engineers would penetrate 200 meters below the polar ice cap in the only known accessible reservoir of water on the planet. The probe would be manifested with a suite of science instruments which will (1) examine the climatic history of Mars as reflected in the layers of ice-the Mars Surveyor Orbiter Camera (MOC) has revealed exciting images of the polar ice cap indicating the layers to be on the order of 1 to 100 meters thick; (2) look for organics and bio-signatures potentially transported via wind and trapped in the ice; (3) examine trapped minerals and understand the chemical make-up of soluble constituents; and (4) provide the first-ever polar cap surface images as well as characterize the polar cap meteorology. Although radioisotope power is baselined for the Mars '07 version of the Cryobot, no decision on the final design of the Cryobot will be made until the environmental review process is complete. Any use of the Cryobot for Mars will conform to all environmental and planetary protection requirements. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Zimmerman, W (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 16 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 305 EP 315 PG 11 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800028 ER PT S AU Kuhlman, KR Hecht, MH Friedman, L Kelly, L Oslick, J Polk, K Moller, LE Trowbridge, K Sherman, J Marshall, A Diaz, AL Waldron, A Lewis, C Gyulai, C Powell, G Meloy, T Smith, P AF Kuhlman, KR Hecht, MH Friedman, L Kelly, L Oslick, J Polk, K Moller, LE Trowbridge, K Sherman, J Marshall, A Diaz, AL Waldron, A Lewis, C Gyulai, C Powell, G Meloy, T Smith, P GP IEEE IEEE TI SNOOPY: Student Nanoexperiments for Outreach and Observational Planetary InquirY SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID REPOSE; ANGLE AB Student Nanoexperiments for Outreach and Observational Planetary Inquiry (SNOOPY) is an example of directly involving students and teachers in planetary science missions. The SNOOPY Project evolved from the Mars Environmental Compatibility Assessment (MECA) Student Nanoexperiment Project, a partnership between MECA, The Planetary Society and Visionary Products, Inc. The MECA instrument suite, developed at the Jet Propulsion Laboratory, was scheduled for launch aboard the canceled Mars Surveyor Lander 2001. Students 18 years of age and younger were invited to propose experiments that were consistent with MECA's Mission: to help us better understand how humans will be able to live on Mars. Two nanoexperiments were chosen for flight, the Angle of Repose of Martian Dust and Contradistinctive Copper. These experiments addressed the behavior of windblown Martian dust on surfaces and the oxidation of copper. The SNOOPY paradigm for planetary science experiments could be used on a variety of future space exploration missions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kuhlman, KR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 21 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 317 EP 325 PG 9 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800029 ER PT S AU Hall, JL Kerzhanovich, VV Jones, JA Cutts, JA Yavrouian, AA Colozza, A Lorenz, RD AF Hall, JL Kerzhanovich, VV Jones, JA Cutts, JA Yavrouian, AA Colozza, A Lorenz, RD GP IEEE IEEE TI Titan airship explorer SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID ATMOSPHERE AB Saturn's moon Titan is considered to be one of the prime locations for understanding the origins of life due to its rich environment of organic chemicals. A unique combination of dense atmosphere (more than four times that of the Earth), low gravity (one-sixth of that on the Earth) and small temperature variations makes Titan well-suited for studies with buoyant robotic vehicles (aerobots). Moreover, since the methane clouds obscure the entire surface, aerial platforms flying below the clouds are the only means of getting high-resolution global mapping the Titan surface in the visible and infrared wavelengths. Major technicals challenges for Titan aerobots include an extremely cold atmosphere (similar to 90K), remoteness from the Earth (similar to 10 AU), which limit data transmission and prevents meaningful real-time control, and the consequent need for a high degree of autonomous operation. Remoteness from the Sun and obscuring cloud cover make nuclear energy the only practical source of power. Radioisotope Thermal Generators (RTGs) can provide sufficient power to give an aerobot limited propulsion capability. Propeller-driven aerobots are essentially airships that can move to specific targets on Titan rather than being constrained to travel with the prevailing winds. Such vehicles also can be used for in situ studies of the surface either through combined airship/rover concepts ("aerover") or through winching down an instrumented surface platform from a station-keeping airship. An airship baseline design is described in this paper including the key technical aspects of airship configuration, propulsion system, navigation and control concepts, data acquisition and communications. The resulting baselinedesign appears to be very attractive suggests that airships are a good candidate for the post-Cassini exploration of the Titan [1]. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hall, JL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Lorenz, Ralph/0000-0001-8528-4644 NR 23 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 327 EP 336 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800030 ER PT S AU Beauchamp, P Lunine, JI Welch, C AF Beauchamp, P Lunine, JI Welch, C GP IEEE IEEE TI The potential for chemical evolution on Titan SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID HOST-GUEST COMPLEXATION; ZINC PORPHYRIN TWEEZER; ABSOLUTE-CONFIGURATIONS; CIRCULAR-DICHROISM; CHIRAL MOLECULES; ATMOSPHERE; SURFACE; CHROMATOGRAPHY; ORIGIN; OCEAN AB Saturn's moon, Titan, is a Mercury-sized body that is rich in organics and water ice. The Cassini-Huygens mission will arrive at Saturn in July 2004 and deploy the European Space Agency (ESA) Huygens probe, which will descend to the surface, providing in situ chemical analysis, images, spectra and other data that will characterize in detail the atmosphere and, if it survives, a region of the surface. The Saturn Orbiter instruments will map Titan's surface at a range of wavelengths over 4 years and approximately 45 flybys. Radar and near-IR mapping will distinguish between areas of water ice, ammonia-water, and organics, as well as provide perhaps sufficient data to distinguish liquid organics from solid organics. We then need to be prepared to examine what scientific questions would follow from these results and what subsequent mission will enable a more complete picture of Titan to be developed. We propose that Titan is an exciting astrobiological target. If the Cassini/Huygen's data show that there is no variation in the composition of surface organics, then atmospheric photochemistry has dominated the production of organics with little further evolution. However, if there is variation from region to region, this might suggest that additional organic chemistry has acted on the products of stratospheric photochemistry. Should evidence for variability in the organic phases on Titan be found, subsequent exploration of the surface ought to be undertaken, with an eye toward understanding the extent to which organic chemistry has proceeded. Sampling of organics to determine oxygen content, extent of acetylene polymerization, existence of chiral molecules and enantiomeric excesses, and searches for specific polymer products, would be of interest in assessing how organic chemistry evolves toward biochemistry. Such efforts would require fairly sophisticated chemical analyses from landed missions. This paper examines this chemistry and the potential instruments that could distinguish chemical evolution. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Beauchamp, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 48 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 337 EP 347 PG 11 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800031 ER PT S AU Bryant, S AF Bryant, S GP IEEE IEEE TI Ice-embedded transceivers for Europa cryobot communications SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Several studies have been conducted to design robotic exploration vehicles for investigating a sub-surface water ocean within Jupiter's moon Europa. [1] [2] The current data from the Galileo spacecraft indicates a possible sub-surface ocean of undetermined depth covered by a water ice crust on the order of 10 kilometers thick. The ice crust also flexes several tens of meters every Europan day due to tidal forces. This presents several design challenges, especially for the communications link back to the science team on Earth. This paper presents the modeling and analysis for a communications system that uses transceivers embedded within the ice crust. The work was done for a design study that examined using ice-embedded transceivers to communicate between a deep ice penetration "cryobot" at the liquid water ocean and a communications package on the Europan surface. [3]. This paper focuses on the microwave properties of ice and the communications link margin analysis. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bryant, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 238-737, Pasadena, CA 91109 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 349 EP 356 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800032 ER PT S AU Young, LA Aiken, EW Gulick, V Mancinelli, R Briggs, GA AF Young, LA Aiken, EW Gulick, V Mancinelli, R Briggs, GA GP IEEE IEEE TI Rotorcraft as Mars scouts SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB A new approach for the robotic exploration of Mars is detailed in this paper: the use of small, ultra-lightweight, autonomous rotary-wing aerial platforms. Missions based on robotic rotorcraft could make excellent candidates for NASA Mars Scout program. The paper details the work to date and future planning required for the development of such 'Mars rotorcraft.' C1 NASA, Ames Res Ctr, Rotorcraft Div, Moffett Field, CA 94035 USA. RP Young, LA (reprint author), NASA, Ames Res Ctr, Rotorcraft Div, Moffett Field, CA 94035 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 367 EP 378 PG 12 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800034 ER PT S AU Lee, M Weidner, RJ AF Lee, M Weidner, RJ GP IEEE IEEE TI In-Situ Site Knowledge System SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID MARS AB In support of the transition from human-based in-situ mission operations to automated smart operations, the mission simulation and instrument modeling group at JPL has been developing a progressive in-situ automation framework. The In-Situ Site Knowledge System (ISSKS) presented in this paper is the first phase of the automation framework, which addresses flexible virtual site construction, instrument-generic measurement simulation, and intelligent operation service agents. The ISSKS is developed in three tiers. The first tier is composed of site property modeling and synthesis, for construction a virtual in-situ environment. The second tier is composed of sensor system models and mobility platform models, for simulating in-situ exploration and science data products. The third tier is the operation interface, supporting the mobility platform simulation clients with surface interaction and operation planning activity clients with the observed site phenomena. The ISSKS currently supports several research tasks under the Mars technology program including the Smart Landing Systems, the Advanced EDL (Entry, Descent, and Landing), and the Rover technology. C1 Jet Propuls Lab, Pasadena, CA 90272 USA. RP Lee, M (reprint author), Jet Propuls Lab, 4800 Oak Grove, Pasadena, CA 90272 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 379 EP 386 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800035 ER PT S AU Behar, A Carsey, F Wilcox, B AF Behar, A Carsey, F Wilcox, B GP IEEE IEEE TI Polar Traverse Rover development for Mars, Europa and Earth SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID ICE AB The history of Antarctic exploration is filled With traverses for scientific and operational purposes, and they continue to be conducted today. Similarly, traverses are a crucial part of planned planetary science and operations. This paper addresses the proposal for development of an autonomous rover capable of making such extreme environment traverses while accomplishing complex tasks. C1 CALTECH, Jet Prop Lab, Avion Syst & Technol Div, Pasadena, CA 91109 USA. RP Behar, A (reprint author), CALTECH, Jet Prop Lab, Avion Syst & Technol Div, 107-102, Pasadena, CA 91109 USA. NR 18 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 389 EP 395 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800036 ER PT S AU Beauchamp, P Heath, GR Maffei, A Chave, A Howe, B Wilcock, W Delaney, J Kirkham, H AF Beauchamp, P Heath, GR Maffei, A Chave, A Howe, B Wilcock, W Delaney, J Kirkham, H GP IEEE IEEE TI NEPTUNE: An under-sea plate scale observatory SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID SUBDUCTION AB The NEPTUNE project will establish a linked array of undersea observatories on the Juan de Fuca tectonic plate. The NEPTUNE infrastructure, consisting of fiberoptic/power cable and junction boxes, will provide significant amounts of power and an Internet communications link to sensors and sensor networks on, above, and below the seafloor. This observatory will provide a new kind of research platform for real-time, long-term, plate-scale studies in the ocean and Earth sciences. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Beauchamp, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Howe, Bruce/0000-0001-5711-5253; Kirkham, Harold/0000-0003-2893-7586 NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 397 EP 406 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800037 ER PT S AU Buehler, MG Kuhlman, GM Keymeulen, D Kounaves, SP AF Buehler, MG Kuhlman, GM Keymeulen, D Kounaves, SP GP IEEE IEEE TI Advanced Electronic Tongue concept SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB This effort, directed at developing a sensor for evaluating water quality, is based on electrochemical techniques that detect and identify ions in solution. This paper discusses the use of Cyclic Voltammetry (CV), corrosion measurements, and Anodic Stripping Voltammetry (ASV) to measure three marker ions Cu, Fe, and Zn using Electronic Tongue 1. Use of genetic algorithms are suggested as an approach to facilitate the search for optimum measurement conditions. In addition, the possibility of changing the physical conditions of the sample chamber is discussed as a way of increasing the sensor's apparent sensitivity of and confidence in the measurements. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Buehler, MG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Bueno, Ligia/P-1359-2014; OI Kounaves, Samuel/0000-0002-2629-4831 NR 11 TC 3 Z9 3 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 407 EP 416 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800038 ER PT S AU Mattingly, R Matousek, S Gershman, R AF Mattingly, R Matousek, S Gershman, R GP IEEE IEEE TI Mars Sample Return - Studies for a fresh look SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Mars Sample Return (MSR) is a key mission in the plan for Mars Exploration. During 2001, NASA issued contracts to four industrial teams to conduct a broad trade study of what they envisioned to be the best implementation of MSR; the teams were subsequently tasked with focusing on a specific concept and fleshing-out a design sufficiently to provide a cost for the mission. Finally, the teams were asked to identify any technology development or demonstrations that are prerequisite to the mission. This paper describes the breadth of rich trade space that exists for this mission. Included in the paper are both the themes resulting from the industry studies and the general scope of the focused concepts used to assess the current planning for the mission and precursor missions. Included in this conference are papers by the four industrial teams, as well as a fifth study by JPL's Team-X to provide further corroboration of study results. The results suggest that a scientifically justifiable mission is possible, and that technology and precursor mission demonstration plans currently in the Mars Program are justified (with some modifications). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mattingly, R (reprint author), CALTECH, Jet Prop Lab, Mail Stop 301-485,4800 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 493 EP 509 PG 17 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800048 ER PT S AU Oberto, R AF Oberto, R GP IEEE IEEE TI Mars sample return, a concept point design by team-x (JPL's advanced project design team) SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB A Mars sample return mission will answer critical questions concerning the possibility of life on Mars. Shallow drilling from the Lander provides pristine samples while the rover provides samples from a variety of sites. Included are discussions of a Mars Sample Return mission point design where requirements development, mission design, flight system design and identification of technology developments needed to enable the mission are presented. After launch on a Delta IV Heavy the Lander and Orbiter are separated and individually guided to Mars. The Lander is targeted for direct atmospheric entry where it will use active aerodynamic control to arrive within a few kilometers of the landing site. After surface operations the Mars Ascent Vehicle is launched into low Mars orbit where the Orbiter, after Mars orbit insertion and aero-braking, has arrived to rendezvous with the sample. Once the sample is placed in the Earth Entry Vehicle (EEV), the Orbiter returns the EEV for direct Earth entry. Many technology advances are needed to enable a Mars sample return mission. The spacecraft must be able to perform an autonomous landing on Mars while avoiding hazards. An autonomous Mars launch system will need to be developed along with an autonomous system for rendezvous and capture of the sample. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Oberto, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 559 EP 573 PG 15 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800053 ER PT S AU Kahn, CL AF Kahn, CL GP IEEE IEEE TI Challenges in developing the Microwave Instrument for the Rosetta Orbiter SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The Microwave Instrument for the Rosetta Orbiter (MIRO) built by the Jet Propulsion Laboratory, will be launched on the European Space Agency's (ESA) ROSETTA Spacecraft in 2004. MIRO will measure the near surface temperatures of the asteroids OTAWARA and SIWA, and the comet WIRTANEN, thereby allowing scientists to estimate the thermal and electrical properties of these surfaces. The NITRO instrument consists of two heterodyne radiometers, one operating at millimeter wavelengths (190 GHz, similar to1.6 mm) and one operating at submillimeter wavelengths (562 GHz, similar to0.5 mm). The spectrometer portion of MIRO will allow measurements of water, carbon monoxide, ammonia, and methanol in the gaseous coma of comet WIRTANEN. These measurements will allow scientists to study how the comet material sublimates (changes from its frozen state, ice, to a gas) in time and distance from the sun. As an international team, significant challenges to development and integration coordination were required to ensure instrument delivery to the European Space Agency (ESA). Additionally, the instrument, developed under NASA's Faster, Better, Cheaper paradigm challenged the team to find new and inventive ways to achieve the scientific requirements. This paper will explore the various trades, challenges, processes and programmatic issues encountered. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kahn, CL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 575 EP 582 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800054 ER PT S AU Matousek, S AF Matousek, S GP IEEE IEEE TI Current status of Mars Scouts SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The Mars Program institutes the Mars Scout Missions in order to address science goals in the program not otherwise covered in baseline Mars plans. Mars Scout missions will be Principal-Investigator (PI) led science missions. Analogous to the Discovery Program, PI-led investigations optimize the use of limited resources to accomplish focused science and allow the flexibility to quickly respond to discoveries at Mars. Scout missions also require unique investments in technology and reliance upon Mars-based infrastructure such as telecom relay orbiters. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Matousek, S (reprint author), CALTECH, Jet Prop Lab, Mail Stop 264-472,4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 601 EP 605 PG 5 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800057 ER PT S AU Devirian, N AF Devirian, N GP IEEE IEEE TI In search of new worlds: NASA's Astronomical Search for Origins SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB A curiosity for who we are..., where did we come from..., who else is out there..., has been a motivation for exploration from ancestral gatherings around the tribal fire to sophisticated musings at the "electronic hearth" of our computers. NASA's Astronomical Search for Origins (ASO) science theme has brought together a broad array of scientific investigations and technological means to address these most challenging questions. ASO's goals are to understand how galaxies formed in the early universe., to understand how stars and planetary systems form and evolve, and to determine whether habitable or life-bearing planets exist around other stars in our solar neighborhood. This last goal, to find and to characterize planets and planetary systems around other stars, perhaps to image that "pale blue dot" that will be the "new world" of humanity's next era of exploration, this is the purpose of NASA's Navigator Program: In Search of New Worlds. This paper describes the missions, the scientific endeavors, and the network of technology investments that are the Navigator Program, and which are at the heart of the Astronomical Search for Origins. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Devirian, N (reprint author), CALTECH, Jet Prop Lab, 180-701,4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 607 EP 615 PG 9 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800058 ER PT S AU Rose, JR AF Rose, JR GP IEEE IEEE TI Risk management at JPL - Practices and promises SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Risk Management (RM) at JPL has developed in the past few years from a pioneering effort instituted and implemented by a few brave projects to a methodology required on all projects and supported by a well-defined process and training activity. This paper discusses the beginnings of Risk Management at JPL, the lessons learned from those experiences, and the evolution to the current process. The JPL process is discussed in its salient features planning, identification and assessment, decision-making, and risk tracking. For instance, the methods for assessing risk likelihood and impact that are provided to Project Risk Management teams are rich and varied, and have not been standardized to the degree expected and in some sense desired in the beginning by the NASA and Institutional management. This flexibility has enabled projects to tailor the style of RM to the characteristics of the project and the management objectives of the Project Manager, and has avoided some frustration and reluctance to adopt a "new` required activity in the implementation of the project. Some of the risk analysis methods are described here. Specifically, the distinctions between qualitative and quantitative methods are delineated, with the advantages and disadvantages of each described from the viewpoint of the practitioners. Risk Management strategies to allow the desired decisions in pro-actively using resources reserves to mitigate risks are presented. Finally, some observations of the direction of future improvements are discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Rose, JR (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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 641 EP 649 PG 9 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800061 ER PT S AU Beutelschies, G AF Beutelschies, G GP IEEE IEEE TI "That one's gotta work" Mars Odyssey's use of a fault tree driven risk assessment process SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The Odyssey project was the first mission to Mars after the failures of Mars Climate Orbiter and Mars Polar Lander. In addition to incorporating the results of those failure review boards and responding to external "Red Team" reviews., the Odyssey project itself implemented a risk assessment process. This paper describes that process and its use of fault trees as an enabling tool. These trees were used to break the mission down into the functional elements needed to make it a success. By determining how each function could be prevented from executing.. a list of failure modes was created. Each fault was individually assessed as to what mitigations could prevent the fault from occurring, as well as what methods should be used to explicitly verify that mitigation. Fault trees turned out to be an extremely useful tool in both identifying risks as well as structuring the development of mitigations. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Beutelschies, G (reprint author), Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. 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 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 651 EP 671 PG 21 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800062 ER PT S AU Lumsden, JM AF Lumsden, JM GP IEEE IEEE TI Operations safety risk management: Managing integration and test safety risk SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The risk of damage to project hardware during assembly, integration, and test activities prior to a project's "operational" phase is significant. Traditional Test Readiness Reviews are rarely sufficiently detailed or appropriately structured to ensure that all aspects of a pending activity are adequately addressed. A flexible, structured process that brings together appropriate disciplines to assess an impending activity has been developed by Systems Safety and has been repeatedly shown to be value added. Systems safety is an intimate member of the overall Risk Management team, but is often perceived as overburdening projects with a plethora of rigid and highly specialized analyses. Systems Safety can and should contribute principles and processes that have flexibility and adaptability to be effective. The survey process described here does all of this. It is a major tool in the overall Risk Management arsenal. Systems Safety principles utilized in the survey process are also described. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Lumsden, JM (reprint author), Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 673 EP 688 PG 16 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800063 ER PT S AU Aaron, KM Fox, G Ebbeler, DH Walker, WJ AF Aaron, KM Fox, G Ebbeler, DH Walker, WJ GP IEEE IEEE TI Reliability modeling for the Space Interferometry Mission SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Top-level reliability models have been developed for several recent configurations of the Space Interferometry Mission (SIM) and the results used in the decision process for selecting viable configurations for further study. For one configuration, closed-form solutions were obtained. For three configurations, Excel-based Monte Carlo models were developed. The agreement between the closed form and the Monte Carlo models was excellent, verifying that the Excel-based approach had been successfully implemented. The Excel model has the flexibility to extend the model to more complicated arrangements for which it would be impractical to develop closed-form solutions. The Space Interferometry Mission in NASA's Origins Program is a 10m-baseline space-based Michelson interferometer scheduled for launch in 2009. This large instrument will measure the angles between stars to an accuracy of about one billionth of a degree of arc. This is an improvement of about two orders of magnitude over current astrometric instruments. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Aaron, KM (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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 689 EP 704 PG 16 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800064 ER PT S AU Witkowski, MM AF Witkowski, MM GP IEEE IEEE TI Managing Risk for Cassini during Mission Operations and Data Analysis (MO&DA) SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB A Risk Management Process has been tailored for Cassini that not only satisfies the requirements of NASA and JPL, but also allows the Program to proactively identify and assess risks that threaten mission objectives. Cassini Risk Management is a team effort that involves both management and engineering staff. The process is managed and facilitated by the Mission Assurance Manager (MAM), but requires regular interactions with Program Staff and team members to instill the risk management philosophy into the day to day mission operations. While Risk Management is well defined for projects in the development phase, it is a relatively new concept for Mission Operations. The Cassini team has embraced this process and has begun using it in an effective, proactive manner, to ensure mission success. It is hoped that the Cassini Risk Management Process will form the basis by which risk management is conducted during Mission Operations and Data Analysis (MO&DA) on future projects. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Witkowski, MM (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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 705 EP 713 PG 9 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800065 ER PT S AU Carpenter, JR Speyer, JL Chichka, DF Ananyev, S Belanger, G AF Carpenter, JR Speyer, JL Chichka, DF Ananyev, S Belanger, G GP IEEE IEEE TI Assessment of decentralized satellite formation control with distributed hardware-in-the-loop testbeds SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE Aerospace Conference Proceedings LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Decentralized architectures may offer advantages in comparison to centralized schemes for maintaining and establishing satellite formations and constellations. For example, because they are non-hierarchical and exploit parallelism, decentralized control approaches potentially offer reliability and graceful degradation under failure scenarios that may be difficult to match with a centralized approach. Offsetting such advantages is additional complexity, in the form of additional data processing at each node and additional inter-nodal communications channels, and the relatively lower level of application proven technology maturity for decentralized approaches. A complete characterization of the costs and benefits of the centralized/decentralized design trade is difficult to achieve in a monolithic software simulation. To better address these issues, several hardware in the loop distributed computing test-beds are under development. This paper provides a status report on a collaborative research effort that is studying the implementation of decentralized control schemes for satellite formations in such testbeds. Through this and other similar investigations, a better understanding of the issues and trades associated with control of the many proposed satellite formation flying missions will be achieved. C1 NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Ctr, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Ctr, Code 572, Greenbelt, MD 20771 USA. EM russell.carpenter@gsfc.nasa.gov NR 12 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 757 EP 765 PG 9 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800070 ER PT S AU Brown, GM O'Quinn, CF Porter, BS AF Brown, GM O'Quinn, CF Porter, BS GP IEEE IEEE TI Requirements analysis for a multi-spacecraft flight system SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The StarLight mission, scheduled to be launched in June 2006, will demonstrate the separated spacecraft technologies of formation flying, precision formation estimation, and long baseline stellar interferometry. The StarLight flight system consists of two spacecraft that will launch as a stacked cluster, separate from each other after a short post-launch checkout, and then operate for at least six months in an Earth-trailing heliocentric orbit. A variety of demonstrations will be performed at inter-spacecraft separations of 30 m to 1000 m. In order to fully describe the StarLight flight system requirements, we have had to introduce several new dimensions into the typical requirements analysis process. We have used some of these new dimensions to organize our requirements database, in an attempt to create clear distinctions between those requirements that are specific to particular spacecraft, configurations, and/or modes, vs. those requirements that are common to all spacecraft, configurations, and/or modes. This paper will describe our flight system requirements analysis approach, and will also show how we have organized a preliminary set of these requirements within our project requirements database. We believe our approach can be extended to flight systems with larger collections of cooperating spacecraft. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Brown, GM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 767 EP 782 PG 16 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800071 ER PT S AU Imbriale, WA Weinreb, S Jamnejad, V Cucchissi, J AF Imbriale, WA Weinreb, S Jamnejad, V Cucchissi, J GP IEEE IEEE TI Exploring the next generation deep space network SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB As the current 70-meter antennas are quite old (28-35 years) it is necessary to consider replacing these antennas in the near term as well as providing a capability beyond 70-meters in the future. A study was conducted that investigated the remaining service life of the existing antennas and considered alternatives for eventual replacement of the 70m-subnet capability. This paper examines several of the concepts considered and explores some of the options for the next generation Deep Space Network. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Imbriale, WA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 901 EP 910 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800084 ER PT S AU Jamnejad, V Huang, J Levitt, B Pham, T Cesarone, R AF Jamnejad, V Huang, J Levitt, B Pham, T Cesarone, R GP IEEE IEEE TI Array antennas for JPL/NASA deep space network SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Recently, JPL has begun an assessment of the long-term capability of the antennas for the Deep Space Network (DSN). Various alternative plans for upgrading or replacing the present 70-meter antennas have been considered. Several options have been studied which include modifying the present antennas for extended life and reliability, new 70-meter single aperture antennas with offset or symmetric feeds, 100-meter spherical antennas, an array of a few smaller 34-meter antennas., a much larger array (hundreds) of much smaller (5-10 meter) reflector antennas, and finally active planar phased arrays with millions of elements. In this paper we briefly discuss various options but focus on the feasibility of the phased arrays as a viable option for this application. Of particular concern and consideration will be the cost, reliability, and performance compared to the present 70-meter antenna system, particularly the gain/noise temperature levels in the receive mode. Many alternative phased arrays including planar horizontal arrays, hybrid mechanically/electronically steered arrays, phased array of mechanically steered reflectors, multi-faceted planar arrays, phased array-fed lens antennas, and planar reflect-arrays are compared and their viability is assessed. Although they have many advantages including higher reliability, near-instantaneous beam switching or steering capability, the cost of such arrays is presently prohibitive and it is concluded that the only viable array options at the present are the arrays of a few large or many small reflectors. The active planar phased arrays, however, may become feasible options in the next decade and can be considered for deployment in smaller configurations as supplementary options. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jamnejad, V (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 2 Z9 2 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 911 EP 921 PG 11 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800085 ER PT S AU Gawronski, W Craparo, EM AF Gawronski, W Craparo, EM GP IEEE IEEE TI Antenna scanning techniques for estimation of spacecraft position SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Scanning movements are added to tracking antenna trajectory to estimate the true spacecraft position. The scanning movements are composed of harmonic axial movements of an antenna. This scanning motion produces power variations of the received signal, which are used to estimate spacecraft position. Three different scanning patterns (conical scan, Lissajous scan, and rosette scan) are presented and analyzed in this paper. The analysis includes the evaluation of the estimation errors due to random or harmonic variation of the antenna position and due to random and harmonic variations of the power level. Typically, the estimation of the spacecraft position is carried out after completing a full scanning cycle. In this paper sliding window scanning is introduced, wherein the spacecraft position estimation is carried out in an almost continuous manner, and it reduces estimation time by half. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gawronski, W (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 939 EP 948 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800088 ER PT S AU Hussein, ZA Shaffer, S AF Hussein, ZA Shaffer, S GP IEEE IEEE TI RF characterization of the mars exploration rover radar altimeter antennas-airbag interaction SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB This paper presents the experimental results of the Mars Exploration Rover-03 (MER) radar altimeter antennas-airbag interaction. The objective of this work is to determine the impact of the MER airbag on the radiation properties and mutual coupling and return loss of the radar altimeter antennas at the design frequency of 4.3 GHz: and over a frequency band of +/-25 MHz. This is done to ultimately assess any impacts or risks to the radar altimeter system performance. Because the radar altimeter antennas are close (near-field region) to the airbag when it is inflated, we have considered several configurations to characterize the antennas' performance. These characterizations should allow us to determine the proper link budget for the radar altimeter in terms of signal lock during MER descent to the Martian surface. It is shown that the mutual coupling between radar altimeter' antennas may be affected when the airbag is on top or in the close proximity to the antennas, 0 to 15.24 cm (or 2.18lambda), and the radar may not function properly for certain orientations and positions within this region. It is demonstrated that as the airbag is withdrawn away from the antennas (toward the far-field region of the antennas), the antenna's performance will be decoupled from the airbag. In addition, it is shown that the airbag in the close proximity of the antennas, 0 to 6.35 cm (or 0.91lambda), may degrade the antenna radiation patterns, Ibis degradation appears as a ripple in the amplitude patterns. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hussein, ZA (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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 949 EP 955 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800089 ER PT S AU Pollard, BD Rodriguez, E Veilleux, L Akins, T Brown, P Kitiyakara, A Zawadski, M Datthanasombat, S Prata, A AF Pollard, BD Rodriguez, E Veilleux, L Akins, T Brown, P Kitiyakara, A Zawadski, M Datthanasombat, S Prata, A GP IEEE IEEE TI The wide swath ocean altimeter: Radar interferometry for global ocean mapping with centimetric accuracy SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID SAR AB The recent Shuttle Radar Topography Mission (SRTM) has demonstrated the capability for global interferometric topographic mapping with meter level accuracy and 30 meter spatial resolution. The next challenge in radar interferometry is the measurement of ocean topography: the global characterization of ocean mesoscale eddies requires global coverage every 10 days', with centimetric height accuracy, and a spatial resolution of 10-20 km. We have developed an instrument concept that combines a conventional nadir altimeter with a radar interferometer to meet the above requirements. In this paper, we describe the overall mission concept and the interferometric radar design. We also describe several new technology developments that facilitate the inclusion of this instrument on a small, inexpensive spacecraft bus. Those include ultra-light, deployable reflectarray antennas for the radar interferometer; a novel five frequency feed horn for the radiometer and altimeter; a lightweight, low power integrated three frequency radiometer; and a field programma le gate array-based onboard data processor. Finally, we discuss recent Algorithm developments for the onboard date processing, and present the expected instrument performance improvements over previously reported results. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Pollard, BD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1007 EP 1020 PG 14 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800094 ER PT S AU Stosic, DK Lux, JP AF Stosic, DK Lux, JP GP IEEE IEEE TI Ku-band receiver and transmitter for breadboard DSP scatterometer SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The design and test results for the Radio Frequency (RF) portion of a breadboard polarimetric scatterometer operating at 13.402 GHz are presented. An integrated breadboard has been developed at the Jet Propulsion Laboratory (JPL) to evaluate the feasibility of a programmable Digital Signal Processing (DSP) approach for a follow-on scatterometer similar to SeaWinds (scheduled for launch in winter 2002). Early breadboards of an integrated system have been identified as valuable assets in developing effective subsystem requirements for the eventual flight instrument. Many compatibility and partitioning issues between the RF and DSP hardware are addressed with empirical results derived from the aforementioned breadboard. The RF portion of the breadboard consists of a dual channel receiver, heterodyning the received signal of 13.402 GHz down to an IF of 37 MHz prior to the analog to digital conversion, and a single channel transmitter, that converts the I/Q baseband transmit waveform up to Ku band. The breadboard makes provision for emulating capabilities such as programmable attenuators, loop-back calibration, and saturation effects in an actual instrument's power amplifier. It also provides control interfaces to allow early verification of software control algorithms. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Stosic, DK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 161-213, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 1 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1023 EP 1030 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800095 ER PT S AU Gao, JL AF Gao, JL GP IEEE IEEE TI An adaptive network/routing algorithm for energy efficient cooperative signal processing in sensor networks SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB In this paper, we describe an adaptive network/routing algorithm that facilitates both coherent and non-coherent event-based cooperative signal processing. The core of this algorithm is a distributed election procedure that produces one or multiple winners based on a context-dependent election metric. In scenarios where non-coherent signal processing techniques are applied, a central processing node is selected, and highly compressed sensor data will be gathered for processing. Energy efficiency is improved by reducing algorithm overhead because the actual sensor traffic volume is light compared to the messaging overhead of the algorithm. For coherent processing, raw data streams must be relayed from each sensor to the central processing node, producing large data streams. A multi-winner election process is initiated first to select only a limited number of sensors that will provide the raw data; then a second election process will use an energy-based metric to find the optimal central processing node whose location minimize the total relaying cost. Simulation result is provided to demonstrate the inherent overhead-delay trade-off and compare the scalability of the algorithm under different scenarios. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Gao, JL (reprint author), Jet Prop Lab, 4800 Oak Grove Dr,M-S 161-260, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1117 EP 1124 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800105 ER PT S AU Alena, R Evenson, D Rundquist, V AF Alena, R Evenson, D Rundquist, V GP IEEE IEEE TI Analysis and testing of mobile wireless networks SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB As the technology matures, wireless networks are being used in more applications providing significant benefits to mobile users. There are now many products, complying with wireless network standards 802.11 and 802.11b, for linking mobile computing elements together and into the Internet using radio signals. Wireless networks provide mobility, but offer lower reliability and performance compared to wired networks. Standard methods of analyzing and testing Wireless network throughput and compatibility are needed to determine current performance limits of this technology. This paper presents experimental methods of determining wireless network product throughput, latency, range and coverage in the outdoor environment. Field test results from two representative 802.11 and 802.11b products are presented. Radio frequency (RF) domain analysis was performed on the same products allowing calculation of theoretical maximum throughput and range. Comparison of the outdoor field-test data with performance predicted from RF analysis yielded quantitative results applicable to future communication system design. Layering multiple wireless network subnets can increase performance, limited primarily by interference. Wireless network components can be set to different radio frequency-hopping sequences or spreading functions, allowing more than one subnet to coexist. Therefore, we ran multiple 802.11-compliant systems concurrently in the same geographical area to determine scalability. The results can be used to design more robust networks which have multiple layers of wireless data communication paths providing increased throughput overall. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Alena, R (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1131 EP 1144 PG 14 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800107 ER PT S AU Kerczewski, RJ AF Kerczewski, RJ GP IEEE IEEE TI Aeronautical communications research and development needs for future air traffic management applications SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Continuing growth in regional and global air travel has resulted in increasing traffic congestion in the air and on the ground. In spite of occasional temporary downturns due to economic recessions and catastrophic events, average growth rates of air travel have remained high since the 1960s. The resulting congestion, which constrains expansion of the air transportation industry, inflicts schedule delays and decreases overall system efficiency, creating a pressing need to develop more efficient methods of air traffic management (ATM). New ATM techniques, procedures, airspace automation methods and decision support tools are being researched and developed for deployment in time frames stretching from the next few years to the year 2020 and beyond. As these methods become more advanced and increase in complexity, the requirements for information generation, sharing and transfer among the relevant entities in the ATM system increase dramatically. However, current aeronautical communications systems will be inadequate to meet the future information transfer demands created by these advanced ATM systems. Therefore, the NASA Glenn Research Center is undertaking research programs to develop communications methods and key technologies that can meet these future requirements. As part of this process, studies, workshops, testing and experimentation, and research and analysis have established a number of research and technology development needs. The purpose of this paper is to outline the critical research and technology needs that have been identified in these activities, and explain how these needs have been determined. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Kerczewski, RJ (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1169 EP 1176 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800110 ER PT S AU Robinson, DC AF Robinson, DC GP IEEE IEEE TI CSMA versus prioritized CSMA for air-traffic-control improvement SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB OPNET version 7.0 simulations are presented involving an important application of the Aeronautical Telecommunications Network (ATN), Controller Pilot Data Link Communications (CPDLC) over the Very High Frequency Data Link Mode 2 (VDL-2). Communication is modeled for essentially all incoming and outgoing nonstop air-traffic for just three United States cities: Cleveland, Cincinnati, and Detroit. There are 32 airports in the simulation, 29 of which are either sources or destinations for the air-traffic of the aforementioned three airports. The simulation involves 111 Air Traffic Control (ATC) ground stations, and 1,235 equally equipped aircraft-taking off, flying realistic free-flight trajectories, and landing in a 24-hr period. Collisionless, Prioritized Carrier Sense Multiple Access (CSMA) is successfully tested and compared with the traditional CSMA typically associated with VDL-2. The performance measures include latency, throughput, and packet loss. As expected, Prioritized CSMA is much quicker and more efficient than traditional CSMA. These simulation results show the potency of Prioritized CSMA for implementing low latency, high throughput and efficient connectivity. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Robinson, DC (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1191 EP 1196 PG 6 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800113 ER PT S AU Jennings, EH Okino, CM AF Jennings, EH Okino, CM GP IEEE IEEE TI On the diameter of sensor networks SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID GRAPH-THEORY AB In space exploration, cooperative modulation techniques have been proposed for prolonging the life-time of sensor nodes within a multihop network. The desire to efficiently reduce the overall energy-per-bit of a node motivated this study on the hop diameter (synonomous to the number of hops in a path) of sensor networks. In this study, we analysed and found that when the number of transmissions are bounded by constants less than or equal to 20, the likelihood of successful broadcast is small. Using simulations, we observed that the diameter decreases very fast as the transmission radius increases. Another observation is that the largest connected component emerges when the transmission radius reaches 0.3rootA, where A is the area containing the nodes. This may be used to determine the ideal amplification, although further simulations on larger networks could be helpful. We also found a large gap between the number of nodes required to populate the area, when all the nodes must be connected, or when only 90% of the nodes are connected. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jennings, EH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1211 EP 1217 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800115 ER PT S AU Shambayati, S AF Shambayati, S GP IEEE IEEE TI Maximization of data return at X-band and Ka-band at DSN's 34-meter beam-waveguide antennas SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB In this paper we offer a new approach to evaluating the performance advantage of Ka-band frequency over X-band frequency for receiving spacecraft downlink from deep space missions. For a given elevation profile for a pass, this approach uses atmospheric noise temperature statistics to select the optimum data rate to maximize the total data return volume over the pass. For illustration purposes, this approach is used to optimize the performance of a link for both X-band and Ka-band at a DSN 34 m Beam Waveguide tracking stations at both Madrid, Spain and Goldstone, California. Our calculations show that using such an approach an optimized Ka-band link offers between 5.9 dB and 7.2 dB more data volume over an optimized X-band link, and between 8.5 dB and 10.3 dB over an X-band link as currently operated by the DSN. It should be noted that the reliability of link designed in such a manner is relatively low and that a link optimized in this manner may not meet the continuity requirements of a mission. Furthermore, this approach takes only the weather effects into consideration. Other factors which may adversely affect the performance of the link are not taken into account under this approach. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Shambayati, S (reprint author), Jet Prop Lab, 4800 Oak Grove Dr,Ms 238-420, 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1263 EP 1270 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800121 ER PT S AU Morabito, D Hastrup, R AF Morabito, D Hastrup, R GP IEEE IEEE TI Communicating with mars during periods of solar conjunction SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB A reliable communications link between Mars and Earth will be required during the initial phase of the human exploration of Mars. The direct communications link can easily be realized during most of the 780-day Earth-Mars synodic period, except when this link encounters increased intervening charged particles during superior solar conjunctions. The effects of solar charged particles are expected to corrupt the data signals to varying degrees. During superior solar conjunctions of interplanetary spacecraft, flight projects routinely scale down or suspend operations by invoking command moratoriums, reducing tracking schedules, and progressively lowering data rates. The actual operations scenarios will vary between flight projects and from conjunction to conjunction. This paper presents results of a study conducted to determine to what extent and by what techniques communications may be maintained throughout Mars-Sun-Earth superior conjunction periods that could occur during early human Mars exploration missions. Using a number of techniques discussed in this paper, it should be possible to maintain some degree of communication throughout all of the superior conjunctions occurring between 2015 and 2026, except for one occurring in 2023, in which actual occultation of the signal source by the Sun's disk occurs. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Morabito, D (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 1 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1271 EP 1281 PG 11 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800122 ER PT S AU Hurd, WJ Estabrook, P Racho, CS Satorius, EH AF Hurd, WJ Estabrook, P Racho, CS Satorius, EH GP IEEE IEEE TI Critical spacecraft-to-earth communications for Mars Exploration Rover (MER) entry, descent and landing SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB For planetary lander missions, the most challenging phase of the spacecraft to ground communications is during the entry, descent, and landing (EDL). As each 2003 Mars Exploration Rover (MER) enters the Martian atmosphere, it slows dramatically. The extreme acceleration and jerk cause extreme Doppler dynamics on the X-band signal received on Earth. When the vehicle slows sufficiently, the parachute is deployed, causing almost a step in deceleration. After parachute deployment, the lander is lowered beneath the parachute on a bridle. The swinging motion of the lander imparts high Doppler dynamics on the signal and causes the received signal strength to vary widely, due to changing antenna pointing angles. All this time, the vehicle transmits important health and status information that is especially critical if the landing is not successful. Even using the largest Deep Space Network antennas, the weak signal and high dynamics render it impossible to conduct reliable phase coherent communications. Therefore, a specialized form of frequency-shift-keying will be used. This paper describes the EDL scenario, the signal conditions, the methods used to detect and frequency track the carrier and to detect the data modulation, and the resulting performance estimates. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hurd, WJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1283 EP 1292 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800123 ER PT S AU Deutsch, LJ AF Deutsch, LJ GP IEEE IEEE TI Resolving the Cassini/Huygens relay radio anomaly SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB NASA's Cassini mission to Saturn carries the European Space Agency's (ESA's) Huygens probe, which it will release shortly before an encounter with Saturn's moon, Titan, a possible location for extraterrestrial life within our Solar System. As it parachutes towards Titan's surface, Huygens will acquire scientific information which will be relayed to Earth through Cassini. Comprehensive testing of this relay radio link was not performed prior to Cassini launch and cannot be done during cruise. A test using NASA's Deep Space Network (DSN) to mimic the probe's signal was performed in 2000 and uncovered an anomaly that, unchecked, would result in nearly complete loss of the Huygens mission. An international team of experts from NASA and ESA was assembled to solve this problem: the Huygens Recovery Task Force (HRTF.) This team, co-chaired by the author, performed extensive testing, modeling, and simulation to understand the failure mechanism. Each Huygens science team determined mission impacts for various scenarios based on these results. This led to a suggested modification to the Cassini trajectory that Will result in nearly complete data return for Huygens with minimal impact on Cassini. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Deutsch, LJ (reprint author), CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1295 EP 1302 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800124 ER PT S AU Berner, JB Bryant, SH AF Berner, JB Bryant, SH GP IEEE IEEE TI Operations comparison of deep space ranging types: Sequential tone vs. pseudo-noise SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB NASA's Deep Space Network currently has a ranging system that uses a sequence of square wave tones to determine spacecraft distance. This ranging system correlates tones received from the spacecraft with those it transmitted. The phase shift that maximizes the correlation value is then related to the round trip light time distance. A new ranging system is being developed that can be configured to use sequential square wave tones or to use repeating pseudo-noise tones. This allows more flexibility and possibly better performance. The tradeoffs between the two types of ranging are presented A detailed derivation of the ranging performance as a function of configuration, signal strength, and other variables is given. The ranging performance for the two ranging types is compared. A configuration for pseudo-noise ranging that provides better performance is provided. Operational issues and simplifications resulting from using pseudo-noise ranging are also discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Berner, JB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 238-737, Pasadena, CA 91109 USA. NR 10 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1313 EP 1326 PG 14 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800126 ER PT S AU Gunapala, S Bandara, S Bock, J Ressler, M Liu, J Mumolo, J Rafol, S Ting, D Werner, M AF Gunapala, S Bandara, S Bock, J Ressler, M Liu, J Mumolo, J Rafol, S Ting, D Werner, M GP IEEE IEEE TI Large format long-wavelength GaAs/AlGaAs multi-quantum well infrared detector arrays for astronomy SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises 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. The wavelength of the peak response and cutoff can be continuously tailored over a range wide enough to enable light detection at 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 lower operating temperatures (similar to 30 K) due to exponential suppression of dark current. Furthermore, QWIPs offer low cost per pixel and highly uniform large format focal plane arrays (FPAs) mainly due to mature GaAs/AlGaAs growth and processing technologies. The other advantages of GaAs/AlGaAs based QWIPs are higher yield, lower 1/f noise and radiation hardness. 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 1/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. 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 IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1437 EP 1444 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800141 ER PT S AU Coyle, DB Kay, RB Lindauer, SJ AF Coyle, DB Kay, RB Lindauer, SJ GP IEEE IEEE TI Design and performance of the Vegetation Canopy lidar (VCL) laser transmitter SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID SOLID-STATE LASERS; UNSTABLE RESONATORS AB Design details of the Vegetation Canopy Laser (VCL) for the NASA Multi Beam Laser Altimeter (MBLA) earth orbit mission are presented. The laser is a Nd:YAG Q-switched, diode side-pumped, zig-zag slab design producing 10 ns, 15 mJ pulses at 1064 mn. It employs an unstable resonator as well as a graded reflectivity output coupler with a Gaussian reflectivity profile. A cylindrical lens of undoped YAG collimates the 809 run pump diode radiation and focuses it into a region similar to1.5 mm wide down the 100 mm long Nd:YAG- slab. In order to conserve power, a conductively cooled design is employed. The laser is designed to operate over a range of 250 C without active thermal control. Passive cooling is achieved with a large thermal radiator panel consisting of heat-pipes and a change-of-state element. The laser is equipped with a 15X beam expander to limit the output divergence to less than 60 murad. One discussion will explain the compensation of the thermal lens created in the side-pumped slab and the different treatments of the x and y portions of the z-directed beam in order to obtain an output beam of near circular symmetry. Paraxia modeling was used along with performance data to determine the optimum location the thermal compensating lens, and how the slab's thermal lens changed with temperature. This is due to the change in inversion density resulting from the varying overlap of the pump radiation spectral profile with the location of the Nd:YAG pump bands. Performance data as a function of temperature are given. Total-number of shots to date and any change in performance as a function of shot count will be presented. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Coyle, DB (reprint author), NASA, Goddard Space Flight Ctr, Code 920-3, Greenbelt, MD 20771 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1457 EP 1464 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800143 ER PT S AU Laskin, RA AF Laskin, RA GP IEEE IEEE TI The Space Interferometry Mission (SIM): Technology development progress and plans SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises DE interferometry; metrology; pointing; control; nanometer; picometer; optics; lasers ID SPATIAL INTERFEROMETRY; METROLOGY AB Optical and infrared interferometry will open new vistas for astronomy over the next decade. Space based interferometers, operating unfettered by the Earth's atmosphere, will offer the greatest scientific payoff. They also present the greatest technological challenge: laser metrology systems must perform with sub-nanometer precision; mechanical vibrations must be controlled to nanometers requiring orders of magnitude disturbance rejection; a multitude of actuators and sensors must operate flawlessly and in concert. The Jet Propulsion Laboratory along with its industry partners, Lockheed Martin and TRW, are addressing these challenges with a development program that plans to establish technology readiness for the Space Interferometry Mission by end of 2004. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Laskin, RA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 97 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1669 EP 1683 PG 15 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800165 ER PT S AU Serabyn, G AF Serabyn, G GP IEEE IEEE TI Comparison of high dynamic range near-neighhor detection approaches for TPF SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID GROUND-BASED CORONAGRAPHY; STELLAR CORONAGRAPH; ADAPTIVE OPTICS; BROAD-BAND; PHASE-MASK; PLANETS; CORONOGRAPHY AB While observations of stellar Doppler shifts have recently uncovered a population of massive planets orbiting nearby stars, the direct detection of radiation from Earth-like planets is still well beyond reach, because of the high contrast ratios and small angular separations involved. However, a number of high-contrast near-neighbor detection techniques have the potential to enable the direct detection of planets as faint as the Earth from space-borne platforms. Several concepts, ranging from large-aperture visible wavelength coronagraphs to multi-spacecraft infrared interferometers, are currently being considered in the context of NASA's Terrestrial Planet Finder program. Because of their demanding requirements, identification of the most feasible near-term approach calls for careful consideration of the possibilities. This paper compares the optical requirements inherent in two of the primary candidate architectures: nulling interferometry and coronagraphy. At a given wavelength, both approaches share similarly challenging wave-front phasing requirements, but nulling has the advantage that it is sensitive closer to the optical axis. The phasing and dynamic range requirements are eased significantly in the thermal infrared as compared to the visible, but longer baselines and cryogenic cooling are then required. Thus, all of the options are rather complex. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Serabyn, G (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 171-113, Pasadena, CA 91109 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1685 EP 1694 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800166 ER PT S AU Hochberg, EB Motts, EL Larson, SB White, ML AF Hochberg, EB Motts, EL Larson, SB White, ML GP IEEE IEEE TI Optical alignment of the TES cryogenic interferometer SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB This paper contains a description of the methodology used to align the interferometer optics in the TES cryogenic Fourier Transform Spectrometer. By means of a combination of a laser-based component state-of-alignment measurements and a detailed opto-mechanical model, both geometric and physical optics performance are predicted and optimized. The TES instrument is scheduled to be flown on EOS-CHEM in December 2002. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hochberg, EB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1695 EP 1702 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800167 ER PT S AU Duren, RM Lay, OP AF Duren, RM Lay, OP GP IEEE IEEE TI The StarLight formation-flying interferometer system architecture SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The StarLight project, formerly known as ST3 and scheduled for a 6 month mission in 2006. will demonstrate the new technologies of spaceborne long-baseline optical interferometry and precision formation flying necessary for the Terrestrial Planet Finder and other future astrophysics missions. A primary goal is to fully characterize the interferometer capabilities by obtaining 100-500 fringe visibility amplitude measurements for stars in the band 600-1000 mn with a variety of stellar visibilities (0.2-1.0), stellar magnitudes (Mv = 2-5), and baselines (B = 30-125 meters). Interferometry on StarLight will be performed both in a I meter fixed-baseline combiner-only mode and in a formation-flying mode, in which two spacecraft operate in a novel Parabolic Geometry Interferometer configuration. The Interferometer System will consist of the following subsystems, each of which will have components on both the combiner and collector spacecraft: Stellar, Metrology, Optical Bench, Electronics, and Flight Software. This paper provides an overview of the Interferometer System driving requirements, its overall architecture, and subsystems. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Duren, RM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1703 EP 1719 PG 17 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800168 ER PT S AU Dubovitsky, S Lay, OP Abramovici, A Hawley, JG Kuhnert, AC Mulder, JL Asbury, CG AF Dubovitsky, S Lay, OP Abramovici, A Hawley, JG Kuhnert, AC Mulder, JL Asbury, CG GP IEEE IEEE TI The StarLight metrology subsystem SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB We describe a metrology subsystem for NASA's StarLight mission, a space-based separated-spacecraft stellar interferometer. It consists of dual-target linear metrology, based on a heterodyne interferometer with carrier phase modulation, and angular metrology designed to sense the pointing of the laser beam. The dual-target operation enables one metrology beam to sense displacement of two targets independently. We present the current design, breadboard implementation of the Metrology Subsystem in a stellar interferometer testbed and the present state of development of flight qualifiable subsystem components. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Dubovitsky, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 301-451, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1721 EP 1736 PG 16 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800169 ER PT S AU Shields, J Sirlin, S Wette, M AF Shields, J Sirlin, S Wette, M GP IEEE IEEE TI Metrology sensor characterization and pointing control for the formation interferometer testbed (FIT) SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB StarLight is a NASA\JPL sponsored mission that will demonstrate formation flying and interferometric technologies needed for future missions such as Terrestrial Planet Finder (TPF). The StarLight stellar interferometer is composed of two spacecraft, a combiner spacecraft and a collector spacecraft, forming separated apertures. In this paper, the metrology pointing sensor of the StarLight ground instrument prototype is characterized and a siderostat pointing control loop is closed between two optical benches with a 10 meter separation. The Formation Interferometer Testbed (FIT) metrology pointing sensor (MPS) uses four photodiodes to detect gradients in the metrology laser caused by relative motion of the two optical benches. By differencing across the photodiodes, a measurement of the laser beam centroid can be obtained. In the flight design, this signal is passed to the combiner spacecraft, via an interspacecraft communication link, and used as a feedback signal to point a siderostat on the combiner spacecraft. In this paper, a detailed model of the metrology pointing sensor is described based exclusively on experimental data. Both the sensitivity and dynamic range of the sensor are effectively described by this model. The effect of diffraction in the laser light and air path noise on the sensor performance are evaluated. A nonlinear estimation algorithm is proposed that is capable of increasing the capture zone of the sensor by a factor of two. This algorithm relies on using the photodiode sum as an additional measurement. The second part of this paper describes a siderostat pointing control algorithm that uses tachometer, encoder, and the metrology pointing sensor as feedback signals in a nested loop architecture. Experimental results are included that demonstrate the tracking ability of this controller in the presence of spacecraft relative motion caused by Attitude Control System (ACS) deadbands. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Shields, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1737 EP 1745 PG 9 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800170 ER PT S AU Shields, J Sirlin, S Wette, M AF Shields, J Sirlin, S Wette, M GP IEEE IEEE TI Starlight pointing subsystem for the formation interferometer testbed (FIT) SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB StarLight is a NASA\JPL sponsored mission that will be the first spaceborn stellar interferometer. The objective of the mission is to develop and test technologies for performing interferometric observations in space and for the extremely precise formation flying required to make the instrument work. The Formation Interferometer Testbed (FIT) is a ground based prototype of the two spacecraft StarLight instrument. In this paper a complete model of the FIT pointing system is characterized that includes backlash in the siderostar (SD), hysteresis in the PZT actuators of the fast steering mirrors (FSM), time delays, and air path disturbances. Based on this model, a dual stage pointing controller is designed that achieves a bandwidth sufficient to satisfy the pointing requirement. Simulated and experimental results are given that validate the performance of the pointing system. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Shields, J (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 IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1747 EP 1758 PG 12 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800171 ER PT S AU Aaron, KM Stubbs, DM Ames, L Kvamme, T AF Aaron, KM Stubbs, DM Ames, L Kvamme, T GP IEEE IEEE TI Space Interferometry Mission: Recent instrument configuration developments SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB About a year ago, NASA Headquarters requested the SIM project to develop a less costly approach to performing micro-arc-second astrometry. The SIM Team responded by forming a Tiger Team and attacking the problem with vigor. Eliminating two secondary objectives (nulling and imaging) opened up several options that led to a new configuration that met the cost target. Another simplification came about when it was decided to launch using the Space Shuttle. The very large payload bay allowed us to eliminate the hinge in the middle of the precision structure supporting the optical elements. In this paper, we discuss the current reference design of the SIM instrument, and illustrate some of the tradeoffs that led to this arrangement. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Aaron, KM (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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1759 EP 1766 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800172 ER PT S AU Caffrey, RT Simpson, TW Henderson, R Crawley, E AF Caffrey, RT Simpson, TW Henderson, R Crawley, E GP IEEE IEEE TI The strategic issues with implementing open avionics platforms for spacecraft SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Non-aerospace industries from automobiles to consumer electronics are using product platform concepts to accelerate product development. By planning and developing a series of products based on similar architectures, firms can reuse hardware, software, and manufacturing processes to provide a wide range of products, at lower costs and with shorter development cycles. The nature of spacecraft systems creates special technical, strategic, economic, and organizational challenges for implementing product platforms. The low volume, extreme operating environments, long development cycles, short technology cycles, and the nature of government space programs make it difficult for the space industry to benefit from product platform concepts. However, several aerospace organizations are implementing avionics platforms with significant technical, cost, and strategic benefits. This paper discusses the potential strategic benefits. of product platform concepts applied to spacecraft, avionics. C1 NASA, Goddard Space Flight Ctr, MIT, Management Technol Program, Greenbelt, MD 20771 USA. RP Caffrey, RT (reprint author), NASA, Goddard Space Flight Ctr, MIT, Management Technol Program, Mail Stop 400-0, Greenbelt, MD 20771 USA. NR 36 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1825 EP 1841 PG 17 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800178 ER PT S AU Clark, DJ Lux, JP Shirbacheh, M AF Clark, DJ Lux, JP Shirbacheh, M GP IEEE IEEE TI Testbed for development of a DSP-based signal processing subsystem for an earth-orbiting radar scatterometer SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB A testbed for evaluation of general-purpose digital signal processors in earth-orbiting radar scatterometers is discussed. Because general purpose DSP represents a departure from previous radar signal processing techniques used on scatterometers, there was a need to demonstrate key elements of the system to verify feasibility for potential future scatterometer instruments. Construction of the testbed also facilitated identification of an appropriate software development environment and the skills mix necessary to perform the work. A testbed was constructed with three Astrium MCMDSPs, based on the Temic TSC 21020 general purpose DSP. Commercial data conversion hardware and high-speed serial communication hardware was interfaced to the MCMDSPs to allow demonstration of the key interfaces between subsystem elements: DSP program loading, synchronization and communication between multiple DSPs, interface to the scatterometer radio frequency subsystem, commanding, and science data delivery to the instrument data handling subsystem. A baseline set of requirements for the radar signal processing subsystem was established. From these requirements, signal processing algorithms such as digital filters and FFTs were developed using a combination of standard library functions and custom software. A software framework was developed to coordinate execution of the periodic signal acquisition and processing routines with asynchronous commanding and timekeeping functions. Emphasis was placed on developing modular software that would be applicable to a number of potential future instruments. Performance of the. DSP subsystem was evaluated in terms of measured vs. theoretical execution speed, timing accuracy, power consumption, and computational accuracy. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Clark, DJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1881 EP 1890 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800182 ER PT S AU Webb, E AF Webb, E GP IEEE IEEE TI Ethernet for space flight applications SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB NASA's Goddard Space Flight Center (GSFC) is adapting current data networking technologies to fly on future spaceflight missions. The benefits of using commercially based networking standards and protocols have been widely discussed and are expected to include reduction in overall mission cost, shortened integration and test (I&T) schedules, increased operations flexibility, and hardware and software upgradeability/scalability with developments ongoing in the commercial world. The networking effort is a comprehensive one encompassing missions ranging from small University Explorer (UNEX) class spacecraft to large observatories such as the Next Generation Space Telescope (NGST). Mission aspects such as flight hardware and software, ground station hardware and software, operations, RF communications, and security (physical and electronic) are all being addressed to ensure a complete end-to-end system solution. One of the current networking development efforts at GSFC is the SpaceLAN (Spacecraft Local Area Network) project, development of a space-qualifiable Ethernet network. To this end we have purchased an IEEE 802.3-compatible 10/100/1000 Media Access Control (MAC) layer Intellectual Property (IP) core and are designing a network node interface (NNI) and associated network components such as a switch. These systems will ultimately allow the replacement of the typical MIL-STD-1553/1773 and custom interfaces that inhabit most spacecraft.. In this paper we will describe our current Ethernet NNI development along with,,a novel new space qualified physical layer that will be used in place of the standard interfaces. We will outline our plans for development of space qualified network components that will allow future spacecraft to operate insignificant radiation environments while using a single onboard network for reliable commanding and data transfer. There will be a brief discussion of some issues surrounding system implications of a flight Ethernet. Finally, we will show an onboard network architecture for a proposed new mission using Ethernet for science data transport. C1 NASA, Goddard Space Flight Ctr, Flight Elect Branch, Greenbelt, MD 20771 USA. RP Webb, E (reprint author), NASA, Goddard Space Flight Ctr, Flight Elect Branch, Code 561, Greenbelt, MD 20771 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1927 EP 1934 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800187 ER PT S AU Kizhner, S Petrick, DJ Flatley, TP Hestnes, P Jentoft-Nilsen, M Blank, K AF Kizhner, S Petrick, DJ Flatley, TP Hestnes, P Jentoft-Nilsen, M Blank, K GP IEEE IEEE TI Pre-hardware optimization of spacecraft image processing software algorithms and hardware implementation SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Spacecraft telemetry rates and product complexity have steadily increased over the last decade presenting a problem for real-time processing by ground facilities. This paper proposes a solution to a related problem for the Geostationary Operational Environmental Spacecraft (GOES-8) image data processing and color picture generation (GOES-8 application). Although large super-computer facilities are the obvious heritage solution, they are very costly, making it imperative to seek a feasible alternative engineering solution at a fraction of the cost. The proposed solution is based on a Personal Computer (PC) platform and synergy of optimized software algorithms and reconfigurable computing hardware (RC) technologies, such as Field Programmable Gate Arrays (FPGA) and Digital Signal Processors (DSP). The solution involved porting the GOES-8 application from its Silicon Graphics Inc (SGI) Workstation/UNIX platform, making minor platform specific changes to the GOES-8 application (so that it runs on the PC), benchmarking the various code segments, and implementing the most compute intensive functions in hardware. After pre-hardware optimization steps in the PC environment, the necessity for using RC hardware implementation for bottleneck code became more evident. The problem was solved beginning With the methodology described in [1], [2], [3], and implementing a novel methodology for this application. The PC-RC interface bandwidth problem for the class of applications with moderate input-output data rates but large intermediate multi source data streams has been addressed and mitigated. This opens a new class of satellite image processing applications for bottleneck problem solution using RC technologies. The issue of a science algorithm level of abstraction necessary for RC hardware implementation is also described. Selected software functions already implemented in hardware were investigated for their direct applicability With the intent to create a library of RC functions for ongoing work. A complete class of spacecraft image processing applications development using reconfigurable computing technology to meet real-time requirements, including methodology, performance results and comparison with the existing system, is described in this paper. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kizhner, S (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 1975 EP 1992 PG 18 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800192 ER PT S AU Fixsen, DJ Offenberg, JD AF Fixsen, DJ Offenberg, JD GP IEEE IEEE TI Up-the-ramp processing and cosmic ray rejection with limited memory SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID ARRAYS; NOISE; NGST AB We present an algorithm for optimally processing uniformly sampled array image data obtained with a nondestructive readout. The algorithm discards full wells, removes cosmic ray (particle) hits and other glitches, and makes a nearly optimum estimate of the signal and noise on each pixel. The computer requirements, including memory, are modest, and the results are robust. The results are shown and compared to results of Fowler sampled and processed data. Non-ideal detector performance may require some additional code, but this is not expected to cost much processing time. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP Fixsen, DJ (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Code 681, Greenbelt, MD 20771 USA. 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 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2053 EP 2060 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800199 ER PT S AU Rilee, ML Boardsen, SA Bhat, MK Curtis, SA AF Rilee, ML Boardsen, SA Bhat, MK Curtis, SA GP IEEE IEEE TI Onboard science software enabling future space science and Space Weather Missions SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID IMAGE AB On the path towards an operational Space Weather System are science missions involving as many as 100 spacecraft (Magnetospheric Constellation, DRACO, 2010). Multiple spacecraft are required to measure the macro, meso, and micro scale plasma physics that underlies Geospace phenomea. Simultaneous multi point in situ measurements enable the determination of electric current in space and the discrimination of temporal and spatial phenomena. From these quantities, the structure and dynamics of Geospace may be modeled and better understood. We work towards the day when multi point, real time data might be gathered on Earth to produce maps and forecasts of Space Weather conditions. To be feasible, however, multiple spacecraft missions must be no more costly to operate than single spacecraft missions are today. Furthermore, communication availability places severe constraints on an entire mission architecture and hampers the resolution, coverage, timeliness, and hence, usefulness of spacecraft data. To address some of these constraints, we have been studying the possibility of performing some science data processing function's on board a pathfinding mission in NASA's Solar-Terrestrial Probe Line, Magnetospheric Multi Scale (MMS, 2008). The MMS mission involves four or five spacecraft, operating as one, that bring full suites of high resolution plasma diagnostic sensors to focus on Geospace phenomena involving plasma microphysics, i.e. sub-fluid length, time, and frequency scales. In the MMS baseline, totality of coverage, already likely to be hampered by communication availability, is sacrificed to obtain high resolution data in the. vicinity of critical Geospace boundaries. Onboard computation enables the return of additional reduced data from regions immediately surrounding these important Geospace boundaries: data which may be critical to the correct understanding of boundary processes. Furthermore, onboard computation will enable high resolution reduced data for entire orbits to be sent to Earth. Going beyond onboard data reduction, sufficient onboard computation opens the possiblity of onboard autonomous science data management. For purposes ranging from instrument calibration, test, diagnosis, and through scientific discovery, the most fundamental data an instrument produces are often required. However, communications availability places limits on when and how much of this raw data may be transmitted to Earth. With sufficient onboard computational resources, intelligent systems may be implemented that recognize features in sensor data that are important for mission goals. These data may be selected for transmission to Earth at full fidelity, providing the best possible view of the phenomena. Data of lesser importance are more lossily compressed, with routine observations being compressed to summary statistics before transmission to Earth. This sort of autonomous science data management is an important step to science driven autonomous control of spacecraft instrumentation. In this paper we discuss our multi level approach to developing an onboard science analysis system that we are studying for potential use onboard the MMS mission. This analysis system will enhance MMS science by improving sensor coverage and by returning to Earth high-resolution data that would otherwise be discarded or not generated. Results of our work using Space Physics data sets from previous missions will illustrate our approach. C1 NASA, Goddard Space Flight Ctr, Emergent IT, Greenbelt, MD 20771 USA. RP Rilee, ML (reprint author), NASA, Goddard Space Flight Ctr, Emergent IT, Mailstop 931,28-S-207, Greenbelt, MD 20771 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2071 EP 2084 PG 14 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800201 ER PT S AU Bennett, MB Rasmussen, RD AF Bennett, MB Rasmussen, RD GP IEEE IEEE TI Modeling relationships using graph state variables SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The Mission Data System is a unified flight, ground, simulation, and test software system for space missions. Currently, its first application will be the Mars Smart Lander mission, where common MDS software frameworks will be adapted for use in interplanetary cruise, entry-descent-landing, and rover operations. A key architectural theme of MDS is explicit modeling of states. This provides a sound foundation for estimation, control, and data analysis. Certain essential states are relative rather than absolute. Relative states are defined in graph state variables (GSVs) as relationships between nodes in a graph. GSVs are a general graph-based state representation that (1) derives a state's value by combining relationships, (2) produces different results for different derivation paths, (3) handles changes to topology and relationships between nodes, and (4) represents dependencies between relationships (e.g. correlations). This paper shows example GSV representations for spacecraft orientation, location, trajectories, dynamics, and kinematics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bennett, MB (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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2085 EP 2098 PG 14 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800202 ER PT S AU Karapetian, AV Some, RR Beahan, JJ AF Karapetian, AV Some, RR Beahan, JJ GP IEEE IEEE TI Radiation fault Modeling and fault rate estimation for a COTS based space-borne supercomputer SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Development of the Remote Exploration and Experimentation (REE) Commercial Off The Shelf (COTS) based space-borne supercomputer requires a detailed model of Single Event Upset (SEU) induced faults and fault-effects. Extensive ground based radiation testing has been performed on several generations of the Power PC processor family and related components. A set of relevant environments for NASA missions have been analyzed and detailed. Combining radiation test data, environmental data and architectural analysis, we have developed a radiation fault model for the REE system. The fault model is hierarchically organized and includes scaling factors and optional parameters for fault prediction in future technologies and alternative architectures. It has been implemented in a generic tool, which allows for ease of input and straight forward porting. The model currently includes the Power PC750 (G3), PCI bridge chips, L2 Cache SRAM, Main Memory DRAM, and the Myrinet packet switched network. In this paper, we present the REE Radiation Fault Model and accompanying tool set. We explain its derivation, its structure and use, and the work being done to validate it. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Karapetian, AV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2121 EP 2131 PG 11 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800205 ER PT S AU Some, RR Kim, WS Khanoyan, G Callum, L Agrawal, A Beahan, JJ Shamilian, A Nikora, A AF Some, RR Kim, WS Khanoyan, G Callum, L Agrawal, A Beahan, JJ Shamilian, A Nikora, A GP IEEE IEEE TI Fault injection experiment results in space borne parallel application programs SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Development of the REE Commercial-Off-The-Shelf (COTS) based space-borne supercomputer requires a detailed knowledge of system behavior in the presence of Single Event Upset (SEU) induced faults. When combined with a hardware radiation fault model and mission environment data in a medium grained system model, experimentally obtained fault behavior data can be used to: predict system reliability, availability and performance; determine optimal fault detection methods and boundaries; and define high ROI fault tolerance strategies. The REE project has developed a fault injection suite of tools and a methodology for experimentally determining system behavior statistics in the presence of application level SEU induced transient faults. Initial characterization of science data application code for an autonomous Mars Rover geology application indicates that this code is relatively insensitive to SEUs and thus can be made highly immune to application level faults with relatively low overhead strategies. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Some, RR (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 IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2133 EP 2147 PG 15 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800206 ER PT S AU Some, RR Beahan, J Khanoyan, G Callum, LN Agrawal, A AF Some, RR Beahan, J Khanoyan, G Callum, LN Agrawal, A GP IEEE IEEE TI Fault-tolerant systems design - Estimating cache contents and usage SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Development of the Remote Exploration and Experimentation (REE) Commercial Off The Shelf (COTS) based space-borne supercomputer requires a detailed knowledge of system behavior in the presence of Single Even Upset (SEU) induced faults. When combined with a hardware radiation fault model and mission environment data in a medium grained system model, experimentally obtained fault behavior data can be used to: predict system reliability, availability and performance; determine optimal fault detection methods and boundaries; and define high Return On Investment (ROI) fault tolerance strategies. The REE project has developed a fault injection suite of tools and a methodology for experimentally determining system behavior statistics in the presence of SEU induced transient faults in application level codes. Where faults cannot be directly injected, analytic means are used in conjunction with experimental data to determine probabilistic system fault response. In many processors, it is not possible to inject faults directly into onboard cache. In this case, a cache contents estimation tool can be used to define probabilistic fault susceptibility which is then combined with direct memory fault injection data to determined fault behavior statistics. In this paper we discuss the structure, function and usage of a PPC-750 cache contents estimator for the REE project. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Some, RR (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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2149 EP 2157 PG 9 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800207 ER PT S AU Hunter, DJ AF Hunter, DJ GP IEEE IEEE TI Integrated Avionics System (IAS), integrating 3-D technology on a spacecraft panel SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB As spacecraft designs converge toward miniaturization, and with the volumetric and mass challenges placed on avionics, programs will continue to advance the "state of the art" in spacecraft system development with new challenges to reduce power, mass and volume. Traditionally, the trend is to focus on high-density component packaging technologies. Industry has made significant progress in these technologies, and other related internal and external interconnection schemes. Although new technologies have improved packaging densities, a system packaging architecture is required that not only reduces spacecraft volume and mass budgets, but increase integration efficiencies, provide modularity and flexibility to accommodate multiple missions while maintaining a low recurring cost. With these challenges in mind, a novel system packaging approach incorporates solutions that provide broader environmental applications, more flexible system interconnectivity, scalability, and simplified assembly test and integration schemes. The Integrated Avionics System (IAS) provides for a low-mass, modular distributed or centralized packaging architecture which combines ridged-flex. technologies, high-density COTS hardware and a new. 3-D mechanical packaging approach, Horizontal Mounted L Cube (HMC). This paper will describe the fundamental elements of the IAS, HNIC hardware design, system integration and environmental test results. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hunter, DJ (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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2185 EP 2191 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800212 ER PT S AU Clouse, D Padgett, C AF Clouse, D Padgett, C GP IEEE IEEE TI Estimating the position of a sphere from range images SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB This paper describes two algorithms for accurately locating a spherical object in space using data collected from a scanning laser range finder. This work is designed to support the capture phase of a future rendezvous and sample return mission to Mars. The first algorithm finds the parameters of the sphere which optimally fit the set of data points. This method is shown to be quite slow, and unlikely to meet the accuracy requirements of the mission. The second algorithm makes a set of almost-independent estimates of the position of the center of the sphere, one from each scan line of data. These estimates are combined using regression to produce an aggregate estimate of the sphere position. This second algorithm is both fast enough, and accurate enough to meet mission requirements. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Clouse, D (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2193 EP 2204 PG 12 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800213 ER PT S AU Eisenman, AR Liebe, CC Perez, R AF Eisenman, AR Liebe, CC Perez, R GP IEEE IEEE TI Sun sensing on the Mars exploration rovers SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB NASA will send two identical scientific rovers to different locations on Mars in 2003. Two Panorama Cameras (Pancams) are included in the nine cameras on each rover. One function of these Pancams is to image the Sun in order to determine its vector relative to the rover. The vector is determined by centroiding the solar image. This vector is used, in combination with information from an inclinometer, a clock, and ephemeris data, to determine north, and to point the high gain antenna at Earth and provide a reference for the inertial measurement unit that is used for rover navigation. The Pancams, their detectors, optics, electronics, and the Sun detection/centroiding algorithm are described. The required accuracies are shown and an error budget is constructed to demonstrate that the Pancam meets these requirements. The functions and performance of the Pancams are verified at a dedicated solar observing facility. The facility, its calibration, and the transformation of the intensity and angular subtense of the Sun at Mars, are described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Eisenman, AR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 1 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2249 EP 2262 PG 14 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800217 ER PT S AU Liebe, CC Mobasser, S Bae, Y Wrigley, CJ Schroeder, JR Howard, AM AF Liebe, CC Mobasser, S Bae, Y Wrigley, CJ Schroeder, JR Howard, AM GP IEEE IEEE TI Micro sun sensor SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB A prototype micro sun sensor has been developed at the Jet Propulsion Laboratory, California Institute of Technology. It consists of a thin piece of silicon coated with a layer of chrome and a layer of gold with hundreds of small pinholes, placed on top of an Active Pixel Sensor (APS) image detector at a distance of 900 microns. Images of the sun are formed on the APS image detector when the sun illuminates the mask. Sun angles are derived by determining the precise location of the sun images on the detector - just like a sundial. The packaged micro sun sensor has a mass of 11 grams, a volume of 4.2 cm(3) and a power consumption of 30 mW. The accuracy of the micro sun sensor is better than 1 arcminute and the maximum field of view is 160degrees. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Liebe, CC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 16 TC 3 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2263 EP 2273 PG 11 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800218 ER PT S AU Liebe, CC Alkalai, L Domingo, G Hancock, B Hunter, D Mellstrom, J Ruiz, I Sepulveda, C Pain, B AF Liebe, CC Alkalai, L Domingo, G Hancock, B Hunter, D Mellstrom, J Ruiz, I Sepulveda, C Pain, B GP IEEE IEEE TI Micro APS based star tracker SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID IDENTIFICATION AB JPL has conducted a study on how to design future miniaturized star trackers. The study proposes an ultra-low power (70 mW), ultra-low mass (42 grams) and very fast (50 Hz) Micro, APS-based Star Tracker (MAST). The accuracy of the MAST will be similar to7.5 arcseconds at 50 Hz update rate. The MAST is indispensable to all low mass and power micro/nano spacecraft where mass and power is a concern. The MAST consists of only two chips - a breakthrough CMOS Active Pixel Sensor (APS) image detector optimized for star tracker applications and an ASIC chip including (IC)-C-2 interface, memory and an 8051 micro controller. MAST has functionality so it outputs pixel data from small windows and the spacecraft computer performs the processing. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91101 USA. RP Liebe, CC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91101 USA. NR 21 TC 11 Z9 12 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2285 EP 2299 PG 15 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800220 ER PT S AU Duong, V Stubberud, AR AF Duong, V Stubberud, AR GP IEEE IEEE TI System identification by genetic algorithm SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE Aerospace Conference Proceedings LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB This paper presents a method for identifying systems through their input-output behavior and the Genetic Algorithm. The advantages of this technique are, first, it is not dependent on the deterministic or stochastic nature of the systems and, second, the globally optimized models for the original systems can be identified without the need of a differentiable measure function or linearly separable parameters. The results are compared to similar results from Least Squares identification methods. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM vduong@brain.jpl.nasa.gov; arstubbe@uci.edu NR 10 TC 4 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2331 EP 2337 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800224 ER PT S AU Zebulum, RS Stoica, A Keymeulen, D Ferguson, MI Duong, V Daud, T AF Zebulum, RS Stoica, A Keymeulen, D Ferguson, MI Duong, V Daud, T GP IEEE IEEE TI Current mode circuits: Increasing the chances of evolution to find a way SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID PROGRAMMABLE TRANSISTOR ARRAYS; EVOLVABLE HARDWARE AB Evolution of electronic circuits has been intensively investigated for the last five years. The main challenge of the area is the evolution of circuits for industrial applications and also to find methods to improve the performance of Evolutionary Computation in electronic circuit synthesis. The authors have been studying this problem using different approaches, such as new methods for circuit representation and fitness evaluation function. We describe in this paper experiments on the evolution of current mode circuits. Experimental results in the area of computational circuits suggest that the search space for this class of circuits is more amenable for evolution than their voltage mode counterparts. At the end of the paper we propose an application in the area of fuzzy control, which can provide benefits for the aerospace community, such as in applications for propulsion controlled aircrafts. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Zebulum, RS (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 IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2339 EP 2345 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800225 ER PT S AU Benz, HF Gambles, JW Whitaker, SR Hass, KJ Maki, GK Yeh, PS AF Benz, HF Gambles, JW Whitaker, SR Hass, KJ Maki, GK Yeh, PS GP IEEE IEEE TI Low power radiation tolerant VLSI for advanced spacecraft SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The combination of two synergistic VLSI technologies, Ultra Low Power CMOS and Radiation Tolerant by design, offers an opportunity to provide advanced electronics capabilities for future spacecraft. The 500 mV CMOS process can yield orders of magnitude power reduction compared to current space-flight technologies and the radiation tolerance provides immunity against single event latch-up, good single event upset resistance and total ionizing dose immunity of at least 200krads(Si). A study based on the EO-1 spacecraft requirements indicates that the use of these technologies could provide spacecraft power savings of 73% and total mass savings of 16%. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Benz, HF (reprint author), NASA, Langley Res Ctr, MS 473, Hampton, VA 23681 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2401 EP 2406 PG 6 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800232 ER PT S AU Herrero, FA Chornay, DJ AF Herrero, FA Chornay, DJ GP IEEE IEEE TI Miniature imaging plasma spectrometer: A new approach with large geometric factor and wide field of view SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID DESIGN AB Silicon micro-fabrication enables new imaging plasma spectrometers that are small, consume little power, and maintain the performance level of conventional spectrometers; X10 to X100 mass reduction can be achieved, depending on application. Arrays of narrow collimator channels (1degrees divergence) with high transmission (> 70%) allow energy analysis of electrons/ions without the need for focusing, giving effective aperture areas about 20% of detector pixel footprint. With this approach, a 1x1cm(2) pixel may be fabricated having about 2x10(6) collimator channels, 50 energy selector slots, a single field of view, and a single detector anode. A typical spectrometer consists of a set of pixels with common energy scan, each pixel with its own field of view. The energy analyzers operate with relatively small voltage/energy factors. For example, it is possible to have a spectrometer made up of a square array of pixels laid out in a flat configuration with a net field of view 60degreesx60degrees, each pixel with its own viewing angle with energy range 10 eV to 40 keV. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Herrero, FA (reprint author), NASA, Goddard Space Flight Ctr, 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2407 EP 2416 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800233 ER PT S AU Schreiber, JG AF Schreiber, JG GP IEEE IEEE TI Capabilities and technical issues regarding the stirling radioisotope generator SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) has been active in the development of Stirling power conversion technology for over 25 years. Currently, a free-piston Stirling power convertor is being developed for use in a long-life Radioisotope Power System (RPS) to power NASA deep space and planetary surface missions. The Stirling Radioisotope Generator (SRG) design requirement is for greater than 100,000 hour (11.4 year) life providing over 100 watts dc to the spacecraft. The Department of Energy (DOE) is responsible for providing radioisotope power systems for NASA missions, and has managed the development of a free-piston Stirling power convertor for this application. Drawing on expertise acquired from past projects, NASA GRC provides technical support to DOE in the development of the Stirling convertor. Support provided to DOE is in a range of technical areas and makes use of analytical and hardware capabilities. Modest resources have been spent on the project, however, the Stirling convertor technology has matured significantly. Because of the ability to operate in a broad range of environments (vacuum of deep space or atmosphere of Mars), the SRG is being considered for a variety of missions. Applications include free-flying spacecraft and planetary surface rovers, in addition to stationary surface science applications. This paper will briefly describe the role of the NASA GRC in advancing the Stirling technology for space power systems, give examples of technical areas where in-house expertise has been utilized, and highlight some of the contributions that have been made. This paper will also present some examples of how the power system might be used to enhance the capabilities of missions, describe the status of the overall project, and address some critical technical issues. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Schreiber, JG (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2445 EP 2452 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800238 ER PT S AU Carr, GA Wester, G Sauers, J Danielak, B Haskell, R Hogue, D Jud, JW Bingley, J Repp, JD Mulvey, J Linkowsky, F Giampaoli, P Kates, A Holic, J AF Carr, GA Wester, G Sauers, J Danielak, B Haskell, R Hogue, D Jud, JW Bingley, J Repp, JD Mulvey, J Linkowsky, F Giampaoli, P Kates, A Holic, J GP IEEE IEEE TI X2000 power system electronics development SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The Europa Orbiter mission, currently baselined for launch in 2008, is intended to follow up on tantalizing results from the Galileo spacecraft, data from which suggests that there may be a global ocean underneath the jovian satellite Europa's water ice crust. If Europa has an ocean, its volume is likely to be greater than that of all Earth's oceans combined, even though Europa itself is only about the size of Earth's Moon. Scientific objectives for the mission are to ascertain whether or not Europa has a liquid water ocean, to characterize ice layers beneath the surface, and to find the most scientifically enticing landing sites for future missions. Europa orbits in the heart of the jovian magnetosphere's trapped radiation belts, resulting in radiation doses many times those for which civilian spacecraft have been designed in the past. Total dose is projected to be 6-7 MRad [Si] behind 40 mils aluminum in the case of Europa Orbiter. In addition, Europa orbit is propulsively one of the most difficult destinations to reach in the Solar System, making mass a major driver of mission cost. The combination of high radiation and the need for low-mass and -power electronics led to the X2000 avionics development activity, which is now at the core of the Europa Orbiter project. Because X2000 equipment has been designed for scalability and modularity, other missions have adopted the flight computer, memory, and potentially other "slices" of X2000 hardware and accompanying software. At the heart of the X2000 development are 11 rad-hard, high performance application specific integrated circuits (ASICs), which may be utilized either on the avionics "slices" for which they are being designed, or separately if that is beneficial to a user. The Europa mission provides a challenge in terms of extreme environmental requirements. The key driving requirements are the one mega-rad total ionizing dose and the fourteen-year life. devices increases the packaging density of the Power System Electronics. The X2000 PSE has successfully completed a preliminary design review clarifying the requirements. Currently, there are two ASICs that completed fabrication and two others in fabrication. One technology development has been terminated due to cost and schedule risk. The X2000 Power System Electronics (PSE) must reduce its power, mass and volume envelope by incorporating new technology developed by industry partners. The combination of Multi-chip module (MCM) packaging, rad-hard mixed signal ASICs and next-generation power devices increases the packaging density of the Power System Electronics. The X2000 PSE has successfully completed a preliminary design review clarifying the requirements. Currently, there are two ASICs that completed fabrication and two others in fabrication. One technology development has been terminated due to cost and schedule risk. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Carr, GA (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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2453 EP 2465 PG 13 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800239 ER PT S AU Bergman, R Borden, CS Zendejas, S AF Bergman, R Borden, CS Zendejas, S GP IEEE IEEE TI Automated workflow for engineering services SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB In the future users will request engineering services automatically much like we request stock quotes and weather reports today. Rather than requesting an engineering service directly from an engineer, a user will request the service from an automated server, which can be accessed from a web browser or other computer applications. The engineer's duties will shift to maintaining and enhancing the automated services, and performing expert-level analysis. This paradigm shift is beneficial to the engineer who is currently burdened with providing repetitive services. It is also beneficial to the users, who will receive a faster response from an automated server than a person can provide. Unfortunately, it is vastly more difficult to expose engineering services than services such as stock quotes and weather services. This paper argues that service technology is sufficiently mature to provide many engineering services reliably and securely. It also illustrates a methodology for creating engineering services using the engineering applications that today's engineers use to provide their services. Once automated engineering services are available, they can be used in con unction with a workflow management system to transform engineering processes in the same way business processes have been transformed in the last decade. This paper describes a prototype of an automated workflow system, developed by the Jet Propulsion Laboratory, that provides navigation and telecommunication services. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91009 USA. RP Bergman, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91009 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2553 EP 2567 PG 15 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800249 ER PT S AU Rosenberg, LH Gallo, AM AF Rosenberg, LH Gallo, AM GP IEEE IEEE TI Software Quality Assurance engineering at NASA SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB As our missions on the ground and into space expand to reach new horizons, the complexities and importance of software to mission success also increase. Software has taken on a new, enhanced role and now directly impacts not only mission success, but also the safety of the missions. Software Quality Assurance (SQA) is critical to the success of every mission at NASA, but the roles and responsibilities are often misunderstood. SQA covers all phases of the software development process, with specific activities to assure both the processes used and the products developed. It also includes areas such as safety, reliability, IV&V, and metrics. The purpose of this paper is to help the reader understand what software quality assurance entails for both the processes and the products. C1 NASA, Goddard Space Flight Ctr, Off Syst Safety & Mission Assurance, Greenbelt, MD 20771 USA. RP Rosenberg, LH (reprint author), NASA, Goddard Space Flight Ctr, Off Syst Safety & Mission Assurance, Greenbelt, MD 20771 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2569 EP 2575 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800250 ER PT S AU Malin, JT Johnson, K Molin, A Schreckenghost, D AF Malin, JT Johnson, K Molin, A Schreckenghost, D GP IEEE IEEE TI Integrated tools for mission operations teams and software agents SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB A concept and prototypes for a web-based tool set for mission operations teams are described. This tool set is designed for collecting and distributing information concerning events and issues during missions. Key elements are a console logger, a report generator and a workspace for collecting files, links and actions associated with an issue. The tool set is designed for use both by human team members in a mission control center and by software agents. Software assistants will carry out instructions that automate collection, presentation and distribution of information from diverse sources. One information source can be an autonomous agent controlling a space system or spacecraft. The goal is to integrate software agents With tools that support the work processes of teams, thereby making it easier to automate elements of team tasks and to support team interaction With autonomous agents in space. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Malin, JT (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 NASA Rd 1, Houston, TX 77058 USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2599 EP 2614 PG 16 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800253 ER PT S AU Crichton, D Hughes, S Kelly, S Ramirez, P AF Crichton, D Hughes, S Kelly, S Ramirez, P GP IEEE IEEE TI A component framework supporting peer services for space data management SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Knowledge discovery and data correlation require a unified approach to basic data management. However, achieving such an approach is nearly impossible with hundreds of disparate data sources, legacy systems and data formats. This problem is pervasive in the space science community where data models, taxonomies and data management systems are locally implemented and limited metadata has been collected and organized. Technology developed by the Object Oriented Data Technology (OODT) task at NASA's Jet Propulsion Laboratory (JPL) has been exploring component frameworks for managing, locating and exchanging data residing within a geographically distributed network. OODT has taken a novel approach towards solving this problem by exploiting web technologies usually dedicated to e-commerce, combined with a rich, metadata-based environment. The components developed by OODT create a set of distributed peer-to-peer services that allow for data managed by a peer to be searched and returned as part of an integrated data management system. This paper discusses the approach taken to develop a software framework, and two prototype development efforts for the Planetary Data System (PDS) and the Mission and Ground Asset Database. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Crichton, D (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 IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2639 EP 2649 PG 11 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800257 ER PT S AU Park, H Mackey, R James, M Zak, M Kynard, M Sebghati, J Greene, W AF Park, H Mackey, R James, M Zak, M Kynard, M Sebghati, J Greene, W GP IEEE IEEE TI Analysis of space shuttle main engine data using beacon-based exception analysis for multi-missions SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB This paper describes analysis of Space Shuttle Main Engine (SSME) sensor data using Beacon-based Exception Analysis for Multimissions (BEAM), a new technology developed for sensor analysis and diagnostics in autonomous space systems by the Jet Propulsion Laboratory (JPL). The BEAM anomaly detection system has been applied to SSME in a joint effort between JPL and the Marshall Space Flight Center (MSFC). MSFC is evaluating BEAM as an automated tool for rapid analysis of SSME ground-test data. BEAM is an end-to-end method of data analysis intended for real-time (on-board) or non-real-time anomaly detection and characterization. For the SSME application, a custom version of BEAM was built to analyze data gathered during ground tests. Since BEAM consists of modular components, a custom version call be tailored to address specific applications and needs by mixing-and-matching if components. The initial build of BEAM for the SSME focuses on signal processing and contains three , components: Coherence-based Fault Detector (CFD). Dynamical Invariant Anomaly Detector (DIAD), and Symbolic Data Model (SDM). This paper describes the software environment, its training steps, and the analysis results of the SSME data using the DIAD module. The DIAD module was the first applied due to its particular suitability to SSME data features. It detects anomalies by computing coefficients of an auto-regressive model (i.e. dynamical invariants) and comparing them to expected values as extracted from previous data. The DIAD is particularly sensitive to anomalies caused by faulty sensors, subtle and sudden performance shifts, and unexpected transients. This functionality will be illustrated by several examples from actual test data. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Park, H (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 2835 EP 2844 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800273 ER PT S AU Gal-Edd, J Steck, J Fatig, CC Zepp, R AF Gal-Edd, J Steck, J Fatig, CC Zepp, R GP IEEE IEEE TI Low cost ground systems - Fantasy or reality SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB During the concept phase and initial design of a NASA spacecraft, no NASA project says, 'I want an expensive ground system'. In fact, as with other parts of the total project, a zero cost option is the preferred choice. Our experience has shown that putting together a 'low cost' ground system including development systems, control center and ground station, is not as simple as one is first lead to believe. This paper will address several areas of ground system design: onboard spacecraft, ground stations and networks, simulators and laboratories, Telemetry and Command Systems, all of which require careful analysis to accommodate the ground systems cost savings. We have also found that changes to the ground system design are often used to reduce technical risk in other areas of the mission. Many of the ground system impacts from these changes are advertised as 'low cost', but when taken as a whole, the cost impact on the ground system can be large. 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 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3195 EP 3200 PG 6 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800308 ER PT S AU Vinogradova, T Burl, M Mjolsness, E AF Vinogradova, T Burl, M Mjolsness, E GP IEEE IEEE TI Training of a crater detection algorithm for mars crater imagery SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Automatic feature identification from orbital imagery would be of wide use in planetary science. For example, the ability to count craters on homogeneous surfaces would enable relative dating of geological processes. The scaling of crater densities and impact rates with crater size is another important issue which could be addressed by automated crater counting. Geological feature cataloging can practically be achieved by hand-labeled imagery only for restricted numbers of features. To handle massive new data sets and higher resolutions such as those arising from Mars Global Surveyor, automated feature identification will be required. Many pattern recognition algorithms could be applied to this problem, but a systematic validation process will be required to select the best method for each scientific application and to determine its reliability for scientific use. We demonstrate such a validation process applied to a particular trainable feature identification algorithm when used to detect craters in synthetic imagery and in Mars Global Surveyor imagery. The feature identification algorithm is the Continuously Scalable Template Matching algorithm of (Burl et al., 2001) The validation process involves separate experiments for subpopulations selected from a labeled crater corpus. The subpopulations are defined by crater density. For the selected subpopulations, the validation process includes training the algorithm on some craters and testing its identification accuracy on others. These results can be summarized in terms of statistical efficiency measures. Efficiency results depend on the subpopulation tested. We illustrate algorithm performance on data from Martian regions of high scientific interest. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Vinogradova, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 29 TC 2 Z9 4 U1 1 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3201 EP 3211 PG 11 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800309 ER PT S AU Varanasi, P Tyler, S AF Varanasi, P Tyler, S GP IEEE IEEE TI Operations concept for TES mission operations SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB This paper briefly outlines EOS Aura's Tropospheric Emission Spectrometer (TES) experiment and TES Instrument activities in operations. It describes the operations concept being developed for TES commanding, monitoring and analyzing TES health data. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Varanasi, P (reprint author), 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3233 EP 3243 PG 11 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800311 ER PT S AU Norris, JS Wales, R Powell, MW Backes, PG Steinke, RC AF Norris, JS Wales, R Powell, MW Backes, PG Steinke, RC GP IEEE IEEE TI Mars mission science operations facilities design SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB A variety of designs for Mars rover and lander science operations centers are discussed in this paper, beginning with a brief description of the Pathfinder science operations facility and its strengths and limitations. Particular attention is then paid to lessons learned in the design and use of operations facilities for a series of mission-like field tests of the FIDO prototype Mars rover. These lessons are then applied to a proposed science operations facilities design for the 2003 Mars Exploration Rover (MER) mission. Issues discussed include equipment selection, facilities layout, collaborative interfaces, scalability, and dual-purpose environments. The paper concludes with a discussion of advanced concepts for future mission operations centers, including collaborative immersive interfaces and distributed operations. This paper's intended audience includes operations facility and situation room designers and the users of these environments. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Norris, JS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3245 EP 3255 PG 11 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800312 ER PT S AU Backes, PG Norris, JS Powell, M Steinke, R AF Backes, PG Norris, JS Powell, M Steinke, R GP IEEE IEEE TI Relating downlink products to uplink commands in mars rover operations SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Downlink data products in Mars rover missions need to be associated with their uplink commanded target locations and the uplink commands that produced them. A system for automatically associating downlink data products with uplink commands and targets has been developed and used in a terrestrial rover field test. HTML reports viewable in a browser are automatically generated to relate downlink data products with the uplink sequence elements that produced them. The approach assumes that there is only one sequence thread being executed on the rover. This assumption is not true for the 2003 Mars Exploration Rover mission, so the approach cannot be used directly in the MER mission. C1 CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Backes, PG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3257 EP 3264 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800313 ER PT S AU Powell, MW Norris, JS Backes, PG AF Powell, MW Norris, JS Backes, PG GP IEEE IEEE TI Visualization of spectroscopy for remote surface operations SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB This work discusses the role that in-situ spectroscopy plays in remote surface operations and how effective visualization of spectra can benefit planning. We begin by discussing how spectroscopy was used in the Mars Pathfinder mission and field trials with a prototype of the Mars Exploration Rover, paying close attention to shortcomings in visualization that hamper science planning. Next, we will introduce two methods for improving visualization of spectra that will be used during the Mars Exploration Rover 2003 mission: image cubes and data fusion. Image cubes view a collection of spectra as a hyperspectral image and allows spectra to be enhanced using image processing algorithms. Data fusion places spectral data in the context of a conventional image by overlaying an image cube slice onto an image of the terrain. We demonstrate these techniques with examples of image cubes and data fusion using data from FIDO rover field trials. We conclude with a discussion of future directions for these visualization methods. C1 CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Powell, MW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3265 EP 3271 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800314 ER PT S AU Steinke, RC Backes, PG Norris, JS AF Steinke, RC Backes, PG Norris, JS GP IEEE IEEE TI Distributed mission operations with the multi-mission encrypted communication system SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The traditional model of mission operations is centralized with all activities taking place at a single location. The Multi-mission Encrypted Communication System (MECS) is a tool for enabling distributed operations where scientists and engineers at several locations collaborate over the Internet to perform mission operations activities. There are many reasons why distributed operations are desirable. Travel and facilities costs can be reduced. Disruption can also be reduced both at the mission operations facility which no longer has to house remote participants, and in the lives of remote participants who no longer have to leave their homes for weeks at a time. Finally, the level of participation can be increased leading to greater return from a mission. The MECS architecture is centered around maintaining cached file replicas in a consistent state on remote machines. Challenges that are addressed by MECS include security, compatibility with legacy applications, clients that disconnect and reconnect to the network frequently, and user interface issues involved in keeping users informed when files are created or modified. This paper discusses MECS' architecture for distributed operations and lessons learned from a field test in May 2001. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Steinke, RC (reprint author), 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3273 EP 3279 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800315 ER PT S AU Cheung, KM Lee, CH Gearhart, WB Vo, T Sindi, S AF Cheung, KM Lee, CH Gearhart, WB Vo, T Sindi, S GP IEEE IEEE TI Link-capability driven network planning and operation SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Current deep space planning, scheduling, and operation are based on spacecraft-ground-view period and criteria such as mission priority and science returns. There are, however, no network models that take into consideration the real-time link capabilities and communication performances. As a result, many communication resources are under-utilized. In this paper, we develop a network planning and scheduling concept that takes into account communication link capabilities and telecom performances. Valuable link-driven information such as favorable telecom configurations (antenna pattern, frequency, temperature, etc.) and geometry (range, elevation angle, etc.) can be translated into higher supportable data rates during each pass. Therefore larger data volume can be transmitted or received within a period and mission tracking time can be shortened. This approach enables us to maximize the number of missions that the network resources can support. Mathematical framework for sample link models and optimization algorithms along with solutions are presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cheung, KM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3281 EP 3285 PG 5 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800316 ER PT S AU Cox, B AF Cox, B GP IEEE IEEE TI e-STARS - A new view into information management SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB This paper describes a new process of performing on-line documentation for large complex projects. Recent advances in computer power, computer networking and large data storage availably has enabled all aspects of the design process to be captured in the digital form. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cox, B (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3297 EP 3310 PG 14 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800318 ER PT S AU Stoffel, AW AF Stoffel, AW GP IEEE IEEE TI An automated system for distributing literature and managing information overload SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE Aerospace Conference Proceedings LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB A challenge in scientific communities is that one member of the community will acquire new literature but the information never gets passed on to other interested colleagues within the community. We designed and are building a web-based tool to overcome this challenge. This system is the Scientific Literature Exchange and Database System or SciExchange. SciExchange allows a scientist who reads an article, an online journal article or science news update, to log onto the SciExchange website and easily submit the article or link to the article to the database. Next, SciExchange automatically sends a notification email to the list of subscribing scientists who asked to be notified if articles on topics of interest to them were entered into the SciExchange database. The email contains a link to the article referred to. Its design, construction, planned uses, and implications for NASA's Goddard Space Flight Center (GSFC) are detailed in this paper. C1 NASA, Goddard Space Flight Ctr, Astrophys Data Facil, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Astrophys Data Facil, Code 631, Greenbelt, MD 20771 USA. EM bill.Stoffel@gsfc.nasa.gov 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3321 EP 3326 PG 6 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800320 ER PT S AU Balaram, J Austin, R Banerjee, P Bentley, T Henriquez, D Martin, B McMahon, E Sohl, G AF Balaram, J Austin, R Banerjee, P Bentley, T Henriquez, D Martin, B McMahon, E Sohl, G GP IEEE IEEE TI DSENDS - A high-fidelity dynamics and spacecraft simulator for entry, descent and surface landing SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The Jet Propulsion Laboratory (JPL) is developing a high-fidelity spacecraft simulator for Entry, Descent and Landing (EDL) on planetary and small-bodies. This simulator, DSENDS (Dynamics Simulator for Entry, Descent and Surface landing), is an EDL-specific extension of a JPL multi-mission simulation toolkit (Darts/Dshell) which is capable of modeling spacecraft dynamics, devices, and subsystems, and is in use by interplanetary and science-craft missions such as Cassini, Galileo, SIM, and Starlight. DSENDS is currently in use by the JPL Smart Lander project [1] to provide a high-fidelity testbed for the test of precision landing and hazard avoidance functions for future Mars missions. We first briefly describe the core tool capabilities in dynamics, instrument/actuator device models, and real-time simulation engineering. These allow the modeling of the flight-train elements during various phases of EDL and all of the spacecraft responses. We then address the various EDL-specific aspects of the simulator. These include the high-fidelity entry-body and parachute aerodynamic models and supporting atmospheric models. In addition the simulator provides real-time terrain and instrument simulations for terrain imaging lidars and radars. The simulator hosts guidance/navigation simulation modules for hypersonic steering and powered descent. Models for landing kinematics and dynamics are being incorporated to determine contact and impact forces. We also discuss the automated state-machine driven model switching used to handle spacecraft separations and re-configurations, as well as specific visualization tools developed to support EDL execution interpretation. The DSENDS system is capable of supporting the entire mission lifecycle use of simulators. This includes the facility to embed the simulator into a Matlab/Simulink environment where control analysts can use the same high-fidelity simulation used in real-time operations within a familiar analysis environment. DSENDS also provides stand-alone simulations to provide mission visualization and support for Monte-Carlo analysis. Using the real-time features of the underlying Darts/Dshell toolkit, DSENDS can be made to operate in a VxWorks/VxSim real-time testbed. A key aspect of building such a simulator is the verification of its capabilities. We discuss our approach to verification which includes comparisons with off-line simulators (e.g. POST), mission data (e.g. Mars Pathfinder, NEAR asteroid mission), as well as data from terrestrial test programs. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Balaram, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 198-219, Pasadena, CA 91109 USA. NR 21 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3343 EP 3359 PG 17 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800323 ER PT S AU Cornford, SL Dunphy, J Feather, MS AF Cornford, SL Dunphy, J Feather, MS GP IEEE IEEE TI Optimizing the design of end-to-end spacecraft systems using risk as a currency SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Treating risk as a "currency" has proven to be key in systematically optimizing the design of spacecraft systems. This idea has been applied in the design of individual components of spacecraft systems, and in the end-to-end design of such systems. The process, called "Defect Detection and Prevention" (DDP), its tool support, and applications, are described in [1]. The process can be summarized as determining the consequences of various risk elements (technical, programmatic, other) on the various requirements and then determining the optimal combination of approaches to reducing the risks to acceptable levels. We are now extending this process to include consideration of architectural alternatives, qualification of components, fabrication and assembly, integration and test, and mission operation. The results of applying this extended process in the pre-formulation, formulation and implementation phases of various NASA and other government agency missions will be discussed. This paper will also discuss the results of developing optimized technology development and qualification plans. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cornford, SL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3361 EP 3367 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800324 ER PT S AU Offenberg, JD Fixsen, DJ Sengupta, R Mather, JC AF Offenberg, JD Fixsen, DJ Sengupta, R Mather, JC GP IEEE IEEE TI Automated data processing and cosmic ray mitigation of up-the-ramp sampled data SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID REJECTION AB Space-based observatories require the best possible signal-to-noise ratio to return the best possible science for the cost. The method selected for collecting data will have a significant impact upon the science returned, and thus the return on the original investment. For example, the Next Generation Space Telescope (NGST) will have a lifetime cost of approximately $2 Billion (US)---approximately $0.0001 per pixel collected; a loss of a million pixels of data equals a loss of $100. Sampling method impacts the scientific return of a science instrument in several ways. The first is that multiple samples will improve the signal-to-noise ratio of the observation. For example, reading the same pixel multiple times provides a way to mitigate for the effects of uncertainty inherent in the readout process ("read noise"). Depending on the observation goal and the characteristics of the detector, it may be useful to group all of the samples at the start and end of the observation ("Fowler sampling") or to sample at regular intervals ("Up-the-Ramp sampling"). In the case of faint objects near the detection threshold, uniform samples provide modestly (6%) better signal-to-noise than does Fowler sampling. [6] The second way the readout method impacts the scientific return is by determining the available options for processing. In particular, the high flux of charged particles in deep space will cause significant data loss due to particle impacts. When a charged particle impacts an IR detector, it deposits a large but unknown amount of charge in the active layer. This means that the signal is effectively lost when cosmic ray or other charged particle impacts the detector. However, by reading out at regular intervals, it is possible to estimate the "typical" rate of increase for the accumulating charge, identify outliers and discard suspect intervals. Although the Up-the-Ramp approach is most effective, and simplest to implement, when the samples are distributed uniformly, the method can be used when the samples are not uniform. Up-the-ramp sampled data can be used to improve the data beyond reducing the read-noise and mitigating charged particle events. For example, we obtain useful estimates of the signal for saturated data by examining the samples obtained before saturation. We also measure the signal-to-noise of the data while it is being collected. If a target signal-to-noise is required, it is possible to determine if the target is reached ahead of schedule, continue the observation if it is taking longer than expected or abandon a hopeless observation. We demonstrate the effectiveness of an efficient cosmic ray rejection system utilizing Up-the-Ramp sampled InSb radiation test data. The method used is over 99% effective in identifying and removing cosmic rays while preserving good data,, even when over 15% of the detector is impacted by cosmic rays in each sample. We also demonstrate the effectiveness of using Up-the-Ramp sampled data for automated data management solutions. Several approaches for performing this processing are discussed. C1 Sci Syst & Applicat Inc, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Offenberg, JD (reprint author), Sci Syst & Applicat Inc, NASA, Goddard Space Flight Ctr, Code 681, 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3401 EP 3407 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800327 ER PT S AU Clark, KP Van Amringe, KE AF Clark, KP Van Amringe, KE GP IEEE IEEE TI Flight hardware delivery breakthroughs via engineering/business best-practices synthesis SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Development and use of leading-edge engineering and business practices provides firm footing for tremendous advances in the aerospace community. When applied together and systemically across multiple missions, these practices can yield tremendous reduction of technical, schedule and cost risks for project development. An example of this synthesis can be found in the Jet Propulsion Laboratory's (JPL's) Flight Hardware Logistics Program (FHLP), which uses space systems engineering expertise and supply-chain business acumen to achieve breakthroughs in the delivery of space flight hardware. To support the evolution from a few large projects to many smaller projects developed in shorter time, flight hardware delivery must evolve from serial, independent and resource-intensive processes to those characterized by commonality, multi-project support, anticipation, industry-partnering, reuse and easy access to information. These processes are fundamental to the communication, coordination and collaboration that FHLP provides to enhance JPL project success. The heart of FHLP centers on the commonality of flight hardware across multiple projects. As an example, FHLP has demonstrated significant schedule, cost and technical risk reduction using a common buy of 31 flight computers for 9 different projects. Understanding and coordinating similar product requirements for multiple subsystems, instruments, projects and companies can yield even greater savings. Knowledge of upcoming missions, their flight product needs, hardware capabilities and supply sources allow anticipatory procurements of flight hardware to reduce or eliminate lead-time. This is being done for flight electronic parts, connectors and fasteners with replenishment funded by compensation from users for supplied hardware. Partnering with industry is achieved with suppliers and users of hardware. Open contracts and supplier early parts buys are examples of supplier agreements while synchronized procurement and inventory exchange are examples of user agreements between JPL and its contractors. Improved tracking, coordination, record keeping and storage of residual flight hardware can provide crucial cost and schedule benefits to future projects. FHLP has developed a low-cost, JPL-wide system and facilities to significantly increase the capability for current project use of residual material from past projects. Having the right hardware information at the engineer's fingertips saves considerable time and reduces the risk of missing important knowledge. FHLP provides limited hardware information today; tomorrow it will provide much more comprehensive "one-stop shopping." The FHLP information tools include an on-line JPL-wide hardware catalog of available inventory (,with reports, shopping carts and digital pictures), on-line product documentation and database of hardware usage by projects. The many simultaneous smaller projects implemented today do not enjoy the substantial infrastructure and stable expertise more prevalent in the past on fewer large projects. FHLP fills these gaps with services of hardware information, availability, investigation, delivery and storage. Likewise, proposed projects hungry for higher fidelity information, increased heritage and lower costs welcome a menu of support from FHLP that includes information about available hardware, costs, lead-times and suppliers. FHLP's early focus on hardware delivery and inventory will be augmented by enhanced hardware information and expand to include other NASA Centers and industry partners. Breakthroughs will be limited only by imagination, innovation, commitment and energy. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Clark, KP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 301-370, Pasadena, CA 91109 USA. NR 1 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3409 EP 3428 PG 20 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800328 ER PT S AU Watson, WA AF Watson, WA GP IEEE IEEE TI Rapid spacecraft development: Results and lessons learned SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The Rapid Spacecraft Development Office (RSDO) at NASA's Goddard Space Flight Center is responsible for the management and direction of a dynamic and versatile program for the definition, competition, and acquisition of multiple indefinite delivery and indefinite quantity contracts - resulting in a catalog of spacecraft buses. Five spacecraft delivery orders have been placed by the RSDO and two have been launched. Numerous concept and design studies have been performed, most with the intent of leading to a future spacecraft acquisition. A collection of results and lessons learned is recorded to highlight management techniques, methods and processes employed in the conduct of spacecraft acquisition. Topics include working relationships under fixed price delivery orders, price and value, risk management., contingency reserves and information restrictions. C1 Goddard Space Flight Ctr, Rapid Spacecraft Dev Off, Greenbelt, MD 20771 USA. RP Watson, WA (reprint author), Goddard Space Flight Ctr, Rapid Spacecraft Dev Off, Greenbelt, MD 20771 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3429 EP 3436 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800329 ER PT S AU Thomas, RC AF Thomas, RC GP IEEE IEEE TI The impact of small businesses on critical NASA space missions SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB This paper describes the dramatic contributions of small, minority and women owned businesses to the most critical missions of America's Space Program since 1992. Such feats did not occur by accident, however. Rather, they were the end result of NASA's unique mission- oriented approach to small and disadvantaged business utilization. Through strategic organization, meticulous planning, timely execution and continuous learning, NASA rose from having a marginal small business program to one now seen as a model throughout the Federal government and the world. The benefit to NASA has been the delivery of high quality goods and services by small businesses at less cost. It has also meant a broadening of public support for the funding of its major technical projects and programs. Most important, however, is the fact that NASA's emphasis in this area has caused it to function better as an agency. For small businesses this has meant significantly more NASA prime and subcontract dollars, a better quality of contracts and, for many, the freedom from dependence on NASA contracts for survival. NASA's unequivocal success in this arena should cause many governmental and private entities to rethink its traditional approach to small and disadvantaged business utilization. C1 NASA, Washington, DC 20546 USA. RP Thomas, RC (reprint author), NASA, 300 E St SW,Mail Code K, Washington, DC 20546 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3437 EP 3447 PG 11 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800330 ER PT S AU Baroff, LE AF Baroff, LE GP IEEE IEEE TI Distributed teaming on JPL projects SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB NASA projects are created by teams of people. More frequently than ever before, these project teams include members who are "distributed" rather than colocated -- scattered in place, time, discipline or attention rather than collected and focused in every way. Distributed teams share many characteristics with colocated teams, but their geographic distribution precludes frequent face-to-face meetings among team members. This physical distribution makes shared vision and trust much harder to achieve within the team, and creates a vacuum where social aspects of team behavior would normally be. This paper addresses structures,, actions and technologies that contribute to real team development of a distributed team, and the leadership skills and tools that are used to implement that team development. Some of the information is extrapolated from literature describing team development -- I say extrapolated, because nearly all of that literature is focused on co-located teams, and almost none on "virtual" or "distributed" teams. Much more of the information in this paper is gathered from real-life experiences of JPL (and other) project managers who have led distributed teams themselves. They were eager to describe the difficulties they encountered, the various means they used to solve those difficulties, and both the successes and failures of their efforts. They left it to me to compare their experiences with the theories of human dynamics, and to generalize on their experiences. These generalizations are increasingly necessary, as the use of distributed teams increases in every industry. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Baroff, LE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3461 EP 3466 PG 6 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800332 ER PT S AU Gilbert, MG AF Gilbert, MG GP IEEE IEEE TI A systems management approach to improving performance and reducing risks in research projects and programs SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The Systems Management Office at the NASA Langley Research Center has adopted an approach to improving performance and reducing risks in research programs and projects that recognizes the interrelationship of good program or project management and systems engineering processes in achieving success. The approach stresses early identification, improvement, and implementation of good program or project management practices through consulting and facilitated, "just-in-time" training tailored to the specific program or project. The approach also addresses process and policy improvement and value-added independent reviews and assessments. The approach is further detailed and specific activities and highlights indicating effectiveness of the approach are presented. C1 NASA Langley Res Ctr, Hampton, VA 23681 USA. RP Gilbert, MG (reprint author), NASA Langley Res Ctr, 6 E Talor St, Hampton, VA 23681 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3467 EP 3471 PG 5 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800333 ER PT S AU Mohan, SN AF Mohan, SN GP IEEE IEEE TI Managing unmanned flight projects using methods in complex product development SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Recent developments in management science at the MIT Sloan School of Management provide a disciplined approach to managing complex product development. The methods are in wide use in industry both in the US and abroad. The principles involved in complex product development are very much applicable to managing unmanned planetary flight projects. Central to the methods involved is the Decision Structure Matrix, also referred to as the Design Structure Matrix by some. This paper discusses the use of Decision Structure Matrices (DSM) in managing complex unmanned planetary exploration projects. The DSM is a powerful approach for defining, recording, and examining system dependencies, be it at the program-level, project-level or at an individual task-level. It is based on the premise that success in business requires an efficient sharing of information. The DSM provides a disciplined approach and a powerful methodology for managing projects via identification of intrinsic system dependencies during both development and operational phases. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mohan, SN (reprint author), CALTECH, Jet Prop Lab, T1710F,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 1 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3473 EP 3488 PG 16 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800334 ER PT S AU Dumas, R Avila, D Fisher, K AF Dumas, R Avila, D Fisher, K GP IEEE IEEE TI A personnel/user database implementing EAR/ITAR-Compliant access controls to a project information system SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB As the National Aeronautics and Space Administration (NASA) continues to implement geographically and internationally diverse project teams, the necessity of controlling access to shared information causes increasing concern among team members and requires strict implementation of processes and procedures. The complexity of sharing information among such project teams when partners are not collocated has created a need to obtain and validate user credentials. In addition, NASA's missions are increasingly lower-cost and have shorter design and development cycles, forcing cost constraints on information system implementation and maintenance. The Jet Propulsion Laboratory (JPL), a Federally Funded Research and Development Center (FFRDC) under contract to NASA, must comply with all Federal statutes and regulations applicable to import and export control. Specific controls include the Export Administration Regulations (EAR) [1], International Traffic in Arms Regulations (ITAR) [2] [3]. and the Code of Federal Regulations (CFR) [2][3][4], which apply to dissemination of information. Implementing EAR- and ITAR-compliance in a complex information system environment with stringent cost constraints dictates a simple, cost-effective implementation that is easily modifiable for a variety of projects. NASA's Space Infrared Telescope Facility (SIRTF) project recently developed and implemented a combined EAR/ITAR-compliant access request and project personnel database at its JPL project office. SIRTF's implementation of a web-based interface to the database provides access requests, access approval, user account creation and validation, and a project telephone list. NASA's Galaxy Evolution Explorer (GALEX), a low-cost SMEX mission adapted SIRTF's prototype at virtually no cost, proving the portability of the SIRTF solution. This paper describes the approach used in designing the SIRTF prototype, explains the adaptability of the database to varying levels of project complexity, and discusses lessons learned. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Dumas, R (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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3503 EP 3510 PG 8 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800336 ER PT S AU Koch, T Paine, C Husted, L Yun, MH Lange, A Bock, J Bhatia, R Jones, W Ade, P Sudiwala, R AF Koch, T Paine, C Husted, L Yun, MH Lange, A Bock, J Bhatia, R Jones, W Ade, P Sudiwala, R GP IEEE IEEE TI Bolometric detectors for the High Frequency Instrument on Planck SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The High Frequency Instrument (HFI) on Planck will obtain all-sky images of the Cosmic Microwave Background (CMB) and other astrophysical sources of emission with resolution of 9 arcmin at 100 GHz, 7 arcmin at 143 GHz and 5 arcmin at 217, 353, 545 and 857 GHz. The HFI focal plane will contain 48 silicon nitride, micromesh, bolometric detectors operating from a 100 mK heat sink. Four detectors in each of the 6 bands will detect the sum of the power in both linear polarizations. An additional 4 pair of detectors will provide sensitivity to linear polarization of emission at 143, 217 and 353 GHz. We report on the development of these detectors, which are being produced at the JPL Micro Devices Laboratory, packaged at JPL Electronics Packaging, characterized at 100 mK before delivery to our HFI consortium partners at the Cardiff, UK. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Koch, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3535 EP 3541 PG 7 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800340 ER PT S AU Lo, MW AF Lo, MW GP IEEE IEEE TI The InterPlanetary Superhighway and the origins program SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises ID EARTH AB The origin of the universe and of life itself have been central to human inquiries since the dawn of consciousness. To develop and use the technologies to answer these timeless and profound questions is the mission of NASA's Origins Program. The newly discovered "Interplanetary Superhighway" (IPS) by Lo and Ross [1], [2] is a significant and cost-effective technology that can contribute to both Origins' Science and Technology Goals. IPS is a vast network of tunnels providing ultra-low energy transport throughout the entire Solar System, generated by the Lagrange Points of all of the planets and satellites. IPS contributes to Origins by providing: mission-enabling trajectories, human servicing of Origins missions, a new model of the Solar System, new techniques for detecting exo-planets, an important role in the development of life, and other scientific and engineering connections that impact the Origins Program. IPS is a critical technology for the Origins Program. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lo, MW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,301-140L, Pasadena, CA 91109 USA. NR 25 TC 8 Z9 9 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3543 EP 3562 PG 20 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800341 ER PT S AU Kierk, I AF Kierk, I GP IEEE IEEE TI Innovative quantum technologies for microgravity fundamental physics and biological research SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The many advanced technology requirements dictated by the demanding low-Earth orbit research environment can only be satisfied through the adaptation of innovative methods and technologies. The fundamental physics research program currently supports research in four areas: gravitational and relativistic physics, laser cooling and atomic physics., low temperature and condensed matter physics, and biological physics. The microgravity fundamental physics is one of the science disciplines within the new NASA Office of Biological and Physical Sciences Research, where quantum technology plays a major role. Quantum technology, based on controlled manipulation of fundamentally quantum processes of atoms, molecules, or soft matter, enables novel and significantly extended capabilities. This paper presents a new technology program, within the fundamental physics,, focusing on four quantum technology areas: quantum atomics, quantum optics, space superconductivity and quantum sensor technology, and quantum fluid based sensor and modeling technology. C1 Jet Propuls Lab, CALTECH, Pasadena, CA 91106 USA. RP Kierk, I (reprint author), Jet Propuls Lab, CALTECH, 4800 Oak Grove Dr,MS 233-200, Pasadena, CA 91106 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3563 EP 3566 PG 4 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800342 ER PT S AU Watson, JJ Collins, TJ Bush, HG AF Watson, JJ Collins, TJ Bush, HG GP IEEE IEEE TI A history of astronaut construction of large space structures at NASA Langley Research Center SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB During the 1970's through the early 1990's, NASA Langley Research Center (LaRC) conducted studies for the design and construction of large space structures in Low Earth Orbit (LEO). The Langley studies focused on the design and construction of erectable space structures. The construction studies evaluated assembly methods using astronauts with and without mechanized foot-restraints. Astronaut construction was shown to be very effective and efficient when the structure and the construction methods were developed in parallel. This paper presents an overview of the LaRC astronaut construction studies of erectable structures, including a database of assembly rates and lessons learned. In addition this paper presents potential applications of erectable structure assembly methods using EVA astronauts and a suggested integrated approach for construction of large space structures. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Watson, JJ (reprint author), NASA, Langley Res Ctr, MS 190, Hampton, VA 23681 USA. NR 26 TC 2 Z9 2 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3569 EP 3587 PG 19 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800343 ER PT S AU Doggett, W AF Doggett, W GP IEEE IEEE TI Robotic assembly of truss structures for space systems and future research plans SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB Many initiatives under study by both the space science and earth science communities require large space systems, i.e. with apertures > 15 m or dimensions > 20 m. This paper reviews the effort in NASA Langley Research Center's Automated Structural Assembly Laboratory which laid the foundations for robotic construction of these systems. In the Automated Structural Assembly Laboratory reliable autonomous assembly and disassembly of an 8 meter planar structure composed of 102 truss elements covered by 12 panels was demonstrated. The paper reviews the hardware and software design philosophy which led to reliable operation during weeks of near continuous testing. Special attention is given to highlight the features enhancing assembly reliability. C1 NASA, Langley Res Ctr, Hampton, VA 23662 USA. RP Doggett, W (reprint author), NASA, Langley Res Ctr, MS 152D, Hampton, VA 23662 USA. NR 27 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3589 EP 3598 PG 10 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800344 ER PT S AU Purves, LR AF Purves, LR GP IEEE IEEE TI A method for estimating costs and benefits of space assembly and servicing by astronauts and robots SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB One aspect of designing future space missions is to determine whether Space Assembly and Servicing (SAS) is useful and, if so, what combination of robots and astronauts provides the most effective means of accomplishing it. Certain aspects of these choices, such as the societal value of developing the means for humans to live in space,, do not lend themselves to quantification. However, other SAS costs and benefits can be quantified in a manner that can help select the most cost-effective SAS approach. Any space facility, whether it is assembled and serviced or not, entails an eventual replacement cost due to wear and obsolescence. Servicing can reduce this cost by limiting replacement to only failed or obsolete components. However, servicing systems, such as space robots, have their own logistics cost, and astronauts can have even greater logistics requirements. On the other hand, humans can be more capable than robots at performing dexterous and unstructured tasks, which can reduce logistics costs by allowing a reduction in mass of replacement components. Overall, the cost-effectiveness of astronaut SAS depends on its efficiency; and., if astronauts have to be wholly justified by their servicing usefulness, then the serviced space facility has to be large enough to fully occupy them. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Purves, LR (reprint author), NASA, Goddard Space Flight Ctr, Code 661, 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3655 EP 3663 PG 9 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800350 ER PT S AU Fullerton, R Trevino, R AF Fullerton, R Trevino, R GP IEEE IEEE TI Review of components for large spacecraft implementation SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The future of large spacecraft assembly, maintenance and servicing can benefit from the techniques and technologies of the past, present, and future. Not only can existing concepts and hardware be used to reduce implementation costs, but they can also point to deficiencies, which require further attention and development. This paper reviews relevant design trades, tasks and experience associated with actual Shuttle, Mir, and ISS missions as well as some credible developmental projects that were not actually flown. It includes an illustrated summary of some of the latest designs in use for fasteners, mechanical joints., electrical connectors, fluid connectors and related components. Interfaces common to both manual EVA and robotic handling are noted. References are supplied to aid the reader in pursuing additional details. These assembly, maintenance and servicing technologies have application not only to low-earth orbit (LEO), but also for large spacecraft beyond LEO. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Fullerton, R (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3665 EP 3670 PG 6 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800351 ER PT S AU Robinson, RK AF Robinson, RK GP IEEE IEEE TI NASA's commercial space centers: Bringing together government and industry for "out of this world" benefits SO 2002 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOLS 1-7 SE IEEE AEROSPACE CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 09-16, 2002 CL BIG SKY, MT SP IEEE Aerosp & Electr Syst Soc, Aerosp Corp, AstroExpo com, Circle Mt Co, GEB Software Technologies, Jet Propulsion Lab, Opt Energies Technologies Inc, Profet Enterprises AB The National Aeronautics and Space Administration (NASA) is making significant effort to accommodate commercial research in the utilization plans of the International Space Station (ISS)[1]. NASA is providing 30% of the research accommodations in the ISS laboratory modules to support commercial endeavors. However, the availability of resources alone does not necessarily translate into significant private sector participation in NASA's ISS utilization plans. Due to the efforts of NASA's Commercial Space Centers (CSC's), NASA has developed a very robust plan for involving the private sector in ISS utilization activities. Obtaining participation from the private sector requires a demonstrated capability for obtaining commercially significant research results. Since 1985, NASA CSC's have conducted over 200 commercial research activities aboard parabolic aircraft, sounding rockets, the Space Shuttle, and the ISS. The success of these activities has developed substantial investment from private sector companies in commercial space research. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Robinson, RK (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 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 SN 1095-323X BN 0-7803-7231-X J9 AEROSP CONF PROC PY 2002 BP 3673 EP 3678 PG 6 WC Engineering, Aerospace SC Engineering GA BV66P UT WOS:000179697800352 ER PT B AU Gray, AA Lee, C Arabshahi, P Srinivasan, J AF Gray, AA Lee, C Arabshahi, P Srinivasan, J GP IEEE IEEE TI Object-oriented reconfigurable processing for wireless networks SO 2002 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, VOLS 1-5, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Communications CY APR 28-MAY 02, 2002 CL NEW YORK, NY SP IEEE Commun Soc, ICC GLOBECOM, IEEE, AT&T Labs, Avaya Labs, Nippon Telegraph & Telephone, Nokia, Polytech Univ, Verizon Commun ID SOFTWARE RADIO; ARCHITECTURES; EVOLUTION; HARDWARE AB We present an outline of reconfigurable processor technologies and design methods with emphasis on an object-oriented approach, and both full and partial dynamic reconfiguration. A specific broadly applicable architecture for implementing a software reconfigurable network processor for wireless communication applications is presented, a prototype of which is currently operating in the laboratory. This architecture, its associated object oriented design methods, and partial reconfiguration techniques enable rapid-prototyping and rapid implementations of communications and navigation signal processing functions; provide long-life communications infrastructure; and result in dynamic operation within networks with heterogeneous nodes, as well as compatibility with other networks. This work builds upon numerous advances in commercial industry as well as military software radio developments to space-based radios and network processing. The development of such radios and the network processor presented here require defining the correct combination of processing methods ("objects") and developing appropriate dynamic reconfiguration techniques as a function of system goals and operating parameters. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91101 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 238-343, Pasadena, CA 91101 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 BN 0-7803-7400-2 PY 2002 BP 497 EP 501 DI 10.1109/ICC.2002.996903 PG 5 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BV10L UT WOS:000177818300099 ER PT B AU Quirk, KJ Srinivasan, M AF Quirk, KJ Srinivasan, M GP IEEE IEEE TI Analysis of sampling and quantization effects on the performance of PN code tracking loops SO 2002 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, VOLS 1-5, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Communications CY APR 28-MAY 02, 2002 CL NEW YORK, NY SP IEEE Commun Soc, ICC GLOBECOM, IEEE, AT&T Labs, Avaya Labs, Nippon Telegraph & Telephone, Nokia, Polytech Univ, Verizon Commun AB Pseudonoise (PN) code tracking loops in direct-sequence spread-spectrum systems are often implemented using digital hardware. Performance degradation due to quantization and sampling effects is not adequately characterized by the traditional analog system feedback loop analysis. A low-complexity digital PN code tracking loop with one-bit non-commensurate sampling Is analyzed, and the steady-state delay error variance is derived. The results are compared with that of an equivalent analog loop. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Quirk, KJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 0-7803-7400-2 PY 2002 BP 1480 EP 1484 PG 5 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BV10L UT WOS:000177818300285 ER PT B AU Stoica, A Guo, X Zebulum, RS Ferguson, MI Keymeulen, D AF Stoica, A Guo, X Zebulum, RS Ferguson, MI Keymeulen, D GP IEEE IEEE IEEE TI Evolution-based automated reconfiguration of field programmable analog devices SO 2002 IEEE INTERNATIONAL CONFERENCE ON FIELD-PROGRAMMABLE TECHNOLOGY (FPT), PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Field-Programmable Technology (FPT) CY DEC 16-18, 2002 CL CHINESE UNIV HONG KONG, NEW TERRITORIES, PEOPLES R CHINA SP Chung Chi Coll, Croucher Fdn, IEEE Hong Kong Sect Electr Devices Soc, IEEE Comp Soc, IEEE Electr Devices Soc HO CHINESE UNIV HONG KONG AB The paper presents some experiments in automatic reconfiguration of field programmable devices using evolutionary algorithms. The experiments use a Field Programmable Transistor Array (FPTA), reconfigurable at transistor level. While parasitic effects of imperfect switches interconnecting transistors deteriorate performance of conventional designs when mapped to the FPTA, evolutionary algorithms are able to find a working design solution. The experiments are performed with a stand-alone board-level evolvable system (SABLES) in which the evolutionary algorithm is implemented with a DSP. SABLES can automatically configure the FPTA in tens to hundreds of seconds, time in which evaluates similar to100,000 circuit candidate solutions. The paper overviews some examples of evolutionary synthesis of analog circuits on the FP-TA. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. EM adrian.stoica@jpl.nasa.gov NR 4 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7574-2 PY 2002 BP 403 EP 406 DI 10.1109/FPT.2002.1188721 PG 4 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BW47V UT WOS:000182116700066 ER PT B AU Mazzella, F Montgomery, K Latombe, JC AF Mazzella, F Montgomery, K Latombe, JC GP IEEE IEEE IEEE TI The forcegrid: A buffer structure for haptic interaction with virtual elastic objects SO 2002 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT 19th IEEE International Conference on Robotics and Automation (ICRA) CY MAY 11-15, 2002 CL WASHINGTON, DC SP IEEE Robot & Automat Soc DE elastic objects; surgical simulation; haptic interaction; virtual environments ID DEFORMATIONS; SIMULATION AB Real-time surgical simulation often requires computing the deformations of visco-elastic human-body tissue and generating both graphic and haptic renderings. As human users are more sensitive to small haptic discrepancies than visual ones, good force rendering requires a refresh rate of 500Hz or more, which is far beyond the capabilities of current simulators. Moreover, if the simulator runs on a remote server, limited bandwidth, network latency and variance further compromise the quality of haptic rendering. To address these problems, a new interpolation-extrapolation data structure - called the forcegrid - is proposed, which makes it possible to approximate forces at rates greater than 500Hz, regardless of the complexity of the simulated object. The forcegrid is designed for haptic interaction with continuous contact. It is a regular grid defined over the virtual workspace, in which every vertex contains a force. An extrapolation algorithm updates this force at every simulation cycle (similar to30Hz), while an interpolation algorithm computes the force to be rendered on the haptic device at the desired rate (similar to500Hz). The forcegrid has been successfully tested on various virtual deformable objects. C1 NASA, Stanford Natl Biocomputat Ctr, Stanford, CA USA. RP NASA, Stanford Natl Biocomputat Ctr, Stanford, CA USA. EM fred@biocomp.stanford.edu; kevin@biocomp.stanford.edu; latombe@cs.stanford.edu NR 21 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7272-7 PY 2002 BP 939 EP 946 PG 8 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Engineering, Mechanical; Robotics SC Automation & Control Systems; Computer Science; Engineering; Robotics GA BV31M UT WOS:000178573200148 ER PT B AU Williams, LEP Loftin, RB Aldridge, HA Leiss, EL Bluethmann, WJ AF Williams, LEP Loftin, RB Aldridge, HA Leiss, EL Bluethmann, WJ GP IEEE IEEE IEEE TI Kinesthetic and visual force display for telerobotics SO 2002 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT 19th IEEE International Conference on Robotics and Automation (ICRA) CY MAY 11-15, 2002 CL WASHINGTON, DC SP IEEE Robot & Automat Soc AB Effectively controlling a robot remotely - teleoperation - offers benefits in improving human safety, reducing workload providing location accessibility, and achieving convenient operation. In previous work, teleoperator task performance has been shown to improve with the addition of force feedback Here we report on a system providing a human operator with a six-axis kinesthetic and visual force display, its implementation and its experimental evaluation. A system design containing both a six-axis force reflective hand controller and a stereo video head-mounted display with 3D force, display overlay is presented. The system was utilized to evaluate the effects of force display augmentation and substitution by controlling a dexterous anthropomorphic robot called "Robonaut" in the performance of a typical space teleoperation drill task Human test subject performance under four different force feedback scenarios, no force display, visual force display, kinesthetic force display, and bisensory force display is measured Experimental results indicate noticeably lower cumulative force, torque, and variance, lower peak force/torque, yet unchanged task completion times under presence of visual or kinesthetic force display. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Williams, LEP (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 13 TC 7 Z9 7 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7272-7 PY 2002 BP 1249 EP 1254 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Engineering, Mechanical; Robotics SC Automation & Control Systems; Computer Science; Engineering; Robotics GA BV31M UT WOS:000178573200197 ER PT B AU Leger, C AF Leger, C GP IEEE IEEE IEEE TI Efficient sensor/model based on-line collision detection for planetary manipulators SO 2002 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT 19th IEEE International Conference on Robotics and Automation (ICRA) CY MAY 11-15, 2002 CL WASHINGTON, DC SP IEEE Robot & Automat Soc ID OBSTACLE AVOIDANCE; ROBOTS AB Manipulator safeguarding is a critical need for,operations on planetary rovers. The computing environment on a Mars rover is extremely limited, which necessitates a highly efficient collision checking algorithm. We present such an algorithm that uses the Oriented Bounding Box (OBB) and a new primitive called the Oriented Bounding Prism (OBP) to detect potential self-collisions and collisions with terrain objects sensed with the rover's onboard stereo cameras; the algorithm thus has both model-based and sensor-based components. We have implemented the algorithm on JPL's FIDO rover and have tested it under realistic field conditions. Performance analysis indicate this method is significantly faster than previously reported results in the literature, in addition to incorporating sensed geometry. The method is also being used on board NASA's twin Mars Exploration Rovers, which are scheduled to launch in 2003. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM cleger@robotics.jpl.nasa.gov NR 13 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7272-7 PY 2002 BP 1697 EP 1703 PG 7 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Engineering, Mechanical; Robotics SC Automation & Control Systems; Computer Science; Engineering; Robotics GA BV31M UT WOS:000178573200267 ER PT B AU Seraji, H Bon, B AF Seraji, H Bon, B GP IEEE IEEE IEEE TI Multi-range traversability indices for terrain-based navigation SO 2002 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT 19th IEEE International Conference on Robotics and Automation (ICRA) CY MAY 11-15, 2002 CL WASHINGTON, DC SP IEEE Robot & Automat Soc AB This paper presents novel measures of terrain traversability at three different ranges; namely Local, Regional, and Global Traversability Indices. The Local Traversability Index is related by a set of linguistic rules to local obstacles and surface softness within a local perception range, measured by onboard sensors mounted on the robot. The rule-based Regional Traversability Index is computed from the terrain roughness and slope that are extracted from video images of the terrain within a regional perception range obtained by on-board cameras. The Global Traversability Index is obtained from the terrain topographic map, and is based on the natural or man-made surface, features such as mountains and craters within a global perception range. Each traversability index is represented by four fuzzy,sets with the linguistic labels {POOR, LOW, MODERATE, HIGH}, corresponding to surfaces that are unsafe, moderately-unsafe, moderately-safe, or safe for traversal, respectively. These indices are used. to develop a behavior-based navigation strategy for 6 mobile robot traversing a challenging terrain. The traversability indices form the basis of three navigation behaviors; namely, Traverse-Local, Traverse-Regional, and Traverse-Global-behaviors. These behaviors are integrated with the Seek-Goal behavior to ensure that the mobile robot reaches, the goal safely while avoiding obstacles and impassable terrain segments. The paper is concluded by an illustrative graphical simulation study (1). C1 CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, NASA, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7272-7 PY 2002 BP 2674 EP 2681 PG 8 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Engineering, Mechanical; Robotics SC Automation & Control Systems; Computer Science; Engineering; Robotics GA BV31M UT WOS:000178573200422 ER PT B AU Trebi-Ollennu, A Das Nayar, H Aghazarian, H Ganino, A Pirjanian, P Kennedy, B Huntsberger, T Schenker, P AF Trebi-Ollennu, A Das Nayar, H Aghazarian, H Ganino, A Pirjanian, P Kennedy, B Huntsberger, T Schenker, P GP IEEE IEEE IEEE TI Mars rover pair cooperatively transporting a long payload SO 2002 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT 19th IEEE International Conference on Robotics and Automation (ICRA) CY MAY 11-15, 2002 CL WASHINGTON, DC SP IEEE Robot & Automat Soc DE planetary rovers; tight coordination; decentralized compliancy control; multiple mobile robots AB The objective of the Robot Work Crew (RWC) project is to investigate key challenges in multi-robot coordination when performing tightly coupled coordination tasks such as transporting and handling of long objects on challenging planetary terrain. In this paper, we focus on tightly coupled coordination of two Mars rovers transporting a long payload. We have developed practical decentralized compliancy control and coordinated comply control algorithms that effectively address compliant control for compliantly coupled multiple mobile robots. Experiments at the Jet Propulsion Lab in Pasadena, CA of two Mars rovers carry an extended payload over uneven, natural terrain are used to validate and illustrate the approach;. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Trebi-Ollennu, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 14 Z9 14 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7272-7 PY 2002 BP 3136 EP 3141 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Engineering, Mechanical; Robotics SC Automation & Control Systems; Computer Science; Engineering; Robotics GA BV31M UT WOS:000178573200495 ER PT B AU Backes, PG Tso, KS Norris, JS Steinke, R AF Backes, PG Tso, KS Norris, JS Steinke, R GP IEEE IEEE IEEE TI Group collaboration for Mars rover mission operations SO 2002 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT 19th IEEE International Conference on Robotics and Automation (ICRA) CY MAY 11-15, 2002 CL WASHINGTON, DC SP IEEE Robot & Automat Soc ID NETWORKS AB Group collaboration capabilities have been developed for Internet-based Mars rover mission operations. Internet-based operations enables scientists to participate in daily Mars rover mission operations from their home institutions. Group collaboration enables geographically separated users to collaboratively analyze downlinked data and plan new activities for the rover. The motivation for group collaboration in Mars rover mission operations and the technologies developed to provide group collaboration are discussed. The group collaboration capability was developed for use in rover mission operations in the 2003 NASA Mars Exploration Rover mission. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. EM Paul.G.Backes@jpl.nasa.gov; tso@iatech.com NR 12 TC 1 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7272-7 PY 2002 BP 3148 EP 3154 PG 7 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Engineering, Mechanical; Robotics SC Automation & Control Systems; Computer Science; Engineering; Robotics GA BV31M UT WOS:000178573200497 ER PT B AU Huntsberger, T Aghazarian, H Cheng, Y Baumgartner, ET Tunstel, E Leger, C Trebi-Ollennu, A Schenker, PS AF Huntsberger, T Aghazarian, H Cheng, Y Baumgartner, ET Tunstel, E Leger, C Trebi-Ollennu, A Schenker, PS GP IEEE IEEE IEEE TI Rover autonomy for long range navigation and science data acquisition on planetary surfaces SO 2002 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT 19th IEEE International Conference on Robotics and Automation (ICRA) CY MAY 11-15, 2002 CL WASHINGTON, DC SP IEEE Robot & Automat Soc ID STATE ESTIMATION AB This paper describes recent work undertaken at the Jet Propulsion Laboratory in Pasadena, CA in the area of increased rover autonomy for planetary surface operations. The primary vehicle for this work is the Field Integrated, Design and Operations (FIDO) rover. The FIDO rover is an advanced technology prototype that is a terrestrial analog of the Mars Exploration Rovers (MER) being sent to Mars in 2003. We address the autonomy issue through improved integration of rover based sensing and higher level onboard planning capabilities. The sensors. include an inertial navigation unit (INU) with. 3D gyros and accelerometers, a sun sensor, mast and body mounted imagery, and wheel encoders. Multisensor fusion using an Extended Kalman Filter (EKF) approach coupled with pattern recognition and tracking algorithms has enabled the autonomy that is necessary for maximizing science data return while minimizing the number of ground loop interactions. These algorithms are coupled with a long range navigation algorithm called ROAMAN (Road Map Navigation) for an integrated approach to rover autonomy. We also report the results of algorithm validation studies in remote field trials at Black Rock Summit in Central Nevada, California's Mojave Desert, and the Arroyo Seco at JPL. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM terry@telerobotics.jpl.nasa.gov; hrand@telerobotics.jpl.nasa.gov; ycheng@telerobotics.jpl.nasa.gov; ericb@telerobotics.jpl.nasa.gov; tunstel@telerobotics.jpl.nasa.gov; cleger@telerobotics.jpl.nasa.gov; ashitey@telerobotics.jpl.nasa.gov; schenker@telerobotics.jpl.nasa.gov NR 20 TC 15 Z9 15 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7272-7 PY 2002 BP 3161 EP 3168 PG 8 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Engineering, Mechanical; Robotics SC Automation & Control Systems; Computer Science; Engineering; Robotics GA BV31M UT WOS:000178573200499 ER PT B AU Hogg, RW Rankin, AL Roumeliotis, SI McHenry, MC Helmick, DM Bergh, CF Matthies, L AF Hogg, RW Rankin, AL Roumeliotis, SI McHenry, MC Helmick, DM Bergh, CF Matthies, L GP IEEE IEEE IEEE TI Algorithms and sensors for small robot path following SO 2002 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT 19th IEEE International Conference on Robotics and Automation (ICRA) CY MAY 11-15, 2002 CL WASHINGTON, DC SP IEEE Robot & Automat Soc AB Tracked mobile robots in the 20 kg size class are under development for applications in urban reconnaissance. For efficient deployment, it is desirable for teams of robots to be able to automatically execute path following behaviors, with one or more followers tracking the path taken by a leader. The key challenges to enabling such a capability are (1) to develop sensor packages for such small robots that can accurately determine the path of the leader and (2) to develop path following algorithms for the subsequent robots. To date, we have integrated gyros, accelerometers, compass/inclinometers, odometry, and differential GPS into an effective sensing package. This paper describes the sensor package, sensor processing algorithm, and path tracking algorithm we have developed for the leader/follower problem in small robots and shows the results of performance characterization of the system. We also document pragmatic lessons learned about design, construction, and electromagnetic interference issues particular to the performance of state sensors on small robots. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 125-209, Pasadena, CA 91109 USA. EM hogg@jpl.nasa.gov NR 20 TC 10 Z9 14 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7272-7 PY 2002 BP 3850 EP 3857 PG 8 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Engineering, Mechanical; Robotics SC Automation & Control Systems; Computer Science; Engineering; Robotics GA BV31M UT WOS:000178573200609 ER PT B AU Pirjanian, P Leger, C Mumm, E Kennedy, B Garrett, M Aghazarian, H Farritor, S Schenker, P AF Pirjanian, P Leger, C Mumm, E Kennedy, B Garrett, M Aghazarian, H Farritor, S Schenker, P GP IEEE IEEE IEEE TI Distributed control for a modular reconfigurable cliff robot SO 2002 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS I-IV, PROCEEDINGS LA English DT Proceedings Paper CT 19th IEEE International Conference on Robotics and Automation (ICRA) CY MAY 11-15, 2002 CL WASHINGTON, DC SP IEEE Robot & Automat Soc AB We have developed a cliff robot that is capable of descending into a cliff and autonomous navigation to way-points on the cliff wall.. This aggressive mobility system consists of an ensemble of three tethered robots, which cooperate under tight coordinated control and collective state estimation. The distributed task is described as a behavior network, which consists of a network of controllers spread across the robots and which interact through communication links to achieve a collective control objective. Fielded experimental results show that the cliff robot is capable of navigating to designated way-points on a cliff wall using the proposed control scheme. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Pirjanian, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7272-7 PY 2002 BP 4083 EP 4088 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic; Engineering, Mechanical; Robotics SC Automation & Control Systems; Computer Science; Engineering; Robotics GA BV31M UT WOS:000178573200646 ER PT B AU Irom, F Swift, GM Farmanesh, FH Johnston, AH AF Irom, F Swift, GM Farmanesh, FH Johnston, AH GP IEEE IEEE TI Single-event upset in commercial silicon-on-insulator PowerPC microprocessors SO 2002 IEEE INTERNATIONAL SOI CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT IEEE International SOI Conference CY OCT 07-10, 2002 CL WILLIAMSBURG, VA SP IEEE Electron Devices Soc AB Single-event upset effects from heavy ions and protons are measured for Motorola and IBM silicon-on-insulator (SOI) microprocessors, and compared with results for similar devices with bulk substrates. The cross sections of the SOI processors are lower than their bulk counterparts, but the threshold is about the same, even though the charge collections depth is more than an order of magnitude smaller in the SOI devices. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Irom, F (reprint author), Jet Prop Lab, Pasadena, CA 91109 USA. NR 6 TC 0 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7439-8 PY 2002 BP 203 EP 204 PG 2 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Condensed Matter SC Engineering; Instruments & Instrumentation; Physics GA BV40Q UT WOS:000178854400077 ER PT B AU Robinson, RL Scully, RC AF Robinson, RL Scully, RC GP IEEE IEEE TI RF transmissivity measurements of a multilayered circular transparency to characterize attenuation behavior over a frequency range from 500 MHz to 18 GHz SO 2002 IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY, VOLS 1 AND 2, SYMPOSIUM RECORD LA English DT Proceedings Paper CT IEEE International Symposium on Electromagnetic Compatibility CY AUG 19-23, 2002 CL MINNEAPOLIS, MN SP IEEE, EMC Soc, Superior EMC, Laird Technologies, Rohde & Schwarz, TUV Prod Serv, Murata Electr NA Inc, ETS Lindgren, Hoolihan EMC Consulting, IBM Engn Solut Serv, Retlif Testing Labs AB Astronauts engaged in preparatory activities prior to Extravehicular Activity (EVA) may spend one or more hours inside the middeck airlock that has been partially evacuated to the vacuum of space. During this time, the astronauts may wish to review and update non-critical mission information and EVA particulars via a Radio Frequency Local Area Network (RF LAN) connection implemented on a laptop computer. In order to accomplish this, the RF transmission must pass through a multilayer 4-inch transparency, and then propagate to a downlink node located inside the Space Shuttle Orbiter (SSO) vehicle. This paper describes the processes used to verify the transmissivity (essentially the inverse of shielding effectiveness) of such a transparency. Two methods of measurement were employed. The results of each were correlated together after the fact, and showed good agreement. C1 NASA, Lyndon B Johnson Space Ctr, Avion Syst Div, Syst Engn Branch, Houston, TX 77058 USA. RP Robinson, RL (reprint author), NASA, Lyndon B Johnson Space Ctr, Avion Syst Div, Syst Engn Branch, 2101 NASA Rd 1, Houston, TX 77058 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 0-7803-7264-6 PY 2002 BP 128 EP 133 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BV20F UT WOS:000178146200025 ER PT B AU Perez, R AF Perez, R GP IEEE IEEE TI Controlling EMI in telecommunications ICs SO 2002 IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY, VOLS 1 AND 2, SYMPOSIUM RECORD LA English DT Proceedings Paper CT IEEE International Symposium on Electromagnetic Compatibility CY AUG 19-23, 2002 CL MINNEAPOLIS, MN SP IEEE, EMC Soc, Superior EMC, Laird Technologies, Rohde & Schwarz, TUV Prod Serv, Murata Electr NA Inc, ETS Lindgren, Hoolihan EMC Consulting, IBM Engn Solut Serv, Retlif Testing Labs AB Today's complex, deep submicron system-on-chip (SOC) designs, with their smallest feature sizes, increased densities, higher frequencies, and lower supply voltages, have made noise coupling at the packaging and substrate level, key issues for wireless designers of ICs. Until recently, designers have been forced to use rule-of-thumb methodologies to guard against crosstalk at the substrate and packaging level. New substrate modeling and package modeling analysis tools outline in this work have made it possible for designers to understand the effects of noise coupling across their chip's substrates and packaging, and to address the problem early in the design cycle. Finally, transients voltages are a fact of life in telecommunications equipment. The increase complexity of semiconductors has made them more sensitive to the effects of overvoltage due to decreasing geometries. In this work we suggest the selection of protection circuits. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Perez, R (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 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 0-7803-7264-6 PY 2002 BP 345 EP 349 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BV20F UT WOS:000178146200065 ER PT B AU Ngo, HT Scully, RC AF Ngo, HT Scully, RC GP IEEE IEEE TI Technical aspects of specifying and installing a new 3-meter EMI measurement chamber for NASA Johnson Space Center SO 2002 IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY, VOLS 1 AND 2, SYMPOSIUM RECORD LA English DT Proceedings Paper CT IEEE International Symposium on Electromagnetic Compatibility CY AUG 19-23, 2002 CL MINNEAPOLIS, MN SP IEEE, EMC Soc, Superior EMC, Laird Technologies, Rohde & Schwarz, TUV Prod Serv, Murata Electr NA Inc, ETS Lindgren, Hoolihan EMC Consulting, IBM Engn Solut Serv, Retlif Testing Labs AB Recently, the Electromagnetic Interference (EMI) limits and test methods for the National Aeronautics and Space Administration (NASA) Space Shuttle Program (SSP) were revised to incorporate portions of MIL-STD-461E. Use of Commercial Off The Shelf (COTS) equipment is becoming the preferred solution for equipment integration whenever practicable. NASA Johnson Space Center (JSC) Electromagnetic Compatibility (EMC) engineers recommended a commercial 3-meter chamber as an optimal solution for EMI test and flight certification that would best serve the needs of the Program over the next decade. This paper discusses that recommendation and its background, together with other issues associated with the technical specification and installation of such a chamber. C1 NASA, Lyndon B Johnson Space Ctr, Avion Syst Div, Syst Engn Branch, Houston, TX 77058 USA. RP Ngo, HT (reprint author), NASA, Lyndon B Johnson Space Ctr, Avion Syst Div, Syst Engn Branch, 2101 NASA Rd 1, Houston, TX 77058 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 0-7803-7264-6 PY 2002 BP 545 EP 548 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BV20F UT WOS:000178146200103 ER PT B AU Perez, R AF Perez, R GP IEEE IEEE TI Steps for the proper development of an EMC control plan SO 2002 IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY, VOLS 1 AND 2, SYMPOSIUM RECORD LA English DT Proceedings Paper CT IEEE International Symposium on Electromagnetic Compatibility CY AUG 19-23, 2002 CL MINNEAPOLIS, MN SP IEEE, EMC Soc, Superior EMC, Laird Technologies, Rohde & Schwarz, TUV Prod Serv, Murata Electr NA Inc, ETS Lindgren, Hoolihan EMC Consulting, IBM Engn Solut Serv, Retlif Testing Labs AB The development of a major electronic product in a company is usually preceded by the writing of an EMC Control Plan. The EMC Control Plan is written by the senior electromagnetic compatibility engineer and eventually reviewed and approved by management. A product being developed will adhere to the EMC Control Plan. The quality of the EMC Control Plans vary, depending on who writes it, how important is EMC in the culture of the company, the importance of the product itself to the future profitability of the company, and how innovative is the product to be developed. Nevertheless, the proper writing of an EMC Control Plan is crucial to the development of a product that is well designed with EMC in mind. In this work we outlined all the aspects of a well written EMC Control Plan. A well written EMC Control Plan outlines not only testing but design, development, and manufacturing issues. It is intended that present and future EMC engineers could use this EMC Control Plan as a baseline for their companies. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Perez, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7264-6 PY 2002 BP 766 EP 771 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BV20F UT WOS:000178146200139 ER PT S AU Yu, N Tu, M Salik, E Maleki, L AF Yu, N Tu, M Salik, E Maleki, L GP IEEE IEEE TI Opto-electronic generation of low-jitter pulsed signals SO 2002 IEEE/LEOS ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS 1 AND 2 SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 15th Annual Meeting of the IEEE-Lasers-and-Electro-Optics-Society CY NOV 10-14, 2002 CL GLASGOW, SCOTLAND SP IEEE Lasers & Electro Opt Soc ID TO-DIGITAL CONVERTER; FIBER LASER; OSCILLATOR; SYSTEMS C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yu, N (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 2 Z9 2 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8081 BN 0-7803-7500-9 J9 IEEE LEOS ANN MTG PY 2002 BP 337 EP 338 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BV68X UT WOS:000179772700168 ER PT S AU Samoska, L Lin, KY Wang, H Chung, YH Aust, M Weinreb, S Dawson, D AF Samoska, L Lin, KY Wang, H Chung, YH Aust, M Weinreb, S Dawson, D BE Hamilton, R TI On the stability of millimeter-wave power amplifiers SO 2002 IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM DIGEST, VOLS 1-3 SE IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM DIGEST LA English DT Proceedings Paper CT IEEE MTT-S International Microwave Symposium CY JUN 02-07, 2002 CL SEATTLE, WA SP IEEE, MTTS AB In this paper, we discuss issues affecting high frequency power amplifier stability. Two methods for simulating K-factor stability in a monolithic millimeter-wave integrated circuit (MMIC) power amplifier will be discussed. Both methods will be used to predict the occurrence of millimeter-wave oscillations (Ka-band and above) in a W-band power amplifier. We present experimental results confirming the simulation data, and discuss how the methods may be applied to eliminate instabilities in MMIC power amplifiers. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Samoska, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 168-314, Pasadena, CA 91109 USA. OI Lin, Kun-You/0000-0002-4308-3059 NR 5 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0149-645X BN 0-7803-7239-5 J9 IEEE MTT-S PY 2002 BP 429 EP 432 DI 10.1109/MWSYM.2002.1011647 PG 4 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BV24N UT WOS:000178310900098 ER PT S AU Kory, CL Booske, JH Lee, WJ Gallagher, S van der Weide, DW Limbach, S Bhattacharjee, S AF Kory, CL Booske, JH Lee, WJ Gallagher, S van der Weide, DW Limbach, S Bhattacharjee, S BE Hamilton, R TI THz radiation using high power, microfabricated, wideband TWTs SO 2002 IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM DIGEST, VOLS 1-3 SE IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM DIGEST LA English DT Proceedings Paper CT IEEE MTT-S International Microwave Symposium CY JUN 02-07, 2002 CL SEATTLE, WA SP IEEE, MTTS AB Microfabricated, miniature, folded waveguide traveling wave tube (FWG-TWT) devices are potential compact sources of wideband (similar to 20 % instantaneous bandwidth), high power (0.01 - 1 W) THz radiation. We present theoretical analyses and numerical simulations indicating that a 560 GHz, 56 mW, 1% (intrinsic) efficiency oscillator is realistically achievable, and amplifiers with gains between 10 and 30 dB are feasible with circuit lengths of a few centimeters. We also discuss a scale-model experiment at 50 GHz to investigate an oscillator concept using a recirculated power feedback approach, and a 400 GHz proof-of-concept amplifier. C1 Analex Corp, NASA Glenn Res Ctr, Cleveland, OH USA. RP Kory, CL (reprint author), Analex Corp, NASA Glenn Res Ctr, 21000 Brookpk Rd,MS 54-5, Cleveland, OH USA. NR 12 TC 5 Z9 5 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0149-645X BN 0-7803-7239-5 J9 IEEE MTT-S PY 2002 BP 1265 EP 1268 DI 10.1109/MWSYM.2002.1011892 PG 4 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BV24N UT WOS:000178310900295 ER PT S AU Ponchak, GE Dalton, E Tentzeris, EM Papapolymerou, J AF Ponchak, GE Dalton, E Tentzeris, EM Papapolymerou, J BE Hamilton, R TI Coupling between microstrip lines with finite width ground plane embedded in polyimide layers for 3D-MMICs on Si SO 2002 IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM DIGEST, VOLS 1-3 SE IEEE MTT-S International Microwave Symposium LA English DT Proceedings Paper CT IEEE MTT-S International Microwave Symposium CY JUN 02-07, 2002 CL SEATTLE, WA SP IEEE, MTTS AB Three-dimensional circuits built upon multiple layers of polyimide are required for constructing Si/SiGe monolithic microwave/millimeter-wave integrated circuits on CMOS (low resistivity) Si wafers. Thin film microstrip lines (TFMS) with finite width ground planes embedded in the polyimide are often used. However, the closely spaced TFMS lines are susceptible to high levels of coupling, which degrades circuit performance. In this paper, Finite Difference Time Domain (FDTD) analysis and experimental measurements are used to show that the ground planes must be connected by via holes to reduce coupling in both the forward and backward directions. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Ponchak, GE (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0149-645X BN 0-7803-7239-5 J9 IEEE MTT S INT MICR PY 2002 BP 2221 EP 2224 PG 4 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA BV24N UT WOS:000178310900522 ER PT B AU Pritchard, BE Swift, GM Johnston, AH AF Pritchard, BE Swift, GM Johnston, AH GP IEEE IEEE TI Radiation effects predicted, observed, and compared for spacecraft systems SO 2002 IEEE RADIATION EFFECTS DATA WORKSHOP, WORKSHOP RECORD LA English DT Proceedings Paper CT IEEE Radiation Effects Data Workshop held in Conjunction with IEEE Nuclear and Space Radiation Effects Conference (NSREC 2002) CY JUL 15-19, 2002 CL PHOENIX, AZ SP IEEE Nucl & Plasma Sci Soc, Inst Elect Engineers Inc DE radiation; latchap; spacecraft; anomalies; optocouplers AB This paper documents radiation effects observed in selected spacecraft at the system and subsystem levels, and where possible, relates them to predicted radiation effects in parts. Comparisons are also made as functions of design paradigm, assurance philosophy, and the vintage and complexity of the parts and the system. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Pritchard, BE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 28 TC 1 Z9 1 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7544-0 PY 2002 BP 7 EP 13 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Nuclear SC Engineering; Nuclear Science & Technology; Physics GA BV56D UT WOS:000179347500002 ER PT B AU Ott, MN AF Ott, MN GP IEEE IEEE TI Radiation effects data on commercially available optical fiber: Database summary SO 2002 IEEE RADIATION EFFECTS DATA WORKSHOP, WORKSHOP RECORD LA English DT Proceedings Paper CT IEEE Radiation Effects Data Workshop held in Conjunction with IEEE Nuclear and Space Radiation Effects Conference (NSREC 2002) CY JUL 15-19, 2002 CL PHOENIX, AZ SP IEEE Nucl & Plasma Sci Soc, Inst Elect Engineers Inc DE optical fiber; total dose; space fight; radiation; parts; telecommunications AB Presented here are the results of a survey performed at NASA Goddard Space Flight Center on radiation data for commercially available optical fiber. The survey includes data from the past decade that can still be used for currently available parts. The objective of this work was to provide a current central location for relevant radiation data on optical fiber that could be useful for space flight projects. Only valid part numbers that are currently relevant to the manufacturers producing the optical fiber and parts that have been verified as changing number but not process, are included in this study. Presented are the currently available optical fiber types with valid part numbers and manufacturer, the relevant radiation data, and the corresponding data reference. Also included in this summary is the recent unreleased radiation data from experiments conducted at Goddard Space Flight Center on OFS (formerly Spectran) 62.5/125/250 micron optical fiber. This database will serve as a tool for engineers when selecting radiation tested optical fiber for future and current optical fiber systems for space flight applications. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ott, MN (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 21 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7544-0 PY 2002 BP 24 EP 31 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Nuclear SC Engineering; Nuclear Science & Technology; Physics GA BV56D UT WOS:000179347500005 ER PT B AU Nguyen, DN Scheick, LZ AF Nguyen, DN Scheick, LZ GP IEEE IEEE TI SEE and TID of emerging non-volatile memories SO 2002 IEEE RADIATION EFFECTS DATA WORKSHOP, WORKSHOP RECORD LA English DT Proceedings Paper CT IEEE Radiation Effects Data Workshop held in Conjunction with IEEE Nuclear and Space Radiation Effects Conference (NSREC 2002) CY JUL 15-19, 2002 CL PHOENIX, AZ SP IEEE Nucl & Plasma Sci Soc, Inst Elect Engineers Inc AB We report on the SEE and TID tests of higher density flash memories. Stand-by currents and functionality tests were used to characterize the response of radiation effects. Single Event Functional Interrupt (SEFI) errors were observed indicating upsets from complex control circuitry. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Nguyen, DN (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 7 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7544-0 PY 2002 BP 62 EP 66 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Nuclear SC Engineering; Nuclear Science & Technology; Physics GA BV56D UT WOS:000179347500011 ER PT B AU Lehman, J Yui, C Rax, BG Miyahira, TF Wiedeman, A Schrock, P Swift, GM Johnston, AH Kayali, S AF Lehman, J Yui, C Rax, BG Miyahira, TF Wiedeman, A Schrock, P Swift, GM Johnston, AH Kayali, S GP IEEE IEEE TI Low dose failures of hardened DC-DC power converters SO 2002 IEEE RADIATION EFFECTS DATA WORKSHOP, WORKSHOP RECORD LA English DT Proceedings Paper CT IEEE Radiation Effects Data Workshop held in Conjunction with IEEE Nuclear and Space Radiation Effects Conference (NSREC 2002) CY JUL 15-19, 2002 CL PHOENIX, AZ SP IEEE Nucl & Plasma Sci Soc, Inst Elect Engineers Inc AB Radiation tests of Interpoint DC-DC converters, guaranteed by the manufacturer to 100 krad(Si), showed catastrophic failures at total dose levels as low as 4 krad(Si). Special diagnostic tests showed that failures were caused by an internal CMOS MOSFET driver chip being used in an application that differed from earlier radiation tests of the component. This paper discusses radiation testing, failure modes, and the method used to overcome this problem weeks prior to launch of two space systems. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lehman, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7544-0 PY 2002 BP 109 EP 114 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Nuclear SC Engineering; Nuclear Science & Technology; Physics GA BV56D UT WOS:000179347500016 ER PT B AU Yui, CC McClure, SS Rax, BG Lehman, JM Minto, TD Wiedeman, MD AF Yui, CC McClure, SS Rax, BG Lehman, JM Minto, TD Wiedeman, MD GP IEEE IEEE TI Total dose bias dependency and ELDRS effects in bipolar linear devices SO 2002 IEEE RADIATION EFFECTS DATA WORKSHOP, WORKSHOP RECORD LA English DT Proceedings Paper CT IEEE Radiation Effects Data Workshop held in Conjunction with IEEE Nuclear and Space Radiation Effects Conference (NSREC 2002) CY JUL 15-19, 2002 CL PHOENIX, AZ SP IEEE Nucl & Plasma Sci Soc, Inst Elect Engineers Inc DE LM139; LM193; LT1019; LM185; LM134 ID MICROCIRCUITS; RADIATION AB Total dose tests of several bipolar linear devices show sensitivity to both dose rate and bias during exposure. All devices exhibited Enhanced Low Dose Rate Sensitivity (ELDRS). An accelerated ELDRS test method for three different devices demonstrate results similar to tests at low dose rate. Behavior and critical parameters from these tests are compared and discussed. C1 Jet Prop Lab, Elect Parts Engn Off, Pasadena, CA 91109 USA. RP Yui, CC (reprint author), Jet Prop Lab, Elect Parts Engn Off, Pasadena, CA 91109 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7544-0 PY 2002 BP 131 EP 137 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Nuclear SC Engineering; Nuclear Science & Technology; Physics GA BV56D UT WOS:000179347500020 ER PT B AU Marshall, CJ LaBel, KA Reed, RA Marshall, PW Byers, WB Conger, C Peden, J Eid, ES Jones, MR Kniffin, S Gee, G Pickel, J AF Marshall, CJ LaBel, KA Reed, RA Marshall, PW Byers, WB Conger, C Peden, J Eid, ES Jones, MR Kniffin, S Gee, G Pickel, J GP IEEE IEEE TI Heavy ion transient characterization of a hardened-by-design active pixel sensor array SO 2002 IEEE RADIATION EFFECTS DATA WORKSHOP, WORKSHOP RECORD LA English DT Proceedings Paper CT IEEE Radiation Effects Data Workshop held in Conjunction with IEEE Nuclear and Space Radiation Effects Conference (NSREC 2002) CY JUL 15-19, 2002 CL PHOENIX, AZ SP IEEE Nucl & Plasma Sci Soc, Inst Elect Engineers Inc DE radiation effects; active pixel sensor; single event transients AB This paper presents heavy ion test data on the single event transient response of an active pixel sensor four quadrant test chip with different radiation tolerant designs in a commercial 0.35 mum CMOS process. The physical design techniques of enclosed geometry and P-type guard rings are used to design the four N-type active photodiode pixels as described in a previous paper [1]. Transient measurements on the 256 x 256 pixel array as a function of Ar ion incidence angle show a significant variation in the amount of charge collected as well as the charge spreading dependent on the pixel type. The results are correlated with processing and design information provided by Photobit. In addition, there is a significant variability between individual ion strikes for some unit cell designs. No C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Marshall, CJ (reprint author), NASA, Goddard Space Flight Ctr, Code 561, Greenbelt, MD 20771 USA. NR 5 TC 3 Z9 3 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7544-0 PY 2002 BP 187 EP 193 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Nuclear SC Engineering; Nuclear Science & Technology; Physics GA BV56D UT WOS:000179347500029 ER PT B AU Talukder, A Manduchi, R Castano, R Owens, K Matthies, L Castano, A Hogg, R AF Talukder, A Manduchi, R Castano, R Owens, K Matthies, L Castano, A Hogg, R GP IEEE IEEE TI Autonomous terrain characterisation and modelling for dynamic control of unmanned vehicles SO 2002 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, VOLS 1-3, PROCEEDINGS LA English DT Proceedings Paper CT IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2002) CY SEP 30-OCT 04, 2002 CL LAUSANNE, SWITZERLAND SP IEEE Robot & Automat Soc, IEEE Ind Electr Soc, Robot Soc Japan, Soc Instruments & Control Engineers, INRIA Rhone Alpes Grenoble, EPFL Lausanne DE Classification; geometrical reasoning; navigation; obstacle detection obstacle negotiation; terrain perception; terrain modeling; vehicle modeling. AB An often-ignored aspect of unmanned cross-country vehicles is the dynamic response of the vehicle on different terrain. We discuss techniques to predict the dynamic vehicle response to various natural obstacles. This method can then be used to adjust the vehicle dynamics to optimize performance (e.g. speed) while ensuring that the vehicle is not damaged This capability opens up a new area of obstacle negotiation for UGVs, where the vehicle moves over certain obstacles, rather than avoiding them, thereby resulting in more effective achievement of objectives. Robust obstacle negotiation and vehicle dynamics prediction requires several key technologies that will be discussed in this paper. We detect and segment (label) obstacles using a novel 3D obstacle algorithm. The material of each labelled obstacle (rock, vegetation, etc.) is then determined using a texture or color classification scheme. Terrain load-bearing surface models are then constructed using vertical springs to model the compressibility and traversability of each obstacle in front of the vehicle. The terrain model is then combined with the vehicle suspension model to yield an estimate of the maximum safe velocity, and predict the vehicle dynamics as the vehicle follows a path. This end-to-end obstacle negotiation system is envisioned to be useful in optimized path planning and vehicle navigation in terrain conditions cluttered with vegetation, bushes, rocks, etc. Results on natural terrain with various natural materials are presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Talukder, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 8 TC 5 Z9 5 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7398-7 PY 2002 BP 708 EP 713 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Robotics SC Automation & Control Systems; Computer Science; Robotics GA BV53N UT WOS:000179289100116 ER PT B AU Helmick, DM Roumeliotis, SI McHenry, MC Matthies, L AF Helmick, DM Roumeliotis, SI McHenry, MC Matthies, L GP IEEE IEEE TI Multi-sensor, high speed autonomous stair climbing SO 2002 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, VOLS 1-3, PROCEEDINGS LA English DT Proceedings Paper CT IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2002) CY SEP 30-OCT 04, 2002 CL LAUSANNE, SWITZERLAND SP IEEE Robot & Automat Soc, IEEE Ind Electr Soc, Robot Soc Japan, Soc Instruments & Control Engineers, INRIA Rhone Alpes Grenoble, EPFL Lausanne ID ATTITUDE REPRESENTATIONS AB Small, tracked mobile robots designed for general urban mobility have been developed for the purpose of reconnaissance and/or search and rescue missions in buildings and cities. Autonomous stair climbing is a significant capability required for many of these missions. In this paper we present the design and implementation of a new set of estimation and control algorithms that increase the speed and effectiveness of stair climbing. We have developed: (i) a Kalman filter that fuses visual/laser data with inertial measurements and provides attitude estimates of improved accuracy at a high rate, and (ii) a physics based controller that minimizes the heading error and maximizes the effective velocity of the vehicle during stair climbing. Experimental results using a tracked vehicle validate the improved performance of this control and estimation scheme over previous approaches. C1 CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91125 USA. RP Helmick, DM (reprint author), CALTECH, Jet Prop Lab, NASA, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 19 TC 17 Z9 18 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7398-7 PY 2002 BP 733 EP 742 PG 10 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Robotics SC Automation & Control Systems; Computer Science; Robotics GA BV53N UT WOS:000179289100120 ER PT B AU Pedersen, L AF Pedersen, L GP IEEE IEEE TI Science target assessment for Mars rover instrument deployment SO 2002 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS, VOLS 1-3, PROCEEDINGS LA English DT Proceedings Paper CT IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2002) CY SEP 30-OCT 04, 2002 CL LAUSANNE, SWITZERLAND SP IEEE Robot & Automat Soc, IEEE Ind Electr Soc, Robot Soc Japan, Soc Instruments & Control Engineers, INRIA Rhone Alpes Grenoble, EPFL Lausanne AB This paper introduces the system being developed at NASA Ames Research Center, intended for the Mars '09 Smart Lander, to robustly place sensors or tools against rocks in a single communications cycle. Science targets must be assessed prior to instrument placement in order to segment them from the background and determine where, if possible, to position the instrument. An initial result of this research effort is a novel Bayesian based method for segmenting rocks from the ground using 3D data. C1 NASA, Ames Res Ctr, QSS Grp Inc, Moffett Field, CA 94035 USA. RP Pedersen, L (reprint author), NASA, Ames Res Ctr, QSS Grp Inc, Moffett Field, CA 94035 USA. NR 11 TC 2 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7398-7 PY 2002 BP 817 EP 822 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Robotics SC Automation & Control Systems; Computer Science; Robotics GA BV53N UT WOS:000179289100133 ER PT S AU Del Castillo, L Graber, R D'Agostino, S Mojarradi, M Mottiwala, A AF Del Castillo, L Graber, R D'Agostino, S Mojarradi, M Mottiwala, A GP SPIE SPIE TI Flip chip packaging of a MEMS neuro-prosthetic system SO 2002 INTERNATIONAL CONFERENCE ON ADVANCED PACKAGING AND SYSTEMS, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT International Conference on Advanced Packaging and Systems (ICAPS) CY MAR 10-13, 2002 CL RENO, NV SP Int Microelectr & Packaging Soc DE flip chip; MEMS; neuro-prosthetic; soldering; biocompatibility AB A joint research team from California Institute of Technology and Jet Propulsion Laboratory is developing a fully miniaturized, smart implantable neuro-prosthetic system, by combining integrated electronics with Micro Electro Mechanical Structure (MEMS) based electrode arrays. The assembly group in this team has been tasked with developing the technology to combine a MEMS electrode array, capable of extracting signals from brain, and an electronic chip, capable of providing on chip conditioning/processing of extracted data, into a single system that delivers the output data to a remote station located outside the body Area array flip chip technology will be used to attach the electronic chip and the MEMS device (10 x 10 array of fine 1 mm long, electrically isolated Si electrodes). Development efforts included evaluation of different interconnects, underbump metallizations, and underfills as well as optimization of soldering and coating parameters. Some specific challenges of the project include (1) handling of the MEMS array in a way that will allow reliable soldering of the fine 4 mil joints, without damaging the delicate structures and (2) selection of underfills and coatings capable of isolating the electronics from the body while maintaining biocompatibility. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Del Castillo, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 0-930815-65-3 J9 P SOC PHOTO-OPT INS PY 2002 VL 4828 BP 150 EP 155 PG 6 WC Engineering, Manufacturing; Engineering, Electrical & Electronic SC Engineering GA BU59Y UT WOS:000176465700027 ER PT B AU Watson, AB Malo, J AF Watson, AB Malo, J GP IEEE IEEE IEEE TI Video quality measures based on the standard spatial observer SO 2002 INTERNATIONAL CONFERENCE ON IMAGE PROCESSING, VOL III, PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Image Processing CY SEP 22-25, 2002 CL ROCHESTER, NY SP IEEE Signal Proc Soc ID VISION AB Video quality metrics are intended to replace human evaluation with evaluation by machine. To accurately simulate human judgement, they must include some aspects of the human visual system. In this paper we present a class of low-complexity video quality metrics based on the Standard Spatial Observer (SSO). In these metrics, the basic SSO model is improved with several additional features from the current human vision models. To evaluate the metrics, we make use of the data set recently produced by the Video Quality Experts Group (VQEG), which consists of subjective ratings of 160 samples of digital video covering a wide range of quality. For each metric we examine the correlation between its predictions and the subjective ratings. The results show that SSO-based models with local masking obtain the same degree of accuracy as the best metric considered by VQEG (P5), and significantly better correlations than the other VQEG models. The results suggest that local masking is a key feature to improve the correlation of the basic SSO model. C1 NASA, Ames Res Ctr, Vis Grp, Moffett Field, CA 94035 USA. RP Watson, AB (reprint author), NASA, Ames Res Ctr, Vis Grp, MS-262, Moffett Field, CA 94035 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7622-6 PY 2002 BP 41 EP 44 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Software Engineering SC Computer Science GA BX44X UT WOS:000185328900011 ER PT S AU Smith, W AF Smith, W BE Abdelrahman, TS TI A system for monitoring and management of computational grids SO 2002 INTERNATIONAL CONFERENCE ON PARALLEL PROCESSING, PROCEEDING SE PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON PARALLEL PROCESSING LA English DT Proceedings Paper CT 31st International Conference on Parallel Processing (ICPP 2002) CY AUG 18-21, 2002 CL VANCOUVER, CANADA SP Int Assoc Comp & Commun, Ohio State Univ, IBM Res, Microsoft Res, James Madison Univ, CISC AB As organizations begin to deploy large computational grids, it has become apparent that systems for observation and control of the resources, services, and applications that make up such grids are needed Administrators must observe resources and services to ensure that they are operating correctly and must control resources and services to ensure that their operation meets the needs of users. Users are also interested in the operation of resources and services so that they can choose the most appropriate ones to use, In this paper we describe a prototype system to monitor and manage computational grids and describe the general software framework for control and observation in distributed environments that it is based on. C1 NASA, Ames Res Ctr, Comp Sci Corp, Moffett Field, CA 94035 USA. RP Smith, W (reprint author), NASA, Ames Res Ctr, Comp Sci Corp, Moffett Field, CA 94035 USA. OI SMITH, WALLY/0000-0002-1059-6704 NR 41 TC 6 Z9 6 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 0190-3918 BN 0-7695-1677-7 J9 PROC INT CONF PARAL PY 2002 BP 55 EP 62 DI 10.1109/ICPP.2002.1040859 PG 8 WC Computer Science, Information Systems; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BV03Y UT WOS:000177666900006 ER PT B AU Satorius, EH Ye, Z AF Satorius, EH Ye, Z GP IEEE IEEE TI Adaptive modulation and coding techniques in MUOS fading/scintillation environments SO 2002 MILCOM PROCEEDINGS, VOLS 1 AND 2: GLOBAL INFORMATION GRID - ENABLING TRANSFORMATION THROUGH 21ST CENTURY COMMUNICATIONS LA English DT Proceedings Paper CT IEEE Military Communications Conference (MILCOM 2002) CY OCT 07-10, 2002 CL ANAHEIM, CA SP IEEE Commun Soc, AFCEA AB In this paper, adaptive modulation and coding structures are presented that are appropriate for the MUOS environment. The proposed approach adaptively controls the modulation format, FEC coding rate, transmission power and even possibly bandwidth spreading gain in response to changing channel conditions in an attempt to optimize throughput while maintaining acceptable error rate performance. Being able to estimate and then predict the channel is vital to the system performance. Channel prediction algorithms have been developed and the advantages of the adaptive modulation/coding techniques are presented together with implementation issues. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Satorius, EH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7625-0 PY 2002 BP 321 EP 327 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BW09Y UT WOS:000180880500058 ER PT B AU Stoica, A Keymeulen, D Ferguson, MI Guo, X AF Stoica, A Keymeulen, D Ferguson, MI Guo, X BE Stoica, A Lohn, J Katz, R Keymeulen, D Zebulum, RS TI On two new trends in evolvable hardware: Employment of HDL-based structuring, and design of multi-functional circuits SO 2002 NASA/DOD CONFERENCE ON EVOLABLE HARDWARE, PROCEEDINGS LA English DT Proceedings Paper CT NASA/DOD Conference on Evolvable Hardware CY JUL 15-18, 2002 CL ALEXANDRIA, VA SP NASA, Def Adv Res Projects Agcy, NASA, Goddard Space Flight Ctr AB This paper comments on some directions of growth for evolvable hardware, proposes research directions that address the scalability problem and gives examples of results in novel areas approached by EHW. The directions of growth include Software/Hardware hybrids, electronic/non-electronic hybrids, and networked systems. The research directions proposed here are 1) evolutionary compilation of descriptions from behavioral Hardware Description languages (HDL) to structural HDL (for both the case of digital and analog/mixed signal) 2) evolutionary synthesis, i.e. converting from synthesizable HDL to circuits and 3) hardware-software partitioning (co-design) for CPU/FPGA hybrids. The results presented here illustrate evolutionary design of multi-functional/adaptive circuits including polymorphic and reconfiguration based circuits, and evolution of optimized circuits, in particular low-voltage circuits. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Stoica, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 4 Z9 4 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 0-7695-1718-8 PY 2002 BP 56 EP 59 DI 10.1109/EH.2002.1029865 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU89U UT WOS:000177322100006 ER PT B AU Stoica, A Zebulum, RS Ferguson, MI Keymeulen, D Duong, V Guo, X AF Stoica, A Zebulum, RS Ferguson, MI Keymeulen, D Duong, V Guo, X BE Stoica, A Lohn, J Katz, R Keymeulen, D Zebulum, RS TI Evolving circuits in seconds: Experiments with a stand-alone board-level evolvable system SO 2002 NASA/DOD CONFERENCE ON EVOLABLE HARDWARE, PROCEEDINGS LA English DT Proceedings Paper CT NASA/DOD Conference on Evolvable Hardware CY JUL 15-18, 2002 CL ALEXANDRIA, VA SP NASA, Def Adv Res Projects Agcy, NASA, Goddard Space Flight Ctr ID EVOLUTION; HARDWARE; ANALOG AB The purpose of this paper is twofold: first, to illustrate a stand-alone board-level evolvable system (SABLES) and its performance, and second to illustrate some problems that occur during evolution with real hardware in the loop, or when the intention of the user is not completely reflected in the fitness function. SABLES is part of an effort to achieve integrated evolvable systems. SABLES provides autonomous, fast (tens to hundreds of seconds), on-chip evolution involving about 100,000 circuit evaluations. Its main components are a JPL Field Programmable Transistor Array (FPTA) chip used as transistor-level reconfigurable hardware, and a TI DSP that implements the evolutionary algorithm controlling the FPTA reconfiguration. The paper details an example of evolution on SABLES and points out to certain transient and memory effects that affect the stability of solutions obtained reusing the same piece of hardware for rapid testing of individuals during evolution. It also illustrates how specifications not completely reflected in the fitness function, such as the time scales of response for logical circuits, may lead to overall unsatisfactory solutions. Both such situations can be handled with appropriate modification of fitness function and additional testing. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM adrian.stoica@jpl.nasa.gov NR 19 TC 26 Z9 26 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-1718-8 PY 2002 BP 67 EP 74 DI 10.1109/EH.2002.1029868 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU89U UT WOS:000177322100009 ER PT B AU Alkalai, L AF Alkalai, L BE Jacobs, A TI Perspectives on dependable computing for solar system exploration SO 2002 PACIFIC RIM INTERNATIONAL SYMPOSIUM ON DEPENDABLE COMPUTING, PROCEEDINGS LA English DT Proceedings Paper CT 9th Pacific Rim International Symposium on Dependable Computing CY DEC 16-18, 2002 CL TSUKUBA, JAPAN SP IEEE Comp Soc Tech Comm Fault Tolerant Comp, IEEE Tech Grp Dependable Comp, IFIP WG10 4 Dependable Comp & Fault Tolerance, Jet Propuls Lab C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Alkalai, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 0 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 BN 0-7695-1852-4 PY 2002 BP 163 EP 163 DI 10.1109/PRDC.2002.1185634 PG 1 WC Computer Science, Information Systems; Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BV90Q UT WOS:000180357100022 ER PT B AU Hayhurst, KJ Holloway, CN AF Hayhurst, KJ Holloway, CN GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Challenges in software aspects of aerospace systems SO 26TH ANNUAL NASA GODDARD SOFTWARE ENGINEERING WORKSHOP, PROCEEDINGS LA English DT Proceedings Paper CT 26th Annual NASA Goddard Software Engineering Workshop CY NOV 27-29, 2001 CL GREENBELT, MD SP IEEE Comp Soc Tech Council Software Engn, NASA Goddard Space Flight Ctr, Software Engn Lab AB For many years, NASA Langley Research Center has cooperated with the Federal Aviation Administration (FAA) in research about software engineering methods for aerospace applications. Recent research has focused on software aspects of the FAA's certification process. In this paper, the results of the Streamlining Software Aspects of Certification (SSAC) program are examined to provide insight into current challenges in the aerospace industry in developing and assuring complex, software-based systems. We conclude that at the root of many of the current challenges lies the challenge of accurately communicating requirements between groups of people. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Hayhurst, KJ (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 20 TC 0 Z9 0 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-1457-X PY 2002 BP 7 EP 13 DI 10.1109/SEW.2001.992649 PG 7 WC Computer Science, Software Engineering SC Computer Science GA BU29D UT WOS:000175584400001 ER PT B AU Gilliam, DP Powell, JD Kelly, JC Bishop, M AF Gilliam, DP Powell, JD Kelly, JC Bishop, M GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Reducing software security risk through an integrated approach SO 26TH ANNUAL NASA GODDARD SOFTWARE ENGINEERING WORKSHOP, PROCEEDINGS LA English DT Proceedings Paper CT 26th Annual NASA Goddard Software Engineering Workshop CY NOV 27-29, 2001 CL GREENBELT, MD SP IEEE Comp Soc Tech Council Software Engn, NASA Goddard Space Flight Ctr, Software Engn Lab DE security toolset; vulnerability matrix; property-based testing; model checking; security; verification AB This paper presents joint work by the California Institute of Technology's Jet Propulsion Laboratory and the University of California at Davis (UC Davis) sponsored by the National Aeronautics and Space Administration Goddard Independent Verification and Validation Facility to develop a security assessment instrument for the software development and maintenance life Cycle. Vulnerabilities in operating systems and software applications render an otherwise secure environment insecure. Any operating system or application added to a secure environment that has exploitable security vulnerabilities affects the security of the whole environment. An otherwise secure system can be compromised easily if the system or application software on it, or on a linked system, has vulnerabilities. Therefore, it is critical that software on networked computer systems be free from security vulnerabilities. Security, vulnerabilities in software arise from a number of development factors; but these vulnerabilities can generally be traced to poor software development practices, new modes of attacks, mis-configurations, and unsecured links between systems. A Software security assessment instrument can aid in providing a greater level of assurance that software is not exposed to vulnerabilities as a result of defective software requirements, designs, code or exposures due to code complexity, and integration with other applications that are network aware. This paper presents research on the generation of a software security assessment instrument to aid developers in assessing and assuring the security of software in the development and maintenance lifecycles. The research presented here is available at: http://security.jpl.nasa.gov/rssr. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Gilliam, DP (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. EM david.p.Gilliam@jpl.nasa.gov; John.Powell@jpl.nasa.gov; john.c.kellyw@jpl.nasa.gov; bishop@cs.ucdavis.edu NR 8 TC 0 Z9 0 U1 1 U2 3 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-1456-1; 0-7695-1457-X PY 2002 BP 36 EP 42 DI 10.1109/SEW.2001.992653 PG 7 WC Computer Science, Software Engineering SC Computer Science GA BU29D UT WOS:000175584400005 ER PT B AU Feather, MS Sigal, B Cornford, SL Hutchinson, P AF Feather, MS Sigal, B Cornford, SL Hutchinson, P GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Incorporating cost-benefit analyses into software assurance planning SO 26TH ANNUAL NASA GODDARD SOFTWARE ENGINEERING WORKSHOP, PROCEEDINGS LA English DT Proceedings Paper CT 26th Annual NASA Goddard Software Engineering Workshop CY NOV 27-29, 2001 CL GREENBELT, MD SP IEEE Comp Soc Tech Council Software Engn, NASA Goddard Space Flight Ctr, Software Engn Lab AB The objective is to use cost-benefit analyses to identify, for a given project, optimal sets of software assurance activities. Towards this end we have incorporated cost-benefit calculations into a risk management framework. The net result is the capability to rapidly explore the costs and benefits of sets of assurance decisions. We describe the cost-benefit aspects of our framework, and demonstrate them on a small illustrative example. We then address the issues raised by seeking to apply this approach to software assurance planning for large-scale software development efforts. 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; Burton.Sigal@Jpl.Nasa.Gov; Steven.L.Cornford@Jpl.Nasa.Gov; hutchinsonrp@wofford.edu NR 11 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 BN 0-7695-1456-1; 0-7695-1457-X PY 2002 BP 62 EP 68 DI 10.1109/SEW.2001.992656 PG 7 WC Computer Science, Software Engineering SC Computer Science GA BU29D UT WOS:000175584400008 ER PT B AU McCoy, JR AF McCoy, JR GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI NASA software tools for high-quality requirements engineering SO 26TH ANNUAL NASA GODDARD SOFTWARE ENGINEERING WORKSHOP, PROCEEDINGS LA English DT Proceedings Paper CT 26th Annual NASA Goddard Software Engineering Workshop CY NOV 27-29, 2001 CL GREENBELT, MD SP IEEE Comp Soc Tech Council Software Engn, NASA Goddard Space Flight Ctr, Software Engn Lab AB Extensive research has been conducted on writing quality software requirements in a natural language, resulting in the development of guidelines for writing effective requirements and a tool for evaluating them. Concepts from this application, the Automated Requirements Measurement (ARM) tool, which scans a requirements document for specific key words and phrases that impact the quality of the requirements, were then applied to the area of systems safety, resulting in the creation of the Safety Critical Analysis Tool (SCAT). Current research states that use cases provide a more methodological basis for specifying and managing quality functional requirements than the traditional natural language approach. Therefore, the Requirements Use case Tool (RUT) was developed to provide a template and repository for high-quality use cases. This paper describes the contribution to generating high-quality requirements made by each of these three tools. C1 NASA, Goddard Space Flight Ctr, Software Assurance Technol Ctr, Greenbelt, MD 20771 USA. RP McCoy, JR (reprint author), NASA, Goddard Space Flight Ctr, Software Assurance Technol Ctr, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-1457-X PY 2002 BP 69 EP 69 DI 10.1109/SEW.2001.992657 PG 1 WC Computer Science, Software Engineering SC Computer Science GA BU29D UT WOS:000175584400009 ER PT B AU Hinchey, MG Rash, JL Rouff, CA AF Hinchey, MG Rash, JL Rouff, CA GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Verification and validation of autonomous systems SO 26TH ANNUAL NASA GODDARD SOFTWARE ENGINEERING WORKSHOP, PROCEEDINGS LA English DT Proceedings Paper CT 26th Annual NASA Goddard Software Engineering Workshop CY NOV 27-29, 2001 CL GREENBELT, MD SP IEEE Comp Soc Tech Council Software Engn, NASA Goddard Space Flight Ctr, Software Engn Lab AB NASA is working on complex future missions that require cooperation between multiple satellites or rovers. To implement these systems, developers are proposing and using intelligent and autonomous systems. These autonomous missions are new to NASA, and the software development community is just learning to develop such systems. With these new systems, new verification and validation techniques must be used. Current techniques have been developed based on large monolithic systems. These techniques have worked well and reliably, but do not translate to the new autonomous systems that are highly parallel and nondeterministic. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hinchey, MG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 12 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 BN 0-7695-1457-X PY 2002 BP 136 EP 144 DI 10.1109/SEW.2001.992667 PG 9 WC Computer Science, Software Engineering SC Computer Science GA BU29D UT WOS:000175584400019 ER PT B AU Wallace, DR AF Wallace, DR GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Practical software reliability Modeling SO 26TH ANNUAL NASA GODDARD SOFTWARE ENGINEERING WORKSHOP, PROCEEDINGS LA English DT Proceedings Paper CT 26th Annual NASA Goddard Software Engineering Workshop CY NOV 27-29, 2001 CL GREENBELT, MD SP IEEE Comp Soc Tech Council Software Engn, NASA Goddard Space Flight Ctr, Software Engn Lab AB NASA is increasingly dependent upon software in systems critical to the success of NASA's mission, The capability to accurately measure the reliability of the software in these systems is essential to ensuring that NASA systems will meet mission requirements. The Software Assurance Technology Center at the NASA Goddard Space Flight Center explored software reliability modeling as a practical measurement technique. This paper describes software reliability modeling, the effort required to use it, and potential improvements to the models to allow for fault correction. C1 NASA, Goddard Space Flight Ctr, Software Assurance Technol Ctr, SRS Informat Serv, Greenbelt, MD 20771 USA. RP Wallace, DR (reprint author), NASA, Goddard Space Flight Ctr, Software Assurance Technol Ctr, SRS Informat Serv, Greenbelt, MD 20771 USA. NR 9 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 BN 0-7695-1457-X PY 2002 BP 147 EP 155 DI 10.1109/SEW.2001.992668 PG 9 WC Computer Science, Software Engineering SC Computer Science GA BU29D UT WOS:000175584400020 ER PT B AU Smith, JG Connell, JW Hergenrother, PM Yokota, R Criss, JM AF Smith, JG Connell, JW Hergenrother, PM Yokota, R Criss, JM BE Rasmussen, BM Pilato, LA Kliger, HS TI High temperature transfer molding resins based on 2,3,3 ' 4 '-biphenyltetracarboxylic dianhydride SO 47TH INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION, VOL 47, BOOKS 1 AND 2: AFFORDABLE MATERIALS TECHNOLOGY-PLATFORM TO GLOBAL VALUE AND PERFORMANCE LA English DT Proceedings Paper CT 47th International SAMPE Symposium and Exhibition CY MAY 12-16, 2002 CL LONG BEACH, CA SP Soc Advancement Mat & Process Engn DE resin transfer molding; high temperature polymers; polyimides ID TERMINAL PHENYLETHYNYL GROUPS; IMIDE OLIGOMERS; COMPOSITE PROPERTIES; POLYIMIDE OLIGOMERS; MOLECULAR-WEIGHT; ADHESIVE; PENDENT; ANHYDRIDES; BLENDS; DESIGN AB As part of an ongoing effort to develop materials for resin transfer molding (RTM) processes to fabricate high performance/high temperature composite structures, phenylethynyl containing imides have been under investigation. New phenylethynyl containing imide compositions were prepared using 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA) and evaluated for cured glass transition temperature (Tg), melt flow behavior, and for processability into flat composite panels via RTM. The a-BPDA imparts a unique combination of properties that are desirable for high temperature transfer molding resins. In comparison to its symmetrical counterpart (i.e. 3,3',4,4'-biphenyltetracarboxylic dianhydride), a-BPDA affords oligomers with lower melt viscosities and when cured, higher Tgs. Several candidates exhibited the appropriate combination of properties such as a low and stable melt viscosity required for RTM processes, high cured Tg, and moderate toughness. The chemistry, physical, and composite proper-tics of select resins will be discussed. C1 Natl Aeronaut & Space Adm, Langley Res Ctr, Hampton, VA 23681 USA. RP Smith, JG (reprint author), Natl Aeronaut & Space Adm, Langley Res Ctr, Hampton, VA 23681 USA. NR 44 TC 1 Z9 1 U1 0 U2 1 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-92-1 PY 2002 BP 316 EP 327 PG 12 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Materials Science GA BU92A UT WOS:000177401800028 ER PT B AU Thompson, CM Connell, JW Hergenrother, PM AF Thompson, CM Connell, JW Hergenrother, PM BE Rasmussen, BM Pilato, LA Kliger, HS TI Adhesive and composite properties of a new phenylethynyl terminated imide SO 47TH INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION, VOL 47, BOOKS 1 AND 2: AFFORDABLE MATERIALS TECHNOLOGY-PLATFORM TO GLOBAL VALUE AND PERFORMANCE LA English DT Proceedings Paper CT 47th International SAMPE Symposium and Exhibition CY MAY 12-16, 2002 CL LONG BEACH, CA SP Soc Advancement Mat & Process Engn DE phenylethynyl imides; laminates; adhesives ID TEMPERATURE; POLYIMIDES AB A relatively new phenylethynyl terminated imide oligomer (PETI) from the reaction of 2,3,3',4'-biphenyltetracarboxylic dianhydride, 4,4'-oxydianiline and endcapped with 4-phenylethynylphthalic anhydride at a calculated number average molecular weight of 5000 g/mole was evaluated as an adhesive and composite matrix. The asymmetric dianhydride imparts a low melt viscosity to the oligomer and a high glass transition temperature to the cured resin. Preliminary adhesive work with titanium (6Al-4V) adherend gave good room temperature (RT) tensile shear strengths and excellent retention of RT strength at 260degreesC. Preliminary composite work using unsized IM7 carbon fiber provided moderate to high mechanical properties. The chemistry, mechanical, and physical properties of the new PETI in neat resin, adhesive and composite form are presented. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Thompson, CM (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-92-1 PY 2002 BP 328 EP 340 PG 13 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Materials Science GA BU92A UT WOS:000177401800029 ER PT B AU Shin, EE Sutter, JK Eakin, H Inghram, L McCorkle, L Scheiman, D Papadopoulos, D Kerze, F AF Shin, EE Sutter, JK Eakin, H Inghram, L McCorkle, L Scheiman, D Papadopoulos, D Kerze, F BE Rasmussen, BM Pilato, LA Kliger, HS TI Design and fabrication issues of high temperature PMCS for aerospace propulsion applications SO 47TH INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION, VOL 47, BOOKS 1 AND 2: AFFORDABLE MATERIALS TECHNOLOGY-PLATFORM TO GLOBAL VALUE AND PERFORMANCE LA English DT Proceedings Paper CT 47th International SAMPE Symposium and Exhibition CY MAY 12-16, 2002 CL LONG BEACH, CA SP Soc Advancement Mat & Process Engn DE carbon fiber; prepreg; polyimides AB A Second generation PMR (in situ polymerization of monomer reactants) polyimide resin, PMR-II-50, has been considered for high temperature and high stiffness space propulsion composites applications, such as a facesheet of various sandwich structures with high stiffness carbon fibers. Various fiber reinforcement architectures including 4 & 8 harness satin (HS) fabrics, uni-tape, stitched fabrics, tri-axial braided fabric and their hybrid structures have been investigated for optimum stiffness-thickness-weight-hygrothermal performance design criteria. This paper discusses the overall program plan, primary design and fabrication efforts, and initial composite property and performance data of certain architectures. As part of composite processing optimization, two commercial prepregging methods, solution vs. hot-melt processes, were investigated for graphite fiber/PMR-II-50 composites. A systematic chemical, physical, thermal and mechanical characterization of these composites indicated that poor resin-fiber interfacial wetting at the molecular level, especially in hot-melt process, resulted in poor composite quality. Effects of the wetting on composite mechanical properties and high temperature durability will be discussed. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Shin, EE (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 49-1, Cleveland, OH 44135 USA. NR 23 TC 0 Z9 0 U1 0 U2 2 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-92-1 PY 2002 BP 341 EP 355 PG 15 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Materials Science GA BU92A UT WOS:000177401800030 ER PT B AU Grimsley, BW Hubert, P Song, XL Cano, RJ Loos, AC Pipes, RB AF Grimsley, BW Hubert, P Song, XL Cano, RJ Loos, AC Pipes, RB BE Rasmussen, BM Pilato, LA Kliger, HS TI Effects of amine and anhydride curing agents on the VARTM matrix processing properties SO 47TH INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION, VOL 47, BOOKS 1 AND 2: AFFORDABLE MATERIALS TECHNOLOGY-PLATFORM TO GLOBAL VALUE AND PERFORMANCE LA English DT Proceedings Paper CT 47th International SAMPE Symposium and Exhibition CY MAY 12-16, 2002 CL LONG BEACH, CA SP Soc Advancement Mat & Process Engn AB To ensure successful application of composite structure for aerospace vehicles, it is necessary to develop material systems that meet a variety of requirements, The industry has recently developed a number of low-viscosity epoxy resins to meet the processing requirements associated with vacuum assisted resin transfer molding (VARTM) of aerospace components. The curing kinetics and viscosity of two of these resins, an amine-cured epoxy system, Applied Poleramic, Inc. VR-56-4(2), and an anhydride-cured epoxy system, A.T.A.R.D. Laboratories SI-ZG-5A, have been characterized for application in the VARTM process, Simulations were carried out using the process model, COMPRO(R), to examine heat transfer, curing kinetics and viscosity for different panel thicknesses and cure cycles. Results of these simulations indicate that the two resins have significantly different curing behaviors and flow characteristics. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Grimsley, BW (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-92-1 PY 2002 BP 439 EP 453 PG 15 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Materials Science GA BU92A UT WOS:000177401800038 ER PT B AU Banks, BA Demko, R AF Banks, BA Demko, R BE Rasmussen, BM Pilato, LA Kliger, HS TI Atomic oxygen protection of materials in low Earth orbit SO 47TH INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION, VOL 47, BOOKS 1 AND 2: AFFORDABLE MATERIALS TECHNOLOGY-PLATFORM TO GLOBAL VALUE AND PERFORMANCE LA English DT Proceedings Paper CT 47th International SAMPE Symposium and Exhibition CY MAY 12-16, 2002 CL LONG BEACH, CA SP Soc Advancement Mat & Process Engn DE atomic oxygen; coatings; space environment AB Spacecraft polymeric materials as well as polymer-matrix carbon-fiber composites can be significantly eroded as a result of exposure to atomic oxygen in low Earth orbit (LEO). Several now materials now exist, as well as modifications to conventionally used materials, that provide much more resistance to atomic oxygen attack than conventional hydrocarbon polymers, Protective coatings have also been developed which are resistant to atomic oxygen attack and provide protection of underlying materials. However, in actual spacecraft applications, the configuration, choice of materials, surface characteristics and functional requirements of quasi-durable materials or protective coatings can have great impact on the resulting performance and durability. Atomic oxygen degradation phenomena occurring on past and existing spacecraft will be presented. Issues and considerations involved in providing atomic oxygen protection for materials used on spacecraft in low Earth orbit will be addressed, Analysis of in-space results to determine the causes of successes and failures of atomic oxygen protective coatings is presented. C1 NASA, Glen Res Ctr, Cleveland, OH 44135 USA. RP Banks, BA (reprint author), NASA, Glen Res Ctr, Cleveland, OH 44135 USA. NR 15 TC 0 Z9 0 U1 5 U2 5 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-92-1 PY 2002 BP 820 EP 832 PG 13 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Materials Science GA BU92A UT WOS:000177401800071 ER PT B AU Campbell, S Scheiman, D Faile, M Papadopoulos, D AF Campbell, S Scheiman, D Faile, M Papadopoulos, D BE Rasmussen, BM Pilato, LA Kliger, HS TI PMR-15/layered silicate nanocomposites for improved thermal stability and mechanical properties SO 47TH INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION, VOL 47, BOOKS 1 AND 2: AFFORDABLE MATERIALS TECHNOLOGY-PLATFORM TO GLOBAL VALUE AND PERFORMANCE LA English DT Proceedings Paper CT 47th International SAMPE Symposium and Exhibition CY MAY 12-16, 2002 CL LONG BEACH, CA SP Soc Advancement Mat & Process Engn DE nanocomposite; polyimide; polymer matrix composites ID POLYIMIDE CLAY HYBRID; LAYERED SILICATES; MONTMORILLONITE; DEGRADATION; ORGANOCLAY; POLYMER AB Montmorillonite clay was organically modified by co-exchange of an aromatic diamine and a primary alkyl amine. The clay was dispersed into a PMR-15 matrix and the glass transition temperature and thermal oxidative stability of the resulting nanocomposites were evaluated. PMR-15/silicate nanocomposites were also investigated as a matrix material for carbon fabric reinforced composites. Dispersion of the organically modified silicate into the PMR-15 matrix enhanced the thermal oxidative stability, the flexural strength flexural modulus, and interlaminar shear strength of the polymer matrix composite. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Campbell, S (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-92-1 PY 2002 BP 1131 EP 1139 PG 9 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Materials Science GA BU92A UT WOS:000177401800098 ER PT B AU Weiser, ES Grimsley, BW Pipes, RB Williams, MK AF Weiser, ES Grimsley, BW Pipes, RB Williams, MK BE Rasmussen, BM Pilato, LA Kliger, HS TI Polyimide foams from friable balloons SO 47TH INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION, VOL 47, BOOKS 1 AND 2: AFFORDABLE MATERIALS TECHNOLOGY-PLATFORM TO GLOBAL VALUE AND PERFORMANCE LA English DT Proceedings Paper CT 47th International SAMPE Symposium and Exhibition CY MAY 12-16, 2002 CL LONG BEACH, CA SP Soc Advancement Mat & Process Engn DE polyimide; foam; high temperature; insulation AB Recent advancements in high temperature polymeric materials at NASA Langley Research Center have led to the development of new polyimide foam systems with attractive properties. These foam materials have application as insulation for the cryogenic fuel tanks for the next generation reusable launch vehicles, commercial and defense marine ships and commercial aircraft. While the first foaming process developed consisted of thermal cycling the polymer precursor residuum and allowing the inflation of the particles to interact to create the foam. An innovative foaming process has been developed that begins with partially inflated microspheres with incomplete polymer molecular weight gain. Termed, "friable balloons," this new precursor form can be poured into a mold to "foam in place" the desired geometry. In addition, the new foaming concept produces a wide range of foam products with varying degrees of open and closed cell structure, compressive strength and tensile strength. Foamed in place Nomex(R) honeycomb core materials are tested to evaluate the enhancements achieved by the addition of this new polyimide foam to the core material. The addition of the polyimide foam to the Nomex(R) honey comb resulted in an increase in compressive strength by as much as 25% over the unfilled core. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Weiser, ES (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 11 TC 1 Z9 2 U1 1 U2 1 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-92-1 PY 2002 BP 1151 EP 1162 PG 12 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Materials Science GA BU92A UT WOS:000177401800100 ER PT B AU Chuang, KC Papadopoulos, DS Arendt, CP AF Chuang, KC Papadopoulos, DS Arendt, CP BE Rasmussen, BM Pilato, LA Kliger, HS TI High T-g polyimide composites II SO 47TH INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION, VOL 47, BOOKS 1 AND 2: AFFORDABLE MATERIALS TECHNOLOGY-PLATFORM TO GLOBAL VALUE AND PERFORMANCE LA English DT Proceedings Paper CT 47th International SAMPE Symposium and Exhibition CY MAY 12-16, 2002 CL LONG BEACH, CA SP Soc Advancement Mat & Process Engn DE polyimides; oligomers; advanced composites; endcaps AB Previously, a high T-g polyimide composite (DMBZ-15, T-g = 415 degreesC) based on 3,3' ,4,4'-benzophenonctetracarboxylic dimethy ester (BTDE), 2,2'-dimethylbenzidine (DMBZ) and the nadic ester (NE) endcap was reported. In this paper, a similar approach was taken to investigate the polyimide composites based on 4,4'-(hexafluoroisopropylidene)diphthalic acid dimethyl ester (HFDE) and 2,2'-dimethylbenzidine (DMBZ) using 4-phenylethynylphthalic acid ester (PEPE) as the endcap, The physical and mechanical properties as well as the thermal oxidative stability of these polyimide composites were compared to that of PMR-II-50 based on phenylenediamine. Besides the conventional prepreg process, resin infusion technique was also used to fabricate these high T-g polyimides from stitched preforms, The mechanical properties and thermo-oxidative stability of these stitched polyimide composites were shown to exceed the bismaleimide resin, BMI-5270. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Chuang, KC (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 10 TC 1 Z9 1 U1 0 U2 1 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-92-1 PY 2002 BP 1175 EP 1186 PG 12 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Materials Science GA BU92A UT WOS:000177401800102 ER PT B AU de Groh, KK Banks, BA Demko, R AF de Groh, KK Banks, BA Demko, R BE Rasmussen, BM Pilato, LA Kliger, HS TI Techniques for measuring low Earth orbital atomic oxygen erosion of polymers SO 47TH INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION, VOL 47, BOOKS 1 AND 2: AFFORDABLE MATERIALS TECHNOLOGY-PLATFORM TO GLOBAL VALUE AND PERFORMANCE LA English DT Proceedings Paper CT 47th International SAMPE Symposium and Exhibition CY MAY 12-16, 2002 CL LONG BEACH, CA SP Soc Advancement Mat & Process Engn DE atomic oxygen; polymer; durability; space environment; flight experiment AB Polymers such as polyimide Kapton(R) and Teflon(R) FEP (fluorinated ethylene propylene) are commonly used spacecraft materials due to their desirable properties such as flexibility, low density, and in the case of FEP low solar absorptance and high thermal emittance. Polymers on the exterior of spacecraft in the low Earth orbit (LEO) environment are exposed to energetic atomic oxygen. Atomic oxygen reaction with polymers causes erosion, which is a threat to spacecraft durability. It is therefore important to understand the atomic oxygen erosion yield (E, the volume loss per incident oxygen atom) of polymers being considered in spacecraft design. The most common technique for determining E is through mass loss measurements. For limited duration exposure experiments, such as shuttle experiments, where the atomic oxygen fluence is often so small that mass loss measurements can not produce acceptable uncertainties, recession measurements based on atomic force microscopy analyses can be used. Equally necessary to knowing the mass loss or recession depth for determining the erosion yield of polymers is the knowledge of the atomic oxygen fluence that the polymers were exposed to in space. This paper discusses the procedures and relevant issues for mass loss and recession depth measurements for passive atomic oxygen erosion yield characterization of polymers, along with techniques for active atomic oxygen fluence and erosion characterization. One active atomic oxygen erosion technique discussed is a new technique based on optical measurements. Details including the use of both semi-transparent and opaque polymers for active erosion measurement are discussed. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP de Groh, KK (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-92-1 PY 2002 BP 1279 EP 1292 PG 14 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Materials Science GA BU92A UT WOS:000177401800113 ER PT B AU Hulcher, AB McGowan, DM Grimsley, BW Belvin, H Johnson, NJ AF Hulcher, AB McGowan, DM Grimsley, BW Belvin, H Johnson, NJ BE Rasmussen, BM Pilato, LA Kliger, HS TI Processing and testing of thermoplastic composite cylindrical shells fabricated by automated fiber placement SO 47TH INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION, VOL 47, BOOKS 1 AND 2: AFFORDABLE MATERIALS TECHNOLOGY-PLATFORM TO GLOBAL VALUE AND PERFORMANCE LA English DT Proceedings Paper CT 47th International SAMPE Symposium and Exhibition CY MAY 12-16, 2002 CL LONG BEACH, CA SP Soc Advancement Mat & Process Engn DE thermoplastics; fiber placement; composite shells AB Two 61-cm-diameter eight-ply quasi-isotropic IM7/PEEK cylindrical shells were fabricated by automated fiber placement the NASA Langley Research Center using only infrared radiant heat to preheat the substrate and incoming composite uni-tape. The shells were characterized by ultrasonic c-scans for overall consolidation quality, and by optical microscopy and acid digestion for void content. Compression tests were also performed. Although the material used in the study was of generally poor quality due to numerous splits and dry fiber regions, the process was able to achieve a net reduction in void content in the as-placed component. Microscopy of the composite shells revealed well-consolidated, void-free interfaces. The two cylinders were then tested in uni-axial compression in a 1334 kN-capacity hydraulic test machine until buckling occurred. A geometrically nonlinear finite element analysis was conducted, and the differences between the predicted and measured values were 18.0 and 25,8 percent, respectively. Inclusion of measured imperfections of the cylinder into the analysis is expected to reduce these differences. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Hulcher, AB (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 13 TC 0 Z9 0 U1 1 U2 3 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-92-1 PY 2002 BP 1812 EP 1826 PG 15 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Materials Science, Composites SC Materials Science GA BU92A UT WOS:000177401800162 ER PT B AU Riley, JT AF Riley, JT BE Callaos, N HernandezEncinas, L Yetim, F TI A new model for the human in the human-computer interface SO 6TH WORLD MULTICONFERENCE ON SYSTEMICS, CYBERNETICS AND INFORMATICS, VOL I, PROCEEDINGS: INFORMATION SYSTEMS DEVELOPMENT I LA English DT Proceedings Paper CT 6th World Multi-Conference on Systemics, Cybernetics and Informatics (SCI 2002)/8th International Conference on Information Systems Analysis and Synthesis (ISAS 2002) CY JUL 14-18, 2002 CL ORLANDO, FL SP Int Inst Informat & System, World Org System & Cybernet, Ctr Syst Studies, Syst Soc Poland, Soc Appl Syst Res, Slovenian Artificial Intelligence Soc, Simon Bolivar Univ, Polish Syst Soc, Italian Soc System, Int Soc Syst Sci, Int Syst Inst, Int Federat Syst Res, Cybernet & Human Knowing, Journal Second Order Cybernet & Cybersemiot, Blaise Pascal Univ, Engineer Sci Inst, CUST, Univ Las Palmas Gran Canaria, Concurrency & Architecture Grp, Telemat Engn Dept, Tunisian Sci Soc, Acad Non Linear Sci, San Luis Natl Univ, Lab Res Computat Intelligence, Dept Informat, Amer Soc Cybernet (Canada), Wolfram Res Inc, IEEE Comp Soc, Venezuela Chapter, Steacie Inst Molec Sci, Natl Res Council Canada DE human-computer interface; ontology; buy-in; flow AB The current human-computer interface that features windows, mouse, and keyboard is, unfortunately, completely out of date. An effective replacement not only would generate great wealth for the developers but would also provide a significant benefit to society. This new interface must make the user happy, productive, and safe. Enormous amounts of information are now available on how to accomplish these things. The development of the computer capabilities for this interface is advancing powerfully The information for the human side is becoming available but is not, however, being effectively applied. The human information must be organized in some practical way, such as through states of being. Buy-In and Flow are the two key states of being for this application. Displacing an entrenched standard will be difficult but an open, public discussion can lead the way. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Riley, JT (reprint author), NASA, Goddard Space Flight Ctr, Code 556, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU INT INST INFORMATICS & SYSTEMICS PI ORLANDO PA 14269 LORD BARCLAY DR, ORLANDO, FL 32837 USA PY 2002 BP 294 EP 298 PG 5 WC Computer Science, Information Systems; Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BV42E UT WOS:000178906800054 ER PT B AU Brown, ME AF Brown, ME BE Callaos, N Whymark, G Lesso, W TI The contribution of satellite derived vegetation to the variation of food prices in three Sahelian countries SO 6TH WORLD MULTICONFERENCE ON SYSTEMICS, CYBERNETICS AND INFORMATICS, VOL XIII, PROCEEDINGS: CONCEPTS AND APPLICATIONS OF SYSTEMICS, CYBERNETICS AND INFORMATICS III LA English DT Proceedings Paper CT 6th World Multi-Conference on Systemics, Cybernetics and Informatics (SCI 2002)/8th International Conference on Information Systems Analysis and Synthesis (ISAS 2002) CY JUL 14-18, 2002 CL ORLANDO, FL SP Int Inst Informat & System, World Org System & Cybernet, Ctr Syst Studies, Syst Soc Poland, Soc Appl Syst Res, Slovenian Artificial Intelligence Soc, Simon Bolivar Univ, Polish Syst Soc, Italian Soc System, Int Soc Syst Sci, Int Syst Inst, Int Federat Syst Res, Cybernet & Human Knowing, Journal Second Order Cybernet & Cybersemiot, Blaise Pascal Univ, Engineer Sci Inst, CUST, Univ Las Palmas Gran Canaria, Concurrency & Architecture Grp, Telemat Engn Dept, Tunisian Sci Soc, Acad Non Linear Sci, San Luis Natl Univ, Lab Res Computat Intelligence, Dept Informat, Amer Soc Cybernet (Canada), Wolfram Res Inc, IEEE Comp Soc, Venezuela Chapter, Steacie Inst Molec Sci, Natl Res Council Canada DE Sahel; food security; AVHRR; NDVI; millet; prices; food access AB Systematic evaluation of food security throughout the Sahel has been attempted for nearly two decades. Food security analyses have used both food prices to determine the ability of the population to access food, and satellite derived vegetation. indices to establish how much food was grown in a year. By developing and testing a series of multilinear models, the relationship between these different food security indicators was explored. This combined approach benefits from three sources of quantitative data that are readily available: 8km NDVI data from the NOAA Advanced Very High resolution radiometers, net primary productivity data from the GLO-PEM model, and monthly millet prices from 445 markets in Mali, Niger and Burkina Faso. The study extends previous work on predicting agricultural commodity prices by integrating environmental information obtained from satellite data. It was found that the environmental conditions that surround the market, influence the relationship between the next and current month's price, allowing a better prediction. The greatest contribution of remote sensing data to reducing uncertainty in millet price prediction appears to be in markets in the mid-Sahel, bounded by latitudes 13-15 degrees north. C1 Univ Maryland, NASA, Goddard Space Flight Ctr, Dept Geog, Greenbelt, MD 20771 USA. RP Brown, ME (reprint author), Univ Maryland, NASA, Goddard Space Flight Ctr, Dept Geog, Code 923, Greenbelt, MD 20771 USA. RI Brown, Molly/E-2724-2010; Brown, Molly/M-5146-2013 OI Brown, Molly/0000-0001-7384-3314; Brown, Molly/0000-0001-7384-3314 NR 29 TC 0 Z9 0 U1 0 U2 0 PU INT INST INFORMATICS & SYSTEMICS PI ORLANDO PA 14269 LORD BARCLAY DR, ORLANDO, FL 32837 USA PY 2002 BP 159 EP 164 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications; Engineering, Biomedical SC Computer Science; Engineering GA BV59B UT WOS:000179458900029 ER PT B AU Huang, NE Xiang, D Long, SR AF Huang, NE Xiang, D Long, SR BE Callaos, N Hammoud, R Xia, D Li, HS Klovsky, D TI On Instantaneous Frequency SO 6TH WORLD MULTICONFERENCE ON SYSTEMICS, CYBERNETICS AND INFORMATICS, VOL XIV, PROCEEDINGS: IMAGE, ACOUSTIC, SPEECH AND SIGNAL PROCESSING III LA English DT Proceedings Paper CT 6th World Multi-Conference on Systemics, Cybernetics and Informatics (SCI 2002)/8th International Conference on Information Systems Analysis and Synthesis (ISAS 2002) CY JUL 14-18, 2002 CL ORLANDO, FL SP Int Inst Informat & System, World Org System & Cybernet, Ctr Syst Studies, Syst Soc Poland, Soc Appl Syst Res, Slovenian Artificial Intelligence Soc, Simon Bolivar Univ, Polish Syst Soc, Italian Soc System, Int Soc Syst Sci, Int Syst Inst, Int Federat Syst Res, Cybernet & Human Knowing, Journal Second Order Cybernet & Cybersemiot, Blaise Pascal Univ, Engineer Sci Inst, CUST, Univ Las Palmas Gran Canaria, Concurrency & Architecture Grp, Telemat Engn Dept, Tunisian Sci Soc, Acad Non Linear Sci, San Luis Natl Univ, Lab Res Computat Intelligence, Dept Informat, Amer Soc Cybernet (Canada), Wolfram Res Inc, IEEE Comp Soc, Venezuela Chapter, Steacie Inst Molec Sci, Natl Res Council Canada DE Instantaneous Frequency; time-frequency analysis; nonstationary and nonlinear; time series analysis; Hilbert spectrum; wavelet analysis; Instantaneous Frequency; Empirical Mode Decomposition method; Hilbert-Huang transform (HHT) AB The problems related to Instantaneous Frequency (IF) are discussed. The need for a quantity such as IF is clear. Three different approaches, the Hilbert Transform (HT), the Teager Energy Operator (TEO) and the Generalized Zero-Crossing (GZC) are presented. Each of these methods has its own strengths and weaknesses. In general, the HT method gives the most consistently acceptable results when the data is both nonstationary and nonlinear. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Huang, NE (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RI Long, Steven/D-7248-2012 NR 4 TC 0 Z9 0 U1 0 U2 4 PU INT INST INFORMATICS & SYSTEMICS PI ORLANDO PA 14269 LORD BARCLAY DR, ORLANDO, FL 32837 USA PY 2002 BP 271 EP 275 PG 5 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BV42B UT WOS:000178906400055 ER PT B AU Long, SR Huang, NE Xiang, D AF Long, SR Huang, NE Xiang, D BE Callaos, N Hammoud, R Xia, D Li, HS Klovsky, D TI Further enhancements in the use of EMD/HHT in image analysis SO 6TH WORLD MULTICONFERENCE ON SYSTEMICS, CYBERNETICS AND INFORMATICS, VOL XIV, PROCEEDINGS: IMAGE, ACOUSTIC, SPEECH AND SIGNAL PROCESSING III LA English DT Proceedings Paper CT 6th World Multi-Conference on Systemics, Cybernetics and Informatics (SCI 2002)/8th International Conference on Information Systems Analysis and Synthesis (ISAS 2002) CY JUL 14-18, 2002 CL ORLANDO, FL SP Int Inst Informat & System, World Org System & Cybernet, Ctr Syst Studies, Syst Soc Poland, Soc Appl Syst Res, Slovenian Artificial Intelligence Soc, Simon Bolivar Univ, Polish Syst Soc, Italian Soc System, Int Soc Syst Sci, Int Syst Inst, Int Federat Syst Res, Cybernet & Human Knowing, Journal Second Order Cybernet & Cybersemiot, Blaise Pascal Univ, Engineer Sci Inst, CUST, Univ Las Palmas Gran Canaria, Concurrency & Architecture Grp, Telemat Engn Dept, Tunisian Sci Soc, Acad Non Linear Sci, San Luis Natl Univ, Lab Res Computat Intelligence, Dept Informat, Amer Soc Cybernet (Canada), Wolfram Res Inc, IEEE Comp Soc, Venezuela Chapter, Steacie Inst Molec Sci, Natl Res Council Canada DE time-frequency analysis; non-stationary; nonlinear; time series analysis; Hilbert spectrum; wavelet analysis; instantaneous frequency; Empirical Mode Decomposition method; Hilbert-Huang Transform (HHT); image analysis ID HILBERT SPECTRUM AB The new method for analyzing nonlinear and non-stationary data described by Huang et al. [1,2] that has been recently expanded to include the analysis of image data has now been developed further. The key steps of the new approach outlined by Huang et al. [1,2] have been followed in this further development. The images analyzed here are again first decomposed into horizontal strips corresponding to each pixel row. Thus for an image of 512 x 512 pixels, this would mean that a set of 512 slices, each 512 pixels long, would first be obtained from the image. Then the Empirical Mode Decomposition (EMD) method of Huang et al. [1,2] and Huang [3] is applied, resulting in a small number of Intrinsic Mode Functions (IMF) for each image slice. Because the decomposition is based on the local characteristic time scale or length scale of the data, it is applicable to images of nonlinear and non-stationary processes. By next applying the Hilbert transform and other processing to the decomposition components of each image slice, the methods yield instantaneous frequencies or wave numbers as functions of time or distance, that give sharp identifications of imbedded structures. Thus for each image slice, we obtain a decomposed component set, ranging from the smallest time or length scales to the largest. The sum of these component images is just the original starting image data. The results can then be used in several important ways. First, the components resulting can be reassembled into component images, by combining the first component from each slice together into a first component image (containing the highest frequencies or shortest length scales), and then repeating this for each subsequent component from each image slice. This gives a set of images that reveal different scales and other phenomena, from shortest to longest scale. Another presentation is obtained from the Hilbert transforms of the components, which can then be combined into an energy-frequency (or wave number)-time distribution. Examples of this further extension into images is given for water wave slopes under the action of high wind and in the presence of lower frequency backgrounds waves. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Isl, VA 23337 USA. RP Long, SR (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Isl, VA 23337 USA. RI Long, Steven/D-7248-2012 NR 10 TC 0 Z9 0 U1 0 U2 5 PU INT INST INFORMATICS & SYSTEMICS PI ORLANDO PA 14269 LORD BARCLAY DR, ORLANDO, FL 32837 USA PY 2002 BP 276 EP 280 PG 5 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BV42B UT WOS:000178906400056 ER PT B AU Pinzon, JE AF Pinzon, JE BE Callaos, N Hammoud, R Xia, D Li, HS Klovsky, D TI Using HHT to successfully uncouple seasonal and interannual components in remotely sensed data SO 6TH WORLD MULTICONFERENCE ON SYSTEMICS, CYBERNETICS AND INFORMATICS, VOL XIV, PROCEEDINGS: IMAGE, ACOUSTIC, SPEECH AND SIGNAL PROCESSING III LA English DT Proceedings Paper CT 6th World Multi-Conference on Systemics, Cybernetics and Informatics (SCI 2002)/8th International Conference on Information Systems Analysis and Synthesis (ISAS 2002) CY JUL 14-18, 2002 CL ORLANDO, FL SP Int Inst Informat & System, World Org System & Cybernet, Ctr Syst Studies, Syst Soc Poland, Soc Appl Syst Res, Slovenian Artificial Intelligence Soc, Simon Bolivar Univ, Polish Syst Soc, Italian Soc System, Int Soc Syst Sci, Int Syst Inst, Int Federat Syst Res, Cybernet & Human Knowing, Journal Second Order Cybernet & Cybersemiot, Blaise Pascal Univ, Engineer Sci Inst, CUST, Univ Las Palmas Gran Canaria, Concurrency & Architecture Grp, Telemat Engn Dept, Tunisian Sci Soc, Acad Non Linear Sci, San Luis Natl Univ, Lab Res Computat Intelligence, Dept Informat, Amer Soc Cybernet (Canada), Wolfram Res Inc, IEEE Comp Soc, Venezuela Chapter, Steacie Inst Molec Sci, Natl Res Council Canada DE normalized difference vegetation index; seasonal patterns; solar zenith angle; orbital drift; empirical mode decomposition ID DIFFERENCE VEGETATION INDEX; HIGH-RESOLUTION RADIOMETER; NDVI DATA SET; HILBERT SPECTRUM; ORBITAL DRIFT; TIME-SERIES; CLIMATE; LAND AB This paper shows how the EMD can successfully uncouple the seasonal and interannual components of NDVI signals from induced satellite artifacts. The known delay in crossing the equator of the afternoon National Oceanic and Atmospheric Administration (NOAA) polar satellites results in changes of illumination that affects measurements made by the advanced very high resolution radiometer (AVHRR). Despite the improved processing, correction of calibration loss and atmospheric effects, one of the standard AVHRR products, the normalized difference vegetation index (NDVI) time series, still may contain variations due to orbital drift or changes in sun-target-sensor geometry. In this study, we identify solar zenith angle (SZA) trends associated to orbital drifts and analize their effects on NDVI. We present the adaptive empirical mode decomposition (EMD) method as a mean to identify and remove the induced SZA trend from NDVI time series. The EMD is based on the local characteristic time scale of the data, and it is usable to give sharp identifications of embedded structures of nonlinear and nonstationaxy processes. The approach was tested on 1 degree NDVI global data sets. The results show : (1) that regions in the tropics, especially tropical forest, axe the most SZA-affected, and (2) the high northern latitudes are less contaminated. C1 NASA, Goddard Space Flight Ctr, SSAI, Greenbelt, MD 20771 USA. RP Pinzon, JE (reprint author), NASA, Goddard Space Flight Ctr, SSAI, Code 923, Greenbelt, MD 20771 USA. NR 22 TC 0 Z9 1 U1 1 U2 9 PU INT INST INFORMATICS & SYSTEMICS PI ORLANDO PA 14269 LORD BARCLAY DR, ORLANDO, FL 32837 USA PY 2002 BP 287 EP 292 PG 6 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BV42B UT WOS:000178906400058 ER PT B AU Rancic, MD Zhang, H AF Rancic, MD Zhang, H BE Callaos, N He, Y PerezPeraza, JA TI Numerical Modeling in earth sciences: A globalization approach SO 6TH WORLD MULTICONFERENCE ON SYSTEMICS, CYBERNETICS AND INFORMATICS, VOL XVII, PROCEEDINGS: INDUSTRIAL SYSTEMS AND ENGINEERING III LA English DT Proceedings Paper CT 6th World Multi-Conference on Systemics, Cybernetics and Informatics (SCI 2002)/8th International Conference on Information Systems Analysis and Synthesis (ISAS 2002) CY JUL 14-18, 2002 CL ORLANDO, FL SP Int Inst Informat & System, World Org System & Cybernet, Ctr Syst Studies, Syst Soc Poland, Soc Appl Syst Res, Slovenian Artificial Intelligence Soc, Simon Bolivar Univ, Polish Syst Soc, Italian Soc System, Int Soc Syst Sci, Int Syst Inst, Int Federat Syst Res, Cybernet & Human Knowing, Journal Second Order Cybernet & Cybersemiot, Blaise Pascal Univ, Engineer Sci Inst, CUST, Univ Las Palmas Gran Canaria, Concurrency & Architecture Grp, Telemat Engn Dept, Tunisian Sci Soc, Acad Non Linear Sci, San Luis Natl Univ, Lab Res Computat Intelligence, Dept Informat, Amer Soc Cybernet (Canada), Wolfram Res Inc, IEEE Comp Soc, Venezuela Chapter, Steacie Inst Molec Sci, Natl Res Council Canada DE atmospheric modeling; distributed computing; framework; quasi-uniform grids ID PARTIAL-DIFFERENTIAL EQUATIONS; RESOLUTION; SPHERE AB This paper describes a project that investigates a new, original approach to modeling of the Earth-climate system. Its objective is to develop a global model of the atmosphere by using and combing numerical infrastructure of a contemporary regional model. Such an approach allows that many advanced options are included, such as: an intrinsic avoidance of the polar problem, efficient performance on distributed memory computers, local enhancement of resolution, and moving of the locally refined domains. This new model is built using software engineering principles underlying the object-oriented (OO) programming paradigm, so that in the final stage it may easily be converted in a "framework" that could serve for globalization of any regional model of the atmosphere. C1 NASA, Goddard Space Flight Ctr, UMBC, GEST, Greenbelt, MD 20771 USA. RP Rancic, MD (reprint author), NASA, Goddard Space Flight Ctr, UMBC, GEST, Code 900-1, Greenbelt, MD 20771 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU INT INST INFORMATICS & SYSTEMICS PI ORLANDO PA 14269 LORD BARCLAY DR, ORLANDO, FL 32837 USA PY 2002 BP 90 EP 94 PG 5 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Industrial SC Automation & Control Systems; Computer Science; Engineering GA BV43N UT WOS:000178929300016 ER PT J AU Mankins, JC AF Mankins, JC TI Affordable Mars exploration architectures: Applying systems from the commercial development of space SO ACTA ASTRONAUTICA LA English DT Article AB This paper discusses the possibility of leveraging systems concepts and technologies needed for the commercial development of space in innovative, affordable human Mars exploration architectures. Since the late 1980s, various space agencies, industry and university groups have examined a diverse set of human Mars exploration options. In the United States, the 1989 Space Exploration Initiative (SEI) initiated a continuing series of studies and assessments of options for human exploration. Typically, these studies have focused first on the exploration mission itself and have attempted to optimize key mission metrics-such as the initial mass in low Earth orbit (IMLEO)-through the use of government-developed systems. In light of these concepts, technology needs have typically been identified. Occasionally, potential secondary value of these technologies to terrestrial and space applications has been assessed. An alternative approach might involve a consideration of commercial investments might best be leveraged in exploration missions. Such an approach might begin by determining what technologies and systems concepts are needed to enable the robust commercial development of space, and then attempt to use these technologies and concepts in devising human exploration of Mars scenarios; an approach of this type is presented here. This paper examines a variety of prospective commercial space developments-ranging from near-term plans to far-term opportunities-and draws from these a "tool-kit" of potential systems and technologies that might be applied in constructing a more affordable Mars exploration mission architecture. A notional scenario for applying commercial space development technology and systems in a Mars architecture is described. The paper concludes by comparing and contrasting some of the relative benefits of the two approaches and suggests that-if commercial space development is a viable goal-such an approach may substantially strengthen support among international and US policy-makers for human exploration missions. The paper includes various graphs, tables and conceptual renderings of potential commercial space and human exploration approaches. Published by Elsevier Science Ltd. C1 NASA Headquarters, Off Space Flight, Washington, DC 20546 USA. RP Mankins, JC (reprint author), NASA Headquarters, Off Space Flight, Washington, DC 20546 USA. NR 9 TC 1 Z9 1 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JAN PY 2002 VL 50 IS 1 BP 27 EP 37 DI 10.1016/S0094-5765(01)00145-X PG 11 WC Engineering, Aerospace SC Engineering GA 511XG UT WOS:000173290400003 ER PT J AU Hubbard, GS Feldman, W Cox, SA Smith, MA Chu-Thielbar, L AF Hubbard, GS Feldman, W Cox, SA Smith, MA Chu-Thielbar, L TI Lunar Prospector: First results and lessons learned SO ACTA ASTRONAUTICA LA English DT Article ID MOON; NEUTRONS; ICE AB Lunar Prospector, the first competitively selected mission in NASA's Discovery Program, is conducting a one-year orbital survey of the Moon's composition and structure. Launched on January 6 1998, the suite of five instruments is measuring water/ice to a sensitivity of 50 ppm (hydrogen) detecting key elemental constituents, gas release events and mapping the Moon's gravitational and magnetic fields. The mission is described with emphasis on the first scientific results and lessons learned from managing a very low cost project. A mission overview and systems description is given along with final mission trajectories. Lessons learned from government-industry teaming, new modes of project management, and novel contractual arrangements are discussed. The suite of five instruments (neutron spectrometer, alpha particle spectrometer, gamma-ray spectrometer, electron reflectometer and magnetometer) is outlined with attention to final technical performance as well as development on a constrained budget and schedule. A review of our novel approaches to education and public outreach is discussed and a summary with suggestions and implications for future missions is provided. Published by Elsevier Science Ltd. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hubbard, GS (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 13 TC 4 Z9 6 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JAN PY 2002 VL 50 IS 1 BP 39 EP 47 PG 9 WC Engineering, Aerospace SC Engineering GA 511XG UT WOS:000173290400004 ER PT J AU Rejmund, F Bethenod, A Napolitani, P Taieb, J Villagrassa, C Audouin, L Armbruster, P Bacri, CO Benlliure, J Bernas, M Berthier, B Boudard, A Casajeros, E Czajkowski, S Connell, JJ Enqvist, T Faesterman, T George, JS Junghans, A Jurado, B Hammache, F Leray, S Legrain, R Mewaldt, RA Pereira, J Ricciardi, MV Schmidt, KH Stephan, C Summerer, K Tassan-Got, L Volant, C Wiedenbeck, ME Wlazlo, W Yanasak, NE AF Rejmund, F Bethenod, A Napolitani, P Taieb, J Villagrassa, C Audouin, L Armbruster, P Bacri, CO Benlliure, J Bernas, M Berthier, B Boudard, A Casajeros, E Czajkowski, S Connell, JJ Enqvist, T Faesterman, T George, JS Junghans, A Jurado, B Hammache, F Leray, S Legrain, R Mewaldt, RA Pereira, J Ricciardi, MV Schmidt, KH Stephan, C Summerer, K Tassan-Got, L Volant, C Wiedenbeck, ME Wlazlo, W Yanasak, NE TI Disappearance of shell effects and persistence of an even-odd staggering in the fragment production in nuclear reactions at relativistic energies SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article; Proceedings Paper CT 4th Latin American Symposium on Nuclear Physics CY SEP 24-28, 2001 CL COLEGIO NACL, MEXICO CITY, MEXICO HO COLEGIO NACL DE spallation reaction; fission probabilities; shell effect in level densities; proton-neutron pairing ID PROJECTILE FRAGMENTATION; CROSS-SECTIONS; MEAN-FIELD; COLLISIONS; RESIDUES; YIELDS; MASSES; MODEL AB The isotopic distributions of fragments produced in the spallation. of uranium are strongly influenced by the fission of the excited prefragments, highly fissile nuclei. The competition between fission and evaporation around the doubly-magic nucleus Pb is discussed. The light fragments from Fe beam are produced with a strong enhancement of even-even nuclei compared to the odd-odd in the region of nuclei with equal number of neutrons and protons, N similar to Z. This staggering in the production of light fragments is not observed in the production of heavy fragments, and is in contradiction with the basis of the statistical model of deexcitation of a hot nucleus. Pairing interaction as a function of the excitation energy and as a function of the isospin of the nucleus are questioned. C1 IPN, Orsay, France. GSI Darmstadt, D-6100 Darmstadt, Germany. CEA Saclay, SPhN, DAPNIA, Gif Sur Yvette, France. USC, Santiago De Compostela, Spain. CENBG, Gradingnan, France. Univ Chicago, Chicago, IL 60637 USA. Univ Jyvaskyla, Jyvaskyla, Finland. Tech Univ Munich, D-8046 Garching, Germany. CALTECH, Pasadena, CA 91125 USA. Jet Prop Lab, Pasadena, CA USA. RP Rejmund, F (reprint author), IPN, Orsay, France. RI Junghans, Arnd/D-4596-2012; Hammache, Fairouz/K-6132-2016; Leray, Sylvie/A-3924-2012; Benlliure, Jose/K-8407-2014 OI Leray, Sylvie/0000-0002-1942-2911; Benlliure, Jose/0000-0002-5114-1298 NR 21 TC 0 Z9 0 U1 0 U2 1 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 2002 VL 16 IS 1-4 BP 85 EP 91 DI 10.1556/APH.16.2002.1-4.10 PG 7 WC Physics, Nuclear SC Physics GA 623QL UT WOS:000179714300010 ER PT S AU Wang, Y AF Wang, Y BE Dutta, AK Awwal, AAS Dutta, NK Okamoto, K TI Digital tunable filter for optical communication SO ACTIVE AND PASSIVE OPTICAL COMPONENTS FOR WDM COMMUNICATIONS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Active and Passive Optical Components for WDM Communications II CY JUL 29-AUG 01, 2002 CL BOSTON, MA SP SPIE DE electro-optics; filter; multiplexer; DWDM; digital; switching ID LIQUID-CRYSTAL AB A new technology invented at JPL of active wavelength filtering on electro-optical switching of internal-reflection states have been proposed for use in DWDM, as add/drop multiplexers. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wang, Y (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 SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4649-1 J9 P SOC PHOTO-OPT INS PY 2002 VL 4870 BP 93 EP 95 DI 10.1117/12.475516 PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic; Optics; Telecommunications SC Computer Science; Engineering; Optics; Telecommunications GA BV29V UT WOS:000178481700012 ER PT S AU Mackey, JR Salari, E AF Mackey, JR Salari, E BE VoDinh, T Buttgenbach, S TI A wavelet-based method for the suppression of ringing on force data taken during the extensional rheology of a non-Newtonian fluid polymer SO ADVANCED ENVIRONMENTAL SENSING TECHNOLOGY II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Environmental Sensing Technology II CY OCT 31-NOV 01, 2001 CL NEWTON, MA SP SPIE DE wavelet; noise; polynomial suppression; force; non-Newtonian ID TIME-FREQUENCY LOCALIZATION AB This paper describes the study of wavelet-based methods employed to de-noise a force transducer signal. This signal was extracted during the extensional deformation of a non-Newtonian polymer fluid. The non-Newtonian polymeric fluid was extensionally deformed with an exponentially increasing velocity profile. This velocity profile corresponded to a specific strain rate. Since the motion was stopped quickly (deceleration time was below 50ms for a complete stop), a serious problem of ringing occurred for approximately one second after the motion has ceased. The ringing manifested itself as a damped harmonic oscillation, which overrides the relaxation characteristics of the molecular structure within the boger fluid. In this paper, our goal was to suppress the damped harmonic oscillatory signal while preserving the relaxation characteristics (decaying exponential signal) of the force data. Several wavelet-based techniques provided acceptable noise suppression while preserving the signal of interest. C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. RP Mackey, JR (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Mail Stop 110-3,21000 Brookpk Rd, Cleveland, OH 44135 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 0-8194-4304-2 J9 P SOC PHOTO-OPT INS PY 2002 VL 4576 BP 87 EP 95 DI 10.1117/12.456945 PG 9 WC Engineering, Environmental; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BU23F UT WOS:000175418200012 ER PT S AU White, AL AF White, AL BE Chang, W TI Mean time to unsafe failure SO ADVANCED INTERNET SERVICES AND APPPLICATIONS, PROCEEDINGS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 1st International Workshop on Advanced Internet Services and Applications CY AUG 01-02, 2002 CL SEOUL, SOUTH KOREA SP Minist Commerce, Ind & Energy, Yonsei Univ, Samsung Electr, Serome Technol, Hyundai Datanet, CVnet, C EiSA, Mediaworks, SENA Technol, SNS Solut, SysGate, Seoul Commtech, WIZ Informat Technol AB With the increased use of electronics and networks comes a concern about their failure modes. If they fail, we wish they did so in a benign manner. Hence, a reliability parameter of interest is the expected time to a disastrous failure, where there is a loss of money, information, or time. The models and methods for computing this expectation, however, are still in an early stage. This paper presents new material that permits examining more complex and realistic models. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP White, AL (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 1 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-43968-4 J9 LECT NOTES COMPUT SC PY 2002 VL 2402 BP 11 EP 20 PG 10 WC Computer Science, Information Systems; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BW28E UT WOS:000181438500002 ER PT J AU Gabb, TP Telesman, J Kantzos, P Prevey, PS AF Gabb, TP Telesman, J Kantzos, P Prevey, PS TI Surface enhancement of metallic materials SO ADVANCED MATERIALS & PROCESSES LA English DT Article AB A layer of residual compression developed at the surface through local plastic deformation helps to improve fatigue life for components in the automotive and aerospace industries. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Lambda Res, Cincinnati, OH USA. RP Gabb, TP (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 0882-7958 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD JAN PY 2002 VL 160 IS 1 BP 69 EP 72 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 515GP UT WOS:000173487300009 ER PT S AU Barnes, NP Walsh, BM Filer, ED Hutcheson, RL Equall, RW AF Barnes, NP Walsh, BM Filer, ED Hutcheson, RL Equall, RW BE Fermann, ME Marshall, LR TI Compositional wavelength tuning predictions of garnets; comparison with experimental results SO ADVANCED SOLID-STATE LASERS, PROCEEDINGS SE OSA TRENDS IN OPTICS AND PHOTONICS LA English DT Proceedings Paper CT Topical Meeting on Advanced Solid-State Lasers CY FEB 03-06, 2002 CL Quebec City, CANADA SP Opt Soc Amer, IEEE Lasers & Electro Opt Soc ID LASER AB Laser tuning rates by varying the composition of die laser material are predicted using a quantum mechanical model and compare favorably with experimental results for garnets. The quantum mechanical model uses crystal field components that are calculated using a novel method based on Pauling's theory of electronegativity. The theoretical. results for the garnets are extended to a fluoride material, Nd:YLF, and found to accurately describe the energy levels. C1 NASA Langley Res Ctr, Hampton, VA 23681 USA. RP Barnes, NP (reprint author), NASA Langley Res Ctr, Hampton, VA 23681 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-5695 BN 1-55752-697-4 J9 OSA TRENDS OPT PHOTO PY 2002 VL 68 BP 280 EP 283 PG 4 WC Optics; Physics, Applied SC Optics; Physics GA BAH79 UT WOS:000222298600061 ER PT S AU Barnes, NP Walsh, BM AF Barnes, NP Walsh, BM BE Fermann, ME Marshall, LR TI Quantum efficiency measurements of Nd : YAG, Yb : YAG, and Tm : YAG SO ADVANCED SOLID-STATE LASERS, PROCEEDINGS SE OSA TRENDS IN OPTICS AND PHOTONICS LA English DT Proceedings Paper CT Topical Meeting on Advanced Solid-State Lasers CY FEB 03-06, 2002 CL Quebec City, CANADA SP Opt Soc Amer, IEEE Lasers & Electro Opt Soc AB Quantum efficiencies of Nd:YAG, Yb:YAG, and Tm:YAG were measured using several different approaches. Good agreement is obtained for Nd:YAG and Yb:YAG utilizing 2 different approaches. Because of high fluorescence absorption, Tm:YAG measurements required a different method. C1 NASA Langley Res Ctr, Hampton, VA 23681 USA. RP Barnes, NP (reprint author), NASA Langley Res Ctr, Hampton, VA 23681 USA. NR 2 TC 6 Z9 6 U1 1 U2 1 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-5695 BN 1-55752-697-4 J9 OSA TRENDS OPT PHOTO PY 2002 VL 68 BP 284 EP 287 PG 4 WC Optics; Physics, Applied SC Optics; Physics GA BAH79 UT WOS:000222298600062 ER PT S AU Ames, TJ Case, L AF Ames, TJ Case, L BE Lewis, H TI Distributed framework for dynamic telescope and instrument control SO ADVANCED TELESCOPE AND INSTRUMENTATION CONTROL SOFTWARE II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Telescope and Instrumentation Control Software II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE astronomy; infrared astronomy; XML; instrument : description; telescope : control; SOFIA; NASA : GSFC; Java; IML AB Traditionally, instrument command and control systems have been developed specifically for a single instrument. Such solutions are frequently expensive and are inflexible to support the next instrument development effort. NASA Goddard Space Flight Center is developing an extensible framework, known as Instrument Remote Control (IRC) that applies to any kind of instrument that can be controlled by a computer. IRC combines the platform independent processing capabilities of Java with the power of the Extensible Markup Language (XML). A key aspect of the architecture is software that is driven by an instrument description, written using the Instrument Markup Language (IML). IML is an XML dialect used to describe graphical user interfaces to control and monitor the instrument, command sets and command formats, data streams, communication mechanisms, and data processing algorithms. The IRC framework provides the ability to communicate to components anywhere on a network using the JXTA protocol for dynamic discovery of distributed components. JXTA (see http://www.jxta.org) is a generalized protocol that allows any devices connected by a network to communicate in a peer-to-peer manner. IRC uses JXTA to advertise a device's IML and discover devices of interest on the network. Devices can join or leave the network and thus join or leave the instrument control environment of IRC. Currently, several astronomical instruments are working with the IRC development team to develop custom components for IRC to control their instruments. These instruments include: High resolution Airborne Wideband Camera (HAWC), a first light instrument for the Stratospheric Observatory for Infrared Astronomy (SOFIA); Submillimeter And Far Infrared Experiment (SAFIRE), a Principal Investigator instrument for SOFIA; and Fabry-Perot Interferometer Bolometer Research Experiment (FIBRE), a prototype of the SAFIRE instrument, used at the Caltech Submillimeter Observatory (CSO). Most recently, we have been working with the Submillimetre High Angular Resolution Camera IInd Generation (SHARCII) at the CSO to investigate using IRC capabilities with the SHARC instrument. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ames, TJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4627-0 J9 P SOC PHOTO-OPT INS PY 2002 VL 4848 BP 63 EP 74 DI 10.1117/12.461542 PG 12 WC Automation & Control Systems; Computer Science, Software Engineering; Instruments & Instrumentation SC Automation & Control Systems; Computer Science; Instruments & Instrumentation GA BV91S UT WOS:000180380600007 ER PT S AU Booth, AJ Eychaner, G Hovland, E Johnson, RL Lupton, W Niessner, A Palmer, D Reder, LJ Rudeen, AC Smythe, RF Tsubota, K AF Booth, AJ Eychaner, G Hovland, E Johnson, RL Lupton, W Niessner, A Palmer, D Reder, LJ Rudeen, AC Smythe, RF Tsubota, K BE Lewis, H TI Overview of the control system for the Keck Interferometer SO ADVANCED TELESCOPE AND INSTRUMENTATION CONTROL SOFTWARE II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Telescope and Instrumentation Control Software II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE interferometry; control system; real time control AB The Keck Interferometer links the two 10m Keck Telescopes located atop Mauna Kea in Hawaii. It is the first 10m class, fully AO equipped interferometer to enter operation. Further, it is the first large interferometer designed to be handed over from a design and implementation team to a separate operations team, and be used by astronomers who are not interferometer specialists. As such it offers unique challenges in reducing an extremely complex and powerful system to an apparently simple user interface, and providing a well engineered system that can be maintained by people who did not develop it. This paper gives an overview of the control system that has been implemented for the single baseline operation of the instrument, and indicates how this will be extended to allow control of the future modes of the instrument (nulling, differential phase and astrometry). The control system has several parts. One is for control of "slow" sub-systems, which is based in the EPICS architecture, already ubiquitous at the Keck Observatory. Another, used to control hard real time sub-systems, is based on a new infrastructure developed at JPL, programmed in C++, Java, and using CORBA for communication. This infrastructure has been developed specifically with the problems of interferometric control in mind and is used in JPL's flight testbeds, as well as the Keck Interferometer. Finally, a user interface and high level control layer is in development using a variety of tools including UML based modeling in the Rhapsody tool (using C++ and CORBA), Java, and Tcl/Tk for prototyping. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Booth, AJ (reprint author), CALTECH, Jet Propuls Lab, 4800 Oak Grove Dr,MS171-113, Pasadena, CA 91109 USA. NR 7 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 0-8194-4627-0 J9 P SOC PHOTO-OPT INS PY 2002 VL 4848 BP 107 EP 115 DI 10.1117/12.461555 PG 9 WC Automation & Control Systems; Computer Science, Software Engineering; Instruments & Instrumentation SC Automation & Control Systems; Computer Science; Instruments & Instrumentation GA BV91S UT WOS:000180380600011 ER PT S AU Lockhart, TG AF Lockhart, TG BE Lewis, H TI RTC: a distributed realtime control system toolkit SO ADVANCED TELESCOPE AND INSTRUMENTATION CONTROL SOFTWARE II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Telescope and Instrumentation Control Software II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE RTC; RICST; real-time; realtime; distributed computing; CORBA; JPL; SIM; Keck AB The Jet Propulsion Laboratory (JPL) has built several optical interferometers using a common software framework developed for this purpose. The heart of this framework is the Realtime Control (RTC) software product. RTC has evolved from its initial implementation to include a powerful dynamic configuration capability and to use Common Object Request Broker Architecture (CORBA) technology for commanding and telemetry. This paper describes the current implementation of this toolkit. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lockhart, TG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 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 0-8194-4627-0 J9 P SOC PHOTO-OPT INS PY 2002 VL 4848 BP 197 EP 205 DI 10.1117/12.461589 PG 9 WC Automation & Control Systems; Computer Science, Software Engineering; Instruments & Instrumentation SC Automation & Control Systems; Computer Science; Instruments & Instrumentation GA BV91S UT WOS:000180380600020 ER PT S AU Hall, D Ly, W Howard, R Weir, J Rakoczy, J AF Hall, D Ly, W Howard, R Weir, J Rakoczy, J BE Lewis, H TI Software development for the Hobby-Eberly Telescope's Segment Alignment Maintenance System using LabVIEW SO ADVANCED TELESCOPE AND INSTRUMENTATION CONTROL SOFTWARE II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Telescope and Instrumentation Control Software II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE LabVIEW; software development; segmented mirror; mirror control; HET AB The software development for an upgrade to the Hobby-Eberly Telescope (HET) was done in LabVIEW. In order to improve the performance of the HET at the McDonald Observatory, a closed-loop system had to be implemented to keep the mirror segments aligned during periods of observation. The control system, called the Segment Alignment Maintenance System (SAMS), utilized inductive sensors to measure the relative motions of the mirror segments. Software was developed in LabVIEW to tie the sensors, operator interface, and mirror-control motors together. Developing the software in LabVIEW allowed the system to be flexible, understandable, and able to be modified by the end users. Since LabVIEW is built using block diagrams, the software naturally followed the designed control system's block and flow diagrams, and individual software blocks could be easily verified. LabVIEW's many built-in display routines allowed easy visualization of diagnostic and health-monitoring data during testing. Also, since LabVIEW is a multi-platform software package, different programmers could develop the code remotely on various types of machines. LabVIEW's ease of use facilitated rapid prototyping and field-testing. There were some unanticipated difficulties in the software development, but the use of LabVIEW as the software "language" for the development of SAMS contributed to the overall success of the project. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Hall, D (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 8 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 0-8194-4627-0 J9 P SOC PHOTO-OPT INS PY 2002 VL 4848 BP 239 EP 250 DI 10.1117/12.461269 PG 12 WC Automation & Control Systems; Computer Science, Software Engineering; Instruments & Instrumentation SC Automation & Control Systems; Computer Science; Instruments & Instrumentation GA BV91S UT WOS:000180380600024 ER PT S AU Reder, LJ Lockhart, TG Ko, KC Smith, BT AF Reder, LJ Lockhart, TG Ko, KC Smith, BT BE Lewis, H TI Using scripting languages in optical interferometry SO ADVANCED TELESCOPE AND INSTRUMENTATION CONTROL SOFTWARE II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Telescope and Instrumentation Control Software II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE CORBA; Tcl; Python; Perl; interferometer; Keck; sequencer; align AB Testbeds and production systems need lightweight, capable, and rapidly developed applications. We have developed several such scripts for testing and operating the Keck Interferometer. Two stand-alone (Tcl/Tk script) applications implemented to support the Keck Interferometer are discussed. The first is a front end to automatic and manual optical alignment embedded software, developed using the Keck Observatory Keyword API extension. The second is a user interface to the Interferometer Sequencer that communicates with it via both Keywords and Common Orbject Request Broker Architecture (CORBA). We discuss client-side CORBA scripts implemented in Tcl, Perl and Python. These are all technologies that are either currently being used on testbeds at JPL or being evaluated for future use. Finally, a Python example demonstrating implementation of a simple CORBA server is presented. C1 CALTECH, Jet Prop Lab, Real Time Interferometry Software Grp, Pasadena, CA 91109 USA. RP Reder, LJ (reprint author), CALTECH, Jet Prop Lab, Real Time Interferometry Software Grp, 4800 Oak Grove Dr,Mail Stop 171-113, Pasadena, CA 91109 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 0-8194-4627-0 J9 P SOC PHOTO-OPT INS PY 2002 VL 4848 BP 304 EP 315 DI 10.1117/12.461553 PG 12 WC Automation & Control Systems; Computer Science, Software Engineering; Instruments & Instrumentation SC Automation & Control Systems; Computer Science; Instruments & Instrumentation GA BV91S UT WOS:000180380600030 ER PT S AU Cummings, R Peters, B Sutherlin, S Smithers, M Robinson, J AF Cummings, R Peters, B Sutherlin, S Smithers, M Robinson, J BE Lewis, H TI Analytical verifications of NGST Advanced Mirror System Demonstrators SO ADVANCED TELESCOPE AND INSTRUMENTATION CONTROL SOFTWARE II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Telescope and Instrumentation Control Software II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE analytical verifications; cryogenic testing; AMSD; NGST AB Ground based testing is a critical and costly part of component, assembly, and system verifications of large space telescopes. At such tests, however, with integral teamwork by planners, analysts, and test personnel, segments can be included to validate specific analytical parameters and algorithms at relatively low additional cost. This paper presents analytical verification and validation segments currently added to ambient and vacuum cryogenic testing of Advanced Mirror System Demonstrator (AMSD) assemblies-for the Next Generation Space Telescope (NGST) project. The test segments for workmanship testing; cold survivability, and cold operation optical throughput are supplemented by segments for analytical verifications; of structural, thermal, and optical parameters. Utilizing integrated modeling and separate materials testing, the paper continues with analyses to be performed for AMSD testing, currently slated for calendar year 2003. These segments form a well-verified portion of the integrated modeling being conducted on AMSD for NGST performance predictions. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Cummings, R (reprint author), NASA, George C Marshall Space Flight Ctr, Mail Code ED42, Huntsville, AL 35812 USA. NR 10 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 0-8194-4627-0 J9 P SOC PHOTO-OPT INS PY 2002 VL 4848 BP 490 EP 499 DI 10.1117/12.461417 PG 10 WC Automation & Control Systems; Computer Science, Software Engineering; Instruments & Instrumentation SC Automation & Control Systems; Computer Science; Instruments & Instrumentation GA BV91S UT WOS:000180380600049 ER PT S AU Irwin, PC Johnson, RL AF Irwin, PC Johnson, RL BE Lewis, H TI Real-time control using an open source RTOS SO ADVANCED TELESCOPE AND INSTRUMENTATION CONTROL SOFTWARE II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Advanced Telescope and Instrumentation Control Software II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE real-time; real-time; open source; RTOS; software; RTAI; Linux; VxWorks; RTC AB Complex telescope systems such as interferometers tend to rely heavily on hard real-time operating systems (RTOS). It has been standard practice at NASA's Jet Propulsion Laboratory (JPL) and many other institutions to use costly commercial RTOSs and hardware. After developing a real-time toolkit for VxWorks on the PowerPC platform (dubbed RTC), the interferometry group at JPL is porting this code to the real-time Application Interface (RTAI), an open source RTOS that is essentially an extension to-the Linux kernel. This port has the potential to reduce software and hardware costs for future projects, while increasing the level of performance. The goals of this paper are to briefly describe the RTC toolkit, highlight the successes and pitfalls of porting the toolkit from VxWorks to Linux-RTAI, and to discuss future enhancements that will be implemented as a direct result of this port. The first port of any body of code is always the most difficult since it uncovers the OS-specific calls and forces "red flags" into those portions of the code. For this reason, It has also been a huge benefit that the project chose a generic, platform independent OS extension, ACE, and its CORBA counterpart, TAO. This port of RTC will pave the way for conversions to other environments, the most interesting of which is a non-real-time simulation environment, currently being considered by the Space Interferometry Mission (SIM) and the Terrestrial Planet Finder (TPF) Projects. C1 CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Irwin, PC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA USA. NR 1 TC 0 Z9 0 U1 3 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 0-8194-4627-0 J9 P SOC PHOTO-OPT INS PY 2002 VL 4848 BP 560 EP 567 DI 10.1117/12.463557 PG 8 WC Automation & Control Systems; Computer Science, Software Engineering; Instruments & Instrumentation SC Automation & Control Systems; Computer Science; Instruments & Instrumentation GA BV91S UT WOS:000180380600057 ER PT J AU Hillel, D Rosenzweig, C AF Hillel, D Rosenzweig, C TI Desertification in relation to climate variability and change SO ADVANCES IN AGRONOMY, VOL 77 SE ADVANCES IN AGRONOMY LA English DT Review ID TROPICAL NORTH-AFRICA; SUB-SAHARAN DROUGHT; FEEDBACK MECHANISM; SUMMER RAINFALL; SURFACE-ALBEDO; SAHEL CLIMATE; DESERT DUST; TEMPERATURES; VEGETATION; SATELLITE C1 Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Hillel, D (reprint author), Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. NR 78 TC 30 Z9 34 U1 2 U2 20 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0065-2113 J9 ADV AGRON PY 2002 VL 77 BP 1 EP 38 DI 10.1016/S0065-2113(02)77012-0 PG 44 WC Agronomy SC Agriculture GA BU33L UT WOS:000175714900001 ER PT S AU Boyle, RF Ross, RG AF Boyle, RF Ross, RG BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Overview of NASA space cryocooler programs SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB Mechanical cryocoolers represent a significant enabling technology for NASA's Earth and Space Science Enterprises, as well as augmenting existing capabilities in space exploration. An overview is presented of ongoing efforts at the Goddard Space Flight Center and the Jet Propulsion Laboratory in support of current flight projects, near-term flight instruments, and long-term technology development. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Boyle, RF (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 25 TC 1 Z9 1 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1037 EP 1044 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700128 ER PT S AU Collins, SA Rodriguez, JI Ross, RG AF Collins, SA Rodriguez, JI Ross, RG BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI TES cryocooler system design and development SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB JPL's Tropospheric Emission Spectrometer (TES) instrument is typical of recent NASA cryogenic instruments that take advantage of mechanical cryocoolers to enable the acquisition of important science data using cryogenic focal plane arrays. TES is a high-resolution infrared imaging Fourier transform spectrometer with spectral coverage of 3.2 to 15.4 microns and is under development at JPL for flight on NASA's EOS-Aura spacecraft in the 2003 timeframe. The instrument contains four focal plane arrays in two separate housings that are cooled to 65 K by a pair of TRW pulse tube cryocoolers. The instrument also includes a two-stage passive radiator to cool the optical bench to 180K. The cryocooler system design is tightly coupled with die overall thermal control design to maximize performance of the TES instrument. This paper describes the cryogenic system design including the cryogenic loads, thermal performance margins, and performance properties for the cryocoolers. Test results are presented from recent integration activities that focused on the critical interface between the cryocoolers and the focal plane subsystem. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Collins, SA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1053 EP 1060 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700130 ER PT S AU Kittel, P AF Kittel, P BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Heat switch limitations on multi-stage magnetic refrigeration SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB Heat switches have long been successfully used in single stage Magnetic Refrigerators. The recent rekindled interest in multi-stage magnetic coolers and the use of magnetically controlled isothermal stages place stricter requirements on the performance of heat switches. This paper reviews the application of heat switches to single stage magnetic coolers. It then shows how the heat switch requirements are different for isothermal stages and cascaded multi-stage coolers. In the two latter cases, heat switches do not perform as wen as they do for single stage coolers. This significantly affects the design of multi-stage systems. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Kittel, P (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 28 TC 2 Z9 2 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1167 EP 1174 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700144 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 Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Passive gas-gap heat switches for use in adiabatic demagnetization refrigerators SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE ID TEMPERATURES AB We have designed, built, and tested a gas-gap heat switch that turns on and off passively, without the need for a separate, thermally activated getter. This switch uses He-3 condensed as a thin film on alternating plates of copper. The switch is thermally conductive at temperatures above about 0.2 K, and is insulating if either end of the switch cools below about 0.15 K. The "on" conductance (7 mW/K at 0.25K) is limited by the surface area and gap between the copper leaves, the saturated vapor pressure of the He-3, and the Kapitza boundary resistance between the He-3 and the copper. The "off' conductance is determined by the helium containment shell which physically supports the two conductive ends. We have also designed and are building passive gas-gap heat switches that will passively turn off near I K and near 4 K. For these switches we rely on the strong temperature dependence of the vapor pressure of He-4 adsorbed onto neon or copper substrates, respectively, when the coverage is less than one monolayer. The different binding energies of the He-4 to the neon or copper give rise to the different temperatures where the switches transition between the on and off states. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Shirron, PJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 11 TC 4 Z9 4 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1175 EP 1182 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700145 ER PT S AU Canavan, ER Dipirro, MJ Jackson, M Panek, J Shirron, PJ Tuttle, JG AF Canavan, ER Dipirro, MJ Jackson, M Panek, J Shirron, PJ Tuttle, JG BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI A magnetoresistive heat switch for the continuous ADR SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE C1 NASA, Goddard Space Flight Ctr, Cryogen & Fluids Branch, Greenbelt, MD 20771 USA. RP Canavan, ER (reprint author), NASA, Goddard Space Flight Ctr, Cryogen & Fluids Branch, Code 661, Greenbelt, MD 20771 USA. NR 12 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 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1183 EP 1190 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700146 ER PT S AU King, TT Rowlett, BA Ramirez, RA Shirron, PJ Canavan, ER DiPirro, MJ Panek, JS Tuttle, JG Shull, RD Fry, RA AF King, TT Rowlett, BA Ramirez, RA Shirron, PJ Canavan, ER DiPirro, MJ Panek, JS Tuttle, JG Shull, RD Fry, RA BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Rare-earth garnets and perovskites for space-based ADR cooling at high T and low H SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE ID MAGNETIC REFRIGERATION AB Future NASA satellite detector systems must be cooled to the 0.1 K temperature range to meet the stringent energy resolution and sensitivity requirements demanded by mid-term astronomy missions. The development of adiabatic demagnetization refrigeration (ADR) materials that can efficiently cool from the passive radiative cooling limit of similar to30 K down to sub-Kelvin under low magnetic fields (H less than or equal to 3 T) would represent a significant improvement in space-based cooling technology. Governed by these engineering goals, our efforts have focused on quantifying the change in magnetic entropy of rare-earth garnets and perovskites. Various compositions within the gadolinium gallium iron garnet solid solution series (GGIG, Gd3Ga5-XFeXO12, 0.00 less than or equal to X less than or equal to 5.00) and gadolinium aluminum perovskite (GAP, GdAlO3) have been synthesized via an organometallic complex approach and confirmed with powder x-ray diffraction. The magnetization of the GGIG and GAP materials has been measured as a function of composition (0.00 less than or equal to X less than or equal to 5.00), temperature (2 K less than or equal to T less than or equal to 30 K) and applied magnetic field (0 T less than or equal to H less than or equal to 3 T). The magnetic entropy change (DeltaS(mag)) between 0 T and 3 T was determined from the magnetization data. In the GGIG system, DeltaS(mag) was compositionally dependent; Fe3+ additions up to X less than or equal to 2.44 increased DeltaS(mag) at T > 5 K. For GAP, DeltaS(mag) was similar to that of GGIG, X = 0.00, both in terms of magnitude and temperature dependence at T > 10 K. However, the DeltaS(mag) of GAP at T < 10 K was less than the endmember GGIG composition, X = 0.00, and exhibited maximum similar to5 K. C1 NASA, Goddard Space Flight Ctr, Mat Engn Branch, Greenbelt, MD 20771 USA. RP King, TT (reprint author), NASA, Goddard Space Flight Ctr, Mat Engn Branch, Code 541, Greenbelt, MD 20771 USA. NR 12 TC 2 Z9 2 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1191 EP 1197 PG 7 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700147 ER PT S AU Prina, M Bhandari, P Bowman, RC Wade, LA Pearson, DP Morgante, G AF Prina, M Bhandari, P Bowman, RC Wade, LA Pearson, DP Morgante, G BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Performance prediction of the Planck sorption cooler and initial validation SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB Two continuous operation 18 K/20 K sorption coolers are being developed by JPL for the ESA Planck mission to provide about 200 mW of cooling at 18 K and 1.4 W at 20 K. A detailed performance prediction model has been developed to support the design process and to evaluate the results of prototype testing. The performance of these coolers depends on many related operating parameters (such as the temperatures of precooling thermal shield and the warm radiator) and they can only be assessed through a detailed modeling of each component coupling. This model predicts the time varying temperature, pressure and H-2 concentration gradients within the metal hydride beds, the H-2 flow rate, cooling power produced in the coldhead, and the oscillations of the coldhead temperature. Each component model has been parametrically described to allow trade off evaluation and the possibility to use it for different environmental and cooling requirements and for other sorption coolers. The full validation of the model will be obtained by comparison of the performance predictions to the experimental data for the engineering prototype cooler being built at JPL. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Prina, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 1 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 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1201 EP 1208 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700148 ER PT S AU Pearson, D Bowman, RC Schmelzel, ME Prina, M Bhandari, P Paine, CG Wade, LA AF Pearson, D Bowman, RC Schmelzel, ME Prina, M Bhandari, P Paine, CG Wade, LA BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Characterization and lifecycle testing of hydride compressor elements for the Planck sorption cryocooler SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB Continuous 20 K sorption-based coolers are being developed for the European Space Agency (ESA) Planck mission. Sorbent beds containing the hydrogen absorbing Lanthanum-Nickel-Tin alloy LaNi4.78Sn0.22 are being tested to evaluate their performance as compressor elements for unprecedented two years of flight operation thus demonstrating the basic performances of the cooler: namely cold end temperature, input power and cooling power. To provide basic characterization and life cycling data, a test facility was developed to test three prototype compressor elements under all conditions expected for the flight cooler operation. Each compressor element is continuously cycled in concentration and temperature to follow the absorption and desorption process assumed for the flight cooler. We present data on the hydrogen mass flow rates and thermal characteristics for all phases of the compressor cycle, with an emphasis on the controlled absorption of hydrogen. This function of the compressor element is the major driver of the cold end temperature and its stability. We also present data obtained over thousands of temperature cycles from these beds to determine the extent of degradation of the compressor element performance from changes in the hydride properties or other sources. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Pearson, D (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1209 EP 1216 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700149 ER PT S AU Sirbi, A Bowman, RC Wade, LA Barber, DS AF Sirbi, A Bowman, RC Wade, LA Barber, DS BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Cryogenic system design for a hydrogen sorption cooler SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB We present the design of a Hydrogen Sorption Cooler, part of the cryogenic chain in the Planck Mission (ESA). This cryocooler will provide continuous cooling at a nominal temperature about 18K for a period of about 2 years. Two independent astrophysical instruments will be supplied with a minimum cooling power of 0.135W for the High Frequency Instrument (HFI) and 0.967W for the Low Frequency Instrument (LFI) given a 60 K precooling temperature. Both instruments need highly stable temperatures (stability goal on the ground of 4 mK peak-to-peak). We show several designs for reaching this stability and also present laboratory test results. Gravitational effects on the thermal performance of the liquid reservoirs were determined by measuring behavior in all three orientations. No significant changes in reservoir temperatures were found. A local heater simulated the heat load on each reservoir. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sirbi, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1217 EP 1224 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700150 ER PT S AU Wade, LA Lindensmith, CA AF Wade, LA Lindensmith, CA BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Low-power, zero-vibration 5 K sorption coolers for astrophysics instruments SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB Many space missions now in development in Europe (e.g. Planck, Darwin) and the United States (e.g. SIRTF, NGST, TPF) will fly in orbits which enable passive cooling to <50 K. In such an environment it is possible to greatly reduce the cooling requirements of cryogenic instruments such as infrared cameras. Missions such as SIRTF serve as proof that such a strategy can be successfully implemented to hugely reduce the spacecraft resources required for instrument cooling. Three novel sorption cooler concepts are described in this paper. These coolers derive maximum benefit from passive radiative precooling. All coolers considered herein are sized to provide 2 mW of net refrigeration at 5 K and 10 mW at 16.5 K The concept designs, performance modeling and the development status of these coolers are described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wade, LA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 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 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1225 EP 1232 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700151 ER PT S AU Holmes, W Bamford, R Chui, TCP Craig, J Elliott, S Galloway, S Gannon, J Park, S Rentz, P Thomassen, J AF Holmes, W Bamford, R Chui, TCP Craig, J Elliott, S Galloway, S Gannon, J Park, S Rentz, P Thomassen, J BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI A cryogenic platform for space-borne instruments with nanoKelvin stability SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE ID HEAT-CAPACITY; HELIUM AB We describe the design and test of a modular probe structure to allow nK control of <8 kg space borne instruments operated at liquid helium temperatures for the Low Temperature Microgravity Physics Program. The probe consists of a 25.4 cm diameter plate on which is attached a 24.8cm high 3-stage truss. This assembly is inserted into an evacuated instrument space in a liquid helium cryostat. Germanium resistance thermometers with standard voltage readout and heater servo are used to control stages I and 2, the closest to the plate, to muK stability. Paramagnetic thermometers with DC SQUID readouts are used to control stage 3 to <1 nK. A room temperature random vibration test at 7.7 g(rms) verified that the probe supports a 6.2 kg mock instrument mounted on stage 3 under launch load for the Japanese HII-A rocket or the shuttle. The measured lateral stiffness is 1.8 MegaN/m. Thermal tests at T < 7 K show that for helium bath temperature drifts <0.1 K, stage 3 can be maintained within 1 nK of a set temperature. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Holmes, W (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1249 EP 1259 PG 11 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700154 ER PT S AU Bowman, RC Prina, M Schmelzel, ME Lindensmith, CA Barber, DS Bhandari, P Loc, A Morgante, G AF Bowman, RC Prina, M Schmelzel, ME Lindensmith, CA Barber, DS Bhandari, P Loc, A Morgante, G BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Performance, reliability and life issues for components of the Planck sorption cooler SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB Continuous-duty hydrogen sorption cryocoolers are being developed for the European Space Agency (ESA) Planck mission. To achieve an acceptable level of performance and robust operation with these hydride refrigerators during flight, detailed investigations have been performed on the sorbent materials and on critical hardware components. The sorbent longevity has been verified for both the compressor alloy and the gas gap actuator alloy. Check valves that isolate the high- and low-pressure sides within the sorption compressor are potential single-point failures as internal leaks would short circuit hydrogen flow to the Joule-Thomson (J-T) expander. Check valves were operated using hydrogen gas for over 43,000 pressure cycles at various orientations and temperatures without leaks or other changes. The filters that will be used to protect check valves and J-T expander from particles were tested. The temperature gradients along the tubular heater elements for the compressor beds were evaluated to assess their impact on the dynamics of compressor element heating and hydrogen desorption. The durability and reliability of low-power heaters used for the gas gap actuators were determined by accelerated temperature cycling. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bowman, RC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1260 EP 1267 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700155 ER PT S AU Flachbart, RH Hedayat, A Holt, KA AF Flachbart, RH Hedayat, A Holt, KA BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Modeling and test data analysis of a tank rapid chill and fill system for the Advanced Shuttle Upper Stage (ASUS) concept SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB The Advanced Shuttle Upper Stage (ASUS) concept addresses safety concerns associated with cryogenic stages by launching empty, and filling on ascent. The ASUS employs a rapid chill and fill concept, where a spray bar is used to completely chill the tank before fill. Thus the vent valve can be closed during the fill process. The first tests of this concept, using a flight size (not flight weight) tank, were conducted at Marshall Space Flight Center (MSFC) during the summer of 2000. The objectives of the testing were to: 1. Demonstrate that a flight size tank could be filled in roughly 5 minutes to accommodate the shuttle ascent window, 2. Demonstrate a no-vent fill of the tank, and 3. Gather data to validate analytical models. A total of fourteen tests were conducted. Models of the test facility fill and vent systems, as well as the tank, were constructed. The objective of achieving tank fill in 5 minutes was met during the test series. However, liquid began to accumulate in the tank before it was chilled. Since the tank was not chilled until the end of each test, vent valve closure during fill was not possible. Even though the chill and fill process did not occur as expected, reasonable model correlation with the test data was achieved. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Flachbart, RH (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 3 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1284 EP 1291 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700158 ER PT S AU Jones, JR Fesmire, JE AF Jones, JR Fesmire, JE BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Quick cooling and filling through a single port for cryogenic transfer operations SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB Improved technology for the efficient transfer of cryogens is needed for future on-orbit fueling and remote Lunar/Mars operations. The cooling and filling of a liquid nitrogen (LN2) test vessel through a single port were investigated in a series of experiments. A new "in-space" transfer tube design concept was used to demonstrate the ability to quickly cool and load cryocrens through a single feed-through connection. Three different fill tube configurations with three different diameters were tested. The tubes providing the quickest cooldown time and the quickest fill time for the test article tank were determined. The results demonstrated a clear trade-off between cooling time and filling time for the optimum tube design. This experimental study is intended to improve technology for future flight tank designs by reducing fill system size, complexity, heat leak rate, and operations time. These results may be applied to Space Shuttle Power Reactant Storage and Distribution (PRSD) System upgrades and other future applications. Further study and experimental analysis for optimization of the fill tube design are in progress. C1 NASA, Kennedy Space Ctr, FL 32899 USA. RP Jones, JR (reprint author), NASA, PH-G2, Kennedy Space Ctr, FL 32899 USA. NR 3 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1445 EP 1451 PG 7 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700178 ER PT S AU Fesmire, JE Augustynowicz, SD Demko, JA AF Fesmire, JE Augustynowicz, SD Demko, JA BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Thermal insulation performance of flexible piping for use in HTS power cables SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB High-temperature superconducting (HTS) cables that typically operate at temperatures below 80 kelvin (K) are being developed for power transmission. The practical application of HTS power cables will require the use of flexible piping to contain the cable and the liquid nitrogen coolant. A study of thermal performance of multilayer insulation (MLI) was conducted in geometries representing both rigid and flexible piping. This experimental study performed at the Cryogenics Test Laboratory of NASA Kennedy Space Center provides a framework for the development of cost-effective, efficient thermal insulation systems that will support these long-distance flexible lines containing HTS power cables. The overall thermal performance of the insulation system for a rigid configuration and for a flexible configuration, simulating a flexible HTS power cable, was determined by the steady-state liquid nitrogen boiloff method under the full range of vacuum levels. Two different cylindrically rolled material systems were tested: a standard MLI and a layered composite insulation (LCI). Comparisons of ideal MLI, MLI on rigid piping, and MLI between flexible piping are presented. C1 NASA, YAF2T, Kennedy Space Ctr, FL 32899 USA. RP Fesmire, JE (reprint author), NASA, YAF2T, Kennedy Space Ctr, FL 32899 USA. NR 8 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 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1525 EP 1532 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700188 ER PT S AU Fesmire, JE Augustynowicz, SD Demko, JA AF Fesmire, JE Augustynowicz, SD Demko, JA BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Overall thermal performance of flexible piping under simulated bending conditions SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB Flexible, vacuum-insulated transfer lines for low-temperature applications have higher thermal losses than comparable rigid lines. Typical flexible piping construction uses corrugated tubes, inner and outer, with a multilayer insulation (MLI) system in the annular space. Experiments on vacuum insulation systems in a flexible geometry were conducted at the Cryogenics Test Laboratory of NASA Kennedy Space Center. The effects of bending were simulated by causing the inner tube to be eccentric with the outer tube. The effects of spacers were simulated in a controlled way by inserting spacer tubes for the length of the cylindrical test articles. Two material systems, standard MLI and a layered composite insulation (LCI), were tested under the full range of vacuum levels using a liquid nitrogen boiloff calorimeter to determine the apparent thermal conductivity (k-value). The results indicate that the flexible piping under simulated bending conditions significantly degrades the thermal performance of the insulation system. These data are compared to standard MLI for both straight and flexible piping configurations. The definition of an overall k-value for actual field installations (k(oafi)) is described for use in design and analysis of cryogenic piping systems. C1 NASA, YAF2T, Kennedy Space Ctr, FL 32899 USA. RP Fesmire, JE (reprint author), NASA, YAF2T, Kennedy Space Ctr, FL 32899 USA. NR 6 TC 2 Z9 2 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 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1533 EP 1540 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700189 ER PT S AU Fesmire, JE Augustynowicz, SD Rouanet, S AF Fesmire, JE Augustynowicz, SD Rouanet, S BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Aerogel beads as cryogenic thermal insulation system SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB An investigation of the use of aerogel beads as thermal insulation for cryogenic applications was conducted at the Cryogenics Test Laboratory of NASA Kennedy Space Center. Steady-state liquid nitrogen boiloff methods were used to characterize the thermal performance of aerogel beads in comparison with conventional insulation products such as perlite powder and multilayer insulation (MLI). Aerogel beads produced by Cabot Corporation have a bulk density below 100 kilograms per cubic meter (kg/m(3)) and a mean particle diameter of 1 millimeter (mm). The apparent thermal conductivity values of the bulk material have been determined under steady-state conditions at boundary temperatures of approximately 293 and 77 kelvin (K) and at various cold vacuum pressures (CVP). Vacuum levels ranged from 10(-5) torr to 760 torr. All test articles were made in a cylindrical configuration with a typical insulation thickness of 25 mm. Temperature profiles through the thickness of the test specimens were also measured. The results showed the performance of the aerogel beads was significantly better than the conventional materials in both soft-vacuum (1 to 10 torr) and no-vacuum (760 torr) ranges. Opacified aerogel beads performed better than perlite powder under high-vacuum conditions. Further studies for material optimization and system application are in progress. C1 NASA, YAF2T, Kennedy Space Ctr, FL 32899 USA. RP Fesmire, JE (reprint author), NASA, YAF2T, Kennedy Space Ctr, FL 32899 USA. NR 5 TC 5 Z9 5 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 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1541 EP 1548 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700190 ER PT S AU Patterson, RL Hammoud, A Dickman, JE Gerber, S Elbuluk, ME Overton, E AF Patterson, RL Hammoud, A Dickman, JE Gerber, S Elbuluk, ME Overton, E BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Electronic components and systems for cryogenic space applications SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB Electronic components and systems capable of operation at cryogenic temperatures are anticipated in many future NASA space missions such as deep space probes and planetary surface exploration. For example, an unheated interplanetary probe launched to explore the rings of Saturn would reach an average temperature near Saturn of about -183 degreesC. In addition to surviving the deep space harsh environment, electronics capable of low temperature operation would contribute to improving circuit performance, increasing system efficiency, and reducing payload development and launch costs. Terrestrial applications where components and systems must operate in low temperature environments include cryogenic instrumentation, superconducting; magnetic energy storage, magnetic levitation transportation systems, and arctic exploration. An on-going R&D program at the NASA Glenn Research Center focuses on the development of reliable electronic devices and efficient power systems capable of surviving and operating in low temperature environments. An overview of the program will be presented in this paper. A description of the low temperature test facilities along with selected data obtained from in-house electronic component and small system testing will also be discussed. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Patterson, RL (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 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 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1585 EP 1591 PG 7 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700195 ER PT S AU Kopasakis, G Cairelli, JE Traylor, RM AF Kopasakis, G Cairelli, JE Traylor, RM BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Adaptive vibration reduction controls for a cryocooler with a passive balancer SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB In this paper an adaptive vibration reduction control (AVRC) design is described for a Stirling cryocooler combined with a passive balancer. The AVRC design was based on a mass-spring model of the cooler and balancer, and the AVRC algorithm described in this paper was based on an adaptive binary search. Results are shown comparing the baseline uncontrolled cooler with no balancer, the cooler with the balancer, and, finally, the cooler with the balancer and the AVRC. The comparison shows that it may be possible to meet stringent vibration reduction requirements without an active balancer. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Kopasakis, G (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1605 EP 1612 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700198 ER PT S AU Tuttle, JG DiPirro, MJ Canavan, ER Shirron, PJ Kunes, E Hait, TP AF Tuttle, JG DiPirro, MJ Canavan, ER Shirron, PJ Kunes, E Hait, TP BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI A miniature palladium-iron thermometer for temperatures down to 0.05 Kelvin SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE ID PDFE AB Magnetic thermometers are appealing at temperatures below about 0.1 Kelvin, because they avoid the noise self-heating problems associated with resistive thermometers. In particular, metallic magnetic thermometers add the advantages of chemical stability, high thermal conductivity, and ease in heat sinking. In this work we describe a palladium-iron thermometer which was designed to be small and conveniently packaged and optimized for use at temperatures down to 0.05 Kelvin. The device showed Curie-Weiss behavior above about 0.06 Kelvin, and we achieved 41 nK/rootHz temperature resolution at a temperature of 49 mK. We describe the design and operation of this thermometer and present the test results. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Tuttle, JG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 5 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 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1613 EP 1619 PG 7 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700199 ER PT S AU Paine, CG Bock, JJ Hristov, VV Lange, AE AF Paine, CG Bock, JJ Hristov, VV Lange, AE BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI A low noise, high thermal stability, 0.1 K test facility for the Planck HFI bolometers SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB We are developing a facility which will be used to characterize the bolometric detectors for Planck, an ESA mission to investigate the Cosmic Microwave Background. The bolometers operate at 0.1 K, employing neutron-transmutation doped (NTD) Ge thermistors with resistances of several megohms to achieve NEPs similar to1 x 10(-17) W HZ(-1/2). Characterization of the intrinsic noise of the bolometers at frequencies as low as 0.010 Hz dictates a test apparatus thermal stability of 40 nK Hz(-1/2) to that frequency. This temperature stability is achieved via a multi-stage isolation and control geometry with high resolution thermometry implemented with NTD Ge thermistors, JFET source followers, and dedicated lock-in amplifiers. The test facility accommodates 24 channels of differential signal readout, for measurement of bolometer V(I) characteristics and intrinsic noise. The test facility also provides for modulated radiation in the submillimeter band incident on the bolometers, for measurement of the optical speed-of-response; this illumination can be reduced below detectable limits without interrupting cryogenic operation. A commercial Oxford Instruments dilution refrigerator provides the cryogenic environment for the test facility. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Paine, CG (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 AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1651 EP 1658 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700204 ER PT S AU Mason, PV AF Mason, PV BE Breon, S DiPirro, M Glaister, D Hull, J Kittel, P Pecharsky, V Radebaugh, R Theilacker, J VanSciver, S Weisend, J Zeller, A TI Safety issues of space liquid-helium and solid-cryogen systems SO ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Joint Cryogenic Engineering Conference/International Cryogenic Materials Conference CY JUL 16-20, 2001 CL MADISON, WI SP Alliant Energy Corp, Univ Wisconsin Madison, Appl Superconduct Ctr, Argonne Natl Lab, Florida State Univ, Natl High Magnet Field Lab, Iowa State Univ, Los Alamos Natl Lab, Oak Ridge Natl Lab, Univ Wisconsin, Coll Engn, US DOE AB Safety of hardware and personnel is a major concern in space programs. Space cryogenic systems are particularly prone to risk because of their complexity and because of the potential for overpressurization resulting from blockage of vent paths during the integration and test process. A number of space flight programs with liquid-helium and solid-cryogen systems have had incidents which resulted in risk or actual damage to flight hardware, or in risk to personnel. Since such incidents typically occur late in the development cycle, costs due to delays are extremely high. A second major of area of risk is the use of cooling loops in solid cryogen systems. When cooling is performed, the cryogen contracts and cryogen from warmer locations vaporizes and is deposited in the voids. This can lead to rupture of tankage and plumbing. Risk reduction measures include two-fault tolerant design, systematic use of burst disks and relief valves, careful analysis of possible risks, detailed and well-reviewed procedures and redundancy of critical systems, such as valves and valve drive circuitry. We will discuss the design and operation of space cryogenics systems from a safety point of view. We will also describe a number of incidents, their causes, the corrective steps taken and lessons learned. C1 CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91125 USA. RP Mason, PV (reprint author), CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91125 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0059-8 J9 AIP CONF PROC PY 2002 VL 613 BP 1759 EP 1767 PG 9 WC Thermodynamics; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Engineering; Physics GA BU75R UT WOS:000176920700216 ER PT S AU Wuest, MP Lennartsson, W Craven, PD AF Wuest, MP Lennartsson, W Craven, PD BE Spence, H TI Response of the dawn-side, high-altitude, high-latitude magnetosphere to the arrival of an interplanetary shockwave SO ADVANCES IN GLOBAL MAGNETOSPHERIC STRUCTURE, DYNAMICS, AND REGION COUPLING, PROCEEDINGS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT D3 3 Symposium of COSPAR Scientific Commission D held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Amer Geophys Union, Amer Phys Soc, European Geophys Soc, Natl Ocean & Atmospher Adm, Comm Space Res ID GEOSYNCHRONOUS ORBIT; INSTRUMENT; TRACKING; MISSION AB We investigate in detail the magnetospheric response observed with instruments on the Polar spacecraft during the arrival of a shock wave on January 10, 1997 at 0 105 UT. Magnetic field increases have been observed in the solar wind, the magnetosheath, at the Polar location and on the ground. Particle density increases have been observed in the solar wind, the magnetosheath, but not at the position of the Polar spacecraft. Due to the compression of the magnetosphere we also would have expected a particle density increase, but in fact, a small particle density decrease was observed with low and medium energy particle instruments. The effect is attributed to an electric field pulse that convects downflowing particles onto another trajectory. Polar was located at that time at 8.4 Re, 6.1 MLT and 61.1 MLAT. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 SW Res Inst, San Antonio, TX 78228 USA. Lockheed Martin Adv Technol Ctr, Palo Alto, CA 94304 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35899 USA. RP Wuest, MP (reprint author), SW Res Inst, 6220 Culebra Rd, San Antonio, TX 78228 USA. NR 12 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 30 IS 10 BP 2189 EP 2194 AR PII S0273-1177(02)00686-5 DI 10.1016/S0273-1177(02)80218-6 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW04U UT WOS:000180725700005 ER PT S AU de Gonzalez, ALC Silbergleit, VM Gonzalez, WD Tsurutani, BT AF de Gonzalez, ALC Silbergleit, VM Gonzalez, WD Tsurutani, BT BE Spence, H TI Irregularities in the semiannual variation of the geomagnetic activity SO ADVANCES IN GLOBAL MAGNETOSPHERIC STRUCTURE, DYNAMICS, AND REGION COUPLING, PROCEEDINGS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT D3 3 Symposium of COSPAR Scientific Commission D held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Amer Geophys Union, Amer Phys Soc, European Geophys Soc, Natl Ocean & Atmospher Adm, Comm Space Res ID STORMS AB The annual distribution of geomagnetic activity is studied through the geomagnetic indices Aa, Dst and AE, according to different levels of intensity for each of the indices. It is shown that the well known pattern of seasonal variation, with maxima around the equinoxes and minima near the solstices, is typical for thresholds that correspond to moderate to fairly intense storms, but may be not too realistic for levels associated to the occurrence of very intense storms. In fact, the monthly number of days with Aa greater than or equal to 100 shows the possible existence of a peak in July. This occurrence seems to be evenly distributed along the 12 solar cycles covered by this index. The statistical analysis of the indices Dst and AE reinforce the hypothesis of the existence of this peak. These two indices seem also to indicate the presence of another peak in November in the annual distribution of very disturbed days. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 INPE, BR-12201970 Sao Jose Dos Campos, Brazil. UBA, Fac Ingn, Buenos Aires, DF, Argentina. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP de Gonzalez, ALC (reprint author), INPE, CP 515, BR-12201970 Sao Jose Dos Campos, Brazil. NR 12 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 10 BP 2215 EP 2218 AR PII S0273-1177(02)00690-7 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW04U UT WOS:000180725700009 ER PT S AU Fung, SF Benson, RF Green, JL Reinisch, BW Haines, DM Galkin, IA Bougeret, JL Manning, R Reiff, PH Carpenter, DL Gallagher, DL Taylor, WWL AF Fung, SF Benson, RF Green, JL Reinisch, BW Haines, DM Galkin, IA Bougeret, JL Manning, R Reiff, PH Carpenter, DL Gallagher, DL Taylor, WWL BE Spence, H TI Observations of magnetospheric plasmas by the radio plasma imager (RPI) on the image mission SO ADVANCES IN GLOBAL MAGNETOSPHERIC STRUCTURE, DYNAMICS, AND REGION COUPLING, PROCEEDINGS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT D3 3 Symposium of COSPAR Scientific Commission D held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Amer Geophys Union, Amer Phys Soc, European Geophys Soc, Natl Ocean & Atmospher Adm, Comm Space Res ID FEASIBILITY; SATELLITE AB The Imager for Magnetopause-to-Aurora Global Exploration satellite (IMAGE, see http://image.gsfc.nasa.gov), launched on March 25, 2000, is the first mission dedicated to observing the global-scale structure and dynamics of the magnetosphere. Remote-sensing instruments on IMAGE are designed to observe the magnetopause, ring current, plasmasphere, polar cusp, and the auroral region, in order to reveal the morphologies and interactions among these inter-connected regions. In particular, the RPI, a digital radio sounder with direction-finding capabilities, can transmit radio pulses from 3 kHz to 3 MHz (corresponding to plasma densities of 0.1-10(5) cm(-3)) to probe different magnetospheric plasmas. Using two 500-m tip-to-tip orthogonal dipole antennas in the spin plane and a 20-m tip-to-tip spin-axis dipole antenna, signals reflected at remote plasma regions are received as echoes. The RPI measures the echo amplitude, phase, range, polarization, Doppler shift, and angle of arrival as a function of sounding frequency. Advanced digital techniques allow echoes of low-power transmitted signals to be detected over magnetospheric distances. With a nominal 2-minute IMAGE spin period in a highly inclined (90degrees) elliptical orbit (apogee of 8 R-E), the RPI (with a nominal 1-min resolution) situated in the magnetospheric cavity observes the inner and outer magnetospheric boundaries. Its observations can reveal the electron density profiles and dynamics of key magnetospheric plasma regions. This paper highlights the science objectives of the RPI on IMAGE and presents some early RPI observations. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Massachusetts, Lowell, MA 01854 USA. CNRS, URA 264, DESPA, Observ Paris, F-92195 Meudon, France. Rice Univ, Houston, TX 77251 USA. Stanford Univ, Elect Engn Labs, Stanford, CA 94305 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35805 USA. Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. RP Fung, SF (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt Rd, Greenbelt, MD 20771 USA. RI Fung, Shing/F-5647-2012; Reiff, Patricia/D-2564-2014 OI Reiff, Patricia/0000-0002-8043-5682 NR 26 TC 7 Z9 7 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 10 BP 2259 EP 2266 AR PII S0273-1177(02)00697-X DI 10.1016/S0273-1177(02)80240-X PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW04U UT WOS:000180725700016 ER PT S AU Henize, VK Reiff, PH Reinisch, BW Fung, SF Green, JL Goldstein, J AF Henize, VK Reiff, PH Reinisch, BW Fung, SF Green, JL Goldstein, J BE Spence, H TI Magnetospheric cusp observations using the IMAGE satellite radio plasma imager SO ADVANCES IN GLOBAL MAGNETOSPHERIC STRUCTURE, DYNAMICS, AND REGION COUPLING, PROCEEDINGS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT D3 3 Symposium of COSPAR Scientific Commission D held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Amer Geophys Union, Amer Phys Soc, European Geophys Soc, Natl Ocean & Atmospher Adm, Comm Space Res ID MAGNETOPAUSE AB On March 25, 2000, the Imager for Magnetopause-to-Auroral Global Exploration (IMAGE) satellite mission was launched with the Radio Plasma Imager (RPI) radio sounder instrument onboard. Once deployed, the RPI began remote detection of regions of differing plasma densities via the reflection of transmitted radio waves. One of these regions is the magnetospheric polar cusp, which contains solar wind particles injected onto magnetospheric field lines by the process of dayside reconnection. Using data from the first month of RPI active sounding operation, a candidate cusp plasma echo return was analyzed to confirm that these signatures are in fact due to cusp plasmas. Associated in situ measurements also taken by the RPI instrument, as well as theoretical ray traces within an idealized model magnetosphere, strongly indicate that the RPI can and does remotely observe particle densities within the cusp region. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Rice Univ, Rice Space Inst, Houston, TX 77251 USA. Univ Massachusetts, Ctr Atmospher Res, Lowell, MA 01854 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Henize, VK (reprint author), Rice Univ, Rice Space Inst, MS 108,6100 S Main St, Houston, TX 77251 USA. RI Fung, Shing/F-5647-2012; Reiff, Patricia/D-2564-2014 OI Reiff, Patricia/0000-0002-8043-5682 NR 16 TC 0 Z9 0 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 10 BP 2267 EP 2272 AR PII S0273-1177(02)00698-1 DI 10.1016/S0273-1177(02)80242-3 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW04U UT WOS:000180725700017 ER PT S AU Gonzalez, WD Tsurutani, BT de Gonzalez, ALC AF Gonzalez, WD Tsurutani, BT de Gonzalez, ALC BE Spence, H TI Geomagnetic storms contrasted during solar maximum and near solar minimum SO ADVANCES IN GLOBAL MAGNETOSPHERIC STRUCTURE, DYNAMICS, AND REGION COUPLING, PROCEEDINGS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT D3 3 Symposium of COSPAR Scientific Commission D held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Amer Geophys Union, Amer Phys Soc, European Geophys Soc, Natl Ocean & Atmospher Adm, Comm Space Res ID MAGNETIC STORMS; INTERPLANETARY; ORIGIN AB Although considerable attention has been focused on CMEs/magnetic clouds and geomagnetic activity during solar maximum, very little effort has been expended towards understanding the effects of proto CIRs (Corotating Interaction Regions) during the descending phase of the solar cycle. We show that the three phases of magnetic storms (initial, main and recovery) associated to proto CIRs are considerably different than those during solar maximum. We also indicate that auroral activity can be significantly higher during the descending phase than during solar maximum. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 INPE, BR-12201970 Sao Jose Dos Campos, Brazil. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Gonzalez, WD (reprint author), INPE, CP 515, BR-12201970 Sao Jose Dos Campos, Brazil. NR 11 TC 5 Z9 5 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 10 BP 2301 EP 2304 AR PII S0273-1177(02)00703-2 DI 10.1016/S0273-1177(02)80252-6 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW04U UT WOS:000180725700022 ER PT S AU Tanskanen, E Koskinen, HEJ Pulkkinen, TI Slavin, JA Ogilvie, K AF Tanskanen, E Koskinen, HEJ Pulkkinen, TI Slavin, JA Ogilvie, K BE Spence, H TI Dissipation to the joule heating: Isolated and stormtime substorms SO ADVANCES IN GLOBAL MAGNETOSPHERIC STRUCTURE, DYNAMICS, AND REGION COUPLING, PROCEEDINGS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT D3 3 Symposium of COSPAR Scientific Commission D held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Amer Geophys Union, Amer Phys Soc, European Geophys Soc, Natl Ocean & Atmospher Adm, Comm Space Res ID MAGNETIC-FLUX TRANSFER; MAGNETOSPHERIC SUBSTORMS; WIND; TELL AB We discuss the energy input from the solar wind and its dissipation in the nightside ionosphere, as a form of Joule heating, during both isolated and storm-time substorms. The energy supplied to the magnetosphere by the solar wind is estimated by computing integrals of Akasofu's epsilon parameter determined from WIND satellite measumerents. The northern hemisphere Joule dissipation is estimated using the local electrojet index, IL, derived from the IMAGE magnetometer chain observations in the Scandinavian sector. The integrals of the epsilon parameters and the electrojet index are computed from the beginning of enhanced energy input (southward turning of the IMF) to the end of the recovery phase. The main difference between isolated and storm-time substorms is that while the total ionospheric dissipation of storm-time substorms is considerably larger, its relative role is smaller by a factor of two. As there are cases where the ratio between the input and output energies is much larger than in typical cases, we have computed the epsilon parameter also without the IMF X-component. Statistically this does not make large difference but in single events the input energy computed without the X-component can be only half of what the usual way of computing the epsilon parameter yields. We also note that in events where the input seems to remain small as compared to the output there may well have been considerable input prior to the selected start of integration, indicating that the magnetosphere may have stored energy longer than expected. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Finnish Meteorol Inst, Geophys Res, FIN-00101 Helsinki, Finland. Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Tanskanen, E (reprint author), Finnish Meteorol Inst, Geophys Res, POB 503, FIN-00101 Helsinki, Finland. RI Slavin, James/H-3170-2012; Pulkkinen, Tuija/D-8403-2012; Koskinen, Hannu/B-4971-2017 OI Slavin, James/0000-0002-9206-724X; Pulkkinen, Tuija/0000-0002-6317-381X; Koskinen, Hannu/0000-0003-3839-6461 NR 22 TC 4 Z9 4 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 30 IS 10 BP 2305 EP 2311 AR PII S0273-1177(02)00704-4 DI 10.1016/S0273-1177(02)80254-X PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW04U UT WOS:000180725700023 ER PT S AU Zilberstein, S Washington, R Bernstein, DS Mouaddib, AI AF Zilberstein, S Washington, R Bernstein, DS Mouaddib, AI BE Beetz, M Hertzberg, J Ghallab, M Pollack, ME TI Decision-theoretic control of planetary rovers SO ADVANCES IN PLAN-BASED CONTROL OF ROBOTIC AGENTS SE LECTURE NOTES IN ARTIFICIAL INTELLIGENCE LA English DT Article; Proceedings Paper CT Seminar on Plan-Based Control of Robotic Agents CY OCT 21-26, 2001 CL SCHLOSS DAGSTUHL, GERMANY AB Planetary rovers are small unmanned vehicles equipped with cameras and a variety of sensors used for scientific experiments. They must operate under tight constraints over such resources as operation time, power, storage capacity, and communication bandwidth. Moreover, the limited computational resources of the rover limit the complexity of on-line planning and scheduling. We describe two decision-theoretic approaches to maximize the productivity of planetary rovers: one based on adaptive planning and the other on hierarchical reinforcement learning. Both approaches map the problem into a Markov decision problem and attempt to solve a large part of the problem off-line, exploiting the structure of the plan and independence between plan components. We examine the advantages and limitations of these techniques and their scalability. C1 Univ Massachusetts, Dept Comp Sci, Amherst, MA 01003 USA. NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. Univ Caen, Lab GREYC, F-14032 Caen, France. RP Zilberstein, S (reprint author), Univ Massachusetts, Dept Comp Sci, Amherst, MA 01003 USA. NR 36 TC 10 Z9 10 U1 0 U2 2 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-00168-9 J9 LECT NOTES ARTIF INT PY 2002 VL 2466 BP 270 EP 289 PG 20 WC Automation & Control Systems; Computer Science, Artificial Intelligence SC Automation & Control Systems; Computer Science GA BW65P UT WOS:000182706200016 ER PT B AU Mazzarella, JM AF Mazzarella, JM CA NED Team BE Green, RF Khachikian, EY Sanders, DB TI Using the NASA/IPAC extragalactic database (NED) and federated virtual observatory archives for multiwavelength studies of AGNs SO AGN SURVEYS: IAU COLLOQUIUM 184 SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT IAU Colloquium on AGN Surveys CY JUN 18-22, 2001 CL BYURAKAN, ARMENIA SP Byurakan Astrophys Obser ID MAPS AB We live in an exciting era that offers increasing opportunities for people all over the world to make discoveries about the Universe using interconnected archives on the Internet as a primary research tool. We review how NED (http://ned.ipac.caltech.edu) can be used in concert with globally distributed online archives to perform multi-wavelength, cross-correlated studies of AGNs and other galaxy types. The present status and planned evolution of NED capabilities are discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Mazzarella, JM (reprint author), CALTECH, Jet Prop Lab, MS 100-22, Pasadena, CA 91125 USA. NR 5 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 1-58381-127-3 J9 ASTR SOC P PY 2002 VL 284 BP 379 EP 388 PG 10 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BW48A UT WOS:000182119900072 ER PT J AU Redinger, CF Levine, SP Blotzer, MJ Majewski, MP AF Redinger, CF Levine, SP Blotzer, MJ Majewski, MP TI Evaluation of an occupational health and safety management system performance measurement tool II: Scoring methods and field study sites SO AIHAJ LA English DT Article DE occupational health and safety management system; validation ID ASSESSMENT INSTRUMENT AB With the proliferation of occupational health and safety management systems (OHSMSs) in the 1990s, an assessment instrument was developed at the University of Michigan to measure a wide range of OHSMSs. Due to the range of systems it was designed to measure, the instrument is referred to as a universal assessment instrument (UAI). This article is part of a series of UAI-related articles and presents methods used in the UAI's initial field evaluation efforts. The UAI's measurement scale, case study methods, data management methods, and test site selection criteria are presented. Three test sites were selected from a pool of 15 that responded to a study solicitation. The case study methods, measurement scales, and data management system were found to be effective in performing the initial validation efforts. It is concluded that the qualitative methods used were effective in collecting the necessary information to further understand the complex nature of management system measurement. Companion articles address the actual evaluation assessment. C1 Redinger & Associates Inc, San Rafael, CA 94901 USA. Univ Michigan, Michigan State Univ, WHO Collaborating Ctr Occupat Hlth, Ann Arbor, MI 48109 USA. NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. Syva Corp, Cupertino, CA USA. Raychem Corp, Menlo Pk, CA 95014 USA. RP Redinger, CF (reprint author), Redinger & Associates Inc, 1537 4th St 248, San Rafael, CA 94901 USA. NR 22 TC 11 Z9 11 U1 0 U2 5 PU AMER INDUSTRIAL HYGIENE ASSOC PI FAIRFAX PA 2700 PROSPERITY AVE #250, FAIRFAX, VA 22031-4307 USA SN 1529-8663 J9 AIHAJ JI AIHAJ PD JAN-FEB PY 2002 VL 63 IS 1 BP 34 EP 40 DI 10.1202/0002-8894(2002)063<0034:EOAOHA>2.0.CO;2 PG 7 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA 519UA UT WOS:000173742800007 PM 11843423 ER PT J AU Redinger, CF Levine, SP Blotzer, MJ Majewski, MP AF Redinger, CF Levine, SP Blotzer, MJ Majewski, MP TI Evaluation of an occupational health and safety management system performance measurement tool - III: Measurement of initiation elements SO AIHAJ LA English DT Article DE occupational health and safety management system; universal assessment instrument AB With the proliferation of occupational health and safety management systems (OHSMS) in the 1990s, an assessment instrument was developed at the University of Michigan to measure a wide range of OHSMSs. Due to the range of systems it was designed to measure, the Instrument is referred to as a universal assessment instrument (UAI). Initial evaluation of the Instrument's first four sections is reported here. This study shows that the UAI's initiation measurement criteria and measurement scales could make distinctions between the OHS management systems at three test sites. This was particularly evident In the case in an organization in which a standards-based OHSMS was not implemented. In this case the UAI's two measurement scales-could distinguish between areas that were being developed (development scale) and areas that were in conformance with the measurement criteria (conformance scale). The score totals were consistent with the qualitative assessment using case study methods during field pilot testing; with the exception of Section 2.0, Employee Participation, in which scoring at one test site was not consistent with case study findings. It Is suggested that the variables/measures presented in the UAI's OHSMS Initiation organizing category may contain performance measures that may serve as key leading indicators of overall OHS performance. C1 Redinger & Associates Inc, San Rafael, CA 94901 USA. Univ Michigan, Michigan State Univ, WHO Collaborating Ctr Occupat Hlth, Ann Arbor, MI 48109 USA. NASA, John H Glenn Res Ctr, Cleveland, OH 44134 USA. Syva Corp, Cupertino, CA USA. Raychem Corp, Menlo Pk, CA 95014 USA. RP Redinger, CF (reprint author), Redinger & Associates Inc, 1537 4th St 248, San Rafael, CA 94901 USA. NR 11 TC 7 Z9 7 U1 0 U2 7 PU AMER INDUSTRIAL HYGIENE ASSOC PI FAIRFAX PA 2700 PROSPERITY AVE #250, FAIRFAX, VA 22031-4307 USA SN 1529-8663 J9 AIHAJ JI AIHAJ PD JAN-FEB PY 2002 VL 63 IS 1 BP 41 EP 46 DI 10.1202/0002-8894(2002)063<0041:EOAOHA>2.0.CO;2 PG 6 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA 519UA UT WOS:000173742800008 PM 11843425 ER PT S AU Meyer, AW Erickson, EF AF Meyer, AW Erickson, EF BE Melugin, RK Roser, HP TI Performance summaries for SOFIA science instruments SO AIRBORNE TELESCOPE SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Telescope Systems II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE AB SOFIA will permit observations from the visible to mm wavelengths, and offer higher spectral and spatial resolution than any other facility at some wavelengths. Nine focal-plane instruments are being developed to exploit this capability during the first several years of SOFIA operation. These instruments are being built at universities, at research institutes in Germany, and at NASA's Goddard Space Flight Center. The broad wavelength span of SOFIA implies a wide variety of Science Instrument characteristics, including detector technologies, spectral definition techniques, and science objectives. Here we summarize the performance of the nine instruments in relatively uniform format to facilitate evaluation of feasibility of desired observations. For each instrument, three basic aspects are described: (1) spectral resolution or passbands (2) sensitivity for emission lines and/or continuum (3) angular resolution Spectral resolution ranges from several hundred km/s down to 0.0 1 km/s; some of the instruments have several modes spanning several orders of magnitude within this range. Sensitivities for continuum and for emission line integrated fluxes are given in Janskies (Jy) and W/m(2) respectively, for specified integration time and S/N. For reference some Pogson magnitudes are also given at short (visible, near-IR) wavelengths, and some antenna temperature values are also given at sub-mm wavelengths. Angular resolution is expressed as the FWHM beam size in seconds of arc, as a function of wavelength. With this compilation of basic performance, any researcher may estimate the feasibility of potential observations with any of the first generation instruments. The performance summaries are available online at the SOFIA web site: http://SOFIA.arc.nasa.gov. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Meyer, AW (reprint author), NASA, Ames Res Ctr, M-S 144-2, Moffett Field, CA 94035 USA. NR 0 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 0-8194-4636-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4857 BP 1 EP 10 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW50B UT WOS:000182226000001 ER PT S AU Ames, TJ Case, L AF Ames, TJ Case, L BE Melugin, RK Roser, HP TI Distributed framework for dynamic telescope and instrument control SO AIRBORNE TELESCOPE SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Telescope Systems II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE DE astronomy; infrared astronomy; XML; instrument : description; telescope : control; SOFIA; NASA : GSFC; Java; IML AB Traditionally, instrument command and control systems have been developed specifically for a single instrument. Such solutions are frequently expensive and are inflexible to support the next instrument development effort. NASA Goddard Space Flight Center is developing an extensible framework, known as Instrument Remote Control (IRC) that applies to any kind of instrument that can be controlled by a computer. IRC combines the platform independent processing capabilities of Java with the power of the Extensible Markup Language (XML). A key aspect of the architecture is software that is driven by an instrument description, written using the Instrument Markup Language (IML). IML is an XML dialect used to describe graphical user interfaces to control and monitor the instrument, command sets and command formats, data streams, communication mechanisms, and data processing algorithms. The IRC framework provides the ability to communicate to components anywhere on a network using the JXTA protocol for dynamic discovery of distributed components. JXTA (see http://www.jxta.org) is a generalized protocol that allows any devices connected by a network to communicate in a peer-to-peer manner. IRC uses JXTA to advertise a device's IML and discover devices of interest on the network. Devices can join or leave the network and thus join or leave the instrument control environment of IRC. Currently, several astronomical instruments are working with the IRC development team to develop custom components for IRC to control their instruments. These instruments include: High resolution Airborne Wideband Camera (RAWC), a first light instrument for the Stratospheric Observatory for Infrared Astronomy (SOFIA); Submillimeter And Far Infrared Experiment (SAFIRE), a Principal Investigator instrument for SOFIA; and Fabry-Perot Interferometer Bolometer Research Experiment (FIBRE), a prototype of the SAFIRE instrument, used at the Caltech Submillimeter, Observatory (CSO). Most recently, we have been working with the Submillimetre High Angular Resolution Camera IInd Generation (SHARCII) at the CSO to investigate using IRC capabilities with the SHARC instrument. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ames, TJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 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 0-8194-4636-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4857 BP 73 EP 84 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW50B UT WOS:000182226000009 ER PT S AU Haas, MR AF Haas, MR BE Melugin, RK Roser, HP TI Optical design and diffraction analysis for AIRES: An Airborne InfraRed Echelle Spectometer SO AIRBORNE TELESCOPE SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Telescope Systems II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE DE diffraction; grating; infrared; optical design; SOFIA; spectrometer ID SPECTROMETER; SOFIA AB The optical design is presented for a long-slit grating spectrometer known as AIRES (Airborne InfraRed Echelle Spectrometer). The instrument employs two gratings in series: a small order sorter and a large steeply blazed echelle. The optical path includes four pupil and four field stops, including two narrow slits. A detailed diffraction analysis is performed using GLAD by Applied Optics Research to evaluate critical trade-offs between optical throughput, spectral resolution, and system weight and volume. The effects of slit width, slit length, oversizing the second slit relative to the first, on- vs off-axis throughput, and clipping at the pupil stops and other optical elements are discussed. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Haas, MR (reprint author), NASA, Ames Res Ctr, MS 245-6, 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 0-8194-4636-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4857 BP 85 EP 96 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW50B UT WOS:000182226000010 ER PT S AU Benford, DJ Moseley, SH Stacey, GJ Shafer, RA Staguhn, JG AF Benford, DJ Moseley, SH Stacey, GJ Shafer, RA Staguhn, JG BE Melugin, RK Roser, HP TI Far-Infrared imaging spectroscopy with SAFIRE on SOFIA SO AIRBORNE TELESCOPE SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Telescope Systems II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE DE bolometer array; transition edge sensor; superconducting multiplexer; SQUID multiplexer; SOFIA ID GALAXIES; HAWC AB The Submillimeter and Far-InfraRed Experiment (SAFIRE) on the SOFIA airborne observatory is an imaging Fabry-Perot spectrometer operating at wavelengths between 100 mum and 700 mum. SAFIRE's key science goal is to investigate line emission in galaxies at wavelengths not visible from the ground, and to map the variation in this line emission in nearby galaxies. SOFIA will fly at an altitude where the atmosphere is mostly transparent, permitting SAFIRE to achieve a high point source sensitivity at most wavelengths. With a field of view of 160"x320" at a spectral resolution of similar to200km/s, when SARRE achieved first light in 2006, it will add substantial capability to the first light instrument complement of SOFIA. SAFIRE's top priority observations will be to measure emission lines in the Galactic center, to map emission lines in nearby galaxies, and to understand the physics of the cores of ultraluminous galaxies from the local region to the high redshift universe through far-infrared fine-structure line emission. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Benford, DJ (reprint author), NASA, Goddard Space Flight Ctr, Code 685, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012; Moseley, Harvey/D-5069-2012 OI Benford, Dominic/0000-0002-9884-4206; 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 0-8194-4636-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4857 BP 105 EP 114 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW50B UT WOS:000182226000012 ER PT S AU Benford, DJ Voellmer, GM Chervenak, JA Irwin, KD Moseley, SH Shafer, RA Staguhn, JG AF Benford, DJ Voellmer, GM Chervenak, JA Irwin, KD Moseley, SH Shafer, RA Staguhn, JG BE Melugin, RK Roser, HP TI Design and fabrication of a two-dimensional superconducting bolometer array for SAFIRE SO AIRBORNE TELESCOPE SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Telescope Systems II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE DE bolometer array; transition edge sensor; superconducting multiplexer; SQUID. multiplexer; SOFIA AB The Submillimeter and Far-InfraRed Experiment (SAFIRE) on the SOFIA airborne observatory will employ a large-format, two-dimensional, close-packed bolometer array. SAFIRE is an imaging Fabry-Perot spectrometer operating at wavelengths between 100mum and 700mum. The array format is 1602 pixels, using a 32-element multiplexer developed in part for this instrument. The low backgrounds achieved in spectroscopy require very sensitive detectors with NEPs of order 10(-19) W/rootHz. An architecture which permits 512 pixels to be placed adjacent to each other in an area the size of a postage stamp, integrate them with multiplexers, and provide all the necessary wiring interconnections is a complex proposition, but can be achieved. Superconducting detectors can be close-packed using the Pop-Up Detector (PUD) format, and SQUID multiplexers operating at the detector base temperature can be intimately coupled to them. The result is a compact array, easily scalable to kilopixel arrays. We describe the PUD architecture, superconducting transition edge sensor bolometers we have manufactured and tested using the PUD architecture, and the electronics of SQUID multiplexed readouts. We show the design and assembly of the mechanical model of a 512-element bolometer array. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Benford, DJ (reprint author), NASA, Goddard Space Flight Ctr, Code 685, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012 OI Benford, Dominic/0000-0002-9884-4206 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 0-8194-4636-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4857 BP 125 EP 135 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW50B UT WOS:000182226000014 ER PT S AU Erickson, EF Young, ET Wolf, J Asbrock, JF Lum, NA AF Erickson, EF Young, ET Wolf, J Asbrock, JF Lum, NA BE Melugin, RK Roser, HP TI Specification and design of the SBRC 190: a cryogenic multiplexer for far-infrared photoconductor detectors SO AIRBORNE TELESCOPE SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Telescope Systems II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE DE infrared; astronomy; cryogenic; multiplexer; detector; photoconductor; SOFIA AB We describe the development of a cryogenic multiplexer for far-infrared (FIR) photoconductor detectors operating at moderate backgrounds. The device is called the SBRC 190. Its architecture and basic functions are based on the 1x32-channel CRC 696 CMOS device used on SIRTF. The SBRC 190 is designed to accommodate the higher backgrounds to be encountered on SOFIA and Herschel, to tolerates a wider range of backgrounds, to permit faster sampling, and to facilitate synchronization of sampling with chopping. Major design differences relative to the CRC 696 which have been incorporated in the SBRC 190 design are: (a) an AC coupled, capacitive feedback transimpedence unit cell, which minimizes input offset effects, thereby enabling low detector biases, (b) selectable feedback capacitors to enable operation over a wide range of backgrounds, and (c) clamp and sample-and-hold output circuits to improve sampling efficiency, which can be a concern at the relatively high readout rates required. A relationship between sampling efficiency and noise performance needed to achieve background-limited instrument performance (BLIP) is derived. Requirements for use on SOFIA, the basic circuit design, fabrication, and operation are discussed. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Erickson, EF (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. NR 10 TC 8 Z9 8 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4636-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4857 BP 136 EP 143 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW50B UT WOS:000182226000015 ER PT S AU Ennico, K Greene, T McCreight, C McKelvey, M McMurray, R Cripe, J AF Ennico, K Greene, T McCreight, C McKelvey, M McMurray, R Cripe, J BE Melugin, RK Roser, HP TI Development and testing of a 1024 x 1024 pixel Si : As IBC detector for SOFIA-like applications SO AIRBORNE TELESCOPE SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Telescope Systems II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE DE infrared; mid-infrared; detector; SOFIA; Explorers ID ARRAY; ASTRONOMY; ALADDIN AB Airborne and space telescope astronomical observations in the 5-25 micron wavelength region are critical for understanding the physical conditions, composition, chemistry, and excitation of many environments in the interstellar medium, external galaxies, solar system objects, extra-solar systems, and stars. The scientific impact is particularly unique in the 5-8 micron and 14-25 micron regions which are inaccessible or poorly observed from ground-based observatories. Large format mid-infrared detectors sensitive over these wavelengths and operable under moderate backgrounds (similar to10(6) photons/s/pixel at R=2000, at 10 microns) are essential for efficient large-area survey imaging and for taking moderate resolution spectra over a large spectral range. Both SOFIA and passively cooled Explorer observatories could benefit from this technology. Current first-light SOFIA instruments use small-format mid-infrared focal plane arrays of sizes 256 x 256 pixels. With the collaboration of Raytheon Infrared Operations, NASA-Ames Research Center has developed and tested the first 1024 x 1024 mid-infrared device suitable for operating under moderate backgrounds: a combination of the ALADDIN III readout multiplexer, cryo-processed for 6 K operation, with Si:As IBC detector material designed for high QE. This device has exhibited low dark current, moderate noise levels, and > 200,000 electron linear well size at 6 K operation. We conclude with suggestions for future device development for optimal performance under moderate background, SOFIA- and low Earth orbit-observing conditions. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Ennico, K (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI Ennico, Kimberly/L-9606-2014 NR 13 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 0-8194-4636-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4857 BP 155 EP 165 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW50B UT WOS:000182226000017 ER PT S AU Dotson, JL Koerber, C Mason, C Simpson, J Witteborn, F Witteborn, F Farhoomand, J Erickson, E AF Dotson, JL Koerber, C Mason, C Simpson, J Witteborn, F Witteborn, F Farhoomand, J Erickson, E BE Melugin, RK Roser, HP TI Performance of the SBRC 190, a cryogenic multiplexer for photoconductor arrays SO AIRBORNE TELESCOPE SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Telescope Systems II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE DE cryogenic multiplexers; far-infrared detectors; astronomical airborne instrumentation AB The SBRC 190 cryogenic readouts were developed for use in far-infrared arrays of Ge:Sb and Ge:Ga photoconductor detectors. The SBRC 190 provides an AC-coupled CTIA (capacitive trans-impedance amplifier) unit cell for each detector and multiplexes up to 32 detectors. This paper presents our test results characterizing and optimizing the performance of these novel devices. We discuss their basic behavior and investigate their performance in different clocking schemes. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Dotson, JL (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4636-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4857 BP 175 EP 182 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW50B UT WOS:000182226000019 ER PT S AU Silverberg, RF Aguirre, J Bezaire, J Cheng, ES Christensen, PR Cordone, S Cottingham, DA Crawford, T Fixsen, DJ Kenny, P Knox, L Kristensen, R Meyer, SS Norgaard-Nielsen, HU Timblec, PT Wilson, GW AF Silverberg, RF Aguirre, J Bezaire, J Cheng, ES Christensen, PR Cordone, S Cottingham, DA Crawford, T Fixsen, DJ Kenny, P Knox, L Kristensen, R Meyer, SS Norgaard-Nielsen, HU Timblec, PT Wilson, GW BE Melugin, RK Roser, HP TI The long duration flight of the TopHat experiment SO AIRBORNE TELESCOPE SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Telescope Systems II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE DE balloon; bolometer; cosmology; cryogenic; telescope ID MICROWAVE BACKGROUND ANISOTROPY; ANGULAR POWER SPECTRUM AB The TopHat instrument was designed to operate on the top of a high altitude balloon. From this location, the experiment could efficiently observe using a clean beam with extremely low contamination from the far side lobes of the instrument beam. The experiment was designed to scan a large portion of the sky directly above it and to map the anisotropy of the Cosmic Microwave Background (CMB) and thermal emission from galactic dust. The instrument used a one-meter class telescope with a five-band single pixel radiometer spanning the frequency range from 150-600 GHz. The radiometer used bolometric detectors operating at similar to250mK. Here, we report on the flight of the TopHat experiment over Antarctica in January, 2001 and describe the scientific goals, the operation, and in-flight performance. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Silverberg, RF (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, 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 0-8194-4636-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4857 BP 195 EP 203 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW50B UT WOS:000182226000021 ER PT S AU Davis, PK AF Davis, PK BE Melugin, RK Roser, HP TI SOFIA secondary mirror hindle test analysis SO AIRBORNE TELESCOPE SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Telescope Systems II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE DE SOFIA; Hindle test; secondary mirror; test analysis AB The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a NASA facility, nearing completion, consisting of an infrared telescope of 2.5 meter system aperture flying in a modified Boeing 747. It s Cassegrain secondary mirror has recently completed polishing. The SOFIA Project Office at Ames Research Center considered it important to perform an independent analysis of secondary mirror figure. The polishing was controlled by the standard test for a convex hyperboloid, the Hindle test, in a modified form with a meniscus lens partially reflecting on the concave face, rather than a fully reflecting mirror with a central hole. The spacing between this meniscus lens and the secondary mirror was controlled by three peripherally located spacing spheres. This necessitated special analysis to determine what the resulting curvature and conic constant of the mirror would be, if manufacturing imprecisions of the test set-up components were to be taken into account. This set-up was specially programmed, and the resulting hyperboloid calculated for the nominal case, and all extreme cases from the reported error limits on the manufacturing of the components. The results were then verified using the standard program CODE-V of Optical Research Associates. The conclusion is that the secondary mirror has a vertex radius of curvature of 954.05 min +-. 1 mm (design value: 954.13), and a conic constant of -1.2965 +- .001 (dimensionless, design value: -1.298). Such small divergences from design are to be expected, and these are within the refocusing ability of SOFIA, and would result in an acceptably small amount of spherical aberration in the image. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Davis, PK (reprint author), NASA, Ames Res Ctr, Mail Stop 244-30, Moffett Field, CA 94035 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4636-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4857 BP 286 EP 293 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW50B UT WOS:000182226000030 ER PT S AU Kunz, N AF Kunz, N BE Melugin, RK Roser, HP TI The SOFIA aircraft and its modification SO AIRBORNE TELESCOPE SYSTEMS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Airborne Telescope Systems II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE DE SOFIA; NASA; Astronomy; airborne telescope; aircraft; 747-SP ID TELESCOPE AB The primary focus of this paper is to describe the development of a highly modified aircraft that carries a twenty ton telescope to the stratosphere and then loiters at this desired altitude to act as the observatory platform and "dome". When the aircraft has reached its nominal cruise condition of Mach 0.84 in the stratosphere, a large cavity door opens (the dome opens), exposing a large portion of the interior of the fuselage that contains the telescope optics directly to the Universe. The topics covered in this paper include: tile relevant criteria and the evaluation process that resulted in tile selection of a Boeing 747-SP, the evolution of the design concept, the description of the structural modification including the analysis methods and tools, the aerodynamic issues associated with an open port cavity and how they were addressed, and the aero-loads/disturbances imparted to the telescope and how they were measured in the wind tunnel and extrapolated to full size. This paper is complementary to a previous paper(1) presented at the 2000 Airborne Telescope Systems conference which describes the challenges associated with the development of the SOFIA Telescope. For completeness, this paper also provides a brief overview of the SOFIA project including tile joint project arrangement between NASA and DLR, a top level overview of the requirements, and finally the current project status. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Kunz, N (reprint author), NASA, Ames Res Ctr, MS 244-30, Moffett Field, CA 94035 USA. NR 10 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 0-8194-4636-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4857 BP 333 EP 343 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BW50B UT WOS:000182226000035 ER PT S AU Sherwood, R Chien, S Castano, R Rabideau, G AF Sherwood, R Chien, S Castano, R Rabideau, G BE Mckay, B Slaney, J TI Autonomous planning and scheduling on the TechSat 21 mission SO AL 2002: ADVANCES IN ARTIFICIAL INTELLIGENCE SE Lecture Notes in Artificial Intelligence LA English DT Article; Proceedings Paper CT 15th Australian Joint Conference on Artificial Intelligence CY DEC 02-06, 2002 CL CANBERRA, AUSTRALIA AB The Autonomous Sciencecraft Experiment (ASE) will fly onboard the Air Force TechSat 21 constellation of three spacecraft scheduled for launch in 2006. ASE uses onboard continuous planning, robust task and goal-based execution, model-based mode identification and reconfiguration, and onboard machine learning and pattern recognition to radically increase science return by enabling intelligent downlink selection and autonomous retargeting. In this paper we discuss how these AI technologies are synergistically integrated in a hybrid multi-layer control architecture to enable a virtual spacecraft science agent. Demonstration of these capabilities in a flight environment will open up tremendous new opportunities in planetary science, space physics, and earth science that would be unreachable without this technology. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 15 TC 1 Z9 2 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-00197-2 J9 LECT NOTES ARTIF INT PY 2002 VL 2557 BP 213 EP 224 PG 12 WC Computer Science, Artificial Intelligence SC Computer Science GA BW18A UT WOS:000181083100019 ER PT S AU Kiang, RK AF Kiang, RK BE Shen, SS Lewis, PE TI Utilizing spatial features in classifying high-resolution imagery data SO ALGORITHMS AND TECHNOLOGIES FOR MULTISPECTRAL, HYPERSPECTRAL, AND ULTRASPECTRAL IMAGERY VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery VIII CY APR 01-04, 2002 CL ORLANDO, FL SP SPIE DE spatial; textural; contextual; Ikonos; wavelet transform ID REMOTE-SENSING DATA; CONTEXTUAL CLASSIFICATION; TEXTURE MEASURES AB The spatial resolution of spaceborne instrument has increased substantially in the three decades since Landsat-1 was launched. Higher spatial resolution has made some applications possible. But it has also brought about new challenges in ground cover classification. At a resolution around 1 meter, vegetation often displays distinct textures. Hence texture may make differentiation among some cover types possible. Ikonos panchromatic and multispectral data are used to examine how spatial features improve classification accuracy. In this study, textural features are extracted from co-occurrence matrices, contextual features are derived from neighborhood properties, and maximum likelihood method is used for classifications. It is shown that for the test data both types of spatial features, and especially the contextual measures, can significantly improve the classification accuracies. Discrete wavelet transform is used to extract textural features for two types of vegetation. Transformed divergence, a measure of separability, is shown much enhanced when textural features are included. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kiang, RK (reprint author), NASA, Goddard Space Flight Ctr, Code 902, Greenbelt, MD 20771 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4475-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4725 BP 267 EP 274 DI 10.1117/12.478759 PG 8 WC Engineering, Electrical & Electronic; Remote Sensing; Optics; Spectroscopy SC Engineering; Remote Sensing; Optics; Spectroscopy GA BV33B UT WOS:000178612100027 ER PT S AU Pedelty, JA Morisette, JT Smith, JA AF Pedelty, JA Morisette, JT Smith, JA BE Shen, SS Lewis, PE TI A comparison of Landsat-7 ETM+ and EO-1 ALI images over Rochester, NY SO ALGORITHMS AND TECHNOLOGIES FOR MULTISPECTRAL, HYPERSPECTRAL, AND ULTRASPECTRAL IMAGERY VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery VIII CY APR 01-04, 2002 CL ORLANDO, FL SP SPIE DE EO-1; ALI; Hyperion; Landsat-7; ETM; atmospheric correction; reflectance ID SCATTERING; NETWORK; MODEL AB We present a comparison of images from the ETM+ sensor on Landsat-7 and the ALI instrument on EO-I over a test site in Rochester, NY. The site contains a variety of features, ranging from water of varying depths, deciduous/coniferous forest, grass fields, to urban areas. The nearly coincident cloud-free images were collected just one minute apart on 25 August, 2001. We atmospherically corrected each image with the 6S atmosphere model, using aerosol optical thickness and water vapor column density measured by a Cimel sun photometer within the Aerosol Robotic Network (Aeronet), along with ozone density derived from NCEP data. We present three-color composites from each instrument that show excellent qualitative agreement. We present ETM+ and ALI reflectance spectra for water, grass, and urban targets. We make a more detailed comparison for our forest site, where we use measured geometric and optical properties as input to the SAIL canopy reflectance model, which we compare to the ETM+, ALI, and EO-1 Hyperion reflectance spectra. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Pedelty, JA (reprint author), NASA, Goddard Space Flight Ctr, Code 923, Greenbelt, MD 20771 USA. NR 11 TC 0 Z9 0 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 0-8194-4475-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4725 BP 357 EP 365 DI 10.1117/12.478768 PG 9 WC Engineering, Electrical & Electronic; Remote Sensing; Optics; Spectroscopy SC Engineering; Remote Sensing; Optics; Spectroscopy GA BV33B UT WOS:000178612100035 ER PT S AU Cairns, B Carlson, BE Ying, R Laveigne, J AF Cairns, B Carlson, BE Ying, R Laveigne, J BE Shen, SS Lewis, PE TI Accuracy vs Speed: Evaluation of tradeoffs in atmospheric correction methods SO ALGORITHMS AND TECHNOLOGIES FOR MULTISPECTRAL, HYPERSPECTRAL, AND ULTRASPECTRAL IMAGERY VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery VIII CY APR 01-04, 2002 CL ORLANDO, FL SP SPIE DE atmospheric correction; multiple scattering ID MULTIPLE-SCATTERING; ABSORPTION; LIGHT AB In this paper tradeoffs between speed and accuracy for the atmospheric correction of hyperspectral imagery are examined. Among the issues addressed are: the use of scattering calculations on a sparse spectral grid and consequent accuracy and speed tradeoffs; methods for minimizing the required number of quadrature points in multiple scattering calculations; effects of the vertical profiles of aerosols and absorbing gases on atmospheric correction; and efficient approaches for including the effects of sensor variability, or imperfections, on atmospheric correction. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Cairns, B (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. RI Carlson, Barbara/D-8319-2012; OI Cairns, Brian/0000-0002-1980-1022 NR 18 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4475-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4725 BP 427 EP 437 DI 10.1117/12.478776 PG 11 WC Engineering, Electrical & Electronic; Remote Sensing; Optics; Spectroscopy SC Engineering; Remote Sensing; Optics; Spectroscopy GA BV33B UT WOS:000178612100042 ER PT S AU Domack, MS Dicus, DL AF Domack, MS Dicus, DL BE Gregson, PJ Harris, SJ TI Evaluation of Sc-bearing aluminum alloy C557 for aerospace applications SO ALUMINUM ALLOYS 2002: THEIR PHYSICAL AND MECHANICAL PROPERTIES PTS 1-3 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 8th International Conference on Aluminium Alloys CY JUL 02-05, 2002 CL CAMBRIDGE, ENGLAND SP Alcon Int, Alcoa Europe, Hydro Aluminium, Univ Cambridge, Qinetiq, Univ Southampton, Univ Nottingham DE Al-Mg-Sc alloys; C557; tensile; fracture toughness; thermal exposure ID MECHANICAL-PROPERTIES; FRACTURE-TOUGHNESS AB The performance of the Al-Mg-Sc alloy C557 was evaluated to assess its potential for a broad range of aerospace applications, including airframe and launch vehicle structures. Of specific interest were mechanical properties at anticipated service temperatures and thermal stability of the alloy. Performance was compared with conventional airframe aluminum alloys and with other emerging aluminum alloys developed for specific service environments. Mechanical properties and metallurgical structure were evaluated for commercially rolled sheet in the as-received H116 condition and after thermal exposures at 107degreesC. Metallurgical analyses were performed to define grain morphology and texture, strengthening precipitates, and to assess the effect of thermal exposure. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Domack, MS (reprint author), NASA, Langley Res Ctr, Mail Stop 188A, Hampton, VA 23681 USA. NR 7 TC 5 Z9 7 U1 0 U2 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2002 VL 396-4 BP 839 EP 844 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BU80A UT WOS:000177030500135 ER PT S AU Hall, DK Kelly, REJ Riggs, GA Chang, ATC Foster, JL AF Hall, DK Kelly, REJ Riggs, GA Chang, ATC Foster, JL BE Winther, JG Solberg, R TI Assessment of the relative accuracy of hemispheric-scale snow-cover maps SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID VARIABILITY AB There are several hemispheric-scale satellite-derived snow-cover maps available, but none has been fully validated. For the period 23 October-25 December 2000, we compare snow maps of North America derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and operational snow maps from the U.S. National Oceanic and Atmospheric Administration (NOAA) National Operational Hydrologic Remote Sensing Center (NOHRSC), both of which rely on satellite data from the visible and near-infrared parts of the spectrum; we also compare MODIS maps with Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) passive-microwave snow maps for the same period. The maps derived from visible and near-infrared data are more accurate for mapping snow cover than are the passive-microwave-derived maps, but discrepancies exist as to the location and extent of the snow cover even between operational snow maps. The MODIS snow-cover maps show more snow in each of the 8 day periods than do the NOHRSC maps, in part because MODIS maps the effects of fleeting snowstorms due to its frequent coverage. The large (similar to30 km) footprint of the SSM/I pixel, and the difficulty in distinguishing wet and shallow snow from wet or snow-free ground, reveal differences up to 5.33 X 10 km in the amount of snow mapped using MODIS vs SSM/I data. Algorithms that utilize both visible and passive-microwave data, which would take advantage of the all-weather mapping capability of the passive-microwave data, will be refined following the launch of the Advanced Microwave Scanning Radiometer (AMSR) in the fall of 2001. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Hall, DK (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Code 974, Greenbelt, MD 20771 USA. RI Hall, Dorothy/D-5562-2012 NR 21 TC 45 Z9 47 U1 2 U2 10 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 24 EP 30 DI 10.3189/172756402781817770 PG 7 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100004 ER PT S AU Green, RO Dozier, J Roberts, D Painter, T AF Green, RO Dozier, J Roberts, D Painter, T BE Winther, JG Solberg, R TI Spectral snow-reflectance models for grain-size and liquid-water fraction in melting snow for the solar-reflected spectrum SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID OPTICAL-PROPERTIES; AVIRIS DATA; SCATTERING; ALGORITHMS; ALBEDO AB Two spectral snow-reflectance models that account for the effects of grain-size and liquid-water fraction are described and initial validation results presented. The models are based upon the spectral complex refractive index of liquid water and ice in the region from 400 to 2500 nm. Mie scattering calculations are used to specify the essential optical properties of snow in the models. Two approaches are explored to model the effect of liquid water in the snow. The first accounts for the liquid water as separate spheres interspersed with ice spheres in the snow layer. The second accounts for the liquid water as coatings on ice grains in the snow layer. A discrete-ordinate radiative transfer code is used to model the spectral reflectance of the snow for the Mie-calculated optical properties. Both the interspersed- and coated-sphere models show that the snow-absorption feature at 1030 urn shifts to shorter wavelength as the liquid-water content increased. The expression of these shifts is different for the two models. A comparison of the models with a spectral measurement of frozen and melting snow shows better agreement with the coated-sphere model. A spectral fitting algorithm was developed and tested with the coated-sphere model to derive the grain-size and liquid-water fraction from snow spectral reflectance measurements. Consistent values of grain-size and liquid water were retrieved from the measured snow spectra. This research demonstrates the use of spectral models and spectral measurements to derive surface snow grain-size and liquid-water fraction. The results of this research may be extended to regional and greater scales using data acquired by airborne and spaceborne imaging spectrometers for contributions to energy balance and hydrological modeling. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. RP Green, RO (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Dozier, Jeff/B-7364-2009; Painter, Thomas/B-7806-2016 OI Dozier, Jeff/0000-0001-8542-431X; NR 12 TC 28 Z9 33 U1 2 U2 23 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 71 EP 73 DI 10.3189/172756402781817987 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100011 ER PT S AU Das, SB Alley, RB Reusch, DB Shuman, CA AF Das, SB Alley, RB Reusch, DB Shuman, CA BE Winther, JG Solberg, R TI Temperature variability at Siple Dome, West Antarctica, derived from ECMWF re-analyses, SSM/I and SMMR brightness temperatures and AWS records SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID GREENLAND ICE-SHEET; INTERANNUAL VARIATIONS; SOUTHERN OSCILLATION; MICROWAVE EMISSION; DEPTH HOAR; IN-SITU; SNOW; SATELLITE; CLIMATE; TRENDS AB We produced four independent temperature time series derived from different sensors for the Siple Dome region of West Antarctica to investigate seasonal to interannual temperature variability over the last 20 vears. We use clata f'oni atitornati weather station air-temperature records (1997-99), European Centre for Medium-range Weather Forecasts surface temperature from the 15 year re-analyses (ERA-15, 1979-93) and emissivity-corrected brightness temperatures front the Special Sensor Microwave/ Imager (1987-99) and the Scanning Multichannel Microwave Radiometer (1978-87). Each technique has limitations and errors, but all respond to temperature, and all agree in the large patterns of temperature variability over time. Our results show that there is high seasonal to interannual variability in both mean temperature and variance in the Siple Dome region during the study period. In particular, fluctuations in seasonal to interannual temperature variance occur on an approximately 5 year cycle and correlate with variations in the Southern Oscillation Index. C1 Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. Penn State Univ, Inst Environm, University Pk, PA 16802 USA. NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. RP Das, SB (reprint author), Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. NR 38 TC 6 Z9 6 U1 0 U2 1 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 106 EP 112 DI 10.3189/172756402781817699 PG 7 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100017 ER PT S AU Shuman, CA Comiso, JC AF Shuman, CA Comiso, JC BE Winther, JG Solberg, R TI In situ and satellite surface temperature records in Antarctica SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID GREENLAND ICE-SHEET; VARIABILITY; PENINSULA; CLIMATE; EXTENT; TRENDS AB Air-temperature records (T-A) during 1992 from five inland Antarctic automatic weather station (AWS) sites were compared with the best available infrared temperatures (T-IR) from the Advanced Very High Resolution Radiometer (AVHRR) as well its calibrated passive-microwave temperatures (T-C) from the Special Sensor Microwave/Imager (SSM/I). Daily and monthly average T-A, T-IR, and T-C data indicate that each approach captures generally similar trends at each site but each approach also has limitations. AWS T-A data are considered the most accurate but represent spatially restricted areas and may have long gaps due to sensor or transmission problems. AVHRR T-IR data have daily variability similar to the T-A record but have numerous small gaps due to Cloud cover or observation interruptions. An offset between T-A and T-IR, (>4 K) at the South Pole site was identified that may be due to the inclusion of data with large satellite scan angles necessary to cover this area. SSM/I T-C data have the most continuity but exhibit calibrat- ion problems, a significantly damped daily response and do not cover all of Antarctica. Individual daily differences between T-A and T-IR as well as T-A and T-C can exceed 17 K, but all sites have mean daily differences of about 1 K or better, after compensating for the offset at South Pole, and standard deviations of < 6 K. Monthly temperature differences are typically 5 K or better, with standard deviations generally < 3 K. And finally, using the available data, the 1992 average temperature differences are < 1 K. C1 Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Oceans & Ice Branch, Greenbelt, MD 20771 USA. RP Shuman, CA (reprint author), Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. NR 18 TC 10 Z9 10 U1 1 U2 5 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 113 EP 120 DI 10.3189/172756402781818003 PG 8 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100018 ER PT S AU Fahnestock, MA Abdalati, W Shuman, CA AF Fahnestock, MA Abdalati, W Shuman, CA BE Winther, JG Solberg, R TI Long melt seasons on ice shelves of the Antarctic Peninsula: an analysis using satellite-based microwave emission measurements SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID BREAK-UP; SHEET; RETREAT; COLLAPSE AB We have examined the record of melt-season duration on the Antarctic Peninsula using two techniques for detecting the presence of a melt signal in microwave-emission time series covering the period 1978-2000. We have obtained similar estimates of melt-season length using the cross-polarized gradient ratio (XPGR) technique and calibrations previously applied in Greenland and a technique which detects the jump In emission caused by melt without using a sensor- and frequency-dependent threshold value. The close correspondence between results from the two techniques on peninsula ice shelves suggests that the XPGR analysis can be used over the length of the time series. The results show that the long melt seasons of 1992/93 and several later years were exceptional occurrences on the northern parts of the Larsen Ice Shelf These melt seasons were followed by disintegration events, supporting a possible cause-and-effect relationship. C1 Univ Maryland, Earth Syst Studies Interdisciplinary Ctr, College Pk, MD 20742 USA. NASA Headquarters, Washington, DC 20546 USA. RP Fahnestock, MA (reprint author), Univ Maryland, Earth Syst Studies Interdisciplinary Ctr, College Pk, MD 20742 USA. RI Fahnestock, Mark/N-2678-2013 NR 19 TC 29 Z9 31 U1 0 U2 10 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 127 EP 133 DI 10.3189/172756402781817798 PG 7 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100020 ER PT S AU Bardel, P Fountain, AG Hall, DK Kwok, R AF Bardel, P Fountain, AG Hall, DK Kwok, R BE Winther, JG Solberg, R TI Synthetic aperture radar detection of the snowline on Commonwealth and Howard Glaciers, Taylor Valley, Antarctica SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID GREENLAND ICE-SHEET AB Synthetic aperture radar (SAR) images of Taylor Valley, Antarctica, were acquired in January 1999 in coordination with ground-based measurements to assess SAR detection of the snowline on dry polar glaciers. We expected significant penetration of the radar wave resulting in all offset of the SAR-detected snowline relative to the true snowline. Results indicated no detectable displacement of the SAR snowline. Snow depths of 15 cm over ice can be detected on the imagery. We hypothesize that the optical depth of thin snowpacks is enhanced by reflection and refraction of the radar beam by internal snow layers. The enhanced optical depth increases the volume scattering, and thereby enhances backscatter sufficiently to be detected by the SAR. Consequently, SAR imagery may be used directly to image the position of transient snowlines in dry polar regions. C1 Portland State Univ, Dept Geog, Portland, OR 97207 USA. Portland State Univ, Dept Geol, Portland, OR 97207 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bardel, P (reprint author), Portland State Univ, Dept Geog, Portland, OR 97207 USA. RI Kwok, Ron/A-9762-2008; Hall, Dorothy/D-5562-2012 OI Kwok, Ron/0000-0003-4051-5896; NR 28 TC 2 Z9 3 U1 0 U2 4 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 177 EP 183 DI 10.3189/172756402781818021 PG 7 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100027 ER PT S AU Rignot, E Vaughan, DG Schmeltz, M Dupont, T MacAyeal, D AF Rignot, E Vaughan, DG Schmeltz, M Dupont, T MacAyeal, D BE Winther, JG Solberg, R TI Acceleration of Pine Island and Thwaites Glaciers, West Antarctica SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID ICE-SHEET; RADAR INTERFEROMETRY; MASS-BALANCE; MODEL AB Recent satellite investigations revealed that in the 1990s the grounding line of Pine Island and Thwaites Glaciers, West Antarctica, retreated several kin, the Ice surface on the interior of the basins lowered 10 cm a(-1), and Pine Island Glacier thinned 1.6 m a(-1). These observations, however, were not sufficient to determine the cause of the changes. Here, we present satellite radar interferometry data that show the thinning and retreat of Pine Island Glacier are caused by an acceleration of ice flow of about 18 +/- 2% in 8 years. Thwaites Glacier maintained a nearly constant flow regime at its center, but widened along the sides, and increased its 30 +/- 15% mass deficit by another 4% in 4 years. The combined mass loss from both glaciers, if correct, contributes an estimated 0.08 +/- 0.03 mm a(-1) global sea-level rise in 2000. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. British Antarctic Survey, NERC, Cambridge CB3 0ET, England. Penn State Univ, University Pk, PA 16802 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. RP Rignot, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Vaughan, David/C-8348-2011; Rignot, Eric/A-4560-2014; OI Rignot, Eric/0000-0002-3366-0481; MacAyeal, Douglas/0000-0003-0647-6176 NR 22 TC 103 Z9 105 U1 1 U2 14 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 189 EP 194 DI 10.3189/172756402781817950 PG 6 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100029 ER PT S AU Joughin, I AF Joughin, I BE Winther, JG Solberg, R TI Ice-sheet velocity mapping: a combined interferometric and speckle-tracking approach SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE Annals of Glaciology-Series LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MD SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID SATELLITE RADAR INTERFEROMETRY; FLOW; GREENLAND; MOTION AB The first and second RADARSAT Antarctic Mapping Missions (AMM-1 and -2) have now acquired interferometric synthetic aperture radar (SAR) over much of the ice sheet. The RADARSAT 24 day repeat cycle is nearly ideal for measuring slow ice motion (e.g. < 100 m a(-1)), but application of SAR interferometry is limited in Easter-moving areas. With a 1 day, repeat period, ERS-1/-2 tandem SAR data are much better matched to fast motion, but are not always available. Fortunately, several authors have demonstrated the ability to measure velocity in fast-moving areas by tracking SAR speckle from image to image, which works well even in the absence of visible features. While these estimates have intrinsically lower resolution and poorer accuracy than direct phase measurements, they serve well in areas where there are no data suitable for conventional interferometry. This paper describes algorithms I have developed for merging interferometric and speckle-tracking data from multiple swaths to form a single seamless mosaic of velocity At each point in the mosaic, all the available data are combined to produce estimates of the velocity and the associated error. This technique is demonstrated using RADARSAT data collected over Lambert Glacier, Antarctica, during AMM-1 and -2. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Joughin, I (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Joughin, Ian/A-2998-2008 OI Joughin, Ian/0000-0001-6229-679X NR 16 TC 110 Z9 115 U1 3 U2 20 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL-SER PY 2002 VL 34 BP 195 EP 201 DI 10.3189/172756402781817978 PG 7 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100030 ER PT S AU Schmeltz, M Rignot, E MacAyeal, D AF Schmeltz, M Rignot, E MacAyeal, D BE Winther, JG Solberg, R TI Tidal flexure along ice-sheet margins: comparison of InSAR with an elastic-plate model SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID SATELLITE-RADAR INTERFEROMETRY; HINGE-LINE MIGRATION; PETERMANN-GLETSCHER; GROUNDING LINES; ANTARCTICA; GREENLAND; GLACIER; STREAM; MOTION AB We compare interferometric synthetic aperture radar (InSAR) observations of tidal flexure on Antarctic and Greenland glaciers with a finite-element model simulation of tidal flexure oil all elastic Plate of rice. The results show that the elastic-plate model is able to reproduce with good fidelity the pattern of tidal flexure observed with InSAR. In the case of David Glacier, Antarctica, the model provides independent confirmation of its grounding-line position and usual pattern of tidal flexure. A detailed analysis of temporal changes in tidal flexing on Petermann Gletscher, Greenland, and Pule Island Glacier, West Antarctica.. however, reveals that Young's elastic Modulus of ice, E. employed in the simulations to match observations, needs to vary between 0.8 and 3.5 GPa. This time dependence of E is attributed to visco-plastic effects, not to a migration of the grounding line with tide, or measurement errors. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 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 28 TC 14 Z9 14 U1 2 U2 7 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 202 EP 208 DI 10.3189/172756402781818049 PG 7 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100031 ER PT S AU Rignot, E AF Rignot, E BE Winther, JG Solberg, R TI Mass balance of East Antarctic glaciers and ice shelves from satellite data SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID RADAR INTERFEROMETRY; SHEET; GREENLAND; SYSTEM; FLOW; DISCHARGE; IMAGERY AB The velocity and mass discharge of nine major East Antarctic glaciers not draining, into the Ross or Filchner-Ronne Ice Shelves is investigated using interferometric synthetic aperture radar (InSAR) data from the European Remote-sensing Satellite I and 2 (ERS-1/2) and RADARSAT-1. The glaciers are: David, Ninnis, Mertz, Totten, Scott, Denman, Lambert, Shirase and Stancomb-Wills. InSAR IS used to locate then grounding line with precision. Ice velocity is measured with either InSAR or a speckle-tracking technique. Ice thickness is deduced from prior-determined ice-shelf elevation assuming hydrostatic equilibrium Mass fluxes are calculated both at the grounding line and at a flux gate located downstream. The grounding-line flux is compared to a mass input calculated from snow accumulation to deduce the glacier mass balance. The calculation is repeated at the flux gate downstream of the grounding line to estimate the average bottom melt rate of the ice Shelf under steady-state conditions. The main results arc: (1) Grounding lines are found several tells of km upstream of prior-identified positions, not because of a recent ice-sheet retreat but because of the inadequacy of prior-determined grounding-line positions. (2) No gross imbalance between outflow and inflow is detected oil the little glaciers being investigated gated, with an uncertainty of 10-20%. Prior-determined, largely positive mass imbalances were due to all incorrect localization of the grounding line. (3) High rates of bot torn melting (24 +/- 7 in Ice a(-1)) are inferred near grounding zones, where ice reaches the deepest draft. A few glaciers exhibit lower bottom inch, rates (4 +/- 7 in ice a(-1)). Bottom melting, however, appears to be a major source of mass loss oil Antarctic ice shelves. 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 58 Z9 60 U1 1 U2 19 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 217 EP 227 DI 10.3189/172756402781817419 PG 11 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100033 ER PT S AU Zwally, HJ Beckley, MA Brenner, AC Giovinetto, MB AF Zwally, HJ Beckley, MA Brenner, AC Giovinetto, MB BE Winther, JG Solberg, R TI Motion of major ice-shelf fronts in Antarctica from slant-range analysis of radar altimeter data, 1978-98 SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID MASS-BALANCE; SHEET AB Slant-range analysis of radar altimeter data from the Seasat, Geosat and European Remote-sensing Satellite (ERS-1 and -2) databases is used to determine barrier location at particular times, and estimate barrier motion (km a(-1)) for major Antarctic ice shelves. The analysis covers various multi-year intervals from 1978 to 1998, supplemented by barrier location maps produced elsewhere for 1977 and 1986. Barrier motion is estimated as the ratio between mean annual ice-shelf area change for a particular interval, and the length of the discharge periphery. This value is positive if the barrier location progresses seaward, or negative if the barrier location regresses (break-back). Either positive or negative values are lower-limit estimates because the method does not detect relatively small area changes due to calving or surge events. The findings are discussed in the context of the three ice shelves that lie in large embayments (the Filchner-Ronne, Amery and Ross Ice Shelves), and marginal ice shelves characterized by relatively short distances between main segments of grounding line and barrier (those in the Dronning Maud Land sector between 010.1degrees Wand 032.5degrees E, and the West and Shackleton Ice Shelves). The ice shelves included in the study account for approximately three-quarters of the total ice-shelf area of Antarctica, and discharge approximately two-thirds of the total grounded ice area. C1 NASA, Goddard Space Flight Ctr, 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, Code 971, Greenbelt, MD 20771 USA. NR 35 TC 7 Z9 7 U1 0 U2 7 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 255 EP 262 DI 10.3189/172756402781817653 PG 8 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100038 ER PT S AU Gray, L Short, N Bindschadler, R Joughin, I Padman, L Vornberger, P Khananian, A AF Gray, L Short, N Bindschadler, R Joughin, I Padman, L Vornberger, P Khananian, A BE Winther, JG Solberg, R TI RADARSAT interferometry for Antarctic grounding-zone mapping SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE Annals of Glaciology-Series LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MD SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID ICE STREAM-B; MASS-BALANCE; SHEET; VELOCITY; MOTION; SHELF; TRIBUTARIES; FILCHNER; IMAGERY AB Satellite radar interferometry, (SRI) is used to provide new information on grounding zones in areas of the eastern Ross Ice Shelf and the Filchner Ice Shelf, Antarctica. At the times of the RADARSAT SRI passes, separated by 24 days, a tidal model predicts a change lit vertical displacement of the freely floating ice of >1 m in both areas. The change in vertical position occurs over a 5-10 km flexure zone adjacent to the grounding line and Would lead to a relatively high interferometric phase fringe rate. This was observed in sonic areas, and suitable imagery has been used to map the grounding-zone position to an estimated accuracy of 1-2 km. Results for the "ice-plain" area upstream of the Crary Ice Rise are consistent with the tidal model and improve the previous grounding-line estimates based on field surveys and Systeme Probatoire pour l'Observation de la Terre (SPOT) data. The results Support the suggestion of increased ice grounding in this area, and show that a sub-ice-shelf water channel around the southern end of the Crary Ice Rise is unlikely. Results for the Filchner Ice Shelf also show that existing maps of the grounding zone can he refined. In particular, we identify a large ice rise close to the month of the Bailey Ice Stream. C1 Canada Ctr Remote Sensing, Ottawa, ON K1A OY7, Canada. Intermap Technol, Ottawa, ON K2E 1A2, Canada. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Earth & Space Res, Seattle, WA 98102 USA. RP Gray, L (reprint author), Canada Ctr Remote Sensing, Ottawa, ON K1A OY7, Canada. RI Joughin, Ian/A-2998-2008 OI Joughin, Ian/0000-0001-6229-679X NR 39 TC 20 Z9 21 U1 0 U2 5 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL-SER PY 2002 VL 34 BP 269 EP 276 DI 10.3189/172756402781817879 PG 8 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100040 ER PT S AU Bindschadler, R Scambos, TA Rott, H Skvarca, P Vornberger, P AF Bindschadler, R Scambos, TA Rott, H Skvarca, P Vornberger, P BE Winther, JG Solberg, R TI Ice dolines on Larsen Ice Shelf, Antarctica SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE Annals of Glaciology-Series LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MD SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID SATELLITE IMAGERY; SEA-ICE; PENINSULA; GLACIERS; CLIMATE AB Ice dolines on the Larsen Ice Shelf, Antarctica, arc observed to be elongated depressions a few hundred meters across and up to 19 m deep. One-meter resolution imagery is used to quantify these dimensions. Elevation profiles across five dolines are derived by photoclinometry. Landsat and radar imagery is also used to show thatdolines can form in a sinale inelt season and persist for years. Dolines occur III clusters and in direct proximity to surface meltwater lakes. Field observations suggest dolines form by collapse into a Subsurface cavity. A direct hydraulic connection with the underlying ocean is believed necessary to drain water that would otherwise collect in dolines. A formation hypothesis is discussed consistent with these observations and with energy- and hydrostatic-imbalance considerations. C1 NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. Univ Colorado, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA. Univ Innsbruck, Inst Meteorol & Geophys, A-6020 Innsbruck, Austria. Inst Antartico Argentino, Buenos Aires, DF, Argentina. Gen Sci Corp, SAIC, Beltsville, MD 20705 USA. RP Bindschadler, R (reprint author), NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Code 971, Greenbelt, MD 20771 USA. RI Scambos, Ted/B-1856-2009 NR 16 TC 13 Z9 13 U1 0 U2 2 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL-SER PY 2002 VL 34 BP 283 EP 290 DI 10.3189/172756402781817996 PG 8 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100042 ER PT S AU Jun, L Zwally, HJ AF Jun, L Zwally, HJ BE Winther, JG Solberg, R TI Modeled seasonal variations of firn density induced by steady-state surface air-temperature cycle SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID ICE AB Seasonal variations of firn density in ice-sheet firn layers have been attributed to variations in deposition processes or other processes within the upper firn. A recent high-resolution (mm-scale) density profile, measured along a 181 in core from Antarctica, showed small-scale density variations with a clear seasonal cycle that apparently was not related to seasonal variations in deposition or known near-surface processes (Gerland and others, 1999). A recent model of surface elevation changes (Zwally and Li, in press) produced a seasonal variation in firn densification, and explained the seasonal surface elevation changes observed by satellite radar altimeters. In this study, we apply our one-dimensional time-dependent numerical model of firn densification that includes a temperature-dependent formulation of firn densification based on laboratory measurements of grain growth. The model is driven by a steady-state seasonal surface temperature and a constant accumulation rate appropriate for the measured Antarctic ice core. The modeled seasonal variations in firn density show that the layers of snow deposited during spring to mid-summer that have the highest temperature history compress to the highest density, and the layers deposited during later summer to autumn that have the lowest temperature history compress to the lowest density. The initial amplitude of the seasonal difference of about 0.13 reduces to about 0.09 in 5 years and asymptotically to 0.0 at greater depth, which is consistent with the core measurements. C1 NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. RP Jun, L (reprint author), NASA, Goddard Space Flight Ctr, Raytheon ITSS, Code 971, Greenbelt, MD 20771 USA. NR 12 TC 4 Z9 4 U1 1 U2 7 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 299 EP 302 DI 10.3189/172756402781817707 PG 4 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100044 ER PT S AU Wang, WL Zwally, HJ Abdalati, W Luo, S AF Wang, WL Zwally, HJ Abdalati, W Luo, S BE Winther, JG Solberg, R TI Modeling of ice flow and internal layers along a flowline through Swiss Camp, West Greenland SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID MASS-BALANCE; EAST ANTARCTICA; LAW DOME; SHEET; RHEOLOGY; SOUTH; CORE AB An anisotropic-ice flowline model is applied to a flowline through Swiss Camp (69.57degrees N, 49.28degrees W), West Greenland, to estimate the dates of internal layers detected by radio-echo sounding measurements. The effect of an anisotropic-ice fabric on ice flow is incorporated into the steady-state flowline model. The stress-strain-rate relationship for anisotropic ice is characterized by an enhancement factor based on the laboratory observations of ice deformation under combined compression and shear stresses. By using present-day data of accumulation rate, surface temperature, surface elevation and ice thickness along the flowline as model inputs, a very close agreement is found between the isochrones generated from the model and the observed internal layers with confirmed dates. The results indicate that this part of the Greenland ice sheet is primarily in steady state. C1 NASA, Goddard Space Flight Ctr, Raytheon, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. NASA, Washington, DC 20546 USA. NASA, Goddard Space Flight Ctr, NVI Inc, Greenbelt, MD 20771 USA. RP Wang, WL (reprint author), NASA, Goddard Space Flight Ctr, Raytheon, Code 971, Greenbelt, MD 20771 USA. NR 33 TC 9 Z9 9 U1 1 U2 4 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 303 EP 308 DI 10.3189/172756402781817644 PG 6 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100045 ER PT S AU Kelly, REJ AF Kelly, REJ BE Winther, JG Solberg, R TI Estimation of the ELA on Hardangerjokulen, Norway, during the 1995/96 winter season using repeat-pass SAR coherence SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID SVALBARD; SNOW AB This paper demonstrates the utility of European Remote-sensing Satellite (ERS) synthetic aperture radar (SAR) interferometry for monitoring the transient snow-line (TSL) on Hardangerjokulen ice cap, southern Norway, during the 1995/96 winter. The study shows how coherence information (an interferometry product) over the ice cap can be used to locate the TSL after the summer melt season. Spatial variations in coherence over the ice cap between successive ERS tandem-phase passes from summer to winter are related to surface and volume snow stability and surface ice stability. Temporal differences of coherence images between winter and summer are investigated using histogram analysis. A histogram threshold is found for the 1995/96 winter that can be used to identify the location of the TSL and then estimate the equilibrium-line altitude (ELA). The result shows good agreement (0.5%) with the field-estimated ELA from the Norwegian Water and Energy Administration. The method appears to be straightforward for this ice cap and it is envisaged that it could be a useful complementary method on other ice caps where repeat-pass SAR data are available. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, GEST, Baltimore, MD 21250 USA. Univ London Birkbeck Coll, Sch Geog, London W1P 2LL, England. RP Kelly, REJ (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Code 974, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 4 U2 6 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 349 EP 354 DI 10.3189/172756402781817518 PG 6 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100052 ER PT S AU Markus, T Cavalieri, DJ Ivanoff, A AF Markus, T Cavalieri, DJ Ivanoff, A BE Winther, JG Solberg, R TI The potential of using Landsat 7 ETM+ for the classification of sea-ice surface conditions during summer SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID MELT PONDS AB During spring and summer, the surface of the Arctic sea-ice cover undergoes rapid changes that greatly affect the surface albedo and significantly impact the further decay of the sea ice. These changes are primarily the development of a wet snow cover and the development of melt ponds. As melt ponds generally do not exceed a couple of meters in diameter, the spatial resolutions of sensors like the Advanced Very High Resolution Radiometer and Moderate Resolution Imaging Spectroradiometer are too coarse for their identification. Landsat 7, on the other hand, has a spatial resolution of 30 in (15 m for the panchromatic band) and thus offers the best chance to map the distribution of melt ponds from space. The different wavelengths (bands) from blue to near-infrared offer the potential to distinguish among different surface conditions. Landsat 7 data for the Baffin Bay region for June 2000 have been analyzed. The analysis shows that different surface conditions, such as wet snow and melt-ponded areas, have different signatures in the individual Landsat bands. Consistent with in situ albedo measurements, melt ponds show up as blueish, whereas dry and wet ice have a white to gray appearance in the Landsat true-color image. These spectral differences enable areas with high fractions of melt ponds to be distinguished. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Markus, T (reprint author), NASA, Goddard Space Flight Ctr, Code 971, Greenbelt, MD 20771 USA. RI Markus, Thorsten/D-5365-2012 NR 10 TC 9 Z9 9 U1 0 U2 5 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 415 EP 419 DI 10.3189/172756402781817536 PG 5 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100062 ER PT S AU Comiso, JC AF Comiso, JC BE Winther, JG Solberg, R TI Correlation and trend studies of the sea-ice cover and surface temperatures in the Arctic SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID OCEAN AB Co-registered and continuous satellite data of sca-ice concentrations and surface ice temperatures from 1981 to 2000 are analyzed to evaluate relationships between these two critical climate parameters and what they reveal in tandem about the chan-ing Arctic environment. During the 19 year period, the Arctic ice extent and actual ice area are shown to be declining at a rate of -2.0+/-0.3% dec(-1) and 3.1+/-0.4% dec(-1), respectively while the surface ice temperature has been increasing at 0.4 +/- 0.2 K dec(-1) where dec is decade. The extent and area of the perennial ice cover, estimated from summer minimum values, have been declining at a much faster rate of -6.7+/-2.4% dec(-1) and -8.3+/-2.4% dec(-1) respectively. while the surface ice temperature has been increasing at 0.9+/-0.6 K dec. This usual rate of decline is accompanied by a very variable summer ice cover in the 1990s compared to the 1980s, suggesting increases in the fraction of the relatively thin second-year and hence a thinning in the perennial, ice cover during the last two decades. Yearly anomaly maps show that the ice-concentration anomalies are predominantly positive in the 1980s and negative Ill the 1990s, while surface temperature anomalies were mainly negative in the 1980s and positive ill the 1990s. The yearly ice-concentration and surface temperature anomalies are highly correlated. indicating a strong link especially ill the seasonal region and around the periphery of the perennial ice cover. The surface temperature anomalies also reveal the spatial scope of each warming (or cooling) phenomenon that usually extends beyond the boundaries of the sea-ice cover. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Comiso, JC (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Code 971, Greenbelt, MD 20771 USA. NR 15 TC 14 Z9 14 U1 0 U2 6 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 420 EP 428 DI 10.3189/172756402781818067 PG 9 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100063 ER PT S AU Parkinson, CL AF Parkinson, CL BE Winther, JG Solberg, R TI Trends in the length of the Southern Ocean sea-ice season, 1979-99 SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID ANTARCTIC PENINSULA; TEMPERATURE; PATTERNS AB Satellite passive-microwave data have been used to calculate and map the length of the sea-ice season throughout the Southern Ocean for each year 1979-99. Mapping the slopes of the lines of linear least-squares fit through the 21 years of resulting season-length data reveals a detailed pattern of trends in the length of the sea-ice season around the Antarctic continent. Specifically, most of the Ross Sea ice cover has, on average over the 21 years, undergone a lengthening of the sea-ice season, whereas most of the Amundsen Sea ice cover and almost the entire Bellingshausen Sea ice cover have undergone a shortening of the sea-ice season. Results for the Weddell Sea are mixed, with the northwestern portion of the sea having experienced a shortening of the sca-ice season but a substantial area in the south-central portion of the sea having experienced a lengthening of the ice season. Overall, the area of the Southern Ocean experiencing a lengthening ofthe sea-ice season by at least 1 day per year over the period 1979-99 is 5.6x10(6) km(2), whereas the area experiencing a shortening of the sea ice season by at least 1 day per year is 46% less than that, at 3.0 x 10(6) km(2). C1 NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. RP Parkinson, CL (reprint author), NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Code 971, Greenbelt, MD 20771 USA. RI Parkinson, Claire/E-1747-2012 OI Parkinson, Claire/0000-0001-6730-4197 NR 24 TC 92 Z9 95 U1 2 U2 12 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 435 EP 440 DI 10.3189/172756402781817482 PG 6 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100065 ER PT S AU Parkinson, CL Cavalieri, DJ AF Parkinson, CL Cavalieri, DJ BE Winther, JG Solberg, R TI A 21 year record of Arctic sea-ice extents and their regional, seasonal and monthly variability and trends SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND ID COVER AB Satellite passive-microwave data have been used to calculate sea-ice extents over the period 1979-99 for the north polar sea-ice cover as a whole and for each of nine regions. Over this 21 year time period the trend in yearly-average ice extents for the ice cover as a whole is -32 900+/-6100 km(2) a(-1) (-2.7+/-0.5% per decade), indicating a statistically significant reduction in sea-ice coverage. Regionally, the reductions are greatest in the Arctic Ocean, the Kara and Barents Seas and the Seas of Okhotsk and Japan; and seasonally, the reductions are greatest in summer, for which season the 1979-99 trend in ice extents is -41 600+/-12 900 km(2) a(-1) (-4.9+/-1.5% per decade). On a monthly basis, the reductions are greatest in July and September for the north polar ice cover as a whole, in September for the Arctic Ocean, in June and July for the Kara and Barents Seas, and in April for the Seas of Okhotsk and Japan. Of the nine regions, only the Bering Sea and the Gulf of St Lawrence show positive ice-extent trends on a yearly-average basis. However, the increases in these two regions are not statisticalIy significant. For the north polar region as a whole, and for the Arctic Ocean, the Seas of Okhotsk and Japan, and Hudson Bay, the negative trends in the yearly averages are statistically significant at a 99% confidence level. C1 NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. RP Parkinson, CL (reprint author), NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Code 971, Greenbelt, MD 20771 USA. RI Parkinson, Claire/E-1747-2012 OI Parkinson, Claire/0000-0001-6730-4197 NR 18 TC 83 Z9 84 U1 1 U2 20 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 441 EP 446 DI 10.3189/172756402781817725 PG 6 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100066 ER PT S AU Kwok, R AF Kwok, R BE Winther, JG Solberg, R TI Arctic sea-ice area and volume production: 1996/97 versus 197/98 SO ANNALS OF GLACIOLOGY, VOL 34, 2002 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT 4th International Symposium on Remote Sensing in Glaciology CY JUN 03-08, 2001 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP Int Glaciol Soc, NASA, US Natl Sci Fdn HO UNIV MARYLAND AB The RADARSAT geophysical processor system (RGPS) produces measurements of ice motion and estimates of ice thickness rising repeat synthetic aperture radar maps of the Arctic Ocean. Front the RGPS products, we compute the net deformation and advection of the winter ice cover using the motion observations, and the seasonal ice area and volume production using the estimates of ice thickness. The results from the winters of 1996/97 and 1997/98 are compared. The second winter is of particular interest because it coincides with the Surface Heat Budget of the Arctic Ocean (SHEBA) field program. The character of the deformation of the ice cover from the two years is very different. Over a domain covering a large part of the western Arctic Ocean (similar to2.3 x 10(6) km(2)), the net divergence of that area during the 6 months of the first winter was 2.7% and for the second winter was > 9.3%. In a subregion where the SHEBA camp was located, the net divergence was almost 38% compared to a net divergence of the same subregion of similar to9% in 1996/97. The resulting deformation created a much larger volume of seasonal ice than in the earlier year. The net seasonal ice-volume production is 1.6 times (0.38 m vs 0.62 m) that of the first year. In addition to the larger divergence, this part of the ice cover advected a longer distance toward the Chukchi Sea over the Same time-span. The total coverage of multi-year ice remained almost identical at similar to2.08 X 10(6) km(2), or 83% of the initial area of the domain. In this paper, we compare the behavior of the ice cover over the two winters and discuss these observations in the context of large-scale ice motion and atmospheric-pressure pattern. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 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 8 TC 7 Z9 7 U1 0 U2 1 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-29-6 J9 ANN GLACIOL PY 2002 VL 34 BP 447 EP 453 DI 10.3189/172756402781817527 PG 7 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BU99C UT WOS:000177565100067 ER PT S AU Li, J Wang, WL Zwally, J AF Li, J Wang, WL Zwally, J BE Wolff, EW TI Interannual variations of shallow firn temperature at Greenland summit SO ANNALS OF GLACIOLOGY, VOL 35 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT International Symposium on Ice Cores and Climate CY AUG 19-23, 2001 CL KANGERLUSSUAQ, GREENLAND ID ICE-SHEET AB Firn-temperature profiles are calculated in a thermal model using continuous surface temperatures derived from automatic weather station data and passive-microwave data in the Greenland summit region during the period 1987-99. The results show that significant interannual variations of mean summer (June-August) and annual temperatures occur in the top 15 in, in addition to the normal seasonal cycle of firn temperature. At 5 in depth, the seasonal cycle is damped to 13% of the surface seasonal range, but even at 15 in about 1% or 0.6degreesC of the seasonal cycle persists. Both summer and mean annual temperatures decrease from 1987 to 1992, followed by a general increasing trend. Interannual variability is 5degreesC at the surface, but is dampened to 3.2degreesC at 5 in depth and 0.7degreesC at 15 in depth. Dampening of the interannual variability with depth is slower than dampening of the seasonal cycle, because of the longer time constant of the interannual variation. The warmer spring and summer temperatures experienced in the top 5 in, due to both the seasonal cycle and interannual variations, affect the rate of firn densification, which is nonlinearly dependent on temperature. During the 12 year period 1987-99, the annual mean surface temperature is -29.2degreesC, and the annual mean 15 in temperature is -30.1degreesC, which is > 1degreesC warmer than a 1,5 in borehole temperature representing the period around 1959 and warmer than the best-fit temperature history by Alley and Koci (1990) back to AD 1500. C1 NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. RP Li, J (reprint author), NASA, Goddard Space Flight Ctr, Raytheon ITSS, Code 971, Greenbelt, MD 20771 USA. NR 12 TC 4 Z9 4 U1 0 U2 2 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-30-X J9 ANN GLACIOL PY 2002 VL 35 BP 368 EP 370 PG 3 WC Geosciences, Multidisciplinary SC Geology GA BW44W UT WOS:000182023600059 ER PT S AU Wang, WL Warner, RC Budd, WF AF Wang, WL Warner, RC Budd, WF BE Wolff, EW TI Ice-flow properties at Dome Summit South, Law Dome, East Antarctica SO ANNALS OF GLACIOLOGY, VOL 35 SE ANNALS OF GLACIOLOGY LA English DT Article; Proceedings Paper CT International Symposium on Ice Cores and Climate CY AUG 19-23, 2001 CL KANGERLUSSUAQ, GREENLAND ID GREENLAND; RHEOLOGY AB Ice-flow properties within a polar ice sheet are examined using the comprehensive data gathered from ice-core drilling by Australian National Antarctic Research Expeditions (ANARE) at Dome Summit South (DSS), on Law Dome, East Antarctica. Using the shear strain rates derived from borehole inclination measurements we demonstrate the need to modify the ice-flow relations to treat enhanced shear deformation deep within the ice sheet. We show that the relation between enhanced flow and the measured crystallographic properties is generally in accord with expectations, at least in the upper parts of the ice sheet, but it becomes clear that nearer to the bedrock the situation is more complicated. We also compare the observed shear strain-rate profile with results from a model that describes flow enhancement as a function of the applied stresses. C1 NASA, Goddard Space Flight Ctr, Raytheon ITSS, Oceans & Ice Branch, Greenbelt, MD 20771 USA. Australian Antarctic Div, Hobart, Tas 7001, Australia. Antarctic CRC, Hobart, Tas 7001, Australia. RP Wang, WL (reprint author), NASA, Goddard Space Flight Ctr, Raytheon ITSS, Oceans & Ice Branch, Code 971, Greenbelt, MD 20771 USA. NR 26 TC 9 Z9 9 U1 0 U2 3 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0260-3055 BN 0-946417-30-X J9 ANN GLACIOL PY 2002 VL 35 BP 567 EP 573 DI 10.3189/172756402781816924 PG 7 WC Geosciences, Multidisciplinary SC Geology GA BW44W UT WOS:000182023600089 ER PT S AU Zampino, EJ Burow, D AF Zampino, EJ Burow, D GP IEEE TI The application of RODON to the FMEA of a microgravity facility subsystem SO ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM, 2002 PROCEEDINGS SE PROCEEDINGS : ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM LA English DT Article; Proceedings Paper CT Annual Reliability and Maintainability Symposium CY JAN 28-31, 2001 CL SEATTLE, WASHINGTON SP IEEESAE, IIE, Soc Reliabil Engineers, IEST, SLE, RAMS DE failure modes and effects; failure diagnostics; analyst-dependent; model-based reasoning; reasoning over systems in their entirety; constraint propagation; interval set arithmetic; auto-simulation AB In March of 2000, R.O.S.E. Informatik GmbH and the Risk Management Office of The NASA Glenn Research Center in Cleveland Ohio decided to collaborate on a pilot application of a computerized model-based reasoning tool called RODON. This collaboration resulted in a failure modes and effects analysis (FMEA) of the Fuel/Premixed-Fuel Supply Manifold: a subassembly intended to be part of the Fluid-Combustion Facility (FCF) which was planned for microgravity experiments on the International Space Station (ISS). Clarification of design details and component pressure-drop test data was provided by the design engineering team. The Fuel/Premixed-Fuel Supply Manifold was first analyzed by a reliability engineer using an analyst-dependent technique which "rests" primarily upon experience, knowledge, and imagination. The output of the RODON-generated FMEA was compared to the analyst-dependent FMEA. The analysis process utilizing RODON revealed errors from the analyst-dependent FMEA and also detected a laboratory test problem. C1 NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Zampino, EJ (reprint author), NASA, Glenn Res Ctr Lewis Field, MS 50-4,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 5 TC 0 Z9 0 U1 0 U2 3 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0149-144X BN 0-7803-7348-0 J9 P A REL MAI PY 2002 BP 361 EP 366 DI 10.1109/RAMS.2002.981668 PG 6 WC Computer Science, Software Engineering; Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU19P UT WOS:000175295600058 ER PT S AU Newman, JS Wander, SM AF Newman, JS Wander, SM GP IEEE TI The knowledge path to mission success: Overview of the NASA PBMA-KMS SO ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM, 2002 PROCEEDINGS SE PROCEEDINGS : ANNUAL RELIABILITY AND MAINTAINABILITY SYMPOSIUM LA English DT Article; Proceedings Paper CT Annual Reliability and Maintainability Symposium CY JAN 28-31, 2001 CL SEATTLE, WASHINGTON SP IEEESAE, IIE, Soc Reliabil Engineers, IEST, SLE, RAMS DE knowledge management; risk management; systems engineering; safety; mission success AB Mission success depends on proper integration of safety, risk management, and assurance processes throughout the project life-cycle. In the current government acquisition environment great emphasis is being placed on innovative contracting approaches that involve cooperative agreements, performance-based contracting, and contractor use of best practices. Thus, far fewer prescribed standards and specifications are involved in government acquisition today as compared to the early 1990's. Additionally, the shift from rule-based assurance management to knowledge-based approaches poses a separate set of challenges as clearly underscored in government and industry accident assessments and mishap investigations that followed a costly streak of launch vehicle and spacecraft failures in the late 1990 time frame. In response to these challenges the NASA Off-ice of Safety & Mission Assurance began development of the Process Based Mission Assurance Knowledge Management System (PBMA-K-MS) in mid 1999. The PBMA-KMS is a user-friendly, web-based system designed to support life-cycle safety and mission success management, This paper describes the PBMA-KMS functionality, operation, and plans for future growth. Aerospace professionals are encouraged to use the PBMA-KMS by participating in discipline oriented work groups, and contributing best practices, lessons teamed, and ideas for future functional enhancements. C1 NASA Headquarters, Off Safety & Mission Assurance, Washington, DC 20546 USA. RP Newman, JS (reprint author), NASA Headquarters, Off Safety & Mission Assurance, Washington, DC 20546 USA. NR 8 TC 0 Z9 0 U1 0 U2 2 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0149-144X BN 0-7803-7348-0 J9 P A REL MAI PY 2002 BP 601 EP 606 DI 10.1109/RAMS.2002.981708 PG 6 WC Computer Science, Software Engineering; Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BU19P UT WOS:000175295600099 ER PT J AU Hu, W Dodelson, S AF Hu, W Dodelson, S TI Cosmic microwave background anisotropies SO ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS LA English DT Review DE background radiation; cosmology; theory; dark matter; early universe ID COLD DARK-MATTER; SUNYAEV-ZELDOVICH FLUCTUATIONS; 3-POINT CORRELATION-FUNCTION; BIG-BANG NUCLEOSYNTHESIS; ANGULAR POWER SPECTRUM; LARGE-SCALE STRUCTURE; NON-GAUSSIAN ASPECTS; COSMOLOGICAL CONSTANT; SKY MAPS; INFLATIONARY UNIVERSE AB Cosmic microwave background (CMB) temperature anisotropies have and will continue to revolutionize our understanding of cosmology. The recent discovery of the previously predicted acoustic peaks in the power spectrum has established a working cosmological model: a critical density universe consisting of mainly dark matter and dark energy, which formed its structure through gravitational instability from quantum fluctuations during an inflationary epoch. Future observations should test this model and measure its key cosmological parameters with unprecedented precision. The phenomenology and cosmological implications of the acoustic peaks are developed in detail. Beyond the peaks, the yet to be detected secondary anisotropies and polarization present opportunities to study the physics of inflation and the dark energy. The analysis techniques devised to extract cosmological information from voluminous CMB data sets are outlined, given their increasing importance in experimental cosmology as a whole. C1 Univ Chicago, Ctr Cosmol Phys, Chicago, IL 60637 USA. NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Univ Chicago, Ctr Cosmol Phys, Chicago, IL 60637 USA. EM whu@background.uchicago.edu; dodelson@fnal.gov NR 202 TC 302 Z9 306 U1 3 U2 25 PU ANNUAL REVIEWS PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 USA SN 0066-4146 J9 ANNU REV ASTRON ASTR JI Annu. Rev. Astron. Astrophys. PY 2002 VL 40 BP 171 EP 216 DI 10.1146/annurev.astro.40.060401.093926 PG 50 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 612BU UT WOS:000179054500007 ER PT J AU Hoehler, TM Albert, DB Alperin, MJ Bebout, BM Martens, CS Des Marais, DJ AF Hoehler, TM Albert, DB Alperin, MJ Bebout, BM Martens, CS Des Marais, DJ TI Comparative ecology of H-2 cycling in sedimentary and phototrophic ecosystems SO ANTONIE VAN LEEUWENHOEK INTERNATIONAL JOURNAL OF GENERAL AND MOLECULAR MICROBIOLOGY LA English DT Article DE anoxic sediments; hydrogen; microbial mats ID ANAEROBIC METHANE OXIDATION; COASTAL MARINE BASIN; HYDROGEN METABOLISM; SELENOMONAS-RUMINANTIUM; SYNTROPHIC ASSOCIATION; METHANOGENIC BACTERIA; MICROBIAL CONSORTIUM; DEGRADING BACTERIUM; SULFATE REDUCTION; AQUATIC SEDIMENTS AB The simple biochemistry of H-2 is critical to a large number of microbial processes, affecting the interaction of organisms with each other and with the environment. The sensitivity of each of these processes to H-2 can be described collectively, through the quantitative language of thermodynamics. A necessary prerequisite is to understand the factors that, in turn, control H-2 partial pressures. These factors are assessed for two distinctly different ecosystems. In anoxic sediments from Cape Lookout Bight (North Carolina, USA), H-2 partial pressures are strictly maintained at low, steady-state levels by H-2-consuming organisms, in a fashion that can be quantitatively predicted by simple thermodynamic calculations. In phototrophic microbial mats from Baja California (Mexico), H-2 partial pressures are controlled by the activity of light-sensitive H-2-producing organisms, and consequently fluctuate over orders of magnitude on a daily basis. The differences in H-2 cycling can subsequently impact any of the H-2-sensitive microbial processes in these systems. In one example, methanogenesis in Cape Lookout Bight sediments is completely suppressed through the efficient consumption of H-2 by sulfate-reducing bacteria; in contrast, elevated levels of H-2 prevail in the producer-controlled phototrophic system, and methanogenesis occurs readily in the presence of 40 mM sulfate. C1 NASA, Exobiol Branch, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ N Carolina, Dept Marine Sci, Chapel Hill, NC 27599 USA. RP Hoehler, TM (reprint author), NASA, Exobiol Branch, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 68 TC 40 Z9 41 U1 0 U2 10 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0003-6072 J9 ANTON LEEUW INT J G JI Antonie Van Leeuwenhoek PY 2002 VL 81 IS 1-4 BP 575 EP 585 DI 10.1023/A:1020517924466 PG 11 WC Microbiology SC Microbiology GA 600KY UT WOS:000178390200054 PM 12448753 ER PT S AU Yeh, PS Moury, G Armbruster, P AF Yeh, PS Moury, G Armbruster, P BE Tescher, AG TI The CCSDS data compression recommendations: Development and status SO APPLICATIONS OF DIGITAL IMAGE PROCESSING XXV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Applications of Digital Image Processing XXV CY JUL 08-10, 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 lossless data compression; lossy image compression; CCSDS; standards; space missions AB The Consultative Committee for Space Data Systems (CCSDS) has been engaging in recommending data compression standards for space applications. The first effort focused on a lossless scheme that was adopted in 1997. Since then, space missions benefiting from this recommendation range from deep space probes to near Earth observatories. ne cost savings result not only from reduced onboard storage and reduced bandwidth, but also in ground archive of mission data. In many instances, this recommendation also enables more science data to be collected for added scientific value. Since 1998, the compression sub-panel of CCSDS has been investigating lossy image compression schemes and is currently working towards a common solution for a single recommendation. The recommendation will fulfill the requirements for remote sensing conducted on space platforms. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Yeh, PS (reprint author), NASA, Goddard Space Flight Ctr, Code 564, Greenbelt, MD 20771 USA. NR 15 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 0-8194-4557-6 J9 P SOC PHOTO-OPT INS PY 2002 VL 4790 BP 302 EP 313 DI 10.1117/12.455372 PG 12 WC Computer Science, Software Engineering; Engineering, Electrical & Electronic; Optics; Imaging Science & Photographic Technology SC Computer Science; Engineering; Optics; Imaging Science & Photographic Technology GA BV78G UT WOS:000179998100032 ER PT S AU Grant, J Kaul, R Taylor, S Jackson, K Osei, A Sharma, A AF Grant, J Kaul, R Taylor, S Jackson, K Osei, A Sharma, A BE Lessard, RA Lampropoulos, GA Schinn, GW TI Investigation of structural properties of carbon-epoxy composites using Fiber-Bragg gratings SO APPLICATIONS OF PHOTONIC TECHNOLOGY 5: CLOSING THE GAP BETWEEN THEORY, DEVELOPMENT, AND APPLICATION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 5th International Conference on Applications of Photonic Technology (ICAPT 2002) CY JUN 01-06, 2002 CL QUEBEC CITY, CANADA ID STRAIN AB Fiber Bragg-gratings are embedded in carbon-epoxy laminates as well as bonded on the surface of composite wound pressure vessel. Structural properties of such composites are investigated. The measurements include stress-strain relation in laminates and Poisson's ratio in several specimens with varying orientation of the optical fiber Bragg-sensor with respect to the carbon fiber in an epoxy matrix. Additionally, fiber Bragg gratings are bonded on the surface of cylinders fabricated out of carbon-epoxy composites and longitudinal and hoop strain on the surface is measured. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Grant, J (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 5 TC 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 0-8194-4612-2 J9 P SOC PHOTO-OPT INS PY 2002 VL 4833 BP 191 EP 199 DI 10.1117/12.473813 PG 9 WC Engineering, Biomedical; Materials Science, Multidisciplinary; Optics; Imaging Science & Photographic Technology SC Engineering; Materials Science; Optics; Imaging Science & Photographic Technology GA BW42H UT WOS:000181952600024 ER PT J AU Glenn, J Chattopadhyay, G Edgington, SF Lange, AE Bock, JJ Mauskopf, PD Lee, AT AF Glenn, J Chattopadhyay, G Edgington, SF Lange, AE Bock, JJ Mauskopf, PD Lee, AT TI Numerical optimization of integrating cavities for diffraction-limited millimeter-wave bolometer arrays SO APPLIED OPTICS LA English DT Article ID INFRARED BOLOMETERS; OPTICS; SPIRE AB Far-infrared to millimeter-wave bolometers designed to make astronomical observations are typically encased in integrating cavities at the termination of feedhorns or Winston cones. This photometer combination maximizes absorption of radiation, enables the absorber area to be minimized, and controls the directivity of absorption, thereby reducing susceptibility to stray light. In the next decade, arrays of hundreds of silicon nitride micromesh bolometers with planar architectures will be used in ground-based, suborbital, and orbital platforms for astronomy. The optimization of integrating cavity designs is required for achieving the highest possible sensitivity for these arrays. We report numerical simulations of the electromagnetic fields in integrating cavities with an infinite plane-parallel geometry formed by a solid reflecting backshort and the back surface of a feedhorn array block. Performance of this architecture for the bolometer array camera (Bolocam) for cosmology at a frequency of 214 GHz is investigated. We explore the sensitivity of absorption efficiency to absorber impedance and backshort location and the magnitude of leakage from cavities. The simulations are compared with experimental data from a room-temperature scale model and with the performance of Bolocam at a temperature of 300 mK. The main results of the simulations for Bolocam-type cavities are that (1) monochromatic absorptions as high as 95% are achievable with <1% cross talk between neighboring cavities, (2) the optimum absorber impedances are 400 Omega /sq, but with a broad maximum from similar to 150 to similar to 700 Omega /sq, and (3) maximum absorption is achieved with absorber diameters greater than or equal to1.5 lambda. Good general agreement between the simulations and the experiments was found. (C) 2002 Optical Society of America. C1 Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. CALTECH, Dept Phys, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Cardiff Univ, Dept Phys & Astron, Cardiff, S Glam, Wales. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Glenn, J (reprint author), Univ Colorado, Ctr Astrophys & Space Astron, UCB-389, Boulder, CO 80309 USA. EM jglenn@casa.colorado.edu NR 14 TC 18 Z9 18 U1 1 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD JAN 1 PY 2002 VL 41 IS 1 BP 136 EP 142 DI 10.1364/AO.41.000136 PG 7 WC Optics SC Optics GA 507NL UT WOS:000173034500019 PM 11900429 ER PT J AU Georgiev, G Glenar, DA Hillman, JJ AF Georgiev, G Glenar, DA Hillman, JJ TI Spectral characterization of acousto-optic filters used in imaging spectroscopy SO APPLIED OPTICS LA English DT Article ID TUNABLE FILTERS; TEMPERATURE-DEPENDENCE; PARATELLURITE; TEO2 AB The purpose of this investigation is to improve the study of the characteristics of noncollinear acoustooptic tunable filters (AOTFs) used in imaging spectroscopy. Three filters were characterized and the results compared with tuning models to verify that device-operation can be reliably predicted in advance. All these devices use tellurium dioxide as the interaction medium and have large geometric apertures for spectroscopic imaging applications in the spectral range 0.5-3.5 mum. The device characteristics that we studied were compared with the results of AOTF models, and the spectral and angular dependence of acoustic frequency and bandpass width for both output polarization states were confirmed by measurements. One of the AOTFs was used as a dispersive element coupled to external imaging optics. We summarize measurements of the basic spectral and imaging characteristics in this configuration. (C) 2002 Optical Society of America. C1 Univ Maryland, Dept Astronomy, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Georgiev, G (reprint author), Univ Maryland, Dept Astronomy, Comp Space Sci Bldg, College Pk, MD 20742 USA. EM gtg@spectral.lepvax.gsfc.nasa.gov NR 17 TC 45 Z9 51 U1 1 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD JAN 1 PY 2002 VL 41 IS 1 BP 209 EP 217 DI 10.1364/AO.41.000209 PG 9 WC Optics SC Optics GA 507NL UT WOS:000173034500027 PM 11900437 ER PT S AU Raghavan, P James, MA Newman, JC Seshadri, BR AF Raghavan, P James, MA Newman, JC Seshadri, BR BE Fagerholm, J Haataja, J Jarvinen, J Lyly, M Raback, P Savolainen, V TI Scalable sparse matrix techniques for modeling crack growth SO APPLIED PARALLEL COMPUTING: ADVANCED SCIENTIFIC COMPUTING SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 6th International Conference on Applied Parallel Computing CY JUN 15-18, 2002 CL ESPOO, FINLAND SP IBM, Acad Finland, City Espoo, WM data Ltd, SAS, Springer Verlag ID ALGORITHMS C1 Penn State Univ, University Pk, PA 16802 USA. CNR, Washington, DC 20418 USA. Mississippi State Univ, Mississippi State, MS 39762 USA. Old Dominion Univ, Norfolk, VA 23529 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Raghavan, P (reprint author), Penn State Univ, University Pk, PA 16802 USA. NR 19 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 3-540-43786-X J9 LECT NOTES COMPUT SC PY 2002 VL 2367 BP 588 EP 602 PG 15 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA BW57R UT WOS:000182460300058 ER PT J AU Scott, CD Arepalli, S Nikolaev, P Smalley, RE AF Scott, CD Arepalli, S Nikolaev, P Smalley, RE TI Growth mechanisms for single-wall carbon nanotubes a laser ablation process (vol 72, pg 573, 2001) SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Correction C1 NASA, Johnson Space Ctr, EM2, Houston, TX 77058 USA. GB Tech Lockheed Martin, Houston, TX 77058 USA. Rice Univ, Ctr Nanosci & Technol, Houston, TX 77005 USA. RP Scott, CD (reprint author), NASA, Johnson Space Ctr, EM2, Houston, TX 77058 USA. RI Arepalli, Sivaram/A-5372-2010; Nikolaev, Pavel/B-9960-2009 NR 2 TC 3 Z9 3 U1 0 U2 6 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD JAN PY 2002 VL 74 IS 1 BP 11 EP 11 PG 1 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 498RA UT WOS:000172523200003 ER PT J AU Deshpande, AD Huggett, RJ Halbrook, RA AF Deshpande, AD Huggett, RJ Halbrook, RA TI Polycyclic aromatic hydrocarbon metabolites in the bile of a territorial benthic fish, oyster toadfish (Opsanus tau) from the Elizabeth River, Virginia SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID EXPOSURE; LIVER; BENZOPYRENE; CONTAMINATION; XENOBIOTICS; SEDIMENTS; PREDATION; BIOMARKER; NEBULOSUS; MUSKRATS AB Reverse-phase high-performance liquid chromatographic analyses of bile of a territorial benthic fish, oyster toadfish (Opsanus tau), indicated that fish from reference stations in the York and Elizabeth Rivers, Virginia, contained lower concentrations of polycyclic aromatic hydrocarbon (PAH) metabolites than fish from polluted stations. PAH metabolite levels in the bile of fish from mildly polluted stations were 7 to 10 times greater than those from reference stations. PAH metabolite levels in fish from a moderately polluted station and a highly polluted station were, respectively, 20 and 50 times greater than those from reference stations. Differential patterns of five major PAH metabolites in fish from the same station suggested individual variability in metabolic pathways possibly further convoluted by the differential inductions or suppressions of hepatic mixed-function oxygenase isozyme systems under various natural or anthropogenic habitat parameters. PAH metabolite levels in the bile of oyster toadfish correlated well with the gradient of PAH contamination in the Elizabeth River sediments. High levels of biliary PAH metabolites were not detected in muskrats (Ondatra zibethicus) collected along the polluted sections of the Elizabeth River, probably due to their primarily herbivorous nature. Assuming that the hepatobiliary system and the gastrointestinal tract are the major routes of biotransformation and excretion of PAHs in the muskrats, the contaminated diet appears to be a more important routes of exposure of muskrats (and possibly oyster toadfish) to PAHs than the transdermal transfer. Occurrence permitting, we propose oyster toadfish as a useful biological sentinel for early detection of estuarine PAH pollution. C1 Natl Marine Fisheries Serv, US Dept Commerce, Natl Ocean & Atmospher Adm, NE Fisheries Sci Ctr,James J Howard Marine Sci La, Highlands, NJ 07732 USA. Michigan State Univ, E Lansing, MI 48824 USA. So Illinois Univ, Cooperat Wildlife Res Lab, Carbondale, IL 62901 USA. RP Deshpande, AD (reprint author), Natl Marine Fisheries Serv, US Dept Commerce, Natl Ocean & Atmospher Adm, NE Fisheries Sci Ctr,James J Howard Marine Sci La, Highlands, NJ 07732 USA. NR 37 TC 9 Z9 9 U1 1 U2 8 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD JAN PY 2002 VL 42 IS 1 BP 43 EP 52 PG 10 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 496RD UT WOS:000172409000007 PM 11706367 ER PT J AU Thakoor, S Chahl, J Srinivasan, MV Young, L Werblin, F Hine, B Zornetzer, S AF Thakoor, S Chahl, J Srinivasan, MV Young, L Werblin, F Hine, B Zornetzer, S TI Bioinspired engineering of exploration systems for NASA and DoD SO ARTIFICIAL LIFE LA English DT Article DE bioinspired; navigation; autonomous flight systems; autonomous recognition; Mars exploration ID HONEYBEES AB A new approach called bioinspired engineering of exploration systems (BEES) and its value for solving pressing NASA and DoD needs are described. Insects (for example honeybees and dragonflies) cope remarkably well with their world, despite possessing a brain containing less than 0.01% as many neurons as the human brain. Although most insects have immobile eyes with fixed focus optics and lack stereo vision, they use a number of ingenious, computationally simple strategies for perceiving their world in three dimensions and navigating successfully within it. We are distilling selected insect-inspired strategies to obtain novel solutions for navigation, hazard avoidance, altitude hold, stable flight, terrain following, and gentle deployment of payload. Such functionality provides potential solutions for future autonomous robotic space and planetary explorers. A BEES approach to developing lightweight low-power autonomous flight systems should be useful for flight control of such biomorphic flyers for both NASA and DoD needs. Recent biological studies of mammalian retinas confirm that representations of multiple features of the visual world are systematically parsed and processed in parallel. Features are mapped to a stack of cellular strata within the retina. Each of these representations can be efficiently modeled in semiconductor cellular nonlinear network (CNN) chips. We describe recent breakthroughs in exploring the feasibility of the unique blending of insect strategies of navigation with mammalian visual search, pattern recognition, and image understanding into hybrid biomorphic flyers for future planetary and terrestrial applications. We describe a few future mission scenarios for Mars exploration, uniquely enabled by these newly developed biomorphic flyers. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Australian Natl Univ, Canberra, ACT, Australia. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Thakoor, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Srinivasan, Mandyam/G-5571-2010; OI Chahl, Javaan/0000-0001-6496-0543 NR 15 TC 12 Z9 12 U1 0 U2 6 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 1064-5462 J9 ARTIF LIFE JI Artif. Life PY 2002 VL 8 IS 4 BP 357 EP 369 DI 10.1162/106454602321202426 PG 13 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA 651AD UT WOS:000181296400004 PM 12650645 ER PT B AU Giannakopoulou, D Pasareanu, CS Barringer, H AF Giannakopoulou, D Pasareanu, CS Barringer, H GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Assumption generation for software component verification SO ASE 2002: 17TH IEEE INTERNATIONAL CONFERENCE ON AUTOMATED SOFTWARE ENGINEERING LA English DT Proceedings Paper CT 17th IEEE International Conference on Automated Software Engineering (ASE 2002) CY SEP 23-27, 2002 CL EDINBURGH, SCOTLAND SP IEEE Comp Soc Tech Comm Software Engn, ACM SIGART, ACM SIGSOFT, Scottish Embedded Software Ctr ID SUBMODULE SPECIFICATIONS; MODEL CHECKING; CONSTRUCTION; PROTOCOLS AB Model checking is an automated technique that can be used to determine whether a system satisfies certain required properties. The typical approach to verifying properties of software components is to check them for all possible environments. In reality, however a component is only required to satisfy properties in specific environments. Unless these environments are formally characterized and used during verification (assume-guarantee paradigm), the results returned by verification can be overly pessimistic. This work defines a framework that brings a new dimension to model checking of software components. When checking a component against a property, our model checking algorithms return one of the following three results: the component satisfies a property for any environment; the component violates the property for any environment; or finally, our algorithms generate an assumption that characterizes exactly those environments in which the component satisfies its required property Our approach has been implemented in the LTSA tool and has been applied to the analysis of a NASA application. C1 NASA, Ames Res Ctr, USRA, RIACS, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, USRA, RIACS, Moffett Field, CA 94035 USA. EM dimitra@email.arc.nasa.gov; pcorina@email.arc.nasa.gov; howard@cs.man.ac.uk NR 41 TC 45 Z9 46 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 0-7695-1736-6 PY 2002 BP 3 EP 12 DI 10.1109/ASE.2002.1114984 PG 10 WC Automation & Control Systems; Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BV36Y UT WOS:000178713700001 ER PT B AU Rosu, G Whittle, J AF Rosu, G Whittle, J GP IEEE COMPUTER SOCIETY IEEE COMPUTER SOCIETY TI Towards certifying domain-specific properties of synthesized code - Extended abstract SO ASE 2002: 17TH IEEE INTERNATIONAL CONFERENCE ON AUTOMATED SOFTWARE ENGINEERING LA English DT Proceedings Paper CT 17th IEEE International Conference on Automated Software Engineering (ASE 2002) CY SEP 23-27, 2002 CL EDINBURGH, SCOTLAND SP IEEE Comp Soc Tech Comm Software Engn, ACM SIGART, ACM SIGSOFT, Scottish Embedded Software Ctr AB We present a technique for certifying domain-specific properties of code generated using program synthesis technology. Program synthesis is a maturing technology that generates code from high-level specifications in particular domains. For acceptance in safety-critical applications, the generated code must be thoroughly tested which is a costly process. We show how the program synthesis system AUTOFILTER can be extended to generate not only code but also proofs that properties hold in the code. This technique has the potential to reduce the costs of testing generated code. C1 NASA, Ames Res Ctr, USRA, RIACS, Moffett Field, CA USA. RP Rosu, G (reprint author), NASA, Ames Res Ctr, USRA, RIACS, Moffett Field, CA USA. NR 9 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 BN 0-7695-1736-6 PY 2002 BP 289 EP 294 PG 6 WC Automation & Control Systems; Computer Science, Software Engineering; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BV36Y UT WOS:000178713700036 ER PT S AU Major, GR Olsen, LM AF Major, GR Olsen, LM BE Toms, EG TI Integrating traditional user-based search and retrieval with information technologies for metadata sharing in a global environmental change information system SO ASIST 2002: PROCEEDINGS OF THE 65TH ASIST ANNUAL MEETING, VOL 39, 2002 SE PROCEEDINGS OF THE ASIST ANNUAL MEETING LA English DT Article; Proceedings Paper CT 65th Annual Meeting of the American-Society-for-Information-Science-and-Technology CY NOV 18-21, 2002 CL PHILADELPHIA, PENNSYLVANIA SP Amer Soc Informat Sci & Technol AB The NASA Global Change Master Directory (GCMD) (http://qcmd.nasa.gov) is a dynamic multidisciplinary information retrieval system that holds metadata records describing Earth science data sets, their location, and their access. More than 13,000 metadata records can be searched through a Web-based interface using controlled keywords and/or free-text. Population of the GCMD depends on metadata content offered by Earth science data providers. The GCMD's four-tier system architecture allows the automated sharing of Earth science metadata among partners through the use of object-oriented technologies and XML metadata. Partners have autonomy over their own metadata collections that can be searched through the GCMD's interface, thereby providing a centralized search system of distributed and shared content. In addition to user-based search and retrieval, the GCMD architecture also allows machine-to-machine automated queries of the database using Java servlets over an HTTPD API protocol. C1 SSAI, Lanham, MD 20706 USA. NASA, GSFC, Greenbelt, MD 20770 USA. RP Major, GR (reprint author), SSAI, 10210 Greenbelt Rd,Suite 400, Lanham, MD 20706 USA. NR 3 TC 0 Z9 0 U1 0 U2 2 PU INFORMATION TODAY INC PI MEDFORD PA 143 OLD MARLTON PIKE, MEDFORD, NJ 08055 USA SN 0044-7870 BN 1-57387-167-2 J9 P ASIST ANNU PY 2002 VL 39 BP 545 EP 546 DI 10.1002/meet.14503901104 PG 2 WC Computer Science, Information Systems; Information Science & Library Science; Social Issues SC Computer Science; Information Science & Library Science; Social Issues GA BV87V UT WOS:000180277800104 ER PT S AU Mazzarella, JM Madore, BF Bennett, J Corwin, H Helou, G Kelly, A Schmitz, M Skiff, B AF Mazzarella, JM Madore, BF Bennett, J Corwin, H Helou, G Kelly, A Schmitz, M Skiff, B BE Starck, JL Murtagh, FD TI Analysis and visualization of multiwavelength spectral energy distributions in the NASA/IPAC Extragalactic Database (NED) SO ASTRONOMICAL DATA ANALYSIS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Astronomical Data Analysis II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE databases; information retrieval; knowledge discovery; classification; astronomy; galaxies ID ACTIVE GALACTIC NUCLEI; GALAXIES; FEATURES AB The NASA/IPAC Extragalactic Database (NED, http://ned.i.pac.calteeb..edu/) currently contains over 4.5 million photometric measurements covering the electromagnetic spectrum from gamma rays through radio wavelengths for objects that are being cross-correlated among major sky surveys (e.g., 2MASS, SDSS, IRAS, NVSS, FIRST) and thousands of smaller, but unique and important, catalogs and journal articles. The ability to retrieve photometric data (including uncertainties, aperture information, and references) and display spectral energy distributions (SEDs) for individual objects has been available in NED for six years. In this paper we summarize recent enhancements that enable construction of large panchromatic data sets to facilitate multidimensional photometric analysis. The database can now be queried for samples of objects that meet flux constraints at any wavelength (e.g., objects with any available 20cm flux, or objects with f(nu)[10mum] > 5.0 Jy). The ability to utilize criteria involving flux ratios (e.g., objects with f(nu)[20cm]/f(nu)[60mum] > 0.5) is under development. Such queries can be jointly combined with additional constraints on sky area, redshifts, object types, or sample membership, and the data are output with consistent physical units required for comparative analysis. Some results derived from fused photometric data in NED are presented to highlight the large number and diversity of available SEDs. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Mazzarella, JM (reprint author), CALTECH, Jet Prop Lab, MS 100-22, Pasadena, CA 91125 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 0-8194-4626-2 J9 P SOC PHOTO-OPT INS PY 2002 VL 4847 BP 254 EP 264 DI 10.1117/12.461048 PG 11 WC Astronomy & Astrophysics; Computer Science, Interdisciplinary Applications; Optics; Imaging Science & Photographic Technology; Spectroscopy SC Astronomy & Astrophysics; Computer Science; Optics; Imaging Science & Photographic Technology; Spectroscopy GA BW03E UT WOS:000180673000024 ER PT S AU Yanamandra-Fisher, PA Braverman, A Orton, GS AF Yanamandra-Fisher, PA Braverman, A Orton, GS BE Starck, JL Murtagh, FD TI Physical and statistical modeling of Saturn's troposphere SO ASTRONOMICAL DATA ANALYSIS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Astronomical Data Analysis II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union DE Saturn; planetary atmospheres; spectroscopy; phosphine; statistical methods; PCA ID LINES AB The 5.2-mum atmospheric window on Saturn is dominated by thermal radiation and weak gaseous absorption, with a 20% contribution from sunlight reflected from clouds. The striking variability displayed by Saturn's clouds at 5.2 mum(1) and the detection of PH3 (an atmospheric tracer) variability near or below the 2-bar level and possibly at lower pressures provide salient constraints on the dynamical organization of Saturn's atmosphere by constraining the strength of vertical motions at two levels across the disk. We analyse the 5.2-mum spectra of Saturn by utilising two independent methods: (a) physical models based on the relevant atmospheric parameters and (b) statistical analysis, based on principal components analysis (PCA), to determine the influence of the variation of phosphine and the opacity of clouds deep within Saturn's atmosphere to understand the dynamics in its atmosphere. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yanamandra-Fisher, PA (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 SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4626-2 J9 P SOC PHOTO-OPT INS PY 2002 VL 4847 BP 337 EP 343 DI 10.1117/12.461068 PG 7 WC Astronomy & Astrophysics; Computer Science, Interdisciplinary Applications; Optics; Imaging Science & Photographic Technology; Spectroscopy SC Astronomy & Astrophysics; Computer Science; Optics; Imaging Science & Photographic Technology; Spectroscopy GA BW03E UT WOS:000180673000033 ER PT S AU Pence, WD AF Pence, WD BE Starck, JL Murtagh, FD TI New image compression capabilities in CFITSIO SO ASTRONOMICAL DATA ANALYSIS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Astronomical Data Analysis II CY AUG 27-28, 2002 CL WAIKOLOA, HI SP SPIE, Int Commiss Opt, Amer Astron Soc, European SO Observ, Int Astron Union AB The previously proposed tiled-image compression scheme is now fully supported when reading and writing FITS images using the CFITSIO subroutine library. This scheme generally produces image compression factors that are superior to the standard gzip or unix compress algorithms, especially when compressing floating point data type images. In addition to reducing the required amount of disk space to store the image, this compression technique often makes applications programs run faster because of the reduced amount of magnetic disk I/O that is required to read or write the image. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Pence, WD (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. NR 2 TC 5 Z9 5 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 0-8194-4626-2 J9 P SOC PHOTO-OPT INS PY 2002 VL 4847 BP 444 EP 447 DI 10.1117/12.461053 PG 4 WC Astronomy & Astrophysics; Computer Science, Interdisciplinary Applications; Optics; Imaging Science & Photographic Technology; Spectroscopy SC Astronomy & Astrophysics; Computer Science; Optics; Imaging Science & Photographic Technology; Spectroscopy GA BW03E UT WOS:000180673000045 ER PT B AU McGlynn, T Angelini, L Corcoran, N Drake, S Pence, W White, N Hanisch, R White, R Postman, M Donahue, M Suchkov, A Genova, F Ochsenbein, F Fernique, P Wenger, M AF McGlynn, T Angelini, L Corcoran, N Drake, S Pence, W White, N Hanisch, R White, R Postman, M Donahue, M Suchkov, A Genova, F Ochsenbein, F Fernique, P Wenger, M BE Bohlender, DA Durand, D Handley, TH TI ClassX: Prototyping the Virtual Observatory with an X-ray classifier SO ASTRONOMICAL DATA ANALYSIS SOFTWARE AND SYSTEMS XI SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 11th Annual Conference for Astronomical Data Analysis Software and Systems CY SEP 30-OCT 03, 2001 CL VICTORIA, CANADA SP Natl Res Council Canada, CADC, NCSA, Natl Radio Astron Observ, Canadian France Hawaii Telescope Corp, Natl Sci Fdn, NASA, Natl Opt Astron Observ, IPAC, Space Telescope Sci Inst AB We describe early results from a collaboration of the HEASARC, STScI, and CDS to develop an automated X-ray classifier. This classifier will use existing distributed information on the Web to categorize astronomical sources. While the classifier will be very useful scientifically this project is also funded to prototype several aspects of the Virtual Observatory including coherent combination of information from many remote sites, cross-correlation of large legacy databases, and instantiation of user agents to perform complex tasks over the Internet. In addition to our science goals and the delivery of the X-ray classifier to the user community, we anticipate that our experience building the classifier will suggest appropriate methodologies for building other classifiers and Virtual Observatory tools. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP McGlynn, T (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI White, Richard/A-8143-2012; White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 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 BN 1-58381-124-9 J9 ASTR SOC P PY 2002 VL 281 BP 50 EP 53 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW17P UT WOS:000181074700009 ER PT B AU Berriman, GB Kong, M Good, JC Lonsdale, CJ Voges, W Henry, TJ Bean, JL Blackwell, J AF Berriman, GB Kong, M Good, JC Lonsdale, CJ Voges, W Henry, TJ Bean, JL Blackwell, J BE Bohlender, DA Durand, D Handley, TH TI The On-Line Archive Science Information Services (OASIS) as an enabling technology for visual cross-comparisons between multiple data sets SO ASTRONOMICAL DATA ANALYSIS SOFTWARE AND SYSTEMS XI SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 11th Annual Conference for Astronomical Data Analysis Software and Systems CY SEP 30-OCT 03, 2001 CL VICTORIA, CANADA SP Natl Res Council Canada, CADC, NCSA, Natl Radio Astron Observ, Canadian France Hawaii Telescope Corp, Natl Sci Fdn, NASA, Natl Opt Astron Observ, IPAC, Space Telescope Sci Inst AB Wide differences between the positional and photometric quality of astronomical data sets requires visual examination for accurate cross-identifications of sources between data sets. Given the tedium involved in these comparisons, astronomers need methods to perform rapid cross-comparisons. The On-Line Science Information Services (OASIS), a Java toolkit recently released by the IPAC Infrared Science Archive (IRSA), provides such capability. OASIS is a collection of services, designed to be run independently of each other, that access and integrate multiple image and catalog archives. Its first release provides access to IRAS, 2MASS, MSX, FIRST, and NVSS images, and is interoperable with NED and CDS. We describe its applicability to two projects that require bulk visual cross-identification: the NStars database, which serves quality controlled data for all stellar, substellar, and planetary objects within 25 parsecs of the Sun; and identification of far-IR counterparts of 750 active galaxies measured by ROSAT. C1 CALTECH, Infrared Proc & Anal Ctr, Pasadena, CA 91125 USA. Max Planck Inst Extraterr Phys, MPIA, D-85748 Garching, Germany. Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. NASA, Ames Res Ctr, Nearby Stars Observ, Moffett Field, CA 94035 USA. RP Berriman, GB (reprint author), CALTECH, Infrared Proc & Anal Ctr, Mail Code 100-22,770 S Wilson Ave, Pasadena, CA 91125 USA. NR 0 TC 1 Z9 1 U1 0 U2 3 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-124-9 J9 ASTR SOC P PY 2002 VL 281 BP 63 EP 67 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW17P UT WOS:000181074700012 ER PT B AU Arendt, RG Fixsen, DJ Moseley, SH AF Arendt, RG Fixsen, DJ Moseley, SH BE Bohlender, DA Durand, D Handley, TH TI A practical demonstration of self-calibration of NICMOS HDF north and south data SO ASTRONOMICAL DATA ANALYSIS SOFTWARE AND SYSTEMS XI SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 11th Annual Conference for Astronomical Data Analysis Software and Systems CY SEP 30-OCT 03, 2001 CL VICTORIA, CANADA SP Natl Res Council Canada, CADC, NCSA, Natl Radio Astron Observ, Canadian France Hawaii Telescope Corp, Natl Sci Fdn, NASA, Natl Opt Astron Observ, IPAC, Space Telescope Sci Inst ID ARRAY CAMERA IRAC AB The Hubble Space Telescope (HST) Near Infrared Camera and Multi-Object Spectrometer (NICMOS) observations of the Hubble Deep Field-North (HDF-N) and Hubble Deep Field-South (HDF-S) are used as a test case for application of a least-squares self-calibration procedure. These data are well suited for self-calibration because the observations were dithered in a manner that provides fairly direct correlations between all the pixels of the detector. The data model we use in the self-calibration procedure explicitly includes the sky intensity, the detector gains (flat field), the detector offsets (darks), and a large-scale temporally-variable offset, in this case an offset per detector quadrant per frame which allows modeling of the "pedestal" effect of the NICMOS camera. By applying the self-calibration to the combined HDF-N and HDF-S data set, the detector properties and sky intensities are derived and their uncertainties are formally calculated. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Arendt, RG (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 685, Greenbelt, MD 20771 USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-124-9 J9 ASTR SOC P PY 2002 VL 281 BP 217 EP 227 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW17P UT WOS:000181074700047 ER PT B AU Catanzarite, J Milman, M AF Catanzarite, J Milman, M BE Bohlender, DA Durand, D Handley, TH TI Characterization of least squares interferometric fringe fitting algorithms SO ASTRONOMICAL DATA ANALYSIS SOFTWARE AND SYSTEMS XI SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 11th Annual Conference for Astronomical Data Analysis Software and Systems CY SEP 30-OCT 03, 2001 CL VICTORIA, CANADA SP Natl Res Council Canada, CADC, NCSA, Natl Radio Astron Observ, Canadian France Hawaii Telescope Corp, Natl Sci Fdn, NASA, Natl Opt Astron Observ, IPAC, Space Telescope Sci Inst AB We report results of a comprehensive Monte Carlo simulation study of an eight-bin optimal least squares algorithm for fringe detection. We present a new bias-corrected estimator for squared visibility. We determine ranges of star brightness and initial delay offset for which the algorithm yields accurate bias-corrected estimates of delay and squared visibility. We validate analytic models for the estimator variances. C1 CALTECH, Jet Prop Lab, Interferometry Sci Ctr, Pasadena, CA 91125 USA. RP Catanzarite, J (reprint author), CALTECH, Jet Prop Lab, Interferometry Sci Ctr, 4800 Oak Grove Dr,Mail Stop 301-486, Pasadena, CA 91125 USA. NR 1 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 1-58381-124-9 J9 ASTR SOC P PY 2002 VL 281 BP 256 EP 259 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW17P UT WOS:000181074700053 ER PT B AU Offenberg, JD Fixsen, DJ Sengupta, R Nieto-Santisteban, MA AF Offenberg, JD Fixsen, DJ Sengupta, R Nieto-Santisteban, MA BE Bohlender, DA Durand, D Handley, TH TI Autonomous science instrument operations: Data analysis and processing SO ASTRONOMICAL DATA ANALYSIS SOFTWARE AND SYSTEMS XI SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 11th Annual Conference for Astronomical Data Analysis Software and Systems CY SEP 30-OCT 03, 2001 CL VICTORIA, CANADA SP Natl Res Council Canada, CADC, NCSA, Natl Radio Astron Observ, Canadian France Hawaii Telescope Corp, Natl Sci Fdn, NASA, Natl Opt Astron Observ, IPAC, Space Telescope Sci Inst ID COSMIC-RAY REJECTION AB An autonomous space observatory offers a new method for efficient data collection. For example, autonomous data analysis allows the system to collect data which meets the required signal-to-noise-if the desired metric is reached early, we can quit and move on instead of continuing an already-completed observation. Similarly, if the observation proves to be harder than anticipated, it can be extended until the desired signal-to-noise is attained; or an obviously hopeless observation call be abandoned. Similarly, a quick-look observation enables the observatory to autonomously select the optimal roll angle to minimize confusion for a multi-object spectrometer. We present a system to perform autonomous data analysis for a large-area imaging array. Cosmic ray mitigation, signal-to-noise tracking, and saturating pixel detection are reliably performed in a "lights-out" environment. The software presented is general and can be adapted to many different instruments and goals. The computational requirements are modest and are suitable for use with a flight-configuration computer or in an embedded environment with a DSP. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Offenberg, JD (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 5 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 1-58381-124-9 J9 ASTR SOC P PY 2002 VL 281 BP 328 EP 331 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW17P UT WOS:000181074700070 ER PT B AU Miner, ED AF Miner, ED BE Bohlender, DA Durand, D Handley, TH TI The Cassini-Huygens mission to Saturn and Titan SO ASTRONOMICAL DATA ANALYSIS SOFTWARE AND SYSTEMS XI SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 11th Annual Conference for Astronomical Data Analysis Software and Systems CY SEP 30-OCT 03, 2001 CL VICTORIA, CANADA SP Natl Res Council Canada, CADC, NCSA, Natl Radio Astron Observ, Canadian France Hawaii Telescope Corp, Natl Sci Fdn, NASA, Natl Opt Astron Observ, IPAC, Space Telescope Sci Inst AB On 15 October 1997, the most capable interplanetary spacecraft ever built was launched from Cape Canaveral Air Station near Cocoa Beach, Florida, atop a Titan 4B/Centaur launch vehicle. The Cassini spacecraft has used flyby gravitational assists at Venus (twice), Earth (once), and Jupiter (once) on its way to reaching its target nearly seven years after launch. On July 1, 2004, the spacecraft will be inserted into orbit around the ringed planet; its primary mission concludes four years later on July 1, 2008. This article provides an overview of the design of the Cassini spacecraft (including its Huygens probe), a description of the mission, and a brief outline of the scientific objectives. While the Voyager 1 and 2 flybys in 1980 and 1981 provided a first close examination of the giant planet Saturn, Cassini's 27 scientific investigations will do an in-depth four-year orbital study of the system. Early in its orbital tour around Saturn, Cassini will release its Huygens probe (built by the European Space Agency), which will traverse the atmosphere of Saturn's largest moon, Titan, and collect data from its surface. Titan is the second largest moon in the solar system and the only one that possesses a substantial atmosphere. Six scientific instrument packages are part of the Huygens probe. The Cassini orbiter carries an additional 12,instrument packages. Nine interdisciplinary investigations utilize data from two or more instruments to complete their scientific studies. In addition to Titan, the scientific objectives address better understanding of the atmosphere and interior of Saturn, of the complex ring system, of the seventeen presently known icy moons (excluding the 12 recently discovered outer moons), and of the huge magnetic bubble surrounding Saturn known as the magnetosphere. Scientists from at least 16 nations are involved in these studies. C1 NASA, Jet Prop Lab, Pasadena, CA USA. RP Miner, ED (reprint author), NASA, Jet Prop Lab, Pasadena, CA USA. NR 0 TC 5 Z9 5 U1 0 U2 2 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-124-9 J9 ASTR SOC P PY 2002 VL 281 BP 373 EP 381 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW17P UT WOS:000181074700080 ER PT J AU Szkody, P Nishikida, K Erb, D Mukai, K Hellier, C Uemura, M Kato, T Pavlenko, E Katysheva, N Shugarov, S Cook, L AF Szkody, P Nishikida, K Erb, D Mukai, K Hellier, C Uemura, M Kato, T Pavlenko, E Katysheva, N Shugarov, S Cook, L TI X-ray/optical studies of two outbursts of the intermediate polar YY (DO) Draconis SO ASTRONOMICAL JOURNAL LA English DT Article DE novae, cataclysmic variables; stars : individual (YY Draconis, DO Draconis); X-rays ID CATACLYSMIC VARIABLES; RAPID OSCILLATIONS; TV-COLUMBAE; 3A 1148+719; EX HYDRAE AB YY Draconis ( likely the same variable called DO Draconis) is one of a small number of intermediate polars (IPs) that show outburst behavior. We report results from Target of Opportunity observations with the Rossi X-Ray Timing Explorer, together with ground-based optical photometry during outbursts in 1999 September and 2000 November. Similar behavior was evident in both outbursts. At outburst, the X-ray flux increased by more than a factor of 12, and the spectrum became hotter and more absorbed compared to quiescence. While the spin pulse at 529 s is clearly present in the X-ray data at 2-4 days past outburst peak and during quiescence, it was not detected in the X-ray data closest to outburst (1.5 days). This is contrary to the large increase in spin pulse amplitude that has been seen during outbursts of the IPs GK Per, XY Ari, and EX Hya. The differences in YY Dra are likely due to its unique geometry, with two relatively equal poles located near the white dwarf equator. The equal enhancement of both poles near outburst could account for the low pulse amplitude, while unequal feeding of the poles as the magnetosphere recedes during decline could explain the changes in amplitude and pulse shape. The changing height of the shocks may also have an effect on the visibility of both poles. C1 Univ Washington, Dept Astron, Seattle, WA 98195 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Keele, Dept Phys, Keele ST5 5BG, Staffs, England. Kyoto Univ, Dept Astron, Sakyo Ku, Kyoto 6068502, Japan. Crimean Astrophys Observ, UA-334413 Nauchnyi, Crimea, Ukraine. Isaac Newton Inst Chile, Crimean Branch, Nauchnyi, Ukraine. Moscow MV Lomonosov State Univ, Sternberg Astron Inst, Moscow 119899, Russia. Ctr Backyard Astrophys, Concord, MA 01742 USA. RP Szkody, P (reprint author), Univ Washington, Dept Astron, Box 351580, Seattle, WA 98195 USA. EM szkody@astro.washington.edu; kaori@astro.washington.edu; dkerb@astro.caltech.edu; mukai@milkyway.gsfc.nasa.gov; ch@astgro.keele.ac.uk; uemura@kusastro.kyoto-u.ac.jp; tkato@kusastro.kyoto-u.ac.jp NR 22 TC 20 Z9 20 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD JAN PY 2002 VL 123 IS 1 BP 413 EP 419 DI 10.1086/324733 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 520EJ UT WOS:000173767400031 ER PT J AU Bogdan, TJ Rosenthal, CS Carlsson, M Hansteen, V McMurry, A Zita, EJ Johnson, M Petty-Powell, S McIntosh, SW Nordlund, A Stein, RF Dorch, SBF AF Bogdan, TJ Rosenthal, CS Carlsson, M Hansteen, V McMurry, A Zita, EJ Johnson, M Petty-Powell, S McIntosh, SW Nordlund, A Stein, RF Dorch, SBF TI Waves in magnetic flux concentrations: The critical role of mode mixing and interference SO ASTRONOMISCHE NACHRICHTEN LA English DT Article DE stars : oscillations; stars : spots; Sun AB Time-dependent numerical simulations of nonlinear wave propagation in a two-dimensional (slab) magnetic field geometry show wave mixing and interference to be important aspects of oscillatory phenomena in starspots and sunspots. Discrete sources located within the umbra generate both fast and slow MHD waves, The latter are compressive acoustic waves which are guided along the magnetic field lines and steepen into N-waves with increasing height ill the,pot atmosphere, The former are less compressive, and accelerate rapidly upward through the overlying low-beta portion of the umbral photosphere and chromosphere (beta = 8pip/B-2). As the fast wave fronts impinge upon the beta approximate to 1 penumbral "magnetic canopy" from above, they interfere with the outward-propagating field-guided slow waves, and they also mode convert to (non-magnetic) acoustic-gravity waves as they penetrate into the weak magnetic field region which lies between the penumbral canopy and the base of the Surrounding photosphere. In a three-dimensional situation. one expect,, additional generation. mixing and interference with the remaining torsional Alfven waves. C1 Natl Sci Fdn, Arlington, VA 22300 USA. USN, Res Lab, Washington, DC 20375 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Evergreen State Coll, Olympia, WA 98505 USA. NASA, Goddard Space Flight Ctr, ESA Res & Sci Support Dept, Greenbelt, MD 20771 USA. Univ Copenhagen, NBIfAFG, DK-2100 Copenhagen O, Denmark. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Stockholm Observ, Royal Swedish Acad Sci, SE-13336 Saltsjobaden, Sweden. RP Bogdan, TJ (reprint author), Natl Sci Fdn, 4201 Wilson Blvd, Arlington, VA 22300 USA. RI Dorch, Bertil/A-7378-2012; Nordlund, Aake/M-4528-2014 OI Dorch, Bertil/0000-0003-2594-6778; Nordlund, Aake/0000-0002-2219-0541 NR 5 TC 24 Z9 24 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0004-6337 J9 ASTRON NACHR JI Astro. Nachr. PY 2002 VL 323 IS 3-4 BP 196 EP 202 DI 10.1002/1521-3994(200208)323:3/4<196::AID-ASNA196>3.0.CO;2-E PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 591DU UT WOS:000177865100007 ER PT J AU Ioannou, Z Naylor, T Smale, AP Charles, PA Mukai, K AF Ioannou, Z Naylor, T Smale, AP Charles, PA Mukai, K TI Understanding the LMXB x2127+119 in M15 - I. X-ray eclipses and dips SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE accretion, accretion discs; X-rays : binaries; stars : binaries : eclipsing, coronae; stars : individual : X2127+119, AC211 ID GLOBULAR-CLUSTERS; OPTICAL COUNTERPART; ENERGY-SPECTRA; BINARIES; PERIOD; BURST AB We present X-ray observations of the high-inclination low-mass X-ray binary system X2127+119 (AC211) in the globular cluster M15 (NGC 7078). The observations consist of data acquired in 1996 with the RXTE satellite and in 1995 with the ASCA satellite. Also, the MPC1 data from the 1988 GINGA observations were de-archived and re-analysed. The phase-folded 2{10 keV hardness ratios from all three missions differ significantly indicating that the system can exhibit different spectral behaviours. We find that the X-ray eclipse profiles can be described relatively well using a simple model where the secondary star passes in front of a large X-ray emitting region. For this we require a mass ratio (q = M-1/M-2) of about one. The radius of this X-ray emitting region is similar to0.8 R-L1 and its vertical extent similar to60degrees above the orbital plane. We suggest that if this X-ray emitting region were an optically thick corona, it would explain various puzzling aspects of this system. We also show that the X-ray dip observed at phases around 0.65 does not conform with the idea that the dip is caused by vertically extended material associated with the stream/disc impact region, but that it could be due to structure in the inner parts of the disc. C1 Univ Keele, Dept Phys, Keele ST5 5BG, Staffs, England. Univ Exeter, Sch Phys, Exeter EX4 4QL, Devon, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. RP Ioannou, Z (reprint author), Univ Texas, Dept Astron, C-1400, Austin, TX 78712 USA. RI Naylor, Tim /A-9465-2015 NR 30 TC 7 Z9 7 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JAN PY 2002 VL 382 IS 1 BP 130 EP 140 DI 10.1051/0004-6361:20011581 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 515XT UT WOS:000173522500015 ER PT J AU Markwick, AJ Millar, TJ Charnley, SB AF Markwick, AJ Millar, TJ Charnley, SB TI CH2DCCH along the TMC-1 ridge SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE MHD : waves; ISM : abundances; ISM : molecules; ISM : individual (Taurus molecular cloud) molecular processes ID MOLECULAR CLOUDS; CHEMISTRY AB In this paper we present measurements of the CH2DCCH/CH3CCH ratio along the TMC-1 ridge. The level of deuterium fractionation in this molecule is found to be larger than previously thought, but more significantly, the fractionation increases as one moves from the cyanopolyyne peak to the ammonia peak, as is the case with measurements of other molecules in TMC-1. This confirms the prediction of our recent chemical/dynamical model of TMC-1 and supports the hypothesis that the chemical evolution of TMC-1 has been affected by Alfven waves. C1 UMIST, Dept Phys, Manchester M60 1QD, Lancs, England. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Markwick, AJ (reprint author), UMIST, Dept Phys, POB 88, Manchester M60 1QD, Lancs, England. RI Charnley, Steven/C-9538-2012; OI Millar, Tom/0000-0001-5178-3656 NR 19 TC 5 Z9 5 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD JAN PY 2002 VL 381 IS 2 BP 560 EP 565 DI 10.1051/0004-6361:20011381 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 512UZ UT WOS:000173343100021 ER PT J AU Levinson, A Boldt, E AF Levinson, A Boldt, E TI UHECR production by a compact black hole dynamo: application to Sgr A SO ASTROPARTICLE PHYSICS LA English DT Article DE cosmic rays; gamma rays; Galactic center ID ADVECTION-DOMINATED ACCRETION; SAGITTARIUS A-ASTERISK; GALACTIC-CENTER; COSMIC-RAYS; REMNANTS; GALAXY; MODEL; WINDS AB The possibility that the excess cosmic ray (CR) flax near 10(18) eV, reported recently by the AGASA group, is due to a compact black hole dynamo associated with the Sgr A(+) source is considered. Under the assumption that the Galactic center black hole rotates with nearly maximal spin, and that the magnetic field threading the horizon is in rough equipartition with matter accreted by the hole, the spectra and total fluxes of accelerated CRs and their associated curvature emission depend only on accretion rate. For the accretion rate estimated on the basis of observations of stellar winds near Sgr A* (similar to10(-3) Eddington), the maximum proton energy achievable by this mechanism is of the order of 10(18) eV, and the corresponding CR power is similar to10(41)alpha(CR) ergs(-1), where alpha(CR) much less than 1 is the CR production efficiency. The corresponding spectrum of curvature photons peaks at around 100 GeV, with a total luminosity comparable to the CR power released. For much lower accretion rates both the CR and gamma-ray fluxes predicted are completely insignificant. Upcoming gamma-ray experiments, such as CANGAROO, HESS and GLAST, can be used to probe the parameters of this system. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Tel Aviv Univ, Sch Phys & Astronomy, IL-69978 Tel Aviv, Israel. NASA, Goddard Space Flight Ctr, Lab High Energy Astrophys, Greenbelt, MD 20771 USA. RP Levinson, A (reprint author), Tel Aviv Univ, Sch Phys & Astronomy, IL-69978 Tel Aviv, Israel. NR 22 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 J9 ASTROPART PHYS JI Astropart Phys. PD JAN PY 2002 VL 16 IS 3 BP 265 EP 270 DI 10.1016/S0927-6505(01)00116-5 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 509JE UT WOS:000173144000004 ER PT J AU Scully, ST Stecker, FW AF Scully, ST Stecker, FW TI On the spectrum of ultrahigh energy cosmic rays and the gamma-ray burst origin hypothesis SO ASTROPARTICLE PHYSICS LA English DT Article DE gamma-ray bursts; cosmic rays; theory ID GRB-970508; REDSHIFT AB It has been suggested that cosmological gamma-ray bursts (GRBs) can produce the observed flux of cosmic rays at the highest energies. However, recent studies of GRBs indicate that their redshift distribution likely follows the average star formation rate of the universe and that GRBs were more numerous at high redshifts. As a consequence, we show that photomeson production energy losses suffered by ultrahigh energy cosmic rays coming from GRBs would produce too sharp a spectral energy cutoff to be consistent with the air shower data. Futhermore, we show that cosmolgical GRBs fail to supply the energy input required to account for the cosmic ray flux above 10(19) eV by a factor of 100-1000. (C) 2002 Elsevier Science B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM stecker@twinkie.gsfc.nasa.gov RI Stecker, Floyd/D-3169-2012 NR 38 TC 32 Z9 32 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 EI 1873-2852 J9 ASTROPART PHYS JI Astropart Phys. PD JAN PY 2002 VL 16 IS 3 BP 271 EP 276 DI 10.1016/S0927-6505(01)00133-5 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 509JE UT WOS:000173144000005 ER PT J AU Chiang, J Bottcher, M AF Chiang, J Bottcher, M TI Synchrotron and synchrotron self-Compton spectral signatures and blazar emission models SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; gamma rays : theory; radiation mechanisms : nonthermal ID BL LACERTAE; MULTIWAVELENGTH OBSERVATIONS; RAY; OUTBURST; JETS AB We find that energy losses due to synchrotron self-Compton (SSC) emission in blazar jets can produce distinctive signatures in the time-averaged synchrotron and SSC spectra of these objects. For a fairly broad range of particle injection distributions, SSC-loss-dominated synchrotron emission exhibits a spectral dependence F-v similar to nu(-3/2). The presence or absence of this dependence in the optical and ultraviolet spectra of flat-spectrum radio quasars such as 3C 279 and in the soft X-ray spectra of high-frequency BL Lac objects such as Mrk 501 gives a robust measure of the importance of SSC losses. Furthermore, for partially cooled particle distributions, spectral breaks of varying sizes can appear in the synchrotron and SSC spectra and will be related to the spectral indices of the emission below the break. These spectral signatures place constraints on the size scale and the nonthermal particle content of the emitting plasma, as well as the observer orientation relative to the jet axis. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Joint Ctr Astrophys, Baltimore, MD 21250 USA. Univ Maryland, Dept Phys, Baltimore, MD 21250 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. RP Chiang, J (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 18 TC 21 Z9 21 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 92 EP 96 DI 10.1086/324294 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300010 ER PT J AU Romano, P Turner, TJ Mathur, S George, IM AF Romano, P Turner, TJ Mathur, S George, IM TI A 12 day ASCA observation of the narrow-line Seyfert 1 galaxy Ton S180: Time-selected spectroscopy SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (Ton S180); galaxies : nuclei; galaxies : Seyfert; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; X-RAY PROPERTIES; EMISSION-LINES; QUASARS; VARIABILITY; SPECTRA; IMAGER; SIZES; DISK AB We present an analysis of the X-ray variability properties of the narrow-line Seyfert 1 galaxy Ton S180, based on a 12 day continuous observation with ASCA. Examination of the light curves reveals flux variations of a factor of 3.5 in the 0.7-1.3 keV band and 3.9 in the 2-10 keV band. Time-resolved spectroscopy, using approximately daily sampling, reveals that the broad "soft hump" component at energies less than 2 keV shows flux variations on timescales as short as 1 day that are well correlated with the photon index and the 2-10 keV band flux. A broad Fe Kalpha emission is detected. There is also statistically significant evidence for a narrow Fe Kalpha line at similar to6.8 keV, indicating an origin in ionized material. We do not detect significant variations of the Fe Kalpha line flux or equivalent width on timescales of similar to1 day to 1 week. Despite evidence for correlated events in the power law and soft hump on timescales of a day, the flux correlations clearly do not exist on all timescales. In particular, the softness ratio reveals spectral variability on timescales as short as similar to1000 s, indicating that the power-law continuum and soft hump fluxes are not well correlated on this timescale. The softness ratio also shows a slow decline across the observation, due to a combination of the different time variability of the power-law continuum and soft hump flux on timescales of similar to1 week. Our timing analysis and time-selected spectroscopy indicate that the X-ray emission originates within 12 Schwarzschild radii. The amplitudes and timescales of the rapid variations that we observed are consistent with those expected within disk-corona models. Furthermore, the observed fast variability of the soft hump rules out an origin of the soft emission in large-scale components, such as circumnuclear starburst. The Gamma-soft hump correlation is consistent with the soft hump being produced by upscattering of the accretion disk radiation within a patchy, flaring disk corona. C1 Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Romano, P (reprint author), Ohio State Univ, Dept Astron, 140 W 18th Ave, Columbus, OH 43210 USA. OI Romano, Patrizia/0000-0003-0258-7469 NR 59 TC 15 Z9 15 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 162 EP 175 DI 10.1086/324201 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300018 ER PT J AU Young, AJ Wilson, AS Terashima, Y Arnaud, KA Smith, DA AF Young, AJ Wilson, AS Terashima, Y Arnaud, KA Smith, DA TI A Chandra X-ray study of Cygnus A. II. The nucleus SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (Cygnus A); galaxies : nuclei; X-rays : galaxies ID TYPE-2 SEYFERT-GALAXIES; ACTIVE GALACTIC NUCLEI; ASCA OBSERVATIONS; LINE EMISSION; RADIO GALAXY; SPECTROSCOPY; CONTINUUM; JET; CLUSTERS; SPECTRUM AB We report Chandra Advanced CCD Imaging Spectrometer and quasi-simultaneous Rossi X-Ray Timing Explorer (RXT E) observations of the nearby, powerful radio galaxy Cygnus A, with the present paper focusing on the properties of the active nucleus. In the Chandra observation, the hard (>a few keV) X-ray emission is spatially unresolved with a size less than or similar to1" (1.5 kpc, H-o = km s(-1) Mpc(-1)) and coincides with the radio and near-infrared nuclei. In contrast, the soft (<2 keV) emission exhibits a bipolar nebulosity that aligns with the optical bipolar continuum and emission-line structures and approximately with the radio jet. In particular, the soft X-ray emission corresponds very well with the [O III] λ5007 and Hα + [N II] λλ6548, 6583 nebulosity imaged with Hubble Space Telescope. At the location of the nucleus, there is only weak soft X-ray emission, an effect that may be intrinsic or result from a dust lane that crosses the nucleus perpendicular to the source axis. The spectra of the various X-ray components have been obtained by simultaneous fits to the six detectors. The compact nucleus is detected to 100 keV and is well described by a heavily absorbed power-law spectrum with &UGamma;(h) = 1.52(-0.12)(+0.12) (similar to other narrow-line radio galaxies) and equivalent hydrogen column N-H(nuc) = 2.0(-0.2)(+0.1) x 10(23) cm(-2). This column is compatible with the dust obscuration to the near-infrared source for a normal gas-to-dust ratio. The soft (<2 keV) emission from the nucleus may be described by a power-law spectrum with the same index (i.e., &UGamma;(l) = &UGamma;(h)), although direct fits suggest a slightly larger value for &UGamma;(l). Narrow emission lines from highly ionized neon and silicon, as well as a "neutral" Fe Kα line, are detected in the nucleus and its vicinity (r &LSIM; 2 kpc). The equivalent width (EW) of the Fe Kα line (182(-54)(+40) eV) is in good agreement with theoretical predictions for the EW versus relationship in various geometries. An Fe K edge is also seen. The RXT E observations indicate a temperature of keV for the cluster gas kT = 6.9(-1.0)(+0.3) (discussed in Paper III of this series) and cluster emission lines of Fe Kalpha and Fe Kbeta and/or Ni Kalpha. We consider the possibility that the extended soft X-ray emission is electron-scattered nuclear radiation. Given that 1% of the unabsorbed 2-10 keV nuclear radiation would have to be scattered, the necessary gas column [N-H(scattering) similar or equal to 3.5 x 10(22) cm(-2)] would absorb the X-rays rather than scatter them if the gas is cold. Thus, the scattering plasma must be highly ionized. If this ionization is achieved through photoionization by the nucleus, the ionization parameter xi>1 ergs cm s(-1) and the electron density n(e) similar or equal to 6 cm(-3) given the observed distance of the soft X-ray emission from the nucleus. The electron column density inferred from the X-ray observations is much too low to account for the extended optical scattered light, strongly suggesting that the polarized optical light is scattered by dust. The presence of highly ionized Ne lines in the soft X-ray spectrum requires 20 ergs cm ergs cm s(-1) less than or similar to xi less than or similar to 300 ergs cm s(-1); these lines may originate closer to the nucleus than the extended soft continuum or in a lower density gas. A collisionally ionized thermal model of the extended soft X-rays cannot be ruled out but is unattractive in view of the low metal abundance required (Z = 0.03 Z(.)). The hard X-ray to far-infrared ratio for the nucleus of Cygnus A is similar to that seen in Seyfert 1 and unobscured radio galaxies. By means of the correlation between hard X-ray luminosity and nuclear optical absolute magnitude for these classes of object, we estimate M-B = -22.4 for Cygnus A, near the borderline between Seyfert galaxies and QSOs. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Young, AJ (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NR 47 TC 57 Z9 57 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 176 EP 189 DI 10.1086/324200 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300019 ER PT J AU Wang, JZ Seo, ES Anraku, K Fujikawa, M Imori, M Maeno, T Matsui, N Matsunaga, H Motoki, M Orito, S Saeki, T Sanuki, T Ueda, I Yoshimura, K Makida, Y Suzuki, J Tanaka, K Yamamoto, A Yoshida, T Mitsui, T Matsumoto, H Nozaki, M Sasaki, M Mitchell, J Moiseev, A Ormes, J Streitmatter, R Nishimura, J Yajima, Y Yamagami, T AF Wang, JZ Seo, ES Anraku, K Fujikawa, M Imori, M Maeno, T Matsui, N Matsunaga, H Motoki, M Orito, S Saeki, T Sanuki, T Ueda, I Yoshimura, K Makida, Y Suzuki, J Tanaka, K Yamamoto, A Yoshida, T Mitsui, T Matsumoto, H Nozaki, M Sasaki, M Mitchell, J Moiseev, A Ormes, J Streitmatter, R Nishimura, J Yajima, Y Yamagami, T TI Measurement of cosmic-ray hydrogen and helium and their isotopic composition with the BESS experiment SO ASTROPHYSICAL JOURNAL LA English DT Article DE balloons; cosmic rays; elementary particles; nuclear reactions, nucleosynthesis, abundances ID TOTAL CROSS-SECTIONS; BALLOON-BORNE EXPERIMENT; RELATIVE ABUNDANCE; SOLAR MINIMUM; ENERGY-RANGE; ANTIPROTON FLUX; HE-3/HE-4 RATIO; HE ISOTOPES; PROTONS; SPECTRA AB The cosmic-ray hydrogen and helium spectra have been measured by the Balloon Borne Experiment with a Superconducting Solenoid Spectrometer (BESS), which has been flown from Lynn Lake, Manitoba, Canada, annually since 1993. The BESS experiment provides excellent rigidity measurement and precise particle identification with a large geometric acceptance. We present here the hydrogen and helium nuclei energy spectra from 0.2 to 10 GeV nucleon(-1) and their isotopic composition from 0.2 to about 1 GeV nucleon(-1) for the first BESS flight. This provides the first simultaneous measurements of the cosmic-ray secondaries, deuterons, and He-3, with their primaries, protons, and He-4 over this energy range in a period of solar minimum. In this paper, we have achieved significant improvements in data analysis in the following aspects. First, the latest available cross-section data and their parameterizations were utilized in the simulation code developed for this study. Second, a complete simulation was performed for both protons and heavy ions : the delta-ray effect was properly simulated and showed a large influence on the measurement of heavy ions at high energies. Third, the secondary particle correction, which dominates the systematic uncertainty at low energies for singly charged particles, protons and deuterons, was calculated iteratively with the simultaneously measured primary cosmic-ray spectra. In general, the results of this experiment are consistent with other recent measurements using balloon-borne or satellite experiments, but with better precision. The measured spectra of protons, deuterons, 3He, and 4He and their corresponding ratios are compared with different interstellar/heliospheric propagation calculations, which were derived to fit observations of heavy nuclei. The overall good agreement indicates that the propagation history for light cosmic-ray elements, protons, deuterons, and helium nuclei is similar to that of the heavy nuclei. The H-2/H-1 ratio is sensitive to the propagation models, and our results show a tendency of better agreement with the reacceleration model than the standard leaky-box model. C1 Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Univ Tokyo, Tokyo 1130033, Japan. KEK, Tsukuba, Ibaraki 3050801, Japan. Kobe Univ, Kobe, Hyogo 6578501, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. RP Wang, JZ (reprint author), Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. RI MOTOKI, Masakazu/B-4212-2009; OI Seo, Eun-Suk/0000-0001-8682-805X NR 78 TC 63 Z9 63 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 244 EP 259 DI 10.1086/324140 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300025 ER PT J AU Fitzpatrick, EL Ribas, I Guinan, EF DeWarf, LE Maloney, FP Massa, D AF Fitzpatrick, EL Ribas, I Guinan, EF DeWarf, LE Maloney, FP Massa, D TI Fundamental properties and distances of the Large Magellanic Cloud from eclipsing binaries. II. HV 982 SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : eclipsing; distance scale; Magellanic Clouds; stars : distances; stars : fundamental parameters; stars : individual (HV 982) ID STELLAR MODELS; WIDE-RANGE; INTERSTELLAR EXTINCTION; CCD PHOTOMETRY; VARIABLE-STARS; CURVE; CONSTRAINTS; SPECTRA; HV-2274; X=0.80 AB We have determined the distance to a second eclipsing binary (EB) system in the Large Magellanic Cloud, HV 982 (similar toB1 IV-V + similar toB1 IV-V). The measurement of the distance-among other properties of the system-is based on optical photometry and spectroscopy and space-based UV/optical spectrophotometry. The analysis combines the "classical" EB study of light and radial velocity curves, which yields the stellar masses and radii, with a new analysis of the observed energy distribution, which yields the effective temperature, metallicity, and reddening of the system plus the distance "attenuation factor," essentially (radius/distance)(2). Combining the results gives the distance to HV 982, which is 50.2+/-1.2 kpc. This distance determination consists of a detailed study of well-understood objects (B stars) in a well-understood evolutionary phase (core H burning). The results are entirely consistent with-but do not depend on-stellar evolution calculations. There are no "zero-point" uncertainties as, for example, with the use of Cepheid variables. Neither is the result subject to sampling biases, as may affect techniques that utilize whole stellar populations, such as red giant branch stars. Moreover, the analysis is insensitive to stellar metallicity (although the metallicity of the stars is explicitly determined), and the effects of interstellar extinction are determined for each object studied. After correcting for the location of HV 982, we find an implied distance to the optical center of the LMC's bar of d(LMC) = 50.7+/-1.2 kpc. This result differs by nearly 5 kpc from our earlier result for the EB HV 2274, which implies a bar distance of 45.9 kpc. These results may either reflect marginally compatible measures of a unique LMC distance or, alternatively, suggest a significant depth to the stellar distribution in the LMC. Some evidence for this latter hypothesis is discussed. C1 Villanova Univ, Dept Astron & Astrophys, Villanova, PA 19085 USA. NASA, Emergent IT, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Fitzpatrick, EL (reprint author), Villanova Univ, Dept Astron & Astrophys, Villanova, PA 19085 USA. RI Ribas, Ignasi/M-2134-2014 OI Ribas, Ignasi/0000-0002-6689-0312 NR 46 TC 64 Z9 64 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 260 EP 273 DI 10.1086/324184 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300026 ER PT J AU Slane, P Smith, RK Hughes, JP Petre, R AF Slane, P Smith, RK Hughes, JP Petre, R TI An X-ray study of the supernova remnant G290.1-0.8 SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (G290.1-0.8, MSH 11-61A); supernova remnants; X-rays : ISM ID FORMED DENSE SHELL; INTERSTELLAR-MEDIUM; THERMAL CONDUCTION; MODELING W44; HOT INTERIOR; EMISSION; CLOUDS; GRADIENT; YOUNG; RADIO AB G290.1-0.8 (MSH 11-61A) is a supernova remnant (SNR) whose X-ray morphology is centrally bright. However, unlike the class of X-ray composite SNRs whose centers are dominated by nonthermal emission presumably driven by a central pulsar, we show that the X-ray emission from G290.1-0.8 is thermal in nature, placing the remnant in an emerging class which includes such remnants as W44, W28, 3C391, and others. The evolutionary sequence which leads to such X-ray properties is not well understood. Here we investigate two scenarios for such emission : evolution in a cloudy interstellar medium, and early-stage evolution of a remnant into the radiative phase, including the effects of thermal conduction. We construct models for these scenarios in an attempt to reproduce the observed center-filled X-ray properties of G290.1-0.8, and we derive the associated age, energy, and ambient density conditions implied by the models. We find that for reasonable values of the explosion energy, the remnant age is of order (1-2) x 10(4) yr. This places a fairly strong constraint on any association between G290.1-0.8 and PSR J1105-610, which would require an anomalously large velocity for the pulsar. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. NASA, GSFC, Greenbelt, MD USA. RP Slane, P (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 36 TC 30 Z9 30 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 284 EP 290 DI 10.1086/324155 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300028 ER PT J AU Slysh, VI Migenes, V Val'tts, IE Lyubchenko, SY Horiuchi, S Altunin, VI Fomalont, EB Inoue, M AF Slysh, VI Migenes, V Val'tts, IE Lyubchenko, SY Horiuchi, S Altunin, VI Fomalont, EB Inoue, M TI Total linear polarization in the OH maser W75N: VLBA polarization structure SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (W75 N) ISM : molecules; masers; radio lines : ISM; surveys ID RADIATION; OUTFLOW; SCALE AB W75 N is a star-forming region containing various ultracompact H II regions and OH, H2O, and CH3OH maser emission. Our VLBA map shows that the OH masers are located in a thin disk rotating around an O star, the exciting star of the ultracompact H II region VLA 1. A separate set of maser spots is associated with the ultracompact H II region VLA 2. The radial velocity of OH maser spots varies across the disk from 3.7 to 10.9 km s-1. The diameter of the disk is 4000 AU. All maser spots are strongly polarized. These are the first OH masers showing nearly 100% linear polarization in several spots. Two maser spots seem to be Zeeman pairs, corresponding to a magnetic field of 5.2 and 7.7 mG, and in one case we tentatively find a Zeeman pair consisting of two linearly polarized components. The linearly polarized maser spots are shown to be sigma components, which is the case when the magnetic field is perpendicular to the line of sight. The direction of the magnetic field as determined from linearly polarized spots is perpendicular to the plane of the disk, although the Galactic Faraday rotation may significantly affect this conclusion. C1 PN Lebedev Phys Inst, Ctr Astro Space, Moscow 117810, Russia. Univ Guanajuato, Dept Astron, Guanajuato 36000, Mexico. Natl Astron Observ, Tokyo 1818588, Japan. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Nobeyama Radio Observ, Minamisa Ku, Nagano 38413, Japan. RP Slysh, VI (reprint author), PN Lebedev Phys Inst, Ctr Astro Space, Profsoyuznaya 84-32, Moscow 117810, Russia. RI Migenes, Victor/F-3157-2015; Valtts, Irina/M-6869-2015 OI Migenes, Victor/0000-0002-7990-2191; Valtts, Irina/0000-0003-4032-5590 NR 20 TC 26 Z9 27 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 317 EP 326 DI 10.1086/324152 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300031 ER PT J AU McLaughlin, MA Arzoumanian, Z Cordes, JM Backer, DC Lommen, AN Lorimer, DR Zepka, AF AF McLaughlin, MA Arzoumanian, Z Cordes, JM Backer, DC Lommen, AN Lorimer, DR Zepka, AF TI PSR J1740+1000: A young pulsar well out of the Galactic plane SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (North Polar Spur); pulsars : general; pulsars : individual (J1740+1000) ID STAR POPULATION-DYNAMICS; NEUTRON-STAR; SOUTHERN PULSARS; RADIO PULSARS; MILLISECOND PULSARS; INTERSTELLAR-MEDIUM; POLARIZATION; VELOCITIES; SCATTERING; POLARIMETRY AB We discuss PSR J1740-1000, one of five pulsars recently discovered in a search of 470 deg(2) at 430 MHz during the upgrade of the 305 m Arecibo Telescope. The period P=154 ms and period derivative (P)over dot =2.1x10(-14) s s-(1) imply a spin-down age tau(s) = P/2(P)over dot kyr that is smaller than 95% of all known pulsars. The youth and proximity of this pulsar make it a good candidate for detection at X-ray and gamma-ray energies. Its high Galactic latitude (b=20degrees.4) suggests a very high velocity if the pulsar was born in the midplane of the Galaxy and if its kinematic age equals its spin-down age. Interstellar scintillations, however, suggest a much lower velocity. We discuss possible explanations for this discrepancy, taking into account (1) possible birth sites away from the midplane; (2) contributions from the unmeasured radial velocity; (3) a kinematic age different from the spin-down age; and (4) biasing of the scintillation velocity by enhanced scattering from the North Polar Spur. C1 Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Arecibo Observ, Arecibo, PR 00612 USA. RP McLaughlin, MA (reprint author), Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. NR 52 TC 21 Z9 21 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 333 EP 342 DI 10.1086/324151 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300033 ER PT J AU Nath, NR Strohmayer, TE Swank, JH AF Nath, NR Strohmayer, TE Swank, JH TI Bounds on compactness for low-mass X-ray binary neutron stars from X-ray burst oscillations SO ASTROPHYSICAL JOURNAL LA English DT Article DE equation of state; stars : individual (4U 1636-53, 4U 1728-34); stars : neutron; stars : oscillations; stars : structure; X-rays : bursts ID BRIGHTNESS OSCILLATIONS; HOT-SPOTS; MODEL; PULSARS; MATTER; PHASE AB We have modeled X-ray burst oscillations observed with the Rossi X-Ray Timing Explorer from two low-mass X-ray binaries (LMXB): 4U 1636-53 with a frequency of 580 Hz and 4U 1728-34 at a frequency of 363 Hz. We have computed least-squares fits to the oscillations observed during the rising phase of bursts using a model that includes emission from either a single circular hot spot or a pair of circular antipodal hot spots on the surface of a neutron star. We model the spreading of the thermonuclear hot spots by assuming that the hot spot angular size grows linearly with time. We calculate the flux as a function of rotational phase from the hot spots and take into account photon deflection in the relativistic gravitational field of the neutron star, assuming the exterior spacetime is the Schwarzschild metric. We find acceptable fits with our model in a chi(2) sense and use these to place constraints on the compactness of the neutron stars in these sources. For 4U 1636-53, in which detection of a 290 Hz subharmonic supports the two-spot model, we find that the compactness (i.e., mass/radius ratio) is constrained to be M/R<0.163 at 90% confidence (G=c=1). This requires a relatively stiff equation of state (EOS) for the stellar interior. For example, if the neutron star has a mass of 1.4 M-&ODOT;, then its radius must be greater than 12.8 km. Fits using a single hot spot model are not as highly constraining. We discuss the implications of our findings for recent efforts to calculate the EOS of dense nucleon matter and the structure of neutron stars. C1 NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Nath, NR (reprint author), Sci Syst & Applicat, Lanham, MD 20706 USA. RI Swank, Jean/F-2693-2012 NR 25 TC 48 Z9 48 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 353 EP 360 DI 10.1086/324132 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300035 ER PT J AU Hirotani, K Shibata, S AF Hirotani, K Shibata, S TI Gamma-ray emission from an outer gap accelerator: Constraints on magnetospheric current, magnetic inclination, and distance for PSR B1055-52 SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations; gamma rays : theory; pulsars : individual (PSR B1055-52); stars : magnetic fields; X-rays : stars ID RAPIDLY SPINNING PULSARS; ELECTRIC-FIELD STRUCTURE; CURVATURE-RADIATION; ENERGETIC RADIATION; EGRET OBSERVATIONS; POWERED PULSARS; PAIR-PRODUCTION; POLAR CAPS; MODEL; VELA AB We investigate a stationary pair production cascade in the outer magnetosphere of a spinning neutron star. The charge depletion due to global flows of charged particles causes a large electric field along the magnetic field lines. Migratory electrons and/or positrons are accelerated by this field to radiate curvature c-rays, some of which collide with the X-rays to materialize as pairs in the gap. The replenished charges partially screen the electric field, which is self-consistently solved, together with the distribution functions of particles and c-rays. By solving the Vlasov equations describing this pair production cascade, we demonstrate the existence of a stationary gap in the outer magnetosphere of PSR B1055-52 for a wide range of current densities flowing in the accelerator : from sub- to super-Goldreich-Julian values. However, we find that the expected GeV spectrum becomes very soft if the current density exceeds the Goldreich-Julian value. We also demonstrate that the GeV spectrum softens with decreasing magnetic inclination and with increasing distance to this pulsar. We thus conclude that a sub-Goldreich-Julian current, a large magnetic inclination, and a small distance (500 pc, say) are plausible to account for EGRET observations. Furthermore, it is found that the TeV flux due to inverse Compton scatterings of infrared photons whose spectrum is inferred from the Rayleigh-Jeans side of the soft blackbody spectrum is much less than the observational upper limit. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Yamagata Univ, Dept Phys, Yamagata 9908560, Japan. RP Hirotani, K (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. NR 43 TC 16 Z9 16 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 369 EP 378 DI 10.1086/324199 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300037 ER PT J AU Rodgers, B Wooden, DH Grinin, V Shakhovsky, D Natta, A AF Rodgers, B Wooden, DH Grinin, V Shakhovsky, D Natta, A TI Spectroscopic variability of the UXOR star RR Tauri SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; stars : early-type; stars : emission-line Be; stars : individual (RR Tauri); stars : pre-main-sequence; stars : variables : other ID HERBIG AE/BE STARS; BETA-PICTORIS PHENOMENON; MAIN-SEQUENCE STARS; AB-AURIGAE; YOUNG STARS; ORIONIS; ACCRETION; LINES; PHOTOMETRY; CAMPAIGN AB We present moderate-resolution optical spectra of the highly variable Herbig Ae star RR Tauri over 12 epochs spanning similar to2.5 mag in V. Combining normalized spectra with contemporaneous photometry from two databases, we analyze both equivalent width and flux behavior as a function of system brightness for lines from the Ca II K line in the blue to the Paschen lines in the far red. The wings (Deltav>400 km s(-1)) of the Balmer lines and the equivalent widths of several weak metal lines are essentially constant, indicating very little change in the underlying photosphere over a factor of 10 change in brightness. We detect no measurable change in spectral type. Variability is apparent in the cores of Ha and Hbeta, but the total flux in these lines is not correlated with photometric variability. Forbidden oxygen ([O I] lambda6300) has essentially constant flux, indicating a stable low-density wind component. The low-ionization permitted lines of Fe II, CaII, O I, and Na I are seen strongly in absorption for Vless than or equal to12.2 in these normalized spectra but change dramatically from absorption to emission during deep minima (Vgreater than or similar to12.6). Analysis of the Fe II (42) triplet indicates that these lines originate in circumstellar gas that is partially affected by the photometric minima, in that the absorbing gas changes with the stellar continuum (conserving equivalent width), while a weak emitting region is unaffected (roughly constant flux). Our results are consistent with a model in which the stellar minima are caused by an occulting screen of size such that it obscures the stellar surface and the innermost region of circumstellar gas producing permitted metal absorption lines but not the outer parts or the wind. The circumstellar hydrogen, while variable, is not strongly affected by the occultations. C1 AURA Chile, Gemini Observ, Tucson, AZ 85726 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Pulkovo Astron Observ, St Petersburg 196140, Russia. Crimean Astrophys Observ, UA-334413 Nauchnyi, Ukraine. Osserv Astrofis Arcetri, I-50125 Florence, Italy. RP Rodgers, B (reprint author), AURA Chile, Gemini Observ, POB 26732, Tucson, AZ 85726 USA. RI Grinin, Vladimir/M-9509-2013 OI Grinin, Vladimir/0000-0001-8923-9541 NR 33 TC 25 Z9 25 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 405 EP 420 DI 10.1086/324213 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300041 ER PT J AU Jenkins, JM Caldwell, DA Borucki, WJ AF Jenkins, JM Caldwell, DA Borucki, WJ TI Some tests to establish confidence in planets discovered by transit photometry SO ASTROPHYSICAL JOURNAL LA English DT Article DE planetary systems; techniques : photometric ID TERRESTRIAL EXTRASOLAR PLANETS; CM-DRACONIS; INNER PLANETS; DETECTABILITY; HD-209458; SYSTEMS; MISSION; KEPLER; SEARCH; STARS AB Increased attention is being paid to transit photometry as a viable method for discovering or confirming detections of extrasolar planets. Several ground-based efforts are underway that target short-period, giant planets such as 51 Peg b, and several missions have been proposed to NASA and ESA to detect planets as small as Earth from spaceborne photometers. The success of these efforts depends in part on the ability to establish appropriate detection thresholds to control false alarm rates and the ability to assess the statistical confidence in planetary candidates drawn from any such search. This latter function attains higher importance for the space-based efforts, where direct ground-based confirmation of terrestrial-size planets is not possible. These tasks are complicated by the need to survey tens of thousands of stars to overcome the limited geometric probability of transit alignment and by the nature of the transit signals themselves. In this paper, we present empirical methods for setting appropriate detection thresholds and for establishing the confidence level in planetary candidates obtained from transit photometry of even a large number of stars. The methods are simple and allow the observer to quickly assess the statistical significance of any particular set of transits. C1 NASA, SETI Inst, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Jenkins, JM (reprint author), NASA, SETI Inst, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. RI Caldwell, Douglas/L-7911-2014 OI Caldwell, Douglas/0000-0003-1963-9616 NR 33 TC 94 Z9 94 U1 1 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP 495 EP 507 DI 10.1086/324143 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NR UT WOS:000173154300046 ER PT J AU Gotthelf, EV Gavriil, FP Kaspi, VM Vasisht, G Chakrabarty, D AF Gotthelf, EV Gavriil, FP Kaspi, VM Vasisht, G Chakrabarty, D TI A phase-connected timing solution for the magnetar candidate 1E 1841-045 SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : individual (Kes 73, 1E 1841-045); stars : neutron; supernova remnants; X-rays : stars ID X-RAY PULSAR; NEUTRON-STARS; KES-73 AB We report on a long-term monitoring campaign of 1E 1841-045, the 12 s anomalous X-ray pulsar and magnetar candidate at the center of the supernova remnant Kes 73. We have obtained approximately monthly observations of the pulsar with the Rossi X-Ray Timing Explorer (RXTE) spanning over 2 years, during which time 1E 1841-045 is found to be rotating with sufficient stability to derive a phase-connected timing solution. A linear ephemeris is consistent with measurements of the pulse period made over the last 15 years with the Ginga, ASCA, RXTE, and BeppoSAX observatories. Phase residuals suggest the presence of "timing noise," as is typically observed from young radio pulsars. These results confirm a rapid, constant spin-down for the pulsar, which continues to maintain a steady flux; this is inconsistent with most accretion scenarios. C1 Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. MIT, Dept Phys, Cambridge, MA 02139 USA. MIT, Space Res Ctr, Cambridge, MA 02139 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gotthelf, EV (reprint author), Columbia Univ, Columbia Astrophys Lab, 538 W 120th St, New York, NY 10027 USA. NR 20 TC 29 Z9 30 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 1 PY 2002 VL 564 IS 1 BP L31 EP L34 DI 10.1086/338799 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 509NT UT WOS:000173154400008 ER PT J AU Bushouse, HA Borne, KD Colina, L Lucas, RA Rowan-Robinson, M Baker, AC Clements, DL Lawrence, A Oliver, S AF Bushouse, HA Borne, KD Colina, L Lucas, RA Rowan-Robinson, M Baker, AC Clements, DL Lawrence, A Oliver, S TI Ultraluminous infrared galaxies: Atlas of near-infrared images SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE atlases; galaxies : interactions; galaxies : peculiar; galaxies : starburst; infrared : galaxies; surveys ID DEEP SUBMILLIMETER SURVEY; LUMINOSITY IRAS GALAXIES; OPTICAL SPECTROSCOPY; STAR-FORMATION; HIGH-REDSHIFT; LARGE-SAMPLE; JY SAMPLE; NUCLEAR; MERGERS; MORPHOLOGY AB A sample of 27 ultraluminous infrared galaxy (ULIRG) systems has been imaged at 1.6 mum using the Hubble Space Telescope (HST) Near Infrared Camera and Multi-Object Spectrometer (NICMOS). These ULIRGs are from a larger sample also imaged with HST in the I band. Images and catalog information for the NICMOS subsample, as well as brief morphological descriptions of each system are presented. Inspection of the infrared images and a comparison with optical images of these systems shows that at least 85% are obviously composed of two or more galaxies involved in a close interaction or merger event, with as many as 93% showing some signs of interaction history. Approximately 37% of the systems show either spectroscopic or morphological characteristics of an active galactic nucleus. The infrared morphologies of these systems are generally less complicated or disturbed than their optical morphologies, indicating that some of the small-scale features seen in optical images are likely due to complicated patterns of dust obscuration, as well as widely distributed star formation activity. In some systems the high-resolution HST infrared images have revealed nuclear remnants that are obscured or unidentified in ground-based imaging, which has led to changes in previously determined interaction stage classifications or system content. In general, however, the NICMOS images support previous conclusions from previous HST optical imaging. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Raytheon Informat Technol & Sci Serv, Greenbelt, MD 20771 USA. CSIC, Inst Estructura Mat, E-28006 Madrid, Spain. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. Cardiff Univ, Dept Phys & Astron, Cardiff CF2 3YB, S Glam, Wales. Univ Edinburgh, Inst Astron, Royal Observ, Edinburgh EH9 3HJ, Midlothian, Scotland. Univ Sussex, Ctr Astron, Brighton BN1 9QJ, E Sussex, England. RP Bushouse, HA (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. EM bushouse@stsci.edu; borne@rings.gsfc.nasa.gov; colina@isis.iem.csic.es; lucas@stsci.edu; m.rrobinson@ic.ac.uk; a.baker@astro.cf.ac.uk; david.clements@astro.cf.ac.uk; a.lawrence@roe.ac.uk; s.oliver@sussex.ac.uk RI Oliver, Seb/A-2479-2013 OI Oliver, Seb/0000-0001-7862-1032 NR 54 TC 79 Z9 79 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JAN PY 2002 VL 138 IS 1 BP 1 EP 18 DI 10.1086/324019 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 515QT UT WOS:000173507500001 ER PT J AU Pendleton, YJ Allamandola, LJ AF Pendleton, YJ Allamandola, LJ TI The organic refractory material in the diffuse interstellar medium: Mid-infrared spectroscopic constraints SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Review DE infrared : ISM : lines and bands; ISM : molecules; molecular data ID HYDROGENATED AMORPHOUS-CARBON; POLYCYCLIC AROMATIC-HYDROCARBONS; 3.4 MU-M; TIME-DEPENDENT CHEMISTRY; DENSE MOLECULAR CLOUDS; WOLF-RAYET STARS; INFRARED-SPECTROSCOPY; GALACTIC-CENTER; MURCHISON METEORITE; ABSORPTION FEATURE AB This is an analysis of the 4000-1000 cm(-1) (2.5-10 mum) region of the spectrum of diffuse interstellar medium (DISM) dust compared with the spectra of 13 materials produced in the laboratory which serve as analogs to the interstellar material. The organic signatures of extragalactic dust, carbonaceous chondritic material, and E. coli bacteria are also presented because these have been discussed in the literature as relevant to the diffuse interstellar medium. Spectral analysis of the DISM allows us to place significant constraints on the applicability of proposed candidate materials. The spectra of candidate materials are evaluated using four spectral characteristics based on the interstellar data: (i) comparisons of the profile and subpeak positions of the 2940 cm(-1) (3.4 mum) aliphatic CH stretching-mode band, (ii) the ratio of the optical depth (O.D.) of the aliphatic CH stretch to the O.D. of the OH stretch near 3200 cm(-1) (3.1 mum), (iii) the ratio of the O.D. of the aliphatic CH stretch to the O.D. of the carbonyl band near 1700 cm(-1) (5.9 mum), and (iv) the ratio of the O.D. of the aliphatic CH stretch feature to the O.D. of the CH deformation modes near 1470 cm(-1) (6.8 mum) and 1370 cm(-1) (7.25 mum). We conclude that the organic refractory material in the diffuse interstellar medium is predominantly hydrocarbon in nature, possessing little nitrogen or oxygen, with the carbon distributed between the aromatic and aliphatic forms. Long alkane chains H(3)C-(CH(2))(n)- with n much greater than 4 or 5 are not major constituents of this material. Comparisons to laboratory analogs indicate the DISM organic material resembles plasma processed pure hydrocarbon residues much more so than energetically processed ice residues. This result is consistent with a birth site for the carrier of the 3.4 mum band in the outflow region of evolved carbon stars. The organic material extracted from the Murchison carbonaceous meteorite and the spectrum of E. coli bacteria reveal spectral features in the 5-10 mum region that are absent in the DISM. Although the presence of unaltered circumstellar components in the Murchison meteorite has been established through several lines of evidence, it is unclear whether or not the aliphatic component which gives rise to the 3.4 mum band is in that category. Considering the complete 2-10 mum wavelength region, there is no spectral evidence for a biological origin of the 3.4 mum interstellar absorption band. The similarity of the aliphatic CH stretch region of dust from our own Galaxy compared with that of distant galaxies suggests that the organic component of the ISM is widespread and may be an important universal reservoir of prebiotic organic carbon. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Pendleton, YJ (reprint author), NASA, Ames Res Ctr, Mail Stop 245-3, Moffett Field, CA 94035 USA. NR 104 TC 245 Z9 246 U1 0 U2 19 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JAN PY 2002 VL 138 IS 1 BP 75 EP 98 DI 10.1086/322999 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 515QT UT WOS:000173507500005 ER PT J AU Harmon, BA Fishman, GJ Wilson, CA Paciesas, WS Zhang, SN Finger, MH Koshut, TM McCollough, ML Robinson, CR Rubin, BC AF Harmon, BA Fishman, GJ Wilson, CA Paciesas, WS Zhang, SN Finger, MH Koshut, TM McCollough, ML Robinson, CR Rubin, BC TI The burst and transient source experiment earth occultation technique SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE gamma rays : observations; instrumentation : detectors; methods : data analysis; occultations; surveys; X-rays : stars ID HARD X-RAY; LIGHT CURVES; BATSE; OUTBURSTS; GX-339-4; CATALOG; SPECTRA AB An Earth orbiting detector sensitive to gamma-ray photons will see steplike occultation features in its count rate when a gamma-ray point source crosses the Earth's limb. This is due to the change in atmospheric attenuation of the gamma rays along the line of sight. In an uncollimated detector, these occultation features can be used to locate and monitor astrophysical sources provided their signals can be individually separated from the detector background. We show that the Earth occultation technique applied to the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory (CGRO) is a viable and flexible all-sky monitor in the low-energy gamma-ray and hard X-ray energy range (20 keV-1 MeV). The method is an alternative to more sophisticated photon imaging devices for astronomy and can serve well as a cost-effective science capability for monitoring the high-energy sky. Here we describe the Earth occultation technique for locating new sources and for measuring source intensity and spectra without the use of complex background models. Examples of transform imaging, step searches, spectra, and light curves are presented. Systematic uncertainties due to source confusion, detector response, and contamination from rapid background fluctuations are discussed and analyzed for their effect on intensity measurements. A sky location-dependent average systematic error is derived as a function of Galactic coordinates. The sensitivity of the technique is derived as a function of incident photon energy and also as a function of angle between the source and the normal to the detector entrance window. Occultations of the Crab Nebula by the Moon are used to calibrate Earth occultation flux measurements independent of possible atmospheric scattering effects. C1 NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, SD50, Huntsville, AL 35812 USA. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RP Harmon, BA (reprint author), NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, SD50, Huntsville, AL 35812 USA. NR 84 TC 50 Z9 50 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JAN PY 2002 VL 138 IS 1 BP 149 EP 183 DI 10.1086/324018 PG 35 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 515QT UT WOS:000173507500008 ER PT J AU Liu, XM Shemansky, DE Abgrall, H Roueff, E Dziczek, D Hansen, DL Ajello, JM AF Liu, XM Shemansky, DE Abgrall, H Roueff, E Dziczek, D Hansen, DL Ajello, JM TI Time-resolved electron impact study of excitation of H-2 singlet-gerade states from cascade emission in the vacuum ultraviolet region SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE methods : laboratory; molecular data; molecular processes ID HUBBLE-SPACE-TELESCOPE; QUANTUM-DEFECT THEORY; ENHANCED MULTIPHOTON IONIZATION; DOUBLE-RESONANCE EXCITATION; MINIMUM 1-SIGMA-G+ STATES; MOLECULAR-HYDROGEN; TRANSITION MOMENTS; JUPITER AURORA; ENERGY-LEVELS; BAND SYSTEMS AB Medium-resolution (full width at half-maximum Deltalambda = 0.5 Angstrom) vacuum ultraviolet (VUV) emission spectra of from forbidden excitation to the excited singlet-gerade states and subsequent cascade to H 2 the singlet-ungerade states have been studied with a time-resolved electron-impact technique. Emissions from the B (1)Sigma(u)(+), C (1)Pi(u), B' (1)Sigma(u)(+), and D (1)Pi(u) states that are entirely due to cascade from the singlet-gerade states have been observed. Lyman band emission intensities dominate over the entire 940-1650 Angstrom wavelength region, though Werner band emission intensities are also significant. In addition, very weak cascade emissions from the v(j) = 0 and 1 levels of the B' (1)Sigma(u)(+) and D (1)Pi(u) states are also evident. In contrast to previous assumption, the cascade excitation is observed to take place over all the vibrational levels of the B (1)Sigma(u)(+) and C (1)Pi(u) states, while contributing heavily to low v(j) levels of the B (1)Sigma(u)(+) state. Synthetic spectra based on the calculated transition probabilities of the EF (1)Sigma(g)(+), GK (1)Sigma(g)(+), H(H) over bar $ 1Pig+, I (1)Pi(g), J (1)Delta(g), O (1)Sigma(g)(+) and P (1)Sigma(g)(+) --> B (1)Sigma(u)(+), C (1)Pi(u), B' (1)Sigma(u)(+), and D (1)Pi(u) band systems and Franck-Condon factors of the EF (1)Sigma(g)(+)-X (1)Sigma(g)(+), GK (1)Sigma(g)(+), H(H) over bar $ (1)Sigma(g)(+)-X (1)Sigma(g)(+), J (1)Delta(g)-X (1)Sigma(g)(+), O (1)Sigma(g)(+)-X (1)Sigma(g)(+), and P (1)Sigma(g)(+)-X (1)Sigma(g)(+) are in good agreement with the observed Lyman and Werner band intensities. The present study shows that a number of singlet-gerade and singlet-ungerade states are involved in the cascade excitation process of H-2. The cascade from these states in the VUV provide diagnostic information on astrophysical sources for H-2 emission. C1 Univ So Calif, Dept Aerosp & Mech Engn, Los Angeles, CA 90089 USA. Observ Paris, DAEC, Sect Meudon, F-92195 Meudon, France. CNRS, UMR 8631, F-92195 Meudon, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Liu, XM (reprint author), Univ So Calif, Dept Aerosp & Mech Engn, Los Angeles, CA 90089 USA. RI Dziczek, Dariusz/G-3620-2014 NR 71 TC 19 Z9 19 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD JAN PY 2002 VL 138 IS 1 BP 229 EP 245 DI 10.1086/323630 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 515QT UT WOS:000173507500011 ER PT J AU Zhang, XL AF Zhang, XL TI A large scale energy source for feeding ISM turbulence in spiral galaxies SO ASTROPHYSICS AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 2nd Euroconference on Relevant Basic Building Blocks and Small-scale Processes in Galaxy Evolution CY OCT 16-21, 2001 CL ST DENIS REUNION, FRANCE SP European Commiss, Res DG, Dept Reunion, Conseil Reg Reunion, CNRS, Ctr Natl Etudes Spatiales, Observ Paris Meudon, Dept Astrophys Extragalact & Cosmologie, Comite Tourisme Reunion, France Telecom, Europcar DE turbulence; ISM; spiral density wave shock ID SECULAR EVOLUTION AB One of the important consequences of a newly discovered secular dynamical evolution process of spiral galaxies (Zhang, 1996, 1998, 1999) is that the orbiting disk matter receives energy injection each time it crosses the spiral density wave crest. This energy injection has been shown to be able to quantitatively explain the observed age-velocity-dispersion relation of the solar neighborhood stars. We demostrate in this paper that similar energy injection into the interstellar medium could serve as the large-scale energy source to continuously power the observed interstellar turbulence and to offset its downward cascade tendency. C1 NASA, SSAI, Raytheon ITSS, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Zhang, XL (reprint author), NASA, SSAI, Raytheon ITSS, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0004-640X J9 ASTROPHYS SPACE SCI JI Astrophys. Space Sci. PY 2002 VL 281 IS 1-2 BP 281 EP 284 DI 10.1023/A:1019572517626 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 557RG UT WOS:000175921200056 ER PT J AU Bunker, AJ Spinrad, H McLure, R Dey, A Dunlop, J Peacock, J Stern, D Thompson, R Waddington, I Windhorst, R AF Bunker, AJ Spinrad, H McLure, R Dey, A Dunlop, J Peacock, J Stern, D Thompson, R Waddington, I Windhorst, R TI HST imaging of an old galaxy group at Z=1.55 SO ASTROPHYSICS AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT 2nd Euroconference on Relevant Basic Building Blocks and Small-scale Processes in Galaxy Evolution CY OCT 16-21, 2001 CL ST DENIS REUNION, FRANCE SP European Commiss, Res DG, Dept Reunion, Conseil Reg Reunion, CNRS, Ctr Natl Etudes Spatiales, Observ Paris Meudon, Dept Astrophys Extragalact & Cosmologie, Comite Tourisme Reunion, France Telecom, Europcar C1 Univ Cambridge, Inst Astron, Cambridge CB2 1TN, England. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Oxford, Dept Astrophys, Oxford OX1 3RH, England. Inst Astron, Edinburgh, Midlothian, Scotland. Kitt Peak Natl Observ, Tucson, AZ 85726 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Steward Observ, Tucson, AZ USA. Arizona State Univ, Tempe, AZ 85287 USA. Univ Bristol, Bristol BS8 1TH, Avon, England. RP Bunker, AJ (reprint author), Univ Cambridge, Inst Astron, Cambridge CB2 1TN, England. NR 0 TC 0 Z9 0 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0004-640X J9 ASTROPHYS SPACE SCI JI Astrophys. Space Sci. PY 2002 VL 281 IS 1-2 BP 527 EP 528 DI 10.1023/A:1019537918332 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 557RG UT WOS:000175921200124 ER PT J AU Marcos, RDF Marcos, CDF AF Marcos, RDF Marcos, CDF TI Dynamics of very rich open clusters SO ASTROPHYSICS AND SPACE SCIENCE LA English DT Letter ID OLD OPEN CLUSTERS; INITIAL MASS FUNCTION; GLOBULAR-CLUSTERS; STAR-CLUSTERS; GALACTIC DISK; EVOLUTION; BERKELEY-17; NGC-3597; GALAXY; SYSTEM AB The oldest open clusters in our Galaxy set the lower limit to the age of the Galactic Disk (9-10 Gyr). Although they appear to be very rich now, it is clear that their primordial populations were much larger. Often considered as transitional objects, these populous open clusters show structural differences with respect to globular clusters so their dynamics and characteristic evolutionary time scales can also be different. On the other hand, their large membership lead to different dynamical evolution as compared with average open clusters. In this paper, the differential features of the evolution of rich open clusters are studied using N-body simulations, including several of the largest (10(4) stars) published direct collisional N-body calculations so far, which were performed on a CRAY YMP. The disruption rate of rich open clusters is analysed in detail and the effect of the initial spatial distribution of the stars in the cluster on its dynamics is studied. The results show that cluster life-time depends on this initial distribution, decreasing when it is more concentrated. The effect of stellar evolution on the dynamical evolution of rich clusters is an important subject that also has been considered here. We demonstrate that the cluster's life-expectancy against evaporation increases because of mass loss by evolving high-mass stars. C1 Univ Complutense Madrid, E-28040 Madrid, Spain. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. CDS, SIMBAD Database, Strasbourg, France. NASA, Astrophys Data Syst, Washington, DC 20546 USA. RP Marcos, RDF (reprint author), Univ Complutense Madrid, Ciudad Univ, E-28040 Madrid, Spain. NR 55 TC 8 Z9 8 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0004-640X J9 ASTROPHYS SPACE SCI JI Astrophys. Space Sci. PY 2002 VL 280 IS 4 BP 381 EP 404 DI 10.1023/A:1015612207342 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 555RM UT WOS:000175807100007 ER PT S AU Grebowsky, JM Moses, JI Pesnell, WD AF Grebowsky, JM Moses, JI Pesnell, WD BE Mendillo, M Nagy, A Waite, JH TI Meteoric material - an important component of planetary atmospheres SO ATMOSPHERES IN THE SOLAR SYSTEM: COMPARATIVE AERONOMY SE Geophysical Monograph Series LA English DT Proceedings Paper CT Yosemite Conference on Comparative Aeronomy in the Solar System CY FEB 08-11, 2000 CL YOSEMITE, CA SP NASA, NSF, SW Res Inst ID CARBON-MONOXIDE; TITANS ATMOSPHERE; LOWER THERMOSPHERE; RADIO OCCULTATION; WATER-VAPOR; METAL-IONS; IONOSPHERE; SATURN; JUPITER; DUST AB Interplanetary dust particles (IDPs) interact with all planetary atmospheres and leave their imprint as perturbations of the background atmospheric chemistry and structure. They lead to layers of metal ions that can become the dominant positively charged species in lower ionospheric regions. Theoretical models and radio occultation measurements provide compelling evidence that such layers exist in all planetary atmospheres. In addition IDP ablation products can affect neutral atmospheric chemistry, particularly at the outer planets where the IDPs supply oxygen compounds like water and carbon dioxide to the upper atmospheres. Aerosol or smoke particles from incomplete ablation or recondensation of ablated IDP vapors may also have a significant impact on atmospheric properties. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Grebowsky, JM (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Code 695, Greenbelt, MD 20771 USA. EM u5jmg@lepvax.gsfc.nasa.gov; moses@lpi.usra.edu; pesnell@nomadresearch.com RI Pesnell, William/D-1062-2012; Grebowsky, Joseph/I-7185-2013; Moses, Julianne/I-2151-2013 OI Pesnell, William/0000-0002-8306-2500; Moses, Julianne/0000-0002-8837-0035 NR 63 TC 11 Z9 11 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0065-8448 BN 0-87590-989-2 J9 GEOPHYS MONOGR SER PY 2002 VL 130 BP 235 EP 244 DI 10.1029/130GM15 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU78Y UT WOS:000177015100015 ER PT J AU Gobbi, GP Barnaba, F Blumthaler, M Labow, G Herman, JR AF Gobbi, GP Barnaba, F Blumthaler, M Labow, G Herman, JR TI Observed effects of particles nonsphericity on the retrieval of marine and desert dust aerosol optical depth by lidar SO ATMOSPHERIC RESEARCH LA English DT Article DE desert dust; nonspherical aerosol scattering; lidar ID MINERAL DUST; EXTINCTION; BACKSCATTER; RATIO; SENSITIVITY; ABSORPTION; SURFACE; VOLUME AB Polarization lidar observations of maritime and Saharan dust aerosols collected at Crete (35.5degreesN-23.7degreesE) during the May 1999 PAUR 11 campaign are discussed. Lidar traces are inverted and integrated to provide aerosol optical depth at 532 nm. Two model relationships linking together aerosol backscatter and extinction coefficients are employed to perform such an inversion: one obtained employing the Mic theory, i.e., considering both maritime and dust particles as spheres, and a second one obtained by modeling dust particles as spheroids. The resulting two sets of aerosol optical depths are then compared to the ones measured by two independent, ground-based sunphotometers. These comparisons show that a good agreement exist between both lidar inversions and photometer-derived aerosol optical depths. However, the lidar retrieval employing the nonspherical model leads to a better agreement with photometric data when desert dust is observed. Average lidar-sunphotometer aerosol optical depth differences range between 12% and 24%. These values are comparable and sometimes smaller than ones observed to occur between the two sunphotometers employed in this exercise. (C) 2002 Elsevier Science B.V. All rights reserved. C1 CNR, Ist Fis Atmosfera, I-00133 Rome, Italy. CNR, Ist Inquinamento Atmosfer, Rome, Italy. Univ Innsbruck, Inst Med Phys, A-6020 Innsbruck, Austria. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gobbi, GP (reprint author), CNR, Ist Fis Atmosfera, Via Fosso Cavaliere 100, I-00133 Rome, Italy. EM gobbi@ifa.rm.cnr.it; francesca.barnaba@ifa.rm.cnr.it; Mario.Blumthaler@uibk.ac.at; labow@qhearts.gsfc.nasa.gov OI BARNABA, FRANCESCA/0000-0002-1927-6926; Herman, Jay/0000-0002-9146-1632 NR 19 TC 24 Z9 25 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0169-8095 J9 ATMOS RES JI Atmos. Res. PD JAN PY 2002 VL 61 IS 1 BP 1 EP 14 DI 10.1016/S0169-8095(01)00104-1 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 511XV UT WOS:000173291600001 ER PT S AU Meseguer, J Rosu, G AF Meseguer, J Rosu, G BE Widmayer, P Triguero, F Morales, R Hennessy, M Eidenbenz, S Conejo, R TI A total approach to partial algebraic specification SO AUTOMATA, LANGUAGES AND PROGRAMMING SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 29th International Colloquium on Automata, Languages and Programming CY JUL 08-13, 2002 CL MALAGA, SPAIN SP Unicaja, Univ Malaga, Sci & Technol Minist, Malaga City Council ID LOGIC AB Partiality is a fact of life, but at present explicitly partial algebraic specifications lack tools and have limited proof methods. We propose a sound and complete way to support execution and formal reasoning of explicitly partial algebraic specifications within the total framework of membership equational logic (MEL) which has a high-performance interpreter (Maude) and proving tools. This is accomplished by a sound and complete mapping PMEL --> MEL of partial membership equational (PMEL) theories into total ones. Furthermore, we characterize and give proof methods for a practical class of theories for which this mapping has "almost-zero representational distance," in that the partial theory and its total translation are identical up to minor syntactic sugar conventions. This then supports very direct execution of, and formal reasoning about, partial theories at the total level. In conjunction with tools like Maude and its proving tools, our methods can be used to execute and reason about partial specifications such as those in CASL. C1 Univ Illinois, Urbana, IL 61801 USA. NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. RP Univ Illinois, Urbana, IL 61801 USA. NR 20 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-43864-5 J9 LECT NOTES COMPUT SC PY 2002 VL 2380 BP 572 EP 584 PG 13 WC Computer Science, Theory & Methods SC Computer Science GA BV79X UT WOS:000180069500049 ER PT J AU Dervay, JP Powell, MR Butler, B Fife, CE AF Dervay, JP Powell, MR Butler, B Fife, CE TI The effect of exercise and rest duration on the generation of venous gas bubbles at altitude SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE venous gas emboli; micronuclei; exercise; decompression sickness; bubble lifetime AB Background: Decompression, as occurs with aviators and astronauts undergoing high altitude operations or with deep-sea divers returning to surface, can cause gas bubbles to form within the organism. Pressure changes to evoke bubble formation in vivo during depressurization are several orders of magnitude less than those required for gas phase formation in vitro in quiescent liquids. Preformed micronuclei acting as "seeds" have been proposed, dating back to the 1940's. These tissue gas micronuclei have been attributed to a minute gas phase located in hydrophobic cavities, surfactant-stabilized microbubbles, or arising from musculoskeletal activity. The lifetimes of these micronuclei have been presumed to be from a few minutes to several weeks. Hypothesis. The greatest incidence of venous gas emboli (VGE) will be detected by precordial Doppler ultrasound with depressurization immediately following lower extremity exercise, with progressively reduced levels of VGE observed as the interval from exercise to depressurization lengthens. Methods: In a blinded cross-over design, 20 individuals (15 men, 5 women) at sea level exercised by performing knee-bend squats (150 knee flexes over 10 min, 235-kcal (.) h(-1)) either at the beginning, middle, or end of a 2-h chair-rest period without an oxygen prebreathe. Seated subjects were then depressurized to 6.2 psia (6706 m or 22,000 ft altitude equivalent) for 120 min with no exercise performed at altitude. Results: Of the 20 subjects with VGE in the pulmonary artery, 10 demonstrated a greater incidence of bubbles with exercise performed just prior to depressurization, compared with decreasing bubble grades and incidence as the interval of rest increased prior to depressurization. No decompression illness was reported. Conclusions: There is a significant increase in decompression-induced bubble formation at 6.2 psia when lower extremity exercise is performed just prior to depressurization as compared with longer rest intervals. Analysis indicated that micronuclei half-life is on the order of an hour under these hypobaric conditions. C1 NASA, Johnson Space Ctr SD26, Med Operat Branch, Houston, TX 77058 USA. Univ Texas, Sch Med, Dept Anesthesiol, Houston, TX 77030 USA. Univ Texas, Sch Med, Hermann Ctr Environm Aerosp & Ind Med, Houston, TX 77030 USA. RP Dervay, JP (reprint author), NASA, Johnson Space Ctr SD26, Med Operat Branch, Houston, TX 77058 USA. NR 19 TC 34 Z9 34 U1 0 U2 4 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JAN PY 2002 VL 73 IS 1 BP 22 EP 27 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 509UA UT WOS:000173167000005 PM 11817616 ER PT J AU Cowell, SA Stocks, JM Evans, DG Simonson, SR Greenleaf, JE AF Cowell, SA Stocks, JM Evans, DG Simonson, SR Greenleaf, JE TI The exercise and environmental physiology of extravehicular activity SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Review DE thermoregulation; upper-body exercise; exercise in microgravity; exercise in low pressure; decompression sickness; bed rest deconditioning ID UPPER-BODY EXERCISE; DOWN BED-REST; HYPOBARIC DECOMPRESSION-SICKNESS; MAXIMAL AEROBIC POWER; MIDDLE-AGED MEN; LEG EXERCISE; OXYGEN-UPTAKE; ARM EXERCISE; MUSCLE MASS; HEART-RATE AB Extravehicular activity (EVA), i.e., exercise performed under unique environmental conditions, is indispensable for supporting daily living in weightlessness and for further space exploration. From 1965-1996 an average of 20 h (.) yr(-1) were spent performing EVA. International Space Station (ISS) assembly will require 135 h (.) yr(-1) of EVA, and 138 h (.) yr(-1) is planned for post-construction maintenance. The extravehicular mobility unit (EMU), used to protect astronauts during EVA, has a decreased pressure of 4.3 psi that could increase astronauts' risk of decompression sickness (DCS). Exercise in and repeated exposure to this hypobaria may increase the incidence of DCS, although weightlessness may attenuate this risk, Exercise thermoregulation within the EMU is poorly understood; the liquid cooling garment (LCG), worn next to the skin and designed to handle thermal stress, is manually controlled. Astronauts may become dehydrated (by up to 2.6% of body weight) during a 5-h EVA, further exacerbating the thermoregulatory challenge. The EVA is performed mainly with upper body muscles; but astronauts usually exercise at only 26-32% of their upper body maximal oxygen uptake (Vo(2)max). For a given ground-based work task in air (as opposed to water), the submaximal Vo(2) is greater while Vo(2)max and metabolic efficiency are lower during ground-based arm exercise as compared with leg exercise, and cardiovascular responses to exercise and training are also different for arms and legs. Preflight testing and training, whether conducted in air or water, must account for these differences if ground-based data are extrapolated for flight requirements. Astronauts experience deconditioning during microgravity resulting in a 10-20% loss in arm strength, a 20-30% loss in thigh strength, and decrease lower-body aerobic exercise capacity. Data from ground-based simulations of weightlessness such as bed rest induce a 6-8% decrease in upper-body strength, a 10-16% loss in thigh extensor strength, and a 15-20% decrease in lower-body aerobic exercise capacity. Changes in EVA support systems and training based on a greater understanding of the physiological aspects of exercise in the EVA environment will help to insure the health, safety, and efficiency of working astronauts. C1 NASA, Ames Res Ctr, Gravitat Res Branch 221A2, Lab Human Enviornm Physiol, Moffett Field, CA 94035 USA. Eli Lilly Australia Pty Ltd, W Ryde, NSW, Australia. San Francisco State Univ, Dept Biol, San Francisco, CA 94132 USA. RP Cowell, SA (reprint author), NASA, Ames Res Ctr, Gravitat Res Branch 221A2, Lab Human Enviornm Physiol, Moffett Field, CA 94035 USA. NR 184 TC 16 Z9 19 U1 1 U2 9 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD JAN PY 2002 VL 73 IS 1 BP 54 EP 67 PG 14 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 509UA UT WOS:000173167000010 PM 11817621 ER PT S AU Scargle, JD AF Scargle, JD BE Fry, RL TI Bayesian estimation of time series lags and structure SO BAYESIAN INFERENCE AND MAXIMUM ENTROPY METHODS IN SCIENCE AND ENGINEERING SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 21st International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering CY AUG 04-09, 2001 CL BALTIMORE, MD SP John Hopkins Univ, Appl Phys Lab, John Hopkins Univ, Jayness Fdn AB This paper derives practical algorithms, based on Bayesian inference methods, for several data analysis problems common in time series analysis of astronomical and other data. One problem is the determination of the lag between two time series, for which the cross-correlation function is a sufficient statistic. The second problem is the estimation of structure in a time series of measurements which are a weighted integral over a finite range of the independent variable. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Scargle, JD (reprint author), NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0063-6 J9 AIP CONF PROC PY 2002 VL 617 BP 23 EP 35 PG 13 WC Physics, Mathematical; Statistics & Probability SC Physics; Mathematics GA BU66D UT WOS:000176636900002 ER PT S AU Scargle, JD AF Scargle, JD BE Fry, RL TI Bayesian blocks in two or more dimensions: Image segmentation and cluster analysis SO BAYESIAN INFERENCE AND MAXIMUM ENTROPY METHODS IN SCIENCE AND ENGINEERING SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 21st International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering CY AUG 04-09, 2001 CL BALTIMORE, MD SP John Hopkins Univ, Appl Phys Lab, John Hopkins Univ, Jayness Fdn ID VORONOI AB I describe an extension, to higher dimensions, of the Bayesian Blocks algorithm for estimating signals in noisy time series data [17, 18]. We seek the partition of the data space with the maximum posterior for a model consisting of a homogeneous Poisson process in each partition element. Model M-n attributing the data within region it of the data space to a Poisson process with a fixed event(1) rate lambda(n), has a global posterior depending on only N, the number of data points in the region, and V, its volume: P(Mn) = Phi(N,V) = Gamma(N + 1)Gamma(V - N + 1)/Gamma(V + 2) = N!(V - N)/(V + 1)!. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Scargle, JD (reprint author), NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA. NR 20 TC 1 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 0-7354-0063-6 J9 AIP CONF PROC PY 2002 VL 617 BP 163 EP 173 PG 11 WC Physics, Mathematical; Statistics & Probability SC Physics; Mathematics GA BU66D UT WOS:000176636900012 ER PT S AU Jewell, J AF Jewell, J BE Fry, RL TI Information theoretic approach to Bayesian inference SO BAYESIAN INFERENCE AND MAXIMUM ENTROPY METHODS IN SCIENCE AND ENGINEERING SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 21st International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering CY AUG 04-09, 2001 CL BALTIMORE, MD SP John Hopkins Univ, Appl Phys Lab, John Hopkins Univ, Jayness Fdn AB A problem of central importance in formulating theoretical explanations of some observed process is the construction of a quantitative comparison of observations and examples within the context of a specific theory. From a Bayesian perspective, the ultimate goal is to compute the posterior probability for a theory given the observations. A direct approach to Bayesian inference can be prohibited when the likelihood itself is not known (i.e. or computationally intractable to compute, as in the case of non-linear processes with stochastic initial conditions). An information theoretic approach to this problem is developed in which a sequence of exponential family Gibbs densities are used as approximations to the likelihood. The sequence of Gibbs densities are constructed by successively matching expectation value constraints, giving a positive Gibbs Information Gain, or rate of convergence to the limiting density in the Kullback-Leibler distance sense. Evaluating the sequence of Gibbs densities for the observed data gives a sequence of Bayesian posterior densities which are successively more concentrated. It is shown that the successive confidence intervals form a decreasing sequence of subsets which include, and converge to, the true Bayesian confidence intervals. This provides a justifiable approach for extending Bayesian inference to problems where the likelihood is unknown, as "error bars" are simply larger. Furthermore, the Bayes Information Gain, defined as the rate at which the confidence intervals contract to the limiting interval, is shown to be maximized by a "greedy" approach to inference when constructing the Gibbs likelihoods. C1 Jet Propuls Lab, Pasadena, CA 91109 USA. RP Jewell, J (reprint author), Jet Propuls Lab, Mail Stop 126-347,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0063-6 J9 AIP CONF PROC PY 2002 VL 617 BP 433 EP 448 PG 16 WC Physics, Mathematical; Statistics & Probability SC Physics; Mathematics GA BU66D UT WOS:000176636900030 ER PT B AU Mankins, JC AF Mankins, JC BE Rycroft, M TI The exploration and development of space: The International Space Station and beyond SO BEYOND THE INTERNATIONAL SPACE STATION: THE FUTURE OF HUMAN SPACEFLIGHT SE SPACE STUDIES LA English DT Proceedings Paper CT 7th Annual Symposium on Beyond the International Space Station CY JUN 04-07, 2002 CL STRASBOURG, FRANCE AB This paper addresses a central question facing space-faring peoples at the beginning of the 21st century: why should nations undertake ambitious programs of exploration and development of space - and how should humans be involved in these ventures? The paper touches briefly on the key foundation which the International Space Station (ISS), now nearing completion, will provide. It then discusses a series of challenging future space goals and objectives - each individually important or engaging, but compelling when viewed collectively. The paper concludes with a summary of some notional nearer-term activities that the international community might undertake to refine and plan effectively for these future undertakings. C1 NASA, Headquarters, Adv Programs Off, Washington, DC 20546 USA. RP Mankins, JC (reprint author), NASA, Headquarters, Adv Programs Off, 300 E St SW, Washington, DC 20546 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-0962-3 J9 SPAC STUD PY 2002 VL 7 BP 13 EP 20 PG 8 WC Engineering, Aerospace SC Engineering GA BV99P UT WOS:000180623000003 ER PT B AU Cline, L Finarelli, P Gibbs, G Pryke, I AF Cline, L Finarelli, P Gibbs, G Pryke, I BE Rycroft, M TI Structuring future international cooperation: Learning from the ISS SO BEYOND THE INTERNATIONAL SPACE STATION: THE FUTURE OF HUMAN SPACEFLIGHT SE SPACE STUDIES LA English DT Proceedings Paper CT 7th Annual Symposium on Beyond the International Space Station CY JUN 04-07, 2002 CL STRASBOURG, FRANCE AB As the largest, most complex international scientific and technological cooperation ever undertaken, the Space Station program offers numerous valuable lessons that can be applied in structuring future large-scale international cooperative space endeavors. This paper analyzes the functioning of the cooperation and the lessons learned, both as regards the way the program has been structured and the way in which it has operated to date. Based on practical experience the authors, all of whom have been professionally involved in the development and implementation of the Space Station Freedom (SSF) and International Space Station (ISS) programs, have attempted to determine what elements of the cooperation merit replication and what elements could be improved. The analysis includes such topics as management, operations, cost sharing and partnership expansion. C1 NASA, Headquarters, Washington, DC 20546 USA. RP Cline, L (reprint author), NASA, Headquarters, Code I, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-0962-3 J9 SPAC STUD PY 2002 VL 7 BP 39 EP 54 PG 16 WC Engineering, Aerospace SC Engineering GA BV99P UT WOS:000180623000006 ER PT B AU Grymes, R AF Grymes, R BE Rycroft, M TI Below the surface, life among the stars SO BEYOND THE INTERNATIONAL SPACE STATION: THE FUTURE OF HUMAN SPACEFLIGHT SE SPACE STUDIES LA English DT Proceedings Paper CT 7th Annual Symposium on Beyond the International Space Station CY JUN 04-07, 2002 CL STRASBOURG, FRANCE AB While human missions to other stellar systems are beyond present technological capabilities, understanding the attributes of environments that can initiate and maintain life expands our ability to search and to learn. From the galactic neighborhood to the individual stars within it and the planets orbiting those stars, astrobiologfists explore and define the physico-chemical extremes within which lies safe harbor for biological life. The description of the Galactic Habitable Zone predicts an astro physical niche for "complex," perhaps eventually intelligent, life. Focusing on planetary systems surrounding stars, the Circumstellar Habitable Zone's main, but not only, critical feature is liquid water, life's essential solvent. Recently, another descriptive "zone" has been added to these, the Geological Habitable Zone. The primary inputs determining the life-supporting, life-sheltering potential of a planetary subsurface are heat and pressure. Very little of the extraordinary diversity of the Earth is yet cataloged. Exploring our own backyard and our local neighborhood, we have only scratched the surface, and what a mine of information we have found there. "Follow the water" is the mantra, for wherever we encounter liquid water on Earth we find life. As we explore our solar system, we are not only seeking evidence of life, extant or extinct, we are collecting information on the nature of the processes that permit planetary lithospheres, hydrospheres, and atmospheres to give rise to and sustain a biosphere. We will use all the tools at our disposal, from remote observations and in situ probes to sample return and human expeditions. Our solar system presents other candidates for fruitful search, including those beyond our Sun's Circumstellar Habitable Zone. To reach for life's signature we have to dig deep. C1 NASA, Ames Res Ctr, Astrobiol Inst, Moffett Field, CA 94035 USA. RP Grymes, R (reprint author), NASA, Ames Res Ctr, Astrobiol Inst, MS 240-1, Moffett Field, CA 94035 USA. NR 21 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-0962-3 J9 SPAC STUD PY 2002 VL 7 BP 205 EP 212 PG 8 WC Engineering, Aerospace SC Engineering GA BV99P UT WOS:000180623000024 ER PT J AU McWilliams, T Pusey, ML Ng, JD AF McWilliams, T Pusey, ML Ng, JD TI Contribution of intra- and intermolecular interactions to the conformational stability of canavalin from Canavalia ensiformis SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 Univ Alabama, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD JAN PY 2002 VL 82 IS 1 MA 1445 BP 299A EP 299A PN 2 PG 1 WC Biophysics SC Biophysics GA 511EY UT WOS:000173252701461 ER PT J AU Sumida, JP Kirkland, N Pusey, M AF Sumida, JP Kirkland, N Pusey, M TI Molecular response of chicken egg white lysozyme to buffer salt concentrations and pH SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 Univ Space Res Assoc, Huntsville, AL 35805 USA. Univ Alabama, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD JAN PY 2002 VL 82 IS 1 MA 1550 BP 319A EP 320A PN 2 PG 2 WC Biophysics SC Biophysics GA 511EY UT WOS:000173252701567 ER PT J AU Pusey, ML AF Pusey, ML TI A proposed pathway for the nucleation and growth of the tetgragonal crystal form of lysozyme SO BIOPHYSICAL JOURNAL LA English DT Meeting Abstract C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD JAN PY 2002 VL 82 IS 1 MA 1578 BP 325A EP 325A PN 2 PG 1 WC Biophysics SC Biophysics GA 511EY UT WOS:000173252701595 ER PT J AU Lefsky, MA Cohen, WB Parker, GG Harding, DJ AF Lefsky, MA Cohen, WB Parker, GG Harding, DJ TI Lidar remote sensing for ecosystem studies SO BIOSCIENCE LA English DT Article ID LASER SCANNER DATA; LEAF-AREA INDEX; AIRBORNE LIDAR; ALTIMETER MEASUREMENTS; LIGHT TRANSMITTANCE; DECIDUOUS FORESTS; CANOPY STRUCTURE; HEIGHT PROFILES; BASAL AREA; VEGETATION C1 Oregon State Univ, Dept Forest Sci, Corvallis, OR 97331 USA. Lab Applicat Remote Sensing Ecol, Corvallis, OR 97331 USA. USDA, Forest Serv, Forestry Sci Lab,Pacific NW Res Stn, Lab Applicat Remote Sensing Ecol, Corvallis, OR 97331 USA. Smithsonian Environm Res Ctr, Edgewater, MD 21037 USA. NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. RP Lefsky, MA (reprint author), Oregon State Univ, Dept Forest Sci, Corvallis, OR 97331 USA. EM lefsky@fsl.orst.edu RI Lefsky, Michael/A-7224-2009; Harding, David/F-5913-2012; OI Parker, Geoffrey/0000-0001-7055-6491 NR 68 TC 746 Z9 780 U1 49 U2 320 PU AMER INST BIOLOGICAL SCI PI WASHINGTON PA 1444 EYE ST, NW, STE 200, WASHINGTON, DC 20005 USA SN 0006-3568 J9 BIOSCIENCE JI Bioscience PD JAN PY 2002 VL 52 IS 1 BP 19 EP 30 DI 10.1641/0006-3568(2002)052[0019:LRSFES]2.0.CO;2 PG 12 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 514TG UT WOS:000173456700009 ER PT J AU Crawford, RL Paszczynski, A Lang, QY Erwin, DP Allenbach, L Corti, G Anderson, TJ Cheng, IF Wai, C Barnes, B Wells, R Assefi, T Mojarradi, M AF Crawford, Ronald L. Paszczynski, Andrzej Lang, Qingyong Erwin, Daniel P. Allenbach, Lisa Corti, Giancarlo Anderson, Tony J. Cheng, I. Francis Wai, Chien Barnes, Bruce Wells, Richard Assefi, Touraj Mojarradi, Mohammad TI Measurement of microbial activity in soil by colorimetric observation of in situ dye reduction: an approach to detection of extraterrestrial life SO BMC MICROBIOLOGY LA English DT Article AB Background: Detecting microbial life in extraterrestrial locations is a goal of space exploration because of ecological and health concerns about possible contamination of other planets with earthly organisms, and vice versa. Previously we suggested a method for life detection based on the fact that living entities require a continual input of energy accessed through coupled oxidations and reductions (an electron transport chain). We demonstrated using earthly soils that the identification of extracted components of electron transport chains is useful for remote detection of a chemical signature of life. The instrument package developed used supercritical carbon dioxide for soil extraction, followed by chromatography or electrophoresis to separate extracted compounds, with final detection by voltammetry and tandem mass-spectrometry. Results: Here we used Earth-derived soils to develop a related life detection system based on direct observation of a biological redox signature. We measured the ability of soil microbial communities to reduce artificial electron acceptors. Living organisms in pure culture and those naturally found in soil were shown to reduce 2,3-dichlorophenol indophenol (DCIP) and the tetrazolium dye 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide inner salt (XTT). Uninoculated or sterilized controls did not reduce the dyes. A soil from Antarctica that was determined by chemical signature and DNA analysis to be sterile also did not reduce the dyes. Conclusion: Observation of dye reduction, supplemented with extraction and identification of only a few specific signature redox-active biochemicals such as porphyrins or quinones, provides a simplified means to detect a signature of life in the soils of other planets or their moons. C1 [Crawford, Ronald L.; Paszczynski, Andrzej; Erwin, Daniel P.; Allenbach, Lisa] Univ Idaho, Environm Biotechnol Inst, Moscow, ID 83844 USA. [Lang, Qingyong; Cheng, I. Francis; Wai, Chien] Univ Idaho, Dept Chem, Moscow, ID 83844 USA. [Barnes, Bruce; Wells, Richard] Univ Idaho, Dept Elect Engn, Moscow, ID 83844 USA. [Corti, Giancarlo; Anderson, Tony J.] Univ Idaho, Dept Mech Engn, Moscow, ID 83844 USA. [Assefi, Touraj] Univ Idaho, Microelect Res & Commun Inst, Moscow, ID 83844 USA. [Mojarradi, Mohammad] CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Crawford, RL (reprint author), Univ Idaho, Environm Biotechnol Inst, Moscow, ID 83844 USA. EM crawford@uidaho.edu; andrzej@uidaho.edu; lang9912@uidaho.edu; derwin@moscow.com; lisaa@uidaho.edu; cort4258@uidaho.edu; tandersn@uidaho.edu; ifcheng@uidaho.edu; cwai@uidaho.edu; barnesb@mrc.uidaho.edu; rwells@mrc.uidaho.edu; tassefi@uidaho.edu; mohammad.m.mojarradi@jpl.nasa.gov FU National Aeronautic and Space Administration [1212404] FX The work described here was partially performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautic and Space Administration (award 1212404). We thank Sarah Koerber for editorial assistance. We thank Dorota Parazinska, Andy Parsons, Diana Wall, and Colorado State University for assisting in the collection of soils from Antarctica. NR 29 TC 4 Z9 5 U1 0 U2 3 PU BIOMED CENTRAL LTD PI LONDON PA 236 GRAYS INN RD, FLOOR 6, LONDON WC1X 8HL, ENGLAND SN 1471-2180 J9 BMC MICROBIOL JI BMC Microbiol. PY 2002 VL 2 AR 22 DI 10.1186/1471-2180-2-22 PG 8 WC Microbiology SC Microbiology GA V21TW UT WOS:000208230900022 PM 12150716 ER PT J AU Carls, MG Marty, GD Hose, JE AF Carls, MG Marty, GD Hose, JE TI Synthesis of the toxicological impacts of the Exxon Valdez oil spill on Pacific herring (Clupea pallasi) in Prince William Sound, Alaska, USA SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID WEATHERED CRUDE-OIL; POLYCYCLIC AROMATIC-HYDROCARBONS; SALMON ONCORHYNCHUS-GORBUSCHA; HEMORRHAGIC SEPTICEMIA VIRUS; WATER-SOLUBLE FRACTION; LIFE HISTORY STAGES; PETROLEUM-HYDROCARBONS; MYTILUS-EDULIS; MICROBIAL-DEGRADATION; EMBRYONIC-DEVELOPMENT AB Pacific herring (Clupea pallasi) in Prince William Sound (PWS) were affected by two major events in the past decade: the Exxon Valdez oil spill in 1989 and a 75% collapse in the adult population in 1993. In this review we compare and reinterpret published data from industry and government sources. Combining site-specific estimates of exposure and recent laboratory effects thresholds, 0.4-0.7 mu.L-1 total polynuclear aromatic hydrocarbons, we conclude that 25-32% of the embryos were damaged in PWS in 1989. Significant effects extended beyond those predicted by visual observation of oiling and by toxicity information available in 1989. Oil-induced mortality probably reduced recruitment of the 1989 year class into the fishery, but was impossible to quantify because recruitment was generally low in other Alaskan herring stocks. Significant adult mortality was not observed in 1989; biomass remained high through 1992 but declined precipitously in winter 1992-1993. The collapse was likely caused by high population size, disease, and suboptimal nutrition, but indirect links to the spill cannot be ruled out. These concepts have broad application to future oil spill assessments. For example, safety standards for dissolved aromatics should reflect the previously unrecognized high toxicity of polynuclear aromatic hydrocarbons to adequately protect critical life stages. C1 Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. Univ Calif Davis, Sch Vet Med, Dept Anat Physiol & Cell Biol, Davis, CA 95616 USA. Occidental Coll, Los Angeles, CA 93420 USA. RP Carls, MG (reprint author), Natl Marine Fisheries Serv, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. EM mark.carls@noaa.gov NR 84 TC 56 Z9 59 U1 3 U2 31 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0706-652X EI 1205-7533 J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD JAN PY 2002 VL 59 IS 1 BP 153 EP 172 DI 10.1139/F01-200 PG 20 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 524PN UT WOS:000174022200017 ER PT J AU Vander Wal, RL AF Vander Wal, RL TI Flame synthesis of Ni-catalyzed nanofibers SO CARBON LA English DT Article DE carbon filaments; carbon nanotubes; catalytically grown carbon; combustion; pyrolysis ID WALLED CARBON NANOTUBES; CHEMICAL-VAPOR-DEPOSITION; PULSE INJECTION TECHNIQUE; FIBERS; GROWTH; HYDROCARBONS; PYROLYSIS; MICROSTRUCTURE; TEMPERATURE; COMPOSITES AB Flame synthesis of Ni-catalyzed nanofibers is illustrated. Ni nanoparticles are formed by thermal decomposition of a nebulized Ni nitrate solution entrained into a reactive fuel mixture. Although at the earliest stages of growth, the Ni nanoparticles are sufficiently small to catalyze single-wall nanotubes (SWNTs). only the larger particles appear catalytically active yielding only nanofibers. Using different reactive gas mixtures consisting of CO or C2H2 or their combination, Ni nanoparticles exhibited a high preferential reactivity towards C2H2 to form nanofibers. These results are interpreted as a result of CO enhancing the dissociative adsorption of C2H2 through electronic charge donation mediated by the Ni nanoparticle and physically protecting active sites against blockage by aromatic molecules. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 NASA Glenn, NCMR, Cleveland, OH 44135 USA. RP NASA Glenn, NCMR, MS 110-3,21000 BrookPk Rd, Cleveland, OH 44135 USA. EM randy.vanderwal@grc.nasa.gov NR 36 TC 42 Z9 42 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-6223 EI 1873-3891 J9 CARBON JI Carbon PY 2002 VL 40 IS 12 BP 2101 EP 2107 AR PII S0008-6223(02)00092-1 DI 10.1016/S0008-6223(02)00092-1 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 604FD UT WOS:000178605100004 ER PT B AU Andrews, R Mah, R Jeffrey, S Freitas, K Guerrero, M Papasin, R Reed, C AF Andrews, R Mah, R Jeffrey, S Freitas, K Guerrero, M Papasin, R Reed, C BE Lemke, HU Vannier, MW Inamura, K Farman, AG Doi, K Reiber, JH TI The NASA Smart Probe project for real-time multiple microsensor tissue recognition: automating stereotactic brain biopsy and other procedures SO CARS 2002: COMPUTER ASSISTED RADIOLOGY AND SURGERY, PROCEEDINGS LA English DT Proceedings Paper CT 16th International Congress and Exhibition on Computer Assisted Radiology and Surgery CY JUN 26-29, 2002 CL PARIS, FRANCE SP Amer Acad Oral & Maxillofacial Radiol, Bulgarian Assoc Radiol, British Inst Radiol, Czech Radiol Soc, Deutsch Gesell Comp Roboterassistierte Chirurg, Deutsch Gesell Biomed Tech e V, Deutsch Rontgengesell, European Soc Cardiac Radiol ID IDENTIFICATION; SURGERY AB Automating the sensor, effector, and sensor-effector communication aspects of surgery is essential to perform operations at a site remote from the surgeon, e.g. in Space. Real-time tissue recognition can be combined with image-guidance to augment the sensor component; a robot can be the remote effector component. The NASA Smart Probe uses neural networks to combine data from multiple microsensors in real-time to provide a unique tissue "signature". The concept has been demonstrated in both animal models and clinical trials with women undergoing breast "biopsy" (optical followed by histological). Minimally-invasive multiparameter real-time tissue recognition should improve (1) cancer diagnosis, (2) localization (e.g. functional neurosurgery), and (3) tissue monitoring (e.g. cerebral or cardiac ischemia). The Smart Probe can become the sensor component of a self-contained robotic surgical device. C1 NASA, Ames Res Ctr, Smart Syst Lab, Moffett Field, CA 94035 USA. RP Andrews, R (reprint author), NASA, Ames Res Ctr, Smart Syst Lab, Moffett Field, CA 94035 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-43655-3 PY 2002 BP 161 EP 166 PG 6 WC Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging; Surgery SC Computer Science; Engineering; Radiology, Nuclear Medicine & Medical Imaging; Surgery GA BV16A UT WOS:000178013900027 ER PT B AU Madavan, NK AF Madavan, NK GP IEEE IEEE TI Multiobjective optimization using a pareto Differential Evolution approach SO CEC'02: PROCEEDINGS OF THE 2002 CONGRESS ON EVOLUTIONARY COMPUTATION, VOLS 1 AND 2 SE IEEE Congress on Evolutionary Computation LA English DT Proceedings Paper CT IEEE World Congress on Computational Intelligence (WCCI2002) CY MAY 12-17, 2002 CL HONOLULU, HI SP IEEE, IEEE Neural Network Soc, IEE, Evolut Programming Soc AB Differential Evolution is a simple, fast, and robust evolutionary algorithm that has proven effective in determining the global optimum for several difficult single-objective optimization problems. In this paper, the Differential Evolution algorithm is extended to multiobjective optimization problems by using a Pareto-based approach. The algorithm performs well when applied to several test optimization problems from the literature. C1 NASA, Ames Res Ctr, Adv Supercomp Div, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, Adv Supercomp Div, M-S T27A-1, Moffett Field, CA 94035 USA. EM madavan@nas.nasa.gov NR 17 TC 54 Z9 66 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7282-4 J9 IEEE C EVOL COMPUTAT PY 2002 BP 1145 EP 1150 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BW11H UT WOS:000180919800195 ER PT B AU Lohn, JD Kraus, WF Haith, GL AF Lohn, JD Kraus, WF Haith, GL GP IEEE IEEE TI Comparing a coevolutionary genetic algorithm for multiobjective optimization SO CEC'02: PROCEEDINGS OF THE 2002 CONGRESS ON EVOLUTIONARY COMPUTATION, VOLS 1 AND 2 SE IEEE Congress on Evolutionary Computation LA English DT Proceedings Paper CT IEEE World Congress on Computational Intelligence (WCCI2002) CY MAY 12-17, 2002 CL HONOLULU, HI SP IEEE, IEEE Neural Network Soc, IEE, Evolut Programming Soc AB We present results from a study comparing a recently developed coevolutionary genetic algorithm (CGA) against a set of,evolutionary algorithms using a suite of multiobjective optimization benchmarks. The CGA embodies competitive coevolution and employs a simple, straightforward target population representation and fitness calculation based on developmental theory of learning. Because of these properties, setting up the additional population is trivial making implementation no more difficult than using a standard GA. Empirical results using a suite of two-objective test functions indicate that this CGA performs well at finding solutions on convex, nonconvex, discrete, and deceptive Pareto-optimal fronts, while giving respectable results on a nonuniform optimization. On a multimodal Pareto front, the CGA yields poor coverage across the Pareto front, yet finds a solution that dominates all the solutions produced by the eight other algorithms. C1 NASA, Ames Res Ctr, Computat Sci Div, Moffett Field, CA 94035 USA. RP Lohn, JD (reprint author), NASA, Ames Res Ctr, Computat Sci Div, MS 269-1, Moffett Field, CA 94035 USA. EM jlohn@mail.arc.nasa.gov; bkraus@email.arc.nasa.gov; haith@stanfordalumni.org NR 16 TC 30 Z9 37 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7282-4 J9 IEEE C EVOL COMPUTAT PY 2002 BP 1157 EP 1162 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BW11H UT WOS:000180919800197 ER PT B AU Stoica, A Zebulum, RS Keymeulen, D Ferguson, MI Duong, V AF Stoica, A Zebulum, RS Keymeulen, D Ferguson, MI Duong, V GP IEEE IEEE TI Fuzzy controller implementations with fewer than ten transistors? SO CEC'02: PROCEEDINGS OF THE 2002 CONGRESS ON EVOLUTIONARY COMPUTATION, VOLS 1 AND 2 SE IEEE Congress on Evolutionary Computation LA English DT Proceedings Paper CT IEEE World Congress on Computational Intelligence (WCCI2002) CY MAY 12-17, 2002 CL HONOLULU, HI SP IEEE, IEEE Neural Network Soc, IEE, Evolut Programming Soc AB Evolutionary algorithms (EA) offer good promise for automated design of analog circuits as well as for adaptation and automatic reconfiguration of programmable devices. In particular, EAs facilitate the design of analog circuits for very specific requirements, such as those related to the implementation of fuzzy operators, or even of complete fuzzy systems. The paper starts with a brief overview of the evolutionary process applied to circuit design and of a family of analog programmable devices that support on-chip evolution. As a case study, we describe the evolutionary design of a fuzzy controller, using re-configurable analog chips models and unstructured representation. We were able to achieve a circuit that approximates the control surface of a 2-input fuzzy controller, mapping thus a full fuzzy system in only seven transistors. The paper presents evidence that EA can provide very compact solutions for implementation of fuzzy systems, and that programmable analog devices are an efficient and rapid solution for rapid deployment of fuzzy systems. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Stoica, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM adrian.stoica@jpl.nasa.gov NR 11 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7282-4 J9 IEEE C EVOL COMPUTAT PY 2002 BP 1830 EP 1835 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BW11H UT WOS:000180919800312 ER PT S AU Adams, MA AF Adams, MA BE McCauley, JW Crowson, A Gooch, WA Rajendran, AM Bless, SJ Logan, KV Normandia, M Wax, S TI Theory and experimental test methods for evaluating ceramic armor components SO CERAMIC ARMOR MATERIALS BY DESIGN SE CERAMIC TRANSACTIONS LA English DT Proceedings Paper CT Symposium on Ceramic Armor Materials by Design held at the Pac Rim IV International Conference on Advanced Ceramics and Glass CY NOV 04-08, 2001 CL MAUI, HI AB The Ballistic Performance Map (BPM) and its derivatives are useful constructs for understanding the function and performance of ceramic and other components in hardfaced armor systems. By combining the BPM model with a constant velocity ballistic testing approach and varying the areal densities of the target components, the Protection Areal Density (PAD) testing methodology, the relative and absolute performance of different ceramic materials are readily evaluated. In addition, such methods enable adequate statistical analysis of the unbiased test results to understand the basic uncertainty in the measured performance and the stochastic behavior of any hardfaced armor material or armor system. Examples of the ballistic performance of several classes of hardface materials are given. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Adams, MA (reprint author), Jet Prop Lab, 4800 Oak Grove Dr,Bldg 122-B3, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 1042-1122 BN 1-57498-148-X J9 CERAM TRANS PY 2002 VL 134 BP 139 EP 150 PG 12 WC Engineering, Mechanical; Materials Science, Ceramics; Materials Science, Characterization & Testing SC Engineering; Materials Science GA BW33N UT WOS:000181621000012 ER PT J AU Unal, O Bansal, NP AF Unal, O Bansal, NP TI In-plane and interlaminar shear strength of a unidirectional Hi-Nicalon fiber-reinforced celsian matrix composite SO CERAMICS INTERNATIONAL LA English DT Article DE composites; mechanical properties; silicate; structural applications ID INPLANE AB In-plane and interlaminar shear strength of a unidirectional SiC fiber-reinforced (BaSr)Al2Si2O8 celsian composite were measured by the double-notch shear test method between room temperature and 1200 degreesC. The interlaminar shear strength was lower than the in-plane shear strength at all temperatures. Stress analysis, using finite element modeling, indicated that shear stress concentration was not responsible for the observed difference in strength. Instead, the difference in layer architecture and thus, the favorable alignment of fiber-rich layers with the shear plane in the interlaminar specimens appears to be the reason for the lower strength of this composite. A rapid decrease in strength was observed with temperature due to softening of the glassy phase in the material. Published by Elsevier Science Ltd and Techna S.r.l. C1 NASA, Glenn Res Ctr, Div Mat, Cleveland, OH 44135 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Bansal, NP (reprint author), NASA, Glenn Res Ctr, Div Mat, MS 106-5, Cleveland, OH 44135 USA. NR 29 TC 26 Z9 28 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0272-8842 J9 CERAM INT JI Ceram. Int. PY 2002 VL 28 IS 5 BP 527 EP 540 AR PII S0272-8842(02)00006-8 DI 10.1016/S0272-8842(02)00006-8 PG 14 WC Materials Science, Ceramics SC Materials Science GA 572TE UT WOS:000176790400009 ER PT J AU Zak, M AF Zak, M TI Entanglement-based communications SO CHAOS SOLITONS & FRACTALS LA English DT Article ID QUANTUM AB Based upon quantum entanglement, a simple algorithm for the instantaneous transmission of messages (chosen at random) to remote distances is proposed. A special class of situations when such transmissions are useful is outlined. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Zak, M (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. NR 4 TC 4 Z9 4 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0960-0779 J9 CHAOS SOLITON FRACT JI Chaos Solitons Fractals PD JAN PY 2002 VL 13 IS 1 BP 39 EP 41 DI 10.1016/S0960-0779(00)00235-6 PG 3 WC Mathematics, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 476GN UT WOS:000171218000004 ER PT B AU Loewenstein, M AF Loewenstein, M BE FuscoFemiano, R Matteucci, F TI Chandra observations of cluster abundances and other matters SO CHEMICAL ENRICHMENT OF INTRACLUSTER AND INTERGALACTIC MEDIUM SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Meeting on Chemical Enrichment of Intracluster and Intergalactic Medium CY MAY 14-18, 2001 CL VULCANO, ITALY SP Univ Trieste, Dept Atronom, CNR, Ist Astrofis Spaziale ID METAL-LINE RATIOS; METALLICITY GRADIENTS; INTERGALACTIC MEDIUM; GALAXIES; ENRICHMENT; CLOUDS; FOREST; ASCA; GAS AB I provide a brief overview of Chandra observations of clusters of galaxies, with an emphasis on intracluster medium metal abundance measurements, and abundance gradients and cooling flows. I also cover the following two more specialized topics: the lack of ICM abundance evolution and star formation history in the universe, and hypernovae enrichment of the ICM. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Loewenstein, M (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. NR 44 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 1-58381-093-5 J9 ASTR SOC P PY 2002 VL 253 BP 35 EP 41 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU69P UT WOS:000176731700004 ER PT J AU Thompson, DS Thompson, DW Southward, RE AF Thompson, DS Thompson, DW Southward, RE TI Oxo-metal-polyimide nanocomposites. 2. Enhancement of thermal, mechanical, and chemical properties in soluble hexafluoroisopropylidine-based polyimides via the in situ formation of oxo-lanthanide(III)-polyimide nanocomposites SO CHEMISTRY OF MATERIALS LA English DT Article ID AQUEOUS CHLORIDE SOLUTIONS; X-RAY-DIFFRACTION; RARE-EARTH IONS; CERAMIC POLYMER COMPOSITES; COORDINATION HYDRATION; NANOCLUSTERS; PRECURSORS; CHEMISTRY; SILICA; HYBRID AB Tris(2,4-pentanedionato)lanthanide(III) polyhydrates were added as inorganic sol-gel precursors to DMAc solutions of the polyimides formed from 2,2-bis(3,4-dicarboxyphenyl)-hexafluoropropane dianhydride and 1,3-bis-(aminophenoxy)benzene, 6FDA/1,3(3)-APB and 6FDA/2,2-bis[4-(4-aminophenoxy]hexafluoropropane, 6FDA/4-BDAF. Thermal treatment of doped-resin films gave composite oxo-metal(III) nanocomposite membranes which were visually clear with lower linear coefficients of thermal expansion, increased moduli, and reduced solvent sensitivity. Glass transition temperatures and 10% weight loss temperatures in nitrogen were close to those of the parent polymers. Films were characterized by thermal, mechanical, X-ray, and transmission electron micrographic techniques. C1 Coll William & Mary, Dept Chem, Williamsburg, VA 23187 USA. NASA, Langley Res Ctr, Struct & Mat Competency, Hampton, VA 23681 USA. RP Thompson, DS (reprint author), 3M Co, 3M Ctr, Bldg 201-1W-28, St Paul, MN 55144 USA. NR 47 TC 26 Z9 26 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JAN PY 2002 VL 14 IS 1 BP 30 EP 37 DI 10.1021/cm000855a PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 514UK UT WOS:000173459300011 ER PT S AU Mukai, K Orio, M Ringwald, F Still, M AF Mukai, K Orio, M Ringwald, F Still, M BE Hernanz, M Jose, J TI Chandra observations of old novae SO CLASSICAL NOVA EXPLOSIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT International Conference on Classical Nova Explosions CY MAY 20-24, 2002 CL SITGES, SPAIN SP Inst Space Res Catalonia, Natl Res Council Spain, Polytech Univ Catalonia, Spanish Minist Sci & Technol, Dept Univ & Res, Generalitat Catalunya ID X-RAY OBSERVATIONS; DQ HERCULIS; STARS AB We present highlights of Chandra observations of two old novae, DQ Her and V603 Aql, with the main aim of improving our understanding of the underlying binaries decades after their respective nova eruptions. In DQ Her, we find a partial X-ray eclipse; it is likely that we observe photons scattered in an accretion disk wind. The X-ray spectrum of V603 Aql suggests an origin in multi-temperature plasma; while the low energy lines suggest modest density, the 6.4 keV Fe Kalpha line suggests that the hard continuum arises in a compact emission region. We also report on our searches for nebular X-ray emission around these old novae. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mukai, K (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0092-X J9 AIP CONF PROC PY 2002 VL 637 BP 372 EP 376 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV52R UT WOS:000179251300063 ER PT J AU Bounoua, L DeFries, R Collatz, GJ Sellers, P Khan, H AF Bounoua, L DeFries, R Collatz, GJ Sellers, P Khan, H TI Effects of land cover conversion on surface climate SO CLIMATIC CHANGE LA English DT Article ID GENERAL-CIRCULATION MODEL; DOUBLED ATMOSPHERIC CO2; TERRESTRIAL CARBON METABOLISM; ICE-CLOUD MICROPHYSICS; SEMI-ARID REGIONS; TROPICAL DEFORESTATION; GLOBAL CLIMATE; SOIL-MOISTURE; PARAMETERIZATION SIB2; CANOPY REFLECTANCE AB This study investigates the effects of large-scale human modification of land cover on regional and global climate. A general circulation model (Colorado State University GCM) coupled to a biophysically-based land surface model (SiB2) was used to run two 15-yr climate simulations. The control run used current vegetation distribution as observed by satellite for the year 1987 to derive the vegetation's physiological and morphological properties. The twin simulation used a realistic approximation of vegetation type distribution that would exist in the absence of human disturbance. In temperate latitudes, where anthropogenic modification of the landscape has converted large areas of forest and grassland to cropland, conversion cools canopy temperatures up to 0.7 degrees C in summer and 1.1 degrees C in winter. This cooling results from both (1) morphological changes in vegetation which increase albedo and (2) physiological changes in vegetation which increase latent heat flux of crops compared with undisturbed vegetation during the growing season. In the tropics and subtropics, conversion warms canopy temperature by about 0.8 degrees C year round. The warming results from a combination of morphological changes in vegetation offset by physiological changes that reduce latent heat flux of existing compared with undisturbed vegetation. If water efficient, tropical C4 grasses replace C3 vegetation, latent heat flux is further reduced. The overall effect of land cover conversion is cooling in temperate latitudes and warming in the tropics. Because the effects are opposite in sign in tropics and middle latitudes, they cancel each other when averaged globally. Over land, the surface temperature increased by 0.2 C in winter and remained essentially unchanged in summer. The effects on land surface hydrology were also small when averaged globally. The results suggest that the effects of land use change of the observed magnitude do not have a strong impact on the globally averaged climate but their signature at regional scales is significant and vary according to the type of land cover conversion. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. NASA, JSC, Houston, TX USA. Univ Maryland, Dept Geog, College Pk, MD 20742 USA. RP Bounoua, L (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. EM bounoua@dounia.gsfc.nasa.gov RI collatz, george/D-5381-2012 NR 74 TC 178 Z9 193 U1 9 U2 57 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD JAN PY 2002 VL 52 IS 1-2 BP 29 EP 64 DI 10.1023/A:1013051420309 PG 36 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 497HA UT WOS:000172448300004 ER PT B AU Gatski, TB Rumsey, CL AF Gatski, TB Rumsey, CL BE Launder, BE Sandham, ND TI Linear and nonlinear eddy viscosity models SO CLOSURE STRATEGIES FOR TURBULENT AND TRANSITIONAL FLOWS LA English DT Proceedings Paper CT International Workshop on Closure Strategies for Turbulent and Transitional Flows CY 1999 CL CAMBRIDGE, ENGLAND ID REYNOLDS STRESS MODEL; NEAR-WALL TURBULENCE; HOMOGENEOUS TURBULENCE; 2-EQUATION MODELS; BOUNDARY-LAYERS; SIMULATION DATA; CLOSURE MODELS; COMPLEX FLOWS; EXPLICIT; COMPUTATION C1 NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA. RP Gatski, TB (reprint author), NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Mail Stop 128, Hampton, VA 23681 USA. NR 65 TC 13 Z9 13 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI CAMBRIDGE PA THE PITT BUILDING, TRUMPINGTON ST, CAMBRIDGE CB2 1RP, CAMBS, ENGLAND BN 0-521-79208-8 PY 2002 BP 9 EP 46 PG 8 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA BU53R UT WOS:000176275900001 ER PT J AU Glaessgen, EH Riddell, WT Raju, IS AF Glaessgen, EH Riddell, WT Raju, IS TI Nodal constraint, shear deformation and continuity effects related to the modeling of debonding of laminates, using plate elements SO CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES LA English DT Article ID STRESS INTENSITY FACTORS; FINITE-ELEMENTS; COMPOSITE; PREDICTION AB The effects of several critical assumptions and parameters on the computation of strain energy release rates for delamination and debond configurations modeled with plate elements have been quantified. The method of calculation is based on the virtual crack closure technique (VCCT), and models of the upper and lower surface of the delamination or debond that use two-dimensional (2D) plate elements rather than three-dimensional (3D) solid elements. The major advantages of the plate element modeling technique are a smaller model size and simpler configurational modeling. Specific issues that are discussed include: constraint of translational degrees of freedom, rotational degrees of freedom or both in the neighborhood of the debond front; shear deformation assumptions; and continuity of material properties and section stiffness in the vicinity of the debond front. Where appropriate, the plate element analyses are compared with corresponding two-dimensional plane strain analyses. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Volpe Natl Transportat Syst Ctr, Cambridge, MA 02142 USA. RP Glaessgen, EH (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 32 TC 17 Z9 17 U1 0 U2 0 PU TECH SCIENCE PRESS PI PALMDALE PA PO BOX 900486, PALMDALE, CA 93590-0486 USA SN 1526-1492 J9 CMES-COMP MODEL ENG JI CMES-Comp. Model. Eng. Sci. PY 2002 VL 3 IS 1 BP 103 EP 116 PG 14 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 527PQ UT WOS:000174195200007 ER PT J AU Wei, CY Srivastava, D Cho, K AF Wei, CY Srivastava, D Cho, K TI Molecular dynamics study of temperature dependent plastic collapse of carbon nanotubes under axial compression SO CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES LA English DT Article ID LOAD-TRANSFER; COMPOSITES; FLEXIBILITY; GROWTH AB The temperature dependence of the plastic collapse of single-wall carbon nanotubes under axial compression has been studied with classical molecular dynamics simulations using Tersoff-Brenner potential for C-C interactions. At zero temperature, an (8,0) single-wall carbon nanotube under axial compression collapses by forming fins-like structure which remains within the elastic limit of the system, in agreement of previous molecular dynamics study. At finite temperatures, however, we find that temperature dependent fluctuations can activate the formation of spa bonds, in agreement with a recently proposed plastic collapse mechanism of the same nanotube with a generalized tight-binding molecular dynamics description. Furthermore, Stone-Wales defects are also found in the plastically collapsed structures. The thermal fluctuations are shown to drive nanotubes to overcome the energy barriers leading to plastically collapsed structures which have significantly lower strain energy (0.1eV/atom) than fins-like structure. C1 Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Wei, CY (reprint author), Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. NR 20 TC 15 Z9 16 U1 0 U2 1 PU TECH SCIENCE PRESS PI PALMDALE PA PO BOX 900486, PALMDALE, CA 93590-0486 USA SN 1526-1492 J9 CMES-COMP MODEL ENG JI CMES-Comp. Model. Eng. Sci. PY 2002 VL 3 IS 2 BP 255 EP 261 PG 7 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 546QM UT WOS:000175284900010 ER PT S AU Hazeltine, E AF Hazeltine, E BE Prinz, W Hommel, B TI The representational nature of sequence learning: evidence for goal-based codes SO COMMON MECHANISMS IN PERCEPTION AND ACTION SE ATTENTION AND PERFORMANCE LA English DT Article; Proceedings Paper CT 19th International Symposium on Attention and Performance CY JUL 16-22, 2000 CL Kloster Irsee, GERMANY ID SERIAL REACTION TASK; HUNTINGTONS-DISEASE; PREMOTOR CORTEX; MEMORY-SYSTEMS; STIMULUS; ACCURACY AB Motor sequence learning guides much of our behavior yet the nature of the underlying representations remains elusive: some have argued that stimuli are incorporated in the representations; others have emphasized codes that specify anatomical units; and still others have proposed that the representations are based on locations in egocentric space. To examine what information is learned, the present study used variants of the serial reaction time task in which the responses were associated with task-relevant environmental consequences. In two experiments, these environmental consequences determined whether sequence knowledge transferred to new sets of stimuli and responses, indicating that the learned representation includes the intended goals of the component actions. Such an encoding scheme can account for apparently conflicting findings in the sequence learning literature. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM eliot@socrates.berkeley.edu NR 34 TC 27 Z9 27 U1 0 U2 1 PU OXFORD UNIVERSITY PRESS PI OXFORD PA WALTON ST, OXFORD OX2 6DP, ENGLAND SN 1047-0387 BN 0-19-851069-1 J9 ATTENTION PERFORM PY 2002 VL 19 BP 673 EP 689 PG 17 WC Psychology, Biological; Neurosciences; Psychology; Psychology, Experimental SC Psychology; Neurosciences & Neurology GA BY91H UT WOS:000189493700033 ER PT J AU Jacobson, J Hwang, Z AF Jacobson, J Hwang, Z TI Unreal tournament for immersive interactive theater SO COMMUNICATIONS OF THE ACM LA English DT Article C1 Univ Pittsburgh, Dept Informat Sci & Telecommun, Pittsburgh, PA 15260 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Jacobson, J (reprint author), Univ Pittsburgh, Dept Informat Sci & Telecommun, Pittsburgh, PA 15260 USA. NR 2 TC 18 Z9 18 U1 0 U2 2 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 USA SN 0001-0782 J9 COMMUN ACM JI Commun. ACM PD JAN PY 2002 VL 45 IS 1 BP 39 EP 42 PG 4 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 507HY UT WOS:000173022200008 ER PT J AU Filman, RE Barrett, S Lee, DD Linden, T AF Filman, RE Barrett, S Lee, DD Linden, T TI Inserting ilities by controlling communications SO COMMUNICATIONS OF THE ACM LA English DT Editorial Material C1 NASA Ames Res Ctr, Res Inst Adv Comp Sci, Moffett Field, CA USA. Calebtech, Austin, TX USA. NASA Ames Res Ctr, Sci Appl Int Corp, Moffett Field, CA USA. RP Filman, RE (reprint author), NASA Ames Res Ctr, Res Inst Adv Comp Sci, Moffett Field, CA USA. NR 11 TC 10 Z9 10 U1 0 U2 1 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 USA SN 0001-0782 J9 COMMUN ACM JI Commun. ACM PD JAN PY 2002 VL 45 IS 1 BP 116 EP 122 DI 10.1145/502269.502274 PG 7 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 507HY UT WOS:000173022200025 ER PT S AU Schwabacher, M Samuels, J Brownston, L AF Schwabacher, M Samuels, J Brownston, L BE Willett, PK Kirubarajan, T TI The NASA integrated vehicle health management technology experiment for X-37 SO COMPONENT AND SYSTEMS DIAGNOSTICS, PROGNOSTICS, AND HEALTH MANAGEMENT II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 2nd Conference on Component and Systems Diagnostics, Prognostics, and Health Management CY APR 03-04, 2002 CL ORLANDO, FL SP SPIE DE diagnosis; model-based reasoning; IVHM; spacecraft; spaceplane; RLV; X-37; Livingstone AB The NASA Integrated Vehicle Health Management (IVHM) Technology Experiment for X-37 was intended to run IVHM software on board the X-37 spacecraft. The X-37 is an unpiloted vehicle designed to orbit the Earth for up to 21 days before landing on a runway. The objectives of the experiment were to demonstrate the benefits of in-flight IVHM to the operation of a Reusable Launch Vehicle, to advance the Technology Readiness Level of this IVHM technology within a flight environment, and to demonstrate that the IVHM software could operate on the Vehicle Management Computer. The scope of the experiment was to perform real-time fault detection and isolation for X-37's electrical power system and electro-mechanical actuators. The experiment used Livingstone, a software system that performs diagnosis using a qualitative, model-based reasoning approach that searches system-wide interactions to detect and isolate failures. Two of the challenges we faced were to make this research software more efficient so that it would fit within the limited computational resources that were available to us on the X-37 spacecraft, and to modify it so that it satisfied the X-37's software safety requirements. Although the experiment is currently unfunded, the development effort resulted in major improvements in Livingstone's efficiency and safety. This paper reviews some of the details of the modeling and integration efforts, and some of the lessons that were learned. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Schwabacher, M (reprint author), NASA, Ames Res Ctr, MS 269-3, Moffett Field, CA 94035 USA. NR 3 TC 1 Z9 1 U1 1 U2 8 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4483-9 J9 P SOC PHOTO-OPT INS PY 2002 VL 4733 BP 49 EP 60 DI 10.1117/12.475494 PG 12 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic; Engineering, Mechanical SC Computer Science; Engineering GA BV20P UT WOS:000178157300005 ER PT S AU Nettles, AT Douglas, MJ AF Nettles, AT Douglas, MJ BE Zureick, A Nettles, AT TI A comparison of quasi-static indentation testing to low velocity impact testing SO COMPOSITE MATERIALS: TESTING, DESIGN, AND ACCEPTANCE CRITERIA SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Composite Materials CY MAR 26-27, 2001 CL PHOENIX, AZ SP Amer Soc Testing & Mat Int Comm D30 DE composites; static indentation; impact; transverse loading rate ID DAMAGE; CFRP AB The need for a static test method for modeling low-velocity foreign object impact events to composites would prove to be very beneficial to researchers because much more data can be obtained from a static test than from an impact test. In order to examine if this is feasible, a series of static indentation and low velocity impact tests were carried out and compared, Square specimens of many sizes and thickness were utilized to cover the array of types of low velocity impact events, Laminates with a pi/4 stacking sequence were employed because this is by far the most common type of engineering laminate. Three distinct flexural rigidities under two different boundary conditions were tested in order to obtain damage due to large deflections, contact stresses and to examine if the static indentation-impact comparisons are valid under the spectrum of damage modes that can be experienced. Comparisons between static indentation and low velocity impact tests were based on the maximum applied transverse load. The dependent parameters examined included dent depth, back surface crack length, delamination area and to a limited extent, load-deflection behavior. Results from this particular study showed that no distinct differences could be seen between the static indentation tests and the low velocity impact tests. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Nettles, AT (reprint author), NASA, George C Marshall Space Flight Ctr, ED 34, Huntsville, AL 35812 USA. NR 17 TC 5 Z9 5 U1 2 U2 5 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2893-2 J9 AM SOC TEST MATER PY 2002 VL 1416 BP 116 EP 130 DI 10.1520/STP10634S PG 15 WC Materials Science, Composites SC Materials Science GA BV05S UT WOS:000177718300007 ER PT S AU Walker, JL Russell, SS Lansing, MD AF Walker, JL Russell, SS Lansing, MD BE Zureick, A Nettles, AT TI Detection and characterization of imperfections in composite pressure vessels SO COMPOSITE MATERIALS: TESTING, DESIGN, AND ACCEPTANCE CRITERIA SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Composite Materials CY MAR 26-27, 2001 CL PHOENIX, AZ SP Amer Soc Testing & Mat Int Comm D30 DE thermography; composite materials; microstructure AB Interpreting the information given in a thermogram can be a difficult task under ideal circumstances and extremely challenging in a real world setting, The work discussed in this paper illustrates how the microstructure of several commonly found defects in composite structures relate to their thermographic image counterpart. Two test cases are studied herein, including a large graphite/epoxy RP-1 fuel tank and a graphite composite cryogenic fuel feedline. The structures used in this study were designed to serve as manufacturing proof of concept specimens and to undergo hydroburst testing to verify manufacturing practices and structural design. Prior to hydrostatic testing the structures underwent 100% thermographic evaluation to ensure that no manufacturing or handling damage was present. Due to a large inclusion found in the feedline, it was pulled from service and dissected without performing the hydroproof The thermographic indications found in the RP-1 tank were below critical limits so it underwent a complete hydroproof loading series and finally a hydroburst. Following the hydroburst samples were cut from the tank in regions where thermography had located damage before the test. These regions were re-evaluated thermographically and then were cross-sectioned and photomicrographed. C1 George C Marshall Space Flight Ctr, Nondestruct Evaluat Team ED32, Huntsville, AL 35812 USA. RP Walker, JL (reprint author), George C Marshall Space Flight Ctr, Nondestruct Evaluat Team ED32, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 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 0-8031-2893-2 J9 AM SOC TEST MATER PY 2002 VL 1416 BP 131 EP 138 DI 10.1520/STP10635S PG 8 WC Materials Science, Composites SC Materials Science GA BV05S UT WOS:000177718300008 ER PT J AU Pahr, DH Arnold, SM AF Pahr, DH Arnold, SM TI The applicability of the generalized method of cells for analyzing discontinuously reinforced composites SO COMPOSITES PART B-ENGINEERING LA English DT Article DE metal-matrix composites (MMCs); micro-mechanics; elastic ID METAL-MATRIX COMPOSITES; SHORT-FIBER COMPOSITES; MORI-TANAKA THEORY; MICROMECHANICAL ANALYSIS; TENSILE PROPERTIES; INTERNAL-STRESSES; BEHAVIOR; MICROSTRUCTURES; ALUMINUM; BOUNDS AB The paper begins with a short overview of the recent work done in the field of discontinuous reinforced composites, focusing on the different parameters which influence the material behavior of discontinuous reinforced composites, as well as the various analysis approaches undertaken. Based on this overview it became evident, that in order to investigate the enumerated effects in an efficient and comprehensive manner, an alternative approach to the computationally intensive finite-element based micro-mechanics approach is required. Therefore an investigation is conducted to demonstrate the utility of utilizing the generalized method of cells (GMC), a semi-analytical micromechanics-based approach, to simulate the elastic and elastoplastic material behavior of aligned short fiber composites. The results are compared with: (1) simulations using other micromechanical based mean field models and finite element (FE) unit cell models found in the literature given elastic material behavior, as well as (2) FE unit cell and a new semi-analytical elastoplastic shear lag model in the inelastic range. GMC is shown to definitely have a window of applicability when simulating discontinuously reinforced composite material behavior. (C) 2002 Published by Elsevier Science Ltd. C1 NASA, Glenn Res Ctr, Life Predict Branch, Cleveland, OH 44135 USA. Vienna Univ Technol, Inst Lightweight Struct & Aerosp Engn, A-1040 Vienna, Austria. RP Arnold, SM (reprint author), NASA, Glenn Res Ctr, Life Predict Branch, Cleveland, OH 44135 USA. OI Pahr, Dieter/0000-0002-5822-2082 NR 46 TC 14 Z9 14 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1359-8368 J9 COMPOS PART B-ENG JI Compos. Pt. B-Eng. PY 2002 VL 33 IS 2 BP 153 EP 170 AR PII S1359-8368(01)00061-0 DI 10.1016/S1359-8368(01)00061-0 PG 18 WC Engineering, Multidisciplinary; Materials Science, Composites SC Engineering; Materials Science GA 531LB UT WOS:000174415900007 ER PT J AU Arnold, SM Saleeb, AF Al-Zoubi, NR AF Arnold, SM Saleeb, AF Al-Zoubi, NR TI Deformation and life analysis of composite flywheel disk systems SO COMPOSITES PART B-ENGINEERING LA English DT Review DE anisotropy; failure; fatigue; elasticity; flywheels; multiple disks ID STRESS INTENSITY FACTORS; ROTATING ANISOTROPIC DISKS; BARE FILAMENT FLYWHEELS; FINITE ELASTIC DISK; VARIABLE THICKNESS; THERMAL-STRESSES; ENERGY CAPACITY; CREEP-RUPTURE; CIRCULAR DISK; ANNULAR DISK AB In this study an attempt is made to put into perspective the problem of a rotating disk, be it a single disk or a number of concentric disks forming a unit. An analytical model capable of performing an elastic stress analysis for single/multiple, annular/solid, anisotropic/isotropic disk systems, subjected to pressure surface tractions, body forces (in the form of temperature-changes and rotation fields) and interfacial misfits is summarized. Results of an extensive parametric study are presented to clearly define the key design variables and their associated influence. In general the important parameters were identified as misfit, mean radius, thickness, material property and/or load gradation, and speed; all of which must be simultaneously optimized to achieve the 'best' and most reliable design. Also, the important issue of defining proper performance/merit indices (based on the specific stored energy), in the presence of multiaxiality and material anisotropy is addressed. These merit indices are then utilized to discuss the difference between flywheels made from PMC and TMC materials with either an annular or solid geometry. Finally two major aspects of failure analysis, that is the static and cyclic limit (burst) speeds are addressed. In the case of static limit loads, a lower (first fracture) bound for disks with constant thickness is presented. The results (interaction diagrams) are displayed graphically in designer friendly format. For the case of fatigue, a representative fatigue/life master curve is illustrated in which the normalized limit speed versus number of applied cycles is given for a cladded TMC disk application. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Akron, Akron, OH 44325 USA. RP NASA, Glenn Res Ctr, 21000 Brookpk Rd,Mail Stop 49-7, Cleveland, OH 44135 USA. EM s.arnold@grc.nasa.gov NR 192 TC 23 Z9 27 U1 0 U2 9 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1359-8368 EI 1879-1069 J9 COMPOS PART B-ENG JI Compos. Pt. B-Eng. PY 2002 VL 33 IS 6 BP 433 EP 459 AR PII S1359-8368(02)00032-X DI 10.1016/S1359-8368(02)00032-X PG 27 WC Engineering, Multidisciplinary; Materials Science, Composites SC Engineering; Materials Science GA 593VD UT WOS:000178013800004 ER PT J AU Morscher, GN Gyekenyesi, AL AF Morscher, GN Gyekenyesi, AL TI The velocity and attenuation of acoustic emission waves in SiC/SiC composites loaded in tension SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article DE ceramic matrix composites (CMCs); matrix cracking; acoustic emission ID CERAMIC-MATRIX COMPOSITES; MECHANICS; CRACKING AB The behavior of acoustic waves produced by microfracture events and from pencil lead breaks was studied for two different silicon carbide fiber-reinforced silicon carbide matrix composites. The two composite systems both consisted of Hi-Nicalon(TM) fibers and carbon interfaces but had different matrix compositions that led to considerable differences in damage accumulation and acoustic response. This behavior was primarily due to an order of magnitude difference in the interfacial shear stress for the two composite systems. Load/unload/reload tensile tests were performed and measurements were made over the entire stress range in order to determine the stress-dependence of acoustic activity for increasing damage states. It was found that using the extensional wave velocities from acoustic emission (AE) events or AE produced from pencil lead breaks performed outside of the transducers enabled accurate measurements of the stiffness of the composite. The extensional wave velocities changed as a function of the damage state and the stress where the measurement was taken. A significant increase in attenuation of AE waveforms produced by pencil lead breaks occurred for the composite possessing the lower interfacial shear stress and only at significantly high stresses compared to the attenuation in undamaged material. At zero stress after unloading from a peak stress, no change in attenuation, compared to undamaged material, occurred for this composite because of crack closure. For the high interfacial stress composite no change in attenuation, compared to undamaged material, was discernable at peak or zero stress over the entire stress-range of the composite. From these observations, it is believed that attenuation of AE waveforms is dependent on the magnitude of matrix crack opening. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Ohio Aerosp Inst, Cleveland, OH USA. RP Morscher, GN (reprint author), NASA, Glenn Res Ctr, Lewis Field,MS-106-5, Cleveland, OH 44135 USA. NR 17 TC 29 Z9 29 U1 1 U2 12 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-3538 J9 COMPOS SCI TECHNOL JI Compos. Sci. Technol. PY 2002 VL 62 IS 9 BP 1171 EP 1180 AR PII S0266-3538(02)00065-9 DI 10.1016/S0266-3538(02)00065-9 PG 10 WC Materials Science, Composites SC Materials Science GA 572RM UT WOS:000176788800005 ER PT J AU Gilat, A Goldberg, RK Roberts, GD AF Gilat, A Goldberg, RK Roberts, GD TI Experimental study of strain-rate-dependent behavior of carbon/epoxy composite SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article DE polymer-matrix composites; impact behaviour; stress-strain curves; strain rate effects ID FIBER-REINFORCED COMPOSITES AB The strain rate dependent behavior of IM7/977-2 carbon/epoxy matrix composite in tension is studied by testing the resin and various laminate configurations at different strain rates. Tensile tests have been conducted with a hydraulic machine at quasi-static strain rates of approximately 10(-5) s(-1) and intermediate strain rates of about 1 s(-1). Tensile high strain rate tests have been conducted with the tensile split Hopkinson bar technique at strain rates of approximately 400-600 s(-1). Specimens with identical geometry are used in all the tests. The standard split Hopkinson bar technique is modified to measure strain directly on the specimen. The results show that strain rate has a significant effect on the material response. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 Ohio State Univ, Dept Mech Engn, Columbus, OH 43210 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Gilat, A (reprint author), Ohio State Univ, Dept Mech Engn, 206 W 18th Ave, Columbus, OH 43210 USA. EM gilat.1@osu.edu NR 8 TC 94 Z9 104 U1 7 U2 43 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-3538 EI 1879-1050 J9 COMPOS SCI TECHNOL JI Compos. Sci. Technol. PY 2002 VL 62 IS 10-11 BP 1469 EP 1476 AR PII S0266-3538(02)00100-8 DI 10.1016/S0266-3538(02)00100-8 PG 8 WC Materials Science, Composites SC Materials Science GA 579QK UT WOS:000177189200017 ER PT J AU Gotsis, PK Chamis, CC Minnetyan, L AF Gotsis, PK Chamis, CC Minnetyan, L TI Application of progressive fracture analysis for predicting failure envelopes and stress-strain behaviors of composite laminates: a comparison with experimental results SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article DE composites; computational simulation; laminates AB The theoretical predictions, published in Part A of the failure exercise, are compared with experimental results provided by the organizers of the exercise. Two computer codes, ICAN and CODSTRAN, developed at NASA (Glenn Research Center at Lewis Field), were applied to predict the damage initiation, damage growth and global structural fracture in a wide range of multidirectional laminates. CODSTRAN was employed to predict (I) seven biaxial failure envelopes of [0degrees] unidirectional and [0degrees/+/-45/90degrees](s), [+/-30degrees/90degrees], and [+/-55degrees](s) multi-layered composite laminates and (II) seven stress-strain curves for [0degrees/+/-45degrees/90degrees](s), [+/-55degrees](s), [0degrees/90degrees](s) and [+/-45degrees](s) laminates under uniaxial and biaxial loadings. In general, CODSTRAN gave reasonable predictions for cases where final failure was dominated by fibre fracture. There was, however, large discrepancy between the predicted and measured failure strengths and strains for cases where failure was dominated by matrix failure. Some of the discrepancy is attributed to (a) the effect of residual matrix stiffness that is discounted in simulations and (b) sensitivity of the specimens to the presence of biaxial stress state in certain cases. (C) 2002 Published by Elsevier Science Ltd. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Clarkson Univ, Potsdam, NY 13699 USA. RP Chamis, CC (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 6 TC 24 Z9 24 U1 1 U2 11 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-3538 J9 COMPOS SCI TECHNOL JI Compos. Sci. Technol. PY 2002 VL 62 IS 12-13 BP 1545 EP 1559 AR PII S0266-3538(02)00095-7 DI 10.1016/S0266-3538(02)00095-7 PG 15 WC Materials Science, Composites SC Materials Science GA 593AZ UT WOS:000177970200005 ER PT J AU Odegard, GM Gates, TS Nicholson, LM Wise, KE AF Odegard, GM Gates, TS Nicholson, LM Wise, KE TI Equivalent-continuum modeling of nano-structured materials SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article DE nanotechnology ID WALLED CARBON NANOTUBES; ELASTIC PROPERTIES; YOUNGS MODULUS; LATTICE STRUCTURES; NUCLEIC-ACIDS; LARGE-STRAIN; FORCE-FIELD; SIMULATION; ENERGETICS; MOLECULES AB A method has been proposed for developing structure-property relationships of nano-structured materials. This method serves as a link between computational chemistry and solid mechanics by substituting discrete molecular structures with equivalent-continuum models. It has been shown that this substitution may be accomplished by equating the molecular potential energy of a nano-structured material with the strain energy of representative truss and continuum models. As important examples with direct application to the development and characterization of single-walled carbon nanotubes and the design of nanotube-based structural devices, the modeling technique has been applied to two independent examples: the determination of the effective-continuum geometry and bending rigidity of a graphene sheet. A representative volume element of the chemical structure of graphene has been substituted with equivalent-truss and equivalent-continuum models. As a result, an effective thickness of the continuum model has been determined. The determined effective thickness is significantly larger than the inter-planar spacing of graphite. The effective bending rigidity of the equivalent-continuum model of a graphene sheet was determined by equating the molecular potential energy of the molecular model of a graphene sheet subjected to cylindrical bending (to form a nanotube) with the strain energy of an equivalent-continuum plate subjected to cylindrical bending. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 NASA, Langley Res Ctr, Natl Res Council, Hampton, VA 23681 USA. NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. RP Odegard, GM (reprint author), NASA, Langley Res Ctr, Natl Res Council, MS 188E, Hampton, VA 23681 USA. OI Odegard, Gregory/0000-0001-7577-6565 NR 47 TC 372 Z9 381 U1 9 U2 76 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-3538 J9 COMPOS SCI TECHNOL JI Compos. Sci. Technol. PY 2002 VL 62 IS 14 BP 1869 EP 1880 AR PII S0266-3538(02)00113-6 DI 10.1016/S0266-3538(02)00113-6 PG 12 WC Materials Science, Composites SC Materials Science GA 596CK UT WOS:000178146300007 ER PT S AU Walukiewicz, W Yu, KM Wu, J Ager, JW Haller, EE Miotkowski, I Ramdas, AK Su, CH AF Walukiewicz, W Yu, KM Wu, J Ager, JW Haller, EE Miotkowski, I Ramdas, AK Su, CH BE Arakawa, Y Hirayama, Y Kishino, K Yamaguchi, H TI Band anticrossing in highly mismatched compound semiconductor alloys SO COMPOUND SEMICONDUCTORS 2001 SE INSTITUTE OF PHYSICS CONFERENCE SERIES LA English DT Article; Proceedings Paper CT 28th International Symposium on Compound Semiconductors (ISCS 2001) CY OCT 01-04, 2001 CL UNIV TOKYO, TOKYO, JAPAN SP Seiken Shoreikai (FRIS), Inst Ind Sci, Electr Soc, Inst Electr, Informat & Commun Engineers Japan, IEEE Soc Appl Phys, IEEE Electron Device Soc, IEEE Electron Device Soc, Japan Chapter, IEEE Lasers & Elecro-Optics Soc, Murata Sci Fdn, Fdn Promot Mat Sci & Technol Japan, ASEC Inc, Appl EPI Inc, Clean Act Inc, Daido Air Prod Inc, Fujikura Ltd, Fujitsy Ltd, Fujitsu Quantum Devices Ltd, Furukawa Elect Co Ltd, Hakuto Co Ltd, Hitachi Ltd, Hitachi Cable Ltd, Matsushita Elect Ind Co Ltd, Mitsubishi Elect Corp, Moritani & Co Ltd, NEC Corp, Nichia Corp, Nippon Sanso Corp, Nisshin Elect Co Ltd, NTT Corp, NTT Electr Corp, Oki Elect Ind Co Ltd, ROHM Co Ltd, Sharp Corp, Showa Denko K K, Sony Corp, Sumitomo Chem Co Ltd, Sumitomo Elect Ind Ltd, Sumitomo 3M Ltd, Texas Instruments Japan Ltd, Tomoe Shokai Co Ltd, Toyoda Gosei Co Ltd, Vieetech Japan Co Ltd HO UNIV TOKYO ID GAP; NITROGEN; INNXP1-X; ZNSE; ZNTE AB Photomodulated reflectance and optical absorption spectroscopies were used to measure the composition and hydrostatic pressure dependence of interband optical transitions in ZnSe(1-x)Te(x) alloys. On the Te-rich side the composition and pressure dependence of the optical transitions are well explained by the band anticrossing model. The large band gap reduction observed on the Se-rich side of the alloy system is a result of an interaction between the localized Te level and the valence bands. This interaction leads to the formation of a Te-like valence band edge that strongly interacts with the light hole valence band, Calculations based on a modified k.p model account for the reduction of the band gap and the large increase of the spin-orbit splitting observed in Se-rich ZnSe(1-x)Te(y) alloys. C1 Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Univ Calif Berkeley, Appl Sci & Technol Grad Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. NASA, George C Marshall Space Flight Ctr, Sci Directorate SD47, Huntsville, AL 35812 USA. RP Walukiewicz, W (reprint author), Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RI Yu, Kin Man/J-1399-2012; Wu, Junqiao/G-7840-2011 OI Yu, Kin Man/0000-0003-1350-9642; Wu, Junqiao/0000-0002-1498-0148 NR 20 TC 0 Z9 0 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0951-3248 BN 0-7503-0856-7 J9 INST PHYS CONF SER PY 2002 IS 170 BP 301 EP 306 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Optics; Physics, Multidisciplinary; Physics, Condensed Matter SC Engineering; Materials Science; Optics; Physics GA BV44V UT WOS:000179011200048 ER PT S AU Marcinkevicius, S Siegert, J Leon, R Chaparro, S Johnson, SR Navarro, C Jin, X Zhang, YH AF Marcinkevicius, S Siegert, J Leon, R Chaparro, S Johnson, SR Navarro, C Jin, X Zhang, YH BE Arakawa, Y Hirayama, Y Kishino, K Yamaguchi, H TI Carrier dynamics in spatially ordered InAs quantum dots SO COMPOUND SEMICONDUCTORS 2001 SE INSTITUTE OF PHYSICS CONFERENCE SERIES LA English DT Article; Proceedings Paper CT 28th International Symposium on Compound Semiconductors (ISCS 2001) CY OCT 01-04, 2001 CL UNIV TOKYO, TOKYO, JAPAN SP Seiken Shoreikai (FRIS), Inst Ind Sci, Electr Soc, Inst Electr, Informat & Communicat Engineers Japan, IEEE Soc Appl Phys, IEEE Electron Device Soc, IEEE Electron Device Soc, Japan Chapter, IEEE Laser & Elecro-Optics Soc, Murata Sci Fdn, Fdn Promot Mat Sci & Technol Japan, ASEC Inc, Appl EPI Inc, Clean Act Inc, Daido Air Products Inc, Fujikura Ltd, Fujitsy Ltd, Fujitsu Quantum Devices Ltd, Furukawa Elect Co Ltd, Hakuto Co Ltd, Hitachi Ltd, Hitachi Cable Ltd, Matsushita Elect Ind Co Ltd, Mitsubishi Elect Corp, Moritani & Co Ltd, NEC Corp, Nichia Corp, Nippon Sanso Corp, Nisshin Elect Co Ltd, NTT Corp, NTT Electr Corp, Oki Elect Ind Co Ltd, ROHM Co Ltd, Sharp Corp, Showa Denko K K, Sony Corp, Sumitomo Chem Co Ltd, Sumitomo Elect Ind Ltd, Sumitomo 3M Ltd, Texas Instruments Japan Ltd, Tomoe Shokai Co Ltd, Toyoda Gosei Co Ltd, Vieetech Japan Co Ltd HO UNIV TOKYO ID MISFIT DISLOCATIONS AB Spatial ordering of InAs quantum dots was attained by using misfit dislocations generated in a metastable InGaAs layer by means of thermal annealing. Influence of quantum dot positional ordering and dot proximity to dislocation arrays on carrier dynamics was studied by time-resolved photoluminescence. Substantially narrower inhomogeneous broadening from the ordered quantum dots was observed. Excitation intensity dependence of the photoluminescence intensity and carrier lifetime indicates stronger influence of nonradiative recombination for the ordered quantum dot structures. Short (4-5 ps) photoluminescence rise times in the ordered dots show ultrafast carrier transfer in these quantum dot structures. C1 Royal Inst Technol, Dept Microelect & Informat Technol, S-16440 Kista, Sweden. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Arizona State Univ, Dept Elect Engn, Tempe, AZ 85287 USA. Arizona State Univ, Ctr Solid State Elect Res, Tempe, AZ 85287 USA. RP Marcinkevicius, S (reprint author), Royal Inst Technol, Dept Microelect & Informat Technol, Electrum 229, S-16440 Kista, Sweden. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0951-3248 BN 0-7503-0856-7 J9 INST PHYS CONF SER PY 2002 IS 170 BP 543 EP 548 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Optics; Physics, Multidisciplinary; Physics, Condensed Matter SC Engineering; Materials Science; Optics; Physics GA BV44V UT WOS:000179011200088 ER PT S AU Reichle, RH Koster, RD AF Reichle, RH Koster, RD BE Hassanizadeh, SM Schotting, RJ Gray, WG Pinder, GF TI Land data assimilation with the ensemble Kalman filter: assessing model error parameters using innovations SO COMPUTATIONAL METHODS IN WATER RESOURCES, VOLS 1 AND 2, PROCEEDINGS SE DEVELOPMENTS IN WATER SCIENCE LA English DT Proceedings Paper CT 14th International Conference on Computational Methods in Water Resources CY JUN 23-28, 2002 CL DELFT, NETHERLANDS AB Successful soil moisture data assimilation requires information about the uncertainties in the land surface model and the observations. While the errors in the observations are relatively easy to quantify, it is very difficult to specify the errors in the model, including approximations in the dynamical equations, wrong model parameters, or inaccurate forcing inputs. In synthetic experiments, it is straightforward to derive optimal model error covariances by minimizing the actual estimation errors (estimates minus synthetic "true" fields) as a function of the model error parameters. When satellite observations are used, however, we cannot easily compute the actual estimation errors. By contrast, the innovations (observations minus model forecast) axe always readily available. In a twin experiment we generate synthetic "true" land surface fields and an open loop model trajectory using different model parameters and forcing fields. We also generate synthetic observations from the true fields which are then assimilated into the open loop model many times using different model error covariances. The resulting innovations sequences are analyzed and their statistics are contrasted to the actual estimation errors. We show that for our nonlinear problem the innovations sequence is a valuable tool for assessing the actual estimation errors and thereby for identifying appropriate model error covariances. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Reichle, RH (reprint author), NASA, Goddard Space Flight Ctr, Code 974, Greenbelt, MD 20771 USA. RI Reichle, Rolf/E-1419-2012; Koster, Randal/F-5881-2012 OI Koster, Randal/0000-0001-6418-6383 NR 6 TC 6 Z9 6 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 7108-8070 BN 0-444-50975-5 J9 DEV WATER SCI PY 2002 VL 47 BP 1387 EP 1394 PG 8 WC Engineering, Civil; Mathematics, Applied; Water Resources SC Engineering; Mathematics; Water Resources GA BV40A UT WOS:000178839400180 ER PT S AU Nakai, J AF Nakai, J BE Sloot, P Tan, CJK Dongarra, JJ Hoekstra, AG TI Markets as global scheduling mechanisms: The current state SO COMPUTATIONAL SCIENCE-ICCS 2002, PT I, PROCEEDINGS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT International Conference on Computational Science CY APR 21-24, 2002 CL AMSTERDAM, NETHERLANDS SP Univ Amsterdam, Sect Computat Sci, SHARCNET, Canada, Univ Tennessee, Dept Comp Sci, Power Comp & Commun BV, Elsevier Sci Publ, Springer Verlag, HPCN Fdn, Natl Supercomp Facilities, Sun Microsyst Inc, Queens Univ, Sch Comp Sci ID RESOURCE-ALLOCATION; SYSTEMS AB Viewing the computers as "suppliers" and the users as "consumers" of computing services, markets for computing services/resources have been examined as one of the most promising mechanisms for global scheduling. We first establish how economics can contribute to scheduling. We further define the criterion for a scheme to qualify as an application of economics. Many studies to date have claimed to have applied economics to scheduling. If their scheduling mechanisms do not utilize economics, contrary to their claims, their favorable results do not contribute to the assertion that markets provide the best framework for global scheduling. For any of the schemes examined, we could not reach the conclusion that it makes full use of economics. C1 NASA, AMTI, Ames Res Ctr, Moffett Field, CA 94305 USA. RP Nakai, J (reprint author), NASA, AMTI, Ames Res Ctr, Mail Stop 258-6, Moffett Field, CA 94305 USA. NR 23 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-43591-3 J9 LECT NOTES COMPUT SC PY 2002 VL 2329 BP 256 EP 265 PG 10 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BW26B UT WOS:000181350500025 ER PT B AU Hand, C AF Hand, C BE Subramanya, SR TI CREB nets SO COMPUTER APPLICATIONS IN INDUSTRY AND ENGINEERING LA English DT Proceedings Paper CT 15th International Conference on Computer Applications in Industry and Engineering (CAINE-2002) CY NOV 07-09, 2002 CL SAN DIEGO, CA SP Int Soc Comp & Their Applicat ID MEMORY AB The CREB protein has been identified as a key ingredient for the laying down of enduring long-term memories in biological neural networks. An important characteristic of this process is the persistence of the neuronal patterns of activation. Persistent patterns of activation can be used to make non-recurrent artificial neural networks react to a series of patterns rather than to just a single pattern. This persistence is easy to implement electronically when artificial neural networks are put into Application Specific Integrated Circuits (ASIC). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Hand, C (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU INTERNATIONAL SOCIETY COMPUTER S & THEIR APPLICATIONS (ISCA) PI RALEIGH PA 8820 SIX FORKS ROAD, RALEIGH, NC 27615 USA BN 1-880843-45-5 PY 2002 BP 221 EP 224 PG 4 WC Automation & Control Systems; Computer Science, Interdisciplinary Applications; Engineering, Industrial; Engineering, Electrical & Electronic SC Automation & Control Systems; Computer Science; Engineering GA BV68U UT WOS:000179771500052 ER PT J AU Litvin, FL Fuentes, A Zani, C Pontiggia, M Handschuh, RF AF Litvin, FL Fuentes, A Zani, C Pontiggia, M Handschuh, RF TI Face-gear drive with spur involute pinion: geometry, generation by a worm, stress analysis SO COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING LA English DT Article ID TOOTH SURFACES; CONTACT LINES; SINGULARITIES; SIMULATION; ENVELOPES; FAMILIES; CURVES AB A face-gear drive with a spur involute pinion is considered. The generation of the face gear is based on application of a grinding or cutting worm whereas the conventional method of generation is based on application of an involute shaper. The authors have developed an analytical approach for determination of: (i) the worm thread surface, (ii) avoidance of singularities of the worm, thread surface, (iii) dressing of the worm, and (iv) determination of stresses of the face-gear drive. A computer program is developed for simulation of meshing and contact of the pinion and face gear. Correction of machine-tool settings is proposed for reduction of the shift of the bearing contact caused by misalignment. An automatic development of the model of five contacting teeth has been proposed for stress analysis. Numerical examples for illustration of the developed theory are provided. (C) 2002 Elsevier Science B.V. All rights reserved. C1 Polytechn Univ Cartagena, Dept Mech Engn, Murcia 30202, Spain. Univ Illinois, Dept Mech Engn, Gear Res Ctr, Chicago, IL 60607 USA. NASA, Glenn Res Ctr, USA, Res Lab, Cleveland, OH 44135 USA. RP Fuentes, A (reprint author), Polytechn Univ Cartagena, Dept Mech Engn, Campus Univ Muralla Mar C Dr Fleming S-N, Murcia 30202, Spain. RI Fuentes Aznar, Alfonso/A-4259-2015 OI Fuentes Aznar, Alfonso/0000-0001-7882-4999 NR 23 TC 54 Z9 79 U1 2 U2 13 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0045-7825 J9 COMPUT METHOD APPL M JI Comput. Meth. Appl. Mech. Eng. PY 2002 VL 191 IS 25-26 BP 2785 EP 2813 AR PII S0045-7825(02)00215-3 DI 10.1016/S0045-7825(02)00215-3 PG 29 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications; Mechanics SC Engineering; Mathematics; Mechanics GA 544UT UT WOS:000175180600005 ER PT S AU Smelyansky, VN Morris, RD Kuehnel, FO Maluf, DA Cheeseman, P AF Smelyansky, VN Morris, RD Kuehnel, FO Maluf, DA Cheeseman, P BE Heyden, A Sparr, G Nielsen, M Johansen, P TI Dramatic improvements to feature based stereo SO COMPUTER VISION - ECCV 2002, PT II SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 7th European Conference on Computer Vision CY MAY 28-31, 2002 CL COPENHAGEN, DENMARK SP IT Univ Copenhagen, Univ Copenhagen, Lund Univ AB The camera registration extracted from feature based stereo is usually considered sufficient to accurately localize the 3D points. However, for natural scenes the feature localization is not as precise as in man-made environments. This results in small camera registration errors. We show that even very small registration errors result in large errors in dense surface reconstruction. We describe a method for registering entire images to the inaccurate surface model. This gives small, but crucially important improvements to the camera parameters. The new registration gives dramatically better dense surface reconstruction. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Smelyansky, VN (reprint author), NASA, Ames Res Ctr, MS 269-2, Moffett Field, CA 94035 USA. NR 13 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 3-540-43744-4 J9 LECT NOTES COMPUT SC PY 2002 VL 2351 BP 247 EP 261 PG 15 WC Computer Science, Theory & Methods SC Computer Science GA BV76Q UT WOS:000179968800017 ER PT S AU Ansar, A Daniilidis, K AF Ansar, A Daniilidis, K BE Heyden, A Sparr, G Nielsen, M Johansen, P TI Linear pose estimation from points or lines SO COMPUTER VISION - ECCV 2002, PT IV SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 7th European Conference on Computer Vision CY MAY 28-31, 2002 CL COPENHAGEN, DENMARK SP IT Univ Copenhagen, Univ Copenhagen, Lund Univ ID CLOSED-FORM SOLUTION; ORIENTATION; IMAGES AB Estimation of camera pose from an image of n points or lines with known correspondence is a thoroughly studied problem in computer vision. Most solutions are iterative and depend on nonlinear optimization of some geometric constraint, either on the world coordinates or on the projections to the image plane. For real-time applications we are interested in linear or closed-form solutions free of initialization. We present a general framework which allows for a novel set of linear solutions to the pose estimation problem for both n points and n lines. We present a number of simulations which compare our results to two other recent linear algorithm as well as to iterative approaches. We conclude with tests on real imagery in an augmented reality setup. We also present an analysis of the sensitivity of our algorithms to image noise. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Penn, Grasp Lab, Philadelphia, PA 19104 USA. RP Ansar, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 26 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-43748-7 J9 LECT NOTES COMPUT SC PY 2002 VL 2353 BP 282 EP 296 PG 15 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods; Imaging Science & Photographic Technology SC Computer Science; Imaging Science & Photographic Technology GA BV79J UT WOS:000180067300019 ER PT J AU Guo, C Ye, Z Sun, ZQ Sarkar, P Jamshidi, M AF Guo, C Ye, Z Sun, ZQ Sarkar, P Jamshidi, M TI A hybrid fuzzy cerebellar model articulation controller based autonomous controller SO COMPUTERS & ELECTRICAL ENGINEERING LA English DT Article DE cerebellar model articulation controller; fuzzified CMAC; intelligent control; multimode control; integrated algorithm; neuro-fuzzy control; autonomous control AB This paper proposes a hybrid control architecture and an algorithm which integrates cerebellar model articulation controller (CMAC) or fuzzified CMAC with fuzzy logic control and bang-bang control under an intelligent supervisor. The intelligent control strategy separately dealing vith dynamic and steady state responses of control system is realized. The neuro-fuzzy controller has self-learning abilities in real time and is applied to ship steering and industrial process plants. Simulation case study results demonstrate the effectiveness and robustness of the integrated intelligent control algorithms. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Dalian Maritime Univ, Lab Simulat & Control Navigat Syst, Dalian 116026, Peoples R China. Tsing Hua Univ, Dept Comp Sci & Technol, Beijing 100084, Peoples R China. Univ New Mexico, Ctr Autonomous Control Engn, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Engn Mech, Albuquerque, NM 87131 USA. Univ New Mexico, Dept Comp & Elect Engn, Albuquerque, NM 87131 USA. Univ New Mexico, NASA, Ctr Autonomous Control Engn, Albuquerque, NM 87131 USA. RP Guo, C (reprint author), Dalian Maritime Univ, Lab Simulat & Control Navigat Syst, Dalian 116026, Peoples R China. NR 8 TC 17 Z9 22 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-7906 J9 COMPUT ELECTR ENG JI Comput. Electr. Eng. PD JAN PY 2002 VL 28 IS 1 BP 1 EP 16 DI 10.1016/S0045-7906(00)00037-9 PG 16 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 492MA UT WOS:000172171100001 ER PT J AU Guruswamy, GP AF Guruswamy, GP TI A review of numerical fluids/structures interface methods for computations using high-fidelity equations SO COMPUTERS & STRUCTURES LA English DT Article DE finite elements; Navier-Stokes; computers; high fidelity; aeroelasticity ID FLUID; WINGS AB Domain decomposition approaches require efficient interface techniques when fluids and structures are solved in independent computational domains for aerospace applications. Fluid/structure interfacing techniques for solutions from equations based on low-fidelity approaches that are in the linear domain are well advanced and are incorporated in production codes NASTRAN and ASTROS. However. for computations involving high-fidelity equations such as the Navier-Stokes for fluids and finite elements for structures, interface approaches are still under development. This paper provides a technical overview of methods for interfacing flow solutions from the Euler/Navier-Stokes methods with structural solutions using modal/finite-element methods. Validity of the methods is supported by previously presented results. Published by Elsevier Science Ltd. C1 NAS Div, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Guruswamy, GP (reprint author), NAS Div, Ames Res Ctr, MS T27B-1, Moffett Field, CA 94035 USA. NR 37 TC 21 Z9 23 U1 2 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-7949 J9 COMPUT STRUCT JI Comput. Struct. PD JAN PY 2002 VL 80 IS 1 BP 31 EP 41 DI 10.1016/S0045-7949(01)00164-X PG 11 WC Computer Science, Interdisciplinary Applications; Engineering, Civil SC Computer Science; Engineering GA 518PH UT WOS:000173676700004 ER PT J AU Johnston, WE AF Johnston, WE TI The computing and data grid approach: Infrastructure for distributed science applications SO COMPUTING AND INFORMATICS LA English DT Article DE Computing and Data Grids; distributed computing; distributed science applications AB Grid technology has evolved over the past several years to provide the services and infrastructure needed for building "virtual" systems and organizations. With this Grid based infrastructure that provides for using and managing widely distributed computing and data resources in the science environment, there is now an opportunity to provide a standard, large-scale, computing, data, instrument, and collaboration environment for science that spans many different projects, institutions, and countries. We argue that Grid technology provides an excellent basis for the creation of the integrated environments that can combine the resources needed to support the large-scale science projects located at multiple laboratories and universities. We also present some science case studies that indicate that a paradigm shift in the process of science will come about as a result of Grids providing transparent and secure access to advanced and integrated information and technologies infrastructure: powerful computing systems, large-scale data archives, scientific instruments, and collaboration tools. These changes will be in the form of Grid based services that can be integrated with the user's work environment, and that enable uniform and highly capable access to these computers, data, and instruments, regardless of the location or exact nature of these resources. These services will integrate transient-use resources like computing systems, scientific instruments, and data caches (e.g., as they are needed to perform a simulation or analyze data from a single experiment); persistent-use resources, such as databases, data catalogues, and archives; and collaborators, whose involvement will continue for the lifetime of a project or longer. While we largely address large-scale science requirements in this paper, Grids, particularly when combined with Web Services, will address a broad spectrum of science scenarios, both large and small scale, as well as various commercial and cultural cyberinfrastructure applications. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Johnston, WE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, MS 50B-2239, Berkeley, CA 94720 USA. NR 42 TC 2 Z9 2 U1 0 U2 0 PU SLOVAK ACADEMY SCIENCES INST INFORMATICS PI BRATISLAVA PA DUBRAVSKA CESTA 9, 84237 BRATISLAVA, SLOVAKIA SN 1335-9150 J9 COMPUT INFORM JI Comput. Inform. PY 2002 VL 21 IS 4 BP 293 EP 319 PG 27 WC Computer Science, Artificial Intelligence SC Computer Science GA 660RU UT WOS:000181847400002 ER PT B AU Landis, GA AF Landis, GA GP IEEE IEEE TI Technology for solar array production on the moon SO CONFERENCE RECORD OF THE TWENTY-NINTH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE 2002 LA English DT Proceedings Paper CT 29th IEEE Photovoltaic Specialists Conference CY MAY 19-24, 2002 CL NEW ORLEANS, LA SP IEEE Electron Devices Soc ID LUNAR AB Silicon, aluminum, and glass are the primary raw materials that will be required for production of solar arrays on the moon. A process sequence is proposed for producing these materials from lunar regolith is proposed, consisting of separating the required materials from lunar rock with fluorine. Fluorosilane produced by this process is reduced to silicon; the fluorine salts are reduced to metals by reaction with metallic potassium. Fluorine is recovered from residual MgF and CaF2 by reaction with K2O. Aluminum, calcium oxide, and magnesium oxide are recovered to manufacture structural matelials and glass. C1 NASA, John Glenn Res Ctr, Cleveland, OH 44135 USA. RP Landis, GA (reprint author), NASA, John Glenn Res Ctr, 21000 Brookpark Rd, Cleveland, OH 44135 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7471-1 PY 2002 BP 796 EP 798 DI 10.1109/PVSC.2002.1190692 PG 3 WC Energy & Fuels; Engineering, Chemical; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BW41E UT WOS:000181924600195 ER PT B AU Bailey, S Curtis, H Piszczor, M Surampudi, R Hamilton, T Rapp, D Stella, P Mardesich, N Mondt, J Bunker, R Nesmith, B Gaddy, E Marvin, D Kazmerski, L AF Bailey, S Curtis, H Piszczor, M Surampudi, R Hamilton, T Rapp, D Stella, P Mardesich, N Mondt, J Bunker, R Nesmith, B Gaddy, E Marvin, D Kazmerski, L GP IEEE IEEE TI Photovoltaic cell and array technology development for future unique NASA missions SO CONFERENCE RECORD OF THE TWENTY-NINTH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE 2002 LA English DT Proceedings Paper CT 29th IEEE Photovoltaic Specialists Conference CY MAY 19-24, 2002 CL NEW ORLEANS, LA SP IEEE Electron Devices Soc AB A technology: review committee from NASA, the U.S. Department of Energy (DOE), and the Air Force. Research Lab (AFRL) was formed to assess solar cell and array technologies required for future NASA science missions; After consulting with mission planning offices, solar cell and array manufacturers, universities, and research laboratories, the committee assessed the state of the art of solar cells and arrays and made a comparison with - projected needs.. A technology development program was proposed in high-efficiency-cells,. electrostatically clean arrays, high-temperature solar arrays, high-power arrays for solar electric propulsion, low-intensity/low-temperature array conditions for deep-space mission, high-radiation missions, and Mars arrays that, operate in dusty environments. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Bailey, S (reprint author), NASA, Glenn Res Ctr, MS 302-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7471-1 PY 2002 BP 799 EP 803 DI 10.1109/PVSC.2002.1190694 PG 5 WC Energy & Fuels; Engineering, Chemical; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BW41E UT WOS:000181924600196 ER PT B AU Landis, GA Jenkins, PP AF Landis, GA Jenkins, PP GP IEEE IEEE TI Dust migration for Mars solar arrays SO CONFERENCE RECORD OF THE TWENTY-NINTH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE 2002 LA English DT Proceedings Paper CT 29th IEEE Photovoltaic Specialists Conference CY MAY 19-24, 2002 CL NEW ORLEANS, LA SP IEEE Electron Devices Soc ID PATHFINDER AB Settling of atmospheric dust onto the surface of the, solar array is potentially a lifetime-limiting factor for a power system. on any Mars mission. For long-term operation of arrays on Mars, it will be necessary to develop techniques to remove deposited dust. Dust is expected to adhere to the array by Van der Waals. adhesive forces. These forces are quite strong at the dust particle sizes expected. Dust removal methods must overcome this force. Removal Methods can be categorized briefly into four categories: natural, mechanical, electromechanical, and electrostatic. The environment of Mars is expected to be an. ideal one. for use of electrostatic dust-removal techniques. C1 NASA, John Glenn Res Ctr, Cleveland, OH 44135 USA. RP Landis, GA (reprint author), NASA, John Glenn Res Ctr, 21000 Brookpark Rd, Cleveland, OH 44135 USA. NR 14 TC 2 Z9 2 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7471-1 PY 2002 BP 812 EP 815 DI 10.1109/PVSC.2002.1190698 PG 4 WC Energy & Fuels; Engineering, Chemical; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BW41E UT WOS:000181924600199 ER PT B AU Snyder, DB Scheiman, DA Jenkins, PP Rieke, WJ Blankenship, KS AF Snyder, DB Scheiman, DA Jenkins, PP Rieke, WJ Blankenship, KS GP IEEE IEEE TI Ozone correction for AMO calibrated solar cells for the aircraft method SO CONFERENCE RECORD OF THE TWENTY-NINTH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE 2002 LA English DT Proceedings Paper CT 29th IEEE Photovoltaic Specialists Conference CY MAY 19-24, 2002 CL NEW ORLEANS, LA SP IEEE Electron Devices Soc AB The aircraft solar cell calibration method has provided cells calibrated to space conditions for 37 years. However, it is susceptible to systematic errors due to ozone Concentrations in the stratosphere. The present correction procedure applies a 1% increase to the measured I-sc values. High band-gap cells are more sensitive to ozone absorbed wavelengths (0.4 to 0.8 mum) so it becomes important to reassess the correction technique. This paper evaluates the ozone correction to be 1+O3xFo, where 03 is the total ozone along the optical path, and Fo is 29.8x10(-6)/d.u. for a Silicon solar call, 42.6x10(-6)/du for a GaAs cell and 57.2x10(-6)/d.u. for a InGaP call. These correction factors work best to correct data points obtained during the flight rather than as a correction to the final result. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Snyder, DB (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 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 0-7803-7471-1 PY 2002 BP 832 EP 835 DI 10.1109/PVSC.2002.1190706 PG 4 WC Energy & Fuels; Engineering, Chemical; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BW41E UT WOS:000181924600204 ER PT B AU Mueller, RL Gaddy, E AF Mueller, RL Gaddy, E GP IEEE IEEE TI The performance of advanced III-V solar cells SO CONFERENCE RECORD OF THE TWENTY-NINTH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE 2002 LA English DT Proceedings Paper CT 29th IEEE Photovoltaic Specialists Conference CY MAY 19-24, 2002 CL NEW ORLEANS, LA SP IEEE Electron Devices Soc AB Test results show triple junction solar cells with efficiencies as high as 27% at 28C and 136.7 mw/cm(2). Triple junction cells also achieve up to 27.5% at -120C and 5 mw/cm(2), conditions applicable to missions to Jupiter. Some triple junction cells show, practically no degradation as a result of Low Intensity Low Temperature (LILT) effects, while others show some; this degradation can be overcome with minor changes to the cell design. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mueller, RL (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 PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7471-1 PY 2002 BP 904 EP 907 DI 10.1109/PVSC.2002.1190726 PG 4 WC Energy & Fuels; Engineering, Chemical; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BW41E UT WOS:000181924600222 ER PT B AU Landis, GA AF Landis, GA GP IEEE IEEE TI Integrated bypass battery for reverse-bias protection SO CONFERENCE RECORD OF THE TWENTY-NINTH IEEE PHOTOVOLTAIC SPECIALISTS CONFERENCE 2002 LA English DT Proceedings Paper CT 29th IEEE Photovoltaic Specialists Conference CY MAY 19-24, 2002 CL NEW ORLEANS, LA SP IEEE Electron Devices Soc AB When a single solar cell of a series-connect string is placed in shadow, the entire array current is forced through that cell in reverse bias. Reverse bias current can lead to "hot-spot" heating, where the power produced by the unshadowed cells is dissipated as heat in the shadowed cell. Since occasional shadows are unavoidable in most applications, most solar arrays include shadow protection to prevent damage. In current practice, shadow protection is done with a "bypass diode" on each cell, to shunt the reverse bias current if a cell is shadowed. A new method of reverse bias protection is to use an integral thin-film battery to provide voltage in the case of a shadowed cell. In this case, the shadowed cell continues to provide voltage during the transient shadow. C1 NASA, John Glenn Res Ctr, Cleveland, OH 44135 USA. RP Landis, GA (reprint author), NASA, John Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-7471-1 PY 2002 BP 1539 EP 1540 DI 10.1109/PVSC.2002.1190905 PG 2 WC Energy & Fuels; Engineering, Chemical; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BW41E UT WOS:000181924600380 ER PT J AU Loewenstein, M Mushotzky, RF AF Loewenstein, M Mushotzky, RF TI Are elliptical galaxies really metal-rich? And, if not, then what? SO COSMIC CHEMICAL EVOLUTION SE IAU SYMPOSIA LA English DT Article ID ASCA C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Loewenstein, M (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 J9 IAU SYMP PY 2002 IS 187 BP 139 EP 146 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU60Y UT WOS:000176502200017 ER PT S AU Sahai, R Claussen, MJ Morris, M AF Sahai, R Claussen, MJ Morris, M BE Migenes, V Reid, MJ TI Interferometric observations of OH and H2O masers in protoplanetary nebulae imaged with HST - A unique diagnostic of their spatial-kinematic structure SO COSMIC MASERS: FROM PROTOSTARS TO BLACKHOLES SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT Symposium on Cosmic Masers - From Protostars to Blackholes CY MAR 05-10, 2001 CL ANGRA REIS, BRAZIL SP Int Astron Union ID PLANETARY-NEBULAE; HD-179821; JETS AB One of the most exciting challenge facing theories of postmain sequence evolution today is to understand how Asymptotic Giant Branch (AGB) stars transform themselves into aspherical planetary nebulae (PNe). Recently, high-resolution imaging surveys of young planetary nebulae and protoplanetary nebulae (PPNe: objects in transition between the AGB and PN phases) have revealed that the majority of these objects are characterised by multipolar bubbles distributed roughly point-symmetrically around the central star. These data strongly suggest that the current model for the shaping of PNe is no longer adequate. High angular-resolution kinematic information is sorely needed to complement the imaging data in order to test new hypotheses, such as our proposal that episodic high-speed jet-like outflows, operating during the protoplanetary or very late-AGB phase, are the primary agent. We have therefore begun a program of using interferometric mapping of OH (and H2O, when feasible) maser emission in order to trace the kinematics of the structures discovered in protoplanetary nebulae with HST. These masers provide a unique and crucial probe of the kinematics of the circumstellar material in PPNe, because of the lack of other emission-line diagnostics. Although our work is still in its infancy (only two objects have been studied in detail), we find that the OH masers indicate the presence of multiple low-latitude outflows and an increase of outflow velocity with latitude. This paper summarises our progress so far, the state of current studies, and future prospects. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NRAO, Socorro, NM 87801 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. RP Sahai, R (reprint author), CALTECH, Jet Prop Lab, MS183-900,4800 Oak Grove Dr, Pasadena, CA 91109 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 1-58381-112-5 J9 IAU SYMP PY 2002 IS 206 BP 352 EP 357 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW16P UT WOS:000181054300075 ER PT B AU Moles, A Stone, RP AF Moles, A Stone, RP BE Paul, AJ Dawe, EG Elner, R Jamieson, GS Kruse, GH Otto, RS SainteMarie, B Shirley, TC Woodby, D TI Habitat preferences of juvenile tanner and red king crabs: Substrate and crude oil SO CRABS IN COLD WATER REGIONS: BIOLOGY, MANAGEMENT, AND ECONOMICS SE Lowell Wakefield Fisheries Symposia Series LA English DT Proceedings Paper CT Symposium on Crabs in Cold Water Regions CY JAN 17-20, 2001 CL ANCHORAGE, AK SP Univ Alaska Sea Grant Coll Program, Alaska Dept Fish & Game, N Pacific Fishery Management Council, US Natl Marine Fisheries Serv, Wakefield Endowment, Univ Alaska Fdn ID PRINCE-WILLIAM-SOUND; EXXON-VALDEZ; PARALITHODES-CAMTSCHATICA; CANCER-MAGISTER; DUNGENESS CRAB; SEDIMENTS; SPILL; CONTAMINATION; HYDROCARBONS AB Behavioral preference tests were used to determine whether sediment selection played a role in habitat choice in juvenile red king crab (Paralithodes camtschaticus) and Tanner crab (Chionoecetes bairdi) and how oil pollution might alter sediment preferences. In the absence of oil, 2-year-old juvenile red king crabs preferred a bryozoan-hydroid assemblage or cobble over shale, shell hash, sand, or mud. Sand was chosen <3% of the time and mud was never selected. juvenile Tanner crabs selected bryozoan-hydroid assemblages or buried in either sand or mud and avoided the larger-grain substrates. In oil experiments using three sediment types (mud, sand, cobble), grain size was often more important in sediment selection than the presence or absence of contaminants. If the preferred sediment type was oiled and the alternative sediment was unoiled but of smaller grain size, both species selected the preferred sediment. Red king crabs avoided sediments containing 500-800 mug per g total hydrocarbons if unoiled sediment of the same or larger grain size was available. Addition of oil to the unpreferred sediment increased selection of preferred sediment. In contrast, the Tanner crabs selected fine-grained sediments whether oil was present or not. The lack of avoidance by crabs at concentrations <500 mug per g may lead to long-term exposure to contaminated sediment in areas where benthic sediments are chronically polluted. C1 Alaska Fisherie Sci Ctr, Natl Marine Fisheries Serv, Juneau, AK 99801 USA. RP Moles, A (reprint author), Alaska Fisherie Sci Ctr, Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. EM adam.moles@noaa.gov NR 25 TC 1 Z9 1 U1 0 U2 1 PU UNIV ALASKA SEA GRANT PI FAIRBANKS PA POB 755040, 205 ONEILL BLDG, FAIRBANKS, AK 99775 USA BN 1-56612-077-2 J9 LOW WAKE FI PY 2002 VL 19 BP 631 EP 644 PG 14 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA BV60H UT WOS:000179482700045 ER PT S AU Diedrichsen, J Hazeltine, E Ivry, R Kennerley, S Spencer, B AF Diedrichsen, J Hazeltine, E Ivry, R Kennerley, S Spencer, B BE Highstein, TM Thach, WT TI Comparing continuous and discrete movements with fMRI SO CREBELLUM: RECENT DEVELOPMENTS IN CEREBELLAR RESEARCH SE ANNALS OF THE NEW YORK ACADEMY OF SCIENCES LA English DT Article; Proceedings Paper CT Conference on Recent Developments in Cerebellar Research CY NOV 15-18, 2001 CL ST LOUIS, MISSOURI SP McDonnell Ctr Higher Brain Funct, NIH, Natl Sci Fdn, Washington Univ Continuing Educ, Washington Univ Dept Anatomy & Neurobiol, Neurol, Otolaryngol DE eye movement; fMRI C1 Univ Calif Berkeley, Dept Psychol, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Purdue Univ, Dept Hlth & Kinesiol, W Lafayette, IN 47907 USA. Purdue Univ, Purdue Neurosci Program, W Lafayette, IN 47907 USA. RP Ivry, R (reprint author), Univ Calif Berkeley, Dept Psychol, 3210 Tolman Hall, Berkeley, CA 94720 USA. RI Diedrichsen, Jorn/A-7789-2010 OI Diedrichsen, Jorn/0000-0003-0264-8532 NR 0 TC 4 Z9 4 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 1-57331-436-6 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2002 VL 978 BP 509 EP 510 DI 10.1111/j.1749-6632.2002.tb07595.x PG 2 WC Multidisciplinary Sciences; Neurosciences SC Science & Technology - Other Topics; Neurosciences & Neurology GA BW14B UT WOS:000180980000045 PM 12582081 ER PT B AU DiCarlo, JA Yun, HM AF DiCarlo, JA Yun, HM BE Mishra, RS Earthman, JC Raj, SV TI Creep of ceramic fibers: Mechanisms, models, and composite implications SO CREEP DEFORMATION: FUNDAMENTALS AND APPLICATIONS LA English DT Proceedings Paper CT Symposium on Creep Deformation - Fundamentals and Applications CY FEB 17-21, 2000 CL SEATTLE, WA SP Mech Behav Comm, Struct Mat Div, Minerals Met & Mat Soc, Power Mat Comm, Mat Proc & Mfg Div ID BEHAVIOR AB At the high temperatures of interest for the application of ceramic matrix composites (CMC), current ceramic fibers display time-dependent deformation and fracture, i.e., creep and creep-induced rupture. Because this behavior can strongly affect the service life of CMC reinforced by these fibers, NASA has performed a variety of studies over the years (1) to measure and mechanistically model the creep-related properties of ceramic fibers and (2) to ultimately understand their practical implications for the thermo structural performance of CMC. This paper briefly reviews some recent results from these studies, with focus on alumina- and SiC-based fibers of current and past interest for CMC reinforcement. It is shown that although the effects of time, temperature, stress, and microstructure can be mechanistically and analytically modeled for the creep properties of single fibers under simple test conditions, complications can arise when using these results for CMC creep and rupture analysis. Nevertheless, under certain conditions, correlation has been found between single-fiber and CMC time-dependent structural behavior, thereby allowing an improved understanding of key factors controlling the rupture life of multi-component CMC. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP DiCarlo, JA (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 25 TC 5 Z9 5 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-515-8 PY 2002 BP 195 EP 208 PG 6 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films; Materials Science, Composites SC Metallurgy & Metallurgical Engineering; Materials Science GA BU50E UT WOS:000176154800019 ER PT B AU Whittenberger, JD Raj, SV Locci, IE AF Whittenberger, JD Raj, SV Locci, IE BE Mishra, RS Earthman, JC Raj, SV TI Effect of microstructure on creep in directionally solidified NiAl-31Cr-3Mo SO CREEP DEFORMATION: FUNDAMENTALS AND APPLICATIONS LA English DT Proceedings Paper CT Symposium on Creep Deformation - Fundamentals and Applications CY FEB 17-21, 2000 CL SEATTLE, WA SP Mech Behav Comm, Struct Mat Div, Minerals Met & Mat Soc, Power Mat Comm, Mat Proc & Mfg Div ID EUTECTIC NIAL-CR; ELEVATED-TEMPERATURE; PLASTIC-FLOW; COMPOSITES; TOUGHNESS; ALLOY; SIZE AB The 1200 to 1400 K slow strain rate characteristics of the directionally solidified (DS) eutectic Ni-33Al-31Cr-3 Mo have been determined as a function of growth rate. While differences in the light optical level microstructure were observed in alloys grown at rates ranging from 7.6 to 508 mm/h, compression testing indicated that all had essentially the same strength. The exception was Ni-33Al-31Cr-3Mo DS at 25.4 mm/h which was slightly stronger than the other growth velocities; no microstructual reason could be found for this improvement. Comparison of the similar to1300 K properties revealed that four different DS NiAl-34(Cr,Mo) alloys have a similar creep resistance which suggests that there is a common, but yet unknown, strengthening mechanism. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Whittenberger, JD (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 24 TC 2 Z9 2 U1 0 U2 1 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-515-8 PY 2002 BP 331 EP 340 PG 4 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films; Materials Science, Composites SC Metallurgy & Metallurgical Engineering; Materials Science GA BU50E UT WOS:000176154800032 ER PT B AU Raj, SV AF Raj, SV BE Mishra, RS Earthman, JC Raj, SV TI Creep behavior of near-stoichiometric polycrystalline binary NiAl SO CREEP DEFORMATION: FUNDAMENTALS AND APPLICATIONS LA English DT Proceedings Paper CT Symposium on Creep Deformation - Fundamentals and Applications CY FEB 17-21, 2000 CL SEATTLE, WA SP Mech Behav Comm, Struct Mat Div, Minerals Met & Mat Soc, Power Mat Comm, Mat Proc & Mfg Div ID PLASTIC-FLOW PROPERTIES; GRAIN-SIZE; TEMPERATURE; MECHANISMS; DIFFUSION; ALLOYS AB New and published constant load creep and constant engineering strain rate data on near-stoichiometric binary NiAl in the intermediate temperature range 700 to 1300 K are reviewed. Both normal and inverse primary creep curves are observed depending on stress and temperature. Other characteristics relating to creep of NiAl involving grain size, stress and temperature dependence are critically examined and discussed. At stresses below 25 MPa and temperatures above 1000 K, a new grain boundary sliding mechanism was observed with n similar to 2, Q(c) similar to 100 kJ mol(-1) and a grain size exponent of about 2. It is demonstrated that Coble and current accommodated grain boundary sliding models fail to predict the experimental creep rates by several orders of magnitude. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Raj, SV (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 24-1, Cleveland, OH 44135 USA. NR 25 TC 1 Z9 1 U1 0 U2 1 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-515-8 PY 2002 BP 351 EP 360 PG 4 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films; Materials Science, Composites SC Metallurgy & Metallurgical Engineering; Materials Science GA BU50E UT WOS:000176154800034 ER PT S AU Ohl, RG Barthelmy, MP Zewari, SW Toland, RW McMann, JC Puckett, DF Hagopian, JG Hylan, JE Mentzell, JE Mink, RG Sparr, LM Greenhouse, MA MacKenty, JW AF Ohl, RG Barthelmy, MP Zewari, SW Toland, RW McMann, JC Puckett, DF Hagopian, JG Hylan, JE Mentzell, JE Mink, RG Sparr, LM Greenhouse, MA MacKenty, JW BE Heaney, JB Burriesci, LG TI Comparison of stress relief procedures for cryogenic aluminum mirrors SO CRYOGENIC OPTICAL SYSTEMS AND INSTRUMENTS IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Cryogenic Optical Systems and Instruments IX CY JUL 08, 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 mirrors; cryogenic; aluminum; heat treatment; stress relief; optomechanical design; IRMOS AB The Infrared Multi-Object Spectrograph (IRMOS) is a facility instrument for the Kitt Peak National Observatory Mayall Telescope (3.8 meter). IRMOS is a low- to mid-resolution (R = lambda/Deltalambda = 300-3000), near-IR (0.8-2.5 mum) spectrograph that produces simultaneous spectra of similar to100 objects in its 2.8 x 2.0 arcmin field of view using a commercial MEMS multi-mirror array device. The instrument operating temperature is similar to80 K and the design is athermal. The optical bench and mirrors are machined from aluminum 6061-T651. In spite of its baseline mechanical stress relief, aluminum 6061-T651 harbors some residual stress, which, unless relieved during fabrication, may distort mirror figure to unacceptable levels at the operating temperature (similar to80 K). Other cryogenic instruments using aluminum mirrors for both ground-based and space IR astronomy have employed a variety of heat treatment formulae, with mixed results. We present the results of a test program designed to empirically determine the best stress relief procedure for the IRMOS mirrors. Identical test mirrors with spherical and flat optical prescriptions are processed with five different stress relief formulae from the literature and institutional heritage and compared to samples without any additional processing. After figuring via diamond turning, the mirrors are tested for figure error and radius of curvature at room temperature and at similar to80 K for three thermal cycles. The heat treatment procedure for the mirrors that yielded the least and most repeatable change in figure error is applied to the IRMOS mirror blanks. We correlate the results of our optical testing with heat treatment and metallographic data. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ohl, RG (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 46 TC 7 Z9 7 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4590-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4822 BP 51 EP 71 PG 21 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA BV91M UT WOS:000180378400006 ER PT S AU Parrish, K Thomson, S AF Parrish, K Thomson, S BE Heaney, JB Burriesci, LG TI Cryogenic thermal design overview of the 30 K passively cooled integrated science instrument module (ISIM) for NASA's Next Generation Space Telescope SO CRYOGENIC OPTICAL SYSTEMS AND INSTRUMENTS IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Cryogenic Optical Systems and Instruments IX CY JUL 08, 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 cryogenic; thermal; sunshield; NGST; passive cooling; radiator; ISIM; heat map AB Baseline configurations for NASA's Next Generation Space Telescope (NGST) include a multi-module science instrument package with near-infrared (near-IR) detectors passively cooled to below 30 K. This integrated science instrument model (ISIM) will also house mid-infrared (mid-IR) detectors that are cooled to 6-7 K with a mechanical cooler or stored cryogen. These complex cooling requirements, combined with the NGST concept of a large deployed aperture optical telescope passively cooled to below 40 K, makes NGST one of the most unique and thermally challenging missions flown to date. This paper describes the current status and baseline thermal/cryogenic systems design and analysis approach for the ISIM. The extreme thermal challenges facing the ISIM are presented along with supporting heat maps and analysis results. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Parrish, K (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 8 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 0-8194-4590-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4822 BP 112 EP 122 DI 10.1117/12.454833 PG 11 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA BV91M UT WOS:000180378400011 ER PT S AU Waluschka, E Papalexandris, MV AF Waluschka, E Papalexandris, MV BE Fischer, RE Smith, WJ Johnson, RB TI LISA telescope sensitivity analysis SO CURRENT DEVELOPMENTS IN LENS DESIGN AND OPTICAL ENGINEERING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Current Developments in Lens Design and Optical Engineering III CY JUL 08-09, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol, Washington State Univ, Coll Engn & Architecture DE laser; interferometry; space; antenna; LISA; optics AB The Laser Interferometer Space Antenna (LISA) for the detection of Gravitational Waves is a very long baseline interferometer which will measure the changes in the distance of a five million kilometer arm to picometer accuracies. As with any optical system, even one with such very large separations between the transmitting and receiving telescopes, a sensitivity analysis has to be performed to see how, in this case, the far field phase varies when the telescope parameters change as a result of structural stress relief or temperature changes. The results of the sensitivity analysis are presented. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Waluschka, E (reprint author), NASA, Goddard Space Flight Ctr, 551-0, Greenbelt, MD 20771 USA. NR 3 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4534-7 J9 P SOC PHOTO-OPT INS PY 2002 VL 4767 BP 114 EP 122 DI 10.1117/12.451228 PG 9 WC Optics SC Optics GA BV72W UT WOS:000179912900013 ER PT S AU Mouroulis, P AF Mouroulis, P BE Fischer, RE Smith, WJ Johnson, RB TI Optical design of a reflectance/Raman confocal microspectrometer SO CURRENT DEVELOPMENTS IN LENS DESIGN AND OPTICAL ENGINEERING III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Current Developments in Lens Design and Optical Engineering III CY JUL 08-09, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol, Washington State Univ, Coll Engn & Architecture DE optical design; confocal microscopy; planetary mineralogy; reflectance spectroscopy; Raman spectroscopy AB A miniaturized instrument for systematic planetary mineralogy is presented, and the optical design of the component parts is discussed. The instrument combines the following capabilities: wide field color imaging, confocal imaging at two different resolution/range levels, reflectance spectroscopy in the 400-2500 nm region with a resolution of 10 nm, and Raman spectroscopy over 4000 cm(-1) with an average resolution of 3.3 cm(-1). The instrument can also serve as an expandable platform for adding fluorescence spectroscopy, or for examining samples from a distance of several meters while using the same spectrometer. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mouroulis, P (reprint author), CALTECH, Jet Prop Lab, MS 306-336,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 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 0-8194-4534-7 J9 P SOC PHOTO-OPT INS PY 2002 VL 4767 BP 123 EP 130 DI 10.1117/12.451229 PG 8 WC Optics SC Optics GA BV72W UT WOS:000179912900014 ER PT J AU Avakian, A Kalina, RE Sage, EH Rambhia, AH Elliott, KE Chuang, EL Clark, JI Hwang, JN Parsons-Wingerter, P AF Avakian, A Kalina, RE Sage, EH Rambhia, AH Elliott, KE Chuang, EL Clark, JI Hwang, JN Parsons-Wingerter, P TI Fractal analysis of region-based vascular change in the normal and non-proliferative diabetic retina SO CURRENT EYE RESEARCH LA English DT Article DE fractal; region-based; vascular; retina; image analysis; non-proliferative diabetic retinopathy ID CHORIOALLANTOIC MEMBRANE; VESSELS; ANGIOGENESIS; MODEL; VASCULOGENESIS; PATTERN; DENSITY AB Purpose. Evaluation of normal and abnormal vascular pattern in the human retina using a novel method: quantitative region-based fractal analysis. Methods. Binary (black/white) vascular patterns of the human retina originating at the optic disc were obtained by semi-automatic computer processing of digital images from 60-degree fundus fluorescein angiography of 5 normal eyes and 5 eyes with non-proliferative diabetic retinopathy (NPDR). As determined by image resolution, vascular patterns included vessels with diameters greater than or equal to50 mum and excluded small vessels and capillaries. The density of linearized (i.e., skeletonized) vascular patterns in the macular region versus paramacular region (termed "region-based" linearized vascular pattern) was quantified with the fractal dimension (D-f) and confirmed by grid intersection (rho(v)). Results. By region-based quantification, D-f and rho(v) were significantly higher in the normal macular region than in the NPDR macular region (p = 0.008 and p = 0.019, respectively). However, differences in D-f and rho(v) between the normal and NPDR paramacular regions were not strongly signficant (p = 0.168 and p = 0.337, respectively). Conclusions. Results from the retrospective analytical study demonstrate the feasibility of using quantitative region-based fractal analysis of early-stage vascular disease in the human retina. The results are encouraging for a broader study of diverse patient populations. C1 Univ Washington, Dept Ophthalmol, Seattle, WA 98195 USA. Univ Washington, Dept Biol Struct, Seattle, WA 98195 USA. Univ Washington, Dept Elect Engn, Seattle, WA 98195 USA. RP Parsons-Wingerter, P (reprint author), NASA, Glenn Res Ctr, MS 77-5,21000 Brookpk Rd, Cleveland, OH 44135 USA. FU NEI NIH HHS [R01 EY004542, EY01730] NR 27 TC 62 Z9 63 U1 0 U2 3 PU SWETS ZEITLINGER PUBLISHERS PI LISSE PA P O BOX 825, 2160 SZ LISSE, NETHERLANDS SN 0271-3683 J9 CURR EYE RES JI Curr. Eye Res. PY 2002 VL 24 IS 4 BP 274 EP 280 DI 10.1076/ceyr.24.4.274.8411 PG 7 WC Ophthalmology SC Ophthalmology GA 600BD UT WOS:000178370000005 PM 12324866 ER PT S AU Sun, DL Lynnes, C Kiang, R Kempler, S Serafino, G AF Sun, DL Lynnes, C Kiang, R Kempler, S Serafino, G BE Dasarathy, BV TI Knowledge discovery about scientific papers or proceedings referenced NASA/DAAC data with a rule-based classifier SO DATA MINING AND KNOWLEDGE DISCOVERY: THEORY, TOOLS AND TECHNOLOGY IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Data Mining and Knowledge Discovery - Theory, Tools, and Technology IV CY APR 01-04, 2002 CL ORLANDO, FL SP SPIE DE knowledge discovery; data mining; rule-based classifier; and data-knowledge loop AB Knowledge discovery from online journals, abstracts and citation indices, cross-referenced with the NASA Distributed Active Archive Center (DAAC) user/order database to close the data-knowledge loop. Knowledge discovery in database (KDD) has been defined as the nontrivial process of discovering valid, novel, potentially useful, and ultimately understandable patterns from data. The core step of the KDD process is data mining. Data mining is all about extracting patterns from an organization's stored or warehoused data. These patterns can be used to gain insight into aspects of the organization's operations and predict outcomes for future situations. Patterns often concern the categories to which situations belong. For example, here is the situation, to decide if a journal paper used the NASA DAAC data or not, starting from the Goddard DAAC user/order database record, a rule-based classifier was developed and rules were found firstly with training, samples, then these rules were applied to recognize new patterns. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sun, DL (reprint author), NASA, Goddard Space Flight Ctr, DAAC Code 902, Greenbelt, MD 20771 USA. RI Lynnes, Christopher/B-4506-2010 OI Lynnes, Christopher/0000-0001-6744-3349 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 0-8194-4480-4 J9 P SOC PHOTO-OPT INS PY 2002 VL 4730 BP 103 EP 108 DI 10.1117/12.460217 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems SC Computer Science GA BU57V UT WOS:000176405500013 ER PT S AU Rajkumar, T Aragon, C Bardina, J Britten, R AF Rajkumar, T Aragon, C Bardina, J Britten, R BE Zanasi, A Brebbia, CA Ebecken, NFF Melli, P TI Prediction of aerodynamic coefficients for wind tunnel data using a genetic algorithm optimized neural network SO DATA MINING III SE MANAGEMENT INFORMATION SYSTEMS LA English DT Proceedings Paper CT 3rd International Conference on Data Mining CY SEP 25-27, 2002 CL BOLOGNA, ITALY SP Wessex Inst Technol AB A fast, reliable way of predicting aerodynamic coefficients is produced using a neural network optimized by a genetic algorithm. Basic aerodynamic coefficients (e.g. lift, drag, pitching moment) are modelled as functions of angle of attack and Mach number. The neural network is first trained on a relatively rich set of data from wind tunnel tests or numerical simulations to learn an overall model. Most of the aerodynamic parameters can be well-fitted using polynomial functions. A new set of data, which can be relatively sparse, is then supplied to the network to produce a new model consistent with the previous model and the new data. Because the new model interpolates realistically between the sparse test data points, it is suitable for use in piloted simulations. The genetic algorithm is used to choose a neural network architecture to give best results, avoiding over- and under-fitting of the test data. C1 NASA, Ames Res Ctr, SAIC, Moffett Field, CA 94035 USA. RP Rajkumar, T (reprint author), NASA, Ames Res Ctr, SAIC, Moffett Field, CA 94035 USA. NR 25 TC 0 Z9 0 U1 0 U2 0 PU WIT PRESS PI SOUTHAMPTON PA ASHURST LODGE, SOUTHAMPTON SO40 7AA, ASHURST, ENGLAND SN 1470-6326 BN 1-85312-925-9 J9 MANAG INFORMAT SYST PY 2002 VL 6 BP 473 EP 487 PG 15 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BV88L UT WOS:000180301500046 ER PT J AU Davis, RW Ortega-Ortiz, JG Ribic, CA Evans, WE Biggs, DC Ressler, PH Cady, RB Leben, RR Mullin, KD Wursig, B AF Davis, RW Ortega-Ortiz, JG Ribic, CA Evans, WE Biggs, DC Ressler, PH Cady, RB Leben, RR Mullin, KD Wursig, B TI Cetacean habitat in the northern oceanic Gulf of Mexico SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article DE USA; Gulf of Mexico; aquatic mammals; cetaceans; aquatic environment; habitat ID EASTERN TROPICAL PACIFIC; SPERM WHALE DISTRIBUTIONS; DOPPLER CURRENT PROFILER; WARM-CORE RING; OF-MEXICO; ENVIRONMENTAL FEATURES; ZOOPLANKTON ABUNDANCE; CONTINENTAL-SLOPE; WESTERN GULF; GEORGES BANK AB Cetaceans (whales and dolphins) are diverse and abundant upper trophic level predators in the Gulf of Mexico, a semi-enclosed, intercontinental sea with a total area of about 1.5 million km(2). The objectives of this study were to better define the habitat of cetaceans in the northern oceanic Gulf of Mexico. An integrated methodology was used that included visual surveys and hydrographic collections from ships. Near real-time sea surface altimetry from the TOPEX/POSEIDON and ERS satellites was used during ship surveys to determine the location of hydrographic features (e.g., cyclones, anticyclones and confluence zones). Archival satellite sea surface altimetry data were also used to retrospectively determine the location of hydrographic features for analysis with earlier cetacean sightings. We estimated zooplankton and micronekton biomass using both net and acoustic sampling to indicate the amount of potential food available for higher trophic level foraging by cetaceans. Nineteen cetacean species were identified during ship surveys. Cetaceans were concentrated along the continental slope in or near cyclones and the confluence of cyclone-anticyclone eddy pairs, mesoscale features with locally concentrated zooplankton and micronekton stocks that appear to develop in response to increased nutrient-rich water and primary production in the mixed layer. A significant relationship existed between integrated zooplankton biomass and integrated cephalopod paralarvae numbers, indicating that higher zooplankton and micronekton biomass may correlate with higher concentrations of cetacean prey. In the north-central Gulf, an additional factor affecting cetacean distribution may be the narrow continental shelf south of the Mississippi River delta. Low salinity, nutrient-rich water may occur over the continental slope near the mouth of the Mississippi (MOM) River or be entrained within the confluence of a cyclone-anticyclone eddy pair and transported beyond the continental slope. This creates a deep-water environment with locally enhanced primary and secondary productivity and may explain the presence of a resident, breeding population of sperm whales within 100 km of the Mississippi River delta. Overall, the results suggest that the amount of potential prey for cetaceans may be consistently greater in the cyclone, confluence areas, and south of the MOM, making them preferential areas for foraging. However, this may not be true for bottlenose dolphins, Atlantic spotted dolphins and possibly Bryde's whales, which typically occur on the continental shelf or along the shelf break outside of major influences of eddies. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Texas A&M Univ, Dept Marine Biol, Galveston, TX 77551 USA. Univ Wisconsin, Dept Wildlife Ecol, USGS BRD Wisconsin Cooperat Wildlife Res Unit, Russell Labs 226, Madison, WI 53706 USA. Texas A&M Univ, Dept Oceanog, College Stn, TX 77843 USA. Univ Colorado, Colorado Ctr Astrodynam Res, Boulder, CO 80309 USA. Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Pascagoula, MS 39568 USA. RP Davis, RW (reprint author), Texas A&M Univ, Dept Marine Biol, 5007 Ave U, Galveston, TX 77551 USA. RI Leben, Robert/F-3792-2010 OI Leben, Robert/0000-0003-1067-9515 NR 62 TC 80 Z9 89 U1 3 U2 22 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD JAN PY 2002 VL 49 IS 1 BP 121 EP 142 DI 10.1016/S0967-0637(01)00035-8 PG 22 WC Oceanography SC Oceanography GA 506CY UT WOS:000172953400008 ER PT J AU Carr, ME AF Carr, ME TI Estimation of potential productivity in Eastern Boundary Currents using remote sensing SO DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY LA English DT Article ID PHYTOPLANKTON; SEA; CALIFORNIA; PHOTOSYNTHESIS; ENVIRONMENT; ALGORITHMS; IRRADIANCE; ANCHOVY; SEAWIFS; MODEL AB This study provides a satellite-based estimate of potential primary production in the four Eastern Boundary Currents (EBCs), i.e. the California, Humboldt, Canary, and Benguela currents, from the first 24 months of the Sea-Viewing Wide Field of View Sensor, SeaWiFS. Within each EBC, production was estimated for the area of high chlorophyll concentration (> 1 mg m(-1)) or active area, which is likely to determine the production that can be utilized by higher trophic levels. Primary production decreased with latitude within each EBC while the extent of the active area was related to the magnitude of offshore transport. The most productive EBC was the Benguela Current (0.37 Gt C yr(-1)), followed by the Canary (0.33 Gt C yr(-1)), Humboldt (0.20 Gt C yr(-1)), and California (0.04 Gt C yr(-1)) Currents. Interannual differences between 1997, 1998, and 1999 were largest for 1997 (measured by the Ocean Color Temperature Scanner, OCTS), which may be due primarily to the different sensor and algorithm. The Humboldt Current was more productive, and the Canary much less, during 1997 than in the two following years. The El Nino of 1997-1998 led to smaller annual production in 1998 in the Pacific EBCs. The upper bound of sustainable fish yield was estimated assuming a food chain of 2.6 links and an average trophic efficiency of 10%. The resulting values are 4-150 times larger than the observed fish catch from 1990 through 1997. Actual catch data in the Benguela Current were 20 times smaller than in the Humboldt Current. The most likely explanations for the differences in potential and observed fish catch are related to differing trophic structure and spatial accessibility in different EBCs. If the estimated yield is an upper bound that will be decreased to 10% or 20% by environmental accessibility, the small pelagic fishery in all four EBCs is likely to be food-limited. (C) 2001 Published by Elsevier Science Ltd. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Carr, ME (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-323, Pasadena, CA 91109 USA. EM mec@pacific.jpl.nasa.gov NR 48 TC 203 Z9 207 U1 3 U2 33 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0645 J9 DEEP-SEA RES PT II JI Deep-Sea Res. Part II-Top. Stud. Oceanogr. PY 2002 VL 49 IS 1-3 BP 59 EP 80 PG 22 WC Oceanography SC Oceanography GA 507CE UT WOS:000173008600003 ER PT J AU Gregg, WW AF Gregg, WW TI Tracking the SeaWiFS record with a coupled physical/biogeochemical/radiative model of the global oceans SO DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY LA English DT Article ID 1997-98 EL-NINO; EQUATORIAL PACIFIC; ORGANIC-MATTER; ATLANTIC; BASIN; SIMULATION; SEA AB The Sea-Viewing Wide Field-of-view Sensor (SeaWiFS) has observed multiple years of routine global chlorophyll observations from space. The mission was launched into a record El Nino event, which eventually gave way to one of the most intense and longest-lasting La Nina events ever recorded. The SeaWiFS chlorophyll record captured the response of ocean phytoplankton to these significant events in the tropical Indo-Pacific basins, but also indicated significant interannual variability unrelated to the El Nino/La Nina events. This included large variability in the North Atlantic and Pacific basins, in the North Central and equatorial Atlantic, and milder patterns in the North Central Pacific. This SeaWiFS record was tracked with a coupled physical/biogeochemical/radiative model of the global oceans using near-real-time forcing data such as wind stresses, sea surface temperatures, and sea ice. This provided an opportunity to offer physically and biogeochemically meaningful explanations of the variability observed in the SeaWiFS data set, since the causal mechanisms and interrelationships of the model are completely understood. The coupled model was able to represent the seasonal distributions of chlorophyll during the SeaWiFS era, and was capable of differentiating among the widely different processes and dynamics occurring in the global oceans. The model was also reasonably successful in representing the interannual signal, especially when it was large, such as the El Nino and La Nina events in the tropical Pacific and Indian Oceans. The model provided different phytoplankton group responses for the different events in these regions: diatoms were predominant in the tropical Pacific during the La Nina, but other groups were predominant during El Nino. The opposite condition occurred in the tropical Indian Ocean. Both situations were due to the different responses of the basins to El Nino. Interannual variability in the North Pacific was exhibited as an increase in the spring bloom in 1999 and 2000 relative to 1998. This resulted in the model from a shallower and more rapidly shoaling mixed layer, producing more average irradiance in the water column and preventing herbivore populations to keep pace with increasing phytoplankton populations. However, several aspects of the interannual cycle were not well-represented by the model. Explanations range from inherent model deficiencies, to monthly averaging of forcing fields, to biases in SeaWiFS atmospheric correction procedures. (C) 2001 Published by Elsevier Science Ltd. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Gregg, WW (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Code 661, Greenbelt, MD 20771 USA. NR 39 TC 37 Z9 40 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0645 J9 DEEP-SEA RES PT II JI Deep-Sea Res. Part II-Top. Stud. Oceanogr. PY 2002 VL 49 IS 1-3 BP 81 EP 105 PG 25 WC Oceanography SC Oceanography GA 507CE UT WOS:000173008600004 ER PT J AU Christian, JR Verschell, MA Murtugudde, R Busalacchi, AJ McClain, CR AF Christian, JR Verschell, MA Murtugudde, R Busalacchi, AJ McClain, CR TI Biogeochemical modelling of the tropical Pacific Ocean. I: Seasonal and interannual variability SO DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY LA English DT Article ID CENTRAL EQUATORIAL PACIFIC; GENERAL-CIRCULATION MODEL; EL NINO CONDITIONS; MIXED-LAYER MODEL; ECOSYSTEM MODEL; SOUTHERN OSCILLATION; PHYTOPLANKTON GROWTH; PRIMARY PRODUCTIVITY; COMMUNITY STRUCTURE; IRON HYPOTHESIS AB A coupled physical-biogeochemical model has been developed in order to study physical-biological interactions in the tropical Pacific Ocean on seasonal-to-interannual timescales. The model incorporates both iron- and nitrogen-limited phytoplankton growth, and succession of phytoplankton size classes in accordance with the "ecumenical" iron hypothesis. The model shows a strong El Nino-Southern Oscillation component to phytoplankton variability in the central equatorial Pacific over the period 1980-1998. It is possible that this mode is more dominant in the model than in nature, although the correlation of modelled and observed chlorophyll in this region is strong. The model results show that interannual variability dominates over the mean seasonal cycle for both physical and biogeochemical fields, with the exception of undercurrent transport west of the dateline. Physical and biogeochemical fields show consistent seasonal phasing among the four El Nino events simulated, although there is variability in the magnitudes and exact timing. Nutrient concentration anomalies at constant temperature in the thermocline of the central equatorial Pacific appear to be largely advected from the west, and the strong seasonal cycle of the equatorial undercurrent in the west introduces a significant annual component to the variability of nutrient concentrations at longitudes where the mean seasonal cycle of the local physical forcing is negligible. The biogeochemical model maintains realistic nutrient pools over the time scales required for interannual simulatiowhich introduces additional uncertainty into the validation and prediction of biogeochemical fields. (C) 2001 Elsevier Science Ltd. All rights reserved.n, and responds in a realistic fashion to changing upper ocean hydrography and circulation. The model is quite sensitive to the temporal resolution of the wind forcing, C1 Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Natl Res Council, Greenbelt, MD 20771 USA. RP Christian, JR (reprint author), Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. EM jrc@essic.umd.edu NR 86 TC 82 Z9 85 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0645 J9 DEEP-SEA RES PT II JI Deep-Sea Res. Part II-Top. Stud. Oceanogr. PY 2002 VL 49 IS 1-3 BP 509 EP 543 PG 35 WC Oceanography SC Oceanography GA 507CE UT WOS:000173008600019 ER PT J AU Christian, JR Verschell, MA Murtugudde, R Busalacchi, AJ McClain, CR AF Christian, JR Verschell, MA Murtugudde, R Busalacchi, AJ McClain, CR TI Biogeochemical modelling of the tropical Pacific Ocean. II: Iron biogeochemistry SO DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY LA English DT Article ID CENTRAL EQUATORIAL PACIFIC; CENTRAL NORTH PACIFIC; REGENERATED PRODUCTION; ECOSYSTEM MODEL; PHYTOPLANKTON; DISTRIBUTIONS; WATERS; UNDERCURRENT; VARIABILITY; LIMITATION AB A coupled physical-biogeochemical model of the tropical Pacific Ocean with simultaneous iron and nitrogen limitation was developed to study questions of iron biogeochemistry, its effects on upper ocean production, and ultimately the biogeochemical cycles of the other elements. The model results suggest that iron limitation is ubiquitous in the equatorial Pacific, and extends further west than is generally believed unless there are significant inputs of geothermal iron at quite shallow depths. Most model parameters (e.g., iron solubility, scavenging rates, Fe: N ratios) must be near the limit of their generally accepted range of values in order to prevent elevated surface nitrate concentrations from spreading further into the warm pool than is observed. Transport of geothermal iron in the equatorial undercurrent (EUC) provides a possible mechanism for limiting surface nitrate in the warm pool, but the source must be near the upper boundary of the EUC to provide iron to the surface west of the dateline. Accumulations of ammonium in the western Pacific appear to result from the exhaustion of iron in upwelled water before nitrogen. The realism of the simulation is limited primarily by lack of information about the abundance and distribution of dissolved iron; the assumption of constant Fe: N ratios and the magnitude, distribution and solubility of the aeolian iron flux are also important sources of uncertainty. The sensitivity of the simulation to the way that iron is initialized in the western Pacific thermocline emphasizes the importance of the equatorial undercurrent throughout the tropical Pacific and the need for iron observations in this region. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Natl Res Council, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. RP Christian, JR (reprint author), Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. EM jrc@essic.umd.edu NR 60 TC 54 Z9 54 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0645 J9 DEEP-SEA RES PT II JI Deep-Sea Res. Part II-Top. Stud. Oceanogr. PY 2002 VL 49 IS 1-3 BP 545 EP 565 DI 10.1016/S0967-0645(01)00111-4 PG 21 WC Oceanography SC Oceanography GA 507CE UT WOS:000173008600020 ER PT J AU Wiggert, JD Murtugudde, RG McClain, CR AF Wiggert, JD Murtugudde, RG McClain, CR TI Processes controlling interannual variations in wintertime (Northeast Monsoon) primary productivity in the central Arabian Sea SO DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY LA English DT Article ID TROPICAL INDIAN-OCEAN; MIXED-LAYER; EQUATORIAL PACIFIC; PHYTOPLANKTON; VARIABILITY; DEPTH; MODEL; SEASONALITY; CHLOROPHYLL; SIMULATION AB Three years of ocean color observations obtained by SeaWiFS reveal significant interannual variation in surface chlorophyll a (Chl a) concentrations in the central Arabian Sea during the Northeast (winter) Monsoon (NEM). Consistent with previous findings in the literature, no obvious relation to sea-surface temperature is apparent. A strong relationship with interannual variability in thermocline depth has been established using an interannually forced ocean general circulation model (OGCM). This relationship consists of reduced Chl a concentration associated with a deeper thermocline. Deeper winter convection is generally associated with higher nutrient concentrations and therefore higher phytoplankton biomass. Both in situ observations from the US JGOFS Arabian Sea Expedition and net wintertime nutrient entrainment estimated with the OGCM simulation indicate that mixed-layer concentrations are always sufficiently high to be non-limiting for phytoplankton growth. This raises two questions. What process(es) check phytoplankton growth? What leads to the observed relationship between deeper thermocline and reduced chl a concentration? A prominent feature of the NEM is a large-amplitude diurnal cycle of the mixed layer that is evident in moored temperature time-series. We hypothesize that the night-time penetration of this diurnal mixing, which is defined by the interannually varying thermocline depth, determines the magnitude of phytoplankton biomass that will be retained in the euphotic zone for the following photoperiod. This daily dilution acts to check the accumulation of phytoplankton biomass and prevents a full phytoplankton bloom. A simple 1-D model has been developed to quantify this process. An excellent correspondence exists between model-predicted mixed-layer Chl a concentration as it varies with thermocline depth and the similarly represented SeaWiFS observations. (C) 2002 Published by Elsevier Science Ltd. C1 Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, Interdisciplinary Ctr, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Wiggert, JD (reprint author), Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, Interdisciplinary Ctr, College Pk, MD 20742 USA. NR 52 TC 48 Z9 50 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0645 J9 DEEP-SEA RES PT II JI Deep-Sea Res. Part II-Top. Stud. Oceanogr. PY 2002 VL 49 IS 12 BP 2319 EP 2343 AR PII S0967-0645(02)00039-5 DI 10.1016/S0967-0645(02)00039-5 PG 25 WC Oceanography SC Oceanography GA 567PQ UT WOS:000176493600005 ER PT J AU McClain, CR Christian, JR Signorini, SR Lewis, MR Asanuma, I Turk, D Dupouy-Douchement, C AF McClain, CR Christian, JR Signorini, SR Lewis, MR Asanuma, I Turk, D Dupouy-Douchement, C TI Satellite ocean-color observations of the tropical Pacific Ocean SO DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY LA English DT Article ID WESTERN EQUATORIAL PACIFIC; 1997-98 EL-NINO; PHYTOPLANKTON BLOOM; IRON FERTILIZATION; SOLAR-RADIATION; MIXED-LAYER; TOGA-COARE; WARM POOL; SURFACE; TEMPERATURE AB The Coastal Zone Color Scanner (CZCS) data set provided some insights into biological processes in the equatorial Pacific, but the sampling was too sparse to address questions on temporal and spatial variability. Since late 1996, the Ocean Color-Temperature Sensor (OCTS), the Polarization Detection Environmental Radiometer (POLDER), the Sea-viewing Wide Field-of-View Sensor (SeaWiFS), and the Moderate-Resolution Imaging Spectroradiometer (MODIS) have provided a nearly continuous record of biological processes in this region for the first time. This study summarizes the SeaWiFS observations of the tropical Pacific from September 1997 through March 2000, with particular emphasis on equatorial and mesoscale variability, the influence of biological processes on penetrating irradiance, and the performance of primary production algorithms in this region. Specific mesoscale phenomena described are the phytoplankton blooms along the west coast of Central America, in the vicinity of the Costa Rica dome, and south of the equator. The coastal Central American and Costa Rica dome blooms result from orographically steered coastal winds and Ekman divergence, respectively. An unusual bloom event occurred south of the equator and persisted for several months in 1999; specific mechanisms that would have sustained the bloom could not be identified. Also, the time-evolution of the equatorial bloom during the May August 1998 transition from El Nino to La Nina is discussed. Again, no concise and broadly accepted explanation of the bloom's genesis and migration has yet emerged. During this transition, the monthly mean diffuse attenuation coefficient decreased by a factor of 3 at some locations along the equator. This change in water transparency, coupled with large changes in mixed-layer depth, resulted in significant changes in surface layer heating rates that were substantiated with field observations. Finally, certain primary production algorithms designed to use remotely sensed chlorophyll-a concentrations are evaluated. None of the algorithms capture the observed variability in primary production, and all appear to underestimate the total primary production of the tropical Pacific. (C) 2002 Elsevier Science Ltd. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Off Global Carbon Studies, Greenbelt, MD 20771 USA. Sci Applicat Int Corp, Mclean, VA 22102 USA. Dalhousie Univ, Halifax, NS B3H 3J5, Canada. Inst Pierre Simon Laplace, Paris, France. RP McClain, CR (reprint author), NASA, Goddard Space Flight Ctr, Off Global Carbon Studies, Code 970-2, Greenbelt, MD 20771 USA. NR 87 TC 63 Z9 65 U1 2 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0645 J9 DEEP-SEA RES PT II JI Deep-Sea Res. Part II-Top. Stud. Oceanogr. PY 2002 VL 49 IS 13-14 BP 2533 EP 2560 AR PII S0967-0645(02)00047-4 DI 10.1016/S0967-0645(02)00047-4 PG 28 WC Oceanography SC Oceanography GA 568FJ UT WOS:000176531500005 ER PT J AU Hunt, GL Stabeno, P Walters, G Sinclair, E Brodeur, RD Napp, JM Bond, NA AF Hunt, GL Stabeno, P Walters, G Sinclair, E Brodeur, RD Napp, JM Bond, NA TI Climate change and control of the southeastern Bering Sea pelagic ecosystem SO DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY LA English DT Review ID POLLOCK THERAGRA-CHALCOGRAMMA; JUVENILE WALLEYE POLLOCK; NORTHERN FUR SEALS; SPRING PHYTOPLANKTON DYNAMICS; PRIBILOF-ISLANDS; PHYSICAL-ENVIRONMENT; CALLORHINUS-URSINUS; INTERDECADAL VARIATIONS; TEMPORAL VARIABILITY; ANOMALOUS CONDITIONS AB We propose a new hypothesis, the Oscillating Control Hypothesis (OCH), which predicts that pelagic ecosystem function in the southeastern Bering Sea will alternate between primarily bottom-up control in cold regimes and primarily top-down control in warm regimes. The timing of spring primary production is determined predominately by the timing of ice retreat. Late ice retreat (late March or later) leads to an early, ice-associated bloom in cold water (e.g., 1995, 1997, 1999), whereas no ice, or early ice retreat before mid-March, leads to an open-water bloom in May or June in warm water (e.g., 1996, 1998, 2000). Zooplankton populations are not closely coupled to the spring bloom, but are sensitive to water temperature. In years when the spring bloom occurs in cold water, low temperatures limit the production of zooplankton, the survival of larval/juvenile fish, and their recruitment into the populations of species of large piscivorous fish, such as walleye pollock (Theragra chalcogramma), Pacific cod (Gadus macrocephalus) and arrowtooth flounder (Atheresthes stomias). When continued over decadal scales, this will lead to bottom-up limitation and a decreased biomass of piscivorous fish. Alternatively, in periods when the bloom occurs in warm water, zooplankton populations should grow rapidly, providing plentiful prey for larval and juvenile fish. Abundant zooplankton will support strong recruitment of fish and will lead to abundant predatory fish that control forage fish, including, in the case of pollock, their own juveniles. Piscivorous marine birds and pinnipeds may achieve higher production of young and survival in cold regimes, when there is less competition from large piscivorous fish for coldwater forage fish such as capelin (Mallotus villosus). Piscivorous seabirds and pinnipeds also may be expected to have high productivity in periods of transition from cold regimes to warm regimes, when young of large predatory species of fish are numerous enough to provide forage. The OCH predicts that the ability of large predatory fish populations to sustain fishing pressure will vary between warm and cold regimes. The OCH points to the importance of the timing of ice retreat and water temperatures during the spring bloom for the productivity of zooplankton, and the degree and direction of coupling between zooplankton and forage fish. Forage fish (e.g., juvenile pollock, capelin, Pacific herring [Clupea pallasii]) are key prey for adult pollock and other apex predators. In the southeastern Bering Sea, important changes in the biota since the mid-1970s include a marked increase in the biomass of large piscivorous fish and a concurrent decline in the biomass of forage fish, including age-1 walleye pollock, particularly over the southern portion of the shelf. Populations of northern fur seals (Callorhinus ursinus) and seabirds such as kittiwakes (Rissa spp.) at the Pribilof Islands have declined, most probably in response to a diminished prey base. The available evidence suggests that these changes are unlikely the result of a decrease in total annual new primary production, though the possibility of reduced post-bloom production during summer remains. An ecosystem approach to management of the Bering Sea and its fisheries is of great importance if all of the ecosystem components valued by society are to thrive. Cognizance of how climate regimes may alter relationships within this ecosystem will facilitate reaching that goal. Published by Elsevier Science Ltd. C1 Univ Calif Irvine, Dept Ecol & Evolutionary Biol, Irvine, CA 92697 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. NOAA, Natl Marine Fisheries Serv, Seattle, WA 98115 USA. NOAA, Natl Marine Mammal Lab, Seattle, WA 98115 USA. NOAA, Natl Marine Fisheries Serv, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. RP Univ Calif Irvine, Dept Ecol & Evolutionary Biol, 321 Steinhaus Hall, Irvine, CA 92697 USA. EM glhunt@uci.edu; stabeno@pmel.noaa.gov; gary.walters@noaa.gov; beth.sinclair@noaa.gov; rick.brodeur@noaa.gov; jeff.napp@noaa.gov; bond@pmel.noaa.gov OI Hunt, George/0000-0001-8709-2697 NR 146 TC 337 Z9 348 U1 5 U2 120 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0645 EI 1879-0100 J9 DEEP-SEA RES PT II JI Deep-Sea Res. Part II-Top. Stud. Oceanogr. PY 2002 VL 49 IS 26 BP 5821 EP 5853 AR PII S0967-0645(02)00321-1 DI 10.1016/S0967-0645(02)00321-1 PG 33 WC Oceanography SC Oceanography GA 620WF UT WOS:000179555400004 ER PT J AU Brodeur, RD Wilson, MT Ciannelli, L Doyle, M Napp, JM AF Brodeur, RD Wilson, MT Ciannelli, L Doyle, M Napp, JM TI Interannual and regional variability in distribution and ecology of juvenile pollock and their prey in frontal structures of the Bering Sea SO DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY LA English DT Article ID AGE-0 WALLEYE POLLOCK; THERAGRA-CHALCOGRAMMA PALLAS; COD GADUS-MORHUA; PRIBILOF-ISLANDS; TEMPORAL VARIABILITY; ANOMALOUS CONDITIONS; PHYSICAL PROCESSES; SPATIAL PROXIMITY; SOUND-SCATTERING; GEORGES BANK AB The distribution, size, length-specific weight, growth, and feeding of age-0 walleye pollock (Theragra chalcogramma) were examined along with their prey distribution patterns in two contrasting transects over a 4-year period (1994-1997) in relation to biophysical properties of frontal regions around the Pribilof Islands, Bering Sea. There were significant interannual differences in catch of age-0 pollock, but transect and habitat differences (inshore vs. front vs. offshore) were not significant for either catch or size of pollock. There were significant variations in length-specific weight and growth of pollock, but the trends were inconsistent. Copepods dominated the zooplankton biomass in all habitats and years; there were no consistent differences in the densities of the dominant zooplankton taxa among the habitats. There were, however, strong habitat and transect differences in juvenile pollock diet, particularly for the larger and presumably rarer prey taxa (euphausiids, chaetognaths, fish). We did not find any evidence that occupying a particular habitat was beneficial to young pollock, although other factors (e.g. bioenergetic advantage and predation refuge) that we did not examine here could have been more variable and critical to pollock survival. In a physically dynamic system such as the Pribilof Islands, age-0 pollock may need to continuously search for optimal conditions of high prey availability and low predation pressure. Published by Elsevier Science Ltd. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. Univ Washington, Sch Aquat & Fishery Sci, Seattle, WA 98105 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98105 USA. RP Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Hatfield Marine Sci Ctr, Newport, OR 97365 USA. EM rick.brodeur@noaa.gov NR 59 TC 27 Z9 27 U1 1 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0645 EI 1879-0100 J9 DEEP-SEA RES PT II JI Deep-Sea Res. Part II-Top. Stud. Oceanogr. PY 2002 VL 49 IS 26 BP 6051 EP 6067 AR PII S0967-0645(02)00333-8 DI 10.1016/S0967-0645(02)00333-8 PG 17 WC Oceanography SC Oceanography GA 620WF UT WOS:000179555400016 ER PT S AU Bae, SY Hayworth, KJ Yee, KY Shcheglov, K Wiberg, DV AF Bae, SY Hayworth, KJ Yee, KY Shcheglov, K Wiberg, DV BE Courtois, B Karam, JM Markus, KW Michel, B Mukherjee, T Walker, JA TI High performance MEMS micro-gyroscope SO DESIGN, TEST, INTEGRATION, AND PACKAGING OF MEMS/MOEMS 2002 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Design, Test, Integration, and Packaging of MEMS/MOEMS 2002 CY MAY 06-08, 2002 CL CANNES, FRANCE SP CNRS, INPG, UJF, IEEE, IEEE Comp Soc, Test Technol Tech Council, IEEE CPMT, SPIE, IEEE Circuits & Syst Soc AB This,paper reports on JPL's on-going research into MEMS gyroscopes. [1-4] This paper will describe the gyroscope's fabrication-methods, a new 8-electrode layout developed to improve performance and performance statistics of a batch of six gyroscopes (of the 8-electrode design) recently rate tested. Previously in our group, T. Tang and R. Gutierrez presented the results of their extensive use of ethylene diamine pyrocatechol (EDP) to deep-etch the inertial-sensitive resonators and post-supporting structures in a 4-electrode gyroscope design. Today, JPL is utilizing an in-house STS DRIE, replacing the old wet-etching steps. This has demonstrated superior precision in machining symmetry of the resonators, thus significantly reducing native rocking mode frequency-splits. A performance test of six gyros has shown an average, un-tuned, frequency split of 0.4% (11Hz split for rocking modes at 2.7KHz). The new JPL MEMS gyroscope has a unique 8-electrode layout, whose large electrodes can provide significant electrostatic softening of the resonator's springs. This allows matching of the Coriolis sensitive rocking modal frequencies to be improved from the native 0.4% to an average tuned frequency split of 0.02%. In separate tests, electrostatic tuning in the 8-electrode design has demonstrated the ability to match frequency-splits to within 10mHz, thus ensuring full degeneracy in even a very high Q device. In addition, a newly selected ceramic package-substrate has improved the device's dampening loses such that a mean Q of 28,000 was achieved in the six gyroscope tested. These Q's were measured via the ring-down time method. The improved fabrication development and other modifications described have led to the JPL's MEMS gyroscope achieving an average bias instability (Allan variance 1/f floor estimate) of 11degree/hr with best in the group being 2degree/hr. In an independent test, Honeywell Inc., reported one of our MEMS gyroscopes as achieving 1degree/hr bias instability flicker floor estimate measured at constant temperature. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Bae, SY (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 5 TC 11 Z9 12 U1 1 U2 7 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4518-5 J9 P SOC PHOTO-OPT INS PY 2002 VL 4755 BP 316 EP 324 DI 10.1117/12.462826 PG 9 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BU77X UT WOS:000176995300037 ER PT S AU George, T AF George, T BE Courtois, B Karam, JM Markus, KW Michel, B Mukherjee, T Walker, JA TI MEMS/NEMS development for space applications at NASA/JPL SO DESIGN, TEST, INTEGRATION, AND PACKAGING OF MEMS/MOEMS 2002 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Design, Test, Integration, and Packaging of MEMS/MOEMS 2002 CY MAY 06-08, 2002 CL CANNES, FRANCE SP CNRS, INPG, UJF, IEEE, IEEE Comp Soc, Test Technol Tech Council, IEEE CPMT, SPIE, IEEE Circuits & Syst Soc DE MEMS; NEMS; space; NASA; JPL; inertial guidance; micro-propulsion; micro-instruments; TRL; PICOSAT AB This paper presents an overview of the current technology development activities of the MEMS Technology Group at JPL. The group, in collaboration with other research groups at JPL and outside institutions, pursues the development of a wide range of MEMS/NEMS technologies that are primarily applicable to NASA's needs in the area of robotic planetary exploration. The broad classes of technologies being developed include inertial guidance devices, micro-propulsion devices, adaptive optics for telescope applications, micro-instruments and nano-mechanical resonator devices. End-to-end prototype development of these MEMS/NEMS technologies is conducted at JPL's state-of-the-art Microdevices Laboratory. The group is also pursuing the establishment of a rapid, space-testing program in collaboration with the Aerospace Corporation, in an effort to overcome the traditional barriers to the insertion of new technologies into space missions. C1 CALTECH, Jet Prop Lab, In Situ Technol & Expt SYst Sect, MEMS Technol Grp, Pasadena, CA 91109 USA. RP George, T (reprint author), CALTECH, Jet Prop Lab, In Situ Technol & Expt SYst Sect, MEMS Technol Grp, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 28 TC 8 Z9 8 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 0-8194-4518-5 J9 P SOC PHOTO-OPT INS PY 2002 VL 4755 BP 556 EP 567 DI 10.1117/12.462856 PG 12 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BU77X UT WOS:000176995300064 ER PT S AU Burl, MC Sisk, BC Vaid, TP Lewis, NS AF Burl, MC Sisk, BC Vaid, TP Lewis, NS BE Broach, JT Harmon, RS Dobeck, GJ TI Classification performance of carbon black-polymer composite vapor detector arrays as a function of array size and detector composition SO DETECTION AND REMEDIATION TECHNOLOGIES FOR MINES AND MINELIKE TARGETS VII, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Detection and Remediation Technologies for Mines and Minelike Targets VII CY APR 01-05, 2002 CL ORLANDO, FL SP SPIE DE vapor detectors; detector array size ID SENSOR ARRAYS; PATTERN-RECOGNITION; ELECTRONIC NOSE; ORGANIC VAPORS; MIXTURES; DISCRIMINATION; CHEMIRESISTORS; RESPONSES; TASKS AB The vapor classification performance of arrays of conducting polymer composite vapor detectors has been evaluated as a function of the number and type of detectors in an array. Quantitative performance comparisons were facilitated by challenging a collection of detector arrays with vapor discrimination tasks that were sufficiently difficult that at least some of the arrays did not exhibit perfect classification ability for all of the tasks of interest. For nearly all of the discrimination tasks investigated in this work, classification performance either increased or did not significantly decrease as the number of chemically different detectors in the array increased. Any given subset of the full array of detectors, selected because it yielded the best classification performance at a given array size for one particular task, was invariably outperformed by a different subset of detectors, and by the entire array, when used in at least one other vapor discrimination task. Arrays of detectors were nevertheless identified that yielded robust discrimination performance between compositionally close mixtures of 1-propanol and 2-propanol, n-hexane and n-heptane, and meta-xylene and para-xylene, attesting to the excellent analyte classification performance that can be obtained through the use of such semi-selective vapor detector arrays. C1 Jet Prop Lab, Pasadena, CA 91125 USA. RP Burl, MC (reprint author), Jet Prop Lab, 4800 Oak Grove Blvd, Pasadena, CA 91125 USA. 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 0-8194-4492-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4742 BP 520 EP 531 DI 10.1117/12.479125 PN 1&2 PG 12 WC Acoustics; Remote Sensing; Optics; Imaging Science & Photographic Technology SC Acoustics; Remote Sensing; Optics; Imaging Science & Photographic Technology GA BV54P UT WOS:000179321200051 ER PT S AU Wilson, DW Gogna, PK Chacon, RJ Muller, RE Fourguette, D Modarress, D Taugwalder, F Svitek, P Gharib, M AF Wilson, DW Gogna, PK Chacon, RJ Muller, RE Fourguette, D Modarress, D Taugwalder, F Svitek, P Gharib, M BE Magnusson, R TI Diffractive optics for particle velocimetry and sizing SO DIFFRACTIVE OPTICS AND MICRO-OPTICS, PROCEEDINGS VOLUME SE OSA TRENDS IN OPTICS AND PHOTONICS LA English DT Proceedings Paper CT 6th Topical Meeting on Diffractive Optics and Micro-Optics CY JUN 03-06, 2002 CL Tucson, AZ AB Beam-shaping diffractive optical elements are used to create structured light patterns in fluid flows. Particle scattering results in detected signals that can be used to determine the particle velocity and size. (c) 2002 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wilson, DW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 302-231, Pasadena, CA 91109 USA. NR 6 TC 1 Z9 1 U1 0 U2 1 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-5695 BN 1-55752-710-5 J9 OSA TRENDS OPT PHOTO PY 2002 VL 75 BP 11 EP 13 PG 3 WC Optics SC Optics GA BCU28 UT WOS:000231245800004 ER PT S AU Rajulu, SL Gonzales, LJ AF Rajulu, SL Gonzales, LJ GP VDI VDI TI Dynamic strength correlations SO DIGITAL HUMAN MODELING CONFERENCE SE VDI BERICHTE LA English DT Proceedings Paper CT Digital Human Modeling Conference (DHMC) CY JUN 18-22, 2001 CL MUNICH, GERMANY AB Computer simulations of actual human-work interface interactions, once developed, are less expensive and easier to modify than conducting the actual tests. Due to the successful applications of these virtual human models, efforts are under way to develop such models for generic applications. Unfortunately, there are important issues that need to be addressed before developing such generic models. The purpose of this paper is to address these issues by discussing the analysis of a large sample of dynamic strength of multiple joints. A poor correlation was observed between joint strengths in subjects who fell between the 25(th) and 75(th) percentile range. Virtual human modeling may thus be most accurate in predicting an individual's strength capabilities when he or she is either clearly weak or clearly strong. C1 NASA, Lyndon B Johnson Space Ctr, Anthropometry & Biomech FAcil, Human Factors & Habitabil Off, Houston, TX 77058 USA. RP Rajulu, SL (reprint author), NASA, Lyndon B Johnson Space Ctr, Anthropometry & Biomech FAcil, Human Factors & Habitabil Off, Bld 15,Rm 240B,MC-SF,2101 NASA Rd 1, Houston, TX 77058 USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU V D I-V D E - VERLAG GMBH PI DUSSELDORF PA PO BOX 10 11 39, W-40002 DUSSELDORF, GERMANY SN 0083-5560 BN 3-18-091675-3 J9 VDI BERICHT PY 2002 VL 1675 BP 243 EP 254 PG 12 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Engineering, Manufacturing; Ergonomics SC Computer Science; Engineering GA BU97X UT WOS:000177551900020 ER PT S AU Gore, BF AF Gore, BF GP VDI VDI TI An emergent behavior model of complex human-system performance: An aviation surface-related application SO DIGITAL HUMAN MODELING CONFERENCE SE VDI BERICHTE LA English DT Proceedings Paper CT Digital Human Modeling Conference (DHMC) CY JUN 18-22, 2001 CL MUNICH, GERMANY AB Advanced technologies can have powerful mitigating effects on human error. However, if the user is not adequately considered during the technological development, unforeseen effects on human performance and system vulnerabilities emerge. It is important therefore to be able to quantify and predict precursor events that impact system safety. One enabling methodology for human-system quantification is termed the integrated human performance model. This paper will demonstrate that performance modifiers shown by human-in-the-loop (HITL) simulation data were used as the basis for the predictive, emergent human performance modeling tool Air Man-machine Integrated Design and Analysis System (Air MIDAS) in generating human-system performance predictions. The Air MIDAS software tool demonstrated an agent s sensitivity to a simulated environment through successfully creating emergent behavior. C1 San Jose State Univ, NASA, Ames Res Ctr, San Jose, CA 95192 USA. RP Gore, BF (reprint author), San Jose State Univ, NASA, Ames Res Ctr, San Jose, CA 95192 USA. NR 19 TC 1 Z9 1 U1 1 U2 1 PU V D I-V D E - VERLAG GMBH PI DUSSELDORF PA PO BOX 10 11 39, W-40002 DUSSELDORF, GERMANY SN 0083-5560 BN 3-18-091675-3 J9 VDI BERICHT PY 2002 VL 1675 BP 313 EP 328 PG 16 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Engineering, Manufacturing; Ergonomics SC Computer Science; Engineering GA BU97X UT WOS:000177551900025 ER PT S AU Diskin, GS Podolske, JR Sachse, GW Slate, TA AF Diskin, GS Podolske, JR Sachse, GW Slate, TA BE Fried, A TI Open-path airborne tunable diode laser hygrometer SO DIODE LASERS AND APPLICATIONS IN ATMOSPHERIC SENSING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Diode Lasers and Applications in Atmospheric Sensing CY JUL 10-11, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ Coll Sci, Washington State Univ Coll Engn, Washington State Univ Coll Architecture, Washington Technol Ctr, Univ Washington Coll Engn, Univ Washington Ctr Nanotechnol DE diode lasers; water vapor; spectroscopy; aircraft measurements AB An instrument has been developed for the measurement of water vapor in the troposphere and lower stratosphere. This instrument, dubbed the NASA Langley/Ames Diode Laser Hygrometer (DLH), has been flown on 10 missions aboard NASA's DC-8 aircraft. The DLH utilizes an open-path, double-pass configuration, where the path is defined on one end by a laser transceiver mounted on the interior of a modified window panel, and on the other by a panel of retroreflecting material mounted on the DC-8's outboard engine nacelle. The DLH operates on one of two spectral absorption lines in the 1.4 mum spectral region, in a wavelength-modulated (WM) mode, with the laser locked to the center of the absorption line encountered in a reference cell. The spectral line used is determined by the local conditions - a weak line is used at low altitudes and a stronger one at high altitudes - and is changed at various times during a flight by the operator. Signal detection is accomplished by demodulating the return signal at twice the driving frequency (2F detection). The returned laser power (DC) is also measured. The DLH is calibrated in the laboratory at various combinations of pressure and water vapor density. From the calibration data and a multiparameter spectral model, a set of coefficients is developed, and these coefficients are used to convert the measured 2F/DC ratio, along with local temperature and pressure (which are measured by separate instruments aboard the aircraft), to water vapor mixing ratio. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Diskin, GS (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 4 TC 48 Z9 48 U1 2 U2 6 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4585-1 J9 P SOC PHOTO-OPT INS PY 2002 VL 4817 BP 196 EP 204 DI 10.1117/12.453736 PG 9 WC Remote Sensing; Optics; Physics, Applied SC Remote Sensing; Optics; Physics GA BV36S UT WOS:000178711700021 ER PT S AU Sachse, G Diskin, G Slate, T Tucker, G Hickman, J Podolske, J Kelly, M AF Sachse, G Diskin, G Slate, T Tucker, G Hickman, J Podolske, J Kelly, M BE Fried, A TI Diode laser analysis of the sealed enclosures of the Charters of Freedom SO DIODE LASERS AND APPLICATIONS IN ATMOSPHERIC SENSING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Diode Lasers and Applications in Atmospheric Sensing CY JUL 10-11, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ Coll Sci, Washington State Univ Coll Engn, Washington State Univ Coll Architecture, Washington Technol Ctr, Univ Washington Coll Engn, Univ Washington Ctr Nanotechnol DE diode laser; Charters of Freedom; water vapor; helium AB We report the application of diode laser spectroscopy to the non-intrusive measurement of water vapor and helium content within the enclosures of the Charters of Freedom that were sealed by NBS approximately 50 years ago. The instrument was adapted from the Diode Laser Hygrometer, developed through the NASA Global Tropospheric Experiment program to make open-path water vapor measurements outside the NASA DC-8 research aircraft. Operating in the 1.4-micron wavelength region, laser wavelength scans of water vapor absorption lines enabled the determination of the moisture level and the amount of helium relative to air within the Charters enclosures (an indicator of enclosure leaks). These measurements revealed that at least five of the seven Charters of Freedom enclosures had not leaked since they were sealed approximately 50 years ago. The measurements also revealed that water vapor within these enclosures ranged from 29 to 55% greater than anticipated. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Sachse, G (reprint author), NASA, Langley Res Ctr, MS 468, Hampton, VA 23681 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4585-1 J9 P SOC PHOTO-OPT INS PY 2002 VL 4817 BP 205 EP 215 DI 10.1117/12.453764 PG 11 WC Remote Sensing; Optics; Physics, Applied SC Remote Sensing; Optics; Physics GA BV36S UT WOS:000178711700022 ER PT S AU Biswas, R Frumkin, M Smith, W Van der Wijngaart, R AF Biswas, R Frumkin, M Smith, W Van der Wijngaart, R BE Das, SK Bhattacharya, S TI Tools and techniques for measuring and improving grid performance SO DISTRIBUTED COMPUTING, PROCEEDINGS: MOBILE AND WIRELESS COMPUTING SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 4th International Workshop on Distributed Computing CY DEC 28-31, 2002 CL CALCUTTA, INDIA AB To better utilize its vast collection of heterogeneous resources that are geographically distributed across the United States, NASA is constructing a computational grid called the Information Power Grid (IPG). This paper describes various tools and techniques that we are developing to measure and improve the performance of a broad class of NASA applications when run on the IPG. In particular, we are investigating the areas of grid benchmarking, grid monitoring, user-level application scheduling, and decentralized system-level scheduling. C1 NASA, Ames Res Ctr, NAS Div, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Comp Sci Corp, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, NAS Div, Moffett Field, CA 94035 USA. NR 14 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 3-540-00355-X J9 LECT NOTES COMPUT SC PY 2002 VL 2571 BP 45 EP 54 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BW34W UT WOS:000181655000005 ER PT B AU Grogan, K Dermott, SF AF Grogan, K Dermott, SF BE Green, SF Williams, IP McDonnell, JAM McBride, N TI The size-frequency distribution of zodiacal dust band material SO DUST IN THE SOLAR SYSTEM AND OTHER PLANETARY SYSTEMS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT IAU Colloquium 181 on Dust in the Solar System and Other Planetary Systems CY APR 04-10, 2000 CL UNIV KENT, CANTERBURY, ENGLAND SP IAU, COSPAR HO UNIV KENT ID SOLAR-SYSTEM; ORIGIN AB Recent observations of the size-frequency distribution of zodiacal cloud particles obtained from the Long Duration Exposure Facility (LDEF) cratering record reveal a significant large particle population (100 micron diameter or greater) near 1 AU. While the Solar System Dynamics group at the University of Florida has had much success in modeling the zodiacal cloud from a dynamical standpoint, our work has been limited by the fact that only small particles (25 micron diameter and smaller) have been considered. This was due to the prohibitively large amount of computing power required to numerically analyze the dynamical history of larger particles. The recent availability of cheap, fast processors has finally made this work possible. For the first time, we are able to produce models for the components of the zodiacal cloud that include a size-frequency distribution able to match IR observations in multiple wavebands. An analysis of the Solar System dust bands yields a size-frequency distribution in agreement with LDEF, in that large particles are shown to dominate. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Grogan, K (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND BN 0-08-044194-7 J9 COSPAR COLL PY 2002 VL 15 BP 136 EP 139 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW07W UT WOS:000180813900020 ER PT B AU Hanner, MS AF Hanner, MS BE Green, SF Williams, IP McDonnell, JAM McBride, N TI Comet dust: The view after Hale-Bopp SO DUST IN THE SOLAR SYSTEM AND OTHER PLANETARY SYSTEMS SE COSPAR COLLOQUIA SERIES LA English DT Proceedings Paper CT IAU Colloquium 181 on Dust in the Solar System and Other Planetary Systems CY APR 04-10, 2000 CL UNIV KENT, CANTERBURY, ENGLAND SP IAU, COSPAR HO UNIV KENT ID HALLEY MONITORING PROGRAM; C/1995 O1; INTERPLANETARY DUST; OPTICAL-PROPERTIES; LIGHT-SCATTERING; INNER COMA; AGGREGATE PARTICLES; INTERSTELLAR DUST; AIRBORNE SPECTROPHOTOMETRY; POLARIMETRIC OBSERVATIONS AB Extensive observations of comet Hale-Bopp from the ground and space have considerably expanded our knowledge of cometary dust. There is a clear correlation of stronger polarization, higher albedo, more prominent infrared silicate features, and higher infrared color temperature. The composition of the silicates includes both olivine and pyroxenes, in both crystalline and glassy or amorphous form, similar to the chondritic aggregate interplanetary dust particles. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hanner, MS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 80 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 BN 0-08-044194-7 J9 COSPAR COLL PY 2002 VL 15 BP 239 EP 254 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BW07W UT WOS:000180813900035 ER PT S AU Erlandson, RE Meng, CI Zetzer, JI Kiselev, Y Gavrilov, BG Stenbaek-Nielsen, H Lynch, KA Pfaff, RF Swaminathan, PK Kumar, CK Dogra, VK Stoyanov, BJ Delamere, PA Bounds, S Gatsonis, NA AF Erlandson, RE Meng, CI Zetzer, JI Kiselev, Y Gavrilov, BG Stenbaek-Nielsen, H Lynch, KA Pfaff, RF Swaminathan, PK Kumar, CK Dogra, VK Stoyanov, BJ Delamere, PA Bounds, S Gatsonis, NA BE Raitt, WJ Shukla, PK TI The Apex North Star Experiment: Observations of high-speed plasma jets injected perpendicular to the magnetic field SO DUSTY PLASMAS AND ACTIVE EXPERIMENTS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT D4 1-B1 3 Symposium of COSPAR Scientific Commission D held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP Int Union Radio Sci, Comm Space Res ID IONOSPHERE AB Initial results from the Active Plasma EXperiment North Star experiment are presented. The North Star active experiment included two separate plasma jet injections, both perpendicular to the Earth's magnetic field. The objective of the experiment is to investigate the interaction of high-speed (7-40 km/s) plasma jets with the ionospheric plasma and the coupling to the magnetosphere and lower ionosphere. The plasma jets were produced using an Explosive Type Generator device. This device is a shaped-charge device that vaporizes porous aluminum inside the generator and forces the vaporized products out of a nozzle, resulting in the production of a high-speed, partially ionized aluminum plasma jet. Instrumentation on three different payloads was used to obtain multi-point observations of the plasma jet properties, optical radiation from the jets, and ionospheric perturbations. Imagery, high-speed photometry, and spectrographic imagery using ground- and space-based sensors were used to monitor the dynamics and spectral content of the plasma jet. This paper describes the experiment and summarizes the initial results from the North Star experiment. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Inst Dynam Geospheres, Moscow 117979, Russia. Univ Alaska, Inst Geophys, Fairbanks, AK 99775 USA. Univ New Hampshire, Durham, NH 03824 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Atmospher & Environm Res Inc, Cambridge, MA 02139 USA. Univ Iowa, Iowa City, IA 52242 USA. Worcester Polytech Inst, Worcester, MA 01609 USA. RP Erlandson, RE (reprint author), Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. RI Swaminathan, Pazhayannur/I-3609-2012; Pfaff, Robert/F-5703-2012; Erlandson, Robert/G-2767-2015 OI Swaminathan, Pazhayannur/0000-0003-1272-9694; Pfaff, Robert/0000-0002-4881-9715; NR 11 TC 8 Z9 8 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 9 BP 1317 EP 1326 AR PII S0273-1177(02)00183-7 DI 10.1016/S0273-1177(02)00183-7 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BU90A UT WOS:000177342800011 ER PT J AU Sud, YC Walker, GK Mehta, VM Lau, WKM AF Sud, Y. C. Walker, G. K. Mehta, V. M. Lau, William K. -M. TI Relative Importance of the Annual Cycles of Sea Surface Temperature and Solar Irradiance for Tropical Circulation and Precipitation: A Climate Model Simulation Study SO EARTH INTERACTIONS LA English DT Article DE General Circulation; Radiative processes; Ocean/atmosphere interactions; Theoretical modeling AB A recent version of the Goddard Earth Observing System GCM which contains several upgrades to the model's prognostic cloud physics and microphysics as well as snow and ice hydrology, was used to isolate the influences of the annual cycles of solar irradiation and sea surface temperatures (SSTs) on the annual cycle of circulation and precipitation. Four 50-month-long integrations were produced with the GCM. The first integration, called the control simulation, C, was forced with daily interpolated SSTs from a 30-yr climatology of monthly SST data. In this simulation both SSTs and incoming solar irradiance had their normally prescribed annual cycles. The next two companion simulations were called S1, which used annual mean prescribed incoming solar irradiation, and S2, which used annual mean prescribed SST; everything else was kept similar to C in these two simulations. In the fourth simulation, called S3, both SSTs and incoming solar irradiation at the top of the atmosphere were prescribed to always maintain their annual mean values. This constraint virtually eliminated all the annual cycle forcings in the simulation. Nevertheless, all simulations had the diurnal cycle of solar irradiation. An intercomparison of these simulations revealed the following. 1. The poleward excursions of the zonal mean ITCZ and precipitation are strongly modulated by the annual cycles of SSTs and solar forcings. For the majority of the regions, particularly in the subtropical monsoonal regions, for example, India, Southeast Asia, and Australia, the influence of the annual cycle of solar heating was found to be stronger than that of the annual cycle of SSTs. 2. The precipitation and circulation patterns over the Kuroshio Current region off the east coast of Asia were most affected by the SSTs and were strongly linked to the annual cycle(s) of local SSTs. 3. The annual mode of precipitation over Amazonia had two regimes: an equatorial regime with a maximum in the month of March in S1 and a corresponding maximum in the month of January in S2. Control C, which had both annual cycles, produced both the "month of January'' and "month of March'' modes of precipitation. This shows how solar and SST annual cycles jointly influence the simulated annual modes of precipitation over South America. Surprisingly, the annual modes of precipitation in C were roughly equal to the sum of the annual modes of precipitation of S1 and S2. 4. Precipitation over Sahelian Africa is significantly reduced in simulations lacking the annual cycle of solar irradiation. The opposite kind of influence of the annual cycle of solar radiation was noted in almost all other monsoonal regions: India, Southeast Asia, as well as Australia. The only exception is the continental United States, where the solar annual cycle showed only a relatively minor influence on the annual mode of precipitation. 5. The simulated tropical intraseasonal oscillations (TIOs) were reasonably robust in each of the four simulations. This suggests that TIOs are an outcome of the internal dynamics of the atmosphere that may in turn be forced by the interactions among the physical and dynamical processes of the atmosphere. This conclusion is consistent with the robustness of the observed TIO modes throughout the annual cycle and the significant dependence of TIOs on physical parameterization(s). C1 [Sud, Y. C.; Walker, G. K.; Mehta, V. M.; Lau, William K. -M.] NASA GSFC, Climate & Radiat Branch, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Sud, YC (reprint author), NASA GSFC, Climate & Radiat Branch, Atmospheres Lab, Greenbelt, MD 20771 USA. EM sud@climate.gsfc.nasa.gov RI Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 FU NASA Headquarters; The NASA Oceanography Program FX The funding support of our simulation studies research by NASA Headquarters under the GMAP program helped the participation of GKW. The NASA Oceanography Program supported VM. NR 41 TC 0 Z9 0 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1087-3562 J9 EARTH INTERACT JI Earth Interact. PY 2002 VL 6 PG 32 WC Geosciences, Multidisciplinary SC Geology GA V04NY UT WOS:000207066300002 ER PT J AU Ehrenfreund, P Rodgers, SD Charnley, SB AF Ehrenfreund, P Rodgers, SD Charnley, SB TI Physico-chemistry of comets: Models and laboratory experiments SO EARTH MOON AND PLANETS LA English DT Article; Proceedings Paper CT IAU Colloquium No 186 on Cometary Science after Hale-Bopp CY JAN 21-25, 2002 CL CANARY ISL, SPAIN SP Int Astronom Union DE comet C/1995 O1 Hale-Bopp; comets; laboratory studies; physico-chemsitry ID CLATHRATE-HYDRATE FORMATION; ISO-SWS OBSERVATIONS; OUTER SOLAR NEBULA; C/1999 H1 LEE; HALE-BOPP; WATER-ICE; ASTROPHYSICAL IMPLICATIONS; INTERSTELLAR ICES; MOLECULAR CLOUDS; GRAIN MANTLES AB Until cometary matter can be studied in-situ or cometary samples are brought back to Earth for analysis, theoretical models and laboratory studies remain a crucial tool for revealing the nature of cometary matter. Constraints on the nature of the primordial material available for incorporation into comets and other solar system material comes from analysis of data from space-based and ground-based observatories. The structure of the nuclear ice component, which may have coexisting amorphous/crystalline phases and include clathrates and other trapped guest molecules, strongly influences the cometary outgassing properties. This paper reviews laboratory work on ice and carbonaceous compounds and discusses their significance for cometary chemistry. Special emphasis will be given to studies on the thermal processing of ices and their implications for the structure changes and subsequent release of volatiles. We also describe the preliminary results of a model of nuclear outgassing, and discuss how such models can be used to infer the chemical structure of the nuclear ices. Furthermore, we confront cometary data with the analysis of carbonaceous meteorites. Recent laboratory results on volatile compounds and the macromolecular structure of carbonaceous meteorites allow us to investigate the link of small bodies in the Solar System. Until ROSETTA will land on comet Wirtanen and study directly the nuclear composition, laboratory measurements of ice and refractory analogs will-together with the analysis of meteorites-significantly improve our knowledge on the origin and structure of comets. C1 Leiden Observ, NL-2300 RA Leiden, Netherlands. Leiden Inst Chem, Astrobiol Lab, NL-2300 RA Leiden, Netherlands. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Ehrenfreund, P (reprint author), Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands. RI Charnley, Steven/C-9538-2012 NR 130 TC 4 Z9 5 U1 1 U2 8 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PY 2002 VL 89 IS 1-4 BP 221 EP 246 PG 26 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 622RG UT WOS:000179660300012 ER PT J AU Wooden, DH AF Wooden, DH TI Comet grains: Their IR emission and their relation to ISM grains SO EARTH MOON AND PLANETS LA English DT Article; Proceedings Paper CT IAU Colloquium No 186 on Cometary Science after Hale-Bopp CY JAN 21-25, 2002 CL CANARY ISL, SPAIN SP Int Astronom Union DE amorphous carbon; CPIDPs; crystals; dust; Hale-Bopp; silicates ID INTERPLANETARY DUST PARTICLES; INTERSTELLAR SILICATE MINERALOGY; BOPP C/1995 O1; ANALYTICAL ELECTRON-MICROSCOPE; THIN-FILM ANALYSES; MU-M BAND; HALE-BOPP; ICE ANALOGS; CRYSTALLINE OLIVINE; EVOLVED STARS AB Comets and the chondritic porous interplanetary dust particles (CP IDPs) that they shed in their comae are reservoirs of primitive solar nebula materials. The high porosity and fragility of cometary grains and CP IDPs, and anomalously high deuterium contents of highly fragile, pyroxene-rich Cluster IDPs imply these aggregate particles contain significant abundances of grains from the interstellar medium (ISM). IR spectra of comets (3-40 mum) reveal the presence of a warm (near-IR) featureless emission modeled by amorphous carbon grains. Broad and narrow resonances near 10 and 20 microns are modeled by warm chondritic (50% Fe and 50% Mg) amorphous silicates and cooler Mg-rich crystalline silicate minerals, respectively. Cometary amorphous silicates resonances are well matched by IR spectra of CP IDPs dominated by GEMS (0.1 mum silicate spherules) that are thought to be the interstellar Fe-bearing amorphous silicates produced in AGB stars. Acid-etched ultramicrotomed CP IDP samples, however, show that both the carbon phase ( amorphous and aliphatic) and the Mg-rich amorphous silicate phase in GEMS are not optically absorbing. Rather, it is Fe and FeS nanoparticles embedded in the GEMS that makes the CP IDPs dark. Therefore, CP IDPs suggest significant processing has occurred in the ISM. ISM processing probably includes in He(+) ion bombardment in supernovae shocks. Laboratory experiments show He(+) ion bombardment amorphizes crystalline silicates, increases porosity, and reduces Fe into nanoparticles. Cometary crystalline silicate resonances are well matched by IR spectra of laboratory submicron Mg-rich olivine crystals and pyroxene crystals. Discovery of a Mg-pure olivine crystal in a Cluster IDP with isotopically anomalous oxygen indicates that a small fraction of crystalline silicates may have survived their journey from AGB stars through the ISM to the early solar nebula. The ISM does not have enough crystalline silicates (<5%), however, to account for the deduced abundance of crystalline silicates in comet dust. An insufficient source of ISM Mg-rich crystals leads to the inference that most Mg-rich crystals in comets are primitive grains processed in the early solar nebula prior to their incorporation into comets. Mg-rich crystals may condense in the hot (similar to 1450 K), inner zones of the early solar nebula and then travel large radial distances out to the comet-forming zone. On the other hand, Mg-rich silicate crystals may be ISM amorphous silicates annealed at similar to 1000 K and radially distributed out to the comet-forming zone or annealed in nebular shocks at similar to 5-10 AU. Determining the relative abundance of amorphous and crystalline silicates in comets probes the relative contributions of ISM grains and primitive grains to small, icy bodies in the solar system. The life cycle of dust from its stardust origins through the ISM to its incorporation into comets is discussed. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Wooden, DH (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. EM wooden@delphinus.arc.nasa.gov NR 145 TC 45 Z9 45 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PY 2002 VL 89 IS 1-4 BP 247 EP 287 PG 41 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 622RG UT WOS:000179660300013 ER PT J AU Cochran, A Veverka, J Bell, J Belton, M Benkhoff, J Cheng, A Clark, B Feldman, P Kissel, J Mahaffy, P Malin, M Murchie, S Neimann, H Owen, T Robinson, M Schwehm, G Squyres, S Thomas, P Whipple, F Yeomans, D AF Cochran, A Veverka, J Bell, J Belton, M Benkhoff, J Cheng, A Clark, B Feldman, P Kissel, J Mahaffy, P Malin, M Murchie, S Neimann, H Owen, T Robinson, M Schwehm, G Squyres, S Thomas, P Whipple, F Yeomans, D TI The COmet Nucleus TOUR (CONTOUR) - A NASA discovery mission SO EARTH MOON AND PLANETS LA English DT Article; Proceedings Paper CT IAU Colloquium No 186 on Cometary Science after Hale-Bopp CY JAN 21-25, 2002 CL CANARY ISL, SPAIN SP Int Astronom Union DE comets; missions AB In 1997, the COmet Nucleus TOUR ( CONTOUR) was selected by NASA for a new start as part of the Discovery line. In this paper, we review the status of the mission, the mission timeline and the instruments to be flown. Detail is given of the science goals and how they are to be accomplished. C1 Univ Texas, Dept Astron, Austin, TX 78712 USA. Cornell Univ, Ithaca, NY 14853 USA. Belton Space Explorat Initiat LLC, Tucson, AZ 85716 USA. Inst Space Sensor & Planetary Explorat, D-12489 Berlin, Germany. Johns Hopkins APL, Laurel, MD 20723 USA. Lockheed Martin, Denver, CO 80201 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. MPI Astrophys, D-85741 Garching, Germany. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Malin Space Sci, San Diego, CA 92191 USA. Astron Inst, Honolulu, HI 96822 USA. Northwestern Univ Geol Sco, Evanston, IL 60208 USA. European Space Agcy, Dept Space Sci, SO Div, Estec, NL-2200 AG Noordwijk, Netherlands. Cornell Univ, Ithaca, NY 14853 USA. Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cochran, A (reprint author), Univ Texas, Dept Astron, RLM 15308, Austin, TX 78712 USA. RI Mahaffy, Paul/E-4609-2012; Murchie, Scott/E-8030-2015 OI Murchie, Scott/0000-0002-1616-8751 NR 0 TC 1 Z9 1 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PY 2002 VL 89 IS 1-4 BP 289 EP 300 PG 12 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 622RG UT WOS:000179660300014 ER PT J AU Boice, DC Soderblom, LA Britt, DT Brown, RH Sandel, BR Yelle, RV Buratti, BJ Hicks, MD Nelson, RM Rayman, MD Oberst, J Thomas, N AF Boice, DC Soderblom, LA Britt, DT Brown, RH Sandel, BR Yelle, RV Buratti, BJ Hicks, MD Nelson, RM Rayman, MD Oberst, J Thomas, N TI The Deep Space 1 encounter with comet 19P/Borrelly SO EARTH MOON AND PLANETS LA English DT Article; Proceedings Paper CT IAU Colloquium No 186 on Cometary Science after Hale-Bopp CY JAN 21-25, 2002 CL CANARY ISL, SPAIN SP Int Astronom Union DE coma; comets; Deep Space 1; nucleus; spacecraft exploration ID NUCLEUS; HALLEY; PHOTOMETRY; MISSION; DUST; 253-MATHILDE; MOLECULES AB NASA's Deep Space 1 (DS1) spacecraft successfully encountered comet 19P/Borrelly near perihelion and the Miniature Integrated Camera and Spectrometer (MICAS) imaging system onboard DS1 returned the first high-resolution images of a Jupiter-family comet nucleus and surrounding environment. The images span solar phase angles from 88degrees to 52degrees, providing stereoscopic coverage of the dust coma and nucleus. Numerous surface features are revealed on the 8-km long nucleus in the highest resolution images (47-58 m/pixel). A smooth, broad basin containing brighter regions and mesa-like structures is present in the central part of the nucleus that seems to be the source of jet-like dust features seen in the coma. High ridges seen along the jagged terminator lead to rugged terrain on both ends of the nucleus containing dark patches and smaller series of parallel grooves. No evidence of impact craters with diameters larger than about 200-m are present, indicating a young and active surface. The nucleus is very dark with albedo variations from 0.007 to 0.035. Short-wavelength, infrared spectra from 1.3 to 2.6 mum revealed a hot, dry surface consistent with less than about 10% actively sublimating. Two types of dust features are seen: broad fans and highly collimated "jets" in the sunward hemisphere that can be traced to the surface. The source region of the main jet feature, which resolved into at least three smaller "jets" near the surface, is consistent with an area around the rotation pole that is constantly illuminated by the sun during the encounter. Within a few nuclear radii, entrained dust is rapidly accelerated and fragmented and geometrical effects caused from extended source regions are present, as evidenced in radial intensity profiles centered on the jet features that show an increase in source strength with increasing cometocentric distance. Asymmetries in the dust from dayside to nightside are pronounced and may show evidence of lateral flow transporting dust to structures observed in the nightside coma. A summary of the initial results of the Deep Space 1 Mission is provided, highlighting the new knowledge that has been gained thus far. C1 SW Res Inst, Space Sci & Engn Div, San Antonio, TX 78228 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Univ Tennessee, Dept Geol Sci, Knoxville, TN 37996 USA. Univ Arizona, Dept Planetary Sci, Lunar & Planetary Lab, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. DLR, Inst Space Sensor Technol & Planetary Explorat, D-12489 Berlin, Germany. Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. RP Boice, DC (reprint author), SW Res Inst, Space Sci & Engn Div, PO Drawer 28510, San Antonio, TX 78228 USA. NR 43 TC 14 Z9 14 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PY 2002 VL 89 IS 1-4 BP 301 EP 324 PG 24 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 622RG UT WOS:000179660300015 ER PT S AU Pagano, TS Elliot, DA Gunson, MR Aumann, HH Gaiser, SL Dehghani, N Overoye, K AF Pagano, TS Elliot, DA Gunson, MR Aumann, HH Gaiser, SL Dehghani, N Overoye, K BE Barnes, WL TI Operational readiness for the Atmospheric Infrared Sounder (AIRS) on the Earth Observing System Aqua spacecraft SO EARTH OBSERVING SYSTEMS VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing Systems VI CY AUG 01-03, 2001 CL SAN DIEGO, CA SP SPIE, NASA Langley Res Ctr DE earth science; EOS; Aqua; AIRS; sounder; calibration; operations AB The Atmospheric Infrared Sounder project will measure global atmospheric water vapor and temperature with unprecedented resolution and accuracy. AIRS is an infrared instrument covering 3.7-15.4 microns in 2378 IR channels. This paper describes the AIRS mission and science objectives, the instrument design and operation, the calibration plan, the in-flight operational scenario and the Science Processing System. All aspects of the program are addressed here to demonstrate that the AIRS program is ready to transition to the flight segment of the program. The AIRS instrument meets the majority of instrument design requirements established in order to meet the scientific objectives. A well-defined operational approach has been established, and a sound calibration plan has been developed to ensure optimal performance throughout the life of the mission. C1 CALTECH, Jet Propuls Lab, Pasadena, CA 91109 USA. RP Pagano, TS (reprint author), CALTECH, Jet Propuls Lab, MS 233-300,4800 Oak Grove Dr, Pasadena, CA 91109 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 0-8194-4197-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4483 BP 35 EP 43 AR UNSP 4483-04 DI 10.1117/12.453468 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Remote Sensing SC Engineering; Instruments & Instrumentation; Remote Sensing GA BU15G UT WOS:000175162300004 ER PT S AU Sorensen, IJ Sanchez, MC Priestley, KJ Mahan, JR AF Sorensen, IJ Sanchez, MC Priestley, KJ Mahan, JR BE Barnes, WL TI Theoretical sensitivity of CERES measured radiances to uncertainties in calibration sources and the spectral response of the instrument SO EARTH OBSERVING SYSTEMS VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing Systems VI CY AUG 01-03, 2001 CL SAN DIEGO, CA SP SPIE, NASA Langley Res Ctr ID EARTH AB The objective of the current research is to study the theoretical uncertainty of the CERES ERBE-like level 1 and level 2 instantaneous filtered and unfiltered radiance data products. The instrument views incident radiation from an Earth scene, which is then focused on a blackened thermistor bolometer, where it is converted to an electrical output. The measured digital counts are converted to a filtered radiance by means of instrument calibration coefficients. The filtered radiance is then converted to an unfiltered radiance with an algorithm that utilizes the instrument's spectral response function. Uncertainties in the calibration sources and the spectral response function of the instrument can negatively affect the quality of the final data products. A statistical study of the data products' sensitivity to various instrument and calibration parameters is performed using high-fidelity first-principle numerical models of the CERES instrument. Once the key parameters are identified, fidelity intervals of the data products are calculated using nominal parameter values and uncertainty distributions. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Sorensen, IJ (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4197-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4483 BP 53 EP 63 AR UNSP 4483-06 DI 10.1117/12.453472 PG 11 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Remote Sensing SC Engineering; Instruments & Instrumentation; Remote Sensing GA BU15G UT WOS:000175162300006 ER PT S AU Waluschka, E Esposito, J Sun, JQ Wang, XD Xiong, XX AF Waluschka, E Esposito, J Sun, JQ Wang, XD Xiong, XX BE Barnes, WL TI MODIS solar diffuser - Modeled and actual performance SO EARTH OBSERVING SYSTEMS VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing Systems VI CY AUG 01-03, 2001 CL SAN DIEGO, CA SP SPIE, NASA Langley Res Ctr DE Terra; MODIS; solar; calibration; simulation AB The MODIS instrument's solar diffuser is used in its radiometric calibration for the reflective solar bands (VIS, NIR, and SWIR) ranging from 0.41 to 2.1 micron. The sun illuminates the solar diffuser either directly or through an attenuation screen. The attenuation screen consists of a regular array of pin holes. The attenuated illumination pattern on the solar diffuser is not uniform, but consists of a multitude of pin-hole images of the sun. This non-uniform illumination produces small, but noticeable radiometric effects. A description of the computer model used to simulate the effects of the attenuation screen is given and the predictions of the model are compared with actual, on-orbit, calibration measurements. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Waluschka, E (reprint author), NASA, Goddard Space Flight Ctr, 551-0, Greenbelt, MD 20771 USA. RI Xiong, Xiaoxiong (Jack)/J-9869-2012 NR 1 TC 5 Z9 5 U1 1 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 0-8194-4197-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4483 BP 146 EP 155 AR UNSP 4483-17 DI 10.1117/12.453448 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Remote Sensing SC Engineering; Instruments & Instrumentation; Remote Sensing GA BU15G UT WOS:000175162300015 ER PT S AU Bruegge, CJ Chrien, NL Ando, R Chafin, B AF Bruegge, CJ Chrien, NL Ando, R Chafin, B BE Barnes, WL TI Ancillary Radiometric Product (ARP) usage in the EOS/MISR level 1B radiance product generation SO EARTH OBSERVING SYSTEMS VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing Systems VI CY AUG 01-03, 2001 CL SAN DIEGO, CA SP SPIE, NASA Langley Res Ctr DE radiometric calibration; EOS; MISR; DAAC; ARP ID IMAGING SPECTRORADIOMETER MISR; CALIBRATION AB The radiometric response of the EOS-AM1 Multi-angle Imaging SpectroRadiometer (MISR) is to be measured throughout the six-year mission. To accomplish this task, MISR makes routine use of an on-board calibrator, aircraft flyovers, field exercises, and comparisons to other on-orbit and aircraft sensors. Analyses of these data results in a deliverable called the Ancillary Radiometric Product (ARP). This file contains the radiometric response parameters for all nine cameras and four spectral bands. The instrument on-board calibrator is exercised bi-monthly, and the next ARP time-series file is created shortly thereafter. This file is used in MISR standard product generation to convert the sensor output into a measure of the incident radiance, and is used to process all MISR data acquired in the subsequent two months. Thereafter the process is repeated and the new ARP time-series file is utilized. Due to improvements in the processing algorithms, updates are allowed to the inactive ARP data files. These revisions would be used should a previously generated MISR data product be reordered and reprocessed, as would be the case should an investigator desire to make use of all science software algorithm upgrades. This paper discusses the investigations and algorithm changes that have occurred in the production of the ARP since launch, and discusses changes to the Level I B data that might be expected should data be reprocessed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bruegge, CJ (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 0-8194-4197-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4483 BP 196 EP 202 AR UNSP 4483-23 DI 10.1117/12.453454 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Remote Sensing SC Engineering; Instruments & Instrumentation; Remote Sensing GA BU15G UT WOS:000175162300020 ER PT S AU Smith, GL Peterson, GL Lee, RB Barkstrom, BR AF Smith, GL Peterson, GL Lee, RB Barkstrom, BR BE Barnes, WL TI Optical design of the CERES telescope SO EARTH OBSERVING SYSTEMS VI SE Proceedings of SPIE-The International Society for Optical Engineering LA English DT Proceedings Paper CT Conference on Earth Observing Systems VI CY AUG 01-03, 2001 CL SAN DIEGO, CA SP SPIE, NASA Langley Res Ctr DE optical design; radiometry; Earth Radiation Budget; CERES; TERRA ID ENERGY SYSTEM CERES; THERMISTOR BOLOMETER SENSORS; RADIATION BUDGET EXPERIMENT; RAINFALL MEASURING MISSION; CLOUDS; INSTRUMENT; TRMM AB The Clouds and Earth Radiant Energy System (CERES) instrument was designed to make measurements of solar radiance reflected from the Earth (0.2 - 5.0 microns) and radiance emitted from the Earth (5.0 to 50+ microns) with 1% accuracies. The CERES design evolved from the Earth Radiation Budget Experiment instrument which had similar objectives. The CERES also had a channel to measure radiance in the 8 to 12 micron window emitted by the Earth for studying the effects of water vapor on the Earth's radiation budget. A CERES instrument flew on the Tropical Rainfall Measuring Mission and 2 are operating on the TERRA spacecraft. One instrument will map the geographical distribution of radiation and the other will measure the anisotropy of the radiance field. Two CERES instruments will also fly on the AQUA spacecraft. The design features of the telescope and the rationales are described. These aspects of the instrument should be understood by users of the data for a number of purposes. Each channel has its separate telescope to gather radiation onto its detector, which is a thermistor-bolometer. There is a total channel which measures radiances over the range 0.2 to 50+ microns. The shortwave (0.2-5.0 micron) and window (8-12 micron) channel each have filters to provide the desired band. The emitted radiation is computed as the total minus the shortwave radiance. C1 Virginia Polytech Inst & State Univ, Langley Res Ctr, Hampton, VA 23681 USA. RP Smith, GL (reprint author), Virginia Polytech Inst & State Univ, Langley Res Ctr, MS 420, Hampton, VA 23681 USA. EM g.l.smith@larc.nasa.gov; g.peterson@breault.com; r.b.lee@larc.nasa.gov; b.r.barkstrom@larc.nasa.gov NR 24 TC 1 Z9 1 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4197-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4483 BP 269 EP 278 AR UNSP 4483-32 DI 10.1117/12.453463 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Remote Sensing SC Engineering; Instruments & Instrumentation; Remote Sensing GA BU15G UT WOS:000175162300028 ER PT S AU Moore, M Lowe, D AF Moore, M Lowe, D BE Barnes, WL TI Leveraging open source development in large scale science data management systems SO EARTH OBSERVING SYSTEMS VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing Systems VI CY AUG 01-03, 2001 CL SAN DIEGO, CA SP SPIE, NASA Langley Res Ctr DE open source; science data management systems; software engineering AB When completed, NASA's EOSDIS Core System (ECS) will be the world's largest Earth science data system, managing almost nine petabytes of data and disseminating more than two terabytes each day. The system's original design assumed that all science data archive, processing and dissemination would be done using high performance subsystems with complex distributed object interfaces between them. These interfaces made it difficult for others to extend the system without incurring the prohibitively high costs of supporting this infrastructure. Over the past three years, most of these interfaces have been replaced with greatly simplified script and file-based interfaces. NASA also has encouraged science and Data Center groups to modify and extend the system's core functionality. As these extensions began to emerge, it was apparent that new configuration management and system deployment methods would be needed to leverage each group's extensions across the ECS Data Centers. NASA has adapted several Open Source development techniques to address this need. This paper will describe how the ECS architecture and supporting development methods have evolved to support Open Source development concepts while at the same time satisfying ECS's challenging requirements. It also win describe how these changes have helped lower the system's overall costs and decrease the time it takes for new capabilities to become operational. We plan to build on the success of these initial changes to encourage additional EOSDIS user participation through many new roles: client and portal providers, data providers, algorithm providers, data processing centers, data service providers, distribution centers and data managers. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Moore, M (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4197-X J9 P SOC PHOTO-OPT INS PY 2002 VL 4483 BP 291 EP 300 AR UNSP 4483-38 DI 10.1117/12.453466 PG 10 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Instruments & Instrumentation; Remote Sensing SC Engineering; Instruments & Instrumentation; Remote Sensing GA BU15G UT WOS:000175162300031 ER PT S AU Torres, O Katzberg, SJ AF Torres, O Katzberg, SJ BE Barnes, WL TI Analysis of reflected Global Positioning System (GPS) signals from land for soil moisture determination and topography mapping SO EARTH OBSERVING SYSTEMS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing Systems VII CY JUL 07-10, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol, Univ Washington, Coll Engn & Architecture DE GPS; soil moisture; topography AB GPS signals reflected from the ocean surface have been used in remote sensing applications to determine sea-state and wind speed. Studies show that, with rougher surfaces, GPS signal pulses scatter more, which creates weaker and wider pulses at the receiver. Based on this model, the correlation between soil moisture, topography, and GPS signals was studied using reflections off the ground. The data used for the study were gathered during two flights in 1998 and 2001 around Austin, Texas and Albuquerque, New Mexico and later processed at Langley Research Center. The power of the signals were analyzed and plotted over Digital Elevation Models (DEMs) and Landsat7 images (near- and mid-infrared bands) to interpret the correlation of signal behavior with topography. In addition, the received signal's conduct was correlated with soil moisture data obtained from the Department of Agriculture's Soil Climate Analysis Network (SCAN) sites at Prairie View (Texas) and Adams Ranch (New Mexico). The strengths of the reflected signals were observed larger near known bodies of water and farmlands where soil moisture levels are known to be high. In general, for flat lands, the power of the signals and soil moisture contents appeared to have a close-to-linear relationship. In addition, the received pulses widened when reflected over rapid-changing topography in Texas, but any relationship among these was not perceived in New Mexico. Further studies are needed to obtain a definite relationship among soil moisture and reflected signal strength and to introduce satellite position in the signal-topography study. C1 Univ Texas, Langley Res Ctr, El Paso, TX 79968 USA. RP Torres, O (reprint author), Univ Texas, Langley Res Ctr, El Paso, TX 79968 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4582-7 J9 P SOC PHOTO-OPT INS PY 2002 VL 4814 BP 9 EP 15 DI 10.1117/12.451371 PG 7 WC Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BV51H UT WOS:000179201500002 ER PT S AU Pagano, TS Aumann, HH Broberg, SE Gaiser, SL Hagan, DE Hearty, TJ Hofstadter, MD Overoye, K Weiler, M AF Pagano, TS Aumann, HH Broberg, SE Gaiser, SL Hagan, DE Hearty, TJ Hofstadter, MD Overoye, K Weiler, M BE Barnes, WL TI On-board calibration techniques and test results for the Atmospheric Infrared Sounder (AIRS) SO EARTH OBSERVING SYSTEMS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing Systems VII CY JUL 07-10, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol, Univ Washington, Coll Engn & Architecture DE Earth Science; EOS; aqua; AIRS; sounder; calibration; operations AB The Atmospheric Infrared Sounder (AIRS) is a space based instrument developed for measurement of global atmospheric properties; primarily water vapor and temperature. AIRS is one of several instruments on board NASA's Earth Observing System Aqua spacecraft. AIRS operates in the 3.7 - 15.4 micron region and has 2378 infrared channels and 4 Vis/NIR channels. AIRS spatial resolution is 13.5 km from the orbit of 705 km and it scans +-49.5 degrees. AIRS has a set of on-board calibrators including a single infrared blackbody source, a parylene spectral calibration source, a space view and a Vis/NIR photometric calibrator. The on-board calibration subsystems are described along with a description of special test procedures for using them and results from several tests performed to date. Results are exceptional indicating that the instrument is performing better than expected. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Pagano, TS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 7 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 0-8194-4582-7 J9 P SOC PHOTO-OPT INS PY 2002 VL 4814 BP 243 EP 254 DI 10.1117/12.451547 PG 12 WC Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BV51H UT WOS:000179201500026 ER PT S AU Lee, RB Paden, J Pandey, DK Wilson, RS Bush, KA Smith, GL AF Lee, RB Paden, J Pandey, DK Wilson, RS Bush, KA Smith, GL BE Barnes, WL TI On-orbit radiometric calibrations of the Earth Radiation Budget Experiment (ERBE) active-cavity radiometers on the Earth Radiation Budget Satellite (ERBS) SO EARTH OBSERVING SYSTEMS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing Systems VII CY JUL 07-10, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol, Univ Washington, Coll Engn & Architecture DE active-cavity radiometer; blackbody; total solar irradiance; ERBS; earth irradiance; IPTS-68 ID ENERGY SYSTEM CERES; CLOUDS; INSTRUMENT; SENSORS AB Between November 1984 and July 2002, the Earth Radiation Budget Satellite (ERBS)/Earth Radiation Budget Experiment (ERBE) nonscanning, active cavity radiometers (ACR) were used to measure incoming total solar irradiance, earth-reflected solar irradiance, and earth-emitted outgoing longwave radiation (OLR) irradiance. The ERBE shortwave wide field-of view (SWFOV) and toal wide field-of-view (TWFOV) ACR's measured irradiances from the entire earth disc in the shortwave (0.2-5.0 mum) and total (0.2-100 mum) broadband spectral regions. On-orbit, the ACR's observations of the incoming total solar irradiance, and of reference irradiance from on-board tungsten lamp and blackbodies were used to determine drifts and shifts in the ACR responses/gains. In the cases of the SWFOV ACR, its response/gain changed as much as 8.8% while the TWFOV response was stable at levels better than 0.1%. The precise measurements of gain and offset variations have permitted the generations of ERBE level 1 data products [earth-reflected solar (similar to240 Wm(-2))and earth-emitted (similar to100 Wm(-2)) irradiances] at the precision levels better than 0.3 Wm(-2). In this paper, the ACR radiometric on-orbit calibration approaches and systems are outlined. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Lee, RB (reprint author), NASA, Langley Res Ctr, MS 420,Bldg1250,Rm173, Hampton, VA 23681 USA. NR 34 TC 5 Z9 5 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4582-7 J9 P SOC PHOTO-OPT INS PY 2002 VL 4814 BP 369 EP 379 PG 11 WC Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BV51H UT WOS:000179201500039 ER PT S AU Moore, M Lowe, D AF Moore, M Lowe, D BE Barnes, WL TI Providing rapid access to EOS data via data pools SO EARTH OBSERVING SYSTEMS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing Systems VII CY JUL 07-10, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol, Univ Washington, Coll Engn & Architecture DE data access; navigation-based clients; storage area networks; data grids; workflow management; direct broadcast AB As the EOSDIS archives grow, it could easily become more difficult for users to find and retrieve the data they need and to quickly get that data into a form they can use. NASA has been developing capabilities to address this concern over the past year and recently deployed an initial set of capabilities to its major Distributed Active Archive Centers (DAACs). The solution, called Data Pools, makes a significant portion of the data in the EOSDIS archives available on-line for immediate access, and provides several innovative data navigation, tailoring and rapid access services to help users quickly find just the data they need, get it into a form they can use, and then quickly retrieve the data. This paper describes the Data Pool architecture, and its approach to addressing data location, tailoring and retrieval difficulties that could have eventually plagued EOSDIS users. The paper also discusses how the Data Pools architecture could be expanded to provide a cost-effective evolutionary architecture for EOSDIS. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Moore, M (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-4582-7 J9 P SOC PHOTO-OPT INS PY 2002 VL 4814 BP 392 EP 401 DI 10.1117/12.451871 PG 10 WC Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BV51H UT WOS:000179201500041 ER PT S AU Zavorin, I Stone, HS Le Moigne, J AF Zavorin, I Stone, HS Le Moigne, J BE Barnes, WL TI Iterative pyramid-based approach to subpixel registration of multisensor satellite imagery SO EARTH OBSERVING SYSTEMS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing Systems VII CY JUL 07-10, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol, Univ Washington, Coll Engn & Architecture DE subpixel image registration; multisensor; optimization; wavelets; mutual information AB This paper compares different filters used to register images taken from different satellites to subpixel precision. The registration algorithm is one proposed by Thevenaz; et al which uses a modified Levenberg-Marquardt process to find the rigid transform that best maps one image into another. Our findings are that while applied to single-sensor synthetic data, centered spline filters and the low pass band of Simoncelli steerable pyramid are equally sensitive to initial guess while the bandpass sub-band of the Simoncelli filters exhibits larger senstivity. For multisensor and noisy data, however, the bandpass filters produce the most consistent results. C1 NASA, Goddard Space Flight Ctr, GEST Ctr, Greenbelt, MD 20771 USA. RP Zavorin, I (reprint author), NASA, Goddard Space Flight Ctr, GEST Ctr, Greenbelt, MD 20771 USA. NR 17 TC 2 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 0-8194-4582-7 J9 P SOC PHOTO-OPT INS PY 2002 VL 4814 BP 435 EP 446 DI 10.1117/12.451397 PG 12 WC Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BV51H UT WOS:000179201500045 ER PT S AU Chu, WP Trepte, CR Veiga, RE Cisewski, MS Taha, G AF Chu, WP Trepte, CR Veiga, RE Cisewski, MS Taha, G BE Barnes, WL TI SAGE III measurements SO EARTH OBSERVING SYSTEMS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing Systems VII CY JUL 07-10, 2002 CL SEATTLE, WA SP SPIE, Boeing Co, Pacific NW Natl Lab, Washington State Univ, Coll Sci, Washington Technol Ctr, Univ Washington, Coll Engn, Univ Washington, Ctr Nanotechnol, Univ Washington, Coll Engn & Architecture DE remote sensing; space-borne instrument; aerosols; ozone; environmental monitoring; climate monitoring ID STRATOSPHERIC AEROSOL; INVERSION AB SAGE III is a NASA EOS instrument designed to provide long term measurements of ozone, aerosol, water vapor, and other gases in the atmosphere. The instrument was launched on a Russian Spacecraft Meteor 3M on December 10, 2001. This paper will provide a brief discussion of the SAGE III data that will be made available to the science community to perform study on problem related to global climate change issues. The SAGE III measurement strategy, data retrieval technique, and the expected quality of the data products will be discussed. Preliminary data obtained from the instrument will be presented. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Chu, WP (reprint author), NASA, Langley Res Ctr, MS 475, Hampton, VA 23681 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 0-8194-4582-7 J9 P SOC PHOTO-OPT INS PY 2002 VL 4814 BP 457 EP 464 DI 10.1117/12.451515 PG 8 WC Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BV51H UT WOS:000179201500047 ER PT J AU Kawano, H Le, G Russell, CT Rostoker, G Brittnacher, MJ Parks, GK AF Kawano, H Le, G Russell, CT Rostoker, G Brittnacher, MJ Parks, GK TI Substorm-time magnetic field perturbations in the polar magnetosphere: POLAR observations SO EARTH PLANETS AND SPACE LA English DT Article ID TAIL CURRENT DISRUPTION; EXPANSION; MAGNETOTAIL; INSTRUMENT; ONSETS; SHEET; IMF AB We present a case study of substorm-time magnetic field perturbations in the high-altitude polar magnetosphere, corresponding to the polar lobe, using data from the POLAR spacecraft together with ground-based CANOPUS observations and WIND solar-wind observations. The substorm of this paper had a clear growth phase and one clear major expansion onset, enabling an unmistakable comparison of the substorm timings and those of the magnetic field perturbations observed by POLAR. During the growth phase, the magnetic field strength (B-total) increased and the flaring angle of the field line decreased at POLAR: They are ascribed to the pileup of magnetic field lines over the polar magnetosphere and to the braking effect of the ionosphere on the tailward motion of the piled-up field lines, respectively. For similar to28 min after the expansion onset, Btotal at POLAR did not decrease toward its presubstorm value, in contrast to past tail-lobe observations where Btotal decreased during the expansion phase. This absence of the field-decrease signature in the polar lobe for similar to28 min, reported for the first time in this paper, could be ascribed to dipolarization/compression of the inner magnetosphere during the expansion phase, cancelling the field-decreasing effect. C1 Kyushu Univ, Dept Earth & Planetary Sci, Fukuoka 8128581, Japan. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Univ Washington, Geophys Program, Seattle, WA 98195 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Kawano, H (reprint author), Kyushu Univ, Dept Earth & Planetary Sci, Fukuoka 8128581, Japan. RI Le, Guan/C-9524-2012; OI Le, Guan/0000-0002-9504-5214; Russell, Christopher/0000-0003-1639-8298 NR 20 TC 2 Z9 2 U1 0 U2 2 PU TERRA SCIENTIFIC PUBL CO PI TOKYO PA 2003 SANSEI JIYUGAOKA HAIMU, 5-27-19 OKUSAWA, SETAGAYA-KU, TOKYO, 158, JAPAN SN 1343-8832 J9 EARTH PLANETS SPACE JI Earth Planets Space PY 2002 VL 54 IS 10 BP 963 EP 971 PG 9 WC Geosciences, Multidisciplinary SC Geology GA 620RM UT WOS:000179546400004 ER PT S AU Priestley, KJ Wielicki, BA Green, RN Haeffelin, MPA Lee, RB Loeb, NG AF Priestley, KJ Wielicki, BA Green, RN Haeffelin, MPA Lee, RB Loeb, NG BE Fellous, JL LeMarshall, JF Choudhury, BJ Menenti, M Paxton, LJ Gupta, SP TI Early radiometric validation results of the CERES Flight Model 1 and 2 instruments onboard NASA'S Terra Spacecraft SO EARTH'S ATMOSPHERE, OCEAN AND SURFACE STUDIES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT A0 1, A0 4-A0 5, A3 1, C1 1 and C2 6 Symposia of the COSPAR Scientific Commissions A and C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP NASA, NOAA, NCEP, World Climate Res Programme, Comm Space Res, World Meteorol Org, European Org Exploitat Meteorol Satellites, European Space Agcy, Int Union Radio Sci ID ENERGY SYSTEM CERES; CLOUDS AB The CERES Flight Model 1 and 2 instruments were launched aboard NASA's Earth Observing System (EOS) Terra Spacecraft on December 18, 1999 into a 705 Km sun-synchronous orbit with a 10:30 a.m. equatorial crossing time. These instruments supplement measurements made by the CERES Proto Flight Model (PFM) instrument launched aboard NASA's Tropical Rainfall Measuring Mission (TRMM) spacecraft on November 27, 1997 into a 350 Kin, 38-degree mid-inclined orbit. An important aspect of the EOS program is the rapid archival. and dissemination of datasets measured by EOS instruments to the scientific community. On September 22, 2000 the CERES Science Team voted to archive the Edition I CERES/Terra Level 1b and Level 2 and 3 ERBE-Like data products. These products consist of instantaneous filtered and unfiltered radiances through temporally and spatially averaged TOA fluxes. CERES filtered radiance measurements cover three spectral bands including shortwave (0.3 to 5 mum), total (0.3 to <100 mum) and an atmospheric window channel (8 to 12 mum). The current work summarizes both the philosophy and results of validation efforts undertaken to quantify the quality of the Terra data products as well as the level of agreement between the Terra and TRMM datasets. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Virginia Polytech Inst & State Univ, Dept Mech Engn, Blacksburg, VA 24060 USA. Hampton Univ, Ctr Atmospher Studies, Hampton, VA 23681 USA. RP Priestley, KJ (reprint author), NASA, Langley Res Ctr, 21 Langley Blvd, Hampton, VA 23681 USA. NR 7 TC 6 Z9 6 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 11 BP 2371 EP 2376 AR PII S0273-1177(02)00076-5 DI 10.1016/S0273-1177(02)80278-2 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW01W UT WOS:000180656600003 ER PT S AU Smith, GL Bess, TD Manalo-Smith, N Ramanathan, V Lee, RB Barkstrom, BR AF Smith, GL Bess, TD Manalo-Smith, N Ramanathan, V Lee, RB Barkstrom, BR BE Fellous, JL LeMarshall, JF Choudhury, BJ Menenti, M Paxton, LJ Gupta, SP TI The CERES 8-12 micron window channel SO EARTH'S ATMOSPHERE, OCEAN AND SURFACE STUDIES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Review CT A0 1, A0 4-A0 5, A3 1, C1 1 and C2 6 Symposia of the COSPAR Scientific Commissions A and C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP NASA, NOAA, NCEP, World Climate Res Programme, Comm Space Res, World Meteorol Org, European Org Exploitat Meteorol Satellites, European Space Agcy, Int Union Radio Sci ID ENERGY SYSTEM CERES; CLOUDS AB The CERES (Clouds and Earth Radiant Energy System) scanning radiometer has 3 channels: a shortwave channel for measuring solar radiation reflected from the Earth, a total channel, which combined with the shortwave channel gives the outgoing longwave radiation, and a channel for measuring radiances in the 8 to 12 mu window of the atmosphere. The CERES instrument aboard the Tropical Rainfall Measurement Mission (TRMM) spacecraft provided 8 months of data. This paper discusses the 8-12 mu channel of the CERES. In order to compute fluxes from radiance measurements, limb-darkening functions are required. These limb-darkening functions are also computed from CERES measurements and are then used to compute fluxes from the measured radiances. Finally, maps are examined to show features of radiation in the window channel. Published by Elsevier Science Ltd on behalf of COSPAR. C1 Virginia Polytech Inst & State Univ, Dept Mech Engn, Blacksburg, VA 24061 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Analyt Serv & Mat Inc, Hampton, VA 23666 USA. Univ Calif San Diego, Scripps Inst Oceanog, San Diego, CA USA. RP Smith, GL (reprint author), Virginia Polytech Inst & State Univ, Dept Mech Engn, Blacksburg, VA 24061 USA. NR 9 TC 0 Z9 0 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 11 BP 2377 EP 2382 AR PII S0273-1177(02)00077-7 DI 10.1016/S0273-1177(02)80280-0 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW01W UT WOS:000180656600004 ER PT S AU Le Marshall, JF Leslie, LM Smith, WL AF Le Marshall, JF Leslie, LM Smith, WL BE Fellous, JL LeMarshall, JF Choudhury, BJ Menenti, M Paxton, LJ Gupta, SP TI Initialisation using high spatial, temporal and spectral resolution satellite observations. SO EARTH'S ATMOSPHERE, OCEAN AND SURFACE STUDIES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT A0 1, A0 4-A0 5, A3 1, C1 1 and C2 6 Symposia of the COSPAR Scientific Commissions A and C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP NASA, NOAA, NCEP, World Climate Res Programme, Comm Space Res, World Meteorol Org, European Org Exploitat Meteorol Satellites, European Space Agcy, Int Union Radio Sci ID NUMERICAL WEATHER PREDICTION; GENERALIZED INVERSION; SYSTEM; MODEL AB Recent advances in numerical weather prediction and data assimilation, combined with the availability of high spatial, temporal and spectral resolution satellite observations and burgeoning computer power are leading to significant improvements in our ability to predict weather phenomena at higher and more appropriate resolutions. Here, we describe recent work, illustrating such improvements. High spatial and temporal (at least hourly) resolution data from sequential geostationary multispectral imagery have been used to initialise a high resolution (15km) 4-D variational assimilation (4-D Var.) system to improve tropical cyclone track prediction. The same wind data, sometimes with the addition of TOVS data from NOAA operational satellites, have also been used at higher resolution (5km) to estimate tropical cyclone intensity, demonstrating the importance of very high resolution modelling and data for this enterprise. Finally, we are using very high resolution (1km) 4-D Var. with very high spatial temporal and spectral resolution observations available from experimental advanced sounder instruments such as the High resolution Interferometer Sounder (HIS) and the NPOESS Aircraft Sounder Testbed - Interferometer (NAST - I) to examine the impact after initialisation of the improved delineation of the thermal and moisture fields by these next-generation sounders. This we believe is the first use of advanced sounder data with 4-D Var. and will assist in exploiting such data from the experimental Advanced Infrared Sounder (AIRS), the operational Infrared Atmospheric Sounding Interferometer (IASI), the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) and Cross-track Interferometer Sounder (CrIS) instruments. (C) 2002 Published by Elsevier Science Ltd on behalf of COSPAR. C1 Bur Meteorol, Melbourne, Vic 3000, Australia. Univ New S Wales, Sch Math, Sydney, NSW 2052, Australia. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Le Marshall, JF (reprint author), Bur Meteorol, Melbourne, Vic 3000, Australia. NR 13 TC 3 Z9 3 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 30 IS 11 BP 2441 EP 2446 AR PII S0273-1177(02)00719-6 DI 10.1016/S0273-1177(02)80300-3 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW01W UT WOS:000180656600013 ER PT S AU Halem, M Kouatchou, J Norris, P Rancic, M Geiger, J AF Halem, M Kouatchou, J Norris, P Rancic, M Geiger, J BE Fellous, JL LeMarshall, JF Choudhury, BJ Menenti, M Paxton, LJ Gupta, SP TI Cloud field assimilation using simulated Triana satellite-data SO EARTH'S ATMOSPHERE, OCEAN AND SURFACE STUDIES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT A0 1, A0 4-A0 5, A3 1, C1 1 and C2 6 Symposia of the COSPAR Scientific Commissions A and C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP NASA, NOAA, NCEP, World Climate Res Programme, Comm Space Res, World Meteorol Org, European Org Exploitat Meteorol Satellites, European Space Agcy, Int Union Radio Sci ID MODEL AB In the next few years, NASA plans to launch satellite Triana, a deep space Earth observatory that will take a full-disk view of the sunlit side of the Earth. Triana carries two instruments, EPIC, which will deliver Science products such as total precipitable water, cloud height, aerosol index, total ozone, and a global visible cloud field image, and NISTAR, which obtains precise radiometry integrated over the entire sunlit disk. Using a contemporary atmospheric model (namely the Eta model), we have started a project whose goal is to simulate some of the Triana observations and to assess the impact of Triana data for weather and climate predictions. In this paper, we report on the results of numerical experiments assimilating temperature profiles with and without cloud liquid water for inferring tropical and extra-tropical atmospheric states. We also assess the impact of initializing cloud liquid water for short term forecasts and data assimilation cycles. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Goddard Space Flight Ctr, GEST, Greenbelt, MD 20771 USA. Morgan State Univ, Sch Engn, Baltimore, MD 21251 USA. RP Halem, M (reprint author), NASA, Goddard Space Flight Ctr, GEST, Greenbelt, MD 20771 USA. RI Koutachou, Jules/D-4773-2016 OI Koutachou, Jules/0000-0002-5525-9875 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 30 IS 11 BP 2447 EP 2454 AR PII S0273-1177(02)00722-6 DI 10.1016/S0273-1177(02)80302-7 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW01W UT WOS:000180656600014 ER PT S AU Romanov, P Gutman, G Csiszar, I AF Romanov, P Gutman, G Csiszar, I BE Fellous, JL LeMarshall, JF Choudhury, BJ Menenti, M Paxton, LJ Gupta, SP TI Satellite-derived snow cover maps for North America: Accuracy assessment SO EARTH'S ATMOSPHERE, OCEAN AND SURFACE STUDIES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT A0 1, A0 4-A0 5, A3 1, C1 1 and C2 6 Symposia of the COSPAR Scientific Commissions A and C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP NASA, NOAA, NCEP, World Climate Res Programme, Comm Space Res, World Meteorol Org, European Org Exploitat Meteorol Satellites, European Space Agcy, Int Union Radio Sci ID MODEL AB An automated, satellite-based snow mapping system has been developed at NOAA/NESDIS to provide operational snow cover monitoring over the North American continent. The system uses visible, mid-infrared and infrared observations of the Imager instrument onboard NOAA's Geostationary Operational Environmental Satellite (GOES) and microwave measurements made with a Special Sensor Microwave Imager (SSM/I) of the Defense Meteorological Satellite Program (DMSP) satellite. In the paper we give a brief description of the system and analyze its performance during 1998-1999 and 1999-2000 winter seasons. Snow depth observations made at ground stations were used to assess the accuracy of snow mapping. The sources of satellite snow mapping errors and other reasons leading to discrepancies between satellite retrievals and surface data are discussed. (C) 2002 Published by Elsevier Science Ltd on behalf of COSPAR. C1 NOAA, NESDIS, Off Res & Applicat, Camp Springs, MD 20746 USA. NASA Headquarters, Washington, DC 20546 USA. RP Romanov, P (reprint author), NOAA, NESDIS, Off Res & Applicat, 5200 Auth Rd, Camp Springs, MD 20746 USA. RI Romanov, Peter/F-5622-2010; Csiszar, Ivan/D-2396-2010 OI Romanov, Peter/0000-0002-2153-8307; NR 9 TC 8 Z9 8 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 11 BP 2455 EP 2460 AR PII S0273-1177(02)00723-8 DI 10.1016/S0273-1177(02)80304-0 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW01W UT WOS:000180656600015 ER PT S AU Leslie, LM Le Marshall, JF Smith, WL AF Leslie, LM Le Marshall, JF Smith, WL BE Fellous, JL LeMarshall, JF Choudhury, BJ Menenti, M Paxton, LJ Gupta, SP TI Mesoscale initialisation using advanced sounder data SO EARTH'S ATMOSPHERE, OCEAN AND SURFACE STUDIES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Review CT A0 1, A0 4-A0 5, A3 1, C1 1 and C2 6 Symposia of the COSPAR Scientific Commissions A and C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP NASA, NOAA, NCEP, World Climate Res Programme, Comm Space Res, World Meteorol Org, European Org Exploitat Meteorol Satellites, European Space Agcy, Int Union Radio Sci ID WEATHER PREDICTION MODEL; SATELLITE WIND DATA; CONTINUOUS ASSIMILATION; GENERALIZED INVERSION AB There is increasing availability of continuous, high resolution observations from space-based platforms, for example, cloud and water vapour motion vectors, Advanced TOVS data and scatterometer wind fields, as well as increasing availability of continuous surface observations such as radar and profiler data. In addition, there will be, in the near future, an increase in the density of these data as instruments such as the Atmospheric InfraRed Sounder (AIRS) come into service. Full exploitation of this increased data base is expected to be attained through the use of modem data assimilation techniques such as 3- and 4-dimensional variational assimilation. Here, we briefly review the 4-D variational (4-D Var.) data assimilation system, initially developed by Bennet et al. (1993, 1995, 1996) and recently extended to include the mesoscale assimilation of wind, temperature and moisture data over a limited area (Le Marshall et al. 1999, Leslie et al. 1998). We describe the assimilation methodology and; the summarise initial results obtained by applying this high resolution system to mesoscale data from the NAST-I (NPOESS Advanced Sounder Testbed - Infrared) advanced sounding instrument. (C) 2002 Published by Elsevier Science Ltd on behalf of COSPAR. C1 Univ New S Wales, Sch Math, Sydney, NSW 2052, Australia. Bur Meteorol Res Ctr, Melbourne, Vic 3000, Australia. NASA, Langley Atmospher Res Ctr, Hampton, VA 23681 USA. RP Leslie, LM (reprint author), Univ New S Wales, Sch Math, Sydney, NSW 2052, Australia. NR 18 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES PY 2002 VL 30 IS 11 BP 2479 EP 2484 AR PII S0273-1177(02)00727-5 DI 10.1016/S0273-1177(02)80312-X PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW01W UT WOS:000180656600019 ER PT S AU Choudhury, LJ AF Choudhury, LJ BE Fellous, JL LeMarshall, JF Choudhury, BJ Menenti, M Paxton, LJ Gupta, SP TI A biophysical process based approach for estimating net primary production using satellite and ground observations SO EARTH'S ATMOSPHERE, OCEAN AND SURFACE STUDIES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT A0 1, A0 4-A0 5, A3 1, C1 1 and C2 6 Symposia of the COSPAR Scientific Commissions A and C held at the 33rd COSPAR Scientific Assembly CY JUL, 2000 CL WARSAW, POLAND SP NASA, NOAA, NCEP, World Climate Res Programme, Comm Space Res, World Meteorol Org, European Org Exploitat Meteorol Satellites, European Space Agcy, Int Union Radio Sci ID RADIATION USE EFFICIENCY; CARBON BALANCE; GRAIN-SORGHUM; RESPIRATION; NITROGEN; MODEL; PHOTOSYNTHESIS; LEAF; ACCUMULATION; TEMPERATURE AB An approach is presented for calculating interannual variation of net primary production (C) of terrestrial plant communities at regional scale using satellite and ground measurements. C has been calculated as the difference of gross photosynthesis (A(g)) and respiration (R), recognizing that different biophysical factors exert major control on these two processes. A(g) has been expressed as the product of radiation use efficiency for gross photosynthesis by an unstressed canopy and intercepted photosynthetically active radiation, which is then adjusted for stresses due to soil water shortage and temperature away from optimum. R has been calculated as the sum of growth and maintenance components (respectively, R-g and R-m). The R-m has been determined from nitrogen content of plant tissue per unit ground area, while R-g has been obtained as a fraction of the difference of A(g) and R-m. Model parameters have not been determined by matching the calculated fluxes against observations at any location. Results are presented for cultivated and temperate deciduous forest areas over North America for five consecutive years (1986-1990) and compared with observations. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Choudhury, LJ (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. NR 32 TC 2 Z9 2 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 11 BP 2505 EP 2510 AR PII S0273-1177(02)00373-3 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BW01W UT WOS:000180656600023 ER PT S AU Filman, RE AF Filman, RE BE Magnusson, B TI Polychotomic encoding: A better quasi-optimal bit-vector encoding of tree hierarchies SO ECOOP 2002 - OBJECT-ORIENTED PROGRAMMING SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 16th European Conference on Object Oriented Programming (ECOOP 2002) CY JUN 10-14, 2002 CL MALAGA, SPAIN SP IBM, Microsoft Res, SPI, Coritel BPM, Telelogic, Sadiel, Assoc Int Technol Objects, Univ Malaga, Univ Extremandura, Dept Comp Sci ID TIME AB Polychotomic Encoding is an algorithm for producing bit vector encodings of trees. Polychotomic Encoding is an extension of the Dichotomic Encoding algorithm of Raynaud and Thierry. Polychotomic and Dichotomic Encodings are both examples of hierarchical encoding algorithms, where each node in the tree is given a gene-a subset of {1,...,n}. The encoding of each node is then the union of that node's gene with the genes of its ancestors. Reachability in the tree can then be determined by subset testing on the encodings. Dichotomic Encoding restructures the given tree into a binary tree, and then assigns two bit, incompatible (chotomic) "genes" to each of the two children of a node, Polychotomic Encoding substitutes a multibit encoding for the children of a node when the restructuring operation of Dichotomic Encoding would produce a new heaviest child (child requiring the most bits to represent a tree of its children) for that node. The paper includes a proof that Polychotomic Encoding never produces an encoding using more bits than Dichotomic Encoding. Experimentally, Polychotomic Encoding produces a space savings of up to 15% on examples of naturally occurring hierarchies, and 25% on trees in the randomly generated test set. C1 NASA, Ames Res Ctr, Adv Comp Sci Res Inst, Moffett Field, CA 94025 USA. RP Filman, RE (reprint author), NASA, Ames Res Ctr, Adv Comp Sci Res Inst, MS 269-2, Moffett Field, CA 94025 USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-43759-2 J9 LECT NOTES COMPUT SC PY 2002 VL 2374 BP 545 EP 561 PG 17 WC Computer Science, Theory & Methods SC Computer Science GA BV79V UT WOS:000180069200023 ER PT B AU Lawson, JW Wolpert, DH AF Lawson, JW Wolpert, DH GP AAAI AAAI TI The design of collectives of agents to control non-Markovian systems SO EIGHTEENTH NATIONAL CONFERENCE ON ARTIFICIAL INTELLIGENCE (AAAI-02)/FOURTEENTH INNOVATIVE APPLICATIONS OF ARTIFICIAL INTELLIGENCE CONFERENCE (IAAI-02), PROCEEDINGS LA English DT Proceedings Paper CT 18th National Conference on Artificial Intelligence/14th Conference on Innovative Applications of Artificial Intelligence CY JUL 28-AUG 01, 2002 CL EDMONTON, CANADA SP Amer Assoc Artificial Intelligence, ACM SIGART, Alberta Informat Circle Res Excellence, DARPA, NASA Ames Res Ctr, Natl Sci Fdn, Naval Res Lab ID MULTIAGENT SYSTEMS AB The "Collective Intelligence" (COIN) framework concerns the design of collectives of reinforcement-learning agents such that their interaction causes. a provided "world" utility function concerning the entire collective to be maximized. Previously, we applied that framework to scenarios involving Markovian dynamics where no re-evolution of the system from counter-factual initial conditions (an often expensive calculation) is permitted. This approach sets the individual utility function of each agent to be both aligned with the world utility, and at the same time, easy for the associated agents to optimize. Here we extend that approach to systems involving non-Markovian dynamics. In computer simulations, we compare our techniques with each other and with conventional "team games" We show whereas in team games performance often degrades badly with time, it steadily improves when our techniques are. used. We also investigate situations where the system's dimensionality is effectively reduced. We show that this leads to difficulties in die agents' ability to learn. The implication is that "learning" is a property only of high-enough dimensional systems. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, MS 269-2, Moffett Field, CA 94035 USA. EM lawson@ptolemy.arc.nasa.gov; dhw@ptolemy.arc.nasa.gov NR 25 TC 0 Z9 0 U1 0 U2 0 PU MIT PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA BN 0-262-51129-0 PY 2002 BP 332 EP 337 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BW91S UT WOS:000183593700051 ER PT S AU Tai, H AF Tai, H BE Wasserman, RM DeVore, SL TI Simple numerical simulation of strain measurement SO ELECTRO-OPTICAL SYSTEM DESIGN, SIMULATION, TESTING AND TRAINING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Electro-Optical System Design, Simulation, Testing, and Training 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 Bragg grating; reflectivity; non-uniform strain; photo-elastic effect ID COUPLED-MODE THEORY; OPTICAL-FIBER; MATRIX-METHOD; PROPAGATION; MEDIA AB By adopting the basic principle of the reflection (and transmission) of a plane polarized electromagnetic wave incident normal to a stack of films of alternating refractive index, a simple numerical code was written to simulate the maximum reflectivity (transmittivity) of a fiber optic Bragg grating corresponding to various non- uniform strain conditions including photo-elastic effect in certain cases. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Tai, H (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 22 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 0-8194-4539-8 J9 P SOC PHOTO-OPT INS PY 2002 VL 4772 BP 13 EP 24 DI 10.1117/12.451768 PG 12 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BV73R UT WOS:000179916400002 ER PT S AU Bar-Cohen, Y AF Bar-Cohen, Y BE BarCohen, Y Zhang, QM Fukada, E Bauer, S Chrisey, DB Danforth, SC TI The electroactive polymers infrastructure SO ELECTROACTIVE POLYMERS AND RAPID PROTOTYPING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Rapid Prototyping Technologies-From Tissue Engineering to Conformal Electronics held at the 2001 MRS Fall Meeting CY NOV 28-30, 2001 CL BOSTON, MA SP Mat Res Soc AB In the last ten years, new EAP materials have emerged that exhibit large displacement in response to electrical stimulation enabling great potential for the field. To develop efficient EAP that are robust for practical applications there is a need to establish an adequate EAP infrastructure. This requires developing adequate understanding of EAP materials' behavior, as well as effective processing and characterization techniques. Enhancement of the actuation force necessitates understanding the basic principles using computational chemistry models, comprehensive material science, electro-mechanics analytical tools and improved material processing techniques. Efforts are needed to gain better understanding of the parameters that control the EAP electro-activation force and deformation. The processes of synthesizing, fabricating, electroding, shaping and handling need to be refilled to maximize the EAP materials actuation capability and robustness. Methods of reliably characterizing the response of these materials are required to establish database with documented material properties in order to support design engineers considering use of these materials and towards making EAP as actuators of choice. Various configurations of EAP actuators and sensors need to be studied and modeled to produce an arsenal of effective smart EAP driven system. The development of the infrastructure is a multidisciplinary task involving materials science, chemistry, electromechanics, computers, electronics, and others. This paper reviews the status of the EAP infrastructure and the challenges to practical application of EAP materials as actuators. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bar-Cohen, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,JPL MS 82-105, Pasadena, CA 91109 USA. NR 12 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 1-55899-634-6 J9 MATER RES SOC SYMP P PY 2002 VL 698 BP 37 EP 42 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BU86W UT WOS:000177251300005 ER PT S AU Bar-Cohen, Y Bao, XQ Lih, SS Bhattacharya, K Yu, X AF Bar-Cohen, Y Bao, XQ Lih, SS Bhattacharya, K Yu, X BE BarCohen, Y Zhang, QM Fukada, E Bauer, S Chrisey, DB Danforth, SC TI Characterization of the electromechanical properties of IPMC SO ELECTROACTIVE POLYMERS AND RAPID PROTOTYPING SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Rapid Prototyping Technologies-From Tissue Engineering to Conformal Electronics held at the 2001 MRS Fall Meeting CY NOV 28-30, 2001 CL BOSTON, MA SP Mat Res Soc AB Ionic Polymer-Metal Composite (IPMC) as electroactive polymers (EAP) was the subject of research and development since 1992. Its low required activation voltage and the large bending led to the considerations of various potential applications. However, before the benefits of IPMC can be effectively exploited for practical use, the electromechanical behavior must be properly quantified. An experimental setup was developed for data acquisition from IPMC strips subjected to various tip mass levels and in parallel an analytical model was developed to predict the material response. Using the analytical model and an inversion algorithm the modulus, and relaxation time were determined. The programmable setup was used to acquire the displacement and curvature of IPMC as a function of the electrical signal characteristics. Sample strips were immersed in water to minimize the effect of moisture content and were tested with and without tip mass. In order to avoid hydrolysis the samples were subjected to I-V square wave with either positive or negative polarity. Mathematical models were developed that showed satisfactory results for tetra-n-butylammonium(+) cations/Flamion IPMC, which responds slowly and monotonically without relaxation and Li+ cations/Nafion IPMC, that response quickly with a following back relaxation. These models are macroscopic ordinary differential equations whose solution fits the observed behavior well. C1 JPL, Pasadena, CA 91109 USA. RP Bar-Cohen, Y (reprint author), JPL, MS 82-105,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-634-6 J9 MATER RES SOC SYMP P PY 2002 VL 698 BP 145 EP 150 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BU86W UT WOS:000177251300019 ER PT S AU Sahai, R AF Sahai, R BE Henney, WJ Steffen, W Binette, L Raga, A TI Bipolar and multipolar jets in protoplanetary and planetary nebulae SO EMISSION LINES FROM JET FLOWS SE REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA, SERIE DE CONFERENCIAS LA English DT Proceedings Paper CT Conference on Emission Lines from Jet Flows CY NOV 13-17, 2000 CL ISLA MUJERES, MEXICO SP UNAM, Inst Astron DE circumstellar matter; ISM : jets and outflows; planetarc nebulae; stars : AGB and post-AGB; stars : mass-loss ID HUBBLE-SPACE-TELESCOPE; CIRCUMSTELLAR ENVELOPES; AGB STARS; DISCOVERY; EMISSION; EVOLUTION; WIND AB One of the most exciting challenges facing theories of post-main sequence evolution today is to understand how Asymptotic Giant Branch (AGB) stars and their round circumstellar envelopes (CSEs) transform themselves into planetary nebulae (PNe) with their dazzling variety of aspherical morphologies. The most succesful model for shaping PNe-the "generalised interacting-stellar-winds" model, in which a fast (> 1000 km s(-1)) spherical stellar wind interacts with an equatorially-dense AGB CSE to produce an axisymmetric PN-now appears inadequate as a result of new data from the Hubble Space Telescope (HST). This paper presents new HST images of proto-planetary and planetary nebulae with collimated outflows. The outflows appear to be quite often multipolar in nature, indicating episodic changes in the axis of a bipolar jet-like outflow or the operation of multiple collimated outflows with different orientations. in particular, our serendipitous discovery of a very highly-collimated, extended jet in the planetary nebula Hen 2-90 and its amazing morphological similarity to low-mass YSOs is the strongest evidence yet for a common physical mechanism for collimated outflows in protostars and evolved stars. We briefly summarise current theoretical. hypotheses which may lead to a better understanding of the nature and origin of these outflows. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sahai, R (reprint author), CALTECH, Jet Prop Lab, MS 183-900, Pasadena, CA 91109 USA. NR 44 TC 20 Z9 20 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 BN 968-36-9947-2 J9 REV MEX AST ASTR PY 2002 VL 13 BP 133 EP 138 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV02R UT WOS:000177647500024 ER PT B AU Olson, DG AF Olson, DG BE WeltiChanes, J BarbosaCanovas, GV Aguilera, JM TI NASA Food Technology Commercial Space Center SO ENGINEERING AND FOOD FOR THE 21ST CENTURY SE FOOD PRESERVATION TECHNOLOGY SERIES LA English DT Proceedings Paper CT 8th International Conference on Engineering and Food (ICEF-8) CY APR, 2000 CL PUEBLA, MEXICO AB The Food Technology Commercial Space Center (FTCSC) will develop foods and food processing technologies suitable for space travel and for commercial terrestrial markets. Commercial companies will be the primary developers of the products and technologies, and the marketers to the consumer market or food industry. The FTCSC will facilitate the interaction between NASA and food companies. C1 Iowa State Univ, NASA, Food Technol Commercial Space Ctr, Ames, IA USA. RP Olson, DG (reprint author), Iowa State Univ, NASA, Food Technol Commercial Space Ctr, Ames, IA USA. NR 0 TC 0 Z9 0 U1 3 U2 3 PU CRC PRESS-TAYLOR & FRANCIS GROUP PI BOCA RATON PA 6000 BROKEN SOUND PARKWAY NW, STE 300, BOCA RATON, FL 33487-2742 USA BN 1-56676-963-9 J9 FOOD PRESERV TECHNOL PY 2002 BP 1007 EP 1010 PG 4 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA BU68M UT WOS:000176705200060 ER PT B AU Noor, AK AF Noor, AK BE Topping, BHV Bittnar, Z TI Computing technology: Frontiers and beyond SO ENGINEERING COMPUTATIONAL TECHNOLOGY LA English DT Proceedings Paper CT 3rd International Conference on Engineering Computational Technology CY SEP 04-06, 2002 CL CZECH TECH UNIV, FAC CIVIL ENGN, PRAGUE, CZECH REPUBLIC HO CZECH TECH UNIV, FAC CIVIL ENGN DE computing technology; emerging and future computing paradigms; future computing environment AB A brief history is given of the status and some recent developments in computing technology. Discussion focuses on recent advances in microelectronics, high-performance computing, adaptive/configurable computing, and user-interface hardware and software. Moore's law and the fundamental physical limits of computation are outlined. The emerging paradigms of grid computing, ubiquitous/pervasive computing and autonomic computing are described. Future computing environment and novel non-silicon computing paradigms are outlined. C1 Old Dominion Univ, NASA, Langley Res Ctr, Ctr Adv Engn Environm, Hampton, VA USA. RP Noor, AK (reprint author), Old Dominion Univ, NASA, Langley Res Ctr, Ctr Adv Engn Environm, Hampton, VA USA. NR 27 TC 1 Z9 1 U1 0 U2 0 PU SAXE-COBURG PUBLICATIONS PI EDINBURGH PA 10 SAXE-COBURG PLACE, EDINBURGH EH3 5BR, SCOTLAND BN 1-874672-17-2 PY 2002 BP 1 EP 23 PG 23 WC Engineering, Multidisciplinary; Mathematics, Applied SC Engineering; Mathematics GA BV74S UT WOS:000179942400001 ER PT B AU Miller, AE AF Miller, AE GP ASEM TI The impact of organizational socialization practices on developing knowledge workers role orientation in mechanistic and organic cultures SO ENGINEERING MANAGEMENT IN THE GLOBAL ENVIRONMENTS, PROCEEDINGS LA English DT Proceedings Paper CT 23rd National Conference of the American-Society-for-Engineering-Management CY OCT 02-05, 2002 CL Tampa, FL SP Univ S Florida, Ind & Management Syst, Amer Soc Engn Management ID TACTICS AB In this pilot study, self-report data provided by engineers and scientists working at a NASA field center was used to assess (1) the effects of the six socialization tactics from Van Maanen and Schein's (1979) typology on employee role orientation and (2) the organizational culture at the subgroup level. Results indicate that five of the socialization tactics were negatively related to role orientation indicating that institutionalized tactics in general are associated with a custodial orientation and individualized tactics with an innovative orientation. Two of the socialization tactics-investiture vs. divestiture and fixed vs. variable were positively correlated to organizational culture indicating a positive relationship between some of the custodial socialization tactics and the attributes of an organic organizational culture. C1 NASA, Marshal Space Flight Ctr, Special Projects Team, Struct Design Grp, Huntsville, AL 35812 USA. RP Miller, AE (reprint author), Univ Alabama, Huntsville, AL 35899 USA. NR 9 TC 0 Z9 0 U1 1 U2 5 PU AMER SOC ENGINEERING MANAGEMT PI ROLLA PA 310 HARRIS HALL, UMR, ROLLA, MO 65401 USA PY 2002 BP 390 EP 395 PG 6 WC Engineering, Industrial; Management SC Engineering; Business & Economics GA BY64C UT WOS:000189427900059 ER PT B AU Takada, PW Westbrook, J AF Takada, PW Westbrook, J GP ASEM TI The impact of organization management characteristics on satisfaction of engineering knowledge workers in technology driven organizations SO ENGINEERING MANAGEMENT IN THE GLOBAL ENVIRONMENTS, PROCEEDINGS LA English DT Proceedings Paper CT 23rd National Conference of the American-Society-for-Engineering-Management CY OCT 02-05, 2002 CL Tampa, FL SP Univ S Florida, Ind & Management Syst, Amer Soc Engn Management AB This research examines if the culture of the employing organization has any relationship with the job satisfaction of knowledge workers. The ability of organizations to attract and retain knowledge workers can be seriously impacted by lack of satisfaction. Culture was measured using Likert's Profile of Organization Characteristics (POC). The Minnesota Satisfaction Questionnaire measured intrinsic, extrinsic and global job satisfaction. Results show that organization culture is positively correlated with job satisfaction. The implication is that technology driven organizations should assess their cultures as a way of attracting and retaining the scarce human resources required for sustained viability. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Takada, PW (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC ENGINEERING MANAGEMT PI ROLLA PA 310 HARRIS HALL, UMR, ROLLA, MO 65401 USA PY 2002 BP 491 EP 497 PG 7 WC Engineering, Industrial; Management SC Engineering; Business & Economics GA BY64C UT WOS:000189427900073 ER PT B AU Shih, TH Povinelli, LA Liu, NS AF Shih, TH Povinelli, LA Liu, NS BE Rodi, W Fueyo, N TI Application of generalized wall function for complex turbulent flows SO ENGINEERING TURBULENCE MODELLING AND EXPERIMENTS 5 LA English DT Proceedings Paper CT 5th International Symposium on Engineering Turbulence Modelling and Measurements CY SEP 16-18, 2002 CL MALLORCA, SPAIN SP Spanish Minist Sci & Technol, Univ Zaragoza, Univ Karlsruhe, USAF, European Off Aerosp Res & Dev, CFX Germany, DaimlerChrysler AG, Elect France, NEC European Supercomp Syst DE turbulence modeling; generalized wall function; complex turbulent flows AB This paper describes a generalized new wall function for three dimensional turbulent boundary layer flows. Since the formulation is valid for both favorable and adverse pressure gradients including a zero wall stress, it can be applied to wall bounded complex flows with acceleration, deceleration and recirculation. This generalized wall function is also valid for the whole surface layer (or inner layer) near the wall, including the viscous sublayer, buffer layer and inertial sublayer, therefore it is a unified wall function. This "unified" feature is particularly useful for CFD to deal with flows with complex geometries, because it allows more flexible grid resolution near the wall to provide accurate wall boundary conditions. This paper also describes a systematic procedure for implementing the wall function in a general CFD code. Finally, a few examples of complex turbulent flows are presented to show the performance of the generalized wall function. C1 NASA, ICOMP, OAI, John H Glenn Res Ctr, Cleveland, OH 44142 USA. RP Shih, TH (reprint author), NASA, ICOMP, OAI, John H Glenn Res Ctr, Cleveland, OH 44142 USA. NR 8 TC 0 Z9 0 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-08-044114-9 PY 2002 BP 177 EP 186 DI 10.1016/B978-008044114-6/50016-8 PG 10 WC Engineering, Aerospace; Engineering, Mechanical SC Engineering GA BV33H UT WOS:000178612700015 ER PT S AU Bailey, RE Parrish, RV Arthur, JJ Norman, RM AF Bailey, RE Parrish, RV Arthur, JJ Norman, RM BE Verly, JG TI Flight test evaluation of tactical synthetic vision display concepts in a terrain-challenged operating environment SO ENHANCED AND SYNTHETIC VISION 2002 SE Proceedings of SPIE LA English DT Proceedings Paper CT Enhanced and Synthetic Vision 2002 Conference CY APR 01-02, 2002 CL ORLANDO, FL SP SPIE DE synthetic vision; controlled flight into terrain; terrain awareness; synthetic image; head-up display AB NASA's Aviation Safety Program, Synthetic Vision Systems Project is developing display concepts to improve pilot terrain/situational awareness by providing a perspective synthetic view of the outside world through an on-board database driven by precise aircraft positioning information updating via Global Positioning System-based data. This work is aimed at eliminating visibility-induced errors and low visibility conditions as a causal factor to civil aircraft accidents, as well as replicating the operational benefits of clear day flight operations regardless of the actual outside visibility condition. A flight test evaluation of tactical Synthetic Vision display concepts was recently conducted in the terrain-challenged operating environment of the Eagle County Regional Airport (Colorado). Several display concepts for head-up displays and head-down displays ranging from ARINC Standard Size A through Size X were tested. Seven pilots evaluated these displays for acceptability, usability, and situational/terrain awareness while flying existing commercial airline operating procedures for Eagle County Regional Airport. All tactical Synthetic Vision display concepts provided measurable increases in the pilot's subjective terrain awareness over the baseline aircraft displays. The head-down display presentations yielded better terrain awareness over the head-up display synthetic vision display concepts that were tested. Limitations in the head-up display concepts were uncovered that suggest further research. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP NASA, Langley Res Ctr, 24 W Taylor St, Hampton, VA 23681 USA. EM r.e.bailey@larc.nasa.gov; r.v.parrish@larc.nasa.gov; j.j.arthur@larc.nasa.gov; r.m.Norman@larc.nasa.gov NR 11 TC 12 Z9 12 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 0-8194-4463-4 J9 PROC SPIE PY 2002 VL 4713 BP 178 EP 189 DI 10.1117/12.474423 PG 12 WC Engineering, Aerospace; Computer Science, Artificial Intelligence; Imaging Science & Photographic Technology SC Engineering; Computer Science; Imaging Science & Photographic Technology GA BV20L UT WOS:000178155500018 ER PT J AU Hatcliff, J Dwyer, MB Pasareanu, CS Robby AF Hatcliff, J Dwyer, MB Pasareanu, CS Robby TI Foundations of the Bandera abstraction tools SO ESSENCE OF COMPUTATION: COMPLEXITY ANALYSIS, TRANSFORMATION SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article ID MODEL CHECKER; SPIN AB Current research is demonstrating that model-checking and other forms of automated finite-state verification can be effective for checking properties of software systems. Due to the exponential costs associated with model-checking, multiple forms of abstraction are often necessary to obtain system models that are tractable for automated checking. The Bandera. Tool Set provides multiple forms of automated support for compiling concurrent Java software systems to models that can be supplied to several different model-checking tools. In this paper, we describe the foundations of Bandera's data abstraction mechanism which is used to reduce the cardinality (and the program's state-space) of data domains in software to be model-checked. From a technical standpoint, the form of data abstraction used in Bandera. is simple, and it is based on classical presentations of abstract interpretation. We describe the mechanisms that Bandera provides for declaring abstractions, for attaching abstractions to programs, and for generating abstracted programs and properties. The contributions of this work are the design and implementation of various forms of tool support required for effective application of data abstraction to software components written in a programming language like Java which has a rich set of linguistic features. C1 Kansas State Univ, Dept Comp & Informat Sci, Manhattan, KS 66506 USA. NASA, Ames Res Ctr, Kestrel Technol, Moffett Field, CA 94035 USA. RP Hatcliff, J (reprint author), Kansas State Univ, Dept Comp & Informat Sci, 234 Nichols Hall, Manhattan, KS 66506 USA. NR 30 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 J9 LECT NOTES COMPUT SC PY 2002 VL 2566 BP 172 EP 203 PG 32 WC Computer Science, Artificial Intelligence SC Computer Science GA BW73C UT WOS:000182978300009 ER PT J AU Galleani, L Cohen, L Nelson, D Scargle, JD AF Galleani, L Cohen, L Nelson, D Scargle, JD TI Instantaneous spectrum estimation of event-based densities SO EURASIP JOURNAL ON APPLIED SIGNAL PROCESSING LA English DT Article DE time-frequency analysis; density estimation; kernel method ID DISTRIBUTIONS AB We present a method for obtaining a time-varying spectrum that is particularly suited when the data are in event-based form. This form arises in many areas of science and engineering, and especially in astronomy, where one has photon counting detectors. The method presented consists of three procedures. First, estimating the density using the kernel method; second, highpass filtering the manifestly positive density; finally, obtaining the time-frequency distribution with a modified Welch's method. For the sake of validation, event-based data are generated from a given distribution and the proposed method is used to construct the time-frequency spectrum and is compared to the original density. The results demonstrate the effectiveness of the method. C1 Politecn Torino, Dipartimento Elettron, I-10129 Turin, Italy. CUNY, New York, NY 10021 USA. US Dept Def, Ft George G Meade, MD 20755 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Galleani, L (reprint author), Politecn Torino, Dipartimento Elettron, Cso Duca Abruzzi 24, I-10129 Turin, Italy. EM galleani@polito.it; leon.cohen@hunter.cuny.edu; waveland@erols.com; jeffrey@cosmic.arc.nasa.gov NR 18 TC 2 Z9 2 U1 0 U2 1 PU HINDAWI PUBLISHING CORPORATION PI NEW YORK PA 410 PARK AVENUE, 15TH FLOOR, #287 PMB, NEW YORK, NY 10022 USA SN 1110-8657 J9 EURASIP J APPL SIG P JI EURASIP J Appl. Signal Process. PD JAN PY 2002 VL 2002 IS 1 BP 87 EP 91 DI 10.1155/S1110865702000380 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA 574LY UT WOS:000176892900011 ER PT S AU Gebremedhin, AH Manne, F Pothen, A AF Gebremedhin, AH Manne, F Pothen, A BE Monien, B Feldmann, R TI Parallel distance-k coloring algorithms for numerical optimization SO EURO-PAR 2002 PARALLEL PROCESSING, PROCEEDINGS SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 8th International Euro-Par Conference on Parallel Processing CY AUG 27-30, 2002 CL PADERBORN, GERMANY ID SPARSE JACOBIAN MATRICES AB Matrix partitioning problems that arise in the efficient estimation of sparse Jacobians and Hessians can be modeled using variants of graph coloring problems. In a previous work [6], we argue that distance-2 and distance-3/2 graph coloring are robust and flexible formulations of the respective matrix estimation problems. The problem size in large-scale optimization contexts makes the matrix estimation phase an expensive part of the entire computation both in terms of execution time and memory space. Hence, there is a need for both shared-and distributed-memory parallel algorithms for the stated graph coloring problems. In the current work, we present the first practical shared address space parallel algorithms for these problems. The main idea in our algorithms is to randomly partition the vertex set equally among the available processors, let each processor speculatively color its vertices using information about already colored vertices, detect eventual conflicts in parallel, and finally re-color conflicting vertices sequentially. Randomization is also used in the coloring phases to further reduce conflicts. Our PRAM-analysis shows that the algorithms should give almost linear speedup for sparse graphs that are large relative to the number of processors. Experimental results from our OpenMP implementations on,a Cray Origin2000 using various large graphs show that the algorithms indeed yield reasonable speedup for modest numbers of processors. C1 Univ Bergen, Dept Informat, N-5020 Bergen, Norway. Old Dominion Univ, Dept Comp Sci, Norfolk, VA 23529 USA. Sandia Natl Labs, CSRI, Albuquerque, NM 87185 USA. NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. RP Univ Bergen, Dept Informat, N-5020 Bergen, Norway. EM assefaw@ii.uib.no; fredrikm@ii.uib.no OI Pothen, Alex/0000-0002-3421-3325 NR 12 TC 9 Z9 9 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-44049-6 J9 LECT NOTES COMPUT SC PY 2002 VL 2400 BP 912 EP 921 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BY68Q UT WOS:000189438700130 ER PT J AU Rubinstein, R Zhou, Y AF Rubinstein, R Zhou, Y TI Characterization of sound radiation by unresolved scales of motion in computational aeroacoustics SO EUROPEAN JOURNAL OF MECHANICS B-FLUIDS LA English DT Article ID ISOTROPIC TURBULENCE; NOISE; GENERATION; MODEL AB Evaluation of the sound sources in a high Reynolds number turbulent flow requires time-accurate resolution of an extremely large number of scales of motion. Direct numerical simulations will therefore remain infeasible for the forseeable future; although current large eddy simulation methods can resolve the largest scales of motion accurately, they must leave some scales of motion unresolved. A priori studies show that acoustic power can be underestimated significantly if the contribution of these unresolved scales is simply neglected. In this paper, the problem of evaluating the sound radiation properties of the unresolved, subgrid-scale motions is approached in the spirit of the simplest subgrid stress models: the unresolved velocity field is treated as isotropic turbulence with statistical descriptors evaluated from the resolved field. The theory of isotropic turbulence is applied to derive formulas for the total power and the power spectral density of the sound radiated by a filtered velocity field. These quantities are compared with the corresponding quantities for the unfiltered field for various filter types and widths. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved. C1 NASA, Langley Res Ctr, COmputat Modeling & Simulat Branch, Hampton, VA 23681 USA. RP Rubinstein, R (reprint author), NASA, Langley Res Ctr, COmputat Modeling & Simulat Branch, Hampton, VA 23681 USA. EM r.rubinstein@larc.nasa.gov NR 22 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0997-7546 EI 1873-7390 J9 EUR J MECH B-FLUID JI Eur. J. Mech. B-Fluids PD JAN-FEB PY 2002 VL 21 IS 1 BP 105 EP 111 AR PII S0997-7546(01)01157-8 DI 10.1016/S0997-7546(01)01157-8 PG 7 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 525PD UT WOS:000174079400007 ER PT B AU Kotani, T Band, D Denissyuk, EK Kawai, N Kinugasa, K Namiki, M Safi-Harb, S Trushkin, S AF Kotani, T Band, D Denissyuk, EK Kawai, N Kinugasa, K Namiki, M Safi-Harb, S Trushkin, S BE Tout, CA VanHamme, W TI X-ray observations of SS 433: Review and recent results SO EXOTIC STARS AS CHALLENGES TO EVOLUTION, PROCEEDINGS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 187 Colloquium on Exotic Stars as Challenges to Evolution CY MAR 04-08, 2002 CL MIAMI, FL SP Int Astron Union, Max-Planck Inst Astron, Florida Int Univ, Div Sponsored Res, Florida Int Univ, Coll Art & Sci, Florida Int Univ, Dept Phys ID SS-433; EMISSION; SS433 AB The X-ray characteristics of SS 433 are reviewed together with results of recent multi-wavelength observing campaigns. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kotani, T (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-122-2 J9 ASTR SOC P PY 2002 VL 279 BP 19 EP 24 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV93M UT WOS:000180451700002 ER PT B AU Lissauer, JJ Backman, DE AF Lissauer, JJ Backman, DE BE Tout, CA VanHamme, W TI The beta Pictoris disk: Peculiar or just young? SO EXOTIC STARS AS CHALLENGES TO EVOLUTION, PROCEEDINGS SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT 187 Colloquium on Exotic Stars as Challenges to Evolution CY MAR 04-08, 2002 CL MIAMI, FL SP Int Astron Union, Max-Planck Inst Astron, Florida Int Univ, Div Sponsored Res, Florida Int Univ, Coll Art & Sci, Florida Int Univ, Dept Phys ID HST-GHRS OBSERVATIONS; HERBIG AE/BE STARS; SOLAR-TYPE STARS; CIRCUMSTELLAR DISK; LIGHT VARIATIONS; INFALLING COMETS; MAIN-SEQUENCE; DUSTY DEBRIS; SYSTEM; GAS AB The star beta Pictoris is not in itself very remarkable; however, it is surrounded by a dust disk that is much more prominent than any other main sequence star's disk. The proximity of beta Pic and the nearly edge-on viewing geometry of the disk enhance its appearance,, but do not fully account for the disk's prominence. While it is possible that beta Pic's disk is intrinsically unusual, a more likely explanation is that beta Pic is simply a very young (similar to 20. Myr old) main sequence star with a consequently denser second-generation debris disk remnant of its protostellar disk than possessed by older main sequence A stars. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Lissauer, JJ (reprint author), NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA. EM jlissauer@mail.arc.nasa.gov NR 69 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 1-58381-122-2 J9 ASTR SOC P PY 2002 VL 279 BP 309 EP 317 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BV93M UT WOS:000180451700039 ER PT J AU Fowler, AM Merrill, KM Ball, W Henden, A Vrba, F McCreight, C AF Fowler, AM Merrill, KM Ball, W Henden, A Vrba, F McCreight, C TI Orion: A 1-5 micron focal plane for the 21st century SO EXPERIMENTAL ASTRONOMY LA English DT Article DE buttability; Complementary Metal Oxide Semiconductor (CMOS); focal plane; infrared AB The Orion program is a project to develop a 2K x 2K infrared focal plane using InSb p-on-n diodes for detectors. It is the natural follow-up to the successful Aladdin 1K x 1K program started in the early 90's. The work is being done at the Raytheon Infrared Operations Division (RIO, previously known as the Santa Barbara Research Center) by many of the same people who created the Aladdin focal plane. The design is very similar to the successful Aladdin design with the addition of reference pixels, whole array readout (no quadrants), two-adjacent-side buttability, and a packaging design that includes going directly to the ultimate focal plane size of 4K x 4K. So far we have successfully made a limited number of hybrid modules with InSb detectors. In this paper we will describe the design features and test data taken from some of these devices. C1 Natl Opt Astron Observ, Tucson, AZ 85719 USA. USNO Flagstaff, Flagstaff, AZ USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Fowler, AM (reprint author), Natl Opt Astron Observ, Tucson, AZ 85719 USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0922-6435 J9 EXP ASTRON JI Exp. Astron. PY 2002 VL 14 IS 1 BP 61 EP 68 DI 10.1023/A:1026154825645 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 732AV UT WOS:000185919400007 ER PT J AU Clampin, M Sirianni, M Hartig, GF Ford, HC Illingworth, GD Burmester, B Koldewynd, W Martel, AR Riess, A Schrein, RJ Sullivan, PC AF Clampin, M Sirianni, M Hartig, GF Ford, HC Illingworth, GD Burmester, B Koldewynd, W Martel, AR Riess, A Schrein, RJ Sullivan, PC TI In-flight performance of the advanced camera for surveys CCDs SO EXPERIMENTAL ASTRONOMY LA English DT Article DE Advanced Camera for Surveys (ACS); Charge-Coupled Device (CCD); Hubble Space Telescope (HST); UV imaging; wide field imaging ID TELESCOPE IMAGING SPECTROGRAPH AB The Advanced Camera for Surveys (ACS), installed in the Hubble Space telescope in March 2002, will significantly extend HST's deep, survey imaging capabilities. ACS has met, or exceeded, all of its key performance specifications. In this paper we briefly review the in-flight performance of the instrument's CCD detectors and preview early ACS science observations. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Calif Observ, Lick Observ, Santa Cruz, CA USA. Ball Aerosp & Technol Corp, Boulder, CO USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Clampin, M (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. RI Clampin, mark/D-2738-2012 NR 9 TC 1 Z9 1 U1 1 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0922-6435 J9 EXP ASTRON JI Exp. Astron. PY 2002 VL 14 IS 2 BP 107 EP 115 DI 10.1023/B:EXPA.0000004358.00269.51 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 744MR UT WOS:000186636700006 ER PT S AU Bock, JJ AF Bock, JJ BE DePetris, M Gervasi, M TI Bolometers for millimeter-wave cosmology SO EXPERIMENTAL COSMOLOGY AT MILLIMETRE WAVELENGTHS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Breuil-Cervinia Workshop on Experimental Cosmology at Millimetre Wavelengths CY JUL 09-13, 2001 CL BRUIL-CERVINIA, ITALY SP Rivoira, Agilent Technol, Tektronix, QMC Instruments Ltd, Superelect, Ist San Paolo Torino AB Bolometers offer high sensitivity for observations of the cosmic microwave background, Sunyaev-Zel'Dovich effect in clusters, and far-infrared galaxies. Near background-limited performance may be realized even under the low background conditions available from a space-borne platform. We discuss the achieved performance of silicon nitride micromesh ('spider web') bolometers readout by NTD Ge thermistors. We are developing arrays of such bolometers coupled to single-mode feedhorns. CMB polarization may be studies using a new absorber geometry allowing simultaneous detection of both linear polarizations in a single feedhorn with two individual detectors. Finally we discuss a new bolometer architecture consisting of an array of slot antennae coupled to filters and bolometers via superconducting microstrip. C1 Jet Prop Lab, Pasadena, CA 91107 USA. RP Bock, JJ (reprint author), Jet Prop Lab, M-S 169-327,4800 Oak Grove Dr, Pasadena, CA 91107 USA. NR 5 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0062-8 J9 AIP CONF PROC PY 2002 VL 616 BP 251 EP 258 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU75M UT WOS:000176917100045 ER EF