FN Thomson Reuters Web of Science™ VR 1.0 PT B AU Morelli, MV Juday, RD AF Morelli, MV Juday, RD BE Casasent, DP Chao, TH TI System noise limitations on the utility of an LC-SLM SO OPTICAL PATTERN RECOGNITION VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Pattern Recognition VIII CY APR 22-23, 1997 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers DE optical correlation; spatial light modulator; liquid crystal; noise AB A measure is proposed for the utility of a spatial light modulator, as relates to using the SLM in a realistic optical correlator. In this paper, the metric of utility is particularized to the birefringent liquid crystal SLM. RP Morelli, MV (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,CODE ER4,HOUSTON,TX 77058, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2488-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3073 BP 225 EP 231 DI 10.1117/12.270368 PG 3 WC Optics SC Optics GA BH52H UT WOS:A1997BH52H00023 ER PT B AU Park, Y Chao, TH AF Park, Y Chao, TH BE Casasent, DP Chao, TH TI Automatic target recognition processor using an optical wavelet preprocessor and an electronic neural classifier SO OPTICAL PATTERN RECOGNITION VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Pattern Recognition VIII CY APR 22-23, 1997 CL ORLANDO, FL SP Soc Photo Opt Instrumentat Engineers DE ATR; optical processor; wavelet filter; feature extraction; Hermite Moment; face recognition; vehicle classification; neural network AB A comprehensive automatic target recognition (ATR) system using a wavelet transform based target detection preprocessor and a neural network classifier is described. A compact, high-speed optical wavelet processor with full gray scale filter capability, recently developed at JPL has been used for real-time target detection preprocessing. An innovative feature extraction algorithm using the Hermite Moments has been developed and used for neural net classification. The extracted Hermite Moment features, with their greatly reduced dimension and efficient representation, has enabled rapid neural training with test with very high classification and low false alarm rate. Experimental demonstration for face recognition and vehicle classification has been successfully carried out using this ATR system. RP Park, Y (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,M-S 303-300,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2488-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3073 BP 299 EP 306 DI 10.1117/12.270376 PG 4 WC Optics SC Optics GA BH52H UT WOS:A1997BH52H00030 ER PT S AU Wernet, MP AF Wernet, MP BE Cha, SS Trolinger, JD Kawahashi, M TI PIV for turbomachinery applications SO OPTICAL TECHNOLOGY IN FLUID, THERMAL, AND COMBUSTION FLOW III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Technology in Fluid, Thermal, and Combustion Flow III CY JUL 28-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Visualizat Soc Japan DE particle imaging velocimetry; rotating machinery; turbomachinery; compressor; transonic; correlation processing; light sheet; periscope AB Particle Imaging Velocimetry (PIV) is emerging as a powerful measurement technique which can be used as an alternative or complementary approach to Laser Doppler Velocimetry (LDV) in a wide range of research applications. The instantaneous planar velocity measurements obtained with PIV make it an attractive technique for use in the study of the complex flow fields encountered in turbomachinery. The data acquired offer several advantages over traditional LDV data: higher accuracy; multiple measurement points and the ability to study both transient and steady state flow phenomena. Many of the same issues encountered in the application of LDV techniques to rotating machinery apply in the application of PIV. Techniques for optical access, light sheet delivery and particulate seeding are discussed. Preliminary results from the successful application of the PIV technique to a transonic axial compressor are presented. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Wernet, MP (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 4 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2594-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3172 BP 2 EP 16 DI 10.1117/12.279732 PG 15 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BK08W UT WOS:000071157200001 ER PT S AU Gray, JF AF Gray, JF BE Cha, SS Trolinger, JD Kawahashi, M TI Analysis and design of dual source illumination methods for lateral correction of the flat field luminance function SO OPTICAL TECHNOLOGY IN FLUID, THERMAL, AND COMBUSTION FLOW III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Technology in Fluid, Thermal, and Combustion Flow III CY JUL 28-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Visualizat Soc Japan DE illumination methods; luminance functions; dual source illumination; lighting design AB Uniform flat field detection of reflected light from opaque aerosol particles can be utilized to determine the material densities of an aerosol spray process and predict material distributions and physical properties of the applied substances. Design of an appropriate lighting system for this type of process monitoring involves consideration of numerous optical and dimensional properties affecting the delivery, scattering, collection, and detection of light. A novel design and analysis technique for this type of optical system is presented. C1 NASA, George C Marshall Space Flight Ctr, MAF, Manned Space Syst Div,Lockheed Martin, New Orleans, LA 70189 USA. RP Gray, JF (reprint author), NASA, George C Marshall Space Flight Ctr, MAF, Manned Space Syst Div,Lockheed Martin, New Orleans, LA 70189 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2594-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3172 BP 55 EP 68 DI 10.1117/12.279758 PG 14 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BK08W UT WOS:000071157200006 ER PT S AU Tuma, M Gruhlke, R AF Tuma, M Gruhlke, R BE Cha, SS Trolinger, JD Kawahashi, M TI Integrated thin film fluorescence NOx sensor: Concept SO OPTICAL TECHNOLOGY IN FLUID, THERMAL, AND COMBUSTION FLOW III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Technology in Fluid, Thermal, and Combustion Flow III CY JUL 28-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Visualizat Soc Japan DE fluorescence sensor; emission method; NOx; grating; waveguide; surface plasmon AB A fluorescence sensor system is proposed that integrates emission and detection methods as well as optical and electronic components in a thin film geometry. Predicted properties of this sensor include: increased sensitivity, shielding from unwanted radiation, wavelength filtering, potential operation at high temperatures, and miniaturization. The sensor can be tuned to measure a wide variety of species by varying its thin film corrugation periodicity, in particular, the sensor can be used to detect NOx. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Tuma, M (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 1 Z9 1 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 0-8194-2594-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3172 BP 98 EP 105 DI 10.1117/12.293421 PG 8 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BK08W UT WOS:000071157200010 ER PT S AU Decker, AJ Fite, EB Mehmed, O Thorp, SA AF Decker, AJ Fite, EB Mehmed, O Thorp, SA BE Cha, SS Trolinger, JD Kawahashi, M TI Processing speckle patterns with model trained neural networks SO OPTICAL TECHNOLOGY IN FLUID, THERMAL, AND COMBUSTION FLOW III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Technology in Fluid, Thermal, and Combustion Flow III CY JUL 28-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Visualizat Soc Japan DE speckle patterns; neural networks; electronic holography; models AB Artificial neural networks can be used to process patterns corrupted by the laser speckle effect. This paper discusses an example where neural networks were used to detect structural damage using characteristic fringe patterns as input. The artificial neural networks were trained with fringe patterns generated from a finite element model and a simple model of the laser speckle effect. The neural networks were tested on patterns generated by both models and real structures. The neural networks are being developed as high-speed processors for electronic holography. This paper quantifies the overhead required to make neural networks robust to the laser speckle effect. There is a discussion of the ability of these networks to generalize at finite element resolutions on the underlying fringe patterns. The ultimate objective is to test whether combinations of electronic holography and neural networks can be effective interfaces between computational models and experiments or tests. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Decker, AJ (reprint author), NASA, Lewis Res Ctr, MS 77-1,21000 Brookpk Rd, Cleveland, OH 44135 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 0-8194-2594-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3172 BP 285 EP 293 DI 10.1117/12.279741 PG 9 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BK08W UT WOS:000071157200027 ER PT S AU Buggele, AE Seasholtz, RG AF Buggele, AE Seasholtz, RG BE Cha, SS Trolinger, JD Kawahashi, M TI Improved optical techniques for studying sonic and supersonic injection into Mach 3 flow SO OPTICAL TECHNOLOGY IN FLUID, THERMAL, AND COMBUSTION FLOW III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Technology in Fluid, Thermal, and Combustion Flow III CY JUL 28-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Visualizat Soc Japan AB Filtered Rayleigh Scattering and shadowgraph flow visualization were used to characterize the penetration of helium or moist air injected transversely at several pressures into a Mach 3 flow in the NASA Lewis 3.81 inch by 10 inch continuous flow supersonic wind tunnel. This work is in support of the LOX (liquid oxygen) Augmented Nuclear Thermal Rocket program. The present study used an injection-seeded, frequency doubled Nd:YAG pulsed laser to illuminate a transverse section of the injectant plume. Rayleigh scattered light was passed through an iodine absorption cell to suppress stray laser light and was imaged onto a cooled CCD camera. The scattering was based on condensation of water vapor in the injectant flow. Results are presented for various configurations of sonic and supersonic injector designs mounted primarily in the floor of the tunnel. Injectors studied include a single 0.25 inch diameter hole, five 0.112 inch diameter holes on 0.177 inch spacing, and a 7 degrees half angle wedge. High speed shadowgraph flow visualization images were obtained with several video camera systems. Roof and floor static pressure data are presented several ways for the three configurations of injection designs with and without helium and/or air injection into Mach 3 flow. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Buggele, AE (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 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 0-8194-2594-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3172 BP 504 EP 517 DI 10.1117/12.293408 PG 14 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BK08W UT WOS:000071157200052 ER PT S AU Adamovsky, G Ida, N AF Adamovsky, G Ida, N BE Cha, SS Trolinger, JD Kawahashi, M TI Laser beam propagation through inhomogeneous media with shock-like profiles: modeling and computing SO OPTICAL TECHNOLOGY IN FLUID, THERMAL, AND COMBUSTION FLOW III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Technology in Fluid, Thermal, and Combustion Flow III CY JUL 28-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Visualizat Soc Japan AB Wave propagation in inhomogeneous media has been studied for such diverse applications as propagation of radiowaves in atmosphere, light propagation through thin films and in inhomogeneous waveguides, flow visualization, and others. In recent years an increased interest has been developed in wave propagation through shocks in supersonic flows. Results of experiments conducted in the past few years has shown such interesting phenomena as a laser beam splitting and spreading. The paper describes a model constructed to propagate a laser beam through shock-like inhomogeneous media. Numerical techniques are presented to compute the beam through such media. The results of computation are presented, discussed, and compared with experimental data. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Adamovsky, G (reprint author), NASA, Lewis Res Ctr, Brookpk Rd, Cleveland, OH 44135 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2594-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3172 BP 530 EP 539 DI 10.1117/12.293410 PG 10 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BK08W UT WOS:000071157200054 ER PT S AU Shirinzadeh, B AF Shirinzadeh, B BE Cha, SS Trolinger, JD Kawahashi, M TI The rotational dependence of collisional quenching of OH fluorescence from (2)Sigma(+) (nu '=0) levels due to water molecules near room temperature SO OPTICAL TECHNOLOGY IN FLUID, THERMAL, AND COMBUSTION FLOW III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Technology in Fluid, Thermal, and Combustion Flow III CY JUL 28-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Visualizat Soc Japan AB Using a narrow band, frequency-doubled output of a pulsed-dye-amplifier (PDA), simultaneous absorption and laser-induced fluorescence (LIF) measurements of OH have been performed to study the rotational dependence of the collisional quenching of the OH fluorescence emission from (2) Sigma(+) + (v' = 0) levels due to water molecules. In these studies, the OH was produced in a low pressure (0.6 to 1.6 torr) water vapor microwave discharge cell. The microwave power was varied in the range between 30 to 50 Watts in order to investigate variations in the quenching rate, translational, and rotational temperatures with microwave power. From the absorption lineshape data, it was determined that, for a given microwave setting, the OH molecules in the region of excitation are in both rotational and translational thermal equilibrium (T - 340 K). The quenching results indicate a slight variation (decrease) with increasing microwave power. They also show a variation with the excited rotational level. For K' > 4, the quenching rate decreases as the rotational level excitation increases. This is in agreement with previously observed trends. Finally, the quenching rate data obtained in this study are compared to those available in the literature and discrepancies are discussed. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Shirinzadeh, B (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2594-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3172 BP 605 EP 615 DI 10.1117/12.279760 PG 11 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BK08W UT WOS:000071157200061 ER PT S AU Seasholtz, RG Buggele, AE AF Seasholtz, RG Buggele, AE BE Cha, SS Trolinger, JD Kawahashi, M TI Improvement in suppression of pulsed Nd : YAG laser light with iodine absorption cells for filtered Rayleigh scattering measurements SO OPTICAL TECHNOLOGY IN FLUID, THERMAL, AND COMBUSTION FLOW III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Technology in Fluid, Thermal, and Combustion Flow III CY JUL 28-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Visualizat Soc Japan DE Rayleigh scattering; iodine absorption; Fabry-Perot interferometers; Nd : YAG lasers AB Filtered Rayleigh scattering using iodine absorption cells is an effective technique for obtaining density, temperature, and velocity measurements in high speed confined flows. By tuning a single frequency laser to a strong iodine absorption line, stray scattered laser light can be greatly suppressed. For example, the minimum transmission predicted by an iodine vapor at 0.46 T. Measurements obtained by other researches using a CW Nd:YAG laser agree with the model calculations. However, measurements made by us and by others using Q-switched, injection-seeded, frequency doubled Nd:YAG lasers only show minimum transmission of about 3 x 10(-3). This greatly reduces the applicability of the filtered Rayleigh scattering technique using these lasers in experiments having large amounts of stray scattered laser light. The purposes of the present study are to characterize the spectrum of the excess light transmitted by the iodine cell and to make changes to the laser to reduce the transmitted laser light. Transmission data as a function of laser frequency for the iodine absorption line at 18788.44 cm(-1) are presented. A planar mirror Fabry-Perot interferometer was used to characterize the frequency spectrum of the light passed through the cell. Measurements taken with the laser tuned to the center of the iodine absorption line show the light transmitted through the iodine cell to have a component with a bandwidth of about 40 GHz. This is probably caused by other modes in the laser that exist in spite of the single frequency injection beam. A second broadband component was also observed, possibly caused by the laser flash lamps or by fluorescence. An intracavity etalon was installed in the laser oscillator cavity to suppress the 40 GHz component. Measurements taken with the etalon tuned to the injection frequency showed a reduction in the transmitted laser light. This improvement allows the iodine cell to block significantly more of the stray laser light in filtered Rayleigh scattering experiments. Examples are given of filtered Rayleigh scattering measurements showing the effect of the etalon on measurements taken in a Mach 3 flow in the NASA Lewis 4 inch by 10 inch supersonic wind tunnel. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Seasholtz, RG (reprint author), NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2594-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3172 BP 625 EP 635 DI 10.1117/12.293414 PG 11 WC Engineering, Mechanical; Optics SC Engineering; Optics GA BK08W UT WOS:000071157200063 ER PT B AU Kim, Q Cunningham, TJ Fossum, ER AF Kim, Q Cunningham, TJ Fossum, ER BE Park, YS Ramaswamy, RV TI Monolithic InGaAs JFET active pixel tunable image sensor (MAPTIS) SO OPTOELECTRONIC INTEGRATED CIRCUITS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Optoelectronic Integrated Circuits CY FEB 12-14, 1997 CL SAN JOSE, CA SP USN, Off Naval Res, Soc Photo Opt Instrumentat Engineers, Def Adv Res Projects Agcy DE hyper spectral responses; monolithic; near room temperature; active pixel sensor AB A new Monolithic InGaAs Active Pixel Multispectral Image Sensor is described. This Infrared sensor will utilize high quality InGaAs grown by Molecular Beam Epitaxy on InP substrate for the fabrication of a high speed Junction Field Effect Transistor array. In1-xGaxAs is a III-V alloy whose cutoff wavelength can be tuned from 0.8 mu m (GaAs) to 3.5 mu m (InAs). Due to the spectral windows of 3-5 mu m and 8-12 mu m in atmosphere, this material has not received much attention to date for infrared focal plane arrays even though the responsivities for the 0.8-1.0 mu m, and 2.0-2.5 mu m windows for the water and carbon dioxide molecules in air are excellent. Steady advancements of InGaAs material growth and devices have been made, primarily driven by the optoelectronics industry and the high speed electronics community. Most of this knowledge exists in the public domain and is readily accessible. Detectors at 1.7 mu m cutoff can be ideally implemented as lattice matched In0.53Ga0.47As/InP PIN devices. PIN detectors require high material quality to reduce dark current and decrease bit errors. Additionally, the high intrinsic mobility of In0.53Ga0.47As enables very high speed transistors for monolithic microwave integrated circuit applications. The new Active Pixel Sensor technology, a likely successor to charge coupled device, has been successfully developed for low noise, high signal transfer efficiency imaging circuits in silicon at JPL. The silicon active pixel sensor technology is being adapted to InGaAs/InP in this exploratory development efforts. In this paper, a preliminary result of the monolithic multispectral (visible/near infrared/short-wavelength infrared) active pixel imaging sensor will be discussed for application in transportable shipboard surveillance, night vision and emission spectroscopy. RP Kim, Q (reprint author), CALTECH,JET PROP LAB,CTR SPACE MICROELECT TECHNOL,PASADENA,CA 91109, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2417-X J9 P SOC PHOTO-OPT INS PY 1997 VL 3006 BP 176 EP 185 DI 10.1117/12.264216 PG 10 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BH15A UT WOS:A1997BH15A00019 ER PT S AU Kim, Q Cunningham, TJ Pain, B Lange, MJ Olsen, GH AF Kim, Q Cunningham, TJ Pain, B Lange, MJ Olsen, GH BE Wang, SY Park, YS TI Readout characteristics of integrated monolithic InGaAs active pixel sensor array SO OPTOELECTRONIC INTEGRATED CIRCUITS II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Optoelectronic Integrated Circuits II Conference (OEIC II) CY JAN 28-30, 1998 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers DE readout circuits; dual (visible/IR) responses; monolithic; active pixel sensor (APS); InGaAs; InP imaging detector AB A newly fabricated monolithic InGaAs Active Pixel Image Sensor(1,2) is presented, and its readout characteristics are described. The sensor is fabricated from InGaAs epitaxially deposited on an InP substrate. It consists of an InGaAs photodiode connected to InP depletion-mode junction field effect transistors (JFETs) for signal buffering, selection and reset. The monolithic sensor eliminates the need for hybridization with a silicon multiplexer, and in addition, allows the sensor to be front illuminated, making it sensitive to visible as well as IR radiation. With further development, the sensor is ideal for dual band (Visible/IR) applications, including optical communication. It is also well suited to applications requiring near room temperature, broad band response such as for atmospheric gas sensing and target identification. Two different types of small 4x1 test arrays have been fabricated. One is a source follower per detector architecture. Here the signal charge is integrated on the photodiode capacitance. The photodiode is connected to a gate of a JFET configured as a source-follower, which buffers the photodiode voltage. The other test circuit uses a capacitive transimpedance amplifier. This circuit contains an inverter using an input JFET with a passive JFET load. The photodiode is connected to the JFET gate. A feed back capacitor causes the circuit to act as an integrator,while keeping the diode input bias relatively constant. Both circuits also contain JFET switches for reset and selection. Selection connects the output of the chosen cell onto a common output bus. In this exploratory development effort, the effectiveness of these two different readout circuits will be discussed in terms of leakage, operating frequency, and temperature. These results then will guide for the second phase demonstration of integrated two dimensional monolithic active pixel sensor arrays for application in transportable shipboard surveillance, night-vision and emission spectroscopy. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Kim, Q (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2729-2 J9 P SOC PHOTO-OPT INS PY 1997 VL 3290 BP 278 EP 286 DI 10.1117/12.298251 PG 9 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BK25Z UT WOS:000071633100030 ER PT S AU Kolenkiewicz, R Smith, DE Dunn, PJ Torrence, MH AF Kolenkiewicz, R Smith, DE Dunn, PJ Torrence, MH BE Dow, JM TI Advances in SLR orbit determination SO ORBIT DETERMINATION AND ANALYSIS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT PSD 1 Symposium of COSPAR Technical Panel on Satellite Dynamics - Orbit Determination and Analysis, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res ID LAGEOS; EARTH; SATELLITE AB Since LAGEOS II was launched from the space shuttle in October 1992, the Global Tracking Network has provided an extensive set of Satellite Laser Ranging data which supplement the 20 year record of LAGEOS I. The contrasting behavior of small unmodeled along-track accelerations in the orbits of each satellite can be used to help explain the sources of these perturbations. LAGEOS II's 52 degree inclination provides gravity and tidal sensitivity to improve on the advances from LAGEOS I in a shorter time, as LAGEOS II's nodal precession period is about one half that of LAGEOS I's three year period. The combination of data from the two LAGEOS satellites, together with observations from other geodetic satellites, such as ETALON I and II, allows better definition of polar motion and length-of-day, which can now be resolved at sub-daily intervals during periods of concentrated tracking. The geometry added by LAGEOS II has also been found to improve station positioning accuracy for studies of regional deformation in the vicinity of the laser observatories. The improved SLR global reference frame can now be used to accurately define orbit and station positions from a variety of space and conventional geodetic methods. Published by Elsevier Science on behalf of COSPAR. C1 HUGHES STX CORP,GREENBELT,MD 20770. RP Kolenkiewicz, R (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 926,GREENBELT,MD 20771, USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1177 BN 0-08-043288-3 J9 ADV SPACE RES PY 1997 VL 19 IS 11 BP 1661 EP 1665 DI 10.1016/S0273-1177(97)00321-9 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ16E UT WOS:A1997BJ16E00005 ER PT J AU Watson, AB AF Watson, A. B. TI Entropy masking SO PERCEPTION LA English DT Meeting Abstract C1 [Watson, A. B.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM abwatson@mail.arc.nasa.gov NR 0 TC 8 Z9 8 U1 0 U2 0 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 1997 VL 26 SU S BP 2 EP 2 PG 1 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA V17AS UT WOS:000207910700007 ER PT J AU Ahumada, AJ Beard, BL AF Ahumada, A. J., Jr. Beard, B. L. TI Calibration of a spatiotemporal discrimination model from forward, simultaneous, and backward masking SO PERCEPTION LA English DT Meeting Abstract C1 [Ahumada, A. J., Jr.] NASA, Ames Res Ctr, Moffett Field, CA USA. [Beard, B. L.] Univ Calif Berkeley, Sch Optometry, Berkeley, CA 95720 USA. EM al@vision.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 1997 VL 26 SU S BP 24 EP 24 PG 1 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA V17AS UT WOS:000207910700068 ER PT J AU Eckstein, MP Beutter, BB Stone, LS AF Eckstein, M. P. Beutter, B. B. Stone, L. S. TI The accuracy of saccadic and perceptual decisions in visual search SO PERCEPTION LA English DT Meeting Abstract C1 [Beutter, B. B.; Stone, L. S.] NASA, Ames Res Ctr, Flight Management & Human Factors Div, Moffett Field, CA 94035 USA. [Eckstein, M. P.] Cedars Sinai Med Ctr, Dept Med Phys & Imaging, Los Angeles, CA 90048 USA. EM miguel@vision.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 1 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 1997 VL 26 SU S BP 70 EP 70 PG 1 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA V17AS UT WOS:000207910700193 ER PT J AU Thompson, P Stone, LS AF Thompson, P. Stone, L. S. TI Up-down asymmetries in speed perception SO PERCEPTION LA English DT Meeting Abstract C1 [Thompson, P.] Univ York, Dept Psychol, York YO1 5DD, N Yorkshire, England. [Stone, L. S.] NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA. EM pt2@york.ac.uk NR 0 TC 1 Z9 1 U1 0 U2 0 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 1997 VL 26 SU S BP 79 EP 79 PG 1 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA V17AS UT WOS:000207910700216 ER PT J AU Li, J Cohen, MM DeRoshia, CW Guzy, LT AF Li, J. Cohen, M. M. DeRoshia, C. W. Guzy, L. T. TI Effects of observer orientation on perception of ego- and exocentric spatial locations SO PERCEPTION LA English DT Meeting Abstract C1 [Li, J.; Cohen, M. M.; DeRoshia, C. W.; Guzy, L. T.] NASA, Ames Res Ctr, Gravitat Res Branch, Moffett Field, CA 94035 USA. EM jli@pioneer.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 1997 VL 26 SU S BP 102 EP 103 PG 2 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA V17AS UT WOS:000207910700282 ER PT J AU Beard, BL Ahumada, AJ AF Beard, B. L. Ahumada, A. J., Jr. TI Relevant image features for Vernier acuity SO PERCEPTION LA English DT Meeting Abstract C1 [Beard, B. L.] Univ Calif Berkeley, Sch Optometry, Berkeley, CA 95720 USA. [Ahumada, A. J., Jr.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM tina@adage.berkeley.edu NR 0 TC 0 Z9 0 U1 0 U2 0 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 1997 VL 26 SU S BP 118 EP 118 PG 1 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA V17AS UT WOS:000207910700323 ER PT B AU Bandara, S Gunapala, S Liu, J Hong, W Park, J AF Bandara, S Gunapala, S Liu, J Hong, W Park, J BE Brown, GJ Razeghi, M TI Optical coupling mechanisms in Quantum Well Infrared Photodetectors SO PHOTODETECTORS: MATERIALS AND DEVICES II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Photodetectors - Materials and Devices II CY FEB 12-14, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers, Def Adv Res Projects Agcy DE Quantum Wells; intersubband; infrared; detectors; grating AB Light coupling systems, such as gratings are required because Quantum Well Infrared Photodetectors do not respond to normal incident light due to the quantum mechanical selection rules associated with intersubband transitions. The resolution of the photolithography and accuracy of the etching become key issues in producing smaller,orating feature sizes especially in shorter wavelengths. An enhancement factor of three due to 2D periodic,orating fabricated on a QWIP structure was observed. Variation of the enhancement factor with groove depth and feature size of the grating can be theoretically explained. RP Bandara, S (reprint author), CALTECH,JET PROP LAB,CTR SPACE MICROELECT TECHNOL,PASADENA,CA 91109, USA. NR 0 TC 10 Z9 10 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2410-2 J9 P SOC PHOTO-OPT INS PY 1997 VL 2999 BP 103 EP 108 DI 10.1117/12.271180 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BH75A UT WOS:A1997BH75A00012 ER PT J AU Smith, PM Kalluri, SNV Prince, SD DeFries, R AF Smith, PM Kalluri, SNV Prince, SD DeFries, R TI The NOAA/NASA pathfinder AVHRR 8-km land data set SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Database Review ID SATELLITE DATA; AMAZON DEFORESTATION; COVER CLASSIFICATION; CANOPY REFLECTANCE; WATER-STRESS; VEGETATION; CLIMATE; YIELD; EVAPOTRANSPIRATION; PHOTOSYNTHESIS C1 UNIV MARYLAND,DEPT GEOG,COLLEGE PK,MD 20742. RP Smith, PM (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 902,GREENBELT,MD 20771, USA. NR 62 TC 38 Z9 44 U1 1 U2 1 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD JAN PY 1997 VL 63 IS 1 BP 12 EP & PG 8 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA WC714 UT WOS:A1997WC71400002 ER PT J AU Narumalani, S Jensen, JR Althausen, JD Burkhalter, S Mackey, HE AF Narumalani, S Jensen, JR Althausen, JD Burkhalter, S Mackey, HE TI Aquatic macrophyte modeling using GIS and logistic multiple regression SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID LAKES; VEGETATION; SUCCESSION; RESERVOIR; DYNAMICS; GROWTH; PLANTS AB Aquatic macrophytes are non-woody plants, larger than microscopic size, that grow in water. They are an essential component of wetland communities because they provide food and habitat for a variety of wildlife, and they regulate the chemistry of the open water. Unfortunately, they also hinder human activities by clogging reservoirs and affecting recreational activities. Given their impact on environmental processes as well as on human activities, it is important that aquatic macrophytes be monitored and managed wisely. This research focuses on developing a predictive model, based on several biophysical variables, to determine the future distribution of aquatic macrophytes. Par Pond, a cooling reservoir at the Savannah River Site in South Carolina, was selected as the study area. Four biophysical variables, including water depth, percent slope, fetch, and soils, were digitized into ct geographic information system (GIS) database. A logistic multiple regression (LMR) model was developed to derive coefficients for each variable. The model was applied to seven water depths ranging from the 181-foot contour to the 200-foot contour at Par Pond to determine the probability of aquatic macrophyte occurrence at each water level. Application of the LMR model showed that the total area of wetland would decline by nearly 114 ha between the 200- and 181-foot contours. The modeling techniques described here are useful for predicting areas of aquatic macrophyte growth and distribution, and can be used by environmental scientists to develop effective management strategies. C1 UNIV S CAROLINA,DEPT GEOG,COLUMBIA,SC 29208. UNIV S FLORIDA,DEPT GEOG,ST PETERSBURG,FL 33701. NASA,BAY ST LOUIS,MS 39529. WESTINGHOUSE SAVANNAH RIVER CO,AIKEN,SC 29808. RP Narumalani, S (reprint author), UNIV NEBRASKA,DEPT GEOG,LINCOLN,NE 68588, USA. NR 50 TC 62 Z9 70 U1 0 U2 8 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD JAN PY 1997 VL 63 IS 1 BP 41 EP 49 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA WC714 UT WOS:A1997WC71400015 ER PT J AU Liao, C Hagmann, S Bhalla, CP Grabbe, SR AF Liao, C Hagmann, S Bhalla, CP Grabbe, SR TI Differential electron-ion elastic scattering cross sections extracted from ion-atom collisions of 0.53 MeV/u Cu5+ on H-2 SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 8th International Conference on the Physics of Highly Charged Ions (HCI-96) CY SEP 23-26, 1996 CL OMIYA, JAPAN ID HE TARGETS; H2; SPECTROSCOPY; IONIZATION; PEAK AB A method of extracting electron-ion elastic scattering cross sections from ion-atom collisions has been developed By analyzing the binary encounter electron (BEe) production in energetic ion-atom collisions, which is due to loosely bound target electrons ionized through direct, hard collisions with the projectile ions, differential cross sections of electrons elastic scattered from highly charged ions are derived for a broad range of scattering angles. The cross sections are observed to deviate strongly from the Rutherford cross sections, and immediately yielded an electron diffraction in angular distribution of elastically scattered electrons. Experimental data are compared with a partial-wave treatment using the Hartree-Fock model. C1 KANSAS STATE UNIV, JR MACDONALD LAB, MANHATTAN, KS 66506 USA. RP Liao, C (reprint author), CALTECH, JET PROP LAB, 4800 OAK GROVE DR, MS 121-104, PASADENA, CA 91109 USA. NR 19 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 1997 VL T73 BP 225 EP 226 DI 10.1088/0031-8949/1997/T73/071 PG 2 WC Physics, Multidisciplinary SC Physics GA YC884 UT WOS:A1997YC88400072 ER PT J AU Liao, C Smith, SJ Chutjian, A Hitz, D AF Liao, C Smith, SJ Chutjian, A Hitz, D TI Status of the multiply-charged ion research facility at JPL SO PHYSICA SCRIPTA LA English DT Article ID ELECTRON-ENERGY-LOSS; EXCITATION CROSS-SECTIONS; MERGED-BEAMS METHODS; RESONANCE TRANSITIONS AB A new research facility for the study of interactions of multiply-charged ions has recently been completed at the Jet Propulsion Laboratory. A. 1.2tesla/14.0GHz Caprice-type electron-cyclotron-resonance (ECR) ion source is used to produce highly-charged ions. The JPL facility can deliver ions into three experimental stations. Two are currently in operation for (a) measurement of absolute electron collisional excitation cross sections, and (b) measurement of lifetimes and f-values of metastable levels. C1 CEA,DEPT RECH FONDAMENTALE MAT CONDENSEE,SERV IONS ATOM & AGREGATS,F-38054 GRENOBLE 9,FRANCE. RP Liao, C (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MS 121-104,PASADENA,CA 91109, USA. NR 11 TC 7 Z9 7 U1 1 U2 1 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0031-8949 J9 PHYS SCRIPTA JI Phys. Scr. PY 1997 VL T73 BP 382 EP 383 DI 10.1088/0031-8949/1997/T73/127 PG 2 WC Physics, Multidisciplinary SC Physics GA YC884 UT WOS:A1997YC88400128 ER PT B AU Vermote, E Vermeulen, A Ouaidrari, H Roger, JC AF Vermote, E Vermeulen, A Ouaidrari, H Roger, JC BE Guyot, G Phulpin, T TI Atmospheric correction for shortwave sensors (MODIS, ASTER, MISR, POLDER, SeaWiFs, MERIS, VEGETATION) SO PHYSICAL MEASUREMENTS AND SIGNATURES IN REMOTE SENSING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 7th International Symposium on Physical Measurements and Signatures in Remote Sensing CY APR 07-11, 1997 CL COURCHEVEL, FRANCE SP Int Soc Photogrammetry & Remote Sensing, Deutsch Forschunganstalt Luft & Raumfahrt, NASA, Nat Environm Res Council, European Space Agcy, INRA, CNRS, Assoc Quebecoise Teledetect, Canadian Remote Sensing Soc, European Assoc Remote Sensing Labs, Remote Sensing Soc, Soc Francaise Photogrammetr & Teledetect AB Remote sensing from space of the Earth's surface in the visible and near infrared channels is affected by scattering and absorption processes in the atmosphere and by atmosphere-surface coupling effects. An overview of the different atmospheric effects that have to be taken into account in the correction of the top of atmosphere signal is given. We describe the new remote sensing capabilities of the next generation of satellite sensors that allow improvement of atmospheric correction. We summarize and discuss the atmospheric correction strategies adopted, The assumption adopted in the aerosol retrieval and correction is one of the major limitations of the surface products. Validation approaches adopted for surface reflectance products are presented. C1 Univ Maryland, Dept Geog, NASA, GSFC, Greenbelt, MD 20771 USA. RP Vermote, E (reprint author), Univ Maryland, Dept Geog, NASA, GSFC, Greenbelt, MD 20771 USA. RI Vermote, Eric/K-3733-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU A A BALKEMA PUBLISHERS PI LEIDEN PA SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS BN 90-5410-917-3 PY 1997 BP 3 EP 8 PG 6 WC Remote Sensing SC Remote Sensing GA BK60H UT WOS:000072712600001 ER PT B AU Ouaidrari, H Vermote, E El Saleous, N Roy, D AF Ouaidrari, H Vermote, E El Saleous, N Roy, D BE Guyot, G Phulpin, T TI AVHRR Pathfinder II data set: Evaluation and improvements SO PHYSICAL MEASUREMENTS AND SIGNATURES IN REMOTE SENSING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 7th International Symposium on Physical Measurements and Signatures in Remote Sensing CY APR 07-11, 1997 CL COURCHEVEL, FRANCE SP Int Soc Photogrammetry & Remote Sensing, Deutsch Forschunganstalt Luft & Raumfahrt, NASA, Nat Environm Res Council, European Space Agcy, INRA, CNRS, Assoc Quebecoise Teledetect, Canadian Remote Sensing Soc, European Assoc Remote Sensing Labs, Remote Sensing Soc, Soc Francaise Photogrammetr & Teledetect AB This paper describes evaluations of the initial 8 km AVHRR PATHFINDER II test data set. From these and other evaluation activities, improvements will be made to the PATHFINDER II processing chain. The evaluations include the quantification of radiometric, geometric and temporal characteristics as well as identification of artifacts resulting from the particular processing procedures, including data management. The data set was compared with the 16 km spatial resolution LASUR (Land SUrface Reflectance) data set developed at CESBIO (Centre d'Etudes Spatiales de la BIOsphere) in France, and the 1 degrees x1 degrees FASIR NDVI data set developed at NASA-GSFC. C1 Univ Maryland, Dept Geog, NASA, GSFC, Greenbelt, MD 20771 USA. RP Ouaidrari, H (reprint author), Univ Maryland, Dept Geog, NASA, GSFC, Greenbelt, MD 20771 USA. RI Vermote, Eric/K-3733-2012 NR 0 TC 3 Z9 3 U1 0 U2 0 PU A A BALKEMA PUBLISHERS PI LEIDEN PA SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS BN 90-5410-917-3 PY 1997 BP 131 EP 137 PG 7 WC Remote Sensing SC Remote Sensing GA BK60H UT WOS:000072712600018 ER PT B AU Sandmeier, S Muller, C Hosgood, B Andreoli, G AF Sandmeier, S Muller, C Hosgood, B Andreoli, G BE Guyot, G Phulpin, T TI Sensitivity studies of bidirectional reflectance data using the EGO/JRC goniometer facility SO PHYSICAL MEASUREMENTS AND SIGNATURES IN REMOTE SENSING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 7th International Symposium on Physical Measurements and Signatures in Remote Sensing CY APR 07-11, 1997 CL COURCHEVEL, FRANCE SP Int Soc Photogrammetry & Remote Sensing, Deutsch Forschunganstalt Luft & Raumfahrt, NASA, Nat Environm Res Council, European Space Agcy, INRA, CNRS, Assoc Quebecoise Teledetect, Canadian Remote Sensing Soc, European Assoc Remote Sensing Labs, Remote Sensing Soc, Soc Francaise Photogrammetr & Teledetect AB Field campaigns allow for the acquisition of bidirectional reflectance data under natural conditions. However, already minor changes in the sun position and atmospheric conditions have an influence on the results obtained. Laboratory measurements form an ideal base for sensitivity analysis of the angular resolution and moving source (sun) positions. Moreover, they provide constant atmospheric conditions and are not influenced by the complex problem of diffuse irradiance present in the field. In respect to field applications, sensitivity analyses regarding bidirectional measurements with field-goniometers have been addressed in an EGO/JRC laboratory campaign. As a main focus, the bidirectional reflectance characteristics of a Spectralon panel were determined in order to assess the amount of error in deriving total irradiance from spot panel measurements in field applications. A watercress and a grass surface were chosen as the main targets to test the sensitivity due to the angular resolution. The impact of change in the sun position has been simulated by obtaining datasets from different lamp positions. The analysis allows to optimally compromise between short measurement time and high angular resolution in goniometric field applications. Laboratory specific constraints such as target altering due to lamp heating and impact of the non-parallelism and non-homogeneity of the lamp irradiance are assessed and taken into account in the experiments. Consequently, recommendations for the acquisition of bidirectional reflectance data in field and laboratory campaigns are given. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Sandmeier, S (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU A A BALKEMA PUBLISHERS PI LEIDEN PA SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS BN 90-5410-917-3 PY 1997 BP 357 EP 364 PG 8 WC Remote Sensing SC Remote Sensing GA BK60H UT WOS:000072712600047 ER PT B AU Asrar, G Myneni, RB Tucker, CJ AF Asrar, G Myneni, RB Tucker, CJ BE Guyot, G Phulpin, T TI Enhanced plant growth in the northern high latitudes from 1981-91 SO PHYSICAL MEASUREMENTS AND SIGNATURES IN REMOTE SENSING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 7th International Symposium on Physical Measurements and Signatures in Remote Sensing CY APR 07-11, 1997 CL COURCHEVEL, FRANCE SP Int Soc Photogrammetry & Remote Sensing, Deutsch Forschunganstalt Luft & Raumfahrt, NASA, Nat Environm Res Council, European Space Agcy, INRA, CNRS, Assoc Quebecoise Teledetect, Canadian Remote Sensing Soc, European Assoc Remote Sensing Labs, Remote Sensing Soc, Soc Francaise Photogrammetr & Teledetect AB We present evidence from satellite data that the photosynthetic activity of terrestrial vegetation increased from 1981 to 1991 in a manner suggesting an increase in plant growth associated with an increase in the duration of the active growing season. The regions of greatest increase lie between 45 degrees N and 70 degrees N where marked warming has occurred in the spring time due to an early disappearence of snow. The satellite data indicate that the global carbon cycle has responded to interannual fluctuations in temperature which, although small at the global scale, are regionally highly significant. C1 NASA, MTPE, Washington, DC 20546 USA. RP Asrar, G (reprint author), NASA, MTPE, Washington, DC 20546 USA. RI Myneni, Ranga/F-5129-2012 NR 0 TC 0 Z9 0 U1 0 U2 1 PU A A BALKEMA PUBLISHERS PI LEIDEN PA SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS BN 90-5410-917-3 PY 1997 BP 623 EP 627 PG 5 WC Remote Sensing SC Remote Sensing GA BK60H UT WOS:000072712600081 ER PT B AU Vanderbilt, VC Perry, GL Stearn, JA Ustin, SL Barrios, MCD Zedler, S Syder, J Morrissey, LA Livingston, GP Breon, FM Bouffies, S Leroy, M Herman, M Balois, JY AF Vanderbilt, VC Perry, GL Stearn, JA Ustin, SL Barrios, MCD Zedler, S Syder, J Morrissey, LA Livingston, GP Breon, FM Bouffies, S Leroy, M Herman, M Balois, JY BE Guyot, G Phulpin, T TI Discrimination of wetland and non-wetland community types with multi-spectral, multi-angle, polarized data SO PHYSICAL MEASUREMENTS AND SIGNATURES IN REMOTE SENSING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 7th International Symposium on Physical Measurements and Signatures in Remote Sensing CY APR 07-11, 1997 CL COURCHEVEL, FRANCE SP Int Soc Photogrammetry & Remote Sensing, Deutsch Forschunganstalt Luft & Raumfahrt, NASA, Nat Environm Res Council, European Space Agcy, INRA, CNRS, Assoc Quebecoise Teledetect, Canadian Remote Sensing Soc, European Assoc Remote Sensing Labs, Remote Sensing Soc, Soc Francaise Photogrammetr & Teledetect C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Vanderbilt, VC (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU A A BALKEMA PUBLISHERS PI LEIDEN PA SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS BN 90-5410-917-3 PY 1997 BP 809 EP 813 PG 5 WC Remote Sensing SC Remote Sensing GA BK60H UT WOS:000072712600107 ER PT B AU Vanderbilt, VC Baret, F AF Vanderbilt, VC Baret, F BE Guyot, G Phulpin, T TI Inversion/extraction of bio-geo-physical variables SO PHYSICAL MEASUREMENTS AND SIGNATURES IN REMOTE SENSING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 7th International Symposium on Physical Measurements and Signatures in Remote Sensing CY APR 07-11, 1997 CL COURCHEVEL, FRANCE SP Int Soc Photogrammetry & Remote Sensing, Deutsch Forschunganstalt Luft & Raumfahrt, NASA, Nat Environm Res Council, European Space Agcy, INRA, CNRS, Assoc Quebecoise Teledetect, Canadian Remote Sensing Soc, European Assoc Remote Sensing Labs, Remote Sensing Soc, Soc Francaise Photogrammetr & Teledetect C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Vanderbilt, VC (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI Baret, Fred/C-4135-2011 OI Baret, Fred/0000-0002-7655-8997 NR 0 TC 0 Z9 0 U1 0 U2 0 PU A A BALKEMA PUBLISHERS PI LEIDEN PA SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS BN 90-5410-917-3 PY 1997 BP 887 EP 889 PG 3 WC Remote Sensing SC Remote Sensing GA BK60H UT WOS:000072712600117 ER PT B AU Asrar, G Meyer-Roux, J AF Asrar, G Meyer-Roux, J BE Guyot, G Phulpin, T TI Satellite data assimilation SO PHYSICAL MEASUREMENTS AND SIGNATURES IN REMOTE SENSING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 7th International Symposium on Physical Measurements and Signatures in Remote Sensing CY APR 07-11, 1997 CL COURCHEVEL, FRANCE SP Int Soc Photogrammetry & Remote Sensing, Deutsch Forschunganstalt Luft & Raumfahrt, NASA, Nat Environm Res Council, European Space Agcy, INRA, CNRS, Assoc Quebecoise Teledetect, Canadian Remote Sensing Soc, European Assoc Remote Sensing Labs, Remote Sensing Soc, Soc Francaise Photogrammetr & Teledetect C1 NASA, Washington, DC 20546 USA. RP Asrar, G (reprint author), NASA, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU A A BALKEMA PUBLISHERS PI LEIDEN PA SCHIPHOLWEG 107C, PO BOX 447, 2316 XC LEIDEN, NETHERLANDS BN 90-5410-917-3 PY 1997 BP 897 EP 897 PG 1 WC Remote Sensing SC Remote Sensing GA BK60H UT WOS:000072712600121 ER PT J AU Ristorcelli, JR Blaisdell, GA AF Ristorcelli, JR Blaisdell, GA TI Consistent initial conditions for the DNS of compressible turbulence SO PHYSICS OF FLUIDS LA English DT Letter ID LAYERS AB Relationships between diverse thermodynamic quantities appropriate to weakly compressible turbulence are derived. It is shown that for turbulence of a finite turbulent Mach number there is a finite effect of compressibility. A methodology for generating initial conditions, consistent with finite Mach number, fur the fluctuatiug pressure, density, anti dilatational velocity is given. Use of these initial conditions gives rise to a smooth development of the flow, in contrast to cases in which these fields are specified arbitrarily or set to zero. Comparisons of the effect of different types of initial conditions are made using direct numerical simulation of decaying isotropic turbulence. (C) 1997 American Institute of Physics. C1 PURDUE UNIV,SCH AERONAUT & ASTRONAUT,W LAFAYETTE,IN 47907. RP Ristorcelli, JR (reprint author), NASA,LANGLEY RES CTR,INST COMP APPL SCI & ENGN,HAMPTON,VA 23681, USA. NR 7 TC 46 Z9 47 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD JAN PY 1997 VL 9 IS 1 BP 4 EP 6 DI 10.1063/1.869152 PG 3 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA WA983 UT WOS:A1997WA98300002 ER PT J AU Zaman, KBMQ Foss, JK AF Zaman, KBMQ Foss, JK TI The effect of vortex generators on a jet in a cross-flow SO PHYSICS OF FLUIDS LA English DT Article ID TRANSVERSE JET AB Thc effect of vortex generators in the form of tabs on the penetration and spreading of a jet in a cross-flow has been studied experimentally. It is found that the tab has very little effect when placed on the leeward side, i.e., on the downstream edge of the jet nozzle relative to the free-stream flow. A study of the static pressure distribution reveals significantly lower pressures on the leeward side. Thus, when placed on that side the tab does not produce a ''pressure hill'' of sufficient magnitude that is the primary source of streamwise vorticity in the flow field over the tab. This qualitatively explains the ineffectiveness. In comparison, there is a significant effect on the flow field when the tab is placed on the windward side. The sense of vorticity generated by the tab in the latter configuration is opposite to that of the bound vortex pair that otherwise characterizes the flow. Thus, the strength of the bound vortex pair is diminished and the jet penetration is reduced. (C) 1997 American Institute of Physics. RP Zaman, KBMQ (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 21 TC 35 Z9 38 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD JAN PY 1997 VL 9 IS 1 BP 106 EP 114 DI 10.1063/1.869154 PG 9 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA WA983 UT WOS:A1997WA98300012 ER PT J AU Shebalin, JV Woodruff, SL AF Shebalin, JV Woodruff, SL TI Kolmogorov flow in three dimensions SO PHYSICS OF FLUIDS LA English DT Article ID TURBULENT SHEAR-FLOW; BEHAVIOR AB A numerical study of the long-time evolution of incompressible Navier-Stokes turbulence forced at a single long-wavelength Fourier mode, i.e., a Kolmogorov flow, has been completed. The boundary conditions are periodic in three dimensions and the forcing is effected by imposing a steady, two-dimensional, sinusoidal shear velocity which is directed along the x-direction and varies along the z-direction. A comparison with experimental data shows agreement with measured cross-correlations of the turbulent velocity components which lie in the mean-flow plane. A statistical analysis reveals that the shear-driven turbulence studied here has significant spectral anisotropy which increases with wave number. (C) 1997 American Institute of Physics. C1 NASA, LANGLEY RES CTR, INST COMP APPL SCI & ENGN, HAMPTON, VA 23681 USA. RP NASA, LANGLEY RES CTR, AERODYNAM & ACOUST METHODS BRANCH, HAMPTON, VA 23681 USA. NR 36 TC 11 Z9 11 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 1070-6631 EI 1089-7666 J9 PHYS FLUIDS JI Phys. Fluids PD JAN PY 1997 VL 9 IS 1 BP 164 EP 170 DI 10.1063/1.869159 PG 7 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA WA983 UT WOS:A1997WA98300017 ER PT J AU Dolan, JF AF Dolan, JF TI Discussion of nature of science provokes hit-or-myth debate SO PHYSICS TODAY LA English DT Letter RP Dolan, JF (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD JAN PY 1997 VL 50 IS 1 BP 11 EP 11 DI 10.1063/1.881642 PG 1 WC Physics, Multidisciplinary SC Physics GA WB038 UT WOS:A1997WB03800001 ER PT J AU Wu, X Bender, PL Peale, SJ Rosborough, GW Vincent, MA AF Wu, X Bender, PL Peale, SJ Rosborough, GW Vincent, MA TI Determination of Mercury's 88 day libration and fluid core size from orbit SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT Workshop on Mercury - The Planet and Its Magnetosphere CY MAY, 1995 CL IMPERIAL COLLEGE LONDON, LONDON, ENGLAND SP European Space Agcy, Imperial Coll London, Phys Dept HO IMPERIAL COLLEGE LONDON AB The requirements for determining the existence and size of the suspected fluid outer core of Mercury are discussed. The moment of inertia C-m of Mercury's solid mantle and crust can be calculated from the amplitude of the 88 day forced libration in longitude and some auxiliary information, since the fluid core will not follow this motion unless its viscosity is much higher than expected. The libration amplitude can be determined from camera observations of the surface near periherm during the Mercury Orbiter mission, provided that the spacecraft location and the camera attitude are measured sufficiently well. The accuracies required are roughly 15 m in the spacecraft coordinate normal to the (polar) orbit plane and 15 arcsec in the camera attitude for 10% accuracy in C-m. The fluid core radius follows from C-m plus the total moment of inertia C and models for the composition and thermal history of the planet. Since maintaining a fluid core appears to require having perhaps 2 or 3% sulfur in the core, determination of the existence and size of the core will provide vital information on mixing of materials between different parts of the solar nebula. In this paper, the accuracy achievable for determining the spacecraft location with an X-band transponder system, as is planned for the mission, is investigated. A very preliminary covariance analysis was carried out based on 65 independent arcs starting every 10 days during the mission, with 6 h of tracking data around periherm for each arc. Gravity field coefficients up to degree and order 26 were solved for, and the effects of uncertainties in the other coefficients up to degree and order 36 were ''considered'', along with the effects of uncertainties in some additional parameters. Six of the eight parameters included in the radiation pressure model were ''considered'' rather than solved for in order to make sure that model uncertainties were allowed for adequately. The Im assumed range measurement uncertainty was treated as a bias for each arc rather than a random error. The spacecraft location determination accuracy was found to be consistent with the requirements for measuring C-m to 10% or better accuracy if C-m/C is about 0.5, as suggested by current models. (C) 1997 Published by Elsevier Science Ltd. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. UNIV COLORADO,DEPT AEROSP ENGN SCI,BOULDER,CO 80309. NR 11 TC 12 Z9 12 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JAN PY 1997 VL 45 IS 1 BP 15 EP 19 DI 10.1016/S0032-0633(96)00108-0 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WM407 UT WOS:A1997WM40700003 ER PT J AU Anderson, JD Turyshev, SG Asmar, SW Bird, MK Konopliv, AS Krisher, TP Lau, EL Schubert, G Sjogren, WL AF Anderson, JD Turyshev, SG Asmar, SW Bird, MK Konopliv, AS Krisher, TP Lau, EL Schubert, G Sjogren, WL TI Radio-science investigation on a Mercury Orbiter mission SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT Workshop on Mercury - The Planet and Its Magnetosphere CY MAY, 1995 CL IMPERIAL COLLEGE LONDON, LONDON, ENGLAND SP European Space Agcy, Imperial Coll London, Phys Dept HO IMPERIAL COLLEGE LONDON ID GRAVITATIONAL REDSHIFT; HARMONIC-ANALYSIS; SOLAR; TOPOGRAPHY; RADAR; HELIOSEISMOLOGY; OCCULTATION; PRECESSION; VOYAGER; MASS AB Results from Mariner 10 for Mercury's gravity field and results from radar ranging for elevations are reviewed. Implications of improving these results are discussed, as well as the opportunity to perform relativist gravity tests with a future Mercury Orbiter. With a spacecraft placed in orbit with periherm at 400 km altitude, apherm at 16,800 km, period 13.45 h and latitude of periherm at +30 deg, a significant improvement in measurements of Mercury's gravity field and geophysical properties will result. The 2000 Plus mission that evolved during the European Space Agency (ESA) Mercury Orbiter assessment study (Hechler, 1994) can provide a global gravity field complete through the 25th degree and order in spherical harmonics. If after completion of the main mission, the periherm could be lowered to 200 km altitude, the gravity field could be extended to 50th degree and order. Also, a search for a Hermean ionosphere could be performed during the mission phases featuring Earth occultations. Because of its relatively large eccentricity and proximity to the Sun, Mercury's orbital motion provides one of the best solar system tests of general relativity. Consequently, a number of feasible relativistic gravity tests are described within the context of the parameterized post-Newtonian formalism. Current results on the relativistic precession of Mercury's perihelion are uncertain by 0.5%, and improvements are feasible with a Mercury Orbiter mission. Also, improved limits on a possible time variation in the gravitational constant G as measured in atomic units are feasible. Moreover, by including a space-borne ultrastable crystal oscillator (USO) or an atomic clock in the Mercury Orbiter payload, a new test of the solar gravitational redshift would be possible to an accuracy of one part in 10(4) with a USO, and to an accuracy of one part in 10(7) with an atomic standard. With an atomic clock and additional hardware for a multi-link Doppler system, including Doppler extraction on the spacecraft, the effect of Mercury's gravity field on the USO's frequency could be measured with an accuracy of one part in 10(6). Other relativistic effects are discussed including the geodetic precession of the orbiter's orbital plane about Mercury, a planetary test of the Equivalence Principle (Nordtvedt effect), and a solar conjunction experiment to measure the relativistic time delay (Shapiro effect). (C) 1997 Elsevier Science Ltd. C1 UNIV BONN,INST RADIOASTRON,D-53121 BONN,GERMANY. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,DEPT EARTH & SPACE SCI,LOS ANGELES,CA 90095. RP Anderson, JD (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MS 301-230,PASADENA,CA 91109, USA. NR 60 TC 9 Z9 9 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JAN PY 1997 VL 45 IS 1 BP 21 EP 29 DI 10.1016/S0032-0633(96)00091-8 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WM407 UT WOS:A1997WM40700004 ER PT J AU Clark, PE Trombka, JI AF Clark, PE Trombka, JI TI Remote X-ray fluorescence experiments for future missions to Mercury SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT Workshop on Mercury - The Planet and Its Magnetosphere CY MAY, 1995 CL IMPERIAL COLLEGE LONDON, LONDON, ENGLAND SP European Space Agcy, Imperial Coll London, Phys Dept HO IMPERIAL COLLEGE LONDON AB To date, the only deep space mission to Mercury, Mariner 10, as well as ground-based observations have failed to provide direct measurements of that planet's composition. Such measurements are fundamental for the understanding of Mercury's origin and the inner solar system's history. The spin-stabilized Mercury Orbiter proposed for launch in the first or second decade of the twenty-first century as part of the ESA's Horizon 2000-plus plan could address this problem by including the X-ray spectrometer proposed here. X-ray spectrometers act as detectors for the X-ray emission induced by the solar flux incident on planetary surfaces. This emission is strongly dependent on the chemical composition of the surface as well as on the solar spectrum. Characteristic fluorescent lines, the most prominent being the K-alpha lines, are of sufficient intensity for major elements (Mg, Al, Si, Ca, Fe) to allow orbital measurement by remote X-ray detectors. The X-ray spectrometers described here will all have established heritage for space missions by 2000. These instruments have previously flown, are being flown as part of the NASA NEAR (Near Earth Asteroid Rendezvous) or Clark SSTI (Small Science and Technology Initiative) missions, or are now under development as part of NASA Facility Instrument Development Program. The instrument package would probably consist of an array of solid state detectors for surface measurements, as well as one which would act as a solar monitor. Calculations of anticipated results have been done for a variety of orbital and instrument configurations, and a variety of lunar soil compositions which could be analogous : anorthositic gabbro bearing soils from lunar highlands (Apollo 16), high-Mg basalt-rich soils from a KREEP-bearing area (Apollo 15), and mare basalt bearing soils (Apollo 12). The mission being considered here should result in maps of abundances of major elements, including Mg, Al, Si, Ca, and Fe, for much of Mercury's surface, with resolutions ranging from tens to hundreds of kilometers depending on the element, the orbital eccentricity and altitude of the spacecraft. (C) 1997 Published by Elsevier Science Ltd. RP Clark, PE (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 691,GREENBELT,MD 20771, USA. NR 18 TC 6 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JAN PY 1997 VL 45 IS 1 BP 57 EP 65 DI 10.1016/S0032-0633(96)00115-8 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WM407 UT WOS:A1997WM40700008 ER PT J AU Potter, AE Morgan, TH AF Potter, AE Morgan, TH TI Sodium and potassium atmospheres of Mercury SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT Workshop on Mercury - The Planet and Its Magnetosphere CY MAY, 1995 CL IMPERIAL COLLEGE LONDON, LONDON, ENGLAND SP European Space Agcy, Imperial Coll London, Phys Dept HO IMPERIAL COLLEGE LONDON ID VAPOR AB Same-day images of the sodium and potassium atmospheres of Mercury were collected over a five-day period from December 6 to 10, 1990. Both sodium and potassium emissions were more intense at ''high latitudes and varied from day to day. The maximum emissions for sodium and potassium were strongly correlated with one another. These results support the view that sodium and potassium are both generated by the same process, namely sputtering of the surface at high latitudes by magnetospheric particles. The atmospheric abundance of potassium relative to sodium was less than previously observed. It is suggested that this resulted from more rapid removal of potassium from the atmosphere by photoionization during periods of high solar activity. Published by Elsevier Science Ltd. C1 SW RES INST,SAN ANTONIO,TX. RP Potter, AE (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,SN3,HOUSTON,TX 77058, USA. NR 10 TC 51 Z9 51 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JAN PY 1997 VL 45 IS 1 BP 95 EP 100 DI 10.1016/S0032-0633(96)00100-6 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WM407 UT WOS:A1997WM40700012 ER PT J AU Slavin, JA Owen, JCJ Connerney, JEP Christon, SP AF Slavin, JA Owen, JCJ Connerney, JEP Christon, SP TI Mariner 10 observations of field-aligned currents at Mercury SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT Workshop on Mercury - The Planet and Its Magnetosphere CY MAY, 1995 CL IMPERIAL COLLEGE LONDON, LONDON, ENGLAND SP European Space Agcy, Imperial Coll London, Phys Dept HO IMPERIAL COLLEGE LONDON ID SOLAR-WIND; MAGNETOSPHERE; SUBSTORMS; ACCELERATION; CONDUCTIVITY; IONOSPHERE; DEPENDENCE; ATMOSPHERE; PARTICLES; MODEL AB The Mariner 10 observations firmly established the presence of a modest intrinsic magnetic field (M similar to 300 nT R(M)(3)) at Mercury and a magnetosphere with much the same structure as that found at the Earth. Due to the limited duration of the two passes through this small magnetosphere, about 1 h in total, the opportunities to learn about its dynamics were very limited. However, clear evidence of substorm activity was obtained in the form of intense energetic particle injections similar to those observed in the near-tail region at Earth. In this study the Mariner 10 magnetic field measurements taken during the two nightside fly-bys are re-examined for evidence of field-aligned currents (FACs). Given the very tenuous nature of the Hermean atmosphere and the high resistivity anticipated for its regolith, the FACs coupling the magnetosphere the weak ionosphere and/or planetary surface might be expected to be low in intensity and short-lived. Surprisingly, compelling evidence is found for intense FACs following a substorm-type energetic particle injection observed during the first fly-by in 1974. The interplanetary magnetic field orientation observed several minutes later when Mariner 10 exited into the magnetosheath was southward and, thus, favorable for dayside reconnection which could power substorm processes. The implications of these FAC observations for the height integrated electrical conductivity at low altitudes, for the electrodynamics of this magnetosphere, and for the planning of a future Mercury mission are discussed. (C) 1997 Published by Elsevier Science Ltd. C1 UNIV LONDON QUEEN MARY & WESTFIELD COLL,ASTRON UNIT,LONDON E1 4NS,ENGLAND. UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742. RP Slavin, JA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771, USA. RI Owen, Christopher/C-2999-2008; Slavin, James/H-3170-2012; connerney, john/I-5127-2013; OI Owen, Christopher/0000-0002-5982-4667; Slavin, James/0000-0002-9206-724X; Christon, Stephen/0000-0003-1770-2458 NR 41 TC 58 Z9 59 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JAN PY 1997 VL 45 IS 1 BP 133 EP 141 DI 10.1016/S0032-0633(96)00104-3 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WM407 UT WOS:A1997WM40700017 ER PT S AU Brace, LH Grebowsky, JM Kliore, AJ AF Brace, LH Grebowsky, JM Kliore, AJ BE Zasova, LV TI Pioneer Venus orbiter contributions to a revised Venus reference ionosphere SO PLANETARY ATMOSPHERES AND IONOSPHERES AND REFERENCE ATMOSPHERES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C3.1 Symposium of COSPAR Scientific Commission C on Planetary Atmospheres and Ionospheres and Reference Atmospheres, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP CNES, Comm Space Res, European Space Agcy, Sci Commiss D ID SOLAR-CYCLE VARIATIONS; NIGHTSIDE IONOSPHERE; ELECTRON-TEMPERATURE; DAYSIDE IONOSPHERE; MASS-SPECTROMETER; DENSITY; IONS; EUV; IONOPAUSE; PRESSURE AB The original Venus International Reference Atmosphere (VIRA) included an empirical model of the Venusian ionosphere (Bauer et al. 1985) which was based primarily on in situ and radio occultation measurements made by the Pioneer Venus Orbiter (PVO) in 1979 and 1980, a time of very high solar activity, The solar cycle variations of in situ parameters could not be determined because periapsis rose out of the main ionosphere toward the end of 1980 and remained there for the next Il years, During this period, in situ measurements of the upper nightside ionosphere were made each rime periapsis swept through the umbra. Radio occultation measurements continued to provide detailed information on the solar cycle variations of electron density, Ne, in the main ionosphere, In situ measurements of the main ionosphere resumed briefly in the Summer and Fall of 1992 as periapsis returned to low altitudes. At that time, the remaining fuel supply was used to delay the inevitable atmospheric entry in order to obtain extensive in situ measurements down to altitudes in the vicinity of 140 km, In this paper we present N-e models for solar maximum and solar minimum, and we call attention to what has been learned from the in situ measurements made since the time of the original VIRA model, focusing primarily on the solar cycle variations, These results are offered as a PVO contribution to a planned future revision of the VIRA ionosphere model. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP Brace, LH (reprint author), UNIV MICHIGAN,ANN ARBOR,MI 48109, USA. RI Grebowsky, Joseph/I-7185-2013 NR 26 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1177 BN 0-08-043284-0 J9 ADV SPACE RES PY 1997 VL 19 IS 8 BP 1203 EP 1212 DI 10.1016/S0273-1177(97)00271-8 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ16H UT WOS:A1997BJ16H00006 ER PT S AU Justus, CG James, BF Johnson, DL AF Justus, CG James, BF Johnson, DL BE Zasova, LV TI Recent and planned improvements in the Mars Global Reference Atmospheric Model (Mars-GRAM) SO PLANETARY ATMOSPHERES AND IONOSPHERES AND REFERENCE ATMOSPHERES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C3.1 Symposium of COSPAR Scientific Commission C on Planetary Atmospheres and Ionospheres and Reference Atmospheres, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP CNES, Comm Space Res, European Space Agcy, Sci Commiss D ID GENERAL-CIRCULATION; THERMOSPHERE AB This paper gives a brief review of the Mars Global Reference Atmospheric Model and provides a technical discussion of recent additions and modifications. New features include a stability-limited mountain wave model, automatic comparison with the COSPAR Mars reference atmosphere, revised surface temperature parameterization, revised thermospheric model including new latitude and time-of-day variations and improved thermospheric winds, and capability to input climate adjustment factors to account for possible cooling or other changes since the Viking era. A brief plan is also outlined for future adaptation and use of Mars-GRAM in operational aerobraking applications. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,MARSHALL SPACE FLIGHT CTR,AL 35812. RP Justus, CG (reprint author), COMP SCI CORP,POB 240005,HUNTSVILLE,AL 35824, USA. NR 14 TC 6 Z9 6 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1177 BN 0-08-043284-0 J9 ADV SPACE RES PY 1997 VL 19 IS 8 BP 1223 EP 1231 DI 10.1016/S0273-1177(97)00273-1 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ16H UT WOS:A1997BJ16H00008 ER PT S AU Houben, H Haberle, RM Young, RE Zent, AP AF Houben, H Haberle, RM Young, RE Zent, AP BE Zasova, LV TI Evolution of the Martian water cycle SO PLANETARY ATMOSPHERES AND IONOSPHERES AND REFERENCE ATMOSPHERES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C3.1 Symposium of COSPAR Scientific Commission C on Planetary Atmospheres and Ionospheres and Reference Atmospheres, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP CNES, Comm Space Res, European Space Agcy, Sci Commiss D ID VAPOR; MARS; SEASON AB The current Martian water cycle is extremely asymmetric, with large amounts of vapor subliming off a permanent north polar water ice cap in northern summer, but with no apparent major source of water vapor in the southern hemisphere, Detailed simulations of this process with a three-dimensional circulation model indicate that the summertime interhemispheric exchange (Hadley cell) is very much stronger than transport by eddies in other seasons, As a result, water ice would be distributed globally were it not for the buffering action of regolith soil adsorption which limits the net flux of water vapor off the north polar cap to amounts that are insignificant even on the scale of thousands of years, It has been suggested that the polar layered deposits are the result of exchange on these long time scales, driven by changes in Martian orbital parameters, We therefore are conducting simulations to test the effect of varied orbital parameters on the Martian water cycle, We find that when the perihelion summer pole is charged with a polar water ice cap, large quantities of water are quickly transfered to the aphelion summer pole, setting up an annual cycle that resembles the present one, Thus, the adsorptivity of the Martian regolith may be in the narrow range where it can limit net transport from the aphelion but not the perihelion pole. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. SETI INST,MT VIEW,CA. RP Houben, H (reprint author), SPACE PHYS RES INST,572 HYANNIS DR,SUNNYVALE,CA 94087, USA. NR 11 TC 3 Z9 3 U1 0 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1177 BN 0-08-043284-0 J9 ADV SPACE RES PY 1997 VL 19 IS 8 BP 1233 EP 1236 DI 10.1016/S0273-1177(97)00274-3 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ16H UT WOS:A1997BJ16H00009 PM 11543274 ER PT S AU Hollingsworth, JL Haberle, RM Schaeffer, J AF Hollingsworth, JL Haberle, RM Schaeffer, J BE Zasova, LV TI Seasonal variations of storm zones on Mars SO PLANETARY ATMOSPHERES AND IONOSPHERES AND REFERENCE ATMOSPHERES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C3.1 Symposium of COSPAR Scientific Commission C on Planetary Atmospheres and Ionospheres and Reference Atmospheres, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP CNES, Comm Space Res, European Space Agcy, Sci Commiss D ID GENERAL-CIRCULATION MODEL; ATMOSPHERIC DYNAMICS AB Using the NASA Ames Mars general circulation model, an annual cycle simulation has been performed corresponding to a low atmospheric dust loading. Surface pressure time series near the Viking Lander 2 location have been analyzed using singular spectrum analysis (SSA) and autoregressive models to isolate statistically significant spectral power. Also, circulation statistics have been separated using band-pass time filtering and analyzed for coherent spatial patterns. During northern autumn, winter and spring seasons, localized 'storm zones' can occur which are particularly strong within the lowlands of Arcadia, Acidalia and Utopia planitia. During early northern spring, the transient eddy activity is stronger than that found during any other season. With weakening baroclinicity accompanying seasonal transition toward midspring, the eddies become less vigorous and the associated storm 'belt' shifts into higher latitudes. Since transient baroclinic eddies are active agents in the transport of heat, momentum and moisture in middle latitudes, variations in the storm zones during the seasonal cycle will have important implications for Mars' regional climate. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. STERLING SOFTWARE INC,PALO ALTO,CA 94393. RP Hollingsworth, JL (reprint author), SAN JOSE STATE UNIV FDN,POB 720130,SAN JOSE,CA 95172, USA. NR 16 TC 17 Z9 17 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1177 BN 0-08-043284-0 J9 ADV SPACE RES PY 1997 VL 19 IS 8 BP 1237 EP 1240 DI 10.1016/S0273-1177(97)00275-5 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ16H UT WOS:A1997BJ16H00010 ER PT S AU Siili, T Haberle, RM Murphy, JR AF Siili, T Haberle, RM Murphy, JR BE Zasova, LV TI Sensitivity of Martian Southern polar cap edge winds and surface stresses to dust optical thickness and to the large-scale sublimation flow SO PLANETARY ATMOSPHERES AND IONOSPHERES AND REFERENCE ATMOSPHERES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C3.1 Symposium of COSPAR Scientific Commission C on Planetary Atmospheres and Ionospheres and Reference Atmospheres, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP CNES, Comm Space Res, European Space Agcy, Sci Commiss D ID GENERAL-CIRCULATION; SIMULATIONS; MOISTURE; LAYER; MODEL AB Strong surface thermal contrasts of up to 90 K occur in the spring and early summer between the retreating seasonal polar caps and the adjacent ice-free regolith. This contrast should drive strong winds. Observations indicate local dust storms being common near at least the Southern cap edge in the springtime. Models of the polar cap edge winds have not included dust in the atmosphere. Some NASA Ames Mars Global Circulation Model (MGCM; Pollack ct al., 1990; Haberle et al., 1993) results indicate sensitivity of the surface stress at Southern subtropical latitudes to changes in dust optical thickness (tau) in the 0 < tau < 1 range. In this work we have modelled the sensitivity of the Southern polar cap edge circulation and surface stress to both the dust optical thickness and the springtime sublimation flow. Models used are the MGCM and an improved version of the University of Helsinki 2-D Mars Mesoscale Model (MMM2D; Savijarvi and Siili, 1993). Model results indicate that even when both thermal contrast and mass sublimation wind generation mechanisms are invoked, calculated surface stress values remain too weak to lift dust from a topographically flat surface under conditions of low dust optical thickness. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 FINNISH METEOROL INST,FIN-00101 HELSINKI,FINLAND. RP Siili, T (reprint author), NASA,AMES RES CTR,DIV SPACE SCI,MS 245-3,MOFFETT FIELD,CA 94035, USA. NR 14 TC 16 Z9 16 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1177 BN 0-08-043284-0 J9 ADV SPACE RES PY 1997 VL 19 IS 8 BP 1241 EP 1244 DI 10.1016/S0273-1177(97)00276-7 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ16H UT WOS:A1997BJ16H00011 ER PT S AU Bougher, SW Murphy, J Haberle, RM AF Bougher, SW Murphy, J Haberle, RM BE Zasova, LV TI Dust storm impacts on the Mars upper atmosphere SO PLANETARY ATMOSPHERES AND IONOSPHERES AND REFERENCE ATMOSPHERES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C3.1 Symposium of COSPAR Scientific Commission C on Planetary Atmospheres and Ionospheres and Reference Atmospheres, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP CNES, Comm Space Res, European Space Agcy, Sci Commiss D ID GENERAL-CIRCULATION; THERMOSPHERE AB Coupling between the Mars lower (less than or equal to 80 km) and upper atmospheres is a fundamental issue affecting dynamics, tracer distributions, and energy balance. Also, this coupling has significant bearing on future mission planning to the planet (e.g. Mars Global Surveyor aerobraking). Two general circulation models are currently being run in tandem to investigate tides and their generation, propagation, and impact upon the Mars lower thermosphere. The NASA. Ames Mars General Circulation Model (MGCM) is first run for Mars near-perihelion (Ls similar to 270) conditions for which a 20-SOL dust-storm is initiated and allowed to self-consistently evolve. Subsequently, selected MGCM upper boundary fields are used to specify the height of the lower boundary and to drive semi-diurnal tides in the NCAR Mars Thermospheric General Circulation Model (MTGCM) for identical Mars parameters. MTGCM key fields are presented to illustrate the profound impact of Mars lower atmosphere heating and tides upon the Mars thermospheric structure and dynamics. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP Bougher, SW (reprint author), UNIV ARIZONA,LUNAR & PLANETARY LAB,TUCSON,AZ 85721, USA. RI Bougher, Stephen/C-1913-2013 OI Bougher, Stephen/0000-0002-4178-2729 NR 13 TC 22 Z9 22 U1 0 U2 5 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1177 BN 0-08-043284-0 J9 ADV SPACE RES PY 1997 VL 19 IS 8 BP 1255 EP 1260 DI 10.1016/S0273-1177(97)00278-0 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ16H UT WOS:A1997BJ16H00013 ER PT S AU Joshi, MM Haberle, RM Schaeffer, J Barnes, J AF Joshi, MM Haberle, RM Schaeffer, J Barnes, J BE Zasova, LV TI Seasonal variations in low level flow in the NASA-Ames Mars GCM SO PLANETARY ATMOSPHERES AND IONOSPHERES AND REFERENCE ATMOSPHERES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C3.1 Symposium of COSPAR Scientific Commission C on Planetary Atmospheres and Ionospheres and Reference Atmospheres, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP CNES, Comm Space Res, European Space Agcy, Sci Commiss D ID GENERAL-CIRCULATION; MARTIAN ATMOSPHERE; SIMULATIONS; MODEL AB The Martian Hadley circulation consists of two cells of different sizes at most times of the year, with one cell dominating near the solstices. The lower branch of this flow is strongly topographically controlled, especially east of the Tharsis plateau and Syrtis Major. Simulations using idealized topography show that longitudinal asymmetries in heating also play a role in forming the jets. Nearer the equinoxes, the total cross-equatorial flow intensity is reduced and the effect of the seasonal condensation flow is felt more strongly. Because of effects such as topography, zero cross-equatorial flow is not actually achieved at the equinoxes, but is slightly offset in time. Even when the mean flow is zero, the two jets are still present hut flow in opposite directions: the Tharsis jet flows south and the Syrtis jet north. The latter is a result of the time-averaged effect of slope wind circulations. The two jets are still relatively intense at this time, For example, with an optical depth tau of 0.3, and at a height of 250 m, <(upsilon)over bar> at L-s = 270 degrees is about 9 m s(-1) southward, while at 45 degrees W upsilon is 26 m s(-1). At L-s = 350 degrees, <(upsilon)over bar> is 0.5 m s(-1), while at 45 degrees W it is still above 8 m s(-1). The effect of atmospheric dust loading is also examined. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 OREGON STATE UNIV,DEPT ATMOSPHER SCI,CORVALLIS,OR 97331. RP Joshi, MM (reprint author), NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035, USA. RI Joshi, Manoj/C-1795-2008 OI Joshi, Manoj/0000-0002-2948-2811 NR 8 TC 2 Z9 2 U1 0 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1177 BN 0-08-043284-0 J9 ADV SPACE RES PY 1997 VL 19 IS 8 BP 1261 EP 1265 DI 10.1016/S0273-1177(97)00279-2 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ16H UT WOS:A1997BJ16H00014 ER PT S AU Mahajan, KK Hoegy, WR Pesnell, WD Brace, LH Sethi, NK AF Mahajan, KK Hoegy, WR Pesnell, WD Brace, LH Sethi, NK BE Cravens, TE Kivelson, MG TI A comparison of solar EUV flux from Langmuir probe photoelectron measurements on the Pioneer Venus Orbiter with other solar activity indicators SO PLANETARY IONOSPHERES AND MAGNETOSPHERES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT C3.2 Symposium of COSPAR Scientific Commission C on Planetary Ionospheres and Magnetospheres, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Sci Commiss D, UN Off Outer Space Affairs AB The electron temperature probe acted as a photo-diode on the Pioneer Venus Orbiter (PVO) and measured the integrated solar EUV flux (I-pe) over a 13 year period from January 1979 to December 1991, thus covering the declining phase of solar cyle 21 and the rising phase of solar cycle 22. Gross features in the solar activity variations of this flux during the 13 year period have earlier been studied by Brace et al. (1988) and Hoegy et al. (1993). In this paper, we study the fine features by translating the observed I-pe to the solar longitude of Earth (to be called as EIpe) and comparing it with other solar activity indicators like F-10.7, Lyman alpha and the solar magnetic field. We find that while the daily values of EIpe are highly correlated with F10.7 (correlation coefficient 0.87), there is a large scatter in EIpe for any value of this earth based index. Comparison of EIpe with SME and UARS-SOLSTICE Lyman-alpha measurements taken during the same period indicates that EIpe tracks Lyman-alpha quite faithfully. Similar comparison with the solar magnetic field (B-s) shows that EIpe correlates better with B-s than with F10.7. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NOMAD RES INC, BOWIE, MD 20716 USA. UNIV MICHIGAN, SPACE PHYS RES LAB, ANN ARBOR, MI 48109 USA. RP Mahajan, KK (reprint author), NATL PHYS LAB, DR KS KRISHNAN RD, NEW DELHI 110012, INDIA. RI Pesnell, William/D-1062-2012; Kivelson, Margaret/I-9019-2012 OI Pesnell, William/0000-0002-8306-2500; Kivelson, Margaret/0000-0003-3859-8581 NR 17 TC 0 Z9 0 U1 0 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043297-2 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 2 BP 187 EP 190 DI 10.1016/S0273-1177(97)00532-2 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ57J UT WOS:A1997BJ57J00011 ER PT S AU Kivelson, MG Khurana, KK Russell, CT Walker, RJ Coleman, PJ Coroniti, FV Green, J Joy, S McPherron, RL Polanskey, C Southwood, DJ Bennett, L Warnecke, J Huddleston, DE AF Kivelson, MG Khurana, KK Russell, CT Walker, RJ Coleman, PJ Coroniti, FV Green, J Joy, S McPherron, RL Polanskey, C Southwood, DJ Bennett, L Warnecke, J Huddleston, DE BE Cravens, TE Kivelson, MG TI Galileo at Jupiter: Changing states of the magnetosphere and first looks at Io and Ganymede SO PLANETARY IONOSPHERES AND MAGNETOSPHERES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT C3.2 Symposium of COSPAR Scientific Commission C on Planetary Ionospheres and Magnetospheres, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Sci Commiss D, UN Off Outer Space Affairs ID FLOW PAST IO; MAGNETIC-FIELD; MHD SIMULATION; PLASMA; SPACECRAFT; MAGNETOMETER AB Several investigations based on data from the magnetometer on the Galileo Orbiter are described. From Galileo's initial inbound pass, we learn that the magnetosphere can experience large changes in its magnetic configuration. Between 50 and 30 R-J, the radial magnetic forces on the plasma were larger in 1995 than in 1973 when Pioneer 10 passed through the same region of the magnetosphere, implying that either external or internal plasma forces were also larger. Although there are several ways to interpret the change of the magnetic configuration, we suggest that the variations are governed principally by the solar wind dynamic pressure and that the dayside magnetosphere as far in as similar to 30 R-J may be more strongly affected by the solar wind than has previously been recognized. Minor effects of higher mass loading may also be present. Data from the flyby of Io show a large magnetic perturbation; we argue that it is plausible that Io has an intrinsic magnetic field and that also contributions from plasma perturbations are significant. We find unexpected evidence that molecular ions are being picked up over a large spatial region in the vicinity of the moon. During the pass by Ganymede we observed a large magnetic perturbation consistent with an intrinsic dipole field. The multiple flybys of Ganymede scheduled for later portions of Galileo's mission will allow us to test our understanding of the magnetic signature. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 UNIV CALIF LOS ANGELES, DEPT EARTH & SPACE SCI, LOS ANGELES, CA 90095 USA. UNIV CALIF LOS ANGELES, DEPT PHYS & ASTRON, LOS ANGELES, CA 90095 USA. CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, DEPT PHYS, LONDON SW7 2BZ, ENGLAND. RP Kivelson, MG (reprint author), UNIV CALIF LOS ANGELES, INST GEOPHYS & PLANETARY PHYS, LOS ANGELES, CA 90095 USA. RI Kivelson, Margaret/I-9019-2012; OI Kivelson, Margaret/0000-0003-3859-8581; Russell, Christopher/0000-0003-1639-8298 NR 17 TC 12 Z9 12 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043297-2 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 2 BP 193 EP 204 DI 10.1016/S0273-1177(97)00533-4 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ57J UT WOS:A1997BJ57J00012 ER PT S AU Waite, JH Lewis, WS Gladstone, GR Cravens, TE Maurellis, AN Drossart, P Connerney, JEP Miller, S Lam, HA AF Waite, JH Lewis, WS Gladstone, GR Cravens, TE Maurellis, AN Drossart, P Connerney, JEP Miller, S Lam, HA BE Cravens, TE Kivelson, MG TI Outer planet ionospheres: A review of recent research and a look toward the future SO PLANETARY IONOSPHERES AND MAGNETOSPHERES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT C3.2 Symposium of COSPAR Scientific Commission C on Planetary Ionospheres and Magnetospheres, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Sci Commiss D, UN Off Outer Space Affairs ID AURORAL OXYGEN PRECIPITATION; BREMSSTRAHLUNG X-RAYS; SOLAR-WIND CONTROL; UPPER-ATMOSPHERE; COMET SHOEMAKER-LEVY-9; SATURNS IONOSPHERE; JUPITER ATMOSPHERE; GALILEO PROBE; ELECTRONS; VOYAGER AB A major focus of recent research on the ionospheres of the outer planets has been on the interpretation of jovian amoral emissions at infrared, ultraviolet, and X-ray wavelengths, Analysis of these emissions has provided valuable clues to the still poorly understood nature of the magnetosphere-ionosphere interaction at Jupiter and has furnished evidence for the occurrence of heavy ion precipitation into Jupiter's equatorial region. A model of Jupiter's low-latitude ionosphere incorporating ion precipitation effects and a neutral thermal structure derived from the in-situ measurements of the Galileo probe has been developed and reproduces reasonably well the ionospheric structure determined from Voyager 1 radio science data Other recently developed outer planet ionosphere models include a model of hydrocarbon ions in the jovian ionosphere, a one-dimensional time-dependent model of Saturn's ionosphere, and a photochemical model of Neptune's upper atmosphere, (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 UNIV KANSAS, DEPT PHYS & ASTRON, LAWRENCE, KS 66045 USA. OBSERV PARIS, DESPA, F-92195 MEUDON, FRANCE. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. UNIV LONDON UNIV COLL, DEPT PHYS & ASTRON, LONDON WC1E 6BT, ENGLAND. RP Waite, JH (reprint author), SW RES INST, PO DRAWER 28510, SAN ANTONIO, TX 78228 USA. RI Kivelson, Margaret/I-9019-2012; connerney, john/I-5127-2013 OI Kivelson, Margaret/0000-0003-3859-8581; NR 42 TC 11 Z9 11 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043297-2 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 2 BP 243 EP 252 DI 10.1016/S0273-1177(97)00542-5 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ57J UT WOS:A1997BJ57J00021 ER PT S AU Heap, SR AF Heap, SR BE Habing, HJ Lamers, HJG TI Observations of CSPN SO PLANETARY NEBULAE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 180th Symposium of the International-Astronomical-Union CY AUG 26-30, 1996 CL GRONINGEN, NETHERLANDS SP Int Astronom Union, Kapteyn Astronom Inst, Royal Acad Sci, Univ Groningen, Fdn Sci, Board Univ Groningen, Kluwer Publishers ID HOT STARS; MODEL ATMOSPHERES; SPECTROSCOPY; WINDS C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Heap, SR (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. EM hrsheap@stars.gsfc.nasa.gov NR 24 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0074-1809 BN 0-7923-4892-3 J9 IAU SYMP PY 1997 IS 180 BP 55 EP 63 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL56K UT WOS:000075895400019 ER PT S AU Dinerstein, HL Haas, MR Erickson, EF Werner, MW AF Dinerstein, HL Haas, MR Erickson, EF Werner, MW BE Habing, HJ Lamers, HJG TI Airborne observations of far-infrared emission lines from the photodissociation regions in planetary nebulae: Properties and masses of the neutral components SO PLANETARY NEBULAE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 180th Symposium of the International-Astronomical-Union CY AUG 26-30, 1996 CL GRONINGEN, NETHERLANDS SP Int Astronom Union, Kapteyn Astronom Inst, Royal Acad Sci, Univ Groningen, Fdn Sci, Board Univ Groningen, Kluwer Publishers C1 Univ Texas, Austin, TX 78712 USA. NASA, Ames Res Ctr, Moffett Field, CA USA. Jet Prop Lab, Pasadena, CA USA. RP Dinerstein, HL (reprint author), Univ Texas, Austin, TX 78712 USA. EM harriet@astro.as.utexas.edu NR 6 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 BN 0-7923-4892-3 J9 IAU SYMP PY 1997 IS 180 BP 220 EP 220 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL56K UT WOS:000075895400077 ER PT S AU Hora, JL Latter, WB Deutsch, LK AF Hora, JL Latter, WB Deutsch, LK BE Habing, HJ Lamers, HJG TI A near-infrared spectral survey of planetary nebulae SO PLANETARY NEBULAE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 180th Symposium of the International-Astronomical-Union CY AUG 26-30, 1996 CL GRONINGEN, NETHERLANDS SP Int Astronom Union, Kapteyn Astronom Inst, Royal Acad Sci, Univ Groningen, Fdn Sci, Board Univ Groningen, Kluwer Publishers C1 Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Boston Univ, NASA, Ames Res Ctr, Boston, MA 02215 USA. RP Hora, JL (reprint author), Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. NR 0 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 BN 0-7923-4892-3 J9 IAU SYMP PY 1997 IS 180 BP 238 EP 238 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL56K UT WOS:000075895400094 ER PT S AU Kelly, DM Latter, WB Hora, JL Woodward, CE AF Kelly, DM Latter, WB Hora, JL Woodward, CE BE Habing, HJ Lamers, HJG TI H-2 kinematics in planetary nebulae SO PLANETARY NEBULAE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 180th Symposium of the International-Astronomical-Union CY AUG 26-30, 1996 CL GRONINGEN, NETHERLANDS SP Int Astronom Union, Kapteyn Astronom Inst, Royal Acad Sci, Univ Groningen, Fdn Sci, Board Univ Groningen, Kluwer Publishers C1 Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. NASA, Ames Res Ctr, NRC, Moffett Field, CA 94035 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. RP Kelly, DM (reprint author), Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. NR 0 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 BN 0-7923-4892-3 J9 IAU SYMP PY 1997 IS 180 BP 245 EP 245 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL56K UT WOS:000075895400100 ER PT S AU Latter, WB Hora, JL AF Latter, WB Hora, JL BE Habing, HJ Lamers, HJG TI Investigating the near-IR properties of PN: Deep imaging of molecular hydrogen emission SO PLANETARY NEBULAE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 180th Symposium of the International-Astronomical-Union CY AUG 26-30, 1996 CL GRONINGEN, NETHERLANDS SP Int Astronom Union, Kapteyn Astronom Inst, Royal Acad Sci, Univ Groningen, Fdn Sci, Board Univ Groningen, Kluwer Publishers C1 NASA, Ames Res Ctr, NRC, Moffett Field, CA 94035 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. RP Latter, WB (reprint author), NASA, Ames Res Ctr, NRC, MS 245-3, Moffett Field, CA 94035 USA. NR 0 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 BN 0-7923-4892-3 J9 IAU SYMP PY 1997 IS 180 BP 254 EP 254 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL56K UT WOS:000075895400108 ER PT S AU McKenna, FC Keenan, FP Aller, LH Hyung, S Feibelman, WA Berrington, KA Fleming, J AF McKenna, FC Keenan, FP Aller, LH Hyung, S Feibelman, WA Berrington, KA Fleming, J BE Habing, HJ Lamers, HJG TI The identification of the O V forbidden line in the ultraviolet spectrum of gaseous nebulae SO PLANETARY NEBULAE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 180th Symposium of the International-Astronomical-Union CY AUG 26-30, 1996 CL GRONINGEN, NETHERLANDS SP Int Astronom Union, Kapteyn Astronom Inst, Royal Acad Sci, Univ Groningen, Fdn Sci, Board Univ Groningen, Kluwer Publishers ID STAR RR-TELESCOPII C1 Queens Univ Belfast, Dept Pure & Appl Phys, Belfast BT7 1NN, Antrim, North Ireland. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA USA. NASA, Astron & Solar Phys Lab, Washington, DC 20546 USA. Queens Univ Belfast, Dept Appl Math & Theoret Phys, Belfast BT7 1NN, Antrim, North Ireland. RP McKenna, FC (reprint author), Queens Univ Belfast, Dept Pure & Appl Phys, Belfast BT7 1NN, Antrim, North Ireland. NR 5 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 BN 0-7923-4892-3 J9 IAU SYMP PY 1997 IS 180 BP 259 EP 259 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL56K UT WOS:000075895400113 ER PT S AU Natta, A Hollenbach, D AF Natta, A Hollenbach, D BE Habing, HJ Lamers, HJG TI The neutral shells of planetary nebulae SO PLANETARY NEBULAE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 180th Symposium of the International-Astronomical-Union CY AUG 26-30, 1996 CL GRONINGEN, NETHERLANDS SP Int Astronom Union, Kapteyn Astronom Inst, Royal Acad Sci, Univ Groningen, Fdn Sci, Board Univ Groningen, Kluwer Publishers C1 Osservatorio Astrofis Arcetri, I-50125 Florence, Italy. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Natta, A (reprint author), Osservatorio Astrofis Arcetri, Largo E Fermi 5, I-50125 Florence, Italy. NR 0 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 BN 0-7923-4892-3 J9 IAU SYMP PY 1997 IS 180 BP 265 EP 265 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL56K UT WOS:000075895400119 ER PT S AU Rubin, RH Colgan, SWJ Haas, MR Lord, SD Simpson, JP AF Rubin, RH Colgan, SWJ Haas, MR Lord, SD Simpson, JP BE Habing, HJ Lamers, HJG TI Far-infrared spectroscopy of planetary nebulae with the KAO SO PLANETARY NEBULAE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 180th Symposium of the International-Astronomical-Union CY AUG 26-30, 1996 CL GRONINGEN, NETHERLANDS SP Int Astronom Union, Kapteyn Astronom Inst, Royal Acad Sci, Univ Groningen, Fdn Sci, Board Univ Groningen, Kluwer Publishers ID BRIGHT RING REGION; OPTICAL-SPECTRUM; NGC-7009; AXIS C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. CALTECH, IPAC, Pasadena, CA 91125 USA. RP Rubin, RH (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. RI Colgan, Sean/M-4742-2014 NR 5 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 BN 0-7923-4892-3 J9 IAU SYMP PY 1997 IS 180 BP 278 EP 278 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL56K UT WOS:000075895400132 ER PT S AU Dopita, MA Wood, PR Meatheringham, SJ Vassiliadis, E Bohlin, RC Ford, HC Harrington, JP Stecher, TP Maran, SP AF Dopita, MA Wood, PR Meatheringham, SJ Vassiliadis, E Bohlin, RC Ford, HC Harrington, JP Stecher, TP Maran, SP BE Habing, HJ Lamers, HJG TI Hubble space telescope observations of planetary nebulae in the Magellanic Clouds SO PLANETARY NEBULAE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 180th Symposium of the International-Astronomical-Union CY AUG 26-30, 1996 CL GRONINGEN, NETHERLANDS SP Int Astronom Union, Kapteyn Astronom Inst, Royal Acad Sci, Univ Groningen, Fdn Sci, Board Univ Groningen, Kluwer Publishers ID ASYMPTOTIC GIANT BRANCH; INTERMEDIATE-MASS STARS; LUMINOSITY FUNCTION; ANGULAR DIAMETERS; FAINT STAR; EVOLUTION; SPECTROSCOPY; KINEMATICS; ABUNDANCES; FLUXES AB We present the results of our major HST study of the evolution of PN in the Magellanic Clouds. This consists of imaging studies in [O III] and FOS UV spectroscopy. These data are then used in theoretical photoionisation models in conjuction with ground-based spectrophotometry, absolute flux and expansion velocity and density to derive self consistent diameters, ages, masses, and nebular abundances and to accurately place the central stars on the H-R Diagram. We find that observed sixes and ages can be reconciled with evolutionary theory provided that the He-burners outnumber the H-burners in the approximate ratio 2:1. For the LMC observed abundance patterns are qualitatively consistent with the (mass-dependent) operation of the various chemical dredge-up processes as predicted by theory. However, the observed dredge-up efficiencies do not agree with current theory. Finally, since core masses are determined with adequate precision, we are able to derive, for the first time, the metallicity age relation for of the LMC. We find that the base metallicity of the LMC rapidly increased similar to 2 Gyr ago, consistent with the age of the burst of star formation inferred from field stars and clusters. C1 Australian Natl Univ, Mt Stromlo & Siding Spring Observ, IAS, Weston, ACT 2611, Australia. Inst Astrofis Canarias, E-38200 La Laguna, Tenerife, Spain. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Dopita, MA (reprint author), Australian Natl Univ, Mt Stromlo & Siding Spring Observ, IAS, Weston, ACT 2611, Australia. RI Dopita, Michael/P-5413-2014 OI Dopita, Michael/0000-0003-0922-4986 NR 53 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 BN 0-7923-4892-3 J9 IAU SYMP PY 1997 IS 180 BP 417 EP 427 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL56K UT WOS:000075895400203 ER PT S AU Vassiliadis, E Dopita, M Bohlin, RC Harrington, JP Meatheringham, SJ Ford, HC Wood, PR Stecher, TP Maran, SP AF Vassiliadis, E Dopita, M Bohlin, RC Harrington, JP Meatheringham, SJ Ford, HC Wood, PR Stecher, TP Maran, SP BE Habing, HJ Lamers, HJG TI Imaging and spectroscopy of Magellanic Cloud planetary nebulae obtained with the Hubble Space Telescope SO PLANETARY NEBULAE SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 180th Symposium of the International-Astronomical-Union CY AUG 26-30, 1996 CL GRONINGEN, NETHERLANDS SP Int Astronom Union, Kapteyn Astronom Inst, Royal Acad Sci, Univ Groningen, Fdn Sci, Board Univ Groningen, Kluwer Publishers C1 Inst Astrofis Canarias, E-38200 La Laguna, Tenerife, Spain. Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Weston, ACT 2611, Australia. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Space Telescope Sci Inst, Baltimore, MD USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Goddard Space Flight Ctr, Greenbelt, MD USA. RP Vassiliadis, E (reprint author), Inst Astrofis Canarias, C Via Lactea S-N, E-38200 La Laguna, Tenerife, Spain. RI Dopita, Michael/P-5413-2014 OI Dopita, Michael/0000-0003-0922-4986 NR 0 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 BN 0-7923-4892-3 J9 IAU SYMP PY 1997 IS 180 BP 477 EP 477 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL56K UT WOS:000075895400215 ER PT B AU Kaiser, ML Garcia, LN AF Kaiser, ML Garcia, LN BE Rucker, HO Bauer, SJ Lecacheux, A TI Jupiter's low-frequency radio spectrum: Filling in the gaps SO PLANETARY RADIO EMISSIONS IV LA English DT Proceedings Paper CT 4th International Workshop on Planetary Radio Emissions CY SEP 09-11, 1996 CL GRAZ, AUSTRIA AB We report observations by the WAVES experiment on the Wind spacecraft of Jupiter's low frequency decameter wave radio emission. These observations were made with the unusual combination of low DE and low frequency. With these observing parameters, the Io-C and Io-D sources are very dominant over the Io-A and B sources. The arcs structures in these two sources tend to follow Io as it moves westward. We show that these sources are very likely from the southern auroral region of Jupiter as the Io footprints in the North are beyond the radio horizon. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kaiser, ML (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU VERLAG OSTERREICHISCHEN AKAD WISSENSCHAFTEN PI VIENNA PA DR IGNAY-SEIPEL-PLATZ 2, A-1010 VIENNA, AUSTRIA BN 3-7001-2691-3 PY 1997 BP 17 EP 24 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM59Z UT WOS:000079216300003 ER PT B AU Bolton, SJ Thorne, RM AF Bolton, SJ Thorne, RM BE Rucker, HO Bauer, SJ Lecacheux, A TI Understanding Jupiter's radiation belts through observation and modeling SO PLANETARY RADIO EMISSIONS IV LA English DT Proceedings Paper CT 4th International Workshop on Planetary Radio Emissions CY SEP 09-11, 1996 CL GRAZ, AUSTRIA AB Jupiter's synchrotron radiation has been observed extensively over the last couple decades using primarily single dish operating at 2295 MHz to provide time variability and intensity information antennas [Klein et al., 1989] and occasionally using the VLA operating at 1400 MHz to obtain spatial distribution maps. The study of the synchrotron radiation characteristics and variations has provided substantial insight into the physical properties and processes of Jupiter's inner radiations belts. During 1994 a more intensive program was initiated to obtain data during the impacts of Comet SL-S with Jupiter. The synchrotron radiation variation associated with the comet impacts include an emission intensity increase dependent on wavelength, longitudinal beaming curve distortions and a flattening of the latitudinal beaming curve. The observed changes have resulted in numerous theories on the responsible processes including pitch angle scattering by impacted stimulated plasma waves, increases in radial diffusion rates and/or the shock acceleration of electrons. The characteristics of the emissions will be reviewed along with a discussion on possible interpretations of the observed Comet SL-9 associated variations mentioned above. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bolton, SJ (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 VERLAG OSTERREICHISCHEN AKAD WISSENSCHAFTEN PI VIENNA PA DR IGNAY-SEIPEL-PLATZ 2, A-1010 VIENNA, AUSTRIA BN 3-7001-2691-3 PY 1997 BP 207 EP 216 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM59Z UT WOS:000079216300018 ER PT B AU Klein, MJ Gulkis, S Bolton, SJ AF Klein, MJ Gulkis, S Bolton, SJ BE Rucker, HO Bauer, SJ Lecacheux, A TI Jupiter's synchrotron radiation: Observed variations before, during and after the impacts of Comet SL-9 SO PLANETARY RADIO EMISSIONS IV LA English DT Proceedings Paper CT 4th International Workshop on Planetary Radio Emissions CY SEP 09-11, 1996 CL GRAZ, AUSTRIA AB Results of an observing program to monitor the synchrotron radio emission from Jupiter's inner radiation belts after the impact of Comet SL-9 are reported. The observations were made at 2295 MHz as part of the NASA-JPL Jupiter Patrol, a long term radio astronomy monitoring program begun in 1971. Data from the monitoring program illustrates the long-term variability of the synchrotron radiation with timescales of months to years. Jupiter Patrol observations taken during the period surrounding the Comet SL-9 impacts [Klein et al., 1995] indicate that the intensity of the synchrotron emission at 13 cm wavelength increased by 27 percent within a few days after the comet impacts and the magnetic latitude beaming curves flattened after the week of the impacts. In this paper we report new observations made in 1995-96 showing that the microwave brightening following the comet impacts has decayed with an e-folding time of approximately 170 days and that a new outburst, presumably unrelated to the SL-9 impacts, may have occurred in August 1995. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Klein, MJ (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 VERLAG OSTERREICHISCHEN AKAD WISSENSCHAFTEN PI VIENNA PA DR IGNAY-SEIPEL-PLATZ 2, A-1010 VIENNA, AUSTRIA BN 3-7001-2691-3 PY 1997 BP 217 EP 224 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM59Z UT WOS:000079216300019 ER PT B AU Desch, MD AF Desch, MD BE Rucker, HO Bauer, SJ Lecacheux, A TI Terrestrial LF bursts: Source and solar wind connection SO PLANETARY RADIO EMISSIONS IV LA English DT Proceedings Paper CT 4th International Workshop on Planetary Radio Emissions CY SEP 09-11, 1996 CL GRAZ, AUSTRIA AB Terrestrial low frequency (LF) bursts represent a new and interesting class of radio emissions, apparently associated with the amoral kilometric emissions and having close analogs with a remarkably similar class of Jovian low-frequency bursts. In this paper, I I) review the recently recognized strong correlation of LFs with the solar wind (bulk speed) input as measured just upstream of Earth by the WIND spacecraft, and 2) show via superposed epoch analysis that when the data are examined on shorter time scales, LFs also manifest a clear dependence on IMF direction, similar to that associated with magnetospheric substorms, and entirely consistent with the bulk speed correlation. The 40-minute magnetospheric response time indicated by the epoch analysis is in agreement with studies showing that weak-to-moderate levels of magnetospheric activity are triggered in a time delay fashion by energy storage and release in the magnetotail. Finally, I show that the measured group velocity dispersion of LFs is consistent with a magnetotail source approximately 100-200 R-E downstream of Earth. In view of the correlation results shown here, some comments regarding earlier studies of AKR and Jovian QP (Jovian Type III) bursts with regard to solar wind triggering are appropriate. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Desch, MD (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU VERLAG OSTERREICHISCHEN AKAD WISSENSCHAFTEN PI VIENNA PA DR IGNAY-SEIPEL-PLATZ 2, A-1010 VIENNA, AUSTRIA BN 3-7001-2691-3 PY 1997 BP 251 EP 258 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BM59Z UT WOS:000079216300023 ER PT B AU Thronson, HA AF Thronson, HA BE Soderblom, DR TI Our cosmic origins: NASA's origins theme and the search for Earth-like planets SO PLANETS BEYOND THE SOLAR SYSTEM AND THE NEXT GENERATION OF SPACE MISSIONS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Planets beyond the Solar System and the Next Generation of Space Missions CY OCT 16-18, 1996 CL SPACE TELESCOPE SCI INST, BALTIMORE, MD HO SPACE TELESCOPE SCI INST AB The Origins Program at NASA Headquarters has, as its primary goal, the understanding of the birth and early evolution of some of the fundamental constituents of the Universe: galaxies, stars, planets, and life. As such, it encompasses a wide range of facilities, instruments, and technologies, with a variety of capabilities, including very-high-precision interferometry at visual and infrared wavelengths, large-collecting-area optical systems, spectroscopy from the ultraviolet through the infrared, and a variety of laboratory technology development programs. This paper summarizes the current plans and missions for the Origins Program, specifically within the context of the search for Earth-like planets. C1 NASA Headquarters, Off Space Sci, Washington, DC USA. RP Thronson, HA (reprint author), NASA Headquarters, Off Space Sci, Washington, DC USA. RI Thronson, Harley/E-3382-2012 NR 0 TC 2 Z9 2 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-39-2 J9 ASTR SOC P PY 1997 VL 119 BP 3 EP 7 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK79Z UT WOS:000073439700001 ER PT B AU Colavita, M AF Colavita, M BE Soderblom, DR TI Applications of ground-based optical/IR interferometry SO PLANETS BEYOND THE SOLAR SYSTEM AND THE NEXT GENERATION OF SPACE MISSIONS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Planets beyond the Solar System and the Next Generation of Space Missions CY OCT 16-18, 1996 CL SPACE TELESCOPE SCI INST, BALTIMORE, MD HO SPACE TELESCOPE SCI INST C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Colavita, M (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 ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-39-2 J9 ASTR SOC P PY 1997 VL 119 BP 87 EP 89 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK79Z UT WOS:000073439700008 ER PT B AU Guirado, JC Reynolds, JE Preston, RA Jauncey, DL Lestrade, JF Jones, DL Tzioumis, AK Ferris, RH King, EA Lovell, JEJ McCulloch, PM Johnston, KJ Kingham, KA Martin, JO White, GL Jones, PA Arenou, F Froeschle, M Kovalevsky, J Martin, C Lindegren, L Soderhjelm, S AF Guirado, JC Reynolds, JE Preston, RA Jauncey, DL Lestrade, JF Jones, DL Tzioumis, AK Ferris, RH King, EA Lovell, JEJ McCulloch, PM Johnston, KJ Kingham, KA Martin, JO White, GL Jones, PA Arenou, F Froeschle, M Kovalevsky, J Martin, C Lindegren, L Soderhjelm, S BE Soderblom, DR TI Astrometric detection of a very low-mass companion orbiting a late-type radio star SO PLANETS BEYOND THE SOLAR SYSTEM AND THE NEXT GENERATION OF SPACE MISSIONS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Planets beyond the Solar System and the Next Generation of Space Missions CY OCT 16-18, 1996 CL SPACE TELESCOPE SCI INST, BALTIMORE, MD HO SPACE TELESCOPE SCI INST AB From the combination of VLBI (Very Long Baseline Interferometry) phase-referenced observations and Hipparcos satellite data, we have found evidence of a very low-mass object orbiting the late-type star AB Doradus. The mass of the companion inferred from the observed orbital motion places this object on the boundary between a brown dwarf and a very low-mass star. If accurate photometry of the companion can be obtained, our mass determination will allow the AB Dor companion to serve as an accurate calibration point for the different theoretical evolutionary models of very low-mass objects. This represents the first detection of a low-mass stellar companion using the VLBI technique, which could become an important tool in future searches for planets and brown dwarfs orbiting other stars. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Guirado, JC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI King, Edward/A-1473-2012 OI King, Edward/0000-0002-6898-2130 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 1-886733-39-2 J9 ASTR SOC P PY 1997 VL 119 BP 111 EP 114 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK79Z UT WOS:000073439700013 ER PT B AU Stapelfeldt, K Sahai, R Werner, M Trauger, J AF Stapelfeldt, K Sahai, R Werner, M Trauger, J BE Soderblom, DR TI An HST imaging search for circumstellar matter in young nebulous clusters SO PLANETS BEYOND THE SOLAR SYSTEM AND THE NEXT GENERATION OF SPACE MISSIONS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Planets beyond the Solar System and the Next Generation of Space Missions CY OCT 16-18, 1996 CL SPACE TELESCOPE SCI INST, BALTIMORE, MD HO SPACE TELESCOPE SCI INST AB HST imaging studies of the M42 and M16 H II regions have revealed circumstellar emission and absorption regions with sizes comparable to those expected for protoplanetary disks. In order to determine the uniqueness of these results, and to search for additional objects geometrically suggestive of disks, we observed four other young nebulous clusters with HST/WFPC2 during Cycle 5. Eight fields were observed in H alpha and I-band continuum in the nearby H II regions NGC 2024, NGC 2264, and S155. Two fields were observed in V band in the reflection nebula NGC 7023. In all these fields, no dark silhouettes and only a handful of circumstellar ionized rims were found. These results suggest that the visibility of "proplyds" in the Orion Nebula is due to circumstances unique to the evolutionary state of the Trapezium cluster. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Stapelfeldt, K (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RI Stapelfeldt, Karl/D-2721-2012 NR 0 TC 9 Z9 9 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-39-2 J9 ASTR SOC P PY 1997 VL 119 BP 131 EP 134 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK79Z UT WOS:000073439700018 ER PT B AU Borucki, WJ Koch, DG Dunham, EW Jenkins, JM AF Borucki, WJ Koch, DG Dunham, EW Jenkins, JM BE Soderblom, DR TI The Kepler Mission: A mission to determine the frequency of inner planets near the habitable zone for a wide range of stars SO PLANETS BEYOND THE SOLAR SYSTEM AND THE NEXT GENERATION OF SPACE MISSIONS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Planets beyond the Solar System and the Next Generation of Space Missions CY OCT 16-18, 1996 CL SPACE TELESCOPE SCI INST, BALTIMORE, MD HO SPACE TELESCOPE SCI INST AB The surprising discovery of giant planets in inner orbits around solar-like stars has brought into question our understanding of the development and evolution of planetary systems, including our Solar System. To make further progress, it is critical to detect and obtain data on the frequency and characteristics of Earth-class planets. The Kepler Mission is designed to be a quick, low-cost approach to accomplish that objective. Transits by Earth-class planets produce a fractional change in stellar brightness of 5 x 10(-5) to 40 x 10(-5) lasting for 4 to 16 hours. From the period and depth of the transits, the orbit and size of the planets can be calculated. The proposed instrument is a one-meter aperture photometer with a 12 degrees field-of-view (FOV). To obtain the required precision and to avoid interruptions caused by day-night and seasonal cycles, the photometer will be launched into a heliocentric orbit. It will continuously and simultaneously monitor the flux from 80,000 dwarf stars brighter than 14th magnitude in the Cygnus constellation. The mission tests the hypothesis that the formation of most stars produces Earth-class planets in inner orbits. Based on this assumption and the recent observations that 2% of the stars have giant planets in inner orbits, several types of results are expected from the mission: 1) From transits of Earth-class planets, about 480 planet detections and 60 cases where two or more planets are found in the same system. 2) From transits of giant planets, about 160 detections of inner-orbit planets and 24 detections of outer-orbit planets. 3) From the phase modulation of the reflected light from giant planets, about 1400 planet detections with periods less than a week, albedos for 160 of these giant planets, and densities for seven planets. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Borucki, WJ (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. NR 0 TC 67 Z9 67 U1 1 U2 2 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-39-2 J9 ASTR SOC P PY 1997 VL 119 BP 153 EP 173 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK79Z UT WOS:000073439700021 ER PT B AU Cruikshank, DP Werner, MW AF Cruikshank, DP Werner, MW BE Soderblom, DR TI The study of planetary systems with the Space Infrared Telescope Facility (SIRTF) SO PLANETS BEYOND THE SOLAR SYSTEM AND THE NEXT GENERATION OF SPACE MISSIONS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Planets beyond the Solar System and the Next Generation of Space Missions CY OCT 16-18, 1996 CL SPACE TELESCOPE SCI INST, BALTIMORE, MD HO SPACE TELESCOPE SCI INST AB The first decade of the next century will see the emergence of an extraordinary new view of the Universe, as the Space Infrared Telescope Facility (SIRTF) undertakes its 2.5-yr mission of astrophysical and planetary discovery. Observing from a heliocentric orbit as far as 0.2 AU from Earth, SIRTF will detect and map circumstellar dust disks around solar-type stars, search for brown dwarfs in the Galactic halo and in nearby star clusters, and search for superplanets around stars out to 15 parsecs. Within our Solar System, SIRTF will map the detailed dust structure in the asteroid zone and beyond, and provide in situ measurements of the dust ring in Earth's orbit. In deep surveys, SIRTF will yield statistics of main-belt asteroids as small as 50 meters across, small Trojan asteroids, and Kuiper Disk objects. Inactive comets at large heliocentric distances and active comets in the inner Solar System will be studied. Thermal infrared spectroscopy of the giant planets and their largest satellites will provide important information on their temporal atmospheric variability, and flux measurements in deep absorption bands will probe their atmospheric structures. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Cruikshank, DP (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-39-2 J9 ASTR SOC P PY 1997 VL 119 BP 223 EP 243 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK79Z UT WOS:000073439700025 ER PT B AU Mather, JC Bely, PY Stockman, P Thronson, H AF Mather, JC Bely, PY Stockman, P Thronson, H BE Soderblom, DR TI NGST capabilities for planet and planet formation studies SO PLANETS BEYOND THE SOLAR SYSTEM AND THE NEXT GENERATION OF SPACE MISSIONS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Workshop on Planets beyond the Solar System and the Next Generation of Space Missions CY OCT 16-18, 1996 CL SPACE TELESCOPE SCI INST, BALTIMORE, MD HO SPACE TELESCOPE SCI INST AB The Next Generation Space Telescope (NGST) is conceived as a radiatively-cooled near-IR-optimized telescope of more than 4 m aperture, at the Lagrange point L2, launched on an Atlas IIAS class vehicle around 2007. A deployable telescope, adjusted to correct figure after launch, would allow an aperture of 8 m. A deployable sunshield and suitable isolation structures would permit radiative cooling to 30 to 70 K, enabling operation at wavelengths as long as 20 mu m or more at sensitivities limited by the zodiacal light. Planned instruments include wide field cameras and multiobject spectrometers, optimized for the study of distant galaxies and early star formation in the 1 to 5 mu m band. Such a telescope would be a powerful tool in the study of planet and star formation, circumstellar disks, and the planets, satellites, asteroids, comets, and Kuiper belt objects in our own Solar System. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mather, JC (reprint author), NASA, Goddard Space Flight Ctr, Code 685, Greenbelt, MD 20771 USA. NR 0 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 1-886733-39-2 J9 ASTR SOC P PY 1997 VL 119 BP 245 EP 257 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK79Z UT WOS:000073439700026 ER PT J AU Ruyters, G Scott, TK AF Ruyters, G Scott, TK TI Future research in plant biology in space: Summary of critical issues and recommendations of the workshop SO PLANTA LA English DT Editorial Material C1 NASA,DIV LIFE SCI,WASHINGTON,DC 20546. RP Ruyters, G (reprint author), DARA,GERMAN SPACE AGCY GMBH,ABT BIOWISSENSCH,KONIGSWINTERER STR 5220524,D-53227 BONN,GERMANY. NR 0 TC 25 Z9 27 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0032-0935 J9 PLANTA JI Planta PY 1997 VL 203 SU S BP S211 EP S213 DI 10.1007/PL00008110 PG 3 WC Plant Sciences SC Plant Sciences GA XU208 UT WOS:A1997XU20800027 PM 11540327 ER PT J AU Sievers, A Scott, TK AF Sievers, A Scott, TK TI Plant biology in space - Proceedings of the International Workshop - Bad Honnef (near Bonn), Germany, June 24-27, 1996 - Preface SO PLANTA LA English DT Editorial Material C1 NASA,DIV LIFE SCI,WASHINGTON,DC 20546. RP Sievers, A (reprint author), UNIV BONN,INST BOT,VENUSBERGWEG 22,D-53115 BONN,GERMANY. NR 1 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0032-0935 J9 PLANTA JI Planta PY 1997 VL 203 SU S BP S1 EP S1 DI 10.1007/PL00008096 PG 1 WC Plant Sciences SC Plant Sciences GA XU208 UT WOS:A1997XU20800001 ER PT B AU Waluschka, E AF Waluschka, E BE Goldstein, DH Chipman, RA TI MODIS polarization measurements and simulation and the 4 theta effect SO POLARIZATION: MEASUREMENT, ANALYSIS, AND REMOTE SENSING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Polarization - Measurement, Analysis, and Remote Sensing CY JUL 30-AUG 01, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE polarization; spectroradiometer; earth observing; four theta AB The Moderate Resolution Imaging Spectroradiometer(1) (MODIS) will be one of the primary instruments observing the earth on the Earth Observing System (EOS) scheduled for launch in mid 1998. Its 36 spectral bands ranging from 0.4 to 14.4 microns will image the entire earth. The radiometric requirements are such that the instrument's polarization sensitivity must be very well understood(2). This paper will describe the experimental setup, some of the experimental results and the accompanying analysis. Emphasis will be on a anomalous, ''four theta'' experimental result and its explanation. RP Waluschka, E (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2543-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3121 BP 278 EP 287 DI 10.1117/12.283862 PG 10 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BJ78K UT WOS:A1997BJ78K00031 ER PT B AU Perry, GL Stearn, JA Vanderbilt, VC Ustin, SL Barrios, MCD Morrissey, LA Livingston, GP Breon, FM Bouffies, S Leroy, MM Herman, M Balois, JY AF Perry, GL Stearn, JA Vanderbilt, VC Ustin, SL Barrios, MCD Morrissey, LA Livingston, GP Breon, FM Bouffies, S Leroy, MM Herman, M Balois, JY BE Goldstein, DH Chipman, RA TI Remote sensing of high-latitude wetlands using polarized wide angle imagery SO POLARIZATION: MEASUREMENT, ANALYSIS, AND REMOTE SENSING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Polarization - Measurement, Analysis, and Remote Sensing CY JUL 30-AUG 01, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE methane; circumpolar wetlands; sunglint; multidirectional; polarization; POLDER; classification; unmixing analysis AB Representing the areal extent of circumpolar wetlands is a critical step to quantifying the emission of methane, an important greenhouse gas. Present estimates of the areal extent: of these wetlands differ nearly seven fold, implying large uncertainties exist in the prediction of circumpolar methane emission rates. Our objective is to use multi directional and polarization measurements provided by the French POLDER sensor to improve this estimate. The results show that wetlands can be detected, classified and their area quantified using the unique, highly polarized angular signature of the sunglint measured over their water surfaces. RP Perry, GL (reprint author), NASA,AMES RES CTR,NATL RES COUNCIL,MOFFETT FIELD,CA 94035, USA. RI Breon, Francois-Marie/M-4639-2016 OI Breon, Francois-Marie/0000-0003-2128-739X NR 0 TC 0 Z9 0 U1 1 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2543-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3121 BP 370 EP 381 DI 10.1117/12.283872 PG 12 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BJ78K UT WOS:A1997BJ78K00041 ER PT B AU Cairns, B Carlson, BE Lacis, AA Russell, EE AF Cairns, B Carlson, BE Lacis, AA Russell, EE BE Goldstein, DH Chipman, RA TI An analysis of ground-based polarimetric sky radiance measurements SO POLARIZATION: MEASUREMENT, ANALYSIS, AND REMOTE SENSING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Polarization - Measurement, Analysis, and Remote Sensing CY JUL 30-AUG 01, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE inverse problems; polarization; aerosols AB A parametric analysis of sky radiance and polarization measurements based on a database of calculations indicated that there was information contained in the measurements that was not captured by the database. We therefore developed an iterative algorithm for retrieving a size distribution and size resolved refractive indices of aerosols from cloud free measurements of polarized sky radiances. Preliminary results indicate that it is possible to retrieve a size resolved refractive index for a wide range of aerosol sizes, aswell as an aerosol size distribution. 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 0 TC 6 Z9 6 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2543-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3121 BP 382 EP 393 DI 10.1117/12.278984 PG 12 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BJ78K UT WOS:A1997BJ78K00042 ER PT J AU Kiefer, RL Orwoll, RA Aquino, EC Pierce, AC Glasgow, MB Thibeault, SA AF Kiefer, RL Orwoll, RA Aquino, EC Pierce, AC Glasgow, MB Thibeault, SA TI The effects of atomic oxygen on polymer films containing bis(triphenyltin) oxide SO POLYMER DEGRADATION AND STABILITY LA English DT Article AB A tin-containing compound, bis(triphenyltin) oxide (BTO), was added to two polymeric materials in an effort to reduce the erosion of the materials in the presence of atomic oxygen. The BTO was added to a solution of a thermoplastic polyetherimide, and to the amic acid solution of a polyimide thermoset before curing. The films of these materials were tested in the laboratory by exposing them to atomic oxygen from a plasma generator. Subsequently, they were exposed to the Low Earth Orbit (LEG) on two Space Shuttle flights. In all cases, the BTO-containing materials exhibited significantly less mass loss than the corresponding pure polymer. Analysis by X-ray photoelectron spectroscopy showed that after exposure to atomic oxygen, the BTO-containing films had a predominance of tin oxide on their surfaces. This could serve as a barrier to resist further erosion. (C) 1997 Elsevier Science Limited. C1 NASA,LANGLEY RES CTR,DIV MAT,ENVIRONM INTERACT BRANCH,HAMPTON,VA 23681. RP Kiefer, RL (reprint author), COLL WILLIAM & MARY,DEPT CHEM,POB 8795,WILLIAMSBURG,VA 23187, USA. NR 5 TC 11 Z9 15 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0141-3910 J9 POLYM DEGRAD STABIL JI Polym. Degrad. Stabil. PY 1997 VL 57 IS 2 BP 219 EP 226 DI 10.1016/S0141-3910(97)00003-7 PG 8 WC Polymer Science SC Polymer Science GA XK037 UT WOS:A1997XK03700013 ER PT S AU Baugher, AH Kossler, WJ Petzinger, KG Pater, RH AF Baugher, AH Kossler, WJ Petzinger, KG Pater, RH BE Jean, YC Eldrup, M Schrader, DM West, RN TI Positron annihilation lifetime spectroscopy applied to the measurement of hole volumes in crosslinking polyimides SO POSITRON ANNIHILATION: ICPA-11 - PROCEEDINGS OF THE 11TH INTERNATIONAL CONFERENCE ON POSITRON ANNIHILATION, KANSAS CITY, MISSOURI, USA, MAY 1997 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 11th International Conference on Positron Annihilation (ICPA-11) CY MAY 25-30, 1997 CL KANSAS CITY, MISSOURI SP K L Cheng Trust Fund, Natl Sci Fdn, PHYS, Univ Missouri Kansas City, Dept Chem, Univ Missouri Kansas City, Coll Arts & Sci, Univ Missouri Kansas City, Off Res Adm, Univ Missouri, Acad Affairs, EG&G ORTEC DE positronium localization; crosslinking polyimides; positron lifetimes AB Part I: Positron Annihilation Lifetime Spectroscopy, which is applied to measure distributions of hole volume sizes in polymers, uses a model to relate the positronium (Ps) lifetime to hole volume dimensions. It is assumed in this model that the Ps remains in one site until annihilation. To investigate this assumption we calculated the rate for Ps in one potential well to transfer to a second. We found for appropriate, equal wells, that the transfer rate between sites was rapid on the timescale of Ps lifetimes, while for only slightly unequal wells the transfer is cut off. This cutoff is a consequence of the removal of the degeneracy of the single well energies. For multiple wells it is found that Anderson localization applies so that quite generally a Ps is trapped at only a single hole volume until it decays. Thus Ps-lifetime hole-size-distribution-measurements should be unaffected by tunneling. Part II: Thermally-induced crosslinking in polyimides has been studied by positron annihilation lifetime spectroscopy. A series of norbornene-endcapped polyimides with varied formulated molecular weights was exposed to 316 degrees C heat treatment for up to 2000 hours to obtain samples with a variety of crosslinking densities. It is found that measurements of the intensity of the o-Ps component are directly related to the crosslinking densities in non-highly crosslinked samples. However, in the highly crosslinked samples, o-Ps is no longer formed. The inhibition of o-Ps formation in these samples is attributed both to the small dimensions of the hole volumes in the crosslinked samples and to the presence of strong electron-trapping moieties in the highly crosslinked samples. C1 Coll William & Mary, Dept Phys, Williamsburg, VA 23185 USA. NASA, Composite & Polymer Mat Branch, Hampton, VA USA. RP Baugher, AH (reprint author), 5459 Pernod Ave, St Louis, MO 63139 USA. NR 11 TC 6 Z9 6 U1 0 U2 1 PU TRANSTEC PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-779-X J9 MATER SCI FORUM PY 1997 VL 255-2 BP 57 EP 61 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Physics, Particles & Fields SC Materials Science; Physics GA BK31T UT WOS:000071768100006 ER PT B AU Viterna, LA AF Viterna, LA GP IEEE IEEE TI Nasa's involvement in technology development and transfer: The Ohio hybrid bus project SO PROCEEDINGS: ELECTRICAL INSULATION CONFERENCE AND ELECTRICAL MANUFACTURING & COIL WINDING CONFERENCE LA English DT Proceedings Paper CT Electrical Insulation Conference / Electrical Manufacturing and Coil Winding Conference (EIC/EMCW 97 EXPO) CY SEP 22-25, 1997 CL ROSEMONT, IL SP IEEE, Natl Elect Manufacturers Assoc, Elect Mfg & Coil Winding Assoc AB A government and industry uscooperative is using advanced power technology in a city transit bus that will offer double the fuel economy, and emissions, one tenth of government standards. The heart of the vehicle's power system is a natural gas fueled generator unit. Power from both the generator and an advanced energy storage system is provided to a variable speed electric motor attached to the rear drive axle. A unique aspect of the vehicle's design is its use of "super" capacitors for recovery of energy during braking. This is the largest vehicle ever built using this advanced energy recovery technology. This paper describes the project goals and approach, results of its system performance modeling, and the status of the development team's effort. C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Viterna, LA (reprint author), NASA, Lewis Res Ctr, 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 0-7803-3960-6 PY 1997 BP 449 EP 453 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BK40F UT WOS:000072059100078 ER PT B AU Fleurial, JP Caillat, T Borshchevsky, A AF Fleurial, JP Caillat, T Borshchevsky, A GP IEEE TI Skutterudites: An update SO PROCEEDINGS ICT'97 - XVI INTERNATIONAL CONFERENCE ON THERMOELECTRICS LA English DT Proceedings Paper CT 16th International Conference on Thermoelectrics (XVI ICT 97) CY AUG 26-29, 1997 CL DRESDEN, GERMANY SP Sachs Staatsminist Wissensch & Kunst, Deut Forschungsgemeinsch, European Commiss, Directorate Gen XII, USAF European Off Aerosp Res & Dev, Inst Solid State & Mat Res Dresden, Thermoelect Grp, Int Thermoelect Soc, IEEE, Inst Festkorper Werkstofforsch Dresden AB Materials with the skutterudite crystal structure possess attractive transport properties and have a good potential for achieving ZT values substantially larger than for state-of-the-art thermoelectric materials. Studies conducted at JPL on CoAs3, RhAs3, CoSb3, RhSb3 and IrSb3 have shown that p-type conductivity samples are characterized by carriers with low effective masses and very high mobilities, low electrical resistivities and moderate Seebeck coefficients. The carrier mobilities of n-type samples are about an order of magnitude lower, but low electrical resistivities and relatively large Seebeck coefficients can still be obtained at high doping levels. The room temperature lattice thermal conductivities of these binary skutterudites was found to be 7 to 10 times larger than that of Bi2Te3. This results in low ZT values at 300K, though very heavily doped n-type CoSb3 samples can achieve ZT similar to 1 at 600 degrees C. Several research groups, mostly in the U.S., are now working on understanding and optimizing the transport properties of skutterudites. Most of the efforts are focusing on reducing the lattice thermal conductivity by filling the empty octant cages in the skutterudite structure with rare earth atoms. Additional approaches have also been pursued at JPL, in particular the formation of solid solutions and alloys, and the study of novel ternary skutterudite compounds. Recent experiments have demonstrated that ternary compounds such as Ru0.5Pd0.5Sb3 and filled skutterudites such as CeFe4Sb12 had much lower lattice thermal conductivity. High ZT values have been obtained for several filled skutterudites in the 500-700 degrees C temperature range, but figures of merit at 300K are still low. This paper reviews recent experimental and theoretical results on skutterudites with a particular emphasis on the transport properties of ternary compounds and filled compositions. The latest results obtained at JPL are presented and the possibility of obtaining high ZT values near room temperature is discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Fleurial, JP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 277-207, Pasadena, CA 91109 USA. NR 0 TC 115 Z9 121 U1 1 U2 13 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4057-4 PY 1997 BP 1 EP 11 PG 11 WC Thermodynamics; Engineering, Electrical & Electronic; Engineering, Mechanical; Materials Science, Multidisciplinary SC Thermodynamics; Engineering; Materials Science GA BK89B UT WOS:000073809800001 ER PT B AU Caillat, T Fleurial, JP AF Caillat, T Fleurial, JP GP IEEE TI New low thermal conductivity materials for thermoelectric applications SO PROCEEDINGS ICT'97 - XVI INTERNATIONAL CONFERENCE ON THERMOELECTRICS LA English DT Proceedings Paper CT 16th International Conference on Thermoelectrics (XVI ICT 97) CY AUG 26-29, 1997 CL DRESDEN, GERMANY SP Sachs Staatsminist Wissensch & Kunst, Deut Forschungsgemeinsch, European Commiss, Directorate Gen XII, USAF European Off Aerosp Res & Dev, Inst Solid State & Mat Res Dresden, Thermoelect Grp, Int Thermoelect Soc, IEEE, Inst Festkorper Werkstofforsch Dresden AB A low lattice thermal conductivity is one of the requirements to achieve high thermoelectric figures of merit. Several low thermal conductivity materials were identified and developed over the past few years at JPL, including filled skutterudites and Zn4Sb3-based materials. A study of the mechanisms responsible for the high phonon scattering rates in these compounds has demonstrated that materials with highly disordered or complex structures which can accommodate additional atoms in their lattice are likely to have low lattice thermal conductivity values. Several cluster compounds, including the Chevrel phases (Mo6Se8-type) and Re6Te15, are just such materials and are currently being investigated at JPL. The crystal structures of the Chevrel phases present cavities which can greatly vary in size and can contain a large variety of atoms ranging from large ones such as Pb to small ones such as Cu. These atoms are not localized in the structure and, depending on their size, can move between different sites and may produce significant phonon scattering, Although most of the Chevrel phases studied until now were reported to be metallic, it was found that semiconducting Chevrel phases can be engineered by controlling the number of electrons per [Mo-6] cluster. Initial results obtained on some cluster Chevrel phases and Re6Te15 are presented and discussed. These materials possess very low thermal conductivity values (similar to 10 mW/cmK at 300K) but optimization of their electronic properties will be required to achieve high thermoelectric figures of merit. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Caillat, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 277-207, Pasadena, CA 91109 USA. NR 0 TC 15 Z9 15 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4057-4 PY 1997 BP 446 EP 453 DI 10.1109/ICT.1997.667183 PG 8 WC Thermodynamics; Engineering, Electrical & Electronic; Engineering, Mechanical; Materials Science, Multidisciplinary SC Thermodynamics; Engineering; Materials Science GA BK89B UT WOS:000073809800098 ER PT B AU Fleurial, JP Borshchevsky, A Ryan, MA Phillips, W Kolawa, E Kacisch, T Ewell, R AF Fleurial, JP Borshchevsky, A Ryan, MA Phillips, W Kolawa, E Kacisch, T Ewell, R GP IEEE TI Thermoelectric microcoolers for thermal management applications SO PROCEEDINGS ICT'97 - XVI INTERNATIONAL CONFERENCE ON THERMOELECTRICS LA English DT Proceedings Paper CT 16th International Conference on Thermoelectrics (XVI ICT 97) CY AUG 26-29, 1997 CL DRESDEN, GERMANY SP Sachs Staatsminist Wissensch & Kunst, Deut Forschungsgemeinsch, European Commiss, Directorate Gen XII, USAF European Off Aerosp Res & Dev, Inst Solid State & Mat Res Dresden, Thermoelect Grp, Int Thermoelect Soc, IEEE, Inst Festkorper Werkstofforsch Dresden AB Due to the combined increase in circuit integration and chip power dissipation, there is a rapidly growing demand for solving the thermal management issues of power microelectronics. We are pursuing a novel thermal management approach that actively cools only the key high power devices by using a novel thermoelectric microcooler located under each of these power devices. In this way the device can operate at temperatures at or even below the ambient temperature of the heat sink, resulting in increased reliability and efficiency. To successfully handle the high heat flux densities generated at the back of the power chips, a microcooler with thin legs and low thermal resistance at the interfaces must be built. We are currently developing a thermoelectric microcooler combining thick films of Bi2Te3-based alloys and very high thermal conductivity substrates, such as CVD diamond or AlN. Electrochemical deposition is a very attractive process for depositing thick films of compound semiconductors on metallic surfaces. This paper presents recent results on the deposition of Bi2Te3 and related ternary solid solutions on a variety of metallic substrates. We also report on the development of Cu diffusion barriers for Bi2Te3 and stable metallizations and diffusion barriers for diamond and AIN substrates. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Fleurial, JP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 0 TC 31 Z9 32 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4057-4 PY 1997 BP 641 EP 645 DI 10.1109/ICT.1997.667611 PG 5 WC Thermodynamics; Engineering, Electrical & Electronic; Engineering, Mechanical; Materials Science, Multidisciplinary SC Thermodynamics; Engineering; Materials Science GA BK89B UT WOS:000073809800143 ER PT B AU Fukunaga, AS AF Fukunaga, AS GP IEEE TI Application of an incremental evolution technique to spacecraft design optimization SO PROCEEDINGS OF 1997 IEEE INTERNATIONAL CONFERENCE ON EVOLUTIONARY COMPUTATION (ICEC '97) LA English DT Proceedings Paper CT 1997 IEEE International Conference on Evolutionary Computation (ICEC 97) CY APR 13-16, 1997 CL INDIANAPOLIS, IN SP IEEE, IEEE Neural Network Council, Evolut Programming Soc AB Based on the intuition that it is often easier to learn to solve difficult problems after similar, simpler problems have been learned, incremental evolution is a recently proposed extension to evolutionary algorithms in which the evaluation function against which a population is evolved is scaled over time. This paper presents an application of incremental evolution to the problem of physical design optimization of a Mars microprobe spacecraft. Experimental results that demonstrated the utility of the approach are presented, as well as some new insights into the behavior of incremental evolution which may explain its success. RP Fukunaga, AS (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MS 525-3660,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3949-5 PY 1997 BP 431 EP 435 DI 10.1109/ICEC.1997.592350 PG 5 WC Computer Science, Artificial Intelligence SC Computer Science GA BH58Y UT WOS:A1997BH58Y00077 ER PT B AU Dozier, G Esterline, A Homaifar, A Bikdash, M AF Dozier, G Esterline, A Homaifar, A Bikdash, M GP IEEE TI Hybrid evolutionary motion planning via visibility-based repair SO PROCEEDINGS OF 1997 IEEE INTERNATIONAL CONFERENCE ON EVOLUTIONARY COMPUTATION (ICEC '97) LA English DT Proceedings Paper CT 1997 IEEE International Conference on Evolutionary Computation (ICEC 97) CY APR 13-16, 1997 CL INDIANAPOLIS, IN SP IEEE, IEEE Neural Network Council, Evolut Programming Soc DE motion planning; visibility graphs; visibility-based repair AB This paper introduces a hybrid evolutionary system for global motion planning within unstructured environments. This hybrid system combines a novel obstacle representation scheme, the concept of evolutionary search and a new concept that we refer to as the visibility-based repair to form a hybrid which quickly transforms infeasible motions into feasible ones. Our hybrid evolutionary system differs from other evolutionary motion planners feasible motions rather than using simulated evolution exclusively as a means of discovering feasible motions, (2) a continuous map of the environment is used rather than a discretized map, and (3) it develops motion plans for moving or mobile destinations. In this paper, we demonstrate the effectiveness of this new hybrid by using two challenging motion planning problems where the target tries to move away from our point robot. RP Dozier, G (reprint author), N CAROLINA AGR & TECH STATE UNIV,NASA,CTR AUTONOMOUS CONTROL ENGN,GREENSBORO,NC 27411, USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3949-5 PY 1997 BP 507 EP 511 DI 10.1109/ICEC.1997.592363 PG 5 WC Computer Science, Artificial Intelligence SC Computer Science GA BH58Y UT WOS:A1997BH58Y00090 ER PT B AU Lassiter, JO AF Lassiter, JO GP SOC EXPTL MECH TI Modal testing for add-on damping system evaluations - A poor man's approach SO PROCEEDINGS OF THE 15TH INTERNATIONAL MODAL ANALYSIS CONFERENCE - IMAC, VOLS I AND II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 15th International Modal Analysis Conference - Current Horizon for Structural Damage Detection (IMAC) CY FEB 03-06, 1997 CL ORLANDO, FL SP Soc Exptl Mech Inc AB This paper will describe how experimental modal testing can be used for designing and determining the effectiveness of add-on damping systems for small structures or substructures. These add-on damping systems, also known as surface damping treatments, have been in use for over 30 years as a means of reducing the response of a structure subjected to vibratory loads. By adding damping to the structure, the reduction of vibratory response has prevented ultimate failure, increased fatigue life, and/or reduced structural-borne noise. In many cases through the years, the integration of an add-on damping system to a structure has involved both analytical and experimental processes; in particular, for complex structures and situations requiring an optimum design for a damping treatment due to the need to reduce cost, weight, etc. However there are times when the response of a small structure or substructure needs to be reduced and this can be done with the use of add-on damping treatment designed with only experimental modal data. For this paper, two examples will show how impact modal tests verified the effectiveness of add-on damping systems for small payloads developed by the Marshall Space Flight Center. The dynamic response of both payloads was significantly reduced by the damping systems. Particular emphasis will show that materials for add-on damping systems are readily available and that small channel count impact modal testing can be quickly used for applying add-on damping systems to these structures. RP Lassiter, JO (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,STRUCT & DYNAM LAB,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-912053-53-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 3089 BP 457 EP 463 PG 7 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BH25Y UT WOS:A1997BH25Y00066 ER PT B AU Carney, K Yunis, I Smith, K Peng, CY AF Carney, K Yunis, I Smith, K Peng, CY GP SOC EXPTL MECH TI Nonlinear dynamic behavior in the Cassini spacecraft modal survey SO PROCEEDINGS OF THE 15TH INTERNATIONAL MODAL ANALYSIS CONFERENCE - IMAC, VOLS I AND II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 15th International Modal Analysis Conference - Current Horizon for Structural Damage Detection (IMAC) CY FEB 03-06, 1997 CL ORLANDO, FL SP Soc Exptl Mech Inc AB The Cassini spacecraft underwent a modal survey to produce a test-verified finite element model for coupled loads analysis. This modal survey used the techniques of multi-point random, stepped sine and sine dwell to characterize the dynamics of the Cassini structure. It was determined from the modal survey that the longitudinal natural mode of the Huygens probe was highly nonlinear. The frequency of the longitudinal mode decreased as excitation level increased. It was previously known that this mode was critical in determining the loads on the Huygens probe and that a decrease in the frequency of this mode would result in a design load and qualification test exceedence. A series of probe support stiffness tests and a high load level modal test were conducted on the spacecraft. The source of the nonlinearity was identified and the nonlinear behavior was accurately modeled using a simple system to match the test-derived frequency response functions. The model was extrapolated to flight load levels and was used as a basis of the linear test-verified loads model. The nonlinear behavior of the Huygens probe longitudinal mode was fully determined and characterized. RP Carney, K (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 1 Z9 1 U1 1 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-912053-53-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 3089 BP 811 EP 817 PG 7 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BH25Y UT WOS:A1997BH25Y00119 ER PT B AU Cao, TT Zimmerman, DC AF Cao, TT Zimmerman, DC GP SOC EXPTL MECH TI A procedure to extract Ritz vectors from dynamic testing data SO PROCEEDINGS OF THE 15TH INTERNATIONAL MODAL ANALYSIS CONFERENCE - IMAC, VOLS I AND II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 15th International Modal Analysis Conference - Current Horizon for Structural Damage Detection (IMAC) CY FEB 03-06, 1997 CL ORLANDO, FL SP Soc Exptl Mech Inc AB Ritz vectors represent an alternative to mode shape vectors as suitable basis vectors for n-dimensional space. In numerical analysis, these Ritz vectors have been shown to offer superior performance in model reduction and time-simulations. In a simulation study involving a bridge structure, it was observed that lower Ritz vectors appeared to be more sensitive to artificially induced damage than the corresponding mode shape vectors. However, Ritz vectors have existed only in the numerical domain. In this paper, we extend the usefulness of Ritz vectors by developing an approach to extract Ritz vectors from measured dynamic data. RP Cao, TT (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,STRUCT & DYNAM BRANCH,HOUSTON,TX 77058, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-912053-53-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 3089 BP 1036 EP 1042 PG 7 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BH25Y UT WOS:A1997BH25Y00153 ER PT B AU Pappa, RS Woodard, SE Juang, JN AF Pappa, RS Woodard, SE Juang, JN GP SOC EXPTL MECH TI A benchmark problem for development of autonomous structural modal identification SO PROCEEDINGS OF THE 15TH INTERNATIONAL MODAL ANALYSIS CONFERENCE - IMAC, VOLS I AND II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 15th International Modal Analysis Conference - Current Horizon for Structural Damage Detection (IMAC) CY FEB 03-06, 1997 CL ORLANDO, FL SP Soc Exptl Mech Inc AB This paper summarizes modal identification results obtained using an autonomous version of the Eigensystem Realization Algorithm on a dynamically complex, laboratory structure. The benchmark problem uses 48 of 768 free-decay responses measured in a complete modal survey test. The true modal parameters of the structure are well known from two previous, independent investigations. Without user involvement, the autonomous data analysis identified 24 of 33 structural modes with good to excellent accuracy in 62 seconds of CPU time (on a DEC Alpha 4000 computer). The modal identification technique described in the paper is the baseline algorithm for NASA's Autonomous Dynamics Determination (ADD) experiment scheduled to fly on International Space Station assembly flights in 1997-1999. RP Pappa, RS (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-912053-53-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 3089 BP 1071 EP 1077 PG 7 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BH25Y UT WOS:A1997BH25Y00157 ER PT B AU Cao, TT Zimmerman, DC AF Cao, TT Zimmerman, DC GP SOC EXPTL MECH TI Application of load dependent Ritz vectors in structural damage detection SO PROCEEDINGS OF THE 15TH INTERNATIONAL MODAL ANALYSIS CONFERENCE - IMAC, VOLS I AND II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 15th International Modal Analysis Conference - Current Horizon for Structural Damage Detection (IMAC) CY FEB 03-06, 1997 CL ORLANDO, FL SP Soc Exptl Mech Inc AB In this paper, an approach using dynamic testing data is presented as a method for monitoring the health of a structure. Unlike most vibration based approaches which utilize either modal parameters or frequency response functions, the proposed approach utilizes a Ritz vector description of the experimental data. The motivation behind the use of Ritz vectors, as opposed to modal parameters, have been in the historical demonstration of the superiority of Ritz vectors in the areas of model reduction and transient response simulations. In addition, some small scale numerical studies indicate that lower frequency Ritz vectors are more sensitive to damage than their corresponding mode shape vectors. The developed approach represents an extension of Minimum Rank Perturbation Theory to utilize measured Ritz vector information. RP Cao, TT (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,STRUCT & DYNAM BRANCH,HOUSTON,TX 77058, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-912053-53-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 3089 BP 1319 EP 1324 PG 6 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BH25Y UT WOS:A1997BH25Y00192 ER PT B AU Peng, CY Tsang, SK Smith, KS AF Peng, CY Tsang, SK Smith, KS GP SOC EXPTL MECH TI Test/model correlation for Mars Pathfinder multi-body system drop tests SO PROCEEDINGS OF THE 15TH INTERNATIONAL MODAL ANALYSIS CONFERENCE - IMAC, VOLS I AND II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 15th International Modal Analysis Conference - Current Horizon for Structural Damage Detection (IMAC) CY FEB 03-06, 1997 CL ORLANDO, FL SP Soc Exptl Mech Inc AB A multi-body dynamics computer model was used extensively for the Mars Pathfinder mission to simulate its innovative and unconventional atmospheric entry, descent and landing approach To verify the accuracy and validity of this model which was vital to the success of this mission, two multi-body system drop tests were performed and augmented by an extensive model correlation effort The end product is a test verified model that will be used in the final Mars Pathfinder terminal descent simulation. RP Peng, CY (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 PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-912053-53-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 3089 BP 1407 EP 1414 PG 8 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BH25Y UT WOS:A1997BH25Y00204 ER PT B AU Hines, JW Somps, CJ Madou, MJ Jeutter, DC Singh, A AF Hines, JW Somps, CJ Madou, MJ Jeutter, DC Singh, A BE Boom, H Robinson, C Rutten, W Neuman, M Wijkstra, H TI Telemetric sensors for the space life sciences SO PROCEEDINGS OF THE 18TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 18, PTS 1-5 SE PROCEEDINGS OF THE ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY LA English DT Proceedings Paper CT 18th Annual International Conference of IEEE Engineering-in-Medicine-amd-Biology-Society CY OCT 31-NOV 03, 1996 CL AMSTERDAM, NETHERLANDS SP IEEE Engn Med & Biol Soc AB Telemetric sensors for monitoring physiological changes in animal models in space are being developed by NASA's Sensors 2000! program. The sensors measure a variety of physiological measurands, including temperature, biopotentials, pressure, flow, acceleration, and chemical levels, and transmit these signals from the animals to a remote receiver via a wireless link. Thus physiologic information can be obtained continuously and automatically without animal handling, tethers, or percutaneous leads. We report here on NASA's development and testing of advanced wireless sensor systems for space life sciences research. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hines, JW (reprint author), NASA, Ames Res Ctr, MS 213-2, Moffett Field, CA 94035 USA. RI Madou, Marc/E-5869-2013 OI Madou, Marc/0000-0003-4847-3117 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 0-7803-3812-X J9 P IEEE EMBS PY 1997 VL 18 BP 30 EP 31 PG 2 WC Engineering, Biomedical SC Engineering GA BK41A UT WOS:000072079000015 ER PT B AU Das, H Ohm, T Boswell, C Paljug, E Rodriguez, G Steele, R Barlow, E AF Das, H Ohm, T Boswell, C Paljug, E Rodriguez, G Steele, R Barlow, E BE Boom, H Robinson, C Rutten, W Neuman, M Wijkstra, H TI Telerobotics for microsurgery SO PROCEEDINGS OF THE 18TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 18, PTS 1-5 SE PROCEEDINGS OF THE ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY LA English DT Proceedings Paper CT 18th Annual International Conference of IEEE Engineering-in-Medicine-amd-Biology-Society CY OCT 31-NOV 03, 1996 CL AMSTERDAM, NETHERLANDS SP IEEE Engn Med & Biol Soc AB A telerobotic workstation for microsurgery has been developed that enables scaling down motions and filtering tremor in a surgeon's hand. The system is compact and light-weight and has the potential for improving the performance of all surgeons and enabling the development of new surgical procedures currently limited by the dexterity of even the most skillful surgeons. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Das, H (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 BN 0-7803-3812-X J9 P IEEE EMBS PY 1997 VL 18 BP 227 EP 228 PG 2 WC Engineering, Biomedical SC Engineering GA BK41A UT WOS:000072079000111 ER PT B AU Schmidt, G Frey, MA Vernikos, J Winfield, D AF Schmidt, G Frey, MA Vernikos, J Winfield, D BE Boom, H Robinson, C Rutten, W Neuman, M Wijkstra, H TI NASA's technology transfer program for the early detection of breast cancer SO PROCEEDINGS OF THE 18TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 18, PTS 1-5 SE PROCEEDINGS OF THE ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY LA English DT Proceedings Paper CT 18th Annual International Conference of IEEE Engineering-in-Medicine-amd-Biology-Society CY OCT 31-NOV 03, 1996 CL AMSTERDAM, NETHERLANDS SP IEEE Engn Med & Biol Soc DE digital mammography; breast cancer; X-ray CCD AB The National Aeronautics and Space Administration (NASA) has led the development of advanced imaging sensors and image processing technologies for space science and Earth science missions. NASA considers the transfer and commercialization of such technologies a fundamental mission of the agency. Over the last two years, efforts have been focused on the application of aerospace imaging and computing to the field of diagnostic imaging, specifically to breast cancer imaging. These technology transfer efforts offer significant promise in helping in the national public health priority of the early detection of breast cancer. C1 NASA, Washington, DC 20546 USA. RP Schmidt, G (reprint author), NASA, Washington, DC 20546 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 0-7803-3812-X J9 P IEEE EMBS PY 1997 VL 18 BP 2111 EP 2112 PG 2 WC Engineering, Biomedical SC Engineering GA BK41A UT WOS:000072079001021 ER PT S AU Kramer, CD Kalla, EM AF Kramer, CD Kalla, EM BE Bumgardner, JD Puckett, AD TI The challenge of designing biomedical equipment during human research for long duration low-gravity NASA missions SO PROCEEDINGS OF THE 1997 16TH SOUTHERN BIOMEDICAL ENGINEERING CONFERENCE SE SOUTHERN BIOMEDICAL ENGINEERING CONFERENCE. PROCEEDINGS LA English DT Proceedings Paper CT 16th Southern Biomedical Engineering Conference CY APR 04-06, 1997 CL BILOXI, MS SP Mississippi State Univ, Dept Agr & Biol Engn, Univ Mississippi Med Ctr, Dept Restorat Dent Biomat Orthopaed Surg, Whitaker Fdn, Natl Sci Fdn, IEEE Engn Med & Biol Soc, Biomed Engn Soc, Inst Biol Engn, Soc Biomat AB NASA has been studying human adaptation to low-gravity (zero-g) environments for several years, beginning with the first manned space flight in 1961. As both flight and scientific opportunities have steadily increased, NASA has advanced in the development of sophisticated human experiments. Difficulties encountered include the ability to preserve samples for extended duration flights and the development of flight certifiable biomedical hardware. A major challenge to the development of flight biomedical hardware is that it requires minimal power, must accommodate multi-usages, must meet material concern for small enclosed environments, be functional in space radiation environments, and possess minimal volume. Discussion will include the types of equipment development for use during previous NASA Space Shuttle missions, including the recent joint NASA/Russian mission flown of the Russian Space Station Mir. Also addressed will be the focus on future needs as NASA prepares for the International Space Station, Lunar Mars Exploration, and a dedicated Neuroscience Spacelab mission. All NASA Human Life Sciences experiments are managed at the Lyndon B. Johnson Space Center in Houston, Texas. Principal Investigators (PI's) from around the world have teamed up to perform experiments in a range of disciplines requiring international cooperation. Spacelab 1 (SLS-1) opened the door as the first Space Shuttle Spacelab Mission that was totally dedicated to Human Life Sciences research. Over 400 proposals were submitted in response to the 1978 Announcement of Opportunity, of which 20 experiments were selected. These 20 experiments were grouped into four disciplines: 1) Cardiopulmonary; 2) Musculoskeletal, 3) Neuroscience, and 4) Regulatory Physiology. The disciplines allowed sharing of common hardware and scientific data. Equipment required for Human Life Sciences experiments included: echocardiograph, venous occlusion cuff, bicycle ergometer, baroreflex cuff, cardiopulmonary rebreathing unit, gas analyzer, mass spectrometer, Bag in Box (mixing bag, oxygen bag, and exhaust bag), electronic control assemblies, pneumotachograph, blood sampling equipment, body mass measurement devices, urine sampling and measuring devices, rotating chair, accelerometer recording unit, electro-oculograph, rotating dome assembly, otolith-spinal reflex apparatus, centrifuge, incubators, physiological monitoring systems, systems for venous occlusion plethysmography (SVOP), strip chart recorder, video and data tape recorder, and a system for measurement of the central venous pressure (SMCVP). The above listed hardware outlines the enormous amount of equipment developed for space flight. Since SLS-1 other Human Life Sciences missions have been successfully accomplished including D-2, IML-1, IML-2, SLS-2, and the NASA/Mir missions. Future funded missions include the Neurolab mission (STS-90, March 1998), which is dedicated to the science of Neurology, the International Space Station, and NASA/Mir missions. Studies are currently in progress to meet the needs of the Lunar and Mars exploration. Known requirements for these missions will be addressed, emphasizing the need for biomedical engineers to focus not only on earth-bound medical treatment environments, but also, applications for research in the zero-g environment of space. RP Kramer, CD (reprint author), NASA,JOHNSON SPACE CTR,BIOMED HARDWARE DEV & ENGN OFF,MAIL CODE EA5,HOUSTON,TX 77058, USA. NR 0 TC 4 Z9 4 U1 0 U2 2 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1086-4105 BN 0-7803-3869-3 J9 SO BIOMM ENGN CONF P PY 1997 BP 30 EP 37 DI 10.1109/SBEC.1997.583208 PG 8 WC Engineering, Biomedical SC Engineering GA BH56F UT WOS:A1997BH56F00008 ER PT B AU Evans, JY Evans, JW Li, MJ AF Evans, JY Evans, JW Li, MJ BE Radhakrishnan, MK Ho, P Chim, WK TI Effects of humidity and temperature cycling on 3-D packaging SO PROCEEDINGS OF THE 1997 6TH INTERNATIONAL SYMPOSIUM ON THE PHYSICAL & FAILURE ANALYSIS OF INTEGRATED CIRCUITS LA English DT Proceedings Paper CT 6th International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA 97) CY JUL 21-25, 1997 CL SINGAPORE, SINGAPORE SP IEEE Reliabil CPMT ED, Singapore Chapter, IEEE Electron Device Soc, Natl Univ Singapore, Ctr IC Failure Anal & Reliabil, Inst Microelectr, Singapore AB Three dimensional electronics packaging technologies are emerging for many electronics system applications. Characterizing failure mechanisms, was the focus of this research. Accelerated testing and observing samples at various stages of the testing, with an Environmental Scanning Electron Microscope, were the primary methods used. Interfacial debonding of polyimides and fatigue cracking in bus structures were observed in humidity cycling and thermal cycling. These failures were the result of differential expansion of polyimide adhesives and dielectrics and interfacial degradation by moisture absorption. RP Evans, JY (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3985-1 PY 1997 BP 213 EP 218 DI 10.1109/IPFA.1997.638208 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK01Z UT WOS:A1997BK01Z00040 ER PT S AU Mesbahi, M Papavassilopoulos, GP AF Mesbahi, M Papavassilopoulos, GP GP AMER AUTOMAT CONTROL COUNCIL TI Solving a class of rank minimization problems via semi-definite programs, with applications to the fixed order output feedback synthesis SO PROCEEDINGS OF THE 1997 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NM SP Amer Automat Control Council, Int Federat Automat Control AB We apply certain recent results pertaining to the rank minimization problem under LMI constraints to determine non-trivial lower and upper bounds for the minimal order dynamic output feedback which stabilizes a given linear time invariant plant, via Semi-Definite Programs. RP Mesbahi, M (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0743-1619 BN 0-7803-3833-2 J9 P AMER CONTR CONF PY 1997 BP 77 EP 80 PG 4 WC Automation & Control Systems SC Automation & Control Systems GA BJ29B UT WOS:A1997BJ29B00016 ER PT S AU Motter, MA Principe, JC AF Motter, MA Principe, JC GP AMER AUTOMAT CONTROL COUNCIL TI Neural control of the NASA Langley 16-foot transonic tunnel SO PROCEEDINGS OF THE 1997 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NM SP Amer Automat Control Council, Int Federat Automat Control AB Experimental results of controlling the Mach number in a transonic wind tunnel with a system of artificial neural networks are presented. Kohonen self-organizing maps are used to cluster the local tunnel dynamics and thereby predict the Mach number response to candidate control input sequences. The sequence minimizing the predicted error between the desired and actual Mach number Is applied to the tunnel fare drive system. Comparison is made to gain scheduled automatic control currently in use. RP Motter, MA (reprint author), NASA,LANGLEY RES CTR,FACIL AUTOMATED CONTROLS,HAMPTON,VA 23681, USA. NR 0 TC 4 Z9 4 U1 0 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0743-1619 BN 0-7803-3833-2 J9 P AMER CONTR CONF PY 1997 BP 662 EP 663 PG 2 WC Automation & Control Systems SC Automation & Control Systems GA BJ29B UT WOS:A1997BJ29B00141 ER PT S AU Jardin, MR AF Jardin, MR GP AMER AUTOMAT CONTROL COUNCIL TI 4D air traffic control for non-4D-equipped aircraft SO PROCEEDINGS OF THE 1997 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NM SP Amer Automat Control Council, Int Federat Automat Control AB Current concepts for 4-dimensional (4D) time-based air traffic control automation systems are generally designed to control aircraft so that they cross a final control waypoint at a scheduled time, but the trajectory between the initial waypoint and the control waypoint is not explicitly specified. Instead of this type of single-point 4D control, it may be advantageous to use closed-loop control to reference 4D trajectories. The design of a compensator to help air traffic controllers and pilots accurately and efficiently control aircraft to buffered 4D reference trajectories is presented in this paper. The main technical challenge is to develop a control algorithm that efficiently achieves 4D control for aircraft while maintaining acceptable air traffic controller workload levels. The approach is to soften 4D trajectory clearances by allowing aircraft to be within a well-defined error buffer region around the trajectory and to try and synchronize advisory updates with the reference trajectory advisories such that the aircraft remains within the buffer. A bias estimator is used to remove steady-state errors. The control algorithms are developed and a simple example of a 4D control scenario is presented. RP Jardin, MR (reprint author), NASA,AMES RES CTR,MS 210-9,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0743-1619 BN 0-7803-3833-2 J9 P AMER CONTR CONF PY 1997 BP 1101 EP 1108 PG 8 WC Automation & Control Systems SC Automation & Control Systems GA BJ29B UT WOS:A1997BJ29B00238 ER PT S AU Sridhar, B Chatterji, GB AF Sridhar, B Chatterji, GB GP AMER AUTOMAT CONTROL COUNCIL TI Computationally efficient conflict detection methods for air traffic management SO PROCEEDINGS OF THE 1997 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NM SP Amer Automat Control Council, Int Federat Automat Control AB Air Traffic Management (ATM) combines the roles of Air Traffic Control (ATC) and Traffic Flow Management (TFM). Generally, TFM is concerned with the smooth and efficient flow of traffic in the airspace while ATC has the responsibility for maintaining the separation between aircraft. The challenge for the ATM system is to accommodate growth in air traffic while maintaining the same level of safety and increased operator flexibility. This can only be achieved by introducing the technological innovations in Communication, Navigation and Surveillance (CNS) and by the development of decision support tools for controllers, pilots and airline operations. Basic components of these decision support tools are algorithms and software for conflict detection and resolution. This paper takes a detailed look at the standard approach to conflict detection in order to reduce the number of computations. The number of computations are reduced by posing the conflict detection problem in two steps: (a) spatial separation and (b) temporal separation. Three algorithms for conflict detection are described. The first method describes the standard approach. It computes the Euclidean distance between all aircraft pairs and compares the distance to the allowable minimum separation distance. The number of computations required by this method are of the order of n(2) where n is the number of aircraft. The second algorithm transforms the planned trajectories of the aircraft into a sequence of discrete spatial regions which are then sorted to locate regions in airspace where conflict is possible. The number of computations in this case are of the order of nlog(2) n. The third algorithm uses an accumulator driven by the transformed trajectories to locate regions where conflict is possible. It is shown that the computational complexity of this algorithm is of the order of n. Algorithmic details of the sorting-based and accumulator-based algorithms are provided. Numerical examples are presented to demonstrate the theoretical computational advantage of using the sorting-based and accumulator-based conflict detection algorithms over the standard method. RP Sridhar, B (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0743-1619 BN 0-7803-3833-2 J9 P AMER CONTR CONF PY 1997 BP 1126 EP 1130 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BJ29B UT WOS:A1997BJ29B00243 ER PT S AU Lu, WM Packard, A AF Lu, WM Packard, A GP AMER AUTOMAT CONTROL COUNCIL TI Adaptive H-infinity-control for nonlinear systems SO PROCEEDINGS OF THE 1997 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NM SP Amer Automat Control Council, Int Federat Automat Control AB The adaptive H-infinity-control problem for parameter-dependent nonlinear systems with full information feedback is addressed. The dissipation theoretic techniques as well as projection methods are used to derive the adaptive H-infinity-control laws. RP Lu, WM (reprint author), CALTECH,JET PROP LAB,AUTOMAT & CONTROL SECT 198326,PASADENA,CA 91109, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0743-1619 BN 0-7803-3833-2 J9 P AMER CONTR CONF PY 1997 BP 1208 EP 1212 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BJ29B UT WOS:A1997BJ29B00259 ER PT S AU Bayard, DS AF Bayard, DS GP AMER AUTOMAT CONTROL COUNCIL TI Necessary and sufficient conditions for LTI representations of adaptive systems with sinusoidal regressors SO PROCEEDINGS OF THE 1997 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NM SP Amer Automat Control Council, Int Federat Automat Control AB This paper establishes necessary and sufficient conditions for an adaptive system with a sinusoidal regressor (i.e., a regressor comprised exclusively of sinusoidal signals) to admit an exact linear time-invariant (LTI) representation. These conditions are important because a large number of adaptive systems used in practice have sinusoidal regressors, and the stability, convergence and robustness properties of systems having LTI representations can be completely analyzed by well-known methods. RP Bayard, DS (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 16 Z9 16 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0743-1619 BN 0-7803-3833-2 J9 P AMER CONTR CONF PY 1997 BP 1642 EP 1646 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BJ29B UT WOS:A1997BJ29B00352 ER PT S AU Bayard, DS AF Bayard, DS GP AMER AUTOMAT CONTROL COUNCIL TI LTI representations of adaptive systems with tap delay-line regressors under sinusoidal excitation SO PROCEEDINGS OF THE 1997 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NM SP Amer Automat Control Council, Int Federat Automat Control AB It is shown that an adaptive system whose regressor is formed by tap delay-line (TDL) filtering of a multitone sinusoidal signal is representable as a parallel connection of an linear time-invariant (LTI) block and a linear time-varying (LTV) block. The induced 2-norm of the LTV subsystem decreases as N-1 where N is the number of taps. Hence the adaptive system becomes LTI in the limit as the number of taps goes to infinity. RP Bayard, DS (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 6 Z9 6 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0743-1619 BN 0-7803-3833-2 J9 P AMER CONTR CONF PY 1997 BP 1647 EP 1651 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BJ29B UT WOS:A1997BJ29B00353 ER PT S AU Juang, JN Phan, MQ AF Juang, JN Phan, MQ GP AMER AUTOMAT CONTROL COUNCIL TI Recursive deadbeat predictive control SO PROCEEDINGS OF THE 1997 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NM SP Amer Automat Control Council, Int Federat Automat Control AB This paper presents a recursive algorithm for a deadbeat predictive controller design. The method combines together the concepts of system identification and deadbeat controller designs. It starts with the multi-step output prediction equation and derives the control force in terms of past input and output time histories. The formulation thus derived satisfies simultaneously system identification and deadbeat controller design requirements. As soon as the coefficient matrices are identified satisfying the output prediction equation, no further work is required to compute the deadbeat control gain matrices, The method can be implemented recursively just as any typical recursive system identification techniques. RP Juang, JN (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0743-1619 BN 0-7803-3833-2 J9 P AMER CONTR CONF PY 1997 BP 1778 EP 1782 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BJ29B UT WOS:A1997BJ29B00380 ER PT S AU Lim, KB AF Lim, KB GP AMER AUTOMAT CONTROL COUNCIL TI Closed form solution for minimum norm model-validating uncertainty SO PROCEEDINGS OF THE 1997 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NM SP Amer Automat Control Council, Int Federat Automat Control AB A methodology in which structured uncertainty models are directly constructed from measurement data for use in robust control design of multivariable systems is proposed. The formulation allows a general linear fractional transformation uncertainty structure connections with respect to a given nominal model. Existence conditions are given, and under mild assumptions, a closed-form expression for the smallest norm structured uncertainty that validates the model is given. The uncertainty bound computation is simple and is formulated for both open and closed loop systems. RP Lim, KB (reprint author), NASA,LANGLEY RES CTR,GUIDANCE & CONTROL BRANCH,FLIGHT DYNAM & CONTROL DIV,MS 161,HAMPTON,VA 23681, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0743-1619 BN 0-7803-3833-2 J9 P AMER CONTR CONF PY 1997 BP 1929 EP 1933 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BJ29B UT WOS:A1997BJ29B00410 ER PT S AU Bayard, DS AF Bayard, DS GP AMER AUTOMAT CONTROL COUNCIL TI An LTI/LTV decomposition of adaptive feedforward systems with sinusoidal regressors SO PROCEEDINGS OF THE 1997 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NM SP Amer Automat Control Council, Int Federat Automat Control AB It is shown that a large class of adaptive feedforward controllers having a sinusoidal regressor (i.e., a,regressor comprised exclusively of sinusoidal signals), can be written as the parallel connection of a purely linear time-invariant (LTI) subsystem and a linear time-varying (LTV) subsystem. is important because it can be readily analyzed and designed using modern robust control tools applicable to LTI systems with norm-bounded perturbations. RP Bayard, DS (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0743-1619 BN 0-7803-3833-2 J9 P AMER CONTR CONF PY 1997 BP 2542 EP 2546 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BJ29B UT WOS:A1997BJ29B00549 ER PT S AU Melody, JW Neat, GW AF Melody, JW Neat, GW GP AMER AUTOMAT CONTROL COUNCIL TI Integrated modeling methodology validation using the micro-precision interferometer testbed: Assessment of closed-loop performance prediction capability SO PROCEEDINGS OF THE 1997 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 1997 American Control Conference CY JUN 04-06, 1997 CL ALBUQUERQUE, NM SP Amer Automat Control Council, Int Federat Automat Control AB This paper validates the integrated modeling methodology used for design and performance evaluation of complex opto-mechanical systems, particularly spaceborne interferometers. The methodology integrates structural modeling, optical modeling, and control system modeling and design into a common environment, the Integrated Modeling of Optical Systems (IMOS) software package. The validation uses the Micro-Precision Interferometer (MPI) testbed, a ground-based, full-scale hardware model df a spaceborne interferometer. Parallel development of the MPI testbed and an MPI integrated model enabled a unique opportunity to validate the modeling methodology with actual testbed measurements. This paper assesses the ability of the integrated modeling methodology to predict performance in a closed-loop configuration, namely with high-bandwidth optical control loops operational. The assessment is a comparison of integrated model closed-loop predictions with MPI testbed closed-loop measurements, indicating that the integrated modeling methodology is accurate to within a factor of three. RP Melody, JW (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0743-1619 BN 0-7803-3833-2 J9 P AMER CONTR CONF PY 1997 BP 3531 EP 3536 PG 6 WC Automation & Control Systems SC Automation & Control Systems GA BJ29B UT WOS:A1997BJ29B00757 ER PT B AU Joshi, SM Kelkar, AG AF Joshi, SM Kelkar, AG GP IEEE TI Passivity-based control of elastic systems SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL CONFERENCE ON CONTROL APPLICATIONS LA English DT Proceedings Paper CT 1997 IEEE International Conference on Control Applications CY OCT 05-07, 1997 CL HARTFORD, CT SP IEEE Control Syst Soc, ASME Dynam Syst & Control Div AB This paper addresses passivity-based control of elastic systems. For inherently passive nonlinear and linear elastic systems such as flexible structures with collocated and compatible actuators and sensors, robust linear and nonlinear control laws are presented. For linear elastic systems that are inherently non-passive, a method is presented to render them passive by compensation. The passified system can then be controlled by a class of passive linear controllers. The method is applied to two elastic systems and is found to give robust stability and performance. RP Joshi, SM (reprint author), NASA,LANGLEY RES CTR,M-S 132,HAMPTON,VA 23681, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3877-4 PY 1997 BP 724 EP 729 DI 10.1109/CCA.1997.627745 PG 6 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA BJ81D UT WOS:A1997BJ81D00134 ER PT B AU Prestage, JD Tjoelker, RL Maleki, L AF Prestage, JD Tjoelker, RL Maleki, L GP IEEE TI Radio frequency measurements of cloud size in a linear ion trap SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US AB In this paper we describe a method for measuring the size of an ion cloud inside a linear ion trap. At similar to 10(-12) the 2(nd) order Doppler shift for trapped mercury ion frequency standards is one of the largest frequency offsets in these lamp based systems. Its measurement to the 1% level would represent an advance in insuring the very long term stability of these standards to the 10(-14) or better level. This measurement is implemented with a novel 12-rod linear ion trap which we have developed and describe here. RP Prestage, JD (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,BLDG 298,PASADENA,CA 91104, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 225 EP 227 DI 10.1109/FREQ.1997.638548 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00033 ER PT B AU Greenhall, CA AF Greenhall, CA GP IEEE TI Does Allan variance determine the spectrum? SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US AB The phase-noise spectrum determines the Allan variance by a well-known integral formula. It is shown here that unique inversion of this formula is not possible in general because the mapping from spectrum to Allan variance is not one-to-one. A necessary and sufficient condition for two distinct phase spectra to have the same Allan variance is given. RP Greenhall, CA (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MS 298-100,PASADENA,CA 91109, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 358 EP 365 DI 10.1109/FREQ.1997.638568 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00052 ER PT B AU Greenhall, CA AF Greenhall, CA GP IEEE TI A frequency-drift estimator and its removal from modified Allan variance SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US AB A drift-rate estimator constructed from four values of the cumulative sum of clock residuals is shown to have good error performance in the presence of the five standard power-law noises. A comparison table of several drift estimators is given. The bias and variance (or equivalent degrees of freedom) of a modified Allan variance estimator incorporating drift, removal is calculated. RP Greenhall, CA (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MS 298-100,PASADENA,CA 91109, USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 428 EP 432 DI 10.1109/FREQ.1997.638639 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00063 ER PT B AU Dick, GJ Wang, RT AF Dick, GJ Wang, RT GP IEEE TI Cryo-cooled sapphire oscillator for the Cassini Ka-band experiment SO PROCEEDINGS OF THE 1997 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT 1997 IEEE International Frequency Control Symposium CY MAY 28-30, 1997 CL ORLANDO, FL SP IEEE, Ultrason Ferroelect & Frequency Control Soc, USA CECOM, Ft Monmouth, NJ, US AB We present design aspects of a cryogenic sapphire oscillator which is being developed for ultra-high short term stability and low phase noise in support of the Cassini Ka-band Radio Science experiment. With cooling provided by a commercial cryocooler instead of liquid helium, this standard is designed to operate continuously for periods of a year or more. Performance targets are a stability of 3x10(-15) (1 second less than or equal to tau less than or equal to 100 seconds) and a phase noise of -73dB/Hz @ 1Hz measured at 34 GHz. Test results are reported for several subsystems; including cryocooler, vibration isolation system, and ruby compensating element. RP Dick, GJ (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91109, USA. NR 0 TC 10 Z9 10 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3729-8 PY 1997 BP 1009 EP 1014 DI 10.1109/FREQ.1997.639224 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BJ96F UT WOS:A1997BJ96F00145 ER PT S AU Wilson, WM Rosenberg, LH Hyatt, LE AF Wilson, WM Rosenberg, LH Hyatt, LE GP ACM SIGSOFT TI Automated analysis of requirement specifications SO PROCEEDINGS OF THE 1997 INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING SE INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING LA English DT Proceedings Paper CT 19th International Conference on Software Engineering (ICSE 97) - Pulling Together CY MAY 17-23, 1997 CL BOSTON, MA SP IEEE Comp Soc Tech Council Software Engn, ACM SIGSOFT AB It is generally accepted that poorly written requirements can result in software with the wrong functionality. The Goddard Space Flight Center's (GSFC) Software Assurance Technology Center (SATC) has developed an early life cycle tool for assessing requirements that are specified in natural language. The tool searches the document for terms the SATC has identified as quality indicators, e.g. weak phrases. The reports produced by the tool are used to identify specification statements and structural areas of the requirements specification document that need to be improved. The metrics are used by project managers to recognize and preclude potential areas of risk. RP Wilson, WM (reprint author), GSFC,SOFTWARE ASSURANCE TECHNOL,BLD 6 CODE 300-1,GREENBELT,MD 20771, USA. NR 0 TC 31 Z9 31 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036-9998 SN 0270-5257 BN 0-89791-914-9 J9 PROC INT CONF SOFTW PY 1997 BP 161 EP 171 DI 10.1145/253228.253258 PG 11 WC Computer Science, Software Engineering SC Computer Science GA BH83V UT WOS:A1997BH83V00016 ER PT S AU Hammer, T Rosenberg, L Huffman, L Hyatt, L AF Hammer, T Rosenberg, L Huffman, L Hyatt, L GP ACM SIGSOFT TI Measuring requirements testing - Experience report SO PROCEEDINGS OF THE 1997 INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING SE INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING LA English DT Proceedings Paper CT 19th International Conference on Software Engineering (ICSE 97) - Pulling Together CY MAY 17-23, 1997 CL BOSTON, MA SP IEEE Comp Soc Tech Council Software Engn, ACM SIGSOFT DE requirements; testing; metrics; quality assurance; CASE tools AB Requirements are written to specify the functionality of a completed software system. Software systems are often released in segments called builds, each one adding new functionality and satisfying an additional set of requirements. New software requirements tools are allowing quality assurance engineers to develop and use new metrics to assist them in evaluating the relationships of requirements to tests, thus ensuring the required functionality in the new system. NASA's Goddard Space Flight Center is applying new tools and technology to measure the effectiveness of requirements testing. This paper discusses an effort that uses project data to demonstrate metrics effectiveness. RP Hammer, T (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 303,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036-9998 SN 0270-5257 BN 0-89791-914-9 J9 PROC INT CONF SOFTW PY 1997 BP 372 EP 379 DI 10.1145/253228.253358 PG 8 WC Computer Science, Software Engineering SC Computer Science GA BH83V UT WOS:A1997BH83V00035 ER PT S AU Gunapala, SD Krabach, TN Bandara, SV Liu, JK AF Gunapala, SD Krabach, TN Bandara, SV Liu, JK GP IEEE IEEE TI Portable long-wavelength infrared camera for civilian applications SO PROCEEDINGS OF THE 19TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 19, PTS 1-6: MAGNIFICENT MILESTONES AND EMERGING OPPORTUNITIES IN MEDICAL ENGINEERING SE PROCEEDINGS OF ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY LA English DT Proceedings Paper CT International Conference of the IEEE Engineering-in-Medicine-and-Biology-Society CY OCT 30-NOV 02, 1997 CL CHICAGO, IL SP IEEE Engn Med & Biol Soc, Natl Inst Hlth AB A 9 mu m cutoff 256 x 256 hand-held quantum well infrared photodetector (QWIP) camera has been demonstrated. Excellent imagery, with a noise equivalent differential temperature (NE Delta T) of 26 mK has been achieved. In this paper, we discuss the performance of this portable long-wavelength infrared camera in quantum efficiency, NE Delta T, minimum resolvable temperature difference (MRTD), uniformity, etc, and its civilian applications. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Gunapala, SD (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, 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 1094-687X BN 0-7803-4262-3 J9 P ANN INT IEEE EMBS PY 1997 VL 19 BP 712 EP 717 PN 1-6 PG 6 WC Engineering, Biomedical SC Engineering GA BM91F UT WOS:000080103400204 ER PT S AU Hines, JW Somps, CJ Madou, M AF Hines, JW Somps, CJ Madou, M GP IEEE IEEE TI Space biosensor systems: Implications for technology transfer SO PROCEEDINGS OF THE 19TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOL 19, PTS 1-6: MAGNIFICENT MILESTONES AND EMERGING OPPORTUNITIES IN MEDICAL ENGINEERING SE PROCEEDINGS OF ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY LA English DT Proceedings Paper CT International Conference of the IEEE Engineering-in-Medicine-and-Biology-Society CY OCT 30-NOV 02, 1997 CL CHICAGO, IL SP IEEE Engn Med & Biol Soc, Natl Inst Hlth DE in vivo; chemical sensors; biosensors; biotelemetry; space flight research; technology transfer AB To meet the need for continuous, automated monitoring of animal subjects, including humans, during space flight, NASA is developing advanced physiologic sensor and biotelemetry system technologies. The ability to continuously track basic physiological parameters, such as heart rate, blood pH, and body temperature, in untethered subjects in space is a challenging task. At NASA's Ames Research Center, where a key focus is gravitational biology research, engineers have teamed with life scientists to develop wireless sensor systems for automated physiologic monitoring of animal models as small as the rat. This technology is also being adapted, in collaboration with medical professionals, to meet human clinical monitoring needs both in space and on the ground. Thus, these advanced monitoring technologies have important dual-use functions; they meet space flight data collection requirements and constraints, while concurrently addressing a number of monitoring and data acquisition challenges on the ground in areas of clinical monitoring and biomedical research. Additional applications for these and related technologies are being sought and additional partnerships established that enhance development efforts, reduce costs and facilitate technology infusion between the public and private sectors. This paper describes technology transfer and co-development projects that have evolved out of NASA's miniaturized, implantable chemical sensor development efforts. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hines, JW (reprint author), NASA, Ames Res Ctr, MS 213-2, Moffett Field, CA 94035 USA. RI Madou, Marc/E-5869-2013 OI Madou, Marc/0000-0003-4847-3117 NR 10 TC 0 Z9 0 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1094-687X BN 0-7803-4262-3 J9 P ANN INT IEEE EMBS PY 1997 VL 19 BP 740 EP 743 PN 1-6 PG 4 WC Engineering, Biomedical SC Engineering GA BM91F UT WOS:000080103400211 ER PT S AU Joshi, SS Melody, JW Neat, GW AF Joshi, SS Melody, JW Neat, GW GP IEEE IEEE TI A case study of the role of structural/optical model fidelity in performance prediction of complex opto-mechanical instruments SO PROCEEDINGS OF THE 36TH IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-5 SE IEEE CONFERENCE ON DECISION AND CONTROL - PROCEEDINGS LA English DT Proceedings Paper CT 36th IEEE Conference on Decision and Control CY DEC 10-12, 1997 CL SAN DIEGO, CA SP IEEE Controls Syst Soc, Soc Ind & Appl Math, Inst Operat Res & Management Sci AB This paper determines model performance prediction accuracy as a function of model fidelity for a complex opto-mechanical system. The test article is the Micro-Precision Interferometer testbed; a ground-based hardware model of a future spaceborne interferometer. The primary modeling tool is the Integrated Modeling of Optical Systems (IMOS) package. Three models of the MPI testbed were created for this study; each with a unique optical and structural model fidelity. The paper compares disturbance transfer function predictions from the three models with measured disturbance transfer functions from the hardware testbed. Results suggest meaningful model prediction errors exist when simple models are used to represent a complex opto-mechanical system. However, modest increases in model fidelity can lead to significant improvement. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Joshi, SS (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 0191-2216 BN 0-7803-4187-2 J9 IEEE DECIS CONTR P PY 1997 BP 1367 EP 1372 PG 6 WC Automation & Control Systems; Computer Science, Information Systems; Engineering, Electrical & Electronic; Operations Research & Management Science; Mathematics, Applied SC Automation & Control Systems; Computer Science; Engineering; Operations Research & Management Science; Mathematics GA BK43K UT WOS:000072164400272 ER PT S AU Lu, WM Hadaegh, FY Packard, A AF Lu, WM Hadaegh, FY Packard, A GP IEEE IEEE TI Adaptive robust control for uncertain nonlinear systems SO PROCEEDINGS OF THE 36TH IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-5 SE IEEE CONFERENCE ON DECISION AND CONTROL - PROCEEDINGS LA English DT Proceedings Paper CT 36th IEEE Conference on Decision and Control CY DEC 10-12, 1997 CL SAN DIEGO, CA SP IEEE Controls Syst Soc, Soc Ind & Appl Math, Inst Operat Res & Management Sci AB An adaptive robust control problem for uncertain nonlinear systems with both parametric and dynamic uncertainties is considered by combined standard robust control and adaptive H-infinity-control techniques. A scaled vector projection method is used to derive the adaptive robust control laws. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lu, WM (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 0191-2216 BN 0-7803-4187-2 J9 IEEE DECIS CONTR P PY 1997 BP 2103 EP 2108 PG 6 WC Automation & Control Systems; Computer Science, Information Systems; Engineering, Electrical & Electronic; Operations Research & Management Science; Mathematics, Applied SC Automation & Control Systems; Computer Science; Engineering; Operations Research & Management Science; Mathematics GA BK43K UT WOS:000072164400418 ER PT S AU Jadbabaie, A Titli, A Jamshidi, M AF Jadbabaie, A Titli, A Jamshidi, M GP IEEE IEEE TI Fuzzy observer-based control of nonlinear systems SO PROCEEDINGS OF THE 36TH IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-5 SE IEEE CONFERENCE ON DECISION AND CONTROL - PROCEEDINGS LA English DT Proceedings Paper CT 36th IEEE Conference on Decision and Control CY DEC 10-12, 1997 CL SAN DIEGO, CA SP IEEE Controls Syst Soc, Soc Ind & Appl Math, Inst Operat Res & Management Sci AB In this paper, some recent results on systematic design of model based fuzzy controllers for nonlinear systems with Takagi-Sugeno (T-S) fuzzy models are discussed. These methods are based on finding a common Lyapunov matrix and state feedback gains for the closed loop T-S fuzzy model using Linear Matrix Inequalities(LMI's). However, all of these methods assume that the states are available for measurement, while in reality this is not the case. To solve this problem, the notion of fuzzy observer is introduced and a separation theorem for the observer/controller system is stated and proof sketch is presented. C1 Univ New Mexico, NASA, Ctr Autonomous Control Engn, Dept Elect & Comp Engn, Albuquerque, NM 87131 USA. RP Jadbabaie, A (reprint author), Univ New Mexico, NASA, Ctr Autonomous Control Engn, Dept Elect & Comp Engn, Albuquerque, NM 87131 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0191-2216 BN 0-7803-4187-2 J9 IEEE DECIS CONTR P PY 1997 BP 3347 EP 3349 PG 3 WC Automation & Control Systems; Computer Science, Information Systems; Engineering, Electrical & Electronic; Operations Research & Management Science; Mathematics, Applied SC Automation & Control Systems; Computer Science; Engineering; Operations Research & Management Science; Mathematics GA BK43K UT WOS:000072164400653 ER PT B AU Scott, P AF Scott, P GP USENIX ASSOC TI Automating 24x7 support response to telephone requests SO PROCEEDINGS OF THE ELEVENTH SYSTEMS ADMINISTRATION CONFERENCE (LISA XI) LA English DT Proceedings Paper CT 11th Systems Administration Conference (LISA XI) CY OCT 26-31, 1997 CL SAN DIEGO, CA SP USENIX Assoc, SAGE AB Demands for uninterrupted availability of systems that were hitherto not viewed as critical to the success of the enterprise has placed a burden upon support infrastructures for those systems. The small-to-medium help desk for a system that comprises part of an enterprise information system is under increasing pressure to provide round-the-clock support, while staffing budgets may not have caught up with the fiscal realities of covering second-or third-shift on-site personnel. While the volume of calls outside normal hours may be small, a guaranteed turnaround and response to emergencies is essential for many IT operations to gain the trust of their customers. This paper describes a system for automated answering of the help desk telephone during non-peak hours, and for notifying on-call staff of emergencies within minutes. The system uses two voice-capable modems on a well-maintained computer for presenting to the caller a typical phone menu hierarchical menu which may include an option to record a message about some type of emergency. In this event, the system will notify the staff who are on call at that time for that type of emergency, contacting them by means they have specified in advance, such as voice telephone, numeric or alphanumeric pager, or other means. The system is currently undergoing testing in the Enterprise Information System File Service at JPL. RP Scott, P (reprint author), CALTECH,JET PROP LAB,PASADENA,CA 91125, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU USENIX ASSOC PI BERKELEY PA SUITE 215, 2560 NINTH ST, BERKELEY, CA 94710 BN 1-880446-90-1 PY 1997 BP 27 EP 35 PG 9 WC Computer Science, Information Systems SC Computer Science GA BJ83D UT WOS:A1997BJ83D00004 ER PT B AU Caetta, J AF Caetta, J GP USENIX ASSOC TI Developing interim systems SO PROCEEDINGS OF THE ELEVENTH SYSTEMS ADMINISTRATION CONFERENCE (LISA XI) LA English DT Proceedings Paper CT 11th Systems Administration Conference (LISA XI) CY OCT 26-31, 1997 CL SAN DIEGO, CA SP USENIX Assoc, SAGE AB One of the recent challenges in the aerospace industry has been to smoothly transition operations-oriented computer systems to meet increasing demands on smaller budgets. Sometimes the best solution is not affordable, but the current situation is equally untenable. Change becomes necessary, but is only acceptable at minimal operational impact and financial costs. Frequently, interim software solutions must be developed while new hardware is under design or production. These interim systems are characterized by an immediate need with a limited budget. This paper discusses several factors involved with producing a working software set in minimal time, such as the initial approach, budgetary concerns, and resource-scavenging. By recognizing the importance of these factors, interim system developers will be able to produce working systems with a minimum of setbacks. RP Caetta, J (reprint author), CALTECH,JET PROP LAB,M-S 264-325,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU USENIX ASSOC PI BERKELEY PA SUITE 215, 2560 NINTH ST, BERKELEY, CA 94710 BN 1-880446-90-1 PY 1997 BP 51 EP 57 PG 7 WC Computer Science, Information Systems SC Computer Science GA BJ83D UT WOS:A1997BJ83D00007 ER PT S AU Gehrels, N Shrader, C AF Gehrels, N Shrader, C BE Dermer, CD Strickman, MS Kurfess, JD TI Status and future of the Compton Gamma Ray Observatory SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB The Compton Gamma Ray Observatory and its four experiment packages continue to function in a nearly flawless manner now well into the sixth year of mission operations. We discuss the status of the mission as of mid-1997, as well as the prospects of an extended mission lasting into the next century. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Gehrels, N (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RI Gehrels, Neil/D-2971-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 3 EP 13 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800001 ER PT S AU Thompson, DJ Harding, AK Hermsen, W Ulmer, MP AF Thompson, DJ Harding, AK Hermsen, W Ulmer, MP BE Dermer, CD Strickman, MS Kurfess, JD TI Gamma-ray pulsars: the Compton observatory contribution to the study of isolated neutron stars SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB The four instruments on the Compton Gamma Ray Observatory have identified at least seven isolated neutron stars by their pulsed gamma-ray emission. For all of these, the gamma radiation represents the largest observable fraction of the spin-down luminosity, making the gamma rays important diagnostics of particle acceleration and interaction in the neutron star magnetospheres. Several other "candidate" pulsars have tentative identifications based on pulsed radiation or positional association. The ensemble of CGRO pulsar detections, possible detections, and upper limits yields a number of patterns, most of which have exceptions. Some examples: (1) All except PSR B1509-58 have light curves consistent with double pulses; (2) All except the Crab have radio pulses out of phase with the gamma-ray pulses (the relative phase of the recently-reported radio pulse from Geminga is not known as of this writing); (3) Except possibly for PSR B1509-58 and PSR B0656+14, the gamma-ray energy spectra flatten with increasing pulsar age; (4) All except PSR B1951+32 show evidence of having high-energy spectral cutoffs in the CGRO energy band; (5) The pulsed flux from all the pulsars is relatively constant with time; (6) There is a trend for the pulsar luminosity to increase with increasing polar-cap current (or open field line voltage, or E, all of which are similar). The diversity in the phenomenology of gamma-ray pulsars presents challenges to pulsar models. For example, double-pole models, often invoked by radio astronomers, now seem problematic. Most models have evolved significantly in response to the CGRO discoveries, and no comprehensive explanation for all the observations is yet in hand. 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; Harding, Alice/D-3160-2012 OI Thompson, David/0000-0001-5217-9135; NR 0 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 39 EP 56 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800003 ER PT S AU Finger, MH Prince, TA AF Finger, MH Prince, TA BE Dermer, CD Strickman, MS Kurfess, JD TI Recent results from observations of accreting pulsars SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB Since its launch in 1991, the Compton Gamma Ray Observatory (CGRO) has provided a wealth of new information on binary systems containing a magnetized neutron star accreting from a stellar companion. In particular, the all-sky monitoring capability of the BATSE instrument has allowed the first longterm continuous measurements of the flux and torque histories of the brighter accreting pulsar systems. These have given new insights into the processes by which mass and angular momentum are exchanged between the accretion disk and the neutron star, and the role of radiation and X-ray driven winds in these systems. Observations of transient pulsars with BATSE and OSSE have provided new quantitative tests of standard theories of disk-magnetosphere interactions. Although many new insight have been gained, some of the observations present new puzzles and challenge current models of accretion processes. We review these observations, as well as a sampling of other recent results from CGRO and the ROSSI X-ray Timing Explorer (RXTE). C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Finger, MH (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 57 EP 74 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800004 ER PT S AU Kouveliotou, C van Paradijs, J AF Kouveliotou, C van Paradijs, J BE Dermer, CD Strickman, MS Kurfess, JD TI GRO J1744-28: the bursting pulsar SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB During more than 25 years of studies of X-ray binaries several dozens of X-ray pulsars and X-ray bursters were discovered; not a single one of these showed both pulsations and bursts. Here we describe the properties of the Bursting Pulsar, a unique,X-ray source, discovered in December 1995 with the Burst And Transient Source Experiment (BATSE), which seems to be the first to defy the dictum 'pulsars don't burst, and bursters don't pulse'. C1 NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. RP Kouveliotou, C (reprint author), NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, ES-84, Huntsville, AL 35812 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 96 EP 109 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800006 ER PT S AU Zhang, SN Mirabel, IF Harmon, BA Kroeger, RA Rodriguez, LF Hjellming, RM Rupen, MP AF Zhang, SN Mirabel, IF Harmon, BA Kroeger, RA Rodriguez, LF Hjellming, RM Rupen, MP BE Dermer, CD Strickman, MS Kurfess, JD TI Galactic black hole binaries: Multifrequency connections SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We review the recent multifrequency studies of galactic black hole binaries, aiming at revealing the underlying emission processes and physical properties in these systems. The optical and infrared observations are important for determining their system parameters, such as the companion star type, orbital period and separation, inclination angle and the black hole mass. The radio observations are useful for studying high energy electron acceleration process, jet formation and transport. X-ray observations can be used to probe the inner accretion disk region in order to understand the fundamental physics of the accretion disk in the strongest gravitational field and the properties of the black hole. Future higher sensitivity and better resolution instrumentation will be needed to answer the many fundamental questions that have arisen. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Zhang, SN (reprint author), NASA, George C Marshall Space Flight Ctr, ES-84, Huntsville, AL 35812 USA. NR 0 TC 6 Z9 6 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 141 EP 162 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800009 ER PT S AU Hunter, SD Kinzer, RL Strong, AW AF Hunter, SD Kinzer, RL Strong, AW BE Dermer, CD Strickman, MS Kurfess, JD TI Diffuse galactic continuum radiation SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB The diffuse gamma-ray continuum emission, which arises from cosmic-ray protons and electrons interacting with the interstellar matter and low energy photons, is the dominant feature of the gamma-ray sky. This emission has been studied from 0.05 MeV to over 50 GeV using the observations from OSSE, COMPTEL, and EGRET on the Compton Gamma-Ray Observatory. The OSSE observations show the diffuse continuum to be a composite of three independent components: e(+)e(-) anihilation line plus continuum, a soft low-energy component, and a dominant, hard component. The COMPTEL re suits are the first measurement of the diffuse emission at intermediate energies and the EGRET results have provided a much clearer image of the spatial and spectral distribution of this emission at higher energies. Although significant contributions from unresolved distributions of point sources cannot be excluded, particularly from the COMPTEL and OSSE data, the spectra. from the three instruments, from I MeV to about 1 GeV, can be explained with the sum of bremsstrahlung, nucleon-nucleon (pi(0) decay), and inverse Compton components. However, above about 1 GeV, the EGRET spectrum is harder than expected from the nucleon-nucleon spectrum derived from an E-p(-2.7) cosmic-ray proton spectrum observed in the Solar neighborhood. These observations and results are discussed in terms of the correctness of our interpretations of the observations, what does and what does not conform to the standard picture, the significance of these observations for cosmic-ray physics, and how much of the observed flux is due to point sources. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hunter, SD (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Hunter, Stanley/D-2942-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 192 EP 207 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800012 ER PT S AU Hartman, RC Collmar, W von Montigny, C Dermer, CD AF Hartman, RC Collmar, W von Montigny, C Dermer, CD BE Dermer, CD Strickman, MS Kurfess, JD TI Gamma-ray blazars SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB Roughly 60 blazars have been identified with > 100 MeV EGRET gamma-ray sources, and show inferred isotropic luminosities as large as 3 x 10(49) ergs s(-1) The two most remarkable characteristics about the EGRET observations are that the gamma-ray luminosity often dominates the bolometric power, and that variability on time-scales of one day or less is seen from several sources. Gamma-ray blazars have been detected with redshifts ranging from congruent to 0.03 to congruent to 2.3. The distribution of redshifts is similar to that of flat spectrum radio quasars. The distribution of > 100 MeV photon spectral indices for strong detections is well described by a. Gaussian function peaking near 2.16 with a standard deviation of 0.31. In some cases, flare spectra at > 100 MeV energies are harder than spectra in quiescence. Blazar spectra at hard X-ray and soft gamma-ray energies have harder spectra and, from analyses of contemporaneous data sets, the change in spectral index clearly exceeds 0.5 for 3C 273 and marginally exceeds 0.5 for PKS 0528+134. An index change of 0.5 is predicted by incomplete Compton cooling models. COMPTEL observations reveal a separate class of 2 identified blazars and 3 unidentified candidates with narrow peaks at MeV energies. The combined luminosity and variability data strengthen arguments for relativistic beaming or bulk outflow from the active nucleus. Gamma-ray transparency arguments are based on the pair-production attenuation of gamma rays in a stationary region defined by the variability time-scale, and many violations are indicated. The Elliot-Shapiro relation compares the minimum black hole mass implied by the Eddington limit with the maximum black hole mass implied by the variability time-scale related to the black hole Schwarzschild radius; weak violations have been observed for PKS 0528+134 and PKS 1622-297. Most models adopt a beaming paradigm. In models considering leptons as the directly accelerated and radiating particles, Compton scattering is favored to make the gamma-ray emission, though opinions differ on whether the soft photons are primarily internal synchrotron photons or accretion disk photons which enter the jet either directly or after scattering off clouds. Hadronic models involve secondary production or photomeson production followed by pair cascades, and predict associated neutrino production. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hartman, RC (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 307 EP 327 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800018 ER PT S AU Shrader, CR Wehrle, AE AF Shrader, CR Wehrle, AE BE Dermer, CD Strickman, MS Kurfess, JD TI Multiwavelength campaigns SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB The first six years of the Compton Gamma Ray Observatory mission has led to significant advances in the study of active galactic nuclei, as shown in various contributions to these proceedings. However, the given the inherent nature of AGN - broadband, non-thermal emission which exhibits variability at all wavelengths over many time scales - empirical insight into the multi-epoch, multi-wavelength behavior is essential before the underlying physics can begin to be deciphered. This is particularly true for the blazar subclass of AGN detected by EGRET, but it also pertains to the lower-luminosity radio-quiet AGN detected with OSSE. Fortunately, this situation was recognized early an and a number of coordinated multiwavelength studies have been successfully carried out both as carefully preplanned monitoring campaigns and as targets of opportunity. Also fortunate has been the overlap with the first 6 years of the CGRO mission of several space-based observatories covering portions of the X-ray, ultraviolet, and infrared spectrum inaccessible from the ground, accompanied by recent advances in ground-based gamma-ray astronomy data acquisition and analysis techniques. We review accounts of multiwavelength studies involving CGRO from the published literature and from new material presented at this conference, noting some of the key results as well as some remaining ambiguities. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Shrader, CR (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 328 EP 343 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800019 ER PT S AU Sreekumar, P Stecker, FW Kappadath, SC AF Sreekumar, P Stecker, FW Kappadath, SC BE Dermer, CD Strickman, MS Kurfess, JD TI The extragalactic diffuse Gamma-Ray emission SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB The all-sky surveys in gamma-rays by the imaging Compton telescope (COMPTEL) and the Energetic Gamma Ray Experiment Telescope (EGRET) on board the Compton Gamma Ray Observatory for the first time allows detailed studies of the extragalactic diffuse emission at gamma-ray energies greater 1 MeV. A preliminary analysis of COMPTEL data indicates a significant decrease in the level of the derived cosmic diffuse emission from previous estimates in the 1-30 MeV range, with no evidence for an MeV-excess, at least not at the levels claimed previously, The 1-30 MeV flux measurements are compatible with power-law extrapolation from lower and higher energies. These new results indicate that the possible contributions to the extragalactic emission from processes that could explain the MeV-excess, such as matter-antimatter annihilation, is significantly reduced. At high energies (> 30 MeV), the extragalactic emission is well described by a power law photon spectrum with an index of -(2.10+/-0.03) in the 80 MeV to 100 GeV energy range. No large scale spatial anistropy or changes in the energy spectrum are observed in the deduced extragalactic emission. The most likely explanation for the origin of this extragalactic gamma-ray emission above 10 MeV, is that it arises primarily from unresolved gamma-ray-emitting blazars. The consistency of the average gamma-ray blazar spectrum with the derived extragalactic diffuse spectrum strongly argues in favor of such an origin. The extension of the power law spectrum to 100 GeV implies the average emission from gamma-ray blazars extends to 100 GeV. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sreekumar, P (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Stecker, Floyd/D-3169-2012 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 344 EP 358 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800020 ER PT S AU Meegan, C Hurley, K Connors, A Dingus, B Matz, S AF Meegan, C Hurley, K Connors, A Dingus, B Matz, S BE Dermer, CD Strickman, MS Kurfess, JD TI A review of gamma ray bursts SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB Gamma-ray bursts have continued to puzzle astronomers since their discovery thirty years ago. The sources and emission mechanisms are still uncertain. The instruments on the Compton Gamma Ray Observatory, most notably BATSE. have produced a revolution in our understanding of bursts. BATSE found that the burst spatial distribution was isotropic but inhomogeneous, a result inconsistent with any disk population of sources. The currently favored model is one in which the sources lie st cosmological distances. Recent apparent successes in the detection of X-ray and optical counterparts have generated renewed excitement. C1 NASA, George C Marshall Space Flight Ctr, Greenbelt, MD USA. RP Meegan, C (reprint author), NASA, George C Marshall Space Flight Ctr, Greenbelt, MD USA. NR 0 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 407 EP 417 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800024 ER PT S AU Harris, MJ AF Harris, MJ BE Dermer, CD Strickman, MS Kurfess, JD TI Gamma-ray line transients SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB Early interpretations of the variability of the narrow 0.511 MeV annihilation line from the Galactic center (GC) were confused by the unrecognized presence of a very extended component (mid 70s - mid 80s). Transient behavior was suggested by comparisons of measurements made by instruments with comparable fields of view, and by detection of other Lines which could be interpreted as broadened and Doppler-shifted versions of the line. A new generation of instruments (rate 80s - early 90s) provided more compelling evidence, by improved imaging capability (identifying a known transient high-energy candidate source, 1E 1740.7-2942), and by improved sensitivity. Additional broadened, shifted, and Compton-scattered derivatives of the annihilation Line were detected from this and other sources. At the same time, theoretical developments suggested exciting new physics which might arise in the accretion regimes around black holes, of which these features would be important diagnostics. In the GRO era the existence of such transient lines has been brought into question by the failure of long-term monitoring to detect them. A seemingly critical observation of the GC by three different instruments simultaneously, in which transient emission was detected only by one, provides the strongest evidence that the earlier results were in error. Recent developments in accretion disk theory have weakened the theoretical case for the lines, I draw conclusions concerning the nature of scientific inquiry and public outreach efforts in science. C1 NASA, Goddard Space Flight Ctr, USRA, GVSP, Greenbelt, MD 20771 USA. RP Harris, MJ (reprint author), NASA, Goddard Space Flight Ctr, USRA, GVSP, Code 661, Greenbelt, MD 20771 USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 418 EP 435 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800025 ER PT S AU Fichtel, CE Sreekumar, P AF Fichtel, CE Sreekumar, P BE Dermer, CD Strickman, MS Kurfess, JD TI Constraints from undetected gamma-ray sources SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB The number of positive gamma-ray source detections by the Camp ton Gamma-Ray Observatory has been large, and the significance of the results has been substantial, as is described in other reports at this conference. In addition, searches for gamma rays were made that have led to null results, but that nonetheless deserve attention because of their important scientific implications. In the gamma-ray observations there has been as get no indication of antimatter in the universe other than that produced in cosmic-ray interactions. The upper limit for microsecond bursts has implications for attempts at unified theories of physics. The search for signatures from supersymmetric particles has not revealed any positive evidence. The measurements of the high-energy gamma-ray emission from blazars and its interpretation in terms of the relativistic particles and their origin has been one of the highlights of the EGRET results. However, there are a few flat-spectrum radio quasars that are very strong in the radio regime, but have not been seen in high-energy gamma rays. The derived upper limits from external normal galaxies indicate no evidence for significant deviation from equipartition arguments. A minimum value of 0.4 mu G for the intracluster magnetic field is derived from gamma-raf upper limits on the Coma cluster. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Fichtel, CE (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 436 EP 446 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800026 ER PT S AU Titarchuk, L AF Titarchuk, L BE Dermer, CD Strickman, MS Kurfess, JD TI Comptonization processes in galactic and extragalactic high energy sources SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We review the principal radiation mechanisms which can be responsible for the production of high energy emission of Galactic and extragalactic sources. The spectral properties of Comptonization processes are studied. We present a rigorous treatment of the problem in terms of the Boltzmann kinetic equation formalism. We also overview the different exact and approximate analytical and numerical techniques which decouple the photon transport in six dimensions to that in the configuration space and in energy space separately. CGRO, RXTE, and SAX observations of Galactic black hole candidates, neutron star systems, and Seyfert nuclei show that their spectra can be fitted by thermal Comptonization models in the hard state, and two components in the soft state. In the latter case, these components show a blackbody like spectrum with the color temperature which is a fraction of keV and tens of eV for Galactic and extragalactic sources, respectively, and an extended power-law with spectral index between 1 and 2 (in the neutron star systems in their soft State this power-law component is not detected). We give arguments for an explanation of these two types of spectral states in the framework of the thermal and bulk motion Comptonization processes. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Titarchuk, L (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 477 EP 493 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800029 ER PT S AU Ray, A Harding, AK Strickman, M AF Ray, A Harding, AK Strickman, M BE Dermer, CD Strickman, MS Kurfess, JD TI RXTE observation of PSR1706-44 SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We report on results of an observation with the Rossi X-Ray Timing Explorer of PSR1706-44, to search for pulsed X-ray emission. FSR1706-44 is a radio and high-energy gamma-ray pulsar (detected by EGRET), but no pulsed emission has been detected in the X-ray band. Since most of the other known gamma-ray pulsars emit pulsed X-rays, it is expected that PSR1706-44 would also be an X-ray pulsar. However, ROSAT detected a source at the pulsar position, but did not detect pulsations, giving a pulsed fraction upper limit of 18%. We report here results of a search for modulation at the pulsar period from our approximate to 90K second RXTE observation (out of the total approved time of 147 K second), carried out in November 1996 during a low state of the nearby X-ray binary 4U1705-44. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ray, A (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Harding, Alice/D-3160-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 607 EP 611 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800047 ER PT S AU Dieters, S Wilson, C Finger, M Scott, M van Paradijs, J AF Dieters, S Wilson, C Finger, M Scott, M van Paradijs, J BE Dermer, CD Strickman, MS Kurfess, JD TI RXTE observations of the anomalous pulsar 4U0142+61 SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We have observed the X-ray pulsar X0142+61 using RXTE in March 1996. This pulsar is one of a small group that are either isolated pulsars or members of very compact, low mass binaries. The pulse period is measured as 8.68814(+/-9) sec with an upper limit of (P) over dot/P less than or equal to 8x10(-10) s/s upon the short term spin up/down rate. A compilation of all historical measurements show an overall spin down trend with an episode of more rapid spin up and down between 1984 and 1996. A search for orbital modulations in the pulse arrival times yielded an upper limit less than or equal to 0.28 It.sec. in a(x)sini over the interval 600 to 10(5) sec. C1 NASA, MSFC, Huntsville, AL 35816 USA. RP Dieters, S (reprint author), NASA, MSFC, ES84 Space Sci Bldg 4481, Huntsville, AL 35816 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 617 EP 621 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800049 ER PT S AU Baring, MG Harding, AK AF Baring, MG Harding, AK BE Dermer, CD Strickman, MS Kurfess, JD TI A new class of radio quiet pulsars SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB The complete absence of radio pulsars with periods exceeding a few seconds has lead to the popular notion of the existence of a high P death line. In the standard picture, beyond this boundary, pulsars with low spin rates cannot accelerate particles above the stellar surface to high enough energies to initiated pair cascades through curvature radiation, and the pair creation needed for radio emission is strongly suppressed. In this paper we postulate the existence of another pulsar "death line," corresponding to high magnetic fields B in the upper portion of the (P) over dot-P diagram, a domain where few radio pulsars are observed. The origin of this high B boundary, which occurs when B becomes comparable to or exceeds 10(13) Gauss, is again due to the suppression of magnetic pair creation gamma --> e(+)e(-), but in this instance, primarily because of ineffective competition with the exotic QED process of magnetic photon splitting. This paper describes the origin, shape and position of the new "death line. above which pulsars are expected to be radio quiet, but perhaps still X-ray and gamma-ray bright. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Baring, MG (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. RI Harding, Alice/D-3160-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 638 EP 642 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800053 ER PT S AU Harding, AK Muslimov, A AF Harding, AK Muslimov, A BE Dermer, CD Strickman, MS Kurfess, JD TI Geometry of pulsar X-ray and gamma-ray pulse profiles SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We model the thermal X-ray profiles of Geminga, Vela and PSR0656+14, which have also been detected as gamma-ray pulsars, to constrain the phase space of obliquity and observer angles required to produce the observed X-ray pulse fractions and pulse widths. These geometrical constraints derived from the X-ray light curves are explored for various assumptions about surface temperature distribution and flux anisotropy caused by the magnetized atmosphere. We include curved spacetime effects on photon trajectories and magnetic held. The observed gamma-ray pulse profiles are double peaked with phase separations of 0.4 - 0.5 between the peaks. Assuming that the gamma-ray profiles are due to emission in a hollow cone centered on the magnetic pole, we derive the constraints on the phase space of obliquity and observer angles, for different gamma-ray beam sizes, required to produce the observed gamma-ray peak phase separations. We compare the constraints from the X-ray emission to those derived from the observed gamma-ray pulse profiles, and find that the overlapping phase space allows both obliquity and observer angles to be smaller than 20 - 30 degrees, implying gamma-ray beam opening angles of less than 30 - 35 degrees. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Harding, AK (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Harding, Alice/D-3160-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 648 EP 652 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800055 ER PT S AU Wilson, RB Scott, DM Finger, MH AF Wilson, RB Scott, DM Finger, MH BE Dermer, CD Strickman, MS Kurfess, JD TI Long-term observations of Her X-1 with BATSE SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB Pulsed emission from Her X-l has been observed by BATSE during each Main High state throughout the CGRO mission. This long observation set by a single instrument provides new information on long-term behavior of the Her X-l system. The pulsed emission varies by more than a factor of 3 between different Main High states. Frequency and flux histories do not show a simple relationship between the source intensity and spin behavior, but do show that the source is normally in spinup, and spindown episodes occur at all source flex levels. Orbital analyses are presented, including determination of the orbital period derivative, which is in agreement with Deeter et al. (1991). C1 NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. RP Wilson, RB (reprint author), NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 739 EP 743 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800073 ER PT S AU Wilson, CA Finger, MH Harmon, BA Wilson, RB Chakrabarty, D Strohmayer, T AF Wilson, CA Finger, MH Harmon, BA Wilson, RB Chakrabarty, D Strohmayer, T BE Dermer, CD Strickman, MS Kurfess, JD TI GRO J2058+42 x-ray observations SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB GRO J2058+42, a transient 198 second x-ray pulsar, was discovered by BATSE during a giant outburst in 1995 September-October. The total flux peaked at about 300 mCrab (20-50 keV) as measured by Earth occultation. The pulse period decreased from 198 s to 196 s during the 46-day outburst. BATSE has observed five additional weak outbursts from GRO J2058+42 with peak pulsed fluxes of about 15 mCrab (20-50 keV) that were spaced by about 110 days. The periodicity of the outbursts allowed a ToO observation by the Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) which localized the source to a 4' error Circle. Mie present pulse frequency history, flux histories from pulsed and Earth occultation data, and representative pulse profiles. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Wilson, CA (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 773 EP 777 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800080 ER PT S AU Zhang, SN Cui, W Harmon, BA Paciesas, WS AF Zhang, SN Cui, W Harmon, BA Paciesas, WS BE Dermer, CD Strickman, MS Kurfess, JD TI Spectral evolution of Cyg X-1 during its 1996 soft state transition SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We report the broad band, near continuous spectral evolution of Cyg X-1 during its 1996 soft state transition, observed with ASM/RXTE (1.3-12 keV) and BATSE/CGRO (20-2000 keV). The spectra above 20 keV can be well described by a power law with an exponential cutoff. During the hard to soft state transition the power law became steeper and the cutoff energy became higher, and vise versa during the soft to hard state transition. In the middle of the soft state, there is no evidence for any spectral break up to at least 250 keV. C1 George C Marshall Space Flight Ctr, Huntsville, AL 35810 USA. RP Zhang, SN (reprint author), George C Marshall Space Flight Ctr, Huntsville, AL 35810 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 839 EP 843 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800093 ER PT S AU Focke, W Swank, J Phlips, B Heindl, W Cui, W AF Focke, W Swank, J Phlips, B Heindl, W Cui, W BE Dermer, CD Strickman, MS Kurfess, JD TI Spectral variability of Cygnus X-1 in the soft state SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB Cygnus X-l made a transition to the relatively rare soft state in 1996 May, and stayed in this state until 1996 August. A number of Target of Opportunity (TOO) observations of the source were made during this time with the Rousi X-ray Tinting Explorer (RXTE). The hardness-intensity diagram showed similarity to that of GRS 1915-105 in recent observations. Time-dependent model fits to the spectrum shaw that the photon index of the hard tail varies significantly on minute timescales. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Focke, W (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 854 EP 857 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800096 ER PT S AU Hua, XM Ling, JC Wheaton, WA AF Hua, XM Ling, JC Wheaton, WA BE Dermer, CD Strickman, MS Kurfess, JD TI Modeling Cygnus X-1 gamma 2 spectra observed by BATSE SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB The gamma(2) spectra of Cygnus X-1 from the BATSE earth occultation observations between 25 keV and 1.8 MeV has two components: a Comptonized part seen below 300 keV, and a high-energy tan in the 0.3 - 2 MeV range. The spectra was interpreted in terms of an interacting two-zone model, consisting of a high temperature core embedded in a corona with relatively lower temperature. In this study, we perform a comprehensive search in the l-dimensional parameter space of the two-zone model. We give the estimation of the best fitting parameters of the model and their errors. The results are compared with the one-zone model, both analytical and numerical, traditionally used in spectral data fitting. It is found that the two-zone model yields significantly better fits to the observation, an indication that there exists a high-energy core in the cloud surrounding the black hole candidate. C1 NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RP Hua, XM (reprint author), NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 858 EP 862 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800097 ER PT S AU Zhang, SN Harmon, BA Liang, EP AF Zhang, SN Harmon, BA Liang, EP BE Dermer, CD Strickman, MS Kurfess, JD TI Two distinct states of microquasars 1E1740-294 and GRS1758-258 SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We report the monitoring results over a similar to 5 year period of the two radio and hard X-ray sources 1E1740-294 and GRS1758-258 with BATSE/CGRO since 1991. Two hard X-ray flux and spectral states are found. The hard X-ray high flux state in 1E1740-294 can be represented by a hard power-law with an exponential cutoff, commonly seen in black hole candidates in their hard state. In its hard X-ray low flux state, its energy spectrum becomes a steeper power law without break up to 200-300 keV, usually seen in the soft state of black hole candidates and in the two galactic superluminal jet sources GRS1915+105 and GROJ1655-40. We also discuss the possible nature of the two systems. C1 George C Marshall Space Flight Ctr, Huntsville, AL 35810 USA. RP Zhang, SN (reprint author), George C Marshall Space Flight Ctr, ES-84, Huntsville, AL 35810 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 873 EP 877 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800100 ER PT S AU Bridgman, WT Dermer, CD Skibo, JG AF Bridgman, WT Dermer, CD Skibo, JG BE Dermer, CD Strickman, MS Kurfess, JD TI Temporal characteristics of Compton reflection from accretion disks SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We treat the problem of time-dependent Compton reflection produced by a point source of radiation illuminating an infinite optically-thick disk of cold solar composition material. The problem is treated using a Monte-Carlo radiation transport simulation in the optically thick limit. The reflection produces a broad feature in the power spectrum at a frequency f similar to c/h, where h is the height of the photon source above the disk. C1 NASA, Goddard Space Flight Ctr, USRA, Greenbelt, MD 20771 USA. RP Bridgman, WT (reprint author), NASA, Goddard Space Flight Ctr, USRA, Code 660-1, Greenbelt, MD 20771 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 977 EP 981 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800121 ER PT S AU Kazanas, D Hua, XM Titarchuk, L AF Kazanas, D Hua, XM Titarchuk, L BE Dermer, CD Strickman, MS Kurfess, JD TI Temporal and spectral properties of comptonized radiation SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We have found relations between the temporal and spectral properties of radiation Comptonized in an extended atmosphere associated with compact accreting sources. We demonstrate that the fluctuation power spectrum density (PSD) imposes constraints on the atmosphere scale and profile. Furthermore, we indicate that the slope and low frequency break of the PSD are related to the Thomson depth tau(0) of the atmosphere and the radius of its physical sire respectively. Since the energy spectrum of the escaping radiation depends also on tau(0) (and the electron temperature kT(e)), the relation between spectral and temporal properties follows. This relation allows for the first time an estimate of the accreting matter Thomson depth tau(0) independent of arguments involving Comptonization. C1 NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RP Kazanas, D (reprint author), NASA, Goddard Space Flight Ctr, LHEA, Code 661, Greenbelt, MD 20771 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 982 EP 986 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800122 ER PT S AU Hua, XM Kazanas, D Titarchuk, L AF Hua, XM Kazanas, D Titarchuk, L BE Dermer, CD Strickman, MS Kurfess, JD TI Phase difference and coherence as diagnostics of accreting sources SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We present calculations of the time lags and the coherence function of X-ray photons for a novel model of radiation emission from accretion powered, high-energy sources. Our model involves only Comptonization of soft photons injected near the compact object in an extended but nonuniform atmosphere around the compact object. We show that this model produces time lags between the hard and soft bands of the X-ray spectrum which increase with Fourier period, in agreement with recent observations; it also produces a coherence function equal to one over a wide range of frequencies if the system parameters do not have significant changes, also in agreement with the limited existing observations. We explore various conditions that could affect coherence functions. We indicate that measurements of these statistical quantities could provide diagnostics of the radial structure of the density of this class of sources. C1 NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RP Hua, XM (reprint author), NASA, Goddard Space Flight Ctr, LHEA, Code 661, Greenbelt, MD 20771 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 987 EP 991 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800123 ER PT S AU Teegarden, BJ Cline, TL Gehrels, N Ramaty, R Seifert, H Harris, M Palmer, D Hurley, KH AF Teegarden, BJ Cline, TL Gehrels, N Ramaty, R Seifert, H Harris, M Palmer, D Hurley, KH BE Dermer, CD Strickman, MS Kurfess, JD TI TGRS results on the spatial and temporal behavior of the galactic center 511keV line SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB The TGRS (Transient Gamma-Ray Spectrometer) experiment is a high-resolution germanium detector launched on the WIND satellite on Nov. 1, 1994. Although primarily intended to study gamma-ray bursts and solar flares, TGRS also has the capability of studying steady sources near the ecliptic plane (including the Galactic Center). We present here preliminary results on the narrow 511 keV annihilation line from the general direction of the Galactic Center obtained from the TGRS occultation mode. Data are presented for approximately 2 years beginning 1 Jan. 1995. We detect the narrow annihilation line from the galactic center with an average flux of ((1.10+/-.05)x10(-3) ph cm(-2) s(-1)). The data are consistent with a broadened source at the Galactic Center with a width similar to 25 degrees in ecliptic longitude. No evidence for temporal variability on time scales longer than 1 month was found. Our results are in reasonable agreement with the OSSE 511 keV data, but there are some hints of differences in the spatial distribution at the 2 sigma level. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Teegarden, BJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Gehrels, Neil/D-2971-2012 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1007 EP 1011 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800127 ER PT S AU Ramaty, R Kozlovsky, B Tatischeff, V AF Ramaty, R Kozlovsky, B Tatischeff, V BE Dermer, CD Strickman, MS Kurfess, JD TI Issues concerning the Orion gamma ray line observations: Overview and X-ray emission SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We review the major implications of the COMPTEL gamma ray line observations of Orion. We present new calculations of the expected X-ray line and continuum emissions that accompany the observed gamma ray lines. We show that a serious conflict may exist between the predicted oxygen K-alpha line emission and upper limits from ROSAT. This conflict is alleviated, but not fully resolved, if the gamma rays are produced in the warm, partially ionized medium st cloud boundaries. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ramaty, R (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1049 EP 1053 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800135 ER PT S AU Tatischeff, V Ramaty, R Mandzhavidze, N AF Tatischeff, V Ramaty, R Mandzhavidze, N BE Dermer, CD Strickman, MS Kurfess, JD TI Constraints from pion production on the spectral hardness of the low energy cosmic rays in Orion SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB The gamma ray line emission observed with COMPTEL from Orion is attributed to the interaction within the molecular cloud of fast nuclei resulting from diffusive shock acceleration of a seed source. We have carried out detailed calculations of pion production by such low energy cosmic rays enriched in heavy elements, In the light of the EGRET observations of the molecular complex, we show that the characteristic energy of the accelerated particles spectrum can be quite large, but should not exceed 100 MeV/nucleon in order Do not overproduce the high energy gamma ray emission. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Tatischeff, V (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1054 EP 1058 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800136 ER PT S AU Harris, MJ Purcell, WR McNaron-Brown, K Murphy, RJ Grove, JE Johnson, WN Kinzer, RL Kurfess, JD Share, GH Jung, GV AF Harris, MJ Purcell, WR McNaron-Brown, K Murphy, RJ Grove, JE Johnson, WN Kinzer, RL Kurfess, JD Share, GH Jung, GV BE Dermer, CD Strickman, MS Kurfess, JD TI OSSE results on galactic gamma-ray line emission SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We report progress in an ongoing search for gamma-ray line emission from the Galaxy using OSSE. Four lines are of interest. The 4.4 and 6.1 MeV lines from de-excitation of C-12 and O-16 excited by cosmic-ray impacts, which were detected by COMPTEL from the Orion molecular cloud, have been searched for st several longitudes in the Galactic plane, without success. Constraints can be placed on one specific model of a point-source origin of the lines. The other two lines, the 1.17 and 1.33 MeV lines from Fe-60, may be present at the limit of OSSE's sensitivity at positive longitudes in the central radian of the Galaxy. C1 NASA, Goddard Space Flight Ctr, GVSP, USRA, Greenbelt, MD 20771 USA. RP Harris, MJ (reprint author), NASA, Goddard Space Flight Ctr, GVSP, USRA, Code 661, Greenbelt, MD 20771 USA. NR 0 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1079 EP 1083 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800141 ER PT S AU Harris, MJ AF Harris, MJ BE Dermer, CD Strickman, MS Kurfess, JD TI Fluctuation analysis of OSSE measurements of the 1.275MeV line of Na-22 SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We show that the time-scales on which OSSE makes and repeats observations make possible a very sensitive search for gamma-ray hues which are constrained to vary on compatible time-scales. The method resembles that by which the amplitude of single shot-like events is determined from the fluctuations in the sum of many events, even though individual shots are too weal to detect. The variability of the 1.275 MeV line from decay of Na-22 in novae near the Galactic center (GC) is suitable for this analysis. Applying it to OSSE measurements of this lint during 1991-1995, we obtain a value for the characteristic increase in line flux due to a single nova which is significant at a level similar to 2 sigma. C1 NASA, Goddard Space Flight Ctr, GVSP, USRA, Greenbelt, MD 20771 USA. RP Harris, MJ (reprint author), NASA, Goddard Space Flight Ctr, GVSP, USRA, Code 661, Greenbelt, MD 20771 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1094 EP 1098 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800144 ER PT S AU Baring, MG Ellison, DC Reynolds, SJ Grenier, IA AF Baring, MG Ellison, DC Reynolds, SJ Grenier, IA BE Dermer, CD Strickman, MS Kurfess, JD TI Gamma-rays from supernova remnants: Signatures of non-linear shock acceleration SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB Results from a study of non-linear effects in shock acceleration theory and their impact on the gamma-ray spectra of supernova remnants (SNRs) are presented. These non-linear effects describe the dynamical influence of the accelerated cosmic rays on the shocked plasma at the same time as addressing how the non-uniformities in the fluid flow force the distribution of the cosmic rays to deviate from pure power-laws. Such deviations are crucial to gamma-ray spectral determination. Our self-consistent Monte Carlo approach to shock acceleration, which is ideally suited to addressing SNR spectral issues. is used to predict ion and electron distributions that spawn neutral pion decay, bremsstrahlung and inverse Compton emission components for SNRs. The cessation of acceleration above critical energies in the 1 TeV - 10 TeV range caused by the spatial and temporal limitations of the expanding SNR shell yields gamma-ray spectral cutoffs: the resulting emission spectra are quite consistent with Whipple's TeV upper limits to those EGRET unidentified sources that have SNR associations. C1 NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 USA. RP Baring, MG (reprint author), NASA, Goddard Space Flight Ctr, LHEA, Greenbelt, MD 20771 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1157 EP 1161 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800156 ER PT S AU Digel, SW Grenier, IA Hunter, SD Dame, TM Thaddeus, P AF Digel, SW Grenier, IA Hunter, SD Dame, TM Thaddeus, P BE Dermer, CD Strickman, MS Kurfess, JD TI Diffuse high-energy gamma-ray emission in Monoceros SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We present a study of the diffuse gamma-ray emission observed by EGRET toward Monoceros in the outer Galaxy. The region studied, I = 210 - 250 degrees, b = -15 - +20 degrees, includes the molecular clouds associated with Mon R2 and Maddalena's cloud as well as more distant clouds in the Perseus arm. This is the sector of the third quadrant best suited for study of variations of the gamma-ray emissivity and molecular cloud mass calibration in the outer Galaxy. The molecular mass calibrating ratio in Monoceros is found to be N(H-2)/W-CO = (1.56 +/- 0.29) x 10(20) cm(-2) (K km s(-1))(-1) and the integral gamma-ray emissivity is Q(E > 100 MeV) = (1.92 +/- 0.14) x 10(-26) B-atom(-1) s(-1) sr(-1). The emissivity profile across the outer Galaxy is found to have a minimum between the local interstellar clouds and those in the Perseus arm. C1 NASA, Goddard Space Flight Ctr, Hughes STX, Greenbelt, MD 20771 USA. RP Digel, SW (reprint author), NASA, Goddard Space Flight Ctr, Hughes STX, Code 631, Greenbelt, MD 20771 USA. RI Hunter, Stanley/D-2942-2012 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1188 EP 1192 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800162 ER PT S AU Watanabe, K Hartmann, DH Leising, MD The, LS Share, GH Kinzer, RL AF Watanabe, K Hartmann, DH Leising, MD The, LS Share, GH Kinzer, RL BE Dermer, CD Strickman, MS Kurfess, JD TI The cosmic gamma-ray background from supernovae SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB The Cosmic gamma-ray Background (CGB) near photon energies E-gamma similar to 1 MeV may be partly, or even completely, due to gamma-ray production in supernovae. In particular, gamma-ray line emission from the decay chain Ni-56 --> Co-56 --> Fe-56 (847, 1238, 1770, 2599, 2030, 3250 keV) is the dominant source for the SN-induced CGB. Although iron synthesis occurs in all types of supernovae, SNIa contribute predominantly to the background mostly due to higher photon escape probabilities, Estimates of the global star formation history in the local universe yield a present-day rate density of similar or equal to 3.7 x 10(-2) h(3) M. Mpc(-3) yr(-1), but the star formation rate was about ten times higher st a redshift of order unity. The rate then decreases again, reaching the present-day value near redshifts similar or equal to 5. In addition to gamma-rays from SNIa we also consider contributions to the CGB due to lines from SNII (such as Al-26 at 1.8 MeV, Ti-44 at 1.157 MeV, and Co-60 at 1.17 & 1.33 MeV). The gamma-ray spectrum of Model W10HMM (Pinto & Woosley [8]) was time integrated to derive a template spectrum for Type II supernovae. For SNIa we also included the gamma-ray continuum, using the W7 model (Nomoto et al. [5]), integrated over 600 days, as template. We discuss the various contributions of supernovae to the CGB, and emphasise the value of gamma-ray observations in the MeV range as a potential tool for studies of cosmic chemical evolution. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Watanabe, K (reprint author), NASA, Goddard Space Flight Ctr, Code 6601, Greenbelt, MD 20771 USA. NR 0 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1223 EP 1227 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800169 ER PT S AU Thompson, DJ Bloom, SD Esposito, JA Kniffen, DA von Montigny, C AF Thompson, DJ Bloom, SD Esposito, JA Kniffen, DA von Montigny, C BE Dermer, CD Strickman, MS Kurfess, JD TI Searches for short-term variability of EGRET sources in the galactic anticenter SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB As part of a systematic search of the EGRET data base for shortterm (less than one week) source variability, we have examined observations of the Galactic anticenter. The analysis reconfirms the short-term variability of quasar 0528+134 and the lack of significant variability of the Crab and Geminga pulsars. No other sources in the Galactic anticenter show convincing evidence of variability on 2-day time scales during CGRO Phases 1 and 2. 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 OI Thompson, David/0000-0001-5217-9135 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1257 EP 1261 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800176 ER PT S AU Bloom, SD Thompson, DJ Hartman, RC von Montigny, C AF Bloom, SD Thompson, DJ Hartman, RC von Montigny, C BE Dermer, CD Strickman, MS Kurfess, JD TI Short time-scale gamma-ray variability of blazars and EGRET unidentified sources SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We have begun to examine the EGRET database for short term variations in the fluxes of blazars and the unidentified sources at high Galactic latitudes. We find that several AGN show previously unreported variability. Such variations are consistent with inverse Compton scattering processes in a shock propagating through a relativistic jet. C1 NASA, GSFC, NAS, NRC, Greenbelt, MD USA. RP Bloom, SD (reprint author), NASA, GSFC, NAS, NRC, Greenbelt, MD USA. RI Thompson, David/D-2939-2012 OI Thompson, David/0000-0001-5217-9135 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1262 EP 1266 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800177 ER PT S AU Parsons, A Gehrels, N Paciesas, W Harmon, A Fishman, G Wilson, C Zhang, SN AF Parsons, A Gehrels, N Paciesas, W Harmon, A Fishman, G Wilson, C Zhang, SN BE Dermer, CD Strickman, MS Kurfess, JD TI Multi-year BATSE earth occultation monitoring of NGC4151 SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB Because the Earth occultation technique allows BATSE to be used as an all-sky monitor, BATSE is uniquely able to provide continuous observations of NGC4151 over the entire lifetime of the Compton GRO mission. Continuous 2154 day light-curves for the Seyfert galaxy NGC4151 have been derived from Earth occultation analysis of CGRO BATSE data. Light-curves for the 20-70 keV and 70-200 keV bands are shown and found to have an average flux of 11 x 10(-3) photons cm(-2) s(-1) and 2.3 x 10(-3) photons cm(-2) s(-1) respectively. Evidence for intrinsic source variability is observed in both 20 - 70 keV and 70 - 200 keV bands with a fractional variation ratio measured at Fvar = 0.2. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Parsons, A (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Gehrels, Neil/D-2971-2012; Parsons, Ann/I-6604-2012 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1283 EP 1287 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800181 ER PT S AU Xu, WI Wehrle, AE Marscher, AP AF Xu, WI Wehrle, AE Marscher, AP BE Dermer, CD Strickman, MS Kurfess, JD TI VLBA monitoring of three gamma-ray bright blazars: AO0235+164, 1633+382 (4C38.41) & 2230+114 (CTA102) SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We present VLBA observations of three gamma-ray bright blazars: 0235+164, 1633+382 (4C38.41) and 2230+114 (CTA102). 0235+164 was unresolved at 22 and 43 GHz during the period between Nov. 1993 and Aug. 1996. The brightness of the core varied significantly. 1633+382 (4C38.41) has a sharp leading edge in its jet. The jet edge moved approximately at a constant velocity of (9.9 +/- 0.7) h(-1) c between March 1994 and Mag. 1995. The velocity is much faster than that of (6.1 +/- 1.1) h(-1) c measured by Barthel et al. (1995). This may indicate that a component is moving at a faster speed. 2230+114 (CTA 102) produced several new components between Feb. 1995 and Aug. 1996. These components moved at apparent velocities of (12 - 21) h(-1) c. The components at similar to 1.7 mas and similar to 8 mas seem to be stationary. C1 CALTECH, Jet Prop Lab, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. RP Xu, WI (reprint author), CALTECH, Jet Prop Lab, Ctr Infrared Proc & Anal, MC 100-22, 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1437 EP 1441 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800211 ER PT S AU Kazanas, D Titarchuk, LG Hua, XM AF Kazanas, D Titarchuk, LG Hua, XM BE Dermer, CD Strickman, MS Kurfess, JD TI The duration - Photon energy relation in gamma-ray bursts and its interpretations SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB Fenimore et al. (1995) have recently presented a very tight correlation between the spectral and the temporal structure in Gamma Ray Bursts (hereafter GRBs). In this note we present two simple models which can account in a straightforward fashion for the observed correlation. These models involve: (a) The impulsive injection of a population of relativistic electrons and their subsequent cooling by synchrotron radiation. (b) The impulsive injection of monoenergetic high energy photons in a medium of Thompson depth tau(T) similar to 5 and their subsequent downgrading in energy due to electron scattering. We present arguments for distinguishing between these two models from the existing data. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kazanas, D (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1520 EP 1524 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800226 ER PT S AU Teegarden, BJ Naya, J Seifert, H Sturner, S Vedrenne, G Mandrou, P von Ballmoos, P Roques, JP Jean, P Albernhe, F Borrel, V Schonfelder, V Lichti, GG Diehl, R Georgii, R Durouchoux, P Cordier, B Diallo, N Matteson, J Lin, R Sanchez, F Caraveo, P Leleux, P Skinner, GK Connell, P AF Teegarden, BJ Naya, J Seifert, H Sturner, S Vedrenne, G Mandrou, P von Ballmoos, P Roques, JP Jean, P Albernhe, F Borrel, V Schonfelder, V Lichti, GG Diehl, R Georgii, R Durouchoux, P Cordier, B Diallo, N Matteson, J Lin, R Sanchez, F Caraveo, P Leleux, P Skinner, GK Connell, P BE Dermer, CD Strickman, MS Kurfess, JD TI SPI: A high resolution imaging spectrometer for INTEGRAL SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB SPI (Spectrometer for INTEGRAL) is a high spectral resolution gamma-ray telescope using cooled germanium detectors that will, be flown on board the INTEGRAL mission in 2001. It consists of an array of 19 closely-packed germanium detectors surrounded by an active bismuth germanate (BGO) anti-coincidence shield. The instrument operates over the energy range 20 keV to 8 MeV with an energy resolution of 1-5 keV. A tungsten coded-aperture mask located 1.7 m from the detector array provides imaging over a 15 degrees fully-coded field-of-view with an angular resolution of similar to 3 degrees. The point source narrow-line sensitivity is estimated to be 3-7 x 10(-6) ph cm(-2) s(-1) over most of the range of the instrument (E > 200 keV) for a 10(6) s observation. With its combination of high sensitivity, high spectral resolution and imaging, SPI will improve significantly over the performance of previous instruments such as HEAO-3, OSSE, and Comptel. It can be expected to take a major step forward in experimental studies in nuclear astrophysics. The SPI instrument is being developed under the auspices of the European Space Agency by a large international team of scientists and engineers in both Europe and the United States. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Teegarden, BJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1535 EP 1543 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800228 ER PT S AU Seifert, H Naya, JE Sturner, SJ Teegarden, BJ AF Seifert, H Naya, JE Sturner, SJ Teegarden, BJ BE Dermer, CD Strickman, MS Kurfess, JD TI MGEANT - A generic multi-purpose Monte-Carlo simulation package for gamma-ray experiments SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB We present a generic multi-purpose Monte-Carlo simulation package, based on GEANT and the CERN Program Library, which is appropriate for gamma-ray astronomy, and allows the rapid prototyping of a wide variety of detector systems. Instrument specific geometry and materials data can simply be supplied via input files, and are independent of the main code. The user can select from a standard set of event generators and beam options (implemented as "plug-ins") which would be needed in an astrophysical or instrument calibration context. The philosophy of this approach is to facilitate the implementation of new software add-ons and changes in the instrumental setup. This is especially useful for projects which involve a large group of developers and collaborators. MGEANT has been successfully used to perform background calculations and to generate the instrument response for the WIND/TGRS instrument, and is currently being used to study the background, sensitivity, response, and imaging capabilities of the INTEGRAL/SPI. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Seifert, H (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1567 EP 1571 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800233 ER PT S AU Hunter, SD Belolipetskiy, SV Bertsch, DL Catelli, JR Crawford, H Daniels, WM Deines-Jones, P Esposito, JA Fenker, H Gossan, B Hartman, RC Hutchins, JB Krizmanic, JF Lindenstruth, V Martin, MD Mitchell, JW Pitts, WK Simrall, JH Sreekumar, P Streitmatter, RE Thompson, DJ Visser, G Walsh, KM AF Hunter, SD Belolipetskiy, SV Bertsch, DL Catelli, JR Crawford, H Daniels, WM Deines-Jones, P Esposito, JA Fenker, H Gossan, B Hartman, RC Hutchins, JB Krizmanic, JF Lindenstruth, V Martin, MD Mitchell, JW Pitts, WK Simrall, JH Sreekumar, P Streitmatter, RE Thompson, DJ Visser, G Walsh, KM BE Dermer, CD Strickman, MS Kurfess, JD TI Development of gas micro-structure detectors for gamma-ray astronomy SO PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 4th Compton Symposium CY APR 27-30, 1997 CL WILLIAMSBURG, VA AB Large area gas micro-structure detectors are being developed for the next generation high-energy gamma-ray telescope as part of NASA's SR&T program to support new technologies. These low-cost detectors are produced by laser micromachining of metalized polyimide films layered on carbon fiber composite substrates. This integrated detector and support design reduces the detector complexity and associated assembly costs. Accomplishments to date include testing of a 32 channel ASIC for the front-end electronics and integration of functional hardware into prototype detectors for tests of the FPGA readout system and event display software. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hunter, SD (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Hunter, Stanley/D-2942-2012; Thompson, David/D-2939-2012 OI Thompson, David/0000-0001-5217-9135 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 1-56396-659-X J9 AIP CONF PROC PY 1997 IS 410 BP 1606 EP 1610 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK17N UT WOS:000071400800241 ER PT B AU Bergman, L Morookian, J Yeh, C Monacos, S AF Bergman, L Morookian, J Yeh, C Monacos, S BE Goodman, J Hinton, S Pinkston, T Schenfeld, E TI Experimental verification of the pulse shepherding concept in dispersion-shifted single-mode fiber for bit-parallel wavelength links SO PROCEEDINGS OF THE FOURTH INTERNATIONAL CONFERENCE - MASSIVELY PARALLEL PROCESSING USING OPTICAL INTERCONNECTIONS LA English DT Proceedings Paper CT 4th International Conference on Massively Parallel Processing Using Optical Interconnections (MPPOI 97) CY JUN 22-24, 1997 CL MONTREAL, CANADA SP IEEE Comp Soc, Tech Comm Comp Architecture, ACM, Special Interest Grp Architecture, IEEE, Lasers & Electro Opt Soc, Opt Soc Amer, Soc Photo Opt Instrumentat Engineers AB A new way to dynamically control in-flight pulses by a co-propagating shepherd pulse in a wavelength division multiplexed (WDM) single-mode fiber system was proposed at the MPPOI '96 Conference. That system functionally resembles an optical fiber ribbon cable, except that all the bits pass on one fiber optic waveguide. This single fiber bit parallel wavelength link can be used to extend the (speed x distance) product of emerging cluster computer networks, such as, the MyriNet, SCI, Hippi-6400, ShuffleNet, etc. Here, we shall present the first experimental evidence that this pulse shepherding effect can be observed in a commercially Corning DS (dispersion-shifted) fiber simulation results will first be presented for the case observed in the laboratory setup. A discussion of the experiment setup and measurement procedures will be given. Experimental results will then be compared with computer generated results. Excellent agreement is observed. Future experiments dealing with the shepherding effect among more than two co-propagating pulses will be performed. RP Bergman, L (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 BN 0-8186-7975-1 PY 1997 BP 25 EP 29 DI 10.1109/MPPOI.1997.609071 PG 5 WC Computer Science, Theory & Methods; Optics SC Computer Science; Optics GA BJ14L UT WOS:A1997BJ14L00003 ER PT B AU VanKeuls, FW Miranda, FA Romanofsky, RR Dayton, JA Mueller, CH Rivkin, TV AF VanKeuls, FW Miranda, FA Romanofsky, RR Dayton, JA Mueller, CH Rivkin, TV BE Claeys, CL Raider, SI Deen, MJ Brown, WD Kirschman, RK TI Suitability of SrTiO3/YBa2Cu3O7-delta/LaAlO3 and BaxSr1-xTiO3/LaAlO3 thin film multilayer structures for tunable microwave devices SO PROCEEDINGS OF THE FOURTH SYMPOSIUM ON LOW TEMPERATURE ELECTRONICS AND HIGH TEMPERATURE SUPERCONDUCTIVITY SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 4th Symposium on Low Temperature Electronics and High Temperature Superconductivity at the 191st Meeting of the Electrochemical-Society CY MAY 04-11, 1997 CL MONTREAL, CANADA SP Electrochem Soc, Electr Dielectr Sci & Tech Div AB We report on the characterization of thin film multilayer structures of SrTiO3/YBa2Cu3O7-delta/LaAlO3 (STO/YBCO/LAO) and BaxSr1-xTiO3/LaALO(3) (BSTO/LAO), for x = 0, and x = 0.50, in terms of ferroelectric film deposition, device geometry and tunability. Material properties effects were assessed by varying the ferroelectric deposition temperature from to 800 to 250 degrees C. Geometric aspects were considered by testing these structures in the parallel plate and interdigital capacitor configurations. Measurements of the relative dielectric constant (epsilon(r)) and the loss tangent (tan delta) were made as a function of temperature (300 to 20 K), at a frequency of 1.0 MHz, and at dc electric fields from 0 to 3.5x10(5) V/cm. These measurements allowed us to determine (K=(delta(max) - epsilon(min))/(epsilon(max))x(tan delta)(-1)), which is a figure of merit for the tunability to loss ratio of a given component. We observed that interdigital structures exhibited a larger K than parallel plate capacitors, but at the expense of a larger dc bias. Incorporation of a 300 nm thick ferroelectric film between the substrate and the conducting layer of non-tunable microwave components was investigated. The effect of the ferroelectric layer on the performance of a band reject, 20 GHz Au/STO/LAO ring resonator was minimal. Finally, an insertion phase shift of 17.5 degrees and a frequency shift of 90 MHz were measured at 77 K and 20 GHz for Au/STO/LAO interdigital coupled microstrip line and ring resonator, respectively, for a dc bias of 100 V. RP VanKeuls, FW (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-129-3 J9 ELEC SOC S PY 1997 VL 97 IS 2 BP 47 EP 57 PG 11 WC Chemistry, Applied; Chemistry, Physical; Electrochemistry; Engineering, Electrical & Electronic; Physics, Applied SC Chemistry; Electrochemistry; Engineering; Physics GA BH73E UT WOS:A1997BH73E00005 ER PT B AU Cunningham, TJ Fitzsimmons, MJ AF Cunningham, TJ Fitzsimmons, MJ BE Claeys, CL Raider, SI Deen, MJ Brown, WD Kirschman, RK TI GaAs multiplexers for VLWIR detector readout below 10 Kelvin SO PROCEEDINGS OF THE FOURTH SYMPOSIUM ON LOW TEMPERATURE ELECTRONICS AND HIGH TEMPERATURE SUPERCONDUCTIVITY SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 4th Symposium on Low Temperature Electronics and High Temperature Superconductivity at the 191st Meeting of the Electrochemical-Society CY MAY 04-11, 1997 CL MONTREAL, CANADA SP Electrochem Soc, Electr Dielectr Sci & Tech Div AB A multiplexer and buffer based on GaAs JFET technology is presented. This multiplexer operates normally from room temperature down to 4 Kelvin and is suitable for the readout of Very Long Wavelength Infrared Detectors that must be cooled to below 10 Kelvin. The noise, dark current, and power dissipation of the multiplexer is presented and shown to be within the range required for typical VLWIR detector readout applications. RP Cunningham, TJ (reprint author), CALTECH,JET PROP LAB,CTR SPACE MICROELECT TECHNOL,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-129-3 J9 ELEC SOC S PY 1997 VL 97 IS 2 BP 347 EP 357 PG 11 WC Chemistry, Applied; Chemistry, Physical; Electrochemistry; Engineering, Electrical & Electronic; Physics, Applied SC Chemistry; Electrochemistry; Engineering; Physics GA BH73E UT WOS:A1997BH73E00030 ER PT B AU Duong, T Daud, T Thakoor, A Lee, B AF Duong, T Daud, T Thakoor, A Lee, B BE Claeys, CL Raider, SI Deen, MJ Brown, WD Kirschman, RK TI Room and low temperature performance of highspeed neural network circuits SO PROCEEDINGS OF THE FOURTH SYMPOSIUM ON LOW TEMPERATURE ELECTRONICS AND HIGH TEMPERATURE SUPERCONDUCTIVITY SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 4th Symposium on Low Temperature Electronics and High Temperature Superconductivity at the 191st Meeting of the Electrochemical-Society CY MAY 04-11, 1997 CL MONTREAL, CANADA SP Electrochem Soc, Electr Dielectr Sci & Tech Div AB We have described a challenging neural-network hardware implementation that would mate a 64x64-pixel infrared sensor directly on to a 3-dimensionally packaged set of neural processing chips with parallel input for high speed image processing. We now describe two enhanced schemes. In both schemes, the synapse (analog multiply device) resolution has been increased from 7- to 8-bit without increasing the silicon area. However, one requires low temperature (77K) operation because of the mated IR sensor whereas the other has an innovative chip that permits detachment of the IR sensor without compromising the input speed. This permits room temperature operation of the processor for a projected image processing speed of a tera-operations per second (TOPS). We compare the 7- and 8-bit synapse circuits and provide the test results of the operation (linearity and speed) of the 8-bit circuit both at low and room temperatures. Non linearity effects and range compression issues are also discussed. RP Duong, T (reprint author), CALTECH,JET PROP LAB,CTR SPACE MICROELECT TECHNOL,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-129-3 J9 ELEC SOC S PY 1997 VL 97 IS 2 BP 369 EP 377 PG 9 WC Chemistry, Applied; Chemistry, Physical; Electrochemistry; Engineering, Electrical & Electronic; Physics, Applied SC Chemistry; Electrochemistry; Engineering; Physics GA BH73E UT WOS:A1997BH73E00032 ER PT B AU Shafto, MG Degani, A Kirlik, A AF Shafto, MG Degani, A Kirlik, A GP HUMAN FACTORS & ERGONOM SOC TI Canonical correlation analysis of data on human-automation interaction SO PROCEEDINGS OF THE HUMAN FACTORS AND ERGONOMICS SOCIETY 41ST ANNUAL MEETING, 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT 41st Annual Meeting of the Human-Factors-and-Ergonomics-Society CY 1997 CL ALBUQUERQUE, NM SP Human Factors & Ergonom Soc AB Canonical correlation analysis is a type of multivariate linear statistical analysis, first described by Hotelling (1935), which is used in a wide range of disciplines to analyze tile relationships between multiple independent and multiple dependent variables. We argue that canonical correlation analysis is the method of choice for use with many kinds of datasets encountered in human factors research, including field-study data, part-task and full-mission simulation data, and flight-recorder data. Although canonical correlation analysis is documented in standard textbooks and is available in many statistical computing packages, there are some technical and interpretive problems which prevent its routine use by human factors practitioners. These include problems of computation, interpretation, statistical significance, and treatment of discrete variables. In this paper we discuss these problems and suggest solutions to them. We illustrate the problems and their solutions based on our experience in using canonical correlation in the analysis of a field study of crew-automation interaction in commercial aviation. RP Shafto, MG (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU HUMAN FACTORS AND ERGONOMICS SOC PI SANTA MONICA PA PO BOX 1369, SANTA MONICA, CA 90406-1369 BN 0-945289-07-3 PY 1997 BP 62 EP 65 PG 4 WC Engineering, Aerospace; Computer Science, Cybernetics; Engineering, Industrial; Ergonomics SC Engineering; Computer Science GA BJ82J UT WOS:A1997BJ82J00016 ER PT B AU Gross, AR Gross, MM AF Gross, AR Gross, MM GP HUMAN FACTORS & ERGONOM SOC TI The impact of information technology on human space exploration missions SO PROCEEDINGS OF THE HUMAN FACTORS AND ERGONOMICS SOCIETY 41ST ANNUAL MEETING, 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT 41st Annual Meeting of the Human-Factors-and-Ergonomics-Society CY 1997 CL ALBUQUERQUE, NM SP Human Factors & Ergonom Soc AB Human space expeditions have, from the beginning, involved great risk and complexity. Space flights, accordingly, have utilized substantial quantities of highly skilled labor. The rapid creation and evolution of increasingly powerful information technologies promise a new human-automation systems balance of work. This balance holds the potential of greatly increased crewed and robotic space exploration capability, along with dramatically reduced costs. Since further development of sophisticated information technology systems must, from the outset, consider both the human and the machine as ''components'' of an integrated system, research supporting the development and optimal utilization of such systems will necessarily incorporate significant human factors components. This paper examines the impact of information technologies on lunar and planetary missions; exemplar inherent human factors aspects, such as display and control in virtual environment/teleoperated systems, are considered. RP Gross, AR (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU HUMAN FACTORS AND ERGONOMICS SOC PI SANTA MONICA PA PO BOX 1369, SANTA MONICA, CA 90406-1369 BN 0-945289-07-3 PY 1997 BP 90 EP 94 PG 5 WC Engineering, Aerospace; Computer Science, Cybernetics; Engineering, Industrial; Ergonomics SC Engineering; Computer Science GA BJ82J UT WOS:A1997BJ82J00022 ER PT B AU Ellis, SR Menges, BM Jacoby, RH Adelstein, BD McCandless, JW AF Ellis, SR Menges, BM Jacoby, RH Adelstein, BD McCandless, JW GP HUMAN FACTORS & ERGONOM SOC TI Influence of head motion on the judged distance of monocularly presented virtual objects SO PROCEEDINGS OF THE HUMAN FACTORS AND ERGONOMICS SOCIETY 41ST ANNUAL MEETING, 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT 41st Annual Meeting of the Human-Factors-and-Ergonomics-Society CY 1997 CL ALBUQUERQUE, NM SP Human Factors & Ergonom Soc AB Human subjects localized a monocularly viewed, space-stabilized virtual object presented on a head-mounted, see-through display. They either kept their head stationary or rocked it laterally to produce motion parallax. Their distance estimates had less variability in a head moving condition than in a head stationary condition, but in general were much less precise and much less accurate than comparable stereo-based localizations. RP Ellis, SR (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU HUMAN FACTORS AND ERGONOMICS SOC PI SANTA MONICA PA PO BOX 1369, SANTA MONICA, CA 90406-1369 BN 0-945289-07-3 PY 1997 BP 1234 EP 1238 PG 5 WC Engineering, Aerospace; Computer Science, Cybernetics; Engineering, Industrial; Ergonomics SC Engineering; Computer Science GA BJ82J UT WOS:A1997BJ82J00272 ER PT B AU Christopher, DA Beach, R AF Christopher, DA Beach, R GP IEEE TI Flywheel technology development program for aerospace applications SO PROCEEDINGS OF THE IEEE 1997 AEROSPACE AND ELECTRONICS CONFERENCE - NAECON 1997, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE 1997 National Aerospace and Electronics Conference (NAECON 1997) CY JUL 14-17, 1997 CL DAYTON, OH SP IEEE, Dayton Sect, IEEE, Aerosp & Electr Syst Soc DE energy storage; flywheel; power system AB An overview of advanced flywheel development for energy storage in aerospace applications is presented. The advantages offered by this emerging technology are described and the current NASA approach towards developing the technology is presented. RP Christopher, DA (reprint author), NASA,LEWIS RES CTR,POWER & PROP FLIGHT PROJECTS OFF,MAIL STOP 301-5,21000 BROOKPK RD,CLEVELAND,OH 44135, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3726-3 PY 1997 BP 602 EP 608 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA BJ48D UT WOS:A1997BJ48D00082 ER PT B AU Wilson, BD Mannucci, AJ Yuan, DN Iijima, BA Pi, XQ Ho, CM Lindqwister, UJ AF Wilson, BD Mannucci, AJ Yuan, DN Iijima, BA Pi, XQ Ho, CM Lindqwister, UJ GP INST NAVIGAT INST NAVIGAT INST NAVIGAT TI Monitoring the ionosphere using a global GPS network: Applications and validation SO PROCEEDINGS OF THE NATIONAL TECHNICAL MEETING - NAVIGATION AND POSITIONING IN THE INFORMATION AGE LA English DT Proceedings Paper CT ION National Meeting on Navigation and Positioning in the Information Age CY JAN 14-16, 1997 CL SANTA MONICA, CA SP Inst Navigat AB A globally distributed network of dual-frequency GPS receivers currently exists and enables the monitoring of ionospheric total electron content (TEC) on global scales. By using spatial interpolation and temporal smoothing between the GPS-based TEC measurements, combined with model information from a climatological ionospheric model, we are able to produce global ionospheric maps (GIM) of vertical TEC every 15 minutes. Comparisons to independent ionospheric measurements indicate that the global TEC maps are accurate globally to 5-10 TECU (10(16) electrons/meter(2)) and enable a continuous, global ionospheric specification which is more accurate than any of the existing empirical models. The GIM technique is currently being used as the basis for three operational capabilities: (1) daily global ionospheric calibration for a single-frequency ocean altimetry mission (GFO), (2) hourly global ionospheric monitoring in support of the 50th Weather Squadron of the Air Force, and (3) real-time ionospheric correction over the continental U.S. for use in wide-area differential GPS (WADGPS) applications. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wilson, BD (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 INST NAVIGATION PI WASHINGTON PA 815 15TH ST NW, STE 832, WASHINGTON, DC 20005 USA PY 1997 BP 279 EP 288 PG 10 WC Engineering, Aerospace; Engineering, Marine SC Engineering GA BK05J UT WOS:000071004000025 ER PT B AU Carpenter, JR Hain, RM AF Carpenter, JR Hain, RM GP INST NAVIGAT INST NAVIGAT INST NAVIGAT TI Precise evaluation of orbital GPS attitude determination on the STS-77 GPS Attitude and Navigation Experiment (GANE) SO PROCEEDINGS OF THE NATIONAL TECHNICAL MEETING - NAVIGATION AND POSITIONING IN THE INFORMATION AGE LA English DT Proceedings Paper CT ION National Meeting on Navigation and Positioning in the Information Age CY JAN 14-16, 1997 CL SANTA MONICA, CA SP Inst Navigat AB A recent Shuttle mission, STS-77, carried the GPS Attitude and Navigation Experiment (CANE), the highest priority of a series of risk mitigation experiments being performed by the Shuttle program for the International Space Station (ISS) program. The GANE was a flight test-of the ISS attitude determination and navigation systems, which consist of a multi-antenna interferometric GPS receiver for attitude determination and navigation, and a ring-laser rate gyro system for attitude rate determination. The purpose of CANE was to determine if the proposed ISS attitude determination and navigation system could meet ISS requirements in attitude, position, and semi-major axis. The Space Shuttle attitude reference system was used to determine the performance of attitude solutions from the CANE GPS receiver, a Trimble Advanced Navigation System Vector. These results are the first precise evaluation of a long baseline (1.5-3 meter) GPS attitude determination system in a space environment onboard an actively maneuvering and highly multipath-susceptible vehicle. The receiver generated attitude solutions which generally tracked the Orbiter attitude during all data takes, in several ambiguity resolution and satellite selection modes. Comparisons to the reference indicate periods of performance at the 0.1-0.2 degrees per axis level, and also periods of performance at the 0.3-0.4 degree per axis level. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Carpenter, JR (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU INST NAVIGATION PI WASHINGTON PA 815 15TH ST NW, STE 832, WASHINGTON, DC 20005 USA PY 1997 BP 387 EP 397 PG 11 WC Engineering, Aerospace; Engineering, Marine SC Engineering GA BK05J UT WOS:000071004000036 ER PT B AU Wu, SC Meehan, T Young, L AF Wu, SC Meehan, T Young, L GP INST NAVIGAT INST NAVIGAT INST NAVIGAT TI The potential use of GPS signals as ocean altimetry observables SO PROCEEDINGS OF THE NATIONAL TECHNICAL MEETING - NAVIGATION AND POSITIONING IN THE INFORMATION AGE LA English DT Proceedings Paper CT ION National Meeting on Navigation and Positioning in the Information Age CY JAN 14-16, 1997 CL SANTA MONICA, CA SP Inst Navigat AB This paper investigates a potential application of GPS signals for ocean altimetry. The altimetry information is derived from dual-frequency GPS signals reflected from the ocean surface and received at a low-altitude satellite. Such altimetry would be superior to conventional radar altimetry in three respects: (1) Thanks to the global GPS constellation, sea surface heights at up to 12 points can be determined instead of a single nadir point at any one time; (2) The user satellite only need be equipped with a GPS receiver which also serves as the receiver acquiring direct GPS signals for orbit determination; and (3) The delay spread of the reflected signal is a function of the sea-surface roughness, so that this technique may allow scatterometry-like measurements of surface weather conditions. The paper addresses several criteria for the GPS altimetry to be viable. These include the signal strength, delay characteristics and polarization of the reflected GPS signals, the receiver capability of discriminating and tracking these signals from the direct signals, the determination of the reflection points on the sea surface, and the information content of these signals. C1 CALTECH, Jet Prop Lab, Tracking Syst & Applicat Sect, Pasadena, CA 91125 USA. RP Wu, SC (reprint author), CALTECH, Jet Prop Lab, Tracking Syst & Applicat Sect, Pasadena, CA 91125 USA. NR 0 TC 5 Z9 7 U1 0 U2 1 PU INST NAVIGATION PI WASHINGTON PA 815 15TH ST NW, STE 832, WASHINGTON, DC 20005 USA PY 1997 BP 543 EP 550 PG 8 WC Engineering, Aerospace; Engineering, Marine SC Engineering GA BK05J UT WOS:000071004000051 ER PT B AU Bertiger, WI Bar-Sever, YE Haines, BJ Iijima, BA Lichten, SM Lindqwister, UJ Mannucci, AJ Muellershcoen, RJ Munson, TN Moore, AW Romans, LJ Wilson, BD Wu, SC Yunck, TP Piesinger, G Whitehead, M AF Bertiger, WI Bar-Sever, YE Haines, BJ Iijima, BA Lichten, SM Lindqwister, UJ Mannucci, AJ Muellershcoen, RJ Munson, TN Moore, AW Romans, LJ Wilson, BD Wu, SC Yunck, TP Piesinger, G Whitehead, M GP INST NAVIGAT INST NAVIGAT INST NAVIGAT TI A prototype real-time wide area differential GPS system SO PROCEEDINGS OF THE NATIONAL TECHNICAL MEETING - NAVIGATION AND POSITIONING IN THE INFORMATION AGE LA English DT Proceedings Paper CT ION National Meeting on Navigation and Positioning in the Information Age CY JAN 14-16, 1997 CL SANTA MONICA, CA SP Inst Navigat AB In this paper we describe the system architecture, algorithms, and preliminary results from an operating prototype Wide Area Differential GPS (WADGPS) system spanning the continental US (CONUS). With dual-frequency GPS user equipment and improved positioning algorithms, real-time 3-D RMS user position accuracy is better than 50 cm. Single-frequency users can obtain comparable accuracy with the current ionospheric intensity. There may be some degradation in single-frequency positioning during solar maximum or during ionopheric storms. The system consists of 14 codeless dual-frequency geodetic quality receivers distributed over the CONUS returning real-time data at a 1-Hz rate, and a central processing facility where WADGPS products are computed. These products include: real-time GPS satellite positions with a 3-D RMS accuracy of 1.3 meters; real-time zenith tropospheric delays (at each site) estimated from GPS measurements (surface meteorological data are not needed or used) to an RMS accuracy of about 1.5 cm; GPS fast range corrections (1-Hz rate) which are optimally extrapolated to the time of use using information from the phase data; and a grid of real-time ionospheric corrections for measurements at L1 produced every 5 minutes with a current vertical RMS accuracy of 20 cm. The software for GPS data processing and computation of real-time WADGPS corrections is easily hosted on a single UNIX workstation. The full computation adds only about 3 msec latency for users of the corrections. Commercial availability of the single frequency system is scheduled for the 2nd quarter of 1997. The software for estimation of the WADGPS corrections is also being adapted for use in the Federal Aviation Administration's (FAA) Wide Area Augmentation System (WAAS). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Bertiger, WI (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU INST NAVIGATION PI WASHINGTON PA 815 15TH ST NW, STE 832, WASHINGTON, DC 20005 USA PY 1997 BP 645 EP 660 PG 16 WC Engineering, Aerospace; Engineering, Marine SC Engineering GA BK05J UT WOS:000071004000061 ER PT B AU Muellerschoen, RJ Bertiger, WI Romans, LJ AF Muellerschoen, RJ Bertiger, WI Romans, LJ GP INST NAVIGAT INST NAVIGAT INST NAVIGAT TI Orbit and troposphere results of a real-time prototype WADGPS system SO PROCEEDINGS OF THE NATIONAL TECHNICAL MEETING - NAVIGATION AND POSITIONING IN THE INFORMATION AGE LA English DT Proceedings Paper CT ION National Meeting on Navigation and Positioning in the Information Age CY JAN 14-16, 1997 CL SANTA MONICA, CA SP Inst Navigat AB Implementation and results of a real-time GPS orbit correction process for WADGPS is presented. The current processing utilizes data from SATLOC's North American reference network. It has been in operation since November 13, 1996. Every 15 minutes it processes the accumulated data from the previous 15 minutes. The GPS horizontal orbit accuracy over this network is 1.2 m rms. The horizontal orbit accuracy over the north latitudes of the Western hemisphere 2.0 m rms. Augmenting this network with 6 IGS sites including Hawaii, Alaska, and Bermuda, reduces the horizontal orbit accuracy over the north latitudes of the Western hemisphere to 1 meter rms. The zenith troposphere errors from this processing are 1-2 cm rms. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Muellerschoen, RJ (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 INST NAVIGATION PI WASHINGTON PA 815 15TH ST NW, STE 832, WASHINGTON, DC 20005 USA PY 1997 BP 859 EP 870 PG 12 WC Engineering, Aerospace; Engineering, Marine SC Engineering GA BK05J UT WOS:000071004000084 ER PT B AU Mannucci, AJ Iijima, BA Wilson, BD Peck, S Ahmadi, R Hagen, M AF Mannucci, AJ Iijima, BA Wilson, BD Peck, S Ahmadi, R Hagen, M GP INST NAVIGAT INST NAVIGAT INST NAVIGAT TI Wide area ionospheric delay corrections under ionospheric storm conditions SO PROCEEDINGS OF THE NATIONAL TECHNICAL MEETING - NAVIGATION AND POSITIONING IN THE INFORMATION AGE LA English DT Proceedings Paper CT ION National Meeting on Navigation and Positioning in the Information Age CY JAN 14-16, 1997 CL SANTA MONICA, CA SP Inst Navigat AB The Federal Aviation Administration's wide-area augmentation system (WAAS) for GPS positioning requires near real-time calibration of ionospheric vertical delays at a set of Earth-fixed grid points. These delays, which can exceed 15 meters under solar maximum conditions, are transmitted to users every 5 minutes to improve single-frequency user positioning. The grid delays will be estimated using the WAAS Ionospheric Software (WIS) developed jointly by SPL and Hughes, based on ionospheric delay measurements from 24 dual-frequency GPS reference receivers distributed throughout the WAAS coverage volume. We have investigated the performance of these algorithms under ionospheric storm conditions, when meeting accuracy goals is expected to be most challenging. Testing of ionospheric correction algorithms is complicated by the extreme variability of the ionosphere, arising from the 11 year solar cycle and the intermittent occurrence of ionospheric storms. Recently completed tests of the WIS using data from a real-time network of eight reference receivers in the continental United Stated indicate accuracies in the range of 15-20 cm (RMS). However, these tests were conducted using current GPS data sets (9/96), near the minimum of the solar cycle when ionospheric conditions are favorable. We present the results of additional tests under more challenging conditions nearer to solar maximum, focusing on geomagnetically disturbed periods, using archived GPS data (processed in a real-time mode) obtained from a global network of dual-frequency receivers. The intent is to characterize the accuracy of WIS under a wide variety of geomagnetic and solar activity conditions. In the storm cases examined here, the maximum accuracy degradation was at most a factor of 2-3 relative to recent quiet time tests. These results suggest that accuracy requirements for precision approach may still be met during significant storms. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Mannucci, AJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU INST NAVIGATION PI WASHINGTON PA 815 15TH ST NW, STE 832, WASHINGTON, DC 20005 USA PY 1997 BP 871 EP 882 PG 12 WC Engineering, Aerospace; Engineering, Marine SC Engineering GA BK05J UT WOS:000071004000085 ER PT B AU Van Selst, M Johnston, JC AF Van Selst, M Johnston, JC BE Shafto, MG Langley, P TI Dual-task interference when a response is not required SO PROCEEDINGS OF THE NINETEENTH ANNUAL CONFERENCE OF THE COGNITIVE SCIENCE SOCIETY LA English DT Proceedings Paper CT 19th Annual Conference of the Cognitive-Science-Society CY AUG 07-10, 1997 CL STANFORD UNIV, Stanford, CA SP Cognit Sci Soc HO STANFORD UNIV ID CHRONOMETRIC EVIDENCE; BOTTLENECKS; PERFORMANCE; ATTENTION; MODELS AB When subjects are required to respond to two stimuli presented in rapid succession, responses to the second stimulus are delayed. Such dual-task interference has been attributed to a fundamental processing bottleneck preventing simultaneous processing on both tasks. Two experiments show dual-task interference even when the first task does not require a response. The observed interference is caused by a bottleneck in central cognitive processing, rather than in response initiation or execution. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Van Selst, M (reprint author), NASA, Ames Res Ctr, MS 262-2, Moffett Field, CA 94035 USA. NR 21 TC 3 Z9 3 U1 0 U2 0 PU LAWRENCE ERLBAUM ASSOC PUBL PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430 USA BN 0-8058-2941-5 PY 1997 BP 787 EP 792 PG 6 WC Psychology; Psychology, Multidisciplinary SC Psychology GA BS07J UT WOS:000168551500134 ER PT B AU Jacobson, NS Brady, MP Mehrotra, GM AF Jacobson, NS Brady, MP Mehrotra, GM BE Spear, KE TI Knudsen cell measurements of component activities in Ti-Al and Ti-Al-X alloys SO PROCEEDINGS OF THE NINTH INTERNATIONAL CONFERENCE ON HIGH TEMPERATURE MATERIALS CHEMISTRY SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 9th International Conference on High Temperature Materials Chemistry (HTMC IX) CY MAY 19-23, 1997 CL PENN STATE, UNIVERSITY PK, PA SP Int Union Pure & Appl Chem, Inorgan Chem Div, Commiss II 3 High Temperature, Mat & Solid State Chem, Electrochem Soc, High Temperature Mat Div HO PENN STATE AB A twin Knudsen cell system for measuring component activities in alloys is described. Aluminum activities for three Ti-Al alloys are reported-Ti-48 a/o Al, Ti-52.3Al, and Ti-61.2Al. Activities of aluminum and titanium are also reported for Ti-48Al and Ti-48Al-13Cr. Implications for oxidation behavior are discussed. RP Jacobson, NS (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. RI Brady, Michael/A-8122-2008 OI Brady, Michael/0000-0003-1338-4747 NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-190-0 J9 ELEC SOC S PY 1997 VL 97 IS 39 BP 695 EP 703 PG 9 WC Chemistry, Applied; Chemistry, Inorganic & Nuclear; Electrochemistry SC Chemistry; Electrochemistry GA BK03T UT WOS:A1997BK03T00088 ER PT B AU Jacobson, NS Fox, DS Opila, EJ AF Jacobson, NS Fox, DS Opila, EJ BE Spear, KE TI High temperature oxidation of ceramic matrix composites SO PROCEEDINGS OF THE NINTH INTERNATIONAL CONFERENCE ON HIGH TEMPERATURE MATERIALS CHEMISTRY SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 9th International Conference on High Temperature Materials Chemistry (HTMC IX) CY MAY 19-23, 1997 CL PENN STATE, UNIVERSITY PK, PA SP Int Union Pure & Appl Chem, Inorgan Chem Div, Commiss II 3 High Temperature, Mat & Solid State Chem, Electrochem Soc, High Temperature Mat Div HO PENN STATE AB Ceramic matrix composites are developmental high temperature materials. We focus on composites with SiC matrices, SiC fibers, and BN fiber coatings. High temperature oxidation/corrosion reactions are discussed for each of these constituents. SiC forms a highly protective SiO2 scale in pure oxygen, but problems arise in complex gas mixtures. These include: SiO(g) formation, Si-O-H(g) formation, impurity enhanced SiO2 formation, and fluxing of SiO2 in molten salts and slags. Refractory oxide coatings may minimize these effects. The major issue with these composites is oxidation of the BN fiber coating. The key reactions here are borosilicate glass formation, potential gettering of oxygen by SiC, and volatilization. We conclude with an oxidation study of an actual composite, which illustrates some of these effects. RP Jacobson, NS (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-190-0 J9 ELEC SOC S PY 1997 VL 97 IS 39 BP 770 EP 780 PG 11 WC Chemistry, Applied; Chemistry, Inorganic & Nuclear; Electrochemistry SC Chemistry; Electrochemistry GA BK03T UT WOS:A1997BK03T00098 ER PT B AU Fox, DS Opila, EJ Nguyen, QGN AF Fox, DS Opila, EJ Nguyen, QGN BE Spear, KE TI Paralinear oxidation of silicon nitride in a water vapor oxygen environment SO PROCEEDINGS OF THE NINTH INTERNATIONAL CONFERENCE ON HIGH TEMPERATURE MATERIALS CHEMISTRY SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 9th International Conference on High Temperature Materials Chemistry (HTMC IX) CY MAY 19-23, 1997 CL PENN STATE, UNIVERSITY PK, PA SP Int Union Pure & Appl Chem, Inorgan Chem Div, Commiss II 3 High Temperature, Mat & Solid State Chem, Electrochem Soc, High Temperature Mat Div HO PENN STATE AB Two silicon nitride materials were exposed to a 50% H2O/50% O-2 gas mixture flowing at 4.4 cm/s for 100 hours at temperatures between 1200 degrees and 1400 degrees C. Reaction kinetics were monitored with a continuously recording microbalance. Both materials exhibited paralinear kinetics. This is due to the simultaneous oxidation of Si3N4 by H2O to form SiO2 and volatilization of the silica by H2O. At long times, recession of the Si3N4 can be approximated by the linear loss rate due to silica volatility. RP Fox, DS (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-190-0 J9 ELEC SOC S PY 1997 VL 97 IS 39 BP 804 EP 811 PG 8 WC Chemistry, Applied; Chemistry, Inorganic & Nuclear; Electrochemistry SC Chemistry; Electrochemistry GA BK03T UT WOS:A1997BK03T00102 ER PT B AU Hash, D Meyyappan, M AF Hash, D Meyyappan, M BE Meyyappan, M Economou, DJ Butler, SW TI A DSMC study of flow considerations in tool development for 300 mm processing SO PROCEEDINGS OF THE SECOND INTERNATIONAL SYMPOSIUM ON PROCESS CONTROL, DIAGNOSTICS, AND MODELING IN SEMICONDUCTOR MANUFACTURING SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 2nd International Symposium on Control, Diagnostics and Modeling in Semiconductor Manufacturing, at the 191st Meeting of the Electrochemical-Society CY MAY 04-09, 1997 CL MONTREAL, CANADA SP Electrochem Soc, Dielect Sci & Technol Div, Electrochem Soc, Electr Div, Lam Res Corp, Fremont CA, Texas Instruments Inc AB Fluid flow related issues in plasma process equipment design for 300 mm wafer processing are considered. A direct simulation Monte Carlo technique is used to simulate molecular chlorine flow and chlorine atom etching of polysilicon. The effects of process chamber diameter, wafer location, and exit design on processing uniformity are investigated, and guidelines are provided regarding the choices for these parameters. RP Hash, D (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-136-6 J9 ELEC SOC S PY 1997 VL 97 IS 9 BP 268 EP 274 PG 7 WC Electrochemistry; Engineering, Electrical & Electronic SC Electrochemistry; Engineering GA BJ30U UT WOS:A1997BJ30U00032 ER PT B AU Gross, AR Gross, MM AF Gross, AR Gross, MM GP SILICON VALLEY ERGONOM INST SILICON VALLEY ERGONOM INST TI Information technology impact on space exploration missions SO PROCEEDINGS OF THE SILICON VALLEY ERGONOMICS CONFERENCE & EXPOSITION - ERGOCON'97 LA English DT Proceedings Paper CT Silicon Valley Ergonomics Conference and Exposition (ErgoCon 97) CY 1997 CL PALO ALTO, CA SP Silicon Valley Ergonom Inst AB From the beginning, human space flight expeditions have involved great risk and complexity. These flights, accordingly, have utilized substantial quantities of highly skilled human labor. Not surprisingly, human space fright has proven significantly more expensive than uncrewed missions. The rapid creation and evolution of increasingly powerful information technologies enabling design and development tools, schedulers, vehicle and system health monitoring capabilities, and autonomous systems - promise a new human-automation systems balance of work, a balance that holds the potential of greatly increased crewed and robotic space exploration capability with dramatically reduced costs. Information technology has now attained a level of sophistication such that further development must, from the outset, consider both the human and the machine as "components" of an integrated system, within which emphases vary depending upon the particular task or application. This paper examines the impact of information technologies, including such exemplar inherent human factors considerations as control of teleoperated systems and human/machine task allocation, within the context of a plausible lunar exploration program. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Gross, AR (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SILICON VALLEY ERGONOMICS INSTITUTE PI SAN JOSE PA SAN JOSE STATE UNIVERSITY ONE WASHINGTON SQUARE, SAN JOSE, CA 95192-0180 USA PY 1997 BP 37 EP 44 PG 8 WC Computer Science, Cybernetics; Ergonomics; Public, Environmental & Occupational Health SC Computer Science; Engineering; Public, Environmental & Occupational Health GA BK43N UT WOS:000072169700006 ER PT B AU Berenji, HR Chang, PW Swanson, SR AF Berenji, HR Chang, PW Swanson, SR GP IEEE TI Refining the shuttle training aircraft controller SO PROCEEDINGS OF THE SIXTH IEEE INTERNATIONAL CONFERENCE ON FUZZY SYSTEMS, VOLS I - III LA English DT Proceedings Paper CT 6th IEEE International Conference on Fuzzy Systems (FUZZ-IEEE 97) CY JUL 01-05, 1997 CL BARCELONA, SPAIN SP IEEE, Neural Network Council AB NASA uses the Shuttle Training Aircraft (STA) to train the Shuttle pilot astronauts. Although as compared to the Shuttle, STA is a small aircraft, it does simulate, with some model following errors, aerodynamics of the Shuttle. In this paper, we show how these differences can be reduced significantly by using a new Pitch Predict controller and a new adaptive fuzzy controller. In particular: we show how the collaborative work between NASA Ames and the Shuttle Training Branch of Johnson Space Center has improved the accuracy of STA model following from its current level of 71% to 91% which is equivalent to a 69% error reduction. RP Berenji, HR (reprint author), NASA,AMES RES CTR,INTELLIGENT INFERENCE SYST CORP,DIV COMP SCI,MS 269-2,MOFFETT FIELD,CA 94035, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3797-2 PY 1997 BP 677 EP 682 PG 6 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Multidisciplinary SC Automation & Control Systems; Computer Science; Engineering GA BJ56L UT WOS:A1997BJ56L00111 ER PT B AU Timmerman, P Ratnakumar, BV DiStefano, S AF Timmerman, P Ratnakumar, BV DiStefano, S BE Bennett, PD Gross, S TI Modeling of nickel hydroxide electrode containing multiple phases SO PROCEEDINGS OF THE SYMPOSIUM ON AQUEOUS BATTERIES SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Symposium on Aqueous Batteries / 190th Meeting of the Electrochemical-Society CY OCT 06-11, 1996 CL SAN ANTONIO, TX SP Electrochem Soc AB Mathematical models of alkaline rechargeable nickel cell systems (e.g., Ni-Cd, Ni-H-2 and Ni-MH) have so far been developed based on the assumption that the active material at Ni electrode exists primarily in a single phase as beta-NiOOH - beta-Ni(OH)(2), despite enough experimental evidence for the second phase, i.e., gamma-NiOOH - alpha-Ni(OH)(2), especially under conditions of extended overcharge. Here, we have incorporated the additional couple of gamma-NiOOH - alpha-Ni(OH)(2) into the modeling of the Ni electrode. The reaction scheme includes an electrochemical redox reaction of beta-Ni(OH)(2) - beta-NiOOH, unidirectional conversion of beta-NiOOH to gamma-NiOOH, electrochemical redox reaction alpha-Ni(OH)(2) - gamma-NiOOH and a chemical conversion of alpha-Ni(OH)(2) to beta-Ni(OH)(2). Changes in the electronic conductivities, proton concentrations, and the states of charge are monitored individually and coupled appropriately to obtain the response of the nickel electrode under variety of simulated test conditions. The multi-phase model has provided simulations of Ni electrode behavior with improved accuracy and agreement with the experimental data. RP Timmerman, P (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 ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-166-8 J9 ELEC SOC S PY 1997 VL 96 IS 16 BP 130 EP 141 PG 2 WC Electrochemistry SC Electrochemistry GA BH29S UT WOS:A1997BH29S00011 ER PT B AU Ratnakumar, BV Hightower, A Witham, C Bowman, RC Fultz, B AF Ratnakumar, BV Hightower, A Witham, C Bowman, RC Fultz, B BE Bennett, PD Gross, S TI Kinetics of hydrogen diffusion in LaNi5-xSnx alloys SO PROCEEDINGS OF THE SYMPOSIUM ON AQUEOUS BATTERIES SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Symposium on Aqueous Batteries / 190th Meeting of the Electrochemical-Society CY OCT 06-11, 1996 CL SAN ANTONIO, TX SP Electrochem Soc AB Solid-state diffusion of hydrogen in metal hydride (MH) alloys is recognized as the rate determining step in the discharge of MH alloys in alkaline Ni-MH rechargeable cells. In our pursuit of new ternary solutes in LaNi5 for extended cyclic lifetimes, we have observed noticeable improvement in the cycle life with small substitutions of Sn and Ge for Ni. Furthermore, these substituents also facilitate enhanced charge transfer kinetics for hydriding-dehydriding process. In this paper, we report our studies on the kinetics of hydrogen diffusion in LaNi5-xSnx alloys by electrochemical pulse techniques, chronoamperometry and chronocoulometry. The measured diffusion coefficients for hydrogen in MH alloys are of order of 10(-9) cm(2)/s. RP Ratnakumar, BV (reprint author), CALTECH,JET PROP LAB,ELECTROCHEM TECHNOL GRP,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-166-8 J9 ELEC SOC S PY 1997 VL 96 IS 16 BP 197 EP 208 PG 4 WC Electrochemistry SC Electrochemistry GA BH29S UT WOS:A1997BH29S00019 ER PT B AU Globus, A Bauschlicher, C Han, J Jaffe, R Levit, C Srivastava, D AF Globus, A Bauschlicher, C Han, J Jaffe, R Levit, C Srivastava, D BE Kadish, KM Ruoff, RS TI Machine phase fullerene nanotechnology SO PROCEEDINGS OF THE SYMPOSIUM ON RECENT ADVANCES IN THE CHEMISTRY AND PHYSICS OF FULLERENES AND RELATED MATERIALS, VOL 4 SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT 4th Symposium of the Fullerenes-Group of the Electrochemical-Society, at the 191st Meeting of the Electrochemical-Society - Fullerenes: Chemistry, Physics, and New Directions IX CY MAY 04-09, 1997 CL MONTREAL, CANADA SP Electrochem Soc, Fullerenes Grp AB Recent advances in fullerene science and technology suggest that it may be possible, in the far future, to design and build atomically precise programmable machines composed largely of functionalized fullerenes. Large numbers of such machines with appropriate interconnections could conceivably create a material able to react to the environment and repair itself. This paper reviews some of the experimental and theoretical work relating to these materials, sometimes called machine phase, including the fullerene gears recently designed and simulated in our laboratory. We also describe some of the key theoretical and experimental work that may be useful in developing machine phase fullerene nanotechnology. RP Globus, A (reprint author), NASA,AMES RES CTR,MRJ INC,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-141-2 J9 ELEC SOC S PY 1997 VL 97 IS 14 BP 733 EP 749 PG 17 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical; Electrochemistry; Physics, Condensed Matter SC Chemistry; Electrochemistry; Physics GA BJ44R UT WOS:A1997BJ44R00077 ER PT B AU Chen, LY Hunter, GW Neudeck, PG Knight, D Liu, CC Wu, QH AF Chen, LY Hunter, GW Neudeck, PG Knight, D Liu, CC Wu, QH BE Anderson, HU Liu, M Yamazoe, N TI SiC-based gas sensors SO PROCEEDINGS OF THE THIRD INTERNATIONAL SYMPOSIUM ON CERAMIC SENSORS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT Symposium on Ceramic Sensors III, at the 190th Meeting of the Electrochemical-Society CY OCT 06-11, 1996 CL SAN ANTONIO, TX SP Electrochem Soc AB Electronic grade Silicon Carbide (SiC) is a ceramic material which can operate as a semiconductor at temperatures above 600 degrees C. Recently, SiC semiconductors have been used in Schottky diode gas sensor structures. These sensors have been shown to be functional at temperatures significantly above the normal operating range of Si-based devices. SiC sensor operation at these higher temperatures allows detection of gases such as hydrocarbons which are not detectable at lower temperatures. This paper discusses the development of SiC-based Schottky diode gas sensors for the detection of hydrogen, hydrocarbons, and nitrogen oxides (NOx). Sensor designs for these applications are discussed. High sensitivity is observed for the hydrogen and hydrocarbon sensors using Pd on SiC Schottky diodes while the NOx sensors are still under development. A prototype sensor package has been fabricated which allows high temperature operation in a room temperature ambient by minimizing heat loss to that ambient. It is concluded that SiC-based gas sensors have considerable potential in a variety of gas sensing applications. RP Chen, LY (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 10 S MAIN ST, PENNINGTON, NJ 08534-2896 BN 1-56677-127-7 J9 ELEC SOC S PY 1997 VL 96 IS 27 BP 92 EP 106 PG 15 WC Electrochemistry SC Electrochemistry GA BH80S UT WOS:A1997BH80S00010 ER PT S AU Kim, YT AkbarzadehT, MR Lee, DW AF Kim, YT AkbarzadehT, MR Lee, DW GP IEEE COMP SOC TI State feedback adaptive control of a direct drive motor SO PROCEEDINGS OF THE TWENTY-NINTH SOUTHEASTERN SYMPOSIUM ON SYSTEM THEORY SE PROCEEDINGS - SOUTHEASTERN SYMPOSIUM ON SYSTEM THEORY LA English DT Proceedings Paper CT 24th Southeastern Symposium on System Theory CY MAR 09-11, 1997 CL COOKEVILLE, TN SP Tennessee Technol Univ, Dept Elect & Comp Engn, IEEE Comp Soc, IEEE Control Syst Soc, Tennessee Technol Univ, Ctr Mfg Res, Tennessee Technol Univ, Ctr Elect Power AB Since direct drive motors do not have reduction gears, the variation of the load and the disturbance torque directly influence parameter changes in motor dynamics. In order to solve this problem, this paper presents a state feedback adaptive control method for position control of a direct drive motor. The proposed control scheme does not require an accurate mathematical model of the system. The controller consists of a. feedforward signal from the desired trajectory based on the inverse system model, feedback from the actual trajectory, and an auxiliary input, The feedforward terms are adjusted by an adaptation law that eliminated the steady-state position errors. In order to compensate for incorrect motor parameters, feedback terms are employed. The auxiliary input is introduced to improve the tracking performance. The proposed controller is applied to position control of a direct drive motor with payload and parameter uncertainty, and the effectiveness is verified by simulation results. RP Kim, YT (reprint author), UNIV NEW MEXICO,NASA,CTR AUTONMOUS CONTROL ENGN,ELECT ENGN & COMP ENGN BLDG,ALBUQUERQUE,NM 87131, USA. NR 0 TC 2 Z9 3 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 SN 0094-2898 BN 0-8186-7873-9 J9 SOUTHEAST SYMP SYSTE PY 1997 BP 288 EP 291 DI 10.1109/SSST.1997.581638 PG 4 WC Computer Science, Theory & Methods SC Computer Science GA BH39D UT WOS:A1997BH39D00055 ER PT S AU AkbarzadehT, MR Kim, YT Feerouzbakhsh, B AF AkbarzadehT, MR Kim, YT Feerouzbakhsh, B GP IEEE COMP SOC TI Evolutionary fuzzy speed regulation for a DC motor SO PROCEEDINGS OF THE TWENTY-NINTH SOUTHEASTERN SYMPOSIUM ON SYSTEM THEORY SE PROCEEDINGS - SOUTHEASTERN SYMPOSIUM ON SYSTEM THEORY LA English DT Proceedings Paper CT 24th Southeastern Symposium on System Theory CY MAR 09-11, 1997 CL COOKEVILLE, TN SP Tennessee Technol Univ, Dept Elect & Comp Engn, IEEE Comp Soc, IEEE Control Syst Soc, Tennessee Technol Univ, Ctr Mfg Res, Tennessee Technol Univ, Ctr Elect Power DE DC motor speed regulation; Genetic Algorithms; fuzzy control; GA-fuzzy systems AB Fuzzy logic is a powerful tool in control of systems with ill-defined, inaccurate or unknown mathematical models. In classical applications of fuzzy logic, however, there is a great dependency on proper expert knowledge acquisition. In this paper, we will remove that dependency by using a Genetic Algorithm (GA) to automatically determine parameters of fuzzy rule sets such as membership functions. This approach differs from conventional applications of GA-fuzzy knowledge development in that expert knowledge is incorporated in creating an initial highly fit population while allowing for randomness among members of the population for diversity. This method is useful for search in GA-hard landscapes and is successfully applied to speed regulation of a DC motor. It is shown that the presented method improves upon the initial fuzzy knowledge-base and significantly outperforms classical PID response. RP AkbarzadehT, MR (reprint author), UNIV NEW MEXICO,NASA,CTR AUTONOMOUS CONTROL ENGN,ELECT ENGN & COMP ENGN BLDG,ALBUQUERQUE,NM 87131, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 SN 0094-2898 BN 0-8186-7873-9 J9 SOUTHEAST SYMP SYSTE PY 1997 BP 292 EP 296 DI 10.1109/SSST.1997.581641 PG 5 WC Computer Science, Theory & Methods SC Computer Science GA BH39D UT WOS:A1997BH39D00056 ER PT J AU Ray, RD Mitchum, GT AF Ray, RD Mitchum, GT TI Surface manifestation of internal tides in the deep ocean: observations from altimetry and island gauges SO PROGRESS IN OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Conference on Tidal Science CY OCT 21-22, 1996 CL LONDON, ENGLAND SP Royal Soc London ID PACIFIC-OCEAN; ACOUSTIC TRANSMISSIONS; BAROCLINIC TIDES; TIDAL ENERGY; TIME-SERIES; SEA-LEVEL; BAY; TOPEX/POSEIDON; EVOLUTION; BISCAY AB The sea-surface height signatures of internal tides in the deep ocean, amounting to a few centimeters or less, are studied using two complementary measurement types: satellite altimetry and island tide gauges. Altimetry can detect internal tides that maintain coherence with the astronomical forcing; island gauges can monitor temporal variability which, in some circumstances, is due to internal tides varying in response to changes in the oceanic medium. This latter mechanism is at work at Hilo and other stations on the northern coasts of the Hawaiian islands. By detecting spatially coherent low-frequency internal-tide modulations, the tide gauges, along with inverted echo sounders at sea, suggest that the mean internal tide is also spatially coherent; satellite altimetry confirms this. At Hawaii and in many other places, Topex/Poseidon altimetry detects mean surface waves, spatially coherent and propagating great distances (> 1000 km) before decaying below background noise. When temporal variability is small, the altimetry (plus information on ocean density) sets useful constraints on energy fluxes into internal tides. At the Hawaiian Ridge, 15 GW of tidal power is being converted from barotropic to first-mode baroclinic motion. Examples elsewhere warn that a simplistic interpretation of the altimetry, without regard to variability, noise, or in situ information, may be highly misleading. With such uncertainties, extension of the Hawaiian results into a usefully realistic estimate of the global internal-tide energy balance appears premature at this time. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 NASA, Goddard Space Flight Ctr, HSTX, Greenbelt, MD 20771 USA. Univ S Florida, Dept Marine Sci, St Petersburg, FL 33701 USA. RP Ray, RD (reprint author), NASA, Goddard Space Flight Ctr, HSTX, Code 926, Greenbelt, MD 20771 USA. RI Ray, Richard/D-1034-2012 NR 60 TC 133 Z9 138 U1 1 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 1997 VL 40 IS 1-4 BP 135 EP 162 DI 10.1016/S0079-6611(97)00025-6 PG 28 WC Oceanography SC Oceanography GA 147VX UT WOS:000077519200008 ER PT J AU Gross, RS Chao, BF Desai, SD AF Gross, RS Chao, BF Desai, SD TI Effect of long-period ocean tides on the Earth's polar motion SO PROGRESS IN OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Conference on Tidal Science CY OCT 21-22, 1996 CL LONDON, ENGLAND SP Royal Soc London ID BASE-LINE INTERFEROMETRY; TIDAL ANGULAR-MOMENTUM; SEA-LEVEL RESPONSE; BAROMETRIC-PRESSURE; ROTATION; ORIENTATION; MODEL; VARIABILITY; EXCITATION; ALTIMETRY AB The second-degree zonal tide raising potential is symmetric about the polar axis and hence can excite the Earth's polar motion only through its action upon non-axisymmetric features of the Earth such as the oceans. In the long-period tidal band, spectral peaks occur at the fortnightly tidal frequencies in power spectra of polar motion excitation observations from which atmospheric effects have been removed. Different observed polar motion excitation series are studied, and differ ent methods of removing atmospheric effects from the polar motion excitation observations are explored in order to assess the robustness of the resulting empirical models for the observed effect of long-period ocean tides on polar motion excitation. At fortnightly frequencies, the various observed empirical models are found to agree with each other to within about 1 sigma. However, improved observations of the effect of fortnightly ocean tides on polar motion excitation are required since the observed effects at the Mf and Mf' tidal frequencies are not consistent with the expectation that the oceans should have the same relative response to the tidal potential at these two nearby tidal frequencies. The observations are then compared with predictions of three ocean tide models: two purely hydrodynamic models and one estimated from Topex/Poseidon altimetric sea surface height measurements. At the fortnightly tidal frequencies, the three ocean tide models predict polar motion excitation amplitudes that differ from each other and from the observations by factors as large as 2, and phases that differ by more than 100 degrees. This illustrates the need for improved models for the effect of long-period ocean tides on polar motion excitation. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gross, RS (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RI Chao, Benjamin Fong/N-6156-2013 NR 46 TC 13 Z9 13 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 1997 VL 40 IS 1-4 BP 385 EP 397 DI 10.1016/S0079-6611(98)00009-3 PG 13 WC Oceanography SC Oceanography GA 147VX UT WOS:000077519200019 ER PT J AU Chao, BF Ray, RD AF Chao, BF Ray, RD TI Oceanic tidal angular momentum and Earth's rotation variations SO PROGRESS IN OCEANOGRAPHY LA English DT Article; Proceedings Paper CT Conference on Tidal Science CY OCT 21-22, 1996 CL LONDON, ENGLAND SP Royal Soc London ID BASE-LINE INTERFEROMETRY; SEMIDIURNAL VARIATIONS; PERIODIC CHANGES; POLAR MOTION; TIDES; MODELS; LENGTH AB Luni-solar tides affect Earth's rotation in a variety of ways. We give an overview of the physics and focus on the excitation of Earth rotational Variations by ocean tides under the conservation of angular momentum. Various models for diurnal and semidiurnal tidal height and tidal current fields have been derived, following a legacy of a number of theoretical tide models, from the Topex/Poseidon (T/P) ocean altimetry data. We review the oceanic tidal angular momenta (OTAM) predicted by these T/P models for the eight major tides (Q(1), O-1, P-1, K-1, N-2, M-2, S-2, K-2,), and their excitations on both Earth's rotational speed variation tin terms of length-of-day or UTI) and polar motion (prograde diurnal/semidiurnal components and retrograde semidiurnal components). These small, high-frequency effects have been unambiguously observed in recent years by precise Earth rotation measurements via space geodetic techniques. Here we review the comparison of the very-long-baseline-interferometry (VLBI) data with the T/P OTAM predictions. The agreement is good with discrepancies typically within 1-2 microseconds for UT1 and 10-30 microarcseconds for polar motion. The eight tides collectively explain the majority of subdaily Earth rotation variance during the intensive VLBI campaign Cont94. This establishes the dominant role of OTAM in exciting the diurnal/semidiurnal polar motion and paves the way for detailed studies of short-period non-OTAM excitations, such as atmospheric and oceanic angular momentum variations, earthquakes, the atmospheric thermal tides, Earth librations, and the response of the mantle lateral inhomogeneities to tidal forcing. These studies await further improvements in tide models and Earth rotation measurements. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Space Geodsy Branch, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, HSTX, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Space Geodsy Branch, Greenbelt, MD 20771 USA. RI Ray, Richard/D-1034-2012; Chao, Benjamin Fong/N-6156-2013 NR 44 TC 11 Z9 12 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6611 J9 PROG OCEANOGR JI Prog. Oceanogr. PY 1997 VL 40 IS 1-4 BP 399 EP 421 DI 10.1016/S0079-6611(98)00010-X PG 23 WC Oceanography SC Oceanography GA 147VX UT WOS:000077519200020 ER PT B AU Wang, Y AF Wang, Y BE Wu, MH TI Electronically tunable color filter with surface plasmon waves SO PROJECTION DISPLAYS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Projection Displays III CY FEB 10-12, 1997 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, Soc Photo Opt Instrumentat Engineers DE surface plasmons; tunable filter; electro-optics; thin film; image spectrometer AB Last year, I had reported a novel phenomenon of voltage-induced color-selective absorption with surface plasmons (Appl. Phys. Lett. 67, 2749). When a white light is incident on a metal/EO material interface, in certain condition, surface plasmon waves can be excited; those photons in surface plasmon resonance wavelength range would be totally absorbed and these photons out of the surface plasmon resonance wavelength range would be almost totally reflected. This surface plasmon resonance depends on the dielectric constants of both the metal and the EO material. If a voltage is added on the EO material to change its dielectric constant, the surface plasmon resonance spectrum can be shifted form one wavelength to the other, and this is a tunable notch filter. If coupled surface plasmon waves are used, a tunable bandpass filter can be built. A prototype mode has been built using liquid crystal as the EO material. Experiment result, which has excellent agreement with theory, has shown that the wavelength tunable range can cover almost all of the visible (from 450 nm to 650 nm) when 30-v voltage is applied. Theoretical calculation has shown that this tunable filter can also work in IR range up to at least 10 mu m. RP Wang, Y (reprint author), CALTECH,JET PROP LAB,M-S 300-315,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 2 Z9 3 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2424-2 J9 P SOC PHOTO-OPT INS PY 1997 VL 3013 BP 224 EP 228 DI 10.1117/12.273875 PG 5 WC Optics SC Optics GA BH93G UT WOS:A1997BH93G00025 ER PT B AU VanSnyder, W AF VanSnyder, W BE Boisvert, RF TI Testing functions of one and two arguments SO QUALITY OF NUMERICAL SOFTWARE - ASSESSMENT AND ENHANCEMENT LA English DT Proceedings Paper CT IFIP TC2/WG2.5 Working Conference on the Quality of Numerical Software - Assessment and Enhancement CY JUL 08-12, 1996 CL OXFORD, ENGLAND SP Int Federat Informat Proc, Working Grp 2.5 DE mathematical functions; software evaluation; testing protocols AB Software to evaluate functions of one or two arguments is too often tested or certified, or the accuracy assessed, by ad hoc methods. Systematic methods to test, certify or assess the accuracy of single- or double-precision functions of one or two arguments, and supporting software, are described here. RP VanSnyder, W (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 CHAPMAN & HALL PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN BN 0-412-80530-8 PY 1997 BP 155 EP 166 PG 12 WC Computer Science, Software Engineering SC Computer Science GA BH18B UT WOS:A1997BH18B00012 ER PT S AU Bilitza, D AF Bilitza, D BE Rawer, K Bilitza, D TI International Reference Ionosphere - Status 1995/96 SO QUANTITATIVE DESCRIPTION OF IONOSPHERIC STORM EFFECTS AND IRREGULARITIES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C4.2 Symposium on Quantitative Description of Ionospheric Storm Effects and Irregularities, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Int Union Radio Sci, UN Off Outer Space Affairs ID EMPIRICAL-MODEL; ION COMPOSITION; REGION AB This paper describes the 1995/1996 status of IRT activities listing the improvements/additions that are currently being implemented. It also reports about a special IRI Task Force effort at the International Center for Theoretical Physics focusing on a better description of the "intermediate region" (bottomside and Fl). IRI modelling efforts; are also continuing in the topside ionosphere. Better representations of the region above the F peak are of critical importance for many investigations/applications that require Total Electron Content (TEC) predictions. We will;briefly report about efforts at GSFC to make Alouette/ISIS topside sounder data available for the modelling community. Reliability and accuracy of model predictions can be considerably increased through updating with real-time measurements. IRI has for some time had the facility of updates with co-located simultaneous F peak parameters (foF2, NmF2, hmF2, M(3000)F2). To expand this capability, updating algorithms are now under development that, will allow updates with available peak parameters and/or Total Electron Content (TEC) measurements. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NSSDC, GSFC, HSTX, Greenbelt, MD 20771 USA. RP Bilitza, D (reprint author), NSSDC, GSFC, HSTX, Code 633, Greenbelt, MD 20771 USA. NR 23 TC 122 Z9 131 U1 0 U2 4 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043306-5 J9 ADV SPACE RES PY 1997 VL 20 IS 9 BP 1751 EP 1754 DI 10.1016/S0273-1177(97)00584-X PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK38K UT WOS:000071955500016 ER PT S AU Bilitza, D Bhardwaj, S Koblinsky, C AF Bilitza, D Bhardwaj, S Koblinsky, C BE Rawer, K Bilitza, D TI Improved IRI predictions for the GEOSAT time period SO QUANTITATIVE DESCRIPTION OF IONOSPHERIC STORM EFFECTS AND IRREGULARITIES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C4.2 Symposium on Quantitative Description of Ionospheric Storm Effects and Irregularities, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Int Union Radio Sci, UN Off Outer Space Affairs AB Single-frequency altimeter measurements require an estimate of the signal retardation effect in the ionosphere. Ionospheric models like the International Reference Ionosphere (IRI) are being used to obtain these correction factors. Incorporation of worldwide ionosonde measurements is discussed as a way towards more accurate predictions. Using measurements of the F peak critical frequency (foF2) from more than 70 ionosondes we have derived (hour and month dependent) regional and global ionospheric-effective solar indices. Replacing the solar index in IRI with these new indices we could improve the IRI estimates for the GEOSAT time period (1986-1989) by a few percent. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NSSDC, GSFC, HSTX, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bilitza, D (reprint author), NSSDC, GSFC, HSTX, Code 633, Greenbelt, MD 20771 USA. NR 3 TC 8 Z9 8 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043306-5 J9 ADV SPACE RES PY 1997 VL 20 IS 9 BP 1755 EP 1760 DI 10.1016/S0273-1177(97)00585-1 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK38K UT WOS:000071955500017 ER PT S AU Urban, T Shum, C Kruizinga, G Tapley, B Bilitza, D Yuan, D AF Urban, T Shum, C Kruizinga, G Tapley, B Bilitza, D Yuan, D BE Rawer, K Bilitza, D TI Comparison of ionospheric models for single-frequency radar altimeters SO QUANTITATIVE DESCRIPTION OF IONOSPHERIC STORM EFFECTS AND IRREGULARITIES SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT C4.2 Symposium on Quantitative Description of Ionospheric Storm Effects and Irregularities, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Int Union Radio Sci, UN Off Outer Space Affairs AB Relative performances of available ionospheric models for computing path delay corrections to radar altimeter range data have been assessed using altimeter crossover measurements computed for the single-frequency altimeter measurements collected by Geosat and ERS-1, and for the dual-frequency altimeter measurements collected by TOPEX/POSEIDON. The models studied include IRI-90, IRI-95, and JPL GIM. The models are further compared with the ionospheric delay computed from TOPEX/POSEIDON dual-frequency altimeter data. Crossover analyses indicate that IRI-95 is an improved model over IRI-90 for computing ionospheric delays for all three altimetric satellites during low to medium solar activity,periods, It is found that smoothing of the TOPEX/POSEIDON dual-frequency ionospheric correction significantly improved the precision of the TOPEX/POSEIDON data. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 Univ Texas, Ctr Space Res, Austin, TX 78759 USA. Goddard Space Flight Ctr, Natl Space Sci Data Ctr, Greenbelt, MD 20895 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Urban, T (reprint author), Univ Texas, Ctr Space Res, 3925 W Braker,Suite 200, Austin, TX 78759 USA. NR 12 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043306-5 J9 ADV SPACE RES PY 1997 VL 20 IS 9 BP 1769 EP 1772 DI 10.1016/S0273-1177(97)00588-7 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK38K UT WOS:000071955500020 ER PT J AU Tuck, AF Baumgardner, D Chan, KR Dye, JE Elkins, JW Hovde, SJ Kelly, KK Loewenstein, M Margitan, JJ May, RD Podolske, JR Proffitt, MH Rosenlof, KH Smith, WL Webster, CR Wilson, JC AF Tuck, AF Baumgardner, D Chan, KR Dye, JE Elkins, JW Hovde, SJ Kelly, KK Loewenstein, M Margitan, JJ May, RD Podolske, JR Proffitt, MH Rosenlof, KH Smith, WL Webster, CR Wilson, JC TI The Brewer-Dobson circulation in the light of high altitude in situ aircraft observations SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Review DE airborne observations; atmospheric chemistry; stratospheric circulation; troposphere stratosphere interaction ID ANTARCTIC OZONE HOLE; ARCTIC STRATOSPHERIC EXPEDITION; WINTER POLAR STRATOSPHERES; INSITU ER-2 DATA; WATER-VAPOR; SULFURIC-ACID; IRREVERSIBLE TRANSPORT; INFRARED-ABSORPTION; SIZE DISTRIBUTIONS; REACTIVE NITROGEN AB Fast response in situ measurements of a suite of chemical species made from the NASA ER2 high altitude aircraft, between 60 degrees N and 70 degrees S at potential temperatures up to 530 K from March to November 1994 at longitudes 115 degrees W to 150 degrees E, are considered for the view they offer of the Brewer-Dobson circulation in the lower stratosphere and upper troposphere. In the southern hemisphere, where most of the flights occurred, comparisons are made with measurements taken in August/September 1987 at longitudes 120 degrees W to 60 degrees W to examine temporal and longitudinal differences. Interpretations made suggest conceptual modifications to the simple construct of advection in a two-dimensional long-term mean. C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. NOAA,CLIMATE MONITORING & DIAGNOST LAB,BOULDER,CO 80303. UNIV COLORADO,CIRES,BOULDER,CO 80309. CALTECH,JPL,PASADENA,CA 91125. UNIV WISCONSIN,MADISON,WI 53706. UNIV DENVER,DENVER,CO 80208. RP Tuck, AF (reprint author), NOAA,AERON LAB,US DEPT COMMERCE,ENVIRONM RES LABS,325 BROADWAY,BOULDER,CO 80303, USA. RI Tuck, Adrian/F-6024-2011; Rosenlof, Karen/B-5652-2008 OI Tuck, Adrian/0000-0002-2074-0538; Rosenlof, Karen/0000-0002-0903-8270 NR 116 TC 82 Z9 83 U1 1 U2 13 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING, BERKS, ENGLAND RG1 7LJ SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD JAN PY 1997 VL 123 IS 537 BP 1 EP 69 PN A PG 69 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WE692 UT WOS:A1997WE69200001 ER PT J AU Dharssi, I Kershaw, R Tao, WK AF Dharssi, I Kershaw, R Tao, WK TI Sensitivity of a simulated tropical squall line to long-wave radiation SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE cloud-resolving model; deep convection; precipitation enhancement; radiative cooling ID MESOSCALE CONVECTIVE SYSTEM; PARAMETERIZATION; MODEL; DYNAMICS; CLIMATE; BUDGETS; CIRRUS; CLOUDS; EMEX AB A two-dimensional cloud-resolving model is used to simulate a tropical squall line and to examine its sensitivity to long-wave radiation. Model results show that the magnitude of the sensitivity to long-wave radiation depend on the organization and structure of the squall line. For one simulation, the inclusion of long-wave radiation increased surface precipitation by nearly a third. Long-wave radiation is also found to enhance the mid-level rear inflow and upper-level outflow of the squall line. Sensitivity experiments are performed to examine the role of cloud-top cooling and cloud-base warming, differential cooling between clear and cloudy regions, and domain-wide cooling. C1 METEOROL OFF,BRACKNELL RB12 2SZ,BERKS,ENGLAND. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NR 29 TC 10 Z9 13 U1 0 U2 0 PU ROYAL METEOROLOGICAL SOC PI READING PA 104 OXFORD ROAD, READING, BERKS, ENGLAND RG1 7LJ SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD JAN PY 1997 VL 123 IS 537 BP 187 EP 206 DI 10.1002/qj.49712353708 PN A PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WE692 UT WOS:A1997WE69200007 ER PT J AU Cucinotta, FA Wilson, JW Dicello, JF AF Cucinotta, FA Wilson, JW Dicello, JF TI Physics and biophysics problems in cosmic ray exposures and risk assessment SO RADIATION EFFECTS AND DEFECTS IN SOLIDS LA English DT Article; Proceedings Paper CT 3rd International Conference on Computer Simulation of Radiation Effects in Solids (COSIRES) CY JUL 22-26, 1996 CL UNIV SURREY, GUILDFORD, ENGLAND SP Danfysik, Silvaco, TMA, IOP, Applied Mat, Univ Surrey HO UNIV SURREY C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Johns Hopkins Univ, Sch Med, Ctr Oncol, Baltimore, MD 21287 USA. RP Cucinotta, FA (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1042-0150 J9 RADIAT EFF DEFECT S JI Radiat. Eff. Defects Solids PY 1997 VL 141 IS 1-4 BP 457 EP 457 DI 10.1080/10420159708211589 PG 1 WC Nuclear Science & Technology; Physics, Fluids & Plasmas; Physics, Condensed Matter SC Nuclear Science & Technology; Physics GA 190YL UT WOS:000079992800039 ER PT S AU Ebisawa, K AF Ebisawa, K BE Day, C Mukai, T Schweihm, G Philbrick, CR TI X-ray spectral properties of CYG X-1 SO RADIATION FROM BLACK HOLES, FUTURE MISSIONS TO PRIMITIVE BODIES AND MIDDLE ATMOSPHERIC FINE STRUCTURES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT Symposia on Radiation from Black Holes, Future Missions to Primitive Bodies and Middle Atmospheric Fine Structures, at the 30th COSPAR Scientific Assembly CY JUL 11-21, 1994 CL HAMBURG, GERMANY SP Comm Space Res, Commiss E B & C, Int Astron Union ID ACTIVE GALACTIC NUCLEI; ACCRETION DISKS; BLACK-HOLE; LINE-PROFILES; COLD MATTER; RELATIVISTIC DISKS; TRANSIENT DIPS; NOVA MUSCAE; IRON LINE; CYGNUS-X-1 AB Cyg X-1 is a prototype of black hole candidates with fiducial evidence of large mass. In this paper, I review X-ray spectral properties of Cyg X-1. Usually, Cyg X-1 is in the low state (hard spectral state), in which the energy spectrum in 2 - 10 keV is roughly represented with a power-law function, and sub-second short-term variations are significant. The continuum of the low state energy spectrum is consistent with the superposition of a power-law function with an exponential cut-off and its reflection component by an optically thick accretion disk. Thermal Comptonization of soft photons by hot plasma is a likely model for the intrinsic power-law emission. Iron K-emission lines have been reported, and study of those emission lines have a potential to verify strong gravitational fields around a black hole. However, the line emission is not prominent, as opposed to the cases of AGNs, and the line parameters are dependent on the choice of the continuum model. To determine the continuum spectral shape precisely and disentangle the iron line emission, observations having both high spectral resolution and wide energy coverage will be required. ASCA and XTE simultaneous observations may provide such a chance. (C) 1997. Published by Elsevier Science Ltd on behalf of COSPAR. C1 UNIV SPACE RES ASSOC, GREENBELT, MD USA. RP Ebisawa, K (reprint author), NASA, GODDARD SPACE FLIGHT CTR, CODE 668, GREENBELT, MD 20771 USA. NR 78 TC 1 Z9 1 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043097-X J9 ADV SPACE RES-SERIES PY 1997 VL 19 IS 1 BP 5 EP 14 DI 10.1016/S0273-1177(97)00030-6 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BH61X UT WOS:A1997BH61X00001 ER PT S AU Titarchuk, LG Hua, XM AF Titarchuk, LG Hua, XM BE Day, C Mukai, T Schweihm, G Philbrick, CR TI Comptonization models and spectroscopy of X-ray and gamma-ray sources SO RADIATION FROM BLACK HOLES, FUTURE MISSIONS TO PRIMITIVE BODIES AND MIDDLE ATMOSPHERIC FINE STRUCTURES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT Symposia on Radiation from Black Holes, Future Missions to Primitive Bodies and Middle Atmospheric Fine Structures, at the 30th COSPAR Scientific Assembly CY JUL 11-21, 1994 CL HAMBURG, GERMANY SP Comm Space Res, Commiss E B & C, Int Astron Union ID THERMAL PLASMAS; ACCRETION DISKS; SPECTRA; RADIATION; GEOMETRY AB We compare the analytical Generalized Comptonization model which takes into account the relativistic effects /1/, and Monte Carlo calculations for photon Comptonization by relativistic plasma clouds. We show that the new analytical model extends the previous work to a much wider range of plasma temperatures and optical depths. In general, the emergent spectra from a hot plasma cloud depend upon the spectral and spatial distributions of source photons as well as the plasma temperature and geometry. Based on the comparison between the theoretical and Monte Carlo calculations, we determine quantitatively a range of plasma geometry parameters and temperatures for which the emergent upscattering spectra are insensitive to the spectral and spatial distribution of source photons. Within this parameter range, we show that the shape of the emergent spectrum depends on two parameters only,namely the plasma temperature and beta, the parameter which characterizes the photon distribution over the number of scatterings which the soft photons undergo in the plasma cloud in order to become the hard ones. We find the exact solution of the Kompaneets equation in the case of subrelativistic energies and plasma temperatures, in the optically thick regime. The solution recovers the low and high energy asymptotic forms studied in /1/. Also, we modify the Sunyaev & Titarchuk formula /2/ in order to obtain a fairly good subrealtivistic analytical approximation. This new formula, verified by Monte-Carlo calculations, contains as partial cases the Titarchuk's analytical results /1/, for optically thick and thin cases respectively. The analytical models, examined by the present Monte Carlo calculations, make possible a more efficient spectral analysis of data obtained from X-ray and gamma-ray sources. Published by Elsevier Science on behalf of COSPAR. RP Titarchuk, LG (reprint author), NASA, GODDARD SPACE FLIGHT CTR, CODE 668, GREENBELT, MD 20771 USA. NR 16 TC 3 Z9 3 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043097-X J9 ADV SPACE RES-SERIES PY 1997 VL 19 IS 1 BP 99 EP 108 DI 10.1016/S0273-1177(97)00043-4 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BH61X UT WOS:A1997BH61X00014 ER PT J AU Nghiem, SV Kwok, R Yueh, SH Gow, AJ Perovich, DK Kong, JA Hsu, CC AF Nghiem, SV Kwok, R Yueh, SH Gow, AJ Perovich, DK Kong, JA Hsu, CC TI Evolution in polarimetric signatures of thin saline ice under constant growth SO RADIO SCIENCE LA English DT Article ID COMPLEX-DIELECTRIC-CONSTANT; SEA-ICE; MICROWAVE-FREQUENCIES; LAYERED MEDIA; BRINE; MODEL; SNOW; BACKSCATTER; SCATTERERS AB An experiment is carried out to measure polarimetric backscatter signatures at C band together with physical characteristics of thin saline ice grown at a constant rate under quiescent conditions. The objectives are to investigate the electromagnetic scattering mechanism in saline ice, to relate the polarimetric backscatter to ice physical characteristics, and to assess the inversion of ice thickness from backscatter data. Controlled laboratory conditions are utilized to avoid complicated variations in interrelated characteristics of saline ice and the environment. The ice sheet was grown in a refrigerated facility at the U.S. Army Cold Regions Research and Engineering Laboratory. Growth conditions, thickness and growth rate, temperatures and salinities, and internal and interfacial structures of the ice sheet were monitored. Measurements indicate that the laboratory saline ice has characteristics similar to thin sea ice in the Arctic. A strong increase of 6-10 dB is observed in backscatter as the ice grows from 3 to 11.2 cm in thickness. Ice characteristics and processes suggest that the large enhancement in backscatter relates to the interconnection and increase in the size of brine inclusions during the desalination process. Polarimetric signatures calculated with a physically based sea ice model agree with backscatter data at incident angles from 20 degrees to 35 degrees over the thickness range of the ice growth. Furthermore, backscattering coefficients of the saline ice sheet are shown to be similar to airborne radar measurements of thin sea ice growing ina newly opened lead in the Beaufort Sea. For the inversion the large increase in backscatter indicates that the ice thickness is retrievable for thin ice grown under the conditions in this experiment. More complicated conditions should be considered in future experiments to study their effects on the retrieval of sea ice parameters. C1 USA,COLD REG RES & ENGN LAB,HANOVER,NH 03755. MIT,DEPT ELECT ENGN & COMP SCI,CAMBRIDGE,MA 02139. MIT,ELECT RES LAB,CAMBRIDGE,MA 02139. RP Nghiem, SV (reprint author), CALTECH,JET PROP LAB,CTR SPACE MICROELECT TECHNOL,MAIL STOP 300-325,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 45 TC 22 Z9 22 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD JAN-FEB PY 1997 VL 32 IS 1 BP 127 EP 151 DI 10.1029/96RS03051 PG 25 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA WF147 UT WOS:A1997WF14700011 ER PT J AU Calvert, W Benson, RF Carpenter, DL Fung, SF Gallagher, DL Green, JL Haines, DM Reiff, PH Reinisch, BW Smith, MF Taylor, WWL AF Calvert, W Benson, RF Carpenter, DL Fung, SF Gallagher, DL Green, JL Haines, DM Reiff, PH Reinisch, BW Smith, MF Taylor, WWL TI The feasibility of radio sounding of the magnetosphere - Reply SO RADIO SCIENCE LA English DT Editorial Material C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. STANFORD UNIV,STAR LAB,STANFORD,CA 94305. NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812. UNIV MASSACHUSETTS LOWELL,CTR ATMOSPHER RES,LOWELL,MA 01854. RICE UNIV,DEPT SPACE PHYS & ASTRON,HOUSTON,TX 77251. RP Calvert, W (reprint author), UNIV MASSACHUSETTS LOWELL,219 FRIENDSHIP ST,IOWA CITY,IA 52245, USA. RI Fung, Shing/F-5647-2012; Reiff, Patricia/D-2564-2014 OI Reiff, Patricia/0000-0002-8043-5682 NR 4 TC 6 Z9 6 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD JAN-FEB PY 1997 VL 32 IS 1 BP 281 EP 284 DI 10.1029/96RS03522 PG 4 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA WF147 UT WOS:A1997WF14700023 ER PT B AU Easterbrook, S Callahan, J AF Easterbrook, S Callahan, J GP IEEE COMP SOC TI Formal methods for V&V of partial specifications: An experience report SO RE '97 - PROCEEDINGS OF THE THIRD IEEE INTERNATIONAL SYMPOSIUM ON REQUIREMENTS ENGINEERING LA English DT Proceedings Paper CT 3rd IEEE International Symposium on Requirements Engineering (RE 97) CY JAN 06-10, 1997 CL ANNAPOLIS, MD SP IEEE Comp Soc Tech Council Software Engn, Assoc Comp Machinery, SIGSOFT, IFIP Working Grp 2.9 AB This paper describes our work exploring the suitability of formal specification methods for independent verification and validation (IV&V) of software specifications for large, safety critical systems. An IV&V contractor often has to perform rapid analysis on incomplete specifications with no control over how those specifications are represented. Lightweight formal methods show significant promise in this context, as they offer a way of uncovering major errors, without the burden of full proofs of correctness. We describe an experiment in the application of the method SCR to testing for consistency properties of a partial model of the requirements for Fault Detection Isolation and Recovery on the space station. We conclude that the insights gained from formalizing a specification is valuable, and it is the process of formalization, rather than the end product that is important. It was only necessary to build enough of the formal model to test the properties in which we were interested. Maintenance of fidelity between multiple representations of the same requirements (as they evolve) is still a problem, and deserves further study. RP Easterbrook, S (reprint author), UNIV VIRGINIA,SOFTWARE IV&V FACIL,NASA,100 UNIV DR,FAIRMONT,WV 26554, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 BN 0-8186-7740-6 PY 1997 BP 160 EP 168 DI 10.1109/ISRE.1997.566865 PG 3 WC Computer Science, Software Engineering SC Computer Science GA BH24Y UT WOS:A1997BH24Y00024 ER PT B AU Bejczy, AK AF Bejczy, AK BE CamarinhaMatos, LM TI Virtual reality in manufacturing SO RE-ENGINEERING FOR SUSTAINABLE INDUSTRIAL PRODUCTION LA English DT Proceedings Paper CT OE/IFIP/IEEE International Conference on Integrated and Sustainable Industrial Production CY MAY, 1997 CL LISBON, PORTUGAL SP Ordem dos Engenheiros, Int Federat Informat Proc, IEEE Robot & Automat Soc, IEEE Syst Man & Cybernet Soc DE computer graphics; visualization; modeling; operator interface; computer programming and control AB Computer graphics based virtual reality techniques offer powerful and very valuable task visualization aids for planning system set-up and system processes, for previewing system and device actions, and even for seeing some invisible things in a complex action or production environment. Virtual reality techniques connected to CAD data banks can also offer 3-D simulation based programming and control tools for computer-controlled devices and can provide real-time interactive operator interface to those devices. Virtual reality techniques can also be applied to quick product prototyping by high-fidelity product modeling. RP Bejczy, AK (reprint author), CALTECH,JET PROP LAB,MS198-219,PASADENA,CA 91109, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU CHAPMAN & HALL PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN BN 0-412-79950-2 PY 1997 BP 48 EP 60 PG 13 WC Automation & Control Systems; Engineering, Industrial; Engineering, Manufacturing SC Automation & Control Systems; Engineering GA BH94A UT WOS:A1997BH94A00005 ER PT S AU Birn, J Hesse, M Schindler, K AF Birn, J Hesse, M Schindler, K BE Priest, ER Baker, DN TI Theory of magnetic reconnection in three dimensions SO RECONNECTION IN THE SOLAR CORONA AND MAGNETOSPHERIC SUBSTORMS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT DO 4 Symposium of COSPAR Scientific Commission D on Reconnection in the Solar Corona and Magnetospheric Substorms, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Sci Comm Solar Terr Phys, Int Astron Union, UN Off Outer Space Affairs ID FLOWS; TAIL AB Magnetic reconnection in traditional, two-dimensional theory can be closely associated with topological properties of the magnetic field, separatrices, neutral lines, or separators. Such well-defined topological properties may no longer exist, or become hopelessly complicated, in more general three-dimensional configurations, that otherwise behave physically quite similarly to the two-dimensional configurations. We discuss generalized definitions of reconnection applied to such situations and illustrate typical properties with simulations of three-dimensional reconnection in the magnetotail. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. RUHR UNIV BOCHUM, INST THEORET PHYS 4, D-4630 BOCHUM, GERMANY. RP Birn, J (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. RI Hesse, Michael/D-2031-2012 NR 23 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043292-1 J9 ADV SPACE RES-SERIES PY 1997 VL 19 IS 12 BP 1763 EP 1771 DI 10.1016/S0273-1177(97)00072-0 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ39X UT WOS:A1997BJ39X00002 ER PT S AU Engman, ET AF Engman, ET BE Baumgartner, MF Schultz, GA Johnson, AI TI Soil moisture, the hydrologic interface between surface and ground waters SO REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEMS FOR DESIGN AND OPERATION OF WATER RESOURCES SYSTEMS SE IAHS PUBLICATION LA English DT Proceedings Paper CT International Symposium on Remote Sensing and Geographic Information Systems for Design and Operation of Water Resources Systems, at 5th Scientific Assembly of IAHS CY APR 23-MAY 03, 1997 CL RABAT, MOROCCO SP Int Assoc Hydrol Sci, Int Comm Remote Sensing & Data Transmiss, Int Assoc Hydrol Sci, Int Comm Water Resources Syst, UNESCO, World Meteorol Org, Moroccan Water Resources Assoc AB A hypothesis is presented that many hydrologic processes display a unique signature that is detectable with microwave remote sensing. These signatures are in the form of the spatial and temporal distributions of surface soil moisture. The specific hydrologic processes that may be detected include groundwater recharge and discharge zones, storm runoff contributing areas, regions of potential and less than potential evapotranspiration (ET), and information about the hydrologic properties of soils. In basin and hillslope hydrology, soil moisture is the interface between surface and ground waters. RP Engman, ET (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HYDROL SCI BRANCH,LAB HYDROSPHER PROC,CODE 974,GREENBELT,MD 20771, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU INT ASSOC HYDROLOGICAL SCIENCES PI WALLINGFORD PA INST OF HYDROLOGY, WALLINGFORD, ENGLAND OX10 8BB SN 0144-7815 BN 1-901502-15-5 J9 IAHS-AISH P PY 1997 IS 242 BP 129 EP 140 PG 12 WC Remote Sensing; Water Resources SC Remote Sensing; Water Resources GA BJ32G UT WOS:A1997BJ32G00014 ER PT S AU Mattikalli, NM Engman, ET AF Mattikalli, NM Engman, ET BE Baumgartner, MF Schultz, GA Johnson, AI TI Microwave remote sensing and GIS for monitoring surface soil moisture and estimation of soil properties SO REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEMS FOR DESIGN AND OPERATION OF WATER RESOURCES SYSTEMS SE IAHS PUBLICATION LA English DT Proceedings Paper CT International Symposium on Remote Sensing and Geographic Information Systems for Design and Operation of Water Resources Systems, at 5th Scientific Assembly of IAHS CY APR 23-MAY 03, 1997 CL RABAT, MOROCCO SP Int Assoc Hydrol Sci, Int Comm Remote Sensing & Data Transmiss, Int Assoc Hydrol Sci, Int Comm Water Resources Syst, UNESCO, World Meteorol Org, Moroccan Water Resources Assoc AB Passive microwave remote sensing and a geographic information system (GIS) were employed for monitoring and quantifying spatial and temporal variability of surface soil moisture over the Little Washita drainage basin, Oklahoma, USA, between 10 and 18 June 1992. Daily microwave measurements at a ground resolution of 200 m were obtained from airborne ESTAR instrument. Surface soil moisture values were derived from brightness temperatures. This data set aias georeferenced in a GIS for spatial analysis and to quantify temporal variations of soil moisture during the dry-down period. Analysis of soil moisture changes with digital soils data revealed a direct relationship between changes in soil moisture and soil texture. Areas identified by loam/silt loam soils are characterized by higher changes of total soil moisture and those of sand/fine sandy loam soils by remarkably lower amounts of change. This analysis suggested that changes in soil moisture could be used as indicators of soil texture and soil hydraulic conductivity (K-sat). A methodology was developed for deriving sub-surface K-sat from remotely sensed surface soil moisture. Results yielded good correlations between two-day soil moisture change and K-sat for 0-5 cm, 0-30 cm and 0-60 cm depths. These results have potential applications of microwave remote sensing for obtaining quick estimates of spatial distributions of soil properties over large area for input to large scale hydrologic models. RP Mattikalli, NM (reprint author), NASA,GODDARD SPACE FLIGHT CTR,LAB HYDROSPHER PROC,HYDROL SCI BRANCH,CODE 974,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU INT ASSOC HYDROLOGICAL SCIENCES PI WALLINGFORD PA INST OF HYDROLOGY, WALLINGFORD, ENGLAND OX10 8BB SN 0144-7815 BN 1-901502-15-5 J9 IAHS-AISH P PY 1997 IS 242 BP 229 EP 236 PG 8 WC Remote Sensing; Water Resources SC Remote Sensing; Water Resources GA BJ32G UT WOS:A1997BJ32G00025 ER PT J AU Mattikalli, NM AF Mattikalli, NM TI Soil color modeling for the visible and near-infrared bands of Landsat sensors using laboratory spectral measurements SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID REFLECTANCE; RANGELANDS AB Color is a key feature used in the identification and classification of soils. Soil reflectance has a direct relationship with soil color, as well as to other parameters such as texture, soil moisture, and organic matter. Earlier studies have quantified the relationship between reflectance and soil color using simple linear regression equations having correlation coefficients of about 0.5. In the present study, a method called optimal rotational transformation technique has been employed to maximize the correlation between soil color and transformed reflectance. Seventy-six soil samples having a wide range of soil color were employed in the laboratory measurements. Multispectral reflectances were measured using an Exotech radiometer in the visible and near-infrared bands of the Landsat MSS sensor, and soil color was measured using the Munsell color charts. The soil color data were quantified using the RGB color coordinate system since colors recorded in the Munsell system are not readily usable in numerical analysis. Simple linear regression models using the raw reflectance data yielded correlations of about 0.5. Optimal rotational transformation of the reflectance data and multiple linear regressions showed an improved correlation of r more than 0.8, and the models predicted the main color component (viz. hue) with acceptable accuracy. Hue images can be used for identification and discrimination of soils and lithological formations, since hue is independent of illumination and therefore capable of suppressing shadows. Optimal models can be developed to predict soil reflectance using color data since metamerism is rarely observed in the care of soils. Results of this study have a potential application for identification and mapping of soil and geologic materials of nonvegetated or sparsely vegetated regions using data received from airborne and space-borne remote sensors operating in the visible and near-infrared bands. (C) Elsevier Science Inc., 1997 RP Mattikalli, NM (reprint author), NASA,GODDARD SPACE FLIGHT CTR,LAB HYDROSPHER PROC HYDROL SCI BRANCH,CODE 974,GREENBELT,MD 20771, USA. NR 47 TC 35 Z9 37 U1 1 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD JAN PY 1997 VL 59 IS 1 BP 14 EP 28 DI 10.1016/S0034-4257(96)00075-2 PG 15 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA VY616 UT WOS:A1997VY61600002 ER PT J AU Imhoff, ML Lawrence, WT Elvidge, CD Paul, T Levine, E Privalsky, MV AF Imhoff, ML Lawrence, WT Elvidge, CD Paul, T Levine, E Privalsky, MV TI Using nighttime DMSP/OLS images of city lights to estimate the impact of urban land use on soil resources in the United States SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID SATELLITE; SURFACE AB Nightime ''city light'' footprints derived from DMSP/ OLS satellite images were merged with census data and a digital soils map in a continental-scale test of a remote sensing and geographic information system methodology for approximating the extent of built-up land and its potential impact on soil resources in the United States. Using image processing techniques and census data, we generated maps where the ''city lights'' class represented mean population densities of 947 persons km(-2) and 392 housing units km(-2), areas clearly not available to agriculture. By our analysis, such ''city lights'' representing urban areas accounted for 2.7% of the surface area in the United States, an area approximately equal to the State of Minnesota or one half the size of California. Using the UN/FAO Fertility Capability Classification System to rank soils, results for the United States show that development appears to be following soil resources, with the better agricultural soils being the most unbanized. Some unique soil types appear to be on the verge of being entirely coopted by ''urban sprawl.'' Urban area figures derived from the DMSP/OLS imagery compare well to those derived from statistical sources. Further testing and refinement of the methodology remain but the technique shows promise for possible extension to global evaluations of urbanization, population and even global productivity. (C) Elsevier Science Inc., 1997 C1 UNIV MARYLAND,DEPT GEOG,COLLEGE PK,MD 20742. UNIV NEVADA,DESERT RES INST,RENO,NV 89506. ROWAN COLL,GLASSBORO,NJ 08028. RP Imhoff, ML (reprint author), NASA,GODDARD SPACE FLIGHT CTR,BIOSPHER SCI BRANCH,CODE 923,GREENBELT,MD 20771, USA. RI Elvidge, Christopher/C-3012-2009 NR 33 TC 123 Z9 151 U1 7 U2 64 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD JAN PY 1997 VL 59 IS 1 BP 105 EP 117 DI 10.1016/S0034-4257(96)00110-1 PG 13 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA VY616 UT WOS:A1997VY61600008 ER PT J AU Ranson, KJ Sun, G Weishampel, JF Knox, RG AF Ranson, KJ Sun, G Weishampel, JF Knox, RG TI Forest biomass from combined ecosystem and radar backscatter modeling SO REMOTE SENSING OF ENVIRONMENT LA English DT Article ID BOREAL FORESTS; VEGETATION CANOPIES; SAR DATA; SOIL; SUCCESSION; INVERSION AB Above-ground woody biomass ii nn important parameter for describing the function and productivity of forested ecosystems. Recent studies have demonstrated that synthetic aperture radar (SAR) can be used to estimate above-ground standing biomass. To date, these studies have relied on extensive ground-truth measurements to construct relationships between biomass and SAR backscatter. In this article toe discuss the use of models to help develop a relationship between biomass and radar backscatter and compare the predictions ruth measurements. A gap-type forest succession model was used to simulate growth and development of a northern hardwood-boreal transitional Sorest typical of central Maine, USA. Model results of species, and bole diameter at breast height (dbh) of individual trees in a 900 m(2) stand I were used to run discontinuous canopy backscatter models to determine radar backscatter coefficients for a wide range of simulated forest stands. Using model results, relationships of copolarized backscatter to forest biomass were developed and applied to an airborne SAR (AIRSAR) image over a forested area in Maine. A relationship derived totally from model results was found to underestimate biomass. Calibrating the modeled backscatter with limited AIRSAR backscatter measurements improved the biomass estimation when compared to field measurements. The approach of rising a combination of forest succession and remote sensing models to develop algorithms for inferring forest attributes produced comparable results with techniques using only measurements. Applying the model derived algorithm to SAR imagery produced reasonable results when mapped biomass was limited to 15 kg/m(2) or less. (C) Elsevier Science Inc., 1997. C1 SCI SYST APPLICAT INC,LANHAM,MD. UNIV CENT FLORIDA,DEPT BIOL,ORLANDO,FL 32816. RP Ranson, KJ (reprint author), NASA,GODDARD SPACE FLIGHT CTR,BIOSPHER SCI BRANCH,CODE 923,GREENBELT,MD 20771, USA. RI Knox, Robert/E-9657-2011; Ranson, Kenneth/G-2446-2012 OI Ranson, Kenneth/0000-0003-3806-7270 NR 57 TC 53 Z9 57 U1 1 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD JAN PY 1997 VL 59 IS 1 BP 118 EP 133 DI 10.1016/S0034-4257(96)00114-9 PG 16 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA VY616 UT WOS:A1997VY61600009 ER PT B AU Kim, MS Krizek, DT Daughtry, CST McMurtrey, JE Sandhu, R Chappelle, EW Corp, LA Middleton, EM AF Kim, MS Krizek, DT Daughtry, CST McMurtrey, JE Sandhu, R Chappelle, EW Corp, LA Middleton, EM BE Cecchi, G DUrso, G Engman, ET Gudmandsen, P TI Fluorescence imaging system: Application for the assessment of vegetation stresses SO REMOTE SENSING OF VEGETATION AND SEA SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing of Vegetation and Sea CY SEP 23-26, 1996 CL TAORMINA, ITALY SP CNR, Ctr Natl Etud Spatiales, City Taormina, Univ Catania, Dept Bot, Italian Assoc Remote Sensing, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev DE laser induced fluorescence (LIF); fluorescence imaging system (FIS); EDU; photosynthesis; vegetation stress AB As a part of an ongoing laser induced fluorescence (LIF) project, our laboratories have developed a fluorescence imaging system (FIS) to acquire fluorescence images at wavelengths centered at 450 nm, 550 nm, 680 nm, and 740 nm. The system consists of ultraviolet (UV) fluorescent lamps as an exciting source, automated filter wheel, and charge coupled device (CCD) camera. The automated filter wheel and CCD camera are controlled by a microcomputer via a computer interface, and digital images are captured. The FIS is capable of capturing steady state fluorescence and chlorophyll fluorescence induction images. Experimental studies were conducted to demonstrate the utility of the FIS. One such study included experiments to observe the effects of ethylenediurea (EDU: N-[2-(2-oxo-1-imidazolidinyl) ethyl]-N'-phenylurea) in soybean leaves with FIS. Five different concentrations of EDU were used to establish a dose-response relationship. Although visual effects of EDU treatment were not apparent, the intensities of the fluorescence images of the plant leaves varied depending on the EDU concentration, the location on the leaf surface and the emission wavelength. EDU appeared mainly to affect the photosynthetic apparatus causing non-uniform increases in red and far-red fluorescence. Ratio images of red/green and blue/far-red were found to be sensitive indicators in detecting EDU effects. A ratio of fluorescence induction to steady state fluorescence had a curvilinear relationship with EDU-dosage. Such kinetic measurements can be used to assess photosynthetic activity in response to a range of chemical and environmental stresses. This study demonstrates that FIS is an excellent tool to detect stress symptoms before the onset of visible injury (e.g., chlorosis, discoloration, and necrosis). It will enhance our understanding of the interactions among photosynthetic activity, vegetative stresses and fluorescence responses. Characterization of steady state fluorescence patterns in leaves is of significant value in our LIF research studies, and images taken with FIS greatly complement non-imaging fluorescence measurements by finding the spatial distribution of fluorescence in leaves. RP Kim, MS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,TERR PHYS LAB,GREENBELT,MD 20771, USA. NR 0 TC 2 Z9 2 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2363-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 2959 BP 4 EP 13 DI 10.1117/12.264255 PG 10 WC Agronomy; Ecology; Remote Sensing; Optics; Water Resources SC Agriculture; Environmental Sciences & Ecology; Remote Sensing; Optics; Water Resources GA BH14X UT WOS:A1997BH14X00001 ER PT B AU Chappelle, EW Corp, LA McMurtrey, JE Kim, MS Daughtry, CST AF Chappelle, EW Corp, LA McMurtrey, JE Kim, MS Daughtry, CST BE Cecchi, G DUrso, G Engman, ET Gudmandsen, P TI Fluorescence: A diagnostic tool for the detection of stress in plants SO REMOTE SENSING OF VEGETATION AND SEA SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing of Vegetation and Sea CY SEP 23-26, 1996 CL TAORMINA, ITALY SP CNR, Ctr Natl Etud Spatiales, City Taormina, Univ Catania, Dept Bot, Italian Assoc Remote Sensing, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev DE fluorescence; plant stress; remote sensing; nitrogen fertilization level; remote estimation of protein concentration AB Green vegetation when excited by specific wavelengths of light dissipates a portion of the absorbed energy as light emissions in the form of fluorescence in several broad areas of the spectrum. Currently, leaf level fluorescence emissions have been broken down into five primary regions, namely; ultraviolet (UV), blue, green, red, and near-infrared (NIR). The optimal excitation wavelengths for each of these bands was verified for healthy soybean leaves through the use of the EEM (excitation and emission matrix). Intact vegetation when excited at 280 nm emits substantial fluorescence in two bands; the first centered near 335 nm (UV band), and the second centered near 440 nm (blue band). UV band fluorescence from vegetation treated with varying levels of nitrogen decreases relative to the blue fluorescence as a function of total protein concentration. These studies indicate that in vivo UV band fluorescence can be utilized as a non-destructive tool to remotely sense variations in protein concentration due to nitrogen fertilization level. It has been well established that this fluorescence emission originates from proteins containing aromatic amino acids. The majority of plant proteins contain these amino acids and as a result have the potential to fluoresce in the region of the spectrum discussed here. Pure ribulose 1,5-bisphosphate carboxylase (RubisCO) in aqueous solution exhibited intense UV fluorescence characteristics with excitation and emission distributions similar to those of intact vegetation. Due to its high concentration (up to 70 % of the soluble leaf proteins) we believe this protein contributes to the UV band fluorescence emanating from the intact leaf. The red and NIR fluorescent emissions can be excited within the broad wavelength region from 250 to 675 nm with excitation maxima at 430 nm, 470 nm, 600 nm, and 660 nm. The ratio of red to NIR fluorescence excitation spectra produces a ratio spectrum which exhibits striking similarities to the action spectrum of photosynthesis. The relative differences between these two emission bands depend on the wavelength of excitation. Moreover, by comparing the ratio spectrum of a healthy versus nitrogen deficient leaf, one finds areas of crossover where trends can be completely reversed by changing excitation wavelength. As a result, the success of studies involving the measurement of chlorophyll a fluorescence depend greatly on the appropriate selection of excitation wavelength. Fluorescence sensing systems based on the above emission bands are being proposed or developed for ground based mobile vans, helicopters, and small aircraft. The goals of these efforts were to better define the origins of fluorescence and to improve our understanding of these light emissions in relationship to the physiological status of the plant. RP Chappelle, EW (reprint author), NASA,GODDARD SPACE FLIGHT CTR,TERR PHYS LAB,GREENBELT,MD 20771, USA. NR 0 TC 2 Z9 2 U1 2 U2 5 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2363-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 2959 BP 14 EP 23 DI 10.1117/12.264261 PG 10 WC Agronomy; Ecology; Remote Sensing; Optics; Water Resources SC Agriculture; Environmental Sciences & Ecology; Remote Sensing; Optics; Water Resources GA BH14X UT WOS:A1997BH14X00002 ER PT J AU Kautz, HE AF Kautz, HE TI Noncontact determination of antisymmetric plate wave velocity in ceramic matrix composites SO RESEARCH IN NONDESTRUCTIVE EVALUATION LA English DT Article AB A 13-mJoule NdYAG 1064-nm, 4-nsec laser pulse was employed to produce ultrasonic plate waves in 20% porous SiC/SiC composite tensile specimens of three different architectures. An air-coupled 0.5-MHz transducer was used to detect and collect the waveforms that contained first antisymmetric plate wave pulses for determining the group velocity (VS). These results were compared to VS values determined on the same specimens with 0.5-MHz ultrasonic transducers with contact coupling. Averages of four noncontact determinations on each of 18 specimens were compared to averages of four contact values. The noncontact VSs fall in the same range as the contact. The standard deviations for the noncontact VS values averaged 2.8%. The standard deviations for the contact measurements averaged 2.3%, indicating similar reproducibility. Repeated laser pulsing at the same location always leads to deterioration of the ultrasonic signal. The signal would recover in about 24 h in air, however, indicating that no permanent damage was produced. RP Kautz, HE (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 21 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0934-9847 J9 RES NONDESTRUCT EVAL JI Res. Nondestruct. Eval. PY 1997 VL 9 IS 3 BP 137 EP 146 PG 10 WC Materials Science, Characterization & Testing SC Materials Science GA YD148 UT WOS:A1997YD14800002 ER PT J AU Roth, DJ Bodis, JR Bishop, C AF Roth, DJ Bodis, JR Bishop, C TI Thermographic imaging for high-temperature composite materials - A defect detection study SO RESEARCH IN NONDESTRUCTIVE EVALUATION LA English DT Article AB The ability of a thermographic imaging technique for detecting flat-bottom hole defects of various diameters and depths was evaluated in four composite systems (two types of ceramic-matrix composites, one metal-matrix composite, and one polymer-matrix composite) of interest as high-temperature structural materials. The holes ranged from 1 to 13 mm in diameter and 0.1 to 2.5 mm in depth in samples approximately 2-3 mm thick. The thermographic imaging system utilized a scanning mirror optical system and infrared (IR) focusing lens in conjunction with a mercury-cadmium-telluride infrared detector element to obtain high-resolution infrared images. High-intensity flash lamps located on the same side as the infrared camera were used to heat the samples. After heating, up to 30 images were sequentially acquired at 70-150 ms intervals. Limits of detectability based on depth and diameter of the flat-botton holes were defined for each composite material. Ultrasonic and radiographic images of the samples were obtained and compared with the thermographic images. This study was done under a nonreimbursable Space Act Agreement between NASA-Lewis Research Center and Bales Scientific, Inc., to allow several heating configurations to be evaluated in a cost-effective and timely fashion. C1 CLEVELAND STATE UNIV,CLEVELAND,OH 44115. BALES SCI INC,WALNUT CREEK,CA 94595. RP Roth, DJ (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 8 TC 7 Z9 7 U1 2 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0934-9847 J9 RES NONDESTRUCT EVAL JI Res. Nondestruct. Eval. PY 1997 VL 9 IS 3 BP 147 EP 169 DI 10.1080/09349849708968126 PG 23 WC Materials Science, Characterization & Testing SC Materials Science GA YD148 UT WOS:A1997YD14800003 ER PT S AU Baker, DN Carovillano, R AF Baker, DN Carovillano, R BE Russell, CT TI IASTP and solar-terrestrial physics SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm ID PARTICLE AB The InterAgency Solar-Terrestrial Physics (IASTP) Program developed out of an international need to obtain a comprehensive, global understanding of the generation and transfer of energy from the Sun to the near-Earth space and atmospheric environment. The goal was (and is) to establish cause and-effect relationships between key regions (and processes) within the solar-terrestrial system. The program is coordinated by the InterAgency Consultative Group (IACG) consisting of the heads of the U.S., European, Japanese, and Russian space agencies. This paper presents the IASTP program from the American viewpoint. It briefly discusses the program evolution and several of the key milestones. It describes the program as it now is, including scientific goals and mission objectives, program elements, and examples of science achievements to date. Emphasis is placed on the Global Geospace Science (GGS) portion of the overall program. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA, WASHINGTON, DC 20546 USA. RP Baker, DN (reprint author), UNIV COLORADO, ATMOSPHER & SPACE PHYS LAB, BOULDER, CO 80303 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 531 EP 538 DI 10.1016/S0273-1177(97)00436-5 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00001 ER PT S AU Ogilvie, KW Desch, MD AF Ogilvie, KW Desch, MD BE Russell, CT TI The WIND spacecraft and its early scientific results SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm ID GEOMAGNETIC-ACTIVITY; LUNAR WAKE; UPSTREAM; WAVES AB The WIND spacecraft, part of the ISTP program, was launched by NASA on 1 November 1994, to study the interplanetary medium and the effects of changes and disturbances in it upon the magnetosphere. Initially placed in a double-lunar-swing by orbit, which presently has a perigee of similar to 1.5 and an apogee of similar to 250 earth radii, the spacecraft may be inserted in 1997 into a halo orbit about the forward libration point, L1 where it will remain for at least a year. WIND carries modern instrumentation to measure the magnetic field, solar wind and hot plasma, energetic particles and low energy cosmic rays, plasma and radio waves and plasma composition, in addition to two Gamma-ray burst detectors. One of the Gamma-ray instruments is the first Russian instrument to fly on a US spacecraft. This paper describes the spacecraft and some new results in various disciplines. Published by Elsevier Science Ltd on behalf of COSPAR. RP Ogilvie, KW (reprint author), NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NR 13 TC 20 Z9 20 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 559 EP 568 DI 10.1016/S0273-1177(97)00439-0 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00004 ER PT S AU Hoffman, RA AF Hoffman, RA BE Russell, CT TI Polar - From the top down SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm AB The Polar spacecraft plays a key role in the Inter Agency Solar Terrestrial Physics Program, whose primary objective is to acquire a global understanding of the flow of energy, momentum and mass through the Sun-Earth connected system. With its high apogee over the northern polar region it is positioned to observe many phenomena associated with coupling between the solar wind, the polar magnetosphere, the geomagnetic tail and the ionosphere and atmosphere below, Its full complement of space plasma instruments and three auroral imagers represent the state-of-the-art in experimental capabilities, Participation in the Polar mission is open to all scientists, both to affect the operation of the spacecraft to collect data for particular science problems, and to lead the analysis of data pertaining to identified geophysical events. Considerable information to aid scientific participation is available on the world wide web. Published by Elsevier Science Ltd on behalf of COSPAR. RP Hoffman, RA (reprint author), NASA, GODDARD SPACE FLIGHT CTR, EXTRATERR PHYS LAB, CODE 696, GREENBELT, MD 20771 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 569 EP 573 DI 10.1016/S0273-1177(97)00440-7 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00005 ER PT S AU Schmidt, R Escoubet, CP Goldstein, ML AF Schmidt, R Escoubet, CP Goldstein, ML BE Russell, CT TI Phoenix and cluster .2. Towards a recovery from the loss of cluster SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm AB The four-spacecraft Cluster mission was to aim, for the first time ever, at 3-dimensional measurements of small-scale processes (scale lengths ranging from a few hundred to thousands of kilometres) in the magnetosphere and the solar wind. The four spacecraft were identically equipped with a state-of the-art set of instruments to measure fields, particles and the composition of the plasmas along their highly eccentric, polar orbit. The launch took place on 4 June 1996. Unfortunately, the launcher blew up at an altitude of about 3700 m due to a major malfunction of its guidance system. The spacecraft were lost in this accident. The scientific community is trying to recover from this tragic loss by actively pursuing two alternatives for a replacement mission. As an immediate step towards a recovery, the European Space Agency has already given the go-ahead to industry to assemble the Cluster spare spacecraft and negotiations for a launch vehicle are underway. The scientific community prepares the case for a decision by the relevant funding authorities to either rebuild the Cluster mission or to build for small satellites carrying as many of the original Cluster instruments as possible. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. RP Schmidt, R (reprint author), EUROPEAN SPACE AGCY, DEPT SPACE SCI, KEPLERLAAN 1, NL-2200 AG NOORDWIJK, NETHERLANDS. RI Goldstein, Melvyn/B-1724-2008 NR 1 TC 0 Z9 1 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 575 EP 579 DI 10.1016/S0273-1177(97)00441-9 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00006 ER PT S AU Domingo, V AF Domingo, V BE Russell, CT TI SOHO, its day in the sun SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm ID SOLAR; MISSION; OSCILLATIONS; SPECTROMETER AB SOHO, the Solar and Heliospheric Observatory, is a project of international cooperation between ESA and NASA to study the Sun, from its deep core to the outer corona, and the solar wind. Three helioseismology instruments are providing unique data for the study of the structure and dynamics of the solar interior, from the very deep core to the outermost layers of the convection zone. A set of five complementary remote sensing instruments, consisting of EUV, UV and visible light imagers, spectrographs and coronagraphs, give us our first comprehensive view of the outer solar atmosphere and corona, leading to a better understanding of the enigmatic coronal heating and solar wind acceleration processes. Finally, three experiments complement the remote sensing observations by making in-situ measurements of the composition and energy of the solar wind and charged energetic particles, and another instrument maps the neutral hydrogen in the heliosphere, and its dynamic change of the Solar Wind. This paper highlights some of the first results from SOHO. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. RP Domingo, V (reprint author), ESA, MAIL CODE 682, GREENBELT, MD 20771 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 581 EP 594 DI 10.1016/S0273-1177(97)00442-0 PG 14 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00007 ER PT S AU King, JH AF King, JH BE Russell, CT TI Additional spacecraft data sources contributing to the ISTP program SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm AB Descriptions of the most salient characteristics of several spacecraft and associated data relevant to the science objectives of the International Solar Terrestrial Physics (ISTP) program are given. An appendix uniformly describes all relevant spacecraft and lists URL's when available. The body of the paper gives further descriptive material concerning the subset of these spacecraft that have not been considered as ''core'' ISTP spacecraft. The core spacecraft are further described in the accompanying papers in this proceedings. Published by Elsevier Science Ltd on behalf of COSPAR. RP King, JH (reprint author), NASA, GODDARD SPACE FLIGHT CTR, NATL SPACE SCI DATA CTR, CODE 633, GREENBELT, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 595 EP 608 DI 10.1016/S0273-1177(97)00443-2 PG 14 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00008 ER PT S AU Terasawa, T Shimada, N Tsuboubouchi, K Hoshino, M Mukai, T Saito, Y Yamamoto, T Nishida, A Machida, S Kokubun, S Matsumoto, H Kojima, H Sanderson, TR Lazarus, AJ Steinberg, JT Lepping, RP AF Terasawa, T Shimada, N Tsuboubouchi, K Hoshino, M Mukai, T Saito, Y Yamamoto, T Nishida, A Machida, S Kokubun, S Matsumoto, H Kojima, H Sanderson, TR Lazarus, AJ Steinberg, JT Lepping, RP BE Russell, CT TI Particle acceleration at the interplanetary shock ahead of a large magnetic cloud on October 18, 1995: Geotail-wind collaboration SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm ID IONS AB It has been known that an efficient re-acceleration of energetic storm ions can occur between a propagating interplanetary shock and the bow shock. However, it has not been known whether a similar event could occur for electrons. In this paper, we shall report the first observational evidence of re-acceleration of energetic electrons at the front of an interplanetary shock. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 INST SPACE & ASTRONAUT SCI, SAGAMIHARA, KANAGAWA 229, JAPAN. NAGOYA UNIV, STEI, TOYAKAWA 442, JAPAN. KYOTO UNIV, DEPT GEOPHYS, KYOTO 606, JAPAN. KYOTO UNIV, RASC, UJI 611, JAPAN. EUROPEAN SPACE AGCY, EUROPEAN SPACE RES & TECHNOL CTR, DEPT SPACE SCI, NL-2200 AG NOORDWIJK, NETHERLANDS. MIT, SPACE RES CTR, CAMBRIDGE, MA 02139 USA. NASA, GODDARD SPACE FLIGHT CTR, EXTRATERR PHYS LAB, GREENBELT, MD 20771 USA. RP Terasawa, T (reprint author), UNIV TOKYO, DEPT EARTH & PLANETARY SCI, BUNKYO KU, TOKYO 113, JAPAN. NR 6 TC 2 Z9 2 U1 0 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 641 EP 644 DI 10.1016/S0273-1177(97)00451-1 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00012 ER PT S AU Larson, DE Lin, RP Ergun, RE McTiernan, JM McFadden, JP Carlson, CW Anderson, KA McCarthy, M Parks, GK Reme, H Sanderson, TR Kaiser, M Lepping, RP AF Larson, DE Lin, RP Ergun, RE McTiernan, JM McFadden, JP Carlson, CW Anderson, KA McCarthy, M Parks, GK Reme, H Sanderson, TR Kaiser, M Lepping, RP BE Russell, CT TI Using energetic electrons to probe the topology of the October 18-20, 1995 magnetic cloud SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm ID WIND SPACECRAFT; SOLAR-WIND; RECONNECTION; PLASMA AB We present similar to 0.1-10(2) keV electron observations from the 3-D Plasma and Energetic Particles experiment of a magnetic cloud which passed by the WIND spacecraft on October 18 - 20, 1995. Although the magnetic field exhibits the smooth, continuous rotation signature of a helical flux rope, the electron observations show numerous abrupt discontinuities in flux level and anisotropy within the cloud. In addition, five solar impulsive electron events, accompanied by solar type III radio bursts, were observed while the cloud was passing by the spacecraft. The electron/type III events showed that some of the cloud field lines were magnetically connected to solar active region 7912. Analysis of the velocity dispersion in the arrival times of the solar impulsive electrons provides the length of magnetic field lines. The field line length is found to be longest (similar to 4 AU) near the exterior with a minimum (similar to 1.5 AU) near the center of the cloud, consistent with a helical flux rope model. We interpret the discontinuities in electron fluxes as evidence of disconnection of magnetic field lines from the Sun. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 UNIV WASHINGTON, GEOPHYS PROGRAM, SEATTLE, WA 98195 USA. CTR ETUD SPATIALE RAYONNEMENTS, TOULOUSE, FRANCE. EUROPEAN SPACE AGCY, EUROPEAN SPACE RES & TECHNOL CTR, DEPT SPACE SCI, NL-2200 AG NOORDWIJK, NETHERLANDS. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. RP Larson, DE (reprint author), UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. NR 11 TC 10 Z9 10 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 655 EP 658 DI 10.1016/S0273-1177(97)00453-5 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00014 ER PT S AU Meziane, K Mazelle, C dUston, C Reme, H Lin, RP Carlson, CW Larson, D McFadden, JP Ergun, RE Anderson, KA Parks, GK Berdichevsky, D Lepping, RP AF Meziane, K Mazelle, C dUston, C Reme, H Lin, RP Carlson, CW Larson, D McFadden, JP Ergun, RE Anderson, KA Parks, GK Berdichevsky, D Lepping, RP BE Russell, CT TI Wind observation of gyrating-like ion distributions and low frequency waves upstream from the earth's bow shock SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm ID SUPRATHERMAL IONS; ASSOCIATION AB Several upstream ion distributions having a gyrating signature have been identified with the 3DP/PESA-High analyser on board the WIND spacecraft. These distributions are observed at distances greater than 20 R, from the Earth's bow shock. The distributions are observed in association with low frequency waves propagating quasi-parallel to the background magnetic field, By estimating the bulk velocity of the gyrating ions, we have found that the waves resonate with the particles. The observation of gyrating ions at large distances from the shock suggests their local production, probably from field-aligned beam disruption. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. UNIV WASHINGTON, GEOPHYS PROGRAM, SEATTLE, WA 98195 USA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. RP Meziane, K (reprint author), CTR ETUD SPATIALE RAYONNEMENTS, 9 AVE COLONEL ROCHE, F-31400 TOULOUSE, FRANCE. NR 10 TC 14 Z9 14 U1 0 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 703 EP 706 DI 10.1016/S0273-1177(97)00459-6 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00020 ER PT S AU Tsubouchi, K Terasawa, T Shimada, N Mukai, T Saito, Y Yamamoto, T Machida, S Kokubun, S Matsumoto, H Kojima, H Lazarus, AJ Steinberg, JT Lepping, RP AF Tsubouchi, K Terasawa, T Shimada, N Mukai, T Saito, Y Yamamoto, T Machida, S Kokubun, S Matsumoto, H Kojima, H Lazarus, AJ Steinberg, JT Lepping, RP BE Russell, CT TI Bow shock expansion caused by the magnetic cloud passage on October 18, 1995 SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm ID IMP-8 OBSERVATIONS; UNUSUAL LOCATIONS; WIND AB During Oct. 18-20, 1995, the WIND and GEOTAIL spacecraft recorded passage of a large magnetic cloud. Soon after entering into the cloud, plasma/field/wave measurements on GEOTAIL showed that the earth's bow shock appeared about 10 Re upstream from the nominal position ((9, -23, -2) Re in GSE). This shock expansion were apparently triggered by the arrival of the magnetic cloud: A high Alfven velocity within the magnetic cloud, which was due to the combination of high magnetic field intensity and low plasma density, made the magnetosonic Mach number of the bow shock small, and in turn resulted in the rapid outward expansion of the bow shock. We discuss the transient phenomena caused by this rapid expansion and sequential bow shock crossings associated with the solar wind condition inside this magnetic cloud. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 KYOTO UNIV, DEPT EARTH & PLANETARY SCI, SAKYO KU, KYOTO 606, JAPAN. NAGOYA UNIV, STEL, TOYOKAWA, AICHI 442, JAPAN. KYOTO UNIV, RASC, UJI, KYOTO 611, JAPAN. MIT, SPACE RES CTR, CAMBRIDGE, MA 02139 USA. NASA, GODDARD SPACE FLIGHT CTR, EXTRATERR PHYS LAB, GREENBELT, MD 20771 USA. RP Tsubouchi, K (reprint author), UNIV TOKYO, DEPT EARTH PLANETARY PHYS, BUNKYO KU, TOKYO 113, JAPAN. NR 11 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 725 EP 728 DI 10.1016/S0273-1177(97)00462-6 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00023 ER PT S AU Phan, TD Larson, D Moyer, M McFadden, JP Lin, RP Carlson, CW McCarthy, M Parks, GK Reme, H Sanderson, TR Lepping, RP Paularena, KI AF Phan, TD Larson, D Moyer, M McFadden, JP Lin, RP Carlson, CW McCarthy, M Parks, GK Reme, H Sanderson, TR Lepping, RP Paularena, KI BE Russell, CT TI The low-latitude flank magnetosheath, magnetopause and boundary layer: Wind observations SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm ID DAYSIDE MAGNETOPAUSE; MAGNETIC-FIELD; PLASMA AB This paper presents highlights of a survey of the WIND spacecraft crossings of the low-latitude dawn and dusk magnetosheath, magnetopause (MP), and the low-latitude boundary layer (LLBL). In the magnetosheath the plasma flow direction is found to be remarkably steady, irrespective of the local magnetic field direction. In the LLBL, the flow direction in a substantial portion of the region is nearly aligned with that in the magnetosheath, while the flow tangential to the MP slows down gradually across the LLBL. This flow characteristic seems to be independent of the external magnetosheath magnetic field orientation, and may suggest that the LLBL is locally coupled to the adjacent magnetosheath, irrespective of the magnetic shear across the local MP. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 UNIV WASHINGTON, GEOPHYS PROGRAM, SEATTLE, WA 98195 USA. CTR ETUD SPATIALE RAYONNEMENTS, TOULOUSE, FRANCE. EUROPEAN SPACE AGCY, ESTEC, DEPT SPACE SCI, NL-2200 AG NOORDWIJK, NETHERLANDS. NASA, GODDARD SPACE FLIGHT CTR, EXTRATERR PHYS LAB, GREENBELT, MD 20771 USA. MIT, CTR SPACE RES, CAMBRIDGE, MA 02139 USA. RP Phan, TD (reprint author), UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 809 EP 812 DI 10.1016/S0273-1177(97)00513-9 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00032 ER PT S AU Sandahl, I Lundin, R Yamauchi, M Eklund, U Safrankova, J Nemecek, Z Kudela, K Lepping, RP Lin, RP Lutsenko, VN Sauvaud, JA AF Sandahl, I Lundin, R Yamauchi, M Eklund, U Safrankova, J Nemecek, Z Kudela, K Lepping, RP Lin, RP Lutsenko, VN Sauvaud, JA BE Russell, CT TI Cusp and boundary layer observations by interball SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm AB Interball Tail Probe was launched on August 2, 1995 together with its subsatellite MAGION-4 into a highly elliptical orbit with apogee at 31 R-E and inclination 63 degrees. During the course of one year all local times are visited, In this paper we will present initial results obtained from measurements in the cusp, mantle and eveningside plasma sheet in January, 1996, It is found that the cusp was well defined and persistent at altitudes of 4-10 R-E, In one case both the main satellite and the subsatellite were in the cusp proper for two uninterrupted hours. We believe this to be the first ever multi-point satellite observation of the high-altitude cusp. The data indicate that the cusp was very stable with a wide entry area and that plasma entry took place at high latitudes rather than at the subsolar point. Pressure pulses, possibly due to Alfven waves were found, Sunward and antisunward moving plasma was measured simultaneously during a case of northward IMF but no convection was discovered, Plenty of plasma of cusp/magnetosheath type was also found mixed with plasma sheet plasma both equatorward of the cusp and in the eveningside plasma sheet. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 SWEDISH INST SPACE PHYS, S-98128 KIRUNA, SWEDEN. CHARLES UNIV, FAC MATH & PHYS, CR-18000 PRAGUE 8, CZECH REPUBLIC. SLOVAK ACAD SCI, INST EXPT PHYS, KOSICE 04353, SLOVAKIA. NASA, GODDARD SPACE FLIGHT CTR, EXTRATERR PHYS LAB, GREENBELT, MD 20771 USA. UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. MOSCOW SPACE RES INST, MOSCOW 117810, RUSSIA. CTR ETUD SPATIALE RAYONNEMENTS, F-31029 TOULOUSE, FRANCE. RP Sandahl, I (reprint author), INST SPACE & ASTRONAUT SCI, 3-1-1 YOSHINODAI, SAGAMIHARA, KANAGAWA 229, JAPAN. RI Eklund, Ulrik/F-9264-2013 OI Eklund, Ulrik/0000-0001-8943-6166 NR 5 TC 19 Z9 19 U1 0 U2 4 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 823 EP 832 DI 10.1016/S0273-1177(97)00515-2 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00034 ER PT S AU Brittnacher, M Spann, J Parks, G Germany, G AF Brittnacher, M Spann, J Parks, G Germany, G BE Russell, CT TI Auroral observations by the polar ultraviolet imager (UVI) SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm ID TERRESTRIAL PHYSICS MISSION; SPACECRAFT; EMISSIONS; ATMOSPHERE; PARTICLE AB The Ultraviolet Imager (UVI) experiment on the Polar spacecraft has been operating since 21 March 1996, and is returning high quality global images of auroral activity. This article presents first images of global aurora from the UVI experiment. We discuss the capabilities of the UVI instrument and how the data can be used to study substorm physics, A preliminary survey of 80 days of UVI images indicates that the dayside auroral activity is intense and dynamic, and occurs as frequently as the nightside activity. These features are demonstrated using the images obtained on 9 April 1995 when the UVI observed simultaneous dayside and nightside activities. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA, GEORGE C MARSHALL SPACE FLIGHT CTR, SPACE SCI LAB, HUNTSVILLE, AL 35812 USA. UNIV ALABAMA, OPT AERON LAB, HUNTSVILLE, AL 35899 USA. RP Brittnacher, M (reprint author), UNIV WASHINGTON, GEOPHYS PROGRAM, SEATTLE, WA 98195 USA. NR 20 TC 11 Z9 11 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 1037 EP 1042 DI 10.1016/S0273-1177(97)00558-9 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00057 ER PT S AU Papitashvili, VO Papitashvili, NE King, JH AF Papitashvili, VO Papitashvili, NE King, JH BE Russell, CT TI Magnetospheric geomagnetic coordinates for space physics data presentation and visualization SO RESULTS OF THE IASTP PROGRAM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT D0.1 Symposium of COSPAR Scientific Commission D on Results of the IASTP Program at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, Program Comm ID MODEL AB Corrected geomagnetic coordinates, which account for the multipolar geomagnetic field, are frequently used to organize the ionospheric-altitude data. However, realistic organization of data measured simultaneously in the magnetosphere and ionosphere in a some sort of magnetic coordinate system requires a combination of the high-altitude external magnetic fields and the multipolar low-altitude field. Such combinations have been non-existent in the past. A new magnetospheric geomagnetic coordinate system is introduced providing such a combination. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 NASA, GODDARD SPACE FLIGHT CTR, NATL SPACE SCI DATA CTR, GREENBELT, MD 20771 USA. RP Papitashvili, VO (reprint author), UNIV MICHIGAN, SPACE PHYS RES LAB, ANN ARBOR, MI 48109 USA. OI Papitashvili, Vladimir/0000-0001-6955-4894 NR 10 TC 1 Z9 1 U1 0 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043301-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 4-5 BP 1097 EP 1100 DI 10.1016/S0273-1177(97)00565-6 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ97P UT WOS:A1997BJ97P00064 ER PT B AU Namkung, M Nath, S Fulton, JP AF Namkung, M Nath, S Fulton, JP BE Thompson, DO Chimenti, DE TI Characteristics of frequency domain spectrum of self-nulling eddy current probe output SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 16A AND 16B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 23rd Symposium on Quantitative Nondestructive Evaluation CY JUL 28-AUG 02, 1996 CL BRUNSWICK, ME SP Iowa State Univ, Ctr NDE, Amer Soc Nondestruct Testing, US DOE, Ames Lab, FAA, NIST, Natl Sci Fdn, Ind Univ Cooperat Res Ctr Program RP Namkung, M (reprint author), NASA,LANGLEY RES CTR,MS 231,HAMPTON,VA 23681, USA. RI Namkung, Min/E-1533-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 BN 0-306-45597-8 J9 REV PROG Q PY 1997 VL 16 BP 997 EP 1003 PN A&B PG 7 WC Materials Science, Characterization & Testing SC Materials Science GA BJ03K UT WOS:A1997BJ03K00130 ER PT B AU Wincheski, B Nath, S Sharma, S Simpson, J AF Wincheski, B Nath, S Sharma, S Simpson, J BE Thompson, DO Chimenti, DE TI Optimization of Self-Nulling Eddy Current Probe for the detection of shallow fatigue cracks SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 16A AND 16B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 23rd Symposium on Quantitative Nondestructive Evaluation CY JUL 28-AUG 02, 1996 CL BRUNSWICK, ME SP Iowa State Univ, Ctr NDE, Amer Soc Nondestruct Testing, US DOE, Ames Lab, FAA, NIST, Natl Sci Fdn, Ind Univ Cooperat Res Ctr Program RP Wincheski, B (reprint author), NASA,LANGLEY RES CTR,AS&M,MS 231,107 RES DR,HAMPTON,VA 23666, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 BN 0-306-45597-8 J9 REV PROG Q PY 1997 VL 16 BP 1013 EP 1020 PN A&B PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA BJ03K UT WOS:A1997BJ03K00132 ER PT B AU Roth, DJ Bodis, JR Bishop, C AF Roth, DJ Bodis, JR Bishop, C BE Thompson, DO Chimenti, DE TI Capability of single-sided transient thermographic imaging method for detection of flat bottom hole defects in high-temperature composite materials SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 16A AND 16B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 23rd Symposium on Quantitative Nondestructive Evaluation CY JUL 28-AUG 02, 1996 CL BRUNSWICK, ME SP Iowa State Univ, Ctr NDE, Amer Soc Nondestruct Testing, US DOE, Ames Lab, FAA, NIST, Natl Sci Fdn, Ind Univ Cooperat Res Ctr Program RP Roth, DJ (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 BN 0-306-45597-8 J9 REV PROG Q PY 1997 VL 16 BP 1127 EP 1134 PN A&B PG 8 WC Materials Science, Characterization & Testing SC Materials Science GA BJ03K UT WOS:A1997BJ03K00147 ER PT J AU Kawamura, S Abramovici, A Zucker, ME AF Kawamura, S Abramovici, A Zucker, ME TI Improved multistage wide band laser frequency stabilization SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID MODULATION SPECTROSCOPY; OPTICAL-RESONATOR AB Suppression of laser frequency fluctuations is an essential technology for planned interferometric detectors for astrophysical gravitational waves. Because of the low degree of residual frequency noise which is ultimately required, control topologies comprising two or more cascaded loops are favored. One such topology, used in the Laser Interferometer Gravitational-Wave Observatory 40 m interferometer, relied on electro-optic Pockels cell phase correction as a fast actuator for the final stage. This actuation method proved susceptible to spurious amplitude modulation effects, which provided an unintended parasitic feedback path. An alternate arrangement, which achieves comparably effective frequency stabilization without using a phase correcting Pockels cell, was introduced and successfully tested. (C) 1997 American Institute of Physics. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. MIT,CAMBRIDGE,MA 02139. RP Kawamura, S (reprint author), CALTECH,M-S 51-33,PASADENA,CA 91125, USA. NR 12 TC 18 Z9 18 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JAN PY 1997 VL 68 IS 1 BP 223 EP 229 DI 10.1063/1.1147813 PN 1 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WD236 UT WOS:A1997WD23600042 ER PT J AU Waller, WH AF Waller, WH BE Franco, J Terlevich, R Serrano, A TI Starburst anatomy: Stellar and nebular properties of nearby giant H II regions SO REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA: SERIE DE CONFERENCIAS, VOL 6, MAYO 1997: 1ST GUILLERMO HARO CONFERENCE ON ASTROPHYSICS - STARBURST ACTIVITY IN GALAXIES SE REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA, SERIE DE CONFERENCIAS LA English DT Proceedings Paper CT 1st Guillermo Haro Conference on Astrophysics - Starburst Activity in Galaxies CY APR 29-MAY 03, 1996 CL PUEBLA, MEXICO SP Univ Nacl Autonoma Mexico, Inst Astron DE galaxies, starburst; ISM, dust, extinction; H II regions; stars, early type; ultraviolet, stars AB Resolution of nearby giant H II regions into their stellar and nebular constituents provides fundamental insights for interpreting more distant and powerful starburst activity. Photometry and spectroscopy of ionizing clusters in the Galaxy, LMC, and SMC reveal no significant relation between metallicity and the slope of the power-law initial stellar mass function (IMF). HST/WFPC2 photometry of 3 giant H II regions in M33 also does not show any consistent trend involving metal abundance and IMF slope -contrary to predictions based on emission-line ratios. The upper stellar mass limit appears to be constrained more by cluster age than by anything else. The ionizing luminosities from some of the resolved stellar populations are insufficient to account for the ionization rates inferred from measurements of the composite (integrated) H alpha emission. Absorption of stellar EUV emission by nebular dust grains would only amplify these photoionizing shortfalls. Leakage of ionizing photons from the HII regions would further exacerbate the situation. What then is providing the additional ionization? Prospects for higher stellar EUV luminosities and/or alternative sources of nebular ionization (e.g., shocks) are evaluated with this question in mind. RP Waller, WH (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,HUGHES STX CORP,CODE 681,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVERSIDAD NACIONAL AUTONOMA MEXICO INSTITUTO ASTRONOMIA PI MEXICO CITY PA APARTADO POSTAL 70-264, MEXICO CITY 04510, MEXICO SN 1405-2059 J9 REV MEX AST ASTR PY 1997 VL 6 BP 123 EP 125 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ20T UT WOS:A1997BJ20T00030 ER PT S AU Borne, KD Appleton, P Lucas, RA Struck, C Schultz, AB AF Borne, KD Appleton, P Lucas, RA Struck, C Schultz, AB BE Franco, J Terlevich, R Serrano, A TI Collision-induced star formation in ring galaxies SO REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA: SERIE DE CONFERENCIAS, VOL 6, MAYO 1997: 1ST GUILLERMO HARO CONFERENCE ON ASTROPHYSICS - STARBURST ACTIVITY IN GALAXIES SE REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA, SERIE DE CONFERENCIAS LA English DT Proceedings Paper CT 1st Guillermo Haro Conference on Astrophysics - Starburst Activity in Galaxies CY APR 29-MAY 03, 1996 CL PUEBLA, MEXICO SP Univ Nacl Autonoma Mexico, Inst Astron DE galaxies, individual, cartwheel; galaxies, interactions; galaxies, starburst; stars, formation AB We present results from HST WFPC2 B- and I-band imaging observations of the ''Cartwheel'' ring galaxy and its two nearest companions. The combination of images has been used to study and to characterize the intense star formation activity in and around the expanding ring density wave, in the Cartwheel's ''spokes'' region, in the nucleus of the galaxy, and in the two companions. Fine structure is observed down to the resolution limit of the HST images and very young compact objects (perhaps massive young clusters) are found throughout the star-forming regions. The primary ring around the galaxy is full of loops, filaments, bubbles, and blue star-forming knots, which are well resolved in our images. The ''spokes'' of the Cartwheel, which are interior to the primary ring, are clearly visible, though their structure is somewhat more amorphous than that of the outer ring, suggesting that indeed the massive star formation behind the expanding density wave has subsided and the stellar associations that comprise the spokes are dispersing as they age. RP Borne, KD (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HUGHES STX,GREENBELT,MD 20771, USA. OI Struck, Curtis/0000-0002-6490-2156; Appleton, Philip/0000-0002-7607-8766 NR 0 TC 6 Z9 6 U1 0 U2 0 PU UNIVERSIDAD NACIONAL AUTONOMA MEXICO INSTITUTO ASTRONOMIA PI MEXICO CITY PA APARTADO POSTAL 70-264, MEXICO CITY 04510, MEXICO SN 1405-2059 J9 REV MEX AST ASTR PY 1997 VL 6 BP 141 EP + PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ20T UT WOS:A1997BJ20T00034 ER PT J AU Mushotzky, R AF Mushotzky, R BE Franco, J Terlevich, R Serrano, A TI Recent ASCA results on active galaxies SO REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA: SERIE DE CONFERENCIAS, VOL 6, MAYO 1997: 1ST GUILLERMO HARO CONFERENCE ON ASTROPHYSICS - STARBURST ACTIVITY IN GALAXIES SE REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA, SERIE DE CONFERENCIAS LA English DT Proceedings Paper CT 1st Guillermo Haro Conference on Astrophysics - Starburst Activity in Galaxies CY APR 29-MAY 03, 1996 CL PUEBLA, MEXICO SP Univ Nacl Autonoma Mexico, Inst Astron DE galaxies, active; galaxies, starburst; X-ray, galaxies AB The launch of ASCA has radically changed the observational situation in high energy astrophysics. With an energy resolution 6 times better than previously available at E > 2 keV, E/Delta E similar to 50 at 6 keV, a bandwidth from 0.4-10 keV, and an increase in sensitivity of a factor of 100 at E > 2 keV compared to previous missions, combined with true X-ray spectral imaging, ASCA has enabled a fundamentally new class of observations. RP Mushotzky, R (reprint author), GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU UNIVERSIDAD NACIONAL AUTONOMA MEXICO INSTITUTO ASTRONOMIA PI MEXICO CITY PA APARTADO POSTAL 70-264, MEXICO CITY 04510, MEXICO SN 1405-2059 J9 REV MEX AST ASTR PY 1997 VL 6 BP 213 EP 217 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ20T UT WOS:A1997BJ20T00052 ER PT S AU Roberts, DA Gosling, JT AF Roberts, DA Gosling, JT BE Habbal, SR TI In situ measurement requirements for a solar probe SO ROBOTIC EXPLORATION CLOSE TO THE SUN: SCIENTIFIC BASIS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Scientific Basis for Robotic Exploration Close to the Sun CY APR 15-18, 1996 CL MARLBOROUGH, MA SP Smithsonian Astrophys Observ, NASA AB We present the rationale and in situ, measurement requirements for a near-Sun mission intended to answer the central questions of the heating of the corona and the acceleration of the solar wind. These conclusions are based on panel discussions and presentations at the Marlboro workshop. We have in mind not a ''minimum'' mission [1], but rather one that is constrained but feasible within the current mass and telemetry rate restrictions. To distinguish between thermal, wave-driven, and microflare-driven models, the measurements must determine wave levels in a broad range of frequencies, resolve fine-scale structures, find the energetic particle content and its variations, and determine the bulk properties of a few species with detailed distributions for at least electrons and protons. We find that the in situ. measurements needed to answer the main questions are similar to those proposed previously [4] (magnetic field, plasma, high-energy particles, and plasma wave instruments) but without neutron and dust experiments. Telemetry and mass constraints will be significant but should not be prohibitive. RP Roberts, DA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 692,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-618-2 J9 AIP CONF PROC PY 1997 IS 385 BP 3 EP 8 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BH28X UT WOS:A1997BH28X00001 ER PT S AU Neugebauer, M Ruzmaikin, A McComas, DJ AF Neugebauer, M Ruzmaikin, A McComas, DJ BE Habbal, SR TI Wavelet analysis of the structure of microstreams in the polar solar wind SO ROBOTIC EXPLORATION CLOSE TO THE SUN: SCIENTIFIC BASIS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Scientific Basis for Robotic Exploration Close to the Sun CY APR 15-18, 1996 CL MARLBOROUGH, MA SP Smithsonian Astrophys Observ, NASA AB The fluctuations in solar-wind velocity measured by the Ulysses spacecraft above the polar regions of the Sun are organized into structures called microstreams. The application of wavelet transformations to the Ulysses data reveals the scales and positions of the microstreams and their association with variations in the helium content of the solar wind. It is concluded that the microstreams must have their origin in solar structures associated with the acceleration of the solar wind with little modification resulting from interplanetary phenomena. RP Neugebauer, M (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-618-2 J9 AIP CONF PROC PY 1997 IS 385 BP 41 EP 46 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BH28X UT WOS:A1997BH28X00005 ER PT S AU Sittler, EC Chornay, D Keller, J Ogilvie, KW Roberts, A AF Sittler, EC Chornay, D Keller, J Ogilvie, KW Roberts, A BE Habbal, SR TI Observational requirements for in situ plasma instrumentation for solar probe SO ROBOTIC EXPLORATION CLOSE TO THE SUN: SCIENTIFIC BASIS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Scientific Basis for Robotic Exploration Close to the Sun CY APR 15-18, 1996 CL MARLBOROUGH, MA SP Smithsonian Astrophys Observ, NASA AB An MHD model of a polar coronal hole based on white light coronagraph observations is used to make predictions of plasma observations in the spacecraft frame along the spacecraft trajectory for the Solar Probe Mission. This study will identify the design requirements for in situ plasma instrumentation with regard to field-of-view issues, energy coverage, instrument geometric factors and mass separation requirements. The instrument design must consider the need to accurately observe MHD wave motions in the plasma and electron heat flux both of which are thought to play an important role with regard to the coronal expansion. These requirements emphasize the need for 3-D plasma measurements and the requirement for nadir viewing. RP Sittler, EC (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 692,GREENBELT,MD 20771, USA. RI Keller, John/I-5097-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-618-2 J9 AIP CONF PROC PY 1997 IS 385 BP 59 EP 66 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BH28X UT WOS:A1997BH28X00007 ER PT S AU Woo, R AF Woo, R BE Habbal, SR TI Morphology of the solar corona from radio occultation measurements: Implications for solar probe SO ROBOTIC EXPLORATION CLOSE TO THE SUN: SCIENTIFIC BASIS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Scientific Basis for Robotic Exploration Close to the Sun CY APR 15-18, 1996 CL MARLBOROUGH, MA SP Smithsonian Astrophys Observ, NASA AB While ray-like structures in the solar corona have been observed in white-light coronagraph and solar eclipse images for many years, recent progress using radio occultation measurements have revealed a plethora of structures extending to sizes as small as 1 km - three orders of magnitude smaller than those observed in white-light and eclipse measurements. Advances have also been made in understanding the variation of large- and small-scale structures in the extended corona and their organization by the heliospheric current sheet. This paper summarizes the latest results on the morphology of the near-Sun solar wind obtained from radio occultation measurements, and their impact on the planning and conduct of a mission to the Sun such as Solar Probe. RP Woo, R (reprint author), CALTECH,JET PROP LAB,MS 238-725,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-618-2 J9 AIP CONF PROC PY 1997 IS 385 BP 85 EP 95 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BH28X UT WOS:A1997BH28X00010 ER PT S AU Guhathakurta, M Fisher, R AF Guhathakurta, M Fisher, R BE Habbal, SR TI Importance of white-light of observations of the extended corona SO ROBOTIC EXPLORATION CLOSE TO THE SUN: SCIENTIFIC BASIS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Scientific Basis for Robotic Exploration Close to the Sun CY APR 15-18, 1996 CL MARLBOROUGH, MA SP Smithsonian Astrophys Observ, NASA AB White-light observations of the extended K-corona are an integral part of our understanding of the solar wind phenomenon and the coronal heating process. In this paper we outline why white-light observations of the corona are indispensible for establishing the connection between the sun and the inner/outer heliosphere and why inclusion of such an observational capability as a context instrument is crucial for the Solar Probe mission. RP Guhathakurta, M (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 682,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-618-2 J9 AIP CONF PROC PY 1997 IS 385 BP 121 EP 128 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BH28X UT WOS:A1997BH28X00014 ER PT S AU Roberts, DA AF Roberts, DA BE Habbal, SR TI The role of waves, turbulence, and structures in heating and accelerating the solar wind SO ROBOTIC EXPLORATION CLOSE TO THE SUN: SCIENTIFIC BASIS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Scientific Basis for Robotic Exploration Close to the Sun CY APR 15-18, 1996 CL MARLBOROUGH, MA SP Smithsonian Astrophys Observ, NASA AB Spacecraft measurements and MHD simulations strongly suggest the following conclusions on the role of waves, turbulence, and structures in the heating and acceleration of the solar wind: If waves heat and accelerate the solar wind, whether or not by a turbulence mechanism, these waves are not those observed in situ at 0.3 AU and beyond; the relevant waves will have been mostly dissipated by then. The solar surface is not likely to be the source of waves that heat or accelerate, because the surface motions do not produce flat enough spectra. Finally, the wave heating and acceleration picture is a highly constrained, finely tuned version of the ''microflare'' scenario because a wave source in the lower coronal or below must tap magnetic field structures or bulk how energy and microflares are the most natural source of these. The main problem for wave and related models is that of finding an energy source for short time-scale fluctuations. RP Roberts, DA (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-618-2 J9 AIP CONF PROC PY 1997 IS 385 BP 185 EP 188 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BH28X UT WOS:A1997BH28X00021 ER PT S AU Ofman, L Davila, JM AF Ofman, L Davila, JM BE Habbal, SR TI Solitary waves in coronal holes - Predicted signatures close to the sun SO ROBOTIC EXPLORATION CLOSE TO THE SUN: SCIENTIFIC BASIS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Scientific Basis for Robotic Exploration Close to the Sun CY APR 15-18, 1996 CL MARLBOROUGH, MA SP Smithsonian Astrophys Observ, NASA AB Coronal holes are well known sources of the high speed solar wind, however, the exact acceleration mechanism of the wind is still unknown. We find that solitary waves may be generated in coronal holes nonlinearly by Alfven waves. The solitary waves may efficiently accelerate the fast solar wind in addition to thermal conduction. We solve numerically the time-dependent, nonlinear, resistive 2.5-D MHD equations in spherical geometry with aximuthal symmetry to model solar wind acceleration by waves in coronal holes. Torsional Alfven waves are driven at the base of the model coronal hole and propagate into the corona. Ohmic heating layers are found to occur at the coronal hole boundaries due to phase-mixing of the torsional Alfven waves. The nonlinear coupling of the perpendicular (to the background magnetic field) components of the velocity and the magnetic field to the radial component of the momentum equation leads to the acceleration of the solar wind in the radial direction and to the generation of solitary waves. The solitary wave phase velocity was found to be above the sound speed in the coronal hole, with the driving Alfven wave amplitude upsilon(d) approximate to 25 km s(-1), and plasma beta = 2.5%. We discuss the implication of our results to the proposed in-situ observations in the region r < 10R(s) with the future solar probe mission. RP Ofman, L (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,CODE 6821,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-618-2 J9 AIP CONF PROC PY 1997 IS 385 BP 227 EP 234 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BH28X UT WOS:A1997BH28X00027 ER PT S AU Randolph, JE Turner, PR AF Randolph, JE Turner, PR BE Habbal, SR TI The Solar Probe mission and system design history SO ROBOTIC EXPLORATION CLOSE TO THE SUN: SCIENTIFIC BASIS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Scientific Basis for Robotic Exploration Close to the Sun CY APR 15-18, 1996 CL MARLBOROUGH, MA SP Smithsonian Astrophys Observ, NASA AB This is an invited overview of the history of the Solar Probe mission and system design that includes a review of some of the basic mission requirements, as well as a review of the evolution of the spacecraft designs over the past two decades. The mission requirements reflect the recent changes in scientific objectives and instrument design concepts. Another recent mission change is the new joint design concept with the Russians. They will design a spacecraft called Plamya to arrive simultaneously at perihelion at a radial distance of 10 solar radii (versus 4 solar radii for the U.S. Solar Probe). The U.S. Solar Probe design has evolved from an ancient ''Galileo'' class spacecraft with a mass of over 1000 kg to a modern ''lightsat'' class spacecraft with a mass of less than 200 kg. The project cost has been reduced by almost an order of magnitude during this history. RP Randolph, JE (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 AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-618-2 J9 AIP CONF PROC PY 1997 IS 385 BP 243 EP 253 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BH28X UT WOS:A1997BH28X00029 ER PT S AU Tsurutani, BT Vaisberg, O AF Tsurutani, BT Vaisberg, O BE Habbal, SR TI The Solar Probe mission and comments on plasma wave observations SO ROBOTIC EXPLORATION CLOSE TO THE SUN: SCIENTIFIC BASIS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Workshop on Scientific Basis for Robotic Exploration Close to the Sun CY APR 15-18, 1996 CL MARLBOROUGH, MA SP Smithsonian Astrophys Observ, NASA AB We review the current FIRE plans, both the U.S. and Russian spacecraft, developed under the Gore-Chernomyrdin agreement. We also make comments on specific requirements for plasma wave instruments for FIRE. RP Tsurutani, BT (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 AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-618-2 J9 AIP CONF PROC PY 1997 IS 385 BP 255 EP 264 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BH28X UT WOS:A1997BH28X00030 ER PT S AU Rosekind, MR Gregory, KB Miller, DL Oyung, RL Neri, DF Dinges, DF AF Rosekind, MR Gregory, KB Miller, DL Oyung, RL Neri, DF Dinges, DF GP FLIGHT SAFETY FDN TI Sleep quantity and quality of augmented long-haul flight crews in on-board crew rest facilities SO SAFETY IN A CHANGING ENVIRONMENT: PROCEEDINGS OF THE 42ND ANNUAL CORPORATE AVIATION SAFETY SEMINAR (CASS) SE PROCEEDINGS - CORPORATE AVIATION SAFETY SEMINAR LA English DT Proceedings Paper CT 42nd Annual Corporate Aviation Safety Seminar (CASS) - Safety in a Changing Environment CY APR 29-MAY 01, 1997 CL PHOENIX, AZ SP Flight Safety Fdn, Associated Aviat Underwriters, ENRON, FACTS Training Int, MedAire Inc, K C Aviation Inc, Dallas Airmotive, Allied Signal, AVEDSOFT, SimuFlite, Business Aircraft, Securaplane, DASSAULT Falcon Jet, GE, Collins Avionics, A Continuum Innovat, Heartstream, Gulfstream, Natl Businessaircraft Assoc Inc, A V DATA 2000, ICEMAN, GALAXY, Honeywell, Multi Serv, IHS Transport Data Solut, R Dixon Speas Associates, Du Pont, Bell Helicopter, TEXTRON, FlightSafety Int, Mobil, XEROX, Boeing Business Jets, USAIG, Amer Express, Signature, Chrysler Pentastar Aviat, Rols royce RP Rosekind, MR (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU FLIGHT SAFETY FOUNDATION PI ALEXANDRIA PA 601 MADISON STREET STE 300, ALEXANDRIA, VA 22314 SN 0736-4709 J9 P CORP AVIAT SAF SEM PY 1997 BP 133 EP 134 PG 2 WC Engineering, Aerospace; Ergonomics SC Engineering GA BJ55B UT WOS:A1997BJ55B00013 ER PT J AU Neri, DF Rosekind, MR Co, EL Gregory, KB Miller, DL AF Neri, DF Rosekind, MR Co, EL Gregory, KB Miller, DL GP FLIGHT SAFETY FDN TI Research on the effects of fatigue within the corporate/business aircraft environment SO SAFETY - THE GLOBAL CHALLENGE: PROCEEDINGS OF THE 9TH ANNUAL EUROPEAN AVIATION SAFETY SEMINAR (EASS) LA English DT Proceedings Paper CT 9th Annual European Aviation Safety Seminar on Safety - The Global Challenge CY MAR 03-05, 1997 CL AMSTERDAM, NETHERLANDS SP Flight Safety Fdn, Airbus Ind, Computed Air Serv VIEWIT, Business Aircraft, Amsterdam Airport Schiphol, Flight Int, GE, A V Date 2000, DASSAULT Int, Schreiner Airways, SimuFlight, FlightSafety Int, CROSSAIR, KLM Cityhopper, Helikopter Serv, SAAB, NLR, FOKKER Serv RP Neri, DF (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FLIGHT SAFETY FOUNDATION PI ALEXANDRIA PA 601 MADISON STREET STE 300, ALEXANDRIA, VA 22314 PY 1997 BP 295 EP 296 PG 2 WC Engineering, Aerospace; Ergonomics SC Engineering GA BJ55C UT WOS:A1997BJ55C00020 ER PT B AU Rosekind, MR Co, EL Gregory, KB Miller, DL Neri, DF AF Rosekind, MR Co, EL Gregory, KB Miller, DL Neri, DF GP FLIGHT SAFETY FDN TI A survey of fatigue factors in corporate/executive aviation operations SO SAFETY - THE GLOBAL CHALLENGE: PROCEEDINGS OF THE 9TH ANNUAL EUROPEAN AVIATION SAFETY SEMINAR (EASS) LA English DT Proceedings Paper CT 9th Annual European Aviation Safety Seminar on Safety - The Global Challenge CY MAR 03-05, 1997 CL AMSTERDAM, NETHERLANDS SP Flight Safety Fdn, Airbus Ind, Computed Air Serv VIEWIT, Business Aircraft, Amsterdam Airport Schiphol, Flight Int, GE, A V Date 2000, DASSAULT Int, Schreiner Airways, SimuFlight, FlightSafety Int, CROSSAIR, KLM Cityhopper, Helikopter Serv, SAAB, NLR, FOKKER Serv RP Rosekind, MR (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU FLIGHT SAFETY FOUNDATION PI ALEXANDRIA PA 601 MADISON STREET STE 300, ALEXANDRIA, VA 22314 PY 1997 BP 297 EP 298 PG 2 WC Engineering, Aerospace; Ergonomics SC Engineering GA BJ55C UT WOS:A1997BJ55C00021 ER PT J AU Goldsworthy, B Rutan, B Hiel, C AF Goldsworthy, B Rutan, B Hiel, C TI From complete chaos to clear concepts .3. SO SAMPE JOURNAL LA English DT Article AB The fundamental message is that engineers should use more creative thinking when designing composite structures. It is important for a design engineer not to be limited to traditional methods, which slow you down, and the standards and procedures, which usually only tell you ''what not to do!'' Creative engineering design, enriched by comprehension, imagination, and proper judgement, will provide the gateway for tapping the full potential of composite materials. C1 W BRANDT GOLDSWORTHY & ASSOCIATES INC,TORRANCE,CA 90505. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. RP Goldsworthy, B (reprint author), SCALED COMPOSITES INC,HANGAR 78,MOJAVE AIRPORT,CA 93501, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 SN 0091-1062 J9 SAMPE J JI Sampe J. PD JAN-FEB PY 1997 VL 33 IS 1 BP 17 EP 25 PG 9 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WA621 UT WOS:A1997WA62100005 ER PT S AU Chang, ATC Chiu, LS AF Chang, ATC Chiu, LS BE Ellingson, RG TI Uncertainty in satellite rainfall estimates: Time series comparison SO SATELLITE DATA APPLICATIONS: WEATHER AND CLIMATE SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT A0.1 Symposium of COSPAR Scientific Commission A, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP European Org Exploitat Meteorol Satellites, Natl Ocean & Atmospher Adm, Natl Environm Satellite Data & Informat Serv ID OCEANIC PRECIPITATION; MICROWAVE; CLIMATOLOGIES; MSU AB We examined nine satellite rainfall algorithms and compared the rain fields produced from these algorithms for the period of August 1987 to December 1988. Preliminary results show algorithms which use the same satellite sensor data tend to be similar, suggesting the importance of sampling. Oceanic global mean rainfall ranges from 2.7 to 3.6 mm/d. The variability in zonal mean rain rate is about 1.5-2 mm/d for these algorithms. C1 GEN SCI CORP, SAIC, LAUREL, MD 20707 USA. RP Chang, ATC (reprint author), NASA, GODDARD SPACE FLIGHT CTR, HYDROL SCI BRANCH, GREENBELT, MD 20771 USA. NR 13 TC 2 Z9 3 U1 0 U2 3 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043100-3 J9 ADV SPACE RES-SERIES PY 1997 VL 19 IS 3 BP 469 EP 472 DI 10.1016/S0273-1177(97)00056-2 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BH75B UT WOS:A1997BH75B00009 ER PT S AU Schubert, SD Min, W Takacs, L Joiner, J AF Schubert, SD Min, W Takacs, L Joiner, J BE Ellingson, RG TI Reanalysis of historical observations and its role in the development of the Goddard EOS climate Data Assimilation System SO SATELLITE DATA APPLICATIONS: WEATHER AND CLIMATE SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT A0.1 Symposium of COSPAR Scientific Commission A, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP European Org Exploitat Meteorol Satellites, Natl Ocean & Atmospher Adm, Natl Environm Satellite Data & Informat Serv ID MODELS; EQUATIONS AB The Data Assimilation Office at NASA's Goddard Space Flight Center is currently producing a global multi-year reanalysis of historical observations for the period 1980-1994. The assimilation employs a fixed analysis,system (version 1 of the Goddard Earth Observing System or GEOS-1). This eliminates artificial climate signals resulting from system modifications typically found in operational analyses. The GEOS-1 reanalysis has proven to be an important research tool for studying a number of Earth Science problems on time scales ranging from diurnal to interannual. The long record of the reanalysis also allows a more direct study of the role of the observations in the assimilation process. In particular, we examine here the degree to which the observed boundary conditions force the climate variations of the assimilation. We also discuss the near term development of the GEOS system and how the process of data assimilation naturally lends itself to assessing model deficiencies. C1 NASA, GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC, DATA ASSIMILAT OFF,GODDARD LAB ATMOSPHERES, GREENBELT, MD 20771 USA. NASA, GODDARD SPACE FLIGHT CTR,GEN SCI CORP, DATA ASSIMILAT OFF,GODDARD LAB ATMOSPHERES, GREENBELT, MD 20771 USA. RP Schubert, SD (reprint author), NASA, GODDARD SPACE FLIGHT CTR, GODDARD LAB ATMOSPHERES, DATA ASSIMILAT OFF, CODE 910-3, GREENBELT, MD 20771 USA. RI Joiner, Joanna/D-6264-2012 NR 31 TC 3 Z9 5 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043100-3 J9 ADV SPACE RES-SERIES PY 1997 VL 19 IS 3 BP 491 EP 501 DI 10.1016/S0273-1177(97)00060-4 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BH75B UT WOS:A1997BH75B00013 ER PT J AU Huang, D McClure, JC Nunes, AC AF Huang, D McClure, JC Nunes, AC TI Gas contamination during plasma welding in Al-Li alloy 2195 SO SCIENCE AND TECHNOLOGY OF WELDING AND JOINING LA English DT Article ID CONTAINING ALUMINUM-ALLOYS; WELDABILITY AB Keyhole and cover pass variable polarity plasma arc welds were made on aluminium alloy 2195 with measured contamination levels of nitrogen, oxygen, and hydrogen. Contamination levels ranged from less than 10 to 500 ppm in both the argon plasma gas and the helium shield gas. It was found that nitrogen leads to more severe porosity than either hydrogen or oxygen, and that rear shielding is required for keyhole welding of Al-Li 2195 alloy to protect the weld from nitrogen in the atmosphere. Both nitrogen and oxygen contamination produced a dark surface on the weld bead, which comprised metallic aluminium particles, nucleated in the melt, that had aggregated at the surface of the weld pool. (C) 1997 The Institute of Materials. C1 AC Compressor Corp, Appleton, WI USA. Univ Texas, Dept Mat & Met Engn, El Paso, TX 79968 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Huang, D (reprint author), AC Compressor Corp, Appleton, WI USA. NR 9 TC 3 Z9 3 U1 0 U2 4 PU INST MATERIALS PI LONDON PA 1 CARLTON HOUSE TERRACE, LONDON SW1Y 5DB, ENGLAND SN 1362-1718 J9 SCI TECHNOL WELD JOI JI Sci. Technol. Weld. Join. PY 1997 VL 2 IS 5 BP 209 EP 212 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YW611 UT WOS:000071953900004 ER PT J AU Davis, SE Lowery, FS AF Davis, SE Lowery, FS BE Whitaker, AF ClarkIngram, M Hessler, SL TI Oxygen systems cleaners for aerospace applications SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB New environmental regulations have forced extensive evaluations of man!: different cleaning agents for use in oxygen systems. This is no simple process because pure oxygen is a very strong oxidizer, and when placed in contact with a foreign substance, the combination may be explosive. This foreign substance can easily be a cleaning agent residue left over in the oxygen system after cleaning. This paper focuses on the factors that must be considered when selecting a cleaning agent for oxygen systems, as well as the approval processes which are currently being utilized by NASA for oxygen compatibility of materials. This paper will provide a working description of how to begin selecting a cleaning agent for oxygen systems. The paper will present the following: Background information on the necessity of a stringent selection process for oxygen system cleaners; Specifications and regulations concerning cleaning for oxygen service; Changing oxygen cleaning specifications given current environmental concerns; Testing for cleanliness in oxygen systems; Cleaning agents that have been tested for oxygen systems, including an extensive list of some of the newer 'environmentally friendly'' cleaning agents; Test results and conclusions from the testing. The paper will also provide instructions on the proper procedures for obtaining NASA approval on a candidate oxygen systems cleaning agent. RP Davis, SE (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,MAT & PROC LAB,PROJECT & ENVIRONM ENGN DIV,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 49 EP 57 PG 9 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00007 ER PT J AU Blevins, E AF Blevins, E BE Whitaker, AF ClarkIngram, M Hessler, SL TI Experimental strategies in the development of a polyisocyanurate foam insulation with HCFC 141b blowing agent SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB The MSFC TPS Materials Research Laboratory has utilized statistical techniques in the design of experiments to develop an insulation that meets the requirements for usage on the External Tank of the Space Shuttle. This insulation, with an average density of 2.15 lb/ft(3), is foamed with the environmentally friendly blowing agent HCFC 14lb. HCFC 14lb has an ozone depletion potential that is approximately one tenth that of the previous blowing agent CFC 11, but the thermodynamic properties of HCFC 14lb affect the reaction kinetics and material properties. Statistically based experiments were designed to optimize the formulation for maximum mechanical strength at cryogenic temperatures with a minimum foam density. The experimental approach, chemistry, processing, and foam properties are described. RP Blevins, E (reprint author), MARSHALL SPACE FLIGHT CTR,LOCKHEED MARTIN MANNED SPACE SYST,POB 9008,HUNTSVILLE,AL 35758, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 85 EP 92 PG 8 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00011 ER PT J AU Sharpe, J AF Sharpe, J BE Whitaker, AF ClarkIngram, M Hessler, SL TI Evaluation of polyurethane foam insulation blowing agents with zero ozone depletion potential SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB The MSFC Thermal Protection Systems (TPS) Materials Research Laboratory is currently investigating environmentally friendly blowing agents for use in the insulations of the Space Shuttle's External Tank. The original TPS foam materials of the External Tank were blown with chlorofluorocarbon (CFC) 11 that is now regulated because of its high Ozone Depletion Potential (ODP). Hydrochlorofluorocarbons (HCFCs), with an ODP that is one tenth that of CFCs, have been widely adopted as an interim blowing agent in urethane insulations. In FY96. Lockheed Martin completed the production qualification and validation of HCFC 14lb blown insulations. Due to the expected limited commercial lifetime of HCFC 14lb, research efforts are underway to identify and develop alternatives with zero ozone depletion potential. Physical blowing agents identified have included hydrocarbons, fluorocarbons, fluoroiodocarbons, hydrofluoroethers, and more predominantly, hydrofluorocarbons (HFCs). This paper will describe results from a research program with candidate HFC blowing agents. RP Sharpe, J (reprint author), MARSHALL SPACE FLIGHT CTR,LOCKHEED MARTIN MANNED SPACE SYST,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 93 EP 97 PG 5 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00012 ER PT J AU MacArthur, D AF MacArthur, D BE Whitaker, AF ClarkIngram, M Hessler, SL TI A tooling foam with zero ozone depletion potential for composites fabrication SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB The MSFC TPS Materials Research Laboratory has developed a tooling foam for use in composites processing with mechanical and thermal properties superior to those of commercially available materials. MARCORE(TM) is a urethane modified polyisocyanurate foam system blown with an environmentally friendly blowing agent with zero ozone depiction potential. The patented material has the advantages of rapid prototyping, processing with unlimited cross sectional area, and compatibility with most preimpregnated composite resins anti their associated cure cycles. The tooling foam is dimensionally stable at temperatures above 250 degrees F and can withstand pressures greater than 100 psi. The chemistry, liquid properties, material properties, and applications are presented. RP MacArthur, D (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,LOCKHEED MARTIN MANNED SPACE SYST,POB 9008,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 99 EP 107 PG 9 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00013 ER PT J AU Hutchens, DE Doan, PA Boothe, RE AF Hutchens, DE Doan, PA Boothe, RE BE Whitaker, AF ClarkIngram, M Hessler, SL TI Development of statistical process control methodology for an environmentally compliant surface cleaning process in a bonding laboratory SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB Bonding labs at both MSFC and the northern Utah production plant prepare bond test specimens which simulate or witness the production of NASA's Reusable Solid Rocket Motor (RSRM). The current process for preparing the bonding surfaces employs 1,1,1 trichloroethane vapor degreasing, which simulates the current RSRM process. Government regulations (e.g., the 1990 Amendments to the Clean Air Act) have mandated a production phase-out of a number of ozone depleting compounds (ODC) including 1,1,1 trichloroethane. In order to comply with these regulations, the RSRM Program is qualifying a spray-in-air (SIA) precision cleaning process using Brulin 1990, an aqueous blend of surfactants. Accordingly, surface preparation prior to bonding process simulation test specimens must reflect the new production cleaning process. The Bonding Lab Statistical Process Control (SPC) program monitors the progress of the lab and its capabilities, as well as certifies the bonding technicians, by periodically preparing D6AC steel tensile adhesion panels with EA-913NA epoxy adhesive using a standardized process. SPC methods are then used to ensure the process is statistically in control, thus producing reliable data for bonding studies, and identify any problems which might develop. Since the specimen cleaning process is being changed, new SPC limits must be established. This report summarizes side-by-side testing of D6AC steel tensile adhesion witness panels and tapered double cantilevered beams (TDCBs) using both the current baseline vapor degreasing process and a lab-scale spray-in-air process. A Proceco 26 '' Typhoon dishwasher cleaned both tensile adhesion witness panels and TDCBs in a process which simulates the new production process. The tests were performed six times during 1995, subsequent statistical analysis of the data established new upper control limits (UCL) and lower control limits (ICL). The data also demonstrated that the new process was equivalent to the vapor degreasing process. RP Hutchens, DE (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE SPACE OFF,THIOKOL CORP,BLDG 4712,ROOM B300,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 175 EP 183 PG 9 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00022 ER PT B AU Beeson, H Kirsch, M Hornung, S Biesinger, P AF Beeson, H Kirsch, M Hornung, S Biesinger, P BE Whitaker, AF ClarkIngram, M Hessler, SL TI Replacement technologies for precision cleaning of aerospace hardware for propellant service SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB The NASA White Sands Test Facility (WSTF) is developing cleaning and verification processes to replace currently used chlorofluorocarbon-113-(CFC-113-) based processes. The processes being evaluated include both aqueous-and solvent-based techniques. Replacement technologies are being investigated for aerospace hardware and for gauges and instrumentation. This paper includes the findings of investigations of aqueous cleaning and verification of aerospace hardware using known contaminants, such as hydraulic fluid and commonly used oils. The results correlate nonvolatile residue with CFC 113. The studies also include enhancements to aqueous sampling for organic and particulate contamination. Although aqueous alternatives have been identified for several processes, a need still exists for nonaqueous solvent cleaning, such as the cleaning and cleanliness verification of gauges used for oxygen service. The cleaning effectiveness of tetrachloroethylene (PCE), trichloroethylene (TCE), ethanol, hydrochlorofluorocarbon 225 (HCFC 225), HCFC 141b, HFE 7100(R)(1), and Vertrel MCA(R)(2) was evaluated using aerospace gauges and precision instruments and then compared to the cleaning effectiveness of CFC 113. Solvents considered for use in oxygen systems were also tested for oxygen compatibility using high-pressure oxygen autogenous ignition and liquid oxygen mechanical impact testing. RP Beeson, H (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,WHITE SANDS TEST FACIL,LAS CRUCES,NM, USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 185 EP 192 PG 8 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00023 ER PT J AU Keen, JM DeWeese, CD Key, LW AF Keen, JM DeWeese, CD Key, LW BE Whitaker, AF ClarkIngram, M Hessler, SL TI Shuttle Reusable Solid Rocket Motor (RSRM) hand cleaning solvent replacement at Kennedy Space Center (KSC) SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB At Kennedy Space Center (KSC), Thiokol Corporation provides the engineering to assemble and prepare the Space Shuttle Reusable Solid Rocket Motor (RSRM) for launch. This requires hand cleaning over 86 surfaces including metals, adhesives, rubber and electrical insulations, various painted surfaces and thermal protective materials. Due to the phase-out of certain ozone depleting chemical (ODC) solvents, all RSRM hand wipe operations being performed sit KSC using 1,1,l-trichloroethane (TCA) were eliminated. This presentation summarizes the approach used and the data gathered in the effort to eliminate TCA from KSC hand wipe operations. RP Keen, JM (reprint author), THIOKOL CORP,MARSHALL SPACE FLIGHT CTR,HUNTSVILLE SPACE OFF,BLDG 4712,ROOM B300,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 277 EP 286 PG 10 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00032 ER PT J AU Melendez, O Trizzino, M Fedderson, B AF Melendez, O Trizzino, M Fedderson, B BE Whitaker, AF ClarkIngram, M Hessler, SL TI Evaluation of AK-225(R), Vertrel(R) MCA and HFE A 7100 as alternative solvents for precision cleaning and verification technology SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB The National Aeronautics and Space Administration (NASA), Kennedy Space Center (KSC) Materials Science Division conducted a study to evaluate alternative solvents for CFC-113 in. precision cleaning and verification on typical samples that are used in the KSC environment. The effects of AK-225(R), Vertrel(R) MCA, and HFE A 7100 on selected metal and polymer materials were studied over 1, 7 and 30 day test times. This report addresses a study on the compatibility aspects of replacement solvents for materials in aerospace applications. RP Melendez, O (reprint author), NASA,JOHN F KENNEDY SPACE CTR,DIV SCI MAT,KENNEDY SPACE CTR,FL 32899, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 319 EP 327 PG 9 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00036 ER PT J AU Jett, TR Baker, MA Thom, RL AF Jett, TR Baker, MA Thom, RL BE Whitaker, AF ClarkIngram, M Hessler, SL TI Comparison of environmentally friendly space compatible grease to its predecessor in a space mechanism bearing test rig SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB Perfluoroakylpolyether (PFPE) greases are used extensively in critical night hardware in a space environment. In the past, these greases have been processed using chlorofluorocarbon (CFC) based solvents. In response to the recent ban of CFC's, new formulations of environmentally friendly PFPE greases that are not processed with CFC based solvents were developed. The purpose of this study was to compare the performance of a new environmentally friendly formulation PFPE grease to a previously proven space compatible formulation PFPE grease. A one year test using 20 small electrical motors (two bearings per motor) was conducted in a high vacuum environment(2.0*10(-6)) Torr at a temperature of 90 degrees C. Twenty bearings were lubricated with a new environmentally friendly formulation, and twenty bearings were lubricated with an old formulation. The mass of each lubricated bearing was measured both pre and post test. Along with mass loss measurements a profilometer trace was taken to measure post test wear of the bearings. In addition the bearings were visually examined and analyzed using an optical microscope. RP Jett, TR (reprint author), NASA,MARSHALL SPACE FLIGHT CTR,MAT & PROC LAB,NONDESTRUCT EVALUAT & TRIBOL BRANCH,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 391 EP 412 PG 22 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00043 ER PT J AU Perey, DF AF Perey, DF BE Whitaker, AF ClarkIngram, M Hessler, SL TI An OSEE based portable surface contamination monitor SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB Many industrial and aerospace processes involving the joining of materials, require sufficient surface cleanliness to insure proper bonding. Processes as diverse as painting, welding, or the soldering of electronic circuits will be compromised if prior inspection and removal of surface contaminants is inadequate. As process requirements become more stringent and the number of different materials and identified contaminants increases, various instruments and techniques have been developed for improved inspection. One such technique based on the principle of Optically Stimulated Electron Emission (OSEE) has been explored for a number of years as a tool for surface contamination monitoring. Some of the benefits of OSEE are: it's non-contacting; requires little operator training; and has very high contamination sensitivity. This paper describes the development of a portable OSEE based surface contamination monitor. The instrument is suitable for both hand-held and robotic inspections with either manual or automated control of instrument operation. In addition, instrument output data is visually displayed to the operator and may be output to an external computer for archiving or analysis. RP Perey, DF (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 231,HAMPTON,VA 23681, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 469 EP 476 PG 8 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00050 ER PT J AU Cook, B AF Cook, B BE Whitaker, AF ClarkIngram, M Hessler, SL TI An interagency study of depainting techniques SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB Many popular and widely used paint stripping products now contain methylene chloride as their active ingredient. However, the Environmental Protection Agency (EPA) will critically curb the use of. methylene chloride under an aerospace national emission standard for hazardous air pollutants (NESHAP) within the next 2-1/2 years. An effort is underway to identify and evaluate alternative depainting technologies emphasizing those believed to be both effective and environmentally benign. On behalf of the EPA and in cooperation with the U. S. Air Force (USAF), the National Aeronautics and Space Administration (NASA) is conducting a technical assessment of nine alternative technologies (i.e.: chemical stripping, two CO2 blasting processes, FLASHJET(TM) coating removal, laser stripping, plastic media blasting, sodium bicarbonate wet stripping, high-pressure water stripping, and wheat starch blasting). These depainting processes represent five removal method categories, namely abrasive, impact, cryogenic, thermal, and/or molecular bonding dissociation. This paper discusses the test plan and parameters for this interagency study. Several thicknesses of clad arid non-dad aluminum substrates were used to prepare test specimens, which have been cut, cleaned, painted, and environmentally aged. Each depainting process has been assigned a specimen lot, which is now undergoing an initial strip cycle. Metallurgical impacts will be determined after these specimens complete five cycles of preparation and stripping. RP Cook, B (reprint author), NASA,ENVIRONM & ANALYT CHEM BRANCH,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 585 EP 590 PG 6 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00060 ER PT J AU Engle, G Whitfield, S AF Engle, G Whitfield, S BE Whitaker, AF ClarkIngram, M Hessler, SL TI The effects of long term cure on offgassed products of coatings SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB The Environmental Chemistry and Compatability Team at The Marshall Space Flight Center conducts toxic offgassing analysis on materials and flight hardware for use in habitable environments aboard the Space Shuttle and the International Space Station. As part of Research and Development, the Toxic Offgassing Laboratory conducted a long term cure study on four polyurethane coatings which are slated for potential use on Space Station (see list below). This study demonstrates the effects of cure time and temperature on the total tox value (sum T) and the maximum usage weight for each coating. All analysis was conducted according to test procedures outlined specifically for Space Station environments. Therefore, the ratings and weight limits generated for these materials are most applicable to space environments. However, this test does give some indication of rime frames for soh ent removal and is therefore of interest to the environmental community as a whole. RP Engle, G (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,EH42,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 607 EP 613 PG 7 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00063 ER PT J AU Predmore, R Woods, C Hovanec, A AF Predmore, R Woods, C Hovanec, A BE Whitaker, AF ClarkIngram, M Hessler, SL TI The GSFC combined approach of ODC stockpiling and tribological testing to mitigate the risks of ODC elimination SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB In response to the elimination of production of several Ozone Depleting Chemicals (ODCs) which have been widely used in successful space flight mechanism cleaning and lubricating procedures, GSFC developed and implemented an overall philosophy of mitigating the risks to flight hardware during the transition phase to ODC-Free cleaning procedures. One leg of that philosophy is the initiation of a several tier testing program which will deliver increasing amounts of information over the next few years, starting with original surface analysis comparisons between ODC and various ODC-Free cleaning technologies, The other leg is the stockpiling of an appropriate amount of ODC solvents such that all short term GSFC missions will be able to stay with or revert to heritage cleaning and lubricating procedures in the face of life issues. While tribological testing, mechanism life testing and space-flight experience will ultimately bring us into the 21st century with environmentally friendly means of cleaning long-life precision mechanism components, many satellites will be launched over the next few years with a number of important tribological questions unanswered. In order to prepare for this challenge, the Materials Engineering Branch in cooperation with the Electromechanical Branch launched an intensive review of all ongoing missions. The failure risk was determined for each long-life mechanism based on a number of parameters, including a comparison of flight solvents used to clean the heritage/life test hardware. Also studied was the ability of the mechanism manufacturers to stockpile ODCs based on state laws and company policies, A stockpiling strategy was constructed based on this information and subsequently implemented, This paper provides an overview of the GSFC ODC elimination risk mitigation philosophy as well as a detailed examination of the development of the ODC stockpiling plan. RP Predmore, R (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 313,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 693 EP 701 PG 9 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00072 ER PT B AU Hall, PB Thom, RL AF Hall, PB Thom, RL BE Whitaker, AF ClarkIngram, M Hessler, SL TI Adhesion performance of solid film lubricants on substrates cleaned with environmentally compliant cleaners SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville AB Solid film adhesion testing was used to determine the effect different environmentally compliant cleaners have on the adhesion properties of solid film lubricants used for several NASA programs. In an action to remove ozone depleting chemicals from aerospace processes, a replacement cleaner must be identified that does not affect the adhesion of solid film lubricants used on flight critical NASA hardware. ASTM D2510-83 Standard Test Method for Adhesion of Solid Film Lubricants was used to evaluate the cleaners. Two different lubricants - Inlox 88 and Boosterlube - were tested using various commercially available cleaners. Inlox 88 is produced by E/M Corporation and is a liquid oxygen compatible lubricant used in the Space Shuttle Main Engine, and Boosterlube is a new lubricant being implemented for use on the Space Shuttle Solid Rocket Booster. These lubricants were selected because of their specific use on flight critical NASA components. Results of this testing are presented in the paper. RP Hall, PB (reprint author), NASA,NONDESTRUCT EVALUAT & TRIBOL BRANCH,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 703 EP 707 PG 5 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00073 ER PT J AU Jones, WR Toddy, TJ Predmore, R Shogrin, B HerreraFierro, P AF Jones, WR Toddy, TJ Predmore, R Shogrin, B HerreraFierro, P BE Whitaker, AF ClarkIngram, M Hessler, SL TI The effect of ODC-free cleaning techniques on bearing lifetimes in the parched elastohydrodynamic regime SO SECOND AEROSPACE ENVIRONMENTAL TECHNOLOGY CONFERENCE SE NASA CONFERENCE PUBLICATION LA English DT Proceedings Paper CT 2nd Aerospace Environmental Technology Conference CY AUG 06-08, 1996 CL HUNTSVILLE, AL SP NASA, NASA Operat Environm Team, NASA, Off Space Flight, SAMPE Space Mfg Trust Comm, Aerosp Ind Assoc, Air Transport Assoc, Amer Inst Aeronaut & Astronaut, Amer Soc Met Int, Environm Protect Agcy, Natl Ctr Mfg Sci, Univ Alabama Huntsville DE bearings; cleaning; elastohydrodynamics AB A parched elastohydrodynamic rig was used to determine relative bearing lifetimes as a function of cleaning procedures in a series of accelerated tests. Two ODC-free cleaning procedures (super critical CO2 and ultraviolet-ozone) were compared to a CFC-113 control. Bearings (52100 steel) were run in the counter rotating mode (equivalent to 4600 rpm) with a full complement (i.e. no retainer) and a single charge of lubricant (Krytox 143 AC). Test conditions included: an air atmosphere, 445N load, similar to 1.0 GPa mean Hertz stress. There was approximately a 50% reduction in life with bearings cleaned with UV/ozone and a 70% reduction in life with SFE CO2 when compared to the Freon control. Possible reasons for these decreases in lifetimes are presented. RP Jones, WR (reprint author), NASA,LEWIS RES CTR,21000 BROOKPARK RD,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NASA PI WASHINGTON PA WASHINGTON, DC 20546 J9 NASA CONF P PY 1997 VL 3349 BP 709 EP 721 PG 13 WC Engineering, Aerospace; Engineering, Environmental SC Engineering GA BJ47U UT WOS:A1997BJ47U00074 ER PT B AU DiNucci, DC AF DiNucci, DC GP IEEE COMP SOC TI Tolerant (parallel) programming with F-Nets and software cabling SO SECOND INTERNATIONAL WORKSHOP ON SOFTWARE ENGINEERING FOR PARALLEL AND DISTRIBUTED SYSTEMS, PROCEEDINGS LA English DT Proceedings Paper CT 2nd International Workshop on Software Engineering for Parallel and Distributed Systems CY MAY 17-18, 1997 CL BOSTON, MA SP ACM SIGSOFT, IEEE Comp Soc, Int Federat Informat Proc AB In order to be truly portable, a program must be tolerant of a wide range of development and execution environments, and a parallel program is just one which must be tolerant of a very wide range. First, the term ''tolerant programming'' is defined. Then, a formal model called F-Nets is described in which parallel algorithms are expressed as folded partial-orderings of operations, and this is argued to provide a suitable framework for building tolerant programs. Finally, Software Cabling (SC), a very-high-level graphical programming language, demonstrates how many Of the features normally expected from today's computer languages (e.g. data abstraction and data parallelism) can be obtained within the F-Net paradigm. RP DiNucci, DC (reprint author), NASA,AMES RES CTR,MRJ TECHNOL SOLUT INC,M-S T27A-2,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 BN 0-8186-8043-1 PY 1997 BP 198 EP 209 DI 10.1109/PDSE.1997.596839 PG 12 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BH93A UT WOS:A1997BH93A00018 ER PT B AU Hasan, H Pfenniger, D AF Hasan, H Pfenniger, D BE Arnaboldi, M daCosta, GS Saha, P TI Unstable axial orbits in cuspy elliptical galaxies SO SECOND STROMLO SYMPOSIUM: THE NATURE OF ELLIPTICAL GALAXIES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Stromlo Symposium on the Nature of Elliptical Galaxies CY AUG 26-30, 1996 CL AUSTR ACAD SCI, CANBERRA, AUSTRALIA SP Austr Natl Univ, Mt Stromlo Observ, Austr Natl Univ, Siding Spring Observ, Austr Govt, Dept Ind Sci & Tourism, QANTAS, Austr Telescope Natl Facil, Univ Sydney, Res Ctr Theoret Astrophys, Anglo Austr Observ, Austr Acad Sci HO AUSTR ACAD SCI C1 NASA Headquarters, Washington, DC USA. RP Hasan, H (reprint author), NASA Headquarters, Washington, DC USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-36-8 J9 ASTR SOC P PY 1997 VL 116 BP 88 EP 90 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK73M UT WOS:000073252500013 ER PT B AU Dorman, B AF Dorman, B BE Arnaboldi, M daCosta, GS Saha, P TI Ultraviolet light from old stellar populations SO SECOND STROMLO SYMPOSIUM: THE NATURE OF ELLIPTICAL GALAXIES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Stromlo Symposium on the Nature of Elliptical Galaxies CY AUG 26-30, 1996 CL AUSTR ACAD SCI, CANBERRA, AUSTRALIA SP Austr Natl Univ, Mt Stromlo Observ, Austr Natl Univ, Siding Spring Observ, Austr Govt, Dept Ind Sci & Tourism, QANTAS, Austr Telescope Natl Facil, Univ Sydney, Res Ctr Theoret Astrophys, Anglo Austr Observ, Austr Acad Sci HO AUSTR ACAD SCI AB We consider the general theoretical problem of ultraviolet light from old stellar populations (t greater than or similar to 2 Gyr), and the interpretation of galaxy spectra at short wavelengths (lambda < 3000 Angstrom). The sources believed to be responsible for the observed 'ultraviolet upturn phenomenon' (UVX) are Post-AGE (P-AGB), extreme horizontal branch (EHB) and AGB-Manque (AGBM) stars. All of these have observational counterparts in old Galactic stellar populations, i.e. in globular clusters and in the Galactic field. The production of EHB stars depends on mass loss on the red giant branch, which is poorly understood, making the far-UV flux problematical as an indicator of the gross properties, such as the age, of a given galaxy. On the other hand, the longer, mid-UV wavelengths are radiated by stars near the main sequence turnoff which has well understood and predictable behavior. We discuss the current state of the comparison between theory and observation for the UVX phenomenon, and revisit the interpretation of the well-known UVX-Mg-2 correlation. In particular, we draw attention to the fact that the UVX appears not to be correlated with indices that measure the iron abundance, which has implications for models that explain the UV-Mg-2 correlation as an abundance-driven effect. Finally, we note the potential utility of ultraviolet observations in distinguishing age and metallicity from galaxy spectral energy distributions. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Dorman, B (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. NR 0 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 1-886733-36-8 J9 ASTR SOC P PY 1997 VL 116 BP 195 EP 207 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK73M UT WOS:000073252500039 ER PT B AU Grillmair, CJ Mould, JR Worthey, G Holtzman, JA Trauger, J Ballester, GE Burrows, C Clarke, J Crisp, D Gallagher, JS Griffiths, R Hester, J Hoessel, JG Krist, J Scowen, P Stapelfeldt, K Watson, A Westphal, J AF Grillmair, CJ Mould, JR Worthey, G Holtzman, JA Trauger, J Ballester, GE Burrows, C Clarke, J Crisp, D Gallagher, JS Griffiths, R Hester, J Hoessel, JG Krist, J Scowen, P Stapelfeldt, K Watson, A Westphal, J BE Arnaboldi, M daCosta, GS Saha, P TI Hubble space telescope observations of the Draco dwarf spheroidal SO SECOND STROMLO SYMPOSIUM: THE NATURE OF ELLIPTICAL GALAXIES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Stromlo Symposium on the Nature of Elliptical Galaxies CY AUG 26-30, 1996 CL AUSTR ACAD SCI, CANBERRA, AUSTRALIA SP Austr Natl Univ, Mt Stromlo Observ, Austr Natl Univ, Siding Spring Observ, Austr Govt, Dept Ind Sci & Tourism, QANTAS, Austr Telescope Natl Facil, Univ Sydney, Res Ctr Theoret Astrophys, Anglo Austr Observ, Austr Acad Sci HO AUSTR ACAD SCI C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Grillmair, CJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. RI Stapelfeldt, Karl/D-2721-2012 NR 0 TC 0 Z9 0 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-36-8 J9 ASTR SOC P PY 1997 VL 116 BP 306 EP 307 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK73M UT WOS:000073252500063 ER PT B AU Grillmair, CJ Lauer, TR Worthey, G Faber, SM Freedman, WL Madore, BF Ajhar, EA Baum, WA Holtzman, JA Lynds, CR O'Neil, EJ Stetson, PB AF Grillmair, CJ Lauer, TR Worthey, G Faber, SM Freedman, WL Madore, BF Ajhar, EA Baum, WA Holtzman, JA Lynds, CR O'Neil, EJ Stetson, PB BE Arnaboldi, M daCosta, GS Saha, P TI Hubble space telescope observations of M32 SO SECOND STROMLO SYMPOSIUM: THE NATURE OF ELLIPTICAL GALAXIES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Stromlo Symposium on the Nature of Elliptical Galaxies CY AUG 26-30, 1996 CL AUSTR ACAD SCI, CANBERRA, AUSTRALIA SP Austr Natl Univ, Mt Stromlo Observ, Austr Natl Univ, Siding Spring Observ, Austr Govt, Dept Ind Sci & Tourism, QANTAS, Austr Telescope Natl Facil, Univ Sydney, Res Ctr Theoret Astrophys, Anglo Austr Observ, Austr Acad Sci HO AUSTR ACAD SCI C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Grillmair, CJ (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 ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-36-8 J9 ASTR SOC P PY 1997 VL 116 BP 308 EP 309 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK73M UT WOS:000073252500064 ER PT S AU Parsons, A Palmer, DM Kurczynski, P Barbier, L Barthelmy, S Bartlett, L Gehrels, N Krizmanic, J Stahle, CM Tueller, J Teegarden, B AF Parsons, A Palmer, DM Kurczynski, P Barbier, L Barthelmy, S Bartlett, L Gehrels, N Krizmanic, J Stahle, CM Tueller, J Teegarden, B BE James, RB Schlesinger, TE Siffert, P Dusi, W Squillante, MR OConnell, M Cuzin, M TI Performance of prototype segmented CdZnTe arrays SO SEMICONDUCTORS FOR ROOM-TEMPERATURE RADIATION DETECTOR APPLICATIONS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 2nd Symposium on Semiconductors for Room-Temperature Radiation Detector Applications, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc, Amptek Inc, Bicron Corp, CEA LETI, US DOE, Off Nonproliferat, eV Products, Johnson Matthey Electr, Moxtek Inc, Noranda Adv Mat, RMD Inc, Sandia Natl Labs, Spire Corp AB The Burst and All Sky Imaging Survey (BASIS) is a proposed mission to provide similar to 3 are second locations of approximately 90 Gamma-Ray Bursts (GRBs) per year. The BASIS coded aperture imaging system requires a segmented detector plane able to detect the interaction position of (10 - 150 keV) photons to less than 100 mu m. To develop prototype detector arrays with such fine position resolution we have fabricated many 15 mm x 15 mm x 2 mm 100 mu m pitch CdZnTe strip detectors. We have assembled these fine pitch CdZnTe strip detectors into prototype 2 x 2 and 6 x 6 element arrays read out by ASIC electronics. The assembly and electronics readout of the 6 x 6 flight prototype array will be discussed, and preliminary data illustrating the uniformity and efficiency of the array will be presented. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Parsons, A (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Barthelmy, Scott/D-2943-2012; Gehrels, Neil/D-2971-2012; Tueller, Jack/D-5334-2012; Parsons, Ann/I-6604-2012 NR 0 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 1-55899-392-4 J9 MATER RES SOC SYMP P PY 1997 VL 487 BP 147 EP 152 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Nuclear Science & Technology SC Engineering; Materials Science; Nuclear Science & Technology GA BL33B UT WOS:000075187100021 ER PT S AU Stahle, CM Shi, ZQ Hu, K Barthelmy, SD Snodgrass, SJ Lehtonen, SJ Mach, KJ Barbier, L Gehrels, N Krizmanic, JF Palmer, D Parsons, AM Shu, P AF Stahle, CM Shi, ZQ Hu, K Barthelmy, SD Snodgrass, SJ Lehtonen, SJ Mach, KJ Barbier, L Gehrels, N Krizmanic, JF Palmer, D Parsons, AM Shu, P BE James, RB Schlesinger, TE Siffert, P Dusi, W Squillante, MR OConnell, M Cuzin, M TI Fabrication of CdZnTe strip detectors for large area arrays SO SEMICONDUCTORS FOR ROOM-TEMPERATURE RADIATION DETECTOR APPLICATIONS II SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 2nd Symposium on Semiconductors for Room-Temperature Radiation Detector Applications, at the 1997 MRS Fall Meeting CY DEC 01-05, 1997 CL BOSTON, MA SP Mat Res Soc, Amptek Inc, Bicron Corp, CEA LETI, US DOE, Off Nonproliferat, eV Products, Johnson Matthey Electr, Moxtek Inc, Noranda Adv Mat, RMD Inc, Sandia Natl Labs, Spire Corp AB A CdZnTe strip detector large area array (similar to 60 cm(2) with 36 detectors) with capabilities for high resolution imaging and spectroscopy has been built as a prototype for a space flight gamma ray burst instrument. The detector array also has applications in nuclear medical imaging. Two dimensional orthogonal strip detectors with 100 mu m pitch have been fabricated and tested. Details for the array design, fabrication and evaluation of the detectors will be presented. C1 NASA, Goddard Space Flight Ctr, Orbital Sci Corp, Greenbelt, MD 20771 USA. RP Stahle, CM (reprint author), NASA, Goddard Space Flight Ctr, Orbital Sci Corp, Greenbelt, MD 20771 USA. RI Gehrels, Neil/D-2971-2012; Barthelmy, Scott/D-2943-2012; Parsons, Ann/I-6604-2012 NR 0 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 1-55899-392-4 J9 MATER RES SOC SYMP P PY 1997 VL 487 BP 257 EP 262 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Nuclear Science & Technology SC Engineering; Materials Science; Nuclear Science & Technology GA BL33B UT WOS:000075187100036 ER PT S AU Neeck, SP Scolese, CJ Bordi, F AF Neeck, SP Scolese, CJ Bordi, F BE Fujisada, H TI EOS AM-1: Launch 9 months SO SENSORS, SYSTEMS, AND NEXT-GENERATION SATELLITES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems, and Next-Generation Satellites CY SEP 22-25, 1997 CL LONDON, ENGLAND SP CNR, NASA, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Neeck, SP (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 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 0-8194-2653-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3221 BP 150 EP 161 DI 10.1117/12.298075 PG 12 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BK34T UT WOS:000071862000016 ER PT S AU Markham, BL Barker, JL Kaita, E Gorin, I AF Markham, BL Barker, JL Kaita, E Gorin, I BE Fujisada, H TI Landsat-7 enhanced thematic mapper plus: Radiometric calibration and pre-launch performance SO SENSORS, SYSTEMS, AND NEXT-GENERATION SATELLITES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems, and Next-Generation Satellites CY SEP 22-25, 1997 CL LONDON, ENGLAND SP CNR, NASA, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev DE Landsat-7; ETM+; radiometry; calibration; spectral response; noise; dynamic range AB Landsat-7 will carry the Enhanced Thematic Mapper Plus (ETM+) as its payload. This instrument is a derivative of the Thematic Mapper (TM) instruments flown on the Landsat 4 and 5 spacecraft. Key changes to the instrument include a new 15 meter panchromatic band, an increased spatial resolution 60 meter thermal band and two new solar calibrators to improve the radiometric calibration of the reflective bands. The ETM+ is currently going through a series of radiometric performance tests to evaluate spectral responsivity, noise performance, linearity, radiometric stability, and absolute radiometric calibration in ambient and vacuum. To date, spectral responsivity, dynamic range, noise performance and absolute calibration tests have been conducted in ambient conditions for the reflective channels. System spectral responsivity, based on component level measurements, is similar to previous TM instruments. One notable difference is in band 5, where the ETM+ response cuts off near the nominal value of 1.75 mu m versus the 1.78 mu m of Landsat 4 and 5 TM's, providing a bandpass freer of atmospheric absorption. The gain setting on the reflective channels provided within-specification values of dynamic range and variations of less than 2% between detectors in a band for bands 1-5, and less than 4% for bands 7 and 8. Generally within-specification noise performance is observed on the instrument, with signal-to-noise ratios in the range of 150-300 at the upper end of the dynamic range. The current notable exception is the panchromatic band which shows significant coherent noise. In orbit, the ETM+ has three on board devices available for performing radiometric calibration: the Internal Calibrator (IC), the Partial Aperture Solar Calibrator (PASC) and the Full Aperture Solar Calibrator (FASC). The IC, which is similar to the Internal Calibrator on the Thematic Mappers, consists of two lamps, a blackbody and a shutter flag which transmits the light from the lamps and blackbody to the focal plane. The IC is calibrated prior to launch by reference to an external integrating sphere, using the ETM+ as a transfer instrument. The PASC provides a reduced aperture image of the sun on a daily basis. The FASC is a diffuser panel periodically deployed in front of the ETM+ aperture. BRDF measurements on a flight panel have recently been completed. The panel's reflectance varies little across the first four ETM+ bands, averaging about 0.91. C1 NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. RP Markham, BL (reprint author), NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. RI Markham, Brian/M-4842-2013 OI Markham, Brian/0000-0002-9612-8169 NR 0 TC 2 Z9 2 U1 3 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 0-8194-2653-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3221 BP 170 EP 178 DI 10.1117/12.298078 PG 9 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BK34T UT WOS:000071862000018 ER PT S AU Chapman, JJ AF Chapman, JJ BE Fujisada, H TI Virtual instrument simulator for CERES SO SENSORS, SYSTEMS, AND NEXT-GENERATION SATELLITES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems, and Next-Generation Satellites CY SEP 22-25, 1997 CL LONDON, ENGLAND SP CNR, NASA, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev DE satellite; simulation; microprocessor; software; instrument AB A benchtop virtual instrument simulator for CERES (Clouds and the Earth's Radiant Energy System) has been built at NASA, Langley Research Center in Hampton, VA. The CERES instruments will fly on several earth orbiting platforms notably NASDA's Tropical Rainfall Measurement Mission (TRMM) and NASA's Earth Observing System (EOS) satellites. CERES measures top of the atmosphere radiative fluxes using microprocessor controlled scanning radiometers. The CERES Virtual Instrument Simulator consists of electronic circuitry identical to the flight unit's twin microprocessors and telemetry interface to the supporting spacecraft electronics and two personal computers (PC) connected to the I/O ports that control azimuth and elevation gimbals. Software consists of the unmodified TRW developed Flight Code and Ground Support Software which serves as the instrument monitor and NASA/TRW developed engineering models of the scanners. The CERES Instrument Simulator will serve as a testbed for testing of custom instrument commands intended to solve in-flight anomalies of the instruments which could arise during the CERES mission. One of the supporting computers supports the telemetry display which monitors the simulator microprocessors during the development and testing of custom instrument commands. The CERES engineering development software models have been modified to provide a virtual instrument running on a second supporting computer linked in real time to the instrument flight microprocessor control ports. The CERES Instrument Simulator will be used to verify memory uploads by the CERES Flight Operations TEAM at NASA. Plots of the virtual scanner. models match the actual instrument scan plots. A high speed logic analyzer has been used to track the performance of the flight microprocessor. The concept of using an identical but non-flight qualified microprocessor and electronics ensemble linked to a virtual instrument with identical system software affords a relatively inexpensive simulation system capable of high fidelity. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Chapman, JJ (reprint author), NASA, Langley Res Ctr, 21 Langley Blvd,MS 423, Hampton, VA 23681 USA. NR 0 TC 0 Z9 0 U1 0 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2653-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3221 BP 179 EP 190 DI 10.1117/12.298079 PG 12 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BK34T UT WOS:000071862000019 ER PT S AU Priestley, KJ Kopia, L Lee, RL Mahan, JR Haeffelin, M Smith, GL Paden, J AF Priestley, KJ Kopia, L Lee, RL Mahan, JR Haeffelin, M Smith, GL Paden, J BE Fujisada, H TI Use of first-principle numerical models to enhance the understanding of the CERES point spread function SO SENSORS, SYSTEMS, AND NEXT-GENERATION SATELLITES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems, and Next-Generation Satellites CY SEP 22-25, 1997 CL LONDON, ENGLAND SP CNR, NASA, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev DE radiometry; thermistor bolometers; remote sensing; CERES; numerical modeling AB NASA's Clouds and the Earth's Radiant Energy System (CERES) program is a key component of the Earth Observing System (EOS). The CERES Proto-Flight Model (PFM) instrument is to be launched on NASA's Tropical Rainfall Measuring Mission (TRMM) platform on 1 November 1997. Each CERES instrument contains three scanning thermistor bolometer radiometers to monitor the longwave and visible components of the Earth's radiative energy budget. An integral part of analyzing these measurements will be the use of high-resolution cloud imager data in conjunction with data from the CERES instruments. The use of high-resolution cloud imager data requires that the Point Spread Function (PSF), or the dynamic response of the radiometric channels as they scan across a far-field point source, be well characterized. The PSF is determined by the field-of-view of the radiometric channel, its optical geometry, and the time response of the thermistor bolometer and its associated signal conditioning electronics. The PSF of the CERES instruments is measured in the laboratory using a state of the art Radiometric Calibration Facility (RCF) developed by TRW. Intrinsic difficulties in making this measurement suggest that a better understanding of the data could be obtained by the use of an independent instrument model. High-level first-principle dynamic electrothermal models of the CERES radiometric channels have been completed under NASA sponsorship [1]. These first-principle models consist of optical, thermal and electrical modules. Accurate optical characterization of the channels is assured by Monte-Carlo-based ray-traces in which tens of millions of rays are traced. Accurate thermal and electrical characterization is assured by transient finite-difference formulations involving thousands of nodes to describe thermal and electrical diffusion within the thermistor bolometer sensing elements and the instrument mechanical structure. The signal conditioning electronics are also included in the models. Numerical simulations of the PSF's of the CERES Proto-Flight Model (PFM) Radiometric channels have been completed. This paper presents a comparison between the measured PSF and the independent numerically predicted PSF for the CERES Proto-Flight Model total channel. Agreement between the measured and predicted PSF's is excellent. The result of this agreement is a high confidence in the model to predict other aspects of instrument performance. For example, the model may now be used to predict channel PSF's for elevation scan rates different from the nominal Earth scan rate. C1 NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. RP Priestley, KJ (reprint author), NASA, Langley Res Ctr, Div Atmospher Sci, MS 420, Hampton, VA 23681 USA. NR 0 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 0-8194-2653-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3221 BP 191 EP 200 DI 10.1117/12.298080 PG 10 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BK34T UT WOS:000071862000020 ER PT S AU Wu, C Graf, J Spencer, M Winn, C AF Wu, C Graf, J Spencer, M Winn, C BE Fujisada, H TI The SeaWinds scatterometer instrument using a pulse compression radar SO SENSORS, SYSTEMS, AND NEXT-GENERATION SATELLITES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems, and Next-Generation Satellites CY SEP 22-25, 1997 CL LONDON, ENGLAND SP CNR, NASA, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev DE scatterometer; chirp radar; ADEOS; SASS; pencil beam; wind velocity AB The SeaWinds scatterometer instrument is currently being developed by NASA/JPL, as a part of the NASA EOS Program, for flight on the Japanese ADEOS II mission in 1999. This Ku-band radar scatterometer will infer sea surface wind speed and direction by detecting the normalized radar backscatter cross section over several different azimuth angles. This paper presents the design characteristics of and operational approach to the instrument itself. The SeaWinds pencil-beam-antenna conical-scan design is a departure from the fixed fan-beam antennas of SASS and NSCAT. The purpose of this change is to develop a more compact design consistent with the resource constraints of the ADEOS II spacecraft. The SeaWinds conical-scan arrangement has a I-m reflector dish antenna that produces a time-shared dual antenna beam at 40 degrees and 46 degrees look angles. The dual-beam operation provides up to four azimuth look directions for each wind measurement cell. At an orbit height of 803 km, the conical scan provides a broad and contiguous wind measurement swath width of about 1800 km for each orbital pass. The radar has a linear frequency modulation, or chirp, encoded transmitter waveform. The bandwidth of modulation is nominally 375 kHz. For each transmitted pulse, an onboard pulse compression processor will produce 12 measurement cells of 6-km resolution in range and about 26 km in azimuth (cross-track). Key specifications of the SeaWinds instrument and associated trade-offs and performance are described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wu, C (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 0-8194-2653-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3221 BP 340 EP 345 DI 10.1117/12.298100 PG 6 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BK34T UT WOS:000071862000034 ER PT S AU Tsai, WY Graf, JE Winn, C Yueh, S AF Tsai, WY Graf, JE Winn, C Yueh, S BE Fujisada, H TI SeaWinds-1B: a combination of ku-band scatterometer and wind radiometer for global ocean wind measurements SO SENSORS, SYSTEMS, AND NEXT-GENERATION SATELLITES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems, and Next-Generation Satellites CY SEP 22-25, 1997 CL LONDON, ENGLAND SP CNR, NASA, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev DE scatterometer; microwave; polarimetric radiometer; winds AB Satellite wind scatterometers are microwave radar instruments designed specifically to measure near-surface wind speed and direction over the global ocean. NASA has a long term commitment to ocean wind remote sensing, starting from Seasat-A Satellite Scatterometer (SASS),through NASA Scatterometer (NSCAT), to SeaWinds. SASS was launched in June, 1978 and operated for three months. NSCAT was launched on Japan's Advanced Earth Observation Satellite (ADEOS) in August, 1996, and SeaWinds will be launched on ADEOS-2 in 1999. As a continuation of the NASA wind measurement program, we are developing a next generation wind vector measurement instrument, called SeaWinds-1B, scheduled to be launched in year 2003 on Japan's Advanced Earth Observation Satellite-3 (ADEOS-3). The purpose of this paper is to present the system parameters and system design of this new instrument. SeaWinds-1B is a combination of two instruments into a single design: scatterometer, and polarimetric wind-radiometer (WINDRAD). The scatterometer instrument is used as a baseline to continue the active microwave wind measurements. The WINDRAD instrument is incorporated to demonstrate a new concept of wind vector measurements from space using polarimetric radiometer. WINDRAD can also be used to measure the atmospheric attenuation to improve the scatterometer measurement accuracy. Furthermore, the combination of the scatterometer and WINDRAD will improve the accuracy of the wind vector measurements and the skills for removing the wind direction retrieval ambiguity. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tsai, WY (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 0-8194-2653-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3221 BP 346 EP 356 DI 10.1117/12.298101 PG 11 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BK34T UT WOS:000071862000035 ER PT S AU Huddleston, JN Tsai, WY Spencer, MW West, R AF Huddleston, JN Tsai, WY Spencer, MW West, R BE Fujisada, H TI Modeling and simulation for SeaWinds-1B system design and performance evaluation SO SENSORS, SYSTEMS, AND NEXT-GENERATION SATELLITES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems, and Next-Generation Satellites CY SEP 22-25, 1997 CL LONDON, ENGLAND SP CNR, NASA, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev DE scatterometer; simulation; radar; ocean; winds; NSCAT; SeaWinds AB SeaWinds-1B is an spaceborne instrument, under design at the jet propulsion laboratory, to accurately measure the speed and direction of ocean surface winds at high resolutions. SeaWinds-1B consists of a scatterometer and a polarimetric wind radiometer. The scatterometer employs range compression to increase the resolution of its sigma-0 measurements. The polarimetric radiometer will be used to verify new techniques of passively measuring wind vectors from space. The SeaWinds-1B instrument will also be used to investigate the benefits of combining scatterometer and radiometer data to increase the accuracy of resulting wind products. Since SeaWinds-1B is still in the design phase, there are many system design issues which need to be studied. To aid in such studies, a simulation is being developed which will stimulate the operation of the spacecraft (attitude and ephemeris), the scatterometer instrument, and the ground data processing system (sigma-0 and wind products). The simulation will provide an estimate of the wind retrieval performance and sigma-0 measurement accuracy of the SeaWinds-1B scatterometer over realistic wind fields and land targets. Perhaps the most important features of any simulation are the considerations that are used to guide its construction. The SeaWinds-1B simulation will incorporate many factors including instrument RF stability, measurement error correlation, geophysical model function errors, and spacecraft attitude stability. Experience from simulations devised for the NASA scatterometer (NSCAT) and SeaWinds scatterometer will be applied to the SeaWinds-1B simulation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Huddleston, JN (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 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 0-8194-2653-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3221 BP 357 EP 364 DI 10.1117/12.298102 PG 8 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BK34T UT WOS:000071862000036 ER PT S AU Park, H Soulen, PF Prasad, CR AF Park, H Soulen, PF Prasad, CR BE Fujisada, H TI Novel spectrograph/radiometer for cloud top height measurement using three complementary techniques SO SENSORS, SYSTEMS, AND NEXT-GENERATION SATELLITES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems, and Next-Generation Satellites CY SEP 22-25, 1997 CL LONDON, ENGLAND SP CNR, NASA, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev DE cloud; IR; UV; molecular oxygen; Ring effect; Fraunhofer line filling-in effect; spectrograph AB A proof-of-concept (POC) instrument system to measure cloud top height from space using three complementary techniques is presented. These techniques use measurements of 1) thermal infrared (IR), 2) molecular oxygen "A" band absorption, and 3) filling-in of Fraunhofer lines (the Ring effect), respectively. Combining three techniques is achieved with a single grating spectrograph with bandpass and order sorting filters by measuring 11 mu m radiation from the zeroth order of the grating for the IR, 750-780 nm radiation from the first order for the "A" band absorption, and 390-400 nm radiation from the second order for the Ca K and H Fraunhofer line filling-in effect. The POC system and its measurement results with the POC system are described. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Park, H (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2653-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3221 BP 365 EP 371 DI 10.1117/12.298103 PG 7 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BK34T UT WOS:000071862000037 ER PT S AU Little, AD Neil, DO Sachse, GW Fishman, J Krueger, AJ AF Little, AD Neil, DO Sachse, GW Fishman, J Krueger, AJ BE Fujisada, H TI Remote sensing from geostationary orbit: GEO TROPSTAT, a new concept for atmospheric remote sensing SO SENSORS, SYSTEMS, AND NEXT-GENERATION SATELLITES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems, and Next-Generation Satellites CY SEP 22-25, 1997 CL LONDON, ENGLAND SP CNR, NASA, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev DE space mission design; atmospheric processes; geostationary; focal plane array applications; tropospheric pollution; secondary payload; communications satellite; GEO TROPSAT; Geo Express Pathfinder AB The Geostationary Tropospheric Pollution Satellite (GEO TROPSAT) mission is a new approach to measuring the critical constituents of tropospheric ozone chemistry: ozone, carbon monoxide, nitrogen dioxide, and aerosols. The GEO TROPSAT mission comprises a constellation of three instruments flying as secondary payloads on geostationary communications satellites around the world. This proposed approach can significantly reduce the cost of getting a science payload to geostationary orbit and also generates revenue for the satellite owners. The geostationary vantage point enables simultaneous high temporal and spatial resolution measurement of tropospheric trace gases, leading to greatly improved atmospheric ozone chemistry knowledge. The science data processing, conducted as a research (not operational) activity, will provide atmospheric trace gas data many times per day over the same region at better than 25 km ground footprint. The high temporal resolution identifies short time scale processes, diurnal variations, seasonal trends, and interannual variation. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Little, AD (reprint author), NASA, Langley Res Ctr, M-S 468, Hampton, VA 23681 USA. NR 0 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 0-8194-2653-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3221 BP 480 EP 488 DI 10.1117/12.298116 PG 9 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BK34T UT WOS:000071862000048 ER PT S AU Eisenman, AR Liebe, CC Jorgensen, JL AF Eisenman, AR Liebe, CC Jorgensen, JL BE Fujisada, H TI The new generation of autonomous star trackers SO SENSORS, SYSTEMS, AND NEXT-GENERATION SATELLITES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, Systems, and Next-Generation Satellites CY SEP 22-25, 1997 CL LONDON, ENGLAND SP CNR, NASA, European Opt Soc, Soc Photo Opt Instrumentat Engineers, Commiss European Communities, Directorate Gen Sci Res & Dev AB The most accurate instrument for spacecraft attitude determination is a star tracker. Generally, these are CCD-based instruments. Until recently, only first-generation units were available. However, these first-generation designs are limited to outputting positions of a few stars in sensor-referenced coordinates and require extensive external processing. Fortunately, advancing technology has enabled the development of a new second-generation class of star trackers. These designs are fully autonomous, solve the lost-in-space problem, have large internal star catalogs, use many stars for each data frame, have higher accuracy, smoother and more robust operation, potentially lower cost, and output attitudes which are referenced directly to inertial space without any further external data processing. Two currently available designs which are in production and meet these requirements are the AST-201 from Lockheed Martin Missile & Space and the ASC from the Technical University of Denmark. The first design is in the general size, power, mass, and reliability class of typical, conventional star trackers. The second one features reduced size, power, mass, and cost, with commercial off-the-shelf components. Second-generation star trackers have a promising future with a likely evolution to low cost, miniature, stock instruments with wide application to a growing variety of space missions. 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 0 TC 4 Z9 5 U1 2 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2653-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3221 BP 524 EP 535 DI 10.1117/12.298121 PG 12 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BK34T UT WOS:000071862000053 ER PT J AU Bookout, PS AF Bookout, PS TI Statistically generated weighted curve fit of residual functions for modal analysis of structures SO SHOCK AND VIBRATION LA English DT Article AB A statistically generated weighting function for a second-order polynomial curve fit of residual functions has been developed. The residual flexibility test method, from which a residual function is generated, is a procedure to modal test large structures in a free-free environment to measure the effects of higher order modes and stiffness at distinct degree of freedom interfaces. Due to the present damping estimate limitations in the modal parameter evaluation (natural frequencies and mode shapes) of test data, the residual function has regions of irregular data, which should be a smooth curve in a second-order polynomial form. A weighting function of the data is generated by examining the variances between neighboring data points. From a weighted second-order polynomial curve fit, an accurate residual flexibility value call be obtained. The residual flexibility value and free-free modes from testing are used to improve a mathematical model of the structure, which is used to predict constrained mode shapes. C1 NASA, George C Marshall Space Flight Ctr, Struct Anal Div, Huntsville, AL 35812 USA. RP Bookout, PS (reprint author), NASA, George C Marshall Space Flight Ctr, Struct Anal Div, ED23, Huntsville, AL 35812 USA. NR 11 TC 0 Z9 0 U1 1 U2 1 PU IOS PRESS PI AMSTERDAM PA VAN DIEMENSTRAAT 94, 1013 CN AMSTERDAM, NETHERLANDS SN 1070-9622 J9 SHOCK VIB JI Shock Vib. PY 1997 VL 4 IS 4 BP 211 EP 222 PG 12 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 112XQ UT WOS:000075520400001 ER PT S AU Sridhar, KR MacElroy, RD AF Sridhar, KR MacElroy, RD BE Guyenne, TD TI Oxygen scrubbing and sensing in plant growth chambers using solid oxide electrolyzers SO SIXTH EUROPEAN SYMPOSIUM ON SPACE ENVIRONMENTAL CONTROL SYSTEMS, VOLS 1 AND 2 SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 6th European Symposium on Space Environmental Control Systems CY MAY 20-22, 1997 CL NOORDWIJK, NETHERLANDS SP European Space Agcy AB The maintenance of optimal levels of oxygen in the gaseous environment of plant growth chamber during both light and dark periods is essential for the proper growth of plants. Solid oxide electrolyzers can be used to control the oxygen levels by removing the excess gaseous oxygen during the periods of illumination and full scale photosynthesis. Part of the oxygen that is removed by this process can be stored and supplied back to the plant chamber during periods of darkness. The excess oxygen can be used by the crew for respiration. In addition, the electrolyzer can be used, in its open circuit mode, to sense oxygen concentrations in the plant chamber gas environment. The solid oxide electrolysis process and its applicability to plant growth chambers are described in this paper. RP Sridhar, KR (reprint author), NASA,AMES RES CTR,MS 239-23,ROOM 175,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-283-4 J9 ESA SP PUBL PY 1997 VL 400 BP 771 EP 775 PG 5 WC Engineering, Aerospace SC Engineering GA BJ69Y UT WOS:A1997BJ69Y00094 ER PT S AU Heyenga, AG AF Heyenga, AG BE Guyenne, TD TI The utilization of passive water and nutrient support systems is in space flight plant cultivation and research SO SIXTH EUROPEAN SYMPOSIUM ON SPACE ENVIRONMENTAL CONTROL SYSTEMS, VOLS 1 AND 2 SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 6th European Symposium on Space Environmental Control Systems CY MAY 20-22, 1997 CL NOORDWIJK, NETHERLANDS SP European Space Agcy AB The maintenance of suitable plant growth conditions is an essential prerequisite to the successful cultivation of plants in a controlled artificial environment. In space flight, the provision of such conditions is challenging particularly with respect to the appropriate supply of water, nutrients, and gas exchange to the plant root environment. An approach directed towards the passive supply of these components may be preferable to an active delivery system in which the demand on power, mass, and operational complexity is not necessarily compatible with space flight resources. Design of the passive 'Nutrient Pack' system is based on the direct supply of a water and nutrient substrate to plants as a serf-contained unit. The additional implementation of substrate compartmentalization extends the possible opportunities in plant biology research not previously feasible in space flight. Further development of the nutrient pack design, with the incorporation of a passive water replenishment capability, has extended the utilization of the system for long term plant cultivation. RP Heyenga, AG (reprint author), NASA,AMES RES CTR,NATL RES COUNCIL,M-S 239-23,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-283-4 J9 ESA SP PUBL PY 1997 VL 400 BP 867 EP 871 PG 5 WC Engineering, Aerospace SC Engineering GA BJ69Y UT WOS:A1997BJ69Y00107 ER PT B AU Nitzberg, B Lo, V AF Nitzberg, B Lo, V GP IEEE COMP SOC TI Collective buffering: Improving parallel I/O performance SO SIXTH IEEE INTERNATIONAL SYMPOSIUM ON HIGH PERFORMANCE DISTRIBUTED COMPUTING, PROCEEDINGS LA English DT Proceedings Paper CT 6th IEEE International Symposium on High Performance Distributed Computing CY AUG 05-08, 1997 CL PORTLAND STATE UNIV, PORTLAND, OR SP UEEE Comp Soc, Tech Comm Distributed Proc, Syracuse Univ, HPDC Lab, Oregon State Univ, Portland State Univ, Cabletron Syst HO PORTLAND STATE UNIV AB ''Parallel I/O'' is the support of a single parallel application run an many nodes; application data is distributed among the nodes, and is read or written to a single logical fife, itself spread across nodes and and disks. Parallel I/O is a mapping problem from the data layout in node memory to the file layout on disks. Since the mapping can be quite complicated and involve significant data movement, optimizing the mapping is critical for performance. We discuss our general model of the problem, describe four Collective Buffering algorithms we designed, and report experiments testing their performance on an Intel Paragon and an IBM SP2 both housed at NASA Ames Research Center. Our experiments show improvements of up to two order of magnitude over standard techniques and the potential to deliver peak performance with minimal hardware support. RP Nitzberg, B (reprint author), NASA,AMES RES CTR,MRJ TECHNOL SOLUT,MOFFETT FIELD,CA 94035, USA. NR 0 TC 11 Z9 12 U1 0 U2 0 PU I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 BN 0-8186-8118-7 PY 1997 BP 148 EP 157 DI 10.1109/HPDC.1997.622371 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BJ51V UT WOS:A1997BJ51V00015 ER PT S AU Rubin, RH Dufour, RJ Ferland, GJ Martin, PG Baldwin, JA Hester, JJ Walter, DK AF Rubin, RH Dufour, RJ Ferland, GJ Martin, PG Baldwin, JA Hester, JJ Walter, DK BE Dufour, RJ TorresPeimbert, S TI T-e-fluctuations and N+/O+ in the Orion Nebula SO SIXTH TEXAS-MEXICO CONFERENCE ON ASTROPHYSICS: ASTROPHYSICAL PLASMAS NEAR AND FAR SE REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA, SERIE DE CONFERENCIAS LA English DT Proceedings Paper CT 6th Texas-Mexico Conference on Astrophysics : Astrophysical Plasmas - Near and Far CY MAR 06-08, 1997 CL RICE UNIV, HOUSTON, TX HO RICE UNIV DE H II regions; ISM, abundances; ISM, individual objects (Orion Nebula) AB Using the Faint Object Spectrograph (FOS) on the Hubble Space Telescope, we measured the flux of the N II] (2s2p(3) S-5(2) --> 2s(2)2p(2) P-3(2,1)) lines at lambda(vac) = 2143.45, 2139.68 Angstrom in the Orion Nebula. Tn order to assess the N+/O+ ratio, we also measured the flux of the [O II] (2p(3) 2P(1/2,3/2)(0)-->2p(3) S-4(3/2)0) lines at lambda(vac) = 2471.05, 2471.12 Angstrom. In addition, with the FOS, other emission lines were measured in the same aperture in order to assess the average electron temperature and mean-square temperature variation (t(2)) in the N+ region as well as the N+/O+ ratio. When we require that the empirically-determined values be equal for (N+/O+)(uv) (obtained from the [O II] 2471 and N II] 2142 lines) and (N+/O+)(opt) (obtained from the [O II] 3728 and [N II] 6585 lines), we obtain the following. For the (N+, O+)-zone, the average electron density is similar to 7000 cm(-3): the average electron temperature is 9500 K, t(2) is 0.032, and N+/O+ is 0.14. In order to obtain N/O, the empirically-derived N+/O+ value requires a correction for the possibility that the N+ and O+ regions are not identical. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Rubin, RH (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVERSIDAD NACIONAL AUTONOMA MEXICO INSTITUTO ASTRONOMIA PI MEXICO CITY PA APARTADO POSTAL 70-264, MEXICO CITY 04510, MEXICO SN 1405-2059 J9 REV MEX AST ASTR PY 1997 VL 7 BP 34 EP 41 PG 8 WC Astronomy & Astrophysics; Physics, Fluids & Plasmas SC Astronomy & Astrophysics; Physics GA BK86R UT WOS:000073706100006 ER PT B AU Blue, RC AF Blue, RC BE Allahdadi, FA Casani, EK Maclay, TD TI Instrumentation for the New Millennium Program, Mars Microprobe Project: Design approach and test results SO SMALL SPACECRAFT, SPACE ENVIRONMENTS, AND INSTRUMENTATION TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Small Spacecraft, Space Environments, and Instrumentation Technologies CY JUL 27-28, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers AB The Mars Microprobe Project provides a unique opportunity to validate instrumentation technologies for performing relevant science experiments on the Martian surface and at a depth of up to two meters. The instrumentation package of the Mars Microprobe includes a meteorological instrument for measuring atmospheric pressure and temperature, accelerometers to measure the atmospheric drag on the probe aeroshell during descent, accelerometers for measuring the forces on the probe at impact, temperature sensors in the penetrator to measure the soil thermal conductivity at depth, and an experiment to collect a small sample of the Martian regolith and determine if water is present in the sample. These instruments have been designed to withstand the deceleration forces resulting from the impact and penetration of the probe into the Martian surface and to function in the harsh temperature environment beneath the surface. Results from the design and environmental test of these instruments are presented. RP Blue, RC (reprint author), CALTECH,JET PROP LAB,MARS MICROPROBE MISS,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 PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2538-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3116 BP 4 EP 11 DI 10.1117/12.293325 PG 8 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BJ97X UT WOS:A1997BJ97X00001 ER PT B AU Gursel, Y AF Gursel, Y BE Allahdadi, FA Casani, EK Maclay, TD TI Metrology for spatial interferometry IV SO SMALL SPACECRAFT, SPACE ENVIRONMENTS, AND INSTRUMENTATION TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Small Spacecraft, Space Environments, and Instrumentation Technologies CY JUL 27-28, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers AB The proposed Space Interferometry Mission (SIM) spacecraft carries high resolution stellar interferometers for micro-are-second accuracy astrometric measurements. These stellar interferometers require picometer accuracy one dimensional metrology gauges, surface metrology gauges and 3-dimensional metrology gauges. The absolute metrology gauges required by these interferometers can be considerably less accurate due to the careful design of the astrometric interferometers on the spacecraft. Open-faced, hollow corner cube retro-reflectors are used as fiducials in the one-dimensional relative and absolute metrology gauges and the 3-dimensional metrology gauge. The diffraction caused by the assembly and the component defects of these hollow retro-reflectors affects the accuracy of these metrology gauges. A simulation quantifying some of the effects of the component and assembly defects of hollow retro-reflectors on the accuracy of a picometer linear metrology gauge is presented. An auto-aligning, 3-dimensional metrology gauge constructed using the sub-picometer linear metrology gauges was described in earlier papers. The functioning automatic alignment and the sub-nanometer, in-air tracking results from this 3-dimensional metrology gauge are presented. RP Gursel, Y (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 9 Z9 9 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2538-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3116 BP 12 EP 26 DI 10.1117/12.293333 PG 15 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BJ97X UT WOS:A1997BJ97X00002 ER PT B AU Gaunce, M Scharf, R Johnson, N Christiansen, E AF Gaunce, M Scharf, R Johnson, N Christiansen, E BE Allahdadi, FA Casani, EK Maclay, TD TI Photographic surveys of the Mir space station and the detection of orbital debris and meteoroid impacts SO SMALL SPACECRAFT, SPACE ENVIRONMENTS, AND INSTRUMENTATION TECHNOLOGIES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Small Spacecraft, Space Environments, and Instrumentation Technologies CY JUL 27-28, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE orbital debris; meteoroids; photographic; Mir space station AB During the period February 1995-May 1997, the US Space Shuttle visited the Russian Mir space station on one close rendezvous and six docking missions. A Detailed Test Objective (DTO-1118) called for extensive photographic and video imagery of the Mir complex for several purposes, including to assess the overall condition of the station and to study the effects of the space environment on a long-duration orbiting platform. Thousands of photographs of Mir from 35 mm Nikon and 70 mm Hasselblad cameras were taken, and more than one hundred hours of video from several cameras located in the Space Shuttle cargo bay were collected. A review of these photographic data has revealed evidence of numerous small particle impacts. This paper describes the photographic analysis effort at the NASA Johnson Space Center with an emphasis on Mir particulate damage assessment. Sample photographs depicting impact effects are provided. A preliminary attempt is made to compare the observed impacts with predictions based on environmental models. A comprehensive comparison between data and the models is hampered by the lack of a complete historical record of the attitude of the Mir space station and by an inability to distinguish between orbital debris and meteoroid impacts from only remote photographic evidence. C1 NASA,LYNDON B JOHNSON SPACE CTR,SN,HOUSTON,TX 77058. RP Johnson, N (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,SN,HOUSTON,TX 77058, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2538-9 J9 P SOC PHOTO-OPT INS PY 1997 VL 3116 BP 192 EP 199 DI 10.1117/12.293332 PG 8 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BJ97X UT WOS:A1997BJ97X00018 ER PT B AU BarCohen, Y Xue, T Joffe, B Lih, SS Shahinpoor, M Simpson, J Smith, J Willis, P AF BarCohen, Y Xue, T Joffe, B Lih, SS Shahinpoor, M Simpson, J Smith, J Willis, P BE Regelbrugge, ME TI Electroactive polymers (EAP) low mass muscle actuators SO SMART STRUCTURES AND INTEGRATED SYSTEMS - SMART STRUCTURES AND MATERIALS 1997 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Integrated Systems - Smart Structures and Materials 1997 CY MAR 03-06, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, USAF Wright Lab, Def Adv Res Projects Agcy, Amer Inst Chem Engineers, Amer Phys Soc, Div Mat Phys, Ceram Soc Japan, USA Res Lab, Intelligent Mat Forum, Japan DE actuators; electroactive polymers; active materials; ionomers AB Actuation devices are used for many space applications with an increasing need to reduce their size, mass, and power consumption as well as cut their cost. Existing transducing actuators, such as piezoceramics, induce limited displacement levels. Potentially, electroactive polymers (EAP) have the potential for low-mass, low-power, inexpensive miniature muscle actuators that are superior to the widely used actuators. Under electrical excitation, EAPs contract and thus form a basis for muscle actuators. Efforts are being made to develop EAP materials that provide large displacements, and two EAP categories were identified to produce actuation strain of more than 10%. These categories include: (a) ion-exchange membrane - platinum composite polymer (so-called ionomers); and (b) electrostatically driven polymers. A comparison between EAP and the widely used transducing actuators shows that, while lagging in force delivering capability, these materials are superior in mass, power consumption and displacement levels. This produces an enabling technology of a new class of devices. Several muscle configurations were constructed to demonstrate the capabilities of these EAP actuators. The emphasis of this manuscript is on ionomer actuators. RP BarCohen, Y (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 15 Z9 15 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2454-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 3041 BP 697 EP 701 DI 10.1117/12.275721 PG 5 WC Acoustics; Engineering, Mechanical; Optics SC Acoustics; Engineering; Optics GA BJ06V UT WOS:A1997BJ06V00061 ER PT B AU Lih, SS BarCohen, Y Grandia, W AF Lih, SS BarCohen, Y Grandia, W BE Regelbrugge, ME TI Rotary ultrasonic motors actuated by traveling flexural waves SO SMART STRUCTURES AND INTEGRATED SYSTEMS - SMART STRUCTURES AND MATERIALS 1997 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Integrated Systems - Smart Structures and Materials 1997 CY MAR 03-06, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, USAF Wright Lab, Def Adv Res Projects Agcy, Amer Inst Chem Engineers, Amer Phys Soc, Div Mat Phys, Ceram Soc Japan, USA Res Lab, Intelligent Mat Forum, Japan DE actuators; active materials; piezoelectric motors; ultrasonic motors (USMs); stators and rotors; modal analysis AB Ultrasonic rotary motors are being developed as actuators for miniature spacecraft instruments and subsystems. The technology that has emerged in commercial products requires rigorous analytical tools for effective design of such motors. An analytical model was developed to examine the excitation of flexural plate wave traveling in a rotary piezoelectrically actuated motor. The model uses annular finite elements that are applied to predict the excitation frequency and modal response of the annular stator. This model allows to design efficient ultrasonic motors (USMs) and it incorporates the details of the stator which include the teeth, piezoelectric crystals, stator geometry, etc. The theoretical predictions and the experimental corroboration showed a remarkable agreement. Parallel to this effort, USMs are made and incorporated into a robotic arm and their capability to operate at the environment of Mars is being studied. RP Lih, SS (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 2 Z9 2 U1 2 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2454-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 3041 BP 912 EP 917 DI 10.1117/12.275717 PG 6 WC Acoustics; Engineering, Mechanical; Optics SC Acoustics; Engineering; Optics GA BJ06V UT WOS:A1997BJ06V00083 ER PT B AU Schenker, PS BarCohen, Y Brown, DK Lindemann, RA Garrett, MS Baumgartner, ET Lee, S Lih, SS Joffe, B AF Schenker, PS BarCohen, Y Brown, DK Lindemann, RA Garrett, MS Baumgartner, ET Lee, S Lih, SS Joffe, B BE Regelbrugge, ME TI A composite manipulator utilizing rotary piezoelectric motors: New robotic technologies for Mars in-situ planetary science SO SMART STRUCTURES AND INTEGRATED SYSTEMS - SMART STRUCTURES AND MATERIALS 1997 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Structures and Integrated Systems - Smart Structures and Materials 1997 CY MAR 03-06, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers, Soc Exptl Mech Inc, Amer Soc Mech Engineers, USAF Wright Lab, Def Adv Res Projects Agcy, Amer Inst Chem Engineers, Amer Phys Soc, Div Mat Phys, Ceram Soc Japan, USA Res Lab, Intelligent Mat Forum, Japan DE robots; actuators; composites; space exploration; sample acquisition AB We report a significant advance in space robotics design based on innovation of 3D composite structures and piezoelectric actuation. The essence of this work is development of a new all-composite robotic manipulator utilizing rotary ultrasonic motors (USM). ''MarsArmII'' is 40% lighter than a prior ''MarsArmI'' JPL design based in more massive, bulky hybrid metal-composite, joint-link system architecture and DC-motor driven actuation. MarsArmII is a four d.o.f. torso-shoulder-elbow, wrist-pitch robot of over two meters length, weighing four kilograms, and carrying a one kilogram multi-functional science effector with actuated opposable scoops, micro-viewing camera, and active tooling (abrader). MarsArmII construction is composite throughout, with all critical load-bearing joints and effector components being based in a new 3D air layup carbon fiber RTM composite process of our design, and links formed of 2D graphite epoxy. The 3D RTM composite is machinable by traditional metal shop practice, and in early tests such parts bench-marked favorably with aluminum based designs. Each arm link incorporates a surface mounted semiconductor strain gauge, enabling force-referenced closed loop positioning. The principal arm joints are six in-lb rotary USMs acting under optically encoded PLD servo control through harmonic drives. We have demonstrated the MarsArmII system for inverse kinematics positioning tasks (utilizing computes vision derived stereo workspace coordinates) that include simulated Martian soil trenching, sample acquisition and instrument transfers, and fresh rock surface exposure by abrasion. RP Schenker, PS (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MS 125-224,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2454-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 3041 BP 918 EP 926 DI 10.1117/12.275719 PG 9 WC Acoustics; Engineering, Mechanical; Optics SC Acoustics; Engineering; Optics GA BJ06V UT WOS:A1997BJ06V00084 ER PT S AU Baghdadchi, J Homaifar, A AF Baghdadchi, J Homaifar, A GP IEEE TI Decision making in an environment with unknown parameters SO SMC '97 CONFERENCE PROCEEDINGS - 1997 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: CONFERENCE THEME: COMPUTATIONAL CYBERNETICS AND SIMULATION SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNATICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 1997 IEEE International Conference on Systems, Man, and Cybernetics - Computational Cybernetics and Simulation (SMC 97) CY OCT 12-15, 1997 CL ORLANDO, FL SP IEEE Syst Man & Cybernet Soc AB Decision making is the core of any control system. The driving metaphor for a traditional decision maker is the existence of an explicit memory base and its ability to analyze and express any situation that the controlled plant experiences, by a set of mutually disjoint rules. The disjoint nature of the rules reflects the fact that in engineering world we tend to partition the problems to smaller tasks, deal with each individual task separately, and then reassemble the overall solution. Given the ever increasing need for mechanical systems operating in environments with unknown parameters, and the fact that certain situations in real-time do not lend themselves easily to this method of partitioning, we are proposing a decision making scheme which develops its own rule base as it goes along and confronts the problems in their entirety, thus, functioning to a great extent like the human brain. RP Baghdadchi, J (reprint author), N CAROLINA AGR & TECH STATE UNIV,NASA,AUTONOMOUS CONTROL ENGN CTR,GREENSBORO,NC 27411, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1062-922X BN 0-7803-4054-X J9 IEEE SYS MAN CYBERN PY 1997 BP 1005 EP 1010 PG 6 WC Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ80Y UT WOS:A1997BJ80Y00174 ER PT S AU Truszkowski, W Grubb, T Murphy, ED Norman, KL AF Truszkowski, W Grubb, T Murphy, ED Norman, KL GP IEEE TI Investigating Human/System Interfaces and Interactions in a ''Lights-Out'' operational environment SO SMC '97 CONFERENCE PROCEEDINGS - 1997 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: CONFERENCE THEME: COMPUTATIONAL CYBERNETICS AND SIMULATION SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNATICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 1997 IEEE International Conference on Systems, Man, and Cybernetics - Computational Cybernetics and Simulation (SMC 97) CY OCT 12-15, 1997 CL ORLANDO, FL SP IEEE Syst Man & Cybernet Soc AB The concepts of ''Lights-Out'' operations and Human/Computer Interfaces and Interactions (HCI) are not incongruous ideas. The concept of automated operations without the immediate presence of people raises interesting and complicated issues associated with human/computer interfaces and interactions when, in fact, people are integrated back into and must interact with the automated operational environment for some complicated problem-solving exercise. The cognitive research proposed to investigate these issues will focus first on the representation question, that is, how best to represent system status to the remotely-located analyst. Studies will be conducted to test the efficacy of several three-dimensional (3D) techniques for problem representation which have been developed at NASA-Goddard Space Flight Center. RP Truszkowski, W (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1062-922X BN 0-7803-4054-X J9 IEEE SYS MAN CYBERN PY 1997 BP 1168 EP 1173 PG 6 WC Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ80Y UT WOS:A1997BJ80Y00203 ER PT S AU Rouff, C Message, P AF Rouff, C Message, P GP IEEE TI Modeling space systems with the Data Systems Dynamic Simulator Plus SO SMC '97 CONFERENCE PROCEEDINGS - 1997 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: CONFERENCE THEME: COMPUTATIONAL CYBERNETICS AND SIMULATION SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNATICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 1997 IEEE International Conference on Systems, Man, and Cybernetics - Computational Cybernetics and Simulation (SMC 97) CY OCT 12-15, 1997 CL ORLANDO, FL SP IEEE Syst Man & Cybernet Soc AB The Data Systems Dynamic Simulator Plus (DSDS+) is a discrete-event-based simulator used to simulate complex, high-data-rate, end-to-end systems. It was developed for the specific purpose of evaluating candidate data systems for spacecraft. DSDS+ features a graphical user interface and hierarchical modeling. A data system is modeled in DSDS+ by selecting pre-programmed elements from the simulation library, placing them in a work area, and connecting them together using direct manipulation to form a model of an end-to-end system. When using DSDS+ the user has access to a library of standard pre-programmed elements. These elements represent tailorable components of NASA data systems and can be connected in any logical manner. Additional elements can also be developed which allows the more sophisticated user the option of extending the standard element set. Next, DSDS+ supports the use of data streams simulation. Data streams is the name given to a technique that ignores packet boundaries, but is sensitive to rate changes. Because rate changes are rare compared to packet arrivals in a typical NASA data system, data stream simulations require a fi action of the CPU run time. RP Rouff, C (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 522-1,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1062-922X BN 0-7803-4054-X J9 IEEE SYS MAN CYBERN PY 1997 BP 1274 EP 1279 PG 6 WC Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ80Y UT WOS:A1997BJ80Y00221 ER PT S AU Kim, YT Akbarzadeh, MR Lee, DW Lee, SR AF Kim, YT Akbarzadeh, MR Lee, DW Lee, SR GP IEEE TI Adaptive fuzzy sliding mode control of a direct drive motor SO SMC '97 CONFERENCE PROCEEDINGS - 1997 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: CONFERENCE THEME: COMPUTATIONAL CYBERNETICS AND SIMULATION SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNATICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 1997 IEEE International Conference on Systems, Man, and Cybernetics - Computational Cybernetics and Simulation (SMC 97) CY OCT 12-15, 1997 CL ORLANDO, FL SP IEEE Syst Man & Cybernet Soc AB A new approach to stable adaptive fuzzy sliding mode control of systems is proposed. The proposed scheme does not require an accurate mathematical model, yet it guarantees asymptotic stability. It incorporates an integral term in the sliding surface which eliminates steady state error. To verify the actual performance of the proposed controller, it is then applied to a position control of direct drive motor with payload and parameter uncertainty. Since direct drive motors do not have reduction gears, the variation of the load and the disturbance torque directly influence parameter changes in motor dynamics. RP Kim, YT (reprint author), UNIV NEW MEXICO,NASA,CTR AUTONOMOUS CONTROL ENGN ACE,ELECT ENGN & COMP ENGN BLDG,ALBUQUERQUE,NM 87131, USA. NR 0 TC 0 Z9 1 U1 0 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1062-922X BN 0-7803-4054-X J9 IEEE SYS MAN CYBERN PY 1997 BP 1668 EP 1673 PG 6 WC Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ80Y UT WOS:A1997BJ80Y00291 ER PT S AU Kumbla, KK Jamshidi, M AF Kumbla, KK Jamshidi, M GP IEEE TI Real time control of a direct drive motor by a learning neuro-fuzzy controller SO SMC '97 CONFERENCE PROCEEDINGS - 1997 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: CONFERENCE THEME: COMPUTATIONAL CYBERNETICS AND SIMULATION SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNATICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 1997 IEEE International Conference on Systems, Man, and Cybernetics - Computational Cybernetics and Simulation (SMC 97) CY OCT 12-15, 1997 CL ORLANDO, FL SP IEEE Syst Man & Cybernet Soc AB A neuro-fussy controller is presented which uses neural networks (NN) to modify the parameters of an adaptive fuzzy logic controller. The adaptiveness of the fuzzy controller is derived from a rule generation mechanism and changing the scaling factor or the shape of the membership functions. The neural network functions as a classifier of the system's temporal responses. A multi-layer perceptron NN is used to classify the temporal response of the system into different patterns. Depending on the type of pattern such as ''response with overshoot'', ''damped response'', ''oscillating response'' etc. the scaling factor of the input and output membership functions are adjusted to make the system respond in a desired manner. The rule generation mechanism also utilises the temporal response of the system to evaluate new fuzzy rules. The non-redundant rules are appended to the existing rule base during the tuning cycles. This controller architecture is used in real-time to control a direct drive motor. The control system hardware utilizes a digital signal processor and a PC to implement the controller architecture. Experimental results using this controller on a direct drive motor control are illustrated. RP Kumbla, KK (reprint author), UNIV NEW MEXICO,NASA,CTR AUTONOMOUS CONTROL ENGN,DEPT ELECT & COMP ENGN,ALBUQUERQUE,NM 87131, USA. NR 0 TC 0 Z9 1 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1062-922X BN 0-7803-4054-X J9 IEEE SYS MAN CYBERN PY 1997 BP 1674 EP 1679 PG 6 WC Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ80Y UT WOS:A1997BJ80Y00292 ER PT S AU Patterson, FG Evans, RP AF Patterson, FG Evans, RP GP IEEE TI Objects preserve options SO SMC '97 CONFERENCE PROCEEDINGS - 1997 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: CONFERENCE THEME: COMPUTATIONAL CYBERNETICS AND SIMULATION SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNATICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 1997 IEEE International Conference on Systems, Man, and Cybernetics - Computational Cybernetics and Simulation (SMC 97) CY OCT 12-15, 1997 CL ORLANDO, FL SP IEEE Syst Man & Cybernet Soc AB We describe a unique perspective on the value of using objects in system development as a vehicle for ''nominating-up'' design options for decisions that are then the basis for requirements. We show how using objects preserves options - capitalizing on available system knowledge bl,enabling the scheduling of design decisions to coincide with the availability of requisite knowledge. We also present the advantages of ''nominating-up'' design options for customer decision, an approach that contrasts completely with the more traditional model of customers ''imposing-down'' so-called ''what'' requirements in advance of any ''how'' design option trades. A primary benefit is seen to be that the ''nominate-up'' identification of options is a primary means to achieve the needed system knowledge that the use of objects can then effectively employ. RP Patterson, FG (reprint author), NASA,WASHINGTON,DC 20546, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1062-922X BN 0-7803-4054-X J9 IEEE SYS MAN CYBERN PY 1997 BP 1843 EP 1848 PG 6 WC Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ80Y UT WOS:A1997BJ80Y00321 ER PT S AU Trujillo, AC AF Trujillo, AC GP IEEE TI Pilot performance with predictive system status information SO SMC '97 CONFERENCE PROCEEDINGS - 1997 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: CONFERENCE THEME: COMPUTATIONAL CYBERNETICS AND SIMULATION SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNATICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 1997 IEEE International Conference on Systems, Man, and Cybernetics - Computational Cybernetics and Simulation (SMC 97) CY OCT 12-15, 1997 CL ORLANDO, FL SP IEEE Syst Man & Cybernet Soc AB Research has shown a strong pilot preference for predictive information of aircraft system status in the flight deck. However, the benefits of predictive information have not been quantitatively demonstrated. The study described here attempted to identify and quantify these benefits if they existed. In this simulator experiment, three types of predictive information (none, whether a parameter was changing abnormally, and the time for a parameter to reach an alert range) and four initial times to an alert (1 minute, 5 minutes, 15 minutes, and ETA+45 minutes) were found to affect when subjects accomplished certain actions, such as accessing pertinent checklists, declaring emergencies, diverting, and calling the flight attendant and dispatch. RP Trujillo, AC (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1062-922X BN 0-7803-4054-X J9 IEEE SYS MAN CYBERN PY 1997 BP 1972 EP 1977 PG 6 WC Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ80Y UT WOS:A1997BJ80Y00343 ER PT S AU Schutte, PC Willshire, KF AF Schutte, PC Willshire, KF GP IEEE TI Designing to control flight crew errors SO SMC '97 CONFERENCE PROCEEDINGS - 1997 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: CONFERENCE THEME: COMPUTATIONAL CYBERNETICS AND SIMULATION SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNATICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 1997 IEEE International Conference on Systems, Man, and Cybernetics - Computational Cybernetics and Simulation (SMC 97) CY OCT 12-15, 1997 CL ORLANDO, FL SP IEEE Syst Man & Cybernet Soc AB It is widely accepted that human error is a major contributing factor in aircraft accidents. There has been a significant amount of research in why these errors occurred and many reports state that the design of flight deck can actually dispose humans to err. This research has led to the call for changes in design according to human factors and human-centered principles. The National Aeronautics and Space Administration's (NASA) Langley Research Center has initiated an effort to design a human-centered flight deck from a clean slate (i.e., without constraints of existing designs.) The effort will be based on recent research in human-centered design philosophy and mission management categories. This design will match the human's model of the mission and function of the aircraft to reduce unnatural or nonintuitive interfaces. The product of this effort will be a flight deck design description, including training and procedures, and a cross reference or paper trail back to design hypotheses, and an evaluation of the design. The present paper will discuss the philosophy, process, and status of this design effort. RP Schutte, PC (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1062-922X BN 0-7803-4054-X J9 IEEE SYS MAN CYBERN PY 1997 BP 1978 EP 1983 PG 6 WC Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ80Y UT WOS:A1997BJ80Y00344 ER PT S AU Callantine, TJ Palmer, EA Smith, N AF Callantine, TJ Palmer, EA Smith, N GP IEEE TI Model-based crew activity tracking for precision descent procedure refinement SO SMC '97 CONFERENCE PROCEEDINGS - 1997 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5: CONFERENCE THEME: COMPUTATIONAL CYBERNETICS AND SIMULATION SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNATICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 1997 IEEE International Conference on Systems, Man, and Cybernetics - Computational Cybernetics and Simulation (SMC 97) CY OCT 12-15, 1997 CL ORLANDO, FL SP IEEE Syst Man & Cybernet Soc AB New procedures for human operators in complex systems must be both operationally effective and inexpensive to introduce. Procedures may require refinement to meet these objectives. This paper illustrates how process measures about operator performance using a new procedure can be derived via activity tracking, and how this information can supplement product measures to support procedure refinement.(1) RP Callantine, TJ (reprint author), NASA,AMES RES CTR,MAIL STOP 262-4,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 1062-922X BN 0-7803-4054-X J9 IEEE SYS MAN CYBERN PY 1997 BP 3126 EP 3131 PG 6 WC Computer Science, Cybernetics; Computer Science, Interdisciplinary Applications SC Computer Science GA BJ80Y UT WOS:A1997BJ80Y00546 ER PT B AU Miller, DF AF Miller, DF GP SOC TECH COMMUN TI Using the web to bring space science and technology down to earth SO SOCIETY FOR TECHNICAL COMMUNICATION 44TH ANNUAL CONFERENCE, 1997 PROCEEDINGS LA English DT Proceedings Paper CT 44th Annual Conference of the Society-for-Technical-Communication CY MAY 11-14, 1997 CL TORONTO, CANADA SP Soc Tech Commun AB At JPL, the World-Wide Web has become an invaluable educational outreach mechanism. In the area of space flight mission operations, for example, we have been able to make publicly accessible two workbooks found to be of much wider interest than their original internal training purposes would have suggested. These electronic documents, by using simple language and illustrations, and focusing on pithy content and good writing style, have met with great success not only in disseminating important scientific and technological concepts to a society pitifully behind the curve in these areas, but also in promoting understanding and enthusiasm for NASA's unmanned space exploration programs. C1 CALTECH,JET PROP LAB,MISSION OPERAT SECT,PASADENA,CA 91109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC TECHNICAL COMMUNICATION PI ARLINGTON PA 901 N STUART ST, SUITE 904, ARLINGTON, VA 22203-1854 BN 0-914548-95-6 PY 1997 BP 331 EP 333 PG 3 WC Communication SC Communication GA BJ02T UT WOS:A1997BJ02T00140 ER PT B AU Neal, RD AF Neal, RD BE Tasso, C Pighin, M Adey, RA TI A taxonomy of object-oriented measures SO SOFTWARE QUALITY ENGINEERING LA English DT Proceedings Paper CT 1st International Conference on Software Quality Engineering (SQE 97) CY MAY, 1997 CL UDINE, ITALY SP Univ Udine, Italy, Wessex Inst Technol, Assoc Italiana Calcolo Automatico, GR INF CEDES & HERMES SOFTLAB AB Software and software development are extremely complex. We should not expect to measure something so complex with one, two, or even a dozen measures. Measures have to be developed to allow us to view software from many perspectives. To facilitate this process, this paper builds on taxonomies proposed by [1] and [16] that not only allows us to classify measures but also helps us model the object-oriented space. In this paper, as per [8], a metric is any proposed measurement (not necessarily validated); a measure is a validated metric, i.e., all measures are metrics but not all metrics are measures. RP Neal, RD (reprint author), W VIRGINIA UNIV,NASA,SOFTWARE RES LAB,100 UNIV DR,FAIRMONT,WV 26554, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COMPUTATIONAL MECHANICS PUBLICATIONS LTD PI SOUTHAMPTON PA ASHURST LODGE, SOUTHAMPTON, HANTS, ENGLAND S04 2AA BN 1-85312-403-6 PY 1997 BP 213 EP 221 PG 9 WC Computer Science, Software Engineering; Engineering, Multidisciplinary SC Computer Science; Engineering GA BJ12E UT WOS:A1997BJ12E00020 ER PT J AU Jain, RK Flood, DJ AF Jain, RK Flood, DJ TI Effects of recombination parameters in p(+)n indium phosphide solar cells SO SOLAR ENERGY MATERIALS AND SOLAR CELLS LA English DT Article DE efficiency; indium phosphide InP; solar cells; space applications AB This work, using a numerical code PC-1D, describes the effects of surface and bulk recombination on the performance of p(+)n indium phosphide solar cells. It is shown that surface recombination velocity and minority carrier diffusion lengths play a dominant role in controlling the efficiency of p(+)n cells. In order to have an acceptable series resistance, a pin cell must have an emitter that is thicker than a nip cell emitter. Consequently the performance of a p(+)n cell is more sensitive to the front surface recombination velocity. Improved surface and bulk recombination parameters can lead to cell efficiencies in excess of 24% AMO at 25 degrees C. RP Jain, RK (reprint author), NASA, LEWIS RES CTR, CLEVELAND, OH 44135 USA. NR 11 TC 1 Z9 1 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0248 J9 SOL ENERG MAT SOL C JI Sol. Energy Mater. Sol. Cells PD JAN 1 PY 1997 VL 45 IS 1 BP 51 EP 55 DI 10.1016/S0927-0248(96)00056-6 PG 5 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA WE338 UT WOS:A1997WE33800006 ER PT J AU Frohlich, C Andersen, BN Appourchaux, T Berthomieu, G Crommelynck, DA Domingo, V Fichot, A Finsterle, W Gomez, MF Gough, D Jimenez, A Leifsen, T Lombaerts, M Pap, JM Provost, J Cortes, TR Romero, J Roth, H Sekii, T Telljohann, U Toutain, T Wehrli, C AF Frohlich, C Andersen, BN Appourchaux, T Berthomieu, G Crommelynck, DA Domingo, V Fichot, A Finsterle, W Gomez, MF Gough, D Jimenez, A Leifsen, T Lombaerts, M Pap, JM Provost, J Cortes, TR Romero, J Roth, H Sekii, T Telljohann, U Toutain, T Wehrli, C TI First results from VIRGO, the experiment for helioseismology and solar irradiance monitoring on SOHO SO SOLAR PHYSICS LA English DT Article ID P-MODES AB First results from the VIRGO experiment (Variability of solar IRradiance and Gravity Oscillations) on the ESA/NASA Mission SOHO (Solar and Heliospheric Observatory) are reported. The observations started mid-January 1996 for the radiometers and sunphotometers and near the end of March for the luminosity oscillation imager. The performance of all the instruments is very good, and the time series of the first 4-6 months are evaluated in terms of solar irradiance variability, solar background noise characteristics and p-mode oscillations. The solar irradiance is modulated by the passage of active regions across the disk, but not all of the modulation is straightforwardly explained in terms of sunspot flux blocking and facular enhancement. Helioseismic inversions of the observed p-mode frequencies are more-or-less in agreement with the latest standard solar models. The comparison of VIRGO results with earlier ones shows evidence that magnetic activity plays a significant role in the dynamics of the oscillations beyond its modulation of the resonant frequencies. Moreover, by comparing the amplitudes of different components of p-mode multiplets, each of which are influenced differently by spatial inhomogeneity, we have found that activity enhances excitation. C1 NORWEGIAN SPACE CTR,N-0309 OSLO 3,NORWAY. EUROPEAN SPACE AGCY,ESTEC,DEPT SPACE SCI,NL-2200 AG NOORDWIJK,NETHERLANDS. OBSERV COTE AZUR,DEPT CASSINI,URA 1362,CNRS,F-06304 NICE 4,FRANCE. INST ROYAL METEOROL BELGIQUE,B-1180 BRUSSELS,BELGIUM. UNIV LA LAGUNA,E-38071 LA LAGUNA,SPAIN. UNIV CAMBRIDGE,INST ASTRON,CAMBRIDGE CB3 0HA,ENGLAND. UNIV CAMBRIDGE,DEPT APPL MATH & THEORET PHYS,CAMBRIDGE CB3 9EW,ENGLAND. UNIV OSLO,INST THEORET ASTROPHYS,N-0315 OSLO,NORWAY. UNIV CALIF LOS ANGELES,DEPT PHYS & ASTRON,DIV ASTRON & ASTROPHYS,LOS ANGELES,CA 90095. CALTECH,JET PROP LAB,PASADENA,CA 91109. RP Frohlich, C (reprint author), PHYS METEOROL OBSERV DAVOS,WORD RADIAT CTR,CH-7260 DAVOS,SWITZERLAND. NR 26 TC 181 Z9 184 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JAN PY 1997 VL 170 IS 1 BP 1 EP 25 DI 10.1023/A:1004969622753 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WP474 UT WOS:A1997WP47400001 ER PT J AU Kosovichev, AG Schou, J Scherrer, PH Bogart, RS Bush, RI Hoeksema, JT Aloise, J Bacon, L Burnette, A DeForest, C Giles, PM Leibrand, K Nigam, R Rubin, M Scott, K Williams, SD Basu, S ChristensenDalsgaard, J Dappen, W Rhodes, EJ Duvall, TL Howe, R Thompson, MJ Gough, DO Sekii, T Toomre, J Tarbell, TD Title, AM Mathur, D Morrison, M Saba, JLR Wolfson, CJ Zayer, I Milford, PN AF Kosovichev, AG Schou, J Scherrer, PH Bogart, RS Bush, RI Hoeksema, JT Aloise, J Bacon, L Burnette, A DeForest, C Giles, PM Leibrand, K Nigam, R Rubin, M Scott, K Williams, SD Basu, S ChristensenDalsgaard, J Dappen, W Rhodes, EJ Duvall, TL Howe, R Thompson, MJ Gough, DO Sekii, T Toomre, J Tarbell, TD Title, AM Mathur, D Morrison, M Saba, JLR Wolfson, CJ Zayer, I Milford, PN TI Structure and rotation of the solar interior: Initial results from the MDI medium-l program SO SOLAR PHYSICS LA English DT Article ID OSCILLATIONS; CONVECTION; EXCITATION; DEPTH; MODES AB The medium-l program of the Michelson Doppler Imager instrument on board SOHO provides continuous observations of oscillation modes of angular degree, l, from 0 to similar to 300. The data for the program are partly processed on board because only about 3% of MDI observations can be transmitted continuously to the ground. The on-board data processing, the main component of which is Gaussian-weighted binning, has been optimized to reduce the negative influence of spatial aliasing of the high-degree oscillation modes. The data processing is completed in a data analysis pipeline at the SOI Stanford Support Center to determine the mean multiplet frequencies and splitting coefficients. The initial results show that the noise in the medium-l oscillation power spectrum is substantially lower than in ground-based measurements. This enables us to detect lower amplitude modes and, thus, to extend the range of measured mode frequencies. This is important for inferring the Sun's internal structure and rotation. The MDI observations also reveal the asymmetry of oscillation spectral lines. The line asymmetries agree with the theory of mode excitation by acoustic sources localized in the upper convective boundary layer. The sound-speed profile inferred from the mean frequencies gives evidence for a sharp variation at the edge of the energy-generating core. The results also confirm the previous finding by the GONG (Gough et al., 1996) that, in a thin layer just beneath the convection zone, helium appears to be less abundant than predicted by theory. Inverting the multiplet frequency splittings from MDI, we detect significant rotational shear in this thin layer. This layer is likely to be the place where the solar dynamo operates. In order to understand how the Sun works, it is extremely important to observe the evolution of this transition layer throughout the 11-year activity cycle. C1 AARHUS UNIV,THEORET ASTROPHYS CTR,DANISH NATL RES FDN,DK-8000 AARHUS C,DENMARK. AARHUS UNIV,INST PHYS & ASTRON,DK-8000 AARHUS C,DENMARK. UNIV SO CALIF,DEPT PHYS & ASTRON,LOS ANGELES,CA 90089. NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771. UNIV LONDON QUEEN MARY & WESTFIELD COLL,ASTRON UNIT,LONDON E1 4NS,ENGLAND. UNIV CAMBRIDGE,INST ASTRON,CAMBRIDGE CB3 0HA,ENGLAND. UNIV CAMBRIDGE,DEPT APPL MATH & THEORET PHYS,CAMBRIDGE CB3 0HA,ENGLAND. UNIV COLORADO,JILA,COLORADO SPRINGS,CO 80309. LOCKHEED MARTIN ADV TECHNOL CTR,PALO ALTO,CA 94304. PARALLEL RULES INC,LOS GATOS,CA 95030. RP Kosovichev, AG (reprint author), STANFORD UNIV,WW HANSEN EXPT PHYS LAB,STANFORD,CA 94305, USA. RI Duvall, Thomas/C-9998-2012; Basu, Sarbani/B-8015-2014 OI Basu, Sarbani/0000-0002-6163-3472 NR 44 TC 240 Z9 240 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JAN PY 1997 VL 170 IS 1 BP 43 EP 61 DI 10.1023/A:1004949311268 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WP474 UT WOS:A1997WP47400003 ER PT J AU Duvall, TL Kosovichev, AG Scherrer, PH Bogart, RS Bush, RI DeForest, C Hoeksema, JT Schou, J Saba, JLR Tarbell, TD Title, AM Wolfson, CJ Milford, PN AF Duvall, TL Kosovichev, AG Scherrer, PH Bogart, RS Bush, RI DeForest, C Hoeksema, JT Schou, J Saba, JLR Tarbell, TD Title, AM Wolfson, CJ Milford, PN TI Time-distance helioseismology with the MDI instrument: Initial results SO SOLAR PHYSICS LA English DT Article AB In time-distance helioseismology, the travel time of acoustic waves is measured between various points on the solar surface. To some approximation, the waves can be considered to follow ray paths that depend only on a mean solar model, with the curvature of the ray paths being caused by the increasing sound speed with depth below the surface. The travel time is affected by various inhomogeneities along the ray path, including flows, temperature inhomogeneities, and magnetic fields. By measuring a large number of times between different locations and using an inversion method, it is possible to construct 3-dimensional maps of the subsurface inhomogeneities. The SOI/MDI experiment on SOHO has several unique capabilities for time-distance helioseismology. The great stability of the images observed without benefit of an intervening atmosphere is quite striking. It has made it possible for us to detect the travel time for separations of points as small as 2.4 Mm in the high-resolution mode of MDI (0.6 are sec pixel(-1)). This has enabled the detection of the supergranulation flow. Coupled with the inversion technique, we can now study the 3-dimensional evolution of the Rows near the solar surface. C1 STANFORD UNIV,WW HANSEN EXPT PHYS LAB,STANFORD,CA 94305. LOCKHEED MARTIN ADV TECHNOL CTR,PALO ALTO,CA 94304. PARALLEL RULES INC,LOS GATOS,CA 95030. RP Duvall, TL (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771, USA. RI Duvall, Thomas/C-9998-2012 NR 8 TC 169 Z9 169 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JAN PY 1997 VL 170 IS 1 BP 63 EP 73 DI 10.1023/A:1004907220393 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WP474 UT WOS:A1997WP47400004 ER PT J AU Wilhelm, K Lemaire, P Curdt, W Schuhle, U Marsch, E Poland, AI Jordan, SD Thomas, RJ Hassler, DM Huber, MCE Vial, JC Kuhne, M Siegmund, OHW Gabriel, A Timothy, JG Grewing, M Feldman, U Hollandt, J Brekke, P AF Wilhelm, K Lemaire, P Curdt, W Schuhle, U Marsch, E Poland, AI Jordan, SD Thomas, RJ Hassler, DM Huber, MCE Vial, JC Kuhne, M Siegmund, OHW Gabriel, A Timothy, JG Grewing, M Feldman, U Hollandt, J Brekke, P TI First results of the SUMER telescope and spectrometer on SOHO .1. Spectra and spectroradiometry SO SOLAR PHYSICS LA English DT Article ID SOLAR SPECTRUM; TRANSITION REGION; EXPLOSIVE EVENTS; LINES; SPECTROGRAPH; CHROMOSPHERE; CORONA; ATM; INSTRUMENTS; ATMOSPHERE AB SUMER - the Solar Ultraviolet Measurements of the Emitted Radiation instrument on the Solar and Heliospheric Observatory (SOHO) - observed its first light on January 24, 1996, and subsequently obtained a detailed spectrum with detector B in the wavelength range from 660 to 1490 Angstrom (in first order) inside and above the limb in the north polar coronal hole. Using detector A of the instrument, this range was later extended to 1610 Angstrom. The second-order spectra of detectors A and B cover 330 to 805 Angstrom and are superimposed on the first-order spectra. Many more features and areas of the Sun and their spectra have been observed since, including coronal holes, polar plumes and active regions. The atoms and ions emitting this radiation exist at temperatures below 2 x 10(6) K and are thus ideally suited to investigate the solar transition region where the temperature increases from chromospheric to coronal values. SUMER can also be: operated in a manner such that it makes Images or spectroheliograms of different sizes in selected spectral lines. A detailed line profile with spectral resolution elements between 22 and 45 m Angstrom is produced for each line at each spatial location along the slit. From the line width, intensity and wavelength position we are able to deduce temperature, density, and velocity of the emitting atoms and ions for each emission line and spatial element in the spectroheliogram. Because of the high spectral resolution and low noise of SUMER, we have been able to detect faint lines not previously observed and, in addition, to determine their spectral profiles. SUMER has already recorded over 2000 extreme ultraviolet emission lines and many identifications have been made on the disk and in the corona. C1 UNIV PARIS 11, INST ASTROPHYS SPATIALE, CNRS, F-91405 ORSAY, FRANCE. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NATL CTR ATMOSPHER RES, HIGH ALTITUDE OBSERV, BOULDER, CO 80307 USA. EUROPEAN SPACE AGCY, ESTEC, DEPT SPACE SCI, NL-2200 AG NOORDWIJK, NETHERLANDS. PHYS TECH BUNDESANSTALT, D-10587 BERLIN, GERMANY. UNIV CALIF BERKELEY, SPACE SCI LAB, BERKELEY, CA 94720 USA. UNIV NEW BRUNSWICK, FREDERICTON, NB E3B 5A3, CANADA. INST ASTRON, D-72076 TUBINGEN, GERMANY. USN, RES LAB, WASHINGTON, DC 20375 USA. UNIV OSLO, INST THEORET ASTROPHYS, N-0315 OSLO, NORWAY. RP Wilhelm, K (reprint author), MAX PLANCK INST AERON, D-37189 KATLENBURG DUHM, GERMANY. RI Hollandt, Jorg/A-2124-2014 NR 59 TC 292 Z9 293 U1 0 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JAN PY 1997 VL 170 IS 1 BP 75 EP 104 DI 10.1023/A:1004923511980 PG 30 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WP474 UT WOS:A1997WP47400005 ER PT J AU Lemaire, P Wilhelm, K Curdt, W Schule, U Marsch, E Poland, AI Jordan, SD Thomas, RJ Hassler, DM Vial, JC Kuhne, M Huber, MCE Siegmund, OHW Gabriel, A Timothy, JG Grewing, M AF Lemaire, P Wilhelm, K Curdt, W Schule, U Marsch, E Poland, AI Jordan, SD Thomas, RJ Hassler, DM Vial, JC Kuhne, M Huber, MCE Siegmund, OHW Gabriel, A Timothy, JG Grewing, M TI First results of the SUMER telescope and spectrometer on SOHO .2. Imagery and data management SO SOLAR PHYSICS LA English DT Article ID EXTREME AB SUMER - Solar Ultraviolet Measurements of Emitted Radiation - is not only an extreme ultraviolet (EUV) spectrometer capable of obtaining detailed spectra in the range from 500 to 1610 Angstrom, but, using the telescope mechanisms, it also provides monochromatic images over the full solar disk and beyond, into the corona, with high spatial resolution. We report on some aspects of the observation programmes that have already led us to a new view of many aspects of the Sun, including quiet Sun, chromospheric and transition region network, coronal hole, polar plume, prominence and active region studies. After an introduction, where we compare the SUMER imaging capabilities to previous experiments in our wavelength range, we describe the results of tests performed in order to characterize and optimize the telescope under operational conditions. We find the spatial resolution to be 1.2 are sec across the slit and 2 are sec (2 detector pixels) along the slit. Resolution and sensitivity are adequate to provide details on the structure, physical properties, and evolution of several solar features which we then present. Finally some information is given on the data availability and the data management system. C1 MAX PLANCK INST AERON,D-37189 KATLENBURG DUHM,GERMANY. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. NATL CTR ATMOSPHER RES,HIGH ALTITUDE OBSERV,BOULDER,CO 80307. PHYS TECH BUNDESANSTALT,D-10587 BERLIN,GERMANY. EUROPEAN SPACE AGCY,ESTEC,DEPT SPACE SCI,NL-2200 AG NOORDWIJK,NETHERLANDS. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. UNIV NEW BRUNSWICK,FREDERICTON,NB E3B 5A3,CANADA. INST ASTRON,D-72076 TUBINGEN,GERMANY. RP Lemaire, P (reprint author), UNIV PARIS 11,INST ASTROPHYS SPATIALE,CNRS,BAT 121,F-91405 ORSAY,FRANCE. NR 19 TC 226 Z9 229 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JAN PY 1997 VL 170 IS 1 BP 105 EP 121 DI 10.1023/A:1004994702333 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WP474 UT WOS:A1997WP47400006 ER PT J AU Harrison, RA Fludra, A Pike, CD Payne, J Thompson, WT Poland, AI Breeveld, ER Breeveld, AA Culhane, JL KjeldsethMoe, O Huber, MCE Aschenbach, B AF Harrison, RA Fludra, A Pike, CD Payne, J Thompson, WT Poland, AI Breeveld, ER Breeveld, AA Culhane, JL KjeldsethMoe, O Huber, MCE Aschenbach, B TI High-resolution observations of the extreme ultraviolet sun SO SOLAR PHYSICS LA English DT Article AB This paper presents first results of the Coronal Diagnostic Spectrometer (CDS) recently launched aboard the Solar and Heliospheric Observatory (SOHO). CDS is a twin spectrometer, operating in the extreme ultraviolet range 151-785 Angstrom. Thus, it can detect emission lines from trace elements in the corona and transition region which will be used to provide diagnostic information on the solar atmosphere. In this paper, we present early spectra and images, to illustrate the performance of the instrument and to pave the way for future studies. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. UCL, MULLARD SPACE SCI LAB, DORKING RH5 6NT, SURREY, ENGLAND. UNIV OSLO, INST THEORET ASTROPHYS, N-0315 OSLO, NORWAY. EUROPEAN SPACE AGCY, DEPT SPACE SCI, NL-2200 AG NOORDWIJK, NETHERLANDS. MAX PLANCK INST EXTRATERR PHYS, D-85748 GARCHING, GERMANY. RP Harrison, RA (reprint author), RUTHERFORD APPLETON LAB, DIV ASTROPHYS, DIDCOT OX11 0QX, OXON, ENGLAND. RI Thompson, William/D-7376-2012 NR 3 TC 76 Z9 76 U1 1 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD JAN PY 1997 VL 170 IS 1 BP 123 EP 141 DI 10.1023/A:1004913326580 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WP474 UT WOS:A1997WP47400007 ER PT S AU Williams, RM Ryan, MA Saipetch, C LeDuc, HG AF Williams, RM Ryan, MA Saipetch, C LeDuc, HG BE Davies, PK Jacobson, AJ Torardi, CC Vanderah, TA TI A quantitative tunneling/desorption model for the exchange current at the porous electrode beta''-alumina alkali metal gas three phase zone at 700-1300K SO SOLID-STATE CHEMISTRY OF INORGANIC MATERIALS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Solid-State Chemistry of Inorganic Materials CY DEC 02-05, 1996 CL BOSTON, MA SP Mat Res Soc, Natl Sci Fdn, Univ Houston, Texas Ctr Superconduct, DuPont Co, Exxon Res & Engn Co AB The exchange current observed at porous metal electrodes on sodium or potassium beta ''-alumina solid electrolytes in alkali metal vapor is quantitatively modeled with a multi-step process with good agreement with experimental results. No empirically adjusted parameters were used, although some physical parameters have poor precision. Steps include: (1) diffusion of Na ions to the reaction site; (2) stretching of the Na+ ionic bond with the beta ''-alumina surface to reach a configuration suitable for accepting an electron to form a surface bound Na-0 atom; (3) electron tunneling from the Mo electrode to the ions; and (4) desorption of Na-0 atoms weakly bound at the reaction site on the beta ''-alumina surface; (5) electron tunneling between Na-0 or Na+ on the defect block and (6) Na-0 and/or Na+ mobility on the spinel block surface may extend the reaction area substantially. The rate is increasingly dominated by the region close to the three-phase boundary as temperature increases and the rate near the three-phase boundary increases fastest, because desorption has a higher energy than reorganization. At high temperatures, surface diffusion of Na+ ions from the defect block edges to the spinel block edges is responsible for an increase in the total effective reaction zone area near the three-phase boundary. RP Williams, RM (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 MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-357-6 J9 MATER RES SOC SYMP P PY 1997 VL 453 BP 597 EP 604 PG 8 WC Chemistry, Inorganic & Nuclear; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA BH92W UT WOS:A1997BH92W00089 ER PT B AU Wang, Y AF Wang, Y BE Blouke, MM TI Surface plasmon high efficiency projection display SO SOLID STATE SENSOR ARRAYS: DEVELOPMENT AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Solid State Sensor Arrays - Development and Applications CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, Soc Photo Opt Instrumentat Engineers AB A novel projection display, based on a new phenomenon of voltage-induced color-selective absorption with surface plasmons, is able to generate bright image on a large screen with high efficiency. In addition, neither color filter nor phosphor is needed to generate the color. With an incident beam of +/-7 degrees half cone angle, the color purity of this device can be as good as the CRT displays, and the contrast ratio can reach over 200:1. System analysis shows that, for a color sequential single panel 1.8'' surface plasmon projector, the luminous efficiency can reach 3 Lumens/Watt, and for a 1.8'' surface plasmon ''smart card'' projector, the luminous efficiency can reach over 10 Lumens/Watt. RP Wang, Y (reprint author), CALTECH,JET PROP LAB,M-S 300-315,PASADENA,CA 91009, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2430-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 3019 BP 35 EP 40 DI 10.1117/12.275188 PG 6 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BH76F UT WOS:A1997BH76F00004 ER PT B AU YadidPecht, O Mansoorian, B Fossum, ER Pain, B AF YadidPecht, O Mansoorian, B Fossum, ER Pain, B BE Blouke, MM TI Optimization of noise and responsivity in CMOS active pixel sensors for detection of ultra low light levels SO SOLID STATE SENSOR ARRAYS: DEVELOPMENT AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Solid State Sensor Arrays - Development and Applications CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, Soc Photo Opt Instrumentat Engineers AB In this paper, we present results of the investigation of the design and operation of CMOS active pixel sensors for detection of ultra-low light levels. We present a detailed noise model of APS pixel and signal chain. Utilizing the noise model, we have developed APS pixel designs that can achieve ultra-low noise and high responsivity. We present results from two test chips, that indicate (1) that less than 5 electrons of read noise is possible with CMOS APS by reducing the size of the pixel transistors, and (2) that high responsivity can be achieved when the fill-factor of the photodiode is reduced. RP YadidPecht, O (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 33 Z9 33 U1 1 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2430-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 3019 BP 125 EP 136 DI 10.1117/12.275185 PG 12 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BH76F UT WOS:A1997BH76F00011 ER PT B AU Nikzad, S Smith, AL Elliott, ST Jones, TJ Tombrello, TA Yu, Q AF Nikzad, S Smith, AL Elliott, ST Jones, TJ Tombrello, TA Yu, Q BE Blouke, MM TI Low-energy electron detection with delta-doped CCDs SO SOLID STATE SENSOR ARRAYS: DEVELOPMENT AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Solid State Sensor Arrays - Development and Applications CY FEB 10-11, 1997 CL SAN JOSE, CA SP Soc Imaging Sci & Technol, Soc Photo Opt Instrumentat Engineers AB Delta-doped CCDs have achieved stable quantum efficiency, at the theoretical limit imposed by reflection from the Si surface in the near UV and visible. In this approach, an epitaxial silicon layer is grown on a fully-processed CCD using molecular beam epitaxy. During the silicon growth on the CCD, 30% of a monolayer of boron atoms are deposited nominally within a single atomic layer, resulting in the effective elimination of the backside potential well. In this paper, we will briefly discuss delta-doped CCDs and their application of to low-energy electron detection. We show that modification of the surface this way can greatly improve sensitivity to low-energy electrons. Measurements comparing the response of delta-doped CCDs with untreated CCDs were made in the 50 eV-1.5 keV energy range. For electrons with energies below 300 eV, the signal from untreated CCDs was below the detection limit for our apparatus, and data are presented only for the response of delta-doped CCDs at these energies. The effects of multiple electron hole pair (EHP) production and backscattering on the observed signals are discussed. RP Nikzad, S (reprint author), CALTECH,JET PROP LAB,CTR SPACE MICROELECT TECHNOL,PASADENA,CA 91109, USA. NR 0 TC 4 Z9 4 U1 0 U2 3 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2430-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 3019 BP 241 EP 248 DI 10.1117/12.275183 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BH76F UT WOS:A1997BH76F00023 ER PT S AU Nicogossian, AE AF Nicogossian, AE BE Bainum, PM May, GL Nagatomo, M Uesugi, KT Fu, BC Zhang, H TI Microgravity research and exploration SO SPACE COOPERATION INTO THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 7th International Space Conference of Pacific Basin Societies (7th ISCOPS) - Space Cooperation into the 21st-Century CY JUL 15-18, 1997 CL NAGASAKI, JAPAN SP Japanese Rocket Soc, Chinese Soc Astronaut, Amer Astronaut Soc C1 NASA, Off Life & Micrograv Sci & Applicat, Washington, DC 20546 USA. RP Nicogossian, AE (reprint author), NASA, Off Life & Micrograv Sci & Applicat, Code 4,300 E St SW, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-438-9 J9 ADV ASTRONAUT SCI PY 1997 VL 96 BP 11 EP 22 PG 12 WC Engineering, Aerospace SC Engineering GA BK50K UT WOS:000072379900001 ER PT S AU Schumacher, JD AF Schumacher, JD BE Bainum, PM May, GL Nagatomo, M Uesugi, KT Fu, BC Zhang, H TI NASA - A look to the future SO SPACE COOPERATION INTO THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 7th International Space Conference of Pacific Basin Societies (7th ISCOPS) - Space Cooperation into the 21st-Century CY JUL 15-18, 1997 CL NAGASAKI, JAPAN SP Japanese Rocket Soc, Chinese Soc Astronaut, Amer Astronaut Soc C1 NASA, Washington, DC 20546 USA. RP Schumacher, JD (reprint author), NASA, 300 E St SW, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-438-9 J9 ADV ASTRONAUT SCI PY 1997 VL 96 BP 29 EP 39 PG 11 WC Engineering, Aerospace SC Engineering GA BK50K UT WOS:000072379900003 ER PT S AU Diarra, C AF Diarra, C BE Bainum, PM May, GL Nagatomo, M Uesugi, KT Fu, BC Zhang, H TI Mars exploration program at JPL: The 1996 missions SO SPACE COOPERATION INTO THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Meeting Abstract CT 7th International Space Conference of Pacific Basin Societies (7th ISCOPS) - Space Cooperation into the 21st-Century CY JUL 15-18, 1997 CL NAGASAKI, JAPAN SP Japanese Rocket Soc, Chinese Soc Astronaut, Amer Astronaut Soc C1 CALTECH, Jet Prop Lab, Mars Explorat Program Off, Pasadena, CA 91109 USA. RP Diarra, C (reprint author), CALTECH, Jet Prop Lab, Mars Explorat Program Off, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-438-9 J9 ADV ASTRONAUT SCI PY 1997 VL 96 BP 331 EP 331 PG 1 WC Engineering, Aerospace SC Engineering GA BK50K UT WOS:000072379900033 ER PT S AU Kallemeyn, P Cook, R Spear, A Golombek, M AF Kallemeyn, P Cook, R Spear, A Golombek, M BE Bainum, PM May, GL Nagatomo, M Uesugi, KT Fu, BC Zhang, H TI The Mars Pathfinder mission SO SPACE COOPERATION INTO THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 7th International Space Conference of Pacific Basin Societies (7th ISCOPS) - Space Cooperation into the 21st-Century CY JUL 15-18, 1997 CL NAGASAKI, JAPAN SP Japanese Rocket Soc, Chinese Soc Astronaut, Amer Astronaut Soc AB On July 4th, 1997, Mars Pathfinder became the third spacecraft to successfully land on the planet Mars. The mission's primary objective was to demonstrate a low-cost system for delivering a small science payload to the surface of Mars, and to test the operation of a rover. Scientific objectives include the characterization of the geological and elemental composition of rocks and soil near the lander, imaging, and measurement of the temperature and pressure during descent and at the surface. The Sojourner microrover is capable of traversing tens of meters from the lander to analyze racks and soil in the immediate area The lander's primary mission is 30 Martian days (30 Sols) after landing, with an extended mission lasting for one year. This paper describes the science instruments, the spacecraft and the rover, and a summary of the flight operations history from launch through the second day on the surface. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kallemeyn, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-438-9 J9 ADV ASTRONAUT SCI PY 1997 VL 96 BP 333 EP 346 PG 14 WC Engineering, Aerospace SC Engineering GA BK50K UT WOS:000072379900034 ER PT S AU Palluconi, FD Albee, AL AF Palluconi, FD Albee, AL BE Bainum, PM May, GL Nagatomo, M Uesugi, KT Fu, BC Zhang, H TI Mars Global Surveyor: On the way to Mars SO SPACE COOPERATION INTO THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 7th International Space Conference of Pacific Basin Societies (7th ISCOPS) - Space Cooperation into the 21st-Century CY JUL 15-18, 1997 CL NAGASAKI, JAPAN SP Japanese Rocket Soc, Chinese Soc Astronaut, Amer Astronaut Soc AB The Mars Global Surveyor (MCS) spacecraft was launched toward Mars on 7 November 1996 and will arrive at Mars on 12 September 1997. This mission is the first in the extensive NASA Mars Surveyor Program and had a two year development period. In this report the status of the MGS mission, prior to entry into Mars orbit, will be described along with a description of the experiments to be conducted. The Mars Global Surveyor mission is intended to accomplish a portion of the scientific objectives of the Mars Observer mission which was lost in 1993, three days before entering Mars orbit. To meet the established objectives a low, sun-synchronous, near circular, polar-mapping orbit is required which drives the need for aerobraking before mapping begins in March of 1998. MGS will carry a lander to orbiter relay capability for use with several small probes to be dropped to the surface of Mars by the 1998 Surveyor mission and the Surveyor lander. The MGS mission is designed for one Mars year (687 days) of mapping operation at Mars and will overlap in time the 1998 Surveyor mission and the start of the Planet B mission providing the opportunity to conduct cooperative experiments with multiple landed and orbiting vehicles at Mars. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Palluconi, FD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 183-501, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-438-9 J9 ADV ASTRONAUT SCI PY 1997 VL 96 BP 347 EP 355 PG 9 WC Engineering, Aerospace SC Engineering GA BK50K UT WOS:000072379900035 ER PT S AU Ohsaka, K Rhim, WK AF Ohsaka, K Rhim, WK BE Bainum, PM May, GL Nagatomo, M Uesugi, KT Fu, BC Zhang, H TI Electrostatic levitation technique for thermophysical property measurements of molten materials on Earth and in space SO SPACE COOPERATION INTO THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 7th International Space Conference of Pacific Basin Societies (7th ISCOPS) - Space Cooperation into the 21st-Century CY JUL 15-18, 1997 CL NAGASAKI, JAPAN SP Japanese Rocket Soc, Chinese Soc Astronaut, Amer Astronaut Soc AB Themophysical properties of high temperature molten materials are measured using an electrostatic levitator in combination with several diagnostic devices. An objective of this study is to find the limitation of the earth-based measurements in order to evaluate the necessity of similar measurements in space, It is found that the hemispherical total emissivity, specific heat, specific volume, density and surface tension can be satisfactorily measured by the earth-based measurements. The viscosity measurement is not conclusive because of the suspected interference by the levitation force on the measurement. Further investigation is necessary to elucidate the degree of the interference by performing the same measurement under a short duration microgravity environment realized on earth. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Rhim, WK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 183-401, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-438-9 J9 ADV ASTRONAUT SCI PY 1997 VL 96 BP 501 EP 510 PG 10 WC Engineering, Aerospace SC Engineering GA BK50K UT WOS:000072379900049 ER PT S AU Kirkham, G AF Kirkham, G BE Bainum, PM May, GL Nagatomo, M Uesugi, KT Fu, BC Zhang, H TI Bridging the value gap: A discussion about offsets SO SPACE COOPERATION INTO THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 7th International Space Conference of Pacific Basin Societies (7th ISCOPS) - Space Cooperation into the 21st-Century CY JUL 15-18, 1997 CL NAGASAKI, JAPAN SP Japanese Rocket Soc, Chinese Soc Astronaut, Amer Astronaut Soc C1 NASA, Off External Relat, Washington, DC 20546 USA. RP Kirkham, G (reprint author), NASA, Off External Relat, 300 E St SW, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-438-9 J9 ADV ASTRONAUT SCI PY 1997 VL 96 BP 537 EP 539 PG 3 WC Engineering, Aerospace SC Engineering GA BK50K UT WOS:000072379900053 ER PT S AU Hawes, WM AF Hawes, WM BE Bainum, PM May, GL Nagatomo, M Uesugi, KT Fu, BC Zhang, H TI International space station: Moving to flight SO SPACE COOPERATION INTO THE 21ST CENTURY SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT 7th International Space Conference of Pacific Basin Societies (7th ISCOPS) - Space Cooperation into the 21st-Century CY JUL 15-18, 1997 CL NAGASAKI, JAPAN SP Japanese Rocket Soc, Chinese Soc Astronaut, Amer Astronaut Soc C1 NASA, Washington, DC 20546 USA. RP Hawes, WM (reprint author), NASA, 300 E St SW, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 USA SN 1081-6003 BN 0-87703-438-9 J9 ADV ASTRONAUT SCI PY 1997 VL 96 BP 567 EP 569 PG 3 WC Engineering, Aerospace SC Engineering GA BK50K UT WOS:000072379900056 ER PT S AU Potter, AE Mulrooney, M AF Potter, AE Mulrooney, M BE Flury, W TI Liquid metal mirror for optical measurements of orbital debris SO SPACE DEBRIS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT B0.7 Symposium of COSPAR Scientific Commission on Space Debris, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP COSPAR, Int Acad Astron, Int Astron Federat, Int Astron Union, UN Off Outer Space Affairs AB A telescope employing a liquid metal (mercury) mirror that is three meters in diameter was developed for the purpose of measuring the population of small orbital debris. The telescope is installed at a 9,000 ft site in the mountains of New Mexico at a latitude of 32.98 degrees, and has completed final optical performance tests. A Ford 2048 x 2048 CCD detector is used at the image plane. With this detector, the limiting stellar magnitude of the telescope was measured to be 23 at a S/N of about 3, with a nominal full width, half maximum for stellar images of 1.3 arcsec. Safety problems with toxic mercury vapor were minimal at operating temperatures below 60 F, greatly simplifying operations with the mirror. Performance of the telescope for debris at geosynchronous orbit (GEO) altitudes is estimated to be in the range 5 to 10 cm using the existing CCD detector. However, at its present location in New Mexico, the telescope cannot be used for detection of debris in the GEO region, since it cannot see debris with inclinations below 32 degrees. Performance of the telescope for debris in low earth orbit depends on the kind of detector that is used. Efforts were made to use the CCD detector for fast-moving low earth orbit debris by reading out the detector at the same rate and in the same direction as the debris object crosses the field of view of the telescope. In this mode, the telescope was capable of detecting debris as small as 3 centimeters at 900 km altitude. However, this mode is very inefficient, since debris moving in other directions is not detected. Observations have also been done using an intensified CCD video camera as the detector. The limiting detectable size for this detector was about 4 centimeters at 500 km, and 7 centimeters at 1000 km. A design was developed for the optimum detector for fast-moving debris in low earth orbit based on currently available technology. This is a 1024x1024 element CCD detector operating at 200 frames per second, with pixels binned to 16x16. This detector should be capable of detecting 1 cm debris at 500 km and 1.5 cm debris at 1000 km. New data processing algorithms will be required to process the data stream from this detector. Published by Elsevier Science Ltd on behalf of COSPAR. C1 LOCKHEED MARTIN ENGN SERV, HOUSTON, TX 77058 USA. RP Potter, AE (reprint author), NASA, LYNDON B JOHNSON SPACE CTR, HOUSTON, TX 77058 USA. NR 4 TC 16 Z9 16 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043099-6 J9 ADV SPACE RES-SERIES PY 1997 VL 19 IS 2 BP 213 EP 219 DI 10.1016/S0273-1177(97)00003-3 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BH61Y UT WOS:A1997BH61Y00002 ER PT S AU Zhang, J Kessler, DJ Matney, MJ Eichler, P Reynolds, RC AnzMeador, PD Stansbery, EG AF Zhang, J Kessler, DJ Matney, MJ Eichler, P Reynolds, RC AnzMeador, PD Stansbery, EG BE Flury, W TI The NASA engineering model: A new approach SO SPACE DEBRIS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT B0.7 Symposium of COSPAR Scientific Commission on Space Debris, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP COSPAR, Int Acad Astron, Int Astron Federat, Int Astron Union, UN Off Outer Space Affairs AB A computer-based semi-empirical orbital debris model has been developed which combines direct measurements of the environment with the output and theory of more complex orbital debris models. It approximates the environment with 6 different inclination bands. Each band has a unique distribution of semi-major axis, for near circular orbits, and a unique perigee distribution, for highly elliptical orbits. In addition, each inclination band has unique size distributions which depend on the source of debris. Collision probability equations are used to relate the distributions of orbital elements to flux on a spacecraft or through the field of vie iv of a ground sensor. The distributions of semimajor axis, perigee, and inclination are consistent with the U.S. Space Command catalogue for sizes larger than about 10 cm, taking the limitations of the sensors into account. For smaller sizes, these distributions are adjusted to be consistent with the nux measured by ground telescopes, the Haystack radar, and the Goldstone radar as well as the flux measured by the Long Duration Exposure Facility (LDEF) and the Space Shuttle. The computer program requires less than 1 second to calculate the flux and velocity distribution for a given size debris relative to an orbiting spacecraft. (C) 1997 COSPAR. C1 NASA, LYNDON B JOHNSON SPACE CTR, HOUSTON, TX 77058 USA. VIKING SCI & TECHNOL INC, HOUSTON, TX 77058 USA. RP Zhang, J (reprint author), LOCKHEED MARTIN ENGN & SCI SERV, 2400 NASA RD 1, HOUSTON, TX 77058 USA. NR 10 TC 0 Z9 1 U1 1 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043099-6 J9 ADV SPACE RES-SERIES PY 1997 VL 19 IS 2 BP 281 EP 290 DI 10.1016/S0273-1177(97)00013-6 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BH61Y UT WOS:A1997BH61Y00013 ER PT S AU Reynolds, RC Loftus, JP Kessler, DJ AF Reynolds, RC Loftus, JP Kessler, DJ BE Flury, W TI Issues arising from the NASA Safety Standard to control orbital debris SO SPACE DEBRIS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT B0.7 Symposium of COSPAR Scientific Commission on Space Debris, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP COSPAR, Int Acad Astron, Int Astron Federat, Int Astron Union, UN Off Outer Space Affairs AB In 1992 NASA adopted a policy to limit the generation of orbital debris. This policy is stated in NASA Management Instruction (NIM) 1700.8, and provides a general statement of policy to take action to limit orbital debris generation if this action is cost effective and consistent with achieving mission objectives. The only specific requirement in the policy is to perform debris assessments during development of NASA programs. To implement this policy, the NASA Office of Safety and Mission Assurance, the sponsor of NMI 1700.8, tasked NASA Johnson Space Center (JSC) with developing guidelines to implement the policy. This tasking resulted in the development of NASA Safety Standard 1740.14: Guidelines and Assessment Procedures for Limiting Orbital Debris. The Safety Standard has been reviewed and approved by all NASA organizations and NASA programs are now required to perform two debris evaluations, one at Preliminary Design Review (PDR) and a second 45 days prior to Critical Design Review, once the final space system design has been approved. The purpose of the first report is to identify potential problems that a program may encounter in meeting the guidelines, and the second report is to document efforts by the program to resolve those problems. At this point in time, a primary concern by NASA managers has been the issue of postmission disposal of low Earth orbit systems and upper stages left in high eccentricity orbits. These systems in general wish to deorbit using atmospheric drag to limit the remaining orbit lifetime to 25 years, as stated by the guidelines. To address this issue, JSC has started a series of studies to investigate the most efficient options for reducing orbit lifetime. In this paper we will review issues raised by the NASA community and the responses that have been made to resolve concerns. Two studies that were designed to minimize costs for postmission disposal will also be discussed in this paper. The first investigates options for disposal maneuvers of upper stages that minimize the cost impact on upper stage development. The second investigates options for high altitude low Earth orbit satellites (e.g. Sun-synchronous spacecraft) that have no significant on-board propulsion. (C) 1997 COSPAR. C1 NASA, LYNDON B JOHNSON SPACE CTR, HOUSTON, TX 77058 USA. RP Reynolds, RC (reprint author), LOCKHEED MARTIN ENGN & SCI SERV, 2400 NASA RD 1, HOUSTON, TX 77058 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043099-6 J9 ADV SPACE RES-SERIES PY 1997 VL 19 IS 2 BP 381 EP 389 DI 10.1016/S0273-1177(97)00021-5 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BH61Y UT WOS:A1997BH61Y00026 ER PT B AU Soffen, G AF Soffen, G BE Haskell, G Rycroft, M TI Lessons learned from the Viking missions which are relevant to Mission to Planet Earth SO SPACE OF SERVICE TO HUMANITY: PRESERVING EARTH AND IMPROVING LIFE SE SPACE STUDIES LA English DT Proceedings Paper CT International Symposium on Space of Service to Humanity - Preserving Earth and Improving Life CY FEB 05-07, 1996 CL STRASBOURG, FRANCE SP Int Space Univ, Comm Earth Observat Satellites, IEEE, Commun Soc, UN Off Outer Space Affairs AB The Viking missions to Mars (1976) were pioneering soft lander/orbiters to search for evidence of life, map the planet, and combine several measurements and observations to characterize the surface. The missions lasted on the surface over five years and involved the dedicated work of hundreds of scientists for over a decade (1968-83). This massive scientific and engineering undertaking was comprehensive and educated many about thinking holistically about the planets. From these thoughts about Mars (our sister planet) came a new view of the Earth, and this gave rise to Earth System Science, a recognized interdisciplinary field of study. Earth System Science is an approach to understanding how the physical-chemical-biological processes interact and influence each other. This permits an understanding of how the whole system works (as contrasted by the disciplinary nature of each individual field of research). This systems approach produces a strategy between observation and modeling that allows an understanding of the ''whole'', in the same way as systems engineering reveals the understanding of the ''black box'' in counter distinction to a collection of individual engineering subsystems. This line of thought eventually led to a program called Mission to Planet Earth (MTPE), and to the development of a series of spacecraft observation. MTPE will occupy many hundreds of scientists and thousands of engineers from around the globe for several decades. The demand for these broad overviews and planned comprehensive programs came mostly from scientists who recognized the need to cross disciplinary lines in order to understand their particular scientific problems. RP Soffen, G (reprint author), NASA,GODDARD SPACE FLIGHT CTR,UNIV PROGRAMS OFF,CODE 160,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4344-1 J9 SPAC STUD PY 1997 VL 1 BP 65 EP 69 PG 5 WC Environmental Sciences; Environmental Studies; Remote Sensing; Telecommunications SC Environmental Sciences & Ecology; Remote Sensing; Telecommunications GA BJ39V UT WOS:A1997BJ39V00007 ER PT B AU Hornstein, RS Willoughby, JK AF Hornstein, RS Willoughby, JK BE Haskell, G Rycroft, M TI Proposal to apply results of NASA-sponsored research for space operations to improve the quality and quantity of goods and services SO SPACE OF SERVICE TO HUMANITY: PRESERVING EARTH AND IMPROVING LIFE SE SPACE STUDIES LA English DT Proceedings Paper CT International Symposium on Space of Service to Humanity - Preserving Earth and Improving Life CY FEB 05-07, 1996 CL STRASBOURG, FRANCE SP Int Space Univ, Comm Earth Observat Satellites, IEEE, Commun Soc, UN Off Outer Space Affairs AB NASA-sponsored research has produced a basic framework for characterizing space mission operations and for structuring systems that enable cost-effective operations planning and execution. The researchers never wavered from their focus on simplicity and generality as the means of realizing demonstrable operational effectiveness and life cycle economies. As a result, the framework can be transferred beyond the space program communities to domains that were not originally the targets of the effort. The story line of this paper is a proposal to transform the space operations results into innovative solutions for preserving Earth and improving life. The authors describe the space operations framework and suggest that its methodology, associated technology, and decision-support strategies can be applied in managing environmental factors, human capabilities, and natural resources that are the determinants of the quality of life on Earth. A concept for reusability of space mission program elements is also presented. Called ''Fundamental Reusables for Enterprise Deployment'' or ''FRED'', this was formulated in response to a challenge from the NASA Administrator to confront the status quo (of developing mission-peculiar, project-unique, and organization-specific systems) and recommend a target architecture for providing cross-cutting and cost-cutting Agency services for space mission operations. The authors propose to explore the relevance of a FRED-like concept for sustainable exploitation of a nation's resources. The paper is authored by members of NASA's COST LESS Team for Mission Operations, an international, interdisciplinary, and non-parochial team of government, industry, and academia, charged with reducing the cost of success for space mission operations. RP Hornstein, RS (reprint author), NASA,COST LESS TEAM,WASHINGTON,DC 20546, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4344-1 J9 SPAC STUD PY 1997 VL 1 BP 249 EP 259 PG 11 WC Environmental Sciences; Environmental Studies; Remote Sensing; Telecommunications SC Environmental Sciences & Ecology; Remote Sensing; Telecommunications GA BJ39V UT WOS:A1997BJ39V00025 ER PT J AU Escoubet, CP Schmidt, R Goldstein, ML AF Escoubet, CP Schmidt, R Goldstein, ML TI Cluster - Science and mission overview SO SPACE SCIENCE REVIEWS LA English DT Article ID FLUX-TRANSFER EVENTS; EARTHS BOW SHOCK; SOLAR-WIND; MAGNETOSPHERE; MAGNETOPAUSE; SIGNATURES; PLASMA; SHAPE; FIELD; HOT AB The European Space Agency's Cluster programme is designed to study the small-scale spatial and temporal characteristics of the magnetospheric and near-Earth solar wind plasma. The programme is composed of four identical spacecraft which will be able to make physical measurements in three dimensions. The relative distance between the four spacecraft will be varied between 200 and 18 000 km during the course of the mission. This paper provides a general overview of the scientific objectives, the configuration and the orbit of the four spacecraft and the relation of Cluster to other missions. C1 NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. RP Escoubet, CP (reprint author), EUROPEAN SPACE AGCY,EUROPEAN SPACE RES & TECHNOL CTR,DEPT SPACE SCI,POB 299,NL-2200 AG NOORDWIJK,NETHERLANDS. RI Goldstein, Melvyn/B-1724-2008 NR 26 TC 151 Z9 154 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JAN PY 1997 VL 79 IS 1-2 BP 11 EP 32 DI 10.1023/A:1004923124586 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WN946 UT WOS:A1997WN94600003 ER PT J AU Balogh, A Dunlop, MW Cowley, SWH Southwood, DJ Thomlinson, JG Glassmeier, KH Musmann, G Luhr, H Buchert, S Acuna, MH Fairfield, DH Slavin, JA Riedler, W Schwingenschuh, K Kivelson, MG AF Balogh, A Dunlop, MW Cowley, SWH Southwood, DJ Thomlinson, JG Glassmeier, KH Musmann, G Luhr, H Buchert, S Acuna, MH Fairfield, DH Slavin, JA Riedler, W Schwingenschuh, K Kivelson, MG TI The Cluster magnetic field investigation SO SPACE SCIENCE REVIEWS LA English DT Article ID SHOCK RE-FORMATION; UPSTREAM WAVES; PARALLEL; SIMULATIONS AB The Cluster mission provides a new opportunity to study plasma processes and structures in the near-Earth plasma environment. Four-point measurements of the magnetic field will enable the analysis of the three dimensional structure and dynamics of a range of phenomena which shape the macroscopic properties of the magnetosphere. Difference measurements of the magnetic field data will be combined to derive a range of parameters, such as the current density vector, wave vectors, and discontinuity normals and curvatures, using classical time series analysis techniques iteratively with physical models and simulation of the phenomena encountered along the Cluster orbit. The control and understanding of error sources which affect the four-point measurements are integral parts of the analysis techniques to be used. The flight instrumentation consists of two, tri-axial fluxgate magnetometers and an on-board data-processing unit on each spacecraft, built using a highly fault-tolerant architecture. High vector sample rates (up to 67 vectors s(-1)) at high resolution (up to 8 pT) are combined with on-board event detection software and a burst memory to capture the signature of a range of dynamic phenomena. Data-processing plans are designed to ensure rapid dissemination of magnetic-field data to underpin the collaborative analysis of magnetospheric phenomena encountered by Cluster. C1 TECH UNIV CAROLO WILHELMINA BRAUNSCHWEIG,INST GEOPHYS & METEOROL,D-3300 BRAUNSCHWEIG,GERMANY. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. INST WELTRAUMFORSCH,GRAZ,AUSTRIA. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024. RP Balogh, A (reprint author), UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,PRINCE CONSORT RD,LONDON,ENGLAND. RI dunlop, malcolm/F-1347-2010; Kivelson, Margaret/I-9019-2012; Slavin, James/H-3170-2012 OI Kivelson, Margaret/0000-0003-3859-8581; Slavin, James/0000-0002-9206-724X NR 39 TC 344 Z9 348 U1 0 U2 15 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JAN PY 1997 VL 79 IS 1-2 BP 65 EP 91 DI 10.1023/A:1004970907748 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WN946 UT WOS:A1997WN94600005 ER PT J AU Riedler, W Torkar, K Rudenauer, F Fehringer, M Pedersen, A Schmidt, R Grard, RJL Arends, H Narheim, BT Troim, J Torbert, R Olsen, RC Whipple, E Goldstein, R Valavanoglou, N Zhao, H AF Riedler, W Torkar, K Rudenauer, F Fehringer, M Pedersen, A Schmidt, R Grard, RJL Arends, H Narheim, BT Troim, J Torbert, R Olsen, RC Whipple, E Goldstein, R Valavanoglou, N Zhao, H TI Active spacecraft potential control SO SPACE SCIENCE REVIEWS LA English DT Article ID METAL ION-SOURCE; PLASMA; PHOTOEMISSION; INSTABILITY; CYCLOTRON; EMISSION; DENSITY AB Charging of the outer surface or of the entire structure of a spacecraft in orbit can have a severe impact on the scientific output of the instruments. Typical floating potentials for magnetospheric satellites (from +1 to several tens of volts in sunlight) make it practically impossible to measure the cold (several eV) component of the ambient plasma. Effects of spacecraft charging are reduced by an entirely conductive surface of the spacecraft and by active charge neutralisation, which in the case of Cluster only deals with a positive potential. The Cluster spacecraft are instrumented with ion emitters of the liquid-metal ion-source type, which will produce indium ions at 5 to 8 keV energy. The operating principle is field evaporation of indium in the apex field of a needle. The advantages are low power consumption, compactness and high mass efficiency. The ion current will be adjusted in a feedback loop with instruments measuring the spacecraft potential (EFW and PEACE). A stand alone mode is also foreseen as a back-up. The design and principles of the operation of the active spacecraft potential control instrument (ASPOC) are presented in detail. Flight experience with a similar instrument on the Geotail spacecraft is outlined. C1 OSTERREICH FORSCHUNGSZENT SEIBERSDORF GMBH,A-2444 SEIBERSDORF,AUSTRIA. EUROPEAN SPACE AGCY,EUROPEAN SPACE RES & TECHNOL CTR,DEPT SPACE SCI,NL-2200 AG NOORDWIJK,NETHERLANDS. FORSVARETS FORSKNINGINST,N-2007 KJELLER,NORWAY. UNIV NEW HAMPSHIRE,DURHAM,NH 03824. USN,POSTGRAD SCH,MONTEREY,CA 93943. UNIV WASHINGTON,SEATTLE,WA 98195. CALTECH,JET PROP LAB,PASADENA,CA 91109. GRAZ TECH UNIV,A-8010 GRAZ,AUSTRIA. CHINESE ACAD SCI,CTR SPACE SCI & APPL RES,BEIJING 100080,PEOPLES R CHINA. RP Riedler, W (reprint author), AUSTRIAN ACAD SCI,INST WELTRAUMFORSCH,INFFELDGASSE 12,A-8010 GRAZ,AUSTRIA. RI Olsen, Richard/O-2699-2015 OI Olsen, Richard/0000-0002-8344-9297 NR 38 TC 34 Z9 34 U1 1 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD JAN PY 1997 VL 79 IS 1-2 BP 271 EP 302 DI 10.1023/A:1004921614592 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WN946 UT WOS:A1997WN94600013 ER PT S AU White, NE AF White, NE BE ElGenk, MS TI Future horizons in X-ray astronomy SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Some possible X-ray astronomy missions that may follow the currently approved missions during the first decade of the 21st century are reviewed. These include a high throughput, broadband, and high resolution X-ray spectroscopy mission; a deep all-sky X-ray survey; a wide field of view X-ray telescope; a spectroscopic survey of the hot interstellar medium; and a next generation all-sky monitor. RP White, NE (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,CODE 662,GREENBELT,MD 20771, USA. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 0 TC 0 Z9 1 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 1 EP 6 DI 10.1063/1.51990 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00001 ER PT S AU Marshall, F Phenix, J White, N Tananbaum, H Bookbinder, J AF Marshall, F Phenix, J White, N Tananbaum, H Bookbinder, J BE ElGenk, MS TI Mission study of HTXS SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The High Throughput X-ray Spectroscopy (HTXS) mission is under study for flight during the first decade of the next century. This paper provides a status report of the on-going optimization of the mission design including spacecraft, orbit, launch vehicle, mission operations, and instruments. The scientific instrumentation consists of two co-aligned X-ray telescope systems with the corresponding detectors. The Spectroscopic X-ray Telescope (SXT) covers the 0.25 to 12 keV band with a spectral resolution of more than 300 and an effective area of about 1.5 m**2 at 1 keV. A Hard X-ray Telescope (HXT) system will also use focusing optics to extend the bandpass up to at least 40 keV. Six identical spacecraft will be launched within about two years on a Delta 2-class launch vehicle. An extendable optical bench is a key supporting technology for this mission so that launch vehicles of modest size can be used A light-weight dewar with a lifetime of 5 years is another key supporting technology. RP Marshall, F (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 662,GREENBELT,MD 20771, USA. RI White, Nicholas/B-6428-2012 OI White, Nicholas/0000-0003-3853-3462 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 7 EP 10 DI 10.1063/1.52114 PG 4 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00002 ER PT S AU Stahle, CK Kelley, RL Moseley, SH Mott, DB Szymkowiak, AE Finkbeiner, FM Gendreau, KC Porter, FS McCammon, D Juda, M Zhang, J AF Stahle, CK Kelley, RL Moseley, SH Mott, DB Szymkowiak, AE Finkbeiner, FM Gendreau, KC Porter, FS McCammon, D Juda, M Zhang, J BE ElGenk, MS TI Calorimeters for very high resolution x-ray spectroscopy SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB In our work following the invention of the x-ray calorimeter, we improved the resolution to 7.3 eV, at which point our emphasis changed from demonstration to application. Our recent calorimeter development effort has proceeded along two tracks, one for soft (<1 keV) x-rays and the other for broad band (0.5 - 12 keV) x-ray spectroscopy. We have achieved 10 - 15 eV resolution with 0.25 mm(2) pixels with HgTe absorbers providing high quantum efficiency through 12 keV, and we have achieved 7 - 10 eV resolution with 1 mm(2) pixels with HgTe absorbers providing high quantum efficiency through 1 keV. Our future calorimeter development will continue to be guided by the different demands of soft x-ray and hard x-ray band experiments. In the soft band, improvements to the existing technology should improve the uniformity of performance across an array and improve the spectral resolution, to perhaps as good as 2 eV. Major improvement in the hard band will require the development of alternative thermometers to replace the ion-implanted silicon thermistors now used. We will summarize the status of the technology and will report the results of our latest development efforts. RP Stahle, CK (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 662,GREENBELT,MD 20771, USA. RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Porter, Frederick/0000-0002-6374-1119; NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 11 EP 17 DI 10.1063/1.51904 PG 7 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00003 ER PT S AU Gehrels, N Macomb, D AF Gehrels, N Macomb, D BE ElGenk, MS TI Gamma-ray astronomy: Promise for the future SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB We are in a very active period in gamma-ray astronomy due primarily to new discoveries from the Compton Gamma Ray Observatory (CGRO). While the near future looks bright with the ESA INTEGRAL mission scheduled for launch in similar to 2001, there are currently no major missions being planned beyond INTEGRAL and none being planned at all by NASA. This paper reviews current missions and then looks beyond INTEGRAL to see what mission concepts are being considered. Based on new technologies that are under development such as Si strip detectors for tracking electron-positron pairs in high-energy instruments, CdZnTe strip detectors for fine spatial resolution of hard x-rays, and grazing incidence mirrors with multilayer coatings that work in the 10 - 100 keV range, several exciting new concepts for future instruments and missions are under study. These include intermediate class high-energy gamma-ray missions (30 MeV - 300 GeV) with two order-of-magnitude better point-source sensitivity than the current EGRET instrument on CGRO, intermediate class focusing-optics hard xray missions with micro-Crab sensitivities (two order-of-magnitude better than the Rossi X-ray Timing Explorer), MIDEX class hard x-ray (10 - 200 keV) all-sky survey missions with much better sensitivity and angular resolution than previous surveys, and SMEX and MIDEX class gamma-ray burst missions that can locate bursts to arcsecond accuracies to allow deep counterpart searches at other wavelengths. RP Gehrels, N (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,GREENBELT,MD 20771, USA. RI Gehrels, Neil/D-2971-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 25 EP 30 DI 10.1063/1.52001 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00005 ER PT S AU Bennett, CL AF Bennett, CL BE ElGenk, MS TI Submillimeter astronomy and cosmology SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB In this paper I summarize some key astrophysics questions and the future space missions needed to address them. These missions, and the questions that drive them, fall under the aegis of two of the four thematic areas of NASA's Office of Space Science: ''The Astronomical Search for Origins and Planetary Systems'' covers astrophysics in the near-infrared, optical, and ultraviolet wavelengths (100 mu m - 912 Angstrom); and ''Structure and Evolution of the Universe,'' covers astrophysics in the remaining gamma-ray, x-ray, far-infrared/submillimeter, and radio wavelengths. This paper focuses on future space missions in the long wavelength (lambda > 100 mu m) regime of the Structure and Evolution of the Universe area. RP Bennett, CL (reprint author), GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20071, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 31 EP 36 DI 10.1063/1.52010 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00006 ER PT S AU Bilbro, JW Coulter, DD Martin, GL AF Bilbro, JW Coulter, DD Martin, GL BE ElGenk, MS TI Technology requirements and plans for the Next Generation Space Telescope SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB This paper discusses the concepts and key technologies associated with the Next Generation Space Telescope, a space based telescope that would be developed and launched as a follow-on to the Hubble Space Telescope in the 2005 - 2007 time frame. The telescope is conceived as being optimized in the near infrared region (1-5 microns), but with instruments capable of observing from the visible all the way to 30 microns. The material contained in this presentation is drawn from three separate studies. Two of the studies resulted in an 8 meter diameter deployable telescope launched on an Atlas II-AS, the third study developed the concept of a 6 meter diameter monolithic telescope which would be launched on a rocket with a 6 meter shroud. The planned technology program is also discussed. RP Bilbro, JW (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,MAIL CODE EB51,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 51 EP 56 DI 10.1063/1.52137 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00010 ER PT S AU Mather, JC Seery, BD Bely, PY Stockman, HS AF Mather, JC Seery, BD Bely, PY Stockman, HS BE ElGenk, MS TI The Next Generation Space Telescope (NGST) - Scientific requirements SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The scientific requirements and the implications for the instruments and telescope design for the Next Generation Space Telescope are described. One candidate concept is a deployable 8 meter diameter telescope optimized for the near infrared region (1-5 mu m), but with instruments capable of observing from the visible all the way to 30 mu m. The observatory is radiatively cooled to about 30 K and could be launched on an Atlas II-AS to the Lagrange Point L2. RP Mather, JC (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 685,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 57 EP 62 DI 10.1063/1.52049 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00011 ER PT S AU Unwin, S Boden, A Shao, M AF Unwin, S Boden, A Shao, M BE ElGenk, MS TI Space Interferometry Mission SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The Space Interferometry Mission (SIM) is NASA's first space science interferometer, and will enable fundamental new discoveries in both Galactic and extra-galactic astronomy, including cosmic distance scale. It will also address questions related to the origins and prevalence of planetary systems. SIM is designed with a 10m baseline, providing high-throughput 4 mu as global astrometry and synthesis imaging in the visible at a resolution of 10 milliarcsec. It demonstrates several key technologies, including coronagraphic-type 10(4) extinction nulling of a central bright source, needed for future missions in NASA's Origins Program, such as the Next Generation Space Telescope (NGST) and Terrestrial Planet Finder (TPF). RP Unwin, S (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 AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 63 EP 71 DI 10.1063/1.52058 PG 9 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00012 ER PT S AU Rahe, J Gulkis, S AF Rahe, J Gulkis, S BE ElGenk, MS TI Solar System exploration Road Map SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB NASA has commissioned a group of scientists, engineers, educators and technologists to prepare a ''Road Map'' for Solar System exploration which covers the next 15-20 years. This Road Map is expected to serve as a guide for the continuation of Solar System exploration and future space science activities supported by NASA. The Road Map is currently in draft form, however, it is sufficiently developed at this time to be able to describe the process used to generate it, and to give an overview of the current plan. A discussion of the planning process and a status report on the Road Map for Solar System exploration for the next two decades is described in this paper. Emphasis in this paper is on the science goals. RP Rahe, J (reprint author), NASA,OFF SPACE SCI,WASHINGTON,DC 20546, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 73 EP 77 DI 10.1063/1.52074 PG 5 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00013 ER PT S AU Shirley, DL Haynes, NR AF Shirley, DL Haynes, NR BE ElGenk, MS TI The Mars Exploration Program SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The Mars Exploration Program was initiated in 1994. It currently consists of a Discovery mission (Mars Pathfinder which will land in 1997) and the Mars Surveyor Program. The objectives of the Mars Surveyor Program are to launch 2 robotic missions every 26 months to address the three themes of Life, Climate, and Resources, with the focus of initial missions being on volatiles and climate. With the possible discovery of chemical tracers to the former existence of life on Mars in the meteorite ALH84001, the emphasis of the program may shift more towards the search for evidence of past and present life. If so, a program of sample-caching revers, preceded by orbital mapping and followed by sample return missions, has been defined as one possible option for pursuing the life question. An augmentation of the current Mars Exploration Program budget will be required to realize such a life-oriented program. RP Shirley, DL (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MAIL STOP 180-401,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 79 EP 84 DI 10.1063/1.52083 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00014 ER PT S AU Staehle, RL Alkalai, LJ Wyatt, EJ Dohoney, J AF Staehle, RL Alkalai, LJ Wyatt, EJ Dohoney, J BE ElGenk, MS TI Pluto Express: Advanced technologies enable lower cost missions to the outer Solar System and beyond SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Missions to Pluto and the outer Solar System are typically driven by factors which tend to increase cost, such as: long life, high radiation exposure, a large power source, high Delta V requirements, difficult telecommunications links, low solar illumination at the destination, and demanding science measurements. Advanced technology is a central part of responding to such challenges in a manner which permits the cost of development and operations to be an order of magnitude less than for prior outer planet missions. Managing the process of technology planning and advanced development versus the associated cost and mission risk is a formidable challenge. Outer Solar System/Europa/Pluto/Solar Probe development activities are leveraging the latest products from the industry, government lab and academia technology pipeline in the areas of software, low power integrated microelectronics, low mass, high efficiency radioisotope power if used, and telecommunications. This paper summarizes the current technology development plan, which is tightly coupled to the New Millennium Program (NMP) Deep Space I technology validation flight. Specific detail will be presented about advanced microelectronics technology. This technology will also be shown in the context of an on-going technology roadmap that extends beyond the Pluto Express mission. Other details focus on new technologies available for low cost mission operations, and the processes required to best develop and utilize these technologies. The development goal is to create an integrated flight and ground system with the functional simplicity necessary to achieve high reliability, operability, and a low total mission cost. The development process leverages the JPL Flight System Testbed and commercial off-the-shelf (COTS) products. A university partnership provides additional development support and is leading to a partnership for operations. Software technologies for spacecraft self-commanding and self-monitoring play a key role in meeting an operations vision called Beacon Monitoring. This approach is expected to decrease operations cost significantly by reducing the amount of routine interaction with the spacecraft. The experience gathered may be valuable to Earth orbiting missions, the Mars Exploration Program, and Mission to Planet Earth. RP Staehle, RL (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 1 U2 3 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 85 EP 93 DI 10.1063/1.52091 PG 9 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00015 ER PT S AU Wallace, RA Rowley, RW Wercinski, PF AF Wallace, RA Rowley, RW Wercinski, PF BE ElGenk, MS TI Low cost atmospheric probe missions to the outer planets SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Outer planet probe missions are part of the on-going Mission and Technology Roadmap effort to define the framework for the future NASA Solar System Exploration program. The potential science returned from the probe missions is in the break through category and enabled by advanced technologies described in the paper. Technology needs are predicted on mission/system studies carried out over the past several years. A baseline mission/system design is described to which the technology needs can be related. RP Wallace, RA (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 AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 95 EP 100 DI 10.1063/1.52105 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00016 ER PT S AU Lemmerman, LA Wercinski, PF AF Lemmerman, LA Wercinski, PF BE ElGenk, MS TI Small Neptune Orbiter using aerocapture SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Following the successful fly-by reconnaissance of the outer planets achieved by the Pioneer and Voyager spacecraft, the next logical step in planetary exploration involves the long-term, orbital observations of these planets. The Galileo spacecraft is the first such mission to accomplish this goal. The recently-completed Mission to the Solar System Road Map calls for a significant effort to be devoted to future outer planet exploration missions. However, NASA's current strategy for future mission design requires that planetary exploration be accomplished at a significantly lower cost than previous missions. This implies that future missions will be characterized by small spacecraft launched with low cost launch vehicles and operated with minimal ground operations. These pressures create substantial challenges for developers of such missions. Missions to the outer planets escalate these challenges even further due to the large distances involved. In the face of these pressures, moreover, these missions are expected to be high science value, high data return missions. To resolve the apparent conflict between needs and capabilities, a totally new approach is necessary. The study described in this paper is one conducted at JPL over the last year to assess the feasibility of conducting an orbital mission to Neptune consistent with modern challenges to cost and mission capability. For this mission, aerocapture is a critical enabling maneuver and this paper will present a description of that maneuver the supporting design methodologies and the necessary thermal protection system. RP Lemmerman, LA (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 101 EP 110 DI 10.1063/1.51918 PG 10 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00017 ER PT S AU Randolph, JE Ayon, JA Harvey, GD Imbriale, WA Miyake, RN Mueller, RL Nesmith, BJ Turner, PR Dirling, RB Preble, JC Rawal, S Vaughn, WL AF Randolph, JE Ayon, JA Harvey, GD Imbriale, WA Miyake, RN Mueller, RL Nesmith, BJ Turner, PR Dirling, RB Preble, JC Rawal, S Vaughn, WL BE ElGenk, MS TI The technology development status of the Solar Probe SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The continuing development of new spacecraft technologies promises to enable the Solar Probe to be the first mission to travel in the atmosphere or corona of the sun. The most significant technology challenge is the thermal shield that would protect the spacecraft from the flux of 3000 suns (400 W/cm **2) at the perihelion radius of 4 solar radii while allowing the spacecraft subsystems to operate at near room temperature. One of the key design issues of the shield is not simply surviving, but operating at temperatures well above 2000K while minimizing the sublimation from the shield surface. Excessive sublimation could cause interference with the plasma science experiments that are fundamental to the Solar Probe's scientific objectives of measuring the birth and development of the solar wind. The selection of a special type of carbon-carbon as the shield material seems assured at this time. Tests of this material in late 1996 were designed to confirm its optical surface properties and mass loss characteristics and the results are encouraging. The shield concept incorporates dual functions as a thermal shield and as a large high gain antenna. This latter function is important because of the difficult communications environment encountered within the solar corona. A high temperature feed concept under development is discussed here. The NASA guideline requiring non-nuclear power sources has introduced the requirement for alternative power sources. The current concept uses high temperature photovoltaic arrays as well as high energy, low mass batteries to provide power during the perihelion phase of the mission. Testing of photovoltaic cells at high sun angles was completed in 1996 and the results are presented here. Finally, a miniaturized science payload which relies on a the latest advances in analyzer and detector technologies will be developed to minimize mass and power requirements. RP Randolph, JE (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 AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 123 EP 130 DI 10.1063/1.52140 PG 8 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00020 ER PT S AU Tsurutani, BT Leschly, K Nikzad, S Fossum, ER Title, AM Chenette, DL Mann, I Murphy, G Musmann, G Gliem, F Tuzzolino, AJ Killeen, TL Kennedy, BC Moses, SL AF Tsurutani, BT Leschly, K Nikzad, S Fossum, ER Title, AM Chenette, DL Mann, I Murphy, G Musmann, G Gliem, F Tuzzolino, AJ Killeen, TL Kennedy, BC Moses, SL BE ElGenk, MS TI An Integrated Space Physics Instrument (ISPI) for Solar Probe SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Instruments for the Solar Probe mission must be designed not only to address the unique scientific measurement requirements, but must be compatible with the modest resource dollars as well as tight constraints on mass and power. Another unique aspect of the Solar Probe mission is its constraint on telemetry and the fact that the prime science is conducted in a single flyby. The instrument system must be optimized to take advantage of the telemetry and observing time available. JPL, together with industry and university partners, is designing an Integrated Space Physics Instrument (ISPI) which will measure magnetic fields, plasma waves, thermal plasma, energetic particles, dust, and perform EUV/visible and coronal imaging for the Solar Probe mission. ISPI uses a new architecture and incorporates technology which not only eliminates unnecessary duplication of function, but allows sensors to share data and optimize science. The current ISPI design goal (for a flight package) is a 5 kilogram/10 watt payload. RP Tsurutani, BT (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Killeen, Timothy/F-2215-2013 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 131 EP 132 DI 10.1063/1.51942 PG 2 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00021 ER PT S AU Caruso, P Price, R AF Caruso, P Price, R BE ElGenk, MS TI Mission to Planet Earth: The role of new technologies SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The Mission to Planet Earth (MTPE) Enterprise is a long-duration, comprehensive program to advance scientific knowledge of the Earth as a system. It includes both national and international elements. A diverse array of spacecraft-borne instruments will be placed into various orbits to continuously monitor the land, oceans, atmosphere, ice cover, and solar irradiation. In addition to extending certain sets of data critical to assessing global change, new measurements will be made that further expand our understanding of the world and its dynamic environment. Because the program extends well into the 21st century, programmatic and technical changes are inevitable. This paper addresses the role of new flight and ground system technologies in sustaining the vitality of the MTPE program and describes some specific initiatives that will assist the technology infusion process. RP Caruso, P (reprint author), NASA,GODDARD SPACE FLIGHT CTR,MISSION PLANET EARTH PROGRAM OFF,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 2 U2 2 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 137 EP 138 DI 10.1063/1.51952 PG 2 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00022 ER PT S AU Duda, JL AF Duda, JL BE ElGenk, MS TI National Polar-orbiting Operational Environmental Satellite System: New program, new century, new technologies SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Scheduled for early next century, the National Polar-orbiting Operational Environmental Satellite System (NPOESS) is a convergence initiative to reduce the life cycle costs of current operations. NPOESS combines a number of programs supporting weather, national security, and science needs. Meteorological, science, and national security data are now being collected on a multitude of platforms including the Polar-orbiting Operational Environmental Satellite (FOES) program, Defense Meteorological Satellite Program (DMSP), and several NASA and international spacecraft. New technologies will be needed to reduce the power, mass, and volume requirements of current spacecraft and sensors, to improve the performance and reliability of existing instruments, and to obtain measurements not currently available. This paper identifies some of the technologies needed to fit a multitude of instruments onto a single platform, in addition to the technologies needed to satisfy more stringent requirements and measurements not yet successfully taken from space. RP Duda, JL (reprint author), NASA,GSFC,INTEGRATED PROGRAM OFF,SUITE 1450,CTR BLDG,8455 COLESVILLE RD,SILVER SPRING,MD 20910, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 143 EP 144 DI 10.1063/1.51959 PG 2 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00023 ER PT S AU Tuyahov, AJ AF Tuyahov, AJ BE ElGenk, MS TI Earth Science Applications Program overview SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Meeting Abstract CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF C1 NASA,OFF MISSION PLANET EARTH,WASHINGTON,DC 20546. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 149 EP 150 DI 10.1063/1.51970 PG 2 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00024 ER PT S AU Hayduk, RJ Scott, WS Walberg, GD Butts, JJ Starr, RD AF Hayduk, RJ Scott, WS Walberg, GD Butts, JJ Starr, RD BE ElGenk, MS TI Earth Imaging and Scientific Observations by SSTI ''Clark'' - A NASA technology demonstration spacecraft SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The Small Satellite Technology Initiative (SSTI) is a National Aeronautics and Space Administration (NASA) program to demonstrate smaller, high technology satellites constructed rapidly and less expensively. Under SSTI, NASA funded the development of ''Clark,'' a high technology demonstration satellite to provide 3-m resolution panchromatic and 15-m resolution multispectral images, as well as collect atmospheric constituent and cosmic x-ray data. The 690-lb. satellite, to be launched in early 1997, will be in a 476 km, circular, sun-synchronous polar orbit. This paper describes the program objectives, the technical characteristics of the sensors and satellite, image processing, archiving and distribution. Data archiving and distribution will be performed by NASA Stennis Space Center and by the EROS Data Center, Sioux Falls, South Dakota, USA. RP Hayduk, RJ (reprint author), NASA,300 E ST SW,WASHINGTON,DC 20024, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 151 EP 152 DI 10.1063/1.51973 PG 2 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00025 ER PT S AU Cramer, B Seery, B Paules, G AF Cramer, B Seery, B Paules, G BE ElGenk, MS TI New Millennium Program's Earth Orbiter #1 Flight SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB NASA's Mission To Planet Earth is responsible for maintaining future Landsat data continuity while the New Millennium Program is responsible for flight validating breakthrough technologies to both reduce the cost of future science missions and to enhance their scientific capabilities. These two responsibilities are combined and met in the New Millennium Program's Earth Orbiter #1 Flight (EO-1). EO-1 will flight validate a number of advanced technologies that will reduce the cost of Landsat follow-on instruments while maintaining data continuity with earlier Landsat missions. These technologies are combined in an Advanced Land Imager (ALI) which includes a multispectral capability with Landsat-like bands, a miniature hyperspectral grating spectrometer to validate a new miniature hyperspectral wedge spectrometer, and a third hyperspectral imaging system to provide continual atmospheric correction. Mass-saving technologies have been systematically incorporated into the ALI with the result that it represents a seven-fold reduction in the mass, power, and volume of its predecessor. RP Cramer, B (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 161 EP 162 DI 10.1063/1.51986 PG 2 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00026 ER PT S AU Barnes, JC Costulis, JA AF Barnes, JC Costulis, JA BE ElGenk, MS TI Advanced laser Earth observing capabilities SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The global study of the health of planet Earth and the understanding of how the Earth functions as a system can best be accomplished by measurements from a series of space-based laser remote sensing instruments complementing passive remote sensing instruments by providing vertical profile information. The addition of active laser sensors to the current and planned set of passive optical instruments will provide an unprecedented capability and database for performing global change research. The deployment of laser-based sensors on a suite of small satellites will allow global coverage at reasonable cost and risk. Advances in lidar systems technologies are required in order to reduce the mass, power, size, and cost over present systems and to enable deployments of the next generation of Earth remote sensing capability on small satellites. Technology advances in diode pumped lasers, high energy diode laser pump sources, along with new receiver technologies such as tunable, narrow-band filters, detectors, and large aperture, light weight deployable telescopes provide the key to successful development of small space-based lidar systems. This paper will primarily focus on laser transmitter technologies to enable small laser based sensors for making important global climate change observations. RP Barnes, JC (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 474,HAMPTON,VA 23681, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 167 EP 173 DI 10.1063/1.51987 PG 7 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00027 ER PT S AU Casani, EK AF Casani, EK BE ElGenk, MS TI The New Millennium Program: An overview SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The National Aeronautics and Space Administration (NASA) has established the New Millennium Program (NMP), a science-driven technology-validation program that is designed to accelerate the availability of technology needed for NASA's science missions of the 21st century. Through a series of deep space and Earth orbiting flights, NMP will validate suites of advanced technologies in order to help lower the risks and costs to future missions that use them. Since its inception less then two years ago, the NMP has moved ahead quickly to create implementation elements and processes to identify, develop, deliver, and validate these advanced technologies for flight, and has so far defined the first two deep space and the first Earth orbiting flights, which are currently in the design and development process. RP Casani, EK (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 AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 225 EP 230 DI 10.1063/1.51995 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00035 ER PT S AU Doyle, RJ Gor, V Man, GK Stolorz, PE Chapman, C Merline, WJ Stern, A AF Doyle, RJ Gor, V Man, GK Stolorz, PE Chapman, C Merline, WJ Stern, A BE ElGenk, MS TI Autonomy enables new science missions SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The challenge of space flight in NASA's future is to enable smaller, more frequent and intensive space exploration at much lower total cost without substantially decreasing mission reliability, capability, or the scientific return on investment. The most effective way to achieve this goal is to build intelligent capabilities into the spacecraft themselves. Our technological vision for meeting the challenge of returning quality science through limited communication bandwidth will actually put scientists in a more direct link with the spacecraft than they have enjoyed to date. Technologies such as pattern recognition and machine learning can place a part of the scientist's awareness onboard the spacecraft to prioritize downlink or to autonomously trigger time-critical follow-up observations - particularly important in flyby missions - without ground interaction. Onboard knowledge discovery methods can be used to include candidate discoveries in each downlink for scientists' scrutiny. Such capabilities will allow scientists to quickly reprioritize missions in a much more intimate and efficient manner than is possible today. Ultimately, new classes of exploration missions will be enabled. RP Doyle, RJ (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 AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 231 EP 240 DI 10.1063/1.51996 PG 10 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00036 ER PT S AU Bolton, SJ Young, DT Burch, JL Eaker, N Nordholt, JE Funsten, HO McComas, DJ AF Bolton, SJ Young, DT Burch, JL Eaker, N Nordholt, JE Funsten, HO McComas, DJ BE ElGenk, MS TI Plasma Experiment for Planetary Exploration (PEPE) SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The Plasma Experiment for Planetary Exploration (PEPE) is one of the new instrument technologies being demonstrated with the New Millennium Deep Space One mission. PEPE will serve three purposes, (1) the characterization of the environment induced by the Solar Electric Propulsion (SEP) system while validating the feasibility of flying high performance plasma instrumentation on future SEP missions, (2) to carry out state-of-the-art plasma measurements in support of the scientific investigation of an asteroid and comet flyby, and (3) to validate several new plasma sensor technologies needed for future space physics and planetary missions. PEPE's measurement capabilities approach those of the Cassini Plasma Spectrometer (CAPS) instrument, but with much lower resource requirements, at a lower cost and delivered on a much faster time table. PEPE will provide three dimensional mass-resolved plasma distributions up to 30 keV over 2.8 pi ster on a time frame of 64 seconds. PEPE simultaneously measures both ions and electrons and provides energy per charge analysis and time-of-flight measurements to yield high resolution mass analysis. Details of the PEPE design are presented as well as an overview of both the technology and scientifically driven measurement objectives. The potential future applications of PEPE technology are also discussed. RP Bolton, SJ (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 2 U2 2 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 241 EP 244 DI 10.1063/1.51997 PG 4 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00037 ER PT S AU Lau, K Colavita, M Shao, M AF Lau, K Colavita, M Shao, M BE ElGenk, MS TI The New Millennium separated spacecraft interferometer SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Spaceborne optical interferometry has been identified as a critical technology for many of NASA's 21(st) century science visions. Included in the visions are interferometers that can probe the origins of stars and galaxies, and can ultimately study Earth-like planets around nearby stars. To accomplish this feat, separation of an interferometer's small collecting apertures by large baselines are required hundreds of meters up to thousands of kilometers. Thus the large separations require multiple spacecraft formation flying. Furthermore, optical pathlengths over these distances must be controlled to the nanometer level. This level of control demands tightly coupled spacecraft controls, active optics, metrology, and starlight detection technologies. To date, these technologies have been demonstrated only in ground applications with baselines of order of a hundred meters; space operation will require a significant capability enhancement. This paper describes the New Millennium separated spacecraft optical interferometer mission concept and technologies. The mission is designed to provide a technology demonstration for tightly coupled multiple spacecraft formations and very long baseline two optical interferometry. The interferometer would be distributed over three small spacecraft: spacecraft would collectors, directing starlight toward a third spacecraft which would combine the light and perform the interferometric detection. The interferometer baselines would serve variable, allowing baselines of 100 m to 1 km in an equilateral formation, to provide angular resolutions from 5 to 0.5 nanoradian (1 to 0.1 milliarcsec). RP Lau, K (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 AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 245 EP 250 DI 10.1063/1.51998 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00038 ER PT S AU Baez, AN Kimnach, GL AF Baez, AN Kimnach, GL BE ElGenk, MS TI The Integrated Solar Upper Stage engine ground demonstration power management and distribution subsystem design SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The National Aeronautics and Space Administration (NASA), the Air Force Phillips Laboratory (PL), and the Defense Special Weapons Agency (DSWA) in a joint effort are developing technologies for a solar bimodal system. A solar bimodal system combines thermal propulsion and electric power generation in a single integrated system. A spacecraft Integrated Solar Upper Stage (ISUS) bimodal system combines orbital transfer propulsion, electric power generation, and on-board propulsion into one overall system. A key benefit of such integrated system is the augmentation of payload to spacecraft mass ratio thus resulting in lower launch vehicle requirements. Scaling down to smaller launch vehicles increases space access by reducing overall mission cost. The NASA/PL/DSWA ISUS program is concentrating efforts on a near-term ground test demonstration of the bimodal concept. A successful ground demonstration of the ISUS various technologies will enable a full system flight demonstration of the bimodal concept. NASA Lewis Research Center in Cleveland Ohio will be the site for the engine ground demonstrator (EGD). The ISUS bimodal system uses solar concentrators to focus solar energy into an integrated receiver, absorber, and converter (RAG) power plant. The power plant main body is a graphite blackbody that stores thermal energy within a cavity in its main core. During the propulsion phase of the bimodal system a propellant flows into the graphite main core and is distributed uniformly through axial flow channels in the heated cavity. The blackbody core heats the propellant that is then discharged into an output tube thus creating thrust. An array of thermionic generators encircles the graphite core cavity and provides electrical energy conversion functions during the power generation phase. The power management and distribution subsystem's main functions are to condition raw electrical power generated by the RAC power plant and deliver it to the spacecraft payloads. This paper presents a detail description of the power management and distribution subsystem design for the ISUS ground demonstration program. RP Baez, AN (reprint author), NASA,LEWIS RES CTR,21000 BROOKPK RD MS 301-5,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 251 EP 256 DI 10.1063/1.51999 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00039 ER PT S AU Button, RM AF Button, RM BE ElGenk, MS TI A modular PMAD system for small spacecraft SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Current trends in satellite design are focused on developing small, reliable, and inexpensive spacecraft. To that end, a modular power management and distribution system (PMAD) is proposed which will help transition the aerospace industry towards an assembly line approach to building spacecraft. The modular system is based on an innovative DC voltage boost converter called the Series Connected Boost Unit (SCBU). The SCBU uses existing DC-DC converters and adds a unique series connection. This simple modification provides the SCBU topology with many advantages over existing boost converters. Efficiencies of 94-98%, power densities above 1,000 W-c/kg, and inherent fault tolerance are just a few of the characteristics presented. Limitations of the SCBU technology are presented, and it is shown that the SCBU makes an ideal photovoltaic array regulator. A modular design based on the series connected boost unit is outlined and functional descriptions of the components are given. RP Button, RM (reprint author), NASA,LEWIS RES CTR,21000 BROOKPK RD,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 263 EP 268 DI 10.1063/1.52117 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00041 ER PT S AU Poljak, MD Soltis, JV Fox, DA AF Poljak, MD Soltis, JV Fox, DA BE ElGenk, MS TI Advanced distribution, switching, and conversion technology for Fluids/Combustion Facility electric power control SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The Electrical Power Control Unit (EPCU) under development for use in the Fluids/Combustion Facility (FCF) on International Space Station (ISS) is the precursor of modular power distribution and conversion concepts for future high power and small spacecraft applications. The EPCU is built from modular, current limiting Flexible Remote Power Controllers (FRPCs) and paralleled power converters packaged into a common orbital replacement unit. Multiple EPCUs are combined at the next higher level of integration to form the three-rack FCF Electrical Power System (EPS). This modular building block approach allows for the quick development of expandable power systems tailored to customer needs. RP Poljak, MD (reprint author), NASA,LEWIS RES CTR,21000 BROOKPK RD,CLEVELAND,OH 44145, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 269 EP 275 DI 10.1063/1.52002 PG 7 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00042 ER PT S AU Halpert, G Narayanan, SR Frank, H Kindler, A Valdez, T Chun, W Surampudi, S AF Halpert, G Narayanan, SR Frank, H Kindler, A Valdez, T Chun, W Surampudi, S BE ElGenk, MS TI Commercialization of a direct methanol fuel cell system SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB This paper describes a major breakthrough in energy technology developed at the Jet Propulsion Laboratory that can be used in a wide variety of portable, remote and transportation applications without polluting the environment. The status, performance, and design considerations of the JPL non-polluting, Direct Methanol. Fuel Cell system for consumer equipment and transportation applications are reported herein. This new fuel cell technology utilizes the direct oxidation of a 3% aqueous liquid methanol solution as the fuel and air (O-2) as the oxidant. The only products are CO2 and water. Therefore, because recharging can be accomplished by refueling with methanol, vehicles can enjoy unlimited range and extended use compared to battery operated devices requiring recharge time and power accessibility. RP Halpert, G (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 285 EP 291 DI 10.1063/1.52004 PG 7 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00044 ER PT S AU Fleurial, JP Borshchevsky, A Caillat, T AF Fleurial, JP Borshchevsky, A Caillat, T BE ElGenk, MS TI New thermoelectric materials and devices for terrestrial power generators SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The development of new, more efficient, materials and devices is the key to expand the range of applications of thermoelectric generators. New potential terrestrial applications have been recently described in the literature. There exists a wide range of heat source temperatures for these applications, from low grade waste heat, at 320-350K, up to 80 to 1100K, such as in the heat recovery from a processing plant of combustible solid waste. The automobile industry has also recently developed a strong interest in a waste exhaust heat recovery power source operating in the 375-775K temperature range to supplement or replace the alternator and thus decrease fuel consumption. Because of the relatively small temperature drop across the generator and of the generator mass requirements, it is estimated that values of 1.5 to 2.0 are needed for the dimensionless thermoelectric figure of merit, ZT, in order to develop an economically viable system. Of course, there are other factors besides ZT when considering the potential use of thermoelectrics. For example, most commercial applications also require that the materials have also to be cheap enough, or environmentally friendly to make the thermoelectric power generation a viable option. Due to the need for reductions in the mass, cost and volume of radioisotope thermoelectric generators (RTGs) used to power spacecrafts for deep space missions, a search for new advanced materials with ZT values substantially higher than state-of-the-art S0.8Ge0.2 alloys (ZT(SiGe) A 0.65 from 575 to 1275K) was initiated a few years ago at the Jet Propulsion Laboratory. Recent results on novel materials have demonstrated that ZT values significantly larger than 1.0 could be obtained in the 475 to 975K temperature range. These materials are excellent candidates to be used in terrestrial thermoelectric power generators using waste heat or liquid fuels. RP Fleurial, JP (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 293 EP 298 DI 10.1063/1.52005 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00045 ER PT S AU Millis, MG AF Millis, MG BE ElGenk, MS TI Design factors for applying cryogen storage and delivery technology to solar thermal propulsion SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Thermodynamic Vent System (TVS) and Multilayer Insulation (MLI) technology, originally developed for long term storage of cryogen propellants in microgravity, is ideally suited for propellant storage and delivery systems far solar thermal propulsion. With this technology the heat-induced pressure rise in the tank provides the propellant delivery pressure without the need for an auxiliary pressurant system, and propellant delivery is used to remove the excess heat to control tank pressure. The factors to consider in designing such a balanced system are presented. An example of a minimum system design is presented along with examples of laboratory-tested hardware. RP Millis, MG (reprint author), NASA,LEWIS RES CTR,21000 BROOKPK RD,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 511 EP 516 DI 10.1063/1.52040 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00078 ER PT S AU Chato, DJ Hastings, L AF Chato, DJ Hastings, L BE ElGenk, MS TI An experiment to demonstrate key cryogenic technologies for solar thermal rockets SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB This paper discusses the design of a small experiment called Hydrogen On-orbit Storage and Supply (HOSS). The objectives of the experiment are: Show stable gas supply for storage and direct gain solar-thermal thruster designs; and evaluate and compare low-g performance of active and passive pressure control via a thermodynamic vent system (TVS) suitable for solar-thermal upper stages. This paper shows these can be done with a 149 kg spacecraft. This spacecraft is suitable for launch on a low cost launch vehicle. Other topics include the following: Background of cryogenic fluid management efforts; unique requirements of cryogenic fluid management for solar-rocket; how these requirements are met in a small scale experiment. RP Chato, DJ (reprint author), NASA,LEWIS RES CTR,MAIL STOP 60-4,21000 BROOKPK RD,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 517 EP 522 DI 10.1063/1.52041 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00079 ER PT S AU Hurlbert, KM AF Hurlbert, KM BE ElGenk, MS TI Active thermal control systems for future space missions SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The future missions of the National Aeronautics and Space Administration (NASA) may include orbiting satellites, orbiting platforms or stations, interplanetary vehicles, planetary surface missions, and planetary research probes. Many of these proposed missions will include humans to conduct research for scientific and terresterial benefits, and to establish a permanent human prescence beyond Earth's confines. Other missions will be autonomous (e.g., satellites, robotic exploration), and will also support NASA's goal of exploring space and providing benefits to Earth's populace. A thermal control system is an essential part of any space vehicle, as it provides the necessary thermal environment for the crew and equipment to operate efficiently during the mission. The requirements for human rating and the specified temperature range (275 K - 310 K) drive the Johnson Space Center (JSC) to develop enhancing and/or enabling active thermal control technologies to uniquely support human space exploration. A primary JSC goal is to provide advanced thermal system technologies which are highly reliable and possess low mass, size and power requirements (i.e., reduced cost). This plenary presentation provides an overview of some recent programs which ae in progress at JSC in the area of advanced thermal control system technology development. RP Hurlbert, KM (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,CREW & THERMAL SYST DIV,HOUSTON,TX 77058, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 533 EP 536 DI 10.1063/1.52119 PG 4 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00082 ER PT S AU Hurlbert, KM AF Hurlbert, KM BE ElGenk, MS TI The two-phase extended evaluation in microgravity (TEEM) flight experiment: Description and overview SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The future missions of the National Aeronautics and Space Administration (NASA) may include orbiting satellites, orbiting platforms or stations, interplanetary vehicles, planetary surface missions, and planetary research probes. Current thermal control technology, using single-phase liquid coolant loops, is not a viable option for some of these future missions due to the associated power system weight and size penalty. Two-phase (liquid-vapor) flow thermal control systems can offer significant advantages over single-phase thermal systems in reducing the required power system mass and size. The Two-Phase Extended Evaluation in Microgravity (TEEM) Flight Experiment is currently being developed by NASA, and the Department of Defense (DOD) Space Test Program (STP) and the United States Air Force (USAF) Phillips Laboratory, with the cooperation of university researchers, to demonstrate operations of a closed-loop, two-phase system in a relevant mission environment. TEEM will also provide fully developed, two-phase flow data for zero-g conditions. This paper presents a description of the flight experiment, and a summary of the science of interest to the NASA Johnson Space Center (JSC). RP Hurlbert, KM (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,CREW & THERMAL SYST DIV,HOUSTON,TX 77058, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 547 EP 553 DI 10.1063/1.52045 PG 7 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00085 ER PT S AU Parrish, K Carlson, B AF Parrish, K Carlson, B BE ElGenk, MS TI The use of high thermal conductivity composites in the satellite bus structure of the Wide Field Infrared Explorer SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The Wide-field Infrared Explorer (WIRE) spacecraft, the fifth of NASA's Small Explorer (SMEX) series of scientific satellites, is scheduled to be launched in mid 1998 by a pegasus XL launch vehicle. The WIRE mission will conduct a wide field infrared survey in search for galaxies with an unusually high star formation rate. Once detected, these interesting galaxies can be studied more closely with ground based observatories or with on-orbit telescopes. To maximize the mass allocated to the spacecraft's single infrared telescope, the spacecraft will utilize a lightweight, fully bonded fiber reinforced composite structure. The use of composite materials presents unique challenges to the design of the spacecraft's relatively simple passive thermal control system and necessitates the use of Amoco's high thermal conductivity K1100X fibers in specific areas of the structure. This paper describes the spacecraft's passive thermal control system and focuses on the engineering design, analyses and tests performed to insure the proper mechanical and thermal implementation of high conductivity composites into the WIRE structure. RP Parrish, K (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 573 EP 579 DI 10.1063/1.52048 PG 7 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00089 ER PT S AU Lyons, V Friedman, R AF Lyons, V Friedman, R BE ElGenk, MS TI Overview of microgravity combustion research at NASA Lewis Research Center and its potential commercial impact SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The near-zero (microgravity) environment of orbiting spacecraft minimizes buoyant flows, greatly simplifying combustion processes and isolating important phenomena ordinarily concealed by the overwhelming gravity-driven forces and flows. Fundamental combustion understanding has greatly benefited from analyses and experiments conducted in the microgravity environment. Because of the economic and commercial importance of combustion in practice, there is strong motivation to seek wider applications for the microgravity-combustion findings. This paper reviews selected technology developments to illustrate some emerging applications. Topics cover improved firesafety technology in spacecraft and terrestrial systems, innovative combustor designs for aerospace and ground propulsion, applied sensors and controls for combustion processes, and self-sustaining synthesis techniques for advanced materials. RP Lyons, V (reprint author), NASA,LEWIS RES CTR,21000 BROOKPK RD,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 743 EP 748 DI 10.1063/1.52075 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00114 ER PT S AU Anderson, JL AF Anderson, JL BE ElGenk, MS TI Advanced human-'intelligent' machine concepts SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Development and settlement of the moon during the 21st century will drive the market for unprecedented collaborations between humans and increasingly 'intelligent' machines. An expanded concept of human endeavor in space - developing a lunar territory - has identified novel human-'intelligent' machine concepts (HIMACs) to support this new human reach. These HIMACs could enable entirely new functions and capabilities, provide quantum improvements in productivity including lower costs, challenge human ingenuity and inspire sustained public interest in human space exploration and commercial development. The paper describes HIMACs resulting from a workshop using the Horizon Mission Methodology to address a Lunar Territory of 2050. Such a 'future' mission has direct application to any future intent of large-scale space development. The HIMACs generated fall into four functional classes:lunar-development ecology; self-expansion of lunar endeavors; human extensions; and a two-planet economy. RP Anderson, JL (reprint author), NASA,ADV CONCEPTS OFF,WASHINGTON,DC 20546, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 865 EP 870 DI 10.1063/1.52092 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00132 ER PT S AU Avery, DE Kaszubowski, MJ Kearney, ME Howard, TP AF Avery, DE Kaszubowski, MJ Kearney, ME Howard, TP BE ElGenk, MS TI The Attached Payload Facility Program: A family of in-space commercial facilities for technology, science and industry SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB It is anticipated that as the utilization of space increases in both the government and commercial sectors there will be a high degree of interest in materials and coatings research as well as research in space environment definition, deployable structures, multi-functional structures and electronics. The International Space Station (ISS) is an excellent platform for long-term technology development because it provides large areas for external attached payloads, power and data capability, and ready access for experiment exchange and return An alliance of SPACEHAB, Micro Craft,Inc. and SpaceTec, Inc. has been formed to satisfy this research need through commercial utilization of the capabilities of ISS. The alliance will provide a family of facilities designed to provide low-cost, reliable access to space for experimenters. This service would start as early as 1997 and mature to a fully functional attached facility on ISS by 2001. The alliance's facilities are based on early activities by NASA, Langley Research Center (LaRC) to determine the feasibility of a Material Exposure Facility (MEF). RP Avery, DE (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 359,HAMPTON,VA 23681, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 871 EP 875 DI 10.1063/1.52093 PG 5 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00133 ER PT S AU Samson, J Peterson, L Harmon, L Conrad, D Clark, K AF Samson, J Peterson, L Harmon, L Conrad, D Clark, K BE ElGenk, MS TI The Remote Scientist SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Observation and interaction are fundamental aspects of empirical scientific research. While individual requirements for observation and interaction vary across disciplines, there are important common elements. These ''common elements'' are the basis of the $15 billion dollar laboratory automation industry. The United States presently leads the world in this industry, providing products for sample manipulation, sensing (e.g. microscopic and macroscopic imaging devices), data analysis (e.g. image processing, 3D modeling, exploratory data analysis), and human-computer interfaces (e.g. computer graphics, visualization). This paper outlines the preliminary design of a unique and innovative system for conducting experiments at a distance, the ''Remote Scientist''. The Remote Scientist extends laboratory automation capability to the microgravity environment. While the Remote Scientist conceptually encompasses a broad spectrum of elements and functionalities, the development approach taken is to: establish a baseline capability that is both flexible and versatile incrementally augment the baseline with additional functionalities over time. The baseline capability that we have identified as having the most significant impact across multiple research disciplines is the ability to observe on-going experiments during exposure to the microgravity environment. This capability is achievable with technology available today and, additionally, will be able to take advantage of the rapid advances in the underlying technologies that are taking place in the commercial sector. The Remote Scientist will support a wide range of experiments through customizable components for: data collection (observation and measurement) manipulation (automated and semi-automated experiment control) investigator interaction (communication between experiment and researcher independent of location) By designing for multiple levels of automation, from fully automatic action through remote control and telemanipulation, investigator interaction can be incorporated into experiments at any desired level. The Remote Scientist is designed to offer a full range of digital imaging on both microscopic and macroscopic scales. The system will support spatial and spectral analysis for on-board extraction of important features, thus reducing bandwidth requirements for communications to ground-based investigators. Confocal imaging (optical sectioning), hyperspectral imaging, interferometry, laser scattering, and fluorescence can also be considered as value-added instrumentation within the proposed framework without significant redesign. The system is designed to operate within the constraints of a microgravity environment while offering innovative functionality to enhance ground-based experiments as well. The Remote Scientist is initially focused on applications currently being pursued in microgravity such as tissue culture, protein crystal growth and zeolite crystal growth. The real-world requirements of these biomedical and materials applications provide important insight in establishing design-criteria for the system. However, the longer-term applications are envisioned to be much broader. RP Samson, J (reprint author), NASA,SPACE APPLICAT TECHNOL CTR,ERIM,POB 134001,ANN ARBOR,MI 48113, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 877 EP 879 DI 10.1063/1.52094 PG 3 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00134 ER PT S AU Escher, WJD AF Escher, WJD BE ElGenk, MS TI Leading design choices for spaceliner class aerospace transports SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Using an existing advanced reusable space transport design concept as a point of departure in the quest for new enabling, or at least expanded first-order mission-enhancing design features, two divergent ''what if'' approaches of inquiry are employed. The first is to greatly expand the vehicle service arena well beyond just Earth-to-LEG operations. An expansive ''trimarket'' purview is examined: orbital, transglobal and cislunar transportation service. The second examines the implications to design of the mission-abandonment subset of post launch-commit possibilities. A hierarchy of characteristic loss categories results, one providing a number of focused targets for remedial design choices. Several insightful design-choice findings arise from each of these two quick-look assessments. An example is vertical landing capability, which, while originally stipulated for the selected vehicle concept, is shown to also be a leading design choice as invoked by both of the special inquiries described here. RP Escher, WJD (reprint author), NASA,SPACE TRANSPORTAT DIV,WASHINGTON,DC 20546, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 1065 EP 1072 DI 10.1063/1.51925 PG 8 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00163 ER PT S AU Blosser, ML AF Blosser, ML BE ElGenk, MS TI Development of metallic thermal protection systems for the reusable launch vehicle SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB A reusable Thermal Protection System (TPS) that is not only lightweight, but durable, operable and cost effective is one of the technologies required by the Reusable Launch Vehicle (RLV) to achieve the goal of drastically reducing the cost of delivering payload to orbit. Metallic TPS is one of the systems being developed to meet this challenge. Current efforts involve improving the superalloy honeycomb TPS concept, which consists of a foil-gage metallic box encapsulating a low density fibrous insulation, and evaluating it for RLV requirements. The superalloy honeycomb TPS concept is mechanically attached to the vehicle structure. Improvements include more efficient internal insulation, a simpler, lighter weight configuration, and a quick-release fastener system for easier installation and removal. Evaluation includes thermal and structural analysis, fabrication and testing of both coupons and TPS panels under conditions simulating RLV environments. Coupons of metallic honeycomb sandwich, representative of the outer TPS surface, were subjected to low speed impact, hypervelocity impact, and rain erosion testing as well as subsequent arcjet exposure. Arrays of TPS panels have been subjected to radiant heating in a thermal/vacuum facility, aerodynamic heating in an arcjet facility and acoustic loading. RP Blosser, ML (reprint author), NASA,LANGLEY RES CTR,MAIL STOP 396,HAMPTON,VA 23681, USA. NR 0 TC 2 Z9 2 U1 0 U2 5 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 1125 EP 1143 DI 10.1063/1.51930 PG 19 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00170 ER PT S AU Hurlbert, E Moreland, R AF Hurlbert, E Moreland, R BE ElGenk, MS TI A non-toxic reusable on-board propulsion system for orbiter upgrade and the human exploration and development of space SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB A non-toxic on-board propulsion system for the Space Shuttle orbiter promises high payoffs in terms of safety, cost, reliability, reduced ground operations, and improved mission flexibility. Significant cost savings and safety enhancements can be realized by eliminating toxic propellant handling from the orbiter processing flow, including elimination of SCAPE suit operations, relaxing leakage concerns, and reducing propellant cost. Mission reliability and safety can be enhanced by reducing the number of critical components that must operate, while maintaining the same fault tolerance as the current propulsion systems. Mission flexibility and management of propellant reserves can be improved by combining the propellant storage and pressurization systems for the orbital maneuvering system (OMS) and the reaction control system (RCS). The reduction and automation of checkout requirements for the upgraded propulsion system can enhance operational ease and reduce the turnaround cost. System integration with the environmental control and life support system (ECLSS) and the power system may save additional turnaround costs by sharing common components such as the storage tanks. Finally, there can be commonality of this technology with Human Exploration and Development of Space (HEDS) missions that utilize oxygen produced from in-situ planetary resources. This is a major advancement in the state-of-the-art. RP Hurlbert, E (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,PROP & POWER DIV EP4,2101 NASA RD 1,HOUSTON,TX 77058, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 1145 EP 1150 DI 10.1063/1.51931 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00171 ER PT S AU Sawyer, JW Bush, H Sutter, T AF Sawyer, JW Bush, H Sutter, T BE ElGenk, MS TI Experimental investigation of a graphite-composite wing-box section for a reusable launch vehicle SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB The use of graphite-composites as primary structure is essential for the development of a cost effective single-stage-to-orbit reusable launch vehicle (RLV) to replace the Space Shuttle. A full-scale segment of a graphite-composite wing was designed and fabricated by an industry team and tested at NASA Langley Research Center as a part of the RLV technology development program. The wing-box test component was 1.5 m wide by 3.0 m long and 1.1 m deep. It was construction from honeycomb sandwich panels with graphite-bisaleimide composite skins. The test component was loaded to design limit load in reverse bending followed by a test to design ultimate load, also in reverse bending. It was then loaded to failure. Resistance and fiber optic gages were used to measure strains in the wing box section during the test. A comprehensive finite element analysis of the specimen was performed. The test results verified the structural integrity of the wing-box component for RLV design loads, and good correlation between test and analysis was obtained. Both the failure location and the failure load were accurately predicted by the analysis. RP Sawyer, JW (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23681, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 1245 EP 1257 DI 10.1063/1.51910 PG 13 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00186 ER PT S AU Zapata, E AF Zapata, E BE ElGenk, MS TI A quality function deployment method applied to highly reusable space transportation SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB This paper will describe a Quality Function Deployment (QFD) currently in work the goal of which is to add definition and insight to the development of long term Highly Reusable Space Transportation (HRST). The objective here is twofold. First, to describe the process, the actual QFD experience as applies to the HRST study. Second, to describe the preliminary results of this process, in particular the assessment of possible directions for future pursuit such as promising candidate technologies or approaches that may finally open the space frontier. The iterative and synergistic nature of QFD provides opportunities in the process for the discovery of what is key in so far as it is useful, what is not, and what is merely true. Key observations on the QFD process will be presented. The importance of a customer definition as well as the similarity of the process of developing a technology portfolio to product development will be shown. Also, the relation of identified cost and operating drivers to future space vehicle designs that are robust to an uncertain future will be discussed. The results in particular of this HRST evaluation will be preliminary given the somewhat long term (or perhaps not?) nature of the task being considered. RP Zapata, E (reprint author), NASA,KENNEDY SPACE CTR,FL 32899, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 1265 EP 1270 DI 10.1063/1.51911 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00188 ER PT S AU Hunt, JL Lockwood, MK Petley, DH Pegg, RJ AF Hunt, JL Lockwood, MK Petley, DH Pegg, RJ BE ElGenk, MS TI Hypersonic airbreathing vehicle visions and enhancing technologies SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB This paper addresses the visions for hypersonic airbreathing vehicles and the advanced technologies that forge and enhance the designs. The matrix includes space access vehicles (single-stage-to-orbit (SSTO), two-stage-to-orbit (2STO) and three-stage-to-orbit (3STO)) and endoatmospheric vehicles (airplanes-missiles are omitted). The characteristics, the performance potential, the technologies and the synergies will be discussed. A common design constraint is that all vehicles (space access and endoatmospheric) have enclosed payload bays. RP Hunt, JL (reprint author), NASA,LANGLEY RES CTR,HAMPTON,VA 23665, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 1285 EP 1295 DI 10.1063/1.51938 PG 11 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00191 ER PT S AU Millis, MG AF Millis, MG BE ElGenk, MS TI Breakthrough propulsion physics research program SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB In 1996, a team of government, university and industry researchers proposed a program to seek the ultimate breakthroughs in space transportation: propulsion that requires no propellant mass, propulsion that can approach and, if possible, circumvent light speed, and breakthrough methods of energy production to power such devices. This Breakthrough Propulsion Physics program, managed by Lewis Research Center, is one part of a comprehensive, long rang Advanced Space Transportation Plan managed by Marshall Space Flight Center. Because the breakthrough goals are beyond existing science, a main emphasis of this program is to establish metrics and ground rules to produce near-term credible progress toward these incredible possibilities. An introduction to the emerging scientific possibilities from which such solutions can be sought is also presented. RP Millis, MG (reprint author), NASA,LEWIS RES CTR,21000 BROOKPK RD,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 1297 EP 1302 DI 10.1063/1.51939 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00192 ER PT S AU Polk, J Frisbee, R Krauthamer, S Tikhonov, V Semenikhin, S Kim, V AF Polk, J Frisbee, R Krauthamer, S Tikhonov, V Semenikhin, S Kim, V BE ElGenk, MS TI Technology requirements for high-power Lithium Lorentz Force Accelerators SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM, PTS 1-3: 1ST CONFERENCE ON FUTURE SCIENCE & EARTH SCIENCE MISSIONS; 1ST CONFERENCE ON SYNERGISTIC POWER & PROPULSION SYSTEMS TECHNOLOGY; 1ST CONFERENCE ON APPLICATIONS OF THERMOPHYSICS IN MICROGRAVITY; 2ND CONFERENCE ON COMMERCIAL DEVELOPMENT OF SPACE; - 2ND CONFERENCE ON NEXT GENERATION LAUNCH SYSTEMS; 14TH SYMPOSIUM ON SPACE NUCLEAR POWER AND PROPULSION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF-97) CY JAN 26-30, 1997 CL ALBUQUERQUE, NM SP Def Special Weapons Agcy, NASA, UN DOE, USAF AB Lithium Lorentz Force Accelerators (LFA's) are capable of processing very high power levels and are therefore applicable to a wide range of challenging missions. An analysis of a reusable orbit transfer vehicle with a solar or nuclear electric power source was performed to assess the applicability of high-power LFA's to this mission and to define engine performance and lifetime goals to help guide the technology development program. For this class of missions, the emphasis must be on achieving high efficiency at an Isp of 4000-5000 s at power levels of 200-250 kWe. The engines must demonstrate very reliable operation for a service life of about 3000 hours. These goals appear to be achievable with engine technologies currently under development. RP Polk, J (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-679-4 J9 AIP CONF PROC PY 1997 IS 387 BP 1505 EP 1513 DI 10.1063/1.51971 PG 9 WC Engineering, Aerospace; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BH56D UT WOS:A1997BH56D00223 ER PT S AU Lo, MW AF Lo, MW BE Howell, KC Cicci, DA Cochran, JE Kelso, TS TI Halo orbit generation using the center manifold SO SPACEFLIGHT MECHANICS 1997, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Space Flight Mechanics Conference CY FEB 10-12, 1997 CL HUNTSVILLE, AL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB In recent years, halo orbits around the Sun-Earth Lagrange points, L-1 and LP2, have become extremely popular for NASA missions due to the ideal observation environment and low launch energy (C-3=-0.6). Traditional methods for the generation of halo orbits require an initial guess provided by some high order analytic expansion. A separate expansion may be required for different systems due to differences in perturbations and small parameter assumptions. Since periodic orbits and quasiperiodic orbits live on the center manifold of the Lagrange point, approximations of the center manifold provide good initial conditions for halo orbit generation. Such a method relies solely on the dynamics of the three body problem and is uniformly applicable for all Sun-Planet and Planet-Moon systems. The approximation of the center manifold is achieved by linearizing the equations of motion of the circular restricted three body problem at the collinear Lagrange points, Using differential correction, a halo orbit is quickly found. RP Lo, MW (reprint author), CALTECH,JET PROP LAB,NAVIGAT & FLIGHT MECH SECT,MS 301-140L,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 2 Z9 2 U1 0 U2 1 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-432-X J9 ADV ASTRONAUT SCI PY 1997 VL 95 BP 109 EP 116 PN 1&2 PG 8 WC Engineering, Aerospace SC Engineering GA BJ27M UT WOS:A1997BJ27M00006 ER PT S AU Hart, RC Truong, S Long, AC Lee, T Chan, J Oza, DH AF Hart, RC Truong, S Long, AC Lee, T Chan, J Oza, DH BE Howell, KC Cicci, DA Cochran, JE Kelso, TS TI GPS navigation initiatives at Goddard Space Flight Center Flight Dynamics Division SO SPACEFLIGHT MECHANICS 1997, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Space Flight Mechanics Conference CY FEB 10-12, 1997 CL HUNTSVILLE, AL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB The National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) is pursuing the application of Global Positioning System (GPS) technology to improve the accuracy and economy of spacecraft navigation. High-accuracy autonomous navigation algorithms are being flight qualified in conjunction with GSFC's GPS Attitude Determination Flyer (GADFLY) experiment on the Small Satellite Technology Initiative Lewis spacecraft, which is scheduled for launch in early 1997. Preflight performance assessments indicate that these algorithms can provide a real-time total position accuracy of better than 10 meters (1 sigma) and velocity accuracy of better than 0.01 meter per second (1 sigma), with selective availability at typical levels. This accuracy is projected to improve to the 2-meter level if corrections to be provided by the GPS Wide Area Augmentation System (WAAS) are included. In addition, GSFC FDD has used object-oriented analysis and design technologies to define a modular software architecture that supports the development of highly reusable GPS navigation components. Work is in progress to develop a high-accuracy GPS navigation application based on this architecture, which can be provided to any spacecraft project to support real-time autonomous navigation. RP Hart, RC (reprint author), NASA,GODDARD SPACE FLIGHT CTR,FLIGHT MECH BRANCH,CODE 552,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-432-X J9 ADV ASTRONAUT SCI PY 1997 VL 95 BP 137 EP 152 PN 1&2 PG 16 WC Engineering, Aerospace SC Engineering GA BJ27M UT WOS:A1997BJ27M00008 ER PT S AU Heaton, AF AF Heaton, AF BE Howell, KC Cicci, DA Cochran, JE Kelso, TS TI The effect of orbiter-induced perturbations on the trajectory from a payload perspective SO SPACEFLIGHT MECHANICS 1997, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Space Flight Mechanics Conference CY FEB 10-12, 1997 CL HUNTSVILLE, AL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB The Orbiter generates many small perturbations to it's trajectory via so-called 'vent forces'. The effect of these forces can be quite significant over the length of a typical mission. The main sources of vent forces are RCS firings, waste water dumps, and the Flash Evaporator System (FES) exhaust. By far the most significant of these on the Orbiter ephemeris is RCS firings for attitude hold and maneuver. Microgravity materials science Principal Investigators (PI's) generally tend to want the acceleration environment to be as quiescent as possible. This paper takes a look at the effect of vent forces on the acceleration environment aboard the Orbiter and describes one attempt to gauge the effect of RCS thruster firings. RP Heaton, AF (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,ORBITAL ANAL TEAM,MISSION PLANNING DIV,CODE EO46,HUNTSVILLE,AL 35812, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-432-X J9 ADV ASTRONAUT SCI PY 1997 VL 95 BP 725 EP 732 PN 1&2 PG 8 WC Engineering, Aerospace SC Engineering GA BJ27M UT WOS:A1997BJ27M00049 ER PT S AU Penzo, PA AF Penzo, PA BE Howell, KC Cicci, DA Cochran, JE Kelso, TS TI Lunar and planetary missions launched from a geosynchronous transfer orbit SO SPACEFLIGHT MECHANICS 1997, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Space Flight Mechanics Conference CY FEB 10-12, 1997 CL HUNTSVILLE, AL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB Considerable cost and mass savings are possible by launching small spacecraft into lunar and planetary space as secondary payloads. The Ariane, for example, provides a platform for several such payloads on each of its monthly launches of placing communication satellites into geosynchronous orbits. Specifically, the second stage injects into a geosynchronous transfer orbit (GTO), and can accommodate eight auxiliary spacecraft, each weighing about 80 kg. This paper addresses the question of how and for what propellant cost can a spacecraft be injected from a GTO orbit to the Moon or to other deep space bodies. The analysis begins with a discussion on the restrictions due to the highly elliptic and specifically oriented GTO. The importance of target choice and wait time in GTO, perhaps for months, are noted. Only these are suitable for single burn using a solid propulsion stage. Specific application to Venus, Mars and near-Earth bodies are presented. More versatility is gained using a liquid stage where multiple burns are possible, allowing plane changes, and swingbys of the Earth and Moon. This greatly expands the mission possibilities to all targets, as well as to Mars and small bodies. Scenarios can include direct and indirect lunar flybys, Apollo type circumlunar trajectories, the lunar flip trajectory, and Belbruno's use of the weak stability boundary beyond the Moon to aid or control the direction of escape. It is concluded that GTO secondary launches can play a significant role in solar system exploration, but that it will depend on having a small restartable propulsion system, and a small spacecraft capable of flying intricate trajectories in the Earth-Moon system. RP Penzo, PA (reprint author), CALTECH,JET PROP LAB,MS 301-142,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-432-X J9 ADV ASTRONAUT SCI PY 1997 VL 95 BP 881 EP 890 PN 1&2 PG 10 WC Engineering, Aerospace SC Engineering GA BJ27M UT WOS:A1997BJ27M00061 ER PT S AU Sweetser, TH Maddock, R Johannesen, J Bell, J Penzo, PA Wolf, A Williams, SN Matousek, S Weinstein, S AF Sweetser, TH Maddock, R Johannesen, J Bell, J Penzo, PA Wolf, A Williams, SN Matousek, S Weinstein, S BE Howell, KC Cicci, DA Cochran, JE Kelso, TS TI Trajectory design for a Europa orbiter mission: A plethora of astrodynamic challenges SO SPACEFLIGHT MECHANICS 1997, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Space Flight Mechanics Conference CY FEB 10-12, 1997 CL HUNTSVILLE, AL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB The icy moon of Europa is a hot topic in planetary exploration. This paper discusses the trajectory design of a Europa orbiter mission intended to find out if Europa is a possible habitat for extraterrestrial life. Getting into orbit at Europa is difficult; the simplest trajectory design (a direct Hohmann-type transfer to Jupiter followed by an immediate insertion into orbit at Europa) requires more than 5.5 km/s of velocity change (Delta V) capability by the spacecraft. This paper describes a number of trajectory design techniques which can reduce this Delta V requirement step by step down to around 2.5 km/s. The variety of trajectory ''tricks'' involved make this mission a showcase of modern trajectory design. RP Sweetser, TH (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 9 Z9 9 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-432-X J9 ADV ASTRONAUT SCI PY 1997 VL 95 BP 901 EP 919 PN 1&2 PG 19 WC Engineering, Aerospace SC Engineering GA BJ27M UT WOS:A1997BJ27M00063 ER PT S AU Williams, BG Helfrich, CE Miller, JK Owen, WM Scheeres, DJ Yeomans, DK Dunham, DW Farquhar, RW Heyler, GL McAdams, JV Murchie, SL AF Williams, BG Helfrich, CE Miller, JK Owen, WM Scheeres, DJ Yeomans, DK Dunham, DW Farquhar, RW Heyler, GL McAdams, JV Murchie, SL BE Howell, KC Cicci, DA Cochran, JE Kelso, TS TI Preliminary plans for a close encounter with 253 Mathilde SO SPACEFLIGHT MECHANICS 1997, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Space Flight Mechanics Conference CY FEB 10-12, 1997 CL HUNTSVILLE, AL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB NASA's Near Earth Asteroid Rendezvous (NEAR) mission is planning a close flyby of the asteroid 253 Mathilde in June 1997. The asteroid 253 Mathilde appears to be a distinct and interesting body worthy of further investigation. Unlike the S-class asteroids Gaspra and Ida explored in recent years by Galileo spacecraft flybys, Mathilde is a C-class spectral object and it has a larger diameter of about 61 km. Furthermore, Mathilde appears to have a very slow rotation period, possibly 17 days or longer. The plan is to navigate the NEAR spacecraft to within 1200 km of the center of Mathilde using a combination of NASA's Deep Space Network radio metric tracking and on-board optical imaging. The planned sequence of spacecraft activities will result in high resolution, multi-spectral images of Mathilde made throughout the approach ard departure. In addition, the navigation tracking will be used to estimate Mathilde's mass. The mass estimate should be accurate to about ten percent. RP Williams, BG (reprint author), CALTECH,JET PROP LAB,NAVIGAT & FLIGHT MECH SECT,4800 OAK GROVE DR,PASADENA,CA 91109, USA. RI Murchie, Scott/E-8030-2015 OI Murchie, Scott/0000-0002-1616-8751 NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-432-X J9 ADV ASTRONAUT SCI PY 1997 VL 95 BP 955 EP 971 PN 1&2 PG 17 WC Engineering, Aerospace SC Engineering GA BJ27M UT WOS:A1997BJ27M00066 ER PT S AU Ocampo, CA Rosborough, GW AF Ocampo, CA Rosborough, GW BE Howell, KC Cicci, DA Cochran, JE Kelso, TS TI Trajectory optimization with dual thrust limited propulsion systems SO SPACEFLIGHT MECHANICS 1997, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Meeting Abstract CT AAS/AIAA Space Flight Mechanics Conference CY FEB 10-12, 1997 CL HUNTSVILLE, AL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV COLORADO,BOULDER,CO 80309. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-432-X J9 ADV ASTRONAUT SCI PY 1997 VL 95 BP 1067 EP 1067 PN 1&2 PG 1 WC Engineering, Aerospace SC Engineering GA BJ27M UT WOS:A1997BJ27M00075 ER PT S AU Ocampo, CA Rosborough, GW AF Ocampo, CA Rosborough, GW BE Howell, KC Cicci, DA Cochran, JE Kelso, TS TI The multiple spacecraft orbit transfer problem: Case I no booster SO SPACEFLIGHT MECHANICS 1997, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Meeting Abstract CT AAS/AIAA Space Flight Mechanics Conference CY FEB 10-12, 1997 CL HUNTSVILLE, AL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV COLORADO,BOULDER,CO 80309. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-432-X J9 ADV ASTRONAUT SCI PY 1997 VL 95 BP 1068 EP 1068 PN 1&2 PG 1 WC Engineering, Aerospace SC Engineering GA BJ27M UT WOS:A1997BJ27M00076 ER PT S AU Salama, AH Kennedy, BM Guinn, JR Williams, BG AF Salama, AH Kennedy, BM Guinn, JR Williams, BG BE Howell, KC Cicci, DA Cochran, JE Kelso, TS TI Performance of TOPEX/POSEIDON ''quick-look'' precision orbit determination in the extended mission SO SPACEFLIGHT MECHANICS 1997, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Space Flight Mechanics Conference CY FEB 10-12, 1997 CL HUNTSVILLE, AL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB The TOPEX/POSEIDON spacecraft, launched on 10 August 1992, has just completed the first year of a three-year extended mission. This year has been characterized by a flight team operating with minimal resources, two satellite safeholds, reduction in Satellite Laser Ranging (SLR) tracking data, and some Global Positioning System Development Receiver (GPSDR) problems. This paper presents a summary of TOPEX/POSEIDON ''quicklook'' orbit determination using GPS and SLR tracking data since the fall of 1995 (beginning of extended mission). The main feature of this process is that orbits are produced with small radial position errors (< 5 cm RMS), on a short production schedule (4 days), with minimal resources. The paper also addresses the extended mission shortcomings and their impact on the precision orbit determination process. The ''quick-look'' orbits are used in support of the Interim Geophysical Data Record (IGDR) production. RP Salama, AH (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 UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-432-X J9 ADV ASTRONAUT SCI PY 1997 VL 95 BP 1073 EP 1085 PN 1&2 PG 13 WC Engineering, Aerospace SC Engineering GA BJ27M UT WOS:A1997BJ27M00078 ER PT S AU Garrison, JL Axelrad, P Kasdin, NJ AF Garrison, JL Axelrad, P Kasdin, NJ BE Howell, KC Cicci, DA Cochran, JE Kelso, TS TI On the possibility of ill-conditioned covariance matrices in the first-order two-step estimator SO SPACEFLIGHT MECHANICS 1997, PTS 1 AND 2 SE ADVANCES IN THE ASTRONAUTICAL SCIENCES LA English DT Proceedings Paper CT AAS/AIAA Space Flight Mechanics Conference CY FEB 10-12, 1997 CL HUNTSVILLE, AL SP Amer Astronaut Soc, Amer Inst Aeronaut & Astronaut AB The first-order two-step nonlinear estimator, when applied to a problem of orbital navigation, is found to occasionally produce first step covariance matrices with very low eigenvalues at certain trajectory points. This anomaly is the result of the linear approximation to the first step covariance propagation. The study of this anomaly begins with expressing the propagation of the first and second step covariance matrices in terms of a single matrix. This matrix is shown to have a rank equal to the difference between the number of first step states and the number of second step states. Furthermore, under some simplifying assumptions, it is found that the basis of the column space of this matrix remains fixed once the filter has removed the large initial state error. A test matrix containing the basis of this column space and the partial derivative matrix relating first and second step states is derived. This square test matrix, which has dimensions equal to the number of first step states, numerically drops rank at the same locations that the first step covariance does. It is formulated in terms of a set of constant vectors (the basis) and a matrix which can be computed from a reference trajectory (the partial derivative matrix). A simple example problem involving dynamics which are described by two states and a range measurement illustrate the cause of this anomaly and the application of the aforementioned numerical test in more detail. RP Garrison, JL (reprint author), NASA,LANGLEY RES CTR,SPACECRAFT SENSORS BRANCH,MS 328,HAMPTON,VA 23681, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU UNIVELT INC PI SAN DIEGO PA PO BOX 28130, SAN DIEGO, CA 92128 SN 0065-3438 BN 0-87703-432-X J9 ADV ASTRONAUT SCI PY 1997 VL 95 BP 1087 EP 1102 PN 1&2 PG 16 WC Engineering, Aerospace SC Engineering GA BJ27M UT WOS:A1997BJ27M00079 ER PT J AU Mulligan, JB AF Mulligan, JB TI Application of M-JPEG compression hardware to dynamic stimulus production SO SPATIAL VISION LA English DT Article ID MASKING AB Inexpensive circuit boards have appeared on the market which transform a normal microcomputer's disk drive into a video disk capable of playing extended video sequences in real time. This technology enables the performance of experiments which were previously impossible, or at least prohibitively expensive. The new technology achieves this capability using special-purpose hardware to compress and decompress individual video frames, enabling a video stream to be transferred over relatively low-bandwidth disk interfaces. This paper will describe the use of such devices for visual psychophysics and present the technical issues that must be considered when evaluating individual products. RP NASA, AMES RES CTR, MS 262-2, MOFFETT FIELD, CA 94035 USA. NR 27 TC 2 Z9 2 U1 0 U2 0 PU VSP BV PI LEIDEN PA BRILL ACADEMIC PUBLISHERS, PO BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 0169-1015 J9 SPATIAL VISION JI Spatial Vis. PY 1997 VL 11 IS 1 BP 19 EP 32 DI 10.1163/156856897X00032 PG 14 WC Biophysics; Psychology; Psychology, Multidisciplinary SC Biophysics; Psychology GA XV928 UT WOS:A1997XV92800003 PM 9304750 ER PT J AU Watson, AB Solomon, JA AF Watson, AB Solomon, JA TI Psychophysica: Mathematica notebooks for psychophysical experiments (Cinematica-Psychometrica-Quest) SO SPATIAL VISION LA English DT Article ID CONTRAST DETECTION AB Psychophysica is a set of software tools for psychophysical reasearch. Functions are provided for calibrated visual displays, for fitting and plotting of psychometric functions, and for the QUEST adaptive staircase procedure. The functions are written in the Mathematica programming language. C1 INST OPHTHALMOL,LONDON EC1V 9EL,ENGLAND. RP Watson, AB (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 15 TC 20 Z9 20 U1 0 U2 1 PU VSP BV PI ZEIST PA PO BOX 346, 3700 AH ZEIST, NETHERLANDS SN 0169-1015 J9 SPATIAL VISION JI Spatial Vis. PY 1997 VL 10 IS 4 BP 447 EP 466 DI 10.1163/156856897X00384 PG 20 WC Biophysics; Psychology; Psychology, Multidisciplinary SC Biophysics; Psychology GA WZ536 UT WOS:A1997WZ53600017 PM 9176955 ER PT S AU Barnes, NP Morrison, CA Filer, ED Rodriguez, WJ Walsh, BM AF Barnes, NP Morrison, CA Filer, ED Rodriguez, WJ Walsh, BM BE DiBartolo, B TI Spectroscopy and development of solid state lasers at NASA SO SPECTROSCOPY AND DYNAMICS OF COLLECTIVE EXCITATIONS IN SOLIDS SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES B, PHYSICS LA English DT Proceedings Paper CT NATO Advanced-Study-Institute / International-School-of-Atomic-and-Molecular-Spectroscopy Workshop on Spectroscopy and Dynamics of Collective Excitation in Solids CY JUN 17-JUL 01, 1995 CL ERICE, ITALY SP Ettore Majorana Ctr Sci Culture, Int Sch Atom & Molec Spectroscopy, NATO, Sci Affairs Div, ENEA Org, Boston Coll, European Phys Soc, Italian Minist Educ, Italian Minist Univ & Sci Res, Sicilian Reg Govt AB NASA Langley has developed expeditious methods of evaluating new laser materials and laser systems using quantum mechanical and energy transfer models. Veracity of these models has been tested against measured spectroscopic parameters as well as measured laser amplifier performance. In particular, these methods have been applied to the development of 2.0 mu m laser such as the Ho:Tm laser materials. RP Barnes, NP (reprint author), NASA,LANGLEY RES CTR,MS 474,HAMPTON,VA 23681, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0258-1221 BN 0-306-45390-8 J9 NATO ADV SCI I B-PHY PY 1997 VL 356 BP 485 EP 492 PG 8 WC Physics, Condensed Matter; Spectroscopy SC Physics; Spectroscopy GA BH43Q UT WOS:A1997BH43Q00016 ER PT S AU Waller, WH Stecher, TP AF Waller, WH Stecher, TP BE Holt, SS Mundy, LG TI Orchestration of starbirth activity in disk galaxies: New perspectives from ultraviolet imaging SO STAR FORMATION NEAR AND FAR - SEVENTH ASTROPHYSICS CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th Annual October Astrophysics Conference on Star Formation, Near and Far CY OCT, 1996 CL COLLEGE PK, MD SP Goddard Space Flight Ctr, Univ Maryland AB Ultraviolet imaging of nearby disk galaxies reveals the star-forming activity in these systems with unprecedented clarity. UV images recently obtained with the Shuttle-borne Ultraviolet Imaging Telescope (UIT) reveal a remarkable variety of star-forming morphologies. The respective roles of tides, waves, and resonances in orchestrating the observed patterns of starbirth activity are discussed in terms of the extant UV data. RP Waller, WH (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,CODE 680,GREENBELT,MD 20771, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-678-6 J9 AIP CONF PROC PY 1997 IS 393 BP 287 EP 290 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ23B UT WOS:A1997BJ23B00044 ER PT S AU Borne, KD Bushouse, H Colina, L Lucas, RA AF Borne, KD Bushouse, H Colina, L Lucas, RA BE Holt, SS Mundy, LG TI Early results from an HST imaging survey of the ultraluminous IR galaxies SO STAR FORMATION NEAR AND FAR - SEVENTH ASTROPHYSICS CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th Annual October Astrophysics Conference on Star Formation, Near and Far CY OCT, 1996 CL COLLEGE PK, MD SP Goddard Space Flight Ctr, Univ Maryland AB We present results derived from a recent Hubble Space Telescope (HST) imaging survey of the Ultraluminous IR Galaxies. The most significant issue related to this sample of galaxies has been identifying the nature of the primary energy source: starburst or AGN? Through a high-resolution imaging survey of a large sample, some properties of this class of objects are now being better defined, which is helping to clarify the nature of the energy source. Fine structure is seen within the central arcsecond of each galaxy in the sample. In some cases, the structure is smooth and centrally concentrated, suggestive of a bright nuclear energy source (AGN?). In many other cases, the sub-arcsecond morphology is chaotic and extended, suggestive of strong starburst activity. The peculiar, disturbed morphologies that are seen on large (kiloparsec) scales among this sample of galaxies are continued down to the smallest scales in the cores of these strongly starbursting systems. A rich variety of morphological features are noted, many of which are related to the recent intense interaction-induced star formation episode. These starburst-related features (e.g., numerous bright clumps of star formation, shells, and bubbles) are similar to those seen in previous HST imaging observations of other strongly interacting and merging galaxies. RP Borne, KD (reprint author), HUGHES STX,NASA,GSFC,7701 GREENBELT RD,GREENBELT,MD 20770, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-678-6 J9 AIP CONF PROC PY 1997 IS 393 BP 295 EP 298 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ23B UT WOS:A1997BJ23B00046 ER PT S AU Heap, SR AF Heap, SR BE Holt, SS Mundy, LG TI Observations of the extragalactic Initial Mass Function and modes of star formation SO STAR FORMATION NEAR AND FAR - SEVENTH ASTROPHYSICS CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th Annual October Astrophysics Conference on Star Formation, Near and Far CY OCT, 1996 CL COLLEGE PK, MD SP Goddard Space Flight Ctr, Univ Maryland AB I review recent measurements of the Initial Mass Function in other galaxies for three modes of star formation: stars formed in isolation, in associations, and in starburst clusters. While the observed differences in the IMF are mild, they are enough to rule Out a universal IMF. RP Heap, SR (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-678-6 J9 AIP CONF PROC PY 1997 IS 393 BP 414 EP 422 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ23B UT WOS:A1997BJ23B00069 ER PT S AU Leisawitz, D Digel, SW Hanson, MM AF Leisawitz, D Digel, SW Hanson, MM BE Holt, SS Mundy, LG TI Toward a better understanding of the IR spectral energy distributions of H II regions SO STAR FORMATION NEAR AND FAR - SEVENTH ASTROPHYSICS CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th Annual October Astrophysics Conference on Star Formation, Near and Far CY OCT, 1996 CL COLLEGE PK, MD SP Goddard Space Flight Ctr, Univ Maryland AB Infrared spectral energy distributions (SEDs) of several isolated star-forming regions were derived from observations made by the Diffuse Infrared Background Experiment (DIRBE) on NASA's Cosmic Background Explorer (COBE) (1). Recently obtained near-IR photometric observations of five regions will be used in conjunction with 2 mu m spectroscopy to locate and classify visually obscured O and early-B stars. Our goal is to learn in some detail how the stellar population and the local interstellar environment affect the IR SED. RP Leisawitz, D (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 631,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-678-6 J9 AIP CONF PROC PY 1997 IS 393 BP 465 EP 468 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ23B UT WOS:A1997BJ23B00079 ER PT S AU Neff, SG Hollis, JE Hill, JK Fanelli, MN Smith, DA Smith, AM Stecher, TP Bohlin, RC OConnell, RW Roberts, MS AF Neff, SG Hollis, JE Hill, JK Fanelli, MN Smith, DA Smith, AM Stecher, TP Bohlin, RC OConnell, RW Roberts, MS BE Holt, SS Mundy, LG TI Far-Ultraviolet emission from NGC 4038/4039, ''the antennae'': Massive star formation in compact clusters SO STAR FORMATION NEAR AND FAR - SEVENTH ASTROPHYSICS CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th Annual October Astrophysics Conference on Star Formation, Near and Far CY OCT, 1996 CL COLLEGE PK, MD SP Goddard Space Flight Ctr, Univ Maryland AB Far-Ultraviolet (FUV) emission from NGC4038/4039 traces recent massive star formation in the system. The FUV is used to determine the massive star content and to identify compact regions of recent star formation. FUV measurements are combined with ground-based observations and starburst models to determine ages, mass functions, and current star formation rates. RP Neff, SG (reprint author), NASA,GODDARD SPACE FLIGHT CTR,LASP,CODE 681,GREENBELT,MD 20771, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-678-6 J9 AIP CONF PROC PY 1997 IS 393 BP 473 EP 474 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ23B UT WOS:A1997BJ23B00081 ER PT S AU Gardner, JP Sharples, RM Frenk, CS Carrasco, BE AF Gardner, JP Sharples, RM Frenk, CS Carrasco, BE BE Holt, SS Mundy, LG TI The K-band luminosity function of galaxies SO STAR FORMATION NEAR AND FAR - SEVENTH ASTROPHYSICS CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th Annual October Astrophysics Conference on Star Formation, Near and Far CY OCT, 1996 CL COLLEGE PK, MD SP Goddard Space Flight Ctr, Univ Maryland AB We present the first determination of the near-infrared K-band luminosity function of field galaxies from a wide field K-selected redshift. survey. The best fit Schechter function parameters are M* = -23.12 + 5log(h), alpha = -0.91, and phi* = 1.66 x 10(-2)h(3) MpC(-3). We estimate that systematics are no more than O.lmag in M* and 0.1 in alpha, which is comparable to the statistical errors on this measurement. RP Gardner, JP (reprint author), NASA,GODDARD SPACE FLIGHT CTR,CODE 681,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-678-6 J9 AIP CONF PROC PY 1997 IS 393 BP 543 EP 546 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ23B UT WOS:A1997BJ23B00092 ER PT S AU Smith, EP Bohlin, RC Bothun, GD OConnell, RW Roberts, MS Neff, SG Smith, AM Stecher, TP AF Smith, EP Bohlin, RC Bothun, GD OConnell, RW Roberts, MS Neff, SG Smith, AM Stecher, TP BE Holt, SS Mundy, LG TI Ultraviolet imaging observations of Abell 1795: Further evidence for massive starformation SO STAR FORMATION NEAR AND FAR - SEVENTH ASTROPHYSICS CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th Annual October Astrophysics Conference on Star Formation, Near and Far CY OCT, 1996 CL COLLEGE PK, MD SP Goddard Space Flight Ctr, Univ Maryland AB We dicuss observations from the Ultraviolet Imaging Telescope of the Abell 1795 cluster of galaxies. We compare the cD galaxy morphology and photometry of these data with those from existing archival and published data. The addition of a far-UV color helps us to construct and test star formation model scenarios for the sources of UV emission. Models of star formation with rates in the range similar to 5 - 20M.yr(-1) indicate that the best fitting models are those with continuous star formation or a recent (similar to 4 Myr old) burst superimposed on an old population. RP Smith, EP (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-678-6 J9 AIP CONF PROC PY 1997 IS 393 BP 551 EP 554 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ23B UT WOS:A1997BJ23B00094 ER PT S AU Cornett, RH Stecher, TP AF Cornett, RH Stecher, TP BE Holt, SS Mundy, LG TI UIT observations of the SMC SO STAR FORMATION NEAR AND FAR - SEVENTH ASTROPHYSICS CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th Annual October Astrophysics Conference on Star Formation, Near and Far CY OCT, 1996 CL COLLEGE PK, MD SP Goddard Space Flight Ctr, Univ Maryland AB A mosaic of four UIT far-UV (FUV; 1620 Angstrom) images, which covers most of the SMC bar, is presented, with derived stellar and HII region photometry. The UV morphology of the SMC's Bar shows that recent star formation there has left striking features including: a) four concentrations of UV-bright stars spread from northeast to southwest at nearly equal (similar to 30 arcmin=0.5 kpc) spacings; b) one concentration comprising a well-defined 8-arcmin diameter ring surrounded by a larger H alpha ring, suggestive of sequential star formation. FUV PSF photometry is obtained for 11,306 stars, and FUV photometry is obtained for 42 H alpha-selected HII regions, both for the stars and for the total emission contained in the apertures defined by KH [1]. The flux-weighted average ratio of total to stellar FUV flux is 2.15; the stellar FUV luminosity function indicates that most of the excess total flux is due to scattered FUV radiation, rather than faint stars. Both stellar and total emission are well correlated with H alpha fluxes measured by KH, and yield FUV/H alpha flux ratios that are consistent with models of single-burst clusters with SMC metallicity, ages from 1-5 Myr, and moderate (E(B-V)=0.0-0.1 mag) internal SMC extinction. RP Cornett, RH (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,HUGHES STX,CODE 681,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-678-6 J9 AIP CONF PROC PY 1997 IS 393 BP 590 EP 593 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ23B UT WOS:A1997BJ23B00100 ER PT S AU Hill, RS Fanelli, MN Smith, DA Bohlin, RC Neff, SG OConnell, RW Roberts, MS Smith, AM Stecher, TP AF Hill, RS Fanelli, MN Smith, DA Bohlin, RC Neff, SG OConnell, RW Roberts, MS Smith, AM Stecher, TP BE Holt, SS Mundy, LG TI UIT Astro-2 observations of NGC 4449 SO STAR FORMATION NEAR AND FAR - SEVENTH ASTROPHYSICS CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th Annual October Astrophysics Conference on Star Formation, Near and Far CY OCT, 1996 CL COLLEGE PK, MD SP Goddard Space Flight Ctr, Univ Maryland AB The bright Magellanic irregular galaxy NGC 4449 was observed by the Ultraviolet Imaging Telescope (UIT) during the Astro-2 Spacelab mission in March, 1995. Far ultraviolet (FUV) images at a spatial resolution of similar to 3 '' show bright star-forming knots that are consistent with the general optical morphology of the galaxy and are often coincident with bright H II regions. Comparison of FUV with H alpha shows that in a few regions, sequential star formation may have occurred over the last few Myr. The bright star forming complexes in NGC 4449 are superposed on a smooth, diffuse FUV background that may be associated with the H alpha ''froth.'' RP Hill, RS (reprint author), NASA,GODDARD SPACE FLIGHT CTR,HUGHES STX CORP,CODE 681,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-678-6 J9 AIP CONF PROC PY 1997 IS 393 BP 594 EP 597 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ23B UT WOS:A1997BJ23B00101 ER PT S AU Fanelli, MN Stecher, TP AF Fanelli, MN Stecher, TP BE Holt, SS Mundy, LG TI Luminosities and star formation rates of galaxies observed with the Ultraviolet Imaging Telescope: A comparison of far-UV, H alpha, and far-IR diagnostics SO STAR FORMATION NEAR AND FAR - SEVENTH ASTROPHYSICS CONFERENCE SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 7th Annual October Astrophysics Conference on Star Formation, Near and Far CY OCT, 1996 CL COLLEGE PK, MD SP Goddard Space Flight Ctr, Univ Maryland AB During the UIT/Astro Spacelab missions, the Ultraviolet Imaging Telescope obtained spatially resolved far-UV (lambda lambda 1500 Angstrom) imagery of similar to 35 galaxies exhibiting recent massive star formation. The sample includes disk systems, irregular, dwarf, and blue compact galaxies. The objects span an observed FUV luminosity range from -17 to -22 magnitudes. The estimate global star formation rates by comparing the observed FUV fluxes to the predictions of stellar population models, and compare the FUV-derived astration rates to those derived from H alpha and far-IR photometry. RP Fanelli, MN (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-678-6 J9 AIP CONF PROC PY 1997 IS 393 BP 598 EP 601 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ23B UT WOS:A1997BJ23B00102 ER PT B AU Scargle, JD AF Scargle, JD BE Babu, GJ Feigelson, ED TI Wavelet and other multi-resolution methods for time series analysis SO STATISTICAL CHALLENGES IN MODERN ASTRONOMY II LA English DT Proceedings Paper CT Statistical Challenges in Modern Astronomy II Conference (SCMA II) CY JUN, 1996 CL PENN STATE UNIV, UNIVERSITY PK, PA SP Int Astron Union, Int Stat Inst, Inst Math Stat HO PENN STATE UNIV AB Wavelets are the central idea of a broad framework for thinking about, displaying, and analyzing data. These localized basis functions provide flexible and efficient methods for analysis of time series and image data - including noise removal, characterization of stochastic behavior, depiction of power spectrum time-variations, and data compression. RP Scargle, JD (reprint author), NASA,AMES RES CTR,MAIL STOP 245-3,MOFFETT FIELD,CA 94035, USA. NR 0 TC 2 Z9 2 U1 6 U2 6 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 BN 0-387-98203-5 PY 1997 BP 333 EP 347 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ16X UT WOS:A1997BJ16X00019 ER PT B AU Turmon, MJ Pap, JM AF Turmon, MJ Pap, JM BE Babu, GJ Feigelson, ED TI Segmenting chromospheric images with Markov random fields SO STATISTICAL CHALLENGES IN MODERN ASTRONOMY II LA English DT Proceedings Paper CT Statistical Challenges in Modern Astronomy II Conference (SCMA II) CY JUN, 1996 CL PENN STATE UNIV, UNIVERSITY PK, PA SP Int Astron Union, Int Stat Inst, Inst Math Stat HO PENN STATE UNIV AB The solar chromosphere roughly consists of three types of region: plage, network, and background. Thresholding individual pixel intensities is typically used to identify these regions in solar images. We have incorporated spatial information by using a Bayesian setup with an image prior that prefers spatially coherent labelings; resulting segmentations are more physically reasonable. These priors are a first step in developing an appropriate model for chromospheric images. RP Turmon, MJ (reprint author), CALTECH,JET PROP LAB,M-S 525-3550,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 BN 0-387-98203-5 PY 1997 BP 409 EP 411 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ16X UT WOS:A1997BJ16X00031 ER PT B AU Montgomery, KN AF Montgomery, KN BE Fisher, SS Merritt, JO Bolas, MT TI VERS - A virtual environment for reconstructive surgery planning SO STEREOSCOPIC DISPLAYS AND VIRTUAL REALITY SYSTEMS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Stereoscopic Displays and Virtual Reality Systems IV CY FEB 11-14, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers, Soc Imaging Sci & Technol DE reconstruction; mesh generation; surgical planning; virtual environments AB The Virtual Environment for Reconstructive Surgery (VERS) project at the NASA Ames Biocomputation Center is applying virtual reality technology to aid surgeons in planning surgeries. We are working with a craniofacial surgeon at Stanford to assemble and visualize the bone structure of patients requiring reconstructive surgery either through developmental abnormalities or trauma. This project is an extension of our previous work in 3D reconstruction, mesh generation, and immersive visualization. The current VR system, consisting of an SGI Onyx RE2, FakeSpace BOOM and Immersive Workbench, Virtual Technologies CyberGlove, and Ascension Technologies tracker, is currently in development and has already been used to visualize defects preoperatively. In the near future it will be used to more fully plan the surgery and compute the projected result to soft tissue structure. This paper will present the work in progress and detail the production of a high-performance, collaborative, and networked virtual environment. RP Montgomery, KN (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2423-4 J9 P SOC PHOTO-OPT INS PY 1997 VL 3012 BP 487 EP 492 DI 10.1117/12.274491 PG 6 WC Computer Science, Cybernetics; Optics SC Computer Science; Optics GA BH98B UT WOS:A1997BH98B00056 ER PT J AU Andrews, R Mah, R Galvagni, A Guerrero, M Papasin, R Wallace, M Winters, J AF Andrews, R Mah, R Galvagni, A Guerrero, M Papasin, R Wallace, M Winters, J TI Robotic multimodality stereotactic grain tissue identification: Work in progress SO STEREOTACTIC AND FUNCTIONAL NEUROSURGERY LA English DT Article; Proceedings Paper CT XIIth Meeting of the World Society for Stereotactic and Functional Neurosurgery CY JUL 01-04, 1997 CL LYON, FRANCE SP World Soc Stereotact & Funct Neurosurg DE brain biopsy; computer; neural network; robotics; stereotaxy AB Real-time identification of tissue would improve procedures such as stereotactic brain biopsy (SBX), functional and implantation neurosurgery, and brain tumor excision. To standard SEX equipment has been added: (I) computer-controlled stepper motors to drive the biopsy needle/probe precisely; (2) multiple microprobes to track tissue density, detect blood vessels and changes in blood flow, and distinguish the various tissues being penetrated; (3) neural net learning programs to allow real-time comparisons of current data with a normative data bank; (4) three-dimensional graphic displays to follow the probe as it traverses brain tissue. The probe can differentiate substances such as pig brain, differing consistencies of the 'brain-like' foodstuff tofu, and gels made to simulate brain, as well as detect blood vessels imbedded in these substances. Multimodality probes should improve the safety, efficacy, and diagnostic accuracy of SEX and other neurosurgical procedures. C1 SUNY Hlth Sci Ctr, Dept Neurosurg, Syracuse, NY 13210 USA. NASA, Ames Res Ctr, Mt View, CA USA. RP Andrews, R (reprint author), SUNY Hlth Sci Ctr, Dept Neurosurg, 750 E Adams St, Syracuse, NY 13210 USA. NR 6 TC 9 Z9 9 U1 0 U2 0 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 1011-6125 J9 STEREOT FUNCT NEUROS JI Stereotact. Funct. Neurosurg. PY 1997 VL 68 IS 1-4 BP 72 EP 79 DI 10.1159/000099906 PG 8 WC Neurosciences; Neuroimaging; Surgery SC Neurosciences & Neurology; Surgery GA ZZ207 UT WOS:000074706300012 PM 9711699 ER PT B AU Anastasi, RF Friedman, AD Hinders, MK Madaras, EI AF Anastasi, RF Friedman, AD Hinders, MK Madaras, EI BE Chang, FK TI Nondestructive evaluation of damage in stitched composites using laser based ultrasound SO STRUCTURAL HEALT H MONITORING: CURRENT STATUS AND PERSPECTIVES LA English DT Proceedings Paper CT International Workshop on Structural Health Monitoring CY SEP 18-20, 1997 CL STANFORD UNIV, STANFORD, CA SP USAF Off Sci Res, USA Res Off, Natl Sci Fdn HO STANFORD UNIV AB Composite material applications in civil transport aircraft primary structures such as wings are currently being planned. In a building block approach, sub components of the wing structure are tested to understand the structural response and failure characteristics. Nondestructive evaluation is an important element which can provide quantitative information on the damage initiation, propagation, and final failure modes for the composite structural components. Although ultrasound is generally accepted as a test method, the use of conventional ultrasound in situ health monitoring of damage during a test is not practical. The use of lasers to both generate and detect ultrasound extends the application of ultrasound to in situ sensing of damage in a deformed structure remotely and in a non-contact manner. The goal of the present research is to utilize this technology to monitor damage progression during testing. The present paper describes the application of laser based ultrasound to quantify damage in thick stitched composite structural elements to demonstrate the method. This method involves using a Q-switched laser to generate a rapid, local linear thermal strain on the surface of the structure. This causes the generation of ultrasonic waves into the material. A second laser illuminates the surface and a Fabry-Perot interferometer measures the surface deflections from the reflected light. The use of fiber optics provides a convenient method of delivering the laser over long distances to the specimens. The material for these structural elements is composed of several stacks of composite material assembled together by stitching through the laminate thickness. The specimen thickness varies from 0.5 to 1.0 inch. The specimens used for these nondestructive evaluation studies had either impact damage or skin/stiffener interlaminar failure. Although no visible surface damage existed internal damage was detected by laser based ultrasound. C1 NASA, Langley Res Ctr, Nondestruct Evaluat Sci Branch, ARL,USA,Vehicle Technol Ctr, Hampton, VA 23681 USA. RP Anastasi, RF (reprint author), NASA, Langley Res Ctr, Nondestruct Evaluat Sci Branch, ARL,USA,Vehicle Technol Ctr, Hampton, VA 23681 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA BN 1-56676-605-2 PY 1997 BP 66 EP 77 PG 12 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA BP91G UT WOS:000086581600006 ER PT B AU Melvin, L Childers, B Rogowski, R Prosser, W Moore, J Frogatt, M Allison, S Wu, MC Bly, J Aude, C Bouvier, C Zisk, E Enright, E Cassadaban, Z Reightler, R Sirkis, J Tang, I Peng, T Wegreich, R Garbos, R Mouyos, W Aibel, D Bodan, F AF Melvin, L Childers, B Rogowski, R Prosser, W Moore, J Frogatt, M Allison, S Wu, MC Bly, J Aude, C Bouvier, C Zisk, E Enright, E Cassadaban, Z Reightler, R Sirkis, J Tang, I Peng, T Wegreich, R Garbos, R Mouyos, W Aibel, D Bodan, F BE Chang, FK TI Integrated Vehicle Health Monitoring (IVHM) for aerospace vehicles SO STRUCTURAL HEALT H MONITORING: CURRENT STATUS AND PERSPECTIVES LA English DT Proceedings Paper CT International Workshop on Structural Health Monitoring CY SEP 18-20, 1997 CL STANFORD UNIV, STANFORD, CA SP USAF Off Sci Res, USA Res Off, Natl Sci Fdn HO STANFORD UNIV ID OPTICAL-FIBER AB The vehicle launch community is evaluating methods for reducing the excessive costs associated with access to space. System design strategies for future launch vehicles, like the X-33 Reuseable Launch Vehicle (RLV) demonstrator, focus on providing easy repair access for simplified servicing of infrastructures and expedited decision making from detected faults and anomalies. The Integrated Vehicle Health Monitoring (IVHM) system supports these strategies by providing reliable and low cost maintainability for the Single Stage to Orbit (SSTO) RLV, the planned replacement for the space shuttle. The objective of IVHM is to provide an automated collection and paperless health decision, maintenance and logistics system. This paper will discuss the sensor components, fiber optic and acoustic emission, of IVHM and their application to the X-33 demonstrator and their extension to the RLV. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Melvin, L (reprint author), NASA, Langley Res Ctr, M-S 231, Hampton, VA 23681 USA. NR 7 TC 5 Z9 5 U1 0 U2 0 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA BN 1-56676-605-2 PY 1997 BP 705 EP 714 PG 10 WC Engineering, Aerospace; Engineering, Civil SC Engineering GA BP91G UT WOS:000086581600058 ER PT S AU Boscher, DM Fung, SF Tan, LC AF Boscher, DM Fung, SF Tan, LC BE Chen, MW TI Spatial distributions of the inner radiation belt electrons: A comparison between observations and radial diffusion theory predictions SO SUBAURORAL IONOSPHERE, PLASMASPHERE, RING CURRENT AND INNER MAGNETOSPHERE SYSTEM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT Symposium of COSPAR Scientific Commission D on the Subauroral Ionosphere, Plasmasphere, Ring Current and Inner Magnetosphere System, at 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res AB It is well known that the quiet-time electron radiation belts exhibit a two-zone radial structure. Although the inner radiation belt does show dynamic variations during geomagnetically active periods, the stably trapped electrons found in this region are thought to be populated primarily by diffusive transport processes. Recent analyses of the long-term (1984-1987) energetic electron (0.19-3.2 MeV) observations taken at 350-850 km altitude by the OHZORA satellite indicate that the trapped electrons also show local-time variations in pitch angle distributions. We here report the observed L-shell distributions of the energetic electrons and show that they are in good agreement with the azimuthally averaged predictions of the radial diffusion theory (the Salammbo model) for inner zone electron fluxes. We also compare the OHZORA observations with earlier observations as compiled in the NASA empirical radiation belt models. Published by Elsevier Science Ltd on behalf of COSPAR. C1 HUGHES STX CORP, GREENBELT, MD 20770 USA. RP Boscher, DM (reprint author), NASA, GODDARD SPACE FLIGHT CTR, SPACE PHYS DATA FACIL, GREENBELT, MD 20771 USA. RI Fung, Shing/F-5647-2012 NR 14 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043299-9 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 3 BP 369 EP 372 DI 10.1016/S0273-1177(97)00693-5 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ74K UT WOS:A1997BJ74K00009 ER PT S AU Delaboudiniere, JP Stern, RA Maucherat, A Portier-Fozzani, F Neupert, WM Gurman, JB Catura, RC Lemen, JR Shing, L Artzner, GE Brunaud, J Gabriel, AH Michels, DJ Moses, JD Au, B Dere, KP Howard, RA Kreplin, R Defise, JM Jamar, C Rochus, P Chauvineau, JP Marioge, JP Clette, F Cugnon, P Van Dessel, EL AF Delaboudiniere, JP Stern, RA Maucherat, A Portier-Fozzani, F Neupert, WM Gurman, JB Catura, RC Lemen, JR Shing, L Artzner, GE Brunaud, J Gabriel, AH Michels, DJ Moses, JD Au, B Dere, KP Howard, RA Kreplin, R Defise, JM Jamar, C Rochus, P Chauvineau, JP Marioge, JP Clette, F Cugnon, P Van Dessel, EL BE Antonucci, E Shea, MA TI Imaging the solar corona in the EUV SO SUN AND ITS ATMOSPHERE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT E2.1 Symposium of COSPAR Scientific Commission E on the Sun and Its Atmosphere, at the 31st COSPAR Scientific Assembly CY JUL 14-SEP 21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, Inst Space & Astron Sci ID TELESCOPE AB The SOHO (SOlar and Heliospheric Observatory) satellite was launched on December 2nd 1995. After arriving at the Earth-Sun (L1) Lagrangian point on February 14th 1996, it began to continuously observe the Sun. As one of the instruments onboard SOHO, the EIT (Extreme ultraviolet Imaging Telescope) images the Sun's corona in 4 EUV wavelengths, The Hell filter at 304 Angstrom images the chromosphere and the base of the transition region at a temperature of 5 - 8 x 10(4) K; the Fe IX-X filter at 171 Angstrom images the corona at a temperature of similar to 1.3 x 10(6) K; the Fe XII filter at 195 Angstrom images the quiet corona outside coronal holes at a temperature of similar to 1.6 x 10(6) K; and the Fe XV filter at 284 Angstrom images active regions with a temperature of similar to 2.0 x 10(6) K. About 5000 images have been obtained up to the present, In this paper, we describe also some aspects of the telescope and the detector performance for application in the observations, Images and movies of all the wavelengths allow a look at different phenomena present in the Sun's corona, and in particular, magnetic field reconnection. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. Astron Spatiale Lab, F-13376 Marseille 12, France. Lockheed Martin, Solar & Astrophys Lab, Palo Alto, CA 94304 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Naval Res Lab, Washington, DC 20365 USA. Ctr Spatial Liege, Liege, Belgium. Inst Opt Theor & Appl, F-91403 Orsay, France. Observ Royal Belgique, B-1180 Brussels, Belgium. RP Delaboudiniere, JP (reprint author), Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. NR 10 TC 5 Z9 5 U1 0 U2 3 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043309-X J9 ADV SPACE RES PY 1997 VL 20 IS 12 BP 2231 EP 2237 DI 10.1016/S0273-1177(97)01049-1 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK38L UT WOS:000071955600003 ER PT S AU Harrison, RA Fludra, A Sawyer, EC Culhane, JL Norman, K Poland, AI Thompson, WT Kjeldseth-Moe, O Aschenbach, B Huber, MCE Gabriel, AH Mason, HE AF Harrison, RA Fludra, A Sawyer, EC Culhane, JL Norman, K Poland, AI Thompson, WT Kjeldseth-Moe, O Aschenbach, B Huber, MCE Gabriel, AH Mason, HE BE Antonucci, E Shea, MA TI Extreme ultraviolet observations of the solar corona: First results from the coronal diagnostic spectrometer on SOHO SO SUN AND ITS ATMOSPHERE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT E2.1 Symposium of COSPAR Scientific Commission E on the Sun and Its Atmosphere, at the 31st COSPAR Scientific Assembly CY JUL 14-SEP 21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, Inst Space & Astron Sci AB We present first results from the Coronal Diagnostic Spectrometer (CDS) aboard the ESA/NASA Solar and Heliospheric Observatory (SOHO). CDS is a double spectrometer operating in the 151-785 Angstrom range. This region of the solar spectrum is rich in emission lines from trace elements in the solar atmosphere, which can be used to derive diagnostic information on coronal and transition region plasmas. Early spectra are presented and well identified lines are listed. In addition, examples of images in selected wavelength ranges are shown, for a prominence, a loop system and a bright point, demonstrating well the power of such extreme ultraviolet observations. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 Rutherford Appleton Lab, Div Astrophys, Didcot OX11 0QX, Oxon, England. Mullard Space Sci Lab, Surrey RH5 6NT, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Max Planck Inst Extraterr Phys, D-85748 Garching, Germany. ESA, Estec, Dept Space Sci, NL-2200 AG Noordwijk, Netherlands. Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France. Univ Cambridge, Dept Appl Math & Theoret Phys, Cambridge CB3 9EW, England. RP Harrison, RA (reprint author), Rutherford Appleton Lab, Div Astrophys, Didcot OX11 0QX, Oxon, England. RI Thompson, William/D-7376-2012 NR 4 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043309-X J9 ADV SPACE RES PY 1997 VL 20 IS 12 BP 2239 EP 2248 DI 10.1016/S0273-1177(97)01059-4 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK38L UT WOS:000071955600004 ER PT S AU Lemaire, P Wilhelm, K Schuhle, U Curdt, W Poland, AI Jordan, SD Thomas, RJ Hassler, DM Vial, JC AF Lemaire, P Wilhelm, K Schuhle, U Curdt, W Poland, AI Jordan, SD Thomas, RJ Hassler, DM Vial, JC BE Antonucci, E Shea, MA TI High resolution solar ultraviolet measurements SO SUN AND ITS ATMOSPHERE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT E2.1 Symposium of COSPAR Scientific Commission E on the Sun and Its Atmosphere, at the 31st COSPAR Scientific Assembly CY JUL 14-SEP 21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, Inst Space & Astron Sci AB The increase of our understanding of the processes acting in the solar corona and maintaining it is strongly dependent on the quality of the data that are obtained to check theories. The fine structure of the solar atmosphere seen from the photosphere and extending to the hottest parts of the corona requires data with high resolution in all parameter space (angular, spectral and temporal), To constrain the hypotheses that are proposed to describe the solar corona, it is necessary to establish an accurate energy budget taking into account the processes which are acting from the chromosphere to the corona. Some requirements can be established and compared with the data collected so far (or about to be collected) with the present SUMER (Solar Utraviolet Measurements of Emitted Radiations) instrumentation. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 Univ Paris 11, Inst Astrophys Spatiale, Unite Mixte CNRS, F-91405 Orsay, France. Max Planck Inst Aeron, D-3411 Katlenburg Lindau, Germany. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. RP Lemaire, P (reprint author), Univ Paris 11, Inst Astrophys Spatiale, Unite Mixte CNRS, Bat 121, F-91405 Orsay, France. NR 13 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043309-X J9 ADV SPACE RES PY 1997 VL 20 IS 12 BP 2249 EP 2258 DI 10.1016/S0273-1177(97)00896-X PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK38L UT WOS:000071955600005 ER PT S AU Schmelz, JT Chauvin, JC Saba, JLR AF Schmelz, JT Chauvin, JC Saba, JLR BE Antonucci, E Shea, MA TI Opacity effects in soft X-ray spectral lines of the solar corona SO SUN AND ITS ATMOSPHERE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT E2.1 Symposium of COSPAR Scientific Commission E on the Sun and Its Atmosphere, at the 31st COSPAR Scientific Assembly CY JUL 14-SEP 21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, Inst Space & Astron Sci ID FE-XVII AB Current literature suggests that several lines in the soft X-ray portion of the coronal spectrum may not be optically thin. Here, we confirm the results of Schmelz et al. (1996) who find no significant opacity effects for three of the brightest non-iron resonance lines in this part of the spectrum -O VIII at 18.97 Angstrom, Ne IX at 13.45 Angstrom, and Mg XI at 9.17 Angstrom. A comparison is made between each of these Lines and an optically thin "reference" line produced by the same element in the same ionization state -O VIII at 15.18 Angstrom, Ne IX at 13.55 Angstrom, and Mg XI at 9.23 Angstrom. In the latter two cases, the comparison line is the intersystem line of the He-like triplet. 33 spectra from the Solar Maximum Mission Flat Crystal Spectrometer are analyzed, all of which were obtained from non-flaring, quasi-stable active regions. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 Rhodes Coll, Memphis, TN 38112 USA. NASA, Goddard Space Flight Ctr, Lockheed Solar & Astrophys Lab, Greenbelt, MD 20771 USA. RP Schmelz, JT (reprint author), Rhodes Coll, 200 N Pkwy, Memphis, TN 38112 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043309-X J9 ADV SPACE RES PY 1997 VL 20 IS 12 BP 2259 EP 2262 DI 10.1016/S0273-1177(97)01050-8 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK38L UT WOS:000071955600006 ER PT S AU Phillips, KJH Greer, CJ Bhatia, AK Coffey, IH Barnsley, R Keenan, FP AF Phillips, KJH Greer, CJ Bhatia, AK Coffey, IH Barnsley, R Keenan, FP BE Antonucci, E Shea, MA TI FeXVII x-ray lines in solar coronal plasmas SO SUN AND ITS ATMOSPHERE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT E2.1 Symposium of COSPAR Scientific Commission E on the Sun and Its Atmosphere, at the 31st COSPAR Scientific Assembly CY JUL 14-SEP 21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, Inst Space & Astron Sci ID FE-XVII; MAXIMUM-MISSION; RATIOS AB Calculated intensities of the Fe XVII X-ray lines due to transitions 2p(6)-2p(5)3d lines (near 15 Angstrom) and 2p(6)-2p(5)3s lines (near 17 Angstrom) are compared with measured line intensities in solar and tokamak spectra, For the solar spectra, temperature T-e is obtained from the ratio of the Fe XVII 16.776 Angstrom line to a nearby Fe XVIII line. We find excellent agreement for all the major Fe XVII line features in the 15-17 Angstrom region except the Fe XVII 15.015 Angstrom line, the observed flus of which is less than the theoretical by a factor f, We find that f strongly depends on the heliocentric angle theta of the emitting region, being smallest (0.2) when the region is nearest Sun centre, but nearly 1 near the limb, Attributing this to resonance scattering, we are able to deduce the path length and electron density from the observations. Possible application to stellar active regions is given. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Queens Univ Belfast, Dept Phys, Belfast BT7 1NN, Antrim, North Ireland. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Jet Joint Undertaking, Abingdon OX14 3EA, Oxon, England. RP Phillips, KJH (reprint author), Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. NR 8 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043309-X J9 ADV SPACE RES PY 1997 VL 20 IS 12 BP 2267 EP 2270 DI 10.1016/S0273-1177(97)00897-1 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK38L UT WOS:000071955600008 ER PT S AU Davila, JM Thomas, RJ Brosius, J Poland, A AF Davila, JM Thomas, RJ Brosius, J Poland, A BE Antonucci, E Shea, MA TI The structure of the solar corona as observed by the Solar Extreme Ultraviolet Rocket Telescope and Spectrograph SO SUN AND ITS ATMOSPHERE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT E2.1 Symposium of COSPAR Scientific Commission E on the Sun and Its Atmosphere, at the 31st COSPAR Scientific Assembly CY JUL 14-SEP 21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, Inst Space & Astron Sci ID EMISSION-LINES; SERTS; DIAGNOSTICS; VIII; IONS AB Data from the Solar Extreme-ultraviolet Rocket Telescope and Spectrograph (SERTS) have been used to address a number of important scientific problems, The primary strength of the SERTS data is the fact that this spectral range is rich with emission lines. Over 270 lines are seen in the SERTS active Sun spectrum, from 57 different ions. For example, multiple (greater than or equal to 4) lines are observed for all ionization states of iron from Fe IX to Fe XVII. Temperatures and densities have been derived for a number of active and quiet Sun regions, the coronal magnetic field strength has been estimated for both a plage region and an active region. Published by Elsevier Science Ltd on behalf of COSPAR. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Davila, JM (reprint author), NASA, Goddard Space Flight Ctr, Code 682, Greenbelt, MD 20771 USA. NR 16 TC 1 Z9 1 U1 1 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043309-X J9 ADV SPACE RES PY 1997 VL 20 IS 12 BP 2293 EP 2298 DI 10.1016/S0273-1177(97)00904-6 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK38L UT WOS:000071955600013 ER PT S AU McDonald, L Harra-Murnion, LK Culhane, JL Schwartz AF McDonald, L Harra-Murnion, LK Culhane, JL Schwartz BE Antonucci, E Shea, MA TI An investigation of small goes flares with intense hard X-ray bursts SO SUN AND ITS ATMOSPHERE SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT E2.1 Symposium of COSPAR Scientific Commission E on the Sun and Its Atmosphere, at the 31st COSPAR Scientific Assembly CY JUL 14-SEP 21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, European Space Agcy, Inst Space & Astron Sci ID SOLAR AB Most solar flare observations show that intense hard X-ray bursts come from large flares that have a large GOES classification (large peak 1-8 Angstrom flux). This correlation, known as the "Big Flare Syndrome", suggests that more intense flares tend to have harder spectra. We have observed 7 flares that are exceptions to this. These flares have small GOES classifications ranging from B1.4 to C5.5 and peak hard X-ray count rates similar to those often observed from M class flares. This paper examines the cause of this anomoly using the Yohkoh Soft X-Ray Telescope, Hard X-Ray Telescope, and Bragg Crystal Spectrometer. Two hypotheses are proposed for the exceptions: (1) flares with multiple magnetic loops and common footpoints, producing multiple hard X-ray emission regions and low density thermal plasma distributed over a large volume, and (2) high densities in the magnetic loops restricting the propagation of the non-thermal electrons in the loop after magnetic reconnection has occurred and suppressing chromospheric evaporation. Two of the flares support the first hypothesis. The other flares either have data missing or are too small to be properly analysed by the Yohkoh instruments. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP McDonald, L (reprint author), UCL, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England. OI Harra, Louise/0000-0001-9457-6200 NR 5 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043309-X J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 12 BP 2327 EP 2331 DI 10.1016/S0273-1177(97)01055-7 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BK38L UT WOS:000071955600020 ER PT S AU Riley, P Bame, SJ Barraclough, BL Feldman, WC Gosling, JT Hoogeveen, GW McComas, DJ Phillips, JL Goldstein, BE Neugebauer, M AF Riley, P Bame, SJ Barraclough, BL Feldman, WC Gosling, JT Hoogeveen, GW McComas, DJ Phillips, JL Goldstein, BE Neugebauer, M BE Antonucci, E Page, DE TI Ulysses solar wind plasma observations at high latitudes SO SUN AND ITS ROLE IN THE HELIOSPHERE SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT E2.2 Symposium of COSPAR Scientific Commission E on the Sun and Its Role in the Heliosphere, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996-1997 CL BIRMINGHAM, ENGLAND SP Comm space Res, Comm E, European Space Agcy, Inst Space & Astronaut Sci ID HEMISPHERES; NORTHERN; SOUTHERN AB Ulysses reached its peak northerly heliolatitude of 80.2 degrees N on. July 31st, 1995, and is now moving towards aphelion at 5.41 AU which it will reach in May, 1998. We summarize measurements from the solar wind plasma experiment, SWOOPS, emphasizing northern hemispheric observations but also providing southern and equatorial results for comparison. The solar wind momentum flux during Ulysses' fast pole-to-pole transit at solar minimum was significantly higher over the poles than at near-equatorial latitudes, suggesting a non-circular cross section for the heliosphere. Furthermore, modest asymmetries in wind speed, density, and mass flux were observed between the two hemispheres during the fast latitude scan. The solar wind was faster and less dense in the north than in the south. These asymmetries persist in the most recent high- and mid-latitude data but are less pronounced. As of July, 1996 the northern fast solar wind has lacked any strong stream interactions or shocks and, although a comprehensive search has not yet been made, no CMEs have yet been identified during this interval. On the other hand, Alfvenic, compressional, and pressure-balanced features are abundant at high latitudes. The most recent data, at 4 AU and 32 degrees degrees N, has begun to show the effects of solar rotation modulated features in the form of recurrent compressed regions. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. RP Riley, P (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. NR 18 TC 17 Z9 17 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043296-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 1 BP 15 EP 22 DI 10.1016/S0273-1177(97)00473-0 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ54C UT WOS:A1997BJ54C00002 ER PT S AU Smith, EJ Balogh, A Burton, ME Forsyth, R Lepping, RP AF Smith, EJ Balogh, A Burton, ME Forsyth, R Lepping, RP BE Antonucci, E Page, DE TI Radial and azimuthal components of the heliospheric magnetic field: Ulysses observations SO SUN AND ITS ROLE IN THE HELIOSPHERE SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT E2.2 Symposium of COSPAR Scientific Commission E on the Sun and Its Role in the Heliosphere, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996-1997 CL BIRMINGHAM, ENGLAND SP Comm space Res, Comm E, European Space Agcy, Inst Space & Astronaut Sci ID 1-AU AB Two invariants associated with the Parker model of the solar wind involve the radial, B-R, and azimuthal, B-T, components of the heliospheric magnetic field. These invariants have been investigated using Ulysses data obtained at high latitudes in both the north and south solar hemispheres. The magnetic flux invariant, r(2)B(R), is essentially independent of latitude in both hemispheres. However, comparisons with in-ecliptic IMP-I and WIND observations reveal a small decrease with time of similar to 6%. Average values of the second invariant, rV(R)B(T), which is related to the heliospheric electric field, differ systematically from the Parker theory, the difference being a function of latitude that cannot be accounted for simply by a changing solar rotation period. No asymmetry in the discrepancy is found between the two hemispheres. The difference vanishes at the solar equator as shown by a comparison with the in-ecliptic measurements. These results are consistent with the average spiral angle being more radial (underwound) at high latitude than is predicted by the Parker angle and an interval has been identified in which the observed angle is approximately zero on average. This behavior contrasts with the most probable value of the invariant or the spiral angle which does agree with theory. The difference between the average and the most probable value is caused by an asymmetry in the probability distribution. This apparent reduction in average BT may bear on the long-standing issue of a ''flux deficit'' in the distant heliospheric field. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, LONDON SW7 2BZ, ENGLAND. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. NR 15 TC 21 Z9 21 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043296-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 1 BP 47 EP 53 DI 10.1016/S0273-1177(97)00480-8 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ54C UT WOS:A1997BJ54C00009 ER PT S AU Smith, EJ Neugebauer, M Tsurutani, BT Balogh, A Forsyth, R McComas, D AF Smith, EJ Neugebauer, M Tsurutani, BT Balogh, A Forsyth, R McComas, D BE Antonucci, E Page, DE TI Properties of hydromagnetic waves in the polar caps: Ulysses SO SUN AND ITS ROLE IN THE HELIOSPHERE SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT E2.2 Symposium of COSPAR Scientific Commission E on the Sun and Its Role in the Heliosphere, at the 31st COSPAR Scientific Assembly CY JUL 14-21, 1996-1997 CL BIRMINGHAM, ENGLAND SP Comm space Res, Comm E, European Space Agcy, Inst Space & Astronaut Sci ID ALFVEN WAVES; SOLAR-WIND; MAGNETIC-FIELD; FLUCTUATIONS; VARIANCES; LATITUDE AB Properties of the large amplitude Alfven waves which are a dominant feature of the high latitude solar wind have been studied during the pole-to-pole passage of Ulysses. In addition, an effort has begun to identify magnetosonic waves at high latitude in spite of their expected small amplitude and the presence of the large amplitude Alfven waves. The power in the fatter is essentially the same in both solar hemispheres without evidence of any significant north-south asymmetry. The increased power as Ulysses approached the poles is not, in fact, dependent on latitude but is caused by a power law dependence on distance. The Alfvenicity of the fluctuations, as indicated by the covariance of the held and velocity, increases to high levels (0.8) at high latitudes. Principal axis analyses indicate that the field vector appears to wander randomly over a hemisphere whose radius is the nearly constant field magnitude. This behavior is consistent with a stochastic model introduced by Barnes as demonstrated by a statistical analysis of the field variations observed by Ulysses. The principal axis analysis also shows that the direction associated with the minimum eigenvalue is nearly radial. The strategy for identifying magnetosonic waves involves searching for them in the weak interaction regions accompanying microstreams. Simultaneous variations in the magnetic, kinetic, and total pressures are qualitatively consistent with the presence of magnetosonic waves. (C) 1997 COSPAR. Published by Elsevier Science Ltd. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, LONDON SW7 2BZ, ENGLAND. LOS ALAMOS NATL LAB, SPACE & ATMOSPHER SCI GRP, LOS ALAMOS, NM 87545 USA. RP Smith, EJ (reprint author), CALTECH, JET PROP LAB, 4800 OAK GROVE DR, PASADENA, CA 91109 USA. NR 16 TC 13 Z9 13 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043296-4 J9 ADV SPACE RES-SERIES PY 1997 VL 20 IS 1 BP 55 EP 63 DI 10.1016/S0273-1177(97)00481-X PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BJ54C UT WOS:A1997BJ54C00010 ER PT J AU Meajil, AI ElGhazawi, T Sterling, T AF Meajil, AI ElGhazawi, T Sterling, T TI Performance prediction of parallel systems based on workload similarity SO SUPERCOMPUTER LA English DT Article ID PROGRAMS AB Performance prediction of workloads on parallel systems use a priori information to estimate performance when the input data size, or the machine parameters, change. This work fills an important gap. Given an application that has never been implemented on a target machine, we propose a methodology to predict the performance of such an application on that machine. This allows application developers to make intelligent choices before committing to a specific machine, directly without having their own benchmarking activity. This is accomplished by representing the workloads using the parallel instruction centroid, which is a metric that embodies parallelism, critical path length, and instruction mixes properties. The difference between these centroids is measured as a representation of similarity. The most similar workload to ours is used for prediction, after compensating for the difference in communication requirements. In addition to filling the previously described gap, it will be shown that this method provides higher prediction accuracy in the majority of the cases, and accounts for dynamic code behaviors. C1 NASA,GODDARD SPACE FLIGHT CTR,CTR EXCELLENCE SPACE DATA & INFORMAT SCI,GREENBELT,MD. CALTECH,NASA,JET PROP LAB,CTR ADV COMP RES,PASADENA,CA 91125. RP Meajil, AI (reprint author), GEORGE WASHINGTON UNIV,DEPT ELECT ENGN & COMP SCI,WASHINGTON,DC 20052, USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU ASFRA PI EDAM PA VOORHAVEN 33, 1135 BL EDAM, NETHERLANDS SN 0168-7875 J9 SUPERCOMPUTER JI Supercomputer PY 1997 VL 13 IS 2 BP 15 EP 30 PG 16 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA XV367 UT WOS:A1997XV36700002 ER PT B AU Golub, MA Wydeven, T Finney, LS AF Golub, MA Wydeven, T Finney, LS BE Ratner, BD Castner, DG TI Plasma copolymerization of tetrafluoroethylene and chlorotrifluoroethylene SO SURFACE MODIFICATION OF POLYMERIC BIOMATERIALS LA English DT Proceedings Paper CT International Symposium of the Division-of-Polymer-Chemistry of the American-Chemical-Society on Surface Modification of Polymeric Biomaterials CY APR 02-06, 1995 CL ANAHEIM, CA SP Amer Chem Soc, Div Polym Chem RP Golub, MA (reprint author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 BN 0-306-45512-9 PY 1997 BP 53 EP 60 PG 8 WC Engineering, Biomedical; Polymer Science SC Engineering; Polymer Science GA BH15Z UT WOS:A1997BH15Z00007 ER PT J AU Lo, VY AF Lo, VY TI Simulation of deep space network traffic under various loading conditions SO TELECOMMUNICATION SYSTEMS LA English DT Article AB This is a follow-up report on the end-to-end data link performance of the NASA deep space network. The focus of this report is the effect of traffic loading on data delivery. Architecture of the existing network is modeled via COMNET. The contribution of the data latency to the overall acquisition time is simulated as a function of network traffic conditions. The results show steady-state latencies in the range of tenths of milli-seconds under a mild loading condition. During heavy traffic, a delay rate of over a hundred seconds of increased delay per hour of network operation time is observed. This is primarily due to the queueing delays associated with large volume of data stored in the buffers throughout the link. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lo, VY (reprint author), CALTECH, Jet Prop Lab, M-S 161-241,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BALTZER SCI PUBL BV PI BUSSUM PA PO BOX 221, 1400 AE BUSSUM, NETHERLANDS SN 1018-4864 J9 TELECOMMUN SYST JI Telecommun. Syst. PY 1997 VL 8 IS 2-4 BP 293 EP 301 DI 10.1023/A:1019121723232 PG 9 WC Telecommunications SC Telecommunications GA YU489 UT WOS:000071723000010 ER PT S AU Parrish, JC AF Parrish, JC BE Stein, MR TI The Ranger Telerobotic Shuttle Experiment: Status report SO TELEMANIPULATOR AND TELEPRESENCE TECHNOLOGIES IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 4th Conference on Telemanipulator and Telepresence Technologies CY OCT 14-15, 1997 CL PITTSBURGH, PA SP Soc Photo Opt Instrumentat Engineers, NIST, Coalit Intelligent Mfg Syst, Acad Coalit Intelligent Mfg Syst DE telerobotics; spacecraft servicing; neutral buoyancy; manipulator; space station; space shuttle; virtual reality AB This paper updates the status of the Ranger Telerobotic Shuttle Experiment (TSX). Originally planned as the Ranger Telerobotic Flight Experiment (TFX), a free-flying spacecraft servicing telerobot to be launched on an expendable launch vehicle, the Ranger mission has been recast as a Space Shuttle-based flight experiment to demonstrate key telerobotic technologies associated with servicing the International Space Station (ISS) and other orbital assets. Several modifications have been made to the flight system configuration and the operational concept, but the primary payload package-namely the four manipulator arms and their supporting structure-have remained relatively unchanged. This paper addresses these technical and operational modifications, and lays out the plans for the future of the flight experiment. C1 NASA Headquarters, Washington, DC 20546 USA. RP Parrish, JC (reprint author), NASA Headquarters, Washington, DC 20546 USA. NR 0 TC 2 Z9 2 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2638-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 3206 BP 189 EP 197 DI 10.1117/12.295584 PG 9 WC Automation & Control Systems; Computer Science, Cybernetics; Optics SC Automation & Control Systems; Computer Science; Optics GA BK21T UT WOS:000071551000020 ER PT B AU Baldi, P Brunak, S Chauvin, Y Krogh, A AF Baldi, P Brunak, S Chauvin, Y Krogh, A BE Suhai, S TI Hidden Markov models for human genes - Periodic patterns in exon sequences SO THEORETICAL AND COMPUTATIONAL METHODS IN GENOME RESEARCH LA English DT Proceedings Paper CT International Symposium on Theoretical and Computational Genome Research CY MAR 24-27, 1996 CL HEIDELBERG, GERMANY SP Commiss European Communities AB We analyse the sequential structure of human genomic DNA by hidden Markov models. We apply models of widely different design: conventional left-right constructs and models with a built-in periodic architecture. The models are trained on segments of DNA sequences extracted such that they cover complete internal exons flanked by introns, or splice sites flanked by coding and non-coding sequence. Together, models of donor site regions, acceptor site regions and flanked internal exons, show that exons - besides the reading frame - hold a specific periodic pattern. The pattern has the consensus: non-T(A/T)G and a minimal periodicity of roughly 10 nucleotides. RP Baldi, P (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 PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 BN 0-306-45503-X PY 1997 BP 15 EP 32 PG 18 WC Biochemistry & Molecular Biology; Biophysics; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Genetics & Heredity SC Biochemistry & Molecular Biology; Biophysics; Biotechnology & Applied Microbiology; Computer Science; Genetics & Heredity GA BJ19F UT WOS:A1997BJ19F00002 ER PT S AU Espenak, F AF Espenak, F BE Mouradian, Z Stavinschi, M TI NASA bulletin for the total solar eclipse of 1999 SO THEORETICAL AND OBSERVATIONAL PROBLEMS RELATED TO SOLAR ECLIPSES SE NATO ADVANCED SCIENCE INSTITUTES SERIES, SERIES C, MATHEMATICAL AND PHYSICAL SCIENCES LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Theoretical and Observational Problems Related to Solar Eclipses CY JUN 01-05, 1996 CL BUCHAREST, ROMANIA SP NATO, Sci Affairs Div, Romanian Acad, Romanian Minist Sci & Technol, Paris Observatory AB On 1999 August 11, a total eclipse of the Sun will be visible from parts of central Europe, Turkey, the Middle East and India. NASA is preparing a special bulletin on the eclipse which contains detailed predictions, tables, maps, and meteorological data useful for planning eclipse expeditions and scientific observations. Public information is also provided for eye safety, viewing and eclipse photography. The bulletin will be published by the end of 1996. It will also be available via the World Wide Web from: http://umbra.nascom.nasa.gov/eclipse/index.html. RP Espenak, F (reprint author), NASA,GODDARD SPACE FLIGHT CTR,PLANETARY SYST BRANCH,CODE 693,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0258-2023 BN 0-7923-4619-X J9 NATO ADV SCI I C-MAT PY 1997 VL 494 BP 199 EP 207 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BJ38X UT WOS:A1997BJ38X00033 ER PT S AU Verrilli, MJ Calomino, AM Brewer, DN AF Verrilli, MJ Calomino, AM Brewer, DN BE Jenkins, MG LaraCurzio, E Gonczy, ST Ashbaugh, NE Zawada, LP TI Creep-rupture behavior of a Nicalon/SiC composite SO THERMAL AND MECHANICAL TEST METHODS AND BEHAVIOR OF CONTINUOUS-FIBER CERAMIC COMPOSITES SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Thermal and Mechanical Test Methods and Behavior of Continuous Fiber Ceramic Composites CY JAN 08-09, 1996 CL COCOA BEACH, FL SP Amer Soc Testing & Mat, Comm E08 Fatigue & Fracture, Amer Ceram Soc, Engn Ceram Div DE Nicalon/SiC composites; creep-rupture; oxidation; test method; continuous fiber ceramic composite; pesting AB A study of the high temperature tensile creep rupture behavior of a commercially available woven [0/90] Nicalon/SiC composite was performed. Tests were performed at temperatures of 500 to 1149 degrees C. At a creep stress of 83 MPa, lives of less than 40 hours for temperatures above 600 degrees C in air were obtained. At the reduced stress level of 69 MPa, lives were twice as long. However, a test conducted at 83 MBa and temperature of 982 degrees C in vacuum yielded a run-out life of more than 1000 hours. Also, the tests performed in air have significantly shorter lives than those reported by the composite manufacturer, Post test investigations focused on identifying the mechanisms responsible for the unexpected difference in life and results are presented, Analytical modeling and supplemental testing revealed an unexpected environmentally assisted material degradation at an intermediate temperature range of 700 to 800 degrees C. Microscopic and chemical analyses indicate that a combination of applied stress and temperature produces an oxidation-embrittlement damage mechanism. The role of the selected specimen geometry and testing conditions, which was instrumental in the detection of this failure mechanism, is thoroughly discussed. RP Verrilli, MJ (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 SN 1071-5827 BN 0-8031-2033-8 J9 AM SOC TEST MATER PY 1997 VL 1309 BP 158 EP 175 DI 10.1520/STP11819S PG 2 WC Materials Science, Ceramics; Materials Science, Characterization & Testing SC Materials Science GA BH57U UT WOS:A1997BH57U00010 ER PT S AU Caillat, T Borshchevsky, A Fleurial, JP AF Caillat, T Borshchevsky, A Fleurial, JP BE Tritt, TM Kanatzidis, MG Lyon, HB Maham, GD TI Thermal conductivity of Zn4-xCdxSb3 solid solutions SO THERMOELECTRIC MATERIALS - NEW DIRECTIONS AND APPROACHES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Thermoelectric Materials - New Directions and Approaches CY MAR 31-APR 03, 1997 CL SAN FRANCISCO, CA SP Mat Res Soc, USN, Off Naval Res, USA, Res Off, DARPA, USN, Naval Res Lab AB beta-Zn4Sb3 was recently identified at the Jet Propulsion Laboratory as a new high performance p-type thermoelectric material with a maximum dimensionless thermoelectric figure of merit ZT of 1.4 at a temperature of 673K. A usual approach, used for many state-of-the-art thermoelectric materials, to further improve ZT values is to alloy beta-Zn4Sb3 with isostructural compounds because of the expected decrease in lattice thermal conductivity. We have grown Zn4-xCdxSb3 crystals with 0.2 less than or equal to x<1.2 and measured their thermal conductivity from 10 to 500K. The thermal conductivity values of Zn4-xCdxSb3 alloys are significantly lower than those measured for beta-Zn4Sb3 and are comparable to its calculated minimum thermal conductivity. A strong atomic disorder is believed to be primarily at the origin of the very low thermal conductivity of these materials which are also fairly good electrical conductors and are therefore excellent candidates for thermoelectric applications. RP Caillat, T (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 22 Z9 22 U1 0 U2 6 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-382-7 J9 MATER RES SOC SYMP P PY 1997 VL 478 BP 103 EP 108 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BJ57R UT WOS:A1997BJ57R00011 ER PT S AU Fleurial, JP Caillat, T Borshchevsky, A AF Fleurial, JP Caillat, T Borshchevsky, A BE Tritt, TM Kanatzidis, MG Lyon, HB Maham, GD TI Low thermal conductivity skutterudites SO THERMOELECTRIC MATERIALS - NEW DIRECTIONS AND APPROACHES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Thermoelectric Materials - New Directions and Approaches CY MAR 31-APR 03, 1997 CL SAN FRANCISCO, CA SP Mat Res Soc, USN, Off Naval Res, USA, Res Off, DARPA, USN, Naval Res Lab AB Recent experimental results on semiconductors with the skutterudite crystal structure show that these materials possess attractive transport properties and have a good potential for achieving ZT values substantially larger than for state-of-the-art thermoelectric materials. Both n-type and p-type conductivity samples have been obtained, using several preparation techniques. Associated with a low hole effective mass, very high carrier mobilities, low electrical resistivities and moderate Seebeck coefficients are obtained in p-type skutterudites. For a comparable doping level, the carrier mobilities of n-type samples are about an order of magnitude lower than the values achieved on p-type samples. However, the much larger electron effective masses and Seebeck coefficients make n-type skutterudites promising candidates as well. Unfortunately, the thermal conductivities of the binary skutterudite compounds are too large, particularly at low temperatures, to be useful for thermoelectric applications. Several approaches to the reduction of the lattice thermal conductivity in skutterudites are being pursued: heavy doping, formation of solid solutions and alloys, study of novel ternary and filled skutterudite compounds. All those approaches have already resulted in skutterudite compositions with substantially lower thermal conductivity values in these materials. Recently, superior thermoelectric properties in the moderate to high temperature range were achieved for compositions combining alloying and ''filling'' of the skutterudite structure. Experimental results and mechanisms responsible for low thermal conductivity in skutterudites are discussed. RP Fleurial, JP (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MS 277-207,PASADENA,CA 91109, USA. NR 0 TC 8 Z9 8 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-382-7 J9 MATER RES SOC SYMP P PY 1997 VL 478 BP 175 EP 186 PG 12 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BJ57R UT WOS:A1997BJ57R00023 ER PT S AU Kramer, CD AF Kramer, CD BE Tritt, TM Kanatzidis, MG Lyon, HB Maham, GD TI Thermoelectric applications as related to biomedical engineering for NASA Johnson Space Center SO THERMOELECTRIC MATERIALS - NEW DIRECTIONS AND APPROACHES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Thermoelectric Materials - New Directions and Approaches CY MAR 31-APR 03, 1997 CL SAN FRANCISCO, CA SP Mat Res Soc, USN, Off Naval Res, USA, Res Off, DARPA, USN, Naval Res Lab AB This paper presents current NASA biomedical developments and applications using thermoelectrics. Discussion will include future technology enhancements that would be most beneficial to the application of thermoelectric technology. A great deal of thermoelectric applications have focused on electronic cooling. As with all technological developments within NASA, if the application cannot be related to the average consumer, the technology will not be mass-produced and widely available to the public (a key to research and development expenditures and thermoelectric companies). Included are discussions of thermoelectric applications to cool astronauts during launch and reentry. The earth-based applications, or spin-offs, include such innovations as tank and race car driver cooling, to cooling infants with high temperatures, as well as, the prevention of hair loss during chemotherapy. In order to preserve the scientific value of metabolic samples during long-term space missions, cooling is required to enable scientific studies. Results of one such study should provide a better understanding of osteoporosis and may lead to a possible cure for the disease. In the space environment, noise has to be kept to a minimum. In long-term space applications such as the International Space Station, thermoelectric technology provides the acoustic relief and the reliability for food, as well as, scientific refrigeration/freezers. Applications and future needs are discussed as NASA moves closer to a continued space presence in Mir, International Space Station, and Lunar-Mars Exploration. RP Kramer, CD (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,EA5,HOUSTON,TX 77058, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 SN 0272-9172 BN 1-55899-382-7 J9 MATER RES SOC SYMP P PY 1997 VL 478 BP 309 EP 314 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA BJ57R UT WOS:A1997BJ57R00038 ER PT S AU Wilt, DM Fatemi, NS Jenkins, PP Weizer, VG Hoffmann, RW Jain, RK Murray, CS Riley, DR AF Wilt, DM Fatemi, NS Jenkins, PP Weizer, VG Hoffmann, RW Jain, RK Murray, CS Riley, DR BE Coutts, TJ Allman, CS Benner, JP TI Electrical and optical performance characteristics of 0.74 p/n InGaAs monolithic interconnected modules SO THERMOPHOTOVOLTAIC GENERATION OF ELECTRICITY SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 3rd NREL Conference on Thermophotovoltaic Generation of Electricity CY MAY, 1997 CL COLORADO SPRINGS, CO SP NREL, DOE, DARPA, ARO, NASA Lewis Res ctr AB There has been a traditional trade-off in thermophotovoltaic (TPV) energy conversion development between system efficiency and power density. This trade-off originates from the use of front surface spectral controls such as selective emitters and various types of filters. A monolithic interconnected module (MIM) structure has been developed which allows for both high power densities and high system efficiencies. The MIM device consists of many individual indium gallium arsenide (InGaAs) cells series-connected on a single semi-insulating indium phosphide (InP) substrate. The MIM is exposed to the entire emitter output, thereby maximizing output power density. An infrared (IR) reflector placed on the rear surface of the substrate returns the unused portion of the emitter output spectrum back to the emitter for recycling, thereby providing for high system efficiencies. Initial MIM development has focused on a 1 cm(2) device consisting of eight series interconnected cells. MIM devices, produced from 0.74 eV InGaAs, have demonstrated V-oc=3.2 V, J(sc)=70 mA/cm(2) and a fill factor of 66% under flashlamp testing. Infrared (IR) reflectance measurements (>2 mu m) of these devices indicate a reflectivity of >82%. MIM devices produced from 0.55 eV InGaAs have also been demonstrated. In addition, conventional p/n InGaAs devices with record efficiencies (11.7% AM0) have been demonstrated. RP Wilt, DM (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-734-0 J9 AIP CONF PROC PY 1997 IS 401 BP 237 EP 247 PG 11 WC Thermodynamics; Energy & Fuels; Materials Science, Characterization & Testing; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Energy & Fuels; Materials Science; Physics GA BJ69V UT WOS:A1997BJ69V00020 ER PT S AU Chubb, DL Good, BS Clark, EB Chen, Z AF Chubb, DL Good, BS Clark, EB Chen, Z BE Coutts, TJ Allman, CS Benner, JP TI Effect of temperature gradient on thick film selective emitter emittance SO THERMOPHOTOVOLTAIC GENERATION OF ELECTRICITY SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 3rd NREL Conference on Thermophotovoltaic Generation of Electricity CY MAY, 1997 CL COLORADO SPRINGS, CO SP NREL, DOE, DARPA, ARO, NASA Lewis Res ctr AB A temperature gradient across a thick (greater than or equal to .1 mm) film selective emitter will produce a significant reduction in the spectral emittance from the no temperature gradient case, Thick film selective emitters of rare earth doped host materials such as yttrium-aluminum-garnet (YAG) are examples where temperature gradient effects are important. In this paper a model is developed for the spectral emittance assuming a linear temperature gradient across the film. Results of the model indicate that temperature gradients will result in reductions the order of 20% or more in the spectral emittance. RP Chubb, DL (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-734-0 J9 AIP CONF PROC PY 1997 IS 401 BP 293 EP 313 PG 21 WC Thermodynamics; Energy & Fuels; Materials Science, Characterization & Testing; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Energy & Fuels; Materials Science; Physics GA BJ69V UT WOS:A1997BJ69V00024 ER PT S AU Good, BS Chubb, DL AF Good, BS Chubb, DL BE Coutts, TJ Allman, CS Benner, JP TI Effects of geometry on the efficiency of TPV energy conversion SO THERMOPHOTOVOLTAIC GENERATION OF ELECTRICITY SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 3rd NREL Conference on Thermophotovoltaic Generation of Electricity CY MAY, 1997 CL COLORADO SPRINGS, CO SP NREL, DOE, DARPA, ARO, NASA Lewis Res ctr AB The importance of view factors in determining the efficiency of a thermophotovoltaic (TPV) energy conversion system was pointed out at the first NREL TPV meeting by D. C. White and Hi C. Hottel. In this paper we consider the effect of view factors on efficiency for both planar-and cylindrical-geometry TPV systems. One method for reducing the view factor radiation loss is to introduce reflecting surfaces at locations where the radiation loss occurs. We also consider the effect of these additional reflectors on efficiency. To determine the cavity efficiency (efficiency of emitter, window, filter and lateral reflector in combination) a set of nine algebraic equations for the radiation fluxes incident on each of the cavity components must be solved. The solution depends on the wavelength-dependent optical properties of the components, as well as the view factors between components. Once the fluxes are obtained as functions of wavelength, the cavity efficiency can be calculated. Results to be presented will include a comparison of the view factor effect for planar and cylindrical geometries. The effect of including lateral reflectors in the cavity will be discussed. Finally, the effects of the interaction of the filter with the lateral reflectors will be considered. RP Good, BS (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AIP PRESS PI WOODBURY PA AMERICAN INSTITUTE OF PHYSICS 500 SUNNYSIDE BOULEVARD, WOODBURY, NY 11797-2999 SN 0094-243X BN 1-56396-734-0 J9 AIP CONF PROC PY 1997 IS 401 BP 487 EP 503 PG 17 WC Thermodynamics; Energy & Fuels; Materials Science, Characterization & Testing; Physics, Applied; Physics, Condensed Matter SC Thermodynamics; Energy & Fuels; Materials Science; Physics GA BJ69V UT WOS:A1997BJ69V00039 ER PT S AU Greenleaf, JE AF Greenleaf, JE BE Blatteis, CM TI Exercise thermoregulation with bed rest, confinement, and immersion deconditioning SO THERMOREGULATION: TENTH INTERNATIONAL SYMPOSIUM ON THE PHARMACOLOGY OF THERMOREGULATION SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT 10th International Symposium on Thermoregulation CY AUG 17-22, 1996 CL MEMPHIS, TN SP New York Acad Sci, Mini Mitter Co Inc, Data Sci Int, Augustine Med Inc, Int Sci Fdn, Int Union Physiol Sci, IUPS Commiss Thermal Physiol, Univ Tennessee, Memphis, Dept Physiol & Biophys ID TEMPERATURE; RESPONSES; DOGS; HYPERTHERMIA; PERFORMANCE; METABOLISM; MEN C1 NASA, Ames Res Ctr, Gravitat Res Branch 239 11, Lab Human Environm Physiol, Moffett Field, CA 94035 USA. RP Greenleaf, JE (reprint author), NASA, Ames Res Ctr, Gravitat Res Branch 239 11, Lab Human Environm Physiol, Moffett Field, CA 94035 USA. EM jgreenleaf@mail.arc.nasa.gov NR 22 TC 9 Z9 9 U1 0 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-088-3 J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 1997 VL 813 BP 741 EP 750 DI 10.1111/j.1749-6632.1997.tb51777.x PG 10 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA BM49A UT WOS:000078895700113 PM 9100965 ER PT S AU Werner, CL Rosen, P Hensley, S Fielding, E Buckley, S AF Werner, CL Rosen, P Hensley, S Fielding, E Buckley, S GP ESA TI Detection of aseismic creep along the San Andreas Fault near Parkfield, California with ERS-1 radar interferometry SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOL 1 SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy AB Parkfield, California lies an area along the San Andreas fault in Southern California that has experienced strong earthquakes at apparently regular intervals in historic times. Differential interferometric analysis of ERS data of this region reveals the wide-area distribution of creep along the moving fault segment over a 15 month interval. Removal of the inter-ferometric phase related to the surface topography was done by simulation of an interferogram in the absence of motion given a topographic map of the region. A sharp phase discontinuity in the differential interferogram is equivalent to approximately 1.5 cm change in the line of sight. This displacement is consistent with current models of motion along the fault. We compare the observed phase signature with a predictions of the differential phase based upon the Okada model for elastic deformation. The ERS differential interferometric data are compared with a 6 month differential interferogram collected by the NASA SIR-C L-Band instrument in 1994. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Werner, CL (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. OI Fielding, Eric/0000-0002-6648-8067 NR 0 TC 0 Z9 0 U1 0 U2 0 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 521 EP 524 PG 4 WC Environmental Sciences; Geosciences, Multidisciplinary; Remote Sensing SC Environmental Sciences & Ecology; Geology; Remote Sensing GA BK74Q UT WOS:000073315300088 ER PT S AU Peltzer, G Rosen, P Rogez, F Hudnut, K AF Peltzer, G Rosen, P Rogez, F Hudnut, K GP ESA TI Crustal deformation in Southern California using SAR interferometry SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOL 1 SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy AB By combining pairs of ERS-1/2 SAR images of Southern California spanning long time intervals (1-4 years), we were able to measure the rate of slow deformation processes along faults activated during the Landers 1992 earthquake. Interferograms revealed several centimeters of post-seismic rebound in step-overs of the 1992 break, with a characteristic decay rate of similar to 280 days. We interpreted this process as due to pore fluid flow as pore pressure gradients caused by coseismic stress changes dissipate. The data also revealed evidence of after-slip on different sections of the fault. The southern branches of the 1992 break experienced surface creep producing sharp phase cuts in the interferometric maps. The same approach was used in the Los Angeles basin, which is currently undergoing NS shortening at a rate of similar to 8 mm/yr. The tectonic signal in interferograms of the Los Angeles basin is intermingled with signals due to other sources such as ground subsidence caused by oil and water withdrawal. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Peltzer, G (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RI Hudnut, Kenneth/G-5713-2010; Hudnut, Kenneth/B-1945-2009 OI Hudnut, Kenneth/0000-0002-3168-4797 NR 0 TC 0 Z9 0 U1 0 U2 2 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 545 EP 548 PG 4 WC Environmental Sciences; Geosciences, Multidisciplinary; Remote Sensing SC Environmental Sciences & Ecology; Geology; Remote Sensing GA BK74Q UT WOS:000073315300093 ER PT S AU Rignot, E AF Rignot, E GP ESA TI Ice discharge from north and northeast Greenland using ERS data SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOLS. II & III SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy AB Ice discharge from north and northeast Greenland glaciers was calculated at the grounding line using ERS radar interferometry data acquired during the tandem phase. The resulting estimates exceed the production of icebergs at the glacier fronts by a factor 3.5. This large decrease in ice flux is attributed to extensive melting at the underside of the floating sections. When compared to the predicted grounding line ice discharge of an ice sheet in balance, the results show an excess 28 km(3)/yr of ice lost to the ocean. The north and northeast sectors of the Greenland Ice Sheet are therefore thinning and contributing positively to sea-level rise. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Rignot, E (reprint author), 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 0 TC 2 Z9 2 U1 0 U2 0 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 815 EP 818 PG 4 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL05P UT WOS:000074128900042 ER PT S AU Rignot, E MacAyeal, DR AF Rignot, E MacAyeal, DR GP ESA TI Ice velocity at the ice front of the Filchner-Ronne Ice Shelf, Antarctica, as observed with ERS interferometry SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOLS. II & III SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy AB ERS images of the two ends of the ice front of the Filchner-Ronne Ice Shelf, Antarctica, were utilized interferometrically to study the deformation rate of the ice shelf in response to viscous creep. On the western flank of Berkner Island (BI), near Hemmen Ice Rise (HIR), a time series of ERS data acquired in Feb 1992, in both ascending and descending mode, and with a 3-day time interval, were utilized to map the ice velocity in two dimensions. Finite-element ice-shelf flow simulations are compared with the ERS interferograms to interpret the ice motion in terms of the physical constraints on ice-shelf flow. Our efforts to fit artificial interferograms generated with model velocity output suggest that the how regime is strongly influenced by three processes. First, a void-creation process responsible for rifts at coastal margins tends to uncouple the ice shelf from the ice rise and neighboring coast of BI. Second, sea ice within the void space appears to act as a binding agent between discrete ice-shelf fragments, allowing rigid-body rotations of these fragments. Third, strain rates appear to be enhanced in a narrow zone adjacent to HIR, implying significant strain softening along the boundary. We believe that SAR interferogram/model intercomparison represents a powerful impetus toward the development of better, more physically realistic ice-shelf flow models. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Rignot, E (reprint author), 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 0 TC 0 Z9 0 U1 0 U2 0 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 863 EP 866 PG 4 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL05P UT WOS:000074128900051 ER PT S AU Goldstein, R Werner, C AF Goldstein, R Werner, C GP ESA TI Radar ice motion interferometry SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOLS. II & III SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy AB We have used tandem pairs of ERS-1/2 radar observations of the Jakobshavn Glacier, in Greenland, for the purpose of estimating the ice motion. Interferograms are made from two such pairs, separated by the 35 day repeat cycle. Motion can be estimated from these without knowledge of the local topography. Although the temporal baseline of the interferograms was only one day, the correlation from the fast moving ice was very low. Because of the resulting phase noise, we have used a scene-dependent filter to help unwrap the interferograms. For the upper part of the glacier, the filter worked well. The filter and the measured ice motion are presented below. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Goldstein, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 2 Z9 3 U1 0 U2 1 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 969 EP 972 PG 4 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL05P UT WOS:000074128900070 ER PT S AU Joughin, I Kwok, R Fahnestock, M Winebrenner, D Tulaczyk, S Gogenini, P AF Joughin, I Kwok, R Fahnestock, M Winebrenner, D Tulaczyk, S Gogenini, P GP ESA TI Interferometric estimation of ice sheet motion and topography SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOLS. II & III SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy AB With ERS-1/2 satellite radar interferometry, it is now possible to make measurements of glacier motion with high accuracy and fine spatial resolution. We have applied interferometric techniques to map velocity and topography for several outlet glaciers in Greenland. For the Humboldt and Petermann glaciers, we have combined data from several adjacent tracks to make a wide-area map that includes the enhanced flow regions of both glaciers. Using these data in combination with thickness data from the University of Kansas Coherent Radar Depth Sounder (CoRDS), we have estimated the discharge flux of the Petermann Glacier upstream of the grounding line, thereby establishing the potential use of ERS-1/2 interferometric data for monitoring ice-sheet discharge. Interferograms collected along a single track are sensitive to only one component of motion. By utilizing data from ascending and descending passes and by making a surface-parallel flow assumption, it is possible to measure the full three-dimensional vector flow field. We demonstrate the application of this technique for an area on the Ryder Glacier. Finally, we have used ERS-1/2 interferograms to observe a mini-surge on the Ryder Glacier that occurred in the Fall of 1995. 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. NR 0 TC 1 Z9 1 U1 0 U2 0 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 973 EP 977 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL05P UT WOS:000074128900071 ER PT S AU Drinkwater, MR Liu, X AF Drinkwater, MR Liu, X GP ESA TI ERS satellite microwave radar observations of antarctic sea-ice dynamics SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOLS. II & III SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy DE Antarctic; SAR images; sea-ice dynamics; Ronne polynya; Weddell polynya; Antarctic circumpolar wave AB ERS-1 and ERS-2 scatterometer and SAR data are used to monitor and track large and small-scale sea-ice dynamics in the Southern Ocean, and in particular in the Weddell Sea, Antarctica. Sea-ice formation in the Weddell Sea regulates vertical and horizontal thermohaline circulation and influences bottom water production rates. Significant seasonal to interannual variability is observed in the sea-ice drift dynamics. Coupled model simulations reproduce this variability and indicate that there is significant interannual variability in Weddell Sea ice formation, drift and extent on the ENSO timescale, with a period of similar to 8 years. Changes in ice dynamics on these timescales regulate the amount of sea-ice divergence and polynya formation. Anomalies in timing and duration of the opening of the Ronne ice-shelf polynya system are closely related to the variability in outflow of Weddell Sea bottom water measured at Joinville Island. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Drinkwater, MR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Drinkwater, Mark/0000-0002-9250-3806 NR 0 TC 0 Z9 0 U1 0 U2 0 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 1109 EP 1114 PG 4 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL05P UT WOS:000074128900094 ER PT S AU Liu, AK Hsu, MK Liang, NK AF Liu, AK Hsu, MK Liang, NK GP ESA TI Evolution of nonlinear internal waves in China Seas SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOLS. II & III SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy AB Synthetic Aperture Radar (SAR) images from ERS-1 have been used to study the characteristics of internal waves northeast and south of Taiwan in the East China Sea, and east of Hainan Island in the South China Sea. Rank-ordered packets of internal solitons propagating shoreward from the edge of the continental shelf were observed in the SAR images. Based on the assumption of a semidiurnal tidal origin, the wave speed can be estimated and is consistent with the internal wave theory. By using the SAR images and hydrographic data, internal waves of elevation have been identified in shallow water due to a thicker mixed layer as compared with the bottom layer on the continental shelf. The generation mechanism includes the influences of the tide and the Kuroshio intrusion across the continental shelf for the formations of elevation internal waves. The effects of water depth on the evolution of solitons and wave packets are modeled by nonlinear Kortweg-deVries (KdV) type equation and linked to satellite image observations. The numerical calculations of internal wave evolution on the continental shelf have been performed and compared with the SAR observations. For a case of depression waves in deep water, the solitons first disintegrate into dispersive wave trains and then evolve to a packet of elevation waves in the shallow water area after they pass through a "turning point" of approximately equal layer depths has been observed in the SAR image and simulated by numerical model. C1 NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. RP Liu, AK (reprint author), NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 1311 EP 1316 PG 4 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL05P UT WOS:000074128900128 ER PT S AU Bouzinac, C Font, J Vazquez, J Millot, C AF Bouzinac, C Font, J Vazquez, J Millot, C GP ESA TI CEOF analysis of ERS-1 and TOPEX/POSEIDON combined altimetric data in the region of the Algerian current SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOLS. II & III SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy AB Maps of Sea Level Anomalies (SLA) relative to the annual 1993 mean sea level combine the data from the ERS-1 and TOPEX/POSEIDON (T/P) altimeters. These regular maps in space and time are used in the region of the Algerian current, where the mesoscale eddies are of primary importance to the circulation of all the Mediterranean water masses. One of these anticyclonic eddies revealed by the SLA maps is confirmed with an ERS-1/ATSR image. Complex Empirical Orthogonal Functions (CEOF) analysis is performed on the SLA data set. The first resulting two modes explain nearly 85% of the variability, with 80% of the total variance for the first one and 5% of the total variance for the second one. The temporal phase of the first mode indicates that a constant frequency of 1 cycle per year is clearly dominant corresponding to the seasonal signal. The temporal amplitude and the temporal phase of the second mode show a periodicity of about 6 months which appears associated with the variability of the Algerian current. C1 CSIC, Inst Ciencias Mar, Barcelona, Spain. CALTECH, Jet Prop Lab, Pasadena, CA USA. Ctr Oceanol Marseille, CNRS, Marseille, France. RP Bouzinac, C (reprint author), CSIC, Inst Ciencias Mar, Barcelona, Spain. RI Font, Jordi/E-5355-2013 OI Font, Jordi/0000-0003-2590-1457 NR 0 TC 0 Z9 0 U1 0 U2 1 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 1497 EP 1500 PG 4 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL05P UT WOS:000074128900160 ER PT S AU Liu, WT Tang, WQ AF Liu, WT Tang, WQ GP ESA TI Application of ERS scatterometer winds to typhoon, monsoon, rain, and El Nino studies SO THIRD ERS SYMPOSIUM ON SPACE AT THE SERVICE OF OUR ENVIRONMENT, VOLS. II & III SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd ERS Symposium on Space at the Service of Our Environment CY MAR 14-21, 1997 CL FLORENCE, ITALY SP European Space Agcy AB The ocean surface wind and pressure derived from the ERS-1 scatterometer, with high spatial resolution, are used to improve the monitoring of the intensity and location of typhoon. The scatterometer winds are used in conjunction with coincident observations of sea surface temperature and precipitable water by other spaceborne sensors to compare the annual and interannual Variations of monsoons in the South China Sea and in the Bay of Bengal. The scatterometer data are also used to estimate rain rate through the improved computation of surface wind divergence, vertical velocity profile, and the hydrologic balance in the atmosphere. Finally scatterometer winds, as the forcing or precursor of equatorial Kelvin waves and temperature anomalies, are examined in one of the warming event in the equatorial Pacific. C1 Jet Prop Lab 300 323, Pasadena, CA 91109 USA. RP Liu, WT (reprint author), Jet Prop Lab 300 323, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-656-2 J9 ESA SP PUBL PY 1997 VL 414 BP 1585 EP 1589 PG 3 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BL05P UT WOS:000074128900176 ER PT S AU Chang, KY Scharton, TD AF Chang, KY Scharton, TD BE Guyenne, TD TI Cassini spacecraft and instrument force limited vibration testing SO THIRD INTERNATIONAL SYMPOSIUM ON ENVIRONMENTAL TESTING FOR SPACE PROGRAMMES SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 3rd International Symposium on Environmental Testing for Space Programmes CY JUN 24-27, 1997 CL ESTEC, NOORDWIJK, NETHERLANDS SP European Space Agcy, ESTEC HO ESTEC AB During the past three years, force limiting has been used in the vibration tests of most of the instruments and major equipment on the Cassini spacecraft, as well as in the vibration test of the complete flight spacecraft in November of 1996. Force limits for the Cassini instruments and complete spacecraft vibration tests were developed using a simple, semi-empirical method which requires only the acceleration specification and data from a low level pre-test to determine the apparent mass of the test item. This semi-empirical method of predicting force limits was validated with force data measured at the instrument/spacecraft interface in acoustic tests of the spacecraft DTM structure.The application of force limiting to spacecraft equipment is illustrated with a discussion of the random vibration test of the Cassini Radio Plasma Wave Subsystem Antenna instrument. The environmental test program for the Cassini spacecraft included a force-limited vertical-axis random vibration test. The semi-empirical force limit specified in the Cassini spacecraft vibration test procedure was used without any modifications during the test, Acceleration responses at critical locations were monitored in the spacecraft vibration test, but only the total axial force was used in the control loop to notch the input acceleration. The flight limit loads were achieved at a number of critical locations on the spacecraft, and the instrument responses were similar to those in the component random vibration tests. RP Chang, KY (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,MS 157-410,PASADENA,CA 91109, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU EUROPEAN SPACE AGENCY PI PARIS PA 8-10 RUE MARIO NIKIS, 75738 PARIS, FRANCE SN 0379-6566 BN 92-9092-315-6 J9 ESA SP PUBL PY 1997 VL 408 BP 123 EP 131 PG 9 WC Engineering, Aerospace SC Engineering GA BJ77Q UT WOS:A1997BJ77Q00015 ER PT B AU Wallyn, P Mahoney, WA Ling, JC Wheaton, WA Radocinski, RG Skelton, RT AF Wallyn, P Mahoney, WA Ling, JC Wheaton, WA Radocinski, RG Skelton, RT BE Leung, KC TI BATSE observations of X-ray binaries using the JPL-EBOP Earth occultation method SO THIRD PACIFIC RIM CONFERENCE ON RECENT DEVELOPMENT ON BINARY STAR RESEARCH SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 3rd Pacific Rim Conference on Recent Development on Binary Star Research CY OCT 26-NOV 01, 1995 CL CHIANG MAI, THAILAND SP Chiang Mai Univ, Thai Astronom Soc, Univ Nebraska Lincoln, Natl Res Council Thailand, Think Earth Thailand, Trantraphun Dept Store, Thailand, Tra Co Ltd, Thailand AB The JPL BATSE Earth Occultation Package (EBOP) is currently used to study low energy gamma-ray sources (30 keV -1.8 MeV) using the Burst and Transient Source Experiment (BATSE) on board the Compton Gamma-Ray Observatory (CGRO). We present a list of the X-ray binaries currently included in the EBOP input catalog, and we show results which are currently produced by EBOP on the black hole candidates such as Cygnus X-1. C1 CALTECH, Jet Prop Lab 169 327, Pasadena, CA 91109 USA. RP Wallyn, P (reprint author), CALTECH, Jet Prop Lab 169 327, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-886733-50-3 J9 ASTR SOC P PY 1997 VL 130 BP 45 EP 48 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BK80J UT WOS:000073445600009 ER PT S AU Rice, RF AF Rice, RF BE Singh, A TI Lossless coding standards for space data systems SO THIRTIETH ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS & COMPUTERS, VOLS 1 AND 2 SE CONFERENCE RECORD OF THE ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS LA English DT Proceedings Paper CT 30th Asilomar Conference on Signals, Systems and Computers CY NOV 03-06, 1996 CL PACIFIC GROVE, CA SP Naval Postgrad Sch, Monterey, California, San Jose State Univ, San Jose, California, IEEE Signal Proc Soc AB The international Consultative Committee for Space Data Systems (CCSDS) is preparing to issue its first recommendation for a digital data compression standard. Because the space data systems of primary interest are employed to support scientific investigations requiring accurate representation, this initial standard will be restricted to lossless compression. In particular, the demonstrated breadth of applicability and high performance of what has become known as ''The Rice Algorithms'', has led the CCSDS to recommend a version of these algorithms. The key algorithmic and performance characteristics that have driven the development of this recommendation are discussed. RP Rice, RF (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 I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 SN 1058-6393 BN 0-8186-7646-9 J9 CONF REC ASILOMAR C PY 1997 BP 577 EP 585 PG 9 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BH95W UT WOS:A1997BH95W00115 ER PT S AU Lay, NE Dillon, M Satorius, EH Mulligan, JJ AF Lay, NE Dillon, M Satorius, EH Mulligan, JJ BE Singh, A TI A communications system testbed SO THIRTIETH ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS & COMPUTERS, VOLS 1 AND 2 SE CONFERENCE RECORD OF THE ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS LA English DT Proceedings Paper CT 30th Asilomar Conference on Signals, Systems and Computers CY NOV 03-06, 1996 CL PACIFIC GROVE, CA SP Naval Postgrad Sch, Monterey, California, San Jose State Univ, San Jose, California, IEEE Signal Proc Soc AB In this paper, we describe a testbed that is being developed for the evaluation of demodulation algorithms in communication systems. This testbed is intended to provide a research tool in the area of signal demodulation and is built around easily programmable, general purpose and digital signal processors. A variety of analog and digital modulations can be evaluated in real and non-realtime scenarios and under different channel conditions ranging from intersymbol interference to modulated or unmodulated co-channel interference. Testbed architectural and design details are presented along with preliminary results of our algorithm development and testing program. RP Lay, NE (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 I E E E, COMPUTER SOC PRESS PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, LOS ALAMITOS, CA 90720 SN 1058-6393 BN 0-8186-7646-9 J9 CONF REC ASILOMAR C PY 1997 BP 663 EP 667 PG 5 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BH95W UT WOS:A1997BH95W00131 ER PT S AU Ames, CK Burleigh, SC Mitchell, SJ AF Ames, CK Burleigh, SC Mitchell, SJ BE Nunamaker, JF Sprague, RH TI WWWorkflow: World Wide Web based workflow SO THIRTIETH HAWAII INTERNATIONAL CONFERENCE ON SYSTEM SCIENCES, VOL 4: INFORMATION SYSTEMS - INTERNET AND THE DIGITAL ECONOMY SE PROCEEDINGS OF THE ANNUAL HAWAII INTERNATIONAL CONFERENCE ON SYSTEM SCIENCES LA English DT Proceedings Paper CT 30th Hawaii International Conference on System Sciences (HICSS 30) CY JAN 07-10, 1997 CL WAILEA, HI SP Univ Hawaii, Univ Hawaii Manoa, Coll Business Adm AB This paper describes WWWorkflow, a system developed at the Jet Propulsion Laboratory for the computer mediation of work through an organization. WWWorkflow exploits an opportunity created by organizational intranets to provide a common user interface across heterogeneous platforms. A distinctive feature of WWWorkflow is the careful separation of process mediation from product data management. WWWorkflow supports many types of workflow and is not focused on any single information structure. Three major components of the system are presented: a relational database approach to process definition and management, process initiation and event response software used to drive the flow of work through the organization, and a World Wide Web (WWW) based user interface and mechanism for integrating workflow with existing data management services. Lessons learned from its deployment at the Johnson Space Center, Houston are discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ames, CK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 3 Z9 3 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 1060-3425 BN 0-8186-7743-0 J9 P ANN HICSS PY 1997 BP 397 EP 404 PG 8 WC Computer Science, Information Systems SC Computer Science GA BK74W UT WOS:000073325300041 ER PT B AU Ovryn, B Khaydarov, JD AF Ovryn, B Khaydarov, JD BE Cogswell, CJ Conchello, JA Wilson, T Katzir, A TI Forward scattering particle image velocimetry (FSPIV): Application of Mie and imaging theory to measure 3D velocities in microscopy flows using partially coherent illumination and high aperture optics SO THREE-DIMENSIONAL MICROSCOPY: IMAGE ACQUISITION AND PROCESSING IV, PROCEEDINGS OF SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Three-Dimensional Microscopy - Image Acquisition and Processing IV CY FEB 12-13, 1997 CL SAN JOSE, CA SP Soc Photo Opt Instrumentat Engineers, Amer Soc Laser Med & Surg Inc AB We have combined Mie scattering theory and image theory to predict the forward scattering of light from spherical particles in a seeded fluid using high numerical aperture collection optics. Using this method, it is possible to determine all three components of a fluid's velocity by measuring the scattering from homogeneous spherical particles without moving the optics. The transverse velocity component is determined by following the centroid of the scattering pattern (with respect to time), while the component along the optical axis is determined by comparing the experimental data with numerical computations. We have verified our theoretical model and computer code by measuring the scattering from polystyrene particles illuminated with partially coherent, Koehler illumination in a transmitted light microscope. The three-dimensional scattering data is in quite good agreement with our model. To further verify our approach, we have measured the three-dimensional (parabolic) profile of a parallel flow of a low viscosity, seeded fluid in a straight channel (6 mm x 48 mm x 0.314 mm). The channel was placed on the stage of a conventional microscope equipped with a long working distance microscope objective, with the narrow dimension along the optical axis (OA). Instead of directly imaging the seed particles, the forward scattered light is recorded from the spherical, polystyrene seed particles (7 mu m diameter). RP Ovryn, B (reprint author), NASA,LEWIS RES CTR,NYMA INC,LEWIS GRP,21000 BROOKPK RD,MS 110-3,CLEVELAND,OH 44135, USA. NR 0 TC 2 Z9 2 U1 0 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2395-5 J9 P SOC PHOTO-OPT INS PY 1997 VL 2984 BP 243 EP 254 DI 10.1117/12.271265 PG 4 WC Engineering, Biomedical; Microscopy; Optics SC Engineering; Microscopy; Optics GA BH66B UT WOS:A1997BH66B00026 ER PT B AU O'Neil, WJ AF O'Neil, WJ BE Barbieri, C Rahe, JH Johnson, TV Sohus, AM TI Project Galileo - The Jupiter mission SO THREE GALILEOS: THE MAN, THE SPACECRAFT, THE TELESCOPE LA English DT Proceedings Paper CT Conference on the 3 Galileos: The Man, The Spacecraft, The Telescope CY JAN 07-10, 1997 CL PADUA, ITALY C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP O'Neil, WJ (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 SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4861-3 PY 1997 BP 17 EP 32 PG 16 WC Engineering, Aerospace; Astronomy & Astrophysics; History & Philosophy Of Science SC Engineering; Astronomy & Astrophysics; History & Philosophy of Science GA BL48Q UT WOS:000075676900004 ER PT B AU Johnson, TV AF Johnson, TV BE Barbieri, C Rahe, JH Johnson, TV Sohus, AM TI Galileo at Jupiter: First results SO THREE GALILEOS: THE MAN, THE SPACECRAFT, THE TELESCOPE LA English DT Proceedings Paper CT Conference on the 3 Galileos: The Man, The Spacecraft, The Telescope CY JAN 07-10, 1997 CL PADUA, ITALY C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Johnson, TV (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 SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4861-3 PY 1997 BP 51 EP 63 PG 13 WC Engineering, Aerospace; Astronomy & Astrophysics; History & Philosophy Of Science SC Engineering; Astronomy & Astrophysics; History & Philosophy of Science GA BL48Q UT WOS:000075676900006 ER PT B AU O'Neil, WJ AF O'Neil, WJ BE Barbieri, C Rahe, JH Johnson, TV Sohus, AM TI The Galileo Spacecraft architecture SO THREE GALILEOS: THE MAN, THE SPACECRAFT, THE TELESCOPE LA English DT Proceedings Paper CT Conference on the 3 Galileos: The Man, The Spacecraft, The Telescope CY JAN 07-10, 1997 CL PADUA, ITALY C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP O'Neil, WJ (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 SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4861-3 PY 1997 BP 75 EP 94 PG 20 WC Engineering, Aerospace; Astronomy & Astrophysics; History & Philosophy Of Science SC Engineering; Astronomy & Astrophysics; History & Philosophy of Science GA BL48Q UT WOS:000075676900008 ER PT B AU Deutsch, LJ AF Deutsch, LJ BE Barbieri, C Rahe, JH Johnson, TV Sohus, AM TI The Galileo spacecraft: A communications legacy for future space flight SO THREE GALILEOS: THE MAN, THE SPACECRAFT, THE TELESCOPE LA English DT Proceedings Paper CT Conference on the 3 Galileos: The Man, The Spacecraft, The Telescope CY JAN 07-10, 1997 CL PADUA, ITALY AB The Galileo mission to Jupiter has implemented a wide range of telecommunication improvements in response to the loss of its high gain antenna. These have resulted in a 20 dB (100 fold) increase in returned information, allowing the mission to meet the vast majority of its science objectives. While necessity dictated the use of these new techniques for Galileo, they have now been proven in flight and are available for future deep space missions. This telecommunications legacy of Galileo will aid in our ability to conduct a meaningful exploration of the solar system, and beyond, at a reasonable cost. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Deutsch, LJ (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 SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4861-3 PY 1997 BP 95 EP 106 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics; History & Philosophy Of Science SC Engineering; Astronomy & Astrophysics; History & Philosophy of Science GA BL48Q UT WOS:000075676900009 ER PT B AU Statman, JI Deutsch, LJ AF Statman, JI Deutsch, LJ BE Barbieri, C Rahe, JH Johnson, TV Sohus, AM TI Galileo's telecommunications using the low-gain spacecraft antenna SO THREE GALILEOS: THE MAN, THE SPACECRAFT, THE TELESCOPE LA English DT Proceedings Paper CT Conference on the 3 Galileos: The Man, The Spacecraft, The Telescope CY JAN 07-10, 1997 CL PADUA, ITALY AB Galileo's accomplishment of a science-rich mission through a low-gain antenna was made possible by the coordinated efforts of the Deep Space Network (DSN) support team, the spacecraft designers, and the science principal investigators. This team has worked together since late 1991, its efforts resulting in the flawless transition of Galileo, on May 23, 1996, to a completely new telecommunications link. The efforts included extensive changes in the DSN facilities in Goldstone (USA), Canberra (Australia), and Madrid (Spain) and at the Parkes Observatory in Australia, as well as new uploads of Galileo's onboard software. The DSN/Parkes upgrades include increasing the antenna sensitivity; adding wide-area arraying between the Goldstone and Canberra 70-m antennas, the Canberra 34-m antennas, and the Parkes 64-m antenna; installing new error-correcting coding; and providing the infrastructure to ensure gap-free, guaranteed-delivery telemetry processing. At the same time, Galileo has developed extensive onboard data editing and compression capabilities. Together, the DSN/Parkes and Galileo upgrades increase the raw downlink volume by a factor of 10, and its value by another factor of 10, resulting in Galileo meeting 70% of the original science goals. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Statman, JI (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 SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4861-3 PY 1997 BP 107 EP 113 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; History & Philosophy Of Science SC Engineering; Astronomy & Astrophysics; History & Philosophy of Science GA BL48Q UT WOS:000075676900010 ER PT B AU D'Amario, LA AF D'Amario, LA BE Barbieri, C Rahe, JH Johnson, TV Sohus, AM TI Navigation of the Galileo spacecraft SO THREE GALILEOS: THE MAN, THE SPACECRAFT, THE TELESCOPE LA English DT Proceedings Paper CT Conference on the 3 Galileos: The Man, The Spacecraft, The Telescope CY JAN 07-10, 1997 CL PADUA, ITALY C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP D'Amario, LA (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 SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4861-3 PY 1997 BP 115 EP 143 PG 29 WC Engineering, Aerospace; Astronomy & Astrophysics; History & Philosophy Of Science SC Engineering; Astronomy & Astrophysics; History & Philosophy of Science GA BL48Q UT WOS:000075676900011 ER PT B AU Landano, MR AF Landano, MR BE Barbieri, C Rahe, JH Johnson, TV Sohus, AM TI Galileo spacecraft operations SO THREE GALILEOS: THE MAN, THE SPACECRAFT, THE TELESCOPE LA English DT Proceedings Paper CT Conference on the 3 Galileos: The Man, The Spacecraft, The Telescope CY JAN 07-10, 1997 CL PADUA, ITALY C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Landano, MR (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 SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4861-3 PY 1997 BP 145 EP 157 PG 13 WC Engineering, Aerospace; Astronomy & Astrophysics; History & Philosophy Of Science SC Engineering; Astronomy & Astrophysics; History & Philosophy of Science GA BL48Q UT WOS:000075676900012 ER PT B AU Matson, DL Lebreton, JP AF Matson, DL Lebreton, JP BE Barbieri, C Rahe, JH Johnson, TV Sohus, AM TI Galileos' legacy to Cassini: Historical, philosophical, and physical SO THREE GALILEOS: THE MAN, THE SPACECRAFT, THE TELESCOPE LA English DT Proceedings Paper CT Conference on the 3 Galileos: The Man, The Spacecraft, The Telescope CY JAN 07-10, 1997 CL PADUA, ITALY AB Galileo Galilei left a rich scientific legacy that enabled Cassini, Huygens, and other scientists to continue to open the modern era of planetary exploration. The legacy relationship also applies to the spacecraft and missions named after these men. The fundamental philosophy of the Cassini/Huygens mission and its investigative approach were adopted from the Galileo mission. The Cassini spacecraft even uses spare hardware that the Galileo Project did not use. Thus the parallels between the two missions run very deep. This thesis is reinforced in the following description of the Cassini and Huygens missions. Many things are seen to resemble their counterparts on the Galileo mission at Jupiter. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Matson, DL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-4861-3 PY 1997 BP 159 EP 176 PG 18 WC Engineering, Aerospace; Astronomy & Astrophysics; History & Philosophy Of Science SC Engineering; Astronomy & Astrophysics; History & Philosophy of Science GA BL48Q UT WOS:000075676900013 ER PT B AU Gutierrez, RC Tang, TK Stell, CB Vorperian, V Shcheglov, K AF Gutierrez, RC Tang, TK Stell, CB Vorperian, V Shcheglov, K GP IEEE TI Bulk micromachined vacuum sensor SO TRANSDUCERS 97 - 1997 INTERNATIONAL CONFERENCE ON SOLID-STATE SENSORS AND ACTUATORS, DIGEST OF TECHNICAL PAPERS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1997 International Conference on Solid-State Sensors and Actuators CY JUN 16-19, 1997 CL CHICAGO, IL SP IEEE Electron Devices Soc DE vacuum; sensor; resonator AB In this paper, we present recent work on the fabrication and testing of a silicon bulk micromachined vacuum sensor. The fabrication process, electronics, and various modes of operation are described. The pressure sensitivity is demonstrated between 10(-6) Torr and 10(-1) Torr by ''calibrating'' against a thermocouple gauge, a capacitance manometer, a spinning rotor gauge, and a hot cathode ionization gauge. For the preferred mode of operation, the frequency dependence on temperature is 0.007 Hz/degrees C, the device is vibration insensitive, and has a measured intrinsic Q-factor above 100,000. RP Gutierrez, RC (reprint author), CALTECH,JET PROP LAB,MICRODEVICES LAB,4800 OAK GROVE DR,PASADENA,CA 91125, USA. NR 0 TC 1 Z9 2 U1 0 U2 1 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3829-4 PY 1997 BP 1497 EP 1500 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BJ35B UT WOS:A1997BJ35B00369 ER PT B AU Chao, TH Lau, B Park, Y AF Chao, TH Lau, B Park, Y BE Chachich, AC DeVries, MJ TI Vehicle detection and classification in shadowy traffic images using wavelets and neural networks SO TRANSPORTATION SENSORS AND CONTROLS: COLLISION AVOIDANCE, TRAFFIC MANAGEMENT, AND ITS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Transportation Sensors and Controls - Collision Avoidance, Traffic Management and ITS CY NOV 18-20, 1996 CL BOSTON, MA SP Soc Photo Opt Instrumentat Engineers DE vehicle detection; wavelet segmentation; Hermite moment; feature extraction; neural net classification AB A vision-based traffic surveillance processor is being developed at JPL. This processor uses innovative image segmentation and classification techniques for vehicles in freeway images, including those with large shadows. These results enable the computation of many useful traffic parameters. A wavelet-based algorithm has been developed for vehicle detection and segmentation. Specifically, two types of mother wavelet has been created and tested: the first for shape-size discrimination of vehicles from their background; and the second for locating where vehicles join their shadows, thus enabling segmentation of the vehicles from their shadows. Combining these two wavelets enables robust segmentation of vehicles from busy freeways. This method reduces the false-alarm rate in vehicle counts, since shadows are no longer mistaken for vehicles. We use neural networks for vehicle classification. To reduce system complexity and training time, we use, as preprocessors, several feature extraction methods, such as invariant-moment and Hermite-moment computations. This preprocessing enables orders of magnitude reductions in training time and a great increase in classification accuracy. RP Chao, TH (reprint author), CALTECH,JET PROP LAB,4800 OAK GROVE DR,PASADENA,CA 91109, USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2304-1 J9 P SOC PHOTO-OPT INS PY 1997 VL 2902 BP 136 EP 147 DI 10.1117/12.267139 PG 12 WC Optics; Transportation SC Optics; Transportation GA BH32J UT WOS:A1997BH32J00014 ER PT S AU Davis, TJ Isaacson, DR Robinson, JE den Braven, W Lee, KK Sanford, B AF Davis, TJ Isaacson, DR Robinson, JE den Braven, W Lee, KK Sanford, B BE Papageorgiou, M Pouliezos, A TI Operational test results of the passive final approach spacing tool SO TRANSPORTATION SYSTEMS 1997, VOLS 1-3 SE IFAC SYMPOSIA SERIES LA English DT Proceedings Paper CT 8th IFAC/IFIP/IFORS Symposium on Transportation Systems CY JUN 16-18, 1997 CL TECH UNIV CRETE, DEPT PROD MANAGEMENT ENGN, KHANIA, GREECE SP Int Federat Automat Control, Tech Comm Transportat Syst, Int Federat Informat Proc, Int Federat Operat Res Soc, Int Federat Automat Control, Tech Comm Air Traff Control Automat, Int Federat Automat Control, Tech Comm Automot Control, Int Federat Automat Control, Tech Comm Marine Syst, Tech Chamber Greece HO TECH UNIV CRETE, DEPT PROD MANAGEMENT ENGN DE air traffic control; decision support systems; automation; human factors AB A prototype decision support tool for terminal area air traffic controllers, referred to as the Final Approach Spacing Tool (FAST), was recently evaluated in operation with live air traffic at the Dallas/Fort Worth, Texas Airport. Controllers utilized FAST's runway and sequence advisories to manage and control arrival traffic during more than twenty-five peak rush traffic periods. This paper presents the results of these tests, describing data on FAST's impact on airport capacity, in-trail separation on final. approach, safety, and controller workload. Results demonstrate airport throughput increases of more than 13 percent with no negative impact on controller workload or safety. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Davis, TJ (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0962-9505 BN 0-08-042931-9 J9 IFAC SYMP SERIES PY 1997 BP 175 EP 181 PG 3 WC Automation & Control Systems; Transportation SC Automation & Control Systems; Transportation GA BL38N UT WOS:000075340900029 ER PT J AU Hall, PB Thom, R Chang, L AF Hall, PB Thom, R Chang, L TI An experimental/analytical study of high-speed, high-load rolling/sliding contacts with ultra-low viscosity fluids SO TRIBOLOGY TRANSACTIONS LA English DT Article DE rolling-contact fatigue; lubricant rheology; rolling-element bearings ID ROUGH AB Experiments and theoretical analyses were carried out in, this research to study the operating and lubrication conditions in highspeed, high-load rolling/sliding contacts with liquid oxygen (LO(2)). A cryogenic traction tester having a single rolling/sliding contact conjunction was used in the experiments. Contact between two AISI 440C stainless steel rolling elements was studied at a rolling velocity of 47 m/s and at a load that generates a Hertzian peak pressure of 2.2 GPa. Tests were run with a slide-to-roll ratio up to one percent, and traction and specimen wear were measured. Experiments were also conducted at rolling velocities of 1.0 m/s and 11.7 m/s to provide evidence of LO(2) load support at high speeds and to deduce parameters for subsequent theoretical analyses. The measured total traction and asperity friction were then used as inputs to an analytical model to determine the load-carrying capacity and average film thickness of LO(2). The analyses show that the traction is mainly due to asperity friction; however, LO(2) can support a large portion of the total load despite its extremely low viscosity. This analytical result is also supported by the specimen wear data. The analyses in conjunction with the experimental data also provide a meaningful estimate of the average film thickness and LO(2) viscosity in the contact nip. C1 PENN STATE UNIV,DEPT MECH ENGN,UNIVERSITY PK,PA 16802. RP Hall, PB (reprint author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,TRIBIOL RES BRANCH,HUNTSVILLE,AL 35812, USA. NR 20 TC 3 Z9 6 U1 0 U2 5 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0569-8197 J9 TRIBOL T JI Tribol. Trans. PD JAN PY 1997 VL 40 IS 1 BP 41 EP 48 DI 10.1080/10402009708983626 PG 8 WC Engineering, Mechanical SC Engineering GA WF791 UT WOS:A1997WF79100005 ER PT J AU Zaretsky, EV Coe, HH August, R AF Zaretsky, EV Coe, HH August, R TI Effect of hoop stress on ball bearing life prediction SO TRIBOLOGY TRANSACTIONS LA English DT Article DE wear and failure; rolling-element bearings; engineering analysis and computing; life prediction methods AB A finite-element analysis (FEA) of a generic, dimensionally normalized inner race of an angular-contact ball bearing was performed under varying conditions of speed and the press (or interference) fit of the inner-race bare on a journal. The FEA results at the ball-race contact were used to derive an equation from which the radius of an equivalent cylindrical bearing race with the same or similar hoop stress was obtained. The radius of the equivalent cylinder was used to obtain a generalized closed-form approximation of the hoop stresses at the ball-inner race contact in an angular-contact ball bearing A life analysis was performed on both a 45 and a 120 mm-bore, angular-contact ball bearing The Predicted lives with and without hoop stress were compared with experimental endurance results obtained at 12,000 and 25,000 rpm with the 120 mm-bore ball bearing. A life factor equation based on hoop stress is presented. C1 NYMA INC,ENGN SERV DIV,BROOKPARK,OH 44142. RP Zaretsky, EV (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. RI Coe, Hugh/C-8733-2013 NR 12 TC 1 Z9 1 U1 0 U2 3 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0569-8197 J9 TRIBOL T JI Tribol. Trans. PD JAN PY 1997 VL 40 IS 1 BP 91 EP 100 DI 10.1080/10402009708983634 PG 10 WC Engineering, Mechanical SC Engineering GA WF791 UT WOS:A1997WF79100013 ER PT J AU Dellacorte, C Laskowski, JA AF Dellacorte, C Laskowski, JA TI Tribological evaluation of PS300: A new chrome oxide-based solid lubricant coating sliding against Al2O3 from 25 degrees to 650 degrees C SO TRIBOLOGY TRANSACTIONS LA English DT Article; Proceedings Paper CT ASME/STLE 1996 Tribology Conference CY OCT 13-17, 1996 CL SAN FRANCISCO, CA SP Amer Soc Mech Engineers, Soc Tribologists & Lubricat Engineers DE tribology; friction; wear; ceramics; high temperature; solid lubricants; surface films/coatings AB This paper presents the tribological characteristics of Al2O3 sliding against PS300, a chrome oxide-based self-lubricating coating. Al2O3 pins were slid against PS300-coated superalloy disks in air under a 4.9 N load at velocities of 1 to 8 m/s. At a sliding velocity of 1 m/s, friction ranged from 0.6 at 25 degrees C to 0.2 at 650 degrees C. Wear factors for the Al2O3 pins were in the 10(-7) mm(3)/N-m range and in the 10(-5) mm(3)/N-m range for the PS300 coating. The test results suggest that increased surface temperature resulting from either functional heating, generated by increased sliding velocity, or ambient heating caused a reduction in friction and wear of the sliding couple. Based upon these results, the tested material combination is a promising candidate for high temperature wear applications. C1 ST LOUIS UNIV,PARKS COLL,CAHOKIA,IL 62206. RP Dellacorte, C (reprint author), NASA,LEWIS RES CTR,CLEVELAND,OH 44135, USA. NR 10 TC 30 Z9 30 U1 1 U2 6 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 SN 0569-8197 J9 TRIBOL T JI Tribol. Trans. PD JAN PY 1997 VL 40 IS 1 BP 163 EP 167 DI 10.1080/10402009708983642 PG 5 WC Engineering, Mechanical SC Engineering GA WF791 UT WOS:A1997WF79100023 ER PT B AU Hah, C AF Hah, C BE Hah, C TI Computational modelling of the generation and transport of aerodynamic losses in turbine blade rows SO TURBOMACHINERY FLUID DYNAMICS AND HEAT TRANSFER SE MECHANICAL ENGINEERING : A SERIES OF TEXTBOOKS AND REFERENCE BOOKS LA English DT Proceedings Paper CT Symposium on Turbomachinery Fluid Dynamics and Heat Transfer, on the Occasion of Dr B Lakshminarayanas 60th Birthday CY JUN 13-14, 1995 CL PENN STATE UNIV, UNIVERSITY PK, PA SP Penn State Univ, USN, Off Naval Res HO PENN STATE UNIV RP Hah, C (reprint author), NASA,LEWIS RES CTR,INTERNAL FLUID MECH DIV,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MARCEL DEKKER PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 BN 0-8247-9829-5 J9 MECH ENG SE PY 1997 VL 110 BP 223 EP 238 PG 16 WC Engineering, Aerospace; Thermodynamics; Engineering, Mechanical SC Engineering; Thermodynamics GA BH15X UT WOS:A1997BH15X00010 ER PT B AU Rao, G Vaidyanathan, H Nakhleh, W AF Rao, G Vaidyanathan, H Nakhleh, W BE Frank, HA Seo, ET TI Behavior of a cycled Ni-Cd battery during pulse discharge SO TWELFTH ANNUAL BATTERY CONFERENCE ON APPLICATIONS AND ADVANCES LA English DT Proceedings Paper CT 12th Annual Battery Conference on Applications and Advances CY JAN 14-17, 1997 CL CALIF STATE UNIV, LONG BEACH, CA SP Adv Lead Acid Battery Consortium, Amer Inst Aeronaut & Astronaut, Electrochem Soc Inc, Independent Battery Manufacturers Assoc, IEEE Aerosp & Electr Syst Soc, Int Cadmium Assoc, N Amer Off, Arvin Instruments, So Calif Edison Co, Batteries Int Ltd, Darnell Grp, Int Battery Technol Inc, Intertec Int Inc, ITE JEC Press Inc, 7 Mt Sci Inc, Business Commun Co Inc HO CALIF STATE UNIV AB The pulse discharge behavior of a 9-Ah, 12-V nickel-cadmium (Ni-Cd) battery fabricated for the FAST program was studied. The response of the battery voltage to a pulse with a current of 60 A and duration of 10 to 200 ms was measured, along with the capacity remaining at the end of pulse discharge. The maximum drop in voltage at the beginning of the pulse was 505 to 1,049 mV, and battery capacity remained stable. RP Rao, G (reprint author), NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3631-3 PY 1997 BP 99 EP 101 DI 10.1109/BCAA.1997.574086 PG 3 WC Electrochemistry; Engineering, Electrical & Electronic; Engineering, Mechanical SC Electrochemistry; Engineering GA BH34J UT WOS:A1997BH34J00019 ER PT B AU Valdez, TI Narayanan, SR Frank, H Chun, W AF Valdez, TI Narayanan, SR Frank, H Chun, W BE Frank, HA Seo, ET TI Direct methanol fuel cell for portable applications SO TWELFTH ANNUAL BATTERY CONFERENCE ON APPLICATIONS AND ADVANCES LA English DT Proceedings Paper CT 12th Annual Battery Conference on Applications and Advances CY JAN 14-17, 1997 CL CALIF STATE UNIV, LONG BEACH, CA SP Adv Lead Acid Battery Consortium, Amer Inst Aeronaut & Astronaut, Electrochem Soc Inc, Independent Battery Manufacturers Assoc, IEEE Aerosp & Electr Syst Soc, Int Cadmium Assoc, N Amer Off, Arvin Instruments, So Calif Edison Co, Batteries Int Ltd, Darnell Grp, Int Battery Technol Inc, Intertec Int Inc, ITE JEC Press Inc, 7 Mt Sci Inc, Business Commun Co Inc HO CALIF STATE UNIV AB A five cell direct methanol fuel cell stack has been developed at the jet Propulsion Laboratory. Presently direct methanol fuel cell technology is being incorporated into a system for portable applications. Electrochemical performance and its dependence on flow rate and temperature for a five cell stack are presented. Water transport data, and water transport mechanisms for direct methanol fuel cells are discussed. Stack response to pulse loads has been characterized. Implications of stack performance and operating conditions on system design have been addressed. RP Valdez, TI (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 I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3631-3 PY 1997 BP 239 EP 244 DI 10.1109/BCAA.1997.574110 PG 6 WC Electrochemistry; Engineering, Electrical & Electronic; Engineering, Mechanical SC Electrochemistry; Engineering GA BH34J UT WOS:A1997BH34J00043 ER PT B AU Gorton, SA Meyers, JF Berry, JD AF Gorton, SA Meyers, JF Berry, JD BE Chait, R Kominos, C Shur, MS Stroscio, M Valdes, JJ TI Laser velocimetry and Doppler Global Velocimetry measurements of velocity near the empennage of a small-scale helicopter model SO TWENTIETH ARMY SCIENCE CONFERENCE - AWARD WINNING PAPERS LA English DT Proceedings Paper CT 20th United-States-Army Science Conference - Science and Technology for Force XXI: The Force of the 21st-Century CY JUN 24-JUL 27, 1996 CL NORFOLK, VA SP USA, Assistant Secretary Army Res Dev & Acquisit AB A test program was conducted in the NASA Langley 14- by 22-Foot Subsonic Tunnel to measure the flow near the empennage of a small-scale powered helicopter model with an operating tail fan configuration. Velocity profiles were measured with three-component Laser Velocimetry (LV) one chord forward of the horizontal tail for four forward speeds to evaluate the effect of the rotor wake impingement on the horizontal tail angle of attack. These velocity data indicate the horizontal tail can experience unsteady downwash angle variations of over 30 degrees due to the rotor wake influence. The horizontal tail is most affected by the rotor wake above speeds of 23 m/s (44 knots). Three-component velocity measurements of the flow on the inlet side of the fan were made for a low-speed flight condition using both LV and a promising, non-intrusive, global, three-component velocity measurement technique called Doppler Global Velocimetry (DGV). The velocity data show an accelerated and non-uniform flow into the fan. DGV shows promise as an evolving tool for rotor flowfield diagnostics. C1 Langley Res Ctr, JRPO, AFDD, ATCOM, Hampton, VA 23681 USA. RP Gorton, SA (reprint author), Langley Res Ctr, JRPO, AFDD, ATCOM, Hampton, VA 23681 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3178-4 PY 1997 BP 75 EP 79 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA BK31P UT WOS:000071758900013 ER PT S AU Stecher, TP AF Stecher, TP CA Ultraviolet Imaging Telescope Team BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI The Ultraviolet Imaging Telescope: Instrument and data characteristics SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB The Ultraviolet Imaging Telescope (UIT) was flown as part of the Astro Observatory on the Space Shuttle Columbia in December 1990 (see Figure 1) and again oil the Space Shuttle Endeavour in March 1995. Ultraviolet (1200-3300 Angstrom) images of a wide variety of astronomical objects were detected with UV image intensifiers and recorded on photographic film. Typical angular resolutions were 2-3 arcsec over a 40 arcmin field of view. The reduced and calibrated images front the first flight are available to the astronomical community through the National Space Science Data Center (NSSDC); the data recorded during the second Eight mill soon be available as well. UIT's design, operation, data reduction, and calibration are described in detail in Stecher et al. (1997), including a comprehensive description of the data characteristics. This publication provides UIT data users with information for understanding and using the data, as well as guidelines for analyzing other astronomical imagery made with image intensifiers and photographic film. Further information on the Astro missions and tile UIT science program is available at the following website http://fondue.gsfc.nasa.gov/UIT/UIT_HomePage.html and ill an educational slideset that is available from the Astronomical Society of the Pacific (Waller & Offenberg 1994). C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Stecher, TP (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 680, Greenbelt, MD 20771 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 36 EP 38 PG 3 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900005 ER PT S AU Waller, WH Fanelli, MN Collins, NR Cornett, RH Offenberg, J Marcum, PM Stecher, TP AF Waller, WH Fanelli, MN Collins, NR Cornett, RH Offenberg, J Marcum, PM Stecher, TP CA UIT Sci Team BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Ultraviolet morphologies of nearby barred and unbarred spiral galaxies SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB Deep high-resolution imaging of galaxies at high-redshift has revealed a remarkable diversity of emission structures in the restframe ultraviolet. To better understand these remote and primeval realms, it is important to compare them with UV-emitting counterparts in the local universe. As part of two Spacelab/Astro missions, the Ultraviolet Imaging Telescope (UIT) has obtained wide-field (40-arcmin), well-resolved (3 arcsec) images of similar to 50 nearby galaxies in the vacuum ultraviolet. Followup groundbased imaging at UBVRI and Ha bands has been completed for most of the well-resolved galaxies. Analysis of a small subset of these galaxies has revealed strong variations in the emission morphologies as a function of restframe wavelength. In the present study, we compare the UV morphologies of barred and unbarred spiral galaxies as a function of Hubble type and absolute luminosity. Radial extents are measured relative to their visible counterparts, and characteristic UV emission structures are identified (e.g. rings, tars, bi-symmetric hotspots, crooked-arms, etc). Morphological UV indicators for classifying the galaxies within the traditional Hubble sequence are explored. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Waller, WH (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 680, Greenbelt, MD 20771 USA. NR 0 TC 7 Z9 7 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 39 EP + PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900006 ER PT S AU Smith, DA Neff, SG Stecher, TP Smith, AM Bothun, G Fanelli, MN Offenberg, JD Waller, WH Bohlin, R O'Connell, RW Roberts, MS AF Smith, DA Neff, SG Stecher, TP Smith, AM Bothun, G Fanelli, MN Offenberg, JD Waller, WH Bohlin, R O'Connell, RW Roberts, MS BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Ultraviolet imaging of nearby starburst: NGC 3310 SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB Optical surveys for high-redshift (z similar to 2-5) star forming galaxies will preferentially identify UV-bright systems since the observed optical emission corresponds to the rest-frame UV. Studies of nearby UV-bright starbursts thus provide a unique opportunity to obtain a detailed understanding of the phenomena observed at high redshifts. We discuss the far-ultraviolet (FUV; lambda similar to 1500 Angstrom) properties of the nearby blue starburst galaxy NGC 3310. The FUV morphology is compared to that observed at longer wavelengths. The stellar content of selected star forming regions is also discussed. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Smith, DA (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 45 EP 49 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900007 ER PT S AU Cornett, RH Hollis, J Stecher, TP AF Cornett, RH Hollis, J Stecher, TP CA Ultraviolet Imaging Telescope Team BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Comparison of UV and H alpha morphologies in the Magellanic Clouds SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB Ultraviolet continuum and H alpha fluxes measure two critical spectral regions of the emission from hot stars in galaxies. Ha indirectly measures the Lyman continuum's ionizing flux, while the 1400 Angstrom-3200 Angstrom band, such as that imaged by the Ultraviolet Imaging Telescope (UIT), directly measures non-ionizing flux produced by O, B and A-type stars. The ratio of the two gives a "color" which is extremely sensitive to the age of the young stellar populations: model spectral energy distributions show that the ratio of Lyman continuum photon flux to the UIT 1520 Angstrom bandpass flux decreases monotonically by a factor of 100 during the first 10 Myr of cluster evolution. We compare the ultraviolet morphology of the Magellanic Clouds, from the UIT and a rocket-borne wide-field UIT predecessor, with H alpha morphology derived from the "Parking Lot Camera" images made by Bothun and Thompson (1988). In the LMC, the 30 Doradus region stands out as a region of large H alpha/UV sandwiched between two regions with much smaller H alpha/UV. The Shapley III constellation has UV-bright components (e.g the "fleur-de-lis") but very little Ha. In the SMC, evolutionary extremes are suggested by the UV-bright clusters NGC 330 (nearly H alpha-free) and NGC 346 (surrounded by a bright HII region). We present "color" images in the H alpha/UV ratio for the entire LMC and most of the SMC bar. We interpret the images, compare them with other data, and discuss their implications for recent star formation, on large and small scales, in the Magellanic Clouds. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Cornett, RH (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 55 EP 59 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900009 ER PT S AU Neff, SG Hollis, JE Hill, JK Fanelli, MN Smith, DA Smith, AM Stecher, TP Bohlin, RC O'Connell, RW Roberts, MS AF Neff, SG Hollis, JE Hill, JK Fanelli, MN Smith, DA Smith, AM Stecher, TP Bohlin, RC O'Connell, RW Roberts, MS BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Far-ultraviolet emission from NGC4038/4039, "the antennae": Massive star formation in compact clusters SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Meeting Abstract CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 60 EP + PG 2 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900010 ER PT S AU Fanelli, MN Marcum, PM Waller, WH Cornett, RH O'Connell, RW Roberts, MS Bohlin, R Neff, SG Smith, A Stecher, TP AF Fanelli, MN Marcum, PM Waller, WH Cornett, RH O'Connell, RW Roberts, MS Bohlin, R Neff, SG Smith, A Stecher, TP BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Spatially-resolved far-UV properties of disk galaxies SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB The Ultraviolet Imaging Telescope (UIT) has returned the first signifcant sample of ultraviolet imagery of galaxies combining a large field-of-view and spatial resolution comparable to ground-based observatories. During the Astro Spacelab missions, UIT obtained spatially-resolved far-UV (lambda lambda 1500 Angstrom) imagery of similar to 35 disk galaxies. We have utilized the FUV light profiles and morphology to characterize the high-mass stellar populations in these systems; A variety of radial light profiles are found, including two systems, NGC 4214 and NGC 3310, which exhibit R-1/4 profiles produced by their Population I stellar components. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Fanelli, MN (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 83 EP 87 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900013 ER PT S AU Lauroesch, JT Welty, DE Blades, JC Hobbs, LM York, DG AF Lauroesch, JT Welty, DE Blades, JC Hobbs, LM York, DG BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Interstellar abundances in the Magellanic Clouds - GHRS observations of the SMC star Sk108 SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB We present an analysis of HST GHRS echelle-B and G160M spectra of the O7 Ia + WN3 binary Sk 108 located in the Small Magellanic Cloud. We find that the relative gas-phase abundances (and inferred depletions) for Si II, Cr II: Mn II, Fe II, Ni II, and Zn II found for the SMC components along this line-of-sight are similar to those Found for interstellar clouds in the Galactic halo. We discuss some implications of these results for understanding the abundances found for QSO absorption-line systems, and conclude that both nucleosynthetic and depletion effects contribute to the observed abundances. C1 NASA, Goddard Space Flight Ctr, Natl Res Council, Greenbelt, MD 20771 USA. RP Lauroesch, JT (reprint author), NASA, Goddard Space Flight Ctr, Natl Res Council, Code 631, Greenbelt, MD 20771 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 144 EP 148 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900024 ER PT S AU Brown, TM Ferguson, HC Stanford, SA Deharveng, JM Davidsen, AF AF Brown, TM Ferguson, HC Stanford, SA Deharveng, JM Davidsen, AF BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Hot evolved stars in the centers of M 31 and M 32 SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB We present UV images of M 31 and M 32, as observed by HST with the refurbished FOG. The galaxies were observed through the F175W and F275W filters, allowing the construction of color magnitude diagrams (CMDs) for the hundreds of detected sources found in each image. Comparison of these data with the stellar evolutionary tracks of horizontal branch stars and their progeny shows that for the first time outside of our own Galaxy, we may be measuring the colors of individual stars that are evolving along post asymptotic giant branch (PAGE), post-early AGE, and AGB-Manque paths. Searching to the 6 sigma detection limit, we find 1349 stars in M 31 and 183 stars in M 32. We compare the distribution of stars in the CMDs with the expectations from theory. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Brown, TM (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 187 EP 191 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900030 ER PT S AU Hill, RS Gardner, JP Heap, SR Malumuth, EM Collins, NR AF Hill, RS Gardner, JP Heap, SR Malumuth, EM Collins, NR BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Galaxy number counts at 300nm from WFPC2 images SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB We have begun analyzing archival WFPC2 F300W images to obtain galaxy counts over a wider area and at brighter magnitudes than those measured in the Hubble Deep Field (HDF), and to develop techniques for analyzing future random-field data. Galaxy counts at 300 nm are sensitive to evolutionary effects on relatively short timescales. Locally, in galaxies with a constant star formation rate, F300W detects stars averaging similar to 500 Myr in age, as compared to similar to 1.6 Gyr for B. At a redshift of 0.5, F300W detects stars averaging similar to 60 Myr in age. In order to determine the galaxy counts, we have developed a semi-automated analysis based on the SExtractor program of Bertin. An IDL program parses input parameters, removes cosmic rays, and invokes SExtractor, which generates the source catalogs. Another IDL program merges selected data from the catalogs after applying photometric zero points and correcting for Galactic extinction. A preliminary comparison of our F300W number counts to those from the HDF will be presented. C1 NASA, Goddard Space Flight Ctr, Hughes STX Corp, Greenbelt, MD 20771 USA. RP Hill, RS (reprint author), NASA, Goddard Space Flight Ctr, Hughes STX Corp, Code 681, Greenbelt, MD 20771 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 247 EP 251 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900039 ER PT S AU Yi, SY AF Yi, SY BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI The impact of the UV upturn on the optical color evolution of E galaxies SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB The UV upturn in giant elliptical galaxies (gEs) implies significant. corrections to the model-predicted optical colors of distant galaxies. However, since the origin of the UV upturn is still not clear, observers often use models that may not be acceptable. We show that "the HE hypothesis" of Yi et al. (1997) that explains most of the empirical constrains predicts a significantly different optical color evolution from some popular models. We fan test this model against others using modern data. Meanwhile: it seems dangerous to draw serious conclusions on cosmology when the analysis is based on oversimplified models, such as k-correction-only models or k+e correction models that do not explain the UV upturn. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Yi, SY (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 681, Greenbelt, MD 20771 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 258 EP 263 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900041 ER PT S AU Heap, SR AF Heap, SR BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI HST spectroscopy of Q0302-003 SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB The Goddard High Resolution Spectrograph (GHRS) has obtained spectra of QSO 0302-003 in an effort to detect and measure He II Ly alpha absorp??? tion from the diffuse intergalactic medium and/or discrete clouds. The strong observed absorption - even in the "Dobrzycki-Bechtold void" - suggests that at least some of it originates in the diffuse gas. Future observations with the newly installed Space Telescope Imaging Spectrograph (STIS) on HST, and possibly with the Cosmic Origins Spectrograph (COS), an instrument recently proposed to NASA for installation on HST in 2002, should separate decisively the cloud and inter-cloud contributions. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Heap, SR (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt 681, Greenbelt, MD 20771 USA. RI heap, sara/E-2237-2012 NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 329 EP 333 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900049 ER PT S AU Varosi, F Dwek, E AF Varosi, F Dwek, E BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Radiative transfer in clumpy and fractal media SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB A Monte Carlo model of radiative transfer in multi-phase dusty media is applied to the situation of stars and clumpy dust in a sphere or a disk. The distribution of escaping and absorbed photons are shown for a range of clump filling factors and densities. Analytical methods of approximating the escaping fraction of radiation, based on the Mega-Grains approach [4], are discussed. Comparison with the Monte Carlo results shows that the escape probability formulae provide a reasonable approximation of the escaping/absorbed fractions, for a wide range of parameters characterizing the clumpy dusty medium. A possibly more realistic model of the interstellar medium is one in which clouds have a hierarchical structure of denser and denser clumps within clumps [2], resulting in a fractal distribution of gas and dust. Monte Carlo simulations of radiative transfer in such multi-phase fractal media are compared with the two-phase clumpy case. C1 NASA, Goddard Space Flight Ctr, Infrared Astrophys Branch, Greenbelt, MD 20771 USA. RP Varosi, F (reprint author), NASA, Goddard Space Flight Ctr, Infrared Astrophys Branch, Code 685, Greenbelt, MD 20771 USA. NR 0 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 370 EP + PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900056 ER PT S AU Borne, KD Bushouse, H Colina, L Lucas, RA AF Borne, KD Bushouse, H Colina, L Lucas, RA BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Morphological similarities between HDF and ultraluminous IR galaxies SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB High-resolution HST images of galaxies in the Hubble Deep Field (HDF) reveal a striking morphological similarity to HST images of the ultraluminous IR galaxies (ULIRGs). The HDF images typically represent high-redshift galaxies observed in the rest-frame UV, whereas the ULIRG images represent low-to-moderate-redshift galaxies observed in the rest-frame I-band. It is likely that many of the HDF galaxies are high-redshift counterparts of the low-redshift ULIRGs. The overwhelming majority of the ULIRGs are strongly disturbed, starbursting systems that owe their extraordinarily peculiar morphologies and intense star formation rates to recent tidal interaction/merger events. Some of the HDF galaxies may in fact be of this type. However, results from other groups have now revealed similar peculiar morphologies in the rest-frame UV of optically normal nearby galaxies. Comparisons between the ULIRGs and the HDF galaxies therefore require further analysis of the UV morphologies of local galaxies before a tidal/starburst origin can be conclusively ascribed to the HDF galaxies. C1 NASA, GSFC, Hughes STX, Greenbelt, MD 20771 USA. RP Borne, KD (reprint author), NASA, GSFC, Hughes STX, Greenbelt, MD 20771 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 423 EP + PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900065 ER PT S AU Gardner, JP Heap, SR Malumuth, EM Hill, RS Smith, EP AF Gardner, JP Heap, SR Malumuth, EM Hill, RS Smith, EP BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Morphological evolution of galaxies SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB Recent studies of the Hubble Deep Field (Abraham et al. 1996) [1] and Medium Deep Survey (Driver, Windhorst & Griffiths 1995) [6] find that the frequency of irregular/peculiar/merger systems rises with increasing redshift. However, this finding must be carefully interpreted in light of UV images of low-redshift galaxies obtained by the Ultraviolet Imaging Telescope (Stecher et al. 1992) [9]. These UV images imply that K-correction effects may be at least partially responsible for the apparent increase in Irr galaxies with redshift. To assess the degree to which there is an overabundance of Irregular galaxies (relative to the present epoch), we must understand the degree to which the K-correction biases morphological studies. We demonstrate the importance of the morphological K-correction to the classification schemes used in the HDF. We find that high-redshift spiral galaxies are misclassified as Irr galaxies, while Elliptical/SO galaxies, should not be affected substantially. We have been granted 40 orbits in Cycle 7 with STIS to place these conclusions on a statistical basis. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Gardner, JP (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 681, Greenbelt, MD 20771 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 429 EP 433 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900066 ER PT S AU Smith, AM Collins, NR Waller, WH Fanelli, MN Stecher, TP AF Smith, AM Collins, NR Waller, WH Fanelli, MN Stecher, TP CA Ultraviolet Imaging Telescope Team BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Edge-on galaxies at ultraviolet wavelengths SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB Recent rest-frame ultraviolet imaging of galaxies at apparently high redshift have revealed a population of very blue galaxies with aspect ratios approaching 30 which have been interpreted to be chains of star formation regions in the initial stages of galaxy formation [1]. We compare these optical observations with rest-frame far-ultraviolet observations of nearby edge-on galaxies with a view to illustrating their noteworthy simularities. For the comparison we use far ultraviolet (FUV) images of NGC 253 (SAB(s)c), NGC 891 (SA(s)b), NGC 3034 (M82) (IO), NGC 4248 (IO), UGC 6697 (Im),and NGC 4631 (SB(s)d) which were recorded by the Ultraviolet Imaging Telescope. We focus primarily on NGC 4631, 7.5 Mpc distant, which in the FUV exhibits a linear beaded structure, an axial ratio of similar to 24 and a (lambda 1520 Angstrom)-U color of -0.70. At z approximate to 1.9 (lambda lambda 1520 Angstrom)-U would approximate (B-I) and would appear to be very blue. NGC 4248 and UGC 6697 are additional examples of edge-on galaxies which give the appearance of "chain galaxies" in the far ultraviolet. NGC 891 and NGC 253 illustrate a variation on the theme. These galaxies were barely detectable at lambda lambda 2500 Angstrom, very likely due to extinction. However, their linear morphology is clearly shown. The small starburst galaxy M82 is not completely linear, but would be seen as a very blue object at faint magnitudes. Our conclusion is that at least a portion of the faint blue objects seen at redshifts between 0.5 and 3 are not exotic objects, but are galaxies with familiar morphologies seen in the rest-frame ultraviolet. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Smith, AM (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 439 EP 443 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900068 ER PT S AU Mather, JC Smith, EP Seery, BD Bely, PY Stiavelli, M Stockman, HS Burg, R AF Mather, JC Smith, EP Seery, BD Bely, PY Stiavelli, M Stockman, HS Burg, R BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Redshifted UV astronomy with The next generation space telescope SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB The Next Generation Space Telescope, as currently conceived, will have an aperture > 4 m and will be optimized for observations in the near infrared, 1 - 5 mu m for studies of the origins of stars and galaxies at high redshift z. Its scientific charter comes from the HST and Beyond report (1996). Initial study results by three engineering teams show that a telescope of aperture up to 8 m could be launched by 2007 with a construction phase budget of $500 M, providing that adequate technology development is done prior to the start around 2003. The telescope would be placed far from Earth, at the Lagrange point L2 or beyond, allowing radiative cooling of the telescope to 30 - 80 K. It would use hundreds to thousands of optical adjustments to achieve the required figure accuracy. The instrument package would include wide field cameras and multiobject spectrometers for the core scientific program. Extension of the wavelength range to cover at least 0.5 to 20 mu m is highly desirable. Detectors for 0.5 to 5 mu m could be InSb, while the 5 - 10 mu m range can be covered by HgCdTe and the 5-25 mu m range can be covered with Si:As. With these concepts, the sensitivity achieved would be in the nanojansky range; 1 nJy = 31.4 magnitudes on the AB, scale. Supernovae and star forming regions of early globular clusters and galactic centers could be seen to redshifts of 10 or more. Such a telescope would also be a powerful tool in the study of planet and star formation, circumstellar disks, and the planets, satellites, asteroids, comets, and Kuiper belt objects in our own Solar system. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mather, JC (reprint author), NASA, Goddard Space Flight Ctr, Code 685, Greenbelt, MD 20771 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 467 EP 477 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900072 ER PT S AU Smith, EP Mather, J Bely, P Koratkar, A Stiavelli, M Stockman, HSP AF Smith, EP Mather, J Bely, P Koratkar, A Stiavelli, M Stockman, HSP BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI The next generation space telescope design reference mission SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB We review the Next Generation Space Telescope (NGST) design reference mission (DRM). The NGST DRM contains the scientific goals of the observatory and consists of primary and secondary targets and their characteristics. The purpose of the DRM is to establish a metric against which cost/capability trades, instrumental configurations, and operational scenarios fan be tested. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Smith, EP (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 681, Greenbelt, MD 20771 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 478 EP 482 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900073 ER PT S AU Bowers, C Woodgate, B Kimble, R Kaiser, M Kraemer, S Gull, T Heap, S Danks, A Lindler, D Plait, P Beck, T Baum, S Bohlin, R Ferguson, H Hartig, G Hulbert, S AF Bowers, C Woodgate, B Kimble, R Kaiser, M Kraemer, S Gull, T Heap, S Danks, A Lindler, D Plait, P Beck, T Baum, S Bohlin, R Ferguson, H Hartig, G Hulbert, S CA STIS Sci Team BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI Performance of the space telescope imaging spectrograph SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron AB The Space Telescope Imaging Spectrograph (STIS) was installed aboard the Hubble Space Telescope (HST) in February, 1997. STIS operates from the ultraviolet to the near infrared (115-1000 nm) in a variety of spectroscopic and imaging modes. Orbital characterization of STIS performance is currently underway and some of the initial results are presented here. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Bowers, C (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 680, Greenbelt, MD 20771 USA. RI heap, sara/E-2237-2012; Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 483 EP 492 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900074 ER PT S AU Heap, SR AF Heap, SR CA COS Team BE Waller, WH Fanelli, MN Hollis, JE Danks, AC TI New for HST 2002: The cosmic origins spectrograph SO ULTRAVIOLET UNIVERSE AT LOW AND HIGH REDSHIFT: PROBING THE PROGRESS OF GALAXY EVOLUTION SE AIP CONFERENCE PROCEEDINGS LA English DT Meeting Abstract CT Conference on Ultraviolet Universe at Low and High Redshift - Probing the Progress of Galaxy Evolution CY MAY 02-04, 1997 CL COLLEGE PK, MD SP Hughes STX Corp, Ctr Astron & Space Phys, NASA Goddard Space Flight Ctr, Lab Astron & Solar Phys, Univ Maryland, Dept Astron C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Heap, SR (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RI heap, sara/E-2237-2012 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 1-56396-708-1 J9 AIP CONF PROC PY 1997 VL 408 BP 497 EP 497 PG 1 WC Engineering, Aerospace; Astronomy & Astrophysics SC Engineering; Astronomy & Astrophysics GA BK19P UT WOS:000071461900076 ER PT B AU Lulla, KP AF Lulla, KP GP ASPRS ASPRS TI International space station: New opportunities for developing databases of color photography and videography SO VIDEOGRAPHY AND COLOR PHOTOGRAPHY IN RESOURCE ASSESSMENT LA English DT Proceedings Paper CT 16th Biennial Workshop on Videography and Color Photography in Resource Assessment CY APR 29-MAY 01, 1997 CL WESLACO, TX SP Amer Soc Photogrammetry & Remote Sensing, USDA Subtrop Agr Res Lab AB The advent of the International Space Station (ISS) provides an opportunity to remote sensing and GIS community to build and expand the capabilities of conventional color photography and videography. The ISS will include a nadir-viewing, optical quality window located in the United States Laboratory of ISS. Through this window earth observations image data will be collected as color photographs and video coverage. An overview of the ISS remote sensing capabilities and integration of this data with the existing databases, and spatial technologies of GIS are the objectives of this paper. The opportunities to participate in the International Space Station Earth observations and imaging activities are highlighted. C1 NASA, Lyndon B Johnson Space Ctr, Earth Sci Branch, Houston, TX 77058 USA. RP Lulla, KP (reprint author), NASA, Lyndon B Johnson Space Ctr, Earth Sci Branch, Houston, TX 77058 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC PHOTOGRAMMETRY & REMOTE SENSING PI BETHESDA PA 5410 GROSVENOR LAND, SUITE 210, BETHESDA, MD 20814-2160 USA BN 1-57083-050-9 PY 1997 BP 1 EP 6 PG 6 WC Agronomy; Forestry; Remote Sensing SC Agriculture; Forestry; Remote Sensing GA BM62X UT WOS:000079306700001 ER PT B AU Burner, AW Radeztsky, RH Liu, TS AF Burner, AW Radeztsky, RH Liu, TS BE ElHakim, SF TI Videometric applications in wind tunnels SO VIDEOMETRICS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE 5th Conference on Videometrics CY JUL 30-31, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE wind tunnels; angle measurements; displacement measurements; photogrammetry; model deformation; angle-of-attack; twist measurements; bending measurements; sting bending AB Videometric measurements in wind tunnels can be very challenging due to the limited optical access, model dynamics, optical path variability during testing large range of temperature and pressure, hostile environment and the requirements for high productivity and large amounts of data on a daily basis. Other complications for wind tunnel testing include the model support mechanism and stringent surface finish requirements for the models in order to maintain aerodynamic fidelity. For these reasons nontraditional photogrammetric techniques and procedures sometimes must be employed. In this paper several such applications are discussed for wind tunnels which include test conditions with Mach numbers from low speed to hypersonic, pressures from less than an atmosphere to nearly seven atmospheres, and temperatures from cryogenic to above room temperature. Several of the wind tunnel facilities are continuous flow while one is a short duration blow-down facility. Videometric techniques and calibration procedures developed to measure angle of attack the change in wing twist and bending induced by aerodynamic load and the effects of varying model injection rates are described. Some advantages and disadvantages of these techniques are given and comparisons are made with non-optical and more traditional video photogrammetric techniques. RP Burner, AW (reprint author), NASA,LANGLEY RES CTR,MS 236,HAMPTON,VA 23681, USA. NR 0 TC 8 Z9 8 U1 0 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2596-6 J9 P SOC PHOTO-OPT INS PY 1997 VL 3174 BP 234 EP 247 DI 10.1117/12.279785 PG 4 WC Computer Science, Artificial Intelligence; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Computer Science; Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BJ22E UT WOS:A1997BJ22E00023 ER PT B AU Cox, M Ellsworth, D AF Cox, M Ellsworth, D BE Yagel, R Hagen, H TI Application-controlled demand paging for out-of-core visualization SO VISUALIZATION '97 - PROCEEDINGS LA English DT Proceedings Paper CT 8th Annual IEEE Conference on Visualization CY OCT 19-24, 1997 CL PHOENIX, AZ SP IEEE Comp Soc, Tech Comm Comp Graph, ACM, SIGGRAPH DE computational fluid dynamics; visualization; out-of-core visualization AB In the area of scientific visualization, input data sets are often very large. In visualization of Computational Fluid Dynamics (CFD) in particular, input data sets today can surpass 100 Gbytes, and are expected to scale with the ability of supercomputers to generate them. Some visualization tools already partition large data sets into segments, and load appropriate segments as they are needed. However, this does not remove the problem for two reasons: 1) there are data sets for which even the individual segments are too large for the largest graphics workstations, 2) many practitioners do not have access to workstations with the memory capacity required to load even a segment, especially since the state-of-the-art visualization tools tend to be developed by researchers with much more powerful machines. When the size of the data that must be accessed is larger than the size of memory, some form of virtual memory is simply required. This may be by segmentation, paging, or by paged segments. In this paper we demonstrate that complete reliance on operating system virtual memory for out-of-core visualization leads to egregious performance. We then describe a paged segment system that we have implemented, and explore the principles of memory management that can be employed by the application for out-of-core visualization. We show that application control over some of these can significantly improve performance. We show that sparse traversal can be exploited by loading only those data actually required. We show also that application control over data loading can be exploited by 1) loading data from alternative storage format tin particular 3-dimensional data stored in subcubes), 2) controlling the page size. Both of these techniques effectively reduce the total memory required by visualization at run-time. We also describe experiments we have done on remote out-of-core visualization (when pages are read by demand from remote disk) whose results are promising. C1 Intel Corp, NASA, Ames Res Ctr, MRJ,Microcomp Res Labs, Santa Clara, CA 95051 USA. RP Cox, M (reprint author), Intel Corp, NASA, Ames Res Ctr, MRJ,Microcomp Res Labs, Santa Clara, CA 95051 USA. NR 0 TC 56 Z9 58 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 1-58113-011-2 PY 1997 BP 235 EP + DI 10.1109/VISUAL.1997.663888 PG 11 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Optics SC Computer Science; Optics GA BK72H UT WOS:000073211800029 ER PT B AU Ma, KL Interrante, V AF Ma, KL Interrante, V BE Yagel, R Hagen, H TI Extracting feature lines from 3D unstructured grids SO VISUALIZATION '97 - PROCEEDINGS LA English DT Proceedings Paper CT 8th Annual IEEE Conference on Visualization CY OCT 19-24, 1997 CL PHOENIX, AZ SP IEEE Comp Soc, Tech Comm Comp Graph, ACM, SIGGRAPH AB This paper discusses techniques for extracting feature lines from three-dimensional unstructured grids. Our twin objectives are to facilitate the interactive manipulation of these typically very large and dense meshes, and to clarify the visualization of the solution data that accompanies them. We describe the perceptual importance of specific viewpoint-dependent and view-independent features, discuss the relative advantages and disadvantages of several alternative algorithms for identifying these features (taking into consideration both local and global criteria), and demonstrate the results of these methods on a variety of different data sets. C1 NASA, Langley Res Ctr, Inst Comp Appl Sci & Engn, Hampton, VA 23681 USA. RP Ma, KL (reprint author), NASA, Langley Res Ctr, Inst Comp Appl Sci & Engn, Hampton, VA 23681 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 1-58113-011-2 PY 1997 BP 285 EP + DI 10.1109/VISUAL.1997.663894 PG 9 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Optics SC Computer Science; Optics GA BK72H UT WOS:000073211800035 ER PT B AU Shen, HW Kao, DL AF Shen, HW Kao, DL BE Yagel, R Hagen, H TI UFLIC: A line integral convolution algorithm for visualizing unsteady flows SO VISUALIZATION '97 - PROCEEDINGS LA English DT Proceedings Paper CT 8th Annual IEEE Conference on Visualization CY OCT 19-24, 1997 CL PHOENIX, AZ SP IEEE Comp Soc, Tech Comm Comp Graph, ACM, SIGGRAPH DE flow visualization; vector field visualization; image convolution; line integral convolution; flow animation; unsteady flows; surface flows; texture synthesis AB This paper presents an algorithm, UFLIC (Unsteady Flow LIC), to visualize vector data in unsteady flow fields. Using the Line Integral Convolution (LIC) as the underlying method, a new convolution algorithm is proposed that can effectively trace the flow's global features over time. The new algorithm consists of a time-accurate value depositing scheme and a successive feed-forward method. The value depositing scheme accurately models the flow advection, and the successive feed-forward method maintains the coherence between animation frames. Our new algorithm can produce time-accurate, highly coherent flow animations to highlight global features in unsteady flow fields. CFD scientists, for the first time, are able to visualize unsteady surface flows using our algorithm. C1 NASA, Ames Res Ctr, MRJ Technol Solut, Moffett Field, CA 94035 USA. RP Shen, HW (reprint author), NASA, Ames Res Ctr, MRJ Technol Solut, Mail Stop T27A-2, Moffett Field, CA 94035 USA. NR 0 TC 1 Z9 3 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 1-58113-011-2 PY 1997 BP 317 EP + DI 10.1109/VISUAL.1997.663898 PG 7 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Optics SC Computer Science; Optics GA BK72H UT WOS:000073211800039 ER PT B AU Kenwright, D Haimes, R AF Kenwright, D Haimes, R BE Yagel, R Hagen, H TI Vortex identification - Applications in aerodynamics: A case study SO VISUALIZATION '97 - PROCEEDINGS LA English DT Proceedings Paper CT 8th Annual IEEE Conference on Visualization CY OCT 19-24, 1997 CL PHOENIX, AZ SP IEEE Comp Soc, Tech Comm Comp Graph, ACM, SIGGRAPH AB An eigenvector method for vortex identification [1] has been applied to recent numerical and experimental studies in external flow aerodynamics. It is shown to be an effective way to extract and visualize features such as vortex cores, spiral vortex breakdowns, vortex bursting, and vortex diffusion. Several problems are reported and illustrated in the accompanying video. These include: disjointed line segments, detecting non-vortical flow features, and vortex core displacement. Future research and applications are discussed, such as using vortex cores to guide automatic grid refinement. C1 NASA, Ames Res Ctr, MRJ Technol Solut Inc, Moffett Field, CA 94035 USA. RP Kenwright, D (reprint author), NASA, Ames Res Ctr, MRJ Technol Solut Inc, Mail Stop T27A-2, Moffett Field, CA 94035 USA. NR 0 TC 15 Z9 16 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 1-58113-011-2 PY 1997 BP 413 EP + DI 10.1109/VISUAL.1997.663910 PG 5 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Optics SC Computer Science; Optics GA BK72H UT WOS:000073211800051 ER PT B AU Uselton, SP AF Uselton, SP BE Yagel, R Hagen, H TI exVis: Developing a wind tunnel data visualization tool SO VISUALIZATION '97 - PROCEEDINGS LA English DT Proceedings Paper CT 8th Annual IEEE Conference on Visualization CY OCT 19-24, 1997 CL PHOENIX, AZ SP IEEE Comp Soc, Tech Comm Comp Graph, ACM, SIGGRAPH AB Software has been developed to apply visualization techniques to aeronautics data collected during wind tunnel experiments. Interaction between the software developers and the aeroscientists has been crucial in making the software useful to these particular users. The interaction has also been important in building the scientists' confidence in the use of interactive, computer-mediated analysis tools. C1 NASA, Ames Res Ctr, MRJ Technol Solut, Moffett Field, CA 94035 USA. RP Uselton, SP (reprint author), NASA, Ames Res Ctr, MRJ Technol Solut, MS T27A-1, Moffett Field, CA 94035 USA. NR 0 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 1-58113-011-2 PY 1997 BP 417 EP + DI 10.1109/VISUAL.1997.663911 PG 5 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Optics SC Computer Science; Optics GA BK72H UT WOS:000073211800052 ER PT B AU Cox, M Crawfis, R Hamann, B Hansen, C Miller, M AF Cox, M Crawfis, R Hamann, B Hansen, C Miller, M BE Yagel, R Hagen, H TI Terascale visualization: Approaches, pitfalls and issues SO VISUALIZATION '97 - PROCEEDINGS LA English DT Proceedings Paper CT 8th Annual IEEE Conference on Visualization CY OCT 19-24, 1997 CL PHOENIX, AZ SP IEEE Comp Soc, Tech Comm Comp Graph, ACM, SIGGRAPH C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Cox, M (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 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 1-58113-011-2 PY 1997 BP 507 EP 509 PG 3 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Optics SC Computer Science; Optics GA BK72H UT WOS:000073211800073 ER PT J AU Braidich, DJ Puzak, RM AF Braidich, DJ Puzak, RM TI Inadequate fire protection leads NASA center to implement repair program SO WATER-ENGINEERING & MANAGEMENT LA English DT Article C1 NASA,PLUM BROOK STN,SANDUSKY,OH. RP Braidich, DJ (reprint author), NASA,LEWIS RES CTR,FACIL ENGN DIV,CLEVELAND,OH 44135, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SCRANTON GILLETTE COMMUNICATIONS INC PI DES PLAINES PA 380 NORTHWEST HIGHWAY, DES PLAINES, IL 60016 SN 0273-2238 J9 WATER ENG MANAG JI Water Eng. Manage. PD JAN PY 1997 VL 144 IS 1 BP 18 EP 21 PG 4 WC Engineering, Environmental; Water Resources SC Engineering; Water Resources GA WD600 UT WOS:A1997WD60000010 ER PT J AU Koenig, DW Pierson, DL AF Koenig, DW Pierson, DL TI Microbiology of the space shuttle water system SO WATER SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 8th Symposium of the Health-Related-Water-Microbiology-Group of the IAWQ CY OCT, 1996 CL MALLORCA, SPAIN SP IAWQ, Hlth Related Water Microbiol Grp DE spacecraft; potable water; biofilm; Burkholderia cepacia; microbiology ID BACTERIA AB The Space Shuttle has a once-through water system that is initially filled on the ground, partially drained before launch and then refilled with fuel-cell generated water on orbit. The microbiological standard for the Space Shuttle potable water system during this study period allowed only I microbe of any kind per 100mL and no detectable coliforms. Contamination episodes in more than 15 years of Shuttle operation have been rare; however, for the past 24 missions, bacterial contamination has been detected in 33% of the samples collected 3d before launch. These samples have had on average 55CFU/100mL of bacteria, with the median less than ICFU/100mL. Burkholderia cepacia has been the primary contaminant of the Shuttle water supply system both before and after flight. Water samples assessed during the STS-7G mission aboard the Space Shuttle Discovery were found to be contaminated (<20CFU/100mL) with B. cepacia and B. pickettii. In 1991, waste and water lines were removed from the Space Shuttle Columbia and the waste lines were found to harbor biofilms containing Bacillus spp. Nevertheless, the water systems of the four Space Shuttle vehicles provide extremely pure water. (C) 1997 IAWQ. Published by Elsevier Science Ltd. C1 NASA,LYNDON B JOHNSON SPACE CTR,BIOMED OPERAT & RES BRANCH,HOUSTON,TX 77058. RP Koenig, DW (reprint author), NASA,LYNDON B JOHNSON SPACE CTR,KRUG LIFE SCI,MAIL CODE SD4,HOUSTON,TX 77058, USA. NR 11 TC 33 Z9 33 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0273-1223 J9 WATER SCI TECHNOL JI Water Sci. Technol. PY 1997 VL 35 IS 11-12 BP 59 EP 64 DI 10.1016/S0273-1223(97)00235-7 PG 6 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA XV495 UT WOS:A1997XV49500012 PM 11540417 ER PT S AU van Zyl, JJ AF van Zyl, JJ BE Mott, H Boerner, WM TI Overview of SAR polarimetry and interferometry SO WIDEBAND INTERFEROMETRIC SENSING AND IMAGING POLARIMETRY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wideband Interferometric Sensing and Imaging Polarimetry CY JUL 28-29, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers DE SAR; polarimetry; interferometry; calibration AB This paper summarizes the recent work in the fields of Synthetic Aperture Radar (SAR) polarimetry and interferometry. These fields have seen very significant development during the last five years, and these fields are now well understood. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP van Zyl, JJ (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 SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2542-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 3120 BP 16 EP 27 DI 10.1117/12.300619 PG 12 WC Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BK25W UT WOS:000071632400003 ER PT S AU Freeman, A Saatchi, SS AF Freeman, A Saatchi, SS BE Mott, H Boerner, WM TI The effects of Faraday rotation on backscatter signatures in SAR image data SO WIDEBAND INTERFEROMETRIC SENSING AND IMAGING POLARIMETRY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Wideband Interferometric Sensing and Imaging Polarimetry CY JUL 28-29, 1997 CL SAN DIEGO, CA SP Soc Photo Opt Instrumentat Engineers AB The effect of Faraday rotation on spaceborne polarimetric SAR measurements is addressed. Single-polarized, dual-polarized and quad-polarized backscatter measurements subject to Faraday rotation are modeled. It is shown that due to Faraday rotation, the received signal includes other polarization characteristics of the surface. Techniques are developed to detect the presence of Faraday rotation in dual-polarized and quad-polarized SAR data. Finally, a novel approach for the correction (or calibration) of linearly polarized fully polarimetric data for Faraday rotation, to recover the 'true' scattering matrix, is presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Freeman, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 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 0-8194-2542-7 J9 P SOC PHOTO-OPT INS PY 1997 VL 3120 BP 37 EP 44 DI 10.1117/12.300633 PG 8 WC Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BK25W UT WOS:000071632400005 ER EF