FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Kory, CL Dayton, JA AF Kory, CL Dayton, JA TI Computational investigation of helical traveling wave tube transverse RF field forces SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE helix; MAFIA; RF defocusing; TWT AB Electron beam focusing structures are typically designed using beam optics codes primarily based on balancing radial space charge forces from the electron beam, neglecting RF field forces from the slow-wave circuit. The RF field forces of a helical traveling wave tube (TWT) have been calculated using an accurate three-dimensional (3-D) cold-test (no electron beam present) circuit model [1] and compared to radial space charge forces to determine their relative significance on electron beam behavior. The forces due to radial, azimuthal and axial RF electric fields at the tube output reach 61, 26, and 132% of radial space charge forces, respectively, at 26 GHz for the device studied. This effect is expected to increase with increased frequency and beam diameter. These results indicate that the RF fields are comparable in magnitude to the focusing fields and have a significant effect on electron beam behavior; their implementation into the beam-focusing design could significantly improve beam transmission near the output of the tube. C1 NASA, Lewis Res Ctr, ANALEX Corp, Cleveland, OH 44135 USA. Hughes Telecomm & Space Co, Electron Dynam Div, Torrance, CA 90509 USA. RP Kory, CL (reprint author), NASA, Lewis Res Ctr, ANALEX Corp, Cleveland, OH 44135 USA. NR 17 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD JAN PY 2000 VL 47 IS 1 BP 253 EP 256 DI 10.1109/16.817593 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 273QF UT WOS:000084717800033 ER PT J AU Yueh, SH West, R Li, FK Tsai, WY Lay, R AF Yueh, SH West, R Li, FK Tsai, WY Lay, R TI Dual-polarized Ku-band backscatter signatures of hurricane ocean winds SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID WAVE-NUMBER SPECTRA; RADAR; MODEL; SEA; SCATTEROMETRY; SYSTEM AB The Ku-band dual-polarized backscatter signatures of ocean surfaces are described in this paper with the airborne scatterometer measurements collected in the Hurricane Ocean Wind Experiment:in September 1997, The data collected from flights over:Hurricane Erika provide a direct evidence that there are wind direction signals in the vertically and horizontally polarized Ku-band backscatter of ocean surfaces under the influence of hurricane-force winds. At 46 degrees incidence angle, the vertically polarized backscatter acquired at the upwind direction increases by about I dB as the wind speed increases from 22 m.s(-1) to 35 m.s(-1), while the horizontally polarized backscatter appears to he twice as sensitive with a change of about 2 dB. At 35 m.s(-1) wind speeds, the difference between upwind and crosswind observations of vertically polarized backscatter is about 1.5 dB, smaller than the 2 dB difference for the horizontally polarized backscatter. This demonstrates that the horizontal polarization has a greater sensitivity to wind speed and direction than the vertical polarization in the high wind regime. The data also suggest that the upwind and downwind asymmetry of Ku-band backscatter decreases with increasing wind speed and can fall below 0 dB at small incidence-angles (<35 degrees) for the vertical polarization. A combined interaction of the geometric optics scattering and the short wave modulation by long waves is proposed to interpret this phenomenonn and appears to agree with the dependence of the signature on incidence, wind speed, and polarization. The aircraft flight data-support the feasibility of dual-polarized Ku-band radar for hurricane ocean wind measurements, although the data do suggest a reduced wind speed and direction sensitivity in the high wind regime. Also, the differing polarization backscatter signatures suggest the relative contributions of various surface scattering mechanisms. An improved Ku-band GMF is described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yueh, SH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 25 TC 18 Z9 19 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2000 VL 38 IS 1 BP 73 EP 88 DI 10.1109/36.823903 PN 1 PG 16 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 283XF UT WOS:000085300800008 ER PT J AU Spencer, MW Wu, CL Long, DG AF Spencer, MW Wu, CL Long, DG TI Improved resolution backscatter measurements with the SeaWinds pencil-beam scatterometer SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE radar; scatterometry; sea winds ID SPACEBORNE; INSTRUMENT; SATELLITE AB The SeaWinds scatterometer was launched on the NASA QuikSCAT spacecraft in June 1999 and is planned for the Japanese ADEOS-II mission in 2000. In addition to generating a global Ku-band backscatter data set useful for a variety of climate studies, these flights will provide ocean-surface wind estimates for use in operational weather forecasting. SeaWinds employs a compact " pencil-beam " design rather than the "fan-beam" approach previously used with SASS on Seasat, NSCAT on ADEOS-I, and the AMI scatterometer on ERS-1, 2, As originally envisioned and reported, the resolution of the SeaWinds backscatter measurements were to be antenna-beamwidth limited. In order to satisfy an emerging demand for higher resolution backscatter data, however, the SeaWinds signal-processing design has been significantly modified. Here, the various options considered for improving the resolution of the SeaWinds measurements are discussed, and the selected:hardware modification (the addition of deramp processing for range discrimination) is described. The radar equation specific to a rotating pencil-beam scatterometer with digital range filtering is developed, and the new challenges associated with calibrating the resulting improved resolution measurements are discussed. A formulation for assessing the variance of the measurements due to fading and thermal noise is presented. Finally, the utility of improved resolution SeaWinds measurements for land and ice studies is demonstrated by simulated enhanced-resolution imaging of a synthetic Earth backscatter scene. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Brigham Young Univ, Dept Elect & Comp Engn, Provo, UT 84602 USA. RP Spencer, MW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 23 TC 116 Z9 124 U1 4 U2 15 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2000 VL 38 IS 1 BP 89 EP 104 DI 10.1109/36.823904 PN 1 PG 16 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 283XF UT WOS:000085300800009 ER PT J AU Barnet, CD Blaisdell, JM Susskind, J AF Barnet, CD Blaisdell, JM Susskind, J TI Practical methods for rapid and accurate computation of interferometric spectra for remote sensing applications SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE convolution; cosine transforms; digital filters; discrete cosine transforms; optical interferometry; optical transfer functions; remote sensing; satellite applications ID SOUNDING DATA; TRANSMITTANCE AB The apodization of an interferogram corresponds to a linear transformation in spectral space between unapodized and apodized radiances. Many apodization functions have well-behaved numerical inverse transformations, and we show an analytic inverse for the Hamming apodization function. The inverse transformation has many practical uses for remote sensing; applications and can also be used theoretically to show the equivalence between unapodized spectra and properly apodized spectra. The inverse transformation, which is a representation of the discrete convolution theorem, can be used to readily convert computed apodized spectra to spectra computed for other symmetric apodization functions (including unapodized), which may have poorer characteristics with regard to calculating channel-transmittance parameters or radiances. We also show a quantitative method for comparing apodization functions of different mathematical forms. C1 Gen Sci Corp, Sci Applicat Int Corp, Beltsville, MD 20705 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Barnet, CD (reprint author), Gen Sci Corp, Sci Applicat Int Corp, Beltsville, MD 20705 USA. RI Barnet, Christopher/F-5573-2010 NR 21 TC 18 Z9 18 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2000 VL 38 IS 1 BP 169 EP 183 DI 10.1109/36.823910 PN 1 PG 15 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 283XF UT WOS:000085300800015 ER PT J AU Wang, MH Franz, BA AF Wang, MH Franz, BA TI Comparing the ocean color measurements between MOS and SeaWiFS: A vicarious intercalibration approach for MOS SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE atmospheric correction; ocean color; remote sensing; vicarious calibration ID WATER-LEAVING RADIANCE; ATMOSPHERIC CORRECTION; ALGORITHM; IMAGERY; SENSORS AB The modular optoelectronic scanner (MOS) is a German instrument that was launched in the spring of 1996 on the Indian IRS-P3 satellite. With the successful launch of NASA's Sea-viewing Wide Field-of-view Sensor (SeaWiFS) in the summer of 1997, there are non two ocean color missions in concurrent operation, and there is interest within the scientific community to compare data from these two sensors. In this paper, we describe our efforts to retrieve ocean-optical properties from both SeaWiFS and MOS using consistent methods. We first briefly review the atmospheric correction, which removes more than 90% of the observed radiances in the visible, and then we describe how the atmospheric-correction algorithm used for the SeaWiFS data can be modified for application to other ocean color sensors. Next, since the retrieved water-leaving radiances in the visible between MOS and SeaWiFS are significantly different, we developed a vicarious intercalibration method to recalibrate the MOS spectral bands based on the optical properties of the ocean and atmosphere derived from the coincident SeaWiFS measurements. Furthermore, because of the strange calibration behavior of the MOS 750 nm band, we modified the atmospheric correction such that the MOS 685 and 868 nm bands can also be used. We present and discuss the MOS-retrieved, ocean-optical properties before and after the vicarious calibration using both the MOS 685 and 750 nm coupled with 868 nm bands in comparison with results from SeaWiFS and demonstrate the efficacy of this approach. We show that it is possible and efficient to vicariously intercalibrate sensors between one and another. C1 Univ Maryland, Baltimore, MD 21201 USA. NASA, Goddard Space Flight Ctr, SAIC Gen Sci Corp, Greenbelt, MD 20771 USA. RP Wang, MH (reprint author), Univ Maryland, Baltimore, MD 21201 USA. RI Wang, Menghua/F-5631-2010; Franz, Bryan/D-6284-2012 OI Wang, Menghua/0000-0001-7019-3125; Franz, Bryan/0000-0003-0293-2082 NR 21 TC 48 Z9 54 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2000 VL 38 IS 1 BP 184 EP 197 DI 10.1109/36.823911 PN 1 PG 14 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 283XF UT WOS:000085300800016 ER PT J AU Cailliau, D Zlotnicki, V AF Cailliau, D Zlotnicki, V TI Precipitation detection by the TOPEX/Poseidon dual frequency radar altimeter, TOPEX microwave radiometer, special sensor microwave/imager and climatological shipboard reports SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE C band; Ku band; radar altimetry; rain; TOPEX-Poseidon ID GLOBAL OCEANIC PRECIPITATION; RAIN; ALGORITHM; PROJECT; TMR; PERFORMANCE AB We evaluate the ability of a dual-frequency radar (C and Ku band) altimeter to detect rain events. A TOPEX/Poseidon (T/P) altimeter rain flag for the year 1994 is compared to collocated rain rate (RR) from the Defense Meteorological Satellite Program's Special Sensor Microwave Imager (DMSP SSM/I), as processed by [1], to the TOPEX/Poseidon passive radiometer's (TMR) liquid-water content, and to a 34-year climatology of shipboard present-weather reports compiled by [2], The altimeter-SSM/I analysis is couched in terms of the tradeoff between the probability of a false positive and the probability of a failure to detect rain. We show that the ability of the SSM/I and TMR datasets to detect precipitation are closer to each other than to either the altimeter or the shipboard climatology, and this difference is accentuated at latitudes poleward of 45 degrees. We argue that the different footprint sizes explain only part of this discrepancy. We propose that the difference at high latitudes is caused by the altimeter data's sensitivity to snow. In order to detect precipitation (as opposed to detecting bad altimetric values or out-of-range altimetric corrections), a TMR-only flag with liquid-water content of 600 mu m recovers too few rain events, 400 mu m is close to climatological moderate-to-heavy intensity rains, and 200 mu m is dose to rain of any intensity, For the same purpose, a combined altimeter and TMR flag, with a TMR threshold of 100 mu m and with the Ku radar cross section 1.5 standard deviations below an average Ku/C curve, gives the best match for climatological precipitation of any intensity class. C1 Ctr Natl Etud Spatiales, DSO, ED, AL,Dept JASON TOPEX, F-31055 Toulouse, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cailliau, D (reprint author), Ctr Natl Etud Spatiales, DSO, ED, AL,Dept JASON TOPEX, 18 Ave Edouard Belin, F-31055 Toulouse, France. NR 33 TC 11 Z9 11 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2000 VL 38 IS 1 BP 205 EP 213 DI 10.1109/36.823913 PN 1 PG 9 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 283XF UT WOS:000085300800018 ER PT J AU Galantowicz, JF Entekhabi, D Njoku, EG AF Galantowicz, JF Entekhabi, D Njoku, EG TI Estimation of soil-type heterogeneity effects in the retrieval of soil moisture from radiobrightness SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE microwave radiometry; moisture models; soil coupled heat; soil moisture; spatial heterogeneity ID TEXTURE AB We estimate the magnitude of the beam-filling error due to soil-type heterogeneity in the determination of sensor-footprint average soil moisture (<(theta)over bar>(f)) retrieved from remote L-band radiometer measurements. Sets of randomly chosen soils are given uniform initial wetness and are subjected to atmospheric drying ol er 15 days in a numerical model. Results indicate that soil heterogeneity contributes less than 0.7% volumetric soil-moisture error (0.007 m(water)(3)/m(soil)(3)). C1 MIT, Ralph M Parsons Lab, Dept Civil & Environm Engn, Cambridge, MA 02139 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91106 USA. RP Galantowicz, JF (reprint author), Atmospher & Environm Res Inc, 840 Mem Dr, Cambridge, MA 02139 USA. NR 12 TC 17 Z9 17 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2000 VL 38 IS 1 BP 312 EP 316 DI 10.1109/36.823924 PN 1 PG 5 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 283XF UT WOS:000085300800029 ER PT J AU Freeman, A Johnson, WTK Huneycutt, B Jordan, R Hensley, S Siqueira, P Curlander, J AF Freeman, A Johnson, WTK Huneycutt, B Jordan, R Hensley, S Siqueira, P Curlander, J TI The "myth" of the minimum SAR antenna area constraint SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE antenna area; synthetic aperture radar (SAR) ID RADAR AB A design constraint traceable to the early days of spaceborne synthetic aperture radar (SAR) is known as the minimum antenna area constraint for SAR. In this paper, it is confirmed that this constraint strictly applies only to the case in which both the best possible resolution and the widest possible swath are the design goals, SAR antennas with area smaller than the constraint allows are shown to he possible, have been used on spaceborne SAR missions in the past, and should permit further, lower-cost SAR missions in the future. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Vexcel Corp, Boulder, CO 80302 USA. RP Freeman, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Siqueira, Paul/D-9760-2016 OI Siqueira, Paul/0000-0001-5781-8282 NR 9 TC 38 Z9 52 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2000 VL 38 IS 1 BP 320 EP 324 DI 10.1109/36.823926 PN 1 PG 5 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 283XF UT WOS:000085300800031 ER PT J AU Emardson, TR Johansson, J Elgered, G AF Emardson, TR Johansson, J Elgered, G TI The systematic behavior of water vapor estimates using four years of GPS observations SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE Global Positioning System (GPS); time series analysis; water vapor ID GLOBAL POSITIONING SYSTEM; PRECIPITABLE WATER; ASSIMILATION; MODEL AB We have used four years of Global Positioning System (GPS) data to study the amount of integrated water vapor (IWV) in the atmosphere. We find that the presence of certain radomes at some sites highly affects the water vapor estimates at other sites. These effects are eliminated by using a technique in which data from each station are processed individually. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Chalmers Univ Technol, Onsala Space Observ, S-43992 Onsala, Sweden. RP Emardson, TR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Elgered, Gunnar/B-7052-2016 OI Elgered, Gunnar/0000-0001-5711-0073 NR 12 TC 33 Z9 34 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2000 VL 38 IS 1 BP 324 EP 329 DI 10.1109/36.823927 PN 1 PG 6 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 283XF UT WOS:000085300800032 ER PT J AU Rignot, EJM AF Rignot, EJM TI Effect of Faraday rotation on L-band interferometric and polarimetric synthetic-aperture radar data SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE ionosphere; SAR interferometry; SAR polarimetry ID FOREST BIOMASS; IMAGING RADAR; BACKSCATTER AB Electromagnetic waves traveling through the ionosphere undergo a Faraday rotation of the polarization vector, which modifies the polarization and phase characteristics of the electromagnetic signal, Using L-band (lambda = 24 cm), polarimetric synthetic aperture radar (SAR) data from the shuttle imaging radar C (SIR-C) acquired in 1994, we simulate the effect of a change in the Faraday rotation angle psi on spaceborne imterferometric and polarimetric data. In one experiment, we find that phase coherence is reduced by up to 33% when psi changes between successive data acquisitions. If psi changes by more than 40 degrees, a differential phase signal, which varies from field to field, appears in the interferogram and impairs the mapping of surface topography and/or the detection of ground deformation. This signal is caused by phase differences between horizontal-polarized and vertical-polarized radar signals from intermediate levels of vegetation canopy, similar to the phase difference measured between II-polarized and V-polarized signals on a single date. In a second experiment, data from the Japanese Earth Resources Satellite (JERS-1) L-band radar acquired in an area of active deforestation in Rondonia, Brazil, are compared with SIR-C L-band polarimetric data acquired at the same incidence, two weeks later, but from a lower orbiting altitude. Large differences in scattering behavior are recorded between the two datasets in the areas of slash and burn forest, which are difficult to reconcile with surface changes, A simulation with SIR-C polarimetric data, however, suggests that those differences are consistent with a Faraday rotation angle of about 30 +/- 10 degrees in the JERS-1 data and 0 degrees in the SIR-C data. Based on these two experiments and on global positioning system (GPS) records of ionospheric activity, we conclude that Faraday rotation should not affect the analysis of L-band spaceborne data during periods of low ionospheric activity (solar minima). Yet during ionospheric storms or near solar maxima, the effects should become significant and impair data analysis. Corrections for Faraday rotation are impractical in the case of single-channel SAR data. SAR data must be acquired with the full polarimetry to recover from these effects. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Rignot, EJM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Rignot, Eric/A-4560-2014 OI Rignot, Eric/0000-0002-3366-0481 NR 11 TC 31 Z9 36 U1 2 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2000 VL 38 IS 1 BP 383 EP 390 DI 10.1109/36.823934 PN 2 PG 8 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 283XH UT WOS:000085301000006 ER PT J AU Gamba, P Houshmand, B Saccani, M AF Gamba, P Houshmand, B Saccani, M TI Detection and extraction of buildings from interferometric SAR data SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE SAR urban analysis; 3-D building extraction ID RADAR INTERFEROMETRY; SEGMENTATION; IMAGERY AB In this paper, we present a complete procedure for the extraction and characterization of building structures starting from the three-dimensional (3-D) terrain elevation data provided by interferometric SAR measurements. Each building is detected and isolated from the surroundings by means of a suitably modified machine vision approach, originally developed for range image segmentation. The procedure is based an a local approximation of the 3-D data by means of best-fitting planes. In this way, a building footprint, height and position, as well as its description with a simple 3-D model, are recovered by a self-consistent partitioning of the topographic surface reconstructed from interferometric radar data. C1 Univ Pavia, Dipartimento Elettr, I-27100 Pavia, Italy. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gamba, P (reprint author), Univ Pavia, Dipartimento Elettr, I-27100 Pavia, Italy. RI Gamba, Paolo/G-1959-2010 OI Gamba, Paolo/0000-0002-9576-6337 NR 32 TC 82 Z9 86 U1 2 U2 20 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2000 VL 38 IS 1 BP 611 EP 618 DI 10.1109/36.823956 PN 2 PG 8 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 283XH UT WOS:000085301000028 ER PT J AU Yan, CH Whalen, RT Beaupre, GS Yen, SY Napel, S AF Yan, CH Whalen, RT Beaupre, GS Yen, SY Napel, S TI Reconstruction algorithm for polychromatic CT imaging: Application to beam hardening correction SO IEEE TRANSACTIONS ON MEDICAL IMAGING LA English DT Article DE beam hardening correction; dual-energy correction; polychromatic computed tomography imaging; quantitative computed tomography; single energy correction ID QUANTITATIVE COMPUTED-TOMOGRAPHY; BONE-MINERAL DENSITY; ARTIFACTS; ENERGY; IMAGES; WOMEN AB This paper presents a new reconstruction algorithm for both single- and dual-energy computed tomography (CT) imaging. By incorporating the polychromatic characteristics of the X-ray beam into the reconstruction process, the algorithm is capable of eliminating beam hardening artifacts. The single energy version of the algorithm assumes that each voxel in the scan field can be expressed as a mixture of two known substances, for example, a mixture of trabecular bone and marrow, or a mixture of fat and flesh. These assumptions are easily satisfied in a quantitative computed tomography (QCT) setting, We have compared our algorithm to three commonly used single-energy correction techniques. Experimental results show that our algorithm is much more robust and accurate. We have also shown that QCT measurements obtained using our algorithm are five times more accurate than that from current QCT systems (using calibration). The dual-energy mode does not require any prior knowledge of the object in the scan field, and can be used to estimate the attenuation coefficient function of unknown materials. We have tested the dual-energy setup to obtain an accurate estimate for the attenuation coefficient function of K2HPO4 solution. C1 Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. NASA, Ames Res Ctr, Div Life Sci, Mt View, CA USA. Rehabil R&D Ctr, Palo Alto, CA USA. Stanford Univ, Dept Radiol, Stanford, CA 94305 USA. RP Yan, CH (reprint author), Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. OI Beaupre, Gary/0000-0002-6211-7621 FU NCRR NIH HHS [P41 RR09784] NR 22 TC 69 Z9 78 U1 2 U2 16 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0278-0062 J9 IEEE T MED IMAGING JI IEEE Trans. Med. Imaging PD JAN PY 2000 VL 19 IS 1 BP 1 EP 11 PG 11 WC Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging SC Computer Science; Engineering; Imaging Science & Photographic Technology; Radiology, Nuclear Medicine & Medical Imaging GA 304QV UT WOS:000086495700001 PM 10782614 ER PT J AU Epp, LW Khan, AR Smith, HK Smith, RP AF Epp, LW Khan, AR Smith, HK Smith, RP TI A compact dual-polarized 8.51-GHz rectenna for high-voltage (50 V) actuator applications SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE actuators; free-space power combining and rectification; microstrip patch; rectenna ID COUPLED MICROSTRIP ANTENNAS; MICROWAVE-POWER; SLOT AB This paper describes a dual-polarized rectenna capable of producing a 50-V output voltage that can be used for driving mechanical actuators. This study demonstrates a circuit topology that allows the output of multiple rectenna elements to be combined in order to step up the output voltage. In this paper, an independent rectifying circuit is used for each of two orthogonal polarizations. By proper combination, the output voltage is doubled over that of the single polarization case. Such panels are being explored for use on the nest-generation space telescope to eliminate wiring between actuators and provide for true mechanical isolation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Epp, LW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 25 TC 58 Z9 59 U1 1 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD JAN PY 2000 VL 48 IS 1 BP 111 EP 120 DI 10.1109/22.817479 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA 276FQ UT WOS:000084865300015 ER PT J AU Maghami, PG Sparks, DW AF Maghami, PG Sparks, DW TI Design of neural networks for fast convergence and accuracy: Dynamics and control SO IEEE TRANSACTIONS ON NEURAL NETWORKS LA English DT Article DE dynamics and control; feedforward neural networks; neural-network accuracy; probabilistic-based design AB A procedure for the design and training of artificial neural networks, used for rapid and efficient controls and dynamics design and analysis for flexible space systems, has been developed, Artificial neural networks are employed, such that once properly trained, they provide a means of evaluating the impact of design changes rapidly. Specifically, two-layer feedforward neural networks are designed to approximate the functional relationship between the component/spacecraft design changes and measures of its performance or nonlinear dynamics of the system/components. A training algorithm, based on statistical sampling theory, is presented, which guarantees that the trained networks provide a designer-specified degree of accuracy in mapping the functional relationship. Within each iteration of this statistical-based algorithm, a sequential design algorithm is used for the design and training of the feedforward network to provide rapid convergence to the network goals. Here, at each sequence a new network is trained to minimize the error of previous network. The proposed method should work for applications wherein an arbitrary large source of training data can be generated. Two numerical examples are performed on a spacecraft application in order to demonstrate the feasibility of the proposed approach. C1 NASA, Langley Res Ctr, Guidance & Control Branch, Hampton, VA 23681 USA. RP NASA, Langley Res Ctr, Guidance & Control Branch, Hampton, VA 23681 USA. NR 10 TC 17 Z9 18 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1045-9227 EI 1941-0093 J9 IEEE T NEURAL NETWOR JI IEEE Trans. Neural Netw. PD JAN PY 2000 VL 11 IS 1 BP 113 EP 123 DI 10.1109/72.822515 PG 11 WC Computer Science, Artificial Intelligence; Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 287UC UT WOS:000085524000012 PM 18249744 ER PT J AU Shakeri, M Raghavan, V Pattipati, KR Patterson-Hine, A AF Shakeri, M Raghavan, V Pattipati, KR Patterson-Hine, A TI Sequential testing algorithms for multiple fault diagnosis SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART A-SYSTEMS AND HUMANS LA English DT Article DE AND/OR graph search; extended single fault strategy; hidden faults; masking faults; minimal faults; minimal hitting sets; multiple fault diagnosis; sure strategies; test sequencing; tree and digraph diagnostic strategies ID BEHAVIOR AB A common simplifying assumption made by the existing testability analysis and diagnostic tools is that there exists, at most, a single fault in the system at any given time. This assumption does not hold for complex systems with large numbers of components and/or systems with little or no opportunity for maintenance during operation. In this paper, we consider the problem of constructing optimal and near-optimal test sequences for multiple fault diagnosis. The computational complexity of solving the optimal multiple-fault isolation problem is super exponential, that is, it is much more difficult than the single-fault isolation problem, which, by itself, is NP-hard(1) [1]. By employing concepts from information theory and AND/OR graph search and by exploiting the single fault testing strategies of [1], we present several test sequencing algorithms for the multiple fault isolation problem. These algorithms provide a tradeoff between the degree of suboptimality and computational complexity. Furthermore, we present novel diagnostic strategies that generate a diagnostic directed graph (digraph), instead of a traditional diagnostic tree, for multiple fault diagnosis, Using this approach, the storage complexity of the overall diagnostic strategy reduces substantially, The algorithms developed herein have been successfully applied to several real-world systems. Computational results indicate that the size of a multiple fault diagnostic strategy is strictly related to the structure of the system. C1 Mathworks Inc, Natick, MA 01760 USA. Univ Connecticut, Dept Elect & Syst Engn, Storrs, CT 06269 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Shakeri, M (reprint author), Mathworks Inc, Natick, MA 01760 USA. NR 25 TC 36 Z9 52 U1 2 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1083-4427 J9 IEEE T SYST MAN CY A JI IEEE Trans. Syst. Man Cybern. Paart A-Syst. Hum. PD JAN PY 2000 VL 30 IS 1 BP 1 EP 14 DI 10.1109/3468.823474 PG 14 WC Computer Science, Cybernetics; Computer Science, Theory & Methods SC Computer Science GA 288ZL UT WOS:000085594800001 ER PT B AU Treuhaft, RN Law, BE Asner, GP Hensley, S AF Treuhaft, RN Law, BE Asner, GP Hensley, S BE Stein, TI TI Vegetation profile estimates from multialtitude, multifrequency radar interferometric and polarimetric data SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Treuhaft, RN (reprint author), CALTECH, Jet Prop Lab, MS 138-212,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Asner, Gregory/G-9268-2013 OI Asner, Gregory/0000-0001-7893-6421 NR 5 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 126 EP 128 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000043 ER PT B AU Jiang, JH Wu, DL AF Jiang, JH Wu, DL BE Stein, TI TI Analysis of UARS NMS radiance variances and their relationship with stratospheric wind SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing IGARSS LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jiang, JH (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-701, Pasadena, CA 91109 USA. EM jonathan@mls.jpl.nasa.gov RI Wu, Dong/D-5375-2012 NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 213 EP 215 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000071 ER PT B AU West, RD Moghaddam, M Johnson, WTK Janssen, MA Hamilton, GA Liepack, OG Bunker, A Berkun, AC Roth, LE AF West, RD Moghaddam, M Johnson, WTK Janssen, MA Hamilton, GA Liepack, OG Bunker, A Berkun, AC Roth, LE BE Stein, TI TI Cassini observes the earth with Ku-band RADAR and radiometry SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB In this paper, we discuss the passive and active Ku-band observations of the Earth made by the Cassini RADAR during its Earth swingby. The brightness temperature data show an abrupt transition at the ocean-land boundary, and more subtle details over South America. The backscatter data show a low wind region off the west coast of South America, consistent with QuikSCAT observations, followed by higher backscatter levels over the land area. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP West, RD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 298 EP 300 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000097 ER PT B AU Hildebrand, PH AF Hildebrand, PH BE Stein, TI TI Hail growth and recirculation in a multicellular hailstorm observed during VORTEX-95 SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hildebrand, PH (reprint author), NASA, Goddard Space Flight Ctr, Code 975, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 313 EP 315 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000102 ER PT B AU Johnson, LF Nemani, RR Pierce, LL Bobo, MR Bosch, D AF Johnson, LF Nemani, RR Pierce, LL Bobo, MR Bosch, D BE Stein, TI TI Toward the improved use of remote sensing and process modeling in California's premium wine industry SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID LEAF-AREA INDEX; VEGETATION C1 Calif State Univ, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Johnson, LF (reprint author), Calif State Univ, NASA, Ames Res Ctr, MS 242-4, Moffett Field, CA 94035 USA. NR 8 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 363 EP 365 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000119 ER PT B AU Arvidson, T Gasch, J Goward, SN AF Arvidson, T Gasch, J Goward, SN BE Stein, TI TI Global vegetation - Assessing Landsat-7/ETM+ coverage of tropical rainforest and global agricultural and forest extents SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB This paper presents the state of the 10-month old Landsat 7 archive of high resolution, multi-spectral imagery of global vegetation, including global agricultural extent, forests, and tropical rainforests. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Arvidson, T (reprint author), NASA, Goddard Space Flight Ctr, Code 428-1,Bldg 32,Rm W210A, Greenbelt, MD 20771 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 393 EP 395 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000129 ER PT B AU Gasch, J Arvidson, T Goward, SN AF Gasch, J Arvidson, T Goward, SN BE Stein, TI TI Fire and ice: An assessment of Landsat 7/ETM+ acquisitions over glaciers, volcanoes, Antarctica and sea ice SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB With the successful deployment of its spacecraft, Landsat 7 is achieving unprecedented worldwide coverage toward its goal of acquiring and periodically refreshing a global archive of sunlit, substantially cloud-free images. There are many science niche communities benefiting from satellite remote sensing observations in support of their research objectives. Landsat 7 has granted special consideration to regions of scientific interest, including volcanoes, glaciers, and sea ice extents. This paper presents the state of the Landsat 7 archive of imagery of volcanoes, glaciers, sea ice, and Antarctica after nearly 10 months of operation. The summary of coverage includes the average and best image quality and frequency of coverage for each of these study areas. C1 NASA, Goddard Space Flight Ctr, Landsat 7 Mission Operat, Greenbelt, MD 20771 USA. RP Gasch, J (reprint author), NASA, Goddard Space Flight Ctr, Landsat 7 Mission Operat, Code 428-1,Bldg 32 Rm W210A, Greenbelt, MD 20771 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 457 EP 459 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000150 ER PT B AU Moussessian, A Jordan, RL Rodriguez, E Safaeinili, A Akins, TL Edelstein, WN Kim, Y Gogineni, SP AF Moussessian, A Jordan, RL Rodriguez, E Safaeinili, A Akins, TL Edelstein, WN Kim, Y Gogineni, SP BE Stein, TI TI A new coherent radar for ice sounding in Greenland SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB This paper will discuss a new multifrequency dual channel coherent radar depth sounder for sounding ice. This sounder is unique, since it is a fully coherent chirp radar designed to operate at low (1,500ft) as well as high altitudes (30,000ft). The dynamic range of the radar is sufficient for simultaneously imaging both the top and bottom returns from ice without the need for data blanking or Sensitivity Time Control (STC) equalization of the return signal. The first deployment of this radar on board a P-3 aircraft took place in May of 1999 over Greenland with successful results. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Moussessian, A (reprint author), CALTECH, Jet Prop Lab, MS 300-241,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 484 EP 486 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000159 ER PT B AU Arvidson, T Gasch, J Goward, SN AF Arvidson, T Gasch, J Goward, SN BE Stein, TI TI A tool for taking the pulse of the planet - The long term acquisition plan intelligently stocks the landsat 7 archive SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB This paper presents the Long Term Acquisition Plan used to determine which scenes are acquired by Landsat 7 for the global archive. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Arvidson, T (reprint author), NASA, Goddard Space Flight Ctr, Code 428-1,Bldg 32 Rm W210A, Greenbelt, MD 20771 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 512 EP 514 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000168 ER PT B AU Yeh, PS Venbrux, J Bhatia, P Miller, WH AF Yeh, PS Venbrux, J Bhatia, P Miller, WH BE Stein, TI TI A real-time high performance data compression technique for space applications SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci DE coding; lossy data compression; telemetry; space science applications; push-broom instruments AB A high performance lossy data compression technique is currently being developed for space science applications under the requirement of high-speed push-broom scanning. The technique is also applicable to frame based imaging and is error-resilient in that error propagation is contained within a few scan lines. The algorithm is based on a hybrid of modulated lapped transform (MLT) and discrete cosine transform (DCT) combined with bit-plane encoding; this combination results in an embedded bit string with exactly the desirable compression rate as desired by the user. The approach requires no unique table to maximize its performance. The compression scheme performs well on a suite of test images typical of images from spacecraft instruments. Flight qualified hardware implementations are in development; a functional chip set is expected by the end of 2001. The chip set is being designed to compress data in excess of 20 Msamples/sec and support quantizations from 2 to 16 bits. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Yeh, PS (reprint author), NASA, Goddard Space Flight Ctr, Code 564, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 612 EP 614 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000202 ER PT B AU Tilton, JC Lawrence, WT AF Tilton, JC Lawrence, WT BE Stein, TI TI Interactive analysis of hierarchical image segmentation SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Tilton, JC (reprint author), NASA, Goddard Space Flight Ctr, Code 935, Greenbelt, MD 20771 USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 733 EP 735 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000241 ER PT B AU Gualtieri, JA Chettri, S AF Gualtieri, JA Chettri, S BE Stein, TI TI Support vector machines for classification of hyperspectral data SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Global Sci & Technol Appl Informat Sci Branch, Greenbelt, MD 20771 USA. RP Gualtieri, JA (reprint author), NASA, Goddard Space Flight Ctr, Global Sci & Technol Appl Informat Sci Branch, Code 935, Greenbelt, MD 20771 USA. NR 9 TC 17 Z9 17 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 813 EP 815 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000267 ER PT B AU Hammer, PD Johnson, LF Strawa, AW Dunagan, SE Higgins, R Brass, J Slye, RE Sullivan, DV Lobitz, BM Smith, WH Peterson, DL AF Hammer, PD Johnson, LF Strawa, AW Dunagan, SE Higgins, R Brass, J Slye, RE Sullivan, DV Lobitz, BM Smith, WH Peterson, DL BE Stein, TI TI Surface reflectance mapping using interferometric spectral imagery from remotely piloted aircraft SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID ARRAY SCANNED INTERFEROMETER C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hammer, PD (reprint author), NASA, Ames Res Ctr, M-S 242-4, Moffett Field, CA 94035 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 816 EP 818 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000268 ER PT B AU Yang, K Fleig, AJ Wolfe, RE Nishihama, M AF Yang, K Fleig, AJ Wolfe, RE Nishihama, M BE Stein, TI TI MODIS band-to-band registration SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB We describe the image correlation method implemented for calculation of band-to-band registration of the Moderate-Resolution Imaging Spectroradiometer (MODIS). Early results for the registration of first seven MODIS bands are presented. These results show that registration among these bands are better than 0.1 pixel. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP Yang, K (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Code 922, Greenbelt, MD 20771 USA. RI Wolfe, Robert/E-1485-2012 OI Wolfe, Robert/0000-0002-0915-1855 NR 3 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 887 EP 889 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000290 ER PT B AU Barkstrom, BR Wielicki, BA AF Barkstrom, BR Wielicki, BA BE Stein, TI TI An overview of CERES with TRMM and Terra SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID BUDGET C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Barkstrom, BR (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 937 EP 940 PG 4 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000304 ER PT B AU Diner, DJ AF Diner, DJ CA MISR Sci Team BE Stein, TI TI First results from the Terra Multi-angle Imaging SpectroRadiometer (MISR) SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The Multi-angle Imaging SpectroRadiometer (MISR) is one of five instruments aboard the EOS Terra platform. MISR acquires pushbroom images of the Earth at 9 viewing angles ranging from 70.5 degrees forward to 70.5 degrees aftward of nadir, in 4 visible/near-IR spectral bands. Data are acquired over a swath width of approximately 400 km, with selectable footprints in each channel ranging from 275 m to 1.1 km. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Diner, DJ (reprint author), CALTECH, Jet Prop Lab, Mail Stop 169-237,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 1 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 941 EP 942 PG 2 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000305 ER PT B AU Salomonson, VV Guenther, B Barnes, WL Therrien, NJ Murphy, RE AF Salomonson, VV Guenther, B Barnes, WL Therrien, NJ Murphy, RE BE Stein, TI TI Early instrument performance results from the Terra/Moderate Resolution Imaging Spectroradiometer (MODIS) SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Salomonson, VV (reprint author), NASA, Goddard Space Flight Ctr, Code 900, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 943 EP 946 PG 4 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000306 ER PT B AU Moghaddam, M Dungan, JL AF Moghaddam, M Dungan, JL BE Stein, TI TI Fusion of SAR and TM data for quantitative estimation of forest variables over an extended range of validity SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Near-simultaneous AIRSAR and Landsat TM data are used, along with radar scattering models and optical regression-based models, to estimate vegetation variables for a mixed old-growth dense forest in the US Pacific Northwest. The main variable of interest here is the foliage biomass, which is related to fundamental scattering properties of the forest stands used to model SAR data, through the allometric relations for the species under study. Polarimetric and interferometric SAR data and the Landsat TM data are first coregistered, taking care of the effects of surface topography. Relationships between foliage mass and TM data channels are derived through a regression analysis applied to ground measurements of the variable. Analytical scattering models are used to derive parallel relationships between SAR data and foliage mass. A nonlinear estimation algorithm applied simultaneously to both data types results in estimates of foliage mass which are expected to be more accurate and have a larger range of validity than what could be obtained from either data type alone. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Moghaddam, M (reprint author), Jet Prop Lab, MS 300-227,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Dungan, Jennifer/G-9921-2016 OI Dungan, Jennifer/0000-0002-4863-1616 NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 954 EP 956 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000309 ER PT B AU Safaeinili, A Jordan, RL AF Safaeinili, A Jordan, RL BE Stein, TI TI Low frequency radar sounding through Martian ionosphere SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB In radar sounding, it is highly desirable to operate at low frequencies to improve the depth of peneteration. For a spaceborne sounder that is orbiting a planet with an ionosphere, the lowest operating frequency is limited by the plasma frequency of the ionosphere. The ionosphere affects the radar signal through dispersion which changes the shape of the signal and introduces a propagation time delay. The impact on the operation of the sounder is twofold by 1) introducing an unknown delay which makes the surface tracking difficult, and 2) degrading the range compression by changing the chirp shape and duration. In this paper, we first demonstrate the effect of the ionosphere on the radar signal through development of an approximate model for the ionosphere of Mars and then present a scheme to compensate for the ionospheric dispersion by taking advantage of the strong specular surface reflection which is expected at low frequencies on Mars. Although the example which is presented in this paper is limited to Mars, the technique is generic and can be used for low frequency radar sounding in general. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Safaeinili, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 987 EP 989 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000319 ER PT B AU Tsai, WY Spencer, M Wu, C Winn, C Kellogg, K AF Tsai, WY Spencer, M Wu, C Winn, C Kellogg, K BE Stein, TI TI SeaWinds on QuikSCAT: Sensor description and mission overview SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID SCATTEROMETER AB The SeaWinds instrument is the first "pencil-beam" scatterometer to routinely measure ocean surface winds from space. Developed to fly on-board the Japanese ADEOS-II mission, the first flight of SeaWinds was moved up several years when the ADEOS-I satellite carrying the NASA Scatterometer (NSCAT) failed. Utilizing only a one year development time, a dedicated small spacecraft was purchased and the SeaWinds spare hardware was adapted for flight. The SeaWinds on QuikSCAT mission was successfully launched on June 19, 1999. Here, the QuikSCAT mission, the SeaWinds instrument, and the SeaWinds ground data processing are briefly described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tsai, WY (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-319, Pasadena, CA 91109 USA. NR 3 TC 7 Z9 7 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1021 EP 1023 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000330 ER PT B AU Huddleston, JN Tsai, WY Spencer, MW Stiles, BW Dunbar, RS AF Huddleston, JN Tsai, WY Spencer, MW Stiles, BW Dunbar, RS BE Stein, TI TI SeaWinds on QuikSCAT: Postlaunch calibration and validation SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID SCATTEROMETER AB The SeaWinds scatterometer was successfully launched aboard the QuikSCAT platform on June 19, 1999. It was designed to accurately determine the speed and direction of ocean surface winds via measurements of the normalized radar cross section, sigma (0). Since the retrieved wind vector accuracy depends heavily upon the sigma (0) measurement accuracy, the SeaWinds instrument has undergone extensive prelaunch and postlaunch calibration. The postlaunch verification and calibration effort included assessments of instrument functionality and stability, hardware component characterization, data processing algorithm validation, calibration table development, and sigma (0) calibration. The achieved accuracy of sigma (0) makes SeaWinds on QuikSCAT well suited for a variety of scientific applications over ocean, land, and ice. We outline the postlaunch calibration approach and indicate the expected accuracy of SeaWinds on QuikSCAT cr, measurements. We focus predominantly on the use of distributed Earth targets, both for addressing the critical issue of spacecraft pointing and for achieving calibration consistency between the backscatter measurements made by SeaWinds' two antenna beams. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Huddleston, JN (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-319, Pasadena, CA 91109 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1024 EP 1026 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000331 ER PT B AU Stiles, B Pollard, B Dunbar, RS AF Stiles, B Pollard, B Dunbar, RS BE Stein, TI TI Direction interval retrieval with thresholded nudging: A method for improving the accuracy of QuikSCAT winds SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID SCATTEROMETER AB The SeaWinds on QuikSCAT scatterometer (QSCAT) was developed by NASA JPL to measure the speed and direction of ocean surface winds. The accuracy of the majority of the swath, and the size of the swath are such that QSCAT meets its science requirements despite shortcomings at certain cross track positions. Nonetheless, it was desirable to modify the baseline processing in order to improve the quality of the less accurate portions of the swath, in particular near the far swath and nadir. Two disparate problems have been identified for far swath and nadir. At far swath, ambiguity removal skill is degraded due to the absence of inner beam measurements, limited azimuth diversity, and boundary effects. Near nadir, due to nonoptimal measurement geometry, (measurement azimuths approximately 180 degrees apart) there is a marked decrease in directional accuracy even when ambiguity removal works correctly. Two algorithms were developed, direction interval retrieval (DIR) to address the nadir performance issue, and thresholded nudging (TN) to improve ambiguity removal at far swath. We illustrate the impact of the two techniques by exhibiting post-launch statistical performance metrics with respect to European Center for Medium-range Weather Forecasting (ECMWF) wind fields. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Stiles, B (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-319, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1030 EP 1032 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000333 ER PT B AU Yueh, SH Stiles, BW Tsai, WY AF Yueh, SH Stiles, BW Tsai, WY BE Stein, TI TI QuikSCAT geophysical model function and imaging of tropical cyclone winds SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID OCEAN BACKSCATTER; KU-BAND AB The feasibility of spaceborne scatterometers for the measurements of tropical cyclone wind fields has been investigated with the data from the SeaWinds scatterometer on QuikSCAT. We have examined about fifty revs of Quikscat data from seven hurricanes with collocated SSM/I rain rate. The data have been examined to determine the depedence of Quikscat sigma 0s on wind speed and rain rate. It is demonstrated that an improvement of GMF together with the use of rain rate information for retrieval can improve the scatterometer estimates of TC wind speeds with a good agreement with the NHC best track analysis. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yueh, SH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-235, Pasadena, CA 91109 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1048 EP 1050 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000339 ER PT B AU Njoku, E Wilson, W Yueh, S Jackson, T Lakshmi, V AF Njoku, E Wilson, W Yueh, S Jackson, T Lakshmi, V BE Stein, TI TI Soil moisture and vegetation observations during SGP99 using the PALS airborne microwave radiometer-radar system SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID FIFE AB The Passive/Active L/S-band (PALS) airborne microwave sensor was flown for the first time during the 1999 Southern Great Plains (SGP99) experiment. The objective was to acquire a dataset for studying a combined radiometer-radar multifrequency, multi polarization approach to soil moisture sensing under varied terrain conditions. Six days of PALS flight data were acquired over the Little Washita and El Reno areas in Oklahoma, in conjunction with ground-based soil and vegetation in-situ sampling. The data illustrate the different sensitivities of the PALS channels to soil moisture, temperature, surface roughness, and vegetation cover, and will provide a basis for development of passive and active multichannel algorithms for soil moisture sensing. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Njoku, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1054 EP 1056 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000341 ER PT B AU Yueh, SH Njoku, EG Wilson, WJ Li, FK Jackson, T Lakshmi, V AF Yueh, SH Njoku, EG Wilson, WJ Li, FK Jackson, T Lakshmi, V BE Stein, TI TI PALS radar signatures of soil surfaces and vegetated sites in Oklahoma during SGP'99 SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The Passive/Active L-/S-band (PALS) microwave instrument has been developed by the Jet Propulsion Laboratory (JPL) to investigate the synergism of radiometer and radar measurements for soil moisture remote sensing. In July 1999, PALS was installed on the NCAR C-130 with six successful flights near the Oklahoma City during the Southern Great Plains 1999 (SGP99) Experiment. The data from these and subsequent ocean flights indicate a calibration stability of better than 0.1 dB for each flight. During the SGP99 experiment, there was a significant rain event between the second and the third flights. The data from before and after the rain event indicate a change of 3 to 4 dB in all radar polarization channels, and a decreasing radar backscatter with the drying of surfaces. The dataset enables us to illustrate the correlation of multi-polarization radar signatures with the soil moisture and vegetation bio-mass. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yueh, SH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1057 EP 1059 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000342 ER PT B AU Kim, EJ Shiue, JC Doiron, T Principe, C Rodriguez, A Gong, L AF Kim, EJ Shiue, JC Doiron, T Principe, C Rodriguez, A Gong, L BE Stein, TI TI A preview of AMSR: Airborne C-band microwave radiometer (ACMR) observations from SGP99 SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Although L-band (1.4 GHz) is generally considered ideal for passive microwave sensing of soil moisture, near-future satellite instruments such as the Advanced Microwave Scanning Radiometer (AMSR) will provide C-band (similar to7 GHz) observations, not L-band observations. Prior to 1999, adequate field testing of soil moisture retrieval algorithms using C-band observations had been hampered due to a lack of suitable data, particularly aircraft datasets over regions at satellite pixel scales (> 1000 km(2)). The Southern Great Plains '99 (SGP99) Experiment was designed to fill this gap with aircraft flights featuring five low-frequency passive microwave instruments. The C-band observations described in this paper were collected using one of the two new C-band instruments deployed during SGP99: the Airborne C-band Microwave Radiometer (ACMR). C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Microwave Sensors Branch 975, Greenbelt, MD 20771 USA. RP Kim, EJ (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Microwave Sensors Branch 975, Greenbelt, MD 20771 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1060 EP 1062 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000343 ER PT B AU Le Vine, DM Haken, M Bidwell, S Swift, CT Jackson, T AF Le Vine, DM Haken, M Bidwell, S Swift, CT Jackson, T BE Stein, TI TI ESTAR measurements during SGP-99 SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID RADIOMETER AB The synthetic aperture radiometer, ESTAR, provided L-band brightness temperature maps of the experiment site during the Southern Great Plains Experiment in 1999. ESTAR flew on the NASA P-3B Orion aircraft at an altitude of 7.6 km and mapped a swath about 50 km wide and about 300 km long, extending west from Oklahoma City to El Reno and north from below the Little Washita River watershed to the Kansas border. The brightness temperature maps reflect the patterns of soil moisture expected from rainfall and observed at the surface sites within the SGP99 study area. C1 NASA, Goddard Space Flight Ctr, Microwave Sensors Branch, Greenbelt, MD 20771 USA. RP Le Vine, DM (reprint author), NASA, Goddard Space Flight Ctr, Microwave Sensors Branch, Greenbelt, MD 20771 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1063 EP 1065 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000344 ER PT B AU O'Neill, PE Hsu, AY Kim, EJ Burke, EJ AF O'Neill, PE Hsu, AY Kim, EJ Burke, EJ BE Stein, TI TI Use of coupled SVAT and microwave emission models for soil moisture estimation in SGP97 SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Hydrol Sci Branch 974, Greenbelt, MD 20771 USA. RP O'Neill, PE (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Hydrol Sci Branch 974, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1066 EP 1068 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000345 ER PT B AU Racette, P Westwater, E Han, Y Manning, W Gasiewski, A Jones, D AF Racette, P Westwater, E Han, Y Manning, W Gasiewski, A Jones, D BE Stein, TI TI Millimeter-wave measurements of low amounts of precipitable water vapor SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Racette, P (reprint author), NASA, Goddard Space Flight Ctr, 555, Greenbelt, MD 20771 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1154 EP 1156 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000375 ER PT B AU Schoeberl, M Andrucyk, DJ Ryschkewitsch, MG Meeson, BW AF Schoeberl, M Andrucyk, DJ Ryschkewitsch, MG Meeson, BW BE Stein, TI TI The Earth Science Vision SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB One key goal of NASA's Earth Science Enterprise is answering the question: What will sustain the habitability of Earth? To bring this question into focus, and to chart a course to our future, the Earth Science Vision Initiative (ESVI) was established to develop the Earth Science Vision (ESV), a series of key science and application targets which can be achieved in the 2020 time frame and beyond. Assuming a strong partnership with operational and other national agencies, the ESVI has formulated science, technology and information science investment priorities needed to reach the targets. For identified applications, critical technology is paired with required measurements to reach the target. ESVI also takes into account commercial and other agency investments in technology as part of its strategy. It is intended that the ESV process be ongoing with a review of progress toward goals and identification of new targets taking place on an annual basis. The ESV, as it exists today, is a starting point for discussions with other governmental and non-governmental entities. These entities need to reach consensus on participation and the broad requirements needed to reach the earth science and applications goals. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Schoeberl, M (reprint author), NASA, Goddard Space Flight Ctr, M-S 916, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1163 EP 1167 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000377 ER PT B AU Hensley, S Rosen, P Gurrola, E AF Hensley, S Rosen, P Gurrola, E BE Stein, TI TI The SRTM topographic mapping processor SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID RADAR INTERFEROMETRY C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Hensley, S (reprint author), Jet Prop Lab, MS 300-235,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 3 Z9 3 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1168 EP 1170 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000378 ER PT B AU Pfister, R Wichmann, K AF Pfister, R Wichmann, K BE Stein, TI TI New paradigm for search and order in EOSDIS SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Pfister, R (reprint author), NASA, Goddard Space Flight Ctr, Code 423, Greenbelt, MD 20771 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1208 EP 1210 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000391 ER PT B AU Huddleston, JN Stiles, BW AF Huddleston, JN Stiles, BW BE Stein, TI TI A multidimensional histogram rain-flagging technique for SeaWinds on QuikSCAT SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The SeaWinds scatterometer was developed by NASA JPL to measure the speed and direction of global ocean surface winds. SeaWinds was launched aboard the QuikSCAT spacecraft on June 19, 1999 and has continued to operate successfully since being turned on. Although the initial SeaWinds wind vector products were of excellent quality, they were occasionally degraded by the presence of rain. It soon became obvious that a way to flag wind vector cells for rain contamination was needed. We have determined a set of parameters that are sensitive to rain and are computed from the scatterometer measurements. These parameters are: 1) the retrieved wind speed, 2) the retrieved wind direction relative to the satellite ground track, 3) the normalized beam difference, which indicates a statistically significant imbalance in the beams relative to the geophysical model function, 4) the maximum likelihood estimate calculated by the wind retrieval algorithm, and 5) the radiometric brightness temperature. Using these parameters and external rain information (SSM/I) an estimate of the conditional probability of rain given the parameters is developed using a multidimensional histogram technique. This probability estimate is then used to flag rain contaminated wind vector cells using only scatterometer data. This technique is currently employed to generate a rain flag for SeaWinds on QuikSCAT data. In this paper, the effects of rain on SeaWinds data are explored, the rain flagging technique is explained, and the performance of the rain flag is illustrated using a number of metrics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Huddleston, JN (reprint author), CALTECH, Jet Prop Lab, MS 300-319,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1232 EP 1234 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000399 ER PT B AU Njoku, EG Li, L Chan, TK AF Njoku, EG Li, L Chan, TK BE Stein, TI TI Retrieving soil moisture from spaceborne passive microwave data SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID CLASSIFICATION AB Soil moisture products will be generated from data acquired by the Advanced Microwave Scanning Radiometer (AMSR-E) on the Aqua satellite. The AMSR instrument, built in Japan, will also be launched on the ADEOS-II satellite. The AMSR-E level 2 and 3 data processing will be performed at the NASA Marshall Space Flight Center (MSFC), and the products will be archived for public distribution at the National Snow and Ice Data Center (NSIDC). The soil moisture products will be generated at a spatial resolution of approximately 56 km and will include associated estimates of vegetation water content and surface temperature at the same spatial resolution. The products will be generated on an earth-fixed grid with a nominal grid spacing of 25 km. Gridded brightness temperatures will be included in the archived level 3 product to facilitate algorithm updates and intercomparisons during the post-launch validation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Njoku, EG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1247 EP 1249 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000404 ER PT B AU Houser, PR AF Houser, PR BE Stein, TI TI Challenges and progress towards multi-scale hydrologic data assimilation SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID MODELS; PARAMETERIZATION; SCHEMES; IMPACT AB Subsurface moisture and temperature, and snow/ice stores exhibit persistence on seasonal to interannual time scales. This persistence has important implications for the extended prediction of climate and hydrologic extremes. However, errors in forcing, parameterization, and physics, accumulate in modeled land surface stores, which leads to future errors in water and energy partitioning. This has motivated the development of land surface data assimilation methods, which constrain land surface simulation models by forcing them primarily by observations, and by using observations of land_surface storages to realistically constrain model evolution using data assimilation techniques. This development: (1) improves understanding of the time and space variability of hydrological and energy budgets, (2) mitigates land surface parameterization and observation errors through continuous simulation-observation intercomparison, and (3) improves the initialization and dynamics of land surface states in numerical weather prediction models, for more realistic weather and climate predictions. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Houser, PR (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Mailcode 974, Greenbelt, MD 20771 USA. RI Houser, Paul/J-9515-2013 OI Houser, Paul/0000-0002-2991-0441 NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1259 EP 1261 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000408 ER PT B AU Kim, Y van Zyl, J AF Kim, Y van Zyl, J BE Stein, TI TI On the relationship between polarimetric parameters SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID RADAR AB SAR polarimetry has been used to extract both electrical and geometrical properties of an area of scientific interest. For example, polarimetric SAR signatures are used to estimate biomass and soil moisture. Since an electromagnetic interaction with natural objects is complex, it is not easy to derive accurate inversion algorithms to estimate physical properties from polarimetric SAR signatures. The most important part of the algorithm derivation is to identify the most sensitive polarimetric parameters for the desired geophysical information. In this paper, we present the relationship between physical properties and polarimetric parameters using NASA/JPL AIRSAR data. The sensitivity of a polarimetric parameter to the variation of physical properties was evaluated by the polarimetric parameter sensitivity factor at all three AIRSAR frequencies. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kim, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1298 EP 1300 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000421 ER PT B AU van Zyl, JJ Kim, Y AF van Zyl, JJ Kim, Y BE Stein, TI TI The relationship between radar polarimetric and interferometric phase SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID CLASSIFICATION; SAR AB Generally, the polarimetric phase difference between the VV and HH channels is interpreted in terms of the spatial difference between the HH and VV scattering centers. In the case of interferometry, the phase difference at a particular polarization combination is usually interpreted as a three-dimensional position of a scattering center, allowing one to reconstruct the topography of the scene. Recent results from polarimetric radar interferometers suggest that a slightly different phase value is measured when different polarizations are used at each end of the interferometric baseline. If this interferometric phase difference is indeed interpreted in the same way as the traditional interferometric phase, it suggests that a slightly different elevation would be measured at each polarization, leading to the idea that polarimetric interferometry could provide information about the vertical structure of vegetation. This paper examines the relationship between the phase measured by a radar polarimeter and a radar interferometer. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP van Zyl, JJ (reprint author), CALTECH, Jet Prop Lab, Mail Stop 264-686,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1301 EP 1303 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000422 ER PT B AU Comiso, JC Stock, LV AF Comiso, JC Stock, LV BE Stein, TI TI Interannual variability of Arctic summer ice surface characteristics using satellite observations SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID COVER AB Surface air temperatures recorded by stations in the Arctic region have been observed to be increasing at 0.07 K/decade while at the same time, the sea ice cover has declined by about 6% during the last 20 years. In order to gain insights into this phenomenon, albedo and surface temperature data from AVHRR have been processed and analyzed in conjunction with co-registered ice cover data from passive microwave observations. This study puts emphasis on the summer period because it is during this time when the impact of changes in surface temperature on the character of the ice cover is most critical. The results of our analysis show that the spatial and interannual variability in surface temperature in the Arctic during the last 18 years has been large and the impact is reflected on the albedo and ice data. There is also good coherence in the different variables studied, including ice concentration and brightness temperatures. Lengths of summer melt periods are also shown to be vary considerably and can be as short as 7 weeks or as long as 19 weeks. Abnormally warm temperatures are usually correlated with abnormally low albedos but not always. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Comiso, JC (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Code 971, Greenbelt, MD 20771 USA. NR 7 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1329 EP 1333 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000431 ER PT B AU Haddad, ZS Meagher, JP AF Haddad, ZS Meagher, JP BE Stein, TI TI Improved combined radar/radiometer rain profiling SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The current TRMM combined radar/radiometer profiling algorithm compensates for the known shortcomings of each instrument by exploiting the strengths of the other. It turns out that the strengths/weaknesses of the radiometer measurements are not as they seemed before TRMM. Specifically, the current algorithm presumes that the radiances at the various frequencies are approximately independent (to compute probability weights). It turns out there are strong correlations between the channels. New estimates of the conditional covariance of the radiances given the rain should make the probability weights more realistic. The second problem stems from the representativity of the TRMM cloud database. It turns out that the database is significantly off, especially at higher frequencies. To reduce the rain over-estimation produced by this discrepancy, the database was re-sampled and mean rain-radiances relations were re-derived. The third problem is the lack of any ice estimates. The reason was the large number of unknown variables involved. A principal component analysis has revealed that the frozen hydrometeor profiles can be approximated by a single variable each for ice, snow, and graupel. A straightforward method is currently being implemented to estimate these additional variables, and to include them in the output structure of the algorithm. Linear formulas will enable users to reconstruct the corresponding graupel/snow/ice profiles, and estimate the corresponding latent heating. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Haddad, ZS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1349 EP 1351 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000437 ER PT B AU Im, E Durden, SL Haddad, ZS Sadowy, G Berkun, A Huang, J Lou, M Lopez, BC Rahmat-Samii, Y Rengarajan, S AF Im, E Durden, SL Haddad, ZS Sadowy, G Berkun, A Huang, J Lou, M Lopez, BC Rahmat-Samii, Y Rengarajan, S BE Stein, TI TI Second-generation spaceborne precipitation radar SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The Global Precipitation Mission is currently being planned as a follow-on to the Tropical Rainfall Measuring Mission. One of the key components of the GPM science instrumentation is an advanced, dual-frequency rain mapping radar. In this paper, we present a potential system concept for this second-generation spaceborne precipitation radar. This proposed design incorporates several advanced features, including 13.6/35-GHz dual frequency radar channels; a dual-frequency, wide-swath scanning, deployable antenna; digital chirp generation and the corresponding on-board pulse compression scheme; and adaptively antenna scanning. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Im, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1361 EP 1363 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000441 ER PT B AU Chang, ATC Chiu, LS AF Chang, ATC Chiu, LS BE Stein, TI TI Monthly oceanic rainfall derived from SSM/I and TMI data SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Chang, ATC (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Hydrol Sci Branch, Code 661, Greenbelt, MD 20771 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1367 EP 1369 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000443 ER PT B AU Moghaddam, M Saatchi, S AF Moghaddam, M Saatchi, S BE Stein, TI TI Estimation of vegetation variables using AIRSAR data containing multiple scattering mechanisms SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Polarimetric and multifrequency SAR data are used to construct a multi-tier estimation algorithm for successive derivation of the variables describing the entire forest canopy. This is in contrast to previous algorithms by the authors which dealt with the estimation of variables using a single scattering mechanism and the variables of a single canopy layer. The solution method starts with the upper canopy layer and higher frequencies, and works down to the lower layers using lower frequencies. Several stand types are considered, each of which has different scattering characteristics. The flexibility and applicability of this approach to various canopy types is demonstrated. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Moghaddam, M (reprint author), Jet Prop Lab, MS 300-227,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1408 EP 1410 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000455 ER PT B AU Spencer, MW Daffer, WH AF Spencer, MW Daffer, WH BE Stein, TI TI Value added products for SeaWinds on QuikSCAT SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The SeaWinds scatterometer generates near real-time surface wind data over the global oceans. In order to make this data more accessible to non-governmental organization and individuals, the SeaWinds Value-Added Product (VAP) effort was initiated. Daily wind data is available to the public via the VAP website. Various data visualization techniques, such as merger with the more familiar geosynchronous cloud images and vector field animation, have been employed to make the SeaWinds data more accessible to a variety of users. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Spencer, MW (reprint author), CALTECH, Jet Prop Lab, MS 300-319,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1439 EP 1440 PG 2 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000465 ER PT B AU Guillevic, P Gastellu-Etchegorry, JP AF Guillevic, P Gastellu-Etchegorry, JP BE Stein, TI TI Modeling thermal infrared radiative transfer within 3D vegetation covers SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID TEMPERATURES AB Radiometric temperature of vegetation surfaces can vary widely depending on many factors (viewing direction, temperature distribution, canopy structure, etc.), which makes it difficult to interpret remotely sensed thermal infrared (TIR) data. We present a 3D radiative transfer model that simulates the TIR radiative budget (absorption and emission) and upward radiance of vegetation covers. The model is an extension to the TIR region of the DART (Discrete Anisotropic Radiative Transfer) model developed for the short wave domain. Radiative transfer simulation relies on discrete 3D scene representations which include any distribution of trees, understory and soil surfaces, possibly with topography. Propagation of emitted and scattered radiation is tracked with a ray tracing approach and the discrete ordinate method. The model verifies the Kirchhoff law and was successfully tested against a physically bas model for homogeneous canopies and a geometric projection model specifically for row crops. Moreover, a partial validation was carried out with directional TIR measurements of a cotton crop. An application of the model is presented here in order to illustrate the influence of canopy architecture on directional brightness temperature, in the case of tree covers (maritime pine stand) and row crops. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Guillevic, P (reprint author), NASA, Goddard Space Flight Ctr, Mailcode 974-0, Greenbelt, MD 20771 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1480 EP 1482 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000479 ER PT B AU Vandemark, D Chapron, B Walsh, EJ Elfouhaily, T AF Vandemark, D Chapron, B Walsh, EJ Elfouhaily, T BE Stein, TI TI Measurement and modeling of steep ocean wave slopes and absolute calibration of the radar altimeter SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID MEAN-SQUARE SLOPE; SURFACE AB The frequently cited work of Cox and Munk is reviewed to highlight their inference that sea surface slopes often exceed what one would predict using a Gaussian assumption for the slope probability density function (pdr). The importance and validity of this observation is then discussed within the context of near-nadir microwave radar backscatter measurements. We illustrate the nearly direct analogy and quantitative agreement between Cox and Munk's glitter estimation technique and that of airborne radars operating at 14 and 36 GHz. The demonstration points out the error and confusion that can arise in slope variance estimation when the Gaussian assumption is invoked in radar data analysis. Moreover, the study suggests a robust approach for absolute calibration of the satellite radar altimeter through use of the angular dependence of near-nadir radar observations. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Isl, VA 23337 USA. RP Vandemark, D (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Code 972, Wallops Isl, VA 23337 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1495 EP 1497 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000484 ER PT B AU Le Moigne, J Netanyahu, NS Masek, JG Mount, DM Goward, S Honzak, M AF Le Moigne, J Netanyahu, NS Masek, JG Mount, DM Goward, S Honzak, M BE Stein, TI TI Geo-registration of landsat data by robust matching of wavelet features SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The goal of our project is to build an operational system, which will provide a sub-pixel accuracy registration of Landsat-5 and Landsat-7 data. Integrated within an automated mass processing/analysis system for Landsat data (REALM), the input to our registration method consists of scenes that have been geometrically and radiometrically corrected, as well as preprocessed for detection of clouds and cloud shadows. Such pre-processed scenes are then geo-registered relative to a database of Landsat chips. This paper describes our registration process, including the use of a database of landmark chips, a feature extraction performed by an overcomplete wavelet representation, and feature matching using statistically robust techniques. Knowing the approximate longitudes and latitudes of the four corners of the scene, a subset of chips which represent landmarks included in the scene are extracted from the database. For each of these selected landmark chips, a corresponding window is extracted from the scene, and each chip-window pair is registered using our robust wavelet feature matching. First results and future directions are presented in the paper. C1 NASA, Goddard Space Flight Ctr, Appl Informat & Sci Branch, Greenbelt, MD 20771 USA. RP Le Moigne, J (reprint author), NASA, Goddard Space Flight Ctr, Appl Informat & Sci Branch, Code 935, Greenbelt, MD 20771 USA. RI Masek, Jeffrey/D-7673-2012 NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1610 EP 1612 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000520 ER PT B AU Nghiem, SV Tsai, WY Neumann, G Sturm, M Perovich, DK Taras, B Elder, B AF Nghiem, SV Tsai, WY Neumann, G Sturm, M Perovich, DK Taras, B Elder, B BE Stein, TI TI Global snow signature in Ku-band backscatter SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID PASSIVE MICROWAVE RESPONSE; PARAMETERS AB We present Ku-band backscatter signatures of snow for applications to global snow monitoring with NASA Scatterometer (NSCAT) on the ADEOS satellite and the SeaWinds scatterometer on the QuikSCAT satellite. We carried out the 1999 Alaska Snow Experiment to study the relation between Ku-band backscatter and snow physical properties. The experimental results are applied to interpret backscatter data acquired by the satellite scatterometers. Results from NSCAT show regional patterns matching various global snow types, early snow melt conditions, and the snow event leading to the 1997 Flood of the Century in the U.S. midwest regions and in Manitoba of Canada. SeaWinds/QuikSCAT results reveal the expansion and retreat of global snow cover during the 2000 snow season. The anomalous warming event in late December 1999 was captured by the satellite data. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nghiem, SV (reprint author), CALTECH, Jet Prop Lab, MS 300-235,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1748 EP 1750 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000565 ER PT B AU West, RD AF West, RD BE Stein, TI TI The application of L-band and C-band radar measurements to monitoring land snow cover SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB L-band and C-band microwave radar observations can help to measure the properties of snow cover on land by providing information about the soil-snow boundary condition. In this theoretical study, we examine the sensitivities of microwave radar measurements to soil and snow characteristics, and we compare a simple model with previously published data. These data show that the thermal insulation provided by snow cover can have a powerful effect on the soil-snow boundary by altering the soil temperature and therefore changing the dielectric contrast. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP West, RD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1751 EP 1753 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000566 ER PT B AU Hall, DK Riggs, GA Salomonson, VV Scharfen, GR AF Hall, DK Riggs, GA Salomonson, VV Scharfen, GR BE Stein, TI TI Early results from the Moderate Resolution Imaging Spectroradiometer (MODIS) global snow and ice cover products SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Early snow cover and sea ice map products derived from MODIS data are shown to represent a potential improvement on, or enhancement to, existing maps. Field and aircraft data, obtained on March 6, 2000, will help to validate the MODIS snow-cover maps. Qualitative comparison with operational snow maps has provided promising results. Snow and sea ice products will be archived and distributed by the National Snow and Ice Data Center beginning in the summer of 2000. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Hall, DK (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Code 974, Greenbelt, MD 20771 USA. RI Hall, Dorothy/D-5562-2012 NR 9 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1763 EP 1765 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000570 ER PT B AU Menzies, RT Tratt, DM Haner, DA AF Menzies, RT Tratt, DM Haner, DA BE Stein, TI TI Atmospheric and surface backscatter: Dynamic range and spatial variability effects on lidar design and performance SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID BIDIRECTIONAL REFLECTANCE; SPECTROSCOPY AB Although nearly all the airborne and orbiting active laser sensors to date have operated at near nadir pointing angles, in either lidar or altimeter mode, we anticipate dual-mode instruments such as GLAS to emerge and impact the remote sensing community in the next decade. We discuss the variability which off-nadir scanning brings to the measurement concepts - variability which can engender new measurement capabilities as well as cause interpretational problems. In that context we discuss the dynamic range of surface reflectance (backscatter) over water and various land surfaces, including dependence on nadir angle. A new measurement opportunity which exists using scanning lidar systems optimized for wide dynamic range is the measurement of surface wind over oceans. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Menzies, RT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Tratt, David/0000-0002-3942-6848 NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1775 EP 1777 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000574 ER PT B AU Spinhirne, JD Duda, DP Eloranta, EW AF Spinhirne, JD Duda, DP Eloranta, EW BE Stein, TI TI Cloud and aerosol multiple scattering effects for the GLAS atmospheric and surface measurements SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Spinhirne, JD (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 912, Greenbelt, MD 20771 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1781 EP 1783 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000576 ER PT B AU Bidwell, SW Meneghini, R Liao, L Rincon, RF Heymsfield, GM AF Bidwell, SW Meneghini, R Liao, L Rincon, RF Heymsfield, GM BE Stein, TI TI Application of a differential reflectivity technique to the EDOP radar in ground-based operation SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB This paper discusses modification of a single-frequency Doppler radar (9.6 GHz) to accommodate dual-frequency operation for the study of the microphysical character of precipitation. The modification involves the ER-2 Doppler radar (EDOP), an airborne, meteorological research radar of the NASA/Goddard Space Flight Center[1]. Radar operation is modified to provide reflectivity signals at two distinct frequencies at 9% separation. Differential reflectivity results are shown from ground-based measurement. Future work will derive drop size distribution estimates from these measurements. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bidwell, SW (reprint author), NASA, Goddard Space Flight Ctr, Code 555, Greenbelt, MD 20771 USA. NR 5 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1789 EP 1791 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000578 ER PT B AU Durden, SL Li, FK Im, E AF Durden, SL Li, FK Im, E BE Stein, TI TI Surface clutter due to antenna sidelobes for spaceborne atmospheric radar SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID TRMM AB A spaceborne radar for atmospheric observation must be able to detect atmospheric backscatter in the presence of clutter due to antenna sidelobes. Here, we analyze the problem in detail, deriving a method for computing clutter which includes effects of all contributing transmit pulses, Doppler shifting, finite receiver bandwidth, and curved earth's surface. The results are applied to analysis of existing radars and design of future radar systems. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Durden, SL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1795 EP 1797 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000580 ER PT B AU Liao, L Meneghini, R AF Liao, L Meneghini, R BE Stein, TI TI Investigation of the dielectric constants of inhomogeneous air-ice and snow-water spheres SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Caelum Res Corp, Greenbelt, MD 20771 USA. RP Liao, L (reprint author), NASA, Goddard Space Flight Ctr, Caelum Res Corp, Code 975, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1804 EP 1806 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000583 ER PT B AU Garvin, JB Mahmood, A Parashar, S Banik, B AF Garvin, JB Mahmood, A Parashar, S Banik, B BE Stein, TI TI Characterizing landscape and land cover in the azores with RADARSAT-1 imagery SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Landscape and land cover patterns of a selected group of islands in the Azores Archipelago have been assessed on the basis of Synthetic Aperture Radar (SAR) image data of Canada's RADARSAT-1 satellite. These data were acquired as part of RADARSAT-1 baseline data acquisitions called Background Mission. RADARSAT-1 SAR allows for the discrimination of landcover units associated with steep coastal cliffs, dense montane forests, localized areas of intense agriculture, recently active volcanic terrain, and narrow gravel beaches. Human dwellings often appear as distinct targets of bright radar response and can be easily delineated. Despite the presence of a continuous veneer of vegetation, the underlying volcanic terrane and associated landforms, particularly the Holocene caldera structures, are discernable on RADARSAT-1 images. The erosional signatures of gullies and other drainage systems are apparent, as are escarpments with local slopes at or above the angle of repose. Residual cloud forests on several of the islands are mappable, although there is evidence for spatial fragmentation. The all-weather, multi-mode imaging capabilities make RADARSAT-1 a useful tool for studying landcover variations of anthropogenic and natural causes in this perenially cloud-covered region of the world. C1 NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. RP Garvin, JB (reprint author), NASA, Goddard Space Flight Ctr, Terr Phys Lab, Code 921,Bldg 33,Room F326, Greenbelt, MD 20771 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 1981 EP 1983 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000641 ER PT B AU Nghiem, SV Liu, WT Tsai, WY Xie, X AF Nghiem, SV Liu, WT Tsai, WY Xie, X BE Stein, TI TI Flood mapping over the Asian continent during the 1999 summer Monsoon season SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Backscatter data from the SeaWinds scatterometer on the QuikSCAT satellite are used to delineate floods over the Asian continent. SeaWinds acquires Ku-band (13.4 GHz) data at the vertical polarization over a very large swath of 1800 km, and at the horizontal polarization over a 1400-km swath. We present the flood areas together with topography on land and wind field on ocean. Results show extensive flood in China, India, Bangladesh, and other Asian countries. Timely flood mapping can provide crucial information for flood relief efforts. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nghiem, SV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-235, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2027 EP 2028 PG 2 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000656 ER PT B AU Fleig, AJ Blanchette, JJ Kuyper, JA Seaton, JM Wolfe, RE Masuoka, EJ AF Fleig, AJ Blanchette, JJ Kuyper, JA Seaton, JM Wolfe, RE Masuoka, EJ BE Stein, TI TI Resources for developing algorithms and processing level 1A and geolocation information. SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Every satellite data system starts with some form of Level 1 and geolocation processing. This paper provides information to help future missions better estimate the personnel, schedule, and computing requirements for their data processing and algorithm development, The level of development effort and the computational resources for Level 1A and Geolocation processing for the MODIS instrument are described. This information is related to the requirements for the Level 1A and Geolocation tasks. Estimates of how both development and processing resource requirements scale to these functional requirements are provided. C1 NASA, Goddard Space Flight Ctr, PITA, Greenbelt, MD 20771 USA. RP Fleig, AJ (reprint author), NASA, Goddard Space Flight Ctr, PITA, Code 922, Greenbelt, MD 20771 USA. RI Wolfe, Robert/E-1485-2012 OI Wolfe, Robert/0000-0002-0915-1855 NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2047 EP 2049 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000663 ER PT B AU Masuoka, E Tilmes, C Ye, G Devine, N AF Masuoka, E Tilmes, C Ye, G Devine, N BE Stein, TI TI Producing global science products for the moderate resolution imaging spectroradiometer (MODIS) in MODAPS SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Masuoka, E (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Tilmes, Curt/D-5637-2012; OI Tilmes, Curt/0000-0002-6512-0287 NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2050 EP 2052 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000664 ER PT B AU Nisihama, M Wolfe, RE Fleig, AJ Blanchette, J Kuyper, J AF Nisihama, M Wolfe, RE Fleig, AJ Blanchette, J Kuyper, J BE Stein, TI TI MODIS geolocation algorithm and error analysis tools SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The Moderate Resolution Imaging Spectroradiometer (MODIS) contains 36 bands from the visible to the thermal infrared with the nominal ground field of views of 250 m, 500 m and 1 km. This paper summarizes the MODIS Earth location algorithm from the focal plane/detector system through the telescope system, rotating scan mirror system, spacecraft ephemeris/attitude processing system, and digital elevation model. It also describes how the geolocation of other bands can be derived from the ideal band ground coordinates. Some tools have been developed to check the model accuracy and validity of the geolocation. This paper describes these tools including a ground control point matching program a trend and bias error analysis program, and a MODIS image simulation program using Landsat TM (Thematic Mapper) images. Some post launch findings on the model accuracy and necessary changes to the model are also described. C1 NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. RP Nisihama, M (reprint author), NASA, Goddard Space Flight Ctr, Raytheon ITSS, Code 922,Bld 32,Rm S15D, Greenbelt, MD 20771 USA. RI Wolfe, Robert/E-1485-2012 OI Wolfe, Robert/0000-0002-0915-1855 NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2053 EP 2055 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000665 ER PT B AU Tilmes, C Masuoka, E McKerley, P AF Tilmes, C Masuoka, E McKerley, P BE Stein, TI TI Concepts for scaling the processing capability of the MODIS data processing system(MODAPS) SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Tilmes, C (reprint author), NASA, Goddard Space Flight Ctr, Code 922, Greenbelt, MD 20771 USA. RI Tilmes, Curt/D-5637-2012; OI Tilmes, Curt/0000-0002-6512-0287 NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2062 EP 2064 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000668 ER PT B AU Wolfe, RE Nishihama, M Fleig, AJ Unger, JM Roy, DP AF Wolfe, RE Nishihama, M Fleig, AJ Unger, JM Roy, DP BE Stein, TI TI The MODIS operational geolocation error analysis and reduction early results SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID LAND AB The Moderate Resolution Imaging Spectroradiometer (MODIS) was launched December 1999 on the polar orbiting Terra satellite and since February 2000 has been acquiring earth observation data. The Terra satellite has onboard exterior orientation (position and attitude) measurement systems designed to enable unaided navigation of MODIS data to within approximately 150 m (1 sigma) at nadir. A global network of ground control points will be used to improve the navigation* to approximately 50 m (1 sigma). This approach allows an operational characterization of the MODIS geolocation errors and enables individual MODIS observations to be geolocated to the sub-pixel accuracies required for terrestrial global change applications. C1 NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. RP Wolfe, RE (reprint author), NASA, Goddard Space Flight Ctr, Raytheon ITSS, Code 922, Greenbelt, MD 20771 USA. RI Wolfe, Robert/E-1485-2012 OI Wolfe, Robert/0000-0002-0915-1855 NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2065 EP 2067 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000669 ER PT B AU Graham, S Herring, D Ward, K Simmon, R Stockman, S Heney, M Cole, S Weier, J Syvertson, M Varani, A AF Graham, S Herring, D Ward, K Simmon, R Stockman, S Heney, M Cole, S Weier, J Syvertson, M Varani, A BE Stein, TI TI The Earth Observatory: NASA's new Web environment for learning about Earth SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Graham, S (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2090 EP 2091 PG 2 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000677 ER PT B AU Lutz, B Roy, DP Leff, C Lewicki, S Geier, E Ziskin, D Kilpatrick, K Chu, A AF Lutz, B Roy, DP Leff, C Lewicki, S Geier, E Ziskin, D Kilpatrick, K Chu, A BE Stein, TI TI A review of EOS Terra quality assessment SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Terra is the flagship platform of NASA's Earth Observing System (EOS) carrying the ASTER, CERES, MISR, MODIS, and MOPITT instruments in a polar sun-synchronous orbit. These instruments sense approximately 200 gigabytes of data per day which are processed to produce a suite of standard products. QA involves the identification and labeling of those products which obviously and significantly do not conform to their expected accuracy/performance. This paper overviews the components of EOS QA and the different QA strategies developed by the Terra science teams. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lutz, B (reprint author), NASA, Goddard Space Flight Ctr, Code 423, Greenbelt, MD 20771 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2092 EP 2095 PG 4 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000678 ER PT B AU Simard, M Saatchi, S DeGrandi, G AF Simard, M Saatchi, S DeGrandi, G BE Stein, TI TI Comparison of a decision tree and maximum likelihood classifiers: Application to SAR image of tropical forest SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 Jet Propuls Lab, Radar Sci & Engn Sect, Pasadena, CA 91109 USA. RP Simard, M (reprint author), Jet Propuls Lab, Radar Sci & Engn Sect, Pasadena, CA 91109 USA. OI Simard, Marc/0000-0002-9442-4562 NR 3 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2129 EP 2130 PG 2 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000690 ER PT B AU Durden, SL Haddad, ZS AF Durden, SL Haddad, ZS BE Stein, TI TI Unsupervised classification of radar imagery of wetlands using the soft competition scheme SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID POLARIMETRIC SAR DATA; SEGMENTATION; AREA AB We apply a technique developed in the field of vector quantization to the problem of unsupervised classification of radar imagery of wetlands. The method can perform better than traditional unsupervised methods, such as k-means, because it performs soft classification at each step. The method is applied to Alaska data and shown to give results that are similar to previous results using supervised classification. Results are also shown for data from Belize. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Durden, SL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2158 EP 2160 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000700 ER PT B AU Lowe, ST Zuffada, C LaBrecque, JL Lough, M Lerma, J Young, LE AF Lowe, ST Zuffada, C LaBrecque, JL Lough, M Lerma, J Young, LE BE Stein, TI TI An ocean-altimetry measurement using reflected GPS signals observed from a low-altitude aircraft SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB We present the first airborne ocean-altimetry measurement made using reflected GPS signals. Data were collected from a Cessna airplane flying off the coast of Santa Barbara, California, where the direct and ocean-reflected GPS Ll signals were downconverted and recorded onboard at 20.456 MHz. In addition, the direct signals were processed with a TurboRogue GPS receiver and used to derive accurate receiver positioning. The 20 MHz samples were processed with a "software GPS receiver", developed for this task, to extract the direct and reflected signal waveforms, using both the C/A and Y-codes. These waveforms were fit to obtain a direct/reflected reception delay difference, each second. These delays were fit for ocean height and clock offset. First results for the C/A-code waveforms show the mean of the measured 1-sec values agrees well with altimetry database values. The residual height RMS was 3.1 m during straight, level flight, and 4.7 m for all data and all PRNs. Further analysis refinements, including more accurate waveform modeling and fitting, CIA-code sidelobe elimination, atmospheric modeling, and the use of Y-code waveforms, will likely improve these results. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lowe, ST (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 238-600, Pasadena, CA 91109 USA. NR 3 TC 3 Z9 6 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2185 EP 2187 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000709 ER PT B AU Montgomery, H Che, N Bowser, J AF Montgomery, H Che, N Bowser, J BE Stein, TI TI Determination of MODIS band-to-band co-registration on-orbit using the SRCA SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB This paper presents the measurement results of how well the thirty-six MODIS bands are registered with respect to each other on the earth at nadir. Test data show that the SRCA provides consistent results. Excluding FPA shifts, the repeatability on-orbit for four tests is within +/-0.01 km. Results indicate that the worst band-to-band registration is +/-0.11 km in along-scan direction (perpendicular to the satellite ground track) and +/-0.17 km along-track. C1 NASA, GSFC, Greenbelt, MD 20708 USA. RP Montgomery, H (reprint author), NASA, GSFC, Greenbelt, MD 20708 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2203 EP 2205 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000715 ER PT B AU Johnson, JW Munden, WM Lawrence, RW AF Johnson, JW Munden, WM Lawrence, RW BE Stein, TI TI Efficiency and performance in coherent detection algorithms for synthetic aperture radiometry SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Synthetic aperture interferometric radiometers require phase coherent detection to allow the visibility function to be measured and subsequently converted to brightness temperature images. Products of signals between channels produce the complex "visibility" terms of the spatial spectrum of the brightness temperature scene. Today's technology offers the choice of either analog or digital detection methods for relatively low microwave frequencies. Digital detection may offer advantages, particularly in certain instrument configurations. This paper reviews the results of an evaluation of a particular digital method and a variety of FIR filter designs. A programmable, real time processor was developed to study various Hilbert Transform algorithms for digitally forming the in-phase (I) and quadrature (Q) components of the received signals. An overview of the test set-up and test results using several FIR filters will be presented, allowing a trade between numerical simplicity and the gain and phase balance between I and Q. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Johnson, JW (reprint author), NASA, Langley Res Ctr, MS 473, Hampton, VA 23681 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2266 EP 2268 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000736 ER PT B AU Zuzek, JE AF Zuzek, JE BE Stein, TI TI Sensor frequency allocation issues for WRC-2000 SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Zuzek, JE (reprint author), NASA, Glenn Res Ctr, 2100 Brookpk Rd,MS 54-2, Cleveland, OH 44135 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2444 EP 2446 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000795 ER PT B AU Wende, CD AF Wende, CD BE Stein, TI TI NASA remote sensing missions and frequency issues SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA Headquarters, Off Earth Sci, Washington, DC 20546 USA. RP Wende, CD (reprint author), NASA Headquarters, Off Earth Sci, Code YF,300 E St SW, 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 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2447 EP 2451 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000796 ER PT B AU Huneycutt, B Zuzek, J AF Huneycutt, B Zuzek, J BE Stein, TI TI Frequency use and needs of spaceborne active sensors SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB Spaceborne active sensors have been used for several years to study the Earth's surface and atmosphere. The intent of this paper is to present the unique types of sensors and their characteristics that determine their individual frequency needs; to present performance and interference criteria necessary for compatibility studies with other services in the frequency bands of interest; and to present a status of current frequency spectrum use and needs and compatibility studies of spaceborne active sensors and other services, along with any issues or concerns. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Huneycutt, B (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-241, Pasadena, CA 91109 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2457 EP 2463 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000799 ER PT B AU Zuzek, JE Stevens, G Marelli, E AF Zuzek, JE Stevens, G Marelli, E BE Stein, TI TI Protection of passive sensing use in the 18.6-18.8 GHz band SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Zuzek, JE (reprint author), NASA, Glenn Res Ctr, 2100 Brookpk Rd,MS 54-2, Cleveland, OH 44135 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2464 EP 2466 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000800 ER PT B AU Blom, RG Crippen, RE Zarins, J Hedges, GR AF Blom, RG Crippen, RE Zarins, J Hedges, GR BE Stein, TI TI Remote sensing, shuttle radar topographic mapper data, and ancient frankincense trade routes SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID SUBSURFACE AB Over the last fifteen years, an unusual combination of space technologies coupled with traditional archaeology has given insight into the ancient southern Arabian frankincense trade, including the discovery of the lost "city" of Ubar in present day Oman. Continued research indicates a series of desert caravansaries to the west in modem Yemen. Pliny. the ancient Roman historian, reports that there were "octomansiones" (eight fortresses, or mansions) along the desert frankincense trade route. Our present work seeks to document this, and illuminate the poorly known civilization which supported frankincense trade. We presently have Landsat Thematic Mapper (TM) coverage of most of southern Arabia. We also have geographically discontinuous SIR-C and ERS coverage. At present we also have publicly released quicklook SRTM data for the border area between Yemen and Oman, and eagerly await full coverage with SRTM topographic data. Topographic data will provide critical insight into trade routes and fortresses with regards to water sources and routes from the coast and mountains, where people lived, to the interior desert. Given the nature of this research, comprehensive geographic coverage provided by SRTM and Landsat are a fundamental requirement. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Blom, RG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 300-233, Pasadena, CA 91109 USA. NR 13 TC 1 Z9 1 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2477 EP 2479 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000804 ER PT B AU Blom, RG Chapman, B Podest, E Murowchick, R AF Blom, RG Chapman, B Podest, E Murowchick, R BE Stein, TI TI Applications of remote sensing to archaeological studies of early Shang civilization in northern China SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB This is a preliminary report on our collaborative work with an ongoing archaeology project undertaken by the East Asian Archaeology Center, Boston University, and the Institute of Archaeology, Chinese Academy of Social Sciences (CASS-IA). Since 1990, that project has sought to locate and investigate sites of the early Shang Dynasty (ca. 2000-1500 BC), including the site of the first Shang capital and ritual center, Great City Shang. The research area centers on Shangqiu Man (or Shang-ch'iu Hsien) at the far eastern end of Henan Province in the North China Plain, an area that has been blanketed by alluvial deposits from the Yellow River as its course has wandered across eastern Henan during the past four millennia. As a result, this part of the North China Plain - home of a number of the most important of China's early civilizations - is poorly known archaeologically, a situation that can be significantly improved with the application of a variety of remote sensing technologies. Rapid economic development in the area demands more efficient archaeological prospection before important sites are lost to development. We have assembled radar data from JERS, Corona reconnaissance image data, several Landsat 5 Thematic Mapper data sets, SPOT images, and most recently we have acquired 8 new Landsat 7 data sets of the region. Initial remote sensing efforts include standard image processing and analysis methods. We also seek sites related to early copper mining and other infrastructural elements to this early culture using Landsat band ratios and a new vegetation removal algorithm. A highly speculative application of radar data involves InSAR measurements seeking potential elevation changes related to differential swelling/shrinking of soils with moisture content. At present, we have succeeded in generating interferograms, but do not have InSAR results at this writing. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Blom, RG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 300-233, Pasadena, CA 91109 USA. NR 2 TC 1 Z9 1 U1 1 U2 7 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2483 EP 2485 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000806 ER PT B AU Garegnani, J Gualtieri, JA Chettri, S Robinson, J Hunt, JP Bechdol, M Vermeullen, A AF Garegnani, J Gualtieri, JA Chettri, S Robinson, J Hunt, JP Bechdol, M Vermeullen, A BE Stein, TI TI Preliminary tests of the utility of hyperspectral image data to precision farming SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Goddard Space Flight Ctr, Appl Informat Sci Branch, Greenbelt, MD 20771 USA. RP Garegnani, J (reprint author), NASA, Goddard Space Flight Ctr, Appl Informat Sci Branch, Code 935, Greenbelt, MD 20771 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2519 EP 2521 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000818 ER PT B AU Le Vine, DM Koblinsky, C Howden, S Haken, M Goodberlet, M AF Le Vine, DM Koblinsky, C Howden, S Haken, M Goodberlet, M BE Stein, TI TI Salinity measurements during the Gulf Stream experiment SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The Gulf Stream Experiment was conducted in late summer, 1999, as part of research at the Goddard Space Flight Center on passive, microwave remote sensing of salinity in the open ocean. Measurements were made about 250 kin cast of Delaware Bay between the waters of the continental shelf and the north wall of the Gulf Stream. The instruments included the airborne L-band radiometers ESTAR and SLFMR. Ships and drifter buoys provided surface truth. Preliminary results show good agreement between the microwave measurements and ship measurements of salinity. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Le Vine, DM (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2537 EP 2539 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000824 ER PT B AU Li, FK Wilson, WJ Yueh, SH Dinardo, SJ Howden, S AF Li, FK Wilson, WJ Yueh, SH Dinardo, SJ Howden, S BE Stein, TI TI Passive active L/S-band microwave aircraft sensor for ocean salinity measurements SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB A Passive/Active L/S-band (PALS) microwave aircraft instrument to measure ocean salinity has been built and tested. Because the L-band brightness temperatures associated with salinity changes are expected to be small, it was necessary to build a very sensitive and stable system. This new instrument has dual-frequency, dual polarization radiometer and radar sensors. The antenna is a high beam efficiency conical horn. The PALS instrument was installed on the NCAR C-130 aircraft and salinity measurement missions were flown on July 17-19, 1999, southeast of Norfolk, Virginia over the Gulf Stream. The measurements indicated a clear and repeatable salinity signal during these three days, which was in good agreement with the R/V Cape Hatteras salinity data. Data was also taken in the open ocean and a small decrease of 0.2 K was measured in the brightness temperature, which corresponded to the salinity increase of 0.4 psu measured by the M/V Oleander vessel. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Li, FK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Bldg 168-327, Pasadena, CA 91109 USA. NR 4 TC 1 Z9 1 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2540 EP 2542 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000825 ER PT B AU Yueh, SH Wilson, WJ Njoku, E Li, FK West, R AF Yueh, SH Wilson, WJ Njoku, E Li, FK West, R BE Stein, TI TI Retrieval modeling and error sources for microwave remote sensing of ocean surface salinity SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB A set of geophysical error sources for the microwave remote sensing of ocean surface salinity have been examined. The error sources include the sea surface temperature, sea surface roughness, atmospheric gases, ionospheric Faraday rotation, and planetary and galatic emission sources. It is shown that the brightness temperature errors of a few Kelvin can be expected for most of these error sources. The key requirements for corrections are the knowledge accuracy of 0.5 degreesC for the sea surface temperature (SST), 10 degreesC for the surface air temperature, 0.2 degrees accuracy for the Faraday rotation, and 0.3 m/s for the surface wind speed, We suggest the use of data products from AMSR-type instruments for the corrections of SST and liquid cloud water, the numerical weather analysis for the surface air temperature, and on-board radar and polarimetric radiometer channel for surface roughness and Faraday rotation. The most significant sky radiation is from the sun. A careful design of the antenna is necessary to minimize the leakage of solar radiation or reflection into the antenna side lobe. The narrowband radiation from galatic hydrogen clouds is also significant, but can be corrected with an accurate radio sky survey or minimized with a notched (band-rejection) filter centered at 1.420 GHz in the receiver. The other planetary and galatic radio sources can be flagged with negligible data loss. We have performed a sampling analysis for a polar-orbiting satellite with 900 km swath width to determine the number of satellite observations from a given surface pixel over an extended duration. Under the assumption that the observations from different satellite passes are independent, it is suggested that an accuracy of 0.1 psu is reachable for global monthly I-degree latitude and 1-degree longitude gridded products. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yueh, SH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-235, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2546 EP 2548 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000827 ER PT B AU Wilson, WJ Njoku, EG Yueh, SH AF Wilson, WJ Njoku, EG Yueh, SH BE Stein, TI TI Active/Passive microwave system with deployable mesh antenna for spaceborne ocean salinity measurements SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB A concept has been studied for remote sensing of sea surface salinity from space using a large deployable mesh antenna system. The antenna has a 6-m-diameter offset-fed parabolic reflector with multichannel feedhorns and radiometers and a radar, operating at L and S bands. The entire system rotates about the nadir axis, providing a conical scan across a 900km wide swath at a spatial resolution of about 40 kin from a 600-km orbit attitude. The study includes evaluation of deployable mesh antennas and preferred antenna, spacecraft, and launch vehicle configurations. Designs for compact, lightweight feedhorns and radiometer/radar electronics were also developed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wilson, WJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 3 TC 0 Z9 1 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2549 EP 2551 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000828 ER PT B AU Li, L Im, E AF Li, L Im, E BE Stein, TI TI Influence of sea surface backscattering on the spaceborne radar measurements of rainfall SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB A critical issue for TRMM Precipitation Radar (PR) is to estimate path integrated attenuation using Surface Reference Technique (RST), which assumes uniform ocean surface backscattering background at precipitation scale, and attributes the difference in measured surface backscattering cross sections inside and outside of storms to path-integrated attenuation. Since ocean surface winds are the major force that controls the strength of the backscattering signals, it is very desirable to examine or "explain" the measured ocean backscattering using ocean surface wind fields. To this end, we examined the feasibility of retrieving ocean surface winds from TRMM PR data for the benefit of surface reference technique. A geophysical model function, a forward model, is developed based on ocean surface wind speed retrieved from TRMM Microwave Imager data. A field-wise wind retrieval procedure, an inverse model, is formulated using maximum likelihood estimation, TRMM PR data are analyzed to demonstrate that the PR derived ocean wind speed can explain the ocean backscattering successfully Possible improvements on the existing surface reference technique are also discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Li, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2561 EP 2563 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000832 ER PT B AU Spinhirne, JD AF Spinhirne, JD BE Stein, TI TI Cirrus parameter retrieval by combined analysis of spectral thermal infrad and lidar sensing from aircraft and space SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci ID RADIOMETER C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Spinhirne, JD (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 912, Greenbelt, MD 20771 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2583 EP 2583 PG 1 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000839 ER PT B AU Skofronick-Jackson, GM Wang, JR AF Skofronick-Jackson, GM Wang, JR BE Stein, TI TI Convective cloud profile estimations using wideband radiometer and radar observations SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 Univ Space Res Assoc, NASA Goddard, Greenbelt, MD 20771 USA. RP Skofronick-Jackson, GM (reprint author), Univ Space Res Assoc, NASA Goddard, Code 975, Greenbelt, MD 20771 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2584 EP 2586 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000840 ER PT B AU Gasch, J Arvidson, T Goward, SN Andrefouet, S Hu, CM Muller-Karger, FE AF Gasch, J Arvidson, T Goward, SN Andrefouet, S Hu, CM Muller-Karger, FE BE Stein, TI TI An assessment of landsat 7/ETM+ coverage of coral reefs worldwide SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB This paper presents the state of the Landsat 7 archive of high resolution, multi-spectral imagery of coral reef after nearly 10 months of operation. C1 Goddard Space Flight Ctr, Landsat Miss Operat 7, Greenbelt, MD 20771 USA. RP Gasch, J (reprint author), Goddard Space Flight Ctr, Landsat Miss Operat 7, Code 428-1,Bldg 32 Rm W210A, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2687 EP 2689 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000874 ER PT B AU Lawrence, RW Campbell, TG AF Lawrence, RW Campbell, TG BE Stein, TI TI Radiometric characterization of mesh reflector material for deployable real aperture remote sensing applications SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB The simultaneous requirement for long wavelength and high spatial resolution for important geophysical remote sensing application, such as soil moisture and salinity, suggest the use of large to moderate sized deployable reflectors as a possible solution. Many studies have recognized the potential advantages of mesh reflectors [1] However, the emissivity of the reflector and its stability are major concerns and must the carefully considered to enable the advantages of deployable reflector technology for remote sensing applications. This paper will describe an advanced measurement system to evaluate the emissivity of reflector materials for these applications. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Lawrence, RW (reprint author), NASA, Langley Res Ctr, 8 N Dryden St,MS-473, Hampton, VA 23681 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2724 EP 2726 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000886 ER PT B AU Walsh, EJ Wright, CW Vandemark, DC Krabill, WB Garcia, AW Houston, SH Powell, MD Black, PG Marks, FD AF Walsh, EJ Wright, CW Vandemark, DC Krabill, WB Garcia, AW Houston, SH Powell, MD Black, PG Marks, FD BE Stein, TI TI Hurricane directional wave spectrum spatial variation in open ocean and at landfall SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci AB On 24 August 1998, the NASA/Goddard Space Flight Center Scanning Radar Altimeter (SRA) provided the first documentation of the sea surface directional wave spectrum in all quadrants of a hurricane in open water when Bonnie, a large Category 3 hurricane, was east of the Bahamas. The SRA flew into Bonnie again on 26 August 1998, when she was making landfall near Wilmington, NC, documenting the wave field in the region between Charleston, SC and Cape Hatteras, NC. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Flight Facil, Wallops Isl, VA 23337 USA. RP Walsh, EJ (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Flight Facil, Code 972, Wallops Isl, VA 23337 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2750 EP 2752 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000895 ER PT B AU Prior, EJ Pinelli, TE Starr, RM Massenberg, SE AF Prior, EJ Pinelli, TE Starr, RM Massenberg, SE BE Stein, TI TI New distance learning approaches to remote sensing education SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 NASA, Langley Res Ctr, Off Educ, Hampton, VA 23681 USA. RP Prior, EJ (reprint author), NASA, Langley Res Ctr, Off Educ, 17 Langley Blvd,Mail Stop 400, Hampton, VA 23681 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2774 EP 2776 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000903 ER PT B AU Wu, DL Jiang, JH AF Wu, DL Jiang, JH BE Stein, TI TI Mapping atmospheric gravity wave activity with limb-viewing microwave radiometer (UARS MLS) SO IGARSS 2000: IEEE 2000 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM, VOL I - VI, PROCEEDINGS SE IEEE International Symposium on Geoscience and Remote Sensing (IGARSS) LA English DT Proceedings Paper CT IEEE International Geoscience and Remote Sensing Symposium CY JUL 24-28, 2000 CL HONOLULU, HI SP IEEE, IEEE Geosci & Remote Sensing Soc, NASA, NOAA, USN, Off Res, Nat Resources Canada, Canadian Space Agcy, Natl Space Dev Agcy Japan, Int Union Radio Sci C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wu, DL (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-701, Pasadena, CA 91109 USA. RI Wu, Dong/D-5375-2012 NR 7 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6359-0 J9 INT GEOSCI REMOTE SE PY 2000 BP 2800 EP 2802 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Physical Geography; Geology; Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BT13Y UT WOS:000172046000912 ER PT S AU Talukder, A Casasent, D AF Talukder, A Casasent, D BE Amari, SI Giles, CL Mori, M Piuri, V TI Neural net with adaptive activation functions for face recognition SO IJCNN 2000: PROCEEDINGS OF THE IEEE-INNS-ENNS INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOL III SE IEEE International Joint Conference on Neural Networks (IJCNN) LA English DT Proceedings Paper CT IEEE/INNS/ENNS International Joint Conference on Neural Networks (IJCNN 2000) CY JUL 24-27, 2000 CL COMO, ITALY SP IEEE Neural Network Council, Int Neural Network Soc, European Neural Network Soc ID OBJECT CLASSES AB A new efficient two-stage algorithm to compute nonlinear features is described. Its implementation on a neural net with adaptive activation functions that raise the input data to an arbitrary power is described. Its use in face recognition with unknown input poses is presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM casasent@ece.cmu.edu NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 2161-4393 J9 IEEE IJCNN PY 2000 BP 311 EP 314 DI 10.1109/IJCNN.2000.861322 PG 4 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BQ71H UT WOS:000089240300050 ER PT S AU Motter, MA AF Motter, MA BE Amari, SI Giles, CL Gori, M Piuri, V TI Predictive multiple model switching control with the self-organizing map SO IJCNN 2000: PROCEEDINGS OF THE IEEE-INNS-ENNS INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOL IV SE IEEE International Joint Conference on Neural Networks (IJCNN) LA English DT Proceedings Paper CT IEEE/INNS/ENNS International Joint Conference on Neural Networks (IJCNN 2000) CY JUL 24-27, 2000 CL COMO, ITALY SP IEEE Neural Network Council, Int Neural Network Soc, European Neural Network Soc AB A predictive, multiple model control strategy is developed by extension of self-organizing map (SOM) local dynamic modeling of nonlinear autonomous systems to a control framework. Multiple SOMs collectively model the global response of a nonautonomous system to a finite set of representative prototype controls. Each SOM provides a codebook representation of the dynamics corresponding to a prototype control. Different dynamic regimes are organized into topological neighborhoods where the adjacent entries in the codebook represent the global minimization of a similarity metric. The SOM is additionally employed to identify the local dynamical regime, and consequently implements a switching scheme that selects the best available model for the applied control. SOM based linear models are used to predict the response to a larger family of control sequences which are clustered on the representative prototypes. The control sequence which corresponds to the prediction that best satisfies the requirements on the system output is applied as the external driving signal. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Motter, MA (reprint author), NASA, Langley Res Ctr, Mail Stop 132, Hampton, VA 23681 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 1098-7576 J9 IEEE IJCNN PY 2000 BP 317 EP 322 DI 10.1109/IJCNN.2000.860791 PG 6 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BQ71J UT WOS:000089240400053 ER PT S AU Mukai, R Arabshahi, P Vilnrotter, VA AF Mukai, R Arabshahi, P Vilnrotter, VA BE Amari, SI Giles, CL Gori, M Piuri, V TI An array feed radial basis function tracking system for NASA's deep space network antennas SO IJCNN 2000: PROCEEDINGS OF THE IEEE-INNS-ENNS INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOL VI SE IEEE International Joint Conference on Neural Networks (IJCNN) LA English DT Proceedings Paper CT IEEE/INNS/ENNS International Joint Conference on Neural Networks (IJCNN 2000) CY JUL 24-27, 2000 CL COMO, ITALY SP IEEE Neural Network Council, Int Neural Network Soc, European Neural Network Soc ID COMPENSATION AB The use of radial basis function networks for fine pointing NASA's 70-meter deep space network antennas is described and evaluated We demonstrate that such a network, working in conjunction with the army feed compensation system, and trained using the computationally efficient orthogonal least-squares algorithm, can point a 70-meter deep space antenna with mts errors of less than 0.3 millidegree under good signal-to-noise ratio conditions, achieving significantly higher accuracies than the 0.8 millidegree benchmark for communications at Ka-band frequencies of 32 GHz. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mukai, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 1098-7576 J9 IEEE IJCNN PY 2000 BP 259 EP 264 DI 10.1109/IJCNN.2000.859406 PG 6 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BQ71L UT WOS:000089240600043 ER PT S AU White, CV Levine, MB Ingham, M AF White, CV Levine, MB Ingham, M GP SEM SEM TI Expansion of time history response measurements for visualization SO IMAC-XVIII: A CONFERENCE ON STRUCTURAL DYNAMICS, VOLS 1 AND 2, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 18th IMAC Conference on Computational Challenges in Structural Dynamics CY FEB 07-10, 2000 CL SAN ANTONIO, TX SP IMAC AB To date many methods have been developed to expand measured mode shapes from a limited number of sensors up to the full set of degrees of freedom (DOFs) of an analytical FEM model. Previous papers have evaluated the accuracy of these techniques on actual experimental data [1]. However, many of these methods are limited to the expansion of mode shapes, and often require a priori knowledge of the measured and analytical modal frequencies, as well as pairings between the experimental and analytical modes. These methods cannot be applied to the general case of a measured time history with multi-mode, transient or steady-state response information. A class of methods for estimating the full state vector from a limited set of measurements, typically used in conjunction with a full-state feedback controller, is an attractive approach for expanding measured time histories. One such method, known as the Kalman filter [2], is a recursive linear state estimator based on least-squares minimization, and can be applied even when measured time histories are noisy or the system dynamics are not known precisely. This paper will explore the methodology of the Kalman filter, and the deterministic counterpart, the Luenberger observer. and evaluate their accuracy on an analytical simulation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP White, CV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 157-316, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-67-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4062 BP 278 EP 283 PG 6 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics; Optics SC Computer Science; Engineering; Mechanics; Optics GA BP87R UT WOS:000086462600043 ER PT S AU Buehrle, RD Fleming, GA Pappa, RS Grosveld, FW AF Buehrle, RD Fleming, GA Pappa, RS Grosveld, FW GP SEM SEM TI Finite element model development and validation for aircraft fuselage structures SO IMAC-XVIII: A CONFERENCE ON STRUCTURAL DYNAMICS, VOLS 1 AND 2, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 18th IMAC Conference on Computational Challenges in Structural Dynamics CY FEB 07-10, 2000 CL SAN ANTONIO, TX SP IMAC AB The ability to extend the valid frequency range for finite element based structural dynamic predictions using detailed models of the structural components and attachment interfaces is examined for several stiffened aircraft fuselage structures. This extended dynamic prediction capability is needed for the integration of mid-frequency noise control technology. Beam, plate and solid element models of the stiffener components are evaluated. Attachment models between the stiffener and panel skin range from a line along the rivets of the physical structure to a constraint over the entire contact surface. The finite element models are validated using experimental modal analysis results. The increased frequency range results in a corresponding increase in the number of modes, modal density and spatial resolution requirements. In this study, conventional modal tests using accelerometers are complemented with Scanning Laser Doppler Velocimetry and Electro-Optic Holography measurements to further resolve the spatial response characteristics. Whenever possible, component and subassembly modal tests are used to validate the finite element models at lower levels of assembly. Normal mode predictions for different finite element representations of components and assemblies are compared with experimental results to assess the most accurate techniques for modeling aircraft fuselage type structures. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Buehrle, RD (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 8 TC 0 Z9 0 U1 1 U2 2 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-67-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4062 BP 356 EP 362 PG 7 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics; Optics SC Computer Science; Engineering; Mechanics; Optics GA BP87R UT WOS:000086462600054 ER PT S AU Pierpont, DW AF Pierpont, DW GP SEM SEM TI Langley Research Center RCM implementation SO IMAC-XVIII: A CONFERENCE ON STRUCTURAL DYNAMICS, VOLS 1 AND 2, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 18th IMAC Conference on Computational Challenges in Structural Dynamics CY FEB 07-10, 2000 CL SAN ANTONIO, TX SP IMAC AB NASA Langley Research Center (LaRC), established in 1917, is located on 800 acres in Hampton, Virginia. It has been and continues to be a leader in the fields of aeronautics, structures and materials, and earth sciences. Presently there are approximately 30 wind tunnels (subsonic to hypersonic), 15 structures and materials laboratories, five acoustic test facilities, and 150 institutional facilities. Equipment types include motors up to 135,000hp, compressors up to 6000psi, hydraulic systems up to 10,000 psi and various types of test equipment. LaRC is nearing completion of the development and implementation of a comprehensive Reliability Centered Maintenance (RCM) program that includes 35,000 pieces of equipment. The incorporation of RCM was accomplished concurrently with the conversion to a new Computerized Maintenance Management System (CMMS), development of a Predictive Testing &Inspection program (PT&I), inventory of center equipment, and change of the facilities systems support services maintenance contract from level of effort, cost plus, award fee to a Performance Based Contract (PBC). Evidence of significant reductions in the preventive maintenance program has been realized through the proper application of time based, condition based, and reactive maintenance using a stream lined RCM approach. C1 NASA, Langley Res Ctr, Facil Planning Sect, Syst Engn Competency, Hampton, VA 23665 USA. RP Pierpont, DW (reprint author), NASA, Langley Res Ctr, Facil Planning Sect, Syst Engn Competency, M-S466, Hampton, VA 23665 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-67-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4062 BP 1123 EP 1125 PG 3 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics; Optics SC Computer Science; Engineering; Mechanics; Optics GA BP87R UT WOS:000086462600168 ER PT S AU Davis, SS Laub, JA AF Davis, SS Laub, JA GP SEM SEM TI Extraction of rotating machinery noise from accelerometer data using the spectral distribution function SO IMAC-XVIII: A CONFERENCE ON STRUCTURAL DYNAMICS, VOLS 1 AND 2, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 18th IMAC Conference on Computational Challenges in Structural Dynamics CY FEB 07-10, 2000 CL SAN ANTONIO, TX SP IMAC AB The early detection of machinery faults is crucial information for an effective health-monitoring program. In this paper, a modification of the spectral distribution function is used to derive a new parameter to detect gear tooth problems in a simple single-geared transmission system. A new wear parameter (or "health index") is presented by tracking the broad band noise component associated with vibration sensor data. This underlying broad band signal is masked by discrete tones when conventional measures are used. Results of the analysis show that clear and unambiguous signals regarding incipient problems are uncovered by this new parameter. C1 NASA, Ames Res Ctr, Fluid Mech Lab, Moffett Field, CA 94035 USA. RP Davis, SS (reprint author), NASA, Ames Res Ctr, Fluid Mech Lab, MS 260-1, Moffett Field, CA 94035 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-67-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4062 BP 1136 EP 1139 PG 4 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics; Optics SC Computer Science; Engineering; Mechanics; Optics GA BP87R UT WOS:000086462600170 ER PT S AU Pappa, RS Doebling, SW Kholwad, TD AF Pappa, RS Doebling, SW Kholwad, TD GP SEM SEM TI On-line database of vibration-based damage detection experiments SO IMAC-XVIII: A CONFERENCE ON STRUCTURAL DYNAMICS, VOLS 1 AND 2, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 18th IMAC Conference on Computational Challenges in Structural Dynamics CY FEB 07-10, 2000 CL SAN ANTONIO, TX SP IMAC AB This paper describes a new, on-line bibliographic database of vibration-based damage detection experiments. Publications in the database discuss experiments conducted on actual structures as well as those conducted with simulated data. The database can be searched and sorted in many ways, and it provides photographs of test structures when available. It currently contains 100 publications, which is estimated to be about 5%-10% of the number of papers written to date on this subject. Additional entries are forthcoming. This database is available for public use on the Internet at the following address: http://sdbpappa-mac.larc.nasa.gov. Click on the link named "dd_experiments.fp3" and then type "guest" as the password. No user name is required. C1 NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. RP Pappa, RS (reprint author), NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-67-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4062 BP 1179 EP 1185 PG 7 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics; Optics SC Computer Science; Engineering; Mechanics; Optics GA BP87R UT WOS:000086462600177 ER PT S AU Peng, CY Tsuha, W AF Peng, CY Tsuha, W GP SEM SEM TI SRTM modal survey and Hybrid Guyan Expansion SO IMAC-XVIII: A CONFERENCE ON STRUCTURAL DYNAMICS, VOLS 1 AND 2, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 18th IMAC Conference on Computational Challenges in Structural Dynamics CY FEB 07-10, 2000 CL SAN ANTONIO, TX SP IMAC AB This paper describes a successful modal survey and subsequent model correlation conducted for the structural system of the Shuttle Radar Topography Mission (SRTM). During the modal survey, some nonlinear behavior of the test article was observed and its source was identified. The SRTM model correlation was also a challenging task. First, access to the mast inside the canister was limited. This led to inadequate instrumentation for the mast, which caused problems when orthogonality and cross-orthogonality were checked. As a result, a "Hybrid" Guyan Expansion method was developed to resolve the problems. The model correlation task was made even more complicated by the mast bounce mode, which coupled strongly with a few of the significant modes of the structure. The development of a good mast model was crucial to the final success of the model correlation. Based on the correlation results, all significant modes of the structure were considered test-verified. C1 Jet Prop Lab, Mech Engn Sect, Spacecraft Struct & Dynam Grp, Pasadena, CA 91109 USA. RP Peng, CY (reprint author), Jet Prop Lab, Mech Engn Sect, Spacecraft Struct & Dynam Grp, Pasadena, CA 91109 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-67-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4062 BP 1281 EP 1287 PG 7 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics; Optics SC Computer Science; Engineering; Mechanics; Optics GA BP87R UT WOS:000086462600193 ER PT S AU Gawronski, W AF Gawronski, W GP SEM SEM TI Simultaneous placement of actuators and sensors SO IMAC-XVIII: A CONFERENCE ON STRUCTURAL DYNAMICS, VOLS 1 AND 2, PROCEEDINGS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 18th IMAC Conference on Computational Challenges in Structural Dynamics CY FEB 07-10, 2000 CL SAN ANTONIO, TX SP IMAC AB A placement of actuator and sensors for flexible structures is studied using the H-2, H-infinity, and Hankel modal norms. The norm of a flexible structure with multiple actuators and sensors is a root-mean-square sum of norms of structures equipped with single sensor and single actuator. This property allows for the evaluation of the importance of a combination of sensors and actuator, in terms of their participation in the overall structural dynamics. This simple and powerful tool is applicable for structures only, since in a general case, a system norm cannot be decomposed into a combination of singte-input-single-output norms, and consequently complex searching techniques need to be used. The algorithm consists of the determination either H-2, or H-infinity, or Hankel norms for the ith mode, jth actuator, and kth sensor. Using the norms, the sensor and actuator placement matrices are generated far each considered mode, The matrices are used to evaluate each sensor and actuator combination, and to determine the simultaneous actuator and sensor locations such that the norm of the each mode is maximized. The approach is illustrated with the truss example that includes the physical interpretation of the selection. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gawronski, W (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU SOC EXPERIMENTAL MECHANICS INC PI BETHEL PA 7 SCHOOL ST, BETHEL, CT 06801 USA SN 0277-786X BN 0-912053-67-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4062 BP 1474 EP 1478 PG 5 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics; Optics SC Computer Science; Engineering; Mechanics; Optics GA BP87R UT WOS:000086462600224 ER PT B AU Benford, DJ Allen, CA Chervenak, JA Grossman, EN Irwin, KD Kutyrev, AS Martinis, JM Moseley, SH Shafer, RA Reintsema, CD AF Benford, DJ Allen, CA Chervenak, JA Grossman, EN Irwin, KD Kutyrev, AS Martinis, JM Moseley, SH Shafer, RA Reintsema, CD BE Mangum, JG Radford, SJE TI Superconducting bolometer arrays for submillimeter astronomy SO IMAGING AT RADIO THROUGH SUBMILLIMETER WAVELENGTHS, PROCEEDINGS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Symposium on Imaging at Radio Through Submillimeter Wavelengths (Imaging 99) CY JUN 06-09, 1999 CL TUCSON, AZ AB Studies of astrophysical emission in the far-infrared and submillimeter will increasingly require large arrays of detectors containing hundreds to thousands of elements. The last few years have seen an increase from one to a few tens of bolometers on ground based telescopes. A further jump of this magnitude, to a thousand bolometers, requires a fundamental redesign of the technology of making bolometer arrays. One method of achieving this increase is to design bolometers which can be packed into a rectangular array of near unity filling factor while Nyquist sampling the focal plane of the telescope at the operating wavelengths. A multiplexed readout is necessary for this many detectors and can be developed using SQUIDs such that a 32x32 array of bolometers could be read out using 100 wires rather than the > 2000 needed with a brute force expansion of existing arrays. Superconducting transition edge sensors are used as the detectors for these bolometer arrays. This technology is well-suited to low-background instruments such as SPIRE on FIRST and SAFIRE on SOFIA, and can also be used in broadband, high-background instruments such as HAWC on SOFIA. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Benford, DJ (reprint author), NASA, Goddard Space Flight Ctr, Code 685, Greenbelt, MD 20771 USA. RI Benford, Dominic/D-4760-2012; Moseley, Harvey/D-5069-2012 OI Benford, Dominic/0000-0002-9884-4206; NR 7 TC 4 Z9 4 U1 0 U2 2 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-049-8 J9 ASTR SOC P PY 2000 VL 217 BP 134 EP 139 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BR93Y UT WOS:000168121900031 ER PT B AU Moseley, SH Dowell, CD Allen, C Phillips, TG AF Moseley, SH Dowell, CD Allen, C Phillips, TG BE Mangum, JG Radford, SJE TI Semiconducting pop-up bolometers for far-infrared and submillimeter astronomy SO IMAGING AT RADIO THROUGH SUBMILLIMETER WAVELENGTHS, PROCEEDINGS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Symposium on Imaging at Radio Through Submillimeter Wavelengths (Imaging 99) CY JUN 06-09, 1999 CL TUCSON, AZ AB Large format background-limited far infrared and submillimeter detector arrays are essential to enable the scientific exploitation of these important spectral bands. Much of the luminosity of the early universe is emitted in the rest frame far-infrared; we observe much of it at far infrared and submillimeter wavelengths. The success of the first generation of far infrared and submillimeter cameras provides a powerful motivation to extend these capabilities in a new generation of instruments. We describe the development of filled two-dimensional arrays of far-infrared detectors for such instruments. Such arrays make the best possible use of the valuable real estate found in the focal planes of submillimeter telescopes. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Moseley, SH (reprint author), NASA, Goddard Space Flight Ctr, Mail Stop 685-0, Greenbelt, MD 20771 USA. RI Moseley, Harvey/D-5069-2012 NR 11 TC 6 Z9 6 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-049-8 J9 ASTR SOC P PY 2000 VL 217 BP 140 EP 149 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BR93Y UT WOS:000168121900032 ER PT S AU Feinberg, LD Leisawitz, D Leviton, D Zhang, XL Lyon, R AF Feinberg, LD Leisawitz, D Leviton, D Zhang, XL Lyon, R BE Descour, MR Shen, SS TI Design and plans for a wide field imaging interferometry testbed SO IMAGING SPECTROMETRY VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Spectrometry VI CY JUL 31-AUG 02, 2000 CL SAN DIEGO, CA SP SPIE, Remote Sensing Soc DE interferometry; wide field imaging; far infrared; testbed; SPIRIT; SPECS; Michelson AB Future NASA missions will require wide field of view interferometric imaging in order to obtain high angular resolution over large fields of view. In particular, far-infrared and submillimeter missions will, require interferometry because the long wavelengths drive large baselines in order to achieve reasonable spatial resolution and because the scientific motivations require large fields of view.(i) However, the requirement for a direct detection interferometer to cover a wide held of view over a wide spectral band has not been demonstrated. Because of this, we are developing a testbed for demonstrating wide held imaging interferometry algorithms that will. allow us to evaluate the system issues and algorithms associated with this type of observatory. This paper will describe the drivers for this testbed, the design of this testbed, and the tests and algorithms we plan to run and demonstrate. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Feinberg, LD (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Lyon, Richard/D-5022-2012 NR 5 TC 4 Z9 4 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3777-8 J9 P SOC PHOTO-OPT INS PY 2000 VL 4132 BP 365 EP 371 DI 10.1117/12.406606 PG 7 WC Engineering, Aerospace; Remote Sensing; Spectroscopy SC Engineering; Remote Sensing; Spectroscopy GA BR66H UT WOS:000167104600037 ER PT S AU Yang, EH Wiberg, DV Dekany, RG AF Yang, EH Wiberg, DV Dekany, RG BE Bilbro, JW Breckinridge, JB Carreras, RA Czyzak, SR Eckart, MJ Fiete, RD Idell, PS TI Design and fabrication of electrostatic actuators with corrugated membranes for MEMS deformable mirror in space SO IMAGING TECHNOLOGY AND TELESCOPES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Technology and Telescopes CY JUL 30-31, 2000 CL SAN DIEGO, CA SP SPIE DE deformable mirror (DM); Microelectromechanical Systems (MEMS); adaptive optics; electrostatic actuator; single crystal silicon (SCS) membrane; continuous mirror; wafer-level membrane transfer; Next Generation Space Telescope (NGST) AB A novel Microelectromechanical Systems (MEMS) deformable mirror (DM) technology for large, light weight, segmented space telescopes is being proposed. This technology is reported to provide an unprecedented imaging capability in a visible and near infrared spectral range. The MEMS-DM proposed in this paper consists of a continuous membrane mirror supported by electrostatic actuators with a pixel-to-pixel spacing as small as 200 mum An array of 4x4 electrostatic actuators for the DM has been successfully fabricated by a new membrane transfer technique. The fabricated actuator membrane has been characterized by using an optical surface profiler. The actuator shows a vertical deflection of 0.37 mum at 55 V. This device can also address requirements for smaller size and high resolution applications involving optical transmission through aberrating mediums such as imaging and optical communications through atmospheres, high resolution biometric retina signatures through the eye and endoscopic investigation of tissues and organs. C1 CALTECH, Jet Prop Lab, Device Res & Applicat Sect, Pasadena, CA 91109 USA. RP Yang, EH (reprint author), CALTECH, Jet Prop Lab, Device Res & Applicat Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Yang, Eui-Hyeok/0000-0003-4893-1691 NR 8 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 0-8194-3736-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4091 BP 83 EP 89 DI 10.1117/12.405766 PG 7 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BR14Y UT WOS:000165734600010 ER PT S AU Talent, DL Maeda, R Walton, S Sydney, P Hsu, YL Cameron, B Kervin, P Helin, E Pravdo, S Lawrence, K Rabinowitz, D AF Talent, DL Maeda, R Walton, S Sydney, P Hsu, YL Cameron, B Kervin, P Helin, E Pravdo, S Lawrence, K Rabinowitz, D BE Bilbro, JW Breckinridge, JB Carreras, RA Czyzak, SR Eckart, MJ Fiete, RD Idell, PS TI A new home for NEAT on the 1.2-m/B37 at AMOS SO IMAGING TECHNOLOGY AND TELESCOPES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Technology and Telescopes CY JUL 30-31, 2000 CL SAN DIEGO, CA SP SPIE DE space surveillance; asteroids; satellites; NEAT; metrics AB The NASA/JPL Near Earth Asteroid Tracking (NEAT) Program was in operation using the Maul GEODSS as its observing platform for about three years starting in late 1995 and continuing into 1998. In October of 1998 the NASA/AFSPC Near Earth Object Working Group (NEOWG) recommended that the NASA/JPL NEAT program be moved to the AMOS 1.2m/B37 telescope. This paper describes the technical efforts that were required to facilitate the move. The task requirements specified that the modified 1.2m/B37 system be capable of producing a field of view (FOV) greater than or equal to 1.4 degrees X 1.4 degrees at the NEAT camera focal plane. Further, it was specified that no modifications be made to the 1.2m/B37 mirror or the NASA/JPL camera. Thus, activity focused on the development of suitable focal reduction optics (FRO). A new headring and spider, based on the original design, were also built to receive the NEAT FRO and the NASA/JPL camera. Operation of the NEAT system, for asteroid search and discovery, will be autonomous and remotely directed from NASA/JPL. Finally, the potential for use of the NEAT system as regards the satellite metric mission will also be presented. C1 Boeing Rocketdyne Tech Serv, Kihei, HI 96753 USA. Boeing Corp, Canoga Park, CA 91309 USA. USAF, Res Lab, Kihei, HI 96753 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Talent, DL (reprint author), Boeing Rocketdyne Tech Serv, 535 Lipoa Pkwy,Suite 200, Kihei, HI 96753 USA. NR 3 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3736-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4091 BP 225 EP 236 DI 10.1117/12.405779 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BR14Y UT WOS:000165734600025 ER PT S AU Africano, JL Sydney, PF Talent, DL Stansbery, EG Jarvis, KS Monet, DG Seitzer, P AF Africano, JL Sydney, PF Talent, DL Stansbery, EG Jarvis, KS Monet, DG Seitzer, P BE Bilbro, JW Breckinridge, JB Carreras, RA Czyzak, SR Eckart, MJ Fiete, RD Idell, PS TI A geosynchronous Earth orbital debris campaign SO IMAGING TECHNOLOGY AND TELESCOPES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Technology and Telescopes CY JUL 30-31, 2000 CL SAN DIEGO, CA SP SPIE DE NASA; GEO debris; astrometry; photometry; IRAF AB The National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) is conducting systematic searches of the Geosynchronous Earth Orbit (GEO) environment as part of an international measurement campaign under the auspices of the Inter-Agency Space Debris Coordination Committee (IADC). The objectives for this survey are to determine the extent and character of debris in GEO, by obtaining distributions for the brightness, inclination, Right Ascension of Ascending Node (RAAN), and mean motion of the debris. The Charged Coupled Device (CCD) Debris Telescope (CDT), an automated 0.32 meter aperture, transportable Schmidt telescope presently located at Cloudcroft, New Mexico, is used nightly to monitor the GEO debris environment. The CDT is equipped with a CCD camera capable of detecting 17(th) magnitude objects in a 20 second exposure. This corresponds to a 0.6 meter diameter object having a 0.2 albedo at 36000 km. Two other larger telescopes have been used for this purpose, the United States Naval Observatory's new 1.3 meter telescope located in Flagstaff Arizona and a 0.6 m Schmidt telescope located at Cerro Tololo Inter-American Observatory (CTIO) near La Serena Chile. Data reduction and analysis software used to reduce this data exploit tools developed by both the astronomical and DoD communities. These tools and data results are presented. C1 Boeing Co, Seattle, WA 98124 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Michigan, Ann Arbor, MI 48109 USA. RP Africano, JL (reprint author), Boeing Co, Seattle, WA 98124 USA. NR 6 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 0-8194-3736-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4091 BP 248 EP 256 DI 10.1117/12.405781 PG 9 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BR14Y UT WOS:000165734600027 ER PT S AU Hasson, V Corbett, F Kovacs, M Groden, M Hogenboom, D Dryden, G Pohle, R Phipps, C Werling, D Czyak, S Gonglewski, J Campbell, J AF Hasson, V Corbett, F Kovacs, M Groden, M Hogenboom, D Dryden, G Pohle, R Phipps, C Werling, D Czyak, S Gonglewski, J Campbell, J BE Bilbro, JW Breckinridge, JB Carreras, RA Czyzak, SR Eckart, MJ Fiete, RD Idell, PS TI Use of laser radar for small space object experiments SO IMAGING TECHNOLOGY AND TELESCOPES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Technology and Telescopes CY JUL 30-31, 2000 CL SAN DIEGO, CA SP SPIE DE CO2 coherent ladar; HICLASS; Maul Space Surveillance System AB This report briefly reviews the development, capabilities, and current status of pulsed high-power coherent CO2 laser radar systems at the Maul Space Surveillance System (MSSS), HI, for acquisition, tracking, and sizing of orbiting objects. There are two HICLASS systems, one integrated to the 0.6m Laser Beam Director and one just integrated Summer 2000 to the 3.7m Advanced E-O System (AEOS). This new system takes full advantage of the large AEOS aperture to substantially improve the ladar range and sensitivity. These improvements make the AEOS HICLASS system potentially suitable for tracking and characterization experiments of small < 30cm objects in low-earth-orbits. C1 Textron Syst Corp, Wilmington, MA 01887 USA. Textron Syst Corp, Kihei, HI USA. Photon Assoc, Santa Fe, NM USA. USAF, Res Lab, Directed Energy Directorate, Kirtland AFB, NM USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Hasson, V (reprint author), Textron Syst Corp, Wilmington, MA 01887 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 0-8194-3736-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4091 BP 363 EP 374 DI 10.1117/12.405796 PG 12 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BR14Y UT WOS:000165734600040 ER PT S AU Leviton, DB Garza, MS AF Leviton, DB Garza, MS BE Bilbro, JW Breckinridge, JB Carreras, RA Czyzak, SR Eckart, MJ Fiete, RD Idell, PS TI Recent advances and applications for NASA's new, ultra-high sensitivity, absolute, optical pattern recognition encoders SO IMAGING TECHNOLOGY AND TELESCOPES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Imaging Technology and Telescopes CY JUL 30-31, 2000 CL SAN DIEGO, CA SP SPIE DE ultra-high sensitivity; absolute optical encoder; rotary encoder; linear encoder; pattern recognition; cryostatic; cryogenic ID REFRACTIVE-INDEX AB NASA's new optical encoders use pattern recognition for images of encoder scales to encode both rotary and linear, absolute, mechanical position with ultra-high sensitivity. These encoders have advanced beyond prototype stage(1) and are now being used in a variety of demanding applications both in the laboratory and in optical ground support equipment for space flight instrumentation. Rotary versions of these new pattern recognition encoders have sensitivity down to 0.01 arcseconds while linear models have demonstrated sensitivity of 10 nm (0.01 mum) with higher sensitivities achievable in both formats. The means for encoding is a radical departure from that for conventional optical encoders and offers advantages of absolute operation, very low cost, compact form, considerable immunity to scale-damage-induced dropouts of position information, an order of magnitude or more higher sensitivity over commercially available encoders, demonstrated applicability in cryostatic and vacuum environments, and suitability for space flight. Operational details of the encoder are given. Representative sensitivity performance is presented along with several examples of uses to date. Planned future development is also discussed. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Orbital Sci Corp, Greenbelt, MD 20770 USA. RP Leviton, DB (reprint author), NASA, Goddard Space Flight Ctr, Code 551, Greenbelt, MD 20771 USA. NR 4 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3736-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4091 BP 375 EP 384 DI 10.1117/12.405797 PG 10 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BR14Y UT WOS:000165734600041 ER PT B AU Satyapal, S Greenhouse, MA Barclay, R Amato, D Arritt, B Barry, R Holt, C Kuhn, J Higelman, T Fonneland, N Lesnya, L AF Satyapal, S Greenhouse, MA Barclay, R Amato, D Arritt, B Barry, R Holt, C Kuhn, J Higelman, T Fonneland, N Lesnya, L BE VanBreugel, W BlandHawthorn, J TI The tunable filter program for NGST SO IMAGING THE UNIVERSE IN THREE DIMENSIONS: ASTROPHYSICS WITH ADVANCED MULTI-WAVELENGTH IMAGING DEVICES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT International Conference on Imaging the Universe in 3 Dimensions CY MAR 29-APR 01, 1999 CL WALNUT CREEK, CA SP Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Calif Space Inst, Queensgate Instruments Ltd, ITT Aerosp AB We display work in progress on a near-infrared tunable bandpass filter for the wide field camera of the Next Generation Space Telescope (NGST) Integrated Science Instrument Module (ISIM). This Demonstration Unit for Low Order Cryogenic Etalon (DULCE), is designed to demonstrate a high efficiency scanning Fabry-Perot etalon operating in interference orders 1-4 at 30 K with a high stability DSP based servo control system. DULCE is currently the only available tunable filter for low order cryogenic operation in the near-infrared. In this application, scanning etalons will illuminate the focal plane arrays with a single order of interference to enable wide field low resolution (50 < R < 200) hyperspectral imaging over a wide range of redshifts. We discuss the specific science applications in which tunable filters are the instrument of choice. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Satyapal, S (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-022-6 J9 ASTR SOC P PY 2000 VL 195 BP 437 EP 442 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ13X UT WOS:000087281800058 ER PT B AU Moseley, SH Fettig, RK Kutyrev, AS Bowers, CW Kimble, RA Orloff, J Woodgate, BE AF Moseley, SH Fettig, RK Kutyrev, AS Bowers, CW Kimble, RA Orloff, J Woodgate, BE BE VanBreugel, W BlandHawthorn, J TI Programmable 2-dimensional microshutter arrays SO IMAGING THE UNIVERSE IN THREE DIMENSIONS: ASTROPHYSICS WITH ADVANCED MULTI-WAVELENGTH IMAGING DEVICES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT International Conference on Imaging the Universe in 3 Dimensions CY MAR 29-APR 01, 1999 CL WALNUT CREEK, CA SP Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Calif Space Inst, Queensgate Instruments Ltd, ITT Aerosp AB We are developing a two-dimensional array of microshutters which can be used as a high efficiency, high contrast held selection device for a multi-object spectrometer. The device is a close-packed array of shutters, with a typical size of 100 microns square and area filling factor of up to 80%. Each shutter, made of single crystal silicon with an appropriate optical coating, pivots on a torsion flexure along one edge. Each of the shutters is individually selectable. An original double-shutter mechanism is employed for actuation. Since the device works in transmission, there is no loss of contrast due to diffraction from the edges of unactuated pixels. When working in reflection, the device can also be used as a micromirror array. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Moseley, SH (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RI Moseley, Harvey/D-5069-2012; Woodgate, Bruce/D-2970-2012 NR 3 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-022-6 J9 ASTR SOC P PY 2000 VL 195 BP 449 EP 452 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ13X UT WOS:000087281800060 ER PT B AU Palunas, P Woodgate, BE Danks, AC Klingesmith, DA Dunn, RB AF Palunas, P Woodgate, BE Danks, AC Klingesmith, DA Dunn, RB BE VanBreugel, W BlandHawthorn, J TI The GSFC Lyot filter for night time astronomy SO IMAGING THE UNIVERSE IN THREE DIMENSIONS: ASTROPHYSICS WITH ADVANCED MULTI-WAVELENGTH IMAGING DEVICES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT International Conference on Imaging the Universe in 3 Dimensions CY MAR 29-APR 01, 1999 CL WALNUT CREEK, CA SP Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Calif Space Inst, Queensgate Instruments Ltd, ITT Aerosp AB We are developing a tunable narrow-band Lyot filter for night time astronomy. The Lyot filter is an interferometer which acts by recombining beams of light for which a relative phase shift is induced along the fast- and slow-axes of a birefringent crystal. The filter has been fabricated by Dunn & Ramsey and is based on a wide-field tunable design by Title & Rosenberg. The use of high transmission (97%) polarizers and index matching oil between the elements should allow 35% transmission. The aperture is 10cm in diameter and the wide-field elements remain monochromatic in f/3 beam. In this configuration the filter achieves a 400x throughput gain over Fabry-Perot interferometers. The filter has tunable range between 4200 and 7300 Angstrom and a resolution of 4-8 Angstrom FWHM. These properties make it an ideal instrument for detection of extended emission line objects. The filter is currently being integrated with a 2048x2048 STIS-SITe CCD camera. We plan two use the instrument in two modes: at prime focus of a large aperture telescope providing a field of view of 12'(4m f/3 telescope) and behind 300mm focal length f/2.5 lens as a "parking-lot" surveyor of Galactic emission providing a field of view of 8 degrees. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Palunas, P (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 681, Greenbelt, MD 20771 USA. RI Woodgate, Bruce/D-2970-2012 NR 3 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-022-6 J9 ASTR SOC P PY 2000 VL 195 BP 605 EP 608 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ13X UT WOS:000087281800085 ER PT B AU Woodgate, BE AF Woodgate, BE BE VanBreugel, W BlandHawthorn, J TI Conference summary SO IMAGING THE UNIVERSE IN THREE DIMENSIONS: ASTROPHYSICS WITH ADVANCED MULTI-WAVELENGTH IMAGING DEVICES SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT International Conference on Imaging the Universe in 3 Dimensions CY MAR 29-APR 01, 1999 CL WALNUT CREEK, CA SP Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Calif Space Inst, Queensgate Instruments Ltd, ITT Aerosp AB This conference demonstrated the coming of age of 3-D astronomy as a standard tool, rather than as a technological niche. In particular, several integral field spectrometers are now in use, and many more are now in development for the new ground-based 6-10 meter class telescopes, and in study for space use, and are described in the papers of this conference. The astronomical roles of various forms of 3-D technologies are summarized. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Woodgate, BE (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. RI Woodgate, Bruce/D-2970-2012 NR 5 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-022-6 J9 ASTR SOC P PY 2000 VL 195 BP 611 EP 617 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ13X UT WOS:000087281800086 ER PT S AU Daly, JT Johnson, EA Stevenson, WA Greenwald, AC Wollam, JA George, T Jones, EW AF Daly, JT Johnson, EA Stevenson, WA Greenwald, AC Wollam, JA George, T Jones, EW BE Manasreh, MO Stadler, BJH Ferguson, I Zhang, YH TI Tuned infrared emission from lithographically-defined silicon surface structures SO INFRARED APPLICATIONS OF SEMICONDUCTORS III SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Infrared Applications of Semiconductors III held at the 1999 MRS Fall Meeting CY NOV 29-DEC 02, 1999 CL BOSTON, MA SP Mat Res Soc ID PHOTONIC BAND-STRUCTURE; FILTERS AB Photonic bandgap structures have received much attention as optical and infrared filters with controllable narrow-band absorbance. There is a need, however, for the same kind of control of the thermal emittance of surfaces for applications ranging from control of radiative heat transfer to gas absorption spectroscopy. We report on the fabrication of photonic bandgap structures on silicon surfaces using standard lithographic techniques. Substrate resistivity varied from n(-) to n(+) and in some cases background surface emissivity was suppressed with a high reflectivity coating such as aluminum. We have measured the infrared reflectance and emittance of these patterned surfaces. Peak absorption wavelength and spectral purity (linewidth) correlate with photonic bandgap feature size and spacing as well as surface conductivity. We demonstrate band emission with a sharp short wavelength cut-off from these structures when heated. C1 Ion Opt Inc, Waltham, MA 02452 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Daly, JT (reprint author), Ion Opt Inc, Waltham, MA 02452 USA. NR 11 TC 0 Z9 0 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-515-3 J9 MATER RES SOC SYMP P PY 2000 VL 607 BP 175 EP 180 PG 6 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA BQ66Y UT WOS:000089140500024 ER PT S AU Gunapala, SD Bandara, SV Liu, JK Luong, EM Rafol, SB Mumolo, JM Ting, DZ Bock, JJ Ressler, ME Werner, MW LeVan, PD Chehayeb, R Kukkonen, CA Levy, M LeVan, N Fauci, MA AF Gunapala, SD Bandara, SV Liu, JK Luong, EM Rafol, SB Mumolo, JM Ting, DZ Bock, JJ Ressler, ME Werner, MW LeVan, PD Chehayeb, R Kukkonen, CA Levy, M LeVan, N Fauci, MA BE Dereniak, EL Sampson, RE TI Recent developments and applications of quantum well infrared photodetector focal plane arrays SO INFRARED DETECTORS AND FOCAL PLANE ARRAYS VI SE Proceedings of SPIE-The International Society for Optical Engineering LA English DT Proceedings Paper CT 6th Conference on Infrared Detectors and Focal Plane Arrays CY APR 25-27, 2000 CL ORLANDO, FL SP SPIE DE infrared detectors; long-wavelength infrared; multi quantum well; multi-color; focal plane arrays ID QWIP ARRAY; CAMERA; FABRICATION AB One of the simplest device realizations of the classic particle-in-the-box problem of basic quantum mechanics is the Quantum Well Infrared Photodetector (QWIP). In this paper we discuss the effect of focal plane array non-uniformity on the performance, optimization of the detector design, material growth and processing that has culminated in realization of large format long-wavelength QWIP cameras, holding forth great promise for many applications in 6-18 micron wavelength range in science, medicine, defense and industry. In addition, we present the recent developments in long-wavelength/very long-wavelength dualband QWIP imaging camera for various applications. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gunapala, SD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 29 TC 4 Z9 4 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3654-2 J9 P SOC PHOTO-OPT INS PY 2000 VL 4028 BP 262 EP 275 DI 10.1117/12.391739 PG 14 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BR35J UT WOS:000166173100029 ER PT S AU Werner, MW AF Werner, MW BE Strojnik, M Andresen, BF TI SIRTF - An overview SO INFRARED SPACEBORNE REMOTE SENSING VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Infrared Spaceborne Remote Sensing VIII CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE SIRTF; infrared astronomy; infrared detectors; cryogenics ID TELESCOPE FACILITY SIRTF; SPACE AB This paper reports on the status of SIRTF - the Space Infrared Telescope Facility. SIRTF will be a cryogenically-cooled space telescope instrumented with large-format, state of the art infrared detector arrays. SIRTF will complete NASA's family of Great Observatories and also serve as a cornerstone of the Origins program. SIRTF will be launched in 2001, carrying a complement of imaging and spectroscopic instrumentation, for a mission similar to 5yr in duration. SIRF will be placed in an earth-trailing heliocentric orbit; the very favorable thermal environment of this orbit has enabled a novel warm-launch architecture for the cryogenic system. More than 75% of the observing time on SIRTF will be available to the general scientific community. The community involvement in SIRTF began in June of 2000 with the formal release of the call for Legacy Science proposals. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Werner, MW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 17 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 0-8194-3776-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4131 BP 1 EP 6 DI 10.1117/12.406533 PG 6 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BR62C UT WOS:000166963500001 ER PT S AU Jones-Selden, FL Ackerson, T Allen, C Armbruster, M Barney, R Britt, J Eichorn, W Florez, J Fazio, G Glaccum, W Golder, J Gong, Q Grammer, B Hakun, C Haney, P Hendricks, S Hoffman, W Hora, J Jhabvala, M Jungo, R Karpati, G Krebs, D Lander, J Lander, M Losch, P Mann, S Marx, C Moseley, S Polizotti, J Rivera, J Robinson, F Rosborough, W Schwinger, D Shakoorzadeh, K Stewart, K Taylor, R Tomasevich, C Torres, V Trujillo, C Trunzo, R Willner, S Workman, L AF Jones-Selden, FL Ackerson, T Allen, C Armbruster, M Barney, R Britt, J Eichorn, W Florez, J Fazio, G Glaccum, W Golder, J Gong, Q Grammer, B Hakun, C Haney, P Hendricks, S Hoffman, W Hora, J Jhabvala, M Jungo, R Karpati, G Krebs, D Lander, J Lander, M Losch, P Mann, S Marx, C Moseley, S Polizotti, J Rivera, J Robinson, F Rosborough, W Schwinger, D Shakoorzadeh, K Stewart, K Taylor, R Tomasevich, C Torres, V Trujillo, C Trunzo, R Willner, S Workman, L BE Strojnik, M Andresen, BF TI Implementation and testing of SIRTF's Infrared Array Camera (IRAC) SO INFRARED SPACEBORNE REMOTE SENSING VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Infrared Spaceborne Remote Sensing VIII CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE Infrared Array Camera; Space Infrared Telescope Facility; remote sensing; Indium antimonide (InSb) arrays; Arsenic-doped silicon (Si : As) arrays AB The Infrared Array Camera (IRAC) is one of three science instruments that will fly aboard the Space Infrared Telescope Facility (SIRTF) mission scheduled for launch in December, 2001. IRAC is a four-channel camera that provides simultaneous 5.12 x 5.12 are-minute images at 3.6, 4.5, 5.8, and 8 microns. The pixel size is 1.2 arcsec in all bands. Two adjacent fields of view in the SIRTF focal plane are viewed by the four channels in pairs (3.6 and 5.8 microns; 4.5 and 8.0 microns). All four detector arrays in the camera are 256 x 256 pixels in size, with the two short wavelength channels using InSb and the two longer wavelength channels using Si:As IBC detectors. Development and flight of the IRAC is a joint project of the Smithsonian Astrophysical Observatory (SAO), the Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory (JPL), Ames Research Center (ARC), the University of Arizona (UA), and the University of Rochester (UR). The instrument was designed, built and tested at Goddard Space Flight Center in accordance with the requirements established by the IRAC Science Steering Committee (SSC). This paper summarizes the "as built" design of IRAC along with important integration and testing results. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Jones-Selden, FL (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Mann, Steve/B-7736-2012; Moseley, Harvey/D-5069-2012 NR 6 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 0-8194-3776-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4131 BP 50 EP 61 DI 10.1117/12.406572 PG 12 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BR62C UT WOS:000166963500006 ER PT S AU McMurray, RE Johnson, RR McCreight, CR McKelvey, ME Garnett, JD Hoffman, AW Lum, NA Lum, WY Smith, MS Sparkman, KP Toth, AG Domingo, G Krebs, D Jhabvala, M AF McMurray, RE Johnson, RR McCreight, CR McKelvey, ME Garnett, JD Hoffman, AW Lum, NA Lum, WY Smith, MS Sparkman, KP Toth, AG Domingo, G Krebs, D Jhabvala, M BE Strojnik, M Andresen, BF TI Si : As IBC array performance for SIRTF/IRAC SO INFRARED SPACEBORNE REMOTE SENSING VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Infrared Spaceborne Remote Sensing VIII CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE infrared; SIRTF; IRAC; camera; detector; cryogenic; telescope; array; space AB The goal of achieving background-limited performance in SIRTF's cryogenic telescope environment places stringent demands on focal plane sensitivity. SIRTF's prime imaging instrument, the InfraRed Array Camera (IRAC), employs 256X256 Si:As Impurity-Band Conduction (IBC) arrays for its two longest wavelength channels at 5.8 mum and 8.0 mum. Background-limited performance is achieved at very low levels of zodiacal background radiation with cryo-optimized readout and detector technology fi-om Raytheon. Presented here are performance measurements of IRAC flight candidate IBC arrays. Operating at a temperature of 6 K; these devices meet all IRAC sensitivity requirements, with dark currents well below the 10 e-/s specification, Fowler-sampled noise levels of 16 e-, and excellent photometric stability. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP McMurray, RE (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 4 TC 16 Z9 16 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3776-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4131 BP 62 EP 69 PG 8 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BR62C UT WOS:000166963500007 ER PT S AU Stewart, KP Quijada, MA AF Stewart, KP Quijada, MA BE Strojnik, M Andresen, BF TI Cryo-transmittance and -reflectance of filters and beamsplitters for the SIRTF Infrared Array Camera SO INFRARED SPACEBORNE REMOTE SENSING VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Infrared Spaceborne Remote Sensing VIII CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE cryogenic; infrared; space flight optics; transmittance; reflectance AB The Space Infrared Telescope Facility (SIRTF) Infrared Array Camera (IRAC) uses two dichroic beamsplitters, four bandpass filters, and four detector arrays to acquire images in four channels at wavelengths between 3 and 10 mum. Accurate knowledge of the pass bands is necessary because, in order to meet the science objectives, IRAC is required to do 2% relative photometry in each band relative to the other bands. We report the in-band and out-of-band polarized transmittance and reflectance of these optical elements measured near the instrument operating temperature of 1.4 K. Details of the experimental apparatus, which include a continuous flow liquid helium optical cryostat and a Fourier transform infrared (FTIR) spectrometer are discussed. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Stewart, KP (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 4 TC 6 Z9 6 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3776-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4131 BP 218 EP 227 DI 10.1117/12.406543 PG 10 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BR62C UT WOS:000166963500022 ER PT S AU Pearson, D Hardy, J Lysek, M Dooley, J Brown, R Chaney, D Nash, A AF Pearson, D Hardy, J Lysek, M Dooley, J Brown, R Chaney, D Nash, A BE Strojnik, M Andresen, BF TI Verification facility for cryogenic optics, mechanisms, and structures for the SIRTF telescope SO INFRARED SPACEBORNE REMOTE SENSING VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Infrared Spaceborne Remote Sensing VIII CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE cryogenic optics testing; SIRTF; infrared AB NASA's Space Infrared Telescope Facility (SIRTF) is a I-meter class cryogenically-cooled space observatory. The constituent sub-assemblies are currently in their assembly and verification phase. To facilitate the assembly and verification of the telescope, the Space Telescope Test Facility (STTF) has been built at the Jet Propulsion Laboratory (JPL). The STTF allows for the assembly, alignment, and optical characterization of individual components, as well as the telescope assembly with its cryogenic mechanism, at temperatures from 300 to 5 K in a chamber with interior diameter of 1.4 m and a height of 2.3 m. The chamber is surrounded by a class 10,000 or better clean room. This paper reports on the functional and operational capabilities of this facility. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Nash, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3776-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4131 BP 250 EP 254 DI 10.1117/12.406548 PG 5 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BR62C UT WOS:000166963500025 ER PT S AU Hill, MD Herrera, AA Crane, JA Packard, EA Aviado, C Sampler, HP AF Hill, MD Herrera, AA Crane, JA Packard, EA Aviado, C Sampler, HP BE Strojnik, M Andresen, BF TI Alignment measurements of the Microwave Anisotropy Probe (MAP) instrument in a thermal/vacuum chamber using photogrammetry SO INFRARED SPACEBORNE REMOTE SENSING VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Infrared Spaceborne Remote Sensing VIII CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE MAP; photogrammetry; thermal/vacuum; alignment AB The Microwave Anisotropy Probe (MAP) Observatory, scheduled for a 2001 launch, is designed to measure temperature fluctuations (anisotropy) and produce a high sensitivity and high spatial resolution (< 0.3 at 90 GHz.) map of the cosmic microwave background (CMB) radiation over the entire sky between 22 and 90 GHz. MAP utilizes back-to-back Gregorian telescopes to focus the microwave signals into 10 differential microwave receivers, via 20 feed horns. Proper alignment of the telescope reflectors and the feed horns at the operating temperature of 90 K is a critical element to ensure mission success. We describe the hardware and methods used to validate the displacement/deformation predictions of the reflectors and the microwave feed horns during thermal/vacuum testing of the reflectors and the microwave instrument. The smallest deformations to be resolved by the measurement system were on the order of +/- 0.030 inches (0.762 mm). Performance of these alignment measurements inside a thermal/vacuum chamber with conventional alignment equipment posed several limitations. A photogrammetry (PG) system was chosen to perform the measurements since it is a non-contact measurement system, the measurements can be made relatively quickly and accurately, and the photogrammetric camera can be operated remotely. The hardware and methods developed to perform the MAP alignment measurements using PG proved to be highly successful. The PG measurements met the desired requirements, enabling the desired deformations to be measured and even resolved to an order of magnitude smaller than the imposed requirements. Viable data were provided to the MAP Project for a full analysis of the on-orbit performance of the Instrument's microwave system. C1 Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hill, MD (reprint author), Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 2 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3776-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4131 BP 255 EP 265 DI 10.1117/12.406549 PG 11 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BR62C UT WOS:000166963500026 ER PT S AU Mule, P Hill, MD Sampler, HP AF Mule, P Hill, MD Sampler, HP BE Strojnik, M Andresen, BF TI Photogrammetrically measured distortions of a composite microwave reflector system in vacuum at similar to 90K SO INFRARED SPACEBORNE REMOTE SENSING VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Infrared Spaceborne Remote Sensing VIII CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE reflectors; distortions; and photogrammetry AB The Microwave Anisotropy Probe (MAP) Observatory, scheduled for a 2001 launch, is designed to measure temperature fluctuations (anisotropy) and produce a high sensitivity and high spatial resolution (better than 0.3 degrees at 90 GHz.) map of the Cosmic Microwave Background (CMB) radiation over the entire sky between 22 and 90 GHz. MAP utilizes back-to-back composite Gregorian telescopes supported on a composite truss structure to focus the microwave signals into 10 differential microwave receivers. Proper position and shape of the telescope reflectors at the operating temperature of similar to 90 K is a critical element to ensure mission success. We describe the methods and analysis used to validate the in-flight position and shape predictions for the reflectors based on photogrammetric metrology data taken under vacuum with the reflectors at similar to 90K. Contour maps showing reflector distortions were generated. The resulting reflector distortion data are shown to be crucial to the analytical assessment of the MAP instrument's microwave system in-flight performance. C1 Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mule, P (reprint author), Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3776-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4131 BP 266 EP 277 DI 10.1117/12.406550 PG 12 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BR62C UT WOS:000166963500027 ER PT S AU Eng, R Kegley, J Keidel, J AF Eng, R Kegley, J Keidel, J BE Strojnik, M Andresen, BF TI Newly modified cryogenic optical test facility at the Marshall Space Flight Center SO INFRARED SPACEBORNE REMOTE SENSING VIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Infrared Spaceborne Remote Sensing VIII CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE cryogenic test facility; optical testing; Shack-Hartmann sensor; interferometry AB NASA Marshall Space Flight Center (MSFC) has maintained and operated a world-class x-ray optics and detector testing facility known as the X-ray Calibration Facility (XRCF) since the mid 1970's. The ground testing and calibration of the Chandra X-ray Observatory optics and detectors were successfully completed at the XRCF in 1997. In 1999, the facility was upgraded in preparation for cryogenic testing of lightweight telescope mirrors without compromising the existing x-ray testing capability. A gaseous Helium (He) cooled enclosure or shroud capable of 20 degrees Kelvin and vibration isolated instrumentation mount were added to the existing facility. A precision remote-control five-axis motion mirror support was modified to operate under cryogenic conditions. Mirrors with diameters as large as two meters, and radii of curvature up to twenty meters can be accommodated in the He shroud. Optical wavefront measuring instrumentation includes a Shack-Hartmann wavefront sensor, a point diffraction interferometer, a point spread function measuring device, and a radius of curvature measuring instrument. These instruments can provide accurate measurements of the mirror under test. A vibration insensitive phase shifting interferometer is planned for future optical testing. C1 NASA, Space Opt Mfg Technol Ctr, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Eng, R (reprint author), NASA, Space Opt Mfg Technol Ctr, George C Marshall Space Flight Ctr, Mail Code SD73, Huntsville, AL 35812 USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3776-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4131 BP 382 EP 391 DI 10.1117/12.406547 PG 10 WC Instruments & Instrumentation; Remote Sensing; Optics SC Instruments & Instrumentation; Remote Sensing; Optics GA BR62C UT WOS:000166963500039 ER PT S AU Leviton, DB Eichhorn, WL Madison, TJ Miner, LA Sullivan, PC Edelman, JE Garza, MS Kubalak, DA Neuman, MA Skelton, DL Worrel, LR Norton, TA Hartig, GF AF Leviton, DB Eichhorn, WL Madison, TJ Miner, LA Sullivan, PC Edelman, JE Garza, MS Kubalak, DA Neuman, MA Skelton, DL Worrel, LR Norton, TA Hartig, GF BE Fineschi, S Korendyke, CM Siegmund, OHW Woodgate, BE TI High throughput vacuum ultraviolet stimulus for flat fielding and spectral calibration of the HST Advanced Camera for Surveys SO INSTRUMENTATION FOR UV/EUV ASTRONOMY AND SOLAR MISSIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instrumentation for UV/EUV Astronomy and Solar Missions CY JUL 30-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE flat field; MAMA detector; far ultraviolet; radiometric calibration; microlens array diffuser ID SPACE-TELESCOPE AB The Advanced Camera for Surveys (ACS)(1) will fly on the Hubble Space Telescope (HST) Servicing Mission 3b in late-2001 and includes a Solar Blind Channel (SBC) comprising correcting/magnifying relay optics, a far ultraviolet (FUV) filter selection, and a 1K x 1K multi-anode microchannel array (MAMA) detector with cesium iodide photocathode. In order to characterize SBC's flat field response over its full spectral range and to radiometrically calibrate ACS at two FUV lines through as many SEC filters as possible, a sophisticated and automated STimulus for Ultraviolet Flat Fields (STUFF) was developed whose application extends to other vacuum ultraviolet optical instrumentation having similar characterization requirements. Challenges in STUFF's development and resulting design features are presented along with results from in vacuo characterizations carried out before and during thermal vacuum testing of ACS. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Leviton, DB (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Woodgate, Bruce/D-2970-2012 NR 5 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3784-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4139 BP 110 EP 121 DI 10.1117/12.410514 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy GA BR89U UT WOS:000167974600013 ER PT S AU Leviton, DB Miner, LA Rice, SJ Struss, SM Norton, TA McNeil, B AF Leviton, DB Miner, LA Rice, SJ Struss, SM Norton, TA McNeil, B BE Fineschi, S Korendyke, CM Siegmund, OHW Woodgate, BE TI Microlens array coated as a high efficiency, reflective diffuser for the vacuum ultraviolet SO INSTRUMENTATION FOR UV/EUV ASTRONOMY AND SOLAR MISSIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instrumentation for UV/EUV Astronomy and Solar Missions CY JUL 30-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE microlens array; microminor array; far ultraviolet; diffuser; concentration ID SPACE AB The stimulus for ultraviolet flat fields (STUFF)(1) was developed to supply spatially flat, broadband, far ultraviolet irradiance in thermal vacuum testing of the Solar Blind Channel (SBC) of the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS)(2) which will fly on Servicing Mission 3b in mid-2001. Because the SBC's 1K x 1K multi-anode microchannel array (MAMA) detector has a global count rate limit of about 300,000 events/s, it takes a minimum of roughly 10 hours of expensive test time in thermal vacuum to collect a deep flat field having 10,000 signal counts in each pixel (1% certainty in Poisson statistics). As such, a diffuser with far ultraviolet (FUV) throughput substantially higher than conventional state-of-the-art Lambertian diffuser material was sought to insure that the length of flat field exposures could be minimized. An FUV diffuser with concentrating properties was conceived as the overcoating of the convex lens side of commercially available microlens array material with Goddard Space Flight Center's (GSFC) standard aluminum-magnesium fluoride coating optimized for reflectance at 120 nm(3). The concept for this diffuser, a geometric optical model of its performance, visible light measurements to test that model, and the diffuser's FUV performance in STUFF relative to conventional diffuser material is presented. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Leviton, DB (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Woodgate, Bruce/D-2970-2012 NR 3 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3784-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4139 BP 122 EP 130 DI 10.1117/12.410515 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy GA BR89U UT WOS:000167974600014 ER PT S AU Ohl, RG Barkhouser, RH Conard, SJ Friedman, SD Hampton, J Moos, HW Nikulla, P Oliveira, CM Saha, TT AF Ohl, RG Barkhouser, RH Conard, SJ Friedman, SD Hampton, J Moos, HW Nikulla, P Oliveira, CM Saha, TT BE Fineschi, S Korendyke, CM Siegmund, OHW Woodgate, BE TI Performance of the Far Ultraviolet Spectroscopic Explorer mirror assemblies SO INSTRUMENTATION FOR UV/EUV ASTRONOMY AND SOLAR MISSIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instrumentation for UV/EUV Astronomy and Solar Missions CY JUL 30-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE FUSE; satellites; ultraviolet; imaging; mirrors; reflectivity; actuators; optical systems; optomechanical design ID FUSE AB The Far Ultraviolet Spectroscopic Explorer is a NASA astrophysics satellite which produces high-resolution spectra in the far-ultraviolet (90.5-118.7 nm bandpass) using a high effective area and low background detectors. The observatory was launched on its three-year mission from Cape Canaveral Air Station on 24 June 1999. The instrument contains four coaligned, normal incidence, off-axis parabolic mirrors which illuminate separate Rowland circle spectrograph channels equipped with holographically ruled diffraction gratings and delay line microchannel plate detectors. The telescope mirrors have a 352 x 387 mm aperture and 2245 mm focal length and ate attached to actuator assemblies, which provide an-orbit, tip, tilt, and focus control. Two mirrors are coated with silicon carbide (SiC) and two are coated with lithium fluoride over aluminum (Al:LiF). We describe mirror assembly in-night optical and mechanical performance. On-orbit measurements of the far-ultraviolet point spread function associated with each mirror are compared to expectations based on pre-night laboratory measurements and modeling using the Optical Surface Analysis Code and surface metrology data. On-orbit imaging data indicate that the mirrors meet their instrument-level requirement of 50% and 95% slit transmission far the high- and mid-resolution spectrograph entrance slits, respectively. The degradation of mirror reflectivity during satellite integration and test is also discussed. The FUV reflectivity of the SiC- and Al:LiF-coated mirrors decreased about 6% and 3%, respectively, between coating and launch. Each mirror is equipped with three actuators, which consist of a stepper motor driving a ball screw via a two-stage planetary gear train. We also discuss the mechanical performance of the mirror assemblies, including actuator performance and thermal effects. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ohl, RG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Woodgate, Bruce/D-2970-2012 NR 14 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3784-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4139 BP 137 EP 148 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy GA BR89U UT WOS:000167974600016 ER PT S AU Nikzad, S Jones, TJ Elliott, ST Cunningham, TJ Deelman, PW Walker, ABC Oluseyi, HM AF Nikzad, S Jones, TJ Elliott, ST Cunningham, TJ Deelman, PW Walker, ABC Oluseyi, HM BE Fineschi, S Korendyke, CM Siegmund, OHW Woodgate, BE TI Ultrastable and uniform EUV and UV detectors SO INSTRUMENTATION FOR UV/EUV ASTRONOMY AND SOLAR MISSIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instrumentation for UV/EUV Astronomy and Solar Missions CY JUL 30-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE ID DELTA-DOPED CCDS; CHARGE-COUPLED-DEVICES AB The large imaging format, high sensitivity, compact size, and ease of operation of silicon-based sensors have led instrument designers to choose them for most visible-light imagers and spectrometers for space-based applications. This will probably remain the case in the near future. In fact, technologies presently under development will tend to strengthen the position of silicon-based sensors. CCD-CMOS hybrids currently being developed may combine the advantages of both imagers and new high-gain amplifiers and could permit photon-counting sensitivity even in large-format imagers. Back-illumination potentially enables silicon detectors to be used for photometry and imaging applications for which front-illuminated devices are poorly suited. Successful detection by back illumination requires treatment of the back surface using techniques such as delta doping. Delta-doped CCDs were developed at the Microdevices Laboratory at the Jet Propulsion Laboratory in 1992. Using molecular beam epitaxy, fully-processed thinned CCDs are modified for UV enhancement by growing 2.5 nm of boron-doped silicon on the back surface. Named delta-doped CCDs because of the sharply-spiked dopant profile in the thin epitaxial layer, these devices exhibit stable and uniform 100% internal quantum efficiency without hysteresis in the visible and ultraviolet regions of the spectrum. fn this paper we will discuss the performance of delta-doped CCDs in UV and EUV, applicability to electron-bombarded CCD (EBCCD), our inhouse thinning capability, and bonding approaches for producing flat focal plane arrays. Recent activities on the extension of delta-doping to other imaging technologies will also be presented. C1 CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RP Nikzad, S (reprint author), CALTECH, Jet Prop Lab, Ctr Space Microelect Technol, Pasadena, CA 91109 USA. RI Woodgate, Bruce/D-2970-2012 NR 12 TC 8 Z9 8 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3784-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4139 BP 250 EP 258 DI 10.1117/12.410541 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy GA BR89U UT WOS:000167974600026 ER PT S AU Newmark, JS Moses, JD Cook, JW Delaboudiniere, JP Song, XY Carabetian, C Bougnet, M Brunaud, J Defise, JM Clette, F Hochedez, JF AF Newmark, JS Moses, JD Cook, JW Delaboudiniere, JP Song, XY Carabetian, C Bougnet, M Brunaud, J Defise, JM Clette, F Hochedez, JF BE Fineschi, S Korendyke, CM Siegmund, OHW Woodgate, BE TI Calibration and flight of the NRL EIT CalRoc SO INSTRUMENTATION FOR UV/EUV ASTRONOMY AND SOLAR MISSIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instrumentation for UV/EUV Astronomy and Solar Missions CY JUL 30-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE Sun; EUV CCD; multilayer mirrors; calibration; radiation degradation; sounding rocket ID 3-DIMENSIONAL STEREOSCOPIC ANALYSIS; ACTIVE-REGION LOOPS; SOHO; TEMPERATURES; INSTRUMENT AB The ability to derive physical parameters of the Sun from observations by the Solar and Heliospheric Observatory (SOHO) Extreme Ultraviolet Imaging Telescope (EIT) greatly increases the scientific return of the mission. The absolute and time variable calibration of EIT therefore is of extreme interest. The NRL EIT Calibration Sounding Rocket (CalRoc) program was initiated to provide well calibrated, contemporaneous observations in support of SOHO EIT. These observations provide three benefits to the SOHO EIT data, absolute calibration points, temporal and spatial information of the EIT EUV response variability in flight via flat field information and clues to the physics of the degradation. Details of the bandpasses of the multilayered optics and the total telescope photometry are presented. Comparisons are shown with the contemporaneous images from SOHO EIT. Plans for the second CalRoc flight are discussed. Loss of reflectivity in the multilayer mirrors has been identified as a new component to the SOHO EIT and CalRoc degradation. C1 NASA, Goddard Space Flight Ctr, Emergent Informat Technol Inc, Greenbelt, MD 20771 USA. RP Newmark, JS (reprint author), NASA, Goddard Space Flight Ctr, Emergent Informat Technol Inc, Code 682 3, Greenbelt, MD 20771 USA. RI Woodgate, Bruce/D-2970-2012 NR 17 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 0-8194-3784-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4139 BP 328 EP 339 DI 10.1117/12.410532 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy GA BR89U UT WOS:000167974600031 ER PT S AU West, EA Porter, JG Davis, JM Gary, GA Rabin, DM Thomas, RJ Davila, JM AF West, EA Porter, JG Davis, JM Gary, GA Rabin, DM Thomas, RJ Davila, JM BE Fineschi, S Korendyke, CM Siegmund, OHW Woodgate, BE TI Overview of the Solar Ultraviolet Magnetograph Investigation SO INSTRUMENTATION FOR UV/EUV ASTRONOMY AND SOLAR MISSIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instrumentation for UV/EUV Astronomy and Solar Missions CY JUL 30-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE ID MAXIMUM MISSION; REGION AB Traditional magnetographs measure the solar magnetic field at the visible "surface" of the Sun, the photosphere. The Solar Ultraviolet Magnetograph Investigation (SUMI) is a hardware development study for an instrument to measure the solar magnetic field higher in the atmosphere, in the upper chromosphere and in the transition region at the base of the corona. The magnetic pressure at these levels is much stronger than the gas pressure tin contrast to the situation at the photosphere), so the field controls the structure and dynamics of the atmosphere. Rapid changes in the magnetic structure of the atmosphere become possible at this height, with the release of energy. Measurements of the vector magnetic field in this region will significantly improve our understanding of the physical processes heating the Sun's upper atmosphere and driving transient phenomena such as flares and coronal mass ejections. The instrument will incorporate new technologies to achieve the polarization efficiencies required to measure the magnetic splitting of lines in the VUV and UV (CIV at 1550 Angstrom and MgII at 2800 Angstrom). We describe the scientific goals, the optical components that are being developed for a sounding rocket program, and the SUMI baseline design. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP West, EA (reprint author), NASA, George C Marshall Space Flight Ctr, SD50, Huntsville, AL 35812 USA. RI Woodgate, Bruce/D-2970-2012 NR 6 TC 10 Z9 10 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3784-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4139 BP 350 EP 361 DI 10.1117/12.410534 PG 12 WC Engineering, Aerospace; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy SC Engineering; Astronomy & Astrophysics; Meteorology & Atmospheric Sciences; Spectroscopy GA BR89U UT WOS:000167974600033 ER PT S AU McGowan, JF AF McGowan, JF BE Hoover, RB TI Oil and natural gas on Mars SO INSTRUMENTS, METHODS, AND MISSIONS FOR ASTROBIOLOGY III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Instruments, Methods, and Missions for Astrobiology III CY AUG 01-02, 2000 CL SAN DIEGO, CA SP SPIE DE oil; natural gas; Mars; mass spectrometer; infrared spectrometer; aerobot; rover; methane ID ANCIENT OCEANS; NORTH-SEA; METHANE; SPECTROMETER; DEEP; SEEPAGE; SURFACE; CYCLE AB On Earth, according to conventional theory, the largest, by mass and volume, identifiable trace of past life is subsurface oil and natural gas deposits. Nearly all coal and oil on Earth and most sedimentary source rocks associated with coal, oil, and natural gas contain molecules of biological origin and is proof of past life. If Mars possessed an Earth-like biosphere in the past, Mars may contain subsurface deposits of oil and natural gas indicating past life. Life might still exist in these deposits. Subsurface oil and natural gas on Mars would probably cause seepage of hydrocarbon gases such as methane at favorable locations on the Martian surface. Further, if Mars contains substantial subsurface life, the most detectable signature of this life on the Martian surface would be gases generated by the life percolating up to the surface and venting into the Martian atmosphere. In this paper, systems that can detect evidence of subsurface oil and gas, including ground penetrating radar and infrared gas sensors are explored. The limitations and future prospects of infrared gas detection and imaging technologies are explored. The power, mass, and volume requirements for infrared instruments able to detect venting gases, especially methane, from an aerobot is estimated. The maximum range from the infrared sensor to the gas vent and the minimum detectable gas density or fraction of the Martian atmosphere - as appropriate for the instrument type - is estimated. The bit rate and bit error rate requirements for transmitting the data back to Earth are also estimated. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP McGowan, JF (reprint author), NASA, Ames Res Ctr, Mail Stop 233-18, Moffett Field, CA 94035 USA. NR 64 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 0-8194-3782-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4137 BP 63 EP 74 DI 10.1117/12.411610 PG 12 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Instruments & Instrumentation; Microbiology SC Astronomy & Astrophysics; Geochemistry & Geophysics; Instruments & Instrumentation; Microbiology GA BR89G UT WOS:000167921700006 ER PT J AU Miranda, FA Katiyar, RS Fernandez, FE AF Miranda, FA Katiyar, RS Fernandez, FE TI Proceedings of Ferroelectrics Workshop in Puerto Rico (FWPR-99) - Guanica, Puerto Rico - May 12-14, 1999 - Guest editorial SO INTEGRATED FERROELECTRICS LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Cleveland, OH USA. Univ Puerto Rico, Rio Piedras, PR 00931 USA. Univ Puerto Rico, Mayaguez, PR USA. RP Miranda, FA (reprint author), NASA, Glenn Res Ctr, Cleveland, OH USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2000 VL 29 IS 1-2 BP VII EP X PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 342MH UT WOS:000088648000001 ER PT J AU Van Keuls, FW Mueller, CH Miranda, FA Romanofsky, RR Horwitz, JS Chang, W Kim, WJ AF Van Keuls, FW Mueller, CH Miranda, FA Romanofsky, RR Horwitz, JS Chang, W Kim, WJ TI Thin film BaxSr1-xTiO3 Ku- and K-band phase shifters grown on MgO substrates SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT Ferroelectrics Workshop (FWPR 99) CY MAY 12-14, 1999 CL GUANTICA, PUERTO RICO DE BaxSr1-xTiO3; phase shifters; tunable microwave devices ID DIELECTRIC-PROPERTIES; ROOM-TEMPERATURE AB We report measurements of gold circuits fabricated on four BaxSr1-xTiO3 Ferroelectric films doped with 1% Mn grown on MgO substrates by laser ablation. Low frequency (1 MHz) measurements of epsilon(r) and tan delta on interdigital capacitors are compared with high frequency measurements of phase shift and insertion loss on coupled microstrip phase shifters patterned onto the same films. The variation in temperature of both high and low frequency device parameters is compared. Annealed with amorphous buffer layer and unannealed Films are compared. Room temperature figures of merit of phase shift per insertion loss of up to 58.4 degrees/dB at 18 GHz and 400 V de bias were measured. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. USN, Res Lab, Washington, DC 20375 USA. RP Van Keuls, FW (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 8 TC 5 Z9 6 U1 1 U2 4 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2000 VL 29 IS 1-2 BP 49 EP 61 DI 10.1080/10584580008222220 PG 13 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 342MH UT WOS:000088648000006 ER PT J AU Jiang, H Hu, W Liang, S Fouflyguine, V Zhao, J Jia, QX Groves, JR Arendt, P Miranda, F Drehman, A Wang, S Yip, P AF Jiang, H Hu, W Liang, S Fouflyguine, V Zhao, J Jia, QX Groves, JR Arendt, P Miranda, F Drehman, A Wang, S Yip, P TI High quality BaxSr1-xTiO3 films grown by MOCLD and novel ferroelectric/ferrite structures for dual-tuning microwave devices SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT Ferroelectrics Workshop (FWPR 99) CY MAY 12-14, 1999 CL GUANTICA, PUERTO RICO DE ferroelectric; ferrite; dual-tuning; microwave; buffer layer ID THIN-FILMS AB Excellent single crystal BaxSr1-xTiO3 (BST) films were grown on LaAlO3 substrates using the metal-organic chemical liquid deposition (MOCLD) method. Very low losses (tan delta similar to 0.002-0.008) were measured from these films at 400 KHz. Biaxially oriented BST films were successfully grown on polycrystalline YIG substrates using both MOCLD and pulsed laser deposition methods with biaxially oriented MgO and YSZ buffer layers. The dielectric losses of the films range from 0.005 to 0.015 while 25% of dielectric constant change was observed with 40V bias voltage up to 10 MHz. Both the dissipation and dielectric constant of the films remained nearly constants over a wide temperature range (77 K to 380 K). A dual-tuning microwave coplanar phase shifter using a BST film grown on a MgO buffered polycrystalline YIG substrate was fabricated. A significant phase shift was observed in GHz frequency range when an electric bias or a magnetic field was applied to the device. C1 NZ Appl Technol, Woburn, MA 01801 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. USAF, Res Lab, Hanscom AFB, MA 01731 USA. RP Jiang, H (reprint author), NZ Appl Technol, 14A Gill St, Woburn, MA 01801 USA. RI Jia, Q. X./C-5194-2008 NR 8 TC 4 Z9 4 U1 0 U2 2 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2000 VL 29 IS 1-2 BP 63 EP 79 DI 10.1080/10584580008222221 PG 17 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 342MH UT WOS:000088648000007 ER PT J AU Subramanyam, G Van Keuls, FW Miranda, FA AF Subramanyam, G Van Keuls, FW Miranda, FA TI Effect of DC biasing on YBCO/STO/LAO tunable microstrip filters SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT Ferroelectrics Workshop (FWPR 99) CY MAY 12-14, 1999 CL GUANTICA, PUERTO RICO DE ferroelectric thin-films; microstrip lines; K-band microwave frequencies; tunable bandpass filters; YBCO high temperature superconducting thin-films AB One or the critical design aspects in ferroelectric tunable microstrip Filters is choosing the: right bias configuration, for large tunability as well as to maintain the filter's passband characterisitics . This work based on strontium titanate (STO) ferroelectric thin-film based tunable microstrip filters for cryogenic temperature applications. Large tunability factors have been demonstrated in YBCO/STO/LAO two-layered microstrip filters when operated at or below 77 K. The effect of the do electric field (primarily responsible For tuning) and critical design parameters such as the insertion loss, frequency tunability, return loss, and bandwidth of superconductor/feroelectric/dielectric microstrip tunable K-band microwave filters is discussed in this work. C1 Univ Dayton, Dept ECE, Dayton, OH 45469 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Subramanyam, G (reprint author), Univ Dayton, Dept ECE, Dayton, OH 45469 USA. NR 11 TC 4 Z9 4 U1 0 U2 4 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2000 VL 29 IS 1-2 BP 81 EP 93 DI 10.1080/10584580008222222 PG 13 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 342MH UT WOS:000088648000008 ER PT J AU Mueller, CH Van Keuls, FW Romanofsky, RR Miranda, FA Warner, JD Canedy, CL Ramesh, R AF Mueller, CH Van Keuls, FW Romanofsky, RR Miranda, FA Warner, JD Canedy, CL Ramesh, R TI Characterization of (Ba0.5Sr0.5)TiO3 thin films for Ku-band phase shifters SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT Ferroelectrics Workshop (FWPR 99) CY MAY 12-14, 1999 CL GUANTICA, PUERTO RICO DE ferroelectric; paraelectric; thin film; microstructure; phase shifter AB The microstructural properties of (Ba0.5Sr0.5)TiO3(BSTO) thin films (300, 700, and 1400 nm thick) deposited on LaAlO3 (LAO) substrates were characterized using high-resolution x-ray diffractometery. Film crystallinity was the parameter that most directly influenced tunability, and we observed that a) the crystalline quality was highest in the thinnest film and progressively degraded with increasing film thickness; and b) strain at the film/substrate interface was completely relieved via dislocation formation. Paraelectric films such as BSTO offer an attractive means of incorporating low-cost phase shifter circuitry into beam-steerable reflectarray antennas. C1 NASA, Glenn Res Ctr, Space Elect Div, Cleveland, OH 44135 USA. Univ Maryland, College Pk, MD 20742 USA. RP Mueller, CH (reprint author), NASA, Glenn Res Ctr, Space Elect Div, Cleveland, OH 44135 USA. NR 14 TC 8 Z9 9 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 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2000 VL 29 IS 1-2 BP 139 EP 149 DI 10.1080/10584580008222227 PG 11 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 342MH UT WOS:000088648000013 ER PT J AU Chen, CL Zhang, Z Feng, H Luo, GP Chen, SY Heilman, A Chu, WK Chu, CW Gao, J Rafferty, B Pennycook, SJ Liou, Y Miranda, FA Van Keuls, F AF Chen, CL Zhang, Z Feng, H Luo, GP Chen, SY Heilman, A Chu, WK Chu, CW Gao, J Rafferty, B Pennycook, SJ Liou, Y Miranda, FA Van Keuls, F TI Epitaxial behavior and interface structures of BSTO thin films SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT Ferroelectrics Workshop (FWPR 99) CY MAY 12-14, 1999 CL GUANTICA, PUERTO RICO DE ferroelectric films; (B1-xSrx)TiO3; pulsed laser ablation; interface structures; LaAlO3 substrates ID ELECTRICAL-PROPERTIES; DEPOSITION; CAPACITORS AB Ferroelectric Ba(1-x)SrxTiO3 (x = 0.5 and 0.25) thin films were grown on (001) LaAlO3 by using pulsed laser ablation. Extensive x-ray diffraction and selected area electron diffraction reveal that the as-grown films were (001) oriented with a good in-plane relationship of < 100 >(BSTO) // < 100 >(LAO). Rutherford Backscattering Spectroscopy ion-channeling studies suggested that the films had excellent epitaxial quality and crystallinity with an ion beam minimum yield chi(min) of only 2.6%. Atomically sharp interfaces were seen by cross-sectional high-resolution electron microscopy, indicated that the density of misfit dislocations was consistent with the lattice mismatch from the theoretical calculation. C1 Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Glenn Res Ctr, Commun Technol Div, Cleveland, OH 44135 USA. RP Chen, CL (reprint author), Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. NR 16 TC 0 Z9 0 U1 0 U2 5 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2000 VL 29 IS 1-2 BP 237 EP 246 DI 10.1080/10584580008222235 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 342MH UT WOS:000088648000021 ER PT J AU Lin, WY Huang, H Yang, F Schmitt, JJ Hunt, AT Romanofsky, RR Van Keuls, FW Miranda, FA Mueller, CH AF Lin, WY Huang, H Yang, F Schmitt, JJ Hunt, AT Romanofsky, RR Van Keuls, FW Miranda, FA Mueller, CH TI Thin films of CCVD Ba0.5Sr0.5TiO3 and SrTiO3 for electrically tunable coupled microstripline phase shifters SO INTEGRATED FERROELECTRICS LA English DT Article; Proceedings Paper CT Ferroelectrics Workshop (FWPR 99) CY MAY 12-14, 1999 CL GUANTICA, PUERTO RICO DE ferroelectrics; tunability; coupled microstripline phase shifters; thin films; combustion chemical vapor deposition; epitaxy AB Epitaxial barium strontium titanate and strontium titanate thin films were deposited on (100) MgO single-crystal substrates, utilizing Combustion Chemical Vapor Deposition. The as-deposited films were patterned with gold electrodes to form interdigitated structure to function as electrically tunable devices, namely, coupled microstripline phase shifters (CMPS). Microwave dielectric properties were characterized at 11-20 GHz with an applied electric field up to +/-35 V/mu m. A maximum figure of merit of 53 degrees/dB at 20 GHz and 23 degrees C was measured. The demonstrated high degree of tunability and relatively low loss showed great potential of these films for the targeted frequency agile device applications. Characterization, using SEM, EDS, and XRD, is presented in addition to microwave performance as a function of do bias and frequency. C1 MicroCoating Technol Inc, Chamblee, GA 30341 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Lin, WY (reprint author), MicroCoating Technol Inc, Chamblee, GA 30341 USA. NR 5 TC 2 Z9 2 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 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2000 VL 29 IS 1-2 BP A1 EP A12 PG 12 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 342MH UT WOS:000088648000024 ER PT J AU Miranda, FA Katiyar, RS Fernandez, FE AF Miranda, FA Katiyar, RS Fernandez, FE TI Proceedings of Ferroelectrics Workshop in Puerto Rico (FWPR-99) - Guanica, Puerto Rico - May 12-14, 1999 - Guest editorial SO INTEGRATED FERROELECTRICS LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Cleveland, OH USA. Univ Puerto Rico, Rio Piedras, PR 00931 USA. Univ Puerto Rico, Mayaguez, PR USA. RP Miranda, FA (reprint author), NASA, Glenn Res Ctr, Cleveland, OH USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1058-4587 J9 INTEGR FERROELECTR JI Integr. Ferroelectr. PY 2000 VL 29 IS 1-2 BP AR7 EP AR10 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 342MH UT WOS:000088648000023 ER PT J AU Kamel, M Jamshidi, M AF Kamel, M Jamshidi, M TI Distributed intelligent systems SO INTELLIGENT AUTOMATION AND SOFT COMPUTING LA English DT Editorial Material C1 Univ Waterloo, Dept Syst Design Engn, Pattern Anal & Machine Intelligence Lab, Waterloo, ON N2L 3G1, Canada. Univ New Mexico, Dept Elect & Comp Engn, Albuquerque, NM 87131 USA. NASA, Ctr Autonomous Control Engn, Albuquerque, NM 87131 USA. RP Kamel, M (reprint author), Univ Waterloo, Dept Syst Design Engn, Pattern Anal & Machine Intelligence Lab, Waterloo, ON N2L 3G1, Canada. RI Kamel, Mohamed/D-9323-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AUTOSOFT PRESS PI ALBUGUERQUE PA PO BOX 14126, ALBUGUERQUE, NM 87191-4126 USA SN 1079-8587 J9 INTELL AUTOM SOFT CO JI Intell. Autom. Soft Comput. PY 2000 VL 6 IS 3 BP 171 EP 172 PG 2 WC Automation & Control Systems; Computer Science, Artificial Intelligence SC Automation & Control Systems; Computer Science GA 342VE UT WOS:000088665200001 ER PT B AU Matthies, L Xiong, Y Hogg, R Zhu, D Rankin, A Kennedy, B Hebert, M Maclachlan, R Won, C Frost, T Sukhatme, G McHenry, M Goldberg, S AF Matthies, L Xiong, Y Hogg, R Zhu, D Rankin, A Kennedy, B Hebert, M Maclachlan, R Won, C Frost, T Sukhatme, G McHenry, M Goldberg, S BE Pagello, E Groen, F Arai, T Dillmann, R Stentz, A TI A portable, autonomous, urban reconnaissance robot SO INTELLIGENT AUTONOMOUS SYSTEMS 6 LA English DT Proceedings Paper CT 6th International Conference on Intelligent Autonomous Systems (IAS-6) CY JUL 25-27, 2000 CL VENICE, ITALY SP Intelligent Autonomous Syst Soc, Italian Assoc Artificial Intelligence, Italian Assoc Robot AB Portable mobile robots, in the size class of 20 kg or less, could be extremely valuable as autonomous reconnaissance platforms in urban warfare, hostage situations, and urban disaster relief. We have developed a prototype urban robot under the Tactical Mobile Robotics (TMR) Program funded by DARPA. The robot is built on a novel chassis with articulated tracks that enable stair climbing and scrambling over rubble. Autonomous navigation capabilities of the robot include stereo vision-based obstacle avoidance. visual servoing to user-designated goals, and autonomous vision-guided stair climbing. The system was demonstrated in an urban reconnaissance mission scenario at Fort Sam Houston in October, 1999. A two-axis scanning laser rangefinder has been developed and will be integrated in the coming year for indoor mapping and position estimation. This paper describes the robot, its performance in field trials, and some of the technical challenges that remain to enable fieldable urban reconnaissance robots. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Matthies, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU I O S PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS BN 1-58603-078-7 PY 2000 BP 647 EP 654 PG 8 WC Automation & Control Systems SC Automation & Control Systems GA BQ87B UT WOS:000089885200084 ER PT B AU Muscettola, N Dorais, GA Fry, C Levinson, R Plaunt, C AF Muscettola, N Dorais, GA Fry, C Levinson, R Plaunt, C BE Pagello, E Groen, F Arai, T Dillmann, R Stentz, A TI A unified approach to model-based planning and execution SO INTELLIGENT AUTONOMOUS SYSTEMS 6 LA English DT Proceedings Paper CT 6th International Conference on Intelligent Autonomous Systems (IAS-6) CY JUL 25-27, 2000 CL VENICE, ITALY SP Intelligent Autonomous Syst Soc, Italian Assoc Artificial Intelligence, Italian Assoc Robot AB Several successful autonomous systems are separated into technologically diverse functional layers operating at different levels of abstraction. This diversity makes them difficult to implement and validate. In this paper, we present a unified planning and execution framework that relies on a single model, plan database, plan runner and on a variety of planners, both reactive and deliberative. The framework allows the specification of agents that operate within a guaranteed reaction time and supports flexible specification of reactive vs. deliberative agent behavior. The new agent framework aims at fully duplicating the functionalities of the DSI Remote Agent in domains of equal or higher complexity than autonomous spacecraft control. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Muscettola, N (reprint author), NASA, Ames Res Ctr, Mail Stop 269-2, Moffett Field, CA 94035 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU I O S PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS BN 1-58603-078-7 PY 2000 BP 751 EP 758 PG 8 WC Automation & Control Systems SC Automation & Control Systems GA BQ87B UT WOS:000089885200098 ER PT S AU Colavita, MM Wizinowich, PL AF Colavita, MM Wizinowich, PL BE Lena, PJ Quirrenbach, A TI Keck Interferometer: progress report SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE optical/IR interferometry; astrometry; nulling ID ASTROMETRY AB The Keck Interferometer is a NASA-funded joint development between JPL and the W. M. Keck Observatory. The interferometer will combine the two 10-m Keek telescopes with four 1.8-m outrigger telescopes in several observing modes. These include: nulling interferometry at 10 mu m to measure the quantity of exozodiacal emission around nearby stars; near-infrared differential-phase measurements to detect "hot Jupiters" by their direct emission; narrow-angle astrometry to search for exoplanets by their astrometric signature; and near-infrared imaging to address a variety of imaging science. Active development of the instrument subsystems and associated infrastructure is underway at JPL and CARA. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Colavita, MM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 16 TC 17 Z9 17 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 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 310 EP 320 DI 10.1117/12.390221 PN 1&2 PG 11 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500033 ER PT S AU Serabyn, E AF Serabyn, E BE Lena, PJ Quirrenbach, A TI Nulling interferometry: Symmetry requirements and experimental results SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE nulling interferometry; rotational shearing interferometer ID EXTRASOLAR PLANETS; SEARCH; LIFE AB This paper provides a derivation from first principles of the stringent symmetry and stability requirements which deep stellar nulling demands, and also includes a brief status report on recent nulling results obtained with the Jet Propulsion Laboratory's fiber-coupled rotational-shearing interferometer. To date, the deepest transient nulls obtained (at red wavelengths) are 2 x 10(-6) with a laser diode source, and 1.4 x 10(-5) with a single-polarization thermal white-light source filtered to provide an 18% passband. In addition, both the laser and white light nulls have been stabilized to the 10(-4) level. This visible wavelength laboratory nuller thus meets essentially all of the performance goals for the planned nulling experiment on board NASA's Space Interferometer Mission, with the sole exception of dual-polarization operation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Serabyn, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 62 Z9 62 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 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 328 EP 339 DI 10.1117/12.390223 PN 1&2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500035 ER PT S AU Lawson, PR Colavita, MR Dumont, PJ Lane, BF AF Lawson, PR Colavita, MR Dumont, PJ Lane, BF BE Lena, PJ Quirrenbach, A TI Least-squares estimation and group delay in astrometric interferometers SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE astronomy; astrometry; interferometry; group delay AB The Palomar Testbed Interferometer is a long-baseline interferometer that uses both phase and group-delay measurements for narrow-angle astrometry. The group-delay measurements are performed using 5 spectral channels across the band from 2.0 to 2.4 mu m. Group delay is estimated from phasors (sine and cosine of fringe phase) calculated for each spectral channel using pathlength modulation of one wavelength. Normally the group delay is estimated to be the delay corresponding to the peak of the power spectrum of these complex phasors. The Fourier transform does not however yield a least-squares estimate of the delay. Nevertheless, the precision of phase estimation can be achieved in a group-delay estimate using a least-squares approach. We describe the least-squares group-delay estimator that has been implemented at PTI and illustrate its performance as applied to narrow-angle astrometry. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lawson, PR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 8 Z9 8 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 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 397 EP 406 DI 10.1117/12.390232 PN 1&2 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500043 ER PT S AU Unwin, SC Shao, M AF Unwin, SC Shao, M BE Lena, PJ Quirrenbach, A TI The Space Interferometry Mission SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE interferometry; astrometry; planet detection; astrophysics; Galaxy; parallax AB The Space Interferometry Mission (SIM) will be a 10-m Michelson interferometer in Earth-trailing solar orbit. As a part of NASA's Origins program, it will be the first space-based optical interferometer designed for precision astrometry. As well as enabling forefront astronomical science, SIM will serve as a technology pathfinder for future Origins missions, such as the Terrestrial Planet Finder (TPF). SIM is being designed for 4 microarcsecond (mu as) precision absolute position measurements of stars down to 20 magnitude. Launch is currently planned for mid-2006, and the mission duration is 5 years. By searching for the astrometric 'wobble' signature caused by a companion to a target star, SIM will be very sensitive to sub-stellar and planetary companions. By observing stars relative to nearby reference stars, an accuracy of 1 microarcsecond (mu as) in a 1-hour measurement is expected, which is sufficient to detect planets of less than about three Earth masses around the nearest stars. With precision global astrometry, SIM allows parallax distance measurements to 10% accuracy, even on the far side of the Galaxy During its 5-year mission, SIM will address a important variety of science questions relating to the formation and dynamics of our Galaxy. In addition to astrometry, SIM will demonstrate the technique of imaging using aperture synthesis. While this is routinely used by ground-based radio telescopes, a space-based optical synthesis imaging demonstration is the first step toward a later generation of large imaging telescopes. SIM will have resolution of 10 milliarcsec in the V band. It will also perform a demonstration of interferometric nulling, in which the on-axis starlight is suppressed to a level of 10(-4), a key requirement for TPF. In this paper we outline the design of the SIM instrument, and how it will be used in the search for extrasolar planets. We also briefly describe some selected topics from the SIM astrometric science program. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Unwin, SC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 13 Z9 13 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 754 EP 761 DI 10.1117/12.390275 PN 1&2 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500084 ER PT S AU Shao, M Danchi, T DiPirro, M Dragovan, M Finberg, LD Hagopian, M Langer, WD Lawrence, CR Lawson, PR Leisawitz, DT Mather, JC Moseley, SH Swain, MR Yorke, HW Zhang, XL AF Shao, M Danchi, T DiPirro, M Dragovan, M Finberg, LD Hagopian, M Langer, WD Lawrence, CR Lawson, PR Leisawitz, DT Mather, JC Moseley, SH Swain, MR Yorke, HW Zhang, XL BE Lena, PJ Quirrenbach, A TI Space-based interferometric telescopes for the far infrared SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE interferometers; IR telescopes; space telescopes; cryogenic optics; membrane mirrors ID SUBMILLIMETER AB We discuss concepts for deploying direct-detection interferometers in space which are optimized for the wavelength range 40 mu m to 500 mu m. In particular, we introduce two missions in NASA's current strategic plan: SPIRIT (SPace InfraRed Interferometric Telescope) and SPECS (Submillimeter Probe of the Evolution of Cosmic Structure). Passive cooling through a large multi-layered sunshield, cryogenic optics, background-limited detectors, and angular resolution comparable to that of a single 50 meter aperture gives SPTRIT a spectacular combination of sensitivity and angular resolution in the far infrared (FIR). In our strawman mission design, which could be ready for launch by 2010, multiple, cold, membrane mirrors are arranged along two deployable booms. The entire structure rotates, giving SPIRIT good u-v coverage and the ability to make high dynamic range synthesis images. SPECS is an even larger scale FIR/submm direct-detection interferometer. Separated free-flying (or tethered) outrigger mirrors allow a maximum baseline of similar to 1 km. The combination of extremely good spatial resolution, passive and active cooling of the optics, and background limited detectors will allow sensitive imaging well below the confusion limit in the FIR. SPECS is to be launched in the decade following SPIRIT. Both SPIRIT and SPECS operate ina long-stroke Michelson beam combination mode to enable simultaneous imaging over a field size of at least 9 subaperture diffraction spots with spectral resolution of order 1000. An on-demand spectral resolving element could further increase spectral resolution to of order 10(5) for specific science objectives and for maintaining background-limited operation when observing bright objects. A primary science goal for SPIRIT and SPECS is to probe the structure of the early Universe; these missions directly address grand challenge questions regarding the formation of galaxies and the role of star formation in galaxy evolution. In addition, these facilities provide powerful tools for studying the local interstellar medium and the star formation and planet formation processes. SPIRIT and SPECS would be part of NASA's complement of space-based interferometers such as SIM (Space Interferometer Mission), TPF (Terrestrial Planet Finder), and PI (Planet Imager). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Shao, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 18 TC 8 Z9 8 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 772 EP 781 DI 10.1117/12.390278 PN 1&2 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500086 ER PT S AU Goullioud, R Azizi, A AF Goullioud, R Azizi, A BE Lena, PJ Quirrenbach, A TI Optical design of the SIM system testbed 3 SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE interferometry; SIM; optics; pseudo-star ID SPATIAL INTERFEROMETRY; METROLOGY AB The SIM system testbed III (STB3) is a 3-baseline interferometer mounted on a full-scale flexible structure developed at the Jet Propulsion Laboratory. The goal of the testbed is to demonstrate angle and fringe tracking of a dim star by feeding-forward the information from two interferometers looking at bright guide stars. This paper presents the optical architecture of STB3 and the first results obtained with the first interferometers running. The testbed consists of two separate systems isolated from the ground: the pseudo-star and the instrument. The pseudo-star is a passive reverse interferometer on a rigid table. The originality of the pseudo-star design is the diffraction gratings used to split the stellar wavefront into 3 stars. They minimize the differential position jitter of each star from the others, reducing the overall error of the experiment. The instrument is a triple Michelson interferometer on a SIM-like structure. Each interferometer runs a CCD camera and two fast steering mirrors for angle tracking, an internal metrology system, an Avalanche Photo-Diode and an active optical delay-line for fringe tracking. External metrology sensors monitor the relative orientation and length of the baselines. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Goullioud, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 788 EP 799 DI 10.1117/12.390280 PN 1&2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500088 ER PT S AU Papalexandris, MV Basinger, SA Redding, DC AF Papalexandris, MV Basinger, SA Redding, DC BE Lena, PJ Quirrenbach, A TI Average phase calculations with near-field diffraction algorithms for the Space Interferometry Mission SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE near-field diffraction; discrete Fourier Transform; Goertzel-Reincsh algorithm AB This work reports on the computation of the average phase of a beam over an optical element via discrete Fourier transform techniques. The objective is to develop accurate diffraction models for the Space Interferometry Mission (SIM). Applications related to SIM include calibration of metrology measurements, evaluation of cornercube diffraction effects, and others. The algorithms that are used to compute the field are described and numerical tests that assess their accuracy are presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Papalexandris, MV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 800 EP 805 DI 10.1117/12.390281 PN 1&2 PG 6 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500089 ER PT S AU Kuhnert, AC Shaklan, SB Shen, J Carlson, A Azevedo, LS AF Kuhnert, AC Shaklan, SB Shen, J Carlson, A Azevedo, LS BE Lena, PJ Quirrenbach, A TI First tests of the interferometer in the Micro-Arcsecond Metrology Testbed (MAM) SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE interferometry; Space Interferometry Mission; astrometry; picometer metrology AB The Space Interferometry Mission (SIM) relies on interferometry and metrology capable of measuring the change in the optical path difference with picometer accuracy. For the last two years we designed and built the Micro-Arcsecond Metrology (MAM) Testbed, the key technology demonstration for SIM. In a parallel effort the data analysis code was written. The interferometer was first used in a modified configuration: white light and light from a HeNe-laser was emerging from a fiber, collimated and split into the two arms with their respective delay lines. The recombined light was then dispersed onto the CCD camera. The tests done using this interferometer resulted in data on the effects that influence the accurate determination of the fringe phase delay: i) alignment effects; ii) CCD camera parameters; iii) path length stability, and iv) analysis related inaccuracies. While offsetting the interferometer from equal arm length, the OPD was dithered using PZT-actuated mirrors. The white-light fringe was captured for each step. At the same time the (HeNe) laser light was monitored with two photo detectors - one serving as an intensity monitor, the second one monitoring the interfered laser light. This technique was used to accurately measure the path length changes by analyzing the linear parts of the HeNe sinusoidal interference signal normalized by the HeNe intensity signal. This simple metrology system is designed to determine the optical path length changes to about 100 pm. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kuhnert, AC (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 5 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 815 EP 827 DI 10.1117/12.390283 PN 1&2 PG 13 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500091 ER PT S AU Milman, MH Turyshev, SG AF Milman, MH Turyshev, SG BE Lena, PJ Quirrenbach, A TI Observational model for the Space Interferometry Mission SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE SIM; metrology; pathlength feedforward; astrometry; modeling AB The Space Interferometry Mission (SIM) is a space-based long-baseline optical interferometer for precision astrometry. One of the primary objectives of the SIM instrument is to accurately determine the directions to a grid of stars, together with their proper motions and parallax, improving a priori knowledge by nearly three orders of magnitude. The basic astrometric observable of the instrument is the pathlength delay, a measurement made by a combination of internal metrology measurements that determine the distance the starlight travels through the two arms of the interferometer and a measurement of the white light stellar fringe to find the point of equal pathlength. Because this operation requires a non-negligible integration time to accurately measure the stellar fringe position, the interferometer baseline vector is not stationary over this time period, as its absolute length and orientation are time-varying. This conflicts with the consistency condition necessary for extracting the astrometric parameters which requires a stationary baseline vector. This paper addresses how the time-varying baseline is "regularized" so that it may act as a single baseline vector for multiple stars. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Milman, MH (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 3 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 828 EP 837 DI 10.1117/12.390284 PN 1&2 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500092 ER PT S AU Jeganathan, M Dubovitsky, S AF Jeganathan, M Dubovitsky, S BE Lena, PJ Quirrenbach, A TI Demonstration of nm-level active metrology for long range interferometric displacement measurements SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE active metrology; two-laser metrology; heterodyne interferometer; ST3; TPF; LISA AB We report on the laboratory demonstration of an active linear metrology scheme using two separate lasers. In "active" metrology, the passive retroreflector in one arm of a typical heterodyne interferometer is replaced with an active optical transponder. The Transponder can dramatically boost the returned signal strength, thereby providing a way to perform metrology and pathlength control over long (> km) distances. Two Lightwave Electronics non-planar ring oscillator (NPRO) lasers at a wavelength of 1.319 mu m were used as the Source and Transponder. The frequency of the Transponder is offset locked to the signal received from the Source using the Lightwave Laser Offset Locking Accessory (LOLA), and the Transponder beam is sent back to the Source. The phases of the beat signals are measured locally at the Source and Transponder by appropriately demodulating the signal, and post-processed to determine displacement. In initial experiments, the standard deviation of the measurement errors was less than three nanometers. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jeganathan, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 838 EP 846 DI 10.1117/12.390165 PN 1&2 PG 9 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500093 ER PT S AU Goullioud, R Dekens, FG Neat, GW AF Goullioud, R Dekens, FG Neat, GW BE Lena, PJ Quirrenbach, A TI Micro-precision Interferometer: Scorecard on technology readiness for the Space Interferometer Mission SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE interferometry; Micro-precision Interferometer; SIM AB This paper presents the first ever "scorecard" showing how well the Space Interferometer Mission (SIM) is expected to meet the vibration attenuation requirements for its instrument. The spacecraft reaction wheel assembly, the primary on-board vibration source, shakes the structure in the frequency range from 2 Hz to 1000 Hz. Optical path differences and wavefront tip-tilts must be maintained to a few nanometers and tens of milli-arcseconds respectively in this disturbance environment. The vibration attenuation solution employs active six-axis vibration isolation at the reaction wheel attachment point and Various active optical controls which are characterized by allowable servo bandwidth. In the case of SIM observing a dim target star, the usable starlight bandwidth is only 0.01 Hz which provides no help in rejecting the wheel disturbances whereas observing a bright target star enables 100 Rz of bandwidth and thus contributes significantly to the vibration attenuation solution. The Micro-precision Interferometer (MPI) testbed, a ground-based dimensionally representative hardware model of SIM, is used to estimate SIM's on-orbit vibration behavior. After implementing the specific bandwidth constraints unique to each requirement, a transfer function-based performance algorithm predicts the requisite residual optical jitter on the testbed. The "score" for each requirement is the ratio of this estimated jitter to the actual SIM jitter requirement. For the 7 requirements considered, the scores range from 1 (best) to 127 (worst). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91009 USA. RP Neat, GW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91009 USA. NR 15 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 847 EP 858 DI 10.1117/12.390166 PN 1&2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500094 ER PT S AU Hines, B AF Hines, B BE Lena, PJ Quirrenbach, A TI SIM System Testbed III SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE SIM space interferometry pathlength feedforward angle technology control ID SPATIAL INTERFEROMETRY; METROLOGY; DESIGN AB The System Testbed III (STB-3) is the flagship testbed in JPL's Interferometry Technology Program for the Space Interferometry Mission(1,16) in which it holds a place as the piece of ground hardware that looks and acts most like the real SIM space system. STB-3 is a 3-year, $11.2M program targeted at demonstrating that the SIM architecture, using two interferometers trained at bright guide stars to stabilize a third "science" interferometer in pathlength and angle, will work. STB-3 will also demonstrate much of the complexity of full SIM operations in the laboratory by the end of 2001. STB-3 is currently operating on optical tables in its first phase and is in the process of being moved to a full-size flight-like structure where feedforward stabilization of the science interferometer will be re-demonstrated. Finally, in its third phase, STB-3 will add autoalignment and other autonomous operations. This paper will present the current status of STB-3, our approach to feedforward stabilization, and designs and plans for phases 2 and 3. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hines, B (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 15 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 859 EP 870 DI 10.1117/12.390167 PN 1&2 PG 12 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500095 ER PT S AU Laskin, RA Yu, JW AF Laskin, RA Yu, JW BE Lena, PJ Quirrenbach, A TI Overview and status of the Space Interferometry Mission (SIM) technology development SO INTERFEROMETRY IN OPTICAL ASTRONOMY, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Interferometry in Optical Astronomy CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE interferometry; metrology; pointing; control; nanometer; picometer; optics; lasers ID SPATIAL INTERFEROMETRY; METROLOGY AB Optical and infrared interferometry will open new vistas for astronomy over the next decade. Space based interferometers, operating unfettered by the Earth's atmosphere, will offer the greatest scientific payoff. They also present the greatest technological challenge: laser metrology systems must perform with sub-nanometer precision; mechanical vibrations must be controlled to nanometers requiring orders of magnitude disturbance rejection; a multitude of actuators and sensors must operate flawlessly and in concert. The Interferometry Technology Program at NASA's Jet Propulsion Laboratory is addressing these challenges with a development program that plans to establish technology readiness for the Space Interferometry Mission by end of 2001. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Laskin, RA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 73 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 0-8194-3631-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4006 BP 1014 EP 1028 DI 10.1117/12.390181 PN 1&2 PG 15 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ70B UT WOS:000089218500109 ER PT J AU Bozzolo, G Noebe, RD Honecy, F AF Bozzolo, G Noebe, RD Honecy, F TI Modeling of ternary element site substitution in NiAl SO INTERMETALLICS LA English DT Article DE nickel aluminides; based on NiAl; site occupancy ID INTERMETALLIC COMPOUNDS; DEFECT STRUCTURE; ALLOYING ADDITIONS; PHASE; PREFERENCE; FEAL; METALS; OCCUPATION; SYSTEMS; AL AB It is well recognized that ternary alloying additions can have a dramatic impact on the behavior of ordered intermetallic alloys such as nickel aluminides. Properties as diverse as yield strength, fracture strength, fracture mode, cyclic oxidation resistance, creep strength, and thermal and electrical diffusivity can change by orders of magnitude when a few percent or less of a ternary element is added. Yet our understanding of the resulting point defect structures and the simple site preferences of ternary alloying additions is poor because these are extremely difficult characteristics to determine. This disconnection between the understanding of the structure and properties in ordered alloys is at least in part responsible for the limited development and commercialization of these materials. Theoretical methods have provided useful but limited insight in this area, since most techniques suffer from constraints in the type of elements and the crystallographic structures that can be modeled. In an effort to overcome these limitations, the Bozzolo-Ferrante-Smith (BFS) method for alloys was designed. After a brief description of this approximate quantum mechanical approach, we use BFS to investigate the energetics of Si, Ti, V, Cr, Fe, Co, Cu, Zr, Nb, Mo, Ru, Hf, Ta and W additions to B2-ordered, stoichiometric NiAl. In addition to determining the site preference for these alloying additions over a range of compositions, we include results for the concentration dependence of the lattice parameter. In this introductory paper, we performed our analyses in the absence of constitutional and thermal vacancies for alloys of the form Ni-50(Al,X)(50). Where data exist, a comparison between experimental, theoretical, and BFS results is also included. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Bozzolo, G (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA. EM guillermo.bozzolo@lerc.nasa.gov NR 35 TC 55 Z9 56 U1 1 U2 9 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 EI 1879-0216 J9 INTERMETALLICS JI Intermetallics PD JAN PY 2000 VL 8 IS 1 BP 7 EP 18 DI 10.1016/S0966-9795(99)00066-7 PG 12 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 261FB UT WOS:000083997700002 ER PT J AU Dismukes, RK McDonnell, LK Jobe, KK AF Dismukes, RK McDonnell, LK Jobe, KK TI Facilitating LOFT debriefings: Instructor techniques and crew participation SO INTERNATIONAL JOURNAL OF AVIATION PSYCHOLOGY LA English DT Article AB This study analyzes techniques instructor pilots (IPs) use to facilitate crew analysis and evaluation of line-oriented flight training performance. We analyzed IP facilitation and crew participation for 36 debriefing sessions conducted at 5 U.S. airlines. For this analysis we developed a rating instrument termed the Debriefing Assessment Battery and demonstrated that it can be used reliably. IF facilitation skill varied dramatically, suggesting a need for concrete hands-on training in facilitation techniques. All measures of crew participation correlated significantly with IF effectiveness in facilitation. Crews responded to IF guidance but did not lead their own debriefings. We suggest ways to improve debriefing effectiveness. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. San Jose State Univ, San Jose, CA 95192 USA. RP Dismukes, RK (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 14 TC 7 Z9 7 U1 1 U2 2 PU LAWRENCE ERLBAUM ASSOC INC PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430-2262 USA SN 1050-8414 J9 INT J AVIAT PSYCHOL JI Int. J. Aviat. Psychol. PY 2000 VL 10 IS 1 BP 35 EP 57 DI 10.1207/S15327108IJAP1001_3 PG 23 WC Psychology, Applied SC Psychology GA 278WU UT WOS:000085012600003 ER PT J AU Skitka, LJ Mosier, KL Burdick, M Rosenblatt, B AF Skitka, LJ Mosier, KL Burdick, M Rosenblatt, B TI Automation bias and errors: Are crews better than individuals? SO INTERNATIONAL JOURNAL OF AVIATION PSYCHOLOGY LA English DT Article ID PERFORMANCE AB The availability of automated decision aids can sometimes feed into the general human tendency to travel the road of least cognitive effort. Is this tendency toward "automation bias" (the use of automation as a heuristic replacement for vigilant information seeking and processing) ameliorated when more than one decision maker is monitoring system events? This study examined automation bias in two-person crews versus solo performers under varying instruction conditions. Training that focused on automation bias and associated errors successfully reduced commission, but not omission, errors. Teams and solo performers were equally likely to fail to respond to system irregularities or events when automated devices failed to indicate them, and to incorrectly follow automated directives when they contradicted other system information. C1 Univ Illinois, Dept Psychol, Chicago, IL 60607 USA. San Francisco State Univ, Dept Psychol, San Francisco, CA USA. San Jose State Univ, San Jose, CA 95192 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Skitka, LJ (reprint author), Univ Illinois, Dept Psychol, 1007 W Harrison St, Chicago, IL 60607 USA. OI Skitka, Linda/0000-0002-7078-0650 NR 29 TC 18 Z9 18 U1 3 U2 5 PU LAWRENCE ERLBAUM ASSOC INC PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430-2262 USA SN 1050-8414 J9 INT J AVIAT PSYCHOL JI Int. J. Aviat. Psychol. PY 2000 VL 10 IS 1 BP 85 EP 97 DI 10.1207/S15327108IJAP1001_5 PG 13 WC Psychology, Applied SC Psychology GA 278WU UT WOS:000085012600005 PM 11543300 ER PT J AU Prinzel, LJ Freeman, FC Scerbo, MW Mikulka, PJ Pope, AT AF Prinzel, LJ Freeman, FC Scerbo, MW Mikulka, PJ Pope, AT TI A closed-loop system for examining psychophysiological measures for adaptive task allocation SO INTERNATIONAL JOURNAL OF AVIATION PSYCHOLOGY LA English DT Article ID EEG-ANALYSIS; AUTOMATION; HUMANS AB A closed-loop system was evaluated for its efficacy in using psychophysiological indexes to moderate workload. Participants were asked to perform either 1 or 3 tasks from the Multiattribute Task Battery and complete the NASA Task Load Index after each trial. An electroencephalogram (EEG) was sampled continuously while they performed the tasks, and an EEG index (beta/alpha plus theta) was derived. The system made allocation decisions as a function of the level of operator engagement based on the value of the EEG index. The results of the study demonstrated that it was possible to moderate an operator's level of engagement through a closed-loop system driven by the operator's own EEC. In addition, the system had a significant impact on behavioral, subjective, and psychophysiological correlates of workload as task load increased. The theoretical and practical implications of these results for adaptive automation are discussed. C1 Old Dominion Univ, Dept Psychol, Norfolk, VA 23529 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Scerbo, MW (reprint author), Old Dominion Univ, Dept Psychol, Norfolk, VA 23529 USA. NR 58 TC 74 Z9 74 U1 2 U2 6 PU LAWRENCE ERLBAUM ASSOC INC PI MAHWAH PA 10 INDUSTRIAL AVE, MAHWAH, NJ 07430-2262 USA SN 1050-8414 J9 INT J AVIAT PSYCHOL JI Int. J. Aviat. Psychol. PY 2000 VL 10 IS 4 BP 393 EP 410 DI 10.1207/S15327108IJAP1004_6 PG 18 WC Psychology, Applied SC Psychology GA 359MB UT WOS:000089613700006 PM 11762443 ER PT J AU Shih, SH Hixon, DR Mankbadi, RR AF Shih, SH Hixon, DR Mankbadi, RR TI Three dimensional structure in a supersonic jet: Behavior near centerline SO INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS LA English DT Article DE computational aeroacoustics; large-eddy simulations ID INSTABILITY WAVES; SHEAR LAYERS; SOUND; FLOW; FIELD AB The unsteady structure of a supersonic jet is highly three dimensional, though the mean flow is axisymmetric. In simulating a circular jet, the centerline represents a computational boundary. As such, spurious modes can be generated near centerline, unless special attention is given to the behavior of the 3D structure near the centerline. Improper treatment of the dependent variables near the centerline results in the solution diverging or being suitable only for small amplitude excitation. With a careful treatment of the centerline formulation, no spurious mode is generated, The results show that a near linear disturbance growth is obtained, as the linear stability theory indicates. At high levels of excitation, nonlinear development of disturbances is evident and saturation is reached downstream. C1 NASA, Lewis Res Ctr, Inst Computat Mech Prop, Cleveland, OH 44135 USA. NASA, Lewis Res Ctr, CAA, Cleveland, OH 44135 USA. RP Shih, SH (reprint author), NASA, Lewis Res Ctr, Inst Computat Mech Prop, Cleveland, OH 44135 USA. NR 22 TC 1 Z9 1 U1 0 U2 0 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1061-8562 J9 INT J COMPUT FLUID D JI Int. J. Comput. Fluid Dyn. PY 2000 VL 13 IS 2 BP 109 EP + DI 10.1080/10618560008940893 PG 17 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 309ZR UT WOS:000086800500001 ER PT J AU Hixon, R AF Hixon, R TI Nonlinear comparison of high-order and optimized finite-difference schemes SO INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS LA English DT Article DE computational aeroacoustics; high-order finite-differences; dispersion relation preserving schemes; nonlinear wave propagation ID COMPUTATIONAL ACOUSTICS; COMPACT AB The effect of reducing the formal order of accuracy of a finite-difference scheme in order to optimize its high-wavenumber performance, is investigated using the 1-D nonlinear unsteady inviscid Burgers' equation. Both explicit and compact schemes are compared to schemes with various levels of optimization. Results are given for the absolute and L2 errors as a function of time. It is found that the benefits of optimization do carry over into nonlinear applications. C1 NASA, Glenn Res Ctr, Inst Computat Mech Propuls, Cleveland, OH 44135 USA. RP Hixon, R (reprint author), NASA, Glenn Res Ctr, Inst Computat Mech Propuls, Cleveland, OH 44135 USA. NR 17 TC 7 Z9 7 U1 1 U2 2 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 1061-8562 J9 INT J COMPUT FLUID D JI Int. J. Comput. Fluid Dyn. PY 2000 VL 13 IS 3 BP 259 EP 277 DI 10.1080/10618560008940902 PG 19 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 331DR UT WOS:000088002500004 ER PT J AU Anderson, GT Shelton, RO AF Anderson, GT Shelton, RO TI Confidence limits on rough set rules generated from a limited number of examples SO INTERNATIONAL JOURNAL OF GENERAL SYSTEMS LA English DT Article DE rough sets; confidence limits; artificial intelligence; binomial distribution AB The rough sets method is used for extracting both certain and possible rules from data. This paper shows that, in reality, there are no certain rules. Probability theory is used to determine the best distribution to use when evaluating the strength of rules. A method of determining the confidence limits for rules is presented, and this is used to determine what rule to follow when conflicts occur. Finally, a way to apply these results to situations where the cost of wrong decisions is different from the rewards for correct decisions is discussed. C1 Univ Arkansas, Dept Appl Sci, Little Rock, AR 72204 USA. NASA, Houston, TX 77058 USA. RP Anderson, GT (reprint author), Univ Arkansas, Dept Appl Sci, Little Rock, AR 72204 USA. NR 8 TC 0 Z9 0 U1 0 U2 3 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 0308-1079 J9 INT J GEN SYST JI Int. J. Gen. Syst. PY 2000 VL 29 IS 6 BP 867 EP 877 DI 10.1080/03081070008960976 PG 11 WC Computer Science, Theory & Methods; Ergonomics SC Computer Science; Engineering GA 383UV UT WOS:000165902200002 ER PT J AU Lissenden, CJ Arnold, SM Iyer, SK AF Lissenden, CJ Arnold, SM Iyer, SK TI Flow/damage surfaces for fiber-reinforced metals having different periodic microstructures SO INTERNATIONAL JOURNAL OF PLASTICITY LA English DT Article DE microstructures; elastic-viscoplastic material; fibre-reinforced composite material; finite elements; micromechanics ID ELASTIC-PLASTIC BEHAVIOR; BORON ALUMINUM COMPOSITE; MATRIX COMPOSITES; MICROMECHANICAL ANALYSIS; DOMINATED MODE; DEFORMATION AB Flow/damage surfaces can be defined in terms of stress, inelastic strain rate; and internal variables using a thermodynamics framework. A macroscale definition relevant to thermodynamics and usable in an experimental program is employed to map out surfaces of constant inelastic power in various stress planes. The inelastic flow of a model silicon carbide/titanium composite system having rectangular, hexagonal, and square diagonal fiber packing arrays subjected to biaxial stresses is quantified by flow/damage surfaces that are determined numerically from micromechanics, using both finite element analysis and the generalized method of cells. Residual stresses from processing are explicitly included and damage in the form of fiber-matrix debonding under transverse tensile and/or shear loading is represented by a simple interface model. The influence of microstructural architecture is largest whenever fiber-matrix debonding is not an issue; for example in the presence of transverse compressive stresses. Additionally, as the fiber volume fraction increases, so does the effect of microstructural architecture. These results indicate that microstructural architecture needs to be accounted for in an accurate continuum model, thus complicating development of such a model. With regard to the micromechanics analysis, the overall inelastic flow predicted by the generalized method of cells is in excellent agreement with that predicted using a large number of displacement-based finite elements. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Penn State Univ, University Pk, PA 16802 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Lissenden, CJ (reprint author), Penn State Univ, University Pk, PA 16802 USA. NR 31 TC 11 Z9 11 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0749-6419 J9 INT J PLASTICITY JI Int. J. Plast. PY 2000 VL 16 IS 9 BP 1049 EP 1074 DI 10.1016/S0749-6419(99)00087-X PG 26 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA 346BP UT WOS:000088850700002 ER PT J AU Probasco, DP Wolff, JM Copenhaver, WW Chriss, RM AF Probasco, DP Wolff, JM Copenhaver, WW Chriss, RM TI Axial spacing effects in a transonic compressor on the upstream vane loading SO INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES LA English DT Article AB A set of inlet guide vane (IGV) unsteady surface pressure measurements is presented. The unsteady aerodynamic effects of a highly loaded, high speed downstream compression stage on the upstream inlet guide vane/stator surface pressures are characterized by experimental analysis methods. The axial spacing between the IGV and rotor was varied between 12%, 26% and 56% of the rotor chord for a 105% speed near stall operating condition, which is transonic. Unsteady IGV surface pressures were acquired for two spanwise locations on both blade surfaces. Variations in axial spacing have significant influence on the magnitude and phase of the upstream pressure fluctuations. The largest unsteady surface pressure magnitude, 49.6 kPa, was obtained for the 12% axial spacing configuration at 75% span and 95% chord. Spanwise variation effects caused by the increased relative Mach number were measured. The upstream bow shock effect is strongly non-linear in character. The results of the study indicate significant variations in the IGV unsteady loading caused by axial spacing variations. C1 Wright State Univ, Dept Mech & Mat Engn, Dayton, OH 45435 USA. USAF, Wright Lab, Wright Patterson AFB, OH 45433 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Probasco, DP (reprint author), ADAPCO Inc, Melville, NY 11747 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-0082 J9 INT J TURBO JET ENG JI Int. J. Turbo. Jet-Engines PY 2000 VL 17 IS 3 BP 197 EP 206 PG 10 WC Engineering, Aerospace SC Engineering GA 349KF UT WOS:000089043700002 ER PT J AU Dorney, DJ Lake, JP King, PI Ashpis, DE AF Dorney, DJ Lake, JP King, PI Ashpis, DE TI Experimental and numerical investigation of losses in low-pressure turbine blade rows SO INTERNATIONAL JOURNAL OF TURBO & JET-ENGINES LA English DT Article ID BOUNDARY-LAYER-TRANSITION; TURBULENCE; SEPARATION; FLOWS AB Experimental data and numerical simulations of low-pressure turbines have shown that unsteady blade row interactions and separation can have a significant impact on the turbine efficiency. Measured turbine efficiencies at takeoff can be as much as two points higher than those at cruise conditions. Several recent studies have revealed that the performance of low-pressure turbine blades is a strong function of the Reynolds number. In the current investigation, experiments and simulations have been performed to study the behavior of a low-pressure turbine blade at several Reynolds numbers. Both the predicted and experimental results indicate increased cascade losses as the Reynolds number is reduced to the values associated with aircraft cruise conditions. tn addition, both sets of data show that tripping the boundary layer helps reduce the losses at lower Reynolds numbers. Overall, the predicted aerodynamic and performance results exhibit fair agreement with experimental data. C1 Virginia Commonwealth Univ, Richmond, VA 23284 USA. AFRL, PRRS, Edwards AFB, CA USA. USAF, Inst Technol, Wright Patterson AFB, OH USA. NASA, Glenn Res Ctr, Cleveland, OH USA. RP Dorney, DJ (reprint author), Virginia Commonwealth Univ, Med Coll Virginia Campus, Richmond, VA 23284 USA. NR 29 TC 2 Z9 2 U1 0 U2 0 PU FREUND PUBLISHING HOUSE LTD PI LONDON PA STE 500, CHESHAM HOUSE, 150 REGENT ST, LONDON W1R 5FA, ENGLAND SN 0334-0082 J9 INT J TURBO JET ENG JI Int. J. Turbo. Jet-Engines PY 2000 VL 17 IS 4 BP 241 EP 253 PG 13 WC Engineering, Aerospace SC Engineering GA 359NE UT WOS:000089616300001 ER PT B AU Uhran, ML AF Uhran, ML BE Haskell, G Rycroft, M TI Commercial development of the International Space Station SO INTERNATIONAL SPACE STATION: THE NEXT SPACE MARKETPLACE SE SPACE STUDIES LA English DT Proceedings Paper CT International Symposium on International Space Station - The Next Space Marketplace CY MAY 26-28, 1999 CL STRASBOURG, FRANCE SP Boeing Co, Daimler Chrysler Aerosp AG, Space Infrastruct, European Space Agcy, UN, Off Outer Space Affairs AB The Commercial Space Act of 1998 was signed into law by President William Clinton on 21 October 1998 (Public Law 105-303). Section 101 df the Act addresses Commercialization of the Space Station and establishes the economic development of Earth orbital space as a priority goal of the space station, while encouraging the fullest possible engagement of commercial providers and users in order to reduce government operating costs. The Act also requires NASA to submit to the Congress a series of reports delineating potential commercial opportunities, specific policies and initiatives to stimulate economic development, and an independent market study. In response to the law, NASA has produced a Commercial Development Plan for the International Space Station which proposes a range of actions to be undertaken in pursuit of the Legislative and Executive Branch objectives. These actions fall into three broad categories: (1) completion of an internal study on potential pathfinders for economic development, to be complemented by the independent external market study; (2) approval of an Organizational Work Instruction (OWI), under the auspices of the agency-wide ISO-9000 certification initiative, to establish a clearing house function at NASA headquarters for the dispositioning and auditing of commercial proposals; and (3) development of the concept for a Non-Government Organization (NGO) to manage utilization and economic development of the United States stake in the International Space Station. These actions are currently in the nascent stage; however, they are anticipated to grow in terms of their impact on space station utilization and operations as the assembly sequence and economic development plan progress. C1 NASA, Washington, DC 20546 USA. RP Uhran, ML (reprint author), NASA, Code US,300 E St SW, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6142-3 J9 SPAC STUD PY 2000 VL 4 BP 185 EP 194 PG 10 WC Engineering, Aerospace; Economics SC Engineering; Business & Economics GA BQ84B UT WOS:000089789200022 ER PT B AU Jorgensen, C AF Jorgensen, C BE Haskell, G Rycroft, M TI An initial strategy for commercial industry awareness of the International Space Station SO INTERNATIONAL SPACE STATION: THE NEXT SPACE MARKETPLACE SE SPACE STUDIES LA English DT Proceedings Paper CT International Symposium on International Space Station - The Next Space Marketplace CY MAY 26-28, 1999 CL STRASBOURG, FRANCE SP Boeing Co, Daimler Chrysler Aerosp AG, Space Infrastruct, European Space Agcy, UN, Off Outer Space Affairs AB The on-orbit assembly of the International Space Station (ISS) began in December 1998. While plans are being developed to utilize the ISS for scientific research, and human and microgravity experiments, it is time to consider the future of the ISS as a world-wide commercial marketplace developed from a government owned, operated and controlled facility. Commercial industry will be able to seize this opportunity to utilize the ISS as a unique manufacturing platform and engineering testbed for advanced technology. Activities to allow the initial planning of the commercialization of the ISS have begun. NASA is currently in the strategic planning phase of the evolution and commercialization of the ISS, an essential and critical step. The Pre-Planned Program Improvement ((PI)-I-3) Working Group at NASA is assessing the future ISS needs and technology plans to enhance ISS performance. Plans are being formulated for ISS enhancements to accommodate commercial applications and the Human Exploration and Development of Space mission support. As this information develops, it is essential to disseminate this information to commercial industry, targeting not only the private and public space sector but also the non-aerospace commercial industries. An approach is presented for early dissemination of this information that includes ISS baseline system information, baseline utilization and operations plans, advanced technologies, future utilization opportunities, ISS evolution and Design Reference Missions (DRM). This information is being consolidated into the ISS Evolution Data Book, an initial source and tool to be used as catalyst in the commercial world for the generation of ideas and options to enhance the current capabilities of the ISS. C1 FDC Inc, NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Jorgensen, C (reprint author), FDC Inc, NASA, Langley Res Ctr, 8 Langley Rd,MS 328, Hampton, VA 23681 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6142-3 J9 SPAC STUD PY 2000 VL 4 BP 211 EP 218 PG 8 WC Engineering, Aerospace; Economics SC Engineering; Business & Economics GA BQ84B UT WOS:000089789200025 ER PT B AU Nakagawa, R Askew, R AF Nakagawa, R Askew, R BE Haskell, G Rycroft, M TI Market potential for the International Space Station (ISS) service sector SO INTERNATIONAL SPACE STATION: THE NEXT SPACE MARKETPLACE SE SPACE STUDIES LA English DT Proceedings Paper CT International Symposium on International Space Station - The Next Space Marketplace CY MAY 26-28, 1999 CL STRASBOURG, FRANCE SP Boeing Co, Daimler Chrysler Aerosp AG, Space Infrastruct, European Space Agcy, UN, Off Outer Space Affairs AB are two fronts to the commercialization of the International Space Station (ISS). One involves commercial use of ISS, while the other involves commercial service to ISS. This paper addresses the latter. How big is the market? Last year, United Space Alliance, the joint venture formed only a few years ago, came in second in a top 100 list of federal prime contractors. Their contract covers about a third of NASA's $3.2 billion annual budget for Space Shuttle operations. As other responsibilities are transferred to private industry, that percentage could double to two-thirds of NASA's shuttle budget. NASA's ISS budget may not be as big, but if one includes the projected operational costs of all of the international partners combined, the figure is quite high. What services could private industry provide? This paper touches upon some of the possibilities, and also introduces how firms in Japan are well-positioned to capture pieces of the emerging market. The key to success will be the ability of the service provider to save costs, reduce risk, add value, and spin-off newly acquired know how. Examples include the use of commercial satellite communications service for the downlink of payload data, microgravity environment upgrades for improving science performance, telescience systems and robotic servicers to reduce crew workload and risk. Another more general way is for a service provider to facilitate the overcoming of traditional barriers and disincentives for commercial use of ISS. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Nakagawa, R (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6142-3 J9 SPAC STUD PY 2000 VL 4 BP 219 EP 226 PG 8 WC Engineering, Aerospace; Economics SC Engineering; Business & Economics GA BQ84B UT WOS:000089789200026 ER PT S AU Gunapala, SD Bandara, SV AF Gunapala, SD Bandara, SV BE Liu, HC Capasso, F TI Quantum well infrared photodetector (QWIP) focal plane arrays SO INTERSUBBAND TRANSITIONS IN QUANTUM WELLS: PHYSICS AND DEVICE APPLICATIONS I SE Semiconductors and Semimetals LA English DT Article ID CONTINUUM STATE ABSORPTION; MOLECULAR-BEAM-EPITAXY; 8.2 MU-M; INTERSUBBAND ABSORPTION; PHOTOCONDUCTIVE GAIN; DARK CURRENT; IMPROVED RESPONSIVITY; LIMITED PERFORMANCE; MULTIQUANTUM WELLS; NOISE PERFORMANCE C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Gunapala, SD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 140 TC 50 Z9 50 U1 2 U2 3 PU ELSEVIER ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0080-8784 BN 0-12-752171-2 J9 SEMICOND SEMIMET JI Semicond. Sdemimet. PY 2000 VL 62 BP 197 EP 282 PG 86 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BQ09D UT WOS:000087109500004 ER PT S AU Giering, R AF Giering, R BE Kasibhatla, P Heimann, M Rayner, P Mahowald, N Prinn, RG Hartley, DE TI Tangent linear and adjoint biogeochemical models SO INVERSE METHODS IN GLOBAL BIOGEOCHEMICAL CYCLES SE Geophysical Monograph Series LA English DT Proceedings Paper CT Symposium Workshop on Inverse Modeling of Global Biogeochemical Cycles CY MAR, 1998 CL IRAKLION, GREECE SP European Union Training & Mobil Researchers (TMR) Program, German IGBP Secretariat ID GENERALIZED STABILITY THEORY; OCEAN CIRCULATION MODELS; NORTH-ATLANTIC; PHYSICAL PROCESSES; DATA ASSIMILATION; PARAMETERIZED DISCONTINUITIES; SENSITIVITY; OPERATORS AB Adjoint models are powerful tools for inverse modeling. They are increasingly being used in meteorology and oceanography for sensitivity studies, data assimilation, and parameter estimation. Covering the range from simple box models to sophisticated General Circulation Models, they efficiently compute the sensitivity of a few model output variables with respect to arbitrarily many input variables. To the contrary, tangent linear models efficiently compute the model output perturbation resulting from an initial input perturbation. Mathematically, both models evaluate the first derivative or Jacobian matrix of the mapping defined by the original model. Efficiency is an important issue for sophisticated models and in practice often determine whether a problem is solvable or not. We discuss here the advantages of tangent linear and adjoint models, as well as when to use either of them. The construction of adjoint and tangent linear models by hand is tedious and error prone. Computational Differentiation reduces this work substantially. The basics of Computational Differentiation, its advantages and limitations are presented. Three different kinds of sensitivities are shown: the sensitivity of a passive tracer concentration in the ocean to previous concentrations, the sensitivity of atmospheric CO2 at Mauna Loa, Hawaii, to surface fluxes, and the sensitivity of the North Atlantic meridional heat flux to subsurface salinity. They are discussed in terms of the chains of cause and effect. For biogeochemical models of passive tracers sensitivities can be explained by advective and diffusive processes. However, for dynamically active tracers, the sensitivities are modified by an additional path of influence. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Giering, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-323, Pasadena, CA 91109 USA. EM Ralf.Giering@jpl.nasa.gov NR 50 TC 12 Z9 12 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0065-8448 BN 0-87590-097-6 J9 GEOPHYS MONOGR SER PY 2000 VL 114 BP 33 EP 48 PG 16 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA BP49B UT WOS:000085292500004 ER PT S AU Todling, R AF Todling, R BE Kasibhatla, P Heimann, M Rayner, P Mahowald, N Prinn, RG Hartley, DE TI Estimation theory and atmospheric data assimilation SO INVERSE METHODS IN GLOBAL BIOGEOCHEMICAL CYCLES SE GEOPHYSICAL MONOGRAPH SERIES LA English DT Proceedings Paper CT Symposium Workshop on Inverse Modeling of Global Biogeochemical Cycles CY MAR, 1998 CL IRAKLION, GREECE SP European Union Training & Mobil Researchers (TMR) Program, German IGBP Secretariat ID RETROSPECTIVE DATA ASSIMILATION; LAG KALMAN SMOOTHER; SUBOPTIMAL SCHEMES AB This article is an introduction to estimation theory for problems in atmospheric data assimilation. A background on estimation theory is given using the Bayesian view point. The approaches of minimum variance, maximum a posteriori probability, and maximum likelihood estimation are reviewed. The linear Kalman filter and fixed-lag Kalman smoother are derived as they serve as motivator for the development of advanced data assimilation procedures. The connection of the Kalman filter and smoother with the probabilistic Bayesian approach is made. Exercises are provided in a separate chapter to help solidify understanding. C1 NASA, Goddard Space Flight Ctr, Data Assimilat Off, Gen Sci Corp, Greenbelt, MD 20771 USA. RP Todling, R (reprint author), NASA, Goddard Space Flight Ctr, Data Assimilat Off, Gen Sci Corp, Code 910-3, Greenbelt, MD 20771 USA. NR 35 TC 6 Z9 7 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0065-8448 BN 0-87590-097-6 J9 GEOPH MONOG SERIES PY 2000 VL 114 BP 49 EP 65 PG 17 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA BP49B UT WOS:000085292500005 ER PT S AU Menard, R AF Menard, R BE Kasibhatla, P Heimann, M Rayner, P Mahowald, N Prinn, RG Hartley, DE TI Tracer assimilation SO INVERSE METHODS IN GLOBAL BIOGEOCHEMICAL CYCLES SE GEOPHYSICAL MONOGRAPH SERIES LA English DT Proceedings Paper CT Symposium Workshop on Inverse Modeling of Global Biogeochemical Cycles CY MAR, 1998 CL IRAKLION, GREECE SP European Union Training & Mobil Researchers (TMR) Program, German IGBP Secretariat ID 4-DIMENSIONAL VARIATIONAL ASSIMILATION; WEATHER-PREDICTION MODELS; DYNAMICS AB The purpose of this paper is to provide practical material and any further theoretical aspects needed for implementing a sequential assimilation scheme for chemical tracer observations. We outline several implementations of statistical interpolation, including a positive analysis scheme based on lognormally-distributed errors. These schemes involve prescribing the forecast error covariance as an analytical function for computational simplification. Since the performance of these schemes depends strongly on the proper specification of the error covariances, we draw our attention to chi-square validation, covariance modeling, and estimation of the covariance parameters. The dynamics of the forecast error covariance is also studied for a prototype transport model. Finally, results of assimilation of CH4 observations using a Kalman filter, statistical interpolation and two other simplified schemes; one that prescribes only the error variance and the other that prescribes only the error correlation, are presented and have permitted us to establish the importance of variance and correlation dynamics. C1 NASA, Goddard Space Flight Ctr, Data Assimilat Off, Greenbelt, MD 20771 USA. RP Menard, R (reprint author), NASA, Goddard Space Flight Ctr, Data Assimilat Off, Code 910-3, Greenbelt, MD 20771 USA. NR 22 TC 2 Z9 2 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0065-8448 BN 0-87590-097-6 J9 GEOPH MONOG SERIES PY 2000 VL 114 BP 67 EP 79 PG 13 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA BP49B UT WOS:000085292500006 ER PT J AU Maneri, E Gawronski, W AF Maneri, E Gawronski, W TI LQG controller design using GUI: Application to antennas and radio-telescopes SO ISA TRANSACTIONS LA English DT Article AB The Linear Quadratic Gaussian (LQG) algorithm has been used to control the JPL's beam wave-guide, and 70-m antennas. This algorithm significantly improves tracking precision in a wind disturbed environment. Based on this algorithm and the implementation experience a Matlab based Graphical User Interface (GUI) was developed to design the LQG controllers applicable to antennas and radiotelescopes. The GUI is described in this paper. It consists of two parts the basic LQG design and the fine-tuning of the basic design using a constrained optimization algorithm. The presented GUI was developed to simplify the design process, to make the design process user-friendly, and to enable design of an LQG controller for one with a limited control engineering background. The user is asked to manipulate the GUI sliders and radio buttons to watch the antenna performance. Simple rules are given at the GUI display. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Montana State Univ, Bozeman, MT 59719 USA. RP Gawronski, W (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 8 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0019-0578 J9 ISA T JI ISA Trans. PY 2000 VL 39 IS 2 BP 243 EP 264 DI 10.1016/S0019-0578(99)00047-6 PG 22 WC Automation & Control Systems; Engineering, Multidisciplinary; Instruments & Instrumentation SC Automation & Control Systems; Engineering; Instruments & Instrumentation GA 322DG UT WOS:000087494500012 ER PT B AU Fang, WC AF Fang, WC GP IEEE IEEE IEEE TI Design based on programmable neural processor integrated with active pixel sensor SO ISCAS 2000: IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS - PROCEEDINGS, VOL II: EMERGING TECHNOLOGIES FOR THE 21ST CENTURY LA English DT Proceedings Paper CT IEEE International Symposium on Circuits and Systems (ISCAS 2000) CY MAY 28-31, 2000 CL GENEVA, SWITZERLAND SP IEEE Circuits & Syst Soc, Swiss Fed Inst Technol ID NETWORKS AB A low power smart vision system based on a large format (currently 1Kx1K) active pixel sensor (APS) integrated with a programmable neural processor for fast vision applications is presented. The concept of building a low power smart vision system is demonstrated by a system design, which is composed with an APS sensor, a smart image window handler, and a neural processor. The paper also shows that it is feasible to put the whole smart vision system into a single MCM chip in a standard CMOS technology. This smart vision system on-a-chip can take the combined advantages of the optics and electronics to achieve ultra-high-speed smart sensory information processing and analysis at the focal plane. The proposed system will enable many applications including robotics and machine vision, guidance and navigation, automotive applications, and consumer electronics. Future applications will also include scientific sensors such as those suitable for highly integrated imaging systems used in NASA deep space and planetary spacecraft. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Fang, WC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA PY 2000 BP 128 EP 131 PG 4 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BQ57S UT WOS:000088843300033 ER PT S AU Korsmeyer, DJ Chow, ET Conroy, MP AF Korsmeyer, DJ Chow, ET Conroy, MP BE Tohme, S Ulema, M TI IsoWAN: A NASA science and engineering information and services framework SO ISCC 2000: FIFTH IEEE SYMPOSIUM ON COMPUTERS AND COMMUNICATIONS, PROCEEDINGS SE IEEE Symposium on Computers and Communications ISCC LA English DT Proceedings Paper CT 5th IEEE Symposium on Computers and Communications (ISCC 2000) CY JUL 03-06, 2000 CL JUAN LES PINS, FRANCE SP IEEE Commun Soc, IEEE Comp Soc AB We believe that the next evolutionary step in supporting wide-area application and services delivery to customers is a network framework that provides for collocation of applications and services at distinct sites in the network an interconnection between these sires that is performance optimized for these applications, and value-added services for applications. We use the term IsoWAN to describe an advanced, isolated network interconnect services framework that will enable applications to be more secure, and able to access Md be in use in both local and remote environments. The main functions of an IsoWAN are virtual localization of application services, an application service interface, coordinated delivery of applications and associated data to the customer, and supporting collaborative application development for customers. An initial pilot network between three NASA Centers; Ames Research Center, the Jet Propulsion Laboratory, and Marshall Space Flight Center, has been built and its properties will be discussed. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Korsmeyer, DJ (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM dkorsmeyer@arc.nasa.gov; edward.chow@jpl.nasa.gov; michael.conroy-1@ksc.nasa.gov NR 9 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 SN 1530-1346 BN 0-7695-0722-0 J9 IEEE SYMP COMP COMMU PY 2000 BP 534 EP 539 DI 10.1109/ISCC.2000.860692 PG 6 WC Computer Science, Interdisciplinary Applications; Telecommunications SC Computer Science; Telecommunications GA BQ69X UT WOS:000089217600083 ER PT S AU Fajardo-Acosta, SB Backman, DE Stencel, RE AF Fajardo-Acosta, SB Backman, DE Stencel, RE BE Laureijs, RJ Leech, K Kessler, MF TI ISOPHOT mapping of Vega-type circumstellar dust SO ISO BEYOND POINT SOURCES: STUDIES OF EXTENDED INFRARED EMISSION WORKSHOP SE ESA Special Publications LA English DT Proceedings Paper CT Workshop on ISO Beyond Point Sources - Studies of Extended Infrared Emission CY SEP 14-17, 1999 CL ISO DATA CTR, VILLAFRANCA DEL CASTILLO, SPAIN HO ISO DATA CTR DE ISO; circumstellar matter; dust; extinction; infrared : stars ID STARS AB We searched for far-infrared (60 mu m) extended emission, in the form of circumstellar dust disks, in the maps of seven main-sequence stars. Direct detection of circumstellar disks in these systems can advance our understanding of the Vega phenomenon. We obtained 60 mu m maps with the PHOT C100 3x3-pixel far-infrared camera on-board the Infrared Space Observatory (ISO), in the PHT32 microscanning dedicated slapping mode. The spatial resolution of the maps is approximate to 30 ". The Vega-type stars we observed are gamma Oph, alpha PsA, gamma Tri, 61 Cyg A, tau(1) Eri, tau Cet, and epsilon Eri. We compared the maps of these systems with similar maps of the stars alpha Boo and alpha Aq1, which do not possess circumstellar dust. We discuss techniques to model point-spread functions (PSFs) from the latter, and their subtraction from our Vega-type stellar maps. We did not spatially resolve extended emission in the maps of gamma Oph, gamma Tri, 61 Cyg A, tau(1) Eri, epsilon Eri, and tau Cet. The map of alpha PsA definitely shows extended emission as far as similar to 700 AU from the star, when compared with model PSFs. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. EM fajardo@ipac.caltech.edu NR 14 TC 0 Z9 0 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-661-9 J9 ESA SPEC PUBL PY 2000 VL 455 BP 73 EP 78 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80B UT WOS:000089547500013 ER PT S AU Chiar, JE Tielens, AGGM Whittet, DCB Schutte, WA Boogert, ACA Lutz, D van Dishoeck, EF Bernstein, MP AF Chiar, JE Tielens, AGGM Whittet, DCB Schutte, WA Boogert, ACA Lutz, D van Dishoeck, EF Bernstein, MP BE Salama, A Kessler, MF Leech, K Schulz, B TI The composition and distribution of dust along the line of sight towards the Galactic Center SO ISO BEYOND THE PEAKS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 2nd Infrared Space Observatory on Analytical Spectroscopy CY FEB 02-04, 2000 CL MADRID, SPAIN SP Infrared Space Observ DE dust, extinction; ISM : molecules; Galaxy : center; infrared : ISM : lines and bands; infrared : stars ID DIFFUSE INTERSTELLAR-MEDIUM; H-II REGIONS; SWS OBSERVATIONS; MOLECULAR CLOUDS; SPECTROSCOPY; BAND; H2O; CARBON AB We discuss the composition of dust and ice along the line of sight to the Galactic Center (GC) based on analysis of mid-infrared spectra (2.4-13 mum) from the Short Wavelength Spectrometer (SWS) on the Infrared Space Observatory (ISO). The complete results of this work appear in The Astrophysical Journal (Chiar et al. 2000; hereafter referred to as C00). C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Chiar, JE (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 28 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 92-9092-665-1 J9 ESA SP PUBL PY 2000 VL 456 BP 45 EP 48 PG 4 WC Astronomy & Astrophysics; Spectroscopy SC Astronomy & Astrophysics; Spectroscopy GA BR83U UT WOS:000167740000009 ER PT B AU Gibbel, M Larson, T AF Gibbel, M Larson, T BE Kromann, GB Culham, JR Ramakrishna, K TI An engineering-of-failure approach to designing and executing an accelerated product qualification test SO ITHERM 2000: SEVENTH INTERSOCIETY CONFERENCE ON THERMAL AND THERMOMECHANICAL PHENOMENA IN ELECTRONIC SYSTEMS, VOL I, PROCEEDINGS LA English DT Proceedings Paper CT 7th Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems CY MAY 23-26, 2000 CL LAS VEGAS, NV SP IEEE, CPMT, Amer Soc Mechan Engineers, US Natl Inst Stand & Technol, Int Microelectr & Packaging Soc AB An Engineering-of-Failure approach to designing and executing an accelerated product qualification test was performed to support a risk assessment of a "work-around" necessitated by an on-orbit failure of another piece of hardware on the Mars Global Surveyor spacecraft. The proposed work-around involved exceeding the previous qualification experience both in terms of extreme cold exposure level and in terms of demonstrated low cycle fatigue life for the power shunt assemblies. An analysis was performed to identify potential failure sites, modes and associated failure mechanisms consistent with the new use conditions. A test was then designed and executed which accelerated the failure mechanisms identified by analysis. Verification of the resulting failure mechanism concluded the effort. MIL STD. 883C calls out several tests that are intended to assess the quality of wire bonds used in packaged semiconductor devices. Unfortunately, these same tests do not necessarily assure the reliability of these same wirebonds under field use conditions. This is particularly true for missions that involve a significant number of thermal cycles either as a result of power cycles or environmentally induced thermal cycles. This paper concludes with a brief discussion of this and its implications. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91009 USA. RP Gibbel, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91009 USA. NR 5 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5912-7 PY 2000 BP 271 EP 276 DI 10.1109/ITHERM.2000.866835 PG 6 WC Thermodynamics; Engineering, Electrical & Electronic SC Thermodynamics; Engineering GA BQ63S UT WOS:000089019500034 ER PT B AU Fan, MS Plante, J Shaw, H AF Fan, MS Plante, J Shaw, H BE Kromann, GB Culham, JR Ramakrishna, K TI Thermal characterization for a modular 3-d multichip module SO ITHERM 2000: SEVENTH INTERSOCIETY CONFERENCE ON THERMAL AND THERMOMECHANICAL PHENOMENA IN ELECTRONIC SYSTEMS, VOL I, PROCEEDINGS LA English DT Proceedings Paper CT 7th Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems CY MAY 23-26, 2000 CL LAS VEGAS, NV SP IEEE, CPMT, Amer Soc Mechan Engineers, US Natl Inst Stand & Technol, Int Microelectr & Packaging Soc AB NASA Goddard Space Flight Center has designed a high-density modular 3-D multichip module (MCM) for future spaceflight use. This MCM features a complete modular structure, i.e., each stack can be removed from the package without damaging the structure. The interconnection to the PCB is through the Column Grid Allay (CCA) technology. Because of its high-density nature, large power dissipation from multiple layers of circuitry is anticipated and CVD diamond films are used in the assembly for heal conduction enhancement. Since each stacked layer dissipates certain amount of heat, designing effective heal conduction paths through each stack and balancing the heal dissipation within each stack for optimal thermal performance become a challenging task. To effectively remove the dissipated heat front the package, extensive thermal analysis has been performed with finite element methods. Through these anal),ses, we are able to improve the thermal design and increase the total wattage of the package for maximum electrical performance. This paper provides details on the design-oriented thermal analysis and performance enhancement. It also addresses issues relating to contact thermal resistance between the diamond film and the metallic hear conduction paths. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Fan, MS (reprint author), NASA, Goddard Space Flight Ctr, Code 562, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5912-7 PY 2000 BP 277 EP 282 DI 10.1109/ITHERM.2000.866836 PG 6 WC Thermodynamics; Engineering, Electrical & Electronic SC Thermodynamics; Engineering GA BQ63S UT WOS:000089019500035 ER PT B AU Bailey, MC Campbell, TG Brandt, D Cassapakis, C AF Bailey, MC Campbell, TG Brandt, D Cassapakis, C BE Pellegrino, S Guest, SD TI Inflatable tensioned membrane waveguide antenna array for space applications SO IUTAM-IASS SYMPOSIUM ON DEPLOYABLE STRUCTURES: THEORY AND APPLICATIONS SE SOLID MECHANICS AND ITS APPLICATIONS LA English DT Proceedings Paper CT IUTAM-IASS Symposium on Deployable Structures, Theory and Applications CY SEP 06-09, 1998 CL UNIV CAMBRIDGE, DEPT ENGN, CAMBRIDGE, ENGLAND SP Int Union Theoret & Applied Mechan, Int Assoc Shell & Spatial Struct HO UNIV CAMBRIDGE, DEPT ENGN C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Bailey, MC (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6516-X J9 SOLID MECH APPL PY 2000 VL 80 BP 11 EP 16 PG 6 WC Engineering, Aerospace; Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BR48P UT WOS:000166593200002 ER PT B AU Liu, X Jenkins, CH Schur, WW AF Liu, X Jenkins, CH Schur, WW BE Pellegrino, S Guest, SD TI Computational issues in the modeling of wrinkling during parachute deployment SO IUTAM-IASS SYMPOSIUM ON DEPLOYABLE STRUCTURES: THEORY AND APPLICATIONS SE SOLID MECHANICS AND ITS APPLICATIONS LA English DT Proceedings Paper CT IUTAM-IASS Symposium on Deployable Structures, Theory and Applications CY SEP 06-09, 1998 CL UNIV CAMBRIDGE, DEPT ENGN, CAMBRIDGE, ENGLAND SP Int Union Theoret & Applied Mechan, Int Assoc Shell & Spatial Struct HO UNIV CAMBRIDGE, DEPT ENGN C1 S Dakota Sch Mines & Technol, Dept Mech Engn, Rapid City, SD 57701 USA. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Island, VA 23337 USA. RP Liu, X (reprint author), S Dakota Sch Mines & Technol, Dept Mech Engn, Rapid City, SD 57701 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6516-X J9 SOLID MECH APPL PY 2000 VL 80 BP 239 EP 250 PG 12 WC Engineering, Aerospace; Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BR48P UT WOS:000166593200026 ER PT B AU Lou, MC Feria, VA AF Lou, MC Feria, VA BE Pellegrino, S Guest, SD TI Development of space inflatable/rigidizable structures technology SO IUTAM-IASS SYMPOSIUM ON DEPLOYABLE STRUCTURES: THEORY AND APPLICATIONS SE SOLID MECHANICS AND ITS APPLICATIONS LA English DT Proceedings Paper CT IUTAM-IASS Symposium on Deployable Structures, Theory and Applications CY SEP 06-09, 1998 CL UNIV CAMBRIDGE, DEPT ENGN, CAMBRIDGE, ENGLAND SP Int Union Theoret & Applied Mechan, Int Assoc Shell & Spatial Struct HO UNIV CAMBRIDGE, DEPT ENGN AB Space inflatable and rigidizable structures technology is one of the emerging technologies that can potentially revolutionize the design and applications of large space structural systems. In the last two years, NASA and its industry and academia partners have made significant progress in addressing important technical challenges for the actual implementation of inflatable structures for space flight systems. A summary assessment on the state of the art of three of the challenges, namely controlled deployment, space rigidization and dynamic modeling and simulation, is presented. Also. two recently developed inflatable structural systems, the inflatable SAR and the NGST inflatable sunshield, are described. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91107 USA. RP Lou, MC (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91107 USA. NR 23 TC 0 Z9 0 U1 1 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6516-X J9 SOLID MECH APPL PY 2000 VL 80 BP 251 EP 260 PG 10 WC Engineering, Aerospace; Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BR48P UT WOS:000166593200027 ER PT J AU Watcharapasorn, A Demattei, RC Feigelson, RS Caillat, T Borshchevsky, A Snyder, GJ Fleurial, JP AF Watcharapasorn, Anucha Demattei, Robert C. Feigelson, Robert S. Caillat, Thierry Borshchevsky, Alexander Snyder, G. Jeffiey Fleurial, Jean-Pierre TI Thermoelectric Properties of Some Phosphide Skutterudite Materials SO JAPANESE JOURNAL OF APPLIED PHYSICS LA English DT Article DE thermoelectric; skutterudite; phosphide compounds; transport properties; thermal conductivity AB The synthesis and thermoelectric properties of CoP3, CeFe4P12 and CeRu4P12 have been investigated. These compounds were made by recrystallization from Sn flux. The samples were analyzed by x-ray diffraction and electron microprobe analysis for phase purity. Electrical resistivity and Seebeck coefficient measurements showed that all three compounds are p-type semiconductors, in agreement with theoretical predictions and previous literature results. The large difference between the thermal conductivity of the binary and filled compounds can be primarily attributed to the additional phonon scattering by Ce atoms rattling inside the empty cages. The properties of the phosphide compounds are compared to their antimonide analogs and discussed in order to obtain further insights into the transport properties of skutterudite materials. Guidelines for optimizing thermoelectric properties of this class of compounds are also provided. C1 [Watcharapasorn, Anucha; Feigelson, Robert S.] Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. [Demattei, Robert C.; Feigelson, Robert S.] Stanford Univ, Adv Mat Lab, Stanford, CA 94305 USA. [Caillat, Thierry; Borshchevsky, Alexander; Snyder, G. Jeffiey; Fleurial, Jean-Pierre] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Watcharapasorn, A (reprint author), Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA. RI Snyder, G/I-2263-2015 NR 22 TC 3 Z9 3 U1 2 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0021-4922 EI 1347-4065 J9 JPN J APPL PHYS JI Jpn. J. Appl. Phys. PY 2000 VL 39 IS 1 SU S BP 14 EP 18 PG 5 WC Physics, Applied SC Physics GA V33LH UT WOS:000209019800003 ER PT J AU Wu, S Liu, A Leonard, G Pichel, WG AF Wu, S Liu, A Leonard, G Pichel, WG TI Ocean feature monitoring with wide swath synthetic aperture radar SO JOHNS HOPKINS APL TECHNICAL DIGEST LA English DT Article DE internal wave; oil spill; remote sensing; wavelet transform; wide swath SAR AB By providing better spatial coverage, wide swath synthetic aperture radar (SAR) can offer a more complete picture of various mesoscale ocean features. With better temporal coverage, SAR also supplies crucial information for the tracking and monitoring elf these features using, for instance, the technique of two-dimensional wavelet analysis. Examples presented in this article of fronts in the Gulf of Mexico and off the mid-Atlantic coast, an oil spill off Point Barrow, Alaska, and internal waves in the South China Sea illustrate some of the myriad ocean applications that are better observed and monitored with wide swath SAR. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Wu, S (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Pichel, William/F-5619-2010 OI Pichel, William/0000-0001-6332-0149 NR 8 TC 2 Z9 2 U1 0 U2 2 PU JOHNS HOPKINS UNIV PI LAUREL PA APPLIED PHYSICS LABORATORY ATTN: MANAGING EDITOR JOHN HOPKINS RD, BLDG 1-E254, LAUREL, MD 20723-6099 USA SN 0270-5214 J9 J HOPKINS APL TECH D JI Johns Hopkins APL Tech. Dig. PD JAN-MAR PY 2000 VL 21 IS 1 BP 122 EP 129 PG 8 WC Engineering, Multidisciplinary SC Engineering GA 283RN UT WOS:000085289300018 ER PT J AU Montgomery, DR AF Montgomery, DR TI International fisheries enforcement management using wide swath SAR SO JOHNS HOPKINS APL TECHNICAL DIGEST LA English DT Article DE fisheries enforcement; synthetic aperture radar; vessel monitoring AB The application of wide swath synthetic aperture radar (SAR) for surveillance of commercial fishing grounds can aid in the detection of illegal fishing activities and provide more efficient use of limited aircraft or patrol craft resources. Many nations have vast economic enterprise zones that cannot be monitored for fishing activities with the available patrol resources. This is particularly true for small Pacific Island nations, whose resources preclude any effective monitoring methods. With wide swath SAR, large ocean areas can be monitored on frequent revisit schedules, thus allowing detected ships to be observed and identified by patrols that are vectored on these targets from cuing derived from the SAR information. C1 CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91125 USA. RP Montgomery, DR (reprint author), CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91125 USA. NR 22 TC 6 Z9 6 U1 1 U2 3 PU JOHNS HOPKINS UNIV PI LAUREL PA APPLIED PHYSICS LABORATORY ATTN: MANAGING EDITOR JOHN HOPKINS RD, BLDG 1-E254, LAUREL, MD 20723-6099 USA SN 0270-5214 J9 J HOPKINS APL TECH D JI Johns Hopkins APL Tech. Dig. PD JAN-MAR PY 2000 VL 21 IS 1 BP 141 EP 147 PG 7 WC Engineering, Multidisciplinary SC Engineering GA 283RN UT WOS:000085289300021 ER PT J AU Holt, B Milland, J AF Holt, B Milland, J TI Rapid-repeat SAR imaging of the ocean surface: Are daily observations possible? SO JOHNS HOPKINS APL TECHNICAL DIGEST LA English DT Article DE ocean surface; SAR; satellite design AB The fine resolution of synthetic aperture radar (SAR) yields exciting views of the two-dimensional ocean surface and its interactions with the atmosphere, long waves, ansi currents. However, the high data rates and power required to achieve this fine resolution limit the available swath widths and hence the temporal and spatial sampling of the ocean surface, in rum limiting SAR ocean observations to periodic "snapshots" rather than synoptic, frequent views. The wide swath capability of Radarsat and Envisat enhance ocean sampling, reducing it to a few days. The dynamics of many important ocean and atmospheric processes have shorter timescales, however, and may require an entirely new satellite concept to be adequately captured. We examined two different satellite SAR mission concepts with the goal of achieving daily ocean observations. The first concept was for a mission with increased swath width using a single antenna flown at a higher than normal altitude. The second considered using a spacecraft carrying two antennas in a more conventional orbit. Trade-offs between the two missions are discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Holt, B (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 5 TC 7 Z9 7 U1 0 U2 0 PU JOHNS HOPKINS UNIV PI LAUREL PA APPLIED PHYSICS LABORATORY ATTN: MANAGING EDITOR JOHN HOPKINS RD, BLDG 1-E254, LAUREL, MD 20723-6099 USA SN 0270-5214 J9 J HOPKINS APL TECH D JI Johns Hopkins APL Tech. Dig. PD JAN-MAR PY 2000 VL 21 IS 1 BP 162 EP 169 PG 8 WC Engineering, Multidisciplinary SC Engineering GA 283RN UT WOS:000085289300024 ER PT J AU Smialek, JL AF Smialek, JL TI Maintaining adhesion of protective Al2O3 scales SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID FE-CR-AL; ADHERENCE; ALLOYS; BEHAVIOR; SULFUR; SEGREGATION; IMPURITY; ALUMINA; OXIDATION; ELEMENTS AB Maintaining good adhesion of alumina scales to the surface of heat-resistant alloys is crucial for long-term cyclic oxidation resistance. Traditionally, this is accomplished by doping the alloy with about 0.1% reactive elements. More recently, excellent adhesion has been produced without reactive elements by reducing the sulfur impurity level to less than 1 ppm. Research opportunities exist in fundamentals of sulfur segregation, thermodynamics, and interfacial bonding. C1 NASA, Lewis Field, Cleveland, OH 44135 USA. RP NASA, Lewis Field, 106-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM James.L.Smialek@GRC.NASA.GOV NR 39 TC 30 Z9 30 U1 1 U2 8 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD JAN PY 2000 VL 52 IS 1 BP 22 EP 25 DI 10.1007/s11837-000-0110-4 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 273NE UT WOS:000084713100005 ER PT J AU Chang, AC Jensen, BJ AF Chang, AC Jensen, BJ TI Adhesive properties of cured phenylethynyl-containing imides SO JOURNAL OF ADHESION LA English DT Article; Proceedings Paper CT 22nd Annual Meeting of the Adhesion-Society CY FEB 21-24, 1999 CL PANAMA CITY BEACH, FLORIDA SP Adhes Soc DE polyimides; phenylethynyl; adhesives; processability; high temperature; thermoset; thermal stability AB As part of a program to develop structural adhesives for high-performance aerospace applications, work has continued on phenylethynyl-containing imides. Initial work on linear phenylethynyl-terminated imides (PETI), led to a material called LaRC(TM) PETI-5, which is now commercially available and was selected as the composite matrix resin and adhesive on the High Speed Research Program. In this report, the preparation and evaluation of a series of modified phenylethynyl-containing imides, which are being developed as secondary bonding adhesives, will be discussed. The modification of these materials compared with the linear material involves the use of a small amount of trifunctional monomer to introduce branching. These adhesives exhibit excellent processability at pressures as low as 15 psi and temperatures as low as 288 degrees C. The cured polymers exhibit excellent solvent resistance and high mechanical properties. Polymer properties can be controlled by varying the molecular weight, the amount of branching, and the phenylethynyl content. This research involves changing the flexibility in the copolyimide backbone of the branched, phenylethynyl-terminated adhesives and determining the effect on properties. C1 Lockheed Martin Engn & Sci Corp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Jensen, BJ (reprint author), Lockheed Martin Engn & Sci Corp, Hampton, VA 23666 USA. NR 15 TC 7 Z9 7 U1 1 U2 3 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING RG1 8JL, BERKS, ENGLAND SN 0021-8464 J9 J ADHESION JI J. Adhes. PY 2000 VL 72 IS 2 BP 209 EP 217 DI 10.1080/00218460008029278 PG 9 WC Engineering, Chemical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA 333JM UT WOS:000088127200005 ER PT J AU Mital, SK Murthy, PLN Chamis, CC AF Mital, SK Murthy, PLN Chamis, CC TI Computational simulation of continuous fiber reinforced ceramic matrix composites behavior SO JOURNAL OF ADVANCED MATERIALS LA English DT Article ID FRACTURE AB The purpose of the present paper is to describe a methodology for predicting the behavior of ceramic matrix composites which has been incorporated into a computer code CEMCAN (CEramic Matrix Composite ANalyzer). The basis of the approach is a combination of micromechanics together with a unique fiber substructuring concept. In this new concept, the conventional unit cell (the smallest representative volume element oft he composite) of the micromechanics approach has been modified by substructuring the unit cell into several slices and developing the micromechanics based equations at the slice level. The methodology also takes into account nonlinear ceramic matrix composite (CMC) behavior die to temperature and progressive fracture/degradation of the interphase. The important features of the approach and its effectiveness are described herein with select examples. Comparisons of predictions with limited experimental data are also provided. C1 Univ Toledo, Toledo, OH 43606 USA. NASA, John H Glenn Res Ctr, Cleveland, OH USA. RP Univ Toledo, 2801 W Bancroft St, Toledo, OH 43606 USA. NR 16 TC 1 Z9 1 U1 0 U2 1 PU SAMPE PUBLISHERS PI COVINA PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 USA SN 1070-9789 J9 J ADV MATER-COVINA JI J. Adv. Mater. PD JAN PY 2000 VL 32 IS 1 BP 46 EP 59 PG 14 WC Materials Science, Multidisciplinary SC Materials Science GA 274RF UT WOS:000084778300008 ER PT J AU Holst, TL AF Holst, TL TI Chimera donor cell search algorithm suitable for solving the full potential equation SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA 15th Applied Aerodynamics Conference CY JUN 23-25, 1997 CL ATLANTA, GEORGIA SP Amer Inst Aeronaut & Astronaut AB An approximate iterative search algorithm for finding donor cells associated with the chimera zonal grid approach is presented. This new algorithm is both fast and simple. It is used in conjunction with a chimera-based full potential solver for computing transonic dow solutions about wing and wing/fuselage configurations. Within each grid zone a fully implicit approximate factorization scheme is used to advance the solution one iteration. This is followed by the explicit advance of all common intergrid boundaries using a trilinear interpolation of the velocity potential. The presentation is highlighted with numerical result comparisons, a grid refinement study, and parametric variation of pertinent algorithm parameters. The new search algorithm produces donor cells for the two-zone wing problem at a rate in excess of 60,000 cells/s (single processor Cray C90). The approximate nature of the search algorithm, which causes some of the donor cells to be approximated by nearest neighbor cells, does not cause any impact on solution accuracy Overall the results indicate that the present chimera zonal grid approach is a viable technique for solving the full potential equation for aerodynamic applications. C1 NASA, Ames Res Ctr, Computat Phys & Simulat Branch, Moffett Field, CA 94035 USA. RP Holst, TL (reprint author), NASA, Ames Res Ctr, Computat Phys & Simulat Branch, Moffett Field, CA 94035 USA. NR 24 TC 2 Z9 2 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 2000 VL 37 IS 1 BP 76 EP 84 DI 10.2514/2.2564 PG 9 WC Engineering, Aerospace SC Engineering GA 281YF UT WOS:000085188500011 ER PT J AU Baker, DJ AF Baker, DJ TI Evaluation of thin Kevlar-epoxy fabric panels subjected to shear loading SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 37th Structures, Structural Dynamics, and Materials Conference CY APR 15-17, 1996 CL KISSIMMEE, FLORIDA SP Amer Inst Aeronaut & Astronaut, ASME, ASCE, AHS, ASC AB The results of an analytical and experimental investigation of four-ply Kevlar-49-epoxy panels loaded by Inplane shear are presented. Approximately half of the panels are thin-core sandwich panels, and the other panels are solid-laminate panels. Selected panels were impacted with an aluminum sphere at an energy level of either 2.3 or 5.0 ft Ib. The strength of panels impacted at 2.3 ft Ib of energy was not reduced when compared to the strength of the undamaged panels, but the strength of panels impacted at 5.0 ft Ib of energy was reduced by 27-40%, Results are presented for panels that were cyclically loaded from a load less than the buckling load to a load in the postbuckling load range. The thin-core sandwich panels had a lower fatigue life than the solid panels. The! residual strength of the solid and sandwich panels cycled more than 1 million cycles exceeded the baseline undamaged panel strengths. Results of a nonlinear finite element analysis conducted for each panel design are presented. C1 NASA, Langley Res Ctr, Mech & Durabil Branch, Vehicle Struct Directorate,ARL, Hampton, VA 23681 USA. RP Baker, DJ (reprint author), NASA, Langley Res Ctr, Mech & Durabil Branch, Vehicle Struct Directorate,ARL, Mail Stop 190, Hampton, VA 23681 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD JAN-FEB PY 2000 VL 37 IS 1 BP 138 EP 143 DI 10.2514/2.2573 PG 6 WC Engineering, Aerospace SC Engineering GA 281YF UT WOS:000085188500019 ER PT J AU Jedlovec, GJ Lerner, JA Atkinson, RJ AF Jedlovec, GJ Lerner, JA Atkinson, RJ TI A satellite-derived upper-tropospheric water vapor transport index for climate studies SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID RELATIVE-HUMIDITY; IMAGE DATA; WINDS; TOVS; CIRCULATION; RADIANCES; FIELD; DRY; VAS AB A new approach is presented to quantify upper-level moisture transport from geostationary satellite data Daily time sequences of Geostationary Operational Environmental Satellite GOES-7 water vapor imagery were used to produce estimates of winds and water vapor mixing ratio in the cloud-free region of the upper troposphere sensed by the 6.7-mu m water vapor channel. The winds and mixing ratio values were gridded and then combined to produce a parameter called the water vapor transport index (WVTI), which represents the magnitude of the two-dimensional transport of water vapor in the upper troposphere. Daily grids of WVTI, meridional moisture transport, mixing ratio, pressure, and other associated parameters were averaged to produce monthly fields for June, July, and August (JJA) of 1987 and 1986 over the Americas and surrounding oceanic regions. The WVTI was used to compare upper-tropospheric moisture transport between the summers of 1987 and 1988, contrasting the latter part of the 1986/87 El Nino event and the La Nina period of 1988. A similar product derived from the National Centers for Environmental Prediction (NCEP)-National Center for Atmospheric Research (NCAR) 40-Year Reanalysis Project was used to help to validate the index. Although the goal of this research was to describe the formulation and utility of the WVTI, considerable insight was obtained into the interannual variability of upper-lever water vapor transport. Both datasets showed large upper-level water vapor transport associated with synoptic features over the Americas and with outflow from tropical convective systems. Minimal transport occurred over tropical and subtropical high pressure regions where winds were light. Index values from NCEP-NCAR were 2-3 times larger than that determined from GOES. This difference resulted from large zonal wind differences and an apparent overestimate of upper-tropospheric moisture in the reanalysis model. A comparison of the satellite-derived monthly values between the summers of 1987 and 1988 provided some insight into the impact of the ENSO event on upper-level moisture and its transport during the period. During July 1987, a large portion of the Tropics in the eastern Pacific Ocean and Caribbean Sea was dominated by strong vapor transport in excess of 4.0 g kg(-1) m s(-1), with relatively small amounts in the other months. JJA 1988 transport values reached similar magnitude and showed similar patterns for all three months. The meridional transport of upper-level water vapor indicated large poleward transport from the Tropics to the higher latitudes. This transport favored the Southern Hemisphere, with large transport occurring south of the ITCZ, which extended across the eastern Pacific and northern South America. Zonally averaged monthly transport values were shown to provide a simple way to quantify the monthly and interannual changes in water vapor transport. Zonally averaged WVTI values peaked in the Southern Hemisphere subtropics during both austral winters. Ln the Tropics, a single, more-pronounced peak located over the equator and south latitudes occurred in 1988 as opposed to a dual peak in 1987. The second peak around 20 degrees N latitude is consistent with findings of others in which upper-tropospheric winds were noted to be stronger in this region during warm ENSO events. Zonally averaged meridional transport was southward for all summer months and was stronger in 1988. The asymmetric nature of the zonally averaged meridional transport (more southerly water vapor transport) was enhanced during JJA 1988, thus indicating a stronger upper-level branch of the Hadley circulation during this notably strong La Nina period. C1 NASA, Global Hydrol & Climate Ctr, Huntsville, AL 35806 USA. Univ Alabama, Huntsville, AL 35899 USA. Lockheed Martin Corp, Huntsville, AL USA. RP Jedlovec, GJ (reprint author), NASA, Global Hydrol & Climate Ctr, 977 Explorer Blvd, Huntsville, AL 35806 USA. NR 57 TC 14 Z9 14 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JAN PY 2000 VL 39 IS 1 BP 15 EP 41 DI 10.1175/1520-0450(2000)039<0015:ASDUTW>2.0.CO;2 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 280VR UT WOS:000085124900002 ER PT J AU Negri, AJ Anagnostou, EN Adler, RF AF Negri, AJ Anagnostou, EN Adler, RF TI A 10-yr climatology of Amazonian rainfall derived from passive microwave satellite observations SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID IMAGER SSM/I DATA; CONVECTIVE CLOUDINESS; SOUTHERN OSCILLATION; NORTHEAST BRAZIL; PRECIPITATION; CYCLE AB In this study, a satellite-derived precipitation "climatology" (climate description) over northern South America using a passive microwave technique, the Goddard Profiling algorithm, is presented. The results are statistically adjusted to have the same probability distribution as a rain gauge dataset. The climatologies take the form of the mean estimated rainfall for a 10-yr+ period with subdivisions by month and meteorological season. For the 6-yr period 1992-97, when two satellites were in operation, diurnal variability (to the extent it is discerned by four unequally spaced observations) is presented. In the mean, dramatic patterns of alternating morning and evening maxima are seen stretching from the northeast (Atlantic coast) across the continent to the Pacific. The effects of local circulations caused by topography, coastlines, and geography (river valleys) on the rainfall patterns are evident, particularly in the region around Manaus, Brazil, where the Negro and Solimoes Rivers merge. The interannual variability of the IO-yr rainfall estimate is examined by computing the deviations of yearly and warm-season (December-February) rainfall from their respective long-term means. Rainfall anomalies associated with Fl Nino and La Nina events then become apparent. This gauge-adjusted satellite climatology enhances existing (gauge based) climatologies by increasing the spatial resolution and providing a common, spaceborne platform for assessing interannual variability. It maintains the same first- and second-order statistics as does the gauge dataset, and allows a first attempt at examining the diurnal cycles by utilizing passive microwave observations (up to) four times per day. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Seabrook, MD USA. RP Negri, AJ (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 912, Greenbelt, MD 20771 USA. NR 20 TC 35 Z9 38 U1 2 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD JAN PY 2000 VL 39 IS 1 BP 42 EP 56 DI 10.1175/1520-0450(2000)039<0042:AYCOAR>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 280VR UT WOS:000085124900003 ER PT J AU Gosselink, KL Grindeland, RE Roy, RR Zhong, H Bigbee, AJ Edgerton, VR AF Gosselink, KL Grindeland, RE Roy, RR Zhong, H Bigbee, AJ Edgerton, VR TI Afferent input from rat slow skeletal muscle inhibits bioassayable growth hormone release SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE immunoassay; bioassay; proprioception; electrical stimulation; peripheral nerves; low-threshold afferents ID GENE-RELATED PEPTIDE; IMMUNOREACTIVE NERVE-FIBERS; ANTERIOR-PITUITARY; SUBSTANCE-P; ADRENALECTOMY; INNERVATION; EXERCISE AB The release of a bioassayable form of growth hormone (BGH), distinct from growth hormone as measured by immunoassay (IGH), from the rat pituitary into the blood is differentially regulated by afferent input from fast and slow skeletal muscles. Specifically, activation of low-threshold fast muscle afferents for 15 min increased plasma BGH by 217 and 295% and decreased pituitary BGH by 68 and 45% in male and female rats, respectively. In contrast, activation of slow muscle afferents inhibited BGH release, decreasing plasma BGH by similar to 60% and increasing pituitary BGH by 30-50% in male rats. Female rats from which food had been withheld for similar to 12 h had elevated basal plasma BGH levels, which then were decreased by 81% after slow muscle nerve stimulation. Plasma IGH concentrations were unchanged after any nerve stimulation condition. These results demonstrate that regulation of BGH release can be differentially mediated through low-threshold afferent inputs from fast or slow skeletal muscle. Furthermore, the results indicate that BGH responses are independent of gender or feeding status. C1 Univ Calif Los Angeles, Dept Physiol Sci, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Brain Res Inst, Los Angeles, CA 90095 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Edgerton, VR (reprint author), Univ Calif Los Angeles, Dept Physiol Sci, 405 Hilgard Ave, Los Angeles, CA 90095 USA. FU NIDCR NIH HHS [DE07212] NR 35 TC 12 Z9 13 U1 0 U2 0 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD JAN PY 2000 VL 88 IS 1 BP 142 EP 148 PG 7 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 273ML UT WOS:000084711400021 PM 10642374 ER PT J AU Coppens, D Haddad, ZS Im, E AF Coppens, D Haddad, ZS Im, E TI Estimating the uncertainty in passive-microwave rain retrievals SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID PHYSICAL PRECIPITATION RETRIEVAL; VERTICAL STRUCTURE INFORMATION; CLOUD-RADIATION MODEL; SATELLITE MEASUREMENTS; FOUNDATIONS; ALGORITHM; SPACE AB Current passive-microwave rain-retrieval methods are largely based on databases built offline using cloud models. Since the vertical distribution of hydrometeors within the cloud has a large impact on upwelling brightness temperatures, a forward radiative transfer model can associate microwave radiances with different rain scenarios. Once such a database is available, to estimate the rain from measured brightness temperatures, one would look for the rain scenarios in the database whose associated radiances are closest to the measurements. To understand the uncertainties in this process, the authors have restricted their attention to tropical ocean cases and analyzed the marginal and joint distributions of the radiances observed by the Tropical Rainfall Measuring Mission (TRMM) satellite's passive-microwave imager and of those in the databases used in the TRMM passive rain retrieval. The authors also calculated the covariances of the rain profiles and brightness temperatures in the TRMM passive-microwave database and derived a simple parametric model for the conditional variance, given measured radiances. These results are used to characterize the uncertainty inherent in the passive-microwave retrieval. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Haddad, ZS (reprint author), CALTECH, Jet Prop Lab, MS 300-227,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 12 Z9 12 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PY 2000 VL 17 IS 12 BP 1618 EP 1629 DI 10.1175/1520-0426(2000)017<1618:ETUIPM>2.0.CO;2 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 385ED UT WOS:000165988900005 ER PT J AU Paradis, PF Rhim, WK AF Paradis, PF Rhim, WK TI Non-contact measurements of thermophysical properties of titanium at high temperature SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE titanium; thermophysical properties; high temperature; electrostatic levitation ID NONCONTACT MEASUREMENT TECHNIQUE; HEAT; EMISSIVITY; EXPANSION AB Four thermophysical properties of both solid and liquid titanium measured using the high-temperature electrostatic levitator at JPL are presented. These properties are density, thermal expansion coefficient, constant pressure heat capacity, and hemispherical total emissivity. For the first time, we report the density, the thermal expansion coefficient, and the ratio of the constant pressure heat capacity to the hemispherical total emissivity of undercooled titanium over a wide range of temperatures. Over the 1650 K to 2000 K temperature span, the liquid density can be expressed as rho(T)/(kg.m(-3)) = 4.208 . 10(3) - 0.508 (T - T-m)/K with T-m = 1943 K, and the corresponding volume expansion coefficient as alpha = 1.169 . 10(-4) K-1. Similarly, over the 1540 K to 1940 K temperature range, the measured density of the solid can be expressed as rho(T)/(kg.m(-3)) = 4.321 . 10(3) - 0.212 (T - T-m)/K, giving a volume expansion coefficient alpha = 4.76 10(-5) K-1. The constant pressure heat capacity of the liquid phase could be estimated as C-p,C-m(T)/(J . K-1 . mol(-1)) = 45.5 - 3.21 . 10(-3). (T - T-m)/K if the hemispherical total emissivity of the liquid phase epsilon(T) remains constant at 0.34 over the 1650 K to 2000 K temperature range. Over the 1540 K to 1940 K temperature span, the hemispherical total emissivity of the solid phase could be rendered as epsilon(T)(T) = 0.297 + 5.952 10(-5). (T - T-m)/K. The enthalpy of fusion has also been calculated as 14.3 kJ mol(-1) (C) 2000 Academic Press. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Paradis, PF (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 22 TC 30 Z9 30 U1 4 U2 15 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD JAN PY 2000 VL 32 IS 1 BP 123 EP 133 DI 10.1006/jcht.1999.0576 PG 11 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA 275TY UT WOS:000084837300009 ER PT J AU Chen, T Rossow, WB Zhang, YC AF Chen, T Rossow, WB Zhang, YC TI Radiative effects of cloud-type variations SO JOURNAL OF CLIMATE LA English DT Article ID UPPER-AIR OBSERVATIONS; HIGH-LEVEL CLOUDS; CLIMATE-RESEARCH; ISCCP; SURFACE; FLUXES; SENSITIVITY; AEROSOLS; BALANCE; ALBEDO AB Radiative flux changes induced by the occurrence of different cloud types are investigated using international Satellite Cloud Climatology Project cloud data and a refined radiative transfer model from National Aeronautics and Space Administration/Goddard Institute for Space Studies general circulation model. Cloud types are defined by their top height and optical thickness. Cloud-type variations are shown to be as important as cloud cover in modifying the radiation field of the earth-atmosphere system. Other variables, such as the solar insolation and atmospheric and surface properties, also play significant roles in determining regional cloud radiative effects. The largest "annual" mean (approximated by averaging the results of four particular days, one from each season) changes of the global top-of-atmosphere and surface shortwave radiative fluxes are produced by stratocumulus, altostratus, and cirrostratus clouds (i.e., clouds with moderate optical thicknesses). Cirrus, cirrostratus, and deep convective clouds (i.e., the highest-level clouds) cause most of the annual mean changes in the global top-of-atmosphere longwave radiative fluxes; whereas the largest annual mean changes of the global surface longwave radiative fluxes are caused by stratocumulus, cumulus, and altostratus. C1 Columbia Univ, Dept Earth & Environm Sci, New York, NY 10025 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA. RP Chen, T (reprint author), Columbia Univ, Dept Earth & Environm Sci, 2880 Broadway, New York, NY 10025 USA. RI Rossow, William/F-3138-2015 NR 40 TC 177 Z9 187 U1 3 U2 33 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JAN 1 PY 2000 VL 13 IS 1 BP 264 EP 286 DI 10.1175/1520-0442(2000)013<0264:REOCTV>2.0.CO;2 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273LH UT WOS:000084708800017 ER PT J AU Tang, BY Hsieh, WW Monahan, AH Tangang, FT AF Tang, BY Hsieh, WW Monahan, AH Tangang, FT TI Skill comparisons between neural networks and canonical correlation analysis in predicting the equatorial Pacific sea surface temperatures SO JOURNAL OF CLIMATE LA English DT Article ID EL-NINO; SOUTHERN OSCILLATION; MODELS; ATMOSPHERE; ANOMALIES; ENSO; SST AB Among the statistical methods used for seasonal climate prediction, canonical correlation analysis (CCA), a more sophisticated version of the linear regression (LR) method, is well established. Recently, neural networks (NN) have been applied to seasonal climate prediction. Unlike CCA and LR, NN is a nonlinear method, which leads to the question whether the nonlinearity of NN brings any extra prediction skill. In this study, an objective comparison between the three methods (CCA, LR, and NN) in predicting the equatorial Pacific sea surface temperatures (in regions Nino1 + 2, Nino3, Nino3.4, and Nino4) was made. The skill of NN was found to be comparable to that of LR and CCA. A cross-validated t test showed that the difference between NN and LR and the difference between NN and CCA were not significant at the 5% level. The lack of significant skill difference between the nonlinear NN method and the linear methods suggests that at the seasonal timescale the equatorial Pacific dynamics is basically linear. C1 Univ British Columbia, Dept Earth & Ocean Sci, Vancouver, BC V5Z 1M9, Canada. RP Tang, BY (reprint author), CALTECH, Jet Prop Lab, M-S 300-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Monahan, Adam/J-9895-2012; Hsieh, William/G-8380-2011 OI Hsieh, William/0000-0003-2654-392X NR 27 TC 38 Z9 40 U1 1 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD JAN 1 PY 2000 VL 13 IS 1 BP 287 EP 293 DI 10.1175/1520-0442(2000)013<0287:SCBNNA>2.0.CO;2 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 273LH UT WOS:000084708800018 ER PT J AU Wong, TM Young, DF Haeffelin, M Weckmann, S AF Wong, TM Young, DF Haeffelin, M Weckmann, S TI Validation of the CERES/TRMM ERBE-like monthly mean clear-sky longwave dataset and the effects of the 1998 ENSO event SO JOURNAL OF CLIMATE LA English DT Article ID RADIATION BUDGET EXPERIMENT; ENERGY SYSTEM CERES; SEA-SURFACE TEMPERATURE; CLOUD TYPE; EARTH; BALANCE; RETRIEVAL; SATELLITE; CLIMATE; MISSION AB The Clouds and the Earth's Radiant Energy System (CERES) is a new National Aeronautics and Space Administration space-borne measurement project for monitoring the radiation environment of the earth-atmosphere system. The first CERES instrument was launched into space on board the Tropical Rainfall Measuring Mission (TRMM) satellite on 27 November 1997. The purpose of this paper is 1) to describe the initial validation of the new CERES/TRMM Earth Radiation Budget Experiment (ERBE)-like monthly mean clear-sky longwave (CLW) dataset and 2) to demonstrate the scientific benefit of this new dataset through a data application study on the 1998 El Nino-Southern Oscillation (ENSO) episode. The initial validation of the CERES CLW data is carried out based on comparisons with both historical ERBE observations and radiative transfer simulations. While the observed CERES CLWs are initially larger than the historical ERBE record during the first part of the 1998 ENSO event, these differences are diminished by the end of the ENSO event in July 1998. These unique ENSO-related CLW radiation signatures are captured well by the radiative transfer model simulations. These results demonstrate that the new CERES CLW fluxes are theoretically consistent with the underlying physics of the atmosphere. A CERES data application study is performed to examine the relationship between the CERES CLW anomaly and changes in sea surface temperature (SST) and atmospheric column precipitable water content (PWC) during the January 1998 ENSO event. While the changes in the SST pattern are basically uncorrelated with changes in the CLW field, a negative correlation is found between the PWC anomaly and the changes in the CLW radiation field. These observed features point to 1) the significant role of the water vapor field in modulating the tropical outgoing CLW radiation field during the 1998 ENSO event and 2) the important effects of water vapor absorption in decoupling the top of the atmosphere tropical outgoing CLW radiation from the surface upward CLW field. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. RP Wong, TM (reprint author), NASA, Langley Res Ctr, MS 420, Hampton, VA 23681 USA. NR 26 TC 20 Z9 21 U1 2 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PY 2000 VL 13 IS 24 BP 4256 EP 4267 DI 10.1175/1520-0442(2000)013<4256:VOTCTE>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 385EF UT WOS:000165989100003 ER PT J AU Hazeltine, E Poldrack, R Gabrieli, JDE AF Hazeltine, E Poldrack, R Gabrieli, JDE TI Neural activation during response competition SO JOURNAL OF COGNITIVE NEUROSCIENCE LA English DT Article ID ANTERIOR CINGULATE CORTEX; POSITRON EMISSION TOMOGRAPHY; INFERIOR PREFRONTAL CORTEX; HUMAN CEREBRAL-CORTEX; CARD SORTING TEST; FUNCTIONAL MRI; CHANNEL ACTIVATION; INHIBITORY CONTROL; WORKING-MEMORY; FRONTAL LOBES AB The flanker task, introduced by Eriksen and Eriksen [Eriksen, B. A., & Eriksen, C. W. (1974). Effects of noise letters upon the identification of a target letter in a nonsearch task. Perception C Psychophysics, 16, 143-149], provides a means to selectively manipulate the presence or absence of response competition while keeping other task demands constant. We measured brain activity using functional magnetic resonance imaging (fMRI) during performance of the flanker task. In accordance with previous behavioral studies, trials in which the flanking stimuli indicated a different response than the central stimulus were performed significantly more slowly than trials in which all the stimuli indicated the same response. This reaction time effect was accompanied by increases in activity in four regions: the right ventrolateral prefrontal cortex, the supplementary motor area, the left superior parietal lobe, and the left anterior parietal cortex. The increases were not due to changes in stimulus complexity or the need to overcome previously learned associations between stimuli and responses. Correspondences between this study and other experiments manipulating response interference suggest that the frontal foci may be related to response inhibition processes whereas the posterior foci may be related to the activation of representations of the inappropriate responses. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Stanford Univ, Massachusetts Gen Hosp, NMR Ctr, Stanford, CA 94305 USA. Harvard Univ, Sch Med, Cambridge, MA 02138 USA. RP Hazeltine, E (reprint author), NASA, Ames Res Ctr, Mail Stop 262-4, Moffett Field, CA 94035 USA. FU NIMH NIH HHS [MH11849] NR 50 TC 150 Z9 151 U1 4 U2 18 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 0898-929X J9 J COGNITIVE NEUROSCI JI J. Cogn. Neurosci. PY 2000 VL 12 SU 2 BP 118 EP 129 DI 10.1162/089892900563984 PG 12 WC Neurosciences; Psychology, Experimental SC Neurosciences & Neurology; Psychology GA 388QX UT WOS:000166194100011 PM 11506652 ER PT J AU Zacks, J Mires, J Tversky, B Hazeltine, E AF Zacks, J Mires, J Tversky, B Hazeltine, E TI Individual differences in mental spatial transformations SO JOURNAL OF COGNITIVE NEUROSCIENCE LA English DT Meeting Abstract C1 NASA, Ames Res, Washington, DC 20546 USA. Stanford Univ, Stanford, CA 94305 USA. Washington Univ, St Louis, MO 63130 USA. RI Zacks, Jeffrey/E-9099-2011 OI Zacks, Jeffrey/0000-0003-1171-3690 NR 0 TC 0 Z9 0 U1 0 U2 3 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 0898-929X J9 J COGNITIVE NEUROSCI JI J. Cogn. Neurosci. PY 2000 SU S MA 53C BP 75 EP 75 PG 1 WC Neurosciences; Psychology, Experimental SC Neurosciences & Neurology; Psychology GA 292UQ UT WOS:000085813800315 ER PT J AU Chan, D Ivry, R Hazeltine, E AF Chan, D Ivry, R Hazeltine, E TI Intermanual transfer of learning for mirror and parallel sequences of movements. SO JOURNAL OF COGNITIVE NEUROSCIENCE LA English DT Meeting Abstract C1 Univ Calif Berkeley, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 0898-929X J9 J COGNITIVE NEUROSCI JI J. Cogn. Neurosci. PY 2000 SU S MA 92C BP 82 EP 82 PG 1 WC Neurosciences; Psychology, Experimental SC Neurosciences & Neurology; Psychology GA 292UQ UT WOS:000085813800354 ER PT J AU Hazeltine, E Ivry, R Teague, D AF Hazeltine, E Ivry, R Teague, D TI Dual-task performance with minimal cost: Evidence for concurrent response selection processes. SO JOURNAL OF COGNITIVE NEUROSCIENCE LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 0898-929X J9 J COGNITIVE NEUROSCI JI J. Cogn. Neurosci. PY 2000 SU S MA 15E BP 110 EP 110 PG 1 WC Neurosciences; Psychology, Experimental SC Neurosciences & Neurology; Psychology GA 292UQ UT WOS:000085813800502 ER PT J AU Stone, M Seger, CA Prabakharan, V Gabrieli, JDE AF Stone, M Seger, CA Prabakharan, V Gabrieli, JDE TI Right-hemisphere involvement in self-relevant processing SO JOURNAL OF COGNITIVE NEUROSCIENCE LA English DT Meeting Abstract C1 Stanford Univ, NASA, ARC, Stanford, CA 94305 USA. Colorado State Univ, Ft Collins, CO 80523 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 0898-929X J9 J COGNITIVE NEUROSCI JI J. Cogn. Neurosci. PY 2000 SU S MA 23F BP 133 EP 134 PG 2 WC Neurosciences; Psychology, Experimental SC Neurosciences & Neurology; Psychology GA 292UQ UT WOS:000085813800625 ER PT J AU Seale, MD Madaras, EI AF Seale, MD Madaras, EI TI Lamb wave evaluation of the effects of thermal-mechanical aging on composite stiffness SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE Lamb waves; thermal-mechanical aging; composites; nondestructive evaluation; ultrasonics ID DAMAGE AB Lamb wave methods offer a promising approach for evaluating damage in composite materials. The Lamb wave velocity is directly related to the material parameters, so an effective tool exists to monitor damage in composites by measuring the velocity of these waves. In this work, studies have been conducted which examine the effects of combined thermal and mechanical aging in thermoplastic composite samples using symmetric mode Lamb wave velocity measurements. From the velocity measurements, the in-plane stiffnesses, A(11) and A(22), are calculated. The samples examined include a baseline specimen with 0 hours, specimens which have been aged 3,500 and 5,000 hours, and one specimen with 1,000 hours of accelerated aging. The results of the Lamb wave measurements are compared to C-scans of the panels. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Seale, MD (reprint author), Thomas Nelson Community Coll, POB 9407, Hampton, VA 23670 USA. NR 26 TC 8 Z9 9 U1 0 U2 0 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2000 VL 34 IS 1 BP 27 EP 38 DI 10.1106/WAUE-309Q-JTA0-G9C7 PG 12 WC Materials Science, Composites SC Materials Science GA 282GN UT WOS:000085210000002 ER PT J AU Bednarcyk, BA Pindera, MJ AF Bednarcyk, BA Pindera, MJ TI Inelastic response of a woven carbon/copper composite - Part II: Micromechanics model SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article ID METAL-MATRIX COMPOSITES; FABRIC-REINFORCED COMPOSITES; CONSTITUTIVE-EQUATIONS; FAILURE; BEHAVIOR; FIBER AB Part II of this paper presents a detailed development of an efficient micromechanics model for woven metal matrix composites (MMCs). The approach was to employ Aboudi's (1995) three-dimensional generalized method of cells (GMC-3D) as a global model, and to embed Aboudi's ( 1987) original method of cells within GMC-3D as a local model. Inelastic deformation is modeled on the local level, in the original method of cells. For this reason the field quantities must be passed between the local and global models continuously, as opposed to using the local model once simply to determine local effective properties. This process is computationally intensive, and GMC-3D, in its original form, is not adequately efficient to analyze refined composite geometries. Hence, GMC-SD was reformulated using mixed concentration equations rather than traditional strain concentration equations, improving the model's computational efficiency considerably. The model is now capable of readily analyzing the thermomechanical behavior of elaborate and varied woven and braided composites. Experimental test results for a particular woven MMC, 8-harness satin carbon/copper, were presented in Part I of this paper. The predictions of the model described herein will be correlated with these experimental results in Part III. C1 NASA, Ohio Aerosp Inst, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Virginia, Dept Civil Engn & Appl Mech, Charlottesville, VA 22903 USA. RP Bednarcyk, BA (reprint author), NASA, Ohio Aerosp Inst, Glenn Res Ctr, MS 6-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 29 TC 22 Z9 22 U1 0 U2 6 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2000 VL 34 IS 4 BP 299 EP 331 PG 33 WC Materials Science, Composites SC Materials Science GA 289FK UT WOS:000085609700003 ER PT J AU Bednarcyk, BA Pindera, MJ AF Bednarcyk, BA Pindera, MJ TI Inelastic response of a woven carbon/copper composite - Part III: Model-experiment correlation SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article ID CONSTITUTIVE-EQUATIONS AB This paper compares the predictions of a new micromechanics model for woven metal matrix composites with experimental results for 8-harness (8H) satin carbon/copper (C/Cu). Experimental results for this advanced woven metal matrix composite were presented in Part I of this paper (Bednarcyk and Pindera, 1999), while Part II discussed the development of the micromechanics model (Bednarcyk and Pindera, 2000). The experiments included monotonic, cyclic, and combined tension, compression, and Iosipescu shear tests. The micromechanics model is based on an embedded approach in which Aboudi's (1987) two-dimensional method of cells (MOC) is embedded within a reformulated version of Aboudi's (1995) three-dimensional generalized methods of cells (GMC-3D). In order to obtain accurate and realistic predictions, the model accounts for the effects of porosity, residual stresses, imperfect fiber/matrix bonding, and grip constraints. These effects, and the selection of the parameters, which characterize these effects, are discussed. By judiciously selecting the parameters, good qualitative and reasonable quantitative correlation is obtained between the model predictions and experiment. In particular, the unexpected trend based on matrix alloy type observed in the experimental tensile data has been correctly predicted. C1 NASA, Ohio Aerosp Inst, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Virginia, Dept Civil Engn & Appl Mech, Charlottesville, VA 22903 USA. RP Bednarcyk, BA (reprint author), NASA, Ohio Aerosp Inst, Glenn Res Ctr, MS 6-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 15 TC 8 Z9 8 U1 0 U2 1 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2000 VL 34 IS 5 BP 352 EP 378 DI 10.1106/PKX6-YL87-VC8C-RBDY PG 27 WC Materials Science, Composites SC Materials Science GA 292FN UT WOS:000085783600001 ER PT J AU Smith, JG Connell, JW Hergenrother, PM AF Smith, JG Connell, JW Hergenrother, PM TI The effect of phenylethynyl terminated imide oligomer molecular weight on the properties of composites SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE high temperature polymers; phenylethynyl terminated oligomers; matrix resins; adhesives; composites; imide oligomers ID POLYIMIDE OLIGOMERS; PENDENT; ANHYDRIDES AB As part of a program to develop high temperature/high performance structural resins for applications on a Mach 2.4 high speed civil transport, a phenylethynyl terminated imide oligomer designated PETI-5 has been under investigation. The oligomer was prepared at a calculated number average molecular weight of about 5000 g/mol and has exhibited good processability and excellent mechanical properties upon thermal cure at 350-371 degrees C for 1 hr. However in the fabrication of complex composite structures, primarily skin stringer structure, a resin with improved flow and equivalent or better mechanical properties was desired. To improve melt flow (i.e., processability or compression moldability), 1250 and 2500 g/mol molecular weight versions of PETI-5 were prepared and their solutions used to prepare supported adhesive film and unidirectional carbon fiber prepreg. Imide powder of the oligomers was used for characterization of melt flow behavior and the fabrication of neat resin moldings. The PETI-5 oligomers were fabricated into titanium adhesive specimens and IM-7 carbon fiber laminates under 0.3-1.4 M Pa for 1 hr at 350-371 degrees C. The lower molecular weight oligomers exhibited improved processability, and when cured, higher T(g)s and better retention of mechanical properties at elevated temperature without significantly sacrificing toughness (damage tolerance) than the higher molecular weight oligomer. The neat resin, adhesive and composite properties of the cured polymers are discussed. C1 NASA, Langley Res Ctr, Composites & Polymers Branch, Hampton, VA 23681 USA. RP Smith, JG (reprint author), NASA, Langley Res Ctr, Composites & Polymers Branch, MS 226, Hampton, VA 23681 USA. NR 26 TC 40 Z9 42 U1 1 U2 16 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2000 VL 34 IS 7 BP 614 EP 628 PG 15 WC Materials Science, Composites SC Materials Science GA 299UB UT WOS:000086215300005 ER PT J AU Shah, AR Murthy, PLN Mital, SK Bhatt, RT AF Shah, AR Murthy, PLN Mital, SK Bhatt, RT TI Probabilistic modeling of ceramic matrix composite strength SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE probability theory; simulation; probability density functions; ceramic matrix composites; sensitivity AB Uncertainties associated with the primitive random variables such as manufacturing process (processing temperature, fiber volume ratio, void volume ratio), constituent properties (fiber, matrix and interface), and geometric parameters (ply thickness, interphase thickness) have been simulated to quantify the scatter in the first matrix cracking strength (FMCS) and the ultimate tensile strength of SCS-6/RBSN [SiC fiber (SCS-6) reinforced reaction-bonded silicon nitride composite] ceramic matrix composite laminate at room temperature. Cumulative probability distribution function for the FMCS and ultimate tensile strength at room temperature (RT) of [O](8), [O-2/90(2)](s), and [+/-45(2)](s) laminates have been simulated and the sensitivity of primitive variables to the respective strengths have been quantified. Computationally predicted scatter of the strengths for a uniaxial laminate has been compared with those from limited experimental data. Also the experimental procedure used in the tests has been described briefly. Results show a very good agreement between the computational simulation and the experimental data. Dominating failure modes in [0](8), [0/90](s) and [+/-45](s) laminates have been identified. Results indicate that the first matrix cracking strength for the [0](8) and [0/90](s) laminates is sensitive to the thermal properties, modulus and strengths of both the fiber and matrix whereas the ultimate tensile strength is sensitive to the fiber strength and the fiber volume ratio. In the case of a [+/-45](s) laminate, both the FMCS and the ultimate tensile strengths have a small scatter range and are sensitive to the fiber tensile strength as well as the fiber volume ratio. C1 Sest Inc, N Royalton, OH 44133 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Toledo, Toledo, OH 43606 USA. USA, Res Lab, Glenn Res Ctr, Cleveland, OH 44135 USA. NASA, GRC, Life Predict Branch, Cleveland, OH USA. RP Sest Inc, 13111 Mariner Dr, N Royalton, OH 44133 USA. NR 14 TC 3 Z9 3 U1 0 U2 4 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0021-9983 EI 1530-793X J9 J COMPOS MATER JI J. Compos Mater. PY 2000 VL 34 IS 8 BP 670 EP 688 DI 10.1106/EQNE-PEQM-UQ7F-8XDM PG 19 WC Materials Science, Composites SC Materials Science GA 307NX UT WOS:000086660400003 ER PT J AU Krueger, R Cvitkovich, MK O'Brien, TK Minguet, PJ AF Krueger, R Cvitkovich, MK O'Brien, TK Minguet, PJ TI Testing and analysis of composite skin/stringer debonding under multi-axial loading SO JOURNAL OF COMPOSITE MATERIALS LA English DT Article DE composite materials; testing; finite element analysis; fracture mechanics; skin/flange interface; secondary bonding ID ENERGY RELEASE RATES; CRACK AB A consistent step-wise approach is presented to investigate the damage mechanism in composite bonded skin/stringer constructions under uniaxial and biaxial (in-plane/out-of-plane) loading conditions. The approach uses experiments to detect the failure mechanism, computational stress analysis to determine the location of first matrix cracking and computational fracture mechanics to investigate the potential for delamination growth. In a first step, tests were performed on specimens, which consisted of a tapered composite flange, representing a stringer or frame, bonded onto a composite skin. Tests were performed under monotonic loading conditions in tension, three-point bending, and combined tension/bending to evaluate the debonding mechanisms between the skin and the bonded stringer. For combined tension/bending testing, a unique servohydraulic load frame was used that was capable of applying both in-plane tension and out-of-plane bending loads simultaneously. Specimen edges were examined on the microscope to document the damage occurrence and to identify typical damage patterns. For all three load cases, observed failure initiated in the flange, near the flange tip, causing the flange to almost fully debond from skin. In a second step, a two dimensional plane-strain finite element model was developed to analyze the different test cases using a geometrically nonlinear solution. For all three loading conditions, computed principal stresses exceeded the transverse strength of the material in those areas of the flange where the matrix cracks had developed during the tests. In a third step, delaminations of various lengths were simulated in two locations where delaminations were observed during the tests. The analyses showed that at the loads corresponding to matrix ply crack initiation computed strain energy release rates exceeded the values obtained from a mixed mode failure criterion in one location. Hence, unstable delamination propagation is likely to occur as observed in the experiments. C1 USA, Res Lab, NASA, Langley Res Ctr,Vehicle Technol Directorate, Hampton, VA 23665 USA. NASA, Langley Res Ctr, Natl Res Council Res Associate, Hampton, VA 23681 USA. Boeing Co, Philadelphia, PA 19142 USA. RP O'Brien, TK (reprint author), USA, Res Lab, NASA, Langley Res Ctr,Vehicle Technol Directorate, Hampton, VA 23665 USA. RI Krueger, Ronald/G-5356-2015 NR 18 TC 57 Z9 61 U1 0 U2 16 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0021-9983 J9 J COMPOS MATER JI J. Compos Mater. PY 2000 VL 34 IS 15 BP 1263 EP 1300 DI 10.1106/BDU1-KV0H-XYVT-9R5H PG 38 WC Materials Science, Composites SC Materials Science GA 340CX UT WOS:000088516500002 ER PT J AU Dickinson, LC Farley, GL Hinders, MK AF Dickinson, LC Farley, GL Hinders, MK TI Failure initiation in translaminar reinforced composites SO JOURNAL OF COMPOSITES TECHNOLOGY & RESEARCH LA English DT Article DE composites; reinforced composites; delamination AB A translaminar-reinforced (TLR) composite is an otherwise two-dimensional laminate with through-thickness or Z-direction fibrous reinforcement across the lamina. Only small amounts (less than 5% volume) of TLR are necessary to substantially improve compression-after-impact response, increase fracture toughness, and severely restrict the size and growth of delamination. These improvements have been documented repeatedly in the literature, and it is generally accepted that TLR restricts the size and growth of delamination. In this paper we report a detailed investigation of whether TLR delays the initiation of delamination via finite-element analysis and a strength-of-material approach. The various parameters investigated include TLR material, diameter, spacing, volume fraction, and through-thickness angle. In addition, the unavoidable microstructural features of curved in-plane fibers and resin pockets were examined. Our conclusion is that TLR does not delay damage initiation, even though it has been shown experimentally to restrict damage progression. C1 3TEX Inc, Cary, NC 27511 USA. USA, Res Lab, Vehicle Struct Directorate, NASA LaRC, Hampton, VA 23681 USA. Coll William & Mary, Dept Appl Sci, Williamsburg, VA 23187 USA. RP Dickinson, LC (reprint author), 3TEX Inc, 109 Mackenan Dr, Cary, NC 27511 USA. NR 10 TC 6 Z9 6 U1 2 U2 2 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0884-6804 J9 J COMPOS TECH RES JI J. Compos. Technol. Res. PD JAN PY 2000 VL 22 IS 1 BP 23 EP 32 PG 10 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA 281LQ UT WOS:000085162300003 ER PT J AU Ross, MD Linton, SW Parnas, BR AF Ross, MD Linton, SW Parnas, BR TI Simulation studies of vestibular macular afferent-discharge patterns using a new, quasi-3-D finite volume method SO JOURNAL OF COMPUTATIONAL NEUROSCIENCE LA English DT Article DE finite volume simulator; vestibular maculae; calyx; backpropagation ID PERIPHERAL INNERVATION PATTERNS; COMPUTER GENERATED IMAGERY; SQUIRREL-MONKEY; SEMICIRCULAR CANALS; RESPONSE PROPERTIES; PYRAMIDAL NEURONS; 3-D COMPONENTS; NERVE; DENDRITES; MODEL AB A quasi-three-dimensional finite-volume numerical simulator was developed to study passive voltage spread in vestibular macular afferents. The method, borrowed from computational fluid dynamics, discretizes events transpiring in small volumes over time. The afferent simulated had three calyces with processes. The number of processes and synapses, and direction and timing of synapse activation, were varied. Simultaneous synapse activation resulted in shortest latency, while directional activation (proximal to distal and distal to proximal) yielded most regular discharges. Color-coded visualizations showed that the simulator discretized events and demonstrated that discharge produced a distal spread of voltage from the spike initiator into the ending. The simulations indicate that directional input, morphology, and timing of synapse activation can affect discharge properties, as must also distal spread of voltage from the spike initiator. The finite volume method has generality and can be applied to more complex neurons to explore discrete synaptic effects in four dimensions. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Ames Ctr Bioinformat, Moffett Field, CA 94035 USA. RP Ross, MD (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM mross@mail.arc.nasa.gov FU NIMH NIH HHS [MH47305] NR 50 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0929-5313 J9 J COMPUT NEUROSCI JI J. Comput. Neurosci. PD JAN-FEB PY 2000 VL 8 IS 1 BP 5 EP 18 DI 10.1023/A:1008976030745 PG 14 WC Mathematical & Computational Biology; Neurosciences SC Mathematical & Computational Biology; Neurosciences & Neurology GA 326GP UT WOS:000087725100001 PM 10798497 ER PT J AU Clarke, EB Breen, ML Fanwick, PE Hepp, AF Duraj, SA AF Clarke, EB Breen, ML Fanwick, PE Hepp, AF Duraj, SA TI Synthesis and structural characterization of tris(dimethyldithiocarbamate) indium(III), In[S2CN(CH3)(2)](3) SO JOURNAL OF COORDINATION CHEMISTRY LA English DT Article DE indium; dithiocarbamate; tetralkylthiuram disulfide; tetraalkyldithiocarbamate; photovoltaics; MOCVD ID PRECURSORS AB The synthesis and structure of the indium dithiocarbamate, In[S2CN(CH3)(2)](3) . (1/2) 4-mepy (4-mepy = 4-methylpyridine), is described. Indium metal was oxidized by tetramethylthiuram disulfide in 4-methylpyridine at 25 degreesC to form a new, homoleptic indium(III) dithiocarbamate in yields exceeding 60%. In[S2CN(CH3)(2)](3) exists as a discrete molecule with a distorted-octahedral geometry. The compound crystallizes in the P (1) over bar (No. 2) space group with a = 9.282(1) Angstrom, b = 10.081(1) Angstrom, c = 12.502 Angstrom, alpha = 73.91(1)degrees, beta = 70.21(1)degrees, gamma = 85.84(1)degrees, Z = 2, V(Angstrom) = 1057.3(3), R = 0.046 and R-w = 0.061. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Cleveland State Univ, Dept Chem, Cleveland, OH 44115 USA. Tulane Univ, Dept Chem, New Orleans, LA 70118 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. RP Hepp, AF (reprint author), NASA, Glenn Res Ctr, MS 302-1, Cleveland, OH 44135 USA. NR 15 TC 4 Z9 4 U1 0 U2 0 PU GORDON BREACH PUBLISHING, TAYLOR & FRANCIS GROUP PI PHILADELPHIA PA 325 CHESTNUT ST, 8TH FL, PHILADELPHIA, PA 19106 USA SN 0095-8972 J9 J COORD CHEM JI J. Coord. Chem. PY 2000 VL 52 IS 2 BP 111 EP 117 DI 10.1080/00958970008022579 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 442YM UT WOS:000169312600002 ER PT J AU Su, CH Dudley, M Matyi, R Feth, S Lehoczky, SL AF Su, CH Dudley, M Matyi, R Feth, S Lehoczky, SL TI Characterizations of ZnSe single crystals grown by physical vapor transport SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE ZnSe crystals; vapor growth; PL; SWBXT; HRTXD; GDMS ID MOLECULAR-BEAM EPITAXY; LIGHT-EMITTING-DIODES; INTENSITY-DEPENDENT ENERGY; ACCEPTOR-PAIR BANDS; DOPED ZINC SELENIDE; HIGH-PURITY; PHOTOLUMINESCENCE SPECTRA; DONOR; LUMINESCENCE; COMPENSATION AB ZnSe bulk crystals were grown by self-seeded physical vapor transport technique in horizontal and vertical configurations. The impurities and defects in the grown crystals were studied by glow discharge mass spectroscopy (GDMS) and low-temperature photoluminescence (PL) measurements. The PL results on the starting material and the grown crystals are consistent with the low impurity levels measured by GDMS. The crystalline quality of the grown crystals was examined by synchrotron white beam X-ray topography (SWBXT) and high-resolution triple X-ray diffraction (HRTXD). The SWBXT shows that, aside from twins, the overall crystalline quality of the vapor-grown ZnSe crystals, especially in the contactless grown region, was quite high. The HRTXD results are in line with the SWBXT findings. The comparison between the HRTXD on a chemical-mechanically polished and a cleaved surface seems to indicate that polishing damage can obscure the true microstructure in the as-grown ZnSe crystals. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Micrograv Sci & Applicat Dept, Sci Directorate, Huntsville, AL 35812 USA. SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA. RP Su, CH (reprint author), NASA, George C Marshall Space Flight Ctr, Micrograv Sci & Applicat Dept, Sci Directorate, SN47, Huntsville, AL 35812 USA. RI Feth, Shari/F-6302-2013 OI Feth, Shari/0000-0003-3545-5649 NR 40 TC 12 Z9 13 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JAN PY 2000 VL 208 IS 1-4 BP 237 EP 247 DI 10.1016/S0022-0248(99)00500-X PG 11 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 269PH UT WOS:000084486400035 ER PT J AU Ramachandran, N Su, CH Lehoczky, SL AF Ramachandran, N Su, CH Lehoczky, SL TI Modeling studies of PVT growth of ZnSe: current status and future course SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE physical vapor transport; numerical modeling; microgravity; Stefan flux; buoyancy ID PHYSICAL VAPOR TRANSPORT; CRYSTAL-GROWTH; MICROGRAVITY CONDITIONS; CDTE AB Results from a numerical modeling study of ZnSe crystal growth by physical vapor transport (PVT) are reported in this paper. The influence of a residual gas is included in the two-dimensional model. The simulations show that the Stefan flux dominates the system and the subtle gravitational effects can be gauged by subtracting this flux from the calculated flow fields. Shear flows, due to solutal buoyancy, of the order of 50 mu m/s for the horizontal growth orientation and 10 mu m/s for the vertical orientation are predicted adjacent to the growing crystal. Whether these flows can fully account for the observed gravity-related growth morphological effects and inhomogeneous solute and dopant distributions is a matter of conjecture. A template for future modeling efforts in this area is suggested which incorporates a mathematical approach to the tracking of the growth front based on energy of formation concepts. (C) 2000 Elsevier Science B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Sci Directorate 47, Huntsville, AL 35812 USA. NASA, George C Marshall Space Flight Ctr, Micrograv Sci & Applicat Dept, Sci Directorate 47, Huntsville, AL 35812 USA. RP Ramachandran, N (reprint author), NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Sci Directorate 47, Huntsville, AL 35812 USA. NR 18 TC 10 Z9 10 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JAN PY 2000 VL 208 IS 1-4 BP 269 EP 281 DI 10.1016/S0022-0248(99)00512-6 PG 13 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 269PH UT WOS:000084486400040 ER PT J AU Rhim, WK Ohsaka, K AF Rhim, WK Ohsaka, K TI Thermophysical properties measurement of molten silicon by high-temperature electrostatic levitator: density, volume expansion, specific heat capacity, emissivity, surface tension and viscosity SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE molten silicon; density; heat capacity; surface tension; viscosity; electrostatic levitator ID OSCILLATIONS AB Thermophysical properties of molten silicon measured by the high-temperature electrostatic levitator at JPL are presented. The properties include the density, the volume expansion, the constant pressure specific heat capacity, the hemispherical total emissivity, the surface tension and the viscosity. Over the temperature range investigated (1350-1850 K), the measured liquid density showed a quadratic nature expressed by rho(T) = 2.58 - 1.59 x 10(-4) (T - T-m) - 1.15 x 10(-7) (T - T-m)(2) g/cm(3) with T-m = 1687 K. The volume expansion with respect to the melting point could be expressed by V(T)/V-m = 1 + 6.18 x 10(-5) (T - T-m) + 4.72 x 10(-8) (T - T-m)(2). The hemispherical total emissivity of molten silicon at the melting temperature was 0.18, and the constant pressure specific heat was determined over a 500 K around the melting point. The measured surface tension and the viscosity could be expressed respectively by sigma(T) = 765 - 0.016(T - T-m) mN/m, and eta(T) = 0.75 - 1.22 x 10(-3) (T - T-m) mPa s. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Rhim, WK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 18 TC 98 Z9 101 U1 2 U2 28 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD JAN PY 2000 VL 208 IS 1-4 BP 313 EP 321 DI 10.1016/S0022-0248(99)00437-6 PG 9 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 269PH UT WOS:000084486400045 ER PT J AU Moghaddam, M AF Moghaddam, M TI Effect of medium symmetries on parameter estimation with polarimetric interferometry SO JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS LA English DT Article ID RADAR; CALIBRATION AB The addition of interferometric backscattering pairs to the conventional polarimetric synthetic aperture radar (SAR) data over forests and other vegetated areas increases the dimensionality of the data space, in principle enabling the estimation of a larger number of parameters: In this paper, the effect of medium symmetries on the number of independent interferometric measurements is studied. Reflection, rotation, and azimuthal symmetries are considered. In each case, the number of independent elements of the interferometric covariance matrix is derived, which puts an inherent limit on the number of scatterer parameters that can be estimated using single-baseline polarimetric interferometry. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Moghaddam, M (reprint author), CALTECH, Jet Prop Lab, MS 300-227,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 TC 4 Z9 4 U1 0 U2 0 PU VSP BV PI ZEIST PA PO BOX 346, 3700 AH ZEIST, NETHERLANDS SN 0920-5071 J9 J ELECTROMAGNET WAVE JI J. Electromagn. Waves Appl. PY 2000 VL 14 IS 2 BP 173 EP 184 DI 10.1163/156939300X00716 PG 12 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 296YT UT WOS:000086054900002 ER PT J AU Gyekenyesi, AL AF Gyekenyesi, AL TI Isothermal fatigue behavior and damage modeling of a high temperature woven PMC SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT International Gas Turbine and Aeroengine Congress and Exhibition CY JUN 02-05, 1998 CL STOCKHOLM, SWEDEN ID DEGRADATION; COMPOSITE AB This study focuses on the fully reversed fatigue behavior exhibited by a carbon fiber/polyimide resin woven laminate at room and elevated temperatures. Nondestructive video edge view microscopy and destructive sectioning techniques were used to study the microscopic damage I,mechanisms that evolved. The elastic stiffness was monitored and recorded throughout the fatigue life of the coupon. In addition, residual compressive strength rests were conducted on fatigue coupons with various degrees of damage as quantified by stiffness reduction. Experimental results indicated that the monotonic tensile properties were only minimally influenced by temperature, while the monotonic compressive and fully reversed fatigue properties displayed greater reductions due to the elevated temperature. The stiffness degradation, as a function of cycles, consisted of three stages; a short-lived high degradation period a constant degradation rate segment covering the majority of the life, and a final stage demonstrating an increasing rate of degradation up to failure. Concerning the residual compressive strength tests at room and elevated temperatures, the elevated temperature coupons appeared much more sensitive to damage. At elevated temperatures, coupons experienced a much larger loss in compressive strength when compared to room temperature coupons with equivalent damage. The fatigue damage accumulation law proposed for the model incorporates a scalar representation for damage, but admits a multiaxial, anisotropic evolutionary law. The model predicts the current damage (as quantified by residual stiffness) and remnant life of a composite that has undergone a known load at temperature. The damage/life model is dependent oil the applied multiaxial stress state as well as temperature. Comparisons between the model and data showed good predictive capabilities concerning stiffness degradation and cycles to failure. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Gyekenyesi, AL (reprint author), NASA, Glenn Res Ctr, MS 6-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 8 TC 1 Z9 1 U1 1 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD JAN PY 2000 VL 122 IS 1 BP 62 EP 68 DI 10.1115/1.483176 PG 7 WC Engineering, Mechanical SC Engineering GA 281PH UT WOS:000085169500010 ER PT J AU Sogard, SM Olla, BL AF Sogard, SM Olla, BL TI Endurance of simulated winter conditions by age-0 walleye pollock: effects of body size, water temperature and energy stores SO JOURNAL OF FISH BIOLOGY LA English DT Article DE temperature stress; starvation; overwinter mortality; fish condition; lipids ID THERAGRA-CHALCOGRAMMA PALLAS; PERCH PERCA-FLAVESCENS; VERTICAL-DISTRIBUTION; MENIDIA-MENIDIA; RAINBOW-TROUT; YELLOW PERCH; ATLANTIC SILVERSIDE; OVERWINTER SURVIVAL; SEASONAL-CHANGES; SOCKEYE-SALMON AB Survival of age-0 walleye pollock Theragra chalcogramma in the absence of food followed simple bioenergetic models, with large body size, high initial condition, and cold temperatures all increasing survival rates. High survival after >200 days at cold temperatures (<3.0 degrees C) indicated extended tolerance of extreme cold, as long as sufficient body size and condition are attained during the summer growth period. Analysis of body constituents demonstrated a substantial increase in tissue water and depletion of lipid during starvation. Survivors had significantly higher lipid stores than mortalities, and larger fish had higher levels of lipid than smaller fish among experimental survivors, laboratory fish that were never starved, and wild fish. Fish returned to warm temperatures and high rations following 205 days of food deprivation displayed nearly complete recovery, with rapid increases in length, weight, and condition and minimal mortality (6.8%) during the subsequent 3 months. Age-0 walleye pollock collected in September in the Bering Sea were substantially smaller and generally had lower lipid levels than fish used in laboratory starvation experiments, suggesting they are susceptible to size- and condition-dependent mortality during the winter. The results are interpreted with respect to field distributions of age-0 walleye pollock, overwinter survival, and synergistic effects of food and temperature under varying models of climate change. (C) 2000 The Fisheries Society of the British Isles. C1 Oregon State Univ, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. RP Sogard, SM (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA. EM susan.sogard@hmsc.orst.edu NR 62 TC 80 Z9 82 U1 6 U2 26 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD JAN PY 2000 VL 56 IS 1 BP 1 EP 21 PG 21 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 279FX UT WOS:000085034700001 ER PT J AU McDonald, FB Heikkila, B Lal, N Stone, EC AF McDonald, FB Heikkila, B Lal, N Stone, EC TI The relative recovery of galactic and anomalous cosmic rays in the distant heliosphere: Evidence for modulation in the heliosheath SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID WIND TERMINATION SHOCK; OUTER HELIOSPHERE; SOLAR-WIND; DECREASES; INTENSITY; GRADIENT; BOUNDARY; VOYAGER AB At Voyager 1 (46 AU, 33 degrees N) the recovery of anomalous cosmic rays (ACR) is found to be very different from that of galactic cosmic rays (GCR) following the passage of the large interplanetary disturbances produced by the intensive solar activity of March/June 1991. If the modulation boundary for the GCR were at the termination shock, where anomalous cosmic rays are believed to originate, it would be expected that the intensity of the higher-energy galactic cosmic rays would recover more rapidly than the relatively low energy anomalous component. On the contrary, we find that the time constant for the recovery of 265 MeV/nucleon GCR He is approximately twice as large as that of 43 MeV/nucleon ACR He+ and 13 MeV/nucleon O+. A regression plot of the ACR versus GCR intensity indicates a broad plateau in the ACR intensity over a period of several years while the GCR continues to increase. These differences in the relative recovery of the ACR and GCR strongly suggest that the combined interplanetary disturbances in the form of a global merged interaction region (GMIR) produced by the March/June 1991 solar activity remain an effective modulation agent for GCR after passing beyond the termination shock and into the region of the heliosheath. Some 0.37 years after the passage of the leading portion of the GMIR by Voyager 1, there is a large anisotropy in the ACR He+. One possible interpretation of this anisotropy is that it is produced by the initial flow of the ACR back into the heliosphere at the time that the leading portion of the interplanetary disturbance moves beyond the termination shock. If this interpretation is correct, then the inferred transit time between Voyager 1 and the termination shock of the GMIR along with an estimate of its velocity at 40 AU based on similar features in the Voyager 1 and Pioneer 11 energetic particle data give a value of the heliocentric distance to the termination shock of 88.5 +/- 7 AU at similar to 33 degrees N in early 1992. C1 Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Pasadena, CA 91109 USA. RP McDonald, FB (reprint author), Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. NR 35 TC 37 Z9 37 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 2000 VL 105 IS A1 BP 1 EP 8 DI 10.1029/1999JA900372 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 275AF UT WOS:000084796700001 ER PT J AU Gazis, PR AF Gazis, PR TI A large-scale survey of corotating interaction regions and their successors in the outer heliosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MERGED INTERACTION REGIONS; COSMIC-RAY MODULATION; LARGE HELIOCENTRIC DISTANCES; WIND PLASMA OBSERVATIONS; QUASI-STEADY DYNAMICS; SOLAR-WIND; AU; EVOLUTION; ACCELERATION; ENHANCEMENTS AB Corotating interaction regions (CIRs) and their successors play an important role in the structure and dynamics of the outer heliosphere. CIRs, consisting of a forward and reverse shock pair in association with a region of enhanced solar wind density and temperature, are a dominant structure in the solar wind at low heliographic latitudes at heliocentric distances between 2 and 8 AU. At larger heliocentric distances, CIRs spread, merge, and interact to form merged interaction regions (MIRs). MIRs are a dominant structure at low latitudes between 8 and 12 AU. At even larger heliocentric distances, considerable uncertainty remains regarding the small-scale structure of the solar wind. Solar wind and interplanetary magnetic field observations from the Pioneer 10 and Voyager 2 spacecraft were used to conduct a large-scale survey of CIRs and their successors over solar cycles 21 and 22 between heliocentric distances of 1 and 50 AU to categorize changes that occur as CIRs were convected outward from the Sun. At heliocentric distances less than 37 AU, similar changes were observed at similar heliocentric distances at different spacecraft during different portions of the solar cycle. These changes may reflect qualitative changes in the dynamics of the solar wind as CIRs spread and merge and the flux of kinetic energy available in solar wind streams declines with respect to the flux of thermal energy. At heliocentric distances greater than 37 AU, Pioneer 10 and Voyager 2 observed different types of structure. Interpretation of these differences is complicated by differences in the trajectories of the two spacecraft, and it remains to be determined whether they are associated with latitudinal gradients, solar cycle variations or the effects of interstellar pickup ions at Voyager 2. C1 San Jose State Univ Fdn, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Gazis, PR (reprint author), San Jose State Univ Fdn, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 37 TC 9 Z9 9 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 2000 VL 105 IS A1 BP 19 EP 33 DI 10.1029/1999JA900352 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 275AF UT WOS:000084796700003 ER PT J AU Desai, MI Mason, GM Dwyer, JR Mazur, JE von Rosenvinge, TT Lepping, RP AF Desai, MI Mason, GM Dwyer, JR Mazur, JE von Rosenvinge, TT Lepping, RP TI Characteristics of energetic (greater than or similar to 30 keV/nucleon) ions observed by the Wind/STEP instrument upstream of the Earth's bow shock SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETIC-FIELD; WIND SPACECRAFT; MAGNETOSPHERIC ORIGIN; FAR UPSTREAM; OCTOBER 31; HEAVY-IONS; ACCELERATION; EVENTS; PLASMA; SPECTRA AB We investigate here the characteristics of energetic ions (0.03-2.0 MeV/nucleon) during 1225 upstream events observed by the Energetic Particles: Anisotropy, Composition, and Transport/Suprathermal Energetic Particle (EPACT/STEP) instrument on board the Wind spacecraft from 1994 day 325 to 1999 day 92. We find that (1) the event occurrence rate showed significant variations with changes in the solar cycle, (2) the occurrence rate increased when both the solar wind speed and the geomagnetic activity index were enhanced, (3) most events were observed within +/-80 R-E in Y-GSE and inside similar to 100 R-E in X-GSE, although the events occurred at all locations of the Wind orbit, (4) similar to 73% of the events were observed when the interplanetary magnetic field was radial and in the ecliptic plane, and when the spacecraft was most likely magnetically connected to the bow shock, (5) the events lasted typically between 10 min to 3 hours and exhibited strong sunward field-aligned flow, (6) similar to 25% of the ion events were accompanied by 20-48 keV electrons as measured by the Wind/3DP instrument, (7) the energy spectra 100-300 keV protons and 30-300 keV/nucleon He-Fe during similar to 70% of the events obeyed power laws with gamma between 3 and 5, while the energy spectra of He and CNO for similar to 30% of the events softened above similar to 80 keV/nucleon obeyed power laws with gamma similar to 3-5, (8) the total energy ion spectrum above similar to 0.5 MeV energy was dominated by heavier ions during the events, (9) a substantial fraction (greater than or similar to 40%) of the spectra for all species extended above similar to 150 keV/e, and (10) the heavy ion composition of the events was similar to typical solar wind values. We compare the above findings with the main predictions of the magnetospheric leakage and the Fermi acceleration models and find that neither model can satisfactorily account for our results. We highlight the new challenges and requirements for both models. C1 Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Aerospace Corp, Los Angeles, CA 90009 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. RP Desai, MI (reprint author), Univ Maryland, Dept Phys, College Pk, MD 20742 USA. NR 55 TC 37 Z9 37 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 2000 VL 105 IS A1 BP 61 EP 78 DI 10.1029/1999JA900406 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 275AF UT WOS:000084796700006 ER PT J AU Sibeck, DG Phan, TD Lin, RP Lepping, RP Mukai, T Kokubun, S AF Sibeck, DG Phan, TD Lin, RP Lepping, RP Mukai, T Kokubun, S TI A survey of MHD waves in the magnetosheath: International Solar Terrestial Program observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ALFVEN WAVES; WIND; MAGNETOPAUSE AB We present case and statistical studies of magnetohydrodynamic (MHD) fluctuations observed by the Wind and Geotail spacecraft in the Earth's dawn and dusk magnetosheath. A case study with simultaneous IMP 8 interplanetary magnetic field observations confirms theoretical predictions that most of the fluctuations originate in the solar wind rather than at the magnetopause and that the fluctuations can be almost absent from the outer magnetosheath. A second case study indicates that northward plasma velocity perturbations observed in the prenoon magnetosheath correspond to southward velocity perturbations in the postnoon magnetosheath, implying that the MHD perturbations apply a torque to the magnetosphere. A statistical survey reveals that the fluctuations almost invariably propagate antisunward in the magnetosheath, independent of their propagation direction relative to the interplanetary magnetic field. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Space & Aeronaut Sci, Kanagawa 229, Japan. Nagoya Univ, Solar Terr Environm Lab, Aichi 422, Japan. RP Sibeck, DG (reprint author), Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. RI Sibeck, David/D-4424-2012 NR 12 TC 21 Z9 21 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 2000 VL 105 IS A1 BP 129 EP 137 DI 10.1029/1999JA900433 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 275AF UT WOS:000084796700010 ER PT J AU Gjerloev, JW Hoffman, RA AF Gjerloev, JW Hoffman, RA TI Height-integrated conductivity in auroral substorms - 1. Data SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID NIGHTTIME SECTOR; ELECTRIC-FIELDS; ENERGY; PRECIPITATION; PARAMETERS; DYNAMICS; EISCAT; IMAGES; RADAR AB We present height-integrated Hall and Pedersen conductivity (conductance) calculations from 31 individual Dynamics Explorer 2 (DE 2) substorm crossings. All are northern hemisphere (except one) nighttime passes which took place from September 1981 to January 1982. Global auroral images are used to select substorms which display a typical bulge-type auroral emission pattern and to organize the position of individual DE 2 passes with respect to key features in the emission pattern. The Hall and Pedersen conductances are calculated from electron precipitation data obtained by the low altitude plasma instrument (LAPI) carried on DE 2 and the monoenergetic conductance model by Reiff [1984]. This method is shown to effectively minimize undesirable smearing of parameters in statistical substorm studies. Large spatial gradients in the conductance profiles are common in high-latitude part of the premidnight substorm region. The conductances maximizes in the high-latitude part of the surge with average Hall and Pedersen conductances of 38 and 18 mho respectively. During six different DE 2 passes we found Hall conductance peaks exceeding 100 mho in the high-latitude part of the surge or surge hem. These peaks are highly localized with a typical scale size of similar to 20 km and are associated with energetic (>10 keV) inverted V events. Except in the low-latitude part of the auroral oval the Hall to Pedersen ratio equals or exceeds 1.0, and it peaks in the high-latitude part of the surge where values of 3 or more are common. The latitudinal conductance profiles are strongly asymmetric and have a pronounced local time dependency. C1 NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gjerloev, JW (reprint author), Danish Space Res Inst, Juliane Maries Vej 30, DK-2100 Copenhagen OE, Denmark. NR 24 TC 22 Z9 22 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 2000 VL 105 IS A1 BP 215 EP 226 DI 10.1029/1999JA900354 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 275AF UT WOS:000084796700017 ER PT J AU Gjerloev, JW Hoffman, RA AF Gjerloev, JW Hoffman, RA TI Height-integrated conductivity in auroral substorms - 2. Modeling SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TWO-DIMENSIONAL OBSERVATIONS; WESTWARD TRAVELING SURGE; ELECTRIC-FIELDS; NIGHTTIME SECTOR; ZONE CURRENTS; ENERGY FLUX; PRECIPITATION; PARAMETERS; IMAGES AB Calculations of height-integrated conductivity from 31 individual Dynamics Explorer (DE 2) substorm crossings presented by Gjerloev and Hoffman [this issue] are used to compile empirical models of the height-integrated Pedersen and Hall conductivities (conductances) in a bulge-type auroral substorm. Global auroral images obtained by Dynamics Explorer 1 (DE 1) were used to select substorms displaying a typical bulge-type emission pattern and each individual DE 2 pass was positioned with respect to key features in the observed emission pattern. The conductances were calculated for each DE 2 pass using electron precipitation data and a monoenergetic conductance model. All passes were divided into six different sectors, and average conductance profiles were carefully deduced for each of these sectors. Using a simple boxcar filter, smoothed average sector passes were calculated and from linear interpolation between these, two-dimensional conductance models were compiled. The characteristics of our models are (1) the Hall conductance maximizes in the high-latitude part of the surge at 48 mho with a Hall to Pedersen ratio of 2.4; (2) two channels of enhanced conductance are overlapping in local time near midnight and are fairly separated in latitude; (3) the conductance has a sharp gradient at the high-latitude boundary in the premidnight sector while in the postmidnight sector a broad region of low conductance stretches up to 10 degrees invariant latitude poleward of the local peak; and finally, (4) the enhanced conductance region displays a characteristic broadening toward dawn primarily owing to a poleward shift of the high-latitude boundary. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Gjerloev, JW (reprint author), Danish Space Res Inst, Copenhagen, Denmark. NR 22 TC 14 Z9 14 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 2000 VL 105 IS A1 BP 227 EP 235 DI 10.1029/1999JA900353 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 275AF UT WOS:000084796700018 ER PT J AU Blanchard, GT Lyons, LR Spann, J AF Blanchard, GT Lyons, LR Spann, J TI Predictions of substorms following northward turnings of the interplanetary magnetic field SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERIC SUBSTORMS; SOLAR-WIND AB Substorms are often observed to occur when the interplanetary magnetic field (IMF) turns northward at the end of intervals of southward IMF. Despite the significant correlation between northward turnings and substorms, a direct causal relationship between northward turnings and substorms has not been demonstrated. If such a causal relationship exists, then we should be able to predict that substorms will occur within a particular interval following the observation of a northward turning in the IMF. We have searched Wind IMF data and identified 16 strong northward turnings that following intervals of steady, southward IMF. To enhance the chances that the selected northward turnings impacted the magnetosphere, we required that each of them be also observed at either Geotail or IMP 8 while the separation of the second spacecraft from Wind was more that 10 R-E in the y direction. Additionally, we required that either the second satellite was on the opposite side of the y = 0 plane from Wind or that one of the satellites was near y = 0. These two spacecraft observations also allowed us to more accurately predict the arrival times of the northward turnings at the Earth than we could by using data only from one spacecraft. Of the predicted substorms, 10 predictions were clearly successful to within +/-8 min, Five predictions failed, but these failures reveal important new criteria that must be satisfied for a northward turning to cause a substorm. Three of the failures were caused by an increase in \B-YGSM\ that occurred simultaneously with the northward turning. This suggests that the triggering is associated with sharp reductions in the magnetospheric electric field, since increases in \B-YGSM\ negate the convection reduction associated with northward turnings. Two of the failures occurred for cases with the weakest southward IMF preceding the northward turning, which improves our criteria for the strength of the southward IMF that must precede a substorm. The final northward turning resulted in unusual auroral activity. These results establish the predictability of substorms following sharp northward turnings of the IMF and demonstrate that a direct causal relationship between northward turnings and substorm onset exists. C1 SE Louisiana Univ, Dept Chem & Phys, Hammond, LA 70402 USA. Univ Calif Los Angeles, Dept Atmospher Sci, Los Angeles, CA 90095 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Directorate, Space SCi Dept SD50, Huntsville, AL 35812 USA. RP Blanchard, GT (reprint author), SE Louisiana Univ, Dept Chem & Phys, SLU 10878, Hammond, LA 70402 USA. NR 16 TC 22 Z9 22 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 1 PY 2000 VL 105 IS A1 BP 375 EP 384 DI 10.1029/1999JA900448 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 275AF UT WOS:000084796700031 ER PT J AU Bamber, JL Hardy, RJ Joughin, I AF Bamber, JL Hardy, RJ Joughin, I TI An analysis of balance velocities over the Greenland ice sheet and comparison with synthetic aperture radar interferometry SO JOURNAL OF GLACIOLOGY LA English DT Article ID STEADY-STATE; GLACIER; FLOW; DYNAMICS; MOTION; MODEL AB Balance velocities for the Greenland ice sheet have been calculated from a new digital elevation model (DEM), accumulation rates and an existing ice-thickness grid, using a fully two-dimensional finite-difference scheme. The pattern of velocities is compared with velocities derived from synthetic-aperture radar (SAR) interferometry for three different regions of the ice sheet. Differences between the two estimates of velocity highlight the respective strengths and weaknesses of the datasets and techniques used. A comparison with ten global positioning system-derived velocities indicates that the balance-velocity scheme and input datasets used here provide a remarkably good representation of the velocity distribution inland from the margins. These balance-velocity data, therefore, could help constrain numerical ice-sheet models. The balance velocities were found to be unreliable dose to the ice-sheet margins due to larger errors in ice thickness, surface slope and ablation rate in this region. Comparison of the balance velocities with SAR interferometry in the region of the "Northeast Greenland Ice Stream" indicates the importance of the smoothing distance that must be applied to the DEM before calculating balance velocities. A smoothing distance of 20 times the ice thickness gave good agreement between the two measures of velocity. C1 Univ Bristol, Sch Geog Sci, Glaciol Ctr, Bristol, Avon, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Univ Bristol, Sch Geog Sci, Glaciol Ctr, Bristol, Avon, England. RI Joughin, Ian/A-2998-2008; Bamber, Jonathan/C-7608-2011 OI Joughin, Ian/0000-0001-6229-679X; Bamber, Jonathan/0000-0002-2280-2819 NR 24 TC 39 Z9 39 U1 0 U2 6 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 EI 1727-5652 J9 J GLACIOL JI J. Glaciol. PY 2000 VL 46 IS 152 BP 67 EP 74 DI 10.3189/172756500781833412 PG 8 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 320UX UT WOS:000087419700010 ER PT J AU Bindschadler, R Chen, X Vornberger, P AF Bindschadler, R Chen, X Vornberger, P TI The onset area of Ice Stream D, West Antarctica SO JOURNAL OF GLACIOLOGY LA English DT Article ID SATELLITE IMAGERY; FLOW; VELOCITY; DYNAMICS; MARGINS AB Surface flow in a 10 000 km(2) expanse of the onset area of Ice Stream D, West Antarctica, was measured by repeat, precise global positioning system surveys over a 1 year interval. The pattern of velocity and strain rate shows the development of Ice Stream D, the major flow into which originates south of Byrd station and follows the course of a deep bed channel. Plotting of the driving stress vs the ratio of velocity and ice thickness identifies the onset of streaming flow (roughly 140 km downstream of Byrd station) as a transition between deformation flow and sliding now Along the kinematic center line of the developing ice stream, the ice rheology is linear at stresses below 0.6 bar, and appears temperate at the base well before the onset of streaming is reached. The onset corresponds to a maximum driving stress of 0.8 bar. It occurs downstream of a slight increase in longitudinal strain rate where stronger along-flow lineations are apparent in Landsat imagery and after the ice has passed the center of an overdeepening in the bed channel. No current deviation from equilibrium is detected in this region, but a set of flow stripes misaligned with present flow indicates significant changes in flow have occurred in the past. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Gen Sci Corp, Laurel, MD 20727 USA. RP Bindschadler, R (reprint author), NASA, Goddard Space Flight Ctr, Code 971, Greenbelt, MD 20771 USA. NR 36 TC 13 Z9 13 U1 0 U2 4 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2000 VL 46 IS 152 BP 95 EP 101 DI 10.3189/172756500781833377 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 320UX UT WOS:000087419700013 ER PT J AU Rignot, E Buscarlet, G Csatho, B Gogineni, S Krabill, W Schmeltz, M AF Rignot, E Buscarlet, G Csatho, B Gogineni, S Krabill, W Schmeltz, M TI Mass balance of the northeast sector of the Greenland ice sheet: a remote-sensing perspective SO JOURNAL OF GLACIOLOGY LA English DT Article ID SATELLITE-RADAR INTERFEROMETRY; HINGE-LINE MIGRATION; ENERGY-BALANCE; PETERMANN-GLETSCHER; ABLATION; FLOW AB Synthetic-aperture radar interferometry data and airborne ice-sounding radar (ISR) data are employed to obtain modern estimates of the inland ice production from Nioghalvfjerdsbrae (NB) and Zachariae Isstrom (ZI), the two largest glaciers draining the northeast sector of the Greenland ice sheet. Ice fluxes are measured at the grounding line (14.2 +/- 1 km(3) ice a(-1) for NB and 10.8 +/- 1 km(3) ice a(-1) for ZI) with an ice thickness deduced from ice-shelf hydrostatic equilibrium, and along an ISR profile collected upstream of the grounding line (14.3 +/- 0.7 km(3) ice a(-1) for NB and 11.6 +/- 0.6 km(3) ice a(-1) for ZI). Balance fluxes calculated from a map of snow accumulation and model predictions of surface melt are 11.9 +/- 2 km(3) ice a(-1) for NB and 10.0 +/- 2 km(3) ice a(-1) for ZI at the grounding line, and 12.2 and 10.3 km(3) ice a(-1), respectively, at the ISR line. The two glaciers therefore exhibit a negative mass balance equivalent to 14% of their balance flux, with a +/-12% uncertainty. Independently, we detect a retreat of the grounding line of NB between 1992 and 1996 which is larger at the glacier center (920 +/- 250 m) than on the sides (240 +/- 50 m). The corresponding ice-thinning rates (2 +/- 1 m a(-1) at the glacier center and 0.6 +/- 0.3 m a(-1) on the sides) are too large to be accommodated by temporal changes in ablation or accumulation, and must be due to dynamic thinning. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Ohio State Univ, Byrd Polar Res Ctr, Columbus, OH 43210 USA. Univ Kansas, Radar Syst & Remote Sensing Lab, Lawrence, KS 66045 USA. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Lab Hydrospher Proc, Wallops Island, VA 23337 USA. RP Rignot, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Rignot, Eric/A-4560-2014 OI Rignot, Eric/0000-0002-3366-0481 NR 32 TC 8 Z9 8 U1 0 U2 2 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2000 VL 46 IS 153 BP 265 EP 273 DI 10.3189/172756500781832972 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 369CH UT WOS:000090153900011 ER PT J AU Hall, DK Williams, RS Barton, JS Sigurdsson, O Smith, LC Garvin, JB AF Hall, DK Williams, RS Barton, JS Sigurdsson, O Smith, LC Garvin, JB TI Evaluation of remote-sensing techniques to measure decadal-scale changes of Hofsjokull ice cap, Iceland SO JOURNAL OF GLACIOLOGY LA English DT Article ID SATELLITE RADAR INTERFEROMETRY; SYNTHETIC-APERTURE RADAR; GLACIER FACIES; SAR DATA; SURFACE-PROPERTIES; SHEET; ERS-1; IMAGERY; MODEL AB Dynamic surficial changes and changes in the position of the firn line and the areal extent of Hofsjokull ice cap, Iceland, were studied through analysis of a time series (1973-98) of synthetic-aperture radar (SAR) and Landsat data. A digital elevation model of Hofsjokull, which was constructed using SAR interferometry, was used to plot the SAR backscatter coefficient (sigma degrees) vs elevation and air temperature along transects across the ice cap. Seasonal and daily sigma degrees patterns are caused by freezing or thawing of the ice-cap surface, and abrupt changes in sigma degrees are noted when the air temperature ranges from similar to -5 degrees to 0 degreesC. Late-summer 1997 sigma degrees (SAR) and reflectance (Landsat) boundaries agree and appear to be coincident with the firn line and a SAR sigma degrees boundary that can be seen in the January 1998 SAR image. In January 1994 through 1998, the elevation of this sigma degrees boundary on the icecap was quite stable, ranging from 1000 to 1300 m, while the equilibrium-line altitude, as measured on the ground, varied considerably. Thus the equilibrium line may be obscured by firn from previous years. Techniques are established to measure long-term changes in the elevation of the firn line and changes in the position of the ice margin. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. US Geol Survey, Woods Hole Field Ctr, Woods Hole, MA 02543 USA. Gen Sci Corp, Beltsville, MD 20705 USA. Natl Energy Author, IS-108 Reykjavik, Iceland. Univ Calif Los Angeles, Dept Geog, Los Angeles, CA 90095 USA. NASA, Goddard Space Flight Ctr, Geodynam Branch, Greenbelt, MD 20771 USA. RP Hall, DK (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Code 974, Greenbelt, MD 20771 USA. RI Hall, Dorothy/D-5562-2012; Smith, Laurence/E-7785-2012 OI Smith, Laurence/0000-0001-6866-5904 NR 53 TC 17 Z9 17 U1 4 U2 11 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2000 VL 46 IS 154 BP 375 EP 388 DI 10.3189/172756500781833061 PG 14 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 384CC UT WOS:000165920700003 ER PT J AU Scambos, TA Hulbe, C Fahnestock, M Bohlander, J AF Scambos, TA Hulbe, C Fahnestock, M Bohlander, J TI The link between climate warming and break-up of ice shelves in the Antarctic Peninsula SO JOURNAL OF GLACIOLOGY LA English DT Article ID VARIABILITY; RETREAT; SHEET; DISINTEGRATION; FRACTURE; GLACIERS; COLLAPSE; MARGINS; FIELD AB A review of in situ and remote-sensing data covering the ice shelves of the Antarctic Peninsula provides a series of characteristics closely associated with rapid shelf retreat: deeply embayed ice fronts; calving of myriad small elongate bergs: in punctuated events; increasing flow speed; and the presence of melt ponds on the ice-shelf surface in the vicinity of the break-ups. As climate has warmed in the Antarctic Peninsula region, melt-season duration and the extent of pending have increased. Most break-up events have occurred during longer melt seasons, suggesting that meltwater itself; not just warming, is responsible. Regions that show melting without pond formation are relatively unchanged. Melt ponds thus appear to be a robust harbinger of ice-shelf retreat. We use these observations to guide a model of ice-shelf flow and the effects of meltwater. Crevasses present in a region of surface pending will likely fill to the brim with water. We hypothesize (building on Weertman (1973), Hughes (1983) and Van der Veen (1998)) that crevasse propagation by meltwater is the main mechanism by which ice shelves weaken and retreat. A thermodynamic finite-element model is used to evaluate ice flow and the strain field, and simple extensions of this model are used to investigate crack propagation by meltwater. The model results support the hypothesis. C1 Univ Colorado, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. RP Scambos, TA (reprint author), Univ Colorado, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA. RI Scambos, Ted/B-1856-2009; Fahnestock, Mark/N-2678-2013 NR 51 TC 278 Z9 282 U1 9 U2 56 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2000 VL 46 IS 154 BP 516 EP 530 DI 10.3189/172756500781833043 PG 15 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 384CC UT WOS:000165920700018 ER PT J AU Fahnestock, MA Scambos, TA Bindschadler, RA Kvaran, G AF Fahnestock, MA Scambos, TA Bindschadler, RA Kvaran, G TI A millennium of variable ice flow recorded by the Ross Ice Shelf, Antarctica SO JOURNAL OF GLACIOLOGY LA English DT Article ID NET MASS-BALANCE; WEST ANTARCTICA; STREAM-B; SURFACE-TOPOGRAPHY; LANDSAT IMAGERY; SHEET; SYSTEM; RISE AB An enhanced composite Advanced Very High Resolution Radiometer (AVHRR) image is used to map flow stripes and rifts across the Ross Ice Shelf, Antarctica. The patterns of these flow-related features reveal a history of discharge variations from the ice streams feeding the eastern part of the shelf. The most profound variations are visible in the track of rifts downstream of Crary Ice Rise? flow-stripe bends to the west of this ice rise and adjacent to Steershead ice rise, and changes in the northern margin of Ice Stream B. The track of rifts downstream of Crary Ice Rise indicates that the ice rise has existed for at least 700 years. The character of this track changes about 350 km downstream, indicating a rearrangement of flow patterns about 550 years ago. The large bulge in the flow stripes to the west of Crary Ice Rise is shown in detail, with bent flow stripes extending for several hundred kilometers along flow; this feature formed from the south, possibly due to a change in the discharge of Ice Stream A. The AVHRR image documents a complex history associated with the shutdown of Ice Stream C: with changes in the margins of Ice Stream C and the northern margin of Ice Stream B, and the grounding of Steershead ice rise with an associated bending and truncation of flow stripes. Landsat imagery shows a region that appears to be actively extending just downstream of the ice rise, as the shelf continues to respond to recent chang es in ice-stream discharge. We present a four-stage flow history which accounts for the features preserved in the ice shelf. C1 Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. Univ Colorado, CIRES, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Fahnestock, MA (reprint author), Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. RI Scambos, Ted/B-1856-2009; Fahnestock, Mark/N-2678-2013 NR 41 TC 96 Z9 96 U1 0 U2 4 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2000 VL 46 IS 155 BP 652 EP 664 DI 10.3189/172756500781832693 PG 13 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 401QA UT WOS:000166938600011 ER PT J AU Kwok, R Siegert, MJ Carsey, FD AF Kwok, R Siegert, MJ Carsey, FD TI Ice motion over Lake Vostok, Antarctica: constraints on inferences regarding the accreted ice SO JOURNAL OF GLACIOLOGY LA English DT Article ID CENTRAL EAST-ANTARCTICA; RADAR INTERFEROMETRY; SUBGLACIAL LAKE; SHEET MOTION; TOPOGRAPHY AB Ice motion over Lake Vostok, Antarctica, is measured using repeat-pass synthetic-aperture radar (SAR) interferometry. The coverage of the lake and the components of the vector field are resolved using 10 overlapping data takes from ascending and descending look directions. Seventy-day temporal baselines provide the sensitivity required to observe the range of ice motion (0-6 m a(-1)) over the lake and the adjacent ice sheet. It is remarkable that the scattering field remained coherent over these time separations. This is critical for interferometric analysis and can be attributed to the low surface accumulation and low air temperature at this elevation. The regional flow of the ice sheet around Lake Vostok is from west to east, perpendicular to the surface elevation contours. As the ice flows past the grounding line, a southward component of motion develops that is correlated with the north-south surface slope along the length of the lake. The surface velocity increases slowly from the northern tip of the lake and then more rapidly south of 77 degrees S. At Vostok station, the ice motion is 4.2 m a(-1). Across the lake and away from boundary effects, the down-lake flow pattern takes on a parabolic profile with maximum velocity close to the center line of the lake. The overall influence of the subglacial lake is the addition of a down-lake motion component to the prevailing west-east motion of the ice sheet. As a result, we estimate 10 % of the mass flowing onto the lake is diverted south. Reconstructions based on the Vostok ice core indicate that the ice was grounded up-glacier from the core site approximately 5000 years ago. This suggests a minimum freezing rate of 40 mm a(-1) for the subglacial accretion ice, 10 times greater than that inferred from thermodynamic modeling of the upper 2 km of the ice core. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Bristol, Sch Geog Sci, Bristol Glaciol Ctr, Bristol BS8 1SS, Avon, England. RP Kwok, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Siegert, Martin/A-3826-2008; Kwok, Ron/A-9762-2008 OI Siegert, Martin/0000-0002-0090-4806; Kwok, Ron/0000-0003-4051-5896 NR 15 TC 36 Z9 39 U1 0 U2 1 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE CB2 1ER, ENGLAND SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 2000 VL 46 IS 155 BP 689 EP 694 DI 10.3189/172756500781832710 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 401QA UT WOS:000166938600014 ER PT J AU Hambaba, A AF Hambaba, A TI Robust hybrid architecture to signals from manufacturing and machine monitoring sensors SO JOURNAL OF INTELLIGENT & FUZZY SYSTEMS LA English DT Article ID NEURAL NETWORKS AB The design and implementation of effective control of manufacturing processes depends on the successful monitoring and recognition of process signals. In this paper, we describe an application of robust hybrid model to the prediction of plasma etcher outcome; etcher rate, selectivity, and uniformity. The robust hybrid model consists of two main architectures: robust model and recurrent neural network with real-time recurrent learning. The residual errors are used for the tuning of the weights of the recurrent neural network. The robust hybrid model's performance is compared to Ordinary Least-Square method, Alpha-trimmed mean, and Back-Propagation neural network. C1 NASA, Ames Res Ctr, NRC, Ames, IA USA. San Jose State Univ, Comp Informat & Syst Engn Dept, San Jose, CA 95192 USA. RP Hambaba, A (reprint author), NASA, Ames Res Ctr, NRC, Ames, IA USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 1064-1246 J9 J INTELL FUZZY SYST JI J. Intell. Fuzzy Syst. PY 2000 VL 9 IS 1-2 BP 29 EP 41 PG 13 WC Computer Science, Artificial Intelligence SC Computer Science GA 391GK UT WOS:000166348100003 ER PT J AU Smith, RC Ounaies, Z AF Smith, RC Ounaies, Z TI A domain wall model for hysteresis in piezoelectric materials SO JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES LA English DT Article ID FERROMAGNETIC HYSTERESIS; FERROELECTRIC HYSTERESIS; ACTUATORS AB This paper addresses the modeling of hysteresis and nonlinear constitutive relations in piezoelectric materials at moderate to high drive levels. Hysteresis and nonlinearities are due to the domain structure inherent to the materials and both aspects must be addressed to attain the full potential of the materials as sensors and actuators in high performance applications. The model employed here is based on previously developed theory for hysteresis in general ferroelectric materials. This theory is based on the quantification of the reversible and irreversible motion of domain walls pinned at inclusions in the material. This yields an ordinary differential equation (ODE) model having five parameters. The relationship of the parameters to physical attributes of the materials is detailed and algorithms for determining estimates of the parameters using measured values of the coercive field, differential susceptibility and saturation properties of the materials are detailed. The accuracy of the model and its capability for the prediction of measured polarization at various drive levels is illustrated through a comparison with experimental data from PZT5A, PZT5H and PZT4 compounds. Finally, the ODE model formulation is amenable to inversion which facilitates the construction of an inverse compensator for linear control design. C1 N Carolina State Univ, Dept Math, Ctr Res Sci Computat, Raleigh, NC 27695 USA. NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. RP Smith, RC (reprint author), N Carolina State Univ, Dept Math, Ctr Res Sci Computat, Box 8205, Raleigh, NC 27695 USA. NR 23 TC 48 Z9 51 U1 1 U2 6 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 1045-389X J9 J INTEL MAT SYST STR JI J. Intell. Mater. Syst. Struct. PD JAN PY 2000 VL 11 IS 1 BP 62 EP 79 DI 10.1177/104538900772664413 PG 18 WC Materials Science, Multidisciplinary SC Materials Science GA 413QK UT WOS:000167623100007 ER PT J AU Yao, XS Davis, L Maleki, L AF Yao, XS Davis, L Maleki, L TI Coupled optoelectronic oscillators for generating both RF signal and optical pulses SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article ID MICROWAVE; LASER AB We present experimental results of coupled optoelectronic oscillators (COEO) constructed with a semiconductor optical amplifier-based ring laser and a semiconductor colliding pulse mode-locked laser. Each COEO can simultaneously generate short optical pulses and spectrally pure radio frequency (RF) signals. With these devices, we obtained optical pulses as short as 6.2 ps and RF signals as high, infrequency, as 18.2 GHz with a spectral purity comparable with an HP83731B synthesizer. These experiments demonstrate that COEO's are promising compact sources for generating low jitter optical pulses and low phase noise RF/millimeter wave signals. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yao, XS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 68 Z9 71 U1 1 U2 11 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD JAN PY 2000 VL 18 IS 1 BP 73 EP 78 DI 10.1109/50.818909 PG 6 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA 279UA UT WOS:000085062500010 ER PT J AU Connell, JW Smith, JG Hergenrother, PM AF Connell, JW Smith, JG Hergenrother, PM TI Oligomers and polymers containing phenylethynyl groups SO JOURNAL OF MACROMOLECULAR SCIENCE-REVIEWS IN MACROMOLECULAR CHEMISTRY AND PHYSICS LA English DT Review ID IMIDE OLIGOMERS; MECHANICAL-PROPERTIES; CURE CHEMISTRY; POLYIMIDES; PENDENT; COMPOSITES; PETI-5; POLYPHENYLQUINOXALINES; ANHYDRIDES; ADHESIVE C1 NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. RP Connell, JW (reprint author), NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. NR 81 TC 56 Z9 59 U1 1 U2 14 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0736-6574 J9 J MACROMOL SCI R M C JI J. Macromol. Sci.-Rev. Macromol. Chem. Phys. PY 2000 VL C40 IS 2-3 BP 207 EP 230 PG 24 WC Polymer Science SC Polymer Science GA 341ZN UT WOS:000088621000005 ER PT J AU Subbarao, GV Wheeler, RM Stutte, GW Levine, LH AF Subbarao, GV Wheeler, RM Stutte, GW Levine, LH TI Low potassium enhances sodium uptake in red-beet under moderate saline conditions SO JOURNAL OF PLANT NUTRITION LA English DT Article ID MECHANISMS; TOLERANCE; CHANNELS; PLANTS; LEAVES AB Due to the discrepancy in metabolic sodium (Na) requirements between plants and animals, cycling of Na between humans and plants is limited and critical to the proper functioning of bio-regenerative life support systems, being considered for long-term human habitats in space (e.g., Martian bases). This study was conducted to determine the effects of limited potassium (K) on growth, Na uptake, photosynthesis, ionic partitioning, and water relations of red-beet (Beta vulgar is L. ssp. vulgaris) under moderate Na-saline conditions. Two cultivars, Klein Bol, and Ruby Queen were grown for 42 days in a growth chamber using a re-circulating nutrient film technique where the supplied K levels were 5.0, 1.25, 0.25, and 0.10 mM in a modified half-strength Hoagland solution salinized with 50 mM NaCl. Reducing K levels from 5.0 to 0.10 mM quadrupled the Na uptake, and lamina Na levels reached -20 g kg(-1) dwt. Lamina K levels decreased from -60 g kg(-1) dwt at 5.0 mM K to -4.0 g kg(-1) dwt at 0.10 mM K. Ruby Queen and Klein Bol responded differently to these changes in Na and K status. Klein Bol showed a linear decline in dry matter production with a decrease in available K, whereas for cv. Ruby Queen, growth was stimulated at 1.25 mM K and relatively insensitive to a further decreases of K down to 0.10 mM. Leaf glycinebetaine levels showed no significant response to the changing K treatments. Leaf relative water content and osmotic potential were significantly higher for both cultivars at low-K treatments. Leaf chlorophyll levels were significantly decreased at low-K treatments, but leaf photosynthetic rates showed no significant difference. No substantial changes were observed in the total cation concentration of plant tissues despite major shifts in the relative Na and K uptake at various K levels. Sodium accounted for 90% of the total cation uptake at the low K levels, and thus Na was likely replacing K in osmotic functions without negatively affecting the plant water status, or growth. Our results also suggest that cv. Ruby Queen can tolerate a much higher Na tissue concentration than cv. Klein Bol before there is any growth reduction. C1 Dynamac Corp, Kennedy Space Ctr, FL 32899 USA. NASA, Biomed Off, Kennedy Space Ctr, FL 32899 USA. RP Subbarao, GV (reprint author), Dynamac Corp, Kennedy Space Ctr, FL 32899 USA. NR 44 TC 15 Z9 16 U1 0 U2 8 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0190-4167 J9 J PLANT NUTR JI J. Plant Nutr. PY 2000 VL 23 IS 10 BP 1449 EP 1470 DI 10.1080/01904160009382114 PG 22 WC Plant Sciences SC Plant Sciences GA 369ZV UT WOS:000165098400007 PM 11594364 ER PT J AU Hixon, R Shih, SH Mankbadi, RR AF Hixon, R Shih, SH Mankbadi, RR TI Evaluation of boundary conditions for the gust-cascade problem SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA 2nd Theoretical Fluid Mechanics Meeting CY JUN 15-18, 1998 CL ALBUQUERQUE, NEW MEXICO SP Amer Inst Aeronaut & Astronaut ID HYPERBOLIC SYSTEMS; SCHEMES AB Using a high-order-accuracy finite difference time-domain algorithm, the acoustic scattering from a Rat-plate cascade is computed. Keeping the grid and time step fired, the effect of four different boundary conditions on the accuracy, stability, and convergence of the computed solution is compared. Although none of the boundary conditions tested gave a perfect solution, the Giles and perfectly matched layer boundary conditions performed well. C1 NASA, John H Glenn Res Ctr Lewis Field, Inst Computat Mech Propuls, Cleveland, OH 44135 USA. RP Hixon, R (reprint author), NASA, John H Glenn Res Ctr Lewis Field, Inst Computat Mech Propuls, Cleveland, OH 44135 USA. NR 28 TC 12 Z9 13 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 2000 VL 16 IS 1 BP 72 EP 78 DI 10.2514/2.5533 PG 7 WC Engineering, Aerospace SC Engineering GA 274LF UT WOS:000084766800011 ER PT J AU Dorney, DJ Ashpis, DE Halstead, DE Wisler, DC AF Dorney, DJ Ashpis, DE Halstead, DE Wisler, DC TI Study of boundary-layer development in a two-stage low-pressure turbine SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA 37th Aerospace Sciences Meeting CY JAN 11-14, 1999 CL RENO, NEVADA SP Amer Inst Aeronaut & Astronaut ID TRANSITION; TURBULENCE C1 Virginia Commonwealth Univ, Dept Engn Mech, Richmond, VA 23284 USA. NASA, John N Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. Gen Elect Aircraft Engines, Univ Strateg Alliances & Aero Technol Labs, Cincinnati, OH 45215 USA. RP Dorney, DJ (reprint author), Virginia Commonwealth Univ, Dept Engn Mech, POB 843015, Richmond, VA 23284 USA. OI Ashpis, David/0000-0003-4193-6174 NR 15 TC 4 Z9 4 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD JAN-FEB PY 2000 VL 16 IS 1 BP 160 EP 163 DI 10.2514/2.5550 PG 4 WC Engineering, Aerospace SC Engineering GA 274LF UT WOS:000084766800026 ER PT J AU Birnbaum, G Buechele, A Jiang, T Orton, GS Hadzibabic, Z John, GR AF Birnbaum, G Buechele, A Jiang, T Orton, GS Hadzibabic, Z John, GR TI Absorption in the troughs of the far infrared spectra of NH3 and mixtures of NH3 and H-2 SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID BANDS; SHAPE; TEMPERATURE; AMMONIA AB The absorption coefficients in the troughs between the J-multiplets of the far infrared rotation-inversion spectrum of NH3 and NH3 broadened by H-2 were measured at 296 K in the region from about 65-230 cm(-1). Wave numbers were selected in the troughs that are removed from nearby weak absorption lines, and measurements of the absorption versus the density of NH3 and of H-2 verified that the absorption was due to the wings of distant rather than nearby spectral lines. These measurements were compared with computations of the absorption arising from binary collisions of NH3-NH3 and NH3-H-2 for uncoupled Lorentz lines. Except at the lowest and highest frequencies, the measured continuum absorption in the troughs was less than the computed absorption, a discrepancy that increased with increasing frequency. An improved representation of the measured absorption was obtained by fitting the Rosenkrantz line shape with the Ben-Reuven formulation of the line coupling coefficient of the inversion J-doublets. The application of these results to the spectrum of Jupiter shows clear differences between the spectrum of the above model and the Lorentz line shape, with the largest differences occurring in the dearest troughs. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Catholic Univ Amer, Vitreous State Lab, Washington, DC 20064 USA. CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Birnbaum, G (reprint author), Natl Inst Stand & Technol, 100 Bur Dr,Stop 8500, Gaithersburg, MD 20899 USA. RI Hadzibabic, Zoran/B-8102-2011 OI Hadzibabic, Zoran/0000-0002-0118-9285 NR 29 TC 11 Z9 11 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JAN PY 2000 VL 64 IS 1 BP 47 EP 65 DI 10.1016/S0022-4073(99)00008-4 PG 19 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 236HT UT WOS:000082594700006 ER PT J AU Moreau, G Boissoles, J Boulet, C Tipping, RH Ma, Q AF Moreau, G Boissoles, J Boulet, C Tipping, RH Ma, Q TI Theoretical study of the collision-induced fundamental absorption spectra of O-2-O-2 pairs for temperatures between 193 and 273 K SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID INFRARED-SPECTRA; N2-N2 PAIRS; N-2; MOLECULES; O-2; POLARIZABILITIES; H-2; O2; COEFFICIENTS; MOMENTS AB A theoretical analysis of the collision-induced fundamental absorption spectra of O-2-O-2 pairs is presented for temperatures between 193 and 273 K. Most of the absorption arises from the long-range quadrupole and hexadecapole-induced dipole mechanisms for which accurate matrix elements are available from various other experimental measurements or from ab initio calculations. The line shape used is that obtained from quantum computations of the far infrared collision-induced absorption of N-2, modified to include dips resulting from the effects of intercollisional interference. Several refinements, including contributions from back-reaction and short-range induced-dipole moments, can improve the agreement in certain spectral regions but do not lead to significant improvement in the global fits to the experimental data. The small structural features superimposed on the smooth continuum can be modeled by the modified line shape but the half-widths of the dips have a density dependence inconsistent with that arising from interference. On the other hand, difference spectra obtained by subtracting the theoretical results from the experimental data appear quite similar to those obtained previously at low temperatures, leading to the conclusion that this structure is due to dimers. Further experimental results at higher temperatures and for O-2-N-2 pairs would be useful to validate this interpretation. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Univ Rennes 1, Unite Mixte Rech PALMS, F-35042 Rennes, France. Univ Paris Sud, CNRS, Lab Phys Mol & Applicat, F-91405 Orsay, France. Columbia Univ, Dept Appl Phys, New York, NY USA. NASA, Goddard Space Flight Ctr, Inst Space Studies, New York, NY 10025 USA. RP Tipping, RH (reprint author), Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. NR 37 TC 20 Z9 20 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JAN PY 2000 VL 64 IS 1 BP 87 EP 107 DI 10.1016/S0022-4073(98)00141-1 PG 21 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 236HT UT WOS:000082594700009 ER PT J AU Mital, SK Murthy, PLN AF Mital, SK Murthy, PLN TI Quantifying uncertainties in the thermo-mechanical properties of particulate reinforced composites SO JOURNAL OF REINFORCED PLASTICS AND COMPOSITES LA English DT Article DE modulus; composite mechanics; thermal conductivity; thermal expansion coefficient AB Recently, there has been a growing interest in the use of particulate reinforced composites in a wide variety of applications. Particle reinforced composites are candidate materials for structures where shock or impact loading is expected. The ICAN (Integrated Composites Analyzer) computer code developed at NASA-Glenn Research Center has been modified to include micromechanics equations for particle reinforced composites. In this work, the simplified micromechanics of particulate reinforced composites and a fast probability integration (FPI) technique have been used to obtain the probabilistic composite behavior of a Al/SiCp (silicon carbide particles in aluminum matrix) composite. The probability density functions for composite moduli, thermal expansion coefficient and thermal conductivities along with their sensitivity factors are computed. The effect of different assumed distributions in constituent properties and the effect of reducing scatter in input random variable on a select composite property-namely the thermal expansion coefficient are also evaluated. The variations in the constituent properties that directly effect these composite properties are accounted for by assumed probabilistic distributions. The results show that the present technique provides valuable information about the scatter in composite properties and sensitivity factors, which are useful to test or design engineers. C1 Univ Toledo, Toledo, OH 43606 USA. NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. RP Mital, SK (reprint author), NASA, John H Glenn Res Ctr, Mail Sop 49-7, Cleveland, OH 44135 USA. NR 5 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 SN 0731-6844 J9 J REINF PLAST COMP JI J. Reinf. Plast. Compos. PY 2000 VL 19 IS 8 BP 657 EP 678 DI 10.1106/U001-XLT4-1D60-77MQ PG 22 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA 315LA UT WOS:000087114200004 ER PT J AU Zoby, EV AF Zoby, EV TI Journal support SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Editorial Material C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Zoby, EV (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2000 VL 37 IS 1 BP 1 EP 1 PG 1 WC Engineering, Aerospace SC Engineering GA 285EB UT WOS:000085375800001 ER PT J AU Gatsonis, NA Nanson, RA LeBeau, GJ AF Gatsonis, NA Nanson, RA LeBeau, GJ TI Simulations of cold-gas nozzle and plume flows and flight data comparisons SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID PRESSURE AB The nozzle and plume flows of small cold-gas attitude control thrusters, plume interactions with spacecraft surfaces, and the induced pressure environment are investigated numerically. The motivation for this study originates from pressure measurements that exhibited nonperiodic pulses during the firings of small cold-gas thrusters onboard a suborbital spacecraft. Pitch, yaw, and roll cold-gas thrusters were located on the 0.56-m-diam base of the spacecraft. The conical spacecraft flew at altitudes between 670 and 1200 km and carried inside a pressure sensor connected to the side surface with a tube. Predictions of the pressure inside the sensor chamber are obtained using a semi-analytical model with inputs from coupled continuum and kinetic simulations. The nozzle and plume flows for each thruster are simulated using a three-dimensional Navier-Stokes solver until breakdown. Flowfield properties inside the breakdown surface are used as inputs to the direct simulation Monte Carlo calculations in a domain that includes the spacecraft geometry. Flowfield properties at the entrance of the sensor tube are used as inputs to an analytical model to obtain the pressure inside the sensor chamber. Simulations show plume expansion, reflection off the spacecraft surfaces, and backflow Pressure predictions for the pitch and yaw thruster plumes that reach the sensor after expanding on the spacecraft base are in very good agreement with measurements. Pressure induced by the roll thrusters is shown to be very sensitive to their radial position at the Environmental Monitor Package base and decreases with decreasing radial distance. Pressure overprediction of the roll thrusters is attributed to possible difference between the simulated and actual radial position. C1 Worcester Polytech Inst, Dept Mech Engn, Computat Gas & Plasma Dynam Lab, Worcester, MA 01609 USA. NASA, Lyndon B Johnson Space Ctr, Aerosci & Flight Mech Div EG3, Houston, TX 77058 USA. RP Gatsonis, NA (reprint author), Worcester Polytech Inst, Dept Mech Engn, Computat Gas & Plasma Dynam Lab, 100 Inst Rd, Worcester, MA 01609 USA. NR 24 TC 9 Z9 11 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2000 VL 37 IS 1 BP 39 EP 48 DI 10.2514/2.3547 PG 10 WC Engineering, Aerospace SC Engineering GA 285EB UT WOS:000085375800005 ER PT J AU Sims, JA Longuski, JM Patel, MR AF Sims, JA Longuski, JM Patel, MR TI Aerogravity-assist trajectories to the outer planets and the effect of drag SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB Automated trajectory design software is used to thoroughly search the near-future trajectory space for missions with low launch energies to the outer planets using aerogravity assists at Venus and Mars and at Mars alone. Aerogravity assist is shown to reduce the required hyperbolic excess launch velocities and total flight times by more than half for these missions. An analytic approach is validated using results from the automated search and then is augmented to account for drag losses during the aerogravity-assist maneuvers. The effect that the drag loss has on the interplanetary trajectories is examined. Drag increases the minimum launch energy required to reach a particular planet and increases the flight time for those trajectories that do reach a planet; however, the increase is small compared to the overall reductions achieved using aerogravity assist. Calculations including drag indicate that an aerogravity-assisted spacecraft using lift-to-drag ratios of 10 at Venus and 5 at Mars can reach Pluto with a hyperbolic excess launch velocity of only 7 km/s and a time of flight of only seven years. C1 CALTECH, Jet Prop Lab, Navigat & Flight Mech Sect, Pasadena, CA 91109 USA. Purdue Univ, Sch Aeronaut & Astronaut, W Lafayette, IN 47907 USA. Lockheed Martin Missiles & Space Co, Org K2 46, Sunnyvale, CA 94089 USA. RP Sims, JA (reprint author), CALTECH, Jet Prop Lab, Navigat & Flight Mech Sect, Mail Stop 301-142,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 TC 12 Z9 15 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2000 VL 37 IS 1 BP 49 EP 55 DI 10.2514/2.3525 PG 7 WC Engineering, Aerospace SC Engineering GA 285EB UT WOS:000085375800006 ER PT J AU Haw, RJ Antreasian, PG McElrath, TP Lewis, GD AF Haw, RJ Antreasian, PG McElrath, TP Lewis, GD TI Galileo prime mission navigation SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID JUPITER; IO AB A summary of the navigation performance of the Galileo spacecraft for the first 11 Jupiter satellite encounters is described. The achieved performance is compared against predicted accuracies. The average target miss in the satellite's B-plane coordinate frame (compared against postencounter reconstruction) was 0.9 sigma in B . R, 0.6 sigma in B . T, and 1.6 sigma in encounter time, with a largest single error of 3.4 sigma in B . R. This performance preserved sufficient onboard propellant to enable a follow-on mission of up to four gears. Knowledge of the Galilean Satellite positions has been improved by an order of magnitude. For the first time the low-order gravity coefficients of Io, Europa, Ganymede, and Callisto have been determined, and improvements tee the masses of these satellites and Jupiter have been obtained. The gravity results indicate that the Galilean satellites have differentiated into two or more layers. This and other supporting evidence indicates that a layer of liquid water may exist on Europa beneath an ice lithosphere. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Haw, RJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Robert.Haw@jpl.nasa.gov; P.G.Antreasian@jpl.nasa.gov; T.P.McElrath@jpl.nasa.gov; G.Lewis@jpl.nasa.gov NR 17 TC 8 Z9 8 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2000 VL 37 IS 1 BP 56 EP 63 DI 10.2514/2.3526 PG 8 WC Engineering, Aerospace SC Engineering GA 285EB UT WOS:000085375800007 ER PT J AU Williams, SN Coverstone-Carroll, V AF Williams, SN Coverstone-Carroll, V TI Mars missions using solar electric propulsion SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB Successful demonstration of solar electric propulsion on the Deep Space 1 technology demonstration mission has paved the way for the use of this technology on future planetary missions. Currently there is much interest in retrieving Mars surface samples for scientific exploration, as well as developing the technology to enable human missions to Mars sometime in the next few decades. Solar electric propulsion trajectories for Mars opportunities in the 2004-2011 time frame are examined. All of the trajectories shown were optimized with a gradient based calculus-of-variations tool. In addition, a genetic algorithm was used to search for more nonstandard trajectories. Mission performance is presented as burnout mass along contours of constant Eight time. The superior specific impulse of these propulsion systems results in a larger delivered mass at Mars than a conventional chemical mission. A very curious feature of these missions is that for longer Right times solutions exist that permit a nearly continuous launch opportunity over an entire Earth-Mars synodic period. C1 CALTECH, Jet Prop Lab, Navigat & Flight Mech Sect, Pasadena, CA 91109 USA. Univ Illinois, Dept Aeronaut & Astronaut Engn, Urbana, IL 61801 USA. RP Williams, SN (reprint author), CALTECH, Jet Prop Lab, Navigat & Flight Mech Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 35 Z9 35 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2000 VL 37 IS 1 BP 71 EP 77 DI 10.2514/2.3528 PG 7 WC Engineering, Aerospace SC Engineering GA 285EB UT WOS:000085375800009 ER PT J AU Wu, KC Lepsch, RA AF Wu, KC Lepsch, RA TI Nontangent, developed contour bulkheads for a single-stage launch vehicle SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA 37th Aerospace Sciences Meeting CY JAN 11-14, 1999 CL RENO, NEVADA SP Amer Inst Aeronaut & Astronaut AB Dry weights for single-stage launch vehicles that incorporate nontangent, developed contour bulkheads are estimated and compared to a baseline vehicle with 1,414 aspect ratio ellipsoidal bulkheads. Weights, volumes, and heights of optimized bulkhead designs are computed using a preliminary design bulkhead analysis code. The dry weights of vehicles that Incorporate the optimized bulkheads are predicted using a vehicle weights and sizing Code. Two optimization approaches are employed. A structural-level method, where the vehicle's three major bulkhead regions are optimized separately and then incorporated into a model for computation of the vehicle dry weight, predicts a reduction of 4365 lb (2.2%) from the 200,679-lb baseline vehicle dry weight, in the second, vehicle-level, approach, the vehicle dry weight is the objective function for the optimization. For the vehicle-level analysis, modified bulkhead designs are analyzed and incorporated into the weights model for computation of a dry weight. The optimizer simultaneously manipulates design variables for all three bulkheads to reduce the dry weight. The vehicle-level analysis predicts a dry weight reduction of 5129 lb, a 2.6% reduction from the baseline weight. Based on these results, nontangent, developed contour bulkheads may provide substantial weight savings for single stage vehicles. C1 NASA, Langley Res Ctr, Met & Thermal Struct Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Vehicle Anal Branch, Hampton, VA 23681 USA. RP Wu, KC (reprint author), NASA, Langley Res Ctr, Met & Thermal Struct Branch, Mail Stop 396, Hampton, VA 23681 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2000 VL 37 IS 1 BP 114 EP 121 DI 10.2514/2.3534 PG 8 WC Engineering, Aerospace SC Engineering GA 285EB UT WOS:000085375800015 ER PT J AU Alfano, S Burns, R Pohlen, D Wirsig, G AF Alfano, S Burns, R Pohlen, D Wirsig, G TI Predictive avoidance for ground-based laser illumination SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB Predictive avoidance determines discrete windows of time for safe laser illumination from a ground-based laser platform. That is, the analysis identifies time periods during which the laser will not inadvertently illuminate a satellite. The geometry of the problem is utilized to filter satellites that cannot possibly be illuminated by a specific laser platform. Further, several nongeometric filters are introduced to filter remaining satellites by removing those which cannot lie illuminated by the platform in a specified period. Both sets of filters improve the efficiency of the analysis by reducing the number of state propagations necessary. A method For determining the times of possible accidental illumination using cubic polynomial approximation is also presented. Finally, a test case is run that considers the entire catalog of objects publicly available from the U.S. Space Command. The complete analysis, which considers the entire catalog as potential victims for one target satellite pass, yields verified results in less than 3.5 s on a laptop personal computer running at 266 MHz. C1 US Space Command, Peterson AFB, CO 80914 USA. USAF, Res Lab, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA. RP Alfano, S (reprint author), US Space Command, Peterson AFB, CO 80914 USA. NR 5 TC 4 Z9 4 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2000 VL 37 IS 1 BP 122 EP 128 DI 10.2514/2.3535 PG 7 WC Engineering, Aerospace SC Engineering GA 285EB UT WOS:000085375800016 ER PT J AU Smith, RS Mease, KD Bayard, DS Farless, DL AF Smith, RS Mease, KD Bayard, DS Farless, DL TI Aeromaneuvering in the Martian atmosphere: Simulation-based analyses SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article C1 Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Calif Irvine, Irvine, CA 92697 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Smith, RS (reprint author), Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. RI Smith, Roy/C-7340-2009; OI Smith, Roy/0000-0002-8139-4683; Mease, Kenneth D/0000-0002-5625-8233 NR 11 TC 6 Z9 6 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2000 VL 37 IS 1 BP 139 EP 142 DI 10.2514/2.3538 PG 4 WC Engineering, Aerospace SC Engineering GA 285EB UT WOS:000085375800019 ER PT J AU Hall, JL MacNeal, PD Salama, MA Jones, JA Heun, MK AF Hall, JL MacNeal, PD Salama, MA Jones, JA Heun, MK TI Thermal and structural test results for a Venus deep-atmosphere instrument enclosure SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article C1 CALTECH, Jet Prop Lab, Adv Thermal & Struct Struct Technol Grp, Pasadena, CA 91109 USA. CALTECH, Jet Prop Lab, Instrument Struct & Dynam Grp, Pasadena, CA 91109 USA. RP Hall, JL (reprint author), CALTECH, Jet Prop Lab, Adv Thermal & Struct Struct Technol Grp, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 2 Z9 2 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2000 VL 37 IS 1 BP 142 EP 144 DI 10.2514/2.3539 PG 3 WC Engineering, Aerospace SC Engineering GA 285EB UT WOS:000085375800020 ER PT J AU Glass, DE AF Glass, DE TI Closed-form equations to evaluate heat-pipe-cooled leading-edge design feasibility SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article C1 Analyt Serv & Mat Inc, Hampton, VA 23666 USA. RP Glass, DE (reprint author), NASA, Langley Res Ctr, Mail Stop 396, Hampton, VA 23681 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD JAN-FEB PY 2000 VL 37 IS 1 BP 147 EP 150 DI 10.2514/2.3541 PG 4 WC Engineering, Aerospace SC Engineering GA 285EB UT WOS:000085375800022 ER PT J AU AlMojel, AI El-Ghazawi, T Sterling, T AF AlMojel, AI El-Ghazawi, T Sterling, T TI Characterizing and representing workloads for parallel computer architectures SO JOURNAL OF SYSTEMS ARCHITECTURE LA English DT Article DE workload characterization; workload similarity; computer architecture; performance evaluation; performance prediction AB Experimental design of parallel computers calls for quantifiable methods to compare and evaluate the requirements of different workloads within an application domain. Such methods can help establish the basis for scientific design of parallel computers driven by application needs, to optimize performance to cost. In this paper, a framework is presented for representing and comparing workloads, based on the way they would exercise parallel machines. This workload characterization is derived from parallel instruction centroid and parallel workload similarity. The centroid is a workload approximation that captures the type and amount of parallel work generated by the workload on the average. The centroid is a simple measure that aggregates average parallelism, instruction mix, and critical path length. When captured with abstracted information about communication requirements, the result is a powerful tool in understanding the requirements of workloads and their potential performance on target machines. The workload similarity is based on measuring the normalized Euclidean distance (ned) between workload centroids. It will be shown that this workload representation method outperforms comparable ones in accuracy, as well as in time and space requirements. Analysis of the NAS Parallel Benchmark workloads and their performance will be presented to demonstrate some of the applications and insight provided by this framework. This will include the use of the proposed framework for predicting the performance of real-life workloads on target machines, with good accuracy. (C) 2000 Published by Elsevier Science B.V. All rights reserved. C1 King Fahd Univ Petr & Minerals, Dept Comp Engn, Dhahran 31261, Saudi Arabia. George Mason Univ, Inst Computat Sci & Informat, Fairfax, VA 22032 USA. CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. RP AlMojel, AI (reprint author), King Fahd Univ Petr & Minerals, Dept Comp Engn, POB 2045, Dhahran 31261, Saudi Arabia. NR 17 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1383-7621 J9 J SYST ARCHITECT JI J. Syst. Architect. PD JAN 1 PY 2000 VL 46 IS 1 BP 23 EP 37 DI 10.1016/S1383-7621(98)00056-3 PG 15 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA 247YJ UT WOS:000083248300002 ER PT J AU Gibbs, GP Clark, RL Cox, DE Vipperman, JS AF Gibbs, GP Clark, RL Cox, DE Vipperman, JS TI Radiation modal expansion: Application to active structural acoustic control SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID DESIGN; MODES AB This paper demonstrates active structural acoustic control using multiple input/output adaptive sensoriactuators combined with radiation filters and a feedback control paradigm. A new method of reduced order modeling/design of radiation filters termed radiation modal expansion (RME) is presented. For the experiments detailed in this paper, the RME technique reduced the modeling of the radiation matrix from 400 transfer functions to 6 transfer functions (multiplied by a constant transformation matrix). Experimental results demonstrate reductions of radiated sound power on the order of 5 dB over the bandwidth of 0-800 Hz. (C) 2000 Acoustical Society of America. [S0001-4966(00)00401-X]. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Duke Univ, Durham, NC 27708 USA. Univ Maine, Orono, ME 04469 USA. RP Gibbs, GP (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 12 TC 51 Z9 60 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD JAN PY 2000 VL 107 IS 1 BP 332 EP 339 DI 10.1121/1.428307 PG 8 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 282NX UT WOS:000085225900028 ER PT J AU Hightower, A Delcroix, P Le Caer, G Huang, CK Ratnakumar, BV Ahn, CC Fultz, B AF Hightower, A Delcroix, P Le Caer, G Huang, CK Ratnakumar, BV Ahn, CC Fultz, B TI A Sn-119 Mossbauer spectrometry study of Li-SnO anode materials for Li-ion cells SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID ELECTROCHEMICAL REACTION; LATTICE-DYNAMICS; THIN-FILMS; TIN; LITHIUM; OXIDE; ELECTRODES; DISTRIBUTIONS; DIFFRACTION; TEMPERATURE AB Anodes of SnO were charged reversibly with Li to capacities greater than 600 mAh/g. The anode materials were characterized by Sn-119 Mossbauer spectrometry at 11 and 300 K, and by X-ray diffractometry at 300 K. Trends in the valence of Sn were as expect ed when the Sn oxides are reduced in the presence of Li. At low Li capacities the SnO is reduced to small particles of beta-Sn, and with increasing Li capacity an alloy of Li22Sn5 is formed. Although the Li22Sn5 develops over a range of Li concentrations in the anode material, the Li22Sn5 that forms at low Li insertions is not typical of bulk Li22Sn5 in either its structural or electrochemical properties. The recoil-free fraction of the Sn oxide (and perhaps the metallic Sn) in the anode materials showed an anomalously large temperature dependence. This is indicative of nanoparticles or a severely defective structure. We monitored the changes in the Li-SnO and Li-Sn materials during atmospheric exposure over times up to 2 months. This oxidation process of Sn was very much the reverse of the Sn reduction during the Li insertion, although it occurred over a much longer time scale. We also report the temperature dependencies of recoil-free fractions for standard samples of beta-Sn, SnO2, and the alloy Li22Sn5. (C) 2000 The Electrochemical Society. S0013-4651 (99)05-009-0. All rights reserved. C1 CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. Ecole Mines, Sci & Genie Mat Met Lab, CNRS UMR 7584, F-54042 Nancy, France. CALTECH, Jet Prop Lab, Electrochem Technol Grp, Pasadena, CA 91109 USA. RP Hightower, A (reprint author), CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. NR 46 TC 25 Z9 25 U1 0 U2 10 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD JAN PY 2000 VL 147 IS 1 BP 1 EP 8 DI 10.1149/1.1493855 PG 8 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA 275QZ UT WOS:000084832800001 ER PT J AU Wu, Z Li, F Huang, L Shi, Y Jin, X Fang, S Chuang, K Lyon, RE Harris, FW Cheng, SZD AF Wu, Z Li, F Huang, L Shi, Y Jin, X Fang, S Chuang, K Lyon, RE Harris, FW Cheng, SZD TI The thermal degradation mechanism and thermal mechanical properties of two high performance heterocyclic polymer fibers SO JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY LA English DT Article DE heterocyclic polymers; mechanical properties; thermal degradation ID AROMATIC POLYIMIDE FIBERS; RIGID-ROD POLYMERS; HIGH-STRENGTH; MAIN CHAIN; UNITS AB The thermal mechanical properties and degradation behaviors were studied on fibers prepared from two high-performance, heterocyclic polymers, poly(p-phenylenebenzobisthiazole) (PBZT) and poly(p-phenylenebenzobisoxazole) (PBZO). Our research demonstrated that these two fibers exhibited excellent mechanical properties and outstanding thermal and thermo-oxidative stability. Their long-term mechanical tensile performance at high temperatures was found to be critically associated with the stability of the C-O or C-S linkage at the heterocyclic rings on these polymers' backbones. PBZO fibers with the C-O linkages displayed substantially higher thermal stability compared to PBZT containing C-S linkages. High resolution pyrolysis-gas chromatography/mass spectrometry provided the information of the pyrolyzates' compositions and distributions as well as their relationships with the structures of PBZT and PBZO. Based on the analysis of the compositions and distributions of all pyrolyzates at different temperatures, it was found that the thermal degradation mechanisms for both of these heterocyclic polymers were identical. Kevlar(R)-49 fibers were also studied under the same experimental conditions in order to make a comparison of thermo-oxidative stability and long-term mechanical performance at high temperatures with PBZO and PBZT fibers. The data of two high-performance aromatic polyimide fibers were also included as references. C1 Univ Akron, Maurice Morton Inst, Akron, OH 44325 USA. Univ Akron, Dept Polymer Sci, Akron, OH 44325 USA. Chinese Acad Sci, Inst Chem, Ctr Mol Sci, Polymer Phys Lab, Beijing 100080, Peoples R China. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. Fed Aviat Adm, Fire Res Branch, Atlantic City Int Airport, Atlantic City, NJ 08405 USA. RP Cheng, SZD (reprint author), Univ Akron, Maurice Morton Inst, Akron, OH 44325 USA. NR 21 TC 12 Z9 12 U1 1 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1418-2874 J9 J THERM ANAL CALORIM JI J. Therm. Anal. PY 2000 VL 59 IS 1-2 BP 361 EP 373 DI 10.1023/A:1010173004389 PG 13 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 286TU UT WOS:000085462800027 ER PT J AU Sepka, S Chen, YK Marschall, J Copeland, RA AF Sepka, S Chen, YK Marschall, J Copeland, RA TI Experimental investigation of surface reactions in carbon monoxide and oxygen mixtures SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article; Proceedings Paper CT AIAA 33rd Thermophysics Conference CY JUN 28-JUL 01, 1999 CL NORFOLK, VIRGINIA SP Amer Inst Aeronaut & Astronaut ID 2-PHOTON ABSORPTION; CO; RECOMBINATION; FLUORESCENCE AB During hypersonic entry into the CO2 atmosphere of Mars, competing exothermic chemical reactions may occur on a spacecraft heatshield surface. Two possible surface reactions are O + O --> O-2 and CO + O --> CO2. The relative importance of these reactions on quartz is investigated using a diffusion tube side-arm reactor together with two-photon laser-induced fluorescence for both O and CO species detection. The experiments show 1) that the presence of CO in the gas phase does not significantly affect the oxygen recombination reaction on quartz and 2) that the gas-phase CO concentration is not significantly altered by the presence of atomic oxygen. These results indicate that for our experimental conditions the dominant surface reaction on quartz in oxygen-carbon monoxide mixtures is O + O --> O-2. Current heating computations for Martian entries assume CO oxidation to be fully catalytic. The resulting entry heating values are significantly higher than those computed using the assumption of fully catalytic oxygen recombination. The data presented here indicate that the assumption of fully catalytic CO oxidation may be overly conservative for heatshield sizing purposes. C1 NASA, Ames Res Ctr, Thermal Protect Mat & Syst Branch, Moffett Field, CA 94035 USA. SRI Int, Mol Phys Lab, Menlo Park, CA 94025 USA. RP Sepka, S (reprint author), NASA, Ames Res Ctr, Thermal Protect Mat & Syst Branch, Moffett Field, CA 94035 USA. RI Copeland, Richard/E-2201-2011 NR 27 TC 17 Z9 17 U1 2 U2 6 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JAN-MAR PY 2000 VL 14 IS 1 BP 45 EP 52 DI 10.2514/2.6488 PG 8 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 277YX UT WOS:000084962100005 ER PT J AU Nguyen, DNT Chen, RH Chow, LC Gu, CB AF Nguyen, DNT Chen, RH Chow, LC Gu, CB TI Effects of heater orientation and confinement on liquid nitrogen pool boiling SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER LA English DT Article ID ELECTRONICS; CONVECTION; SURFACE; ARRAY; FLUX C1 Univ Cent Florida, Dept Mech Mat & Aerosp Engn, Orlando, FL 32816 USA. RP Nguyen, DNT (reprint author), NASA, Lockheed Martin Aerospace Corp, Kennedy Space Ctr, FL 32815 USA. NR 16 TC 12 Z9 15 U1 1 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0887-8722 J9 J THERMOPHYS HEAT TR JI J. Thermophys. Heat Transf. PD JAN-MAR PY 2000 VL 14 IS 1 BP 109 EP 111 DI 10.2514/2.6496 PG 3 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 277YX UT WOS:000084962100013 ER PT J AU Seale, MD Madaras, EI AF Seale, MD Madaras, EI TI Nondestructive evaluation of the effects of thermal-mechanical aging on IM7/K3B stiffness SO JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS LA English DT Article DE lamb waves; thermal-mechanical aging; composites; nondestructive evaluation; ultrasonics ID LAMB; COMPOSITES; DAMAGE AB The introduction of new, advanced composite materials into aviation systems requires a thorough understanding of the long-term effects of combined thermal and mechanical loading on these types of materials. Ultrasonic Lamb waves offer a promising method of evaluating stiffness in composite materials. To help assess the effect of aging, a suitably designed Lamb wave measurement system is being used to obtain bending and out-of-plane stiffness coefficients of composite laminates undergoing thermal-mechanical loading. In this study, a series of 16-ply graphite-fiber-reinforced amorphous thermoplastic polyimide laminates, IM7/K3B, were aged in load frames equipped with special environmental chambers. The samples were subjected to both high and low strain profiles. The bending and out-of-plane shear stiffnesses as well as time-of-flight measurements for samples that have undergone up to 4,993 fatigue cycles of combined thermal and mechanical aging are reported. The Lamb wave generated elastic stiffness results show decreases of up to 20% with extended aging. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Seale, MD (reprint author), Thomas Nelson Community Coll, 99 Thomas Nelson Dr, Hampton, VA 23670 USA. NR 20 TC 0 Z9 0 U1 0 U2 1 PU TECHNOMIC PUBL CO INC PI LANCASTER PA 851 NEW HOLLAND AVE, BOX 3535, LANCASTER, PA 17604 USA SN 0892-7057 J9 J THERMOPLAST COMPOS JI J. Thermoplast. Compos. Mater. PD JAN PY 2000 VL 13 IS 1 BP 75 EP 90 DI 10.1106/GVR7-2CBR-M4FQ-58LV PG 16 WC Materials Science, Composites SC Materials Science GA 278QZ UT WOS:000085001600006 ER PT J AU Bloomberg, JJ Merkle, LA Barry, SR Huebner, WP Cohen, HS Mueller, SA Fordice, J AF Bloomberg, JJ Merkle, LA Barry, SR Huebner, WP Cohen, HS Mueller, SA Fordice, J TI Effects of adaptation of vestibule-ocular reflex function on manual target localization SO JOURNAL OF VESTIBULAR RESEARCH-EQUILIBRIUM & ORIENTATION LA English DT Article DE vestibular; pointing; VOR; adaptation ID ADAPTIVE MODIFICATION; VISUAL SPACE; SACCADIC ADAPTATION; HEAD MOVEMENTS; EYE-MOVEMENTS; RESPONSES; OTOLITHS; ROTATION; SYSTEM; DISPLACEMENT AB The goal of the present study was to determine if adaptive modulation of vestibulo-ocular reflex (VOR) function is associated with commensurate alterations in manual target localization. To measure the effects of adapted VOR on manual responses we developed the Vestibular-Contingent Pointing Test(VCP). In the VCP test, subjects pointed to a remembered target following passive whole body rotation in the dark. In the first experiment, subjects performed VCP before and after wearing 0.5X minifying lenses that adaptively attenuate horizontal VOR gain. Results showed that adaptive reduction in horizontal VOR gain was accompanied by a commensurate change in VCP performance. In the second experiment, bilaterally labyrinthine deficient (LD) subjects were tested to confirm that vestibular cues were central to the spatial coding of both eye and hand movements during VCP. LD subjects performed significantly worse than normal subjects. These results demonstrate that adaptive change in VOR can lead to alterations in manual target localization. C1 NASA, Life Sci Res Labs, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Wyle Life Sci, Houston, TX USA. Mt Holyoke Coll, Dept Biol Sci, S Hadley, MA 01075 USA. Baylor Coll Med, Bobby R Alford Dept Otorhinolaryngol & Communicat, Houston, TX 77030 USA. RP Bloomberg, JJ (reprint author), NASA, Life Sci Res Labs, Lyndon B Johnson Space Ctr, Mail Code SD3, Houston, TX 77058 USA. NR 46 TC 8 Z9 8 U1 1 U2 3 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0957-4271 J9 J VESTIBUL RES-EQUIL JI J. Vestib. Res.-Equilib. Orientat. PY 2000 VL 10 IS 2 BP 75 EP 86 PG 12 WC Neurosciences; Otorhinolaryngology SC Neurosciences & Neurology; Otorhinolaryngology GA 337WU UT WOS:000088386800002 PM 10939682 ER PT B AU Mack, LR AF Mack, LR BE Fasel, HF Saric, WS TI Early history of compressible linear stability theory SO LAMINAR-TURBULENT TRANSITION LA English DT Proceedings Paper CT IUTAM Symposium on Laminar-Turbulent Transition CY SEP 13-17, 1999 CL SEDONA, AZ SP Int Union Theoret & Appl Mech, Arizona State Univ, Univ Arizona AB The history of the compressible linear stability theory, as applied to a laminar boundary layer, is reviewed from its inception in 1938 up to 1970. First, the theoretical and experimental work up to 1962 is discussed and the general ideas prevailing at that time are noted. Next an account is given of how work on this subject, starting in the 1950's, came to be done at the Caltech Jet Propulsion Laboratory (JPL). In the main section, the chronology of the numerical and experimental work carried out at JPL in the 1960's is given, along with the key results and additional comments. Finally, the very different ideas arrived at as a result of this work are discussed and the importance of having reliable numerical results is stressed. C1 Jet Prop Lab, Pasadena, CA 91105 USA. NR 27 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-67947-2 PY 2000 BP 9 EP 34 PG 26 WC Mechanics SC Mechanics GA BR76L UT WOS:000167460200002 ER PT B AU King, RA Breuer, KS AF King, RA Breuer, KS BE Fasel, HF Saric, WS TI Non-localized acoustic receptivity and subsequent disturbance growth in a Blasius boundary layer SO LAMINAR-TURBULENT TRANSITION LA English DT Proceedings Paper CT IUTAM Symposium on Laminar-Turbulent Transition CY SEP 13-17, 1999 CL SEDONA, AZ SP Int Union Theoret & Appl Mech, Arizona State Univ, Univ Arizona ID TRANSITION; WAVES AB Acoustic receptivity was experimentally examined for a Blasius boundary layer with receptivity sites in the form of 2-D waviness and oblique waviness. Linear receptivity coefficients obtained for all values of forcing combinations (epsilon . Deltah) are in good agreement with receptivity theory. The measured receptivity increased markedly with increasing wave obliqueness. Detuning was investigated by varying the streamwise wavenumber, alpha (w), of the 2-D and oblique wall waviness. Oblique transition was also investigated by exciting a pair of oblique Orr-Sommerfeld (O-S) modes (f/fo, +/- beta/betaw) = (1, +/-1) For large values of epsilon . Deltah, a secondary instability was observed that ultimately lead to laminar breakdown. This instability appears to be driven by large spanwise velocity gradients, \dU/d delta\. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP King, RA (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-67947-2 PY 2000 BP 79 EP 84 PG 6 WC Mechanics SC Mechanics GA BR76L UT WOS:000167460200009 ER PT B AU Dietz, A Coleman, C Laub, J Poll, DIA AF Dietz, A Coleman, C Laub, J Poll, DIA BE Fasel, HF Saric, WS TI Effect of wall temperature on roughness induced attachment-line transition SO LAMINAR-TURBULENT TRANSITION LA English DT Proceedings Paper CT IUTAM Symposium on Laminar-Turbulent Transition CY SEP 13-17, 1999 CL SEDONA, AZ SP Int Union Theoret & Appl Mech, Arizona State Univ, Univ Arizona AB An experiment on a cooled swept cylinder in a low-disturbance Mach 1.6 wind tunnel is described. The flow attachment line was disturbed by two- and three-dimensional roughness elements of varying size and the laminar/turbulent state of the boundary layer was determined with a hot wire. The results demonstrated that although cooling the wall increased the stability of the boundary layer, it promoted roughness induced transition. Analysis of the data suggested that the attachment-line Reynolds number could account for the effect of wall cooling if the viscosity was evaluated at a particular reference temperature. Three-dimensional trips proved more effective than two-dimensional trips in this low disturbance flow. C1 NASA, Ames Res Ctr, MCAT Inc, Moffett Field, CA 94035 USA. RP Dietz, A (reprint author), NASA, Ames Res Ctr, MCAT Inc, Moffett Field, CA 94035 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-67947-2 PY 2000 BP 249 EP 254 PG 6 WC Mechanics SC Mechanics GA BR76L UT WOS:000167460200036 ER PT B AU Watmuff, JH AF Watmuff, JH BE Fasel, HF Saric, WS TI Distortion of Tollmien-Schlichting waves by leading-edge vortices SO LAMINAR-TURBULENT TRANSITION LA English DT Proceedings Paper CT IUTAM Symposium on Laminar-Turbulent Transition CY SEP 13-17, 1999 CL SEDONA, AZ SP Int Union Theoret & Appl Mech, Arizona State Univ, Univ Arizona AB The base flow consists of Tollmien-Schlchting (TS) waves generated by a vibrating ribbon in a Blasius boundary layer. For small ribbon amplitudes, the waves are 2D and the growth agrees with linear theory. High-resolution 3D studies, using larger ribbon amplitudes, demonstrate the onset of K-type secondary instability, leading to the formation of vortex loops. Streamwise vortices are embedded in the layer by introducing Free Stream Nonuniformity (FSN) in the form of a laminar wake from a fine wire. The vortices locally distort the phase and amplitude distributions of the waves and a different type of breakdown process is observed. C1 NASA, Ames Res Ctr, MCAT Inc, Moffett Field, CA 94035 USA. RP Watmuff, JH (reprint author), NASA, Ames Res Ctr, MCAT Inc, Moffett Field, CA 94035 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-67947-2 PY 2000 BP 333 EP 338 PG 6 WC Mechanics SC Mechanics GA BR76L UT WOS:000167460200049 ER PT S AU Waheed, A Smith, W George, J Yan, J AF Waheed, A Smith, W George, J Yan, J BE Dwarkadas, S TI An infrastructure for monitoring and management in computational grids SO LANGUAGES, COMPILERS, AND RUN-TIME SYSTEMS FOR SCALABLE COMPUTERS SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 5th International Workshop on Languages, Compilers, and Run-Time Systems for Scalable Computers CY MAY 25-27, 2000 CL ROCHESTER, NY SP ACM SIGPLAN AB We present the design and implementation of an infrastructure that enables monitoring of resources, services, and applications in a computational grid and provides a toolkit to help manage these entities when faults occur. This infrastructure builds on three basic monitoring components: sensors to perform measurements, actuators to perform actions, and an event service to communicate events between remote processes. We describe how we apply our infrastructure to support a grid service and an application: (1) the Globus Metacomputing Directory Service; and (2) a long-running and coarse-grained parameter study application. We use these application to show that our monitoring infrastructure is highly modular, conveniently retargettable, and extensible. C1 NASA, Ames Res Ctr, MRJ Technol Solut, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Comp Sci Corp, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, FSC End2End Inc, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, MRJ Technol Solut, Moffett Field, CA 94035 USA. EM waheed@nas.nasa.gov; wwsmith@nas.nasa.gov; jude@nas.nasa.gov; yan@nas.nasa.gov NR 16 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-41185-2 J9 LECT NOTES COMPUT SC PY 2000 VL 1915 BP 235 EP 245 DI 10.1007/3-540-40889-4_18 PG 11 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BU05L UT WOS:000174875400018 ER PT J AU Ohl, R Saha, T Barkhouser, R Friedman, S Moos, HW AF Ohl, R Saha, T Barkhouser, R Friedman, S Moos, HW TI Primary mirrors figure well for space spectroscopy SO LASER FOCUS WORLD LA English DT Article ID ULTRAVIOLET; PERFORMANCE AB Optical testing of the Far Ultraviolet Spectroscopic Explorer primary mirrors demonstrates their readiness for space science. C1 Johns Hopkins Univ, Ctr Astrophys Sci, FUSE Project, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Opt Branch, Greenbelt, MD 20771 USA. RP Ohl, R (reprint author), Johns Hopkins Univ, Ctr Astrophys Sci, FUSE Project, 3400 N Charles St, Baltimore, MD 21218 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU PENNWELL PUBL CO PI NASHUA PA 98 SPIT BROOK RD, NASHUA, NH 03062-2801 USA SN 0740-2511 J9 LASER FOCUS WORLD JI Laser Focus World PD JAN PY 2000 VL 36 IS 1 BP 183 EP + PG 5 WC Optics SC Optics GA 275VX UT WOS:000084841800044 ER PT S AU Ilchenko, VS Yao, XS Maleki, L AF Ilchenko, VS Yao, XS Maleki, L BE Kudryashov, AV Paxton, AH TI Microsphere integration in active and passive photonics devices SO LASER RESONATORS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Laser Resonators CY JAN 26-28, 2000 CL SAN JOSE, CA SP SPIE DE microsphere; microcavity; photonics; microlaser; electrooptic modulator; erbium ID WHISPERING-GALLERY MODES; FIBER COUPLER; LASER; CAVITY; EXCITATION; RESONANCES; RESONATOR AB As important step towards integration of microspheres in compact functional photonics devices, we demonstrate direct efficient coupling of light in and out of high-Q whispering-gallery (WG) modes in silica microspheres using angle-polished single mode fibers. Based on this principle, we present a 1-inch fiber-pigtailed microsphere module that can be used for fiberoptic applications, and a fiber-coupled erbium-doped microsphere laser at 1.55 mu m. In addition, we report preliminary data on the intensity modulation based on high-Q WG modes in a lithium niobate sphere. We also demonstrate a novel geometry WG-mode optical microcavity that combines Q similar to 10(7), typical for microspheres, with few-nanometer mode spacing earlier available in lower quality factor Q similar to 10(4) microfabricated planar rings. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ilchenko, VS (reprint author), CALTECH, Jet Prop Lab, MS 298-100,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 25 TC 34 Z9 34 U1 1 U2 6 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3547-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 3930 BP 154 EP 162 DI 10.1117/12.385398 PG 9 WC Optics SC Optics GA BQ31R UT WOS:000087916300016 ER PT B AU Meyers, JF Fleming, GA Gorton, SA Berry, JD AF Meyers, JF Fleming, GA Gorton, SA Berry, JD BE Adrian, RJ Durao, DFG Durst, F Heitor, MV Maeda, M Whitelaw, JH TI Instantaneous Doppler global velocimetry measurements of a rotor wake: Lessons learned SO LASER TECHNIQUES APPLIED TO FLUID MECHANICS LA English DT Proceedings Paper CT 9th International Symposium on Applications of Laser Techniques to Fluid Mechanics CY JUL 13-16, 1998 CL CALOUSTE GULBENKIAN FDN, LISBON, PORTUGAL SP European Res Off, USA, USN, USAF, Lusoamer Fdn Dev, Calouste Gulbenkian Fdn, Portuguese Sci & Technol Fdn, Inst Superior Tecn HO CALOUSTE GULBENKIAN FDN DE Doppler global velocimetry; helicopter; rotor wake AB A combined Doppler Global Velocimetry (DGV) and Projection Moire Interferometry (PMI) investigation of a helicopter rotor wake flow field and rotor blade deformation is presented. The three-component DGV system uses a single-frequency, frequency-doubled Nd:YAG laser to obtain instantaneous velocity measurements in the flow. The PMI system uses a pulsed laser-diode bar to obtain blade bending and twist measurements at the same instant that DGV measured the flow. The application of pulse lasers to DGV and PMI in large-scale wind tunnel applications represents a major step forward in the development of these technologies. As such, a great deal was learned about the difficulties of using these instruments to obtain instantaneous measurements in large facilities. Laser speckle and other image noise in the DGV data images were found to be traceable to the Nd:YAG laser. Although image processing techniques were used to virtually eliminate laser speckle noise, the source of low-frequency image noise is still under investigation. The PMI results agreed well with theoretical predictions of blade bending and twist. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Meyers, JF (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-66738-5 PY 2000 BP 243 EP 259 PG 17 WC Engineering, Mechanical; Instruments & Instrumentation; Mechanics; Optics; Physics, Fluids & Plasmas SC Engineering; Instruments & Instrumentation; Mechanics; Optics; Physics GA BQ09R UT WOS:000087171900016 ER PT S AU Fischer, DG AF Fischer, DG BE Duncan, DD Hollinger, JO Jacques, SL TI The role of evanescent waves in three-dimensional near field imaging SO LASER-TISSUE INTERACTION XI: PHOTOCHEMICAL, PHOTOTHERMAL, AND PHOTOMECHANICAL SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Laser-Tissue Interaction XI - Photochemical, Photothermal, and Photomechanical CY JAN 22-27, 2000 CL SAN JOSE, CA SP USAF Off Sci Res, SPIE, Int Biomed Opt Soc ID MICROSCOPY; OPTICS AB The structural information carried by the evanescent components of the scattered field is discussed for the case of a single homogeneous plane wave incident on a weakly scattering three-dimensional medium. It is shown that, unlike the homogeneous components of the scattered field, the evanescent components are related to the three-dimensional Fourier transform of the dielectric susceptibility through a generalized Radon transform. The region of the three-dimensional Fourier space that is accessible from evanescent wave measurements is discussed, as well as the spatial resolution attainable in a typical multiple-view scattering experiment. C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Cleveland, OH 44135 USA. RP Fischer, DG (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 9 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 0-8194-3530-9 J9 PROC SPIE PY 2000 VL 3914 BP 599 EP 607 DI 10.1117/12.388084 PG 9 WC Engineering, Biomedical; Optics SC Engineering; Optics GA BQ53Q UT WOS:000088674300068 ER PT B AU Espenak, F AF Espenak, F BE Livingston, WC Ozguc, A TI Digital compositing techniques for coronal imaging SO LAST TOTAL SOLAR ECLIPSE OF THE MILLENNIUM IN TURKEY SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Symposium on the Last Total Solar Eclipse of the Millennium in Turkey CY AUG 13-15, 1999 CL ISTANBUL, TURKEY SP Turkish Prime Minist, Promot Fund, Sci & Tech Res Council Turkey, Bogazici Univ Res Fund, Magister Tours Inc AB The solar corona exhibits a huge range in brightness which cannot be captured in any single photographic exposure. Short exposures show the bright inner corona and prominences, while long exposures reveal faint details in equatorial streamers and polar brushes. For many years, radial gradient filters and other analog techniques have been used to compress the corona's dynamic range in order to study its morphology. Such techniques demand perfect pointing and tracking during the eclipse, and can be difficult to calibrate. In the past decade, the speed, memory and hard disk capacity of personal computers have rapidly increased as prices continue to drop. It is now possible to perform sophisticated image processing of eclipse photographs on commercially available CPU's. Software programs such as Adobe Photoshop permit combining multiple eclipse photographs into a composite image which compresses the corona's dynamic range and can reveal subtle features and structures. Algorithms and digital techniques used for processing 1998 eclipse photographs will be discussed which are equally applicable to the recent eclipse of 1999 August 11. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Espenak, F (reprint author), NASA, Goddard Space Flight Ctr, Code 693, Greenbelt, MD 20771 USA. NR 2 TC 3 Z9 3 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-032-3 J9 ASTR SOC P PY 2000 VL 205 BP 101 EP 112 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80P UT WOS:000089620900012 ER PT S AU Singh, UN AF Singh, UN GP IEEE IEEE TI Solid-state 2-micron laser transmitter for space applications SO LEOS 2000 - IEEE ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS. 1 & 2 SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 13th Annual Meeting of the IEEE Lasers-and-Electro-Optics-Society CY NOV 13-16, 2000 CL RIO GRANDE, PR SP IEEE, Laser & Electroopt Soc, IEEE, Networking World C1 NASA, Langley Res Ctr, Electroopt & Controls Branch, Hampton, VA 23681 USA. RP Singh, UN (reprint author), NASA, Langley Res Ctr, Electroopt & Controls Branch, MS 468, Hampton, VA 23681 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8081 BN 0-7803-5947-X J9 IEEE LEOS ANN MTG PY 2000 BP 539 EP 540 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BR17V UT WOS:000165806400272 ER PT S AU Goorjian, PM Ning, CZ Agrawal, GP AF Goorjian, PM Ning, CZ Agrawal, GP GP IEEE IEEE TI Modeling of spatial dynamics in vertical-cavity surface-emitting laser arrays SO LEOS 2000 - IEEE ANNUAL MEETING CONFERENCE PROCEEDINGS, VOLS. 1 & 2 SE IEEE Lasers and Electro-Optics Society (LEOS) Annual Meeting LA English DT Proceedings Paper CT 13th Annual Meeting of the IEEE Lasers-and-Electro-Optics-Society CY NOV 13-16, 2000 CL RIO GRANDE, PR SP IEEE, Laser & Electroopt Soc, IEEE, Networking World ID SEMICONDUCTOR-LASERS; SIMULATION C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Goorjian, PM (reprint author), NASA, Ames Res Ctr, MS T27A-2, Moffett Field, CA 94035 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1092-8081 BN 0-7803-5947-X J9 IEEE LEOS ANN MTG PY 2000 BP 780 EP 781 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BR17V UT WOS:000165806400392 ER PT S AU Curtis, SB Vazquez, ME Wilson, JW Atwell, W Kim, MHY AF Curtis, SB Vazquez, ME Wilson, JW Atwell, W Kim, MHY BE Slenzka, K Vazquez, M Cucinotta, FA TI Cosmic ray hits in the central nervous system at solar maximum SO LIFE SCIENCES: MICROGRAVITY AND SPACE RADIATION EFFECTS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 6 and F2 5 Symposia of COSPAR Scientific Commission F Held during the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP NASA, European Space Agcy, Deutsch Agentur Raumfahrt, Angellegenheiten GMBH, Comm Space Res ID HUMAN RETINA; GANGLION-CELLS; NEURONS; NUMBER AB It has been suggested that a manned mission to Mars be launched at solar maximum rather than at solar minimum to minimize the radiation exposure to galactic cosmic rays. It is true that the number of hits from highly ionizing particles to critical regions in the brain will be less at solar maximum, and it is of interest to estimate how much less. We present here calculations for several sites within the brain from iron ions (z = 26) and from particles with charge, z, greater than or equal to 15. The same shielding configurations and sites in the brain used in an earlier paper for solar minimum are employed so that direct comparison of results between the two solar activity conditions can be made. A simple pressure-vessel wall and an equipment room onboard a spacecraft are chosen as shielding examples. In the equipment room, typical results for the thalamus are that the probability of any particles with 3 greater than or equal to 15 and from 2.3 percent to 1.3 percent for iron ions. The extra shielding provided in the equipment room makes little difference in these numbers. We conclude that this decrease in hit frequency (less than a factor of two) does not provide a compelling reason to avoid solar minimum for a manned mission to Mars. This conclusion could be revised, however, if a very small number of hits is found to cause critical malfunction within the brain. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 Fred Hutchinson Canc Res Ctr, Seattle, WA 98104 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Boeing N Amer Inc, Houston, TX 77058 USA. RP Curtis, SB (reprint author), Fred Hutchinson Canc Res Ctr, 1124 Columbia St, Seattle, WA 98104 USA. FU NIDCR NIH HHS [DE-AC02-98CH10886] NR 17 TC 7 Z9 8 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2000 VL 25 IS 10 BP 2035 EP 2040 DI 10.1016/S0273-1177(99)01015-7 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BP67D UT WOS:000085822600008 PM 11542854 ER PT S AU Yang, TC Craise, LM Raju, MR AF Yang, TC Craise, LM Raju, MR BE Slenzka, K Vazquez, M Cucinotta, FA TI Oncogenic transformation of mammalian cells by ultrasoft X-rays and alpha particles SO LIFE SCIENCES: MICROGRAVITY AND SPACE RADIATION EFFECTS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 6 and F2 5 Symposia of COSPAR Scientific Commission F Held during the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP NASA, European Space Agcy, Deutsch Agentur Raumfahrt, Angellegenheiten GMBH, Comm Space Res ID HAMSTER-CELLS; CHINESE-HAMSTER; INACTIVATION; RADIOBIOLOGY; RADIATIONS; MUTATION; V79 AB For a better understanding of oncogenic cell transformation by ionizing radiation, we conducted experiments with ultrasoft X rays and low energy alpha particles. Confluent C3H10T1/2 cells were irradiated by Al-K (1.5 keV) X rays or alpha particles from plutonium through a thin mylar sheet, on which the cells attached and grew. Our results indicated that Al-K X rays were more effective in causing cell inactivation and oncogenic transformation than Co-60 gamma rays but less effective than 1.0 and 3.7 MeV alpha particles. There was no significant difference between 1.0 and 3.7 MeV alpha particles in transforming cells although the latter were slightly more effective than the former in producing lethal effect. These results indicated that track structure is important in causing biological effects by ionizing radiation. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Radiat Biophys Lab, Houston, TX 77058 USA. Univ Calif Berkeley, Larence Berkeley Natl Lab, Berkeley, CA USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Yang, TC (reprint author), NASA, Lyndon B Johnson Space Ctr, Radiat Biophys Lab, Houston, TX 77058 USA. NR 17 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 J9 ADV SPACE RES PY 2000 VL 25 IS 10 BP 2123 EP 2130 DI 10.1016/S0273-1177(99)01064-9 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BP67D UT WOS:000085822600019 PM 11542865 ER PT S AU Cucinotta, FA Dicello, JF AF Cucinotta, FA Dicello, JF BE Slenzka, K Vazquez, M Cucinotta, FA TI On the development of biophysical models for space radiation risk assessment SO LIFE SCIENCES: MICROGRAVITY AND SPACE RADIATION EFFECTS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F2 6 and F2 5 Symposia of COSPAR Scientific Commission F Held during the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP NASA, European Space Agcy, Deutsch Agentur Raumfahrt, Angellegenheiten GMBH, Comm Space Res ID CELL-DIVISION CYCLE; RETINOBLASTOMA-PROTEIN; DNA-DAMAGE; IONIZING-RADIATION; P53; SYSTEMS; ARREST; PHOSPHORYLATION; INHIBITION; ACTIVATION AB Experimental techniques in molecular biology are being applied to study biological risks from space radiation. The use of molecular assays presents a challenge to biophysical models which in the past have relied on descriptions of energy deposition and phenomenological treatments of repair. We describe a biochemical kinetics model of cell cycle control and DNA damage response proteins in order to model cellular responses to radiation exposures. Using models of cyclin-cdk, pRB, E2F's, p53, and G1 inhibitors we show that simulations of cell cycle populations and G1 arrest can be described by our biochemical approach. We consider radiation damaged DNA as a substrate for signal transduction processes and consider a dose and dose-rate reduction effectiveness factor (DDREF) for protein expression. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Johns Hopkins Univ, Ctr Oncol, Baltimore, MD 21287 USA. RP Cucinotta, FA (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 35 TC 12 Z9 12 U1 0 U2 1 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2000 VL 25 IS 10 BP 2131 EP 2140 DI 10.1016/S0273-1177(99)01065-0 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BP67D UT WOS:000085822600020 PM 11542866 ER PT S AU Kliss, M Heyenga, AG Hoehn, A Stodieck, LS AF Kliss, M Heyenga, AG Hoehn, A Stodieck, LS BE Tibbitts, TW Wheeler, RM Mitchell, CA Heidmann, J TI Recent advances in technologies required for a "Salad Machine" SO LIFE SCIENCES: SPACE LIFE SUPPORT SYSTEMS AND THE LUNAR FARSIDE CRATER SAHA PROPOSAL SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F4 4 F4 5 and F3 7 Symposia of COSPAR Scientific Commission F Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res, Int Astron Union, Int Inst Space Law ID SYSTEMS AB Future long duration, manned space flight missions will require life support systems that minimize resupply requirements and ultimately approach self-sufficiency in space. Bioregenerative life support systems are a promising approach, but they are far from mature. Early in the development of the NASA Controlled Ecological Life Support System Program, the idea of onboard cultivation of salad-type vegetables for crew consumption was proposed as a first step away from the total reliance on resupply for food in space. Since that time, significant advances in space-based plant growth hardware have occurred, and considerable flight experience has been gained. This paper revisits the "Salad Machine" concept and describes recent developments in subsystem technologies for both plant root and shoot environments that are directly relevant to the development of such a facility. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Colorado, Boulder, CO 80309 USA. RP Kliss, M (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 16 TC 11 Z9 12 U1 0 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2000 VL 26 IS 2 BP 263 EP 269 DI 10.1016/S0273-1177(99)00570-0 PG 7 WC Engineering, Aerospace; Food Science & Technology SC Engineering; Food Science & Technology GA BP89L UT WOS:000086533700003 PM 11543161 ER PT S AU Heyenga, AG Forsman, A Stodieck, LS Hoehn, A Kliss, M AF Heyenga, AG Forsman, A Stodieck, LS Hoehn, A Kliss, M BE Tibbitts, TW Wheeler, RM Mitchell, CA Heidmann, J TI Approaches in the determination of plant nutrient uptake and distribution in space flight conditions SO LIFE SCIENCES: SPACE LIFE SUPPORT SYSTEMS AND THE LUNAR FARSIDE CRATER SAHA PROPOSAL SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F4 4 F4 5 and F3 7 Symposia of COSPAR Scientific Commission F Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res, Int Astron Union, Int Inst Space Law ID ION CHANNELS AB The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the radionuclides calcium-45 and iron-59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Natl Res Council, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Colorado, Boulder, CO 80309 USA. RP Heyenga, AG (reprint author), NASA, Natl Res Council, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 6 TC 2 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 J9 ADV SPACE RES PY 2000 VL 26 IS 2 BP 299 EP 302 DI 10.1016/S0273-1177(99)00574-8 PG 4 WC Engineering, Aerospace; Food Science & Technology SC Engineering; Food Science & Technology GA BP89L UT WOS:000086533700007 PM 11543165 ER PT S AU Porterfield, DM Barta, DJ Ming, DW Morrow, RC Musgrave, ME AF Porterfield, DM Barta, DJ Ming, DW Morrow, RC Musgrave, ME BE Tibbitts, TW Wheeler, RM Mitchell, CA Heidmann, J TI Astroculture (TM) root metabolism and cytochemical analysis SO LIFE SCIENCES: SPACE LIFE SUPPORT SYSTEMS AND THE LUNAR FARSIDE CRATER SAHA PROPOSAL SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F4 4 F4 5 and F3 7 Symposia of COSPAR Scientific Commission F Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res, Int Astron Union, Int Inst Space Law ID LOCALIZATION AB Physiology of the root system is dependent upon oxygen availability and tissue respiration. During hypoxia nutrient and water acquisition may be inhibited, thus affecting the overall biochemical and physiological status of the plant. For the Astroculture(TM) plant growth hardware, the availability of oxygen in the root zone was measured by examining the changes in alcohol dehydrogenase (ADH) activity within the root tissue. ADH activity is a sensitive biochemical indicator of hypoxic conditions in plants and was measured in both spaceflight and control roots. In addition to the biochemical enzyme assays, localization of ADH in the root tissue was examined cytochemically. The results of these analyses showed that ADH activity increased significantly as a result of spaceflight exposure. Enzyme activity increased 248% to 304% in dwarf wheat when compared with the ground controls and Brassica showed increases between 334% and 579% when compared with day zero controls. Cytochemical staining revealed no differences in ADH tissue localization in any of the dwarf wheat treatments. These results show the importance of considering root system oxygenation in designing and building nutrient delivery hardware for spaceflight plant cultivation and confirm previous reports of an ADH response associated with spaceflight exposure. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 Louisiana State Univ, Ctr Agr, Louisiana Agr Expt Stn, Dept Plant Pathol & Crop Physiol, Baton Rouge, LA 70803 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Orbital Technol, Madison, WI USA. RP Porterfield, DM (reprint author), Louisiana State Univ, Ctr Agr, Louisiana Agr Expt Stn, Dept Plant Pathol & Crop Physiol, Baton Rouge, LA 70803 USA. NR 13 TC 15 Z9 17 U1 0 U2 4 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2000 VL 26 IS 2 BP 315 EP 318 DI 10.1016/S0273-1177(99)00578-5 PG 4 WC Engineering, Aerospace; Food Science & Technology SC Engineering; Food Science & Technology GA BP89L UT WOS:000086533700011 PM 11543169 ER PT S AU Wignarajah, K Pisharody, S Fisher, JW AF Wignarajah, K Pisharody, S Fisher, JW BE Tibbitts, TW Wheeler, RM Mitchell, CA Heidmann, J TI Can incineration technology convert CELSS wastes to resources for crop production? A working hypothesis and some preliminary findings SO LIFE SCIENCES: SPACE LIFE SUPPORT SYSTEMS AND THE LUNAR FARSIDE CRATER SAHA PROPOSAL SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT F4 4 F4 5 and F3 7 Symposia of COSPAR Scientific Commission F Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res, Int Astron Union, Int Inst Space Law ID PLANTS; SO2; NOX AB Considerable evidence exists to support the hypothesis that human-generated wastes can be utilized as resources in crop production. In the waste mix from a Closed Ecological Life Support System (CELSS), the elemental resources are found mainly in the solid fraction. In order to make these resources available for crop growth, it is necessary to convert the solid wastes to either an aqueous or a gaseous phase. Incineration is one method for processing solid wastes to produce a gaseous fraction and a small solid fraction of ash. Evidence from literature provides a compelling case for a working hypothesis that plants can utilize the gases of incineration. Although uptake and utilization of inorganic elements in the aqueous phase is well established, the uptake and utilization of inorganic elements in the gaseous phase, with the exception of CO2 and O-2, is not fully understood. This paper attempts to (a) summarize existing literature on uptake/metabolism of inorganic elements in the gaseous fraction, with the exception of CO2 and O-2 and (b) develop a working hypothesis to predict the use of incineration flue gases by plants. Preliminary experimental findings on effects of carbon monoxide, a component of the flue gas, are also presented. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Lockheed Martin Engn & Sci Co, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Wignarajah, K (reprint author), NASA, Lockheed Martin Engn & Sci Co, Ames Res Ctr, Mail Stop 239A-3, Moffett Field, CA 94035 USA. NR 25 TC 5 Z9 6 U1 0 U2 2 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2000 VL 26 IS 2 BP 327 EP 333 DI 10.1016/S0273-1177(99)01072-8 PG 7 WC Engineering, Aerospace; Food Science & Technology SC Engineering; Food Science & Technology GA BP89L UT WOS:000086533700013 PM 11543171 ER PT S AU Ramaty, R Lingenfelter, RE Kozlovsky, B AF Ramaty, R Lingenfelter, RE Kozlovsky, B BE DaSilva, L Spite, M DeMedeiros, JR TI LiBeB evolution: Three models SO LIGHT ELEMENTS AND THEIR EVOLUTION SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 198th Symposium of the International-Astronomical-Union CY NOV 21-27, 1999 CL NATAL, BRAZIL SP Int Astronim Union ID METAL-POOR STARS; GALACTIC COSMIC-RAYS; LIGHT-ELEMENTS; SUPERNOVA-REMNANTS; OXYGEN ABUNDANCES; ORION COMPLEX; HALO STARS; NUCLEOSYNTHESIS; LINES; RATIO AB We consider the three principal LiBeB evolutionary models, CRI in which the cosmic-ray source at all epochs of Galactic evolution is the average ISM, CRI+LECR in which metal enriched low energy cosmic rays (LECRs) are superimposed onto the CRI cosmic rays, and CRS in which the cosmic-ray source, accelerated in superbubbles, is constant, independent of the ISM metallicity. By considering the evolutionary trend of log(Be/H) vs. both [Fe/H] and [O/H], we demonstrate that the CRI model is energetically untenable. We present evolutionary trends for B-11/B-10 and B/Be which, combined with future precision measurements, could distinguish between the CRS and CRI+LECR models. We show that delayed LiBeB synthesis in the CRS model, due to the transport of the cosmic rays, could explain why log(Be/H) is steeper vs. [O/H] than vs. [Fe/H]. We also show that delayed deposition of Fe into star forming regions, due to its incorporation into high velocity dust, could provide an explanation for the possible rise of [O/Fe] with decreasing [Fe/H]. Observations of refractory and volatile a-elements could test this scenario. There seems to be a need for pregalactic or extragalactic Li-6 sources. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif San Diego, CASS, La Jolla, CA 92093 USA. Tel Aviv Univ, IL-69978 Tel Aviv, Israel. RP Ramaty, R (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 40 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-048-X J9 IAU SYMP PY 2000 IS 198 BP 51 EP 60 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU35S UT WOS:000175748500006 ER PT S AU Sahu, MS AF Sahu, MS BE DaSilva, L Spite, M DeMedeiros, JR TI The D/H ratio in interstellar gas toward the hot, white dwarf G191-B2B SO LIGHT ELEMENTS AND THEIR EVOLUTION SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 198th Symposium of the International-Astronomical-Union CY NOV 21-27, 1999 CL NATAL, BRAZIL SP Int Astronim Union ID DEUTERIUM ABUNDANCE; SPATIAL VARIATIONS; CAPELLA; ORIGIN; SIGHT AB Space Telescope Imaging Spectrograph (STIS) observations of the D/H ratio in the two velocity components towards G191-B2B are consistent with 1.5 +/- 0.1 x 10(-5) and do not agree with the values derived using the Goddard High Resolution Spectrograph (GHRS) data. We present some new work on the G191-B2B sightline, and the results we obtain are consistent with those of Sahu et al. (1999). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Opt Astron Observ, Tucson, AZ USA. RP Sahu, MS (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-048-X J9 IAU SYMP PY 2000 IS 198 BP 161 EP 166 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU35S UT WOS:000175748500021 ER PT S AU Iping, RC Sonneborn, G Massa, D Fullerton, AW Hutchings, JB AF Iping, RC Sonneborn, G Massa, D Fullerton, AW Hutchings, JB CA FUSE Sci Team BE DaSilva, L Spite, M DeMedeiros, JR TI FUSE spectra of Sk 80, an O7 supergiant in the Small Magellanic Cloud SO LIGHT ELEMENTS AND THEIR EVOLUTION SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 198th Symposium of the International-Astronomical-Union CY NOV 21-27, 1999 CL NATAL, BRAZIL SP Int Astronim Union AB We present far-UV spectra (910-1190Angstrom) of Sk 80, an 07 supergiant in the Small Magellanic Cloud, observed by the FUSE satellite during its In-Orbit Checkout phase. The spectra reveal many interstellar absorption lines, including H-2, and 0 VI, and several key stellar wind features. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Victoria, Victoria, BC V8W 2Y2, Canada. Natl Res Council Canada, Ottawa, ON K1A 0R6, Canada. RP Iping, RC (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-048-X J9 IAU SYMP PY 2000 IS 198 BP 240 EP 241 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU35S UT WOS:000175748500032 ER PT S AU Sonneborn, G Jenkins, EB Tripp, T Wozniak, P Ferlet, R Vidal-Madjar, A Sofia, UJ AF Sonneborn, G Jenkins, EB Tripp, T Wozniak, P Ferlet, R Vidal-Madjar, A Sofia, UJ BE DaSilva, L Spite, M DeMedeiros, JR TI Spatial variations in the atomic D/H ratio in the ISM SO LIGHT ELEMENTS AND THEIR EVOLUTION SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 198th Symposium of the International-Astronomical-Union CY NOV 21-27, 1999 CL NATAL, BRAZIL SP Int Astronim Union ID INTERSTELLAR-MEDIUM; DEUTERIUM AB Observations with IMAPS demonstrate that interstellar atomic D/H abundance ratios differ by a factor of 3 on the sightlines toward delta Ori A, zeta Pup, and gamma(2) Vel, early-type, stars within similar to500 pc of the Sun. The observed D/H differences are not inversely correlated with N/H, as would be expected if injection of CNO-processed material was the primary mechanism for the D/H abundance variations in the ISM. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. CNRS, IAP, F-75014 Paris, France. Whitman Coll, Dept Astron, Walla Walla, WA 99362 USA. RP Sonneborn, G (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. RI Jenkins, Edward/P-5684-2014 OI Jenkins, Edward/0000-0003-1892-4423 NR 5 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-048-X J9 IAU SYMP PY 2000 IS 198 BP 242 EP 243 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU35S UT WOS:000175748500033 ER PT S AU Sonneborn, G Moos, HW Sembach, KR AF Sonneborn, G Moos, HW Sembach, KR CA FUSE Sci Team BE DaSilva, L Spite, M DeMedeiros, JR TI In-orbit performance of the Far Ultraviolet Spectroscopic Explorer SO LIGHT ELEMENTS AND THEIR EVOLUTION SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 198th Symposium of the International-Astronomical-Union CY NOV 21-27, 1999 CL NATAL, BRAZIL SP Int Astronim Union AB The Far Ultraviolet Spectroscopic Explorer (FUSE) satellite was launched by a Delta II rocket on 24 June 1999 into a similar to768 km, 25degrees orbit. Following the In-Orbit Checkout phase, FUSE is obtaining high-resolution spectra (lambda/Deltalambda greater than or similar to 20,000) in the spectral range 905 - 1187 Angstrom. The sensitivity meets or exceeds the pre-launch predictions. Many QSOs and AGNs have already been observed. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RP Sonneborn, G (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-048-X J9 IAU SYMP PY 2000 IS 198 BP 244 EP 245 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU35S UT WOS:000175748500034 ER PT S AU Knauth, DC Federman, SR Lambert, DL Crane, P AF Knauth, DC Federman, SR Lambert, DL Crane, P BE DaSilva, L Spite, M DeMedeiros, JR TI The interstellar lithium isotope ratio toward Per OB2 SO LIGHT ELEMENTS AND THEIR EVOLUTION SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 198th Symposium of the International-Astronomical-Union CY NOV 21-27, 1999 CL NATAL, BRAZIL SP Int Astronim Union ID LIGHT-ELEMENTS; COSMIC-RAYS; LI-7/LI-6 RATIO; DIFFUSE CLOUDS; ZETA-OPHIUCHI; ABUNDANCE; CARBON; ORIGIN; STARS; LINES AB We are conducting a survey on the Li-7/Li-6 ratio in interstellar space in order to seek limits on the variation in this ratio. The analysis is based on the technique we adopted in extracting the B-11/B-10 ratio. This technique uses a line of comparable strength, from a species Likely to occupy the same volume of the interstellar cloud, as a template for separating velocity components within the line profile. For our study of the Li-7/Li-6 ratio, the K I line at 4044 A serves as the velocity template. Our initial focus is on the variation in the Li-7/Li-6 ratio around the star-forming region IC 348. Our high-resolution observations of the Li I lines toward o and zeta Per show remarkably different isotope. ratios: Li-7/Li-6 = 2-4 and 11, respectively, where the Solar System ratio is 12.3 and cosmic ray spallation yields a ratio of about 2. The significance of the very low ratio toward o Per is that it is essentially the value predicted for cosmic rays through spallation reactions. The direction to o Per passes closer to IC 348, a site of massive star formation, than does the line of sight to zeta Per. Furthermore, our analysis of OH column densities (Federman, Weber, & Lambert 1996) showed that the cosmic ray flux through o Per's diffuse clouds is higher than average, presumably reflecting the nearby presence of IC 348. C1 Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Dartmouth Coll, Dept Phys & Astron, Hanover, NH USA. NASA, Headquarters, Washington, DC 20546 USA. RP Knauth, DC (reprint author), Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA. NR 29 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-048-X J9 IAU SYMP PY 2000 IS 198 BP 338 EP 343 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU35S UT WOS:000175748500046 ER PT S AU Lubowich, DA Smith, VV Turner, BE Sahai, R AF Lubowich, DA Smith, VV Turner, BE Sahai, R BE DaSilva, L Spite, M DeMedeiros, JR TI The lithium abundance and mass loss rate in galactic super-Li-rich carbon and S stars SO LIGHT ELEMENTS AND THEIR EVOLUTION SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 198th Symposium of the International-Astronomical-Union CY NOV 21-27, 1999 CL NATAL, BRAZIL SP Int Astronim Union ID GIANTS AB The super-Li-rich (SLR) stars are rare AGB stars containing enhanced Li/H approximate to 2000 times the ISM Li/H. In order to determine if mass loss from SLR stars is a significant source of ISM Li, we measured their Li/H and the mass loss rate. From the weak Li I 8126 Angstrom line in 2/4 SLR C stars and 6/8 SLR S stars we obtained Li/H = (0.2 - 5) x 10(-6) for SLR C stars and Li/H = (0.2 - 5) x 10(-7) for the SLR S stars. We determined dM/dt from the expansion velocity and line profiles of the circumstellar CO. The dM/dt = 1.3 x 10(-5) M-circle dot/yr, 2.6 x 10(-7) M-circle dot/yr, and 2.6 x 10(-8) M-circle dot/yr for the C stars IY Hya, T Ara, and WZ Cas; and average dM/dt = 5.5 x 10(-7) M-circle dot/yr for the S stars. Thus mass loss from SLR stars is a significant source of Galactic Li. C1 Hofstra Univ, Dept Phys, Hempstead, NY 11550 USA. AIP, Melville, NY USA. Univ Texas, Dept Phys, El Paso, TX 79968 USA. Natl Radio Astron Observ, Charlottesville, VA USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Lubowich, DA (reprint author), Hofstra Univ, Dept Phys, Hempstead, NY 11550 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-048-X J9 IAU SYMP PY 2000 IS 198 BP 377 EP 378 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU35S UT WOS:000175748500060 ER PT S AU Landsman, W AF Landsman, W BE DaSilva, L Spite, M DeMedeiros, JR TI White dwarf probes of interstellar deuterium SO LIGHT ELEMENTS AND THEIR EVOLUTION SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 198th Symposium of the International-Astronomical-Union CY NOV 21-27, 1999 CL NATAL, BRAZIL SP Int Astronim Union ID D/H RATIO; HYDROGEN AB We review the advantages of using hot white dwarfs (WDs) as probes of the deuterium abundance in the local interstellar medium. We then discuss advantages of the Space Telescope Imaging Spectrograph (STIS) for such observations, as compared with earlier observations with the Goddard High Resolution Spectrograph (GHRS). The GHRS Ly alpha profile of the white dwarf HZ 43 is probably modified by the hot "hydrogen wall" surrounding the Sun; but despite this complication, the sightline remains a promising one for an accurate determination of the deuterium abundance in the local interstellar medium. C1 NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. RP Landsman, W (reprint author), NASA, Goddard Space Flight Ctr, Raytheon ITSS, Code 681, Greenbelt, MD 20771 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-048-X J9 IAU SYMP PY 2000 IS 198 BP 485 EP 486 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BU35S UT WOS:000175748500078 ER PT B AU Smart, MC Ratnakumar, BV Surampudi, S AF Smart, MC Ratnakumar, BV Surampudi, S BE Surampudi, S Marsh, RA Ogumi, Z Prakash, J TI Alkyl pyrocarbonate electrolyte additives for performance enhancement of Li ion cells SO LITHIUM BATTERIES, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT International Symposium on Lithium Batteries of the 196th Electrochemical-Society Fall Meeting CY OCT 17-22, 1999 CL HONOLULU, HI SP Electrochem Soc, Battery Div, Electrochem Soc, Energy Technol Div ID LITHIUM AB Lithium ion rechargeable batteries are being developed for various aerospace applications under a NASA-DoD interagency program. Several of these applications possess many challenging performance requirements, specifically long cycle life for LEO and GEO satellites and excellent low temperature performance for the Mars Lander and Rover missions.(1-3) Accordingly, we have been pursuing research studies to achieve improvements in the low temperature performance, long cycle life and calendar life of lithium ion cells. The studies are mainly focused on electrolytes, to identify advanced electrolyte formulations or new electrolyte additives to enhance Li ion mobility (at low temperatures) and stability toward the electrode. The latter approach is particularly aimed at the formation of suitable SEI (solid electrolyte interphase) layers on carbonaceous anodes. In this paper, we report the beneficial effect of using alkyl pyrocarbonates as electrolyte additives to improve the low temperature performance of lithium ion cells. C1 CALTECH, Jet Prop Lab, Electrochem Technol Grp, Pasadena, CA 91109 USA. RP Smart, MC (reprint author), CALTECH, Jet Prop Lab, Electrochem Technol Grp, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-248-6 J9 ELEC SOC S PY 2000 VL 99 IS 25 BP 423 EP 433 PG 5 WC Electrochemistry SC Electrochemistry GA BQ33W UT WOS:000088014200040 ER PT B AU West, WC Whitacre, JF Ratnakumar, BV Brandon, E Blosiu, JO Surampudi, S AF West, WC Whitacre, JF Ratnakumar, BV Brandon, E Blosiu, JO Surampudi, S BE Surampudi, S Marsh, RA Ogumi, Z Prakash, J TI Thin film lithium ion batteries for NASA applications SO LITHIUM BATTERIES, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT International Symposium on Lithium Batteries of the 196th Electrochemical-Society Fall Meeting CY OCT 17-22, 1999 CL HONOLULU, HI SP Electrochem Soc, Battery Div, Electrochem Soc, Energy Technol Div ID COBALT; LICOO2 AB Development of thin film Li ion batteries has been initiated at these laboratories with the goal of preparing miniaturized high capacity, high stability secondary batteries for low power microspacecraft missions. The development work has focused on thin film batteries with a non- Li anode, a solid electrolyte, and an unannealed cathode. Various deposition parameters critical to obtaining desired crystallinity and electrochemical performance from cathode films have been identified, including deposition sequence, pressure, and sputter gas composition. Improvements in the as deposited LixNi((y-1))CoyO2 films, in terms of crystallinity and capacity have been demonstrated, and the effects of deposition parameters are reported. Improved electrochemical performance and/or crystallinity are observed with increasing deposition pressure, increasing oxygen partial pressure in the sputter gas, and lowest deposition time. C1 CALTECH, Jet Prop Lab, Ctr Inegrated Space Microsyst, Pasadena, CA 91109 USA. RP West, WC (reprint author), CALTECH, Jet Prop Lab, Ctr Inegrated Space Microsyst, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-248-6 J9 ELEC SOC S PY 2000 VL 99 IS 25 BP 607 EP 618 PG 6 WC Electrochemistry SC Electrochemistry GA BQ33W UT WOS:000088014200062 ER PT B AU Huang, CK Surampudi, S Sakamoto, JS Wolfenstine, J AF Huang, CK Surampudi, S Sakamoto, JS Wolfenstine, J BE Surampudi, S Marsh, RA Ogumi, Z Prakash, J TI Li-ion cell development for low temperature applications SO LITHIUM BATTERIES, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT International Symposium on Lithium Batteries of the 196th Electrochemical-Society Fall Meeting CY OCT 17-22, 1999 CL HONOLULU, HI SP Electrochem Soc, Battery Div, Electrochem Soc, Energy Technol Div ID CARBONATES; BATTERIES AB The results of electrode and the electrolyte studies at low temperatures (-40 degrees C) suggest that poor low temperature performance of Li-ion cells is limited by the carbon electrodes. It is suggested that the main causes for the poor low temperature Li-ion cell performance are: i) low Li-ion diffusivity in bulk carbon, ii) a Li-ion diffusivity in carbon that decreases with increasing Li composition and iii) limited Li capacity in carbon below -30 degrees C. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Huang, CK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 1 Z9 1 U1 1 U2 3 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-248-6 J9 ELEC SOC S PY 2000 VL 99 IS 25 BP 619 EP 631 PG 5 WC Electrochemistry SC Electrochemistry GA BQ33W UT WOS:000088014200063 ER PT B AU Ratnakumar, BV Smart, MC Blosiu, JO Surampudi, S AF Ratnakumar, BV Smart, MC Blosiu, JO Surampudi, S BE Surampudi, S Marsh, RA Ogumi, Z Prakash, J TI Storage characteristics of lithium ion cells SO LITHIUM BATTERIES, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT International Symposium on Lithium Batteries of the 196th Electrochemical-Society Fall Meeting CY OCT 17-22, 1999 CL HONOLULU, HI SP Electrochem Soc, Battery Div, Electrochem Soc, Energy Technol Div ID BATTERIES; ELECTROLYTES; ELECTRODES; SOLVENT AB Prototype aerospace lithium ion cells have shown impressive performance in several categories, such as specific energy, energy density and low-temperature performance. However, their tolerance to extended storage periods, which is a critical requirement for near and outer planetary missions, is yet to be established. Storage tests have therefore been carried out under different conditions of storage, i.e., storage temperature, state of charge, storage time and storage mode, on various lithium ion chemistries under real-time as well as accelerated mode. These studies are further corroborated by three-electrode cell studies during high temperature storage, to segregate and understand the capacity loss sustained by the carbonaceous anodes and metal oxide cathodes. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ratnakumar, BV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-248-6 J9 ELEC SOC S PY 2000 VL 99 IS 25 BP 706 EP 718 PG 5 WC Electrochemistry SC Electrochemistry GA BQ33W UT WOS:000088014200072 ER PT B AU Frank, H Shakkottai, P Ratnakumar, BV Smart, M Huang, C Timmerman, P Surampudi, S AF Frank, H Shakkottai, P Ratnakumar, BV Smart, M Huang, C Timmerman, P Surampudi, S BE Surampudi, S Marsh, RA Ogumi, Z Prakash, J TI Thermal aspects of lithium ion cells SO LITHIUM BATTERIES, PROCEEDINGS SE ELECTROCHEMICAL SOCIETY SERIES LA English DT Proceedings Paper CT International Symposium on Lithium Batteries of the 196th Electrochemical-Society Fall Meeting CY OCT 17-22, 1999 CL HONOLULU, HI SP Electrochem Soc, Battery Div, Electrochem Soc, Energy Technol Div AB An investigation was carried out to determine and document the necessary inputs for developing a thermal model of Li-Ion cells. The thermal model is, in turn, to be used to specify operating limits and design auxiliary heat transfer equipment so as to maintain desired battery operating temperatures. Test articles were prototype prismatic and cylindrical 25 AH Li-Ion cells. Thermal masses of these were in the range of 900 to 1100 J/oK. Thermal conductivities of both types in the perpendicular direction to the plates were much higher than in the parallel direction to the plates (15 to 33 times greater). Due to the cell configurations (short path length in the perpendicular direction) the thermal resistances of both were comparable in all directions and in the range of 1.0 to 2.0 degrees K/W. Heat generation rates were computed for both types based on a simplified model consisting of the product of current and difference between open circuit voltage and operating voltage. Operating voltages were taken from cycling tests and open circuit voltages were determined experimentally. Complete sets of heat generation curves were then generated for charge and discharge. Support for the heat generation estimates was shown by comparing calculated heat energy with measured electrical energy for complete cycles. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Frank, H (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 1 TC 0 Z9 0 U1 0 U2 4 PU ELECTROCHEMICAL SOCIETY INC PI PENNINGTON PA 65 S MAIN ST, PENNINGTON, NJ 08534-2839 USA BN 1-56677-248-6 J9 ELEC SOC S PY 2000 VL 99 IS 25 BP 730 EP 741 PG 6 WC Electrochemistry SC Electrochemistry GA BQ33W UT WOS:000088014200074 ER PT S AU Bilitza, D Radicella, SM Reinisch, BW Adeniyi, JO Gonzalez, MEM Zhang, SR Obrou, O AF Bilitza, D Radicella, SM Reinisch, BW Adeniyi, JO Gonzalez, MEM Zhang, SR Obrou, O BE Rawer, KM Bilitza, DK Oyama, KI Singer, W TI New B0 and B1 models for IRI SO LOWER IONOSPHERE: MEASUREMENTS AND MODELS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT C4 1 Symposium of COSPAR Scientific Commission C Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP COSPAR, Int Union Radio Sci, Int Union Geodesy & Geophys, Int Assoc Geomagnetism & Aeron, Comm Space Res ID PARAMETERS AB The electron density profile in the F region bottomside is described in the International Reference Ionosphere (IRT) by two parameters: a thickness parameter B0 and a shape parameter B1. The models used for B0 and B1 in IRT are based on ionosonde data from magnetic mid-latitude stations. Comparisons with ionosonde data from several stations close to the magnetic equator show large discrepancies between the model and the data. We propose new models for B0 and B1 based on data from several ionosondes including low and mid latitude stations. Close to the magnetic dip equator the new B0 model provides an improvement over the current IRI model by a factor of up to 1.5. (C) 1999 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Goddard Space Flight Ctr, Raytheon STX, Greenbelt, MD 20771 USA. Abdus Salaam Int Ctr Theoret Phys, Aeron & Radiopropagat Lab, I-34100 Trieste, Italy. Univ Massachusetts Lowell, Ctr Atmospher Res, Lowell, MA 01854 USA. Univ Ilorin, Dept Phys, Ilorin, Nigeria. Consejo Nacl Invest Cient & Tecn, CASLEO, RA-5400 San Juan, Argentina. Wuhan Inst Phys & Math, Wuhan 430071, Hubei Province, Peoples R China. Univ Cocody, SSMT, UFR, Lab Phys Atmosphere, Abidjan, Cote Ivoire. RP Bilitza, D (reprint author), NASA, Goddard Space Flight Ctr, Raytheon STX, Code 632, Greenbelt, MD 20771 USA. RI Zhang, Shun-Rong/G-7593-2015 OI Zhang, Shun-Rong/0000-0002-1946-3166 NR 12 TC 45 Z9 45 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES PY 2000 VL 25 IS 1 BP 89 EP 95 DI 10.1016/S0273-1177(99)00902-3 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geochemistry & Geophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geochemistry & Geophysics; Geology; Meteorology & Atmospheric Sciences GA BP43G UT WOS:000085119800012 ER PT S AU Bilitza, D Williamson, R AF Bilitza, D Williamson, R BE Rawer, KM Bilitza, DK Oyama, KI Singer, W TI Towards a better representation of the IRI topside based on Isis and Alouette data SO LOWER IONOSPHERE: MEASUREMENTS AND MODELS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT C4 1 Symposium of COSPAR Scientific Commission C Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP COSPAR, Int Union Radio Sci, Int Union Geodesy & Geophys, Int Assoc Geomagnetism & Aeron, Comm Space Res AB The current IRI topside model is based on the data compilation and grouping that was used for the Bent model (Bent et al., 1972). The principal data source for Bent were Alouette 1 sounder data from a period of low to medium solar activity. Through a systematic search of the NASA archives, we have established a large data base of topside profiles recorded by the Alouette 1, 2, and ISIS 1, 2 topside sounder instruments. Comparison of IRI with these data reveals shortcomings of the model especially in the upper topside. The largest discrepancies are found at low latitudes and at high solar activities. We will discuss the cause of these model limitations and ways to improve the current model with the help of our data base. (C) 1999 COSPAR. Published by Elsevier Science Ltd. C1 Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. Raytheon ITSS, Greenbelt, MD 20770 USA. RP Bilitza, D (reprint author), Goddard Space Flight Ctr, Raytheon ITSS, Code 632, Greenbelt, MD 20771 USA. NR 8 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 J9 ADV SPACE RES-SERIES PY 2000 VL 25 IS 1 BP 149 EP 152 DI 10.1016/S0273-1177(99)00912-6 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geochemistry & Geophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geochemistry & Geophysics; Geology; Meteorology & Atmospheric Sciences GA BP43G UT WOS:000085119800022 ER PT S AU Grebowsky, JM Bilitza, D AF Grebowsky, JM Bilitza, D BE Rawer, KM Bilitza, DK Oyama, KI Singer, W TI Sounding rocket data base of E- and D-region ion composition SO LOWER IONOSPHERE: MEASUREMENTS AND MODELS SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT C4 1 Symposium of COSPAR Scientific Commission C Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP COSPAR, Int Union Radio Sci, Int Union Geodesy & Geophys, Int Assoc Geomagnetism & Aeron, Comm Space Res ID MASS-SPECTROMETER; LOWER IONOSPHERE; HIGH-LATITUDES; MIDLATITUDES; LAYERS AB Detailed in situ ion composition measurements in the E- and D- region ionosphere are available only from eccentric orbiting satellites with very low perigees and from sounding rockets. The lower limit for existing satellite data is about 130 km. Below this altitude mostly sounding rockets have sampled the ion composition. These sounding rocket data sets have been analyzed in the literature individually in the past on a case-by-case basis. In order to provide the best empirical picture possible of the lower ionosphere molecular ion distributions all available published sounding rocket observations of O-2(+) and NO+ ion concentrations were scanned and digitized to provide an empirical data base of the lower ionosphere. There were 43 such flights selected, which were scattered in latitude and local time. There were few low latitude observations, most of the measurements were made from middle and high latitude launch sites. The distributions are characterized at all latitudes by large drops in the concentrations from day to night with the molecular ion O-2(+) having the greatest range of variation above similar to 100 km and NO+ below 90 km. Features of the sounding rocket data distributions at low latitudes, middle latitudes and at high latitudes and its limitations are discussed and the measurements compared with the International Reference Ionosphere (IRI) to investigate the accuracy of the IRI. ion composition model in the lower ionosphere. The IRI ion composition model is based predominantly on dayside midlatitude observations for equinoctial and summer conditions. Our results show that winter nighttime measurements need to be expanded in order to improve the model. (C) 1999 COSPAR. Published by Elsevier Science Ltd. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Raytheon STX Corp, Greenbelt, MD 20771 USA. RP Grebowsky, JM (reprint author), NASA, Goddard Space Flight Ctr, Code 695, Greenbelt, MD 20771 USA. RI Grebowsky, Joseph/I-7185-2013 NR 31 TC 4 Z9 4 U1 1 U2 3 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES PY 2000 VL 25 IS 1 BP 183 EP 192 DI 10.1016/S0273-1177(99)00916-3 PG 10 WC Engineering, Aerospace; Astronomy & Astrophysics; Geochemistry & Geophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geochemistry & Geophysics; Geology; Meteorology & Atmospheric Sciences GA BP43G UT WOS:000085119800026 ER PT S AU Aulanier, G Schneider, B van Driel-Gesztelyi, L Kucera, T Demoulin, P Fang, C Mein, N Vial, JC Mein, P Tang, YH DeForest, C AF Aulanier, G Schneider, B van Driel-Gesztelyi, L Kucera, T Demoulin, P Fang, C Mein, N Vial, JC Mein, P Tang, YH DeForest, C BE Shibata, K Hoshino, M TI 3-D magnetic configurations for filaments and flares: The role of "magnetic dips" and "bald patches" SO MAGNETIC RECONNECTION PROCESSES IN THE SOLAR ATMOSPHERE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT E2 3 Symposium of COSPAR Scientific Commission E Held at the 32nd COSPAR Scientific Assembly CY JUL 12-19, 1998 CL NAGOYA, JAPAN SP Comm Space Res ID CURRENT-SHEET FORMATION; SOLAR-FLARES; FIELDS AB The 3-D magnetic configuration of a filament and of a low energy flare is reconstructed, using linear magnetohydrostatic (lmhs) extrapolations. In both cases, we find observational signatures of energy release at the locations of computed "bald patches" separatrices, characterised by field lines which are tangent to the photosphere. The filament was observed on Sept. 25, 1996, in H alpha with the MSDP on the German VTT, Tenerife, as well as in Si IV with SOHO/SUMER. It is modeled as a twisted flux-tube deformed by the magnetic polarities observed with SOHO/MDI. The shape and location of the computed dipped field lines are in good agreement with the shape of the filament and its feet observed in H alpha. Some "bald patches" (BPs) are present where the distribution of dips reaches the photosphere. We show that some of the large scale field lines rooted in BPs can be related to bright fine structures in Si Iv. We propose that the plasma there is heated by ohmic dissipation from the currents expected to be present along the BP separatrices. The flare was observed on May 18, 1994, in soft X-rays with Yohkoh/SXT, and in H alpha at Mitaka (Japan). The magnetic field is directly extrapolated from a photospheric magnetogram from Kitt Peak Observatory. The intersections with the photosphere of the computed separatrices match well the bright H alpha ribbons. The later are associated to three BPs, with overlaying dipped field lines. We show that enhanced densities are present in these dips, which can be correlated with dark H alpha fibrils. Both cases show the importance of dipped field lines and BPs in the solar atmosphere. Energy release via ohmic dissipation as well as reconnection along BP separatrices is proposed to provide heating observed as UV brightenings in filament channels and even as small flares. (C) 2000 COSPAR. Published by Elsevier Science Ltd. C1 Observ Paris, F-92195 Meudon, France. Konkoly Observ Budapest, H-1525 Budapest, Hungary. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Nanjing Univ, Dept Astron, Nanjing 210093, Peoples R China. Univ Paris 11, CNRS, IAS, F-91405 Orsay, France. RP Aulanier, G (reprint author), Observ Paris, F-92195 Meudon, France. RI Kucera, Therese/C-9558-2012; OI Demoulin, Pascal/0000-0001-8215-6532 NR 12 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2000 VL 26 IS 3 BP 485 EP 488 DI 10.1016/S0273-1177(99)01100-X PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BP89K UT WOS:000086533400019 ER PT S AU Tsyganenko, NA AF Tsyganenko, NA BE Ohtani, S Fujii, R Hesse, M Lysak, RL TI Recent progress in the data-based modeling of magnetospheric currents SO MAGNETOSPHERIC CURRENT SYSTEMS SE GEOPHYSICAL MONOGRAPH SERIES LA English DT Proceedings Paper CT Conference on Magnetospheric Current Systems CY JAN 10-15, 1999 CL KONA, HI SP Amer Geophys Union, Natl Sci Fdn, NASA, USN Off Naval Res ID NEAR-EARTH MAGNETOTAIL; SOLAR-WIND CONTROL; MAGNETIC-FIELD; QUANTITATIVE MODELS; MAGNETOPAUSE SHAPE; GEOMAGNETIC-FIELD; PRESSURE BALANCE; CURRENT SHEET; SIZE; PARAMETERS AB Magnetospheric currents are very diverse and dynamical. The magnetopause shrinks, expands, and erodes, with varying degree of connection to the IMF. Intrusion of the plasma in the polar cusps results in diamagnetic currents which depress the field at high latitudes. The tail current sheet warps, bends, and twists, and its current density varies as the tail stretches and rebounds. Birkeland currents vary with the IMF and with the substorm cycle, and the ring current builds up and decays in the course of storms. During substorms, a dynamical current wedge develops on the nightside, resulting in a rapid reconfiguration of the near-Earth field. The data-based approach to magnetospheric modeling is to develop a flexible representation for the magnetic field vector and fit it to a large set of spacecraft data. All the above currents should be represented in the models in a meaningful way, and substantial advance was made recently in this direction. The new models feature a continuous parametric dependence on the solar wind conditions, include Birkeland currents, and have a solar-wind controlled magnetopause with a penetration of the IMF. New techniques are now available for modeling the twisting and warping of the cross-tail current, the collapse of the tail field during substorms, and the observed structure of the polar cusps. This article overviews some of those developments. C1 NASA, Goddard Space Flight Ctr, Raytheon ITSS Corp, Greenbelt, MD 20771 USA. RP Tsyganenko, NA (reprint author), NASA, Goddard Space Flight Ctr, Raytheon ITSS Corp, Code 690-2, Greenbelt, MD 20771 USA. RI Tsyganenko, Nikolai/J-7377-2012 OI Tsyganenko, Nikolai/0000-0002-5938-1579 NR 34 TC 3 Z9 3 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0065-8448 BN 0-87590-976-0 J9 GEOPH MONOG SERIES PY 2000 VL 118 BP 61 EP 70 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BV01G UT WOS:000177598400007 ER PT S AU Cummer, SA Vondrak, RR Pfaff, RF Gjerloev, JW Carlson, CW Ergun, RE Peria, WJ Elphic, RC Strangeway, RJ Sigwarth, JB Frank, LA AF Cummer, SA Vondrak, RR Pfaff, RF Gjerloev, JW Carlson, CW Ergun, RE Peria, WJ Elphic, RC Strangeway, RJ Sigwarth, JB Frank, LA BE Ohtani, S Fujii, R Hesse, M Lysak, RL TI Auroral surge currents and electrodynamics with FAST and VIS SO MAGNETOSPHERIC CURRENT SYSTEMS SE GEOPHYSICAL MONOGRAPH SERIES LA English DT Proceedings Paper CT Conference on Magnetospheric Current Systems CY JAN 10-15, 1999 CL KONA, HI SP Amer Geophys Union, Natl Sci Fdn, NASA, USN Off Naval Res ID WESTWARD TRAVELING SURGE; SUBSTORMS; SATELLITE; MODEL AB We analyze data from two FAST satellite passes in the vicinity of auroral surges (as seen in the VIS auroral imager on the Polar satellite) to study the large scale ionospheric electrodynamics of the surge, focusing in particular on the configuration of field-aligned and ionospheric currents. While most previous ground and satellite observations have found the surge to be a region of predominantly upward field-aligned currents (FACs), some satellite observations have found evidence for equal downward and upward FACs near the surge, suggesting that the FACs close locally as opposed to globally through the substorm current wedge. Our observations show that while regions of both upward and downward FACs are present near the surge, there is a significant net upward FAC in the northern portion of meridians passing through the surge and just east of the surge. Current continuity requires that these upward currents be fed by downward currents traditionally thought to be in the eastern portion the auroral substorm bulge. Such a current configuration requires a westward ionospheric current to connect the two FAC regions, and this is supported by our observations of a significant southward electric field in the high Hall conductance surge region, which drives a strong westward Hall electrojet connecting the upward surge FACs and the presumed downward FACs east of the surge. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Cummer, SA (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Code 690, Greenbelt, MD 20771 USA. RI Cummer, Steven/A-6118-2008; Pfaff, Robert/F-5703-2012 OI Cummer, Steven/0000-0002-0002-0613; Pfaff, Robert/0000-0002-4881-9715 NR 18 TC 1 Z9 1 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0065-8448 BN 0-87590-976-0 J9 GEOPH MONOG SERIES PY 2000 VL 118 BP 191 EP 197 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BV01G UT WOS:000177598400018 ER PT S AU Hesse, M Birn, J AF Hesse, M Birn, J BE Ohtani, S Fujii, R Hesse, M Lysak, RL TI Near- and mid-tail current flow during substonns: Small- and large-scale aspects of current disruption SO MAGNETOSPHERIC CURRENT SYSTEMS SE GEOPHYSICAL MONOGRAPH SERIES LA English DT Proceedings Paper CT Conference on Magnetospheric Current Systems CY JAN 10-15, 1999 CL KONA, HI SP Amer Geophys Union, Natl Sci Fdn, NASA, USN Off Naval Res ID COLLISIONLESS MAGNETIC RECONNECTION; THIN CURRENT SHEETS; MAGNETOTAIL RECONNECTION; PARTICLE SIMULATIONS; MHD SIMULATIONS; NEUTRAL SHEET; CURRENT WEDGE; INSTABILITY; PLASMA; MODEL AB We investigate kinetic processes of relevance to the re-arrangement of magnetotail current systems during the substorm growth and expansion phases. The studies address microphysical processes occurring in the magnetotail current layer with clear macroscopic consequences. They are based on fully self-consistent, electromagnetic, particle-in-cell simulations. The first focus of the analyses is on the pre-onset formation of a thin current sheet. The additional current, brought about by the lobe magnetic field increase associated with solar wind-like driving electric fields, appears to be carried by the electrons, in a thin current sheet of substantially enhanced current density. Thin current sheet formation leads to a reduction in the normal magnetic field, which is shown to be sufficient for magnetic reconnection to initiate. This onset is analyzed in detail. Last, an investigation of the kinetic kink instability, which can lead to strong current sheet warping, and potentially to turbulence, is presented. The results here support earlier analytical results indicating that kinetic kinking growth rates are strongly reduced if realistic ion-electron mass ratios are considered. C1 NASA, Goddard Space Flight Ctr, Electrodynam Branch, Greenbelt, MD USA. RP Hesse, M (reprint author), NASA, Goddard Space Flight Ctr, Electrodynam Branch, Greenbelt, MD USA. RI Hesse, Michael/D-2031-2012 NR 33 TC 17 Z9 17 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0065-8448 BN 0-87590-976-0 J9 GEOPH MONOG SERIES PY 2000 VL 118 BP 295 EP 303 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BV01G UT WOS:000177598400030 ER PT J AU Sullivan, MC Cowen, RK Able, KW Fahay, MP AF Sullivan, MC Cowen, RK Able, KW Fahay, MP TI Spatial scaling of recruitment in four continental shelf fishes SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE recruitment; scale; essential fish habitat; continental shelf; New York Bight; Limanda ferruginea; Citharichthys arctifrons; Hippoglossina oblonga; Merluccius bilinearis ID MIDDLE ATLANTIC BIGHT; GREAT-BARRIER-REEF; MARINE FISH; TEMPERATE REEF; GEORGES-BANK; GRAND BANK; VARIABILITY; ABUNDANCE; MORTALITY; PATTERNS AB With the recent decline of several exploited populations of northwest Atlantic fishes,. effort has been directed toward understanding the scales at which recruitment varies along with the deterministic processes underlying this variability. Using surveys from 3 research submersible cruises (1994, 1997, 1998), we examined the distributions of 4 species of recently settled groundfish in relation to spatial scale on the New York Eight region of the continental shelf (USA). A hierarchical sampling design was used to calculate the percent variability in abundance partitioned over 4 nested scales: submersible transect (similar to 100 m), site (similar to 10 km), shelf zone (similar to 25 km), and sampling line (similar to 100 km). For all years, early juveniles of Limanda ferruginea (yellowtail flounder) were highly concentrated at the shelf-zone scale, where abundance followed the thermal contours of a mid-shelf cold pool of remnant winter water. Conversely, Hippoglossina oblonga (fourspot flounder) and Citharichthys arctifrons (Gulf Stream flounder) were highly site-dependent, bounding the distribution of L. ferruginea at inner and outer shelf sites, respectively. Merluccius bilinearis (silver hake) exhibited moderate to high variability partitioned over several scales. For all species, the absence of sampling-line variability suggested that settlement patterns were consistent across the breadth of the shelf, while substantial residual. variance suggested that microscale-level processes generated additional variability. Annual settlement of these early juveniles is highly specialized and cued to distinct aspects of the physical and biological setting of the New York Eight. Conceptually, these local habitat parameters can be used to link nodes of high variability with the possible deterministic processes modifying recruitment. Our results underscore the critical contribution juvenile nursery habitats may have to the subsequent survival and growth of continental shelf species. C1 SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. Rutgers State Univ, Inst Marine & Coastal Sci, Marine Field Stn, Tuckerton, NJ 08857 USA. Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Sandy Hook Lab, Highlands, NJ 07732 USA. RP Sullivan, MC (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Marine Biol & Fisheries, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. EM msullivan@rsmas.miami.edu NR 89 TC 31 Z9 31 U1 1 U2 4 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2000 VL 207 BP 141 EP 154 DI 10.3354/meps207141 PG 14 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 388GE UT WOS:000166168900013 ER PT J AU Humphreys, RL AF Humphreys, RL TI Otolith-based assessment of recruitment variation in a North Pacific seamount population of armorhead Pseudopentaceros wheeleri SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE recruitment variation; characteristics of recruits; pelagic duration; recruit size; otolith-increment width; armorhead; Pseudopentaceros wheeleri; seamounts ID ENGRAULIS-MORDAX; OCEAN; FISHERIES; SALMON; PENTACEROTIDAE; VARIABILITY; ANCHOVY; GROWTH; LARVAL; ALASKA AB An investigation into armorhead Pseudopentaceros wheeleri recruitment variation at Southeast Hancock Seamount (in the central North Pacific) focused on the examination of recruit characteristics, primarily those derived from otolith-increment analysis. Otoliths from recruits were sampled from years representing relatively strong (509 metric tons [t] in 1980), moderate (58 t in 1986), and weak (1 t in 1989) recruitment biomass. Recruit body length was also examined among these 3 years and from 10 additional years, providing even higher recruitment contrast. Transverse sections of sagittal otoliths were prepared, and yielded information on the mean and variability in pre-recruit pelagic duration and increment-width profiles. Mean length of female recruits, and to a lesser extent of mean pelagic duration, decreased with increasing recruitment strength. Although generally similar in shape, the mean increment-width sequence spanning the first 1.8 yr of the 2+ yr pelagic phase differed among recruit years. Transitions in sequential increment-width (inflection points) were exhibited among all recruit years and occurred primarily within the first pelagic year interval. The weak 1989 recruit year was most distinct among recruit years in exhibiting lower increment widths at each of these inflection points. C1 NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, Honolulu, HI 96822 USA. RP Humphreys, RL (reprint author), NOAA, Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Honolulu Lab, 2570 Dole St, Honolulu, HI 96822 USA. EM robert.humphreys@noaa.gov NR 40 TC 11 Z9 11 U1 0 U2 2 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2000 VL 204 BP 213 EP 223 DI 10.3354/meps204213 PG 11 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 365GW UT WOS:000089943900018 ER PT J AU Stoner, AW Ray-Culp, M AF Stoner, AW Ray-Culp, M TI Evidence for Allee effects in an over-harvested marine gastropod: density-dependent mating and egg production SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE conservation; depensation; fisheries management; reproduction; spawning; Strombus gigas ID STROMBUS-GIGAS; QUEEN CONCH; FERTILIZATION SUCCESS; STOCK ENHANCEMENT; FISH STOCKS; BAHAMAS; DEPENSATION; ABUNDANCE AB Conservation programs often focus on studying extinction risks encountered by small populations and determining minimum population sizes below which they cannot recover. In certain cases, per capita rates of population growth become negative at low population density. This 'Allee effect' (or 'depensation') is rarely considered in marine systems. We conducted surveys of adult density, reproductive behavior, and spawning in natural populations of Caribbean queen conch Strombus gigas at 2 locations in the Exuma Gays, Bahamas, to test for Allee effects. Mating never occurred when density was <56 conch ha(-1), and spawning never occurred at <48 conch ha(-1), clearly demonstrating the operation of depensatory mechanisms. Reproductive behavior then increased rapidly to asymptotes at densities near 200 conch ha(-1). Heavily exploited populations of queen conch in the Caribbean have been slow to recover despite fishery closures. Failure to recover could result from spawning stock densities that are reduced to the point at which Allee effects begin to operate on reproductive behavior. C1 Caribbean Marine Res Ctr, Lee Stocking Isl Field Stn, Exuma Cays, Bahamas. RP Stoner, AW (reprint author), NOAA, Natl Marine Fisheries Serv, Fisheries Behav Ecol Program, Alaska Fisheries Sci Ctr, 2030 S Marine Sci Dr, Newport, OR 97365 USA. EM al.stoner@hmsc.orst.edu NR 36 TC 104 Z9 112 U1 4 U2 20 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2000 VL 202 BP 297 EP 302 DI 10.3354/meps202297 PG 6 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 354VF UT WOS:000089349800025 ER PT J AU Rozas, LP Zimmerman, RJ AF Rozas, LP Zimmerman, RJ TI Small-scale patterns of nekton use among marsh and adjacent shallow nonvegetated areas of the Galveston Bay Estuary, Texas (USA) SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE fishery species; Gulf of Mexico; habitat comparisons; habitat selection; nursery areas; penaeid shrimps; tidal marsh; restoration ID CALLINECTES-SAPIDUS RATHBUN; SHRIMP PENAEUS-AZTECUS; JUVENILE BLUE CRABS; SALT-MARSH; BROWN SHRIMP; NORTH-CAROLINA; DECAPOD CRUSTACEANS; NATANT MACROFAUNA; INTERTIDAL CREEK; SOUTH-CAROLINA AB We quantified and compared nekton and infaunal densities among vegetated (edge Spartina alterniflora, inner Spartina alterniflora, Scirpus maritimus, Juncus roemerianus, and Spartina patens marsh) and shallow nonvegetated (marsh pond, marsh channel, cove, and shallow bay) areas of upper Galveston Bay and East Bay, Texas. in 2 seasons (spring and fall) of high nekton abundance, and over 2 yr, we collected 267 quantitative samples (upper Galveston Bay, 1993 = 127 and East Bay, 1994 = 140) using a 1 m(2) drop sampler. The vegetated marsh surface consistently contained more species (i.e, higher species richness) and total numbers of decapod crustaceans than nonvegetated areas. In contrast, fish species richness and densities of total fishes on the marsh and in nonvegetated areas were not significantly different in most comparisons. Most numerically dominant species of nekton seemed to exhibit at least some degree of habitat selection. Within vegetation, 2 factors, elevation and proximity to open water, were most important in influencing the distribution of nekton. Low marsh edge dominated by Spartina alterniflora or Scirpus maritimus was apparently selected by most species that used the marsh surface including brown shrimp Farfantepenaeus aztecus, blue crab Callinectes sapidus, and daggerblade grass shrimp Palaemonetes pugio. White shrimp Litopenaeus setiferus and striped mullet Mugil cephalus also were concentrated in low edge marsh; although in one comparison, densities of these 2 species in edge and inner S, alterniflora were not significantly different. In contrast, gulf killifish Fundulus grandis and sheepshead minnow Cyprinodon variegatus were most abundant on inner S. alterniflora or S, patens marsh. Other fishes (gulf menhaden Brevoortia patronus, spot Leiostomus xanthurus, bay anchovy Anchoa mitchilli, blackcheek tonguefish Symphurus plagiusa, and Atlantic croaker Micropogonias undulatus) had higher densities over nonvegetated bottoms than on the marsh surface. Specific habitat types that these pelagic species seemed to favor were marsh channels (gulf menhaden, bay anchovy), marsh ponds (spot), and coves (Atlantic croaker, blackcheek tonguefish). Overall, marsh-surface and adjacent nonvegetated habitat types contained much higher densities of most nekton than the shallow bay. Infaunal densities were estimated from sediment cores, and taxa (mainly annelids, crustaceans, molluscs, and insects) were most abundant in nonvegetated areas contiguous with marsh in the spring. Factors that influenced infaunal abundance are complex and may include predation, flooding patterns, elevation, and distance to edge. Our study has important implications for designing marsh-creation projects. Based on our results, we recommend creating a variety of marsh and contiguous shallow-water areas to enhance nekton biodiversity. To maximize fishery habitat, priority should be given to constructing low marsh edge by creating large areas of low marsh interspersed with a dense network of shallow channels and interconnected ponds. C1 NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Galveston, TX 77551 USA. RP Rozas, LP (reprint author), NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, 4700 Ave U, Galveston, TX 77551 USA. EM lawrence.rozas@noaa.gov NR 66 TC 95 Z9 100 U1 3 U2 37 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PY 2000 VL 193 BP 217 EP 239 DI 10.3354/meps193217 PG 23 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA 298AA UT WOS:000086115400021 ER PT J AU Nazarova, KA Wasilewski, PJ Dick, HJB AF Nazarova, KA Wasilewski, PJ Dick, HJB TI Magnetic study of serpentinized harzburgites from the Islas Orcadas Fracture Zone SO MARINE GEOPHYSICAL RESEARCHES LA English DT Article ID MID-ATLANTIC RIDGE; PSD GRAIN-SIZE; NATURAL MAGNETITES; OPAQUE MINERALOGY; GRAVITY-ANOMALIES; BURRO MOUNTAIN; ROCKS; PERIDOTITES; CALIFORNIA; PETROLOGY AB Magnetic properties and bulk densities of 27 serpentinized harzburgite samples from the Islas Orcadas Fracture Zone, located in the vicinity of the Bouvet Triple Junction, have been measured and analyzed. Polished sections were examined using reflected light and scanning electron microscopy to characterize the size and geometric arrangement of opaque minerals. The relationship between the saturation magnetization (I-S) and remanent coercive force (H-R) is considered in terms of the amount of ferrimagnetic material and maghemitization. A suite of continental serpentinites from Canada is offered as contrast, to consider the role of weathering and maghemitization. Magnetite in the Islas Orcadas serpentinites is variably maghemitized, whereas continental serpentinites do not appear to contain maghemitized oxides. We verify this with optical microscopy, thermomagnetic analyses and cryogenic temperature cycling of saturation remanence. Maghemitization serves to reduce initial magnetic susceptibility, and introduce error in the use of I-S to evaluate the magnetic mode of magnetite. The presence of maghemite and the existence of a three dimensional vein network for magnetite geometry would suggest that magnetic hysteresis parameters can not reliably indicate grain size. Magnetic hysteresis ratios fall in a restricted range regardless of coercivity. The apparent grain size configured in a three dimensional vein network plus maghemitization might be responsible for this observation. Maghemitization does not affect thermal magnetic stability and enhances the geophysical importance of remanence in serpentinites. Paleomagnetic data suggest that important information about the geologic circumstances for oceanic rock serpentinization is embodied in the paleomagnetic records. This observation may be very important for generation of long wavelength aeromagnetic and possibly even satellite magnetic anomalies. C1 NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. Russian Acad Sci, Inst Phys Earth, Moscow 123810, Russia. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. RP Nazarova, KA (reprint author), NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. NR 39 TC 5 Z9 5 U1 1 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0025-3235 J9 MAR GEOPHYS RES JI Mar. Geophys. Res. PY 2000 VL 21 IS 5 BP 475 EP 488 DI 10.1023/A:1026550011802 PG 14 WC Geochemistry & Geophysics; Oceanography SC Geochemistry & Geophysics; Oceanography GA 382EC UT WOS:000165809000004 ER PT J AU Smialek, JL AF Smialek, JL TI Non-protective alumina growth in sulfur-doped NiAl(Zr) SO MATERIALS AT HIGH TEMPERATURES LA English DT Article; Proceedings Paper CT 4th International Conference on the Microscopy of Oxidation CY SEP 20-22, 1999 CL CAMBRIDGE, ENGLAND DE NiAl; sulfur segregation; oxidation; Al2O3 scales ID OXIDE SCALE ADHERENCE; INTERMETALLIC COMPOUNDS; OXIDATION; SEGREGATION; IMPURITY; YTTRIUM AB The 1,200 degrees C oxidation behavior of NiAl was examined at various levels of sulfur and zirconium dopants to test the possibility of a critical S/Zr ratio required for adhesion. Cyclic furnace testing for 200 l-h cycles and interrupted testing for 500 h were used as screening tests. Pure NiAl and NiAl(Zr) with 0.14 at. % Zr were chosen as model base compositions; they exhibited normal, slow-growing scales (3 mg/cm(2)) with excellent adhesion for the Zr-doped alloys. NiAl with about 120 ppma S exhibited a substantial weight loss (-20 mg/cm(2)) in cyclic tests and a very large weight gain (+60 mg/cm(2)) in interrupted tests. The major surface phase remained as alpha-Al2O3. Sulfur doping the NiA1(Zr) alloy caused massive weight gains of 80-100 mg/cm(2), swelling, cracking, and nearly complete conversion into NiAl2O4 and alpha-Al2O3. The initial objective of determining critical S/Zr ratios for adhesion was therefore unattainable. Initiation of the catastrophic attack was examined after a 10 h exposure, revealing a few sites of broad, raised, and cracked ridges. In cross-section, the ridges appeared as nodular intrusions, with a complex, fractal, oxide-metal interface. They were primarily alumina (with occasional entrapped islands of NiAl2O4 or pure Ni metal). They possessed a unique microstructure consisting of 0.3 mu m lamellae, separated by 0.1 mu m open channels. This allowed for rapid growth controlled by gaseous diffusion. The microstructure is discussed in terms of SO2 evolution and a sulfur-driven depassivation process. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Smialek, JL (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 19 TC 4 Z9 4 U1 0 U2 6 PU SCIENCE & TECHNOLOGY LETTERS PI NORTHWOOD PA PO BOX 81,, NORTHWOOD HA6 3DN, MIDDX, ENGLAND SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 2000 VL 17 IS 1 BP 71 EP 77 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 318NU UT WOS:000087291000012 ER PT J AU Hou, PY Smialek, JL AF Hou, PY Smialek, JL TI The effect of H(2)-anneal on the adhesion of Al(2)O(3) scales on a Fe(3)Al-based alloy SO MATERIALS AT HIGH TEMPERATURES LA English DT Article; Proceedings Paper CT 4th International Conference on the Microscopy of Oxidation CY SEP 20-22, 1999 CL CAMBRIDGE, ENGLAND DE Fe(3)Al; Al(2)O(3); adhesion; sulfur segregation; reactive element ID REACTIVE ELEMENT; SULFUR; SEGREGATION; ADHERENCE; ALUMINA; GROWTH AB The cyclic (1,100 degrees C, air) and isothermal (1,000 degrees C, O(2)) oxidation behavior of a Fe-28Al-5Cr (at%) alloy, with and without a prior H(2)-anneal heat treatment at 1,200 degrees C for 100 h, was studied. Changes in interfacial chemistry were evaluated using Scanning Anger Microscopy after removal of the oxide film in ultra high vacuum. This was achieved by making a scratch on the specimen surface, which caused spallation of the film at various locations along the scratch. The scale thickness and the temperature drop at which spallation took place during cooling were utilized to semi-quantitatively compare the adherence of the scales. Porosity at the scale-alloy interface and the scale microstructure were determined from scanning electron microscope observations. It was found that H(2)-anneal greatly improved scale adhesion and resulted in a pore-free and sulfur-free interface. The effects were similar to that of a 0.1 at% Zr-containing alloy, except that the improvement in scale adhesion was not as great as that from Zr doping. This implies that oxide/alloy interfaces are not intrinsically strong and the effect of reactive elements, such as Zr, is more than preventing impurity from segregating to the interface. Results are also compared with the effect of H(2)-anneal on other model alloys, such as NiCrAl, FeCrAl and NiAl, and on single crystal superalloys. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Hou, PY (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 25 TC 24 Z9 24 U1 0 U2 6 PU SCIENCE REVIEWS 2000 LTD PI ST ALBANS PA PO BOX 314, ST ALBANS AL1 4ZG, HERTS, ENGLAND SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 2000 VL 17 IS 1 BP 79 EP 85 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 318NU UT WOS:000087291000013 ER PT J AU Nesbitt, JA Draper, SL Barrett, CA AF Nesbitt, JA Draper, SL Barrett, CA TI Cyclic oxidation of FeCrAlY/Al2O3 composites SO MATERIALS AT HIGH TEMPERATURES LA English DT Article; Proceedings Paper CT 4th International Conference on the Microscopy of Oxidation CY SEP 20-22, 1999 CL CAMBRIDGE, ENGLAND DE cyclic oxidation; FeCrAlY; FeCrAlY/Al2O3 composites; fibers ID FE-CR-AL; ALPHA-AL2O3; BEHAVIOR; ALLOYS AB Three-ply composites consisting of a FeCrAlY matrix and continuous single crystal Al2O3 (sapphire) fibers were cyclically oxidized at 1,000 degrees and 1,100 degrees C for up to 1,000 l-h cycles. FeCrAlY matrix only samples were also fabricated and tested for comparison. Fiber ends were exposed at the ends of the composite samples. Following cyclic oxidation, cracks running parallel to and perpendicular to the fibers were observed on the large surface of the composite. In addition, there was evidence of increased scale damage and spallation around the exposed fiber ends, particularly around the middle ply fibers. This damage was more pronounced at the higher temperature. The exposed fiber ends showed cracking between fibers in the outer plies, occasionally with Fe and Cr-rich oxides growing out of the cracks. Large gaps developed at the fiber-matrix interface around many of the fibers, especially those in the outer plies. Oxygen penetrated many of these gaps resulting in significant oxide formation at the fiber-matrix interface far within the composite sample. Around several fibers, the matrix was also internally oxidized showing Al2O3 precipitates in a radial band around the fibers. The results show that these composites have poor cyclic oxidation resistance due to the CTE mismatch and inadequate fiber-matrix bond strength at temperatures of 1,000 degrees C and above. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Nesbitt, JA (reprint author), NASA, Glenn Res Ctr, M-S 106-1,2100 Brookpk Rd, Cleveland, OH 44135 USA. NR 12 TC 0 Z9 0 U1 0 U2 2 PU SCIENCE & TECHNOLOGY LETTERS PI NORTHWOOD PA PO BOX 81,, NORTHWOOD HA6 3DN, MIDDX, ENGLAND SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 2000 VL 17 IS 1 BP 139 EP 147 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 318NU UT WOS:000087291000021 ER PT J AU Ogbuji, LUJT AF Ogbuji, LUJT TI Degradation of a SiC/SiC composite in the burner rig: investigation by fractography SO MATERIALS AT HIGH TEMPERATURES LA English DT Article; Proceedings Paper CT 4th International Conference on the Microscopy of Oxidation CY SEP 20-22, 1999 CL CAMBRIDGE, ENGLAND DE SiC/SiC composite; burner rig; fractography ID LOW-OXYGEN; TEMPERATURE AB Oxidation occurs at two levels in a fiber-reinforced composite, the more pernicious form being "internal oxidation". In SiC/SiC composites a compliant interphase layer of carbon or boron nitride permeates the entire structure, and can serve as conduit for deep ingress of ambient oxidants. Because such insidious ("pest") attack is not amenable to the usual analysis by measurement of weight change or oxide thickness, it thwarts efforts at routine prediction of service life. However, it leaves its signature in the microstructure. Hence, microscopy provides a useful tool for assessing pest degradation in SiC/SiC composites. This paper summarizes our studies on the Hi-Nicalon/BN/SiC composite, in which various microscopy tools were used to reveal features and disclose mechanisms behind the catastrophic degradation of this material in a burner rig. C1 NASA, Glenn Res Ctr Lewis Field, Dynacs Engn Co, Cleveland, OH 44135 USA. RP Ogbuji, LUJT (reprint author), NASA, Glenn Res Ctr Lewis Field, Dynacs Engn Co, Cleveland, OH 44135 USA. NR 7 TC 4 Z9 4 U1 1 U2 3 PU SCIENCE & TECHNOLOGY LETTERS PI NORTHWOOD PA PO BOX 81,, NORTHWOOD HA6 3DN, MIDDX, ENGLAND SN 0960-3409 J9 MATER HIGH TEMP JI Mater. High Temp. PY 2000 VL 17 IS 2 BP 369 EP 372 DI 10.3184/096034000783641036 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 344TA UT WOS:000088773900028 ER PT J AU Bar-Cohen, Y AF Bar-Cohen, Y TI Emerging NDT technologies and challenges at the beginning of the third millennium, part 1 SO MATERIALS EVALUATION LA English DT Article ID SUBSURFACE CORROSION; COMPOSITES; AIRCRAFT; SYSTEM C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bar-Cohen, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,82-105, Pasadena, CA 91109 USA. NR 28 TC 31 Z9 31 U1 0 U2 4 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD JAN PY 2000 VL 58 IS 1 BP 17 EP + PG 9 WC Materials Science, Characterization & Testing SC Materials Science GA 272QT UT WOS:000084663000003 ER PT S AU Ting, DZY McGill, TC Chen, NY Wang, JN Li, RG Wang, YQ Ge, WK Schulman, JN AF Ting, DZY McGill, TC Chen, NY Wang, JN Li, RG Wang, YQ Ge, WK Schulman, JN BE Merhari, L Wille, LT Gonsalves, KE Gyure, MF Matsui, S Whitman, LJ TI Effects of interface roughness and embedded nanostructures on device properties SO MATERIALS ISSUES AND MODELING FOR DEVICE NANOFABRICATION SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Issues and Modeling for Device Nanofabrication CY NOV 29-DEC 02, 1999 CL BOSTON, MA SP Mat Res Soc ID DIELECTRIC-BREAKDOWN; TUNNELING STRUCTURES; QUANTUM TRANSPORT; IMPURITIES AB We give an overview of the open-boundary planar supercell stack method (OPSSM), as a means for treating 3D quantum transport in mesoscopic tunnel structures. The flexibility of the method allows us to examine a variety of physical phenomena relevant to quantum transport. In this work we focus on the effects of interface roughness and embedded nanostructures in tunnel devices. Four representative applications of OPSSM are discussed: (1) interface roughness in double barrier resonant tunneling structures, (2) self-organized InAs quantum dot insertions in GaAs/AlAs double barrier structures, (3) tunneling characteristics of ultra-thin oxides with interface roughness, and, (4) embedded quantum wire model of dielectric breakdown. These examples demonstrate scattering and localization effects under different biasing conditions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ting, DZY (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 16 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 1-55899-492-0 J9 MATER RES SOC SYMP P PY 2000 VL 584 BP 223 EP 232 PG 10 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing SC Engineering; Materials Science GA BQ82A UT WOS:000089704100027 ER PT S AU Romanofsky, RR Van Keuls, FW Warner, JD Mueller, CH Alterovitz, SA Miranda, FA Qureshi, RH AF Romanofsky, RR Van Keuls, FW Warner, JD Mueller, CH Alterovitz, SA Miranda, FA Qureshi, RH BE Jia, QX Miranda, FA Oates, DE Xi, XX TI Analysis and optimization of thin film ferroelectric phase shifters SO MATERIALS ISSUES FOR TUNABLE RF AND MICROWAVE DEVICES SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Materials Issues for Tunable RF and Microwave Devices CY NOV 30-DEC 02, 1999 CL BOSTON, MA SP Mat Res Soc AB Microwave phase shifters have been fabricated from (YBa2Cu3O7-delta or Au)/SrTiO3 and Au/BaxSr1-xTiO3 films on LaAlO3 and MgO substrates. These coupled microstrip devices rival the performance of their semiconductor counterparts at Ku- and K-band frequencies. Typical insertion loss for room temperature ferroelectric phase shifters at K-band is approximate to 5 dB. An experimental and theoretical investigation of these novel devices explains the role of the ferroelectric film in overall device performance. A roadmap to the development of a 3 dB insertion loss phase shifter that would enable a new type of phased array antenna is discussed. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Cleveland, OH 44142 USA. Cleveland State Univ, Cleveland, OH 44101 USA. RP Romanofsky, RR (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 13 TC 6 Z9 13 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-511-0 J9 MATER RES SOC SYMP P PY 2000 VL 603 BP 3 EP 14 PG 12 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA BQ82C UT WOS:000089705600001 ER PT S AU Jordan, T Ounaies, Z Tripp, J Tcheng, P AF Jordan, T Ounaies, Z Tripp, J Tcheng, P BE WunFogle, M Uchino, K Ito, Y Gotthardt, R TI Electrical properties and power considerations of a piezoelectric actuator SO MATERIALS OF SMART SYSTEMS III SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 3rd Symposium on Smart Materials held at the 1999 MRS Fall Meeting CY NOV 30-DEC 02, 1999 CL BOSTON, MA SP USN Off Res, Mat Res Soc ID CONSUMPTION AB This paper assesses the electrical characteristics of piezoelectric wafers for use in aeronautical applications such as active noise control in aircraft. Determination of capacitive behavior and power consumption is necessary to optimize the system configuration and to design efficient driving electronics. Empirical relations are developed from experimental data to predict the capacitance and loss tangent of a PZT5A ceramic as nonlinear functions of both applied peak voltage and driving frequency. Power consumed by the PZT is the rate of energy required to excite the piezoelectric system along with power dissipated due to dielectric loss and mechanical and structural damping. Overall power consumption is thus quantified as a function of peak applied voltage and driving frequency. It was demonstrated that by incorporating the variation of capacitance and power loss with voltage and frequency, satisfactory estimates of power requirements can be obtained. These relations allow general guidelines in selection and application of piezoelectric actuators and driving electronics for active control applications. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Jordan, T (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 8 TC 3 Z9 3 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-512-9 J9 MATER RES SOC SYMP P PY 2000 VL 604 BP 203 EP 208 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA BQ82D UT WOS:000089705900029 ER PT B AU Johnson, AR AF Johnson, AR BE Whiteman, JR TI A viscoelastic hybrid shell finite element SO MATHEMATICS OF FINITE ELEMENTS AND APPLICATIONS X LA English DT Proceedings Paper CT 10th Conference on the Mathematics of Finite Elements and Applications (MAFELAP 1999) CY JUN 22-25, 1999 CL BRUNEL UNIV, UXBRIDGE, ENGLAND SP USA, European Res Off, Inst Math & Applicat HO BRUNEL UNIV DE viscoelasticity; hybrid elements; tyre models AB An elastic large displacement thick-shell hybrid finite element is modified to allow for the calculation of viscoelastic stresses. Internal strain variables are introduced at the element's stress nodes and are employed to construct a viscous material model. First order ordinary differential equations relate the internal strain variables to the corresponding elastic strains at the stress nodes. The viscous stresses are computed from the internal strain variables using viscous moduli which are a fraction of the elastic moduli. The energy dissipated by the action of the viscous stresses is included in the mixed variational functional. Nonlinear quasistatic viscous equilibrium equations are then obtained. Previously developed Taylor expansions of the equilibrium equations are modified to include the viscous terms. A predictor-corrector time marching solution algorithm is employed to solve the algebraic-differential equations. The viscous shell element is employed to numerically simulate a stair-step loading and unloading of an aircraft tyre in contact with a frictionless surface. C1 USA, NASA, Langley Res Ctr, Res Lab,Vehicle Technol Directorate, Hampton, VA 23681 USA. RP Johnson, AR (reprint author), USA, NASA, Langley Res Ctr, Res Lab,Vehicle Technol Directorate, MS 240, Hampton, VA 23681 USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-08-043568-8 PY 2000 BP 87 EP 96 DI 10.1016/B978-008043568-8/50005-5 PG 10 WC Mathematics, Applied SC Mathematics GA BQ58L UT WOS:000088869600005 ER PT S AU DiCarlo, JA Yun, HM AF DiCarlo, JA Yun, HM BE Jenkins, MG LaraCurzio, E Gonczy, ST TI Fiber test development for ceramic composite thermomechanical properties SO MECHANICAL, THERMAL AND ENVIRONMENTAL TESTING AND PERFORMANCE OF CERAMIC COMPOSITES AND COMPONENTS SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Environmental, Mechanical, and Thermal Properties and Performance of Continuous Fiber Ceramic Composite (CFCC) Materials and Components CY MAY 18, 1999 CL SEATTLE, WA SP Amer Soc Testing & Mat, Comm E08 Fatigue & Fracture, Amer Soc Testing & Mat, Comm D30 Adv Composites DE fiber testing; fabric testing; creep-rupture; Larson-Miller; Monkman-Grant; CFCC rupture modeling; matrix cracking; environmental effects ID HIGH-TEMPERATURE; CREEP AB Many of the key thermomechanical tensile properties of continuous-fiber ceramic composites (CFCC), such as ultimate fast-fracture strength and long-term rupture strength, are controlled by the dl:formation and fracture properties of the reinforcing fibers. For this reason, research efforts are ongoing at NASA to develop fiber test procedures and composite property models that will allow use of the fiber data to accurately predict these CFCC strength properties for a variety of potential application conditions. Because of the current interest in two-dimensional woven composites, emphasis is being placed on the testing of single small-diameter fibers and single-ply fabrics. The primary objective of this paper is to review the status of these efforts. It is shown that the fabric tests and procedures need further development in order to use bundle strength theory to predict the fast-fracture strength of as-fabricated CFCC. On the other hand, the single-fiber tests using simple composite rupture models yield predictions in good agreement with available data for CFCC rupture strength at high temperatures. C1 NASA, Glenn Res Ctr, Ceram Branch, Cleveland, OH 44135 USA. RP DiCarlo, JA (reprint author), NASA, Glenn Res Ctr, Ceram Branch, MS 106-5,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 22 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2872-X J9 AM SOC TEST MATER PY 2000 VL 1392 BP 134 EP 147 DI 10.1520/STP15010S PG 14 WC Materials Science, Ceramics; Materials Science, Characterization & Testing SC Materials Science GA BR55G UT WOS:000166791500009 ER PT S AU Verrilli, M Kantzos, P Telesman, J AF Verrilli, M Kantzos, P Telesman, J BE Jenkins, MG LaraCurzio, E Gonczy, ST TI Characterization of damage accumulation in a carbon fiber-reinforced silicon carbide ceramic matrix composite (C/SiC) subjected to mechanical loadings at intermediate temperature SO MECHANICAL, THERMAL AND ENVIRONMENTAL TESTING AND PERFORMANCE OF CERAMIC COMPOSITES AND COMPONENTS SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Environmental, Mechanical, and Thermal Properties and Performance of Continuous Fiber Ceramic Composite (CFCC) Materials and Components CY MAY 18, 1999 CL SEATTLE, WA SP Amer Soc Testing & Mat, Comm E08 Fatigue & Fracture, Amer Soc Testing & Mat, Comm D30 Adv Composites DE C/SiC composites; fatigue testing; creep-rupture testing; oxidation; continuous fiber ceramic composite ID OXIDATION; KINETICS; BEHAVIOR AB Creep-rupture and fatigue tests were conducted to identify the failure modes and degradation mechanisms of a [0/90] carbon fiber reinforced silicon carbide (C/SiC) composite at 550 and 650 degreesC. When compared on a maximum stress versus time to failure basis at a given temperature, fatigue testing yielded longer lives than creep-rupture testing. Tests conducted at 550 degreesC had longer lives than 650 degreesC tests. The rate of modulus degradation was similar for both temperatures and loading modes. Examination of tested specimens revealed that oxidation of the carbon fibers was the dominant damage mechanism for C/SiC at these temperatures and test conditions. The oxidation damage occurred globally within the surface of the specimen gage section, and locally in the interior of the composite, around pre-existing matrix cracks and pores. The results of this study indicate that, under the test conditions employed here, specimen life is governed by a combination of time at temperature and time-averaged stress and is not cycle dependent. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Verrilli, M (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 15 TC 5 Z9 5 U1 3 U2 7 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2872-X J9 AM SOC TEST MATER PY 2000 VL 1392 BP 245 EP 261 DI 10.1520/STP15018S PG 17 WC Materials Science, Ceramics; Materials Science, Characterization & Testing SC Materials Science GA BR55G UT WOS:000166791500017 ER PT S AU Morscher, GN Gyekenyesi, JZ Bhatt, RT AF Morscher, GN Gyekenyesi, JZ Bhatt, RT BE Jenkins, MG LaraCurzio, E Gonczy, ST TI Damage accumulation in 2-D woven SiC/SiC ceramic matrix composites SO MECHANICAL, THERMAL AND ENVIRONMENTAL TESTING AND PERFORMANCE OF CERAMIC COMPOSITES AND COMPONENTS SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Environmental, Mechanical, and Thermal Properties and Performance of Continuous Fiber Ceramic Composite (CFCC) Materials and Components CY MAY 18, 1999 CL SEATTLE, WA SP Amer Soc Testing & Mat, Comm E08 Fatigue & Fracture, Amer Soc Testing & Mat, Comm D30 Adv Composites DE SiC/SiC composite; damage accumulation; matrix cracking; intermediate temperature embrittlement ID STRESS-RUPTURE; ACOUSTIC-EMISSION; CRACK INITIATION; AIR; BEHAVIOR; TEMPERATURES; LIFETIME AB Ceramic matrix composites are envisioned for use at elevated temperatures (1000 to 1400 degreesC) in oxidizing environments. For non-oxide composites, the time-dependent failure stress is dependent on the severity of reactions between the environment and the load-bearing fibers and interphase. One of the most severe pitfalls for these types of materials occurs at intermediate temperatures, 600 to 1000 degreesC. Environmental access to load-bearing fibers occurs through matrix cracks that are bridged by load-bearing fibers. The rate at which these composites lose the ability to carry load is partially controlled by the extent of cracking in the matrix. In this study, the damage accumulation of woven SiC/SiC composites tested in tension was quantified using unload/reload hysteresis tests and modal acoustic emission. The behavior of composites reinforced with ceramic-grade Nicalon(TM), Hi-Nicalon(TM), and Sylramic(R) fibers, with carbon or boron nitride interphases and chemically vapor-infiltrated or melt-infiltrated SIC matrices was investigated. The most significant finding of this study is that the formation of matrix cracks that bridge the load-bearing fibers (0 degrees cracks) occurs at approximately the same strain for all of the woven SiC/SiC composites tested. All of these systems have at least a CVI SiC matrix layer adjacent to the interphase. In addition, the onset stress-strain condition for 0 degrees cracks corresponds to the tensile stress-strain condition above which intermediate temperature embrittlement occurs for BN interphase SiC/SiC composites. For carbon interphase SiC/SiC composites, the critical stress-strain condition for the onset of intermediate temperature embrittlement corresponds to the first cracks in the matrix which can occur at stresses half the 0 degrees crack onset stress. C1 NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. RP Morscher, GN (reprint author), NASA, Glenn Res Ctr, Ohio Aerosp Inst, MS 106-5, Cleveland, OH 44135 USA. NR 28 TC 6 Z9 6 U1 1 U2 3 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2872-X J9 AM SOC TEST MATER PY 2000 VL 1392 BP 306 EP 319 DI 10.1520/STP15022S PG 14 WC Materials Science, Ceramics; Materials Science, Characterization & Testing SC Materials Science GA BR55G UT WOS:000166791500021 ER PT J AU Liou, CH Lin, HH Oswald, FB Townsend, DP AF Liou, CH Lin, HH Oswald, FB Townsend, DP TI Using hob offset to balance dynamic strength in spur gears SO MECHANICS OF STRUCTURES AND MACHINES LA English DT Article ID DESIGN AB An analytical study of the effect of hob offset on dynamic tooth strength of spur gears is presented. The study was limited to equal and opposite offset values applied to the pinion and gear to maintain the standard operating center distance. The analysis presented is performed using a new version of the NASA gear dynamics code DANST. The operating speed of a transmission has a significant influence on the amount of hob offset required to equalize dynamic stresses in the pinion and gear. In the transmission studied, at low speeds. the optimum hob offset was found to fluctuate within a range. At higher speeds, the optimum value is constrained by the minimum allowed thickness at the tip of the pinion tooth. For gears that must operate over a range of speeds, an average offset value can be used. Spur gears designed with the procedure presented hen can have significant improvements in load capacity. C1 Univ Memphis, Dept Engn Mech, Memphis, TN 38152 USA. NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Liou, CH (reprint author), Univ Memphis, Dept Engn Mech, Memphis, TN 38152 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0890-5452 J9 MECH STRUCT MACH JI Mech. Struct. Mach. PY 2000 VL 28 IS 2-3 BP 169 EP 184 DI 10.1081/SME-100100616 PG 16 WC Mechanics SC Mechanics GA 347EF UT WOS:000088913900002 ER PT S AU Kuhn, JL Fettig, RK Moseley, SH Kutyrev, AS Orloff, J AF Kuhn, JL Fettig, RK Moseley, SH Kutyrev, AS Orloff, J BE Lawton, RA TI Fracture tests of etched components using a focused ion beam machine SO MEMS RELIABILITY FOR CRITICAL APPLICATIONS SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on MEMS Reliability for Critical Applications CY SEP 20, 2000 CL SANTA CLARA, CA SP SPIE, Semicond Equipment & Mat Int, SolidState Technol, Sandia Natl Labs DE stiffness; strength; fracture; fatigue; silicon nitride; micro-shutters; torsion; hinge AB Many optical MEMS device designs involve large arrays of thin (0.5 to 1 mum) components subjected to high stresses due to cyclic loading. These devices are fabricated from a variety of materials, and the properties strongly depend on size and processing. Our objective is to develop standard and convenient test methods that can be used to measure the properties of large numbers of witness samples, for every device we build. In this work we explore a variety of fracture test configurations for 0.5 mum thick silicon nitride membranes machined using the Reactive Ion Etching (RIE) process. Testing was completed using an FEI 620 dual focused ion beam milling machine. Static loads were applied using a probe, and dynamic loads were applied through a piezo-electric stack mounted at the base of the probe. Results from the tests are presented and compared, and application for predicting fracture probability of large arrays of devices are considered. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kuhn, JL (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 11 TC 6 Z9 6 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 1-8194-3836-7 J9 PROC SPIE PY 2000 VL 4180 BP 40 EP 48 DI 10.1117/12.395707 PG 9 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Optics; Physics, Condensed Matter SC Engineering; Materials Science; Optics; Physics GA BR14Q UT WOS:000165733800005 ER PT S AU Vargo, SE Green, AA Mueller, J Bame, DP Reinicke, RH AF Vargo, SE Green, AA Mueller, J Bame, DP Reinicke, RH BE Lawton, RA TI Characterization of Kovar-Pyrex anodically bonded samples - a new packaging approach for MEMS devices SO MEMS RELIABILITY FOR CRITICAL APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on MEMS Reliability for Critical Applications CY SEP 20, 2000 CL SANTA CLARA, CA SP SPIE, Semicond Equipment & Mat Int, SolidState Technol, Sandia Natl Labs DE anodic bonding; packaging; Pyrex; Kovar AB The ability to anodically bond Kovar to Pyrex 7740 significantly expands the packaging approaches available for MEMS devices. This technique greatly simplifies and reliably interconnects micropropulsion MEMS components (thrusters, valves) with the attached propellant system. Experimental bonds of Kovar plates and fixtures have been made to numerous Pyrex samples in order to investigate the strength and failure modes of these bonds. An emphasis on experimentally bonding at low temperatures (similar to 200 degreesC) using large voltages (< 2000 V) was also a important parameter of this research and a current microvalve project at JPL. Bond strength measurements have been made using calibrated pull and burst tests with their results being comparable to typical silicon to Pyrex anodic bonds. Detailed bonding conditions for the tested samples have been included in this manuscript to aid the MEMS designer in using this approach to satisfy their packaging needs. C1 CALTECH, Jet Prop Lab, Device Res & Applicat Sect, Pasadena, CA 91109 USA. RP Vargo, SE (reprint author), CALTECH, Jet Prop Lab, Device Res & Applicat Sect, 4800 Oak Grove Dr,M-S 302-231, Pasadena, CA 91109 USA. NR 12 TC 3 Z9 4 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 1-8194-3836-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4180 BP 76 EP 83 DI 10.1117/12.395711 PG 8 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Optics; Physics, Condensed Matter SC Engineering; Materials Science; Optics; Physics GA BR14Q UT WOS:000165733800009 ER PT S AU Lawton, RA Lin, G Wellman, J Phinney, LM Uribe, J Griffith, E De Wolf, I Lawrence, E AF Lawton, RA Lin, G Wellman, J Phinney, LM Uribe, J Griffith, E De Wolf, I Lawrence, E BE Lawton, RA TI Micro nano technology visualization (MNTV) of micromachined MEMS polysilicon structures SO MEMS RELIABILITY FOR CRITICAL APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on MEMS Reliability for Critical Applications CY SEP 20, 2000 CL SANTA CLARA, CA SP SPIE, Semicond Equipment & Mat Int, SolidState Technol, Sandia Natl Labs DE MEMS reliability; MEMS visualization; process validation ID RAMAN SPECTROSCOPY AB Micro-Nano Technology Visualization (MNTV) is critical to studies in MEMS reliability. The ability to see and characterize the microstructures and interfaces with high resolution at the microscale and nanoscale is invaluable. In this paper we present the motivation, paradigm, and examples of visualization techniques applied to several aspects of surface micromachined polysilicon structures. High resolution cross-section imaging, using both a FIB/SEM and FIB/STEM is used to acquire information on profile differences between fabrication facilities and grain size and orientation. The AFM is used to compare surface roughness of both sides (top and bottom surfaces) of thin film polysilicon after release etching. The data gathered will be extremely useful feedback for fabrication facilities in terms of process characterization and quality assurance. The data will also be useful for MEMS CAD tools where device and process models must validated. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lawton, RA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 1-8194-3836-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4180 BP 96 EP 105 DI 10.1117/12.395698 PG 10 WC Engineering, Electrical & Electronic; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Optics; Physics, Condensed Matter SC Engineering; Materials Science; Optics; Physics GA BR14Q UT WOS:000165733800012 ER PT J AU Zolensky, ME Pieters, C Clark, B Papike, JJ AF Zolensky, ME Pieters, C Clark, B Papike, JJ TI Small is beautiful: The analysis of nanogram-sized astromaterials SO METEORITICS & PLANETARY SCIENCE LA English DT Review ID INTERPLANETARY DUST PARTICLES; ANALYTICAL ELECTRON-MICROSCOPE; SILICON-CARBIDE GRAINS; MASS-SPECTROMETRY; ION MICROPROBE; ISOTOPIC COMPOSITION; MURCHISON METEORITE; LASER-DESORPTION; CARBONACEOUS CHONDRITES; SAMPLE PREPARATION AB The capability of modem methods to characterize ultra-small samples is well established from analysis of interplanetary dust particles (IDPs), interstellar grains recovered from meteorites, and other materials requiring ultra-sensitive analytical capabilities. Powerful analytical techniques are available that require, under favorable circumstances, single particles of only a few nanograms for entire suites of fairly comprehensive characterizations. A returned sample of > 1000 particles with total mass of just 1 mu g permits comprehensive quantitative geochemical measurements that are impractical to carry out in situ by flight instruments. The main goal of this paper is to describe the state-of-the-art in microanalysis of astromaterials. Given that we can analyze fantastically small quantities of asteroids and comets, etc., we have to ask ourselves, how representative are microscopic samples of bodies that measure a few to many kilometers across? With the Galileo flybys of Gaspra and Ida, it is now recognized that even very small airless bodies have indeed developed a particulate regolith. Acquiring a sample of the bulk regolith, a simple sampling strategy, provides two critical pieces of information about the body. Regolith samples are excellent bulk samples because they normally contain all the key components of the local environment, albeit in particulate form. Furthermore, because this fine fraction dominates remote measurements, regolith samples also provide information about surface alteration processes and are a key link to remote sensing of other bodies. Studies indicate that a statistically significant number of nanogram-sized particles should be able to characterize the regolith of a primitive asteroid, although the presence of larger components (e.g., chondrules, calcium-aluminum-rich inclusions, large crystal fragments, etc.) within even primitive meteorites (e.g., Murchison) points out the limitations of using data obtained from nanogram-sized samples to characterize entire primitive asteroids. However, the most important asteroidal geological processes have left their mark on the matrix, because this is the finest-grained portion and therefore most sensitive to chemical and physical changes. Thus, the following information can be learned from this fine grain size fraction alone: (1) mineral paragenesis; (2) regolith processes; (3) bulk composition; (4) conditions of thermal and aqueous alteration (if any); (5) relationships to planets, comets, meteorites (via isotopic analyses, including O); (6) abundance of water and hydrated material; (7) abundance of organics; (8) history of volatile mobility; (9) presence and origin of presolar and/or interstellar material. Most of this information can be obtained even from dust samples from bodies for which nanogram-sized samples are not truly representative. Future advances in sensitivity and accuracy of laboratory analytical techniques can be expected to enhance the science value of nano- to microgram-sized samples even further. This highlights a key advantage of sample returns-that the most advanced analysis techniques can always be applied in the laboratory and that well-preserved samples are available for future investigations. C1 NASA, Lyndon B Johnson Space Ctr, Planetary Sci Branch, Houston, TX 77058 USA. Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. Lockheed Martin Astronaut, Planetary Protect Lab, Denver, CO 80201 USA. Univ New Mexico, Inst Meteorit, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. RP NASA, Lyndon B Johnson Space Ctr, Planetary Sci Branch, Houston, TX 77058 USA. EM michael.e.zolensky1@jsc.nasa.gov NR 165 TC 45 Z9 45 U1 1 U2 16 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1086-9379 EI 1945-5100 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JAN PY 2000 VL 35 IS 1 BP 9 EP 29 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 281KY UT WOS:000085160100007 ER PT J AU Dickinson, TL Wasilewski, P AF Dickinson, TL Wasilewski, P TI Shock magnetism in fine particle iron SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID SOLAR-SYSTEM; FIELD AB All solid solar system bodies have been affected by impact to varying degrees, and, thus, magnetic records in these bodies may have been modified by shock events. Shock events may have overprinted all primordial magnetic records in meteorites. Shock metamorphism stages ranging from very little to extreme, when melting takes place, have been identified in meteorites. We are examining the creation and destruction of magnetic remanence associated with shock. In this paper, we develop a preliminary framework for understanding the magnetic properties of fine-grained Fe particles (20-110 nm), which carry most of the remanent magnetization in lunar samples and, by extension, the kamacite phase in meteorite samples. Initial experiments on shock effects due to a first-order shock-induced crystallographic transformation are described. The first characterization of pre- and postshock magnetic properties for sized Fe particles and the first characterization of the transformation remanent magnetization (TMRM) associated with the face-centered-cubic (fcc) to body-centered-cubic (bcc) transformation in fine particle Fe spheres are described. This is equivalent to the 13 GPa transitions in bcc Fe. We show that the TMRM is in the same direction as the ambient magnetic field present during the shock, but is deflected from the field direction by 30-45 degrees and that the remanence intensity is 1-2 orders of magnitude less than expected for thermoremanent magnetization (TRM) acquired during cooling through the Curie temperature. Isothermal remanence acquisition curves (RA) reveal the increasing magnetic hardness due to shock. Magnetic hysteresis loops are used to characterize the particle size and the shock-induced magnetic anisotropy. Thermal demagnetization experiments describe the probable presence of particle size effects and the effects associated with recovery-recrystallization due to the annealing that takes place during the thermomagnetic experiment. These observations have implications for paleofield determinations and the recognition of thermal unblocking. A TMRM mechanism could produce a shock overprint in a meteorite and might impart a significant directional feature in an asteroid magnetic signature. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Wasilewski, P (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 691, Greenbelt, MD 20771 USA. NR 27 TC 11 Z9 11 U1 0 U2 1 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JAN PY 2000 VL 35 IS 1 BP 65 EP 74 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 281KY UT WOS:000085160100011 ER PT J AU Swindle, TD Treiman, AH Lindstrom, DJ Burkland, MK Cohen, BA Grier, JA Li, B Olson, EK AF Swindle, TD Treiman, AH Lindstrom, DJ Burkland, MK Cohen, BA Grier, JA Li, B Olson, EK TI Noble gases in iddingsite from the Lafayette meteorite: Evidence for liquid water on Mars in the last few hundred million years SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID ANCIENT MARTIAN ATMOSPHERE; SNC METEORITES; ORTHOPYROXENITE ALH84001; AQUEOUS ALTERATION; NAKHLA; XENON; ALH-84001; EVOLUTION; NITROGEN; KRYPTON AB We analyzed noble gases from 18 samples of weathering products ("iddingsite") from the Lafayette meteorite. Potassium-argon ages of 12 samples range from near zero to 670 +/- 91 Ma. These ages confirm the martian origin of the iddingsite, but it is not clear whether any or all of the ages represent iddingsite formation as opposed to later alteration or incorporation of martian atmospheric Ar-40. In any case, because iddingsite formation requires liquid water, this data requires the presence of liquid water near the surface of Mars at least as recently as 1300 Ma ago, and probably as recently as 650 Ma ago. Krypton and Xe analysis of a single 34 mu g sample indicates the presence of fractionated martian atmosphere within the iddingsite. This also confirms the martian origin of the iddingsite. The mechanism of incorporation could either be through interaction with liquid water during iddingsite formation or a result of shock implantation of adsorbed atmospheric gas. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Lunar & Planetary Inst, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Univ Arizona, Lunar & Planetary Lab, 1629 E Univ Blvd, Tucson, AZ 85721 USA. EM tswindle@u.arizona.edu NR 55 TC 75 Z9 75 U1 1 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1086-9379 EI 1945-5100 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JAN PY 2000 VL 35 IS 1 BP 107 EP 115 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 281KY UT WOS:000085160100015 ER PT J AU Mikouchi, T Miyamoto, M AF Mikouchi, T Miyamoto, M TI Micro Raman spectroscopy of amphiboles and pyroxenes in the martian meteorites Zagami and Lewis Cliff 88516 SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID SNC METEORITES; MELT INCLUSIONS; WATER CONTENTS; MARS; PETROGENESIS AB We studied micro Raman spectroscopy of amphiboles and pyroxenes in the martian meteorites Zagami and Lewis Cliff(LEW) 88516. The obtained Raman spectra of the amphiboles are similar to those of kaersutite, reconfirming the previous studies that they are kaersutitic amphiboles enriched in Ca, Al, and Ti. Even though actinolite belongs to the same amphibole group (calcic amphibole) as kaersutite, the Raman spectra of terrestrial actinolite are distinct from those of kaersutite, probably reflecting complex amphibole crystal structures. The Al-Ti-rich pyroxene observed in the magmatic inclusions within LEW 88516 olivine is compositionally similar to kaersutite but shows Raman spectra nearly identical to the regular pyroxene rather than amphibole. In contrast to amphibole, this will be due to relatively simple crystal structures of pyroxene. Thus, the Raman spectra of Al-Ti-rich phases in the martian meteorites are distinct between kaersutite and Al-Ti-rich pyroxene, and this study demonstrates that micro Raman spectroscopy is one of the best tools to perform mineralogical characterization of mineral phases in martian meteorites. C1 Univ Tokyo, Grad Sch Sci, Inst Mineral, Bunkyo Ku, Tokyo 1130033, Japan. NASA, Lyndon B Johnson Space Ctr, Planetary Sci Branch, Houston, TX 77058 USA. RP Mikouchi, T (reprint author), Univ Tokyo, Grad Sch Sci, Inst Mineral, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan. NR 20 TC 11 Z9 11 U1 2 U2 7 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 0026-1114 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD JAN PY 2000 VL 35 IS 1 BP 155 EP 159 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 281KY UT WOS:000085160100019 ER PT J AU Qian, W Yang, S AF Qian, W Yang, S TI Onset of the regional monsoon over Southeast Asia SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID SUMMER MONSOON; BRIGHTNESS TEMPERATURES; CHINA SEA AB This is an observational study in which regional features of the different summer monsoon components over Asia especially the South China Sea (SCS) are examined. The authors use various data sets including satellite measurements to understand the onset, maintenance, and retreat of monsoon and explain the connection and independence among the variabilities in the monsoon components. It is shown that while outgoing longwave radiation (OLR) data can only measure tropical convection, upper-tropospheric water vapor band brightness temperature (BT) represents appropriately convective precipitation in both the tropics and the extratropics. The authors define criteria for measuring the SCS monsoon using precipitation, BT, OLR, and lower-tropospheric winds and suggest that multi-variables should be considered to depict regional monsoon features adequately. Under the criteria defined in this study, the SCS summer monsoon is considered as an expansion of deep convection from the tropics. The onset of the monsoon occurs in mid-May, with its precursory signal found over the Indochina peninsula. It is characterized by an abrupt establishment, especially over the central SCS. Although the role of convection over the southern SCS in the monsoon onset is unclear, the early precipitation over the northern SCS and South China, resulted from the effect of subtropical fronts, is separated from the tropical monsoon rainfall. The relative independence from one monsoon component to another is explained by the effects from local topography and land-sea thermal contrast. C1 Peking Univ, Dept Geophys, Beijing 100871, Peoples R China. NASA, Goddard Space Flight Ctr, SAIC, Gen Sci Corp, Greenbelt, MD 20771 USA. RP Qian, W (reprint author), Peking Univ, Dept Geophys, Beijing 100871, Peoples R China. RI Yang, Song/B-4952-2009 NR 29 TC 29 Z9 37 U1 1 U2 8 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0177-7971 J9 METEOROL ATMOS PHYS JI Meteorol. Atmos. Phys. PY 2000 VL 75 IS 1-2 BP 29 EP 38 DI 10.1007/s007030070013 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 376RE UT WOS:000165469900004 ER PT B AU Hand, C AF Hand, C BE Valafar, F TI A pliant synaptic network for signal analysis SO METMBS'00: PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON MATHEMATICS AND ENGINEERING TECHNIQUES IN MEDICINE AND BIOLOGICAL SCIENCES, VOLS I AND II LA English DT Proceedings Paper CT International Conference on Mathematics and Engineering Techniques in Medicine and Biological Sciences (METMBS 00) CY JUN 26-29, 2000 CL LAS VEGAS, NV SP Comp Sci, Res, Educ & Applicat Press, Int Technol Inst, Korea Informat Processing Soc, PDPTA DE signal processing; EEG; synaptic networks; sensor fusion AB Many complex systems are monitored with multiple sensors, each of which produces a single time-varying output. One example of such a system is the human body with surface electrodes for monitoring EEG or EKG. To interpret the readings a doctor often looks for waveform "signatures." Some of these signatures have been detected [1,2, and 3] with Artificial Neural Networks (ANN). This paper describes a computer program that automatically creates an ANN to detect user-selected signatures. When the user of the program is satisfied with the performance of the ANN, the ANN parameters can be downloaded directly onto a chip that becomes part of a hardware package for monitoring the system. Thus this program will allow doctors to identify targets, then construct an ANN to recognize the target signatures, test the ANN, and download the ANN onto a chip that can be implanted with electrodes to monitor the patient. The basic techniques in this program have wide applications both inside the medical field (e.g., EKG and MEG) and in non-medical applications (e.g., seismology and factory control). C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hand, C (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU C S R E A PRESS PI ATHENS PA 115 AVALON DR, ATHENS, GA 30606 USA BN 1-892512-62-9 PY 2000 BP 275 EP 281 PG 7 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Engineering, Biomedical; Mathematics, Interdisciplinary Applications SC Computer Science; Engineering; Mathematics GA BR81W UT WOS:000167662700042 ER PT J AU Qiu, S Godden, G Wang, X Guenther, B AF Qiu, S Godden, G Wang, X Guenther, B TI Satellite-Earth remote sensor scatter effects on Earth scene radiometric accuracy SO METROLOGIA LA English DT Article; Proceedings Paper CT 7th International Conference on Radiometry CY OCT 25-27, 1999 CL MADRID, SPAIN AB A general modelling formalism is used to extend near-field point spread function (PSF) measurements over a wide-field off-axis angular range, covering a dynamic range of 5 to 6 orders of magnitude, using bidirectional reflectance distribution function (BRDF) measurements of the scan mirror and other key optical elements. Line spread function (LSF) model results were compared with measured near-field LSF measurements for the Moderate Resolution Imaging Spectroradiometer (MODIS) of the Earth Observing System (EOS), demonstrating excellent agreement between model and measurements. When realistic effects of sensor scattered light are taken into account, significant radiometric bias errors are produced near high-contrast structured scenes (e.g. bright clouds over dark oceans and land; broken snow and ice scenes). Image restoration using an asymptotically exact PSF is shown to produce results significantly different from those produced by traditional near-field 5 x 5, 7 x 7,..., PSF kernel matrix inversion techniques. The results reported have implications for future remote-sensor specifications and testing, in-flight and surface-based calibration comparisons, and the assessment of radiometric bias errors in the presence of moderate- to high-contrast Earth scenes. C1 New Century Appl Sci, Lanham, MD 20706 USA. Phys Applicat Inc, Seabrook, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Qiu, S (reprint author), New Century Appl Sci, 7501 Forbes Blvd,Suite 104, Lanham, MD 20706 USA. NR 4 TC 18 Z9 18 U1 0 U2 0 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PY 2000 VL 37 IS 5 BP 411 EP 414 DI 10.1088/0026-1394/37/5/14 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 403WX UT WOS:000167066700014 ER PT B AU Baaklini, GY Kautz, HE Gyekenyesi, AL Abdul-Aziz, A Martin, RE AF Baaklini, GY Kautz, HE Gyekenyesi, AL Abdul-Aziz, A Martin, RE BE Michel, B Winkler, T Werner, M Fecht, H TI NDE for material characterization in aeronautic and space applications SO MICRO MATERIALS, PROCEEDINGS LA English DT Proceedings Paper CT 3rd International Micro Materials Conference CY APR 17-JUL 19, 2000 CL BERLIN, GERMANY SP Fraunhofer Inst Reliabil & Microintegrat, DVM, Tech Univ Berlin, Fed Inst Mat Res & Testing, VDI, VDE IT, IEEE, CMPT, Amer Soc Mech Engineers, Robot Soc Japan, European Commiss, Informat Soc, European Network High Temp Electr, Int Microelectr & Packaging Soc, Fraunhofer Gesell, DFG, Assoc Francaise Mech, German Soc Nondestruct Testing, Fachverban Sensorike eV, ZVEI, Innovat Relay Ctr N Germany, Int Soc Technol Law & Insurance, European Soc Struct Integr, Soc Francaise Met & Mat, Soc Exptl Mech, Saxon Soc Mech, Siemens AG, Robert Bosch GmbH, Philips Kassel, Deutsch Bank Berlin, Senate of Berlin, British Embassy Berlin, Commercial Sect, ONRIFO, European Off Aerosp Res & Dev, CWM GmbH Chemnitz, Zwick Roell GmbH Ulm, Druckhaus Dresden GmbH DE NDE; nondestructive evaluation; thermal waves; aerospace; finite clement methods; FEM; ceramics; composites; computed tomography; ultrasonics; radiography AB This paper describes selected nondestructive evaluation (NDE) approaches that were developed or tailored at the NASA Glenn Research Center for characterizing advanced material systems. The emphasis is on high-temperature aerospace propulsion applications. The material systems include monolithic ceramics, superalloys, and high temperature composites. In the aeronautic area, examples of cooled ceramic plate structures for turbine applications, Gamma -TiAl blade materials for low-pressure turbines, thermal stress analysis (TSA) for residual stress measurements in titanium based engine materials, and acousto ultrasonics (AU) for creep damage assessment in nickel based alloys are highlighted. In the space area, examples of cooled carbon-carbon composite! for gas generator combustors and polymer matrix composites flywheel for energy storage at the space station are presented. The role of NDE in solving manufacturing problems, the effect of defect results, and the use of NDE-based finite element modeling are discussed. NDE technology needs for improved micro electronic and mechanical systems and health monitoring of micro materials and components are briefly identified. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Baaklini, GY (reprint author), NASA, Glenn Res Ctr, MS 6-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 11 TC 0 Z9 0 U1 1 U2 1 PU DDP GOLDENBOGEN SIGURD GOLDENBOGEN PI DRESDEN PA WEISSE GASSE 6, 01067 DRESDEN, GERMANY BN 3-932434-15-3 PY 2000 BP 102 EP 109 PG 8 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA BS08G UT WOS:000168584000005 ER PT B AU Kolawa, E AF Kolawa, E BE Michel, B Winkler, T Werner, M Fecht, H TI Development and applications of sensors for deep space explorations SO MICRO MATERIALS, PROCEEDINGS LA English DT Proceedings Paper CT 3rd International Micro Materials Conference CY APR 17-JUL 19, 2000 CL BERLIN, GERMANY SP Fraunhofer Inst Reliabil & Microintegrat, DVM, Tech Univ Berlin, Fed Inst Mat Res & Testing, VDI, VDE IT, IEEE, CMPT, Amer Soc Mech Engineers, Robot Soc Japan, European Commiss, Informat Soc, European Network High Temp Electr, Int Microelectr & Packaging Soc, Fraunhofer Gesell, DFG, Assoc Francaise Mech, German Soc Nondestruct Testing, Fachverban Sensorike eV, ZVEI, Innovat Relay Ctr N Germany, Int Soc Technol Law & Insurance, European Soc Struct Integr, Soc Francaise Met & Mat, Soc Exptl Mech, Saxon Soc Mech, Siemens AG, Robert Bosch GmbH, Philips Kassel, Deutsch Bank Berlin, Senate of Berlin, British Embassy Berlin, Commercial Sect, ONRIFO, European Off Aerosp Res & Dev, CWM GmbH Chemnitz, Zwick Roell GmbH Ulm, Druckhaus Dresden GmbH C1 Jet Prop Lab, Pasadena, CA 91108 USA. RP Kolawa, E (reprint author), Jet Prop Lab, Pasadena, CA 91108 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU DDP GOLDENBOGEN SIGURD GOLDENBOGEN PI DRESDEN PA WEISSE GASSE 6, 01067 DRESDEN, GERMANY BN 3-932434-15-3 PY 2000 BP 419 EP 419 PG 1 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA BS08G UT WOS:000168584000077 ER PT S AU Carpenter, P Counce, D Kluk, E Nabelek, C AF Carpenter, P Counce, D Kluk, E Nabelek, C BE Williams, DB Shimizu, R TI Characterization of Corning standard glasses 95IRV, 95IRW, and 95IRX, by ICP-AES, XRF, and EPMA SO MICROBEAM ANALYSIS 2000, PROCEEDINGS SE INSTITUTE OF PHYSICS CONFERENCE SERIES LA English DT Article; Proceedings Paper CT 2nd Conference of the International-Union-of-Microbeam-Analysis-Societies CY JUL 09-14, 2000 CL KAILUA KONA, HAWAII SP Australian Microbeam Anal Soc, Brasilian Soc Microscopy & Microanal, Microscopy Soc Canada, China Joint Comm Microbeam Anal, European Microbeam Anal Soc, Japan Soc Promot Sci, Comm 141 Microbeam Anal, Korean Soc Electron Microscopy, Microbeam Anal Soc C1 NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Alliance Micrograv Mat Sci & Applicat, Huntsville, AL 35812 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Missouri, Dept Geol Sci, Columbia, MO 65211 USA. RP Carpenter, P (reprint author), NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Alliance Micrograv Mat Sci & Applicat, SD47, Huntsville, AL 35812 USA. NR 1 TC 2 Z9 2 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0951-3248 BN 0-7503-0685-8 J9 INST PHYS CONF SER PY 2000 IS 165 BP 401 EP 402 PG 2 WC Instruments & Instrumentation; Microscopy; Physics, Multidisciplinary; Spectroscopy SC Instruments & Instrumentation; Microscopy; Physics; Spectroscopy GA BR57H UT WOS:000166835400201 ER PT S AU Carpenter, P AF Carpenter, P BE Williams, DB Shimizu, R TI An evaluation of the accuracy of EPMA measurements in the system HgTe-CdTe SO MICROBEAM ANALYSIS 2000, PROCEEDINGS SE INSTITUTE OF PHYSICS CONFERENCE SERIES LA English DT Article; Proceedings Paper CT 2nd Conference of the International-Union-of-Microbeam-Analysis-Societies CY JUL 09-14, 2000 CL KAILUA KONA, HAWAII SP Australian Microbeam Anal Soc, Brasilian Soc Microscopy & Microanal, Microscopy Soc Canada, China Joint Comm Microbeam Anal, European Microbeam Anal Soc, Japan Soc Promot Sci, Comm 141 Microbeam Anal, Korean Soc Electron Microscopy, Microbeam Anal Soc C1 NASA, George C Marshall Space Flight Ctr, Alliance Micrograv Mat Sci & Applicat, USRA,SD47, Huntsville, AL 35812 USA. RP Carpenter, P (reprint author), NASA, George C Marshall Space Flight Ctr, Alliance Micrograv Mat Sci & Applicat, USRA,SD47, Huntsville, AL 35812 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TECHNO HOUSE, REDCLIFFE WAY, BRISTOL, ENGLAND BS1 6NX SN 0951-3248 BN 0-7503-0685-8 J9 INST PHYS CONF SER PY 2000 IS 165 BP 433 EP 434 PG 2 WC Instruments & Instrumentation; Microscopy; Physics, Multidisciplinary; Spectroscopy SC Instruments & Instrumentation; Microscopy; Physics; Spectroscopy GA BR57H UT WOS:000166835400217 ER PT B AU Trinh, EH Chung, SK Sadhal, SS AF Trinh, EH Chung, SK Sadhal, SS BE Dhir, V Straub, J Fujita, Y TI Earth-based and microgravity studies of spot-heated levitated single drops SO MICROGRAVITY FLUID PHYSICS AND HEAT TRANSFER LA English DT Proceedings Paper CT International Conference on Microgravity Fluid Physics and Heat Transfer CY SEP 19-24, 1999 CL OAHU, HI SP NSF, NASA, Engn Fdn ID ELECTRIC-FIELD; BREAK-UP; OSCILLATIONS; DROPLETS; DYNAMICS AB Ultrasonic and electrostatic levitation methods allow the detailed experimental investigation of the dynamics and transport processes associated with free single drops stably positioned in a fluid host. The response of these drops to artificially induced controlled stimuli can be recorded and analyzed to deduce some of their thermophysical properties, or to study the characteristics of the nonlinear dynamics of free three-dimensional liquid-gas interfaces. Earth-based levitation, however, requires high field intensities that introduce additional artifacts interfering with the analysis of the drop response. We have carried out experimental studies both at 1-G and in microgravity in order to refine techniques to quiescently position free drops in a gaseous host, and to examine the thermocapillary flows resulting from spot heating. Both spherical and drastically flattened levitated drops have been investigated at 1-G using electrostatic/ultrasonic hybrid levitation systems and spot heating from a focused CO2 laser. Thermocapillary flows in spherical drops at 1-G invariably couple with the overall drop relational motion, while drastically flattened drops reveal more regular flow patterns in agreement with results from theoretical predictions for axisymmetric flows. Low-gravity investigations using a low-cost and compact experimental apparatus in the Shuttle Glovebox Facility have allowed the development of experimental methods for the quiescent positioning of free drops. A better understanding control of simple and compound drop rotation and of the impact of acoustic field positioning on drop internal flows has been obtained. Preliminary data on thermocapillary flows in free drops in microgravity have also been gathered. C1 NASA, Headquaters, Washington, DC 20546 USA. RP Trinh, EH (reprint author), NASA, Headquaters, Code UG,300 E St SW, Washington, DC 20546 USA. NR 29 TC 0 Z9 0 U1 0 U2 0 PU BEGELL HOUSE, INC PI NEW YORK PA 145 MADISON AVE, NEW YORK, NY 10016 USA BN 1-56700-147-5 PY 2000 BP 167 EP 174 PG 8 WC Thermodynamics; Mechanics; Physics, Fluids & Plasmas SC Thermodynamics; Mechanics; Physics GA BQ63W UT WOS:000089019900020 ER PT B AU French, LC Ravikumar, KV Confair, R Frederking, THK AF French, LC Ravikumar, KV Confair, R Frederking, THK BE Dhir, V Straub, J Fujita, Y TI The quench test with perforated plates using cryoliquid at "1g" and at "micro-g" SO MICROGRAVITY FLUID PHYSICS AND HEAT TRANSFER LA English DT Proceedings Paper CT International Conference on Microgravity Fluid Physics and Heat Transfer CY SEP 19-24, 1999 CL OAHU, HI SP NSF, NASA, Engn Fdn AB The quench test has been used by metallurgists for some time in order to probe the effectiveness of quench liquids for optimum properties of metals, e.g. steel. In preparation for "Apollo-11", cryo-liquids, such as Nitrogen, Hydrogen. Helium-4 and others have served to quantify conditions at reduced gravity. Recently perforated plates have been employed by our group extending the range of quench test geometry. Data obtained are compared with He I (normal phase of liquid Helium-4 above the lambda point) and liquid Nitrogen data. In general, geometry parameters and thermophysical properties exert an influence on heat transfer rates, e.g. Bond number and the ratio of gas phase enthalpy differences to latent heat of vaporization (Jacob number). He I data show a rather weak dependence on Bond number. This feature is accompanied by a relatively moderate change of the cooldown rate as "1g" is reduced toward milli-g and micro-g provided vapor removal is secured. In "Part I" of this contribution, cryo-liquid quench test evolution is outlined with focus on geometry and driving force comparisons achieved. In "Part II" details of recent perforated plate studies including flight data are considered. C1 NASA, Jet Prop Lab, Pasadena, CA 91109 USA. RP French, LC (reprint author), NASA, Jet Prop Lab, Pasadena, CA 91109 USA. NR 29 TC 0 Z9 0 U1 0 U2 0 PU BEGELL HOUSE, INC PI NEW YORK PA 145 MADISON AVE, NEW YORK, NY 10016 USA BN 1-56700-147-5 PY 2000 BP 175 EP 182 PG 8 WC Thermodynamics; Mechanics; Physics, Fluids & Plasmas SC Thermodynamics; Mechanics; Physics GA BQ63W UT WOS:000089019900021 ER PT S AU Im, E Tanelli, S Giuli, D Durden, SL Facheris, L AF Im, E Tanelli, S Giuli, D Durden, SL Facheris, L BE Wilheit, TT Masuko, H Wakabayashi, H TI Spaceborne radar measurements of rainfall vertical velocity SO MICROWAVE REMOTE SENSING OF THE ATMOSPHERE AND ENVIRONMENT II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Microwave Remote Sensing of the Atmosphere and Environment II CY OCT 09-12, 2000 CL SENDAI, JAPAN SP SPIE, Natl Space Dev Agcy Japan, Tohoku Inst Technol, NASA Langley Res Ctr, Natl Polar Orbiting Operat Environm Satellite Syst, TRW ID DOPPLER AB This paper studies the performance of a spaceborne precipitation radar in measuring Vertical Doppler velocity of rainfall. As far as a downward pointing precipitation radar is concerned, one of the major problems affecting Doppler measurement at the nadir direction arises from the Non-Uniform Beam-Filling effect (NUBF). That is, when significant variation in rain rate is present within the radar IFOV in the along track direction, the Doppler shift caused by the radial component of the horizontal speed of the satellite is weighted differently among the portions of IFOV. The effects of this non-uniform weighting may dominate any other contribution. Under this condition, shape, average value and width of the Doppler spectrum may not be directly correlated with the vertical velocity of the precipitating particles. However, by using an inversion technique which over-samples the radar measurements in the along track direction, we show that the shift due to NUBF can be evaluated, and that the NUBF induced errors on average fall speed can be reduced. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Im, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3805-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4152 BP 13 EP 24 DI 10.1117/12.410598 PG 12 WC Meteorology & Atmospheric Sciences; Remote Sensing SC Meteorology & Atmospheric Sciences; Remote Sensing GA BR89W UT WOS:000167975400002 ER PT S AU Wang, JR Skofronick-Jackson, G Meneghini, R Heymsfield, G Manning, W AF Wang, JR Skofronick-Jackson, G Meneghini, R Heymsfield, G Manning, W BE Wilheit, TT Masuko, H Wakabayashi, H TI Measurements and calculations of microwave radiance and reflectivity for storm-associated frozen hydrometeors SO MICROWAVE REMOTE SENSING OF THE ATMOSPHERE AND ENVIRONMENT II SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Microwave Remote Sensing of the Atmosphere and Environment II CY OCT 09-12, 2000 CL SENDAI, JAPAN SP SPIE, Natl Space Dev Agcy Japan, Tohoku Inst Technol, NASA Langley Res Ctr, Natl Polar Orbiting Operat Environm Satellite Syst, TRW DE TRMM; microwave radiometer; radar; radiative transfer ID PRECIPITATION RADIOMETER; RADAR; RETRIEVAL; PROFILES; CLOUD; AIRCRAFT AB During the TEFLUN-B (Texas-Florida under-flights for TRMM) field experiment of August-September, 1998, a number of ER-2 aircraft flights with a host of microwave instruments were conducted over many convective storms, including some hurricanes, in the coastal region of Florida and Texas. These instruments include MIR (Millimeter-wave Imaging Radiometer), AMPR (Advanced Microwave Precipitation Radiometer), and EDOP (ER-2 Doppler Radar). EDOP is operated at the frequency of 9.7 GHz, while the AMPR and the MIR together give eleven channels of radiometric measurements in the frequency range of 10-340 GHz. The concurrent measurements from these instruments provide unique data sets for studying the details of the microphysics of hydrometeors. Preliminary examination of these data sets shows features that are generally well understood; i.e., radiometric measurements at frequencies less than or equal to 37 GHz mainly respond to rain, while those at frequencies greater than or equal to 150 GHz, to ice particles above the freezing level. Model calculations of brightness temperature and radar reflectivity are performed and results compared with these measurements. For simplicity the analysis is limited to the anvil region of the storms where hydrometeors are predominantly frozen. Only one ice particle size distribution is examined in the calculations of brightness temperature and radar reflectivity in this initial study. Estimation of ice water path is made based on the best agreement between the measurements and calculations of brightness temperature and reflectivity. Problems associated with these analyses and measurement accuracy will be discussed. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Wang, JR (reprint author), NASA, Goddard Space Flight Ctr, Code 975, Greenbelt, MD 20771 USA. EM wang@sensor2.gsfc.nasa.gov NR 22 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 0-8194-3805-7 J9 PROC SPIE PY 2000 VL 4152 BP 25 EP 32 DI 10.1117/12.410608 PG 8 WC Meteorology & Atmospheric Sciences; Remote Sensing SC Meteorology & Atmospheric Sciences; Remote Sensing GA BR89W UT WOS:000167975400003 ER PT S AU Tsai, WY Nghiem, SV Vanzyl, JJ AF Tsai, WY Nghiem, SV Vanzyl, JJ BE Wilheit, TT Masuko, H Wakabayashi, H TI SeaWinds scatterometer on QnikSCAT mission and the emerging land and ocean applications SO MICROWAVE REMOTE SENSING OF THE ATMOSPHERE AND ENVIRONMENT II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Microwave Remote Sensing of the Atmosphere and Environment II CY OCT 09-12, 2000 CL SENDAI, JAPAN SP SPIE, Natl Space Dev Agcy Japan, Tohoku Inst Technol, NASA Langley Res Ctr, Natl Polar Orbiting Operat Environm Satellite Syst, TRW DE scatterometer; backscatter; wind; snow; ice sheet; monsoon; flood; freeze; thaw; soil wetness; hurricane ID GREENLAND ICE-SHEET AB Spaceborne scatterometers are active microwave radar instruments designed to acquire near-simultaneous, spatially collocated measurements of the normalized radar backscattering cross section (sigma0) of the global surface from several azimuth and/or incidence angles. The primary objective of the scatterometer mission is to measure the near-surface wind speed and direction over the global ocean using sigma0 measurements together with a wind geophysical model function. However, since sigma0 measurements are collected globally all the time, sigma0 data can also be used for global land and ice applications. In this paper, we will first present the objectives of the QSCAT mission, the instrument design, and the unique features of the Ku-band scatterometer currently in operation, called SeaWinds on QuikSCAT (QSCAT). We will then present some emerging land and ocean applications of the QSCAT data, which include (1) global snow detection and monitoring, (2) melt region mapping on the Greenland ice sheet, (3) Monsoon hood detection and monitoring, (4) soil wetness application at large scale, and (5) hurricane monitoring and tracking. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91009 USA. RP Tsai, WY (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91009 USA. NR 9 TC 0 Z9 0 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3805-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4152 BP 89 EP 99 DI 10.1117/12.410586 PG 11 WC Meteorology & Atmospheric Sciences; Remote Sensing SC Meteorology & Atmospheric Sciences; Remote Sensing GA BR89W UT WOS:000167975400010 ER PT S AU Shen, Y Shaffer, SJ Jordan, RL AF Shen, Y Shaffer, SJ Jordan, RL BE Wilheit, TT Masuko, H Wakabayashi, H TI Shuttle Radar Topography Mission (SRTM) flight system design and operations overview SO MICROWAVE REMOTE SENSING OF THE ATMOSPHERE AND ENVIRONMENT II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Microwave Remote Sensing of the Atmosphere and Environment II CY OCT 09-12, 2000 CL SENDAI, JAPAN SP SPIE, Natl Space Dev Agcy Japan, Tohoku Inst Technol, NASA Langley Res Ctr, Natl Polar Orbiting Operat Environm Satellite Syst, TRW DE Shuttle Radar Topography Mission (SRTM); interferometric synthetic aperture radar (InSAR); synthetic aperture; radar (SAR); InSAR system engineering; InSAR system Performance AB This paper provides an overview of the Shuttle Radar Topography Mission (SRTM), with emphasis on flight system implementation and mission operations from systems engineering perspective. Successfully flown in February, 2000, the SRTM's primary payload consists of several subsystems to form the first spaceborne dual-frequency (C-band and X-band) fixed baseline interferometric synthetic aperture radar (InSAR) system, with the mission objective to acquire data sets over 80% of Earth's landmass for height reconstruction. The paper provides system architecture, unique design features, engineering budgets, design verification, in-flight checkout and data acquisition of the SRTM payload, in particular for the C-band system. Mission operation and post-mission data processing activities are also presented. The complexity of the SRTM as a system, the ambitious mission objective, the demanding requirements and the high interdependency between multi-disciplined subsystems posed many challenges. The engineering experience and the insight thus gained have important implications for future spaceborne interferometric SAR mission design and implementation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Shen, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3805-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4152 BP 167 EP 178 DI 10.1117/12.410595 PG 12 WC Meteorology & Atmospheric Sciences; Remote Sensing SC Meteorology & Atmospheric Sciences; Remote Sensing GA BR89W UT WOS:000167975400018 ER PT S AU Hensley, S Rosen, P Gurrola, E AF Hensley, S Rosen, P Gurrola, E BE Wilheit, TT Masuko, H Wakabayashi, H TI Topographic map generation from the Shuttle Radar Topography Mission C-band SCANSAR interferometry SO MICROWAVE REMOTE SENSING OF THE ATMOSPHERE AND ENVIRONMENT II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Microwave Remote Sensing of the Atmosphere and Environment II CY OCT 09-12, 2000 CL SENDAI, JAPAN SP SPIE, Natl Space Dev Agcy Japan, Tohoku Inst Technol, NASA Langley Res Ctr, Natl Polar Orbiting Operat Environm Satellite Syst, TRW DE SRTM; SCANSAR; interferometry; topography; mapping; DEM AB A highly accurate global topographic map of the Earth's surface has been an elusive goal for at least three decades that may soon be achieved with the newly acquired Shuttle Radar Topographic Mission (SRTM) data. SRTM collected data for 99.97% of the Earth's landmass between -57 degrees and 60 degrees latitude during a 11 day mission in February, 2000. A modified version of the SIR-C radar that previously flew on the shuttle in 1994 augmented with a radar mounted on a 62 m boom was used to collect radar interferometric data at C (5.6 cm wavelength) and X (3 cm wavelength) bands. The C-band radar was operated in the SCANSAR mode in order to extend the swath width to 225 km, the minimal amount required to achieve contiguous coverage at the equator. This paper presents an overview of the new algorithms and techniques used to process the SCANSAR data to digital elevation maps. First results of topographic maps generated from the SRTM data are used to illustrate the techniques described in this paper. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hensley, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-235, Pasadena, CA 91109 USA. NR 6 TC 11 Z9 11 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3805-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4152 BP 179 EP 189 DI 10.1117/12.410596 PG 11 WC Meteorology & Atmospheric Sciences; Remote Sensing SC Meteorology & Atmospheric Sciences; Remote Sensing GA BR89W UT WOS:000167975400019 ER PT S AU Chang, ATC Chiu, LS AF Chang, ATC Chiu, LS BE Wilheit, TT Masuko, H Wakabayashi, H TI Monthly oceanic rainfall from TRMM Microwave Imager (TMI) data SO MICROWAVE REMOTE SENSING OF THE ATMOSPHERE AND ENVIRONMENT II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Microwave Remote Sensing of the Atmosphere and Environment II CY OCT 09-12, 2000 CL SENDAI, JAPAN SP SPIE, Natl Space Dev Agcy Japan, Tohoku Inst Technol, NASA Langley Res Ctr, Natl Polar Orbiting Operat Environm Satellite Syst, TRW DE rainfall; microwave radiometry; TMI; SSM/I AB We evaluated the performance of the Tropical Rainfall. Measuring Mission (TRMM) Microwave Imager (TMI) at-launch algorithm for monthly oceanic rain rate using two years (January 1998 - December 1999) of TMI data. The TMI at-launch algorithm is based on Wilheit et al.'s technique for estimating monthly oceanic rainfall that relies on histograms of multichannel microwave measurements. Comparisons with oceanic monthly rain rates derived from the Defense Meteorological Satellite Program (DMSP) F-13 and F-14 Special Sensor Microwave Imager (SSM/I) data show the average rain rates over the TRMM region (between 40(degrees)S and 40 degreesN) are 3.0, 2.85 and 2.89 mm/day, respectively for F-13, F-14 and TMI. Based on the latest version of TB data (version 5), both rainrate and freezing height derived from TMI are similar to those from the F-13 and F-14 SSM/I data. However, regionally the differences are statistically significant at the 95% confidence. Three hourly monthly rainrates are also computed fi-om 3-hourly TB histograms to examine the diurnal cycle of precipitation. Over most of the oceanic TRMM area, a distinct early morning rainfall peak is found. A harmonic analysis shows that the amplitude of the 12h harmonic is significant and comparable to that of the 24h harmonic. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Chang, ATC (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3805-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4152 BP 198 EP 207 DI 10.1117/12.410599 PG 10 WC Meteorology & Atmospheric Sciences; Remote Sensing SC Meteorology & Atmospheric Sciences; Remote Sensing GA BR89W UT WOS:000167975400021 ER PT S AU Chiu, LS Chang, ATC AF Chiu, LS Chang, ATC BE Wilheit, TT Masuko, H Wakabayashi, H TI Non-systematic errors of monthly oceanic rainfall derived from TMI SO MICROWAVE REMOTE SENSING OF THE ATMOSPHERE AND ENVIRONMENT II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Microwave Remote Sensing of the Atmosphere and Environment II CY OCT 09-12, 2000 CL SENDAI, JAPAN SP SPIE, Natl Space Dev Agcy Japan, Tohoku Inst Technol, NASA Langley Res Ctr, Natl Polar Orbiting Operat Environm Satellite Syst, TRW DE non-systematic error; monthly oceanic rainfall; TRMM Microwave Imager ID PROBABILITY-DISTRIBUTION FUNCTIONS; TROPICAL RAINFALL AB A major objective of the Tropical Rainfall Measuring Mission (TRMM) is to produce a multi-year time series of monthly rainfall over 5 degrees latitude by 5 degrees longitude boxes with an uncertainty of 1mm/day for low rain rates and 10% for high rain rates. Based on some simple assumptions about the error structure, we compute the non-systematic errors of monthly oceanic rainfall over the same space/time domain derived from data taken by the Special Sensor Microwave Imager (SSM/I) on board the Defense Meteorological Satellite Program (DMSP) satellites and TRMM Microwave Imager(TMI). The mean rain rates over a two-year period (1998-1999) are calculated to be 3.0, 2.85, 2.94 mm day(-1) for SSM/I onboard the DMSP F-13, F-14 and TMI, respectively. Assuming that the non-systematic errors for each sensor are independent, the errors are calculated to be 22.2%, 22.4% and 19.7% for F-13, F-14 and for TMI, respectively. The non-systematic error for the TMI is smaller than that for either F-13 or F-14 SSM/I at the low rain rates but is comparable at rain rates higher than about 5mm/day. The TRMM objective of 1mm day(-1) for non-systematic error is met by TMI for rain rates up to 5-6mm day(-1). For higher rain rates, the nonsystematic error is in the 15% range. The goal of a 10% error for high rain rates may be realized by a combination of sensor measurements from multiple satellites, such as that advocated by the Global Precipitation Mission (GPM). C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Chiu, LS (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3805-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4152 BP 208 EP 213 DI 10.1117/12.410600 PG 6 WC Meteorology & Atmospheric Sciences; Remote Sensing SC Meteorology & Atmospheric Sciences; Remote Sensing GA BR89W UT WOS:000167975400022 ER PT S AU Ye, Z Saulnier, GJ Medley, MJ AF Ye, Z Saulnier, GJ Medley, MJ GP IEEE IEEE TI Adaptive error control for CDMA packet radio networks SO MILCOM 2000: 21ST CENTURY MILITARY COMMUNICATIONS CONFERENCE PROCEEDINGS, VOLS 1 AND 2: ARCHITECTURES & TECHNOLOGIES FOR INFORMATION SUPERIORITY SE IEEE Military Communications Conference LA English DT Proceedings Paper CT IEEE 21st Century Military Communications Conference (MILCOM 2000) CY OCT 22-25, 2000 CL LOS ANGELES, CA SP IEEE, COMSOC, AFCEA AB The throughput performance of a CDMA packet radio network using adaptive processing gain and forward error correction (FEC) coding is analyzed. The processing gain and/or FEC coding rate of the signal is adaptively controlled based on the number of active users in the network. Network throughtput performance as a function of offered load is presented for a number of different coding schemes and it is shown that the use of adaptation can significantly improve the throughtput performance under all loading conditions. The trade-off between spreading gain and FEC coding is studied and a channel monitoring algorithm is presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ye, Z (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2155-7578 BN 0-7803-6521-6 J9 IEEE MILIT COMMUN C PY 2000 BP 169 EP 173 PG 5 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BR85L UT WOS:000167781800033 ER PT S AU Divsalar, D Dolinar, S Pollara, F AF Divsalar, D Dolinar, S Pollara, F GP IEEE IEEE TI Iterative turbo decoder analysis based on Gaussian density evolution SO MILCOM 2000: 21ST CENTURY MILITARY COMMUNICATIONS CONFERENCE PROCEEDINGS, VOLS 1 AND 2: ARCHITECTURES & TECHNOLOGIES FOR INFORMATION SUPERIORITY SE IEEE Military Communications Conference LA English DT Proceedings Paper CT IEEE 21st Century Military Communications Conference (MILCOM 2000) CY OCT 22-25, 2000 CL LOS ANGELES, CA SP IEEE, COMSOC, AFCEA AB We model the density of extrinsic information in iterative turbo decoders by Gaussian density functions. This model is verified by experimental measurements. We consider evolution of these density functions through the iterative turbo decoder as a nonlinear dynamical system with feedback. Iterative decoding of turbo codes and of serially concatenated codes are analyzed based on this method. We define a "noise figure" for the iterative decoder, such that the turbo decoder will converge to the correct codeword if the noise figure is bounded below 0 dB. Many mysteries of turbo codes can be explained based on this analysis. For example we can explain why certain codes converge better with iterative decoding than more powerful codes which are only suitable for maximum likelihood decoding. The roles of systematic bits and of recursive convolutional codes as constituents of turbo codes are explained based on this analysis. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Divsalar, D (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. EM dariush@shannon.jpl.nasa.gov; sam@shannon.jpl.nasa.gov; fabrizio@shannon.jpl.nasa.gov NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2155-7578 BN 0-7803-6521-6 J9 IEEE MILIT COMMUN C PY 2000 BP 202 EP 208 PG 7 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BR85L UT WOS:000167781800039 ER PT S AU Dolinar, S Divsalar, D Hamkins, J Pollara, F AF Dolinar, S Divsalar, D Hamkins, J Pollara, F GP IEEE IEEE TI Capacity of PPM on APD-detected optical channels SO MILCOM 2000: 21ST CENTURY MILITARY COMMUNICATIONS CONFERENCE PROCEEDINGS, VOLS 1 AND 2: ARCHITECTURES & TECHNOLOGIES FOR INFORMATION SUPERIORITY SE IEEE Military Communications Conference LA English DT Proceedings Paper CT IEEE 21st Century Military Communications Conference (MILCOM 2000) CY OCT 22-25, 2000 CL LOS ANGELES, CA SP IEEE, COMSOC, AFCEA ID PERFORMANCE AB This report defines the fundamental parameters affecting the capacity of a soft-decision optical channel, and relates them to corresponding parameters for the well-understood AWGN channel. For example, just as the performance on a standard additive white Gaussian noise (AWGN) channel is fully characterized by its SNR, a corresponding Webb channel is fully characterized by its SNR, and a single additional skewness parameter delta (2) which depends on the photon detector. In fact, the's Webb channel reduces to the standard AWGN channel when delta (2) --> infinity. Numerical results show that the capacity of M-ary orthogonal signaling on the Webb channel exhibits the same brick-wall Shannon limit (M ln 2)/(M - 1) as on, the AWGN channel (approximate to -1.59 dB for large M), and that soft output channels offer a 3 dB advantage over hard output channels. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Dolinar, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. EM sam@shannon.jpl.nasa.gov; dariush@shannon.jpl.nasa.gov; hamkins@shannon.jpl.nasa.gov; fabrizio@shannon.jpl.nasa.gov NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2155-7578 BN 0-7803-6521-6 J9 IEEE MILIT COMMUN C PY 2000 BP 876 EP 880 PG 5 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BR85L UT WOS:000167781800172 ER PT J AU Jones, JA Hart, SF Baskin, DS Effenhauser, R Johnson, SL Novas, MA Jennings, R Davis, J AF Jones, JA Hart, SF Baskin, DS Effenhauser, R Johnson, SL Novas, MA Jennings, R Davis, J TI Human and behavioral factors contributing to spine-based neurological cockpit injuries in pilots of high-performance aircraft: Recommendations for management and prevention SO MILITARY MEDICINE LA English DT Article ID GZ FORCES; FIGHTER PILOTS; MUSCLE STRAIN; NECK PAIN AB In high-performance aircraft, the need for total environmental awareness coupled with high-g loading (often with abrupt onset) creates a predilection for cervical spine injury while the pilot is performing routine movements within the cockpit. In this study, the prevalence and severity of cervical spine injury are assessed via a modified cross-sectional survey of pilots of multiple aircraft types (T-38 and F-14, F-16, and F/A-18 fighters), Ninety-five surveys were administered, with 58 full responses, Fifty percent of all pilots reported in-flight or immediate post-flight spine-based pain, and 90% of fighter pilots reported at least one event, most commonly (>90%) occurring during high-g (>5 g) turns of the aircraft with the head deviated from the anatomical neutral position. Pre-flight stretching was not associated with a statistically significant reduction in neck pain episodes in this evaluation, whereas a regular weight training program in the F/A-18 group approached a significant reduction (mean = 2.492; p < 0.064), Different cockpit ergonomics may vary the predisposition to cervical injury from airframe to airframe. Several strategies for prevention are possible from both an aircraft design and a preventive medicine standpoint. Countermeasure strategies against spine injury in pilots of high-performance aircraft require additional research, so that future aircraft will not be limited by the human in control. C1 NASA, Lyndon B Johnson Space Ctr, Med Operat Branch, Houston, TX 77058 USA. RP Jones, JA (reprint author), NASA, Lyndon B Johnson Space Ctr, Med Operat Branch, Houston, TX 77058 USA. NR 18 TC 21 Z9 26 U1 0 U2 2 PU ASSN MILITARY SURG US PI BETHESDA PA 9320 OLD GEORGETOWN RD, BETHESDA, MD 20814 USA SN 0026-4075 J9 MIL MED JI Milit. Med. PD JAN PY 2000 VL 165 IS 1 BP 6 EP 12 PG 7 WC Medicine, General & Internal SC General & Internal Medicine GA 276HE UT WOS:000084871300002 PM 10658420 ER PT S AU Moseley, SH Fettig, RK Kutyrev, AS Li, MJ Mott, DB Woodgate, BE AF Moseley, SH Fettig, RK Kutyrev, AS Li, MJ Mott, DB Woodgate, BE BE Motamedi, ME Goring, R TI Status of the development of a 128x128 microshutter array SO MOEMS AND MINIATURIZED SYSTEMS SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on MOEMS and Miniaturized Systems CY SEP 18-20, 2000 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Solid State Technol, Sandia Natl Labs DE microshutters; micro-optics; spatial light modulator; programmable masks; slit mask; DRIE; micromirrors; arrays AB We are developing a lithography process for a two-dimensional array of microshutters which can be used as a high efficiency, high contrast field selection device for a multi-object spectrometer for the Next Generation Space Telescope (NGST). The device is a close-packed array of shutters with an individual shutter size of 100 mum square and area filling factor of about 80%, produced in a 100 mum thick silicon wafer. Out cur rent array size is 128x128. Each shutter made of silicon nitride with an appropriate optical coating, pivots on a torsion flexure along one edge. A CMOS circuit embedded in the flame around the shutters allows individual selection. An original double-shutter mechanism is employed for actuation. Processing includes anisotropic back etching for wafer thinning, a DRIE back etch through the silicon to the mechanical active nitride membrane and a RTE to produce the shutters out of the nitride membrane. Our layout is based on a detailed mechanical analysis for which we determined crucial material parameters experimentally. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Code 685, Greenbelt, MD 20771 USA. EM rainer.fettig@gsic.nasa.gov RI Woodgate, Bruce/D-2970-2012 NR 12 TC 13 Z9 13 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 0-8194-3834-0 J9 PROC SPIE PY 2000 VL 4178 BP 51 EP 58 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BR35P UT WOS:000166175100006 ER PT S AU Kuhn, JL Barclay, RB Greenhouse, MA Mott, DB Satyapal, S AF Kuhn, JL Barclay, RB Greenhouse, MA Mott, DB Satyapal, S BE Motamedi, ME Goring, R TI Electro-mechanical simulation of a large aperture MOEMS Fabry-Perot tunable filter SO MOEMS AND MINIATURIZED SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on MOEMS and Miniaturized Systems CY SEP 18-20, 2000 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Solid State Technol, Sandia Natl Labs DE simulation; electro-mechanical; Fabry-Perot; tunable filter; membrane; optical coating AB We are developing a micro-machined electrostatically actuated Fabry-Perot tunable filter with a large clear aperture for application in high through-put wide-field imaging spectroscopy and lidar systems. In the first phase of this effort, we are developing key components based on coupled electro-mechanical simulations. In particular, the movable etalon plate design leverages high coating stresses to yield a flat surface in drum-head tension over a large diameter (12.5 mm). In this approach, the cylindrical silicon movable plate is back etched, resulting in an optically coated membrane that is suspended from a thick silicon support ring. Understanding the interaction between the support ring, suspended membrane, and coating is critical to developing surfaces that are flat to within stringent etalon requirements. In this work, we present the simulations used to develop the movable plate, spring suspension system, and electrostatic actuation mechanism. We also present results from tests of fabricated proof of concept components. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kuhn, JL (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3834-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4178 BP 325 EP 335 DI 10.1117/12.396504 PG 11 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BR35P UT WOS:000166175100034 ER PT S AU Dutta, SB Ewin, AJ Jhabvala, M Kotecki, CA Kuhn, JL Mott, DB AF Dutta, SB Ewin, AJ Jhabvala, M Kotecki, CA Kuhn, JL Mott, DB BE Motamedi, ME Goring, R TI Development of individually addressable micro-mirror-arrays for space applications SO MOEMS AND MINIATURIZED SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on MOEMS and Miniaturized Systems CY SEP 18-20, 2000 CL SANTA CLARA, CA SP SPIE, Semiconductor Equipment & Mat Int, Solid State Technol, Sandia Natl Labs DE MEMS; micro-mirror-array; cryogenic MEMS; cryogenic CMOS; NGST AB A two dimensional array of individually addressable micro-mirrors with 100 mu mx100 mum pixel size, capable of tilting +/- 10 degrees by electrostatic actuation is being developed and fabricated at the Detector Development Laboratory of NASA, GSFC. The development requires integration of CMOS and MEMS fabrication processes. We have completed extensive analytical studies and performed laboratory tests to compare model predictions with actual performance of a 3x3 array. We are testing the address and driver circuit for a 32x32 array and also developing the process integration of the CMOS and MEMS fabrication of the larger arrays. The mirrors are capable of operating at cryogenic temperature for astronomical applications. Our goal is to extend the development to a 256x256 array for a wide variety of space applications including the Multi-Object-Spectrometer in the Next Generation Space Telescope (NGST). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Dutta, SB (reprint author), NASA, Goddard Space Flight Ctr, Code 553, Greenbelt, MD 20771 USA. NR 8 TC 10 Z9 10 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3834-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4178 BP 365 EP 371 DI 10.1117/12.396508 PG 7 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BR35P UT WOS:000166175100038 ER PT J AU Kamanina, N Barrientos, A Leyderman, A Cui, Y Vikhnin, V Vlasse, M AF Kamanina, N Barrientos, A Leyderman, A Cui, Y Vikhnin, V Vlasse, M TI Effect of fullerene doping on the absorption edge shift in COANP SO MOLECULAR MATERIALS LA English DT Article; Proceedings Paper CT 8th Biennial International Workshop on Fullerenes and Atomic Clusters (IWFAC 99) CY OCT 04-08, 1999 CL ST PETERSBURG, RUSSIA SP Minist Sci & Technologies Russia, Russian Fdn Basic Res ID CRYSTALLINE FILMS; META-NITROANILINE; 2-CYCLOOCTYLAMINO-5-NITROPYRIDINE; GLASSES AB Effect of fullerene doping on spectral properties of 2-cyclooctylamino-5-nitropyridine (COANP) has been investigated. A drastic absorption edge shift in COANP-C-70 system has been observed. A model of explanation for experimental results is proposed. C1 SI Vavilov State Opt Inst, St Petersburg 199034, Russia. UPR, RUM, Dept Phys, Mayaguez, PR USA. AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Kamanina, N (reprint author), SI Vavilov State Opt Inst, St Petersburg 199034, Russia. NR 10 TC 37 Z9 37 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 1058-7276 J9 MOL MATER JI Mol. Mater. PY 2000 VL 13 IS 1-4 BP 275 EP 280 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 376PV UT WOS:000165466700043 ER PT J AU Braun, SA Tao, WK AF Braun, SA Tao, WK TI Sensitivity of high-resolution simulations of Hurricane Bob (1991) to planetary boundary layer parameterizations SO MONTHLY WEATHER REVIEW LA English DT Article ID SEA INTERACTION THEORY; INNER CORE STRUCTURE; TROPICAL CYCLONES; NUMERICAL-MODEL; ANDREW 1992; MESOSCALE; COEFFICIENTS; INTENSITY; DYNAMICS; SCHEME AB The fifth-generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model is used to simulate Hurricane Bob (1991) using grids nested to high resolution (4 km). Tests are conducted to determine the sensitivity of the simulation to the available planetary boundary layer parameterizations, including the bulk aerodynamic, Blackadar, Medium-Range Forecast (MRF) model, and Burk-Thompson boundary layer schemes. Significant sensitivity is seen, with minimum central pressures varying by up to 16 mb and maximum winds by 15 m s(-1). The Burk-Thompson and bulk aerodynamic boundary layer schemes produced the strongest storms while the MRF scheme produced the weakest storm. Simulated horizontal precipitation structures varied substantially between the different PBL schemes, suggesting that accurate forecasts of precipitation in hurricanes can be just as sensitive to the formulation of the PBL as they are to the cloud microphysical parameterizations. Each PBL scheme is different in its formulation of the vertical mixing within the PBL and the surface fluxes, with the exception of the MRF and Blackadar schemes, which share essentially the same surface flux parameterization. Detailed analyses of the PBL schemes describe the key differences in the surface fluxes and how they impact storm intensity. In order to isolate the effects of vertical mixing and surfaces fluxes, simulations were conducted in which each of the surface flux schemes was used in conjunction with the same vertical mixing scheme, and vice versa. These experiments indicate that simulated intensity is largely determined by the surface fluxes rather than by the vertical mixing, with the exception of the MRF PBL case, in which excessively deep vertical mixing acts to dry the lower PBL and reduce hurricane intensity. Simulations that vary only the surface fluxes suggest that the intensity of the simulated hurricane increases with increasing values of the ratio of the exchange coefficients for enthalpy and momentum, C-k/C-D. However, even for identical values of C-k/C-D, the simulated intensity varies depending on the wind speed dependence of the surface roughness parameter z(o). C1 NASA, Atmospheres Lab, Mesoscale Atmospher Proc Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP NASA, Atmospheres Lab, Mesoscale Atmospher Proc Branch, Goddard Space Flight Ctr, Code 912, Greenbelt, MD 20771 USA. EM braun@agnes.gsfc.nasa.gov NR 49 TC 232 Z9 244 U1 0 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PY 2000 VL 128 IS 12 BP 3941 EP 3961 DI 10.1175/1520-0493(2000)129<3941:SOHRSO>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 386AQ UT WOS:000166038300001 ER PT J AU Sherwood, SC AF Sherwood, SC TI On moist instability SO MONTHLY WEATHER REVIEW LA English DT Article AB An argument is made that the concepts of conditional instability and conditional symmetric instability need to be revisited. Confusion in the profession has led to two extant definitions of conditional instability that are superficially similar but fundamentally inconsistent. Only one definition corresponds to a real instability. Further, spillover of this confusion into the analysis of slantwise instability mechanisms appears to be producing inappropriate diagnosis of conditional symmetric instability. Concepts from hydrodynamic stability theory are helpful in discussing the situation. C1 Univ Space Res Assoc, Seabrook, MD USA. RP Sherwood, SC (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 916, Greenbelt, MD 20771 USA. RI Sherwood, Steven/B-5673-2008 OI Sherwood, Steven/0000-0001-7420-8216 NR 5 TC 13 Z9 19 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PY 2000 VL 128 IS 12 BP 4139 EP 4142 DI 10.1175/1520-0493(2000)129<4139:OMI>2.0.CO;2 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 386AQ UT WOS:000166038300016 ER PT S AU Salem, JA Jenkins, MG AF Salem, JA Jenkins, MG BE Kalluri, S Bonacuse, PJ TI Biaxial strength testing of isotropic and anisotropic monoliths SO MULTIAXIAL FATIGUE AND DEFORMATION: TESTING AND PREDICTION SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Multiaxial Fatigue and Deformation CY MAY 19-20, 1999 CL SEATTLE, WA SP Amer Soc Testing & Mat, Comm E8 Fatigue & Fracture, Amer Soc Testing & Mat, Subcomm E08 05 Cycl Deformat & Fatigue Crack Format DE anisotropy; single crystals; ceramics; composites; multiaxial strength; nickel aluminide; tungsten carbide; displacement; strain; stress AB A test apparatus for measuring the multiaxial strength of circular plates was developed and experimentally verified. Contact and frictional stresses were avoided in the highly stressed regions of the test specimen by using fluid pressurization to load the specimen. Both isotropic plates and single-crystal Al plates were considered, and the necessary strain functions for anisotropic plates were formulated. For isotropic plates and single-crystal NiAl plates, the maximum stresses generated in the test rig were within 2% of those calculated by plate theory when the support ring was lubricated. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Salem, JA (reprint author), NASA, Glenn Res Ctr, MS 49-7,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 17 TC 2 Z9 2 U1 0 U2 1 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2865-7 J9 AM SOC TEST MATER PY 2000 VL 1387 BP 13 EP 25 DI 10.1520/STP13495S PG 13 WC Engineering, Mechanical; Materials Science, Characterization & Testing SC Engineering; Materials Science GA BR55H UT WOS:000166793300002 ER PT S AU Kalluri, S Bonacuse, PJ AF Kalluri, S Bonacuse, PJ BE Kalluri, S Bonacuse, PJ TI Cumulative axial and torsional fatigue: An investigation of load-type sequencing effects SO MULTIAXIAL FATIGUE AND DEFORMATION: TESTING AND PREDICTION SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Multiaxial Fatigue and Deformation CY MAY 19-20, 1999 CL SEATTLE, WA SP Amer Soc Testing & Mat, Comm E8 Fatigue & Fracture, Amer Soc Testing & Mat, Subcomm E08 05 Cycl Deformat & Fatigue Crack Format DE axial fatigue; cumulative fatigue; cyclic hardening; damage curve approach; life prediction; linear damage rule; load-type sequencing; torsional fatigue ID DAMAGE; BEHAVIOR; TEMPERATURE; SUPERALLOY AB Cumulative fatigue behavior of a wrought cobalt-base superalloy, Haynes 188, was investigated at 538 degreesC under various single-step sequences of axial and torsional loading conditions. Initially, fully-reversed, axial and torsional Fatigue tests were conducted under strain control at 538 degreesC on thin-walled tubular specimens to establish baseline fatigue life relationships. Subsequently, four sequences (axial/axial. torsional/torsional, axial/torsional, and torsional/axial) of two load-level fatigue tests were conducted to characterize both the load-order (high/low) and load-type sequencing effects. For the two load-level tests, summations of life fractions and the remaining fatigue lives at the second load level were computed by the Miner's linear damage rule (LDR) and a nonlinear damage curve approach (DCA). In general, for all Four cases predictions by LDR were unconservative. Predictions by the DCA were within a factor of two of the experimentally observed fatigue lives for a majority of the cumulative axial and torsional fatigue tests. C1 NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. RP Kalluri, S (reprint author), NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. NR 37 TC 4 Z9 5 U1 2 U2 3 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2865-7 J9 AM SOC TEST MATER PY 2000 VL 1387 BP 281 EP 301 DI 10.1520/STP13510S PG 21 WC Engineering, Mechanical; Materials Science, Characterization & Testing SC Engineering; Materials Science GA BR55H UT WOS:000166793300017 ER PT S AU Krause, DL Bartolotta, PA AF Krause, DL Bartolotta, PA BE Kalluri, S Bonacuse, PJ TI An in-plane biaxial contact extensometer SO MULTIAXIAL FATIGUE AND DEFORMATION: TESTING AND PREDICTION SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Multiaxial Fatigue and Deformation CY MAY 19-20, 1999 CL SEATTLE, WA SP Amer Soc Testing & Mat, Comm E8 Fatigue & Fracture, Amer Soc Testing & Mat, Subcomm E08 05 Cycl Deformat & Fatigue Crack Format DE extensometers; in-plane biaxial testing; strain measurement; experimental techniques; cruciform specimen; cyclic testing; elevated temperature; multiaxial fatigue; deformation ID CRUCIFORM SPECIMENS; DESIGN AB A new extensometer system was developed to measure strains in cruciform specimens under in-plane biaxial loading at elevated temperature. This system incorporates standard axial contact extensometers to provide a cost-effective high-precision instrument, Capabilities, include a minimum strain range of 2.5% and a maximum sensitivity of eight microstrain (mum/m). Allowable environments include elevated temperature, presently tested to 600 degreesC, and pressures from atmospheric to high vacuum. Descriptions of the test facility, modifications, mounting components, and installation procedures are reported. Calibration of the extensometers is described, including setup, error determination, and classification. Test results are presented For a stainless steel specimen. Strain gage and extensometer outputs are compared for static load cases and for combinations of waveform shape, strain range, frequency range, and rest duration for cyclic room temperature rests. Elevated temperature results are presented for free thermal growth conditions and for instrument stability during hot cyclic operation. The results are summarized by the following: the new extensometer system calibrated with a maximum error of 0.8%: room temperature correlation with strain gage data yielded an average variation of 58 mum/m: operation under cyclic conditions resulted in tracking errors less than 3%: elevated temperature results compared accurately with theoretical predictions: and, long duration testing proved to be stable. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Krause, DL (reprint author), NASA, Glenn Res Ctr, Mail Stop 51-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2865-7 J9 AM SOC TEST MATER PY 2000 VL 1387 BP 369 EP 381 DI 10.1520/STP13515S PG 13 WC Engineering, Mechanical; Materials Science, Characterization & Testing SC Engineering; Materials Science GA BR55H UT WOS:000166793300022 ER PT S AU Ellis, JR Sandlass, GS Bayyari, M AF Ellis, JR Sandlass, GS Bayyari, M BE Kalluri, S Bonacuse, PJ TI Design of specimens and reusable fixturing for testing advanced aeropropulsion materials under in-plane biaxial loading SO MULTIAXIAL FATIGUE AND DEFORMATION: TESTING AND PREDICTION SE AMERICAN SOCIETY FOR TESTING AND MATERIALS SPECIAL TECHNICAL PUBLICATION LA English DT Proceedings Paper CT Symposium on Multiaxial Fatigue and Deformation CY MAY 19-20, 1999 CL SEATTLE, WA SP Amer Soc Testing & Mat, Comm E8 Fatigue & Fracture, Amer Soc Testing & Mat, Subcomm E08 05 Cycl Deformat & Fatigue Crack Format DE in-plane biaxial testing; advanced aeropropulsion materials; cruciform specimen design; reusable fixturing; finite-element analysis; optimization techniques; attachment methods; prototype fixturing ID CRUCIFORM SPECIMENS; CRACK AB A design study was undertaken to investigate the feasibility of using simple specimen designs and reusable fixturing for in-plane biaxial tests planned for advanced aeropropulsion materials. Materials of interest in this work include: advanced metallics, polymeric matrix composites, metal and intermetallic matrix composites, and ceramic matrix composites. Early experience with advanced metallics showed that the cruciform specimen design typically used in this type of testing was impractical for these materials, primarily because of concerns regarding complexity and cost. The objective of this research was to develop specimen designs, fixturing, and procedures that would allow in-plane biaxial tests to be conducted on a wide range of aeropropulsion materials while at the same time keeping costs within acceptable limits. With this goal in mind, a conceptual design was developed centered on a specimen incorporating a relatively simple arrangement of slots and fingers for attachment and loading purposes. The ANSYS finite-element code was used to demonstrate the feasibility of the approach and also to develop a number of optimized specimen designs. The same computer code was used to develop the reusable fixturing needed to position and grip the specimens in the load frame. The design adopted uses an assembly of slotted fingers which can be reconfigured as necessary to obtain optimum biaxial stress states in the specimen gage area. Most recently, prototype fixturing was manufactured and is being evaluated over a range of uniaxial and biaxial loading conditions. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Ellis, JR (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 29 TC 0 Z9 0 U1 1 U2 1 PU AMERICAN SOCIETY TESTING AND MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, W CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 0-8031-2865-7 J9 AM SOC TEST MATER PY 2000 VL 1387 BP 382 EP 404 DI 10.1520/STP13516S PG 23 WC Engineering, Mechanical; Materials Science, Characterization & Testing SC Engineering; Materials Science GA BR55H UT WOS:000166793300023 ER PT J AU Stowe, RP Pierson, DL Feeback, DL Barrett, ADT AF Stowe, RP Pierson, DL Feeback, DL Barrett, ADT TI Stress-induced reactivation of Epstein-Barr virus in astronauts SO NEUROIMMUNOMODULATION LA English DT Article DE herpesvirus; Epstein-Barr virus; spaceflight; microgravity; latent virus reactivation ID SHORT-TERM SPACEFLIGHT; MARITAL CONFLICT; PERIPHERAL-BLOOD; SPACE-FLIGHT; IMMUNE; NEUTROPHIL; RISK; RESPONSIVENESS; ACTIVATION; HORMONES AB Herpesviruses are leading causes of infectious blindness and death in immunocompromised individuals. Impaired cellular immunity, which is known to result in increased frequency and severity of herpesvirus infections, has been demonstrated both during and after spaceflight. Therefore, we examined whether Epstein-Barr virus (EBV), a well-characterized latent herpesvirus, undergoes reactivation in astronauts. Sera from Shuttle astronauts, taken before and after spaceflight, were examined for evidence of EBV reactivation. The geometric mean antibody titer to EBV viral capsid antigen (VCA) was significantly increased prior to flight compared to baseline (p = 0.0001). After spaceflight, evidence of acute lytic replication was found in which 8- to 64-fold increases in EBV early antigen (EA) antibodies occurred without significant increases in antibodies to measles virus. Additionally, stress-induced shifts in circulating leukocytes and elevated levels of urinary cortisol and epinephrine were found. Overall, significant increases in EA or high VCA/EA antibody titers were found in 8 of 23 (35%) male astronauts and 3 of 5 (60%) female astronauts. These results indicate that stress reactivates EBV prior to flight and suggest that acute lytic replication of EBV occurs during spaceflight. Copyright (C) 2000 S. Karger AG, Basel. C1 Univ Texas, Med Branch, Dept Pathol, Galveston, TX 77555 USA. NASA, Lyndon B Johnson Space Ctr, Life Sci Res Labs, Houston, TX 77058 USA. RP Stowe, RP (reprint author), Univ Texas, Med Branch, Dept Pathol, Galveston, TX 77555 USA. NR 34 TC 49 Z9 54 U1 0 U2 4 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 1021-7401 J9 NEUROIMMUNOMODULAT JI Neuroimmunomodulation PY 2000 VL 8 IS 2 BP 51 EP 58 DI 10.1159/000026453 PG 8 WC Endocrinology & Metabolism; Immunology; Neurosciences SC Endocrinology & Metabolism; Immunology; Neurosciences & Neurology GA 348YU UT WOS:000089014700001 PM 10965229 ER PT B AU Seery, B AF Seery, B BE Smith, EP Long, KS TI Next generation space telescope program update SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA AB I provide a brief snapshot of the project status and review some of the groundrules for the NGST program. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Seery, B (reprint author), NASA, Goddard Space Flight Ctr, Code 443, Greenbelt, MD 20771 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 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 3 EP 5 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100001 ER PT B AU Mather, J AF Mather, J BE Smith, EP Long, KS TI NGST science instruments and process SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA AB Possible NGST instruments have been studied by NASA, ESA, and CSA teams, and their reports were presented at this meeting and published on the NGST web sites. The instrument capabilities will be evaluated by the Ad Hoc Science Working Group and the technical readiness will be reviewed by a technical panel. Recommendations will be made to the NASA Project Scientist, who will present a report for public comment. NASA, ESA, and the CSA will then allocate instrument responsibilities in early 2000. NASA will choose its scientific investigations with instruments in 2002. C1 NASA, Goddard Space Flight Ctr, Inst Astron, Greenbelt, MD 20771 USA. RP Mather, J (reprint author), NASA, Goddard Space Flight Ctr, Inst Astron, Code 685, Greenbelt, MD 20771 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 18 EP 24 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100003 ER PT B AU Redding, D Basinger, S Lowman, A Shi, F Bowers, C Burns, L Davila, P Dean, B Fitzmaurice, M Hagopian, J Leboeuf, C Mosier, G Norton, T Perkins, B Petrone, P Wheeler, L Wilson, M AF Redding, D Basinger, S Lowman, A Shi, F Bowers, C Burns, L Davila, P Dean, B Fitzmaurice, M Hagopian, J Leboeuf, C Mosier, G Norton, T Perkins, B Petrone, P Wheeler, L Wilson, M BE Smith, EP Long, KS TI Performance of the NGST wavefront control system as tested on DCATT SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA AB The NGST wavefront control testbed (previously known as DCATT) is being used to map out the accuracy and dynamic range of the baseline NGST wavefront controlsystem. Results to date have shown that wavefront sensing and control using focal-plane imagery and phase-retrieval processing is robust and accurate, far exceeding current requirements. Good results have also been obtained for dispersed-fringe sensing, which is used during initial telescope alignment for sensing large segment piston errors. Results agree well with model predictions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Redding, D (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 69 EP 78 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100008 ER PT B AU Lindensmith, CA Bowman, RC Wade, LA Crumb, D AF Lindensmith, CA Bowman, RC Wade, LA Crumb, D BE Smith, EP Long, KS TI Cryocooler options for NGST and other space applications SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA ID REFRIGERATOR; SYSTEMS; DESIGN AB We have assessed the technology status of long-life cryocoolers for space applications below 20 K. Two-stage Joule-Thomson (J-T) cryocoolers are found to be the best candidates for a possible Next Generation Space Telescope (NGST) mid-infrared camera. A combination of a 20 K hydrogen J-T cooler using a sorption compressor precooling a 4 K helium J-T cooler using a mechanical compressor will be flight proven on Planck and provides the lowest risk option for NGST. The 4 K mechanical cooler can be replaced by a 6 K cooler that uses helium as a working gas and charcoal sorbent material in a J-T cycle to provide a vibration-free continuous-cycle cooler. We present a conceptual design and predicted performance for such a helium/charcoal sorption cooler. To provide 10 mW heat lift at 6 K such a cooler would require a total input power of approximately 93.4 W, and have a system mass of approximate to 33 kg. These coolers will also provide enabling technology for future missions, such as TPF, SPECS and IRSI. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lindensmith, CA (reprint author), CALTECH, Jet Prop Lab, MS 79-24, Pasadena, CA 91109 USA. NR 23 TC 1 Z9 2 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 106 EP 115 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100011 ER PT B AU Serabyn, E Barsony, M Beichman, CA Koerner, DW Orton, GS Ressler, ME Werner, MW Xu, C Armus, L Shupe, DL Backman, DE van Dishoeck, EF AF Serabyn, E Barsony, M Beichman, CA Koerner, DW Orton, GS Ressler, ME Werner, MW Xu, C Armus, L Shupe, DL Backman, DE van Dishoeck, EF BE Smith, EP Long, KS TI The potential for mid-infrared astronomy with the Next Generation Space Telescope SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA AB While the baseline for the Next Generation Space Telescope (NGST) is the 1 to 5 mu m wavelength interval, compelling astronomical observations become possible at longer wavelengths. Significant interest therefore exists in a possible extension of NGST's performance into the mid-infrared (MIR). In the following, a report to NASA on the observations enabled with an MIR-capable NGST is summarized. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Serabyn, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 138 EP 148 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100014 ER PT B AU Trauger, JT AF Trauger, JT BE Smith, EP Long, KS TI High contrast coronagraphic imaging with NGST SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA ID DWARF GLIESE 229B; CIRCUMSTELLAR DISKS; PLANETS AB A coronagraphic camera provides NGST with unique discovery capabilities. Enabled science programs and the corresponding instrument concept, as recently developed in the context of an NGST ISIM study, are summarized here. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Trauger, JT (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 28 TC 2 Z9 2 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 165 EP 178 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100017 ER PT B AU Satyapal, S Greenhouse, MA Barclay, R Amato, D Arritt, B Barry, R Holt, C Kuhn, J Higelman, T Fonneland, N Lesyna, L AF Satyapal, S Greenhouse, MA Barclay, R Amato, D Arritt, B Barry, R Holt, C Kuhn, J Higelman, T Fonneland, N Lesyna, L BE Smith, EP Long, KS TI Tunable filters on NGST SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA AB Tunable filters will expand the wavelength choice, spectral resolution, sensitivity, and field of view capabilities of a number of potential science instruments on NGST. They will: 1) provide flexibility in wavelength and bandwidth choice compared with a fixed inventory of filters in conventional cameras, 2) improve the sensitivity of Fourier Transform Spectrometers when full wavelength coverage imaging is not needed, and 3) provide a greater multiplex advantage to multiobject spectrographs when limited spectral coverage is desired. We display work in progress on a near-infrared tunable bandpass filter for the wide field camera of the Next Generation Space Telescope (NGST) Integrated Science Instrument Module (ISIM). This Demonstration Unit for Low Order Cryogenic Etalon (DULCE), is designed to demonstrate a high efficiency scanning Fabry-Perot etalon operating in interference orders 1-4 at 30 K with a high stability DSP based servo control system. DULCE is currently the only available tunable filter for low order cryogenic operation in the near-infrared. in this application, scanning etalons will illuminate che focal plane arrays with a single order of interference to enable wide field low resolution (50 < R < 200) hyperspectral imaging over a wide range of redshifts. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Satyapal, S (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 1 TC 3 Z9 3 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 212 EP 217 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100022 ER PT B AU Moseley, SH Bowers, CW Fettig, RK Gardner, JP Kimble, RA Kutyrev, AS Malumuth, EM Teplitz, HI Wesenberg, RP Woodgate, BE AF Moseley, SH Bowers, CW Fettig, RK Gardner, JP Kimble, RA Kutyrev, AS Malumuth, EM Teplitz, HI Wesenberg, RP Woodgate, BE BE Smith, EP Long, KS TI A high-efficiency, wide-band, multi-object, near-infrared spectrograph for the NGST SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA ID GALAXY AB We report on our study of an innovative high-efficiency, wide-band, multi-object near-infrared spectrograph for the NGST. The spectrograph will simultaneously cover the wavelength range of 0.6-5 mu m with a 4K x 4K mosaic array of InSb detectors and will offer low resolution spectroscopy (R similar to 25-100) of thousands of objects simultaneously, higher resolution spectroscopy (R similar to 1500-5000) of more than a thousand objects simultaneously, and an imaging mode for initial target acquisition and configuration of a high transmission entrance aperture mask. This instrument combines the highest possible point source sensitivity with massive spatial multiplexing and large simultaneous field of view to produce a revolutionary new capability for NGST. The entrance aperture mask, a progammable transmissive microshutter array, is the key enabling technology for this instrument. It has been successfully developed to the level of a 3x3 array, demonstrating the basic mechanical and electrical cell operation, and is ready to be scaled up to larger arrays in the next development phase. We demonstrate that the capability of the core NGST mission is enabled and enhanced by the inclusion of this multi-object spectrograph, and that the key technology, the microshutter array, can be developed in time for use on NGST. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RI Moseley, Harvey/D-5069-2012; Woodgate, Bruce/D-2970-2012 NR 11 TC 4 Z9 4 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 262 EP 275 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100027 ER PT B AU Pacini, L Kaufman, D Adams, M Lou, M Carey, J AF Pacini, L Kaufman, D Adams, M Lou, M Carey, J BE Smith, EP Long, KS TI Next Generation Space Telescope (NGST) pathfinder experiment Inflatable Sunshield in Space (ISIS) SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA AB The Next Generation Space Telescope (NGST) design requires a large sunshield to passively cool the telescope and detectors to temperatures in the 60 to 100 Kelvin range. The government yardstick design for the NGST observatory has baselined an inflatable sunshield. The NGST project plans to fly a one-third-scale sunshield during a Shuttle flight in 2001. The Inflatable Sunshield in Space (ISIS) experiment will demonstrate stable deployment of a large, multilayer thin film sunshield and rigidization of inflatable struts. A new method of modeling large membrane systems will be developed, and data will be obtained in order to validate the model. The flight experiment will also demonstrate the viability of the thermal approach by verifying separation and flatness of membrane layers. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Pacini, L (reprint author), NASA, Goddard Space Flight Ctr, Code 440, Greenbelt, MD 20771 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 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 365 EP 375 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100038 ER PT B AU Keski-Kuha, R Burg, R Davila, P Hagopian, J Bely, P Burge, J Wyant, J Geary, J Jacobson, D Smith, S Lowman, A Macenka, S Redding, D Mangus, J Perrygo, C Saif, B AF Keski-Kuha, R Burg, R Davila, P Hagopian, J Bely, P Burge, J Wyant, J Geary, J Jacobson, D Smith, S Lowman, A Macenka, S Redding, D Mangus, J Perrygo, C Saif, B BE Smith, EP Long, KS TI NGST OTA optical testing SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA ID GENERATION SPACE TELESCOPE AB An Integrated Product Team (IPT) was formed to develop a detailed concept for optical test methodology for testing of the NGST individual primary secondary and tertiary mirrors and the full telescope system on the ground, Optical testing is a significant cost driver therefore the testing has to be understood in detailed fashion early. A brief summary of the preliminary metrology test plan at the mirror component and telescope system level is presented. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Keski-Kuha, R (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 376 EP 384 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100039 ER PT B AU McCreight, C Fowler, A Greene, T Greenhouse, M Martineau, R Hall, D Long, KS MacKenty, J Pipher, J Ressler, M Young, E AF McCreight, C Fowler, A Greene, T Greenhouse, M Martineau, R Hall, D Long, KS MacKenty, J Pipher, J Ressler, M Young, E BE Smith, EP Long, KS TI Interim report: Review of detector requirements for NGST SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA AB Detector arrays will be a truly critical element of the Next Generation Space Telescope instruments, A panel has been formed to explore a wide range of detector topics and to recommend an updated set of detector requirements for the mission. Work is underway to define a clear rationale for deriving detector characteristics from the latest science objectives, and from the low, estimated photon backgrounds. Imaging and spectroscopy objectives clearly drive detector requirements toward increased formats and reduced total noise (of order a few electrons). The near-IR range, owing to its central role in the scientific program, has been identified as highest-priority for detector development. Beyond noise and quantum efficiency, the panel has identified additional factors that must be considered. These include the effects of cosmic radiation, latent images; thermal stability, and detector modulation transfer function. Detailed characterization of candidate NGST detector technology and focal planes is critical. Among the panel's recommendations are: augment funding for detector development; give priority to NIR developments; balance investments in improving sensitivity vs. those which enhance format and producibility; regularly involve detector experts to support system analyses; and improve understanding of radiation effects in candidate detectors. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP McCreight, C (reprint author), NASA, Ames Res Ctr, Mail Stop 244-10, Moffett Field, CA 94035 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 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 385 EP 389 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100040 ER PT B AU Dean, BH Boucarut, R AF Dean, BH Boucarut, R BE Smith, EP Long, KS TI Deformable mirror optical calibration and test results SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA AB We describe the initial setup, configuration, and component level testing procedures used to incorporate a Xinetics 349 channel deformable mirror into the DCATT active optical system. Initial flattening results are presented as well as calibration data on actuator gain and mirror response. The RMS measures of surface quality are also analyzed for drift in the power-up state. C1 NASA, Goddard Space Flight Ctr, Opt Branch, Greenbelt, MD 20771 USA. RP Dean, BH (reprint author), NASA, Goddard Space Flight Ctr, Opt Branch, Greenbelt, MD 20771 USA. NR 3 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 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 446 EP 449 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100051 ER PT B AU Gardner, JP Satyapal, S AF Gardner, JP Satyapal, S BE Smith, EP Long, KS TI Counts and sizes of galaxies in the HDF-S: Implications for the NGST SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA ID HUBBLE DEEP FIELD; DATA REDUCTION; PHOTOMETRY; REDSHIFTS AB Plans for the Next Generation Space Telescope (NGST) include a large component of galaxy surveys, both imaging and spectroscopy. The Hubble Deep Field datasets include the deepest observations ever made in the ultraviolet, optical and near infrared, reaching depths comparable to that expected for NGST spectroscopy. We present the source counts, galaxy sizes and isophotal filling factors of the HDF-South images. The observed integrated galaxy counts reach nearly 1000 galaxies per square arcminute, We extend these counts to fainter levels and further into the infrared using galaxy count models. It was determined from the HDF-N and other deep WFPC2 imaging that fainter galaxies are smaller. This trend continues to AB=29 in the high resolution HDF-S STIS image, where galaxies have a typical half-light radius of 0.1 arcseconds. We have run extensive Monte Carlo simulations of the detection of galaxies in the HDF-S, and show that the small measured sizes are not due to selection effects until m(AB) > 29. We compare observed sizes in the optical and near-infrared using the HDF-S NICMOS image. We discuss the implications of these data on several design concepts of the NGST near-infrared spectrograph. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gardner, JP (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 450 EP 456 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100052 ER PT B AU Gorkavyi, N Ozernoy, L Mather, J Taidakova, T AF Gorkavyi, N Ozernoy, L Mather, J Taidakova, T BE Smith, EP Long, KS TI NGST and the zodiacal light in the solar system SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA ID INTERPLANETARY DUST; NUMERICAL-SOLUTIONS; CLOUD AB We develop a physical model of the zodiacal cloud incorporating the real dust sources of asteroidal, cometary, and kuiperoidal origin. Using the inferred distribution of the zodiacal dust, we compute its thermal emission and scattering at several wavelengths (1.25, 5, and 20 mu m) as a function of NGST location assumed to be at 1 AU or 3 AU. Areas on the sky with a minimum of zodiacal light are determined. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gorkavyi, N (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 9 TC 8 Z9 8 U1 1 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 462 EP 467 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100054 ER PT B AU Shi, F Redding, D Lowman, A Basinger, S Bowers, C Davila, P Wilson, M Norton, T Boucarut, R Petrone, P AF Shi, F Redding, D Lowman, A Basinger, S Bowers, C Davila, P Wilson, M Norton, T Boucarut, R Petrone, P BE Smith, EP Long, KS TI DCATT dispersed fringe sensor: Modeling and experimenting with the transmissive phase plates SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA AB Control algorithms developed for coarse phasing the segmented mirrors of the Next Generation Space Telescope are being tested in realistic modeling and on the NGST wavefront control testbed, also known as DCATT. A dispersed fringe sensor (DFS) is used to detect piston errors between mirror segments during the initial coarse phasing. Both experiments and modeling have shown that the DFS provides an accurate measure of piston errors over a range from just under a millimeter to well under a micron. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Shi, F (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 510 EP 515 PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100062 ER PT B AU Stapelfeldt, K AF Stapelfeldt, K BE Smith, EP Long, KS TI Imaging studies of circumstellar disks with NGST SO NGST SCIENCE AND TECHNOLOGY EXPOSITION SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT NGST Science and Technology Exposition Conference CY SEP 13-16, 1999 CL HYANNIS, MA ID TAURI; STARS; MASS AB I briefly review the scientific motivation and goals for imaging studies of circumstellar disks. After assessing the ongoing contributions being made in this area by the Hubble Space Telescope and adaptive optics, I present simulations of NGST disk imaging performance for simple cameras with and without coronagraphic capability. While the minimal NGST configuration will be capable of some disk imaging work, it is clear that adding a modern coronagraphic camera to the science instrument module will make NGST a significantly more capable machine for the study of solar system origins. 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 12 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-036-6 J9 ASTR SOC P PY 2000 VL 207 BP 521 EP 525 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80R UT WOS:000089621100064 ER PT B AU Berenji, HR Vengerov, D AF Berenji, HR Vengerov, D GP IEEE IEEE TI Advantages of cooperation between reinforcement learning agents in difficult stochastic problems SO NINTH IEEE INTERNATIONAL CONFERENCE ON FUZZY SYSTEMS (FUZZ-IEEE 2000), VOLS 1 AND 2 LA English DT Proceedings Paper CT 9th IEEE International Conference on Fuzzy Systems (FUZZy-IEEE 2000) CY MAY 07-10, 2000 CL SAN ANTONIO, TX SP IEEE Neural Networks Council, Texas A&M Univ, Int Fuzzy Syst Assoc, Japan Soc Fuzzy Theory & Syst AB This paper presents the first results in understanding the reasons for cooperative advantage between reinforcement learning agents. We consider a cooperation method which consists of using and updating a common policy. We tested this method on a complex fuzzy reinforcement learning problem and found that cooperation brings larger than expected benefits. More precisely, we found that K cooperative agents each learning for N time steps outperform K independent agents each learning in a separate world for K*N time steps. In this paper we explain the observed phenomenon and determine the necessary conditions for its presence in a wide class of reinforcement learning problems. C1 NASA, Ames Res Ctr, Computat Sci Div, Intelligent Inference Syst Corp, Moffett Field, CA 94035 USA. RP Berenji, HR (reprint author), NASA, Ames Res Ctr, Computat Sci Div, Intelligent Inference Syst Corp, MS 269-2, Moffett Field, CA 94035 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5878-3 PY 2000 BP 871 EP 876 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BQ42Y UT WOS:000088355300150 ER PT B AU Smith, W Waheed, A Meyers, D Yan, J AF Smith, W Waheed, A Meyers, D Yan, J GP IEEE IEEE TI An evaluation of alternative designs for a grid information service SO NINTH INTERNATIONAL SYMPOSIUM ON HIGH-PERFORMANCE DISTRIBUTED COMPUTING, PROCEEDINGS LA English DT Proceedings Paper CT 9th IEEE International Symposium on High Performance Distributed Computing CY AUG 01-04, 2000 CL PITTSBURGH, PA SP IEEE, Comp Soc Tech Comm Distrib Proc, Univ Arizonia, Dept ECE, Carnegie Mellon Univ, Argonne Natl Lab, Pittsburgh Supercomp Ctr AB Computational grids consisting of large and diverse sets of distributed resources have recently been adopted by organizations such as NASA and the NSF. One key component of a computational grid is an information services that provides information about resources, services, and applications to users and their tools. This information is required to use a computational grid and therefore should be available in a timely and reliable manner. In this work, we describe the Globus information service, describe how this service is used, analyze ifs current performance, and perform trace-driven simulations to evaluate alternative implementations of this grid information service. We find that the majority of the transactions with the information service are changes to the data maintained by the service. We also find that of the three servers we evaluate, one of the commercial products provides the best performance for our workload and that the response time of the information service was not improved during the single experiment we performed with data distributed across two sewers. C1 NASA, Ames Res Ctr, Comp Sci Corp, Moffett Field, CA 94035 USA. RP Smith, W (reprint author), NASA, Ames Res Ctr, Comp Sci Corp, Moffett Field, CA 94035 USA. EM wwsmith@nas.nasa.gov; waheed@nas.nasa.gov; dmeyers@arc.nasa.gov; jyan@arc.nasa.gov NR 12 TC 2 Z9 4 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-0783-2; 0-7695-0784-0 PY 2000 BP 185 EP 192 DI 10.1109/HPDC.2000.868649 PG 8 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BQ76L UT WOS:000089454200021 ER PT B AU Hinke, TH Novotny, J AF Hinke, TH Novotny, J GP IEEE IEEE TI Data mining on NASA's Information Power Grid SO NINTH INTERNATIONAL SYMPOSIUM ON HIGH-PERFORMANCE DISTRIBUTED COMPUTING, PROCEEDINGS LA English DT Proceedings Paper CT 9th IEEE International Symposium on High Performance Distributed Computing CY AUG 01-04, 2000 CL PITTSBURGH, PA SP IEEE, Comp Soc Tech Comm Distrib Proc, Univ Arizonia, Dept ECE, Carnegie Mellon Univ, Argonne Natl Lab, Pittsburgh Supercomp Ctr AB This paper describes the development of a data mining system that is to operate on NASA's Information Power Grid (IPG). Mining agents will be staged to one or more processors on the IPG. There they will grow using just-in-time acquision of new operations. They will mine data delivered using just-in-rime delivery Some initial experimental results are presented. C1 Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hinke, TH (reprint author), Ames Res Ctr, Moffett Field, CA 94035 USA. NR 6 TC 6 Z9 7 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-0784-0 PY 2000 BP 292 EP 293 DI 10.1109/HPDC.2000.868663 PG 2 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BQ76L UT WOS:000089454200035 ER PT B AU Herring, DD Graham, SM Ward, KA Simmon, RB Stockman, SA AF Herring, DD Graham, SM Ward, KA Simmon, RB Stockman, SA GP AMS AMS TI The earth observatory: NASA's new web environment for learning about Earth SO NINTH SYMPOSIUM ON EDUCATION LA English DT Proceedings Paper CT 9th Symposium on Education held at the 80th Annual Meeting of the American-Meteorological-Society CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 3 EP 4 PG 2 WC Education & Educational Research; Meteorology & Atmospheric Sciences SC Education & Educational Research; Meteorology & Atmospheric Sciences GA BS17M UT WOS:000168978800002 ER PT B AU Shepherd, JM AF Shepherd, JM GP AMS AMS TI Addressing issues that society members face in their place of employment. SO NINTH SYMPOSIUM ON EDUCATION LA English DT Proceedings Paper CT 9th Symposium on Education held at the 80th Annual Meeting of the American-Meteorological-Society CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 66 EP 69 PG 4 WC Education & Educational Research; Meteorology & Atmospheric Sciences SC Education & Educational Research; Meteorology & Atmospheric Sciences GA BS17M UT WOS:000168978800028 ER PT B AU Shepherd, JM Howell, C Sisler, W Nelson, A Graham, S Christopher, D Bridgett, L AF Shepherd, JM Howell, C Sisler, W Nelson, A Graham, S Christopher, D Bridgett, L GP AMS AMS TI Informal science education supporting weather broadcasters on-air with TRMM "mini-education supplements SO NINTH SYMPOSIUM ON EDUCATION LA English DT Proceedings Paper CT 9th Symposium on Education held at the 80th Annual Meeting of the American-Meteorological-Society CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 88 EP 89 PG 2 WC Education & Educational Research; Meteorology & Atmospheric Sciences SC Education & Educational Research; Meteorology & Atmospheric Sciences GA BS17M UT WOS:000168978800036 ER PT B AU Digby, SA Nolan, T AF Digby, SA Nolan, T GP AMS AMS TI Physical oceanography in the classroom: Interactive and relevant SO NINTH SYMPOSIUM ON EDUCATION LA English DT Proceedings Paper CT 9th Symposium on Education held at the 80th Annual Meeting of the American-Meteorological-Society CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 Jet Prop Lab, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 107 EP 108 PG 2 WC Education & Educational Research; Meteorology & Atmospheric Sciences SC Education & Educational Research; Meteorology & Atmospheric Sciences GA BS17M UT WOS:000168978800043 ER PT B AU Chambers, LH Young, DF Green, CJ Haberer, SJ Racel, AM AF Chambers, LH Young, DF Green, CJ Haberer, SJ Racel, AM GP AMS AMS TI The CERES S'COOL project: Two years after first launch SO NINTH SYMPOSIUM ON EDUCATION LA English DT Proceedings Paper CT 9th Symposium on Education held at the 80th Annual Meeting of the American-Meteorological-Society CY JAN 09-14, 2000 CL LONG BEACH, CA SP Amer Meteorol Soc C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 2000 BP 111 EP 114 PG 4 WC Education & Educational Research; Meteorology & Atmospheric Sciences SC Education & Educational Research; Meteorology & Atmospheric Sciences GA BS17M UT WOS:000168978800045 ER PT S AU Abdul-Aziz, A Baaklini, GY Zagidulin, D Rauser, RW AF Abdul-Aziz, A Baaklini, GY Zagidulin, D Rauser, RW BE Baaklini, GY Lebowitz, CA Boltz, ES TI Challenges in integrating nondestructive evaluation and finite element methods for realistic structural analysis SO NONDESTRUCTIVE EVALUATION OF AGING MATERIALS AND COMPOSITES IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Nondestructive Evaluation of Aging Materials and Composites IV CY MAR 08-09, 2000 CL NEWPORT BEACH, CA SP SPIE DE finite element analysis; computed tomography; image processing; stress analysis; nondestructive evaluation AB Capabilities and expertise related to the development of links between nondestructive evaluation (NDE) and finite element analysis (FEA) at Glenn Research Center (GRC) are demonstrated. Current tools to analyze data produced by computed tomography (CT) scans are exercised to help assess the damage state in high temperature structural composite materials. A utility translator was written to convert velocity(2) (an image processing software) STL data file to a suitable CAD-FEA type file. Finite element analyses are carried out with MARC, a commercial nonlinear finite element code, and the analytical results are discussed. Modeling was established by building MSC/Patran (a pre and post processing finite element package) generated model and comparing it to a model generated by Velocity(2) in conjunction with MSC/Patran Graphics. Modeling issues and results are discussed in this paper. The entire process that outlines the tie between the data extracted via NDE and the finite element modeling and analysis is fully described. C1 Cleveland State Univ, Dept Civil & Environm Engn, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Abdul-Aziz, A (reprint author), Cleveland State Univ, Dept Civil & Environm Engn, NASA, Glenn Res Ctr, 21000 Brookpk Rd MS 6-1, Cleveland, OH 44135 USA. NR 14 TC 6 Z9 6 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3611-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 3993 BP 35 EP 46 DI 10.1117/12.385504 PG 12 WC Materials Science, Characterization & Testing; Optics SC Materials Science; Optics GA BQ31X UT WOS:000087919400005 ER PT S AU Gyekenyesi, AL Baaklini, GY AF Gyekenyesi, AL Baaklini, GY BE Baaklini, GY Lebowitz, CA Boltz, ES TI Quantifying residual stresses by means of thermoelastic stress analysis SO NONDESTRUCTIVE EVALUATION OF AGING MATERIALS AND COMPOSITES IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Nondestructive Evaluation of Aging Materials and Composites IV CY MAR 08-09, 2000 CL NEWPORT BEACH, CA SP SPIE DE thermoelastic stress analysis; TSA; thermoelastic constant; residual stress; mean stress; SPATE AB This study focused on the application of the Thermoelastic Stress Analysis (TSA) technique as a tool for assessing the residual stress state of structures. TSA is based on the fact that materials experience small temperature changes when compressed or expanded. When a structure is cyclically loaded, a surface temperature profile results which correlates to the surface stresses. The cyclic surface temperature is measured with an infrared camera. Traditionally, the amplitude of a TSA signal was theoretically defined to be linearly dependent on the cyclic stress amplitude. Recent studies have established that the temperature response is also dependent on the cyclic mean stress (i.e., the static stress state of the structure). In a previous study by the authors, it was shown that mean stresses significantly influenced the TSA results for titanium and nickel based alloys. This study continued the effort of accurate direct measurements of the mean stress effect by implementing newly developed temperature correction curves. In addition, a more in-depth analysis was conducted which involved analyzing the second harmonic of the temperature response. By obtaining the amplitudes of the first and second harmonics, the stress amplitude and the mean stress at a given point on a structure subjected to a cyclic load can be simultaneously obtained. The experimental results showed good agreement with the theoretical predictions for both the first and second harmonics of the temperature response. As a result, confidence was achieved concerning the ability to simultaneously obtain values for the static stress state as well as the cyclic stress amplitude of structures subjected to cyclic loads using the TSA technique. With continued research, it is now feasible to establish a protocol that would enable the monitoring of residual stresses in structures utilizing the TSA technique. C1 NASA, Glenn Res Ctr, Cleveland, OH 44115 USA. RP Gyekenyesi, AL (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 6-1, Cleveland, OH 44115 USA. NR 13 TC 2 Z9 2 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 0-8194-3611-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 3993 BP 78 EP 91 DI 10.1117/12.385479 PG 14 WC Materials Science, Characterization & Testing; Optics SC Materials Science; Optics GA BQ31X UT WOS:000087919400009 ER PT S AU Cramer, KE Winfree, WP AF Cramer, KE Winfree, WP BE Aktan, EM Gosselin, SR TI Thermographic imaging of material loss in boiler water-wall tubing by application of scanning line source SO NONDESTRUCTIVE EVALUATION OF HIGHWAYS, UTILITIES, AND PIPELINES IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Nondestructive Evaluation of Highways, Utilities, and Pipelines IV CY MAR 07-09, 2000 CL NEWPORT BEACH, CA SP Int Soc Opt Engn DE infrared; thermal; NDE; corrosion ID CORROSION; AIRCRAFT AB Localized wall thinning due to corrosion in utility boiler water-wall tubing is a significant inspection concern for boiler operators. Historically, conventional ultrasonics has been used for inspection of these tubes. This technique has proven to be very manpower and time intensive. This has resulted in a "spot check" approach to inspections, documenting thickness measurements over a relatively small percentage of the total boiler wall area. NASA Langley Research Center has developed a thermal NDE technique designed to image and quantitatively characterize the amount of material thinning present in steel tubing. The technique involves the movement of a thermal line source across the outer surface of the tubing followed by an infrared imager at a fixed distance behind the line source. Quantitative images of the material loss due to corrosion are reconstructed from measurements of the induced surface temperature variations. This paper will present a discussion of the development of the thermal imaging system as well as the techniques used to reconstruct images of flaws. The application of the thermal line source coupled with the analysis technique represents a significant improvement in the inspection speed for large structures such as boiler water-walls. A theoretical basis for the technique will be presented which explains the quantitative nature of the technique. Further, a dynamic calibration system will be presented for the technique that allows the extraction of thickness information from the temperature data. Additionally, the results of applying this technology to actual water-wall tubing samples and in situ inspections will be presented. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Cramer, KE (reprint author), NASA, Langley Res Ctr, 3B E Taylor St,Mail Stop 231, Hampton, VA 23681 USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3613-5 J9 P SOC PHOTO-OPT INS PY 2000 VL 3995 BP 600 EP 609 DI 10.1117/12.387854 PG 2 WC Engineering, Civil; Instruments & Instrumentation; Materials Science, Characterization & Testing SC Engineering; Instruments & Instrumentation; Materials Science GA BQ47D UT WOS:000088436600058 ER PT S AU Bahoura, M Herman, GS Barnes, NP Bonner, CE Higgins, PT AF Bahoura, M Herman, GS Barnes, NP Bonner, CE Higgins, PT BE Pierce, JW TI Terahertz wave source via difference-frequency mixing using cross-Reststrahlen band dispersion compensation phase matching: a Material Study SO NONLINEAR MATERIALS DEVICES, AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Nonlinear Materials, Devices, and Applications CY JAN 24-25, 2000 CL SAN JOSE, CA SP SPIE DE laser; nonlinear crystal; difference frequency generation; phasematching; THz-wave AB A novel phase-matching technique for coherent THz-wave generation was proposed. This approach uses cross-Reststrahlen band dispersion compensation phase-matching in a collinear optical mixing technique using isotropic, semiconductor nonlinear crystals. The pump and signal sources are in the neat-infrared transmission window of the nonlinear crystal and the generated idler wave is in the far-infrared transmission window, on the other side of the crystal's Reststrahlen band. The choice of the nonlinear crystal for frequency conversion from the near-infrared to the far-infrared is highly dependent on the optical properties of the nonlinear crystal being used as the frequency converter element. We evaluate the use of the proposed phase-matching technique with a variety of III-V and II-VI compounds taking into account their optical dispersion and their phase-matching properties. Theoretical projections of the device performance such as perfect phase-matching conditions, coherence length and wavelength tuning range far different nonlinear crystals are compared. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Bahoura, M (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 10 TC 3 Z9 3 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3545-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 3928 BP 132 EP 140 DI 10.1117/12.379910 PG 9 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA BP95E UT WOS:000086713800017 ER PT S AU Liu, A Ning, CZ AF Liu, A Ning, CZ GP OSA OSA OSA TI Difference-frequency generation of terahertz wave and optical gain in Sb-based quantum wells pumped by near-infrared lasers SO NONLINEAR OPTICS: MATERIALS, FUNDAMENTALS, AND APPLICATIONS SE OSA TRENDS IN OPTICS AND PHOTONICS LA English DT Proceedings Paper CT Conference on Nonlinear Optics: Materials, Fundamentals, and Applications, Technical Digest CY AUG 06-10, 2000 CL KAUA I-LIHUE, HI SP Opt Soc Amer, IEEE, Lasers & ElectroOpt Soc AB We study the terahertz (THz) wave generations arising from intersubband transitions in InGaAs-InP/AlAsSb quantum wells. Difference-frequency generation and Raman-laser schemes are considered. Both approaches show promises as efficient and compact THz sources. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Liu, A (reprint author), NASA, Ames Res Ctr, M-S N229, Moffett Field, CA 94035 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-5695 BN 1-55752-646-X J9 OSA TRENDS OPT PHOTO PY 2000 VL 46 BP 56 EP 58 DI 10.1109/NLO.2000.883573 PG 3 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA BR02P UT WOS:000165407100016 ER PT S AU Goorjian, PM Ning, CZ Agrawal, GP AF Goorjian, PM Ning, CZ Agrawal, GP GP OSA OSA OSA TI Simulations of spatial dynamics in vertical-cavity surface-emitting laser arrays SO NONLINEAR OPTICS: MATERIALS, FUNDAMENTALS, AND APPLICATIONS SE OSA TRENDS IN OPTICS AND PHOTONICS LA English DT Proceedings Paper CT Conference on Nonlinear Optics: Materials, Fundamentals, and Applications, Technical Digest CY AUG 06-10, 2000 CL KAUA I-LIHUE, HI SP Opt Soc Amer, IEEE, Lasers & ElectroOpt Soc ID TRANSVERSE-MODE DYNAMICS; SEMICONDUCTOR-LASERS AB The transverse mode dynamics of vertical cavity laser arrays are modeled by an approximation to the Maxwell-Semiconductor Bloch equations. The interaction between array elements as a function of their separation is studied. (C) 2000 Optical Society of America. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Goorjian, PM (reprint author), NASA, Ames Res Ctr, MS T27A-2, Moffett Field, CA 94035 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-5695 BN 1-55752-646-X J9 OSA TRENDS OPT PHOTO PY 2000 VL 46 BP 380 EP 382 DI 10.1109/NLO.2000.883682 PG 3 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA BR02P UT WOS:000165407100121 ER PT J AU Titarchuk, L Laurent, P AF Titarchuk, L Laurent, P TI A black hole spectral signature SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT XIXth Texas Symposium on Relativistic Astrophysics and Cosmology CY DEC 14-18, 1998 CL PARIS, FRANCE SP CEA, Serv Phys Particules, Serv Phys Theori, CNRS ID CONVERGING FLUID-FLOW; X-RAY-EMISSION; COMPTON-SCATTERING; NEUTRON-STARS; RADIATION; CANDIDATES; ACCRETION AB An accreting black hole is, by definition, characterized by the drain. Namely, the matter falls into a black hole much the same way as water disappears down a drain - matter goes in and nothing comes out. As this can only happen in a black hole, it provides a way to see "a black hole", an unique observational signature. The accretion proceeds almost in a free-fall manner close to the black hole horizon, where the strong gravitational field dominates the pressure forces. In this paper we present analytical calculations and Monte-Carlo simulations of the specific features of X-ray spectra formed as a result of upscattering of the soft (disk) photons in the converging inflow (CI) into the black hole. The full relativistic treatment has been implemented to reproduce these spectra. We show that spectra in the soft state of black hole systems (BHS) can be described as the sum of a thermal (disk) component and the convolution of some fraction of this component with the CI upscattering spread (Greens) function. The latter boosted photon component is seen as an extended power-law at energies much higher than the characteristic energy of the soft photons. We demonstrate the stability of the power spectral index over a wide range of the plasma temperature 0 - 10 keV and mass accretion rates (higher than 3 in Eddington units). We also demonstrate that the sharp high energy cutoff occurs at energies of 200-400 keV which are related to the average energy of electrons m(e)c(2) impinging upon the event horizon. The spectrum is practically identical to the standard thermal Comptonization spectrum when the CI plasma temperature is getting of order of 50 keV (the typical ones for the hard state of BHS). In this case one can see the effect of the bulk motion only at high energies where there is an excess in the CI spectrum with respect to the pure thermal one. Furthermore we demonstrate that the change of spectral shapes from the soft X-ray state to the hard X-ray state is clearly to be related with the temperature of the bulk flow. In other words the effect of the bulk Comptonization compared to the thermal one is getting stronger when the plasma temperature drops below 10 keV. We clearly demonstrate that these spectra emerging from the converging inflow are a inevitable stamp of the BHS where the strong gravitational field dominates the pressure forces. C1 NASA, Goddard Space Flight Ctr, GMU, Greenbelt, MD 20771 USA. CEA, DSM, DAPNIA, SAP, F-91191 Gif Sur Yvette, France. RP Titarchuk, L (reprint author), NASA, Goddard Space Flight Ctr, GMU, Code 661, Greenbelt, MD 20771 USA. NR 23 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JAN PY 2000 VL 80 BP 173 EP 181 DI 10.1016/S0920-5632(99)00839-7 PG 9 WC Physics, Particles & Fields SC Physics GA 305TC UT WOS:000086555500020 ER PT J AU Vangioni-Flam, E Ramaty, R Casse, M AF Vangioni-Flam, E Ramaty, R Casse, M TI Nucleosynthesis and gamma ray-line astronomy SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT XIXth Texas Symposium on Relativistic Astrophysics and Cosmology CY DEC 14-18, 1998 CL PARIS, FRANCE SP CEA, Serv Phys Particules, Serv Phys Theori, CNRS ID CLASSICAL NOVAE; SPECTROSCOPY; ABUNDANCES; SUPERNOVA; EMISSION C1 Inst Astrophys, F-75014 Paris, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CEA, Serv Astrophys, F-91191 Gif Sur Yvette, France. RP Vangioni-Flam, E (reprint author), Inst Astrophys, 98Bis Bd Arago, F-75014 Paris, France. NR 14 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5632 J9 NUCL PHYS B-PROC SUP JI Nucl. Phys. B-Proc. Suppl. PD JAN PY 2000 VL 80 BP 215 EP 217 DI 10.1016/S0920-5632(99)00846-4 PG 3 WC Physics, Particles & Fields SC Physics GA 305TC UT WOS:000086555500027 ER PT B AU Choudhury, B AF Choudhury, B BE Verstraete, MM Menenti, M Peltoniemi, J TI A biophysical process-based estimate of global land surface evaporation using satellite and ancillary data SO OBSERVING LAND FROM SPACE: SCIENCE, CUSTOMERS AND TECHNOLOGY SE ADVANCES IN GLOBAL CHANGE RESEARCH LA English DT Proceedings Paper CT 1st ENAMORS Conference on Optical Remote Sensing of Terrestrial Surfaces: New Sensors, Advanced Algorithms, and the Opportunity for Novel Applications CY SEP 17-19, 1997 CL TUUSULA, FINLAND SP European Network Dev Adv Models Interpret Opt Remote Sesing Data Terrestrial Environm, European Commiss, Environm & Climate Res & Technol Dev Program C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Choudhury, B (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Mail Code 974, Greenbelt, MD 20771 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6503-8 J9 ADV GLOB CHANGE RES PY 2000 VL 4 BP 119 EP 126 PG 8 WC Geochemistry & Geophysics; Geography, Physical; Meteorology & Atmospheric Sciences; Remote Sensing SC Geochemistry & Geophysics; Physical Geography; Meteorology & Atmospheric Sciences; Remote Sensing GA BR55S UT WOS:000166798300012 ER PT B AU Asrar, G AF Asrar, G BE Verstraete, MM Menenti, M Peltoniemi, J TI The NASA Earth system science program in 21st Century SO OBSERVING LAND FROM SPACE: SCIENCE, CUSTOMERS AND TECHNOLOGY SE ADVANCES IN GLOBAL CHANGE RESEARCH LA English DT Proceedings Paper CT 1st ENAMORS Conference on Optical Remote Sensing of Terrestrial Surfaces: New Sensors, Advanced Algorithms, and the Opportunity for Novel Applications CY SEP 17-19, 1997 CL TUUSULA, FINLAND SP European Network Dev Adv Models Interpret Opt Remote Sesing Data Terrestrial Environm, European Commiss, Environm & Climate Res & Technol Dev Program C1 NASA Headquarters, Washington, DC 20546 USA. RP Asrar, G (reprint author), NASA Headquarters, Mail Code YS,300 E St SW, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-6503-8 J9 ADV GLOB CHANGE RES PY 2000 VL 4 BP 257 EP 268 PG 12 WC Geochemistry & Geophysics; Geography, Physical; Meteorology & Atmospheric Sciences; Remote Sensing SC Geochemistry & Geophysics; Physical Geography; Meteorology & Atmospheric Sciences; Remote Sensing GA BR55S UT WOS:000166798300025 ER PT S AU Ansari, RR Datiles, MB King, JF AF Ansari, RR Datiles, MB King, JF BE Rol, PO Joos, KM Manns, F TI A new clinical instrument for the early detection of cataract using dynamic light scattering and corneal topography SO OPHTHALMIC TECHNOLOGIES X SE Proceedings of SPIE LA English DT Proceedings Paper CT 10th Conference on Ophthalmic Technologies CY JAN 22-23, 2000 CL SAN JOSE, CA SP SPIE, Int Biomed Opt Soc ID SYSTEM AB A growing cataract can be detected at the molecular level using the technique of dynamic light scattering (DLS). However, the success of this method in clinical use depends upon the precise control of the scattering volume inside a patient's eye and especially during patient's repeat visits. This is important because the scattering volume (cross-over region between the scattered light and incident light) inside the eye in a high-quality DLS set-up is very small (few microns in dimension). This precise control holds the key for success in the longitudinal studies of cataract and during anti-cataract drug screening. We have circumvented these problems by fabricating a new DLS fiber optic probe with a working distance of 40 mm and by mounting it inside a cone of a corneal analyzer. This analyzer is frequently used in mapping the corneal topography during PRK (photorefractive keratectomy) and LASIK (laser in situ keratomileusis) procedures in shaping of the cornea to correct myopia. This new instrument and some preliminary clinical tests on one of us (RRA) showing the data reproducibility are described. C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Cleveland, OH 44135 USA. RP NASA, Glenn Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Mail Stop 333-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 13 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 0-8194-3524-4 J9 PROC SPIE PY 2000 VL 3908 BP 38 EP 49 DI 10.1117/12.387509 PG 2 WC Engineering, Biomedical; Ophthalmology; Optics SC Engineering; Ophthalmology; Optics GA BQ51V UT WOS:000088608100006 ER PT S AU Bandara, S Gunapala, S Bock, J Ressler, H Liu, J Luong, E Mumolo, J Rafol, S Ting, D Werner, M AF Bandara, S Gunapala, S Bock, J Ressler, H Liu, J Luong, E Mumolo, J Rafol, S Ting, D Werner, M BE Lye, M Moorwood, AFM TI Large format quantum well infrared photodetector arrays for astronomical instrumentation SO OPTICAL AND IR TELESCOPE INSTRUMENTATION AND DETECTORS, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical and IR Telescope Instrumentation and Detectors CY MAR 27-31, 2000 CL MUNICH, GERMANY SP SPIE, European So Observ, DFM Engn Inc ID CAMERA; GAIN AB Quantum Well Infrared Photodetectors (QWIPs) afford greater flexibility than the usual extrinsically doped semiconductor IR detectors. The wavelength of the peak response and cutoff can be continuously tailored over a range wide enough to enable light detection at any wavelength range between 6-20 mu m The spectral band width of these detectors can be tuned from narrow (Delta lambda/lambda similar to 10 %) to wide (similar to lambda/lambda - 40 %) allowing various applications. Also, QWIP device parameters can be optimized to achieve extremely high performances at lower operating temperatures (similar to 30 K) due to exponential suppression of dark current. Furthermore, QWIPs offer low cost per pixel and highly uniform large format focal plane arrays (FPAs) mainly due to mature GaAs/AlGaAs growth and processing technologies. The other advantages of GaAs/AlGaAs based QWIPs are higher yield, lower 1/f noise and radiation hardness. Recently, we operated an infrared camera with a 256x256 QWIP array sensitive at 8.5 mu m at the prime focus of the 5-m Hale telescope, obtaining the images. The remarkable noise stability - and low 1/f noise - of QWIP focal plane arrays enable camera to operate by modulating the optical signal with a nod period up to 100 s. A 500 s observation on dark sky renders a flat image with little indication of the low spacial frequency structures associated with imperfect sky subtraction or detector drifts. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bandara, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3633-X J9 P SOC PHOTO-OPT INS PY 2000 VL 4008 BP 1298 EP 1304 DI 10.1117/12.395446 PN 1&2 PG 7 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BQ82G UT WOS:000089706500133 ER PT S AU Dekany, R Nelson, JE Bauman, B AF Dekany, R Nelson, JE Bauman, B BE Dierickx, P TI Design considerations for CELT adaptive optics SO OPTICAL DESIGN, MATERIALS, FABRICATION, AND MAINTENANCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Design, Materials, Fabrication, and Maintenance CY MAR 27-29, 2000 CL MUNICH, GERMANY SP SPIE, European SO Observ, DFM Engn Inc DE extremely large telescopes; adaptive optics AB California Institute of Technology and University of California have begun conceptual design studies for a new telescope for astronomical research at visible and infrared wavelengths. The California Extremely Large Telescope (CELT) is currently envisioned as a filled-aperture, steerable, segmented telescope of approximately 30m diameter. The key to satisfying many of the science goals of this observatory is the availability of diffraction-limited wavefront control. We describe potential observing modes of CELT, including a discussion of the several major outstanding AO system architectural design issues to be resolved prior to the initiation of the detailed design of the adaptive optics capability. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Dekany, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 23 TC 8 Z9 8 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3628-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4003 BP 212 EP 225 DI 10.1117/12.391511 PG 14 WC Engineering, Manufacturing; Materials Science, Multidisciplinary; Optics SC Engineering; Materials Science; Optics GA BQ69Z UT WOS:000089218100022 ER PT S AU Pusey, M Sumida, J AF Pusey, M Sumida, J BE Andrews, DL Asakura, T Jutamulia, S Kirk, WP Lagally, MG Lal, RB Trolinger, JD TI Fluorescence studies of protein crystal nucleation SO OPTICAL DEVICES AND DIAGNOSTICS IN MATERIALS SCIENCE SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Devices and Diagnostics in Materials Science CY AUG 01-04, 2000 CL SAN DIEGO, CA SP SPIE DE lysozyme; fluorescence energy transfer; crystal nucleation; self-association ID TETRAGONAL LYSOZYME CRYSTALS; ATOMIC-FORCE MICROSCOPY; GROWTH-RATES; CRYSTALLIZATION; MECHANISMS; KINETICS; FACES AB One of the most powerful and versatile methods for studying molecules in solution is fluorescence. Crystallization typically takes place in a concentrated solution environment, whereas fluorescence typically has an upper concentration limit of similar to 1x10(-5)M, thus intrinsic fluorescence cannot be employed, but a fluorescent probe must be added to a sub population of the molecules. However the fluorescent species cannot interfere with the self-assembly process. This can be achieved with macromolecules, where fluorescent probes can be covalently attached to a sub population of molecules that are subsequently used to track the system as a whole. We are using fluorescence resonance energy transfer (FRET) to study the initial solution phase self-assembly process of tetragonal lysozyme crystal nucleatiion, using covalent fluorescent derivatives which crystallize in the characteristic P4(3)2(1)2(1) space group. FRET studies are being carried out between N-terminal lysine bound Texas Red as the donor and N-terminal lysine bound 5-(and-6)-carboxynaphthofluorescein as the acceptor. The estimated Ro for this probe pair, the distance where 50% of the donor energy is transferred to the acceptor, is similar to5.2 nm, giving a useful measurement range from similar to3.5 to 7 nm. The short lifetime of Texas red, coupled with large average distances between the molecules (greater than or equal to 50 nm) in the dilute solutions employed (concentrations less than or equal to 10(-5)M), ensure that any energy transfer observed is not due to random diffusive interactions. Similar results are obtained from both steady state and lifetime methods. The data support our theory that tetragonal chicken egg white lysozyme crystals grow by self-associated units having crystallographic order that form in the solution, then subsequently add to the crystal surface. Results from these and other ongoing studies will be discussed in conjunction with a model for how tetragonal lysozyme crystals nucleate and grow. C1 NASA, George C Marshall Space Flight Ctr, Biophys SD48, Huntsville, AL 35812 USA. RP Pusey, M (reprint author), NASA, George C Marshall Space Flight Ctr, Biophys SD48, Huntsville, AL 35812 USA. NR 18 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 0-8194-3749-3 J9 P SOC PHOTO-OPT INS PY 2000 VL 4098 BP 1 EP 10 DI 10.1117/12.401612 PG 10 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics SC Materials Science; Optics GA BR09B UT WOS:000165629200001 ER PT S AU Hicks, YR Locke, RJ Anderson, RC AF Hicks, YR Locke, RJ Anderson, RC BE Halliwell, NA TI Optical measurement and visualization in high-pressure, high-temperature, aviation gas turbine combustors SO OPTICAL DIAGNOSTICS FOR INDUSTRIAL APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Diagnostics for Industrial Applications CY MAY 22-24, 2000 CL GLASGOW, SCOTLAND SP European Opt Soc, SPIE, Scottish Enterprise, Greater Glasgow & Clyde Valley Tourist Board, Inst Elect Engineers, Inst Mech Engineers DE planar laser-induced fluorescence; Mie imaging; linear Raman scattering; gas turbine combustors ID PATTERNATION AB Planar laser-induced fluorescence (PLIF), planar Mie scattering (PMie), and linear (I-D) spontaneous Raman scattering are applied to flame tube and sector combustors that burn Jet-A fuel at a range of inlet temperatures and pressures that simulate conditions expected in future high-performance civilian gas turbine engines. Chemiluminescence arising from C-2 in the flame was also imaged. Flame spectral emissions measurements were obtained using a scanning spectrometer. Several different advanced concept fuel injectors were examined. First-ever PLIF and chemiluminescence data are presented from the 60-atm gas turbine combustor facility. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Hicks, YR (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 16 TC 5 Z9 5 U1 1 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3713-1 J9 P SOC PHOTO-OPT INS PY 2000 VL 4076 BP 66 EP 77 DI 10.1117/12.397964 PG 12 WC Materials Science, Characterization & Testing; Optics; Physics, Applied SC Materials Science; Optics; Physics GA BR62M UT WOS:000166977400007 ER PT S AU Wang, Y AF Wang, Y BE Farkas, DL Leif, RC TI Miniature optical microscope without imaging lens SO OPTICAL DIAGNOSTICS OF LIVING CELLS III SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Optical Diagnostics of Living Cells III CY JAN 24-25, 2000 CL SAN JOSE, CA SP SPIE, Int Biomed Opt Soc DE microscope; micro-channel; image sensor; optical microscope AB Recently, Jet Propulsion Laboratory has invented and developed a miniature optical microscope, microscope-on-chip using micro-channel and solid state image sensors. It is lightweight, low-power, fast speed instrument, it has no image lens, does not need focus adjustment, and the total mass is less than 50g. A prototype has been built and demonstrated at JPL. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wang, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM yu.wang@jpl.nasa.gov NR 2 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3537-6 J9 PROC SPIE PY 2000 VL 3921 BP 186 EP 189 DI 10.1117/12.384211 PG 4 WC Cell Biology; Microscopy; Optics SC Cell Biology; Microscopy; Optics GA BQ27N UT WOS:000087772400019 ER PT S AU Talukder, A Casasent, D AF Talukder, A Casasent, D BE Casasent, DP Chao, TH TI Pose estimation and transformation for face recognition SO OPTICAL PATTERN RECOGNITION XI SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Optical Pattern Recognition XI CY APR 26-27, 2000 CL ORLANDO, FL SP SPIE ID OBJECT CLASSES AB A new efficient two-stage algorithm to compute nonlinear features is described. Its implementation on a neural net with adaptive activation functions that raise the input data to an arbitrary power is described. Its use in face recognition with unknown input poses is presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM casasent@ece.cmu.edu NR 12 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3669-0 J9 PROC SPIE PY 2000 VL 4043 BP 11 EP 14 DI 10.1117/12.381592 PG 4 WC Computer Science, Artificial Intelligence; Optics SC Computer Science; Optics GA BQ19B UT WOS:000087421100002 ER PT S AU Chao, TH Zhou, HY Reyes, G AF Chao, TH Zhou, HY Reyes, G BE Casasent, DP Chao, TH TI 512 x 512 high-speed grayscale optical correlator SO OPTICAL PATTERN RECOGNITION XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Pattern Recognition XI CY APR 26-27, 2000 CL ORLANDO, FL SP SPIE DE grayscale optical correlator; automatic target recognition; real-time field demonstration; optical MACH correlation filter ID CORRELATION FILTERS AB Jet Propulsion Laboratory (JPL) has developed a new 512 x 512 high-speed grayscale optical correlator (GOC) for real-time automatic target recognition (ATR) applications. As compared with a previous developed 128 x 128 grayscale optical correlator [1-2], the utilization of a pair of high-resolution input spatial light modulator (SLM) has increased the input filed of view by 16 times. The use of a matching high-resolution filter SLM has increased the sharpness of the correlation peak. Key features of this GOC include: A grayscale input SLM (Kopin 640 x 480, 8-bit) to accommodate direct interface with the input imaging sensor, A real-valued (bipolar-amplitude) filter SLM (512 x 512, 4-bit) to enable use of a MACH (Maximum Average Correlation Height) composite correlation filter algorithm [3-6], compact and portable. This GOC architecture has greatly improve the system complexity by removing the need of preprocessing (binarization) the input, and the powerful MACH composite filter has greatly reduced the number of filter templates. In this paper, the criterion of selection of both input and filter SLM will be discussed. System analysis of building a compact correlator will also be provided. Experimental ATR verification of the 512 x 512 GOC will also be illustrated. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chao, TH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 10 Z9 10 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3669-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4043 BP 40 EP 45 DI 10.1117/12.381617 PG 6 WC Computer Science, Artificial Intelligence; Optics SC Computer Science; Optics GA BQ19B UT WOS:000087421100005 ER PT S AU Juday, RD Rollins, JM Monroe, SE Morelli, MV AF Juday, RD Rollins, JM Monroe, SE Morelli, MV BE Casasent, DP Chao, TH TI Full face, full complex characterization of a reflective SLM SO OPTICAL PATTERN RECOGNITION XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Pattern Recognition XI CY APR 26-27, 2000 CL ORLANDO, FL SP SPIE DE spatial light modulator; characterization; quadrature; interferometry; spatially-variant; clustering AB We report algorithms and laboratory practices that tell the full complex behavior of an SLM over its entire face, pixel by pixel, and put the information into a form that is useful to our filter optimization code. We add a quadrature component to the interferometry and image each pixel of the SLM. We analyze the fringes not at one value of drive and in an across-pixels dimension, but instead at each pixel in the drive dimension. We describe details of the method and give examples of spatially-variant filter SLM behavior. We provide examples of performance degradation when the filter's spatial variance has not been accommodated. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Juday, RD (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 4 TC 4 Z9 4 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3669-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4043 BP 80 EP 89 DI 10.1117/12.381582 PG 10 WC Computer Science, Artificial Intelligence; Optics SC Computer Science; Optics GA BQ19B UT WOS:000087421100010 ER PT S AU Zhou, HY Chao, TH Reyes, G AF Zhou, HY Chao, TH Reyes, G BE Casasent, DP Chao, TH TI Practical filter dynamic range compression for grayscale optical correlator using bipolar-amplitude SLM SO OPTICAL PATTERN RECOGNITION XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Pattern Recognition XI CY APR 26-27, 2000 CL ORLANDO, FL SP SPIE DE filter projection; gray-scale optical correlator AB Current optimal filter projection methods either do not take explicit consideration of the limited dynamic range nature of the currently available SLMs or need complicated search and calculation process (for optimal gain and phase angle). To better utilize the limited dynamic range of the bipolar-amplitude SLM used in our recently developed grayscale optical correlator, we devise a simple and rather practical way to improve filter's dynamic range compression after using minimum Euclidean distance projection. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Zhou, HY (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,ms 303-300, Pasadena, CA 91109 USA. NR 10 TC 7 Z9 7 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3669-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4043 BP 90 EP 93 DI 10.1117/12.381583 PG 4 WC Computer Science, Artificial Intelligence; Optics SC Computer Science; Optics GA BQ19B UT WOS:000087421100011 ER PT S AU Milstein, A Monroe, SE Juday, RD AF Milstein, A Monroe, SE Juday, RD BE Casasent, DP Chao, TH TI Optimal region of support for arbitrary filter SLMs SO OPTICAL PATTERN RECOGNITION XI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Pattern Recognition XI CY APR 26-27, 2000 CL ORLANDO, FL SP SPIE DE optical correlation pattern recognition; region of support; spatial light modulators ID SIGNAL; NOISE AB When only certain filter pixels are allowed to transmit light, those "on" pixels constitute the region of support (ROS) for the filter. At those frequencies where noise power overwhelms signal power, or where the available values of the filter are not well aligned with the ideal spectral filter, the filter can actually work against the intent of the metric, and zero transmittance is preferable to what the SLM can do. In contrast to prior theories, which applied to only phase-only filters, we present algorithms for optimizing and studying ROS for an arbitrary SLM. We also present laboratory demonstrations of improvement in signal to noise ratio when a blocking mask is inserted into an optical correlator. A mask has detailed functional dependence on signal, noise power spectral density, the selected metric, and the realizable filter values. Rules are given for designing a mask that will be more broadly useful. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Milstein, A (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 8 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3669-0 J9 P SOC PHOTO-OPT INS PY 2000 VL 4043 BP 192 EP 203 DI 10.1117/12.381595 PG 12 WC Computer Science, Artificial Intelligence; Optics SC Computer Science; Optics GA BQ19B UT WOS:000087421100022 ER PT S AU Harvey, GA AF Harvey, GA BE Chen, PTC Uy, OM TI Thruster residues on returned Mir solar panel SO OPTICAL SYSTEMS CONTAMINATION AND DEGRADATION II: EFFECTS, MEASUREMENTS, AND CONTROL SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Systems Contamination and Degradation II CY AUG 02-03, 2000 CL SAN DIEGO, CA SP SPIE DE Mir; returned solar panel; thruster residues; contamination AB A solar panel with more than ten years space exposure was returned to Earth in January 1998. Several types of residues were deposited or transported onto the solar cell coverglasses during the space exposure. Self-contamination of SiOx films from the silicone potting compound was a major contamination on the coverglasses. A second type of contamination was thick, detergent-like residues of the order of a millimeter diameter on many, but not most of the coverglasses. A third, prevalent type of contamination was very thin irregular shaped films or patterns of millimeter size which are readily visible in brilliant colors when the coverglasses are viewed with a 50x brightfield microscope. These prolific, overlapping, and almost ubiquitous patterns strongly suggest wetting on the surface. The probable cause of most of the wetted patterns on the returned Mir solar cell coverglasses is trace hydrazine nitrate in condensed water droplets produced as reaction products from Mir's and the Orbiters' hypergolic thrusters. This paper presents some of the wetted patterns, information regarding hypergolic reaction products, and type of thrusters associated with Mir operations. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Harvey, GA (reprint author), NASA, Langley Res Ctr, MS 424, Hampton, VA 23681 USA. NR 13 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 0-8194-3741-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4096 BP 41 EP 46 DI 10.1117/12.400835 PG 6 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BR09A UT WOS:000165629100005 ER PT S AU Harvey, GA Kinard, WH Visentine, JT AF Harvey, GA Kinard, WH Visentine, JT BE Chen, PTC Uy, OM TI Particle generation by silicone potting compound of returned Mir solar cells SO OPTICAL SYSTEMS CONTAMINATION AND DEGRADATION II: EFFECTS, MEASUREMENTS, AND CONTROL SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Systems Contamination and Degradation II CY AUG 02-03, 2000 CL SAN DIEGO, CA SP SPIE DE Mir; solar cells; particles; silicone AB A solar panel with more than ten years space exposure was returned to Earth in January 1998. Methyl-phenyl silicone was used for both the adhesive between the coverglasses and silicon wafer, and for the potting compound between individual solar cells. Glass fiber scrim was used for structural integrity of the panel. Atomic oxygen in low-Earth-orbit interacted with the exposed silicone and converted the outermost layer (several microns thick) to oxidized silicon, i.e. SiOx where x similar to2. This brittle SiOx served to protect underlying silicone from oxidation, unless the film was removed by some means. There is much evidence of microeruptions within the potting compound and spewing of silicone and SiOx film debris across the solar cell coverglasses. Ten of 409 solar cells of a returned panel have been scanned with a 50x brightfield microscope. This paper presents measurements of millimeter size SiOx particles and, glass fibers on the returned solar cell coverglasses. Erosion of the potting compound is also discussed. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Harvey, GA (reprint author), NASA, Langley Res Ctr, Mail Sto 424, Hampton, VA 23681 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3741-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4096 BP 47 EP 54 DI 10.1117/12.400836 PG 8 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BR09A UT WOS:000165629100006 ER PT S AU Scialdone, JJ AF Scialdone, JJ BE Chen, PTC Uy, OM TI Preventing damaging pressure gradients at the walls of an inflatable space system. SO OPTICAL SYSTEMS CONTAMINATION AND DEGRADATION II: EFFECTS, MEASUREMENTS, AND CONTROL SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Systems Contamination and Degradation II CY AUG 02-03, 2000 CL SAN DIEGO, CA SP SPIE DE inflatable space systems; stiffening member; material curing; gaseous venting AB An inflatable structural system to deploy a space system such as a solar shield, an antenna or another similar instrument, requires a stiffening element after it is extended by the inflated gas pressure. The stiffening element has to be packaged in a folded configuration before the deployment. It must be relatively small, lightweight, non-damaging to the inflated system, and be able to become stiff in a short time. One stiffening method is to use a flexible material inserted in the deployable system, which, upon a temperature curing, can become stiff and is capable of supporting the entire structure. There are two conditions during the space operations when the inflated volume could be damaged: during the transonic region of the launch phase and when the curing of the rigidizing element occurs. In both cases, an excess of pressure within the volume containing the rigid element could burst the walls of the low-pressure gas inflated portion of the system. This paper investigates those two conditions and indicates the vents, which will prevent those damaging overpressures. Vent openings at the non-inflated volumes have been calculated for the conditions existing during the launch. Those vents allow the initially folded volume to exhaust the trapped atmospheric gas at approximately the same rate as the ambient pressure drops. That will prevent pressure gradients across the container walls which otherwise could be as high as 14.7 psi. The other condition occurring during the curing of the stiffening element has been investigated. This has required the testing of the element to obtain the gas generation during the curing and the transformation from a pliable material to a rigid one. The tested material is a composite graphite/epoxy weave. The outgassing of the uncured sample at 121 degreesC was carried with the Cahn Microbalance and with other outgassing facilities including the micro-CVCM ASTM E-595 facility. The tests provided the mass of gas evolved during the test. That data, including the chemical nature of the evolved gas, provided the data for the calculation of the pressure produced within the volume. The evaluation of the areas of the vents that would prevent excessive pressures and provide a rapid release of the gas away from contamination sensitive surfaces has been carried out. The pressure decay with time has been indicated. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Scialdone, JJ (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 3 TC 0 Z9 0 U1 1 U2 6 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3741-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4096 BP 77 EP 81 DI 10.1117/12.400839 PG 5 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BR09A UT WOS:000165629100009 ER PT S AU Snyder, A Banks, B Miller, S Stueber, T Sechkar, E AF Snyder, A Banks, B Miller, S Stueber, T Sechkar, E BE Chen, PTC Uy, OM TI Modeling of transmittance degradation caused by optical surface contamination by atomic oxygen reaction with adsorbed silicones SO OPTICAL SYSTEMS CONTAMINATION AND DEGRADATION II: EFFECTS, MEASUREMENTS, AND CONTROL SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optical Systems Contamination and Degradation II CY AUG 02-03, 2000 CL SAN DIEGO, CA SP SPIE DE contamination; low Earth orbit; atomic oxygen; silicone; sensor; adsorption; optical transmittance AB A numerical procedure is presented to calculate transmittance degradation caused by contaminant films on spacecraft surfaces produced through the interaction of orbital atomic oxygen (AO) with volatile silicones and hydrocarbons from spacecraft components. In the model, contaminant accretion is dependent on the adsorption of species, depletion reactions due to gas-surface collisions, desorption, and surface reactions between AO and silicone producing SiOx (where x is near 2). A detailed description of the procedure used to calculate the constituents of the contaminant layer is presented, including the equations that govern the evolution of fractional coverage by specie type. As an illustrative example of film growth, calculation results using a prototype code that calculates the evolution of surface coverage by specie type is presented and discussed. An example of the transmittance degradation caused by surface interaction of AO with deposited contaminant is presented for the case of exponentially decaying contaminant flux. These examples are performed using hypothetical values for the process parameters. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Snyder, A (reprint author), NASA, Glenn Res Ctr, MS 309-1, Cleveland, OH 44135 USA. NR 8 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3741-7 J9 P SOC PHOTO-OPT INS PY 2000 VL 4096 BP 157 EP 168 DI 10.1117/12.400826 PG 12 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BR09A UT WOS:000165629100016 ER PT J AU Vikram, CS Witherow, WK AF Vikram, CS Witherow, WK TI Gold coating of fiber tips in near-field scanning optical microscopy SO OPTIK LA English DT Article DE scanning microscopy; coating; fiber optics; micro-optics; near-field ID PROBES; FABRICATION AB We report what is believed to be the first experimental demonstration of gold coating by a chemical baking process on tapered fiber tips used in near-field scanning optical microscopy. Many tips can be simultaneously coated. C1 Univ Alabama, Ctr Appl Opt, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. RP Vikram, CS (reprint author), Univ Alabama, Ctr Appl Opt, Huntsville, AL 35899 USA. NR 27 TC 4 Z9 5 U1 0 U2 0 PU URBAN & FISCHER VERLAG PI JENA PA BRANCH OFFICE JENA, P O BOX 100537, D-07705 JENA, GERMANY SN 0030-4026 J9 OPTIK JI Optik PY 2000 VL 111 IS 9 BP 410 EP 412 PG 3 WC Optics SC Optics GA 360HA UT WOS:000089659300006 ER PT S AU Kim, Q Yano, G Wrigley, CJ Cunningham, TJ Pain, B AF Kim, Q Yano, G Wrigley, CJ Cunningham, TJ Pain, B BE Park, YS Chen, RT TI Modulation transfer function of active pixel focal plane arrays SO OPTOELECTRONIC INTEGRATED CIRCUITS IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Optoelectronic Integrated Circuits IV CY JAN 26-27, 2000 CL SAN JOSE, CA SP SPIE DE active pixel sensor; modulation transfer function; focal plane array; sensor responsivity; crosstalk; star trackers AB Modulation Transfer Function (MTF) is an important figure of merit in focal plane array sensors, especially for accurate target positions such as star trackers. In-situ evaluation by MTF in different stages of imager system developments is necessary for an ideal design of different sensors and their signal processing. Understanding the tradeoff between different figures of merit will enable designers to achieve the most efficient design in specific missions. Advanced active pixel test sensors have been designed and fabricated where different pixel shapes were placed. Research on analyzing the MTF for the proper pixel shape is currently in progress for a centroidal configuration of a star. Explicit formulas for the modulation transfer function have been studied for the rectangular shaped pixel array. MTF will give us a more complete understanding of the tradeoffs opposed by the different pixel designs and by the signal processing conditions. In this paper, preliminary results of two different active pixel sensor (APS) focal plane arrays are presented in terms of crosstalk using a laser. MTF measurements of the APS arrays are achieved by applying only a single image. A rising or falling edge rather than the conventional bar target of slit scanning is needed to perform the measurement in each direction for the evaluation of the design efficiency. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kim, Q (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3567-8 J9 P SOC PHOTO-OPT INS PY 2000 VL 3950 BP 49 EP 56 DI 10.1117/12.382175 PG 8 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA BQ27Z UT WOS:000087783700006 ER PT J AU Beaumont, VI Jahnke, LL Des Marais, DJ AF Beaumont, VI Jahnke, LL Des Marais, DJ TI Nitrogen isotopic fractionation in the synthesis of photosynthetic pigments in Rhodobacter capsulatus and Anabaena cylindrica SO ORGANIC GEOCHEMISTRY LA English DT Article DE N-isotopes; purple nonsulfur bacteria; cyanobacteria; bacteriochlorophyll a; chlorophyll a; nitrogen fixation; lipid biomarkers ID MARINE CYANOBACTERIAL MAT; ORGANIC-MATTER; NATURAL ABUNDANCE; FIXATION; BACTERIA; CARBON; RATIOS; RHODOSPIRILLACEAE; PRINCIPLES; OXYGEN AB Nitrogen isotopic discrimination was investigated for a purple nonsulfur bacterium. Rhodobacter capsulatus, during photoheterotrophic and photoautotrophic growth with N-2 and ammonia, and compared with nitrogen assimilation in a cyanobacterium. In R. capsulatus, the Delta N-15 values for biomass during growth with N-2 fixation and ammonia assimilation. relative to the N-source, ranged from -1.8 to -0.8 parts per thousand and -12.3 to -10.2 parts per thousand respectively. In the cyanobacterium, Anabaena cylindrica, the Delta N-15 value for biomass resulting from growth on molecular nitrogen was -0.8 to -1.7 parts per thousand relative to N-source. These values are similar to those observed for other microorganisms. Bacteriochlorophyll a in R. capsulatus was depleted in N-15 relative to biomass, whereas chlorophyll a in A. cylindrica was relatively enriched in N-15. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Jahnke, LL (reprint author), NASA, Ames Res Ctr, M-S 239-4, Moffett Field, CA 94035 USA. NR 59 TC 26 Z9 26 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PY 2000 VL 31 IS 11 BP 1075 EP 1085 DI 10.1016/S0146-6380(00)00133-9 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 379RU UT WOS:000165656900002 ER PT J AU Cleek, TM Whalen, RT AF Cleek, TM Whalen, RT TI Bone structural properties in the tibia and fibula using DXA SO OSTEOPOROSIS INTERNATIONAL LA English DT Meeting Abstract C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG LONDON LTD PI GODALMING PA SWEETAPPLE HOUSE CATTESHALL ROAD, GODALMING GU7 3DJ, SURREY, ENGLAND SN 0937-941X J9 OSTEOPOROSIS INT JI Osteoporosis Int. PY 2000 VL 11 SU 3 MA P4 BP 21 EP 22 PG 2 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 382RZ UT WOS:000165837400070 ER PT S AU Aranki, N Jiang, WQ Ortega, A AF Aranki, N Jiang, WQ Ortega, A BE Shi, H Coffield, PC Sinha, D TI FPGA-based parallel implementation for the lifting discrete wavelet transform SO PARALLEL AND DISTRIBUTED METHODS FOR IMAGE PROCESSING IV SE Proceedings of SPIE LA English DT Proceedings Paper CT 4th International Conference on Parallel and Distributed Methods for Image Processing IV CY JUL 30, 2000 CL SAN DIEGO, CA SP SPIE, Soc Ind & Appl Math DE discrete wavelet transform; field programmable gate array(FPGA); parallel architecture; overlap-state; split and merge; hardware implementation; reconfigurable platform ID VLSI ARCHITECTURE; BANKS AB The rapidly increasing popularity of the discrete wavelet transform (DWT) as an effective tool in many signal processing and data compression applications, and its integration into JPEG 2000 has given rise to various DWT algorithms and their VLSI implementations to reduce complexity and enhance performance, In this paper, we present an efficient hardware implementation of the discrete wavelet transform and its deployment on a reconfigurable FPGA based platform. Our implementation is a novel architecture based on the lifting factorization of the wavelet filter banks. This factorization leads to a block based parallel DWT architecture suitable for hard-ware implementation. To overcome the communication overhead associated with the DWT block transform, we utilize the new Overlap-State(1,2) technique to compute the DWT near block boundaries. A VHDL description of the lifting polyphase factorization architecture was developed and ported to an FPGA hardware platform that was chosen to allow partial and full reconfigurability to accommodate Various applications with different filter banks. Our hardware implementation improves the performance by better than twofold speed up when compared to an efficient pipelined FPGA based implementation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91101 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91101 USA. EM aranki@brain.jpl.nasa.gov; wqjiang@sipi.usc.edu; Ortega@sipi.usc.edu NR 31 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3763-8 J9 PROC SPIE PY 2000 VL 4118 BP 96 EP 107 DI 10.1117/12.403593 PG 12 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BR08Y UT WOS:000165616600011 ER PT S AU Oliker, L Li, XY Heber, G Biswas, R AF Oliker, L Li, XY Heber, G Biswas, R BE Rolim, J TI Ordering unstructured meshes for sparse matrix computations on leading parallel systems SO PARALLEL AND DISTRIBUTED PROCESSING, PROCEEDINGS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT IEEE International Parallel and Distributed Processing Symposium (IPDP 2000) CY MAY 01-05, 2000 CL CANCUM, MEXICO SP IEEE Comp Soc, Tech Comm Parallel Process, ACM, SIGARCH AB Computer simulations of realistic applications usually require solving a set of non-linear partial differential equations (PDEs) over a finite region. The process of obtaining numerical solutions to the governing PDEs involves solving large sparse linear or eigen systems over the unstructured meshes that model the underlying physical objects. These systems are often solved iteratively, where the sparse matrix-vector multiply (SPMV) is the most expensive operation within each iteration. In this paper, we focus on the efficiency of SPMV using various ordering/partitioning algorithms. We examine different implementations using three leading programming paradigms and architectures. Results show that ordering greatly improves performance, and that cache reuse can be more important than reducing communication. However, a multithreaded implementation indicates that ordering and partitioning are not required on the Tera MTA to obtain an efficient and scalable SPMV. C1 Lawrence Berkeley Natl Lab, NERSC, Berkeley, CA 94720 USA. Cornell Univ, Cornell Theory Ctr, Ithaca, NY 14853 USA. NASA, Ames Res Ctr, MRJ, Moffett Field, CA 94035 USA. RP Oliker, L (reprint author), Lawrence Berkeley Natl Lab, NERSC, Berkeley, CA 94720 USA. NR 7 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-67442-X J9 LECT NOTES COMPUT SC PY 2000 VL 1800 BP 497 EP 503 PG 7 WC Computer Science, Theory & Methods SC Computer Science GA BT03M UT WOS:000171729800060 ER PT B AU Mavriplis, DJ AF Mavriplis, DJ BE Keyes, DE Ecer, A Periaux, J Satofuka, N TI Large-scale parallel viscous flow computations using an unstructured multigrid algorithm SO PARALLEL COMPUTATIONAL FLUID DYNAMICS: TOWARDS TERAFLOPS, OPTIMIZATION, AND NOVEL FORMULATIONS LA English DT Proceedings Paper CT 11th International Conference on Parallel Computational Fluid Dynamics (Parallel CFD 99) CY MAY 23-26, 1999 CL WILLIAMSBURG, VA SP USA, Res Off, IBM Corp, NASA, Natl Sci Fdn, SE Univ Res Assoc ID EQUATIONS; SOLVER; MESHES AB The development and testing of a parallel unstructured agglomeration multigrid algorithm for steady-state aerodynamic flows is discussed. The agglomeration multigrid strategy uses a graph algorithm to construct the coarse multigrid levels from the given fine grid, similar to an algebraic multigrid approach, but operates directly on the non-linear system using the FAS approach. The scalability and convergence rate of the multigrid algorithm axe examined on the SGI ORIGIN 2000 and the Cray T3E. An argument is given which indicates that the asymptotic scalability of the multigrid algorithm should be similar to that of its underlying single grid smoothing scheme. For medium size problems involving several million grid points, near perfect scalability is obtained for the single grid algorithm, while only a slight drop-off in parallel efficiency is observed for the multigrid V and W-cycles, using up to 128 processors on the SGI Origin 2000, and up to 512 processors on the Cray T3E. For a large problem using 25 million grid points, good scalability is observed for the multigrid algorithm using up to 1450 processors on a Cray T3E, even when the coarsest grid level contains fewer points than the total number of processors. C1 NASA, Langley Res Ctr, ICASE, Hampton, VA 23681 USA. RP Mavriplis, DJ (reprint author), NASA, Langley Res Ctr, ICASE, Mail Stop 403, Hampton, VA 23681 USA. NR 26 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-444-82851-6 PY 2000 BP 57 EP 72 DI 10.1016/B978-044482851-4.50010-4 PG 16 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BS93Q UT WOS:000171438000006 ER PT B AU Nielsen, EJ Anderson, WK Kaushik, DK AF Nielsen, EJ Anderson, WK Kaushik, DK BE Keyes, DE Ecer, A Periaux, J Satofuka, N TI Implementation of a parallel framework for aerodynamic design optimization on unstructured meshes SO PARALLEL COMPUTATIONAL FLUID DYNAMICS: TOWARDS TERAFLOPS, OPTIMIZATION, AND NOVEL FORMULATIONS LA English DT Proceedings Paper CT 11th International Conference on Parallel Computational Fluid Dynamics (Parallel CFD 99) CY MAY 23-26, 1999 CL WILLIAMSBURG, VA SP USA, Res Off, IBM Corp, NASA, Natl Sci Fdn, SE Univ Res Assoc ID TURBULENT FLOWS; ALGORITHM; GRIDS AB A parallel framework for performing aerodynamic design optimizations on unstructured meshes is described. The approach utilizes a discrete adjoint formulation which has previously been implemented in a sequential environment and is based on the three-dimensional Reynolds-averaged Navier-Stokes equations coupled with a one-equation turbulence model. Here, only the inviscid terms are treated in order to develop a basic foundation for a multiprocessor design methodology. A parallel version of the adjoint solver is developed using a library of MPI-based linear and nonlinear solvers known as PETSc, while a shared-memory approach is taken for the mesh movement and gradient evaluation codes. Parallel efficiencies are demonstrated and the linearization of the residual is shown to remain valid. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Nielsen, EJ (reprint author), NASA, Langley Res Ctr, MS 128, Hampton, VA 23681 USA. NR 19 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-444-82851-6 PY 2000 BP 313 EP 320 PG 8 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BS93Q UT WOS:000171438000035 ER PT B AU Povitsky, A AF Povitsky, A BE Keyes, DE Ecer, A Periaux, J Satofuka, N TI Efficient parallel-by-line methods in CFD SO PARALLEL COMPUTATIONAL FLUID DYNAMICS: TOWARDS TERAFLOPS, OPTIMIZATION, AND NOVEL FORMULATIONS LA English DT Proceedings Paper CT 11th International Conference on Parallel Computational Fluid Dynamics (Parallel CFD 99) CY MAY 23-26, 1999 CL WILLIAMSBURG, VA SP USA, Res Off, IBM Corp, NASA, Natl Sci Fdn, SE Univ Res Assoc ID IMPLICIT AB We propose a novel methodology for efficient parallelization of implicit structured and block-structured codes. This method creates a parallel code driven by communication and computation schedule instead of usual "creative programming" approach. Using this schedule, processor idle and communication latency times are considerably reduced. C1 NASA, Langley Res Ctr, ICASE, Hampton, VA 23665 USA. RP Povitsky, A (reprint author), NASA, Langley Res Ctr, ICASE, Hampton, VA 23665 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-444-82851-6 PY 2000 BP 337 EP 343 PG 7 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BS93Q UT WOS:000171438000038 ER PT B AU Coblentz, DD Kreinovich, V Penn, BS Starks, SA AF Coblentz, DD Kreinovich, V Penn, BS Starks, SA BE Whalen, T TI Towards reliable sub-division of geological areas: Interval approach SO PEACHFUZZ 2000 : 19TH INTERNATIONAL CONFERENCE OF THE NORTH AMERICAN FUZZY INFORMATION PROCESSING SOCIETY - NAFIPS LA English DT Proceedings Paper CT 19th International Conference of the North-American-Fuzzy-Information-Processing-Society CY JUL 13-15, 2000 CL ATLANTA, GA SP N Amer Fuzzy Informat Proc Soc AB An appropriate subdivision of a geophysical area into segments enables us to extrapolate the results obtained in some locations within the segment (where extensive research was done) to other locations within the same segment, and thus, get a good understanding of the locations which weren't thoroughly analyzed. Often, different evidence and different experts' intuition support different subdivisions schemes. For example, in our area - Rio Grande rift zone - there is some geochemical evidence that this zone,is divided into three segments, but, in the viewpoint of many researchers, this evidence is not yet sufficiently convincing. We show that if we use topographical information (this information, e.g., comes from satellite photos), then interval methods lean to a reliable justification for the tripartite subdivision of the Rio Grande rift zone. C1 Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. RP Coblentz, DD (reprint author), Univ Texas, NASA, Pan Amer Ctr Earth & Environm Studies, El Paso, TX 79968 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6274-8 PY 2000 BP 368 EP 372 DI 10.1109/NAFIPS.2000.877454 PG 5 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BQ89L UT WOS:000089942800073 ER PT J AU Eckstein, MP Beutter, BR Stone, LS AF Eckstein, M. P. Beutter, B. R. Stone, L. S. TI Accumulation of information across saccades during visual search depends on how far the first saccade lands from the target SO PERCEPTION LA English DT Meeting Abstract C1 [Eckstein, M. P.] Cedars Sinai Med Ctr, Los Angeles, CA 90048 USA. [Beutter, B. R.; Stone, L. S.] NASA, Human Factors Res & Technol Div, Ames Res Ctr, Los Angeles, CA USA. EM miguel@medphysics.csmc.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 2000 VL 29 SU S BP 10 EP 10 PG 1 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA V17AR UT WOS:000207910600030 ER PT J AU Watson, AB AF Watson, A. B. TI Efficient adaptive estimation of sensory scales 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 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 2000 VL 29 SU S BP 40 EP 40 PG 1 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA V17AR UT WOS:000207910600120 ER PT J AU Stone, LS Beutter, BR AF Stone, LS Beutter, BR TI Visual motion integration for perception and pursuit SO PERCEPTION LA English DT Article ID CORTICAL AREAS MT; SMOOTH EYE-MOVEMENTS; PURKINJE-CELLS; TARGET MOTION; DIRECTION DISCRIMINATION; VESTIBULOOCULAR REFLEX; PRIMATE FLOCCULUS; NEURAL RESPONSES; PERCEIVED MOTION; VELOCITY AB To examine the relationship between visual motion processing for perception and pursuit, we measured the pursuit eye-movement and perceptual responses to the same complex-motion stimuli. We show that humans can both perceive and pursue the motion of line-figure objects, even when partial occlusion makes the resulting image motion vastly different from the underlying object motion, Our results show that both perception and pursuit can perform largely accurate motion integration, ie the selective combination of local motion signals across the visual field to derive global object motion. Furthermore, because we manipulated perceived motion while keeping image motion identical, the observed parallel changes in perception and pursuit show that the motion signals driving steady-state pursuit and perception are linked. These findings disprove current pursuit models whose control strategy is to minimize retinal image motion, and suggest a new framework for the interplay between visual cortex and cerebellum in visuomotor control. C1 NASA, Ames Res Ctr, Human Factors Res & Technol Div, Moffett Field, CA 94035 USA. San Jose State Univ Fdn, San Jose, CA USA. Coll France, CNRS, Lab Physiol Percept & Act, F-75005 Paris, France. RP Stone, LS (reprint author), NASA, Ames Res Ctr, Human Factors Res & Technol Div, MS 262-2, Moffett Field, CA 94035 USA. NR 84 TC 41 Z9 41 U1 1 U2 1 PU PION LTD PI LONDON PA 207 BRONDESBURY PARK, LONDON NW2 5JN, ENGLAND SN 0301-0066 J9 PERCEPTION JI Perception PY 2000 VL 29 IS 7 BP 771 EP 787 DI 10.1068/p2979 PG 17 WC Ophthalmology; Psychology; Psychology, Experimental SC Ophthalmology; Psychology GA 361JX UT WOS:000089720900003 PM 11064800 ER PT S AU Gerber, S Hammoud, A Patterson, R Elbuluk, M AF Gerber, S Hammoud, A Patterson, R Elbuluk, M GP IEEE IEEE IEEE TI Performance evaluation of low power DC/DC converter modules at cryogenic temperatures SO PESC 2000: 31ST ANNUAL IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE, VOLS 1-3 SE IEEE POWER ELECTRONICS SPECIALISTS CONFERENCE RECORDS LA English DT Proceedings Paper CT 31st Annual IEEE Power Electronics Specialists Conference (PESC 2000) CY JUN 18-23, 2000 CL NATL UNIV IRELAND, GALWAY, IRELAND SP APC, Artesyn Technol, Analog Devices, Convertec, PEI Technol, IEEE, Power Electr Soc HO NATL UNIV IRELAND AB Power electronics capable of operating at cryogenic temperatures is anticipated to play an important role in future NASA deep space missions. Besides having the ability to survive a very cold environment, low temperature electronics could contribute to improving system performance, and reducing development acid launch costs. As part of the NASA Glenn Research Center Low Temperature Electronics Program, several commercial-off-the-shelf, low power, DC/DC converter modules were evaluated under various Lest parameters as a function of temperature in the range of 20 degreesC to -190 degreesC. Due to the significant amount of data generated during the investigations, only selected data pertaining to some of the tested converters will he presented and discussed in this paper. C1 NASA, Glenn Grp, Dynacs Engn Inc, Cleveland, OH 44135 USA. RP Gerber, S (reprint author), NASA, Glenn Grp, Dynacs Engn Inc, Cleveland, OH 44135 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0275-9306 BN 0-7803-5693-4 J9 IEEE POWER ELECTRON PY 2000 BP 1201 EP 1206 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BR59K UT WOS:000166883500189 ER PT J AU Krabill, WB Wright, CW Swift, RN Frederick, EB Manizade, SS Yungel, JK Martin, CF Sonntag, JG Duffy, M Hulslander, W Brock, JC AF Krabill, WB Wright, CW Swift, RN Frederick, EB Manizade, SS Yungel, JK Martin, CF Sonntag, JG Duffy, M Hulslander, W Brock, JC TI Airborne laser mapping of Assateague National Seashore beach SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article AB Results are presented from topographic surveys of the Assateague Island National Seashore using an airborne scanning laser altimeter and kinematic Global Positioning System (GPS) technology. The instrument used was the Airborne Topographic Mapper (ATM), developed by the NASA Arctic Ice Mapping (AIM) group from the Goddard Space Flight Center's Wallops Flight Facility. In November, 1995, and again in May, 1996, these topographic surveys were flown as a functionality check prior to conducting missions to measure the elevation of extensive sections of the Greenland Ice Sheet as part of NASA's Global Climate Change program. Differences between overlapping portions of both surveys are compared for quality control. An independent assessment of the accuracy of the ATM survey is provided by comparison to surface surveys which were conducted using standard techniques. The goal of these projects is to make these measurements to an accuracy of +/- 10 cm. Differences between the fall 1995 and 1996 surveys provides an assessment of net changes in the beach morphology over an annual cycle. C1 NASA, Lab Hydrospher Proc, Wallops Flight Facil, Wallops Island, VA 23337 USA. EG&G Serv, Wallops Island, VA 23337 USA. EG&G Serv, Gaithersburg, MD 20878 USA. Natl Pk Serv, Assateague Isl Nat Seashore, Berlin, MD 21811 USA. NOAA, Coastal Serv Ctr, Charleston, SC 29407 USA. RP Krabill, WB (reprint author), NASA, Lab Hydrospher Proc, Wallops Flight Facil, Wallops Island, VA 23337 USA. NR 13 TC 54 Z9 58 U1 1 U2 8 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 USA SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD JAN PY 2000 VL 66 IS 1 BP 65 EP 71 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 270KL UT WOS:000084534500007 ER PT J AU Sun, GQ Ranson, KJ Bufton, J Roth, M AF Sun, GQ Ranson, KJ Bufton, J Roth, M TI Requirement of ground tie points for InSAR DEM generation SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID INTERFEROMETRIC RADAR AB Ground Sie points have been used to improve the accuracy of a DEM derived from interferometric SAR (InSAR) data. The number of tie points required for ensuring certain accuracy of the InSAR-derived DEM was investigated in this study in two ways. One is the least-squares estimate of the corrections to a DEM using tie points, and the other is using an optimization procedure to estimate the uncertainties in estimations of InSAR parameters, mainly the baseline length, tilt angle, and reference phase using tie points, and resultant DEM error. It was found that, in terms of required tie points, both give comparable results. The latter method, though, can be applied in more realistic cases to design the tie point acquisition strategy for a mission. C1 Univ Maryland, Dept Geog, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RP Sun, GQ (reprint author), Univ Maryland, Dept Geog, College Pk, MD 20742 USA. EM guoqing@aspen.gsfc.nasa.gov; jon.ranson@gsfc.nasa.gov; jack.bufton@gsfc.nasa.gov RI Ranson, Kenneth/G-2446-2012; Namikawa, Laercio/C-5559-2013 OI Ranson, Kenneth/0000-0003-3806-7270; Namikawa, Laercio/0000-0001-7847-1804 NR 14 TC 4 Z9 5 U1 0 U2 1 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 USA SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD JAN PY 2000 VL 66 IS 1 BP 81 EP 85 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 270KL UT WOS:000084534500009 ER PT S AU Ansari, RR AF Ansari, RR GP OSA OSA TI Detection of ocular and other diseases with dynamic light scattering SO PHOTON CORRELATION AND SCATTERING, TECHNICAL DIGEST SE OSA TRENDS IN OPTICS AND PHOTONICS LA English DT Proceedings Paper CT Conference on Photon Correlation and Scattering CY AUG 21-23, 2000 CL WHISTLER, CANADA SP Opt Soc Amer, NASA AB Eye can be considered a "microcosm of the body". Diseases such as uveitis, elevated cholesterol levels, cataract, diabetes, and possibly Alzheimer's disease can be detected much earlier with the technique of dynamic light scattering (DLS). C1 NASA Glenn Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Cleveland, OH 44135 USA. RP Ansari, RR (reprint author), NASA Glenn Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Mail Stop 333-1 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU OPTICAL SOC AMERICA PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-5695 BN 1-55752-648-6 J9 OSA TRENDS OPT PHOTO PY 2000 VL 47 BP 41 EP 43 PG 3 WC Optics; Physics, Applied SC Optics; Physics GA BU35T UT WOS:000175748600014 ER PT S AU George, T Bae, Y Chakraborty, I Cherry, H Evans, C Eyre, B Green, A Hui, A King, K Kim, L Lawton, R Lin, G Marrese, C Mueller, J Podosek, J Shcheglov, K Tang, T VanZandt, T Vargo, S Wellman, J White, V Wiberg, D Yang, EH AF George, T Bae, Y Chakraborty, I Cherry, H Evans, C Eyre, B Green, A Hui, A King, K Kim, L Lawton, R Lin, G Marrese, C Mueller, J Podosek, J Shcheglov, K Tang, T VanZandt, T Vargo, S Wellman, J White, V Wiberg, D Yang, EH BE Taylor, EW TI MEMS technology at NASA's Jet Propulsion Laboratory SO PHOTONICS FOR SPACE ENVIRONMENTS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 7th Photonics for Space Environments Conference (PSE VII) CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE AB The MEMS Technology Group is part of the Microdevices Laboratory (MDL) at the Jet Propulsion Laboratory (JPL). The group pursues the development of a wide range of advanced MEMS technologies that are primarily applicable to NASA's robotic as well as manned exploration missions. Thus these technologies are ideally suited for the demanding requirements of space missions namely, low mass, low power consumption and high reliability, without significant loss of capability. End-to-end development of these technologies is conducted at the MDL, a 38,000 sq. ft. facility with approximately 5500 sq. ft each of cleanroom (class 10 - 100,000) and characterization laboratory space. MDL facilities include computer design and simulation tools, optical and electron-beam lithography, thin film deposition equipment, dry and wet etching facilities including Deep Reactive Ion Etching, device assembly and testing facilities. Following the fabrication of the device prototypes, reliability testing of these devices is conducted at the state-of-the-art Failure Analysis Laboratory at JPL. The MEMS Group is also actively pursuing the rapid, low-cost, space-testing of its devices via a proposed DARPA/NASA/Air Force PICOSAT platform. The space-based tests are expected to provide "space-truth" for critical operational parameters of the MEMS devices that can be correlated to the ground-based reliability assurance testing. Some of the key MEMS technologies being developed currently by the group include a vibratory microgyroscope, LIGA-based devices, micro-propulsion devices, micro-valves, adaptive optics, micro-actuators, biomedical devices, system-on-a-chip, micro-instruments and packaging. Future growth areas for the MEMS group are expected to be in the areas of nano-technology and bio-technology. C1 CALTECH, Jet Prop Lab, MEMS Technol Grp, Device Res & Applicat Sect, Pasadena, CA 91109 USA. RP George, T (reprint author), CALTECH, Jet Prop Lab, MEMS Technol Grp, Device Res & Applicat Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3779-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4134 BP 16 EP 24 DI 10.1117/12.405340 PG 9 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BR51P UT WOS:000166690800003 ER PT S AU Edwards, DL Finckenor, MM O'Neill, MJ McDanal, AJ AF Edwards, DL Finckenor, MM O'Neill, MJ McDanal, AJ BE Taylor, EW TI Optical analysis of transparent polymeric material exposed to simulated space environment SO PHOTONICS FOR SPACE ENVIRONMENTS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 7th Photonics for Space Environments Conference (PSE VII) CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE space environment; environmental effects; ultraviolet; radiation; polymer; solar concentrator; transmission AB Transparent polymeric materials are being designed and utilized as solar concentrating lenses for spacecraft power and propulsion systems. These polymeric lenses concentrate solar energy onto energy conversion devices such as solar cells and thermal energy systems. The conversion efficiency is directly related to the transmissivity of the polymeric lens. The Environmental Effects Group of the Marshall Space Flight Center's Materials, Processes, and Manufacturing Department exposed a variety of material to a simulated space environment and evaluated them for change in optical transmission. These materials include Lexan(TM), polyethylene terephalate (PET), several formulation of Tefzel(TM) and Teflon(TM), and silicone DC 93-500. Samples were exposed to a minimum of 1000 equivalent sun hours (ESH) of near ultraviolet (NW) radiation (250- 400 nm wavelength). Prolonged exposure to the space environment will decrease the polymer film's transmission and thus reduce the conversion efficiency. A method was developed to normalize the transmission loss and thus rank the materials according to their tolerance to space environmental exposure(1). Spectral results and the material ranking according to transmission loss are presented. Power loss over time for a typical solar cell was calculated based on degraded transmission of the polymer material. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Edwards, DL (reprint author), NASA, George C Marshall Space Flight Ctr, Mail Stop ED31, Huntsville, AL 35812 USA. NR 4 TC 2 Z9 2 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3779-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4134 BP 56 EP 64 DI 10.1117/12.405364 PG 9 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BR51P UT WOS:000166690800008 ER PT S AU Tuma, M King, K Kim, L Hansler, R Jones, E George, T AF Tuma, M King, K Kim, L Hansler, R Jones, E George, T BE Taylor, EW TI MEMS incandescent light source SO PHOTONICS FOR SPACE ENVIRONMENTS VII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 7th Photonics for Space Environments Conference (PSE VII) CY JUL 31-AUG 01, 2000 CL SAN DIEGO, CA SP SPIE DE MEMS light source; broadband source; incandescent source AB A MEMS-based, low-power, incandescent light source is being developed. This light source is fabricated using three bonded chips. The bottom chip consists of a reflector on Silicon, the middle chip contains a Tungsten filament bonded to Silicon and the top layer is a transparent window. A 25-mum-thick spiral filament is fabricated in Tungsten using lithography and wet-etching. A proof-of-concept device has been fabricated and tested in a vacuum chamber. Results indicate that the filament is electrically heated to approximately 2650 K. The power required to drive the proof-of-concept spiral filament to incandescence is 1.25 W. The emitted optical power is expected to be approximately 1.0 W with the spectral peak at 1.1 mum. The micromachining techniques used to fabricate this light source can be applied to other MEMS devices. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Tuma, M (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 77-1, Cleveland, OH 44135 USA. NR 9 TC 0 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3779-4 J9 P SOC PHOTO-OPT INS PY 2000 VL 4134 BP 151 EP 158 DI 10.1117/12.405338 PG 8 WC Engineering, Aerospace; Optics SC Engineering; Optics GA BR51P UT WOS:000166690800018 ER PT J AU Chekalyuk, AM Hoge, FE Wright, CW Swift, RN AF Chekalyuk, AM Hoge, FE Wright, CW Swift, RN TI Short-pulse pump-and-probe technique for airborne laser assessment of Photosystem II photochemical characteristics SO PHOTOSYNTHESIS RESEARCH LA English DT Article DE chlorophyll; fluorescence; LIDAR; photosynthesis; Photosystem II; pump and probe; remote sensing; singlet-singlet quenching; singlet-triplet quenching ID CHLOROPHYLL FLUORESCENCE; PHOTOSYNTHETIC CHARACTERISTICS; INDIVIDUAL CELLS; PHYTOPLANKTON; LIGHT; CHLOROPLASTS; FLUOROMETRY; PARTICLES; CHLORELLA; INDUCTION AB The development of a technique for laser measurement of fPhotosystem II (PS II) photochemical characteristics of phytoplankton and terrestrial vegetation from an airborne platform is described. Results of theoretical analysis and experimental study of pump-and-probe measurement of the PS II functional absorption cross-section and photochemical quantum yield are presented. The use of 10 ns probe pulses of PS II sub-saturating intensity provides a significant, up to 150-fold, increase in the fluorescence signal compared to conventional 'weak-probe' protocol. Little effect on the fluorescence yield from the probe-induced closure of PS II reaction centers is expected over the short pulse duration, and thus a relatively intense probe pulse can be used. On the other hand, a correction must be made for the probe-induced carotenoid triplet quenching and singlet-singlet annihilation. A Stern-Volmer model developed for this correction assumes a linear dependence of the quenching rate on the laser pulse fluence, which was experimentally validated. The PS II saturating pump pulse fluence (532 nm excitation) was found to be 10 and 40 mu mol quanta m(-2) for phytoplankton samples and leaves of higher plants, respectively. Thirty mus was determined as the optimal delay in the pump-probe pair. Our results indicate that the short-pulse pump-and-probe measurement of PS II photochemical characteristics can be implemented from an airborne platform using existing laser and LIDAR technologies. C1 CNR, Wallops Isl, VA 23337 USA. NASA, Goddard Space Flight Ctr, EG&G Inc, Wallops Flight Facil, Wallops Isl, VA 23337 USA. RP Chekalyuk, AM (reprint author), CNR, Wallops Isl, VA 23337 USA. EM chekaluk@osb.wff.nasa.gov NR 34 TC 14 Z9 14 U1 0 U2 8 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0166-8595 J9 PHOTOSYNTH RES JI Photosynth. Res. PY 2000 VL 66 IS 1-2 BP 33 EP 44 DI 10.1023/A:1010795820025 PG 12 WC Plant Sciences SC Plant Sciences GA 439QX UT WOS:000169129500004 ER PT J AU Chekalyuk, AM Hoge, FE Wright, CW Swift, RN Yungel, JK AF Chekalyuk, AM Hoge, FE Wright, CW Swift, RN Yungel, JK TI Airborne test of laser pump-and-probe technique for assessment of phytoplankton photochemical characteristics SO PHOTOSYNTHESIS RESEARCH LA English DT Article DE chlorophyll; energy quenching; fluorescence; LIDAR; photochemistry; photosynthesis; Photosystem II; phytoplankton; pump and probe; remote sensing ID OCEAN COLOR MEASUREMENT; CHLOROPHYLL FLUORESCENCE; PHOTOSYSTEM-II; PHOTOSYNTHETIC CHARACTERISTICS; INDIVIDUAL CELLS; VARIABILITY; FLUOROMETER; EFFICIENCY; CHLORELLA; INDUCTION AB Initial results of the airborne LIDAR measurement of photochemical quantum yield, Phi (Po), and functional absorption cross-section, sigma (PSII), of Photosystem II (PS II) are reported. NASA's AOL3 LIDAR was modified to implement short-pulse pump-and-probe (SP-P&P) LIDAR measurement protocol. The prototype system is capable of measuring a pump-induced increase in probe-stimulated chlorophyll fluorescence, DeltaF/F-sat, along with the acquisition of 'conventional' LIDAR-fluorosensor products from an operational altitude of 150 m. The use of a PS II sub-saturating probe pulse increases the response signal but also results in excessive energy quenching (EEQ) affecting the DeltaF/F-sat magnitude. The airborne data indicated up to a 3-fold EEQ-caused decline in DeltaF/F-sat, and 2-fold variability in the EEQ rate constant over a spatial scale a few hundred kilometers. Therefore, continuous monitoring of EEQ parameters must be incorporated in the operational SP-P&P protocol to provide data correction for the EEQ effect. Simultaneous airborne LIDAR measurements of Phi (Po) and sigma (PSII) with EEQ correction were shown to be feasible and optimal laser excitation parameters were determined. Strong daytime DeltaF/F-sat decline under ambient light was found in the near-surface water layer over large aquatic areas. An example of SP-P&P LIDAR measurement of phytoplankton photochemical and fluorescent characteristics in the Chesapeake Bay mouth is presented. Prospects for future SP-P&P development and related problems are discussed. C1 CNR, Wallops Isl, VA 23337 USA. NASA, Goddard Space Flight Ctr, EG&G Inc, Wallops Flight Facil, Wallops Isl, VA 23337 USA. RP Chekalyuk, AM (reprint author), CNR, Wallops Isl, VA 23337 USA. EM chekaluk@osb.wff.nasa.gov NR 32 TC 13 Z9 13 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0166-8595 J9 PHOTOSYNTH RES JI Photosynth. Res. PY 2000 VL 66 IS 1-2 BP 45 EP 56 DI 10.1023/A:1010764420934 PG 12 WC Plant Sciences SC Plant Sciences GA 439QX UT WOS:000169129500005 ER PT J AU Turner, MS AF Turner, MS TI Remembering David N. Schramm - October 25, 1945-December 19, 1997 SO PHYSICA SCRIPTA LA English DT Biographical-Item C1 Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Dept Phys, Chicago, IL 60637 USA. NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Turner, MS (reprint author), Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PY 2000 VL T85 BP 9 EP 11 DI 10.1238/Physica.Topical.085a00009 PG 3 WC Physics, Multidisciplinary SC Physics GA 321ER UT WOS:000087442900002 ER PT J AU Carlstrom, JE Joy, MK Grego, L Holder, GP Holzapfel, WL Mohr, JJ Patel, S Reese, ED AF Carlstrom, JE Joy, MK Grego, L Holder, GP Holzapfel, WL Mohr, JJ Patel, S Reese, ED TI Imaging the Sunyaev-Zel'dovich effect SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 109th Nobel Symposium on Particle Physics and the Universe CY AUG 20-25, 1998 CL HAGA SLOTT, SWEDEN SP Nobel Fdn ID X-RAY; CLUSTERS; COMPTONIZATION; ABELL-2163; SUPERNOVAE; GALAXIES; CONSTANT; UNIVERSE; GHZ AB We report on results of interferometric imaging of the Sunyaev-Zel'dovich Effect (SZE) with the OVRO and BIMA mm-arrays. Using low-noise cm-wave receivers on the arrays, we have obtained high quality images for 27 distant galaxy clusters. We review the use of the SZE as a cosmological tool. Gas mass fractions derived from the SZE data are given for 18 of the clusters, as well as the implied constraint on the matter density of the universe, Omega(M). We find Omega(M)h(100) less than or equal to 0.22(-0.03)(+0.05). A best guess for the matter density obtained by assuming a reasonable value for the Hubble constant and also by attempting to account for the baryons contained in the galaxies as well as those lost during the cluster formation process gives Omega(M) similar to 0.25. We also give preliminary results for the Hubble constant. Lastly, the power for investigating the high redshift universe with a non-targeted high sensitivity SZE survey is discussed and an interferometric survey is proposed. C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RP Carlstrom, JE (reprint author), Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA. RI Holzapfel, William/I-4836-2015 NR 33 TC 38 Z9 39 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PY 2000 VL T85 BP 148 EP 155 DI 10.1238/Physica.Topical.085a00148 PG 8 WC Physics, Multidisciplinary SC Physics GA 321ER UT WOS:000087442900019 ER PT J AU Turner, MS AF Turner, MS TI Dark matter and dark energy in the universe SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 109th Nobel Symposium on Particle Physics and the Universe CY AUG 20-25, 1998 CL HAGA SLOTT, SWEDEN SP Nobel Fdn ID BIG-BANG NUCLEOSYNTHESIS; COSMOLOGICAL CONSTANT; GALAXY CLUSTERS; HIGH-REDSHIFT; SCALAR-FIELD; SUPERNOVAE; DENSITY; OMEGA; FLUCTUATIONS; STATISTICS AB For the first time, we have a plausible and complete accounting of matter and energy in the Universe. Expressed a fraction of the critical density it goes like this: neutrinos, between 0.3% and 15%; stars, between 0.3% and 0.6%; baryons (total) 5% +/- 0.5%; matter (total), 40% +/- 10%; smooth, dark energy, 80% +/- 20%; totaling to the critical density (within the errors). This accounting is consistent with the inflationary prediction of a flat Universe and measurements of the anisotropy of the CBR. It also defines three "dark problems": Where are the dark baryons? What is the nonbaryonic dark matter? What is the nature of the dark energy? The leading candidate for the (optically) dark baryons is diffuse hot gas; the leading candidates for the nonbaryonic dark matter are slowly moving elementary particles left over from the earliest moments (cold dark matter), such as axions or neutralinos; the leading candidates for the dark energy involve fundamental physics and include a cosmological constant (vacuum energy), a rolling scalar field (quintessence), and a network of light, frustrated topological defects. C1 Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Dept Phys, Chicago, IL 60637 USA. NASA, Fermi Natl Accelerator Lab, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. RP Turner, MS (reprint author), Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. NR 80 TC 41 Z9 42 U1 1 U2 2 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PY 2000 VL T85 BP 210 EP 220 DI 10.1238/Physica.Topical.085a00210 PG 11 WC Physics, Multidisciplinary SC Physics GA 321ER UT WOS:000087442900027 ER PT J AU Kolb, EW AF Kolb, EW TI Early-universe issues: seeds of perturbations and birth of dark matter SO PHYSICA SCRIPTA LA English DT Article; Proceedings Paper CT 109th Nobel Symposium on Particle Physics and the Universe CY AUG 20-25, 1998 CL HAGA SLOTT, SWEDEN SP Nobel Fdn ID ENERGY COSMIC-RAYS; PARTICLE-PRODUCTION; INFLATIONARY PERTURBATIONS; COSMOLOGICAL PERTURBATIONS; GRAVITATIONAL-WAVES; DECAY; BARYOGENESIS; INFLATON; MODELS; RECONSTRUCTION AB The signatures of events that occurred in the early universe can be seen today on the sky in the form of large-scale structures and fluctuations in the temperature of the cosmic background radiation. If we can read the signatures, we can learn what occurred in the early universe and something about the physics involved. C1 NASA, Fermi Natl Accelerator Lab, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Kolb, EW (reprint author), NASA, Fermi Natl Accelerator Lab, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. NR 64 TC 0 Z9 0 U1 0 U2 0 PU ROYAL SWEDISH ACAD SCIENCES PI STOCKHOLM PA PUBL DEPT BOX 50005, S-104 05 STOCKHOLM, SWEDEN SN 0281-1847 J9 PHYS SCRIPTA JI Phys. Scr. PY 2000 VL T85 BP 231 EP 245 DI 10.1238/Physica.Topical.085a00231 PG 15 WC Physics, Multidisciplinary SC Physics GA 321ER UT WOS:000087442900029 ER PT J AU Parusel, ABJ AF Parusel, ABJ TI A DFT/MRCI study on the excited state charge transfer states of N-pyrrolobenzene, N-pyrrolobenzonitrile and 4-N,N-dimethylaminobenzonitrile SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-CONFORMATION; ELECTRONIC-SPECTRA; DUAL FLUORESCENCE; AMINOBENZONITRILES; PHENYLPYRROLES; DERIVATIVES; SEPARATION; ABSORPTION AB The ground and excited state properties for the electron donor-acceptor systems N-pyrrolobenzene (PB), N-pyrrolobenzonitrile (PBN) and 4-N,N-dimethylaminobenzonitrile (DMABN) are calculated using the DFT formalism for the ground state and a DFT/MRCI approach for the excited states. Solvent effects are roughly approximated by the Onsager model. A good agreement with experimental data is obtained for the ground state geometry, rotation barriers, and vertical excitation energies. PB fluoresces from an intramolecular charge transfer (ICT) state only in polar solvents whereas PBN shows ICT emission even in an apolar environment. A charge separated state can be formed in BP and BPN for all benzene-pyrrolo rotation angles due to a node at the contributing pyrrolo nitrogen molecular orbital (MO). This ICT state is stabilized for larger twist angles in polar solvent and for PB also in the gas phase. Thus, the red-shifted ICT band of all systems is assigned to emission out of a twisted ICT state. The normal fluorescence of locally excited (LE) character originates from the S-1 minimum at planar geometry. The dual fluorescence of DMABN in slightly polar solvents can be explained by geometrical relaxation with increasing rotation but also the formation of a planar ICT state cannot be ruled out. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Parusel, ABJ (reprint author), Univ Vienna, Inst Theoret Chem & Struct Biol, Althanstr 14, A-1090 Vienna, Austria. NR 46 TC 57 Z9 58 U1 0 U2 5 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PY 2000 VL 2 IS 24 BP 5545 EP 5552 DI 10.1039/b006751m PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 388TH UT WOS:000166198800005 ER PT J AU Khakoo, MA Larsen, M Paolini, B Guo, X Bray, I Stelbovics, A Kanik, I Trajmar, S James, GK AF Khakoo, MA Larsen, M Paolini, B Guo, X Bray, I Stelbovics, A Kanik, I Trajmar, S James, GK TI Electron-impact excitation of the 1 S-2 -> 2 S-2+2 P-2 levels of atomic hydrogen at 30, 40, 50, 54.4, and 100 eV SO PHYSICAL REVIEW A LA English DT Article ID DIFFERENTIAL CROSS-SECTIONS; SCATTERING; HELIUM; TRANSITION; STATES; HE AB Normalized experimental differential cross sections for the electron impact excitation of the 1 S-2 --> 2 S-2 + 2 P-2 levels of H at 30, 40, 50, 54.4, and 100 eV incident energies are presented. Ratios of scattering intensities of electrons incident on a target mixture of II and He and having excited the 11 (n = 2) and He (n = 2) levels are measured using electron-energy-loss spectroscopy. These intensity ratios are normalized to available, accurate, experimental excitation differential cross sections for He (n = 2) [except at 54.4 eV, where theoretical He (n = 2) differential cross sections are used] to obtain relative differential cross sections for electron impact excitation of the H (n = 2) manifold. The relative H (n = 2) differential cross sections are placed on an absolute scale by determining the H/He mixture ratio using energy-loss spectra taken at 100 eV and 25 degrees scattering angle, and normalizing to accurate theoretical H (n = 2) and He (n = 2) differential cross sections at this energy and scattering angle. Comparisons with available calculations and measurements. are made. C1 Calif State Univ Fullerton, Dept Phys, Fullerton, CA 92834 USA. Flinders Univ S Australia, Adelaide, SA 5001, Australia. Murdoch Univ, Ctr Atom Mol & Surface Phys, Murdoch, WA 6150, Australia. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Khakoo, MA (reprint author), Calif State Univ Fullerton, Dept Phys, Fullerton, CA 92834 USA. RI Bray, Igor/B-8586-2009 OI Bray, Igor/0000-0001-7554-8044 NR 30 TC 6 Z9 6 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD JAN PY 2000 VL 61 IS 1 AR 012701 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 281PA UT WOS:000085168800038 ER PT J AU Tokay, A Chamberlain, R Schoenhuber, M AF Tokay, A Chamberlain, R Schoenhuber, M TI Laboratory and field measurements of raindrop oscillations SO PHYSICS AND CHEMISTRY OF THE EARTH PART B-HYDROLOGY OCEANS AND ATMOSPHERE LA English DT Article; Proceedings Paper CT 1st European Conference on Radar Meterology CY SEP 04-08, 2000 CL BOLOGNA, ITALY ID POLARIZATION RADAR; AXIS RATIOS; TERMINAL VELOCITY; DISDROMETER; SHAPE AB This study presents new measurements of raindrop oscillations in laboratory and field conditions. A 2-D video disdrometer is used to detect the shape of oscillating raindrops. The studies that were conducted to examine the oscillatory behavior of drops reveal that there is a lack of observations of the large drop oscillations (Andsager et al. 1999). Yet, these drops have significant importance on radar rain estimation. Therefore, the new laboratory study is particularly designed to expand our knowledge on oscillatory behavior of large raindrops. The preliminary laboratory tests indicate that the drops are less oblate than the equilibrium shapes. Regarding the field studies, a large sample of raindrops was collected in several tropical field campaigns. The raindrops are mostly distorted and canted due to the environmental wind. An algorithm that determines the drop orientation and canting angle is added to the current system. This would reveal one of the most comprehensive data set on the oscillating behavior of raindrops in natural rain. The role of the oscillating raindrops on polarimetric parameters and subsequent rain estimation will be added to the discussion. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 NASA, Goddard Space Flight Ctr, UMBC, JCET, Greenbelt, MD 20771 USA. NASA, WFF, CSC, Wallops Island, VA 23337 USA. Joanneum Res, A-8010 Graz, Austria. RP Tokay, A (reprint author), NASA, Goddard Space Flight Ctr, UMBC, JCET, Greenbelt, MD 20771 USA. NR 17 TC 5 Z9 5 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1909 J9 PHYS CHEM EARTH PT B JI Phys. Chem. Earth Pt B-Hydrol. Oceans Atmos. PY 2000 VL 25 IS 10-12 BP 867 EP 870 DI 10.1016/S1464-1909(00)00117-9 PG 4 WC Meteorology & Atmospheric Sciences; Oceanography; Water Resources SC Meteorology & Atmospheric Sciences; Oceanography; Water Resources GA 356ZD UT WOS:000089473300013 ER PT J AU Marks, DA Kulie, MS Robinson, M Silberstein, DS Wolff, DB Ferrier, BS Amitai, E Fisher, B Wang, J Augustine, D Thiele, O AF Marks, DA Kulie, MS Robinson, M Silberstein, DS Wolff, DB Ferrier, BS Amitai, E Fisher, B Wang, J Augustine, D Thiele, O TI Climatological processing and product development for the TRMM Ground Validation Program SO PHYSICS AND CHEMISTRY OF THE EARTH PART B-HYDROLOGY OCEANS AND ATMOSPHERE LA English DT Article; Proceedings Paper CT 1st European Conference on Radar Meterology CY SEP 04-08, 2000 CL BOLOGNA, ITALY ID MEASURING MISSION TRMM; RAIN-GAUGE DATA; RADAR; REFLECTIVITY AB A comprehensive Ground Validation (GV) Program has been implemented to validate TRMM satellite observations. The primary goal of TRMM GV is to provide basic validation of satellite-derived precipitation measurements over monthly climatologies for the following primary sites: Melbourne, Florida (FL); Houston, Texas (TX); Darwin, Australia; and Kwajalein Atoll, Republic of Marshall Islands (RMI). As part of the TRMM GV effort, research analysts at NASA Goddard Space Flight Center (GSFC) generate standardized rainfall products using quality-controlled ground-based radar data from the four primary GV sites. An overview of TRMM GV climatological processing and product generation, including description of the data now between primary GV sites, NASA GSFC, and the TRMM Science Data and Information System (TSDIS) is presented. The radar data quality control (QC) algorithm, which features eight adjustable height and reflectivity parameters, together with the methodology used to create standardized monthly, gauge-adjusted rainfall products for each primary site is summarized. Presented are statistics from recently reprocessed official GV radar rainfall products which include derived monthly gauge bulk-adjusted Z-R relationships, area-averaged rain rates, radar-to-gauge accumulation ratios, gauge acceptance/rejection ratios, and radar data availability. Climatological GV products, statistics, and descriptions can be found at the Internet address http://trmm.gsfc.nasa.gov/TRMMGV/GVproducts.html. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Sci Syst & Applicat Inc, Lanham, MD 20706 USA. Gen Sci Corp, Beltsville, MD 20705 USA. George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. RP Marks, DA (reprint author), George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. RI Kulie, Mark/C-3289-2011 OI Kulie, Mark/0000-0003-1400-1007 NR 16 TC 18 Z9 18 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1909 J9 PHYS CHEM EARTH PT B JI Phys. Chem. Earth Pt B-Hydrol. Oceans Atmos. PY 2000 VL 25 IS 10-12 BP 871 EP 875 DI 10.1016/S1464-1909(00)00118-0 PG 5 WC Meteorology & Atmospheric Sciences; Oceanography; Water Resources SC Meteorology & Atmospheric Sciences; Oceanography; Water Resources GA 356ZD UT WOS:000089473300014 ER PT J AU Gabella, M Amitai, E AF Gabella, M Amitai, E TI Radar rainfall estimates in an alpine environment using different gage adjustment techniques SO PHYSICS AND CHEMISTRY OF THE EARTH PART B-HYDROLOGY OCEANS AND ATMOSPHERE LA English DT Article; Proceedings Paper CT 1st European Conference on Radar Meterology CY SEP 04-08, 2000 CL BOLOGNA, ITALY ID SURFACE RAINFALL; ACCURACY AB In order to mitigate the hostile effects of a complex orography on radar precipitation estimates, radar observations are here adjusted using a network of gages. Three techniques are analyzed and compared: 1) a simplified bulk adjustment technique based on a Z-R relationship with b=1.5; 2) a non linear Z(dB)-R(dB) is derived by matching unconditional probabilities of rain rates measured by the gages to radar observed reflectivities above the gages (Probability Matching Method); 3) corrections of radar estimates (based on a single Z-R relationship) are derived through a Weighted Multiple Regression as a function of three independent variables. The three variables used in the regression are: A) the distance from the radar; B) the minimum height a meteorological target must reach to be visible from the radar site; C) the height of the ground above sea level. The analysis also focuses on the importance of quality controlling radar-gage data-pairs in order to use only good quality information from "selected" gages. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Politecn Torino, Dipartimento Elettron, I-10129 Turin, Italy. Univ Maryland Baltimore Cty, JCET, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gabella, M (reprint author), Politecn Torino, Dipartimento Elettron, Corso Duca Abruzzi 24, I-10129 Turin, Italy. NR 13 TC 11 Z9 15 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1909 J9 PHYS CHEM EARTH PT B JI Phys. Chem. Earth Pt B-Hydrol. Oceans Atmos. PY 2000 VL 25 IS 10-12 BP 927 EP 931 DI 10.1016/S1464-1909(00)00127-1 PG 5 WC Meteorology & Atmospheric Sciences; Oceanography; Water Resources SC Meteorology & Atmospheric Sciences; Oceanography; Water Resources GA 356ZD UT WOS:000089473300023 ER PT J AU Robinson, M Kulie, MS Silberstein, DS Marks, DA Wolff, DB Amatai, E Ferrier, BS Fisher, BL Wang, J AF Robinson, M Kulie, MS Silberstein, DS Marks, DA Wolff, DB Amatai, E Ferrier, BS Fisher, BL Wang, J TI Evolving improvements to TRMM ground validation rainfall estimates SO PHYSICS AND CHEMISTRY OF THE EARTH PART B-HYDROLOGY OCEANS AND ATMOSPHERE LA English DT Article; Proceedings Paper CT 1st European Conference on Radar Meterology CY SEP 04-08, 2000 CL BOLOGNA, ITALY ID GAUGE DATA; RADAR; ACCURACY; WSR-88D AB The primary function of the TRMM Ground Validation (GV) Program is to create GV rainfall products that provide basic validation of satellite-derived precipitation measurements for select primary sites. Since the successful 1997 launch of the TRMM satellite, GV rainfall estimates have demonstrated systematic improvements directly related to improved radar and rain gauge data, modified science techniques, and software revisions. Improved rainfall estimates have resulted in higher quality GV rainfall products and subsequently, much improved evaluation products for the satellite-based precipitation estimates from TRMM. Early improvements in TRMM GV rainfall products involve replacing a default radar reflectivity (Z(e)) - rain rate (R) relationship with convective and stratiform relationships independently derived using bulk-adjusted, quality-controlled rain gauge data. Upon the development of an automated gauge quality control procedure, poorly correlated gauge-radar data in the bulk-adjustment process are ignored and Z(e)-R relationships are again refined. These Z(e)-R relationships, applied to base scan reflectivity data to produce GV rain maps, are further modified as improvements to intermediate radar and gauge products result in more realistic and internally consistent rainfall statistics. Additionally, improvements to radar and gauge data from the primary GV sites further increase the reliability of rainfall products. Rainfall accumulation statistics for each primary site are presented, demonstrating the evolving improvement in radar rainfall estimation for each successive generation of products. Current generations of GV rainfall products, based on more robust data and science techniques, have removed known biases in radar rainfall estimates. Increased confidence in GV rainfall products results in more meaningful comparisons with satellite-derived precipitation estimates from TRMM. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. Sci & Space Applicat Inc, Lanham, MD 20706 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. Gen Sci Corp, Arlington, VA 22202 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Robinson, M (reprint author), George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. RI Kulie, Mark/C-3289-2011 OI Kulie, Mark/0000-0003-1400-1007 NR 15 TC 8 Z9 8 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1909 J9 PHYS CHEM EARTH PT B JI Phys. Chem. Earth Pt B-Hydrol. Oceans Atmos. PY 2000 VL 25 IS 10-12 BP 971 EP 976 DI 10.1016/S1464-1909(00)00135-0 PG 6 WC Meteorology & Atmospheric Sciences; Oceanography; Water Resources SC Meteorology & Atmospheric Sciences; Oceanography; Water Resources GA 356ZD UT WOS:000089473300031 ER PT J AU Zastenker, GN Dalin, PA Petrukovich, AA Nozdrachev, MN Romanov, SA Paularena, KI Richardson, JD Lazarus, AJ Lepping, RP Szabo, A AF Zastenker, GN Dalin, PA Petrukovich, AA Nozdrachev, MN Romanov, SA Paularena, KI Richardson, JD Lazarus, AJ Lepping, RP Szabo, A TI Solar wind structure dynamics by multipoint observations SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article ID PLASMA CORRELATIONS; INTERBALL-1 AB Six-hour segments of simultaneous solar wind plasma and interplanetary magnetic field data from IMP 8, WIND and INTERBALL-1 are used to compare correlations of the plasma and interplanetary magnetic field for the same solar wind structures. Magnetic field structures are, on average, as well-correlated as plasma structures. The averaged on large statistics crosscorrelation coefficient is equal to 0.75 for ion flux and 0.71 for IMF magnitude comparison. But for many individual 6-hour segments the difference between plasma and IMF correlations is rather large. We find that good IMF correlations coincide with good plasma correlations 65% of the time but that good plasma correlations coincide with good IMF correlations only 44% of the time. Also the dependence of ion flux correlations on the IMF cone angle was studied for two sets of data. The plasma correlations increase as the IMF cone angle increases, suggesting plasma structures may be elongated parallel to the IMF. (C) 1999 Elsevier Science Ltd. All rights reserved. C1 Moscow Space Res Inst, Moscow 117810, Russia. MIT, Ctr Space Res, Cambridge, MA 02139 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Zastenker, GN (reprint author), Moscow Space Res Inst, Profsojuznaia 84-32, Moscow 117810, Russia. RI Petrukovich, Anatoly/G-8764-2011 OI Petrukovich, Anatoly/0000-0002-5344-2967 NR 11 TC 7 Z9 7 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 2000 VL 25 IS 1-2 BP 137 EP 140 DI 10.1016/S1464-1917(99)00055-0 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 259TC UT WOS:000083908800032 ER PT J AU Aikin, AC Smith, HJP AF Aikin, AC Smith, HJP TI Mesopheric odd nitrogen enhancements during relativistic electron precipitation events SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article ID MIDDLE ATMOSPHERE; LOWER THERMOSPHERE; MESOSPHERE; EFFICIENCIES; ATOMS; MODEL AB The behavior of mesospheric odd nitrogen species during and following relativistic and diffuse auroral precipitation events is simulated Below 75 km nitric oxide is enhanced in proportion to the ion pair production function associated with the electron precipitation and the length of the event. Nitrogen dioxide and nitric acid are also enhanced At 65 lan the percentage of odd nitrogen for N is 0.1%, HNO3 is 1.6%, NO2 is 15%, and NO is 83.3%. Between 75 and 85 lan,NO is depleted during particle events due to the faster destruction of NO by N relative to the production of NO by N reacting with O-2. Recovery of NO depends on transport from the lower thermosphere, where NO is produced in abundant amounts during particle events. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20711 USA. TPE Associates, Chesnut Hill, MA 02467 USA. RP Aikin, AC (reprint author), Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20711 USA. NR 21 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 2000 VL 25 IS 3 BP 203 EP 211 DI 10.1016/S1464-1917(00)00007-6 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 296WX UT WOS:000086050700006 ER PT J AU Tobiska, WK AF Tobiska, WK TI Measurement and modeling of solar EUV/UV radiation SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT 2nd TIGER Symposia A Program for Thermospheric-Iono spheric Geospheric Research CY 1999 CL ST PETERSBURG, RUSSIA ID ULTRAVIOLET IRRADIANCE VARIATIONS; REFERENCE SPECTRUM; FLUX MODEL; SOLSPEC SPECTROMETER; QUIET SUN; NM; VARIABILITY C1 FDC JPL, Pasadena, CA 91109 USA. RP Tobiska, WK (reprint author), FDC JPL, MS 264-580,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 33 TC 2 Z9 3 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 2000 VL 25 IS 5-6 BP 371 EP 374 DI 10.1016/S1464-1917(00)00034-9 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348BX UT WOS:000088965500002 ER PT J AU Tobiska, WK AF Tobiska, WK TI Status of the SOLAR2000 solar irradiance model SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT 2nd TIGER Symposia A Program for Thermospheric-Iono spheric Geospheric Research CY 1999 CL ST PETERSBURG, RUSSIA AB SOLAR2000 is a collaborative project for accurately characterizing solar irradiance variability across the full spectrum. The SOLAR2000 model is being developed as an image- and full-disk proxy empirical solar irradiance model covering the spectral range of 1-10,000 nm at 1 nm resolution starting in 1947. The overarching scientific goal of the project is to understand how the Sun varies spectrally and through time from the X-rays to infrared wavelengths by providing a self-consistent solar spectrum derived from space-based measurements. The model is used as a fundamental energy input for planetary atmosphere models and as a baseline for first principles solar models. it is a tool to specify the solar radiation component of the space environment and will be compliant with the International Standards Organization (ISO) solar irradiance standard. SOLAR2000 is being developed in five (spectral range) phases and five forecast time scales for research, contract, operations, and commercial grades of the model. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 FDC JPL, Pasadena, CA 91109 USA. RP Tobiska, WK (reprint author), FDC JPL, MS 264-580,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 13 TC 10 Z9 10 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 2000 VL 25 IS 5-6 BP 383 EP 386 DI 10.1016/S1464-1917(00)00037-4 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348BX UT WOS:000088965500005 ER PT J AU Tobiska, WK Nusinov, AA AF Tobiska, WK Nusinov, AA TI Status of the draft ISO solar irradiance standard SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT 2nd TIGER Symposia A Program for Thermospheric-Iono spheric Geospheric Research CY 1999 CL ST PETERSBURG, RUSSIA AB The International Standards Organization (ISO) is developing a solar irradiance standard to specify the representations of solar irradiances. It is applicable to measurements, reference spectra, empirical models, and first-principles models. Its purpose is to provide a standard specification of all solar irradiances for use by space systems materials and environment. The standard development process, the participants and owners of that process, the scope, concept, assumptions underlying this particular standard, and the ISO solar irradiance standard itself are described. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 FDC JPL, Pasadena, CA 91109 USA. Russian State Comm Hydrometeorol & Environm Contr, Inst Appl Geophys, Moscow 129128, Russia. RP Tobiska, WK (reprint author), FDC JPL, MS 264-580,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 6 Z9 6 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 2000 VL 25 IS 5-6 BP 387 EP 388 DI 10.1016/S1464-1917(00)00038-6 PG 2 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348BX UT WOS:000088965500006 ER PT J AU Wilhelm, K Lemaire, P Dammasch, IE Hollandt, J Schuhle, U Curdt, W Kucera, T Hassler, DM Huber, MCE AF Wilhelm, K Lemaire, P Dammasch, IE Hollandt, J Schuhle, U Curdt, W Kucera, T Hassler, DM Huber, MCE TI Solar irradiances of ultraviolet emission lines measured during the minimum of sunspot activity in 1996 and 1997 SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT 2nd TIGER Symposia A Program for Thermospheric-Iono spheric Geospheric Research CY 1999 CL ST PETERSBURG, RUSSIA ID RADIOMETRIC CALIBRATION; SPECTROMETER SUMER; EUV LINES; SOHO; TELESCOPE; UV; SOLAR-CYCLE-22; VARIABILITY; FLUXES AB Full Sun observations in UV and EUV emission lines were performed by SUMER. (Solar Ultraviolet Measurements of Emitted Radiation) on SOHO (Solar and Heliospheric Observatory) in 1996 and 1997. The pre-flight calibration of SUMER is traceable to a primary radiometric source standard. Irradiance values have been obtained for the lines He I (lambda 584), O V (lambda 629), Ne VIII (lambda 770), S V (lambda 786), O IV (lambda 787), S VI (lambda lambda 933, 944), H I Ly epsilon (lambda 937), C III (lambda 977), N V (lambda 1238), Si I (lambda 1256), and C IV (lambda 1548). The spatially resolved measurements allowed good estimates to be made of the active region contributions to the irradiance of the quiet Sun. The centre-to-limb radiance variations have also been deduced for these lines. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Max Planck Inst Aeron, D-37191 Kaltenburg Lindau, Germany. Univ Paris 11, CNRS, Inst Astrophys Spatiale, F-91405 Orsay, France. Phys Tech Bundesanstalt, D-10587 Berlin, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. SW Res Inst, Boulder, CO 80302 USA. European Space Agcy, European Space Res & Technol Ctr, Dept Space Sci, NL-2200 AG Noordwijk, Netherlands. RP Wilhelm, K (reprint author), Max Planck Inst Aeron, D-37191 Kaltenburg Lindau, Germany. RI Kucera, Therese/C-9558-2012; Hollandt, Jorg/A-2124-2014 NR 25 TC 3 Z9 3 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 2000 VL 25 IS 5-6 BP 389 EP 392 DI 10.1016/S1464-1917(00)00039-8 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348BX UT WOS:000088965500007 ER PT J AU Woods, TN Bailey, S Eparvier, F Lawrence, G Lean, J McClintock, B Roble, R Rottman, GJ Solomon, SC Tobiska, WK White, OR AF Woods, TN Bailey, S Eparvier, F Lawrence, G Lean, J McClintock, B Roble, R Rottman, GJ Solomon, SC Tobiska, WK White, OR TI TIMED Solar EUV Experiment SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT 2nd TIGER Symposia A Program for Thermospheric-Iono spheric Geospheric Research CY 1999 CL ST PETERSBURG, RUSSIA ID X-RAY IRRADIANCE; FAR ULTRAVIOLET AB The Solar EUV Experiment (SEE) on the NASA Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) mission will measure the solar vacuum ultraviolet (VUV) spectral irradiance from 1 to 195 nm. To cover this wide spectral range two different types of instruments are used: a grating spectrograph for spectra above 25 nm and a set of silicon photodiodes with thin film filters for the soft x-ray (XUV) below 35 nm. Redundant channels of the spectrograph and XUV photodiodes provide in-flight calibration checks on the time scale of a week, and annual rocket underflight measurements provide absolute calibration checks traceable to radiometric standards. Both types of instruments have been developed and night proven as part of a NASA solar EUV irradiance rocket experiment. The SEE instrument is currently on the NASA TIMED spacecraft at the Johns Hopkins University (JHU) Applied Physics Laboratory (APL). The TIMED launch is planned for October 2000 as a two year mission. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA. USN, Res Lab, Washington, DC 20375 USA. Fed Data Ctr, Jet Prop Lab, Pasadena, CA 91109 USA. Hampton Univ, Hampton, VA 23668 USA. RP Woods, TN (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Campus Box 392, Boulder, CO 80309 USA. RI Solomon, Stanley/J-4847-2012; OI Solomon, Stanley/0000-0002-5291-3034; Lean, Judith/0000-0002-0087-9639 NR 18 TC 32 Z9 32 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 2000 VL 25 IS 5-6 BP 393 EP 396 DI 10.1016/S1464-1917(00)00040-4 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348BX UT WOS:000088965500008 ER PT J AU Sharber, JR Winningham, JD Frahm, RA Crowley, G Ridley, AJ Link, R AF Sharber, JR Winningham, JD Frahm, RA Crowley, G Ridley, AJ Link, R TI Empirical modeling of particle precipitation and the study of effects on the terrestrial thermosphere and ionosphere SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT 2nd TIGER Symposia A Program for Thermospheric-Iono spheric Geospheric Research CY 1999 CL ST PETERSBURG, RUSSIA ID NOVEMBER 1993 STORM; ENVIRONMENT MONITOR; ELECTRON-PRECIPITATION; GEOMAGNETIC STORMS; ENERGY DEPOSITION; SEPTEMBER 18-19; MESOSPHERE; VALIDATION; DYNAMICS; FEATURES AB In order to study the effects of particles of solar origin on the atmospheric system, the construction of a particle climatology has been adopted as an activity of the International Solar Cycle Study, Working Group-1, Panel-2. The activity is incorporated within the Thermosphere Ionosphere Geospheric Research (TIGER) program. This climatology is an empirical model of particle input providing average spectral characteristics, precipitating particle fluxes, and ionization rate profiles as functions of latitude, local time, and activity level. It is being built upon a model already being developed with particle data from the Upper Atmosphere Research Satellite (UARS). In this paper we describe the development of the UARS particle climatology and show how it is being extended to improve spatial and temporal coverage. We discuss the use of the climatology in global circulation and assimilative modeling and provide the status of its use such models in Thermosphere-Ionosphere modeling to date, (C) 2000 Elsevier Science Ltd. All rights reserved. C1 SW Res Inst, Instrumentat & Space Res Div, San Antonio, TX 78238 USA. NASA Headquarters, Washington, DC 20456 USA. RP Sharber, JR (reprint author), SW Res Inst, Instrumentat & Space Res Div, 6220 Culebra Rd, San Antonio, TX 78238 USA. RI Ridley, Aaron/F-3943-2011 OI Ridley, Aaron/0000-0001-6933-8534 NR 20 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 2000 VL 25 IS 5-6 BP 489 EP 493 DI 10.1016/S1464-1917(00)00063-5 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348BX UT WOS:000088965500031 ER PT J AU Bilitza, D AF Bilitza, D TI The importance of EUV indices for the International Reference Ionosphere SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT 2nd TIGER Symposia A Program for Thermospheric-Iono spheric Geospheric Research CY 1999 CL ST PETERSBURG, RUSSIA ID INTENSE SOLAR-CYCLE AB The International Reference Ionosphere (RU), a standard model for ionospheric densities and temperatures developed by a joint working group of the Committee on Space Research (COSPAR) and the International Union of Radio Science (URSI), is widely used for specifications of the ionospheric environment. This paper will discuss the importance of the solar and/or ionospheric indices for driving the IRI model. The different existing indices will be reviewed and future needs will be outlined. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. RP Bilitza, D (reprint author), NASA, Goddard Space Flight Ctr, Raytheon ITSS, Code 632, Greenbelt, MD 20771 USA. NR 16 TC 29 Z9 30 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 2000 VL 25 IS 5-6 BP 515 EP 521 DI 10.1016/S1464-1917(00)00068-4 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348BX UT WOS:000088965500036 ER PT J AU Kanik, I Beegle, LW Ajello, JM Solomon, SC AF Kanik, I Beegle, LW Ajello, JM Solomon, SC TI Electron-impact excitation/emission and photoabsorption cross sections important in the terrestrial airglow and auroral analysis of rocket and satellite observations SO PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE LA English DT Article; Proceedings Paper CT 2nd TIGER Symposia A Program for Thermospheric-Iono spheric Geospheric Research CY 1999 CL ST PETERSBURG, RUSSIA ID EXTREME ULTRAVIOLET DAYGLOW; ATOMIC OXYGEN; INCIDENT ENERGIES; EMISSION-LINES; NEAR-THRESHOLD; EUV DAYGLOW; 83.4 NM; O-I; N-2; STATES AB The UV line intensities appearing in the spectra of terrestrial auroral and airglow observational data by rockets and high altitude satellites contain important diagnostic information on energy input taking place into the thermosphere. The intensities of the observed emissions are dependent on the atomic and molecular cross sections for both electrons and photons. UV extinction weakens the emission intensity along the line-of-sight to the spacecraft and is determined by the absorption cross sections of the principal constituents: O-2, N(2)square and O. An accurate knowledge of both excitation (emission) and photoabsorption cross sections of the dominant atmospheric molecular gases (O-2 and N-2) is needed for the analysis and interpretation of rocket and satellite observations of airglow and auroral emissions. The absorption cross sections of O-2 and N-2 are difficult to measure since they are highly structured in the UV from predissociation of Rydberg and valence states. The aim of this article is to focus upon certain outstanding issues concerning the available experimental excitation (emission) and photoabsorption cross section data primarily in the far UV (FUV) spectral region. These cross sections are important to terrestrial airglow and auroral observations of N2 and O UV emission fluorescence and to critically review the available data. (C) 2000 Elsevier Science Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80304 USA. RP Kanik, I (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Beegle, Luther/A-6354-2010; Solomon, Stanley/J-4847-2012 OI Solomon, Stanley/0000-0002-5291-3034 NR 52 TC 10 Z9 10 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1464-1917 J9 PHYS CHEM EARTH PT C JI Phys. Chem. Earth Pt. C-Solar-Terr. Planet. Sci. PY 2000 VL 25 IS 5-6 BP 573 EP 581 DI 10.1016/S1464-1917(00)00080-5 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348BX UT WOS:000088965500048 ER PT S AU Goorjian, PM Ning, CZ Agrawal, GP AF Goorjian, PM Ning, CZ Agrawal, GP BE Binder, RH Blood, P Osinski, M TI Transverse mode dynamics of VCSELs undergoing current modulation SO PHYSICS AND SIMULATION OF OPTOELECTRONIC DEVICES VIII, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Physics and Simulation of Optoelectronic Devices VIII CY JAN 24-28, 2000 CL SAN JOSE, CA SP SPIE DE VCSELs; current modulation; gain switching; transverse mode dynamics; computational modeling ID SURFACE-EMITTING LASERS; SIMULATION; BEHAVIOR AB Transverse mode dynamics of, a 20-mum-diameter vertical-cavity surface-emitting laser (VCSEL) undergoing gain switching by deep current modulation is studied numerically. The direct current (dc) level is set slightly below threshold and is modulated by a large alternating current (ac). The resulting optical pulse train and transverse-mode patterns are obtained numerically. The ac frequency is varied from 2.5 GHz to 10 GHz, and the sc amplitude is varied from one-half to four times that of the de level. At high modulation frequencies, a regular pulse train is not generated unless the ac amplitude is large enough. At all modulation frequencies, the transverse spatial profile switches from single-mode to multiple-made pattern as the ac pumping level is increased. Optical pulse widths vary in the range 5-30 ps, with the pulse width. decreasing when either the frequency is increased or the ac amplitude is decreased. The numerical modeling uses an approximation form of the semiconductor Maxwell-Bloch equations. Temporal evolution of the spatial profiles of the laser (and of carrier density) is determined without any assumptions about the type or number of modes. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Goorjian, PM (reprint author), NASA, Ames Res Ctr, MS T27A-2, Moffett Field, CA 94035 USA. NR 18 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3561-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 3944 BP 284 EP 291 DI 10.1117/12.391431 PN 1&2 PG 8 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BR32Y UT WOS:000166107500027 ER PT S AU Li, JZ Ning, CZ AF Li, JZ Ning, CZ BE Binder, RH Blood, P Osinski, M TI Many-body effects on bandgap shrinkage, effective masses and alpha factor SO PHYSICS AND SIMULATION OF OPTOELECTRONIC DEVICES VIII, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Physics and Simulation of Optoelectronic Devices VIII CY JAN 24-28, 2000 CL SAN JOSE, CA SP SPIE DE quantum well; laser diode; many-body effect; bandgap renormalization; effective mass; alpha factor ID SEMICONDUCTOR QUANTUM-WELLS; ELECTRON-HOLE PLASMAS; HIGH MAGNETIC-FIELDS; GAP RENORMALIZATION; EXCITED SEMICONDUCTORS; OPTICAL-PROPERTIES; LASERS; GAIN; LINEWIDTH; LUMINESCENCE AB Many-body Coulomb effects influence the operation of quantum-well (QW) laser diode (LD) strongly. In the present work, we study a two-band electron-hole plasma (EHP) within the Hatree-Fock approximation and the single plasmon pole approximation for static screening. Full inclusion of momentum dependence in the many-body effects is considered. An empirical expression for carrier density dependence of the bandgap renormalization (BGR) in an 8 nm GaAs/Al0.3Ga0.7As single QW will be given, which demonstrates a non-universal scaling behavior for quasi-two-dimension structures, due to size-dependent efficiency of screening. In addition effective mass renormalization (EMR) due to momentum-dependent self-energy many-body correction, for both electrons and holes, is studied and serves as another manifestation of the many-body effects. Finally, the effects on carrier density dependence of the alpha factor is evaluated to assess the sensitivity of the full inclusion of momentum dependence. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Li, JZ (reprint author), NASA, Ames Res Ctr, MS N229-1, Moffett Field, CA 94035 USA. NR 30 TC 1 Z9 1 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3561-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 3944 BP 311 EP 318 DI 10.1117/12.391434 PN 1&2 PG 8 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BR32Y UT WOS:000166107500030 ER PT S AU Liu, AS Ning, CZ AF Liu, AS Ning, CZ BE Binder, RH Blood, P Osinski, M TI Optical control of intersubband absorption in a multiple quantum well-embedded semiconductor microcavity SO PHYSICS AND SIMULATION OF OPTOELECTRONIC DEVICES VIII, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Physics and Simulation of Optoelectronic Devices VIII CY JAN 24-28, 2000 CL SAN JOSE, CA SP SPIE DE quantum well; intersubband transition; semiconductor microcavity; pump-probe spectroscopy ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; POPULATION-INVERSION; LIGHT AMPLIFICATION; COHERENCE; GAIN; INTERFERENCE; TRANSITIONS; LASERS; PULSES; LINE AB Optical intersubband response of a multiple quantum well (MQW)-embedded microcavity driven by a coherent pump field is studied theoretically. The n-type doped MQW structure with three subbands in the conduction band is sandwiched between a semi-infinite medium and a distributed Bragg reflector (DBR). A strong pump field couples the two upper subbands and a weak field probes the two lower subbands. To describe the optical response of the MOW-embedded microcavity, we adopt a semi-classical nonlocal response theory. Taking into account the pump-probe interaction, we derive the probe-induced current density associated with intersubband transitions from the single-particle density-matrix formalism. By incorporating the current density into the Maxwell equation, we solve the probe local field exactly by means of Green's function technique and the transfer-matrix method. We obtain an exact expression for the probe absorption coefficient of the microcavity. For a GaAs/AlxGa1-xAs MQW structure sandwiched between a GaAs/AlAs DBR and vacuum, we performed numerical calculations of the probe absorption spectra for different parameters such as pump intensity, pump detuning, and cavity length. We find that the probe spectrum is strongly dependent on these parameters. In particular, we find that the combination of the cavity effect and the Autler-Townes effect results in a triplet in the optical spectrum of the MQW system. The optical absorption peak value and its location can be feasibly controled by varying the pump intensity and detuning. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Liu, AS (reprint author), NASA, Ames Res Ctr, MS N229-1, Moffett Field, CA 94035 USA. NR 26 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 0-8194-3561-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 3944 BP 353 EP 363 DI 10.1117/12.391439 PN 1&2 PG 11 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BR32Y UT WOS:000166107500035 ER PT S AU Venkateswaran, S Rai, MM Govindan, TR Meyyappan, M AF Venkateswaran, S Rai, MM Govindan, TR Meyyappan, M BE Binder, RH Blood, P Osinski, M TI Neural network modeling of growth processes SO PHYSICS AND SIMULATION OF OPTOELECTRONIC DEVICES VIII, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Physics and Simulation of Optoelectronic Devices VIII CY JAN 24-28, 2000 CL SAN JOSE, CA SP SPIE DE neural network; process control; modeling; deposition AB Process control based on first-principles models is possible if the information from the reactor simulations can be represented in a compact model. This is necessary since on-demand reactor simulation in real time for control purposes is not currently realistic. We have developed a neural network based model for applications in process control and process design. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Venkateswaran, S (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 9 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 0-8194-3561-9 J9 P SOC PHOTO-OPT INS PY 2000 VL 3944 BP 435 EP 442 DI 10.1117/12.391447 PN 1&2 PG 8 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BR32Y UT WOS:000166107500042 ER PT S AU Waite, JH Grodent, D Mauk, BM Majeed, T Gladstone, GR Bolton, SJ Clarke, JT Gerard, JC Lewis, WS Trafton, LM Walker, RJ Ingersoll, AP Connerney, JEP AF Waite, JH Grodent, D Mauk, BM Majeed, T Gladstone, GR Bolton, SJ Clarke, JT Gerard, JC Lewis, WS Trafton, LM Walker, RJ Ingersoll, AP Connerney, JEP BE Huddleston, DE Walker, R TI Multispectral observations of Jupiter's Aurora SO PLANETARY IONOSPHERES AND MAGNETOSPHERES SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT C3 2/D0 9 Symposium of COSPAR Scientific Commission C/B0 5 Symposium of COSPAR Scientific Commission B held at the 32nd COSPAR Scientific Assembly CY JUL, 1998 CL NAGOYA, JAPAN SP Int Acad Astronaut, Comm Space Res ID HUBBLE-SPACE-TELESCOPE; SOLAR-WIND CONTROL; X-RAY EMISSIONS; IO FLUX TUBE; JOVIAN MAGNETOSPHERE; ULTRAVIOLET AURORA; ENERGETIC IONS; PROTON PRECIPITATION; ULYSSES OBSERVATIONS; RADIO-EMISSION AB Remote sensing of Jupiter's aurora from x-ray to radio wavelengths has revealed much about the nature of the jovian aurora and about the impact of ionosphere-magnetosphere coupling on the upper atmosphere of Jupiter, As indicated by the combination of x-ray and ultraviolet observations, both energetic heavy ions and electrons energized in the outer magnetosphere contribute to auroral excitation. Imaging with the Hubble Space Telescope in the ultraviolet and with the InfraRed Telescope Facility at infrared wavelengths shows several distinct regions of interaction: 1) a dusk sector where turbulent auroral patterns extend well into the polar cap; 2) a morning sector generally characterized by a single spatially confined auroral are originating in the outer or middle magnetosphere of Jupiter; 3) diffuse emissions associated with the Io plasma - spectroscopy has provided important information about the thermal structure of Jupiter's auroral atmosphere and the altitude distribution of auroral particle energy deposition, while Lyman alpha line profiles yield clues to the nature of thermospheric dynamical effects. Galileo observations at visible wavelengths on the nightside offer a new view of the jovian aurora with unprecedented spatial information. Infrared observations have added much to the understanding of thermal structure at all latitudes, the dynamics of the thermospheric wind system, and auroral morphology, and may hold the key to understanding the role of Joule heating in Jupiter's thermosphere. ROSAT observations have revealed soft x-ray emissions from Jupiter's lower latitudes as well as from the auroral zones, implying that energetic particle precipitation also occurs at low latitudes in regions magnetically linked to the inner radiation belts. In this review, multispectral observations of jovian auroral emissions are presented within a theoretical/modeling framework that is intended to provide some insight into magnetosphere-ionosphere coupling and its effects on the upper atmosphere. (C) 2000 COSPAR. Published by Elsevier Science Ltd. All rights reserved. C1 SW Res Inst, San Antonio, TX 78228 USA. Lab Phys Atmospher & Planetaire, B-4000 Liege, Belgium. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA. Univ Texas, Austin, TX 78712 USA. Univ Calif Los Angeles, IGPP, Los Angeles, CA 90024 USA. CALTECH, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Waite, JH (reprint author), SW Res Inst, PO Drawer 28510, San Antonio, TX 78228 USA. RI Clarke, John/C-8644-2013; connerney, john/I-5127-2013; Mauk, Barry/E-8420-2017; OI Mauk, Barry/0000-0001-9789-3797; GERARD, Jean-Claude/0000-0002-8565-8746 NR 71 TC 16 Z9 16 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0273-1177 J9 ADV SPACE RES-SERIES PY 2000 VL 26 IS 10 BP 1453 EP 1475 DI 10.1016/S0273-1177(00)00089-2 PG 23 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BR53K UT WOS:000166724300002 ER PT B AU Ma, C MacMillan, DS AF Ma, C MacMillan, DS BE Dick, S McCarthy, D Luzum, B TI VLBI observations of earth orientation SO POLAR MOTION: HISTORICAL AND SCIENTIFIC PROBLEMS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 178th IAU Colloquium on Polar Motion: Historical and Scientific Problems CY SEP 27-30, 1999 CL STN ASTRON CAGLIARI CARLOFORTE, CAGLIARI, ITALY SP Minist Univ Ric Sci & Tecnol, Reg Autonoma Sardegna & Comune Monserrato HO STN ASTRON CAGLIARI CARLOFORTE ID BASE-LINE INTERFEROMETRY; LONG AB VLBI has been used for high precision EOP measurements since 1980. The typical formal error for current routine monitoring of polar motion is similar to 80 mu as. A program for continuous EOP observations using VLBI is being incrementally implemented. There are unexplained differences between EOP values derived from simultaneously observing networks. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ma, C (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-039-0 J9 ASTR SOC P PY 2000 VL 208 BP 251 EP 259 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80S UT WOS:000089621200022 ER PT B AU Chao, BF Gross, RS AF Chao, BF Gross, RS BE Dick, S McCarthy, D Luzum, B TI Coseismic excitation of the Earth's polar motion SO POLAR MOTION: HISTORICAL AND SCIENTIFIC PROBLEMS SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 178th IAU Colloquium on Polar Motion: Historical and Scientific Problems CY SEP 27-30, 1999 CL STN ASTRON CAGLIARI CARLOFORTE, CAGLIARI, ITALY SP Minist Univ Ric Sci & Tecnol, Reg Autonoma Sardegna & Comune Monserrato HO STN ASTRON CAGLIARI CARLOFORTE ID CHANDLER-WOBBLE; SEISMIC EXCITATION; EARTHQUAKES; ROTATION AB Apart from the "shaking" near the epicenter that is the earthquake, a seismic event creates a permanent field of dislocation in the entire Earth. This redistribution of mass changes (slightly) the Earth's inertia tensor; and the Earth's rotation will change in accordance with the conservation of angular momentum. Similar to this seismic excitation of Earth rotation variations, the same mass redistribution causes (slight) changes in the Earth's gravitational field expressible in terms of changes in the Stokes coefficients of its harmonic expansion. In this paper, we give a historical background of the subject and discuss the related physics. We then compute the geodynamic effects caused by earthquakes using Chao and Gross' (1987) formulas based on Gilbert's (1970) normal-mode summation scheme. The effects are computed using the centroid moment tensor (CMT) solutions for 15,814 major earthquakes from Jan., 1977, through Feb., 1999, as provided in the Harvard CMT catalog. The computational results update those of Chao and Gross (1987) and Chao et al. (1996), further strengthening their findings and conclusions: (i) the strong tendency for earthquakes to make the Earth rounder and more compact (however slightly) continues; (ii) so does the trend in the seismic "nudging" of the rotation pole toward the general direction of similar to 140 degrees E, roughly opposite to that of the observed polar drift, but two orders of magnitude smaller in drift speed. C1 NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. RP Chao, BF (reprint author), NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. NR 43 TC 1 Z9 1 U1 0 U2 1 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-039-0 J9 ASTR SOC P PY 2000 VL 208 BP 355 EP 367 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BQ80S UT WOS:000089621200033 ER PT S AU Thompson, WT Brekke, P AF Thompson, WT Brekke, P BE Wilson, A TI EUV irradiance variations measured with the SOHO coronal diagnostic spectrometer SO PROCEEDINGS OF THE 1ST SOLAR AND SPACE WEATHER EUROCONFERENCE ON THE SOLAR CYCLE AND TERRESTRIAL CLIMATE SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 1st Solar and Space Weather Euroconference on the Solar Cycle and Terrestrial Climate CY SEP 25-29, 2000 CL INST ASTROFIS CANARIAS, SANTA CRUZ TENERI, SPAIN SP European Commiss, Spanish Minist Sci & Technol, Cabildo Insular Santa Curz Tenerife, European Space Agcy, CajaCanarias, Ayuntamiento Danta Cruz Tenerife, Ayuntamiento La Laguna, Observ Paris HO INST ASTROFIS CANARIAS DE EUV; irradiance; SOHO; CDS ID SOLAR EUV; MODEL AB The Coronal Diagnostic Spectrometer aboard the Solar and Heliospheric Observatory observes the solar EUV spectrum in two bands between 308-379 Angstrom and 513-633 Angstrom. The full Sun irradiance can be measured by rastering the instrument over the solar disk. Measurements of the solar irradiance have been made starting 25 March 1997 and continuing to the present, ranging from very quiet to very active Sun. These measurements are the only current EUV spectral irradiance measurements taken on a regular basis. As well as irradiance values, the most recent observations also provide moderate resolution solar images to help quantify the important sources of the irradiance variability. The dependence of individual spectral lines on the solar cycle is presented, spanning the temperature range from 3 x 10(4) K to 2.7 x 10(6) K. The important spectral lines of He II and Si XI at 304 Angstrom are observed in second order and separated. The high spectral resolution of these measurements, combined with the coverage of a significant proportion of the solar cycle, provide a unique dataset for understanding solar variability in the EUV. In addition, these data are important input for interpreting data from broadband and lower resolution irradiance monitors, such as the SOHO SEM and TIMED. C1 NASA, Goddard Space Flight Ctr, Emergent IT Inc, Greenbelt, MD 20771 USA. RP Thompson, WT (reprint author), NASA, Goddard Space Flight Ctr, Emergent IT Inc, Code 682-3, Greenbelt, MD 20771 USA. RI Thompson, William/D-7376-2012 NR 5 TC 1 Z9 1 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-693-7 J9 ESA SP PUBL PY 2000 VL 463 BP 435 EP 438 PG 4 WC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences GA BR99Z UT WOS:000168300800074 ER PT S AU Thompson, WT AF Thompson, WT BE Wilson, A TI Standardized coordinate systems for solar image data SO PROCEEDINGS OF THE 1ST SOLAR AND SPACE WEATHER EUROCONFERENCE ON THE SOLAR CYCLE AND TERRESTRIAL CLIMATE SE ESA Special Publications LA English DT Proceedings Paper CT 1st Solar and Space Weather Euroconference on the Solar Cycle and Terrestrial Climate CY SEP 25-29, 2000 CL INST ASTROFIS CANARIAS, SANTA CRUZ TENERI, SPAIN SP European Commiss, Spanish Minist Sci & Technol, Cabildo Insular Santa Curz Tenerife, European Space Agcy, CajaCanarias, Ayuntamiento Danta Cruz Tenerife, Ayuntamiento La Laguna, Observ Paris HO INST ASTROFIS CANARIAS DE solar; coordinates AB The current state of describing the coordinates of solar image data is chaotic, and does not take into account the most recent developments in the coordinate systems for astronomy in general, especially as related to FITS files. A set of formal systems for describing the coordinates of solar image data is proposed. These systems build on current practice in applying coordinates to solar image data. Both heliographic and heliocentric coordinates are discussed. A distinction is also drawn between heliocentric and helioprojective coordinates, where the latter takes the observer's exact geometry into account. The extension of these coordinate systems to observations made from non-terrestial viewpoints, such as STEREO and Solar Probe, is discussed. A formal system for incorporation of these coordinates into FITS files, based on the FITS World Coordinate System, is described. C1 NASA, Goddard Space Flight Ctr, Emergent IT Inc, Greenbelt, MD 20771 USA. RP NASA, Goddard Space Flight Ctr, Emergent IT Inc, Code 682-3, Greenbelt, MD 20771 USA. EM thompson@orpheus.nascom.nasa.gov RI Thompson, William/D-7376-2012 NR 5 TC 0 Z9 0 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-693-7 J9 ESA SPEC PUBL PY 2000 VL 463 BP 645 EP 648 PG 4 WC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Meteorology & Atmospheric Sciences GA BR99Z UT WOS:000168300800119 ER PT S AU Shen, YX Homaifar, A Chen, D AF Shen, YX Homaifar, A Chen, D GP AACC AACC AACC TI Vibration control of flexible structures using fuzzy logic and genetic algorithms SO PROCEEDINGS OF THE 2000 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE Proceedings of the American Control Conference LA English DT Proceedings Paper CT 2000 American Control Conference (ACC 2000) CY JUN 28-30, 2000 CL CHICAGO, IL SP Amer Automat Control Council, IFAC, US Natl Member Org, Int Federat Automat Control DE modeling; active vibration control; genetic algorithms; fuzzy logic AB In this paper, a two degrees of freedom model has been constructed for a structural dynamic system consisting of a linear elastic plate bonded with piezo electric sensors and actuators. An multivariable feedback controller is designed. Two control procedures, based on the minimization of performance output error, have been developed that use Hybrid Fuzzy-PID control(HFPIDC) and Genetic Algorithms-designed PH) control(GAPIDC) control methods. The fitness function for the GA-PID control is approximately proportional to the inverse of the output error. To test these control techniques in an efficient and systematic way we built a control system that uses of MATLAB/SIMULINK modelling software in a personal computer. The simulation results confirm that these two kinds of control methods are reliable and efficient in suppression of steady-state resonance vibrations. C1 N Carolina Agr & Tech State Univ, Dept Elect Engn, NASA, Ctr Aerosp Res, Greensboro, NC 27411 USA. RP N Carolina Agr & Tech State Univ, Dept Elect Engn, NASA, Ctr Aerosp Res, Greensboro, NC 27411 USA. EM yaxi@ncat.edu; homaifar@ncat.edu; dachen@ncat.edu NR 3 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-5519-9; 0-7803-5520-2 J9 P AMER CONTR CONF PY 2000 BP 448 EP 452 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BR32L UT WOS:000166106200092 ER PT S AU Kimiaghalam, B Homaifar, A Bikdash, M AF Kimiaghalam, B Homaifar, A Bikdash, M GP AACC AACC AACC TI Feedback and feedforward control law for a ship crane with Maryland rigging system SO PROCEEDINGS OF THE 2000 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 2000 American Control Conference (ACC 2000) CY JUN 28-30, 2000 CL CHICAGO, IL SP Amer Automat Control Council, IFAC, US Natl Member Org, Int Federat Automat Control DE crane control; feedforward and feedback control; nonlinear control AB A state-space model of the shipboard crane based on implicit description of the crane with no simplifying assumptions is developed. By choosing appropriate states, full control authorities for changing the length of the rope is achieved. Three control actions are considered: changing the luffing angle and changing the length of the rope from two points on the boom. A chaotic rolling moment, with a dominant frequency of the same order as the resonance frequency of the shipboard crane, is applied to the ship as an external disturbance. The effect of this disturbance is studied. Feedforward and feedback controllers are then designed and tested for this shipboard crane to suppress the load pendulation caused by ship rolling. The friction in the pulley is assumed negligible. The simulation results based on these controllers show more than %98 decrease in the pendulation magnitude due to control. C1 N Carolina Agr & Technol State Univ, Dept Elect Engn, NASA, Autonomous Control Engn Ctr, Greensboro, NC 27411 USA. RP Kimiaghalam, B (reprint author), N Carolina Agr & Technol State Univ, Dept Elect Engn, NASA, Autonomous Control Engn Ctr, Greensboro, NC 27411 USA. NR 4 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-5520-2 J9 P AMER CONTR CONF PY 2000 BP 1047 EP 1051 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BR32L UT WOS:000166106200217 ER PT S AU Krupp, DR Shkolnikov, IA Shtessel, YB AF Krupp, DR Shkolnikov, IA Shtessel, YB GP AACC AACC AACC TI High order sliding modes in dynamic sliding manifolds: SMC design with uncertain actuator SO PROCEEDINGS OF THE 2000 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 2000 American Control Conference (ACC 2000) CY JUN 28-30, 2000 CL CHICAGO, IL SP Amer Automat Control Council, IFAC, US Natl Member Org, Int Federat Automat Control AB A problem of sliding mode control design for a SISO system with unmodeled actuators of the first and second order is considered. A design methodology, based on dynamic sliding manifolds (DSM), is proposed to attenuate the chattering phenomenon affecting sliding-mode-controlled plants in presence of unmodeled dynamics. The proposed methodology maintains the sliding mode on the sliding surface, which is designed without actuator dynamics being considered. This goal is achieved via auxiliary dynamic sliding manifold design, the sliding mode on the auxiliary DSM provides for high order asymptotic sliding mode on the initial surface. C1 NASA, George C Marshall Space Flight Ctr, MSFC, AL 35812 USA. RP Krupp, DR (reprint author), NASA, George C Marshall Space Flight Ctr, MSFC, AL 35812 USA. NR 12 TC 4 Z9 4 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-5520-2 J9 P AMER CONTR CONF PY 2000 BP 1124 EP 1128 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BR32L UT WOS:000166106200232 ER PT S AU Joshi, SM Cox, DE Kelkar, AG AF Joshi, SM Cox, DE Kelkar, AG GP AACC AACC AACC TI Robust control of uncertain systems via norm- and sector-bounded LQG-type controllers SO PROCEEDINGS OF THE 2000 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 2000 American Control Conference (ACC 2000) CY JUN 28-30, 2000 CL CHICAGO, IL SP Amer Automat Control Council, IFAC, US Natl Member Org, Int Federat Automat Control AB This paper addresses the design of linear-quadratic-Gaussian (LQG) controllers for uncertain linear time-invariant systems that are either norm-bounded or belong to a given sector. The system matrices are assumed to be affine functions of parameters confined to a convex polytopic region in the parameter space. The resulting controllers themselves satisfy certain norm or sector conditions and provide robust stability as well as optimal performance. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Joshi, SM (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-5520-2 J9 P AMER CONTR CONF PY 2000 BP 1276 EP 1280 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BR32L UT WOS:000166106200262 ER PT S AU Ragunathan, K Bikdash, M Homaifar, A AF Ragunathan, K Bikdash, M Homaifar, A GP AACC AACC AACC TI Disturbance rejection using sliding-mode control of adjustable speed drives SO PROCEEDINGS OF THE 2000 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 2000 American Control Conference (ACC 2000) CY JUN 28-30, 2000 CL CHICAGO, IL SP Amer Automat Control Council, IFAC, US Natl Member Org, Int Federat Automat Control DE sliding mode; disturbance observer; time delay; disturbance rejection ID DC AB We propose a sliding mode controller for a nonlinear voltage-controlled DC motor and consider its use for disturbance rejection. The nonlinearity includes the effect of magnetization saturation and a nonlinear fan load. The performance of the controller under the effects of various torque disturbances and under measurement errors is studied. The SMC is shown to be very effective in suppressing the disturbance when perfect information about the states and disturbance are fed back to the controller. The effect of time delays on the sliding mode controller system is also studied. Using a disturbance observer, an estimate of the disturbance is obtained and fed to the SMC for effective speed control. We are currently tuning this observer and extending it to provide prediction as to reduce the effect of delay. C1 N Carolina A&T State Univ, Dept Elect Engn, NASA, Autonomous Control Engn Ctr, Greensboro, NC 27410 USA. RP Ragunathan, K (reprint author), N Carolina A&T State Univ, Dept Elect Engn, NASA, Autonomous Control Engn Ctr, Greensboro, NC 27410 USA. NR 7 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-5520-2 J9 P AMER CONTR CONF PY 2000 BP 1627 EP 1631 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BR32L UT WOS:000166106200335 ER PT S AU Jardin, MR AF Jardin, MR GP AACC AACC AACC TI Ideal free flight through multiple aircraft neighboring optimal control SO PROCEEDINGS OF THE 2000 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 2000 American Control Conference (ACC 2000) CY JUN 28-30, 2000 CL CHICAGO, IL SP Amer Automat Control Council, IFAC, US Natl Member Org, Int Federat Automat Control AB The general term for any air traffic management concept that minimizes restrictions on aircraft operations while maintaining or improving upon the current level of safety is free flight. This paper proposes an ideal free night concept and develops a practical algorithm based on neighboring optimal control. The mathematical development is carried out for a two-aircraft conflict resolution scenario, followed by the presentation of a simulation example. The benefits of the resulting algorithm are that it approaches single-aircraft optimal guidance as the distance between aircraft increases, and it achieves optimal safe inter-aircraft separation while maintaining near-optimality under disturbances (e.g, initial condition and wind modeling errors). C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Jardin, MR (reprint author), NASA, Ames Res Ctr, MS 210-10, Moffett Field, CA 94035 USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-5520-2 J9 P AMER CONTR CONF PY 2000 BP 2879 EP 2885 PG 7 WC Automation & Control Systems SC Automation & Control Systems GA BR32L UT WOS:000166106200591 ER PT S AU Joshi, SS AF Joshi, SS GP AACC AACC AACC TI Damper placement for spaceborne interferometers using H-infinity-norm optimization SO PROCEEDINGS OF THE 2000 AMERICAN CONTROL CONFERENCE, VOLS 1-6 SE PROCEEDINGS OF THE AMERICAN CONTROL CONFERENCE LA English DT Proceedings Paper CT 2000 American Control Conference (ACC 2000) CY JUN 28-30, 2000 CL CHICAGO, IL SP Amer Automat Control Council, IFAC, US Natl Member Org, Int Federat Automat Control AB A general methodology for damper placement in spaceborne interferometers is introduced. The process consists of combined structural/optical/damper modeling, H-infinity cost selection, and genetic-algorithm or simulated annealing optimization. Combined structural/optical modeling allows the ability to quantitatively predict the effect of mechanical disturbances on optical performance metrics. H-infinity cost allows for the consideration of multiple dissimilar disturbance inputs and multiple dissimilar performance outputs, as well as consideration of worst-case analysis. Genetic-algorithms and simulated annealing allow for an efficient search of a high-dimensional optimization space. A numerical example is shown to demonstrate the methodology. A comparison of placement of a finite-number of passive dampers using genetic algorithms, simulated annealing, and exhaustive search is considered. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Joshi, SS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1619 BN 0-7803-5520-2 J9 P AMER CONTR CONF PY 2000 BP 3855 EP 3859 PG 5 WC Automation & Control Systems SC Automation & Control Systems GA BR32L UT WOS:000166106200792 ER PT B AU Zebulum, RS Stoica, A Keymeulen, D AF Zebulum, RS Stoica, A Keymeulen, D GP IEEE IEEE TI The design process of an evolutionary oriented reconfigurable architecture SO PROCEEDINGS OF THE 2000 CONGRESS ON EVOLUTIONARY COMPUTATION, VOLS 1 AND 2 SE IEEE Congress on Evolutionary Computation LA English DT Proceedings Paper CT 2000 Congress on Evolutionary Computation (CEC2000) CY JUL 16-19, 2000 CL LA JOLLA, CA SP IEEE Neural Network Council, Evolutionary Programming Soc, Inst Elect Engineers, Parallel Problem Solving Nat, EvoNet, Evolut Artificielle, ANTS, SEAL ID PROGRAMMABLE ANALOG AB This paper describes the design of a reconfigurable chip programmable at the transistor level and oriented to the implementation of Evolvable Hardware (EHW) experiments. We tackle the main issues referring to the conception of an Evolutionary Oriented Reconfigurable Architecture (EORA): the cell topology; interconnection between cells; transistor sizing; resistor and capacitor implementation in silicon; selection of inputs and outputs points; and reconfiguration aspects. A set of evolutionary experiments is described, serving as support for the design choices. Additionally, we propose novel approaches to overcome area requirements for the VLSI design, such as the use of differentiated configurable blocks and a variable interconnection density throughout the chip. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Zebulum, RS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ricardo@brain.jpl.nasa.gov; astoica@brain.jpl.nasa.gov; didier@brain.jpl.nasa.gov NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6375-2 J9 IEEE C EVOL COMPUTAT PY 2000 BP 529 EP 536 PG 8 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BQ87A UT WOS:000089884700075 ER PT B AU Keymeulen, D Stoica, A Zebulum, R Duong, V AF Keymeulen, D Stoica, A Zebulum, R Duong, V GP IEEE IEEE TI Results on the fitness and population based fault tolerant approaches using a reconfigurable electronic device SO PROCEEDINGS OF THE 2000 CONGRESS ON EVOLUTIONARY COMPUTATION, VOLS 1 AND 2 SE IEEE Congress on Evolutionary Computation LA English DT Proceedings Paper CT 2000 Congress on Evolutionary Computation (CEC2000) CY JUL 16-19, 2000 CL LA JOLLA, CA SP IEEE Neural Network Council, Evolutionary Programming Soc, Inst Elect Engineers, Parallel Problem Solving Nat, EvoNet, Evolut Artificielle, ANTS, SEAL AB The paper presents and compares two approaches to design fault-tolerant evolvable hardware: one based on the fitness definition and the other based on the population statistics. The fitness approach defines, in an explicit way, the faults that the component may encounter during its life time and evaluates the average behavior of the individuals. The population approach uses the implicit information of the population statistics accumulated by the genetic algorithm over many generations. The paper presents experiments done using both approaches on a fine-grained CMOS Field Programmable Transistor Array (FPTA) architecture for the synthesis of a fault-tolerant XNOR digital circuit. Experiments show that the evolutionary algorithm is able to find a fault-tolerant design for the XNOR function that can recover functionality when lost due to not a-priori known faults, by finding new circuits configurations that circumvent the faults. Our preliminary experiments show that the population approach designs a fault-tolerant circuit with a better performance and in less computation than the fitness based approach. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. EM didier.keymeulen@jpl.nasa.gov NR 25 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6375-2 J9 IEEE C EVOL COMPUTAT PY 2000 BP 537 EP 544 PG 8 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BQ87A UT WOS:000089884700076 ER PT S AU Huang, SH Tu, MR Yao, S Maleki, L AF Huang, SH Tu, MR Yao, S Maleki, L GP IEEE IEEE TI A "turnkey" optoelectronic oscillator with low acceleration sensitivity SO PROCEEDINGS OF THE 2000 IEEE/EIA INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM & EXHIBITION SE PROCEEDINGS OF THE IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT IEEE/EIA International Frequency Control Symposium and Exhibition CY JUN 07-09, 2000 CL KANSAS CITY, MO SP IEEE, Ultrason, Ferroelect, & Frequency Control Soc, EIA Electr Components Assemblies & Mat Assoc AB We present the experimental results on the acceleration sensitivity of the first fully packaged optoelectronic oscillator module operating at 11 GHz. We demonstrate a fiber delay line package technique that reduces the acceleration sensitivity of the module by 40 times. With measured acceleration sensitivity less than 1.5x10(-10) /g, this oscillator is believed to have the lowest acceleration sensitivity of any oscillator operating at 10 GHz and above. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Huang, SH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 6 TC 4 Z9 4 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1075-6787 BN 0-7803-5839-2 J9 P IEEE INT FREQ CONT PY 2000 BP 269 EP 279 DI 10.1109/FREQ.2000.887365 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Instruments & Instrumentation; Materials Science; Physics GA BR19M UT WOS:000165838900044 ER PT S AU Ji, Y Yao, XS Maleki, L AF Ji, Y Yao, XS Maleki, L GP IEEE IEEE TI HIGH-Q whispering gallery mode resonator filter with photonic bandgap spurious mode suppression SO PROCEEDINGS OF THE 2000 IEEE/EIA INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM & EXHIBITION SE IEEE International Frequency Control Symposium LA English DT Proceedings Paper CT IEEE/EIA International Frequency Control Symposium and Exhibition CY JUN 07-09, 2000 CL KANSAS CITY, MO SP IEEE, Ultrason, Ferroelect, & Frequency Control Soc, EIA Electr Components Assemblies & Mat Assoc AB We demonstrate a novel bandpass filter constructed with a dielectric resonator operating in a whispering-gallery mode and a pair of photonic bandgap structured microstrip lines. The photonic bandgap structure is used to suppress the spurious modes around an intended transmission peak. The fabricated filter has a center frequency of 13.7GHz, a Q of 2,000, an insertion loss of 7dB and a spurious-mode suppression of 30dB. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1075-6787 BN 0-7803-5838-4; 0-7803-5839-2 J9 P IEEE INT FREQ CONT PY 2000 BP 471 EP 474 DI 10.1109/FREQ.2000.887402 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Instruments & Instrumentation; Materials Science; Physics GA BR19M UT WOS:000165838900081 ER PT S AU Dick, GJ Wang, RBT AF Dick, GJ Wang, RBT GP IEEE IEEE TI Cryo-cooled sapphire oscillator operating above 35K SO PROCEEDINGS OF THE 2000 IEEE/EIA INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM & EXHIBITION SE PROCEEDINGS OF THE IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT IEEE/EIA International Frequency Control Symposium and Exhibition CY JUN 07-09, 2000 CL KANSAS CITY, MO SP IEEE, Ultrason, Ferroelect, & Frequency Control Soc, EIA Electr Components Assemblies & Mat Assoc AB We present preliminary design features for a second generation thermomechanically compensated sapphire resonator. Developed a few years ago, the "77K CSO" resonator showed a quality factor Q = 2x10(6) at an operating temperature of 85K enabling a frequency stability of deltaf/f < 1x10(-13). The new design promises a frequency stability of parts in 10(15) with cooling provided by a cryocooler consuming several hundred watts or less. Optimization of the resonator design for a temperature of 40K results in a mechanical tuning rate requirement (MHz/micron) reduced by a factor of 8, allowing for reduced EM fields at die surface of the sapphire and reduced sensitivity to mechanical deformation. This optimized EM design is implemented in a self-assembling mechanical design that allows easy disassembly for cleaning together with. a first-order cancellation for expected mechanisms of physical creep. The new design is; expected to share the very short thermal time constants characteristic of the 10K and 77K CSO resonators, thus allowing effective compensation of rapid temperature fluctuations. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Dick, GJ (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NR 10 TC 9 Z9 10 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1075-6787 BN 0-7803-5839-2 J9 P IEEE INT FREQ CONT PY 2000 BP 480 EP 484 DI 10.1109/FREQ.2000.887404 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Instruments & Instrumentation; Materials Science; Physics GA BR19M UT WOS:000165838900083 ER PT S AU Gaidis, MC Lee, KA Samoska, L Wyss, RA AF Gaidis, MC Lee, KA Samoska, L Wyss, RA GP IEEE IEEE TI Frequency-controlled sources of far-infrared radiation for spaceborne applications SO PROCEEDINGS OF THE 2000 IEEE/EIA INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM & EXHIBITION SE PROCEEDINGS OF THE IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT IEEE/EIA International Frequency Control Symposium and Exhibition CY JUN 07-09, 2000 CL KANSAS CITY, MO SP IEEE, Ultrason, Ferroelect, & Frequency Control Soc, EIA Electr Components Assemblies & Mat Assoc ID CARRIER LIFETIME; GAAS; DIODES; POWER; THZ C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gaidis, MC (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RI Gaidis, Michael/D-3327-2013 NR 46 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1075-6787 BN 0-7803-5839-2 J9 P IEEE INT FREQ CONT PY 2000 BP 565 EP 577 DI 10.1109/FREQ.2000.887419 PG 5 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Instruments & Instrumentation; Materials Science; Physics GA BR19M UT WOS:000165838900098 ER PT S AU Naudet, C Jacobs, C Keihm, S Lanyi, G Resch, G Riley, L Rosenberger, H Tanner, A AF Naudet, C Jacobs, C Keihm, S Lanyi, G Resch, G Riley, L Rosenberger, H Tanner, A GP IEEE IEEE TI The propagation of stable radio frequency signals through the atmosphere SO PROCEEDINGS OF THE 2000 IEEE/EIA INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM & EXHIBITION SE PROCEEDINGS OF THE IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT IEEE/EIA International Frequency Control Symposium and Exhibition CY JUN 07-09, 2000 CL KANSAS CITY, MO SP IEEE, Ultrason, Ferroelect, & Frequency Control Soc, EIA Electr Components Assemblies & Mat Assoc AB The terrestrial troposphere and ionosphere are known to;have strong effects on the radiation fields traversing them. The primary types of effects are refraction (deflection, polarization rotation, propagation velocity changes), absorption, and scattering by the turbulent structure in the media. In particular, the phase accuracy of interferometric measurements and spacecraft Doppler tracking at frequencies greater than 5 GHz are dominated by fluctuations in the distribution of water vapor. The Deep Space Network is supporting the Gravitational Wave Experiment (GWE) on the Cassini spacecraft by providing atmospheric media calibration for precise Doppler tracking. The two-way communication link between the ground station and the Cassini spacecraft are in effect an "antenna" for gravitational waves that will perturb the phase of the RF signal between the Earth and the spacecraft. The experiment will be sensitive to gravitational wave perturbations larger than the noise level fluctuations of 3 x 10(-15) as measured in the Allan Standard Deviation Domain. We have designed and are testing a new atmospheric calibration system to sense line-of-sight water vapor and its:physical temperature with a goal of calibrating 95% or more of water vapor fluctuation during the Cassini GWE. The calibration system consists of a newly designed water vapor radiometer having a 1 degree sensing beamwidth, a microwave temperature profiler to constrain the vertical distribution of the vapor physical temperature, and surface meteorology. Two complete water vapor calibration systems have been constructed in order to provide side-by-side testing capability as well as backup during the actual experiment. We will report on an independent test of these calibrations systems done by comparing them to a short baseline radio interferometric measurement at our Goldstone complex. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Naudet, C (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1075-6787 BN 0-7803-5839-2 J9 P IEEE INT FREQ CONT PY 2000 BP 578 EP 585 DI 10.1109/FREQ.2000.887420 PG 4 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Instruments & Instrumentation; Materials Science; Physics GA BR19M UT WOS:000165838900099 ER PT S AU Cangahuala, LA AF Cangahuala, LA GP IEEE IEEE TI Interplanetary navigation overview SO PROCEEDINGS OF THE 2000 IEEE/EIA INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM & EXHIBITION SE PROCEEDINGS OF THE IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT IEEE/EIA International Frequency Control Symposium and Exhibition CY JUN 07-09, 2000 CL KANSAS CITY, MO SP IEEE, Ultrason, Ferroelect, & Frequency Control Soc, EIA Electr Components Assemblies & Mat Assoc C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cangahuala, LA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1075-6787 BN 0-7803-5839-2 J9 P IEEE INT FREQ CONT PY 2000 BP 618 EP 621 DI 10.1109/FREQ.2000.887425 PG 2 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Instruments & Instrumentation; Materials Science; Physics GA BR19M UT WOS:000165838900104 ER PT S AU Tjoelker, RL Chung, S Diener, W Kirk, A Maleki, L Prestage, JD Young, B AF Tjoelker, RL Chung, S Diener, W Kirk, A Maleki, L Prestage, JD Young, B GP IEEE IEEE TI Nitrogen buffer gas experiments in mercury trapped ion frequency standards SO PROCEEDINGS OF THE 2000 IEEE/EIA INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM & EXHIBITION SE PROCEEDINGS OF THE IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM LA English DT Proceedings Paper CT IEEE/EIA International Frequency Control Symposium and Exhibition CY JUN 07-09, 2000 CL KANSAS CITY, MO SP IEEE, Ultrason, Ferroelect, & Frequency Control Soc, EIA Electr Components Assemblies & Mat Assoc AB Practical, continuous operating mercury trapped ion frequency standards have traditionally used a helium buffer gas to increase loading efficiency and cool ions to near room temperature. The fractional frequency shift of the 40,507,347.9968x Hz clock transition due to collisions with helium is measured to be (df/dP(He))(1/f) =+1.2x10(-10)/Pa The use of a nitrogen buffer gas is considered for low power and mass applications where unattended operational life must be greater than 10 years. The nitrogen pressure shift is measured to be (df/dP(N2))(1/f)-8.7x10(-9)/Pa. Nitrogen would allow long operation with a only small ion pump but require increased pressure regulation to achieve the ultra-high stability obtained using helium in multipole Hg+ standards. C1 Jet Prop Lab, Pasadena, CA 91109 USA. RP Tjoelker, RL (reprint author), Jet Prop Lab, Pasadena, CA 91109 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1075-6787 BN 0-7803-5839-2 J9 P IEEE INT FREQ CONT PY 2000 BP 668 EP 671 DI 10.1109/FREQ.2000.887434 PG 2 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Instruments & Instrumentation; Materials Science; Physics GA BR19M UT WOS:000165838900113 ER PT S AU Prestage, JD Tjoelker, RL Maleki, L AF Prestage, JD Tjoelker, RL Maleki, L GP IEEE IEEE TI Mercury-ion clock based on linear multi-pole ion trap SO PROCEEDINGS OF THE 2000 IEEE/EIA INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM & EXHIBITION SE IEEE International Frequency Control Symposium LA English DT Proceedings Paper CT IEEE/EIA International Frequency Control Symposium and Exhibition CY JUN 07-09, 2000 CL KANSAS CITY, MO SP IEEE, Ultrason, Ferroelect, & Frequency Control Soc, EIA Electr Components Assemblies & Mat Assoc ID RF QUADRUPOLE TRAP AB Buffer gas cooled clocks rely on large numbers of ions, typically similar to 10(7), optically pumped by a discharge lamp at scattering fates of a few photons per second per ion. To reduce the 2(nD) Doppler shift from space charge repulsion of ions from the trap node line, novel multi-pole ion traps are now being developed where ions are weakly bound with confining fields that are effectively zero through the trap interior and grow rapidly near the trap electrode 'walls.'. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 6 Z9 7 U1 0 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1075-6787 BN 0-7803-5838-4; 0-7803-5839-2 J9 P IEEE INT FREQ CONT PY 2000 BP 706 EP 710 DI 10.1109/FREQ.2000.887441 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary; Physics, Condensed Matter SC Engineering; Instruments & Instrumentation; Materials Science; Physics GA BR19M UT WOS:000165838900120 ER PT B AU Blosiu, JO Blosiu, CJ AF Blosiu, JO Blosiu, CJ GP IEEE IEEE TI Perfection, ideality, and technology road map as measured by a sliding scale - Technology creativity metrics SO PROCEEDINGS OF THE 2000 IEEE INTERNATIONAL CONFERENCE ON MANAGEMENT OF INNOVATION AND TECHNOLOGY, VOLS 1 AND 2: MANAGEMENT IN THE 21ST CENTURY LA English DT Proceedings Paper CT IEEE International Conference on Management of Innovation and Technology (ICMIT 2000) CY NOV 12-15, 2000 CL SINGAPORE, SINGAPORE SP IEEE EMS, Singapore Chapter, Inst Engineers, Infineon Technol, SIEMENS Med Instruments Pte Ltd, Singapore Technol Electr AB This paper presents an approach to quantify and measure technology evolution levels as forecasted by a technology development road map. The concept of technology perfection performance and ideal performance are defined and contrasted in order to clarify such notions as: current state-of-the-art technology, old proximity to ideal performance, new proximity to ideal, perfection improvement, and technology creativity level. Perfection is defined as a practical and obtainable performance of a technology at a forecasted state-of-the-art development level, where ideal performance is the ultimate imaginary state of unreachable perfection. The creativity levels of technologies displayed on a road map are quantified by the use of a "creativity measurement sliding scale" , also here-by called the "JJ Sliding Scale". These forecasted technology levels are displayed on this road map including the current-state-of-the-art as well as the imaginary ideal performance of selected technology. Such parameters as: functional performance, required energy or power, weight, volume, resources including cost, time to manufacture, and lack or presence of harmful effects are the key parameters used to establish the different forecasted technology levels of perfection vis-a-vis the current state-of-the-art technology. The measurement of creativity at each of the levels of technology displayed on the road map is performed by applying to the above mentioned key parameters a relative weighted factor grading. A quantified total point value for each forecasted technology development level is obtained. The ranking of technology levels by the total earned calculated point value relative to the ideal performance is presented as a metric of technology creativity levels distributed on a technology road map. The proposed methodology is applied to the development and quantification of a technology development road map for the NASA space rechargeable batteries. This paper is also using the Darwinian biological evolution concept, as an analogy, to help better understand the engineering technology forecasting and evolution. C1 CALTECH, Av Syst & Technol Div, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Blosiu, JO (reprint author), CALTECH, Av Syst & Technol Div, Jet Propuls Lab, Pasadena, CA 91125 USA. NR 15 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6652-2 PY 2000 BP 321 EP 326 PG 6 WC Computer Science, Information Systems; Engineering, Industrial; Engineering, Manufacturing SC Computer Science; Engineering GA BT45Z UT WOS:000173048900051 ER PT B AU Homaifar, A Hawari, H Iran-Nejad, A AF Homaifar, A Hawari, H Iran-Nejad, A BE Groumpos, PP Koussoulas, NT Polycarpou, M TI Using biofunctionality as a novel learning method for intelligent agents SO PROCEEDINGS OF THE 2000 IEEE INTERNATIONAL SYMPOSIUM ON INTELLIGENT CONTROL LA English DT Proceedings Paper CT IEEE International Symposium on Intelligent Control/8th IEEE Mediterranean Conference on Control and Automation CY JUL 17-19, 2000 CL UNIV PATRAS, RION, GREECE SP IEEE, Minist Dev, Gen Sceretariat Res & Technol, Tech Chamber Greece, Univ Patras, Res Comm, European Commiss, ICIMS Network Excellence, European Commiss, AMETMAS Network Excellence, European Commiss, Human Potential Programme High Level Sci Conf HO UNIV PATRAS DE biofunctional learning; genetic algorithms; fuzzy logic; classifier systems AB A learning machine envisioned for functioning in the physical world should be reasonably easy to implement. Our daily lives and experiences suggest that human-like learning systems are better suited for functioning in hard-to-navigate environments because of their high degree of flexibility. This paper applies the biofunctional model of human learning to the design and implementation of a learning machine that is effective in navigating complex environments and relatively easy to design using classifier systems. We will portray in this case study how a Fuzzy Logic Controller helps In making the system more conforming to the biofunctional model. The result is vast improvements to the learning rate and the overall efficiency of the whole system. C1 N Carolina A&T State Univ, Dept Elect Engn, NASA, Autonomous Control Engn Ctr, Greensboro, NC 27411 USA. RP Homaifar, A (reprint author), N Carolina A&T State Univ, Dept Elect Engn, NASA, Autonomous Control Engn Ctr, Greensboro, NC 27411 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-6491-0 PY 2000 BP 345 EP 350 DI 10.1109/ISIC.2000.882948 PG 6 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA BR45D UT WOS:000166445300063 ER PT J AU Sankaran, V Menon, S AF Sankaran, V Menon, S TI Structure of premixed turbulent flames in the thin-reaction-zones regime SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID COMBUSTOR AB In practical combustors, the structure of a turbulent premixed flame has many facets due to the widely varying turbulence-chemistry interactions that can occur. Premixed combustion in the flamelet, the corrugated flamelet, and the distributed reaction (recently called the thin reaction zones) regimes can coexist within the same device. Models using large-eddy simulation (LES) methodology to simulate premixed combustion in practical systems must, therefore, be able to predict these space- and time-varying flame structure and propagation characteristics without requiring ad hoc changes. Here, the linear-eddy model (LEM). developed earlier for the flamelet regime, is used without ally modifications to simulate premixed flames over the entire parameter space. A 15-step, Ig-species, methane-air mechanism has been used in the in situ adaptive tabulation (ISAT) procedure to investigate premixed flame structure from the flamelet to the thin-reaction-zones regime. Qualitative and quantitative comparisons with experimental observations show that the LEM is capable of accurately capturing the flame structure in both flamelet and thin-reaction-zones regimes. These simulations confirm that in the thin-reaction-zones regime the preheat zone thickness increases with increase in the Karlovitz number I(a. However, the reaction zone remains very thin and of the order of the laminar flame thickness. These results,along with earlier studies of LEM in non-premixed and flamelet premixed combustion, confirm the viability of LEM as a practical combustion subgrid model for use in reacting LES. C1 Georgia Inst Technol, Sch Aerosp Engn, Atlanta, GA 30332 USA. Univ Erlangen Nurnberg, D-8520 Erlangen, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Rhein Westfal TH Aachen, D-5100 Aachen, Germany. RP Sankaran, V (reprint author), Georgia Inst Technol, Sch Aerosp Engn, Atlanta, GA 30332 USA. NR 22 TC 34 Z9 34 U1 1 U2 10 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 203 EP 209 PN 1 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900027 ER PT J AU Okong'o, N Bellan, J AF Okong'o, N Bellan, J TI Entropy production of emerging turbulent scales in a temporal supercritical n-heptane/nitrogen three-dimensional mixing layer SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID FLUID; SIMULATION; HYDROGEN AB A study of emerging turbulent scales entropy production was conducted for a supercritical shear laver as a precursor to the eventual modeling of subgrid scales (SGS; from a turbulent state) leading to large eddy simulations (LES). The entropy equation was first developed for a real, non-ideal fluid using a validated all-pressure fluid model, and the entropy flux and production terms were identified. Employing a direct numerical simulation (DNS) created database of a temporal three-dimensional supercritical shear Iq er using the fluid model, the different contributions to the irreversible entropy production term were evaluated. Both domain averaged and root mean square (RMS) terms were computed at three different stages of die DNS, representing the timewise ascending, culmination, and descending branches of the spatially averaged positive spanwise vorticity. The unfiltered and filtered databases were compared to evaluate the relative importance of production from viscous, Fourier heat diffusion, and molar fluxes terms. The results show that the average entropy production is dominated by the viscous terms at all stages of the evolution; however, the contribution to the RMS of the molar Aux: term for both the ascending and descending branches is non-negligible. This latter result was traced to the molar gradients tending to be smeared by emerging turbulent scales. Based on this finding, a physical picture of the layer evolution was presented involving competition between large scales entraining heavy fluid from the lower stream and forming, strong density and mass fraction gradients at spatially varying locations with time, and small-scale turbulent structures evolving but being damped by contact with thp newly formed strong density gradient regions which act similar to material surfaces. Analysis of the results showed that the primary contribution to the molar flux dissipation for both the average and the RMS is the mixture non-ideality. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Okong'o, N (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 22 TC 9 Z9 9 U1 0 U2 2 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 497 EP 504 PN 1 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900063 ER PT J AU Schnaubelt, S Moriue, O Coordes, T Eigenbrod, C Rath, HJ AF Schnaubelt, S Moriue, O Coordes, T Eigenbrod, C Rath, HJ TI Detailed numerical simulations of the multistage self-ignition process of n-heptane isolated droplets and their verification by comparison with microgravity experiments SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID COMBUSTION SYSTEMS; LIQUID AB Detailed understanding of the basic physical and chemical processes of self-ignition phenomena for technical fuel sprays is required for many technical combustion applications. Because single droplets as the basic elements of fuel sprays allow: the study of fundamental ignition behavior, this work focuses on the multistage self-ignition behavior of (empty set) 0.7 mm single n-heptane droplets in air. The investigated ambient conditions are temperatures from 580 to 1000 K and pressures from 0.3 to 1 MPa. A substantial physical and chemical model is developed for the detailed numerical simulation. The chemical reaction mechanism consists of a 62-step kinetic model with special consideration of the low-temperature reaction branch. Th program was validated by comparison with results from microgravity experiments at Drop Tower. Bremen. which allow clarification of thr ignition process free from natural convection. Cool flame and hot flame appearances were obtained from non-intrusive interferometric measurement in a well-tested experimental setup. The calculated ignition delays resulting from temperature and temperature gradient criteria, respectively, were compared with these experimental results. Furthermore. the cool flame temperature was measured with a K-type thermocouple of (empty set) 25 mum at the place of its appearance and was also compared with the numerical simulations, A quantitative good agreement for first and total ignition delays as well as for the cool flame temperature could be achieved. With this detailed numerical model, the multistage ignition behavior was analyzed, and die ignition criteria employed in interferometric measurement,which are temperature and temperature gradient, respectively, were confirmed. C1 Univ Bremen, Ctr Appl Space Technol & Micrograv, D-28359 Bremen, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Schnaubelt, S (reprint author), Univ Bremen, Ctr Appl Space Technol & Micrograv, D-28359 Bremen, Germany. NR 24 TC 34 Z9 35 U1 0 U2 7 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 953 EP 960 PN 1 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900116 ER PT J AU Okai, K Moriue, O Araki, M Tsue, M Kono, M Sato, J Dietrich, DL Williams, FA AF Okai, K Moriue, O Araki, M Tsue, M Kono, M Sato, J Dietrich, DL Williams, FA TI Combustion of single droplets and droplet pairs in a vibrating field under microgravity SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID DIFFUSION FLAMES; FUEL DROPLET; INSTABILITY AB This paper presents results of an experimental investigation on acoustic effects on combustion of single droplets and droplet pairs in microgravity The ambient gas was air at atmospheric temperature and pressure, with octane as the fuel. A loudspeaker at the bottom of the chamber produced the acoustic field. Experimental results of single droplets showed that at low frequency acid small to moderate acoustic intensities the evaporation rate increases, and the burning rate constant is nearly proportional to thr product of frequency f, and square of displacement, X-a(2), fX(a)(2). At higher acoustic intensities, the burning rate constant either remains constant or decreases, and, in some cases, flame extinction occurs at a finite droplet diameter. The burning rate constant For a droplet pair is consistently lower than that for a single droplet,At lower frequencies. the burning rate constant reaches a maximum at aml intermediate acoustic intensity At higher frequencies, the bunting rate constant increases monotonically with increasing acoustic intensity Time flame size decreases as a result of interactions, as does the critical spacing that indicates a merged flame around the droplet pair versus individual flames surrounding the droplets. The results also show that interactions stabilize the flame. in that droplet pairs burn to completion under conditions in which the flame surrounding a single droplet extinguishes at a finite droplet diameter. C1 Univ Tokyo, Bunkyo Ku, Tokyo 1138656, Japan. Ishikawajima Harima Heavy Ind Co Ltd, Koto Ku, Tokyo 1358732, Japan. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. RP Okai, K (reprint author), Univ Tokyo, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1138656, Japan. NR 24 TC 11 Z9 12 U1 1 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1540-7489 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 977 EP 983 PN 1 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 451HQ UT WOS:000169795900119 ER PT J AU Urban, DL Yuan, ZG Sunderland, PB Lin, KC Dai, Z Faeth, GM AF Urban, DL Yuan, ZG Sunderland, PB Lin, KC Dai, Z Faeth, GM TI Smoke-point properties of non-buoyant round laminar jet diffusion flames SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID SOOTING BEHAVIOR; MICROGRAVITY AB The laminar smoke-point properties of non-buoyant round laminar jet diffusion flames were studied emphasizing results from long-duration (100-230 s) experiments at microgravity carried out in orbit aboard the space shuttle Columbia. Experimental conditions included ethylene- and propane-fueled dames burning in still air at an ambient temperature of 300 K, pressures of 35-130 kPa, jet exit diameters of 1.6 and 2.7 mm, jet exit velocities of 170-690 mm/s, jet exit Reynolds numbers of 46-172, characteristic flame residence times of 40-302 ms, and luminous flame lengths of 15-63 mm. Contrary to the normal-gravity laminar smoke point, in microgravity, the onset of laminar smoke-point conditions involved two flame configurations: closed-tip flames with soot emissions along the flame axis and open-tip flames with soot emissions from an annular ring about the flame axis. Open-tip flames were observed at large characteristic flame residence times with the onset of soot emissions associated with radiative quenching near die flame tip: nevertheless, unified correlations of laminar smoke-point properties were obtained that included both flame configurations. Flame lengths at laminar smoke-point conditions were well correlated in terms of a corrected fuel flow rate suggested by a simplified analysis of flame shape. The present steady and nonbuoyant flames emitted soot more readily than non-buoyant flames in earlier tests using ground-based microgravity facilities and than buoyant flames at normal gravity, as a result of reduced effects of unsteadiness, flame disturbances, and buoyant motion. For example, present measurements of laminar smoke-point flame lengths at comparable conditions were up to 2.3 times shorter than ground-based microgravity measurements and up to 6.4 times shorter than buoyant flame measurements. Finally present laminar smoke-point flame lengths were roughly inversely proportional to pressure to a degree that is a somewhat smaller than observed during earlier tests both at microgravity (using ground-based facilities) and at normal gravity. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Michigan, Ann Arbor, MI 48109 USA. RP Urban, DL (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. OI Ismail, Mostafa/0000-0001-7530-9764; Sunderland, Peter/0000-0002-8262-7100 NR 30 TC 24 Z9 25 U1 0 U2 1 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 1965 EP 1972 PN 2 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400061 ER PT J AU Takahashi, F Katta, VR AF Takahashi, F Katta, VR TI A reaction kernel hypothesis for the stability limit of methane jet diffusion flames SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH AB The lifting. limit of an axisymmetric, laminar co-flow methane-air jet diffusion flame under normal earth gravity has been successfully predicted. Computations of the time-dependent full Navier-Stokes equations with buoyancy were performed using an implicit, third-order accurate numerical scheme and a detailed C-2 chemistry; model. A one-step global chemistry model was also used to reveal its deficiencies and to demonstrate the need for "tuning" its kinetic parameters for the studies oil flame lifting. The detailed chemistry model resulted in the standoff distance of the flame from the burner rim in good agreement with that measured previously As the mean co-flow air velocity was increased, at a fixed fuel jet velocity under the near-limit condition, the calculated reaction kernel (peak reactivity spot) in the flame base broadened. and rapidly shifted away downstream. As a result, a higher reactivity (heat-release rate, oxygen consumption rate, etc.) at the reaction kernel could be obtained to sustain combustion against a higher incoming flow velocity or a shorter residence time, The reactivity augmentation is due to a "blowing" effect, which caused enhanced convective and diffusive fluxes of oxygen into the reactively low-temperature similar to 1550 K) fuel-lean (equivalence ratio approximate to0.55) reaction kernel. Based on these new finings, a reaction kernel hypothesis is proposed for the diffusion flame stability namely, that a subtle balance between the residence time and reaction time in the reaction kernel is maintained by its continuous movement in the downstream direction in response to the destabilizing, effect caused by all increase in the co-flow air velocity, and the overall reaction time eventually exceeds die available residence time at the stability); limit. If a secondary stabilizing: point is obtained as a result of the transition to a turbulent flame base downstream, the flame lifts off, otherwise it blows off. C1 Univ Dayton, Res Inst, Dayton, OH 45469 USA. Innovat Sci Solut Inc, Dayton, OH 45440 USA. RP Takahashi, F (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. NR 22 TC 37 Z9 38 U1 1 U2 6 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2071 EP 2078 PN 2 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400074 ER PT J AU Lathouwers, D Bellan, J AF Lathouwers, D Bellan, J TI Modeling and simulation of bubbling fluidized beds containing particle mixtures SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID CONSTITUTIVE RELATIONS; SPHERICAL-PARTICLES; GRANULAR-MATERIALS; KINETIC-THEORY; SMOOTH; DENSE; FLOW; GAS; SPHERES AB A comprehensive model is presented for mathematically describing the isothermal, non-reactive, fluid dynamics of a mixture of particles in a gas. A multifluid approach was followed in which macroscopic transport equations were derived by taking suitable ensemble averages of the local gas and particle dynamic equations. A standard phasic ensemble average was selected for the gas phase, whereas the particle equations were derived using a kinetic theory approach in which collisional transfer is included. Separate transport equations were constructed for each of die particle classes. allowing for the description of the independent acceleration of the particles in each class and the equilibration processes whereby momentum and energy are exchanged between each class, leading to a wider range of applicability than common mixture equations have. Closure of the particle equations was exercised by providing separate velocity distributions for each of the particle classes, here specified as Gaussian; this is a valid approach for small gradients in the mean variables, and for nearly elastic particles. In the region of ver) high solids volume fractions, the relations obtained for the stress tensor were augmented by a model describing frictional transfer. The model was applied to three different test cases: (1) prediction of the shear and normal stresses in a homogeneous shear flow, (2) simulation of the particle pressure along the wall of a bubbling bed, and (3) a comparison between simulations of monodisperse and binary mixtures in a homogeneously aerated bed. Where possible to compare, correspondence between simulations and available experimental data is reasonable. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lathouwers, D (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 22 TC 9 Z9 9 U1 1 U2 7 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2297 EP 2304 PN 2 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400099 ER PT J AU Miller, FJ Ross, HD Kim, I Sirignano, WA AF Miller, FJ Ross, HD Kim, I Sirignano, WA TI Parametric investigations of pulsating flame spread across 1-butanol pools SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH AB The experimental realization of pulsating flame spread across a flammable liquid in microgravity was accomplished for the first time through systematic tests in a forced, opposed flow of oxygen-enriched air across shallow and intermediate-depth pools. In tests with the deeper pools, the sequential transition through all three subflash flame spread regimes-from pseudo-uniform to pulsating to uniform spread behavior-was achieved. Normal gravity tests were performed for many of the same conditions and showed similar behavior. In addition. agreement between a detailed numerical model and experiments in both normal gravity and in microgravity was newly obtained through changes in the mass diffusivity and the addition of a heat loss parameter in the two-dimensional model of flame spread over a subflash pool of 1-butanol. The model now: uniquely captures the differences in flame spread character in going from normal to microgravity and provides quantitative agreement in flame spread rate and surface temperature at either gravity level. An earlier hypothesis that lateral thermal expansion in the gas-phase accounted for the initial discrepancy between the two-dimensional model and the three-dimensional experiment is no longer supported: this is because experiments designed to directly eliminate lateral expansion resulted in flame extinction rather than the desired pulsation. C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Micrograv Combus Branch, Cleveland, OH 44135 USA. Univ Michigan, Dept Mech Engn, Dearborn, MI 48128 USA. Univ Calif Irvine, Dept Mech & Aerosp Engn, Irvine, CA 92717 USA. Univ Kentucky, Lexington, KY 40506 USA. RP Miller, FJ (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, MS 110-3, Cleveland, OH 44135 USA. NR 17 TC 9 Z9 9 U1 1 U2 4 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2827 EP 2834 PN 2 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400164 ER PT J AU Delichatsios, MA Altenkirch, RA Bundy, MF Bhattacharjee, S Tang, L Sacksteder, K AF Delichatsios, MA Altenkirch, RA Bundy, MF Bhattacharjee, S Tang, L Sacksteder, K TI Creeping flame spread along fuel cylinders in forced and natural flows and microgravity SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID OPPOSED FLOW AB Semianalytical expressions are developed for creeping flame spread parallel to a fuel cylinder axis so that spread rates measured or predicted for Rat surfaces over the same material can be directly used for cylindrical surfaces. Two phenomena are identified that cause an increased flame spread rate in the cylindrical over the Flat surface geometry: (1) increased heal transfer from the gas phase and (2) faster temperature increase of the solid phase Analytical expressions from approximate solution to a conserved scaler equation are developed For the flame spread rate by simplifying the flowfield using an Oseen approximation for the opposing flow. The spread rate expression for the fuel cylinder is rho (s)c(s)(T-v - T-o)VrhoLsy ( 1 - L-sy/2R(o) ) = C(L-g/R-o)E-FL/ln( 1 + C L-s/R-o) - L(g)epsilon sigma (T-v(4) - T-o(4)) in which the terms containing the constant C account for the enhanced gas-to-surface heat transfer because of die cylindrical curvature, and those containing L-sy the heated layer depth in the solid, account for a reduction in the solid volume preheated in the cylindrical compared to the Rat geometry. The expression is tuned by comparison with complete numerical solutions to the flame spread problem from which the Flame energy E-FL. is determined from the flat surface geometry and the constant C chosen from heat transfer correlations. Results compare favorably with numerical solutions for cylindrical spread in forced and natural flows and microgravity and with experiments on downward flame spread on cylindrical rods in normal gravity and microgravity. C1 CSIRO, DBCE, Fire Safety Engn Div, Fire Sci & Technol Lab, N Ryde, NSW 1670, Australia. Mississippi State Univ, NSF, Engn Res Ctr, Dept Mech Engn, Mississippi State, MS 39762 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. San Diego State Univ, Dept Mech Engn, San Diego, CA 92182 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Delichatsios, MA (reprint author), CSIRO, DBCE, Fire Safety Engn Div, Fire Sci & Technol Lab, N Ryde, NSW 1670, Australia. OI DELICHATSIOS, Michael/0000-0002-3160-0573 NR 24 TC 9 Z9 10 U1 0 U2 3 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2835 EP 2842 PN 2 PG 8 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400165 ER PT J AU Mell, WE Olson, SL Kashiwagi, T AF Mell, WE Olson, SL Kashiwagi, T TI Flame spread along free edges of thermally thin samples in microgravity SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID ENVIRONMENT; FUEL; TRANSITION; QUIESCENT; IGNITION AB The effects of imposed flow velocity on flame spread along open edges of a thermally thin cellulosic sample in microgravity were studied experimentally and theoretically. In this study, the sample was ignited locally at the middle of the 4 cm wide sampler and subsequent flame spread reached both open edges of the sample along the direction of the flow. The following flame behaviors were observed in the experiments and predicted by the numerical calculation in order of increased imposed flow velocity : (1) ignition but subsequent flame spread was not attained. (2) flame spread upstream (opposed mode) without any downstream stream flame, and (3) the upstream flame and two separate downstream flames traveled along the two open edges (concurrent mode). Generally, the upstream and downstream edge flame spread rates were faster than the central flame spread rate for an imposed flow velocity of up to 5 cm/s. This was due to greater oxygen supply from the outer free stream to the edge flames and more efficient heat transfer from the edge flames to the sample surface than the central flames. For the upstream edge flame, flame spread rate was nearly independent of, or decreased gradually with the imposed flow velocity. The spread rate of the downstream edge, however, increased significantly with the imposed flow velocity. C1 Univ Utah, Chem & Fuels Engn Dept, Salt Lake City, UT 84112 USA. NASA, Glenn Res Ctr, Micrograv Combust Sci Branch, Cleveland, OH 44135 USA. Natl Inst Stand & Technol, Bldg & Fires Res Lab, Gaithersburg, MD 20899 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Mell, WE (reprint author), Univ Utah, Chem & Fuels Engn Dept, Salt Lake City, UT 84112 USA. NR 12 TC 8 Z9 10 U1 0 U2 1 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2843 EP 2849 PN 2 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400166 ER PT J AU Nayagam, V Williams, FA AF Nayagam, V Williams, FA TI Diffusion-flame extinction for a spinning fuel disk in an oxidizer counterflow SO PROCEEDINGS OF THE COMBUSTION INSTITUTE LA English DT Article; Proceedings Paper CT 28th International Symposium on Combustion CY JUL 30-AUG 04, 2000 CL UNIV EDINBURGH, EDINBURGH, SCOTLAND HO UNIV EDINBURGH ID SURFACE RADIATION; ASYMPTOTIC THEORY AB Activation-energy asymptotics is applied to predict extinction of a Rat laminar diffusion flame adjacent to a solid fuel disk, which is rotating about its axis with angular velocity b and subjected to an impinging gaseous oxidizer Row having a radial velocity gradient a. By allowing for radiative energy loss from the surface of the disk in the similarity solutions, radiative extinction is obtained for smaller values of the parameter c = (a(2) + b(2))(1/2) as well as diffusive extinction at large values. Flammability boundaries are calculated for a model of poly(methyl methacrylate) burning in oxygen/nitrogen mixtures, showing a minimum ambient oxygen concentration to occur at an intermediate value of c separating radiative and diffusive extinction. The location of the minimum and the flammability boundary; are shown to correlate well with a characteristic flow time. The minimum oxygen index below which combustion is impossible (having spacecraft fire-safety implications) is qualitatively consistent with results of earlier numerical studies, which addressed only the limits in which either a or b is zero and found the lowest value of the limiting index to occur when a = 0. The present generalized theory helps to explain these results. C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. Univ Calif San Diego, MAE Dept, La Jolla, CA 92093 USA. RP Nayagam, V (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. NR 15 TC 5 Z9 5 U1 0 U2 0 PU COMBUSTION INST PI PITTSBURGH PA 5001 BAUM BOULEVARD, STE 635, PITTSBURGH, PA 15213-1851 USA SN 0082-0784 J9 P COMBUST INST JI Proc. Combust. Inst. PY 2000 VL 28 BP 2875 EP 2881 PN 2 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 452QN UT WOS:000169870400170 ER PT S AU Birn, J Hesse, M AF Birn, J Hesse, M BE Wilson, A TI Large-scale stability of the magnetotail SO PROCEEDINGS OF THE FIFTH INTERNATIONAL CONFERENCE ON SUBSTORMS SE ESA Special Publications LA English DT Proceedings Paper CT 5th International Conference on Substorms CY MAY 16-20, 2000 CL ARCTIC & ANTARCTIC RES INST CONGRESS CTR, ST PETERSBURG, RUSSIA SP Russian Fdn Basic Res, Int Assoc Geomagnetism & Aeronom, European Space Agcy HO ARCTIC & ANTARCTIC RES INST CONGRESS CTR DE space; magnetotail; stability ID THIN CURRENT SHEETS; MHD SIMULATIONS; PLASMA SHEET; RECONNECTION; DYNAMICS; SUBSTORM; TAIL; CONVECTION; FIELD AB The large-scale stability of the magnetotail is investigated on the basis of resistive MHD simulations. The initial configurations are varied to study the influence of various properties on the tail stability in the presence of a dissipation mechanism. The properties studied include the flaring of the tail in the y direction, the decrease of typical properties, such as lobe field strength or current density, with distance from the Earth, and a thickening of the tail plasma sheet from midnight toward the tail flanks. All of these might contribute to a stabilization. The flaring, if isolated from the other properties, however, has little effect on the unstable evolution. All of the configurations considered experienced reonnection when a dissipation mechanism was available. However, the effects in the more stable configurations were more localized and less dramatic. Such differences in the tail configuration might be responsible for the differences between pseudo-onsets and full substorms. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RI Hesse, Michael/D-2031-2012 NR 17 TC 0 Z9 0 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-772-0 J9 ESA SPEC PUBL PY 2000 VL 443 BP 15 EP 22 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BR50E UT WOS:000166662000003 ER PT S AU Klimas, AJ Uritsky, V Valdivia, JA Vassiliadis, D Baker, DN AF Klimas, AJ Uritsky, V Valdivia, JA Vassiliadis, D Baker, DN BE Wilson, A TI On the compatibility of the coherent substorm cycle with the complex plasma sheet SO PROCEEDINGS OF THE FIFTH INTERNATIONAL CONFERENCE ON SUBSTORMS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 5th International Conference on Substorms CY MAY 16-20, 2000 CL ARCTIC & ANTARCTIC RES INST CONGRESS CTR, ST PETERSBURG, RUSSIA SP Russian Fdn Basic Res, Int Assoc Geomagnetism & Aeronom, European Space Agcy HO ARCTIC & ANTARCTIC RES INST CONGRESS CTR ID SELF-ORGANIZED CRITICALITY; MAGNETOTAIL; FLOWS AB A numerical study of the current sheet model due to Klimas et al. [2000] is discussed. The behavior of this model in the neighborhood of self-organized criticality (SOC) is examined. A near-SOC neighborhood is defined as that region in which the model exhibits scaling in agreement with that predicted by mean field theory as the SOC limit is approached. It is found that this neighborhood is large, including large input rates and comparable loading and unloading time-scales. Thus, the possibility that the magnetospheric dynamics may lie in a near-SOC domain cannot be discounted. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Klimas, AJ (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 692, Greenbelt, MD 20771 USA. NR 15 TC 2 Z9 2 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-772-0 J9 ESA SP PUBL PY 2000 VL 443 BP 165 EP 168 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BR50E UT WOS:000166662000035 ER PT S AU Uritsky, VM Klimas, AJ Vassiliadis, D AF Uritsky, VM Klimas, AJ Vassiliadis, D BE Wilson, A TI On a new approach to detection of stable critical dynamics of the magnetosphere SO PROCEEDINGS OF THE FIFTH INTERNATIONAL CONFERENCE ON SUBSTORMS SE ESA SPECIAL PUBLICATIONS LA English DT Proceedings Paper CT 5th International Conference on Substorms CY MAY 16-20, 2000 CL ARCTIC & ANTARCTIC RES INST CONGRESS CTR, ST PETERSBURG, RUSSIA SP Russian Fdn Basic Res, Int Assoc Geomagnetism & Aeronom, European Space Agcy HO ARCTIC & ANTARCTIC RES INST CONGRESS CTR ID SELF-ORGANIZED CRITICALITY AB The solar-wind driven magnetosphere is a classic example of an open complex nonlinear system with many interacting degrees of freedom. Such systems are known to produce scale-free spatiotemporal instabilities with power-law correlation functions that can be interpreted in terms of the self-organized criticality (SOC) concept. In the present paper we describe a new method for the investigating SOC in the nonlinear dynamics of the magnetosphere. Using the results of mean-field theory by Vespignani and Zapperi (1998) we argue that the SOC state can be detected not only from statistical analysis of individual unstable events but also from the study of critical scaling of integral characteristics of geomagnetic activity. We demonstrate numerically that one such integral characteristic is the zero field susceptibility, and make a suggestion that this function can be estimated from a response function of the entire magnetosphere. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Uritsky, VM (reprint author), NASA, Goddard Space Flight Ctr, Code 692, Greenbelt, MD 20771 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ESA PUBLICATIONS DIVISION C/O ESTEC PI 2200 AG NOORDWIJK PA PO BOX 299, 2200 AG NOORDWIJK, NETHERLANDS SN 0379-6566 BN 92-9092-772-0 J9 ESA SP PUBL PY 2000 VL 443 BP 213 EP 216 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BR50E UT WOS:000166662000046 ER PT B AU Mack, M Lapir, GM Berkovich, S AF Mack, M Lapir, GM Berkovich, S BE Wang, PP TI An optimal bit-counting algorithm SO PROCEEDINGS OF THE FIFTH JOINT CONFERENCE ON INFORMATION SCIENCES, VOLS 1 AND 2 LA English DT Proceedings Paper CT 5th Joint Conference on Information Sciences (JCIS 2000) CY FEB 27-MAR 03, 2000 CL ATLANTIC CITY, NJ SP Assoc Intelligent Machinery, Machine Intelligent & Fussy Log Lab, Elsevier Publishing Co, Inc, Informat Sci Journal, USA Res Off C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mack, M (reprint author), NASA, Goddard Space Flight Ctr, Code 585,Code 933, Greenbelt, MD 20771 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU ASSOC INTELLIGENT MACHINERY PI DURHAM PA PO BOX 90291, DURHAM, NC 27708-0291 USA BN 0-9643456-9-2 PY 2000 BP 647 EP 650 PG 4 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BV66Q UT WOS:000179698300159 ER EF