ALBERT

Beschreibung: Digital Speckle Pattern Interferometry (DSPI) is a well-established method for the measurement of diffuse objects in experimental mechanics. DSPIs are phase shifting interferometers. Three or four bucket temporal phase shifting algorithms are commonly used to provide phase shifting. These algorithms are sensitive to vibrations and can not be used to measure large optical structures far away from the interferometer. In this research a simultaneous phase shifted interferometer, PhaseCam product of 4D Technology Corporation in Tucson Arizona, is modified to be a Simultaneous phase shifted Digital Speckle Pattern Interferometer (SDSPI). Repeatability, dynamic range, and accuracy of the SDSPI are characterized by measuring a 5 cm x 5 cm carbon fiber coupon.

Beschreibung: This paper introduces a method for predicting the performance of a radiometer design based on calculating the measurement uncertainty. The variety in radiometer designs and the demand for improved radiometric measurements justify the need for a more general and comprehensive method to assess system performance. Radiometric resolution, or sensitivity, is a figure of merit that has been commonly used to characterize the performance of a radiometer. However when evaluating the performance of a calibration design for a radiometer, the use of radiometric resolution has limited application. These limitations are overcome by considering instead the measurement uncertainty. A method for calculating measurement uncertainty for a generic radiometer design including its calibration algorithm is presented. The result is a generalized technique by which system calibration architectures and design parameters can be studied to optimize instrument performance for given requirements and constraints. Example applications demonstrate the utility of using measurement uncertainty as a figure of merit.

Beschreibung: Global measurements of far infrared emission from the upper troposphere are required to test models of cloud radiative forcing, water vapor continuum emission, and cooling rates. Spectra with adequate resolution can also be used for retrieving atmospheric temperature and humidity profiles, and yet there are few spectrally resolved measurements of outgoing longwave flux at wavelengths longer than 16 m. It has been difficult to make measurements in the far infrared due to the need for liquid-helium cooled detectors and large optics to achieve adequate sensitivity and bandwidth. We review design considerations for infrared Fourier transform spectrometers, including the dependence of system performance on basic system parameters, and discuss the prospects for achieving useful sensitivity from a satellite platform with a lightweight spectrometer using uncooled detectors.

Beschreibung: The success of the recent rover missions to Mars has stressed the importance of acquiring the maximum amount of geological information with the least amount of data possible. We have designed, tested and implemented special sensors mounted on a rover s wheel capable of detecting minute changes in surface topology thus eliminating the need for specially- made science platforms. These sensors, based on the previously designed, flight qualified Mars Environmental Compatibility Assessment (MECA) Electrometer, measure the static electricity (triboelectricity) generated between polymer materials and the Martian regolith during rover transverses. The sensors are capable of detecting physical changes in the soil that may not be detectable by other means, such as texture, size and moisture content. Although triboelectricity is a surface phenomenon, the weight of a rover will undoubtedly protrude the sensors below the dust covered layers, exposing underlying regolith whose properties may not be detectable through other means.

Beschreibung: This paper describes the development of the Boresight Adjustment Mechanism (BAM) for the Geoscience Laser Altimeter System (GLAS) Instrument. The BAM was developed late in the integration and test phase of the GLAS instrument flight program. Thermal vacuum tests of the GLAS instrument indicated that the instrument boresight alignment stability over temperature may be marginal. To reduce the risk that GLAS may not be able to meet the boresight alignment requirements, an intensive effort was started to develop a BAM. Observatory-level testing and further evaluation of the boresight alignment data indicated that sufficient margin could be obtained utilizing existing instrument resources and therefore the BAM was never integrated onto the GLAS Instrument. However, the BAM was designed fabricated and fully qualified over a 4 month timeframe to be capable of precisely steering (〈 1 arcsec over 300 arcsec) the output of three independent lasers to ensure the alignment between the transmit and receive paths of the GLAS instrument. The short timeline for the development of the mechanism resulted in several interesting design solutions. This paper discusses the requirement definition, design, and testing processes of the BAM development effort, how the design was affected by the extremely tight development schedule, and the lessons learned throughout the process.

Beschreibung: The NASA Cold-land Processes Field Experiment-1 (CLPX-1) involved several instruments in order to acquire data at different spatial resolutions. Indeed, one of the main tasks of CLPX-1 was to explore scaling issues associated with microwave remote sensing of snowpacks. To achieve this task, microwave brightness temperatures collected at 18.7, 36.5, and 89 GHz at LSOS test site by means of the University of Tokyo s Ground Based Microwave Radiometer-7 (GBMR-7) were compared with brightness temperatures recorded by the NOAA Polarimetric Scanning Radiometer (PSR/A) and by SSM/I and AMSR-E radiometers. Differences between different scales observations were observed and they may be due to the topography of the terrain and to observed footprints. In the case of satellite and airborne data, indeed, it is necessary to consider the heterogeneity of the terrain and the presence of trees inside the observed scene becomes a very important factor. Also when comparing data acquired only by the two satellites, differences were found. Different acquisition times and footprint positions, together with different calibration and validation procedures, can be responsible for the observed differences.

Beschreibung: We have developed a software suite that models complex calorimeters in the time and frequency domain. These models can reproduce all measurements that we currently do in a lab setting, like IV curves, impedance measurements, noise measurements, and pulse generation. Since all these measurements are modeled from one set of parameters, we can fully describe a detector and characterize its behavior. This leads to a model than can be used effectively for engineering and design of detectors for particular applications.

Beschreibung: The Jupiter Icy Moons Orbiter (JIMO) is set to launch between the years 2012 and 2015. It will possibly utilize a nuclear reactor power source and ion engines as it travels to the moons of Jupiter. The nuclear reactor will produce hundreds of kilowatts of power for propulsion, communication and various scientific instruments. Hence, the RF amplification devices aboard will be able to operate at a higher power level and data rate. The initial plan for the communications system is for an output of 1000 watts of RF power, a data rate of at least 10 megabits a second, and a frequency of 32 GHz. A higher data rate would be ideal to fully utilize the instruments aboard JIMO. At NASA Glenn, one of our roles in the JIMO project is to demonstrate RF power combining using multiple traveling wave tubes (TWT). In order for the power of separate TWT s to be combined, the RF output waves from each must be in-phase and have the same amplitude. Since different tubes act differently, we had to characterize each tube using a Network Analyzer. We took frequency sweeps and power sweeps to characterize each tube to ensure that they will behave similarly under the same conditions. The 200 watt Dornier tubes had been optimized to run at a lower power level (120 watts) for their extensive use in the ACTS program, so we also had to experiment with adjusting the voltage settings on several internal components (helix, anode, collector) of the tubes to reach the full 200 watt potential. from the ACTS program. Phase shifters and power attenuators were placed in the waveguide circuit at the inputs to the tubes so that adjustments could be made individually to match them exactly. A magic tee was used to route and combine the amplified electromagnetic RF waves on the tube output side. The demonstration of 200 watts of combined power was successful with efficiencies greater than 90% over a 500 MHz bandwidth. The next step will be to demonstrate the use of three amplifiers using two magic tees by adding a 200 watt Dornier tube to the Varian and Logimetrics combined setup for a total of 400 watts. After that we will use two 200 watt Dorniers for 400 watts and eventually four 200 watt Dornier tubes to demonstrate 800 watts. After demonstrating the success of power combining, we will need to verify the integrity of a modulated signal sent through the combined tubes. The purpose will be to see what effects separating and recombining will have on the modulated signal and also what effect it will have on combining efficiency. A Bit Error Rate (BER) will be determined by a Bit Error Rate Tester (BERT) by comparing the random information it transmits to what it receives back. The process began with two 100 watt tubes, a Varian and a Logimetrics, salvaged

Beschreibung: Calibration and validation of satellite instruments is vital to long-term trend estimates of ozone and other trace species. A satellite instrument is calibrated by comparing it against a particular standard on the ground prior to launch or against know standards in flight. An instrument is validated by making a comparison of the same measurable or measurement. Validation is performed in a number of ways. In particular, measurements by ground, balloon, aircraft, and other satellite instruments are used to provide validation.

Beschreibung: In order to provide high sensitivity rapid imaging at 3.3mm (90GHz) for the Green Bank Telescope - the world's largest steerable aperture - a camera is being built by the University of Pennsylvania, NASA/GSFC, and NRAO. The heart of this camera is an 8x8 close-packed, Nyquist-sampled detector array. We have designed and are fabricating a functional superconducting bolometer array system using a monolithic planar architecture. Read out by SQUID multiplexers, the superconducting transition edge sensors will provide fast, linear, sensitive response for high performance imaging. This will provide the first ever superconducting bolometer array on a facility instrument.

Beschreibung: We have been developing an architecture for producing large format, two dimensional arrays of close-packed bolometers, which will enable submillimeter cameras and spectrometers to obtain images and spectra orders of magnitude faster than present instruments. The low backgrounds achieved in these instruments require very sensitive detectors with NEPs of order 5 x 10(exp -18) W/square root of Hz. Superconducting transition edge sensor bolometers can be close-packed using the Pop-up Detector (PUD) format, and SQUID multiplexers operating at the detector base temperature can be intimately coupled to them. The array unit cell is 8 x 32 pixels, using 32- element detector and multiplexer components. We have fabricated an engineering model array with this technology which features a very compact, modular approach for large format arrays. We report on the production of the 32-element components for the arrays. Planned instruments using this array architecture include the Submillimeter and Far-InfraRed Experiment (SAFIRE) on the SOFIA airborne observatory, the South Pole Imaging Fabry-Perot Interferometer (SPIFI) for the AST/RO observatory, the Millimeter Bolometer Camera for the Atacama Cosmology Telescope (MBC/ACT), and the Redshift (Z) Early Universe Spectrometer (ZEUS j.

Beschreibung: There are several microwave instruments in low Earth orbit (LEO) that are used for atmospheric temperature and humidity sounding in conjunction with companion IR sounders as well as by themselves. These instruments have achieved a certain degree of maturity and undergoing a redesign to minimize their size, mass, and power from the previous generation instruments. An example of these instruments is the AMSU-A series, now flying on POES and AQUA spacecraft with the IR sounders HIRS and AIRS. These older microwave instruments are going to be replaced by the ATMS instruments that will fly on NPP and NPOESS satellites with the CrIS sounder. A number of techniques learned from the ATMS project in instrument hardware design and data processing are directly applicable to a similar microwave sounder on a geosynchronous platform. These techniques can significantly simplify the design of a Geostationary orbit (GEO) microwave instrument, avoiding costly development and minimizing the risk of not being able to meet the scientific requirements. In fact, some of the 'enabling' technology, such as the use of MMIC microwave components (which is the basis for the ATMS' much reduced volume) can be directly applied to a GEO sounder. The benefits of microwave sounders are well known; for example, they penetrate non-precipitating cloud cover and allow for use of colocated IR observations in up to 80% cloud cover. The key advantages of a microwave instrument in GEO will be the ability to provide high temporal resolution as well as uniform spatial resolution and extend the utility of a colocated advanced IR sounder to cases in which partial cloud cover exists. A footprint of the order of 100 km by 100 km resolution with hemispherical coverage within one hour can be easily achieved for sounding channels in the 50 to 59 GHz range. A GEO microwave sounder will also allow mesoscale sampling of select regions.

Beschreibung: Minimum ionizing particles incident on the XRS microcalorimeter array will deposit energy in the pixels on the same scale as an x-ray photon and would be confused with x-rays without an anti-coincidence detector. The XRS anti-coincidence detector is a silicon ionization detector placed directly behind the calorimeter array. Given an isotropic particle flux, 98% of those particles that pass through a calorimeter pixel will also deposit energy in the anti-coincidence detector. Particle events that are not rejected by coincidence are those that pass through at small angles relative to the plane of the array, and thus deposit more energy. Modeling with GEANT4 showed that only 0.1% of all protons incident on the array miss the anti-coincidence detector yet deposit less than 10 keV in a pixel. The unrejected background will thus be dominated by secondary events; we will provide an estimate of this rate. Protons incident on the thick silicon frame around the active area of the array deposit enough energy t o heat the whole chip slightly. This results in small simultaneous pulses on multiple pixels. These can be easily rejected by pixel-to-pixel coincidence. We will discuss the impact of these events on the instrument dead time and will present the expected rate. We will present laboratory background data demonstrating the performance of the anti-coincidence detector and the effectiveness of coincidence analysis in the laboratory environment.

Beschreibung: To detect extra-solar planets by coronography will require unprecedented levels of wavefront correction of both phase and amplitude. To achieve this, we propose a dual Michelson interferometer arrangement, incorporating two deformable mirrors (DM) and a third, fixed mirror (all at pupils) and two beamsplitters: one with unequal (asymmetric) beam splitting and one with symmetric beamsplitting. This design allows high precision correction of phase and amplitude using DMs with relatively coarse steps and is relatively insensitive to small changes in the DMs. We are constructing such an apparatus incorporating two MEMS devices and will report on features of the design and performance.

Beschreibung: We discuss a new type of direct detector, a silicon hot-electron bolometer, for measurements in the far-infrared and submillimeter spectral ranges. High performance bolometers can be made using the electron-phonon conductance in heavily doped silicon to provide thermal isolation from the cryogenic bath. Noise performance is expected to be near thermodynamic limits, allowing background limited performance for many far infrared and submillimeter photometric and spectroscopic applications.

Beschreibung: The Near Infrared Spectrograph (NIRSpec) for the James Webb Space Telescope (JWST) is an essential instrument for measuring the number and density evolution of galaxies following the epoch of initial formation. The NIRSpec is a multi-object spectrograph, allowing simultaneous observation of more than 100 candidate high redshift galaxies. A critical element of the instrument is the programmable field selector, the Microshutter Array. The system consists of four 175 x 384 arrays of individually openable shutters, close packed on a 100 x 200 micron pitch, which allow selection of over 200 candidate objects over the 3 min x 3 min field of the NIRSpec. We will describe the development, production, and test of this critical element of the NIRSpec.

Beschreibung: The amount of UV irradiance reaching the Earth's surface is estimated from the measured cloud reflectivity, ozone, aerosol amounts, and surface reflectivity time series from 1980 to 1992 and 1997 to 2000 to estimate changes that have occurred over a 21-year period. Recent analysis of the TOMS data shows that there has been an apparent increase in reflectivity (decrease in W) in the Southern Hemisphere that is related to a calibration error in EP-TOMS. Data from the well-calibrated SeaWiFS satellite instrument have been used to correct the EP-TOMS reflectivity and UV time series. After correction, some of the local trend features seen in the N7 time series (1980 to 1992) have been continued in the combined time series, but the overall zonal average and global trends have changed. In addition to correcting the EP-TOMS radiance calibration, the use of SeaWiFS cloud data permits estimation of UV irradiance at higher spatial resolution (1 to 4 km) than is available from TOMS (100 km) under the assumption that ozone is slowly varying over a scale of 100 km. The key results include a continuing decrease in cloud cover over Europe and North America with a corresponding increase in UV and a decrease in UV irradiance near Antarctica.

Beschreibung: The optical designs of future NASA infrared (IR) missions and instruments, such as the James Webb Space Telescope's (JWST) Near-Mixed Camera (NIRCam), will rely on accurate knowledge of the index of refraction of various IR optical materials at cryogenic temperatures. To meet this need, we have developed a Cryogenic, High-Accuracy Refraction Measuring System (CHARMS). In this paper we discuss the completion of the design and construction of CHARMS as well as the engineering details that constrained the final design and hardware implementation. In addition, we will present our first light, cryogenic, IR index of refraction data for LiF, BaF2, and CaF2, and compare our results to previously published data for these materials.

Beschreibung: The Zero Degree Detector (ZDD) is a large area pixelated silicon detector that measures secondary particle angular distributions from heavy ion interactions. The ZDD is part of the instrumentation being used in an ongoing measurement program to measure fragmentation cross-sections of heavy nuclei and evaluate the relative effectives of novel materials for spacecraft shielding. The initial performance of the ZDD has been assessed using the primary heavy ions measured. We report here on the ZDD's design, capabilities and signal calibration using heavy ions.

Beschreibung: This paper will describe the objectives of the Marshall Space Flight Center (MSFC) Solar Ultraviolet Magnetograph Investigation (SUMI) and the optical components that have been developed to meet those objectives. In order to test the scientific feasibility of measuring magnetic fields in the W, a sounding rocket payload is being developed. This paper will discuss: (1) the scientific measurements that will be made by the SUMI sounding rocket program, (2) how the optics have been optimized for simultaneous measurements of two magnetic lines CIV (1550 Angstroms) and MgII (2800 Angstroms), and (3) the optical, reflectance, transmission and polarization measurements that have been made on the SUMI telescope mirrors and polarimeter.

Beschreibung: The Laser Interferometer Space Antenna (LISA) mission is a space-borne gravitational wave detector consisting of three spacecraft in heliocentric orbit. Each spacecraft is delivered to it operational orbit by a propulsion module. Because of the strict thermal and mass balancing requirements of LISA, the baseline mission concept requires that the propulsion module separate from the sciencecraft after delivery. The only propulsion system currently baselined for the sciencecraft are micronewton level thrusters, such as FEEP or colloid thrusters, that are used to balance the 30-40 microN of solar radiation pressure and provide the drag-free and attitude control of the spacecraft. Due to these thrusters limited authority, the separation of the propulsion module from the sciencecraft must be well controlled to not induce a large tip-off rotation of the sciencecraft. We present here the results of a design study of the propulsion module separation system that is shown to safely deliver the LISA sciencecraft to its final operational orbit.

Beschreibung: On-orbit calibration of the reflected solar bands on the EOS Moderate Resolution Imaging Spectroradiometer (MODIS) is accomplished by have the instrument view a high reflectance diffuse surface illuminated by the sun. For some of the spectral bands this proves to be much too bright a signal that results in the saturation of detectors designed for measuring low reflectance (ocean) surfaces signals. A mechanical attenuation device in the form of a pin hole screen is used to reduce the signals to calibrate these bands. The sensor response to solar illumination of the SD with and without the attenuation screen in place will be presented. The MODIS detector response to the solar diffuser is smooth when the attenuation screen is absent, but has structures up to a few percent when the attenuation screen is present. This structure corresponds to non-uniform illumination from the solar diffuser. Each pin hole produces a pin-hole image of the sun on the solar diffuser, and there are very many pin hole images of the sun on the solar diffuser for each MODIS detector. Even though there are very many pin-hole images of the sun on the solar diffuser, it is no longer perfectly uniformly illuminated. This non-uniformly illuminated solar diffuser produces intensity variation on the focal planes. The results of a very detailed simulation will be discussed which show how the illumination of the focal plane changes as a result of the attenuation, and the impacts on the calibration will be discussed.

Beschreibung: The Burst Alert Telescope (BAT), a large coded aperture instrument with a wide field-of-view (FOV), provides the gamma-ray burst triggers and locations for the Swift Gamma-Ray Burst Explorer. In addition to providing this imaging information, BAT will perform a 15 keV - 150 keV all-sky hard x-ray survey based on the serendipitous pointings resulting from the study of gamma-ray bursts and will also monitor the sky for transient hard x-ray sources. For BAT to provide spectral and photometric information for the gamma-ray bursts, the transient sources and the all-sky survey, the BAT instrument response must be determined to an increasingly greater accuracy. In this talk, we describe the BAT instrument response as determined to an accuracy suitable for gamma-ray burst studies. We will also discuss the public data analysis tools developed to calculate the BAT response to sources at different energies and locations in the FOV. The level of accuracy required for the BAT instrument response used for the hard x-ray survey is significantly higher because this response must be used in the iterative clean algorithm for finding fainter sources. Because the bright sources add a lot of coding noise to the BAT sky image, fainter sources can be seen only after the counts due to the bright sources are removed. The better we know the BAT response, the lower the noise in the cleaned spectrum and thus the more sensitive the survey. Since the BAT detector plane consists of 32768 individual, 4 mm square CZT gamma-ray detectors, the most accurate BAT response would include 32768 individual detector response functions to separate mask modulation effects from differences in detector efficiencies! We describe OUT continuing work to improve the accuracy of the BAT instrument response and will present the current results of Monte Carlo simulations as well as BAT ground calibration data.

Beschreibung: The production of Earth Science data from orbiting spacecraft is an activity that takes place 24 hours a day, 7 days a week. At the Goddard Earth Sciences Distributed Active Archive Center (GES DAAC), this results in as many as 16,000 program executions each day, far too many to be run by human operators. In fact, when the Moderate Resolution Imaging Spectroradiometer (MODIS) was launched aboard the Terra spacecraft in 1999, the automated commercial system for running science processing was able to manage no more than 4,000 executions per day. Consequently, the GES DAAC developed a lightweight system based on the popular Per1 scripting language, named the Simple, Scalable, Script-based Science Processor (S4P). S4P automates science processing, allowing operators to focus on the rare problems occurring from anomalies in data or algorithms. S4P has been reused in several systems ranging from routine processing of MODIS data to data mining and is publicly available from NASA.

Beschreibung: Some of the most compelling questions in modem astronomy are best addressed with submillimeter and millimeter observations. The question of the role of inflation in the early evolution of the universe is best addressed with large sensitive arrays of millimeter polarimeters. The study of the first generations of galaxies requires sensitive submillimeter imaging, which can help us to understand the history of energy release and nucleosynthesis in the universe. Our ability to address these questions is dramatically increasing, driven by dramatic steps in the sensitivity and size of available detector arrays. While the MIPS instrument on the SIRTF mission will revolutionize far infrared astronomy with its 1024 element array of photoconductors, thermal detectors remain the dominant technology for submillimeter and millimeter imaging and polarimetry. The last decade has seen the deployment of increasingly large arrays of bolometers, ranging from the 48 element arrays deployed on the KAO in the late 198Os, to the SHARC and SCUBA arrays in the 1990s. The past years have seen the deployment of a new generation of larger detector arrays in SHARC II (384 channels) and Bolocam (144 channels). These detectors are in operation and are beginning to make significant impacts on the field. Arrays of sensitive submillimeter bolometers on the SPIRE instrument on Herschel will allow the first large areas surveys of the sky, providing important insight into the evolution of galaxies. The next generation of detectors, led by SCUBA II, will increase the focal scale of these instruments by an order of magnitude. Two major missions are being planned by NASA for which further development of long wavelength detectors is essential, The SAFlR mission, a 10-m class telescope with large arrays of background limited detectors, will extend our reach into the epoch of initial galaxy formation. A major goal of modem cosmology is to test the inflationary paradigm in the early evolution of the universe. To this end, a mission is planned to detect the imprint of inflation on the CMB by precision measurement of its polarization. This work requires very large arrays of sensitive detectors which can provide unprecedented control of a wide range of systematic errors, given the small amplitude of the signal of interest. We will describe the current state of large format detector arrays, the performance requirements set by the new missions, and the different approaches being developed in the community to meet these requirements. We are confident that within a decade, these developments will lead to dramatic advances in our understanding of the evolution of the universe.

Beschreibung: The Geoscience Laser Altimeter System launched in early 2003 is the first satellite instrument IC space to globally observe the distribution of clouds and aerosol through laser remote sensing. The instrument is a basic backscatter lidar that operates at two wavelengths, 532 and 1064 nm. The mission data products for atmospheric observations include the calibrated, observed, attenuated backscatter cross section for cloud and aerosol; height detection for multiple cloud layers; planetary boundary layer height; cirrus and aerosol optical depth and the height distribution of aerosol and cloud scattering cross section profiles. The data will enhance knowledge in several areas of atmospheric science: the distribution, transport and influence of atmospheric aerosol, significantly more accurate measurements of the coverage and height of cirrus and other clouds, polar cloud climatology and radiation influence, the dynamics planetary boundary layer and others. An overview and summary of initial results are presented. Initial results from the first months of operation show the detailed height structure of clouds and aerosol on a global basis as expected. The 532 nm channel was expected to be the more sensitive and primary channel for aerosol measurements, but extensive aerosol loading in many regions are observed by the 1064 nm channel. Sensitivities are down to a few times l0(exp 6) l/(m-sr), much better than originally expected. The 532 channel adds an order of magnitude addition sensitivity. Initial comparisons to aerosol models have been done. Similarly for global cloud cover, good results are obtained just from the 1064 nm channel and from both channels, a measurement of multiple layers and cloud overlap has been made. Antarctica observations show high levels of total cloud cover including unique low-level cirrus and blowing snow. Data products have been generated for cloud, aerosol and PBL presence and heights in addition to the basic scattering cross section profiles.

Beschreibung: The introduction of microwave radiometers for remote sensing of atmospheric temperature and humidity began in early 1970s, when NASA's Nimbus series experimental satellites tested a number of microwave payloads which are the precursors of today's operational microwave temperature and humidity sounders such as the Advanced Microwave Sounding Unit (AMSU-A and AMSU-B), now flying on several Lower Earth Orbiting (LEO) satellites, notably the National Oceanic and Atmospheric (NOAA)-series weather satellites. The Advanced Technology Microwave Sounder (ATMS) will be the next generation microwave sounder, now being developed by NASA for the future U.S. National Polar-orbiting Operational Environmental Satellites System (NPOESS), slated for operation late this decade. The unique feature of a microwave sensor is its cloud-penetrating capability. And the visible and IR sensors are usually greatly degraded by cloud covers. But under the cloud cover is where the weather can be most "active," and atmospheric measurements are most urgently needed. This unique capability has been well proven by AMSU-A, and AMSU-B on LEO satellites. The same capability is also true for a microwave sounder on a GEO satellite. The key advantage of a sensor on a GEO-platform is its "high temporal resolution." A sensor on a GEO-platform can almost "continuous" monitor a given scene on Earth. On the other hand, the major drawback the GEO-platform is its poor spatial resolution. This is probably the main reason why a geosynchronous microwave sounder has yet to be realized. Take the ATMS as an example. It has a 20 cm diameter antenna (temperature channels), producing a 2.2 degree beam, resulting in a footprint of 32 km (from the NPOESS 833 km orbit). From a GEO-orbit the same 32 km footprint would need an antenna 43 times larger, or 860 cm diameter. We will discuss the needs and advantages of such a GEO-microwave sounder with a straw-man design, and show the expected performance characteristics, such as the radiometric temperature sensitivity, surface spatial resolution etc, plus the status of the technology.

Beschreibung: To detect extra-solar planets by coronagraphy will require unprecedented levels of wavefront correction of both phase and amplitude. To achieve this, we propose a dual Michelson interferometer arrangement, incorporating two deformable mirrors (DM) and a third, fixed mirror (all at pupils) and two beamsplitters: one with unequal (asymmetric) beam splitting and one with symmetric beamsplitting. This design allows high precision correction of phase and amplitude using DMs with relatively coarse steps and is relatively insensitive to small changes in the DMs. We are constructing such an apparatus incorporating two MEMS devices and will report on features of the design performance.

Beschreibung: Two-dimensional MEMS microshutter arrays are being developed at NASA Goddard Space Flight Center for use in the near-infrared region on the James Webb Space Telescope (JWST). The microshutter arrays are designed for the selective transmission of light with high efficiency and high contrast. The JWST environment requires cryogenic operation at 35K. Microshutter arrays are fabricated out of silicon-oxide-insulated (SOI) silicon wafers. Arrays are close-packed silicon nitride membranes with a pixel size of 100x200 p. Individual shutters are patterned with a torsion flexure permitting shutters to open 90 degrees with a minimized mechanical stress concentration. The mechanical shutter arrays are fabricated using MEMS technologies. The processing includes a multi- layer metal deposition and patterning of shutter electrodes and magnetic pads, reactive ion etching (NE) of the front side to form shutters out of the nitride membrane, an anisotropic back-etch for wafer thinning, followed by a deep RIE (DRIE) back-etch down to the nitride shutter membrane to form W e s and relieve shutters from the silicon substrate. An additional metal deposition and patterning is used to form back electrodes. Shutters are actuated using a magnetic force and latched using an electrostatic force. . . . KEYWORDS: microshutter, MEMS, RIE, DRIE, micro-optics, near inbred, space telescope

Beschreibung: We demonstrate the use of inbred imaging to locate crystals mounted in cryoloops and cryopreserved in a nitrogen gas stream at 100K. In the home laboratory crystals are clearly seen in the infrared images with light transmitting through the sample while irradiating the crystal from behind, and with illumination from a direction perpendicular to the direction of view. The crystals transmit and reflect infrared radiation differently from the surrounding mother liquor and loop. Because of differences in contrast between crystals and their surrounding mother liquor, it is possible to clearly identify the crystal position. In use at the synchrotron, with robotically mounted crystals the small depth of field of the lens required the recording of multiple images at different focal points. Image processing techniques were then used to produce a clear image of the crystal. The resulting infrared images and intensity profiles show that infrared imaging can be a powerful complement to visual imaging in locating crystals in cryocooled loops.

Beschreibung: The microscopic mapping of the variation in degree of perfection and in type of defects in entire protein crystals by x-rays may well be a prerequisite for better understanding causes of lattice imperfections, the growth history, and properties of protein crystals. However, x-ray microscopic characterization of bulk protein crystals, in the as-grown state, is frequently more challenging than that of small molecular crystals due to the experimental difficulties arising largely from the unique features possessed by protein crystals. In this presentation, we will illustrate ssme recent activities in employing coherence-based phase contrast x-ray imaging and high-angular-resolution diffraction techniques for mapping microdefects and the degree of perfection of protein crystals, and demonstrate a correlation between crystal perfection, diffraction phenomena., and crystallization conditions. The observed features and phenomena will be discussed in context to gain insight into the nature of defects, nucleation and growth, and the properties of protein crystals.

Beschreibung: The Laser Interferometer Space Antenna (LISA) mission, a space based gravitational wave detector, uses laser metrology to measure distance fluctuations between proof masses aboard three spacecraft. The total acceleration disturbance to each proof mass is required to be below 3 x 10(exp 15) m/sq square root of Hz. Self-gravity noise due to spacecraft distortion and spacecraft motion is expected to be a significant contributor to the acceleration noise budget. To minimize these effects, the gravitational field at each proof mass must be kept as small, flat, and constant as possible. It is estimated that the static field must be kept below 5 x 10(exp -10) m/sq s with a gradient below 3 x 10(exp -8)/sq s in order to meet the required noise levels. Most likely it will not be possible to directly verify by measurements that the LISA spacecraft meets these requirements; they must be verified by models. The LISA Integrated Modeling team developed a new self-gravity tool that calculates the gravitational forces and moments on the proof masses to aid in the design and verification of the LISA spacecraft. We present here an overview of&e tool and the latest self-gravity results calculated using the current baseline design of LISA. We also present results of a self-gravity analysis of the ST-7 DRS package that will fly on the LISA Pathfinder mission.

Beschreibung: The National Aeronautics and Space Administration (NASA) has the responsibility for conducting research and development for search and rescue as charged under the National Search and Rescue Plan. For over two decades this task has been undertaken by the Search and Rescue Mission Office at the NASA Goddard Space Flight Center (GSFC). The technology used by the highly successful beacon locating satellite system, Cospas-Sarsat, was conceived and developed at GSFC and is managed by the National Oceanographic and Atmospheric Administration (NOAA). Using beacon-less remote sensing to find people and vessels in distress complements the demonstrated life saving capabilities of this satellite system. The Search and Rescue Mission Office has been investigating the use of fully polarimetric synthetic aperture radar to locate crashed aircraft. An overview of this effort and potential maritime applications of Search and Rescue Synthetic Aperture Radar (SAR) will be presented. The Mission Office has also developed a Laser search and rescue system called L-SAR. The prototype instrument was designed and built by SenSyTech Inc. It specifically targets the location of novel retro-reflective material easily applied to rescue equipment and vessels in distress. An overview of this effort will also be presented.

Beschreibung: The HST Wide Field Camera 3 is a panchromatic UV-visible-near infrared camera whose development is currently nearing completion, for a planned installation into the Hubble Space Telescope during Servicing Mission 4. WFC3 provides two imaging channels. The UVIS channel features a 4096 x 4096 pixel CCD focal plane with sensitivity from 200 to 1000 nm and a 160 x 160 arcsec field of view. The UVIS channel provides unprecedented sensitivity and field of view in the near ultraviolet for HST. The IR channel features a 1014 x 1014 pixel HgCdTe focal plane covering 850 to 1700 nm with a 135 x 135 arcsec field of view, providing an order of magnitude increase in J+H band surveying efficiency for HST. WFC3 offers a rich complement of filters and grisms in each channel. The construction of WFC3 is nearly complete, and the instrument is well into its integration and test program. We present the current status of the instrument and its projected scientific performance.

Beschreibung: Verification of Geoscience Laser Altimeter System (GLAS) optical retrievals is . problematic in that passage over ground sites is both instantaneous and sparse plus space-borne passive sensors such as MODIS are too frequently out of sync with the GLAS position. In October 2003, the GLAS Validation Experiment was executed from NASA Dryden Research Center, California to greatly increase validation possibilities. The high-altitude NASA ER-2 aircraft and onboard instrumentation of Cloud Physics Lidar (CPL), MODIS Airborne Simulator (MAS), and/or MODIS/ASTER Airborne Simulator (MASTER) under-flew seven orbit tracks of GLAS for cirrus, smoke, and urban pollution optical properties inter-comparisons. These highly calibrated suite of instruments are the best data set yet to validate GLAS atmospheric parameters. In this presentation, we will focus on the inter-comparison with GLAS and CPL and draw preliminary conclusions about the accuracies of the GLAS 532nm retrievals of optical depth, extinction, backscatter cross section, and calculated extinction-to-backscatter ratio. Comparisons to an AERONET/MPL ground-based site at Monterey, California will be attempted. Examples of GLAS operational optical data products will be shown.

Beschreibung: The X-ray Spectrometer (XRS) instrument is a revolutionary non-dispersive spectrometer that will form the basis for the Astro-E2 observatory to be launched in 2005. We have recently installed a flight spare X R S microcalorimeter spectrometer at the EBIT-I facility at LLNL replacing the XRS from the earlier Astro-E mission and providing twice the resolution. The X R S microcalorimeter is an x-ray detector that senses the heat deposited by the incident photon. It achieves a high energy resolution by operating at 0.06K and by carefully controlling the heat capacity and thermal conductance. The XRS/EBIT instrument has 32 pixels in a square geometry and achieves an energy resolution of 6 eV at 6 keV, with a bandpass from 0.1 to 12 keV (or more at higher operating temperature). The instrument allows detailed studies of the x-ray line emission of laboratory plasmas. The XRS/EBIT also provides an extensive calibration "library" for the Astro-E2 observatory.

Beschreibung: The Fourier method of interferogram analysis requires the introduction of a constant tilt into the inteferogram to serve as a 'carrier signal' for information on the figure of the surface under test. This tilt is usually removed in the first steps of analysis and ignored thereafter. However, in the problem of aligning optical components and systems, knowledge of part orientation is crucial to proper instrument performance. This paper outlines an algorithm which uses the normally ignored carrier signal in Fourier analysis to compute an absolute tilt (orientation) of the test surface. We also provide a brief outline of how this technique, incorporated in a rotating Twyman-Green interferometer, can be used in alignment and metrology of optical systems.

Beschreibung: Total ozone data from the Total Ozone Mapping Spectrometer (TOMS) and profile/total ozone data from the Solar Backscatter Ultraviolet (SBUV; SBW/2) series of instruments have recently been reprocessed using new retrieval algorithms (referred to as Version 8 for both) and updated calibrations. In this paper, we incorporate the Version 8 data into a TOMS/SBW merged total ozone data set and an S B W merged profile ozone data set. The Total Merged Ozone Data (Total MOD) combines data from multiple TOMS and SBW instruments to form an internally consistent global data set with virtually complete time coverage from October 1978 through December 2003. Calibration differences between instruments are accounted for using external adjustments based on instrument intercomparisons during overlap periods. Previous results showed errors due to aerosol loading and sea glint are significantly reduced in the V8 TOMS retrievals. Using SBW as a transfer standard, calibration differences between V8 Nimbus 7 and Earth Probe TOMS data are approx. 1.3%, suggesting small errors in calibration remain. We will present updated total ozone long-term trends based on the Version 8 data. The Profile Merged Ozone Data (Profile MOD) data set is constructed using data from the SBUV series of instruments. In previous versions, SAGE data were used to establish the long-term external calibration of the combined data set. The SBW Version 8 we assess the V8 profile data through comparisons with SAGE and between SBW instruments in overlap periods. We then construct a consistently-calibrated long term time series. Updated zonal mean trends as a function of altitude and season from the new profile data set will be shown, and uncertainties in determining the best long-term calibration will be discussed.

Beschreibung: The Planetary Geology and Geophysics tasks under this grant have concentrated on the development and testing of tools for remote compositional analyses for the Moon and other airless bodies (especially asteroids). The grant has supported the PI and her students. Detailed analyses of space-weathering analogs were undertaken. Lunar research included development of models for regolith evolution and redistribution of materials across the Moon, with particular emphasis on the interior of South Pole-Aitken Basin. Lunar compositional analyses identified general rock types using Clementine data and mapped their distribution globally and locally based on the type of mafic mineralogy present (or lack thereof). Progress in these areas has been extensively discussed in the literature and in proposals submitted to the PGG program in 2003 and 2004.

Beschreibung: NASA Langley Research Center provided support to the Infrared Development and Thermal Testing Laboratory (IDTTL) to enhance its capabilities with new instrumentation and offer new professional activities. The IDTTL offers an undergraduate research environment that focuses on precision noncontact measurement techniques. The IDTTL supports senior project activities and both funded and non-funded projects that enhance the educational mission of the Department of Integrated Science and Technology. During the term of this support fifteen students benefited directly, several of these students participated in an international conference and were published in conference proceedings. The IDTTL was also successful in proposals to NASA for further support and to NSF for new instrumentation and imaging equipment.

Beschreibung: Knowledge of the spatial and temporal distribution of atmospheric species such as CO2, O3, H2O, and CH4 is important for understanding the chemistry and physical cycles involving Earth s atmosphere. Although several remote sensing techniques are suitable for such measurements they are considered high cost techniques involving complicated instrumentation. Therefore, simultaneous measurement of atmospheric species using a single remote sensing instrument is significant for minimizing cost, size and complexity. While maintaining the instrument sensitivity and range, quality of multicolor detector, in terms of high quantum efficiency and low noise are vital for these missions. As the first step for developing multicolor focal plan array, the structure of a single element multicolor detector is presented in this paper. The detector consists of three p-n junction layers of Si, GaSb and InAs wafer bonded to cover the spectral range UV to 900 nm, 800 nm to 1.7 m, and 1.5 m to 3.4 m, respectively. Modeling of the absorption coefficient for each material was carried out for optimizing the layers thicknesses for maximum absorption. The resulted quantum efficiency of each layer has been determined except InAs layer. The optical and electrical characterization of each layer structure is reported including dark current and spectral response measurements of Si pin structure and of GaSb and InAs p-n junctions. The effect of the material processing is discussed.

Beschreibung: As part of the NASA project, we are investigating the formation, properties, and performance of QD heterostructures, to be incorporated into a novel biomedical device for detecting bacteria and/or viruses in fluids on board space vehicles. We are presently synthesizing the epitaxial quantum dot structures using molecular beam epitaxy. We recently developed a method for controlling the arrangement of QDs, based upon a combination of buffer layer growth and controlled annealing sequences. This method is promising for producing arrangements of QDs with a locally well-controlled distribution of sizes. In the future, we plan to explore selective pre-patterning of the starting surface using focused ion-beam nanopatterning, which will enable us to precisely tune the compositions, sizes, and placement of the QDs, in order laterally tune the emission and detection wavelengths of QD based devices.

Beschreibung: As the benefit-to-cost ratio of advanced optical techniques for wind tunnel measurements such as Video Model Deformation (VMD), Pressure-Sensitive Paint (PSP), and others increases, these techniques are being used more and more often in large-scale production type facilities. Further benefits might be achieved if multiple optical techniques could be deployed in a wind tunnel test simultaneously. The present study discusses the problems and benefits of combining VMD and PSP systems. The desirable attributes of useful optical techniques for wind tunnels, including the ability to accommodate the myriad optical techniques available today, are discussed. The VMD and PSP techniques are briefly reviewed. Commonalties and differences between the two techniques are discussed. Recent wind tunnel experiences and problems when combining PSP and VMD are presented, as are suggestions for future developments in combined PSP and deformation measurements.

Beschreibung: The relative humidity of the atmosphere in the encasements containing the U.S. Constitution Pages 1 and 4, the Declaration of Independence, and the Bill of Rights was measured to be in the range of 55% to 61%. This value is significantly higher than the presumed relative humidity between 25 to 35 %, but is consistent with the measured samples extracted from Pages 2 and 3 of the U.S. Constitution. The cooling/condensation measurement technique used at NARA on July 23, 2001, and described in this paper to measure the water vapor content of the atmosphere in the hermetically sealed encasements containing the U. S. Constitution, the Declaration of Independence, and the Bill of Rights, proved to be a powerful new measurement technique. The cooling/condensation technique developed at NASA LaRC and utilized at NARA has important applications in the non-invasive measurement of relative humidity in the atmospheres of sealed encasements and could become a standard measurement technique in this type of analysis.

Beschreibung: A new method for generating photogrammetric targets by projecting an array of laser beams onto a membrane doped with fluorescent laser dye has recently been developed. In this paper we review this new fluorescence based technique, then proceed to show how it can be used for dynamic measurements, and how a short pulsed (10 ns) laser allows the measurement of vibration modes at frequencies several times the sampling frequency. In addition, we present experimental results showing the determination of fundamental and harmonic vibration modes of a drum style dye-doped polymer membrane tautly mounted on a 12-inch circular hoop and excited with 30 Hz and 62 Hz sinusoidal acoustic waves. The projected laser dot pattern was generated by passing the beam from a pulsed Nd:YAG laser though a diffractive optical element, and the resulting fluorescence was imaged with three digital video cameras, all of which were synchronized with a pulse and delay generator. Although the video cameras are capable of 240 Hz frame rates, the laser s output was limited to 30 Hz and below. Consequently, aliasing techniques were used to allow the measurement of vibration modes up to 186 Hz with a Nyquist limit of less than 15 Hz.

Beschreibung: This viewgraph presentation describes a test simulate the transient effects of cosmic ray impacts on near infrared focal plane arrays. The objectives of the test are to: 1) Characterize proton single events as function of energy and angle of incidence; 2) Measure charge spread (crosstalk) to adjacent pixels; 3) Assess transient recovery time.

Beschreibung: Aerospace mechanism engineering success stories often, if not always, consist of overcoming developmental, test and flight anomalies. Many times it is these anomalies that stimulate technology growth and more reliable future systems. However, one must learn from these to achieve an ultimately successful mission. It is not often that a spacecraft engineer is able to inspect hardware that has flown in orbit for several years. However, in February 1997, the Fine Guidance Sensor-I (FGS-1) was removed from the Hubble Space Telescope (HST) and returned to NASA Goddard Space Flight Center (GSFC) during the second Servicing Mission (SM2). At the time of removal, FGS-1 had nearly 7 years of service and the bearings in the Star Selector Servos (SSS) had accumulated approximately 25 million Coarse Track (CT) cycles. The main reason for its replacement was due to a bearing torque anomaly leading to stalling of the B Star Selector Servo (SSS-B) when reversing direction during a vehicle offset maneuver, referred to herein as a Reversal Bump (RB). The returned HST FGS SSS bearings were disassembled for post-service condition assessment to better understand the actual cause of the torque spikes, identify potential process/design improvements, and provide information for remedial on-orbit operation modifications. The methods and technology utilized for this inspection are not unique to this system and can be adapted to most investigation ai varying stages of the mechanism life from development, through testing, io post night evaluation. The systematic methods used for the HST Fine Guidance Sensor (FGS) SSS and specific findings are the subjects presented in this paper. The lessons learned include the importance of cleanliness and handling for precision instrument bearings and the potential effects from contamination. The paper describes in detail, the analytical techniques used for the SSS and their importance in this investigation. Inspection analytical data and photographs are included throughout the paper.

Beschreibung: The design of the 532 and 1064nm wavelength atmosphere lidar channels of the Geoscience Laser Altimeter System on the ICESat spacecraft is described. The lidar channel performance per on orbit measurements data will be presented.

Beschreibung: We are in the third and final year of our IIP funding to develop a sensor for very precise determination of the CO2 Column. Global measurements of this sort from a satellite platform are needed to improve our understanding of the global carbon budget. In previous reports to this meeting we have described the method by which this system operates and presented data taken during ground based tests of the instrument. Work in the final year has concentrated on building the flight hardened version of the instrument that will be used in our field trials on the Dryden DC-8. The flight unit represents an integration of three channels into a single instrument. These three channels are the CO2 channel, the oxygen pressure sensing channel, and the oxygen temperature sensing channel. Integration of the three channels into a single unit significantly decreases the size of the instrument. The flight unit also employs more rugged optical mounts and integrated optical shielding. Light enters the instrument from below first striking the right angled mirror shown extending over the edge of the platform. The light is then focused through a pinhole to define the instrument field of view, chopped and recollimated. Dichroic mirrors are used to separate the CO2 wavelength from the O2 wavelength and that light is further divided by a 50-50 beamsplitter between the 2 oxygen channels - the pressure channel and the temperature channel. The six white boxes contain the detectors for each of the three channels. The detectors on the left in the photo serve the reference channels and the detectors on the right are for the Fabry-Perots. CO2 is measured by the pair of detectors farthest from the viewer. Pressure via O2 is detected by the central pair of detectors. The closest pair is used to determine temperature via O2.

Beschreibung: The Hazardous Gas Detection Lab (HGDL) at Kennedy Space Center is involved in the design and development of instrumentation that can detect and quantify various hazardous gases. Traditionally these systems are designed for leak detection of the cryogenic gases used for the propulsion of the Shuttle and other vehicles. Mass spectrometers are the basis of these systems, which provide excellent quantitation, sensitivity, selectivity, response times and detection limits. A Table lists common gases monitored for aerospace applications. The first five gases, hydrogen, helium, nitrogen, oxygen, and argon are historically the focus of the HGDL.

Beschreibung: Several types of sensors have been developed over the past few years that quantify the vapor concentrations of the hydrazines. These sensor s are able to detect concentrations as low as 10 parts per billion (ppb) up to several parts per million (ppm). The scope of this review wi ll be focused on those sensors that are most current in the marketpla ce as either leak detectors or personnel monitors. Some technical information on the theory of operations of each hydrazine detector will a lso be included. The review will highlight current operations that utilize hydrazine sensors including the Kennedy Space Center (KSC), the United States Air Force (USAF) at Cape Canaveral Air Station (CCAS), USAF F-16 facilities. The orientation of the review will be towards giving users usable practical information on hydrazine sensors.

Beschreibung: No abstract available

Beschreibung: A batch of experimental diffusion-cooled hot-electron bolometers (HEBs), suitable for use as mixers having input frequencies in the terahertz range and output frequencies up to about a gigahertz, exploit the superconducting/normal-conducting transition in a thin strip of tantalum. The design and operation of these HEB mixers are based on mostly the same principles as those of a prior HEB mixer that exploited the superconducting/normal- conducting transition in a thin strip of niobium and that was described elsewhere.

Beschreibung: An apparatus for measuring the rate of flow and the mass density of a liquid or slurry includes a special section of pipe instrumented with microwave and sonic sensors, and a computer that processes digitized readings taken by the sensors. The apparatus was conceived specifically for monitoring a flow of oil-well-drilling mud, but the basic principles of its design and operation are also applicable to monitoring flows of other liquids and slurries.

Beschreibung: As RGS Integrated Product Team Lead, normal coordination and management efforts in the past year have involved setting and overseeing budgets and schedules, regular status reporting to the Program Manager at Goddard Space Flight Center (GSFC), interacting with Constellation-X groups at GSFC, Smithsonian Astrophysical Observatory (SAO), and RGS team institutions, and supporting the program needs of Constellation-X. In addition to the management aspects described above, there are four significant areas of direct contribution that were accomplished.

Beschreibung: List of publications for final perfomance report are: Detectors for the JWST Near-Infrared Spectrometer Rauscher, B.J., Strada, P., Regan, M.W., Figer, D.F., Jakobsen, P., Moseley, H.S., & Boeker, T. 2004, SPIE Detectors for the JWST Near-Infrared Spectrometer Rauscher, B.J., Strada, P., Regan, M.W., Figer, D.F., Jakobsen, P., Moseley, H.S., & Boeker, T. 2004, AAS, 203, 124.07 Independent Testing of JWST Detector Prototypes Figer, D.F., Rauscher, B. J., Regan, M. W., Morse, E., Balleza, J., Bergeron, L., & Stockman, H. S. 2003 , SPIE, 5 167 The Independent Detector Testing Laboratory and the NGST Detector Program Figer, D.F., Agronin, M., Balleza, J., Barkhouser, R., Bergeron, L., Greene, G. R., McCandliss, S. R., Rauscher, B. J., Reeves, T., Regan, M. W., Sharma, U., Stockman, H. S. 2003, SPIE, 4850,981 Intra-Pixel Sensitivity in NIR Detectors for NGST Sharma, U., Figer, D.F., Sivaramakrishnan, A., Agronin, M., Balleza, J., Barkhouser, R., Bergeron, L., Greene, G. R., McCandliss, S. R., Rauscher, B. J., Reeves, T., Regan, M. W., Stockman, H. S. 2003, SPIE, 4850,1001 NIRCAM Image Simulations for NGST Wavefiont SensinglPS A. Sivaramakrishnan, D. Figer, H. Bushouse, H. S. Stockman (STScI),C. Ohara , D. Redding (JPL), M. Im (IPAC), & J. Offenberg (Raytheon) 2003, SPIE, 4850,388 Ultra-Low Background Operation of Near-Infrared Detectors for NGS Rauscher, B. J., Figer, D. F., Agronin, M., Balleza, J., Barkhouser, R., Bergeron, L., Greene, G. R., McCandliss, S. R., Reeves, T., Regan, M. W., Sharma, U., Stockman, H. S. 2003, SPIE, 4850,962 The Independent Detector Testing Laboratory and the JWST Detector Program Figer, D.F. et a1.2003, AAS201, #131.05

Beschreibung: The current X-ray systems used by airport security personnel for the detection of contraband, and objects such as knives and guns that can impact the security of a flight, have limited effect because of the limited display quality of the X-ray images. Since the displayed images do not possess optimal contrast and sharpness, it is possible for the security personnel to miss potentially hazardous objects. This problem is also common to other disciplines such as medical X-rays, and can be mitigated, to a large extent, by the use of state-of-the-art image processing techniques to enhance the contrast and sharpness of the displayed image. The NASA Langley Research Centers Visual Information Processing Group has developed an image enhancement technology that has direct applications to this problem of inadequate display quality. Airport security X-ray imaging systems would benefit considerably by using this novel technology, making the task of the personnel who have to interpret the X-ray images considerably easier, faster, and more reliable. This improvement would translate into more accurate screening as well as minimizing the screening time delays to airline passengers. This technology, Retinex, has been optimized for consumer applications but has been applied to medical X-rays on a very preliminary basis. The resultant technology could be incorporated into a new breed of commercial x-ray imaging systems which would be transparent to the screener yet allow them to see subtle detail much more easily, reducing the amount of time needed for screening while greatly increasing the effectiveness of contraband detection and thus public safety.

Beschreibung: Classical segmentation algorithms subdivide an image into its constituent components based upon some metric that defines commonality between pixels. Often, these metrics incorporate some measure of "activity" in the scene, e.g. the amount of detail that is in a region. The Multiscale Retinex with Color Restoration (MSRCR) is a general purpose, non-linear image enhancement algorithm that significantly affects the brightness, contrast and sharpness within an image. In this paper, we will analyze the impact the MSRCR has on segmentation results and performance.

Beschreibung: Satellite remote sensing plays a major role in measuring the optical and radiative properties, environmental impact, and spatial and temporal distribution of tropospheric aerosols. In this paper, we envision a new generation of spaceborne imager that integrates the unique strengths of multispectral, multiangle, and polarimetric approaches, thereby achieving better accuracies in aerosol optical depth and particle properties than can be achieved using any one method by itself. Design goals include spectral coverage from the near-UV to the shortwave infrared; global coverage within a few days; intensity and polarimetric imaging simultaneously at multiple view angles; kilometer to sub-kilometer spatial resolution; and measurement of the degree of linear polarization for a subset of the spectral complement with an uncertainty of 0.5% or less. The latter requirement is technically the most challenging. In particular, an approach for dealing with inter-detector gain variations is essential to avoid false polarization signals. We propose using rapid modulation of the input polarization state to overcome this problem, using a high-speed variable retarder in the camera design. Technologies for rapid retardance modulation include mechanically rotating retarders, liquid crystals, and photoelastic modulators (PEMs). We conclude that the latter are the most suitable.

Beschreibung: An image sensor operable to vary the output spatial resolution according to a received light level while maintaining a desired signal-to-noise ratio. Signals from neighboring pixels in a pixel patch with an adjustable size are added to increase both the image brightness and signal-to-noise ratio. One embodiment comprises a sensor array for receiving input signals, a frame memory array for temporarily storing a full frame, and an array of self-calibration column integrators for uniform column-parallel signal summation. The column integrators are capable of substantially canceling fixed pattern noise.

Beschreibung: A micro electromechanical system (MEMS) broad band incandescent light source includes three layers: a top transmission window layer; a middle filament mount layer; and a bottom reflector layer. A tungsten filament with a spiral geometry is positioned over a hole in the middle layer. A portion of the broad band light from the heated filament is reflective off the bottom layer. Light from the filament and the reflected light of the filament are transmitted through the transmission window. The light source may operate at temperatures of 2500 K or above. The light source may be incorporated into an on board calibrator (OBC) for a spectrometer.

Beschreibung: This presentation addresses synthesis imaging with the Space Interferometry Mission (SIM), and its likely future applications. These applications include imaging of crowded fields such as the cores of globular clusters and galaxy clusters. It may be possible to use image restoration in processing data from the SIM's interferometers.

Beschreibung: Independent Earth orientation measurements taken by the space-geodetic techniques of lunar and satellite laser ranging, very long baseline interferometry, and the global positioning system have been combined using a Kalman filter. The resulting combined Earth orientation series, SPACE2003, consists of values and uncertainties for Universal Time, polar motion, and their rates that span from September 28.0, 1976 to January 31.0, 2004 at daily intervals and is available in versions whose epochs are given at either midnight or noon. The space-geodetic measurements used to generate SPACE2003 have then been combined with optical astrometric measurements to form two additional combined Earth orientation series: (1) COMB2003, consisting of values and uncertainties for Universal Time, polar motion, and their rates that span from January 20.0, 1962 to January 31.0, 2004 at daily intervals and which is also available in versions whose epochs are given at either midnight or noon, and (2) POLE2003, consisting of values and uncertainties for polar motion and its rate that span from January 20, 1900 to January 21,2004 at 30.4375-day intervals.

Beschreibung: We describe the technique of wide field mosaic imaging for optical/IR interferometers and present early experimental results from a laboratory instrument designed to validate, experiment with, and refine the technique. A conventional single-detector stellar interferometer operating with narrow bandwidth at center wavelength lambda is limited in its field of view to the primary beam of the individual telescope apertures, or approx. lambda/D(sub tel) radians, where is the telescope diameter. Such a field is too small for many applications; often one wishes to image extended sources. We are developing and testing a technique analogous to the mosaic method employed in millimeter and radio astronomy, but applicable to optical/IR Michelson interferometers, in which beam combination is done in the pupil plane. An N(sub pix) x N(sub pix) detector array placed in the image plane of the interferometer is used to record simultaneously the fringe patterns from many contiguous telescope fields, effectively multiplying the field size by N(sub pix)/2, where the factor 2 allows for Nyquist sampling. This mosaic imaging technique will be especially valuable for far IR and submillimeter interferometric space observatories such as the Space Infrared Interferometric Telescope (SPIRIT) and the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS). SPIRIT and SPECS will be designed to provide sensitive, high angular resolution observations of fields several arcminutes in diameter, and views of the universe complementary to those provided by HST, NGST, and ALMA.

Beschreibung: The Autonomous Sciencecraft Experiment (ASE) is a JPL-led, New Millennium Program mission containing new technology in the form of software to be flown on the Earth Observer-1 (EO-1) satellite in early 2004. This new technology will facilitate an artificially intelligent machine with autonomous science-driven capabilities. Among the ASE flight software is a set of onboard science algorithms designed for autonomous data processing, primarily based on change detection from observation to observation. Using the output from these algorithms, ASE has the ability to autonomously modify the EO-1 observation plan, retargeting itself for a more in-depth observation of a scientific event in progress. Furthermore, intelligent and selective information down-linking will maximize return of the most valuable scientific data. Among the algorithms developed for use on ASE is a Lava-Vegetation (L-V) detection algorithm. This algorithm can effectively identify the initial location and extent of lava and vegetation coverage based on spectral shape. Comparison of several different observations, all classified via this algorithm, can make change detection possible.

Beschreibung: The objective of this project is to support the INTEX aircraft mission by developing experience in the integrated analysis of existing sub-orbital observations and satellite observations with numerical models. Specific tasks include providing guidance to INTEX by identifying discrepancies in satellite observations with (1) in situ measurements, (2) bottom-up emission inventories of nitrogen oxides and volatile organic compounds, and (3) model calculations of the export of pollution from North America to the global atmosphere. An important focus area is developing and improving bottom-up emission inventories by combining top-down and bottom-up information.

Beschreibung: The goal of the Study of High Performance Coronagraphic Techniques project (called CoronaTech) is: 1) to verify the Labeyrie multi-step speckle reduction method and 2) to develop new techniques to manufacture soft-edge occulter masks preferably with Gaussian absorption profile. In a coronagraph, the light from a bright host star which is centered on the optical axis in the image plane is blocked by an occulter centered on the optical axis while the light from a planet passes the occulter (the planet has a certain minimal distance from the optical axis). Unfortunately, stray light originating in the telescope and subsequent optical elements is not completely blocked causing a so-called speckle pattern in the image plane of the coronagraph limiting the sensitivity of the system. The sensitivity can be increased significantly by reducing the amount of speckle light. The Labeyrie multi-step speckle reduction method implements one (or more) phase correction steps to suppress the unwanted speckle light. In each step, the stray light is rephased and then blocked with an additional occulter which affects the planet light (or other companion) only slightly. Since the suppression is still not complete, a series of steps is required in order to achieve significant suppression. The second part of the project is the development of soft-edge occulters. Simulations have shown that soft-edge occulters show better performance in coronagraphs than hard-edge occulters. In order to utilize the performance gain of soft-edge occulters. fabrication methods have to be developed to manufacture these occulters according to the specification set forth by the sensitivity requirements of the coronagraph.

Beschreibung: Wind gusts are the main disturbances that depreciate tracking precision of microwave antennas and radiotelescopes. The linear-quadratic-Gaussian (LQG) controllers - as compared with the proportional-and-integral (PI) controllers significantly improve the tracking precision in wind disturbances. However, their properties have not been satisfactorily understood; consequently, their tuning is a trial-and-error process. A control engineer has two tools to tune an LQG controller: the choice of coordinate system of the controller model and the selection of weights of the LQG performance index. This article analyzes properties of an open- and closed-loop antenna. It shows that the proper choice of coordinates of the open-loop model simplifies the shaping of the closed-loop performance. The closed-loop properties are influenced by the LQG weights. The article shows the impact of the weights on the antenna closed-loop bandwidth, disturbance rejection properties, and antenna acceleration. The bandwidth and the disturbance rejection characterize the antenna performance, while the acceleration represents the performance limit set by the antenna hardware (motors). The article presents the controller tuning procedure, based on the coordinate selection and the weight properties. The procedure rationally shapes the closed-loop performance, as an alternative to the trial-and-error approach.

Beschreibung: Optoelectronic pattern-recognition systems (optical encoders) for measuring positions of objects of interest at temperatures well below or well above room temperature are undergoing development. At present, the development effort is concentrated on absolute linear, rotary, and Cartesian encoders and Cartesian autocollimators for scientific instruments that operate in cryostats.

Beschreibung: Infrared (IR) detectors characterized by a combination of (1) high-quantum-efficiency photoexcitation of inter-valence-subband transitions of charge carriers and (2) high-mobility conduction- band transport of the thus-excited charge carriers have been proposed in an effort to develop focal-plane arrays of such devices for infrared imaging. Like many prior quantum-well infrared photodetectors (QWIPs), the proposed devices would be made from semiconductor heterostructures. In order to obtain the combination of characteristics mentioned above, the proposed devices would be designed and fabricated in novel InAs/GaSb superlattice configurations that would exploit a phenomenon known in the semiconductor art as type-II broken-gap band offset.

Beschreibung: A figure depicts an apparatus that simultaneously records magnified ordinary top-view video images and laser shadowgraph video images of a sessile drop on a flat, horizontal substrate that can be opaque or translucent and is at least partially specularly reflective. The diameter, contact angle, and rate of evaporation of the drop as functions of time can be calculated from the apparent diameters of the drop in sequences of the images acquired at known time intervals, and the shadowgrams that contain flow patterns indicative of thermocapillary convection (if any) within the drop. These time-dependent parameters and flow patterns are important for understanding the physical processes involved in the spreading and evaporation of drops. The apparatus includes a source of white light and a laser (both omitted from the figure), which are used to form the ordinary image and the shadowgram, respectively. Charge-coupled-device (CCD) camera 1 (with zoom) acquires the ordinary video images, while CCD camera 2 acquires the shadowgrams. With respect to the portion of laser light specularly reflected from the substrate, the drop acts as a plano-convex lens, focusing the laser beam to a shadowgram on the projection screen in front of CCD camera 2. The equations for calculating the diameter, contact angle, and rate of evaporation of the drop are readily derived on the basis of Snell s law of refraction and the geometry of the optics.

Beschreibung: A cylindrical-punch indentation technique has been developed as a means of measuring the nonlinear elastic responses of materials -- more specifically, for measuring the moduli of elasticity of materials in cases in which these moduli vary with applied loads. This technique offers no advantage for characterizing materials that exhibit purely linear elastic responses (constant moduli of elasticity, independent of applied loads). However, the technique offers a significant advantage for characterizing such important materials as plasma-sprayed thermal-barrier coatings, which, in cyclic loading, exhibit nonlinear elasticity with hysteresis related to compaction and sliding within their microstructures.

Beschreibung: ACS was launched aboard the Space Shuttle Columbia just before dawn on March 1, 2002. At the time of liftoff, the Hubble Space Telescope (HST) was reflecting the early morning sun as it moved across the sky. After successfully docking with HST, several components were replaced. One of the components was the Advanced Camera for Surveys built by Ball Aerospace & Technologies Corp. (BATC) in Boulder, Colorado. Over the life of the HST contract at BATC, hundreds of employees had the pleasure of working on the concept, design, fabrication, assembly, and test of ACS. Those employees thank NASA - Goddard Space Flight Center and the science team at Johns Hopkins University (JHU) for the opportunity to participate in building a great science instrument for HST.

Beschreibung: The concept of a Comprehensive 2-Dimensional Gas Chromatography coupled with Time-of-Flight Mass Spectrometry (GCxGC-TOWS) for the analysis of organic compounds has been proven with commercially available instrumentation (LECO Corp). The performance of a GCxGC instrument has been characterized in various stages using two independent breadboard systems. The GCxGC separation systems, including the thermal modulator, have been miniaturized to the size of a benchtop configuration. One breadboard system employs a Flame Ionization Detector (FID), whereas the second breadboard system employs a Time-of-Fight mass spectrometer (TOFWS) as a detection system.

Beschreibung: In nine flights between 1993 and 2002, the Balloon Borne Experiment with a Superconducting Spectrometer (BESS) has measured the energy spectrum of cosmic-ray antiprotons between 0.18 and 4.20 GeV, and the spectra of protons and helium to several hundred GeV. BESS has also placed stringent upper limits on the existence of antihelium and antiduterons. Above about 1 GeV, models in which antiprotons are secondary products of the interactions of primary cosmic rays with the ISM agree with the BESS spectrum. Below 1 GeV, BESS data suggest the presence of an additional source of antiprotons. The antiproton/proton ratios measured between 1993 and 1999, during the Sun's positive-polarity phase, are consistent with simple models of solar modulation. Results from the 2000 flight, following the solar magnetic field reversal, show a sudden increase in the antiproton/proton ratio and tend to favor a charge-sign-dependent drift model. To extend BESS measurements to lower energies, a new instrument, BESS-Polar, is under construction for a flight from Antarctica in 2004.

Beschreibung: Laser anemometry was used to make two independent measurements of the flow velocity by capturing individual Doppler signals with high-speed digitizing boards. The two independent measurements were cross-correlated to reduce the contribution of photo detector shot noise on the frequency determination and subsequently on the turbulence estimate. In addition, criteria were developed to eliminate "bad" Doppler bursts from the data set, which then allowed reasonable low turbulence estimates to be made. The laser anemometer measurements were obtained at the inlet of an annular cascade and at the exit of a flow calibration nozzle and were compared with hot-wire data.

Beschreibung: The desire to revolutionize the aircraft design cycle from its currently lethargic pace to a fast turn-around operation enabling the optimization of non-traditional configurations is a critical challenge facing the aeronautics industry. In response, a large scale effort is underway to not only advance the state of the art in wind tunnel testing, computational modeling, and information technology, but to unify these often disparate elements into a cohesive design resource. This paper will address Seamless Data Transfer, the critical central nervous system that will enable a wide variety of varied components to work together.

Beschreibung: The quality of data acquired in a given test facility ultimately resides within the fidelity and implementation of the instrumentation systems. Over the last decade, the emergence of robust optical techniques has vastly expanded the envelope of measurement possibilities. At the same time the capabilities for data processing, data archiving and data visualization required to extract the highest level of knowledge from these global, on and off body measurement techniques have equally expanded. Yet today, while the instrumentation has matured to the production stage, an optimized solution for gaining knowledge from the gigabytes of data acquired per test (or even per test point) is lacking. A technological void has to be filled in order to possess a mechanism for near-real time knowledge extraction during wind tunnel experiments. Under these auspices, the Virtual Diagnostics Interface, or ViDI, was developed.

Beschreibung: Preparation and performance of a water-based pressure sensitive paint (PSP) is described. A water emulsion of an oxygen permeable polymer and a platinum porphyrin type luminescent compound were dispersed in a water matrix to produce a PSP that performs well without the use of volatile, toxic solvents. The primary advantages of this PSP are reduced contamination of wind tunnels in which it is used, lower health risk to its users, and easier cleanup and disposal. This also represents a cost reduction by eliminating the need for elaborate ventilation and user protection during application. The water-based PSP described has all the characteristics associated with water-based paints (low toxicity, very low volatile organic chemicals, and easy water cleanup) but also has high performance as a global pressure sensor for PSP measurements in wind tunnels. The use of a water-based PSP virtually eliminates the toxic fumes associated with the application of PSPs to a model in wind tunnels.

Beschreibung: Spectroscopic data acquired in the laboratory provide the interpretive foundation upon which compositional information about unexplored or unsampled planetary surfaces is derived from remotely obtained reflectance spectra. The RELAB is supported by NASA as a multi-user spectroscopy facility, and laboratory time can be made available at no charge to investigators who are in funded NASA programs. RELAB has two operational spectrometers available to NASA scientists: 1) a near- ultraviolet, visible, and near-infrared bidirectional spectrometer and 2) a near- and mid- infrared FT-IR spectrometer. The overall purpose of the design and operation of the RELAB bidirectional spectrometer is to obtain high precision, high spectral resolution, bidirectional reflectance spectra of earth and planetary materials. One of the key elements of its design is the ability to measure samples using viewing geometries specified by the user. This allows investigators to simulate, under laboratory conditions, reflectance spectra obtained remotely (i.e., with spaceborne, telescopic, and airborne systems) as well as to investigate geometry dependent reflectance properties of geologic materials. The Nicolet 740 FT-IR spectrometer currently operates in reflectance mode from 0.9 to 25 Fm. Use and scheduling of the RELAB is monitored by a 4-member advisory committee. NASA investigators should direct inquiries to the Science Manager or RELAB Operator.

Beschreibung: A method and system for processing an image including capturing an image and storing the image as image pixel data. Each image pixel datum is stored in a respective memory location having a corresponding address. Threshold pixel data is selected from the image pixel data and linear spot segments are identified from the threshold pixel data selected.. Ihe positions of only a first pixel and a last pixel for each linear segment are saved. Movement of one or more objects are tracked by comparing the positions of fust and last pixels of a linear segment present in the captured image with respective first and last pixel positions in subsequent captured images. Alternatively, additional data for each linear data segment is saved such as sum of pixels and the weighted sum of pixels i.e., each threshold pixel value is multiplied by that pixel's x-location).

Beschreibung: Characteristics of albedo, or backscatter current, providing a 'background' for calorimeter experiments in high energy cosmic rays are analyzed. The comparison of experimental data obtained in the flights of the ATIC spectrometer is made with simulations performed using the GEANT 3.21 code. The influence of the backscatter on charge resolution in the ATIC experiment is discussed.

Beschreibung: An optical detector system includes an electrically resistive screen that is substantially transparent to radiation energy having a wavelength of interest. An electron transfer element (e.g., a low work function photoactive material or a carbon nanotube (CNT)-based element) has a first end and a second end with its first end spaced apart from the screen by an evacuated gap. When radiation energy passes through the screen with a bias voltage being applied thereto, transfer of electrons through the electron transfer element is induced from its first to its second end such that a quantity indicative of the electrons transferred can be detected.

Beschreibung: Method and system for processing light signals received by the eye of a human or other animal, where the eye may be compromised or non-functioning. Incident light is received at first and second pixels in a photodetector array and provides a pixel electrical signal representing the received light. Each of an array of carbon nanotube (CNT) towers is connected to a pixel, has a first tower end penetrating a retinal active layer of the animal and has a second tower end positioned to receive to receive and transport the pixel electrical signal to the retinal active layer. The CNT tower may be coated with a biologically active substance or chemically modified to promote neurite connections with the tower. The photoreceptor array can be provide with a signal altering mechanism that alters at least one of light intensity and wavelength intensity sensed by a first pixel relative to a second pixel, to correct for one or more selected eye problems.

Beschreibung: The present invention relates to a heterodyne interferometer system with a pre-processing of the target signal to isolate and remove self-interference signals using a known phase modulation of the carrier signal's frequency. Where self- interference signals do not include a time delay inherent in the target signal that travels to the target reflector, by selecting a modulation frequency tuned to the time delay and then filtering the resultant signal the target beam can be isolated and the self-interference signal can be effectively removed The system includes a modulation unit to apply a phase modulation to the carrier signal, and a mixing unit that demodulates the target signal at the modulation frequency to isolate the target beam.

Beschreibung: A rare earth optical temperature sensor is disclosed for measuring high temperatures. Optical temperature sensors exist that channel emissions from a sensor to a detector using a light pipe. The invention uses a rare earth emitter to transform the sensed thermal energy into a narrow band width optical signal that travels to a detector using a light pipe. An optical bandpass filter at the detector removes any noise signal outside of the band width of the signal from the emitter.

Beschreibung: A multi-element optical detector system includes an electrically resistive screen that is substantially transparent to radiation energy having a wavelength of interest. A plurality of electron transfer elements (e.g., a low work function photoactive material or a carbon nanotube (CNT)-based element) are provided with each having a first end and a second end. The first end of each element is spaced apart from the screen by an evacuated gap. When the radiation energy passes through the screen with a bias voltage applied thereto, transfer of electrons through each element is induced from the first end to the second end such that a quantity indicative of the electrons transferred through each element can be detected.

Beschreibung: Pt/4H-SiC Schottky photodiodes have been fabricated with the device areas up to 1 sq cm. The I-V characteristics and photo-response spectra have been measured and analyzed. For a 5 mm x 5 mm area device leakage current of 1 x 10(exp 15)A at zero bias and 1.2 x 10(exp 14)A at -IV have been established. The quantum efficiency is over 30% from 240nm to 320nm. The specific detectivity, D(sup *), has been calculated from the directly measured leakage current and quantum efficiency data and are shown to be higher than 10(exp 15) cmHz(sup 1/2)/W from 210nm to 350nm with a peak D(sup *) of 3.6 x 10(exp 15)cmH(sup 1/2)/W at 300nm.

Beschreibung: A concept of novel electrochemical in situ self-calibration technique for an oxygen microsensor has been proposed to devise a convenient calibration method without an externally coupled apparatus. Systemic investigations on the influences of various electrochemical (pH) and hydrodynamic (solution stirring) conditions on the proposed microsensor performances are presented. The results suggest that: 1) The calibrating microenvironments can be manipulated with carefully engineered sensor designs and optimized generating signals; 2) The external oxygen permeable membrane is needed to minimize the electrochemical and hydrodynamic interferences.

Beschreibung: In-situ identification of trace minerals, ices, or organics in planetary samples may be difficult with panchromatic microscopic imagery and spot spectroscopy. The panchromatic imagery acquired by a microscopic imager provides morphological information and albedo, but these are generally insufficient for unambiguous identification. The spatially-averaged spectra acquired by a nonimaging ( point- or spot- ) spectrometer may enable identification of the major components but identification of unknown trace components is difficult at best. With our Compact Micro-Imaging Spectrometer (CMIS), however, we acquire spectroscopic data in an imaging format at microscopic scales. The distinct spectra of individual grains, provided by our approach, make detection and identification possible even for trace components in regolith or heterogeneous samples.

Beschreibung: Accurate determination of the transverse properties of carbon fibers is important for assessment and prediction of local material as well as global structural response of composite components. However the measurements are extremely difficult due to the very small diameters of the fibers (few microns only) and must be conducted within a microscope. In this work, environmental scanning electron microscope (ESEM) and transmission electron microscope (TEM) are used to determine the transverse coefficient of thermal expansion of different carbon fibers as a function of temperature.

Beschreibung: An apparatus for determining elasticity characteristics of a thin-film layer. The apparatus comprises a sensor element having a base magnetostrictive element at least one surface of which is at least partially coated with the thin-film layer. The thin-film layer may be of a variety of materials (having a synthetic and/or bio-component) in a state or form capable of being deposited, manually or otherwise, on the base element surface, such as by way of eye-dropper, melting, dripping, brushing, sputtering, spraying, etching, evaporation, dip-coating, laminating, etc. Among suitable thin-film layers for the sensor element of the invention are fluent bio-substances, thin-film deposits used in manufacturing processes, polymeric coatings, paint, an adhesive, and so on. A receiver, preferably remotely located, is used to measure a plurality of values for magneto-elastic emission intensity of the sensor element in either characterization: (a) the measure of the plurality of values is used to identify a magneto-elastic resonant frequency value for the sensor element; and (b) the measure of the plurality of successive values is done at a preselected magneto-elastic frequency.

Beschreibung: KeyMaster Technologies, Inc., develops and markets specialized, hand-held X-ray fluorescence (XRF) instruments and unique tagging technology used to identify and authenticate materials or processes. NASA first met with this Kennewick, Washington-based company as the Agency began seeking companies to develop a hand-held instrument that would detect data matrix symbols on parts covered by paint and other coatings. Since the Federal Aviation Administration was also searching for methods to detect and eliminate the use of unapproved parts, it recommended that NASA and KeyMaster work together to develop a technology that would benefit both agencies.

Beschreibung: When it comes to real-time image processing, everyone is an expert. People begin processing images at birth and rapidly learn to control their responses through the real-time processing of the human visual system. The human eye captures an enormous amount of information in the form of light images. In order to keep the brain from becoming overloaded with all the data, portions of an image are processed at a higher resolution than others, such as a traffic light changing colors. changing colors. In the same manner, image processing products strive to extract the information stored in light in the most efficient way possible. Digital cameras available today capture millions of pixels worth of information from incident light. However, at frame rates more than a few per second, existing digital interfaces are overwhelmed. All the user can do is store several frames to memory until that memory is full and then subsequent information is lost. New technology pairs existing digital interface technology with an off-the-shelf complementary metal oxide semiconductor (CMOS) imager to provide more than 500 frames per second of specialty image processing. The result is a cost-effective detection system unlike any other.

Beschreibung: The Aerospace Mechanisms Symposium (AMS) provides a unique forum for those active in the design, production and use of aerospace mechanisms. A major focus is reporting problems and solutions associated with the development and flight certification of new mechanisms. Organized by the Mechanisms Education Association, NASA and Lockheed Martin Space Systems Company (LMSSC) share the responsibility for hosting the AMS. Now in its 37th symposium, the AMS continues to be well attended, attracting participants from both the U.S. and abroad. The 37th AMS, hosted by the Johnson Space Center (JSC) in Galveston, Texas, was held May 19, 20 and 21, 2004. During these three days, 34 papers were presented. Topics included deployment mechanisms, tribology, actuators, pointing and optical mechanisms, Space Station and Mars Rover mechanisms, release mechanisms, and test equipment. Hardware displays during the supplier exhibit gave attendees an opportunity to meet with developers of current and future mechanism components.

Beschreibung: An imaging device formed as a monolithic complementary metal oxide semiconductor integrated circuit in an industry standard complementary metal oxide semiconductor process, the integrated circuit including a focal plane array of pixel cells, each one of the cells including a photogate overlying the substrate for accumulating photo-generated charge in an underlying portion of the substrate, a readout circuit including at least an output field effect transistor formed in the substrate, and a charge coupled device section formed on the substrate adjacent the photogate having a sensing node connected to the output transistor and at least one charge coupled device stage for transferring charge from the underlying portion of the substrate to the sensing node.

Beschreibung: This experiment measured the reflectance of tarps with ground instruments in order to check radiometric calibration, validate atmospheric correction, and predict at-sensor radiance for satellite instruments. The procedure of this experiment is as follows: 1) Assemble laboratory apparatus to duplicate ground reference measurement geometry and satellite measurement geometry; 2) Measure spectral radiance with Optronics OL 750 double monochromator/spectroradiometer; 3) Measure radiance of NIST-calibrated Spectralon panel irradiated by collimated light at incidence angle of calibrated reflectance (20 deg, 30 deg, 40 deg, or 50 deg), viewing normal to panel surface; 4) Measure radiance of Spectralon panel irradiated at incidence angle equal to solar zenith angle at time of overpass; 5) Calculate reflectance of Spectralon panel irradiated at solar zenith angle, viewing normal to panel surface (ground geometry).

Beschreibung: A high temperature anemometer includes a pair of substrates. One of the substrates has a plurality of electrodes on a facing surface, while the other of the substrates has a sensor cavity on a facing surface. A sensor is received in the sensor cavity, wherein the sensor has a plurality of bondpads, and wherein the bondpads contact the plurality of electrodes when the facing surfaces are mated with one another. The anemometer further includes a plurality of plug-in pins, wherein the substrate with the cavity has a plurality of trenches with each one receiving a plurality of plug-in pins. The plurality of plug-in pins contact the plurality of electrodes when the substrates are mated with one another. The sensor cavity is at an end of one of the substrates such that the sensor partially extends from the substrate. The sensor and the substrates are preferably made of silicon carbide.

Beschreibung: The present invention is a method of processing a digital image that is initially represented by digital data indexed to represent position on a display. The digital data is indicative of an intensity value I(sub i)(x,y) for each position (x,y) in each i-th spectral band. A classification of the image based on its dynamic range is then defined in each of the image's S spectral bands. The intensity value for each position in each i-th spectral band is adjusted to generate an adjusted intensity value for each position in each i-th spectral band in accordance with SIGMA (sup n)(sub n=1) W(sub n)(log I (sub i)(x,y) - log[I(sub i)(x,y)*F(sub n)(x,y)]), i=1,...,S where W(sub n) is a weighting factor, "*" is the convolution operator and S is the total number of unique spectral bands. For each n, the function F(sub n)(x,y) is a unique surround function applied to each position (x,y) and N is the total number of unique surround functions. Each unique surround function is scaled to improve some aspect of the digital image, e.g., dynamic range compression, color constancy, and lightness rendition. The adjusted intensity value to each position in each i-th spectral band of the image is then filtered with a filter function that is based on the dynamic range classification of the image.

Beschreibung: An unexpected tragedy took place on April 28, 1988, when the roof of an Aloha Airlines 737 aircraft ripped open at 24,000 feet, killing a flight attendant and injuring eight people. The in-flight structural failure of Aloha Flight 243 s 19-year-old aircraft prompted NASA Langley Research Center to join with colleagues at the U.S. Federal Aviation Administration and the U.S. Air Force to initiate the Nation's first Aging Aircraft Research program. One of the program's essential goals was to develop reliable, predictive methods for assessing the residual strength of aging aerospace structures.