Spectral data adds a new dimension to remote imaging of Earth

Major advances in detector technology and in the ability to process large amounts of spectrometer data have resulted in imaging spectrometers that allow scientists to see the condition of materials and to monitor processes

Method of Attaching Strain Gauges to Various Materials

A method is provided to bond strain gauges to various materials. First, a tape with an adhesive backing is placed across the inside of the fixture frame. The strain gauge is flatly placed against the adhesive backing and coated with a thin, uniform layer of adhesive. The tape is then removed from the fixture frame and placed, strain gauge side down, on the material to be tested. If the material is a high reluctance material, the induction heating source is placed on the tape. If the material is a low reluctance material, a plate with a ferric side and a rubber side is placed, ferric side down, onto the tape. The induction heating source is then placed upon the rubber side. If the material is an insulator material, a ferric plate is placed on the tape. The induction heating source is then placed on the ferric plate. The inductive heating source then generates frequenty from 60 to 70 kilocycles to inductively heat either low reluctance material, ferric side, of ferric plate and provides incidental pressure of approximately five pounds per square inch to the tape for two minutes, thoroughly curing the adhesive. The induction heating source, and, if necessary, the plate or ferric plate, are then removed from the tape after one minute. The tape is then removed from the bonded strain gauge

U.S. Imports, Exports, and Tariff Data, 1989-2001

This paper describes the updating of the NBER trade dataset, which now provides U.S. import and export values to the year 2001, disaggregated by Harmonized System (HS), Standard International Trade Classification (SITC), and the U.S. Standard Industrial Classification (SIC) categories. In addition, U.S. tariff data at the HS level have been added for the years 1989-2001. Earlier CD-ROMs distributed by the NBER described data on U.S. imports and exports from 1972-1994, and these values have been slightly modified for 1989-1994 and then updated to 2001. Together with the earlier data, there are now 30 years of disaggregate U.S. trade data available to researchers. These data, along with the tariff information for 1989-2001, are all available over the internet at www.nber.org/data/.

Toward a Greater Understanding of the Impact of Anger on Attitudes Toward War: A Consideration of Three Hypotheses

Previous research indicates that emotion is an important factor in shaping attitudes towards war. Specifically, studies have shown that the experience of anger leads to increased support for war. However, little is known about the mechanisms and boundary conditions of the anger-war attitudes effect. In this dissertation, I propose three potential mechanisms: time perspective, changes in risk perception and preference, and cognitive control. Results indicated risk perception and preference and cognitive control were not related to either anger or war attitudes. The consideration of future consequences: CFC) scale, used to measure time perspective, revealed only weak effects as a mediator. However, there was much stronger evidence of its role as a moderator. In particular, participants\u27 position along the CFC scale--their tendency to exhibit or not exhibit a focus on the future--did determine the nature of the relationship between anger and war attitudes. People who focused on the present became more pro-war as their anger increased. Therefore, focusing on present or future consequences appears to be an important factor in war opinion formation. Implications of these results and ideas for future research are discussed

Performance Comparison of Hyperspectral Target Detection Algorithms in Altitude Varying Scenes

Many different hyperspectral target detection algorithms have been developed and tested under various assumptions, methods, and data sets. This work examines the spectral angle mapper (SAM), adaptive coherence estimator (ACE), and constrained energy maximization (CEM) algorithms. Algorithm performance is examined over multiple images, targets, and backgrounds. Methods to examine algorithm performance are plentiful and several different metrics are used here. Quantitative metrics are used to make direct comparisons between algorithms. Further analysis using visual performance metrics is made to examine interesting trends in the data. Results show an increase in detection algorithm performance as image altitude increases and spatial information decreases. Theories to explain this phenomenon are introduced

Validation of Contrast and Phenomenology in the Digital Imaging and Remote Sensing (DIRS) Lab\u27s Image Generation (DIRSIG) Model

Comparison of the components and the overall fidelity of infrared synthetic image generation models with truth data and imagery is a crucial part of determining model validity and identifying areas in which improvements can be made. The Rochester Institute of Technology\u27s Digital Imaging and Remote Sensing Image Generation Model, DIRSIG, was validated in the midwave infrared (MWIR) and longwave infrared (LWIR) regions using measured meteorological, material, and radiometric data. Error propagation techniques clearly defmed areas where improvements to the model could be made (e.g. inclusion of clouds). An overall comparison of truth and synthetic images yields RMS errors of as low as 1.8°C for actual temperature, and 5°C (LWIR) and 6°C (MWIR) for apparent temperatures. Analysis of rank order correlation statistic shows a very high correlation between brightness rank for object in the truth and DIRSIG images for most times of day

Use of LOWTRAN-Derived Atmospheric Parameters in Synthetic Image Generation Models

The Digital Imaging and Remote Sensing laboratory\u27s Image Generation model, DIRSIG, combines computer aided design (CAD), ray tracing techniques, radiometric principles, and thermodynamic models to create synthetic imagery. The model emphasizes rigorous radiometric solutions that account for spectral reflectance effects, angular emissivities, atmospheric transmission and upwelled and downwelled sky radiance. This paper describes enhancements to the radiometric portion of the code that permits inclusion of variations with azimuth of downwelling sky radiance, solution of the radiometric propagation models using specific radiosonde data including adjustments for the time of day, and the incorporation of background effects from objects adjacent to the target. Simulated scenes are presented that show how these enhancements produce imagery that more closely match observed phenomena. In particular, the importance of properly modeled sky radiance is shown both for low altitude oblique imagery where the sky is directly observed and for near nadir imagery where reflected sky radiance is important

Solar and lunar radiometric calibration

The current generation of Earth-imaging satellites is used primarily to produce photographic quality images that are corrected for inherent non-uniformity in the focal plane (flat-fielding) and non-linearity in the sensor. The next generation of satellites requires the extraction of target reflectance with 1-2% uncertainty from these images. This requires the payload to be radiometrically calibrated to 1% uncertainty, or less. In order to achieve these levels of uncertainty, a radiometric standard is needed that is accessible from low Earth-orbit. Unfortunately, there is no such standard currently available. One common approach is to utilize man-made source standards that have calibration traceable to NIST (or other primary standards). Another method is to use detector-based standards (also traceable to NIST) and available uncalibrated sources. Unfortunately, these approaches suffer from degradation during exposure to the low Earth- orbit, which causes an unknown departure from the calibrated state (and increases the radiometric uncertainty of the standard)

Three-Dimensional Longwave Infrared Synthetic Image Generation Incorporating Angular Emissivity Effects Using Ray-Tracing Techniques

A technique for longwave infrared (LWIR) synthetic image generation (510) is shown which yields improved radiomeiric accuracy in the 8-14 .tm bandpass. This process uses a modified LOWTRAN 6 atmospheric transmission/upwelled radiance code and computer graphics ray-tracing techniques. A scene is created by placing faceted objects into world coordinates with rotation, translation, and scaling parameters. Each facet is assigned a material index and temperature. The material index points to optical properties for that material. The modified LOWTRAN 6 code incorporates sensor response function when computing tables of the atmospheric transmission and upwelled and downwelled radiances. A ray-traced image is then generated. A final synthetic LWIR scene is generated to geometrically match an actual acquired scene so that radiometric comparisons can be made