Family of constrained signal detectors for hyperspectral imagery

Generalized likelihood ratio tests (GLRTs) are derived for the problem of detecting targets in hyperspectral images. These detectors are derived under the assumptions that the signals from the materials in the image mix linearly and that the noise in the system is Gaussian. It is also assumed that the abundances of the signals from the various materials in a pixel must sum to one. This constraint models the fact that the material abundances in a pixel are just the fraction of the pixel that they occupy. Under these assumptions, detectors are derived which outperform the detectors derived without the sum-to-one constraint.     

Seasonal and diurnal behavior of NO2 column density in Antarctica as observed by Mark IV,Brewer Ozone Spectrophotometer Number 153

The Meteorology Department of India has been measuring vertical column density of NO₂ at Maitri (70.7°S, 11.7°E), Antarctica since July 1999 using a Mark IV, Brewer Ozone Spectrophotometer. Maitri is situated at the south of the Antarctic circle. An analysis of 6 years of data shows that NO₂ column has seasonal variation with a maximum value during summer. It is also found that during the period when sun does not set, the NO₂ column exhibits a diurnal variation, with a peak around noon and lower values in the morning and afternoon hours. Using a simple steady-state chemical reaction scheme, an attempt has been made to explain these features.     

Integration of waste processing and biomass production systems as part of the KSC Breadboard project.

After initial emphasis on large-scale baseline crop tests, the Kennedy Space Center (KSC) Breadboard project has begun to evaluate long-term operation of the biomass production system with increasing material closure. Our goal is to define the minimum biological processing necessary to make waste streams compatible with plant growth in hydroponic systems, thereby recycling nutrients into plant biomass and recovering water via atmospheric condensate. Initial small and intermediate-scale studies focused on the recycling of nutrients contained in inedible plant biomass. Studies conducted between 1989-1992 indicated that the majority of nutrients could be rapidly solubilized in water, but the direct use of this crop "leachate" was deleterious to plant growth due to the presence of soluble organic compounds. Subsequent studies at both the intermediate scale and in the large-scale Biomass Production Chamber (BPC) have indicated that aerobic microbiological processing of crop residue prior to incorporation into recirculating hydroponic solutions eliminated any phytotoxic effect, even when the majority of the plant nutrient demand was provided from recycled biomass during long term studies (i.e. up to 418 days). Current and future studies are focused on optimizing biological processing of both plant and human waste streams.     

ATC Beacon Interference Characteristics in the New York Area

An experimental program is described that had the objective of measuring the effects of the time-dependent structure of downlink (air craft to ground) interference generated by the Air Traffic Control Radar Beacon System (ATCRBS) in an active air traffic terminal area that are relevant to system and ground controller response time. The results of this program indicate a number of interesting details concerning the correlation of the level of the downlink interference with changes in the arrival and departure rates of aircraft at the local terminal sites.