The Use of the LOWTRAN7 Atmospheric Transmittance and Radiance Computer Program for Detection System Design and Analysis
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
Pagination or Media Count:
The purpose of this study is to demonstrate how the LOWTRAN7 computer model can be used for detection system design and analysis. The LOWTRAN7 code is an atmospheric model that performs low resolution 20cm-1 bandwidth calculations to estimate atmospheric transmittance and radiance under a given set of conditions. Generic imaging and non-imaging systems are analyzed. A hypothetical figure-of-merit is evaluated for each type of system using the transmittance and radiance calculated by LOWTRAN7. The figure-of-merit calculated for the imaging system is contrast, the difference between the target and background input signals divided by the target input signal. The figure-of- merit evaluated for the non-imaging system is the change in signal CS, the difference between the input signal with the target in the field-of-view and the input signal without the target in the field-of-view divided by the input signal without the target in the field-of-view. Changing atmospheric, target, and background characteristics in LOWTRAN7 has different effects on the figures-of- merit. The characteristics tested are background emissivity, target temperature, boundary layer aerosols, atmospheric profiles, relative humidity, and absolute humidity. Two different sensor-target geometries using different paths are studies.
- Atmospheric Physics
- Atomic and Molecular Physics and Spectroscopy