Airborne FLIR (Forward Looking Infrared) Detection of Surface Targets
Abstract
An algorithm is presented for predicting the detection ranges of a surface target by an airborne Forward Looking Infrared system. The total infrared background radiance scene under cloud-free skies is modeled to include the atmospheric path emissions between the target and sensor and the effects of a wind-ruffled sea on the surface emissions and sky radiance reflections. A model is also introduced of the average temperature of a ship based upon the solar heating effects throughout a specified course, the ambient meteorological conditions, and the viewing angle. Together, these two models allow the range to be determined where the difference between the apparent ship's temperature (i.e. , the actual ship temperature degraded by the atmospheric transmittance) and the effective background temperature of the sea surface as viewed from the sensor altitude is equal to the minimum detectable temperature difference of the FLIR. A case study is presented to demonstrate the vulnerability of a frigate-class ship to detection by an airborne FLIR during a 5-hour period where the ship's course changed allowing solar heating of different sides of the ship. Study results show considerable increases in predicted detection ranges with altitude using the present algorithm over those based on a fixed temperature difference between the target and its background. Keywords: Surface targets; TDA(Tactical Decisions Aids); Thermal targets.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1989
- Accession Number
- ADA209250
Entities
People
- H. G. Hughes