Target Vs. Background Discrimination Using Multispectral Channel Data In 1.5 - 14.5 Micron

The spectral background radiance and the spectral transmittance are experimentally investi-gated in 1.5 - 14.5 micron band and compared to LOWTRAN V model calculations. We use a BARNES spectroradiometer with CVF covering continuously 1.5 - 14.5 micron and two AGA Thermovision 782 IR scanners with three discrete filters in 3 - 5 micron band and 8 -12 micron band. Spectral and spatial IR data are available on-line by means of two personal computers: an HP9836 that drives the spectroradiometer and elaborates the data as a function of wave-length and an IBM PC-AT that drives the scanners and elaborates the spatial data in order to obtain pictures (512x512 pixels)displayed on a H.R. monitor. Our final goal is to identify the most important parameters affecting the discrimination of targets from background (spectral band choice, temperature, emissivity, and so on). To this end we measure also the IR energy emitted by a reference plate at different values of temperature and emissivity vs. various background previously investigated. In particular targets that are close to ambient temperature are considered. Emissivity gets estimated in our lab by means of a dedicated experimental set-up. This study is connected with a Piaggio R&D program in the field of IR coating and chemical reduction of IR signature for aircraft application.