Visible through near-IR solar loading influences on characterization

The ability of sensors to discriminate objects in scenes depends on the scene composition and interactions with the available incident radiation. As sensors and camouflage techniques become more complex the nature of the energy interactions become more important to model accurately. Specific areas of interest are the influences of fluctuations in incident total solar loading radiation on terrain surfaces. The means used to produce 3D radiative calculations over the solar spectrum involves coupling the Air Force's Moderate-resolution Transmission (MODTRAN) code to the Army's 3D Atmospheric Illumination Module (AIM). The solar loading outputs calculated by these coupled codes are then used as input to the Army Smart Weapons Operability Enhancement (SWOE) thermal models. Variations in incident radiation produce surface temperature variations of up to 8 degrees C. In the paper we describe the means of evaluating solar loading effects using a correlated-k-distribution-like algorithm to compress spectral processing, and show comparisons between measured and modeled results.