Modeling the effects of image contrast on thermal target acquisition performance

Most sensors allow the user to adjust a parameter at will that will modify the displayed scene contrasts in the image. This parameter is usually referred to as gain. The current US Army thermal target acquisition model (NVThermIP) accounts for gain by introducing a scaling parameter called scene contrast temperature. First, the current US Army theory of target acquisition is reviewed and the particular means for modeling sensor gain are highlighted. Then the definitions of scene and target contrast are discussed. The results of two paired comparison perception experiments are analyzed. One of the experiments gives insight into a target identification task, and another gives some insight into a search task. Conclusions regarding the limits of applicability of values for scene contrast temperature are then discussed