Visibility model for minimum resolvable temperature difference prediction

摘要

We present a new model for predicting the minimum resolvable temperature difference (MRTD) curve of thermal imaging systems. The analysis for the new model concentrates on contrast reduction due to spatial frequency limiting factors of subsystem components. Curves have been generated for this model for a system with typical component values. These results are compared with curves generated from the NVL's static performance model. The proposed visibility model leads to a relatively simpler development for a MRTD predictor which can readily account for artifacts due to a nonzero system phase transfer function. In addition the visibility model makes no assumptions regarding the recognition process and therefore is adaptable to the goal of modeling an objective MRTD measurement. The visibility model agrees with the static performance model except at very low and very high spatial frequencies where the proposed model appears to be in better agreement with observed trends in measured MRTDs.