Calculation of detection and recognition probabilities of imaging infrared seekers

To evaluate the infrared camouflage effect of the target and the detection capability of imaging infrared seekers, an iterative algorithm to calculate the target spatial frequency is deduced, from which the detection and identification probabilities of imaging infrared seekers to extended source target can be derived. In the calculation, factors are taken into account such as target average temperature difference, modified minimum resolvable temperature difference, apparatus modulation transfer function and atmospheric transmissivity, and modification is demonstratedly applied to a point target. A method which quickly calculates detection and recognition probabilities of imaging infrared seekers under various practical conditions is proposed.