Evaluation for detection probability of infrared point target under complicated backgrounds

To solve the negative effect of the traditional detection probability model of infrared (IR) imaging system under complicated backgrounds, a novel model valid for various backgrounds is proposed. Based on the operating distance model of the IR imaging system, this paper analyzes the relationship among detection probability, signal-to-noise ratio, and operating distance. Meanwhile, traditional detection probability model for point target under a unitary background is derived. Then, this paper deduces the new model under a complicated background by introducing the idea of probability distribution. To get the IR radiance of complicated background which is the key information in the new model, the Radiance-Gray function is introduced. Finally, two detection probability calculation instances show that the new model can accurately evaluate the detection probability under complicated backgrounds.