The effect of cloud on the target detection in atmosphere

The target-background contrast has important application in many fields. Since cloud covers about 50% the gound surface and have important influence to the radiative transfer, it is necessary to taking into account the influence of cloud in the computing process of the target-background contrast. In the paper, the effect of the optical properties of cloud models to the target-background contrast was processed on the plane parallel assumption and the probability of cloud free light of sight (PCFLOS).