Mid-wave infrared polarization detection of ship targets for small temperature difference conditions

Ship detection under small temperature difference conditions is an important research direction for infrared (IR) detection of typical targets at present. To solve the problems of low contrast and difficult recognition of ship IR imaging due to small temperature differences, the degree of polarization (DOP) images is applied to the field of low-temperature aberration imaging based on the polarization principle. Meanwhile, the misalignment problem caused by the lens jitter in the polarization calculation is solved by the proposed mutual information iterative algorithm. We demonstrate improvement in the target/background local contrast of low-temperature aberration imaging by using the difference in polarization characteristics between the target and the background. The effectiveness of the method was verified by experiments. The results show that the contrast of DOP images combined with multi-angle polarization information is about 30 times higher indoors and three times higher outdoors than IR intensity images. Therefore, the IR polarization detection technique based on DOP images can effectively deal with the problem of low imaging contrast caused by small temperature differences.