Research on optical target identification based on echo scintillation effect

In order to obtain more characteristic information of optical targets and achieve the goal of target recognition, the scintillation of target echo was considered as one of the means of target recognition by utilizing the difference of modulation characteristics of different target echoes in turbulent atmosphere. The random phase screen was used to generate round trip atmospheric turbulence by power spectrum inversion, using hard edged apertures to expand into finite series sum forms and Collins diffraction integral formula, the complex amplitude distribution of the reflected light of corner reflector, lens and reflector of Lambertian diffuse target was derived. The influence of turbulence intensity and target size on the scintillation index of the three target echoes was analyzed and verified by experiments. The results show that the scintillation index of optical target and diffuse reflection echo have obvious differences, the overall difference is an order of magnitude. With the increase of diameter, optical target echo scintillation index shows a decreasing trend on the whole; The scintillation index of corner reflector and lens target echoes in the numerical difference is not obvious, but the method of plotting the echo scintillation index over time by multiple test results can be used to distinguish the two roughly. This method can quickly identify the optical target from the diffuse background, and also provide a reference value for the classification and recognition of the optical object.