Research On Polarization Detection And Recognition Technology Of Space Target

In order to solve the problem that the complex spatial background and high stray light,the traditional photo detection technology is greatly affected.This paper proposes a polarization imaging telescope optical system based on micro-polarizer array.Aiming at the problem of polarization effect of photoelectric telescope in spatial target polarization detection,based on polarization imaging theory,the analytical expression of Mueller matrix in reflection,refraction and reversal telescope system is derived and the polarization effect model of optical system is constructed.The analytical relationship among the degree of polarization of the incident light,the difference in the angle of the light and the degree of polarization of the emitting light,which clarifies that the difference between the incident angle and the angle of refraction of the optical element is controlled within 5.7°,can effectively reduce the influence of the optical system on the degree of polarization.According to the spatial target polarization imaging requirements and the above theoretical analysis,a Cassegrain telescopic system based on micro-polarizer array is designed to achieve an imaging resolution of 0.5m at 500 km.On the basis of this,when the incident light is partially polarized,the single ray tracing result of different pupil coordinates in refraction and reflection telephoto system is difficult to characterize the full field of view distribution of the whole system polarization degree,the full-field,full-pupil ray tracing of the designed optical system is performed used a dynamic data exchange,and the four Stokes vectors and the degree of polarization full field of view of the reflection and refraction system are obtained.At the same time,the influence of the film system of gold,silver and aluminum on the polarization degree of the reflection system was analyzed,and the influence of the polarization degree of different incident light on the polarization effect of the system was analyzed.The results show that the Cassegrain system of silver-plated film has a relatively small influence on the polarization of incident light due to the small refractive index of the complex refractive index of metallic silver.With the increase of the polarization of incident light,the polarization effect of the system is also will be reduced accordingly.Through the above theoretical research,according to the full field of view distribution of the polarization degree of the system,the polarization effect of the optical system can be calibrated by the polarization degree of the arbitrary field of view and the central field of view of the image plane,and the polarization degree of the incident light is inverted accordingly,thereby improving the imaging contrast and recognition ability of the spatial target.By constructing the principle verification device,the experimental data is analyzed and the feasibility of the method is verified.At the same time,it also provides a theoretical basis and solution for the calibration of the full field of view polarization characteristics of the optical system.