Mueller matrix of targets can reflect the change in the polarization state of the light in the propagation process, and it contains the polarization characteristics of the target itself, such as polarizance and depolarization. In the analysis of the characteristics of the Mueller matrix, most studies analyze the polarizance and depolarization characteristics separately. But in the process of theoretical derivation, it turns out that the two characteristics are independent of each other. Therefore, it is necessary to define a new index that can comprehensively evaluate the two characteristics.
In view of the shortcomings of the existing Mueller matrix measurement systems, this paper, based on the working principle of a polarization analyzer, improves and builds a rotating Mueller matrix measurement system. Then, the linear operation of the change in the polarization state is realized by transforming the propagation process of the light into a correlation semi-positive definite quadratic function, and a novel index is proposed to comprehensively evaluate the polarizance and depolarization characteristics of the Mueller matrix. In addition, we use a polarizer to verify the derived index and test the effectiveness of its comprehensive representation of the polarizance and depolarization characteristics. According to Mueller matrices of different targets published in the literature, their ability to identify targets during target detection is verified. Finally, Mueller matrices of aluminum plates under different incident angles and roughness are measured. The effect of incident angles and roughness on the Mueller matrix is analyzed by defining the influencing factor Q of roughness on polarization characteristics and stability S of the polarization characteristics to incident angle.
From the analysis results, it can be concluded that leaves, sand, soil, and glass of natural objects have weak polarizance characteristics, strong depolarization characteristics, and strong retained depolarization characteristics, and their values are close to 1. Therefore, all of them can be approximated as a complete depolarizing system. Artificial target dielectric, smooth steel plate, rough steel plate, camouflage coating, and camouflage cloth have relatively strong polarizance characteristics but relatively weak retained depolarization characteristics, with 1<PΔ<
By converting the degree of polarization into a correlation semidefinite quadratic function, the linear calculation of the reflection process of incident light with different polarization states on the target surface is realized. In view of the problem that the traditional evaluation indexes of the Mueller matrix can only be used to evaluate the polarizance and depolarization characteristics, the retained depolarization characteristics and