ABSTRACT
This chapter describes polarization matrices such as the scattering matrix, covariance matrix, coherency matrix, and Kennaugh matrix, in addition to their relations. Starting from the scattering matrix, polarization matrices in various forms can be created. When we deal with PolSAR observation data, we often take an ensemble average to retrieve reliable information from the data set. In this case, we use the ensemble term as rather than the scattering matrix itself. There are 3 × 3 and 4 × 4 polarization matrices suitable for ensemble averaging data. Among them, the covariance matrix has specific characteristics such that the element is related to actual radar channel power or correlation, while the coherency matrix has advantages in physical interpretation of the scattering mechanism and in mathematical operations. The Kennaugh matrix consists of real valued elements and is convenient for generating a polarization signature. Even if the form of the polarization matrix is different, nine parameters exist inside the matrix. In this chapter, we deal with representative polarization matrices and derive theoretical average matrices to find the key parameters of PolSAR data.
