Polarimetric scattering analysis using a Brillouin–Wigner perturbative scheme

Abstract

This work presents a Brillouin-Wigner-type perturbative scheme (P-S) for deriving analytical expressions for the eigenvalues and eigenvectors of the coherence matrix, enabling computationally efficient polarimetric scattering analysis. The scheme´s generality allows its application with any scattering models that verifies reciprocity. As an example, it is applied using the second-order Small Perturbation Method (SPM) for both single rough surfaces and layered media. Comparison of P-S results with direct numerical calculations of the coherence matrix demonstrates high accuracy across all studied parameters, with relative mean errors ranging from 0.2% to 7%.