Precision of the estimation of the degree of polarization in active coherent imagery

Abstract

We address the problem of degree of polarization estimation in active polarimetric images acquired with laser illumination. This technique provides two images of the same scene which are perturbed with peckle noise. Because of the presence of non homogeneity in the reflected intensity, it can be preferable to estimate the degree of polarization from the Orthogonal State Contrast Image. It has also been shown that a simple nonlinear transformation of this image leads to data perturbed with additive symmetrical noise, on which simple and efficient estimation and detection techniques can be applied. We propose in this paper to analyse estimation properties of the degree of polarization in these different imaging configurations by comparing the Cramer-Rao bounds for unbiased estimation. We will deduce from this analysis some useful prescriptions for exploiting polarimetric data from such imaging systems.