Polarimetric optical tools and decompositions applied to SAR images

Radar polarimetry aims to determine the scattering properties of a target or scatterer. For this purpose, the scattering matrix can be analyzed and represented in several ways using various techniques to extract information about the scattering mechanisms. Polarimetry and ellipsometry are techniques which both study the properties of the polarization of the scattered waves but traditionally refer to different wavelengths: optical wavelengths for ellipsometry, and high-frequencies radio waves for radar polarimetry. This paper deals with natural targets in the general bistatic case, for which the 16 parameters of the Mueller matrix are independent. We try to answer the following questions: how to deduce the radar polarimetric parameters from the optical measurements of a Mueller ellipsometer? What are the polarimetric parameters traditionally devoted to optical images, and in which extent is it possible to apply and interpret them in the case of SAR images?