The Euler vector: a polarimetric descriptor of the ocean surface

Abstract

The mean polarimetric behavior of the sea surface, on a time-averaged measurement, can be described by its averaged Mueller matrix. A method for the calculation of this matrix has already been proposed: it consists of an extension of the small perturbations technique to the vectorial case, from a two-scale sea surface model. In this article a backscattering model is shown, which is representative of a single instantaneous measurement instead of a time-average of measurements. For this purpose, the polarimetric response is characterized by the sea surface polarization fork, described by the five Euler parameters. A minimal polarimetric descriptor is defined, the Euler vector, characterizing a frozen sea state, and whose components are the averaged values of the Euler parameters. The main interest of such a polarimetric signature of the sea surface is that the component of this new descriptor can be linked with the observation parameters (incidence of the illumination, azimuthal direction of the observa...