Electromagnetic wave scattering from a random layer with rough interfaces II: Diffusive intensity

Abstract

A general approach for the calculation of the incoherent intensity scattered by a random medium with rough boundaries has been developed using a Green function formalism. The random medium consists of spherical particles whose physical repartition is described by a pair-distribution function. The boundary contribution is included in the Green functions with the help of scattering operators which can represent any existing theory of scattering by rough surfaces. By using a standard procedure, we derive the integral Bethe-Salpeter equation under the ladder approximation and, by differentiation, the vectorial radiative transfer equation. Furthermore, with the help of our formalism, the boundary conditions necessary to solve the radiative transfer equation are expressed in terms of the scattering operators of the rough surfaces. Finally, using the reciprocity properties of the Green functions, we are able to include the enhanced backscattering contributions to take into account every state of polarization of the incident and the scattered waves.