Modified Wiener–Hermite expansion in rough-surface scattering

An attempt is made to calculate the coherent and incoherent responses of a conducting rough surface that is a plane on the average. In this approach the surface current is represented as a product between a phase factor, essentially the phase factor of the incoming electromagnetic field, and a correction term to be found as a series of Wiener–Hermite functionals. It is shown that the results thus obtained reduce to those following from lowest-order perturbation theory or the Kirchhoff approximation within their corresponding domains of validity.