Rough surface scattering using the phase‐perturbation technique

Abstract

There is a need for a solution to the problem of wave scattering from rough surfaces that is accurate when both the classical field perturbation and Kirchhoff (physical optics) approximations are not. In this work, the validity of the phase perturbation technique is examined for a region in parameter space when the two classical solutions fail. Numerical results for the phase perturbation scattering strength are compared with exact numerical results for one‐dimensional pressure‐release surfaces having a Gaussian roughness spectrum and Gaussian height and slope distributions. Exact results are obtained using a Monte Carlo technique. It is found that in the region considered the phase perturbation results agree with the exact results over all scattered angles away from low grazing for a fixed angle of incidence. Furthermore, in many cases it is found that exchanging incident and scattered angles in the phase perturbation equations gives an alternate phase perturbation solution whose numerical results are in excellent agreement with exact results. [Work supported by ONR.]