Hybrid method computation of diffraction by trailing edges using reciprocity

A perturbation procedure for combining analytic and numerical methods for the computation of scattering by large bodies and of diffraction coefficients for trailing edges is presented. This procedure has been tested for trailing edge scattering by a conducting half plane. It is seen to eliminate the difficulty encountered by other numerical methods near grazing angle. The approach consists of substituting distorted wave fields for the incident and scattered plane wave fields of a purely numerical calculation. As a demonstration of this method, back-scattering by a conducting half plane was calculated by a combination of physical optics and the method of moments.<>