A PHYSICALLY MOTIVATED SIMULATION TECHNIQUE FOR HIGH-FREQUENCY FORWARD SCATTERING DERIVED USING SPECULAR POINT THEORY

A physically motivated simulation technique using specular point theory (SPT) is developed to examine high-frequency signals forward scattered from a rough surface. This method is used to derive, for small receiver separations, the spatial coherence for an infinite ensemble of signals forward scattered from random surfaces with Gaussian wave-number spectra. The results are compared with those of previously published methods. An SPT single realization procedure is formulated and implemented for frequencies of 30 and 300 kHz using a Gaussian spectrum approximation to the random rough surface. Some SPT predictions for Gaussian and Pierson-Moskowitz surfaces are compared. Both the spatial coherence and the temporal structure of finite ensembles of forward scattered signals are compared for the Gaussian case. The relation between the results for infinite and finite ensembles is then examined, and the practical implications and limitations of SPT for simulating forward scattering are discussed.