Parabolic Equation Simulations of Reverberation Statistics From Non-Gaussian-Distributed Bottom Roughness

In this paper, a two-way parabolic equation (PE) method is developed for modeling rough interface reverberation. The model is employed to estimate the reverberation envelope probability density function from bottom roughness with Gaussian and exponential height distributions. For Gaussian-distributed roughness, the PE gives envelope statistics that closely conform to the expected Rayleigh distribution. However, for non-Gaussian-distributed roughness heights, heavy-tailed reverberation envelope statistics are observed. The PE simulation results are compared to the analytical model of K-distributed reverberation by Abraham and Lyons [IEEE J. Ocean. Eng., vol. 29, pp. 800-813, 2002] for discrete scatterers and to numerical predictions of the first and second moments of the reverberation intensity estimated with a coupled mode reverberation model for the multipath insonification of rough surfaces.