Abstract:
Low-frequency surface backscattering experiments (CST-7, ASREX) show that the surface scattered field statistics are non-Gaussian, which means the intensity statistics will be nonexponential. These data show the intensity distribution to be closer to log normal. In such cases the statistical distribution depends on the scattering area on the surface or, equivalently, on the number of scatterers. An analytical model has been developed for the intensity distribution that results when the scattering area contains multiple, spatially independent, identically distributed scatterers. The individual scatterers, e.g., bubble clouds, are assumed to yield a log-normal intensity distribution. The assumption that the scatterers are spatially independent leads to a Poisson distribution for the number of scatterers in a given surface area. The parameters to be specified are the standard deviation of the log-normal distribution and the average number of scatterers per unit area. Monte Carlo simulations yield estimated intensity distributions in very good agreement with the analytical model. Preliminary comparisons will be made with ASREX data. [Work supported by ONR.]