Effects of a sediment scattering layer in underwater‐acoustic studies of intensity sensitivity and data matching

A scattering layer is introduced at a horizontal water–bottom interface to account for effects of attenuation due to bottom volume scattering. Using a wide‐angle parabolic equation, a formula for the local mean intensity level is found for a shallow‐ocean model consisting of three isospeed fluid layers: water, scattering layer, and bottom. The sensitivity of the theoretical mean to environmental parameters is studied, and the standard deviation of intensity is examined also. Comparisons are made between intensity statistics of the three‐layer model and of other isospeed models. Also, comparisons are made between three‐layer model statistics and data from a recent New Jersey Shelf experiment. Results from the inclusion of a scattering layer for the prediction of relative intensity statistics are evaluated over a wide range of acoustic frequencies. It is found that, with parameter values representative of the experimental site, the three‐layer model can successfully match the local mean and standard deviati...