The Dependence of Long‐Range Reverberation on Bottom Roughness

At long‐range, shallow‐water reverberation can be driven by sub‐critical‐angle scattering, i.e. by rough interrace scattering. The Naval Research Laboratory has recently developed a small‐slope model for elastic seafloors that provides physics‐based estimates of the dependence of scattering on the incident and scattered angles, and physical descriptors of the environment. In this paper, this incoherent model is used as kernels in reverberation models, which in turn are used to assess the sensitivity at 3.5 kHz of long‐range monostatic reverberation to the roughness of the water‐sediment interface. It is shown that when sub‐critical‐angle scattering dominates, the acoustic field could be quite sensitive to the parameter values of the roughness, thus arguing for the need for regional in‐situ methods for its estimation.