Time-evolution modeling of seafloor scatter. I. Concept

A time-series model for acoustic seafloor backscattering is described. The method analytically expresses the elementary time-backscattered response of every seafloor surface and every seafloor volume infinitesimal element. For chosen geometric, acoustical, and acquisition parameters, they are summed to produce in the time domain a realization of the reverberation time-pressure field received at the source. The approach is based on the Kirchhoff approximation for the seafloor interface backscattering and on the Small Perturbation theory for the seafloor volume. It only accounts for single backscattering mechanisms of the compressional wave with the seafloor. The model is implemented using calculated height fields for the water-sediment interface and distributed seafloor volume inhomogeneities. The analytical description of the model and its limitations is described in this paper.