Investigation of Three-Dimensional Sound Field Horizontal Refraction in Heterogeneous Topography

The variability in seafloor topography is a primary factor influencing sound propagation. Complex and varied seabed topographies generate differing degrees of sound propagation effects, thereby altering the sound propagation loss compared to a flat seabed. This paper analyzes and statistically processes the slope data of the selected area's terrain. It utilizes acoustic models to simulate and compare the sound propagation loss in convergence zones and near the deep-sea sound channel axis under different slope conditions. The findings indicate that an upslope terrain reduces propagation loss in convergence zones, and the propagation loss is minimized near the deep-sea sound channel axis when the downslope gradient is 7°. The paper also examines and discusses the impact of different bottom sediment parameters on sound propagation loss and the backscattering of acoustic energy in upslope conditions. Finally, the study analyzes the horizontal refraction effect in the three-dimensional sound field under complex terrain conditions from ray trajectories perspective.