Analysis of three-dimensional spatial characteristics of ocean ambient noise in strait waters

The characteristics of ocean ambient noise in the strait waters are analyzed, which exhibit significant differences compared to those in other seabed waters. This study assumes that the sources of ocean ambient noise are uniformly distributed within a circular area on the sea surface above the receiving array. By employing a 3D ray sound propagation theory that considers horizontal refraction of sound rays, the high-frequency and low-frequency characteristics of ocean ambient noise in the V-shaped strait topography are simulated and calculated. The spatial characteristics of ocean ambient noise at different azimuth angles are analyzed. The research findings indicate that the presence of straits influences the horizontal sound propagation process, leading to a certain degree of convergence effect on sound energy. When the receiving array is positioned directly above the strait seabed, noise from the sea surface converges towards the center of the strait as the receiving depth increases, forming horizontal convergence zones at specific depths. Regarding the sound energy emitted from surface noise sources to the depth of the sound channel axis, the presence of the strait prevents the sound energy from leakage within the strait when it propagates along the strait. Furthermore, when sound energy traverses across the strait, the energy loss remains minimal.