Modeling the forward scattering sound field of targets in shallow water based on ray acoustics

To address the complexity of calculating the forward scattering sound field of a target in shallow water waveguides—a complexity arising from the combined influences of target scattering characteristics and environmental sound propagation properties—a ray-based model is established for the forward scattering sound field of a rigid target in such environments. The method integrates ray acoustics theory with the plane wave scattering function. The far-field calculation formula for the forward scattering sound field of a rigid target in a Pekeris waveguide is derived using the virtual source method， thereby revealing the coupling relationship between the shallow water channel and the target scattering sound field in free space， as well as the sound propagation paths. Based on the established model， the forward scattering sound field of a rigid sphere with a radius of 5 m was simulated. The results indicate that the forward scattering sound field calculated by the ray model shows good agreement with that calculated by the normal mode model. For high- frequency scattering sound field calculations， the proposed ray model demonstrates higher computational efficiency compared to the traditional normal mode model. Furthermore， the model clearly characterizes the geometric sound propagation paths in shallow water waveguides， with clear physical implications.