Simulating surface scattering and sound transmission in a refractive medium

High frequency surface reflection for sound in a refraction ocean is created by statistical geometry. This approach uses Helmholtz-Kirchhoff (HK) scattering theory and ray acoustics. The model is a layered ocean with acoustic ray paths lying in vertical planes. A multiplicity of raypaths and a number of reflections associated with each is simulated. The simulations use the joint probability distribution of surface slopes. An important application of this model is surface duct propagation calculations for certain areas of the world's oceans where sound speed increases with depth. Using this approach, surface curvature effects are fully accounted for.