Applied Underwater Acoustics

5.4. Theoretical Basis for Scattering Calculations

Most mathematical models for scattering from a randomly rough interface fall into two categories: (1) the small roughness perturbation approximation, frequently referred to as the Rayleigh–Rice method and (2) the Helmholtz integral with the Kirchhoff approximation, often called the tangent plane method. The following sections discuss the perturbation approximation and the Helmholtz–Kirchhoff method.

5.4.1. The Perturbation Approximation

The perturbation approximation is widely used to calculate low-frequency acoustic scattering from rough surfaces. Lord Rayleigh [6,67] made the first contribution to this approximation by calculating scattering for a wave normally incident on a periodic corrugated ...