High-frequency images of proud and buried 3D-targets

PC SWAT (Personal Computer Shallow Water Acoustic Tool-set) is a sonar simulation package developed at Coastal Systems Station to predict acoustic sensor performance. This article focuses on the algorithms used by PC SWAT to generate synthetic images of proud, buried, and partially buried three-dimensional targets. High frequency scattering from the target is described by a combination of the Kirchhoff approximation and the geometric theory of diffraction. Propagation of sound into a marine sediment with ripples is described by an application of Snell´s law and second order perturbation theory in terms of Bragg scattering.