A Comparison Of Scattering From 2-D And 3-D Rough Interface

Abstract

In this paper we compared scattered waves from 2-D and 3-D interface structures. The modeling technique is the 3-D time domain finite difference method. The scheme is second-order accurate in time and fourth-order accurate in space. It is implemented on a massively parallel nCUBE computer. In order to investigate the characteristics of 2-D and 3-D rough surface scattering, we consider an acoustic-elastic boundary, which is described by a Gaussian autocorrelation function. The F-K analysis of reflected signals shows that 2-D scattering generates similar amounts of forward and back scattering, while in the 3-D case, more forward and less back scattering. The 3-D effects also show larger reflected energy than the 2-D case, especially near the normal incident. The out-of-plane scatterings are clearly demonstrated on the F-K spectra in the 3-D case. In the 2-D simulations, we have to keep in mind that it tends to overestimate the amount of backscattering energy.