Models for acoustic scattering in high contrast media

Abstract

In this work a numerical method for evaluating backscatter from a three-dimensional medium having high acoustic contrast is presented. The solution is sought in terms of a perturbation expansion in the contrast amplitude. It is shown that limitations of the regular perturbation expansion can be overcome by recasting the perturbation sequence as a rational fraction using Padé approximants. The resulting solution allows for an accurate representation of the pressure and allows for the poles in the frequency response to be modeled. The determination of the pulse-echo response for a high-contrast medium is discussed and presented.