ASA 127th Meeting M.I.T. 1994 June 6-10

3aSAb12. Visualization techniques for acoustic scattered fields.

Sylvia K. Isler

Vineet Mehta

Ctr. for Advanced Computation, Univ. of Massachusetts, Lowell, MA 01854

A numerical simulation and visualization of time-varying pressure fields in inhomogeneous fluid media is considered. Medium inhomogeneities considered included attenuation, compressibility, and density contrasts. Of particular interest is the analysis of scattering from anisotropic media and the corresponding directional characteristics of the scattered field. The simulation model is based on a Pade approximant representation for the pressure. This model allows the computation of scattered fields at size parameters ka~O(1). A finite set of wave-number responses is obtained by a solution of Green's integral equation. The temporal response is obtained by inverse Fourier transformations of the wave-number response modulated by the incident field. Visualization techniques are developed to track strong scattering directions and to identify optimum measurement surfaces. [Work supported in part by and AT&T Bell Laboratories Cooperative Research Fellowship.]