Modeling of acoustic scattering by sphere on a planar seabed.

A model of acoustic scattering from spherical target above a planar seabed is advanced to a condition of irradiation by a point source, with both of T matrix method and complex images method. Compared to the other model [J. A. Fawcett and R. Lim, J. Acoust. Soc. Am. 114, 1406–1415 (2003)], this model could be used to calculate scattering field from target above a planar interface in three dimension space or by bounded source beam. Comparing some coefficients by complex images method with that by analytical formula or numerical quadrature, the computing method of the model is examined to be efficient and accurate. In addition, numerical examples of a rigid sphere and an elastic spherical shell are compared for scattering field from the target on a fluid seabed, and the scattering field dependent angle is investigated from the different of grazing angle of incident wave. [Work supported by the National Natural Science Foundation of China (Grant No. 10704068).]