SCATTERING FROM ELASTIC SEA BEDS - FIRST-ORDER THEORY

A perturbation model for high-frequency sound scattering from an irreg ular elastic sea bed is considered. The sea bed is assumed homogeneous on the average and two kinds of irregularities are assumed to cause s cattering: roughness of the water-sea bed interface and volume inhomog eneities of the sediment mass density and the speeds of compressional and shear waves. The first-order small perturbation approximation is u sed to obtain expressions for the scattering amplitude and bistatic sc attering strength. The angular dependence of the scattering strength i s calculated for sedimentary rock and the influence of shear elasticit y is examined by comparison with the case of a fluid bottom. Shear eff ects are shown to be strong and complicated. (C) 1998 Acoustical Socie ty of America.