A plane-wave reflection loss model including sediment rigidity

A method is presented for computation of the complex plane-wave reflection coefficient of an acoustic wave impinging upon a horizontally stratified ocean bottom consisting of a single inhomogeneous (fluid or solid) sediment layer overlying a semi-infinite homogeneous (fluid or solid) substrate. Within the sediment layer the density, the compressional wave speed and attenuation, and the shear wave speed and attenuation are permitted to vary arbitrarily and independently. A matrix formulation is used in which the depth-separated wave equations are replaced by the ’’propagator’’ matrix. The elements of the propagator are calculated by numerical integration of the Helmholtz equations with depth-dependent wavenumbers.