College of Marine Studies, Univ. Delaware, Newark, DE 19716
Acoustic wave reflection from seafloor is very sensitive to the sediment properties. Assuming a plane wave reflected from an homogeneous but anisotropic seafloor, a parametric study is conducted for seabed properties such as shear and bulk modulus, permeability, porosity, etc. It is demonstrated from the numerical solution by the propagator matrix method that the porosity is the most sensitive parameters that affects the reflection coefficient and bottom loss. The effect is most pronounced at low grazing angles. The numerical evidence is further supported by an asymptotic analysis of the analytical expressions of sediment wave velocity and the reflection coefficient at the water--sediment interface, for homogeneous, isotropic material. The numerical study is then extended to inhomogeneous sediment and the sensitivity to different layering patterns is examined. [sup a)]Present address: Office of Naval Res., Ocean Acoust. Prog. Code 324 OA, 800 N. Quincy St., Arlington, VA 22217.