IMPROVED EQUIVALENT FLUID APPROXIMATIONS FOR A LOW SHEAR SPEED OCEAN-BOTTOM

The acoustic reflection coefficient for a homogeneous fluid over a hom ogeneous solid with a low shear speed can be well approximated by repl acing the solid with a fluid with suitably chosen parameters. It is sh own that previous expressions for the density of this equivalent fluid can be replaced with a single expression which covers a wider range o f practical cases. It is further shown that the use of a complex densi ty gives an equivalent fluid which closely reproduces the reflection c oefficient of typical soft solid seabeds. (C) 1995 Acoustical Society of America.