T. F. Gao
Inst. of Acoust., Academia Sinica, Beijing, People's Republic of China
E. C. Shang
Univ. of Colorado/NOAA/Wave Propagation, Boulder, CO 80303
A formal solution of the scattering field from a rough interface has been derived. Under the Bass perturbation theory, both waveguide and nonwaveguide (half-space) scattering from a rough interface (the sea bottom) can be calculated analytically. By using an identical definition of ``scattering coefficient,'' a relation between the waveguide scattering (the modal S matrix) M[sub lj][sup s] and the nonwaveguide scattering (conventional plane-wave scattering) coefficient m[sub s] has been found: M[sub lj][sup s]=(2(pi))[sup 2]m[sub s]/|V((theta)[sub l])V((theta)[sub j ])|, where V((theta)[sub l]) and V((theta)[sub j]) represent the reflection coefficients of the plane interface for the modal incident angles (theta)[sub l] and (theta)[sub j], respectively. Consequently, based on this relation, the m[sub s] data measured in the conventional sense (half-space) can be bridged into a shallow water reverberation prediction or vice versa.