UNIFIED APPROACH TO VOLUME AND ROUGHNESS SCATTERING

A unified approach is proposed to study scattering from a fluid medium with irregularities of different types: volume inhomogeneities (spati al fluctuations of the compressibility and density) and roughness of t he interfaces. The approach considers the roughness as a volume pertur bation of a specific kind near flat (unperturbed) interfaces. It permi ts a description of the scattering problem on the basis of a unique in tegral equation with a kernel including both types of irregularities:I n the case of small perturbations, the first-order solution of this eq uation is used to obtain the scattering amplitude and scattering cross section for a stratified randomly inhomogeneous fluid medium with an arbitrary number of rough interfaces. Expressions for the roughness an d volume scattering cross section are obtained involving cross-correla tion matrixes between the roughness of different interfaces and betwee n the volume fluctuations of different parameters. Also, an example is considered where roughness-volume correlations are important. The res ults are generalized to the case when the fluid is placed over an arbi trary basement characterized by its own reflection coefficient and sca ttering amplitude. (C) 1998 Acoustical Society of America. [S0001-4966 (98)01302-2].