A 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 (spatial fluctuations of the compressibility and density) and roughness of the interfaces. The approach considers the roughness as a volume perturbation of a specific kind near flat (unperturbed) interfaces. It permits a description of the scattering problem on the basis of a unique integral equation with a kernel including both types of irregularities. In the case of small perturbations, the first-order solution of this equation 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 and volume scattering cross section are obtained involving cross-correlation matrixes between the roughness of different interfaces and between the volume fluctuations of different parameters. Also, an example is considered where roughness–volume corr...