Finite correlation and coherent propagation effects in the normal-mode description of bottom reverberation

A normal-mode scattering formulation that assumes a finite spatial correlation length in the distribution of scattering features is used to compute single-frequency bottom reverberation for bistatic and monostatic scattering geometries in a shallow water and deep water environment. Spatial correlation of the scattering features allows the superposition of modes scattered within each spatially correlated region and produces diffraction in the scattered field that is not predicted in the limit of a zero spatial correlation length (point scattering). For bistatic scattering geometries, the scattered field computed as a function of scattering location in the horizontal plane exhibits a pattern of diffractive maxima and minima for nonzero spatial correlation lengths. The spatial details of the diffraction pattern and its influence on the scattered energy depend on the frequency and spatial correlation length and can result in a significant reduction in the predicted levels of received reverberation. The greate...