Rough seafloor and target far-field scattering prediction using numerically determined Green’s functions

Abstract

Acoustic scattering from rough seafloor, and from targets on and buried within rough seafloor interfaces, is modeled using 3D finite elements to capture the effect of seafloor roughness and variability upon the far-field scattering. Though the model is necessarily small, far-field scattering prediction is achieved using Green’s functions determined numerically within the model. Comparisons to experimental measurements and between models demonstrate the effect that seafloor roughness and variation, as well as target orientation, burial, and asymmetry have upon the measured scattering. Numerically determined Green’s functions are an efficient method for obtaining long-range scattering prediction out of small, localized models, and are practical for complex geometry situations in which the exact Green’s function is difficult to estimate analytically. Best practice techniques for domain truncation in complex environments are also explored and compared in this work. [This work was supported by the Office of Naval Research and by the Strategic Environmental Research and Development Program.]