Computation of scattering by high-aspect ratio spheroids using a new wide-angle on-surface radiation condition approach

Abstract

In a previous study [Calvo et al., IEEE Trans. Antennas Propag. (2003)], a wide-angle on-surface radiation condition (OSRC) was introduced to compute scattering by hard and soft elliptical cylinders. This OSRC was based on a rational approximation of the exact Dirichlet-to-Neumann map for a circular cylinder. As a result of the wide-angle accuracy, exceptional results were obtained for scattering by hard elliptical cylinders when a plane wave was incident end-on with the target. In this talk, the form of the rational approximation is economized and the OSRC is extended to the case of three-dimensional convex bodies (spheroids). A comparison of scattered fields using the OSRC and the BEM methods shows excellent agreement. Owing to the tridiagonal form of the differentiation matrices appearing in the rational approximation, computational costs scale only linearly with frequency making this technique ideal for mid-to-high frequency target scattering computations for orientations where diffraction effects may be important.