On the use of physical basis functions in a sparse expansion for electromagnetic scattering signatures

This paper explores the use of physical basis functions as an efficient and insightful sparse expansion for representing the electromagnetic scattering from large finite targets. Such an expansion is central to applying compressed sensing techniques. The closed-form physical optics solution for scattering from an arbitrary flat plate is used to extract the physical basis functions related to scattering mechanisms of edge and corner diffraction, and specular reflection. Orthogonal matching pursuits is applied to find the coefficients of the sparse expansion from the calculated scattered fields of a plate as a function of frequency and angle. Convergence is demonstrated as a function of the number of basis functions and compressed sensing samples.