Multilevel fast multipole algorithm for general targets on a half-space interface

The multilevel fast multipole algorithm (MLFMA) is considered for scattering from an electrically large conducting or dielectric target resting on the interface of a dielectric half-space. We focus on analysis of the half-space Green's function such that it is computed efficiently and accurately, while retaining a form that is applicable to an MLFMA analysis. Attention is also directed toward development of a simple preconditioner to accelerate convergence of the conjugate-gradient solver. The utility of the model is examined for several applications, including scattering from an electrically large vehicle, trees, and rough dielectric interfaces in the presence of a dielectric half-space background.