Scalable multilevel fast multipole method for multiple targets in the vicinity of a half space

We extend the multilevel fast multipole algorithm (MLFMA) to the case of electromagnetic scattering from an arbitrary number of dielectric and/or perfectly conducting targets in the presence of a half space. This multitarget MLFMA is implemented in an iterative fashion, in which the fields incident on and scattered from each target are updated sequentially by considering each target in isolation, with appropriate field updating to account for intertarget scattering. Each target is analyzed in parallel on a separate computer node, and intertarget interaction is addressed via message passaging between the processors. We also utilize the aforementioned iterative formulation employed for handling interactions between multiple targets to develop a new means of solving the MLFMA matrix equation for an isolated target. This new formulation generally results in significant acceleration in the analysis of scattering from single targets, thereby also accelerating the analysis of scattering from multiple targets (within the context of the iterative multitarget analysis developed).