An Efficient Parallel Multilevel Fast Multipole Algorithm for Large-scale Scattering Problems

In this paper, we present an efficient parallel multilevel fast multipole algorithm (MLFMA) for three dimensional scattering problems of large-scale objects. Several parallel implantation tricks are discussed and analyzed. Firstly, we propose a method that reduces truncation number without loss of accuracy. Furthermore, a matrix-sliced technique, allowing data in the memory transforming into the hard disk, is applied here, in order to solve the problem of extremely large targets. Finally, a transition level scheme is adopted to improve the parallel efficiency. We demonstrate the capability of our code by considering a sphere of 220 lambda discretized with 48,879,411 unknowns and a square patch of 200 lambda discretized with 10,150,143 unknowns. The bi-static RCS is calculated within 41.5 GB memory for the first object and 14.7 GB for the second one.