Wide Angular Sweeping of Dynamic Electromagnetic Responses from Large Targets by MPI Parallel Skeletonization

It has been revealed that the interpolative decomposition (ID) skeletonization can greatly accelerate the wide angular sweeping, which involves repeatedly solving many/massive incidents. However, the peak memory usage required by skeletonization may be a bottleneck of that algorithm. In this communication, a message passing interface parallel skeletonization scheme is developed to alleviate the memory usage and to incorporate with the parallel multilevel fast multipole algorithm (MLFMA) for large targets, which are hundreds of wavelengths in size. The parallel scheme includes two ingredients. One is to feed into the ID, a size-reduced matrix to find skeleton right-hand sides. This matrix is produced upon skeleton RWGs instead of their original counterpart. The other is to integrate the parallel ID into the parallel MLFMA to alleviate the peak memory usage of skeletonization on each participating process. Numerical experiments show that the peak memory usage for the skeletonization can be less than 2 GB in each process for the target about 300 wavelengths in size.