DIAGONAL FACTORIZATION OF INTEGRAL EQUATION MATRICES VIA LOCALIZING SOURCES AND ORTHOGONALLY MATCHED RECEIVERS

A procedure is reported to determine accurate, invertible, block-diagonal factorizations for matrices obtained by discretizing integral equation formulations of electromagnetic interaction problems. The algorithm is based on the combination of localizing source/receiver transformations with orthogonally matched receiver/source transformations. The resulting factorization provides a single, sparse data structure for the system matrix and its inverse, and no approximation is required to convert between the two. Numerical examples illustrate the performance of the factorization for electromagnetic scattering from perfectly conducting elliptical cylinders of different electrical size.