Multi-step spectral preconditioner for fast monostatic radar cross-section calculation

A multi-step preconditioning technique suitable for the solution of a sequence of linear systems arising in monostatic radar cross-section (RCS) calculation is presented. This technique is a combination of a prescribed preconditioner and a low-rank update spectral preconditioner in a successive multi-step manner that computes on the fly approximation of the eigenvectors associated with the smallest eigenvalues. Numerical results show that this technique is very effective in monostatic RCS calculation and can reduce simulation time significantly