Simulation of Complex Multiscale Objects in Half Space With Calderón Preconditioner and Adaptive Cross Approximation

Simulation of electromagnetic scattering by complex multiscale objects in a half space is addressed in this communication. The objects under investigation can be situated above, embedded in, or even penetrating the interface of the half space. In this analysis, the electric field integral equation is formulated with the kernel of a half-space Green´s function. The Calderón preconditioner is employed to improve the convergence of the Krylov-subspace iterative solvers. A new preconditioning operator is proposed to substantially reduce the construction cost, yet maintain the effectiveness. Moreover, a novel multilevel implementation of the adaptive cross approximation (ACA) algorithm is further adopted to make the method capable for problems with moderate size. The proposed scheme is examined by several multiscale problems, which constitute the most common scenarios in the near-surface applications.