A simple extrapolation method based on current for rapid frequency and angle sweep in far-field calculation of an integral equation algorithm

The algorithms based on the iterative solution of the integral equations and accelerated by fast solvers to provide efficient and accurate ways to calculate the scattering by large and complex objects. To further increase the efficiency in producing multi-angle and multi-frequency scattering data, attentions are focused on (a) developing precondition techniques to reduce the number of iterations for a converged solution and (b) developing advanced post processing methods which uses the information of the available solution to predict as much scattering data as possible. In this paper, an approximate extrapolation method is introduced to rapidly fill the angular and frequency far-field points using the solutions at sparsely sampled points.