A method to speed up iterative solutions of terrain scattering problems

A method for speeding up integral calculations occurring in iterative solutions of electromagnetic wave scattering problems is described. Present methods suffer from having to perform time consuming integral calculations at many points. The method involves enumerating the full integral only at certain points and approximating the integral at neighbouring points by making localised phase and amplitude adjustments to the calculated integrals. This is shown to speed up the process tremendously. An example of scattered field calculation over the terrain is given and compared with a regular forward scattering approach.