Forward-backward: a new method for computing low-grazing angle scattering

A new technique called "forward-backward," has been developed for solving the magnetic field integral equation (MFIE) for perfectly conducting azimuthally homogeneous surfaces, including cases where the incident radiation has a lowgrazing angle. The technique involves splitting both the surface current and the MFIE into two pieces; one representing primarily forwardly scattered energy and one representing primarily backwardly scattered energy. Each of the new integral equations can be solved by an iterative stepping procedure. The technique is applied to two sample problems–the classic Sommerfeld wedge and a peaked surface consisting of two filtered exponentials. The obtained solutions are shown to be accurate for each of these problems.