Fringe wave diffraction coefficients for higher order discontinuities

Abstract

We consider the diffraction of waves by objects with higher order discontinuities. The geometric theory of diffraction (gtd) diffracted field for this type of discontinuities have strong divergence near normal incidence. We substract from this diffracted field, the field radiated by the Luneberg-Kline currents to get the fringe diffracted field; and show that this field is finite. The formulae can be used to improve the accuracy of physical theory of diffraction (ptd) for smooth objects without edges. Explicit formulas are given for the discontinuity up to order 5. We present a numerical application for the discontinuity in the curvature. All computations are done by using Maple symbolic computation system.