Discussion of physical optics surface integration for deep interpretation of GTD

This paper reviews the significance of equivalent edge currents for surface-to-line integral reduction in EM scattering and the relations between various high frequency methods are surveyed in this context. It suggests that most of the difficulties in GTD comes from errors in reduction of surface currents into equivalent currents and further into rays. Two unique concepts introduced by the authors are demonstrated; MER as the novel definition of equivalent edge currents is developed for accurate and uniform reduction of radiation integrals.