A hybrid numerical model for long-range electromagnetic wave propagation

A hybrid numerical model is presented for solving long range electromagnetic wave propagation problems involving objects on or above the ground surface by hybridizing the two-way split-step parabolic equation (2W-SSPE) method with the method of moments (MoM). The advantages of the proposed model are twofold: (i) It reduces the staircasing error in irregular terrain modeling, which usually occurs when the standard SSPE method is used alone. This is achieved by employing the MoM to more accurately obtain the scattered fields from slanted/curved surfaces. (ii) It enables the SSPE method to handle the problems involving objects above the Earth's surface, which cannot be easily modeled by the standard SSPE method due to difficulty in imposing boundary conditions. The accuracy of the hybrid method is numerically verified by comparing the numerical results with those of the 2W-SSPE and the GO+UTD (geometric optic + uniform theory of diffraction) methods in some representative propagation problems.