Full-wave analysis of electromagnetic wave propagation over terrain using the Improved Tabulated Interaction Method

Abstract

This paper proposes extending the forward scattering based Tabulated Interaction Method (TIM) for computing electromagnetic wave propagation over terrain profiles to one incorporating backscattering. The proposed method uses a common set of basis functions in conjunction with a "matching technique" to produce a linear system with much fewer unknowns than that created using pulse basis functions and therefore provides a very efficient and accurate method. The original TIM is shown to be a special case of the proposed method whereby the lower triangular portion of the reduced system is retained and solved. The proposed method is compared with the recently proposed Characteristic Basis Function Method with which it shares several features. The complexity and numerical analysis demonstrates that the proposed method has an extremely low computational complexity and storage. Key Points Tabulated Interaction Method offers full wave accuracy for terrain propagation problems The use of large-scale basis functions based on fast far field approximation compresses the impedance matrix and greatly speeds up solution Improved formulation allows incorporation of backscattered fields, and excellent agreement with measured data is obtained