Application of Horner Method to Approximate Fresnel Function

This paper is concerned with reducing computation time of electromagnetic field by using Horner method. Recently, authors have proposed discrete ray tracing method (DRTM) to analyze electromagnetic wave of propagation characteristics along random rough surface (RRS). The DRTM enables us to save much computation time of electromagnetic field in comparison with the conventional ray tracing method (RTM). However, we need many computation times to analyze electromagnetic field because a lot of diffractions occur above RRSs. In this paper, we introduce an approximation by using Horner method for diffraction function which is simple and effective to DRTM analyses.