Dirasat, Engineering Sciences, Volume 34, No. 1, 2007 - 1 - Modeling of Wave Propagation over Different Realistic Types of Environments Using the Parabolic Equation (Research Note) Mohammad H. Ahmad and Mohamed K. Abdelazeez* ABSTRACT In this paper, a computational model is developed for predicting the electromagnetic wave propagation over different realistic types of environments for some realistic conditions. The model allows specification of frequency, polarization, antenna radiation pattern, antenna altitude and elevation angle. It also treats standard and non-standard refractive conditions; super-refractive, sub-refractive, and ducts. In addition, the model allows specification of the electrical characteristics of the ground (permittivity and conductivity). Furthermore, the model is used to deal with mixed path situation composed of user-defined number of sections each with a different electrical characteristic, and it treats flat and non-flat terrain configurations with residential areas and forest environment. Keywords: Electromagnetic, Wave Propagation, Parabolic Equation, Fourier Split Step. I. INTRODUCTION Modeling of wave propagation over different types of environments is a major planning and design problem in communications and radar systems. Although there are different available methods used to model Electro- Magnetic (EM) wave propagation, these methods are appropriate for some types of environments, i.e. forest (Tamir, 1967; Swarup and Tewari, 1979), residential (Walfisch and Bertoni, 1988; Chung and Bertoni, 2002), non-flat terrain (Luebbers, 1984; Ott, 1971), sea (Barrick, 1971; Kuo, 1988), mixed path (Wait, 1961; Damboldt, 1981). These methods cannot be used to model wave propagation over other types of environments. One important and effective method used to model wave propagation is based on the Parabolic Equation (PE) (Fock, 1946). There are many advantages in using the PE to model radio wave propagation. It gives full wave solution for the field in the presence of range-dependent environments. Also, the solution of PE exhibits excellent robustness and accuracy for complicated problems involving vertically and horizontally varying refractive conditions. Solution of PE is performed using Finite Difference (FD) method (McDaniel, 1975), which is a straightforward method in implementing boundary conditions; or/and using Fourier Split Step (FSS) method (Harden and Tappert, 1973), which is significantly more stable numerically, and more efficient in computation times. The derivation of the PE from Maxwell’s equations is found in Kuttler and Dokery (1991) and Ryan (1991); were FSS solution of the PE is summarized by both Ryan (1991) and Levy and Craig (1991). The standard and non-standard refractive index of the troposphere was discussed in Kuttler and Dockery (1991), Dockery (1988) and Barrios (1994). The electrical characteristic of the ground incorporated in the FSS solution of the PE was discussed by Kuttler and Dockery (1991), Dockery and Kuttler (1996), and Kuttler * Al-Quds College, Amman, Jordan; and Department of Electrical Engineering, Faculty of Engineering and Technology, University of Jordan. Received on 14/12/2005 and Accepted for Publication on 17/12/2006. © 2007 DAR Publishers/University of Jordan. All Rights Reserved.