Comparison of Wait and norton Formulations with Parabolic Equation Method in Ground Wave Propagation

Authors: Levent SEVGİ, Selçuk PAKER

Abstract: In this paper, ground wave propagation characteristics are discussed for a vertically polarized short electrical dipole over smooth spherical earth. Analytical solution which is suitable for numerical computations and valid over a broad frequency range as well as medium parameters have not yet appeared. Because of this, attention have been paid to analytical approximate and/or pure numerical solutions. Two main analytical approaches named as Norton and Wait formulations are taken into account together with numerical split step Parabolic Equation (SSPE) method. Analytical and numerical advantages and difficulties of the methods are discussed in detail and various comparison are given among them with their validity regions and accuracies. Based on these comparisons, two efficient computer algorithms, GRWAVE and SSPE are build. GRWAVE combines Norton and Wait formulations in a dynamic way and decides where to switch in between them depending on the initial parameter set. On the other hand, SSPE produces reference solutions in regions where applicable. Also a new interesting method for path loss calculations in surface wave propagations is introduced and comparison of the results with ground wave path loss curves in CCIR Recommendations (CCIR Rec. 368-6, 1990) is given. The study presented here, briefly outlines ground wave propagation, its physical characterics and gives computaional results of a broad parameter range for comparisons.

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