Recursive Two-Way Parabolic Equation Approach for Modeling Terrain Effects in Tropospheric Propagation

2009-09-01
Ozgun, Ozlem
The Fourier split-step method is a one-way marching-type algorithm to efficiently solve the parabolic equation for modeling electromagnetic propagation in troposphere. The main drawback of this method is that it characterizes only forward-propagating waves, and neglects backward-propagating waves, which become important especially in the presence of irregular surfaces. Although ground reflecting boundaries are inherently incorporated into the split-step algorithm, irregular surfaces (such as sharp edges) introduce a formidable challenge. In this paper, a recursive two-way split-step algorithm is presented to model both forward and backward propagation in the presence of multiple knife-edges. The algorithm starts marching in the forward direction until the wave reaches a knife-edge. The wave arriving at the knife-edge is partially-reflected by imposing the boundary conditions at the edge, and is propagated in the backward direction by reversing the paraxial direction in the parabolic equation. In other words, the wave is split into two components, and the components travel in their corresponding directions. The reflected wave is added to the forward-wave in each range step to obtain the total wave. The wave-splitting is performed each time a wave is incident on one of the knife-edges. This procedure is repeated until convergence is achieved inside the entire domain.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION

Suggestions

Two way split step parabolic equation algorithm for tropospheric propagation Tests and comparisons
ÖZGÜN, ÖZLEM; APAYDIN, GÖKHAN; Kuzuoğlu, Mustafa; SEVGİ, LEVENT (2010-08-25)
This paper introduces a two-way split-step parabolic equation propagation tool (2W-SSPE), which is capable of handling both forward and backward scattered waves during groundwave propagation over an irregular terrain, through inhomogeneous atmosphere. The algorithm is calibrated and tested against reference data obtained with the help of image method and the Geometric Optic (GO) + Uniform Theory of Diffraction (UTD).
Multiscale Modeling of Thin-Wire Coupling Problems Using Hybridization of Finite Element and Dipole Moment Methods and GPU Acceleration
ÖZGÜN, ÖZLEM; Mittra, Raj; Kuzuoğlu, Mustafa (2020-01-01)
In this article, a hybrid numerical method, called finite element method (FEM) + dipole moment (DM), is presented for efficient solution of multiscale electromagnetic radiation and scattering problems that involve structures with fine features, such as thin-wire antennas or objects. In this method, the FEM is hybridized with the DM approach to help ease certain computational burdens, such as mesh refinement, ill-conditioning, memory overload, and long computation times, when solving multiscale problems with...
Assessment of alternative simulation techniques in nonlinear time history analyses of multi-story frame buildings: A case study
Karim Zadeh Naghshineh, Shaghayegh; Askan Gündoğan, Ayşegül; Yakut, Ahmet (2017-07-01)
In regions with sparse ground motion data, simulations provide alternative acceleration time series for evaluation of the dynamic response of a structure. Different ground motion simulation methods provide varying levels of goodness of fit between observed and synthetic data. Before using the seismologically acceptable synthetic records for engineering purposes, it is critical to investigate the efficiency of synthetics in predicting observed seismic responses of structures. For this purpose, in this study ...
Numerical Solution of Multi-scale Electromagnetic Boundary Value Problems by Utilizing Transformation-Based Metamaterials
Ozgun, Ozlem; Kuzuoğlu, Mustafa (2011-06-23)
We present numerical solution techniques for efficiently handling multi-scale electromagnetic boundary value problems having fine geometrical details or features, by utilizing spatial coordinate transformations. The principle idea is to modify the computational domain of the finite methods (such as the finite element or finite difference methods) by suitably placing anisotropic metamaterial structures whose material parameters are obtained by coordinate transformations, and hence, to devise easier and effic...
Numerical solution of nonlinear reaction-diffusion and wave equations
Meral, Gülnihal; Tezer, Münevver; Department of Mathematics (2009)
In this thesis, the two-dimensional initial and boundary value problems (IBVPs) and the one-dimensional Cauchy problems defined by the nonlinear reaction- diffusion and wave equations are numerically solved. The dual reciprocity boundary element method (DRBEM) is used to discretize the IBVPs defined by single and system of nonlinear reaction-diffusion equations and nonlinear wave equation, spatially. The advantage of DRBEM for the exterior regions is made use of for the latter problem. The differential quad...
Citation Formats
O. Ozgun, “Recursive Two-Way Parabolic Equation Approach for Modeling Terrain Effects in Tropospheric Propagation,” IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, pp. 2706–2714, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/64084.