A Novel Two-Way Finite-Element Parabolic Equation Groundwave Propagation Tool: Tests With Canonical Structures and Calibration

Apaydin, Gokhan
Ozgun, Ozlem
Kuzuoğlu, Mustafa
Sevgi, Levent
A novel two-way finite-element parabolic equation (PE) (2W-FEMPE) propagation model which handles both forward and backward scattering effects of the groundwave propagation above the Earth's surface over irregular terrain paths through inhomogeneous atmosphere is introduced. A Matlab-based propagation tool for 2W-FEMPE is developed and tested against mathematical exact and asymptotic solutions as well as the recently introduced two-way split-step PE model through a canonical validation, verification, and calibration process for the first time in literature.


A new differential geometric method to rectify digital images of the earth's surface using isothermal coordinates
Karslıoğlu, Mahmut Onur; Friedrich, E (Institute of Electrical and Electronics Engineers (IEEE), 2005-03-01)
A new method to rectify monoscopic digital images and generate orthoimages of the earth's surface is described. It replaces the standard procedure, which transfers the perspective projection of a frame photograph to an orthographic projection of pixels onto a reference plane using corresponding corrections. Instead, the perspective forward projection is kept but every pixel is vertically mapped along the surface normal onto a curved reference surface, for example, the ellipsoid of the World Geodetic System ...
Monte Carlo-Based Characteristic Basis Finite-Element Method (MC-CBFEM) for Numerical Analysis of Scattering From Objects On/Above Rough Sea Surfaces
Ozgun, Ozlem; Kuzuoğlu, Mustafa (Institute of Electrical and Electronics Engineers (IEEE), 2012-03-01)
The Monte Carlo-based Characteristic Basis Finite-Element Method (MC-CBFEM) is developed for predicting the statistical properties of the 2-D electromagnetic scattering from objects (such as ship-and decoy-like objects) on or above random rough sea surfaces. At each realization of the Monte Carlo technique, the 1-D rough sea surface is randomly generated by using the Pierson-Moskowitz spectrum, and the bistatic radar cross section (RCS) is computed by employing the CBFEM approach. The CBFEM is a noniterativ...
Evaluating a mesoscale atmosphere model and a satellite-based algorithm in estimating extreme rainfall events in northwestern Turkey
Yücel, İsmail (Copernicus GmbH, 2014-01-01)
Quantitative precipitation estimates are obtained with more uncertainty under the influence of changing climate variability and complex topography from numerical weather prediction (NWP) models. On the other hand, hydrologic model simulations depend heavily on the availability of reliable precipitation estimates. Difficulties in estimating precipitation impose an important limitation on the possibility and reliability of hydrologic forecasting and early warning systems. This study examines the performance o...
A Domain Decomposition Finite-Element Method for Modeling Electromagnetic Scattering From Rough Sea Surfaces With Emphasis on Near-Forward Scattering
ÖZGÜN, ÖZLEM; Kuzuoğlu, Mustafa (Institute of Electrical and Electronics Engineers (IEEE), 2019-01-01)
A high-fidelity full-wave simulator is presented to perform numerical experiments for rough sea scattering problem by considering different polarizations, frequencies, grazing angles, wind speeds, and sea surface spectra. The simulator is based on a novel finite-element domain decomposition (FEDD) method for solving the problem of 2-D electromagnetic scattering over 1-D sea surface. This noniterative method partitions the computational domain into a number of overlapping subdomains and solves each domain in...
Evaluation of SeaWiFS chlorophyll-a in the Black and Mediterranean seas
Sancak, S; Besiktepe, ST; Yılmaz, Ayşen; Lee, M; Frouin, R (Informa UK Limited, 2005-05-20)
The performance of NASA's OC2 and OC4 algorithms to estimate chlorophyll-a concentrations from SeaWiFS radiometric measurements on the global scale was tested in two contrasted bio-optical environments, the Black Sea and the Mediterranean Sea. The in situ bio-optical measurements were made during October 1999 at 25 stations. Comparisons of the in situ measurements with the concurrent SeaWiFS retrievals indicate that the OC2 and OC4 algorithms are not working satisfactorily in both seas. Case 2 waters domina...
Citation Formats
G. Apaydin, O. Ozgun, M. Kuzuoğlu, and L. Sevgi, “A Novel Two-Way Finite-Element Parabolic Equation Groundwave Propagation Tool: Tests With Canonical Structures and Calibration,” IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, pp. 2887–2899, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/49053.