Communications on Applied Electronics |
Foundation of Computer Science (FCS), NY, USA |
Volume 7 - Number 24 |
Year of Publication: 2018 |
Authors: Simeon Ozuomba, Constant Kalu, Henry Johnson Enyenihi |
10.5120/cae2018652803 |
Simeon Ozuomba, Constant Kalu, Henry Johnson Enyenihi . Comparative Analysis of the Circle Fitting Empirical Method and the International Telecommunication Union Parabola Fitting Method for Determination of the Radius of Curvature for Rounded Edge Diffraction Obstruction. Communications on Applied Electronics. 7, 24 ( Dec 2018), 16-21. DOI=10.5120/cae2018652803
In this paper, comparative analysis of the circle fitting empirical method and the parabola fitting method for determination of the radius of curvature for rounded edge diffraction obstruction was presented. Sample elevation profile data for a 40 Km path with hilly obstruction was collected using web-based Geocontext elevation profile tool. The maximum elevation of 307.4569 m occurred at a distance of 35966.33 m the maximum elevation point from the transmitter. The two radius of curvature methods were applied to the elevation data. The exact radius of curvature based on the circle fitting empirical method is 38,375.22 m whereas the radius of curvature based on the International Telecommunication Union (ITU) parabola fitting method is 34, 029.98 m. Furthermore, while the radius by the empirical circle fitting method remained the same under different microwave frequencies, for the ITU parabola fitting method, there was over 89 % reduction in the radius of curvature from 60,369.69 m at 1 GHz L-band microwave frequency to 11,476.36 m at 12 GHz Ku-band microwave frequency. The essence of this study is to demonstrate the wide variation in the radius of curvature due to the frequency and also to advise that the ITU method may be used only when the ITU method of rounded edge diffraction loss is employed. The other rounded edge diffraction loss methods can use other approximation methods that compare favorably with the exact radius in all frequencies.