Program for Using Path Profile and Coordinate Geometry Approach in the Determination of the Exact Radius of Curvature for Rounded Edge Diffraction Loss Computation

In this paper, the design of a program algorithm for using path profile and coordinate geometry approach in the determination of the exact radius of curvature for rounded edge diffraction loss computation is presented. In addition to the radius of curvature, the program determined the values of other essential parameters required for the computation of rounded edge diffraction loss. The additional parameters include; occultation distance, the line of sight clearance height and the external angle between the tangent lines to the path profile. Importantly, the requisite mathematical expressions and detailed algorithm for the program are presented. Then a program was developed in Visual Basic for Application (VBA) based on the algorithm. Furthermore, sample elevation data was used to demonstrate the effectiveness of the program in the determination of the radius of curvature along with the other essential parameters required for the rounded edge diffraction loss computation. A sample path elevation profile was obtained using Geocontext path profile software for a 5233.692 m path that has a hilly obstruction with a maximum elevation of 593.0363 m that occurred at about a distance of 1861.649 m from the transmitter. The program result showed that for the sample path profile the rounded edge should be of a circle with a radius of 9,392.78 m, the occultation distance is 2,002.15 m, the line of sight clearance height which is 176.469 m and finally the angle between the tangent lines at their point of intersection is 0.212916 radians. The result is particularly useful because it is easy to generate the coordinates of elevation points which the program developed in this paper can use to automatically generate the essential parameters needed for the computation of rounded edge diffraction loss.