Algorithm for Computing N Knife Edge Diffraction Loss Using Epstein-Peterson Method

摘要

In this paper, algorithm for computing N knife edge diffraction loss using Epstein-Peterson method and International Telecommunication Union (ITU) knife edge diffraction loss approximation model is presented. Requisite mathematical expressions for the computations are first presented before the algorithm is presented. Then sample 10 knife edge obstructions are used to demonstrate the application of the algorithm for L-band 1 GHz microwave signal. The results showed that for the 10 knife edge obstructions spread over a path length of 36 km the maximum virtual hop single knife edge diffraction loss is 8.054711 dB and it occurred in virtual hop j =10 which has the highest diffraction parameter of 0.233333. However, the virtual hop j =10 has line of site (LOS) clearance height of 2.333333 m whereas the highest LOS clearance is 3.454545 m and it occurred in virtual hop j =6. The minimum virtual hop single knife edge diffraction loss is 6.109884 dB and it occurred in virtual hop j =3 which has the lowest diffraction parameter of 0.008909 as well as the lowest LOS clearance height of 0.142857 m. The algorithm is useful for development of automated multiple knife edge diffraction loss system based on Epstein-Peterson method and ITU knife edge diffraction loss approximation model.