Prediction of hilly terrain diffraction loss experienced bymicrowaves

摘要

The investigation consisted of carrying out signal loss andnpolarisation measurements using 20 radio paths ranging in length from 3nto 10 km planned over the measurement area which is approximatelynrectangular in shape measuring 20 km by 12 km. This area proved to benvery useful in the study of diffraction loss by terrain features as itncontained six almost parallel valleys running north to south which formnan undulating landscape providing a cross sectional path profile rangingnin height from 100 m to 500 m above sea level. Simultaneous measurementsnof both co-polar and cross-polar components of the received signal werentaken and for each radio path a set of readings consisting of 100 suchnsignal levels (co and cross-polar values) were taken to provideninformation on the variability of the signal caused by wind movements