Rain attenuation statistics of Ka-band Earth-space path

The Olympus Satellite has provided the first opportunity for an extensive propagation measurement campaign at Ka-band in Europe. Results of Olympus propagation measurements at 20 GHz and 28.8° path elevation were presented. The observed annual distribution of rain attenuation agreed very well with the ITU-R rain attenuation model, though the worst month distribution differed significantly. Positive fade rates in excess of 1.5 dB/min were not observed. The results of fade duration analysis revealed that intense fades are in general short-lived. Fade levels in excess of 20 dB were not continuously exceeded for more than 3 minutes at a time during the experimental period. The measurements reported seem to verify the applicability of the ITU-R rain attenuation model to the climatic condition of the experiment site and period. They clearly indicate that the model does at least give good estimates of annual rain attenuation exceedance for systems design in regions with climate and rainfall patterns similar to those in England