Rain attenuation measurement on Ku-band satellite TV downlink in small island countries

摘要

Analysis of 13-year rain-rate measurements in Fiji shows that the rain exceeded 50 mm/h for 0.01% of a year (R_(0.01)), which is significantly lower than those predicted by existing models. Simultaneous measurements of Ku-band attenuation and rain-rate give A_(0.01) and R_(0.01) as 9.7 dB and 54 mm/h, respectively. The ratio of attenuation excee-dence for the worst month and yearly (at A=A_(0.01)) was 1.8, which is lower than that predicted by the ITU-R study group. The attenuation exceeds the Ku-band link margin for about 15.6 h in a year.