Rain attenuation prediction at 6.75 GHz in Malaysia using raingauge and radiometer measurements

摘要

Attenuation due to rain is an important constraint in microwavenradio link design especially at frequencies above 10 GHz in temperatenclimates. However, it has been shown in some literature that rain alsonplays an important role in radio signal attenuation below 10 GHz inntropical and equatorial climates which experience higher precipitationnrates. Due to the scarcity of rain attenuation data for the tropicalnregion, a definitive attenuation model can only be derived from longnterm data collection in this region. In this paper, the results of twonyears rain rate data and six months radiometer data are presented. Thenrain data is measured using a tipping bucket type (0.5 mm) rain gaugenwith one minute integration time. The radiometer data were taken for 45nand 90 degrees elevation using a dual channel unbalanced Dickenradiometer. Both the rain gauge and radiometer data were analysed innevent and statistical terms. The attenuation derived from radiometernmeasurements gives a higher value of attenuation compared to rain gaugenmeasurements. It was also found that at for 0.01% of the time, the rainnrate is lower than that given by the ITU (formerly CCIR) for P regionnclimate