Severe Cause of Cloud Attenuation and Rain Attenuation on Space Communication Link at Millimetre Band and Differentiation between Rain Attenuation and Cloud Attenuation

Rain will be estimated with the formation of cloud consists of water droplets, at higher frequencies such as millimetre band, that experiences a signal degradation and signal reduction due to the cloud consists of water droplets. The atmospheric gases, clouds, rain, snow, fog, cloud droplets, noise, water vapour, hydrometers absorbs electromagnetic energy, which results in the signal degradation. Clouds in generally consists of water droplets of less than 0.10mm in diameter, whereas raindrops in generally consists of range from 0.10mm to 9.5mm in diameter. So all these effects were leads to degradation in the quality of transmissions and in increase in the error rate of digital transmissions. In general, the higher frequency leads to, the more a signal is susceptible to rain in the atmosphere. For the purpose of cloud impact effect evaluation, the cloud cover statistical data, for low level clouds were derived from the earth-satellite link observations. These Extracted statistical data were used to obtain the seasonal drastic fluctuations.