Estimation of Rain Induced Specific Attenuation

This paper describes research on Specific attenuation on a terrestrial microwave communications link set up at Nawandgi-Wadi (Karnataka State), India, which has reported signal failure for a number of times under rainy conditions, especially during July to September, each year. The clear air and rainy climatic data has been secured from India Meteorological Department, Hyderabad for a comparative analysis with the live data of rainfall recorded with the aid of two tipping bucket rain gauges, and a disdrometer. A simple model of interpretation of specific attenuation has been utilized with simple formulae to suit the purpose of estimating the rain-induced specific attenuation at the location of the link. The results of this experimentation are in agreement with the disdrometer observations and the data collected through experiment tallies with the Micro Rain Recorded (MRR) data secured from the ISRO-operated-MRR rainfall data secured. The model used in the experimentation, it is hoped, would enable further research in to the aspects of specific attenuation of terrestrial microwave links in different Terrestrial locations of interest.