Rainrate and rain attenuation statistics for different homogeneous regions of India

Abstract

Rain rate and rain attenuation predictions are one of the most important steps to be considered when analyzing satellite communication links at the Ku and Ka bands. In this paper a simple approach for better estimation of specific rain attenuation and rain rate distributions using TRMM and GPCP datasets is presented.  For the first time estimations are presented over different homogeneous regions of India and compared with TRMM and GPCP data sets. These two datasets are interpolated using the Bi Linear interpolation method for the13 (1998-2010) years monthly data.  Using the modified Dutton Dougherty method One minute rain rate distribution is estimated. These results (CDF) are compared with ITU-R P.837.5 recommendations, and observed the relative error at different (0.001-1%) probabilities. The specific rain attenuation calculation at 0.01% and 0.001% of probabilities for 10-50GHZ frequencies over the 6 homogeneous regions of India are presented using the ITU-R method. Observations indicate maximum specific attenuation in the NE region, Cherapunji at 0.001% of the time, and minimum attenuation observed to be 21.988 dB/km in Bikaner at 0.01% off at 50 GHZ frequency in the NW region. Rain attenuation and rain rate distribution are observed to exhibit similar characteristics over the six homogeneous regions of India.