This study proposes a model for calculating rain attenuation on earth-space path carried out
in Covenant University, Ota, Nigeria, a tropical location. The beacon signals from a
geostationary satellite - ASTRA 28°E (2E/2F/2G) was monitored, recorded and analysed
using a spectrum analyzer operating at frequencies of 12.245 GHz. Rain rates at the station
of the antenna receivers were also logged and analysed. The rainfall rate cumulative
distributions and the resultant rain attenuation are obtained and presented. The results
obtained showed that the cumulative distribution of the measured rainfall rate is not in
agreement with ITU-R prediction. Rainfall rate at 0.001 %, 0.01 %, 0.1 % and 1 % were fed
into the existing Simple Attenuation Model (SAM) and corresponding rain attenuation were
obtained. The measured rain attenuation from the beacon signal was compared with sixteen
existing rain attenuation models in literature only SAM model was closed to the measured
result at the location. SAM model overestimated and underestimated the rain attenuation for
this location at some percentage of time. Hence, a modified SAM model is proposed using
newly obtained specific attenuation coefficients. The proposed modified model is found to
be close to the measured rain attenuation