Modeling of effective rainfall rate and rain attenuation in terrestrial links in the tropics

In this paper, the statistical distribution of the rainfall rate for tropical regions is investigated based on comparisons of measured data with the rain rates obtained from calculations using the ITU-R rain maps. The rain rate distributions are compared with an empirical expression for the effective rainfall rate obtained from the cumulative distribution of measured signal attenuation in converging links with different path lengths, spatial orientations and operation frequencies. Also, a semi- empirical method for the prediction of rain attenuation in terrestrial links is presented. The proposed method is simple to apply and uses the concept of an effective rainfall and the full rainfall rate cumulative probability distribution to predict the attenuation distribution.