Modelling of rain decay parameter for attenuation estimation at a tropical location

Owing to the wide rain variability of the tropical region, the Simple Attenuation Model (SAM) estimated rain attenuation values are often found to exhibit substantial deviation from the actual measurements over the location, Kolkata (22°34′N, 88°22′E). This is due to the variability in rain cell sizes resulting from the diverse rain characteristics of the region. Thus, an attempt has been made to model the rain decay parameter in SAM on the basis of the tropical rain characteristics. A model of rain decay parameter in terms of rain rate is proposed which accounts for different types of rain at the present location. The incorporation of the model of decay parameter provides a better estimation of rain attenuation than the existing SAM and ITU-R model.