Experimental Studies of Slant-Path Rain Attenuation Over Tropical and Equatorial Regions: A Brief Review

Propagation impairment due to rain is one of the most critical considerations for satellite communication (Satcom) links above 10 GHz. The existing studies at tropical and equatorial regions are mostly focused on rain attenuation characteristics derived from rainfall characteristics, which may not be adequate to represent actual rain attenuation characteristics. The experimental studies on the same topic are very scattered and limited over these regions. Consolidating experimental results can provide a good background for rain attenuation studies over these regions and will be helpful to validate new models as well as devise new strategies to combat high fade condition. In this article, we attempt to review and summarize the performance of different rain attenuation models validated against satellite signal measurements at tropical and equatorial locations. This will serve as a benchmark for understanding the rain attenuation characteristics over this part of the globe.