Tropical raindrop size distribution for the prediction of rain attenuation of microwaves in the 10-40 GHz band

This paper describes the measurement of microwave rain attenuation over a ten-year period (1988-1998) in Singapore. The rain attenuation of (vertically and horizontally polarized) microwaves at 15, 21, and 38 GHz propagating over a path length of approximately 1.1 km were recorded. A negative-exponential raindrop size distribution model is then developed by fitting of the experimental data with the total extinction cross sections of oblate spheroidal raindrops computed from the T-matrix approach. Graphs for attenuation versus rain rate (at selected frequencies) and for attenuation versus frequency (at selected rain rates) are also given.