Microwave attenuation by realistically distorted raindrops: Part II - predictions

Abstract

This part of the paper describes the applications of the theoretical results presented in Part I to calculate the specific microwave attenuation due to rainfall. The scattering characteristics of the varying distorted raindrops are first analyzed in detail to study the effects of the large-scale raindrop distortion. The attenuations of the microwaves by rainfall are then computed numerically for two representative regions, i.e., the moderate climatic region and Singapore's tropical region, by using the Marshall-Palmer (MP) distribution and the Singapore local distribution of raindrop sizes. The International Radio Consultative Committee (CCIR) recommended model is compared with the specific attenuation calculated using MP distribution of the raindrop sizes. The two-year experimental data of the rainfall attenuation of CW microwaves in Singapore are finally compared with the predicted specific attenuation computed by using the local raindrop size distribution. Good agreement between the measured data and the calculated results has been achieved demonstrating the applicability and versatility of the analyses. Finally, the specific attenuation of microwaves at 8, 15, and 30 GHz in Singapore's tropical region is predicted.