B.S.T.J. Brief: Perturbation calculations of rain-induced differential attenuation and differential phase shift at microwave frequencies

In a recent note1 calculated results of differential attenuation and differential phase shift, as a function of rain rate, were given at frequencies of 4, 18.1, and 30 GHz. The calculations have since been done at 11 GHz also. These results are based on scattering of a plane electromagnetic wave by oblate spheroidal raindrops. The point matching procedure used to obtain nonperturbative solutions to the problem was briefly described, and full details will be presented later.2 Somewhat similar calculations have been carried out by Oguchi2 at 19.3 and 34.8 GHz.