A comparison of precipitation attenuation and radar backscatter along Earth--Space paths

Measurements of attenuation by precipitation at 4, 8 and 15 GHz have been made along elevated paths through the troposphere. Simultaneous measurements of radar backscatter at 2.9 GHz are used to derive, consistent with existing theoretical relations, empirical expressions relating backscatter to attenuation. It is concluded that, for rains observed at Ottawa, Ont., Canada, and provided that the hydrometeors are liquid, the empirical relations can be used to determine the attenuation caused by rains of different types. However, for situations in which either hail or an intense bright band was observed, the attenuations calculated from the radar data were grossly in error.