The Effect of Mean and Differential Attenuation on the Precision and Accuracy of the Estimates of Reflectivity and Differential Reflectivity

Abstract

Error propagation analysis is applied to evaluate the effects of correcting horizontal and differential attenuation on the precision of the estimates of reflectivity and differential reflectivity. The analysis shows that the loss of precision on reflectivity and differential reflectivity is of the same order of magnitude as the propagation power losses added, notwithstanding how horizontal and differential attenuation are accounted for. Polarimetric weather radar simultaneously transmitting and receiving horizontally and vertically polarized waves is then considered. Differential propagation phase is used as the predictor variable for attenuation. Calculations for three microwave frequencies corresponding to S, C, and X bands show that the losses in accuracy and in precision of the estimates of reflectivity are about 16 and 68 times worse at C and X bands, respectively, than at S band. The corresponding values for the estimates of differential reflectivity are about 20 and 52 times worse.