Comparison of advanced radar polarimetric techniques for operational attenuation correction at C band

Rain path attenuation correction is a challenging task for quantitative use of weather radar measurements at frequencies higher than S band. The proportionality relationship between specific attenuation alpha(hh) (specific differential attenuation alpha(dp)) and specific differential phase K(dp) is the basis for simple path-integrated attenuation correction using differential phase Phi(dp). However, the coefficients of proportionality are known to be dependent upon temperature, on the one hand, and shape and raindrop size distribution, on the other hand. To solve this problem, a Bayesian classification scheme is proposed to empirically find the prevailing rain regime and adapt the Phi(dp)-based method. The proposed approach herein is compared with other polarimetric techniques currently available in the literature. Several episodes observed in the Paris, France, area by the C-band dual-polarized weather radar operating in Trappes (France) are analyzed and results are discussed.