An improved attenuation correction algorithm using dual-polarization radar observations of precipitation

An attenuation correction algorithm based on profiles of reflectivity, differential reflectivity and differential propagation phase is presented. A solution for specific attenuation retrieval in rain medium is proposed, which solves the integral equations for reflectivity and differential reflectivity with cumulative differential propagation phase constraint. The conventional rain profiling algorithms that connect reflectivity and specific attenuation, can retrieve specific attenuation values along the radar path assuming constant intercept parameter, N-w of the normalized drop size distribution. However, in convective storms, the drop size distribution parameters can have significant variation along a path. This paper presents a dual polarization rain profiling algorithm for horizontal looking radars incorporating reflectivity as well as differential reflectivity profiles with cumulative attenuation constraint. The algorithm described in this paper can retrieve the specific attenuation along a path without assuming constant drop size distribution parameters. The dual polarization rain profiling algorithm has been evaluated with X-band radar observations simulated from drop size distribution derived from high-resolution S-band measurements taken by the CSU-CHILL radar. The results show that the proposed algorithm provides an improvement over the current rain profiling algorithms with differential phase constraint.