Rain microphysics estimation using X-band dual polarization radar measurements

Rain microphisycs retrieval has been proposed and demonstrated mainly at S-band where attenuation effects are usually negligible. Recent advances in attenuation correction techniques enable rain microphisycs retrieval also using attenuating frequencies, such as X- and C-band. Most up to date attenuation correction methodologies are based on the use of a constraint represented by the total amount of the attenuation encountered along the path, which is distributed over each range bin contained in the path. The inner self-consistency of radar measurements can be exploited to improve the attenuation estimate obtained using those techniques. In fact, based on the self-consistency principle, an optimization procedure can be devised to obtain the best estimate of specific and cumulative attenuation as well as of specific and cumulative differential attenuation. The main goal of the study is the examination of the drop size distribution retrieval from X-band radar measurements after attenuation correction. The study is based both on simulated and measured data. Simulations based on the use of profiles of gamma drop size distribution parameters obtained from S-band observations are used for quantitative analysis. Examples of the DSD parameter retrievals using radar measurements corrected for attenuation and differential attenuation are also shown.