Raindrop size distribution observation and k-Z relationship analysis for TRMM/PR and GPM/DPR algorithm development

National Institute of Information and Communications Technology (NICT) developed the mobile precipitation observation system (MPOS) for the dual Ka-band radar field campaign for GPM/DPR ground validation. The precipitation measurement instruments are installed on the roof of container. The installed instruments for raindrop size distribution (DSD) measurements are 2-dimensional Video distrometer (2DVD), Joss-type disdrometer, Laser Optical disdrometer (Parsival), Precipitation Occurrence Sensor System (POSS). 2DVD, Persival and POSS can measure not only raindrop size distribution but also ice and snow size distribution. Observations using the MPOS were performed in Okinawa Island, in Tsukuba, over the slope of Mt. Fuji, in Nagaoka, and in Sapporo, Japan. Using these observed DSD data in the different provinces, the characteristics of DSD itself are analyzed and the extinction cross-section and the back scattering cross-section can be processed by the Mie Scattering theory. Then, the specific attenuation (k) and the radar reflectivity (Z) for Ka and Ku-band are estimated for evaluation and improvement of the TRMM/PR and GPM/DPR algorithm.