The Precipitation Rate Retrieval Algorithms for the GPM Dual-frequency Precipitation Radar

ournal of the Meteorological Society of Japan

article

Shinta SETO¹  Toshio IGUCHI²  Robert MENEGHINI³  Jun AWAKA⁴  Takuji KUBOTA⁵  Takeshi MASAKI⁶  Nobuhiro TAKAHASHI⁷ 

[1] Graduate School of Engineering, Nagasaki University;University of Maryland;NASA Goddard Space Flight Center;Tokai University (Emeritus Professor);Earth Observation Research Center;Remote Sensing Technology Center of Japan;Institute for Space-Earth Environmental Research, Nagoya University

关键词: precipitation radar;    drop size distribution;    scattering table;    non-uniform beam filling correction;    surface reference technique;   

DOI  :  10.2151/jmsj.2021-011

来源: Meteorological Society of Japan

【 摘 要 】

In this paper, precipitation rate retrieval algorithms for the Global Precipitation Measurement mission's Dual-frequency Precipitation Radar (DPR) are developed. The DPR consists of a Ku-band radar (KuPR; 13.6 GHz) and a Ka-band radar (KaPR; 35.5 GHz). For the KuPR, an algorithm similar to the Tropical Rainfall Measuring Mission's Precipitation Radar algorithm is developed, with the relation between precipitation rate R and massweighted mean diameter D m ( R−D m relation) replacing the relation between the specific attenuation k and effective radar reflectivity factor Z e . The R−D m relation can also be applied to the KaPR and dual-frequency algorithms. In both the single-frequency and dual-frequency algorithms, the forward retrieval method is applied with an assumed adjustment factor for the R−D m relation ( ε ) and the results are evaluated to select the best value of ε . The advantages of the dual-frequency algorithm are the availability of the dual-frequency surface reference technique and the ZfKa method, which is a method to use the attenuation-corrected radar reflectivity factor Z f of KaPR, to select ε as well as the possibility to selectively use measurements from KuPR or KaPR. This paper also describes the derivation of the scattering table and the R−D m relation as well as the procedure for non-uniform beam filling correction in detail. The outputs are then statistically analyzed to demonstrate algorithm performance.

【 授权许可】

Unknown