Abstract

Several appoaches to control data quality of an X-band coherent pulse dual-Polarimetric Doppler Radar on Wheel (XPDRW radar), cooperatively produced and developed by Institute of Heavy Rain (IHR), China Meteorological Administration, Wuhan and Anhui Sun-Create Electronics Co., Ltd., are described and analyzed. These methods, which have been proposed to estimate precipitation, include error correction of differential reflectivity (Z_DR), unfolding and filtering algorithm for differential phase shift (µg_DP), calculation of special differential phase (K_DP), and attenuation correction for reflectivity factor (Z_H) and Z_DR. And, result analyses of the data quality control through utilizing the methods mentioned above are conducted based on two radar datasets of typhoon Nuri detection respectively derived from XPDRW radar situated at Hailing island, Yangjiang, Guangdong and a CINRAD-SA radar located at the meteorological bureau of the same city. Finally, several conclusions are obtained as below: (1) Low signal-to-noise ratio (SNR) plays an important role to impact on precision of Z_DR measurement. Utilized a relational expression between SNR and Z_DR, the errors of Z_DR affected by noise are corrected improved. (2) The significant quiver, inferred due to backscatter phase shift (¦Ä), and folding of µg_DP, both which are able to cause mistakes on estimation of K_DP and correction of Z_DR, can be diminished through automatic continuous check and filtering. (3) A procedure to compute K_DP based on least squares fitting to µg_DP with 4-km moving window can minimize random errors of µg_DP and influence of ¦Ä. In addition, the performances of K_DP in various rainfall rate events are discussed. (4) After attenuation correction of Z_H and Z_DR by µg_DP, the XPDRW radar performs better coherence with the CINRAD-SA radar in simultaneous Z_H measurement. Besides, the former Z_H is slight bigger than the latter and their difference is greater and greater with increasing Z_H. Also, Z_DR is inclined to present linear increment with increasing Z_H.

Key words£ºX-band, Polarimetric Radar, Quality Control