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 (ZDR), unfolding and filtering algorithm for differential phase shift (µgDP), calculation of special differential phase (KDP), and attenuation correction for reflectivity factor (ZH) and ZDR. 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 ZDR measurement. Utilized a relational expression between SNR and ZDR, the errors of ZDR affected by noise are corrected improved. (2) The significant quiver, inferred due to backscatter phase shift (¦Ä), and folding of µgDP, both which are able to cause mistakes on estimation of KDP and correction of ZDR, can be diminished through automatic continuous check and filtering. (3) A procedure to compute KDP based on least squares fitting to µgDP with 4-km moving window can minimize random errors of µgDP and influence of ¦Ä. In addition, the performances of KDP in various rainfall rate events are discussed. (4) After attenuation correction of ZH and ZDR by µgDP, the XPDRW radar performs better coherence with the CINRAD-SA radar in simultaneous ZH measurement. Besides, the former ZH is slight bigger than the latter and their difference is greater and greater with increasing ZH. Also, ZDR is inclined to present linear increment with increasing ZH.
Key words£ºX-band, Polarimetric Radar, Quality Control
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