Research On Optimization Quantitative Precipitation Estimate Algorithm Based On S-Band Dual-Pclarization Radar

In recent years, the dual polarization radar has been built in Guangdong and other places. With the application of the dual polarization radar in China, a lot of research projects are urgently proposed.In order to evaluate and improve the radar quantitative precipitation estimation,an optimization rainfall algorithm of S-band dual-polarization radar, named HCA-LIQ, is developed by referring to the Colorado State University (CSU)-ICE algorithm in this study. The algorithm is based on hydrometeor classification algorithm (HCA), and gives full play to the advantages of multi parameters of dual polarization radar, selecting a variety of local precipitation measurement relationships in Guangdong.Both the data collected from the S-band dual-polarization radar in Zhuhai,Guangdong Province and a network of rain gauges are used to evaluate the performance of the new algorithm. The comparison is also performed between the HCA-LIQ. CSU-ICE optimization algorithms and the traditional ZH-R method. The results show that the HCA-LIQ optimization algorithm is well correlated with gauges and presents high stability. The HCA-LIQ optimization algorithm is superior to the CSU-ICE. According to the bias statistics of the classification of rainfall intensity,the new HCA-LIQ optimization algorithm bias decrease by 71%?68% for heavy rain?torrential rain respectively in comparison to the traditional ZH-R method.In addition,the paper makes a comparative analysis,including the ZH and the QPE,of the two dual polarization radar in Guangdong and Guangzhou . Because of the difference of sampling space, the attenuation of radar wave in the process of transmission, and the influence of radar calibration, the echo intensity detected in the same area is different. It is found that the QPE of Guangzhou radar is better than Zhuhai radar, the NB of the QPE about Zhuhai radar reached 50%. That means radar shows a serious underestimation and a low correlation with gauge. The main reason is that the system error of Zhuhai radar in 2016 is too large.