Research On C-band Radar Attenuation Correction Based On K-LWP Schem

C-band weather radar has a higher resolution and sensitivity in detecting precipitation,which is conducive to obtaining precipitation information with weaker echo strength,and is a commonly used radar in modern meteorological operational observation systems.However,C-band weather radar is more significantly attenuated by rainfall,thus limiting the further operational application of C-band radar.Therefore,before further processing of the radar reflectivity factors obtained from Cband radars,attenuation revisions are made to improve the reliability of C-band radar inversions of other meteorological products.Without considering gas attenuation,the attenuation on the radar path is mainly caused by raindrop attenuation.Most of the traditional attenuation revision methods are based on the k-Z relationship between the attenuation coefficient and the echo intensity or the k-K_Dp relationship between the attenuation coefficient and the differential propagation phase shift rate of the dual polarisation parameter,but it is difficult to find a stable attenuation coefficient k,due to the influence of the variation of the raindrop spectrum and the measurement error of the dual polarisation parameter,etc.resulting in the variability of the revisions.In this paper,we propose a new scheme for C-band weather radar（k-LWPscheme）based on liquid water path attenuation revisions and fit its empirical parameters.In order to test the attenuation revision effect of the k-LWPscheme,the attenuation revision experiments are carried out using the rainfall data detected by the C-band dual polarimetric weather radar of Nanjing University of Information Science and Technology and the S-band weather radar of Jiangsu Meteorological Bureau,the C-band phased array radar of Beijing Daxing Airport and the S-band weather radar of Beijing Meteorological Bureau,and the classical Z_H method and the integrated Z_H-K_DPrevision method are combined to investigate the revision effect of the k-LWP scheme.The results show that all three revision methods are able to provide the best results.The results show that all three revision methods can effectively revise the C-band radar reflectivity factor data.The k-LWP scheme is more stable in the revision test,and can reasonably increase the percentage of strong echoes,so that the revised echo percentage distribution is close to that of the S-band radar,and the overall effect is better than that of the Z_H revision method and the Z_H-K_DP integrated revision method,indicating the advantages and stability.