基于分级逐库方法的KA波段云雷达反射率因子衰减订正

Attenuation Correction of the KA Band Cloud Radar Reflectivity Factor based on Bin-by-bin Method

针对KA波段云雷达回波衰减引起的数据失真问题,根据雷达气象方程和K-Z经验关系,分析KA波段电磁波传播过程中的液态水及水汽的吸收衰减原理,采用改进的分级逐库订正方法,对学校KA波段云雷达观测数据进行衰减订正试验,并与该雷达目前软件中固定K-Z系数衰减订正效果进行对比分析。分析结果表明,相比云雷达现有反射率因子衰减订正结果,采用分级逐库订正方法后对流性和层状云降水反射率因子的订正有更好的效果,且在回波强度较大时订正效果更为明显,可有效地减少回波的失真。

In order to solve the data distortion problems caused by the echo attenuation of KA band cloud radar,the absorption and attenuation principle of the liquid water and water vapor in the transmission process of KA band micwave is analyzed,according to the radar meteorological equation and K-Z empirical relationship. Moreover,the improved method of bin-by-bin correction in the groups is used,and the attenuation correction experiment based on the data observed by KA band cloud radar at CUIT was carried out. Then it is compared with the correction attenuation effect of K-Z coefficient in the radar at present. The results show that,compared with the existing reflectivity factor attenuation correction results of the cloud radar,the method of bin-by-bin correction in the group has better correction effect for convective and stratiform cloud precipitation reflectivity factor. The correction effect becomes more obvious when the echo intensity is larger,and it can effectively reduce the distortion of the echo.