双偏振相控阵雷达误差评估与相态识别方法  

Error Evaluation and Hydrometeor Classification Method of Dual Polarization Phased Array Radar

作　　者：李哲 吴翀[2] 刘黎平[2] 宗蓉[3] 罗鸣[3] Li Zhe;Wu Chong;Liu Liping;Zong Rong;Luo Ming(Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric Sciences,Fudan University,Shanghai 200438;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081;Shenzhen National Climate Observatory,Shenzhen 518000)

机构地区：[1]复旦大学大气与海洋科学系/大气科学研究院,上海200438 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081 [3]深圳市国家气候观象台,深圳518000

出　　处：《应用气象学报》2022年第1期16-28,共13页Journal of Applied Meteorological Science

基　　金：国家自然科学基金项目(41875036);国家重点研发计划(2018YFC1507400)。

摘　　要：选取2020年3—9月深圳求雨坛的X波段双偏振相控阵雷达探测数据,与同位置的S波段双偏振雷达进行对比。通过一定限制条件定量分析引入误差的原因,发现反射率因子Z_(H)和差分反射率Z_(DR)的标定误差和随机误差较大,其中Z_(H)误差变化范围为-0.5~4.5 dB,Z_(DR)误差变化范围为-0.7~0.2 dB。在上述较大误差影响下,传统模糊逻辑相态识别方法的水凝物相态识别结果不可靠,因此根据不同相态的雷达参量特征范围以及融化层高度建立基本结构为二叉树的决策树相态识别方法。针对上述方法的实际应用效果,分别从水凝物相态识别结果对误差的敏感性和空间分布的合理性进行评估,结果表明:决策树相态识别方法的水凝物相态识别结果稳定性高于模糊逻辑相态识别方法,且在对流云中的水凝物相态分布更加合理,能够发挥X波段双偏振相控阵雷达在研究云内水凝物相态演变的优势。Phased array radar is faster in scanning speed than mechanical scanning radar,but due to the influence of antenna structure and attenuation,phased array radar will produce larger system error and random error.The mainstream fuzzy logic hydrometeor classification method has little difference in the weight coefficients of each parameter,and the calculated composite values are often close,so the hydrometeor classification results are easily affected by data errors.The detection data of the X-band dual polarization phased array radar at Qiuyutan,Shenzhen,from March to September in 2020 are compared with the S-band dual polarization radar at the same location.The points close to the elevation,azimuth and radial distance of the two radars are obtained to establish matching datasets to calculate the errors of X-band dual-polarization phased array radar.Quantitative analysis of the causes for the introduction of errors through certain restriction conditions reveals that the calibration error and random error of the reflectance factor Z_(H) and the differential reflectance Z_(DR) are relatively large.The error range of Z_(H) is-0.5-4.5 dB,and the error of Z_(DR) is-0.7-0.2 dB.After the preliminary correction of calibration error and random error,it is found that there are still some errors in data,which make the hydrometeor classification result of fuzzy logic method unreliable,so the decision tree hydrometeor classification method with the basic structure of binary tree is established according to the characteristic range of radar parameters of different hydrometeors and the height of the melting layer.In order to verify the practical application effects of the above methods,the error sensitivity of hydrometeor classification results and the rationality of hydrometeor spatial distribution are evaluated respectively.Typical examples are selected to further evaluate the rationality of the decision tree hydrometeor classification method by comparing the parameters and hydrometeor classification results of X-band dual polari

关 键 词：双偏振相控阵雷达 误差分析 水凝物相态识别 

分 类 号：P412.25[天文地球—大气科学及气象学]