基于微波链路的雷达回波衰减订正个例分析  

Case Analysis of Radar Attenuation Correction Based on Microwave Links

作　　者：薛杨[1,2] 刘西川 高太长[1] 宋堃[1] 张鹏[3] 

机构地区：[1]国防科技大学气象海洋学院,南京211101 [2]西安卫星测控中心,西安710000 [3]陆军工程大学,南京211101

出　　处：《气象科技》2017年第5期787-794,共8页Meteorological Science and Technology

基　　金：江苏省自然科学基金青年基金项目(BK20150708);国家自然科学基金青年基金项目(41505135);国家自然科学基金面上项目(41475020)资助

摘　　要：降雨对微波的衰减作用在雷达探测和信号通信中有着不可忽略的影响。本文利用近年来出现的微波链路测量新方法,研究了利用微波链路进行天气雷达回波衰减订正的方法。微波链路可以直接获取传播路径上的总衰减,基于此建立衰减订正的约束条件,并利用前向迭代法对天气雷达回波进行逐库订正。首先从现有衰减订正的理论出发,通过确定微波链路衰减参考值、雷达衰减订正算法和衰减系数,建立基于微波链路的天气雷达衰减订正模型;搭建9.47GHz微波链路测量试验系统,对X波段雷达进行衰减订正试验。针对一次个例进行分析,与自动雨量站同步对比观测试验表明:订正后的雷达反射率因子明显高于雷达实测反射率因子;订正后雷达估测的降雨量与自动雨量站的观测差值减小;累积降雨量绝对偏差由-6.11mm减小到1.04mm,相对偏差由0.99%减小到0.17%;订正后估测的降雨强度与雨量计的相关性得以提高。该订正算法主要通过对参数的调整,使得k-Z关系更符合实际,从而提高了探测精度,验证了该方法的可行性与准确性。Weather radar attenuation quantitative precipitation estimation correction has a great significance in improving the accuracy of By using the new method of microwave links, a radar attenuation correction method based on microwave links is analyzed in this paper. The microwave links can measure the path attenuation directly, by which the constraint can be established, and weather radar echoes can be corrected by the forward-iterative correction algorithm. From the existing theories of attenuation correction, the weather radar attenuation correction mode[ based on the microwave links by determiningthe microwave link attenuation reference, radar attenuation correction algorithm and attenuation coefficients is proposed. At last a 9.47 GHz microwave link measurement experiment system is established, and several automatic precipitation stations and a X-band weather radar are used for comparative observation. The results show that the corrected radar reflectivity factors are higher than the uncorrected factors obviously. The discrepancy between the rainfall derived from the corrected radar reflectivity and the rainfall observed by the automatic precipitation station is relatively small; the absolute deviation of precipitation accumulation is within 3 mm; the relative deviation is within 0.6%. The correlation coefficient is higher than before. The results validated the feasibility and accuracy of the above method. Using the microwave links on weather radar attenuation correction can effectively adjust the relationship between K and Z.

关 键 词：定量估测降水 衰减订正 前向迭代 

分 类 号：P407.6[天文地球—大气科学及气象学]