相控阵雷达扫描方式对回波强度测量的影响  

The Measurement Influence of Reflectivity Factor Caused by Scanning Mode from Phased Array Radar

作　　者：吴翀[1,2] 刘黎平[1,3] 汪旭东[4] 范辉[4] 刘琦[4] 

机构地区：[1]中国气象科学研究院灾害天气国家重点实验室,北京100081 [2]成都信息工程学院,成都610225 [3]南京信息工程大学气象灾害预报预警与评估协同创新中心,南京210044 [4]安徽四创电子股份有限公司,合肥230088

出　　处：《应用气象学报》2014年第4期406-414,共9页Journal of Applied Meteorological Science

基　　金：国家自然科学基金项目(41175038);公益性行业(气象)科研专项(GYHY201106046);十二五国家科技支撑计划项目(2012BAC22B00)

摘　　要：有源数字阵列雷达的波束设计非常灵活,可变的波束宽度和多波束模式不仅可以满足不同任务的观测需求,还可有效节约扫描时间,但阵列天线参数随波位改变的特性对相控阵天气雷达回波强度的精确定标提出了挑战。2013年4—6月,中国气象科学研究院与安徽四创电子股份有限公司联合研发的X波段一维有源相控阵天气雷达(X-PAR)进行了装配后的首次测试观测。对比该雷达与相同位置的C波段双线偏振雷达(C-POL)观测资料发现,X-PAR不同宽度的扫描波束均能取得较合理的观测资料。但由于各模式的雷达方程及其标定方法不尽相同,并受到阵列天线照射体积、展宽波束和发射增益的影响,造成X-PAR回波强度存在一定的测量偏差。结合天线参数分析和实际数据统计将测量偏差订正至±1 dB内,为雷达的进一步调试和改进提供了依据。The beam design of active phased array weather radar is flexible,and this variable beam width and multi-beam mode can satisfy the requirement of various tasks and get much higher temporal resolution than general weather radar.However,the performance of active phased array weather radar can be hardly kept consistent due to the massive digital T/R components,and any variations of antenna parameters between the beam direction and axis normal would be a huge challenge for radar calibration.The X-band phased-ar-ray weather radar （X-PAR）developed by State Key Laboratory of Severe Weather of Chinese Academy of Meteorological Sciences and Anhui Sun-create Electronic Co Ltd is tested for the first time from April to June in 2013.The X-PAR and C-band polarization weather radar （C-POL）are installed at the same site, so their observations provide reflectivity measure deviation information and correction scheme for radar de-bugging and calibration of antenna parameters. During the operation of X-PAR,3 kinds of observing modes with different beam width are applied, each using different parameters in their radar equations of calibration algorithm.Observations from C-POL and X-PAR （fine mode）with single scanning beam,X-PAR （quick mode）with multi scanning beams and X-PAR （fine Mode）are contrasted in detail.In order to reduce the comparison bias,severe convection and attenuation should be avoided.Results from statistical analysis indicate that observations from each eleva-tion of X-PAR （fine mode）is 3 dB higher than C-POL,the measurement deviation between quick mode and fine mode changes along 4＆#176;regularly,and is inconsistent in higher elevation.The deviation source of X-PAR （fine mode）and C-POL comes from differences between the antenna parameter and the effective cross section,and the fast mode is also influenced by beam pattern,gaining in different elevation.A cor-rection scheme based on data statistics and fitting is proposed to decrease the bias within 1 dB.By the com-parison through vertica

关 键 词：相控阵天气雷达 回波强度 定量测量 

分 类 号：P412.25[天文地球—大气科学及气象学]