傅立叶相位技术在雷达回波移动矢量特征分析中的应用  

Applications of Fourier Phase Analysis Technique to Computation of Radar Cloud Echo Motion Vectors

作　　者：肖现[1] 肖辉[1] 王振会[2] 何宇翔[1] 秦元明[3] 

机构地区：[1]中国科学院大气物理研究所云降水物理与强风暴实验室,北京100029 [2]南京信息工程大学遥感学院,江苏南京210044 [3]吉林省人工影响天气办公室,吉林长春130062

出　　处：《南京气象学院学报》2008年第4期473-482,共10页Journal of Nanjing Institute of Meteorology

基　　金：中国科学院知识创新工程重要方向项目(KZCX3-SW-225);国家科技支撑计划项目(2006BAC12B00-1);国家自然科学基金重点资助项目(40333033);中国科学院“奥运科技”专项(KACX1-02);中国气象局与吉林省人民政府人工影响天气联合开放实验室0603课题;中国科学院知识创新工程青年人才领域前沿项目(IAP07408)

摘　　要：应用傅立叶相位分析技术,建立了一种新的基于雷达体扫资料的回波移动矢量、移动路径计算和临近预报算法。其基本思路是:对两个相邻时刻的雷达体扫回波资料分别进行快速傅立叶变换,得到两个雷达回波的相位差,再计算出回波的移动方向及移动速度。利用X波段多普勒多偏振雷达在吉林省获得的雷达资料对本算法进行检验,结果表明,此方法可以给出雷达回波内更加精细的回波移动矢量结构,能够较准确地反映出不同类型回波的中小尺度系统移动特征,对雷达回波移动路径有较好的追踪和临近预报能力。对一次飑线过程的计算结果显示,飑线上的强回波区移速移向存在明显的不均匀性。An algorithm of motion vectors, tracking and nowcasting of echoes based on Fast Fourier Transform（FFT） technique is developed for the radar volume-scan data. The basic principle is that firstly, the FFT is separately used to two successive volume-scan radar echo data whose time interval is small, yielding a phasic difference between the two radar echoes;secondly, using the phasic difference, the direction and speed of radar echo motion can be obtained. This algorithm is validated with the data of a Doppler polarimetric meteorological radar from the Institute of Atmospheric Physics, Chinese Academy of Sciences. The retrieved results show that using the new algorithm, a more precise structure of echo motion vectors is captured, and some typical dynamic characteristics of meso- and micro-scale weather systems are also depicted. The technique also has a good performance of tracking and nowcasting radar echo movement. It is also found that there was obvious non-uniformity in movements of strong echoes in a squall line on 12th July 2006.

关 键 词：快速傅立叶变换 雷达回波移动矢量 追踪 临近预测 

分 类 号：P406[天文地球—大气科学及气象学]