基于双基多普勒天气雷达资料的风场重建研究与软件开发

【作者】 于红博；

【导师】 陈钟荣；

【作者基本信息】 南京气象学院 ， 大气物理学与大气环境， 2004， 硕士

【摘要】 本文从双基地多普勒天气雷达系统的原理出发，介绍了双基地多普勒天气雷达的坐标系、基本几何关系、双基地雷达方程。分析了双基地雷达风场合成公式，推导了双基地雷达中目标在子站中的定位方程，其中涉及到从大地坐标系到本课题所定义的坐标系的转换。并通过风场模拟资料在16km×16km×10km的范围内对风场的三个分量进行了分析，分别对匀速风场、非匀速（变速变向）风场进行了重建。结果显示，对匀速风场反演的效果很好，在进行非匀速（变向和变速）风场的模拟时发现反演的垂直速度很不理想，但反演的水平风场效果较好。通过分析发现接收机的方位角范围较广可以接收到不同方向的雷达散射信号，对接收机风场资料的准确性影响很大，同时还与散射角有关。当散射角范围在40°—150°之间时，标准偏差范围在2 ms^-1和3 ms^-1之间。 介绍了数据质量控制，包括旁瓣污染、资料的填补与平滑、双基地最大不模糊速度、从极坐标到直角坐标的转换以及在模拟风场过程中发现的问题和解决办法。运用变分法来确定旁瓣污染指数，运用线性插值进行坐标转换。 另外，在模拟及重建风场过程中，进行系统开发时，使用了VC++6.0为主要编程工具，结合工程计算语言Matlab，运用它的作图功能，来实现双基地气象雷达系统的二维和三维图形显示。 在本文的结束部分提出了用变分法估算风场垂直分量，并给出了方法步骤。更多还原

【Abstract】 My paper introduces reference frame of bistatic Doppler weather radar, basic geometry connection and the equation of bistatic Doppler radar from the theory of bistatic Doppler weather radar . Bistatic wind fields synthesis equations are analysed and I educes target location equation in receiver including conversion from ground reference frame to one defined by us. The three wind fields components in a domain of 16km X 16km X 10km are analysed with simulated radar data so as to reconstruct uniform and shift wind fields. The result shows the effect of uniform wind fields rebuild is good , however the vertical velocity in shift one is not ideal . It is found the azimuth range of receiver is so wide that it can receive echos from different orient. Which affects the data quality of wind fields in receiver. And a standard deviation margin varying between 2 ms-1 and 3 ms-1 within a scattering angle limit of 40 to 150 .Data quality control including sidelobe contamination , data’s filling and smoothing, Nyquist velocity of bistatic Doppler radar, interpolation of velocities from a polar grid to a Cartesian grid and problems found during simulating data and solusion to them. The sidelobe contaminatin index is determined by using variational methods . Coordinate conversion with linear interpolation.Moreover terminal system is empoldered mainly by VC++6.0 Combining with Matlab . Two- and three-dimensional graphics of bistatic Doppler radar system can be showed by using Matlab’s graphics function.The vertical velocity is going to be estimated by using a variational analysis method.更多还原