C波段双多基地多普勒雷达资料处理和三维变分风场反演方法研究

研究了双多基地多普勒雷达资料的配对方法、风场反演的区域和精度,并研制了基于三维变分方法的双多基地多普勒雷达系统的风场反演系统.利用安徽四创电子股份有限公司研制的一个主动雷达和两个侧向接收天线组成的双多基地多普勒雷达系统获取的外场试验资料,进行了风场反演试验.该风场反演方法利用主动雷达和被动接收系统测量的径向速度作为弱约束,用质量连续方程作为强约束,来反演三维速度场.利用Advanced Regional Prediction System(ARPS)模式模拟的一次龙卷过程的结果,进行了风场反演的模拟试验.结果表明:双多基地多普勒雷达系统能较准确再现龙卷的中尺度特征和强上升气流的结构,从上下两个方向进行垂直积分可以减小垂直速度的反演误差,利用两个侧向接收系统的资料能进一步减小径向速度随机误差对风场反演的影响,增大风场反演的范围.三个分系统单独获取的资料空间配对效果很好,利用不同雷达径向速度反演的风场比较近似,反演的风场与径向速度定性分析和速度方位显示方法(VAD)结果比较一致,该双多基地多普勒雷达系统同步观测技术设计合理,在实时探测三维风场特别是探测近地层风场方面有广泛的应用潜力.

Radar Data Processing and a Variational Algorithm for 3-Dimensional Wind Field Retrieval by C Band Bistatic Radar Network

The data processing and variational algorithm for 3-D wind field retrieval by bistatic Doppler radar network are developed and bias of retrieved wind is analyzed.The wind retrieval algorithm is used to analyze the bistatic radar data in the field experiment conducted in Anhui Province in 2004.The algorithm uses the Doppler velocities of the three receivers as weak constraints and uses the continuity equation as a strong constraint in a cost function in which the two horizontal wind components are the control variables.The ARPS simulation outputs for a tornado process are used to examine the performance of the algorithm.The results show that the bistatic radar system could reproduce the mesoscale features of the tornado,upward and downward integrations can reduce the bias of retrieved vertical velocity.The radial velocity data from second bistatic radar can reduce the retrieval bias and extend the coverage.The radar data recorded by three receivers match very well.The wind fields calculated from different datasets are similar and agree with VAD(the Velocity Azimuth Display) results.The design and concept of the bistatic radar system are correct,the data can be used in 3-D wind field analysis,especially in the boundary wind retrieval.