多普勒雷达径向速度退模糊的初步研究

Preliminary study on Doppler velocity data quality control

摘要:

基于雷达变分同化系统(Variational Doppler Radar Analysis System,VDRAS)中雷达速度退模糊方案的思想,建立了一个雷达径向速度退模糊的方案,用于我国多普勒雷达径向速度资料的质量控制,并对方案的质量控制效果进行了检验。该方案的优点是使用模式分析场得到的参考风在每个格点独立地进行退模糊,避免了径向速度大片区域被错误地退模糊,提高了准确度。方案主要包括三步:水平梯度检验、全局退模糊和局部退模糊。利用国家气象中心全球与区域一体化的同化与数值预报系统(Global and Regional Assimilation and Prediction Enhanced System,GRAPES)快速更新循环(Rapid Update Cycle,RUC)系统提供的3 h间隔的分析场资料对多个时次的雷达资料进行退模糊试验。结果表明,该方案能够有效地对模糊速度进行订正,剔除异常资料点,提高可直接用于变分同化的雷达径向风资料的质量,适合业务应用,为我国多普勒雷达资料的质量控制提供了一种新的有效方案。

Abstract:

Based on VDRAS velocity dealiasing technique,a Doppler velocity dealiasing algorithm is developed for the quality control of CINRAD Doppler radar velocity.The advantage of the algorithm is that it dealiases Doppler velocity at each grid point independently by using reference wind obtained from GRAPES RUC analysis,so it reduces the risk of producing incorrectly dealiased velocity in large areas.The algorithm consists of three steps:horizontal shear preserving,global dealiasing,and local dealiasing.Then,the algorithm was tested with radar data obtained from CINRAD during June 2009.The results showed that the algorithm was effective in dealiasing aliased velocities,removing noises and improving the quality of radar observations.It can serve as an operational algorithm for CINRAD Doppler velocity quality control.