基于VAD技术的迭代法在实测多普勒速度缺测区域的填补研究

An iterative filling method for the lacking area in the observational Doppler velocity field based on the VAD technique

中文关键词:  VAD技术，迭代法，填补技术，多普勒速度，缺测区域

英文关键词:VAD technique, Iterative method, Filling technique, Doppler velocity, Lacking region

中文摘要:

      多普勒天气雷达径向速度场缺测区域的存在是影响速度二次产品算法精确度的重要因素，在实际风场为线性分布的假设条件下，文中详细介绍了一种基于VAD技术的迭代填补技术。在合理考虑迭代约束条件的情况下，应用实测多普勒速度数据，根据缺测区域类型随机制造非连续累积10°—180°缺口的缺测区域和连续累积10°—180°缺口的缺测区域进行填补试验。与原数据进行对比分析表明，该方法适用于非连续累积缺口180°以内的缺测区域以及连续累积缺口110°以内的缺测区域，平均绝对误差约在2 m/s以内，填补效果良好。另外，在同时满足线性插值填补法和迭代填补法的前提条件下，对比结果表明两种方法精度可信度均较高，相对于插值法对速度数据正负交替的敏感性，迭代法适用范围更广。

英文摘要:

      The existence of the lacking region in the Doppler weather radar velocity field is one of the most important factors impacting the accuracy of velocity products. An iterative filling method based on the VAD technique is presented in detail under the assumption of the actual wind field of linear distribution. A filling test is conducted for the artificially created random discontinuous cumulative 10°-180° missing gap as well as the continuous cumulative 10°-180° gap according the type of lacking area, based on the observational Doppler data. The analysis shows that the method is suitable for the random discontinuous cumulative gap within 180°and the continuous cumulative gap up to 110°. The average absolute error is in about 2 m/s compared with the original data. The linear interpolation method and the iterative method are also compared with each other under the two methods' prerequisite conditions met concurrently. The results show that the accuracy of the two methods are creditable. Relative to the sensitivity in the positive and negative turn of velocity data in linear interpolation method, iterative method should have a broader application.