新一代多普勒天气雷达强度定标研究

天气雷达回波强度的强弱直接影响预报员对降水强度的判断,在重大气象灾害天气过程中,回波强度偏差有可能导致漏报而产生无法挽回的损失,中国气象局提出“到2022年底全国新一代天气雷达反射率因子标准偏差平均值从4.5dB降低到3.5dB”的目标,就是为了提高雷达监测均一性,降低客观因子对预报质量的影响。本文对岳阳、长沙、湘潭、益阳雷达产品对比分析,利用数据平均偏差方法计算雷达回波强度的扩散特征,得出岳阳雷达回波强度较其他三部雷达均偏弱约4dB以上的结论,并采用“对点测量”方法对岳阳雷达进行重新标定,将平均偏差降低至2.5dB以内,降低了中尺度区域内不同雷达之间的平均偏差,有效增强了回波强度一致性,对提高雷达业务可用性具有十分现实的意义。

Research on intensity calibration of new generation Doppler Weather Radar

The strength of weather radar echo intensity directly affects forecasters" judgment of precipitation intensity. During major meteorological disasters, the deviation of echo intensity may lead to missed reports and irreparable losses. The China Meteorological Administration has proposed the goal of reducing the average standard deviation of the national new generation weather radar reflectivity factor from 4.5dB to 3.5dB by the end of 2022, in order to improve radar monitoring uniformity, Reduce the impact of objective factors on forecast quality. This article compares and analyzes radar products from Yueyang, Changsha, Xiangtan, and Yiyang. The diffusion characteristics of radar echo intensity are calculated using the data average deviation method, and the conclusion is that the echo intensity of Yueyang radar is about 4dB weaker than the other three radars. The "point to point measurement" method is used to recalibrate Yueyang radar, reducing the average deviation to within 2.5dB, t reduces the average deviation between different radars in the mesoscale region, effectively enhances the consistency of echo intensity, and has practical significance for improving the availability of radar services.