A Ka-band solid-state transmitter cloud radar and data merging algorithm for its measurements
A Ka-band solid-state transmitter cloud radar and data merging algorithm for its measurements
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DOI：
10.1007/s00376-016-6044-8
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发表时间：
2017-03
影响因子：
5.8
通讯作者：
Liping Liu;Jiafeng Zheng;Jingya Wu
中科院分区：
文献类型：
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作者：
Liping Liu;Jiafeng Zheng;Jingya Wu
具体介绍了雷达的三种工作模式（即边界模式M1、卷云模式M2和降水模式M3）的设计。同时，提出了三种模式下的云雷达数据合并算法。估计了雷达探测到水成物的次数和不同模式数据对合并数据的贡献百分比。对合并算法的性能进行了评价。结果表明，每种模式的最小可探测反射率与理论结果一致。合并后的数据提供了5 km高度处最小反射率为−35 dBZ的测量值，并获得了0.2 km高度以上的信息。三种工作模式测量的径向速度一致，反射率测量的系统误差小于2 dB。然而，在不同的工作模式下测量的线性退极化比存在较大的差异。通过应用脉冲压缩技术，雷达对中高层云中水成物的探测率提高了60%。
This study concerns a Ka-band solid-state transmitter cloud radar, made in China, which can operate in three different work modes, with different pulse widths, and coherent and incoherent integration numbers, to meet the requirements for cloud remote sensing over the Tibetan Plateau. Specifically, the design of the three operational modes of the radar (i.e., boundary mode M1, cirrus mode M2, and precipitation mode M3) is introduced. Also, a cloud radar data merging algorithm for the three modes is proposed. Using one month’s continuous measurements during summertime at Naqu on the Tibetan Plateau, we analyzed the consistency between the cloud radar measurements of the three modes. The number of occurrences of radar detections of hydrometeors and the percentage contributions of the different modes’ data to the merged data were estimated. The performance of the merging algorithm was evaluated. The results indicated that the minimum detectable reflectivity for each mode was consistent with theoretical results. Merged data provided measurements with a minimum reflectivity of −35 dBZ at the height of 5 km, and obtained information above the height of 0.2 km. Measurements of radial velocity by the three operational modes agreed very well, and systematic errors in measurements of reflectivity were less than 2 dB. However, large discrepancies existed in the measurements of the linear depolarization ratio taken from the different operational modes. The percentage of radar detections of hydrometeors in mid- and high-level clouds increased by 60% through application of pulse compression techniques. In conclusion, the merged data are appropriate for cloud and precipitation studies over the Tibetan Plateau.