双偏振相控阵雷达与业务雷达的定量对比及观测精度研究

相控阵天气雷达突破了全机械驱动天线天气雷达的时空分辨率瓶颈,能够提供更加快速、精细的观测资料。但阵列天线存在性能参数随扫描角偏离法向而恶化的情况,使相控阵雷达定量测量存在困难。本文针对中国华南地区最新布网的双偏振相控阵天气雷达,通过与当地S波段业务雷达在相同区域内的定量对比,评估了反射率因子差分反射率因子的误差量级及其随扫描角、观测时间的变化趋势。研究结果表明,相控阵雷达反射率因子的误差不大、约0.82 dB,而差分反射率因子的误差则高达1.04 dB,并且不同仰角、不同时刻之间也存在一定的波动。为此本文提出了基于S波段雷达实时数据的订正方案,能够较好地解决双偏振相控阵天气雷达的定标问题,为相控阵雷达的业务应用提供了保障。

Research on Quantitative Comparison and Observation Precision of Dual Polarization Phased Array Radar and Operational Radar

The space-time resolution bottleneck of all-mechanical driven antenna weather radar is broken by phased array weather radar,which can provide faster and more detailed observation data. However,the parameters of the array antenna deteriorate when the scanning angle deviates from the normal direction,making the quantitative measurement of phased array radar difficult. At present,the dual-polarization phased array weather radar has been newly deployed in southern China. The quantitative comparison between phased array radar and local S-band operational radar in the same area was compared in this paper,and the bias magnitude of the reflectivity and differential reflectivity and its changing trend with scanning angle and observation time was evaluated.The results showed that the error of the reflectivity of the phased array radar was about 0. 82 dB,while the bias of the differential reflectivity was as high as 1. 04 dB. And the biases also have certain fluctuations between different elevation angles and different times. Therefore,this paper proposes a correction scheme based on real-time data of S-band radar,which can solve the calibration problem of dual-polarization phased array weather radar to a certain extent,and provides a guarantee for the business application of phased array radar.