应用信号源对双偏振多普勒天气雷达探测性能的研究

Application of signal source of dual polarization Doppler weather radar detection performance

双线偏振天气雷达是当前一种比较先进的天气雷达,它能同时获取云和降水特性的参量包括强度(Zh)、速度(V)、谱宽(W)、差反射率(Zdr)、差传输相移(Φdp)、比相差(Kdp)和相关系数(Ρhv)。这些参量的数据精度,决定了识别云和降水粒子和遥测区域降雨量的准确性。因此双线偏振天气雷达使用者必须精确掌握硬件对偏振参数准确性的影响。双线偏振雷达能够发射两路水平和垂直的电磁波,714XDP双线偏振雷达采用同时发射同时接收模式的工作方式,因此两路发射和接收系统的一致性和相位的稳定性对于雷达获取数据的准确性具有非常重要的作用。2012年6月,利用固定信号源对714XDP双线偏振天气雷达进行了外场的测试试验。通过试验发现,雷达接收机最小可测功率变小,天线两通道一致性较差,双铰链引起的Zdr误差不大,但引起的Фdp误差较大。在处理雷达数据时应该将这些因素考虑在内。

Dual linear polarization weather radar is one of the more advanced weather radar, it is able to obtain the parameters of rainfall characteristics and the strength（Zh）, speed（V）, spectral width（W）, differential reflectivity（Zdr）, differential transmission phase shift（DP）, ratio（Kdp） and correlation coefficient（P HV）. These parameters determine the accuracy of recognition accuracy,cloud and precipitation particles and regional rainfall telemetry. Therefore, dual linear polarization weather radar users must accurately grasp the impact of the accuracy of the polarization parameters of the hardware. Dual linear polarization radar is capable of transmitting both horizontal and vertical electromagnetic wave transmitting and receiving mode, working at the same time using 714 XDP dual polarization radar, stability, consistency and therefore the phase two of transmitting and receiving system has very important role for the radar data acquisition accuracy. In 2012 June, the field test of 714 XDP dual linear polarization weather radar using fixed signal source. Through the experiment, the minimum detectable power of radar receiver antenna two channel becomes small, poor consistency, the Zdr error is not caused by the double hinge, but with larger error caused by dp. In the processing of radar data should take these factors into account.