以采用“同时发射同时接收水平与垂直极化波冶工作模式的WSR-98XD雷达为试验平台,分析后得到了差分反射率系统误差的主要来源分别为:发射机功率分配不均、馈线插损不一致与双通道接收机增益不一致。开展信号源法、太阳法、降雨法3种标定方法的试验,发现3种方法标定结果具有比较好的一致性,发射机功率分配不均与双路馈线插损不一致所引入的误差较小,且相对稳定。探测误差主要来源于接收机有源通道的增益不一致,且在全动态接收范围内该误差起伏与输入信噪比有关,将全动态范围分为大信号段、线性段与小信号段3个区间,分别进行误差标定。试验结果表明,有源通道增益不一致引入的误差时间稳定性较差,需要对其进行定时标校。相比硬件幅相修正方式,软件方式更适合差分反射率这种细微、且在全动态范围具有非线性特点的误差修正。

Based on WSR-98XD radar with SHV mode(Simultaneously transmit and receive Horizontal and Vertical polarization wave), biases of differential reflectivity comes mainly from three aspects: the uneven distribution of transmitter power, the inconsistent insertion loss of dual feed lines and the unbalance gain of dual鄄channel active receivers. Through signal source method, the Sun method and weather target method, it is found that three methods have good consistency of calibration results. The errors from transmitter and feed lines are small and relatively stable. The error comes mainly from the active receiver. Since the bias change as variation of input SNR, the full dynamic range of receiver will be divided into three parts: strong power range, linear amplified range and weak power range, each part has its own calibrated value. Based on test results, the calibration should be regularly operated. Finally, the amplitude and phase adjustment is described. Compared to the hardware approach, the software approach is more suitable for tiny and multiple correction over the full dynamic range.

国家高技术研究发展计划(863) 资助项目;国家自然科学基金资助项目