瑞利测风激光雷达接收机校准

介绍了直接探测瑞利测风激光雷达工作及风速反演的原理,说明了激光雷达接收机的内部结构及工作情况。为修正雷达接收机中分光片分束比、单光子计数器探测率等参数与设计值的偏差所导致的风速测量误差,提出了随光强变化比较两信号通道的计数值的接收机校准方案。实验测得了校准系数随信号通道信号强度的变化关系。在弱光下该系统两信号通道性能差异小于25%。在当前系统的标准具透过率条件和对称的风场扫描合成方式下,接收机校准只对系统透过率曲线和径向风速的测量有较大影响,对合成风场没有影响。

Calibration of Rayleigh Doppler wind lidar receiver

The principle of direct detection of Rayleigh Doppler wind lidar and the wind retrieval was introduced,and the internal structure of the lidar receiver was described.Factors that would create a system deviation,like errors of splitting ratio of beam splitters and detection efficiency of the single-photon counter,were analyzed to show the importance of calibration.The calibration can be achieved by counting and comparing the count number from the two signal channels while regulating the intensity of incident laser.The relationship between the calibration coefficient and signal intensity of the signal channel was found.Difference of the performance between the two signal channels was less than 25 % in dim light condition.It is indicated that the calibration has great influence on the detection of the transmission curves and radial velocity.However,with the etalon transmission and symmetrical scanning mode in this system,the calibration has no influence on the detection of wind field.