多普勒测风激光雷达风场数据影响因素分析

Analysis of Factors Affecting the Data Accuracy of Doppler Wind Lidar

介绍了基于法布里-珀罗(F-P)标准具的多普勒测风激光雷达(DWL)的基本工作原理,给出了DWL的典型探测数据;对影响DWL风场探测数据精度的因素进行了深入的剖析,主要包括背景光强度、探测器的工作状态、发射激光的频率锁定、种子激光器的工作环境温度、转场或温度骤变对接收机引起的形变等因素;背景光过强会导致系统信噪比急剧降低,探测器饱和将会处于非线性工作状态,进而生成无效数据,发射激光失锁将会导致风廓线平移,种子激光器工作环境温度不恒定将会导致激光跳变等现象,影响因素逐一克服后,DWL与探空气球的风速偏差在1.4 m/s以内、风向偏差在2.2°以内。

The fundamental working theory of the Doppler wind lidar （DWL） based on Fabry-Perot （F-P） etalon is introduced. The typical detection data of DWL system is provided. The factors depressing DWL wind detection accuracy are analyzed, including background light intensity, operation state of detector, the locking state of laser frequency, the environment of seed laser, deformation of the receiver caused by sudden changes of the workplace temperature, and so on. Strong background light will cause the system signal-to-noise ratio decreases rapidly. Saturated detectors will be in nonlinear working state and generate invalid data. The lose lock on laser will cause wind profile to move parallel, the instability of seed laser environment temperature will cause the laser jump phenomenon. After overcoming the factors one by one, the wind speed variation of DWL with balloons is within 1.4 m/s. wind direction deviation is within 2.2°.