多普勒测风激光雷达的FP标准具透过率曲线校准及风场观测

Calibration of FP Etalon Transmittance Curve and Wind Field Observation Based on Doppler Wind Measurement Lidar

研制了一台基于法布里-珀罗标准具的多普勒测风激光雷达系统,发射激光波长为532 nm,采用300 mm口径望远镜接收回波信号,能够同时探测从边界层到对流层顶的大气风场.为提高法布里-珀罗标准具透过率曲线扫描的准确度,在接收机光路严格装调基础上,通过脉冲光直接对三通道法布里-珀罗标准具频谱进行扫描,通过高速采集卡采集脉冲信号并进行拟合积分得到准确的脉冲信号强度,采用非线性最小二乘法拟合得到FPI-1、FPI-2和FPI-L的谱宽分别为1.20 GHz、1.22 GHz、1.18 GHz,峰值透过率分别为0.817、0.807、0.768,FPI-1和FPI-2及FPI-1和FPI-L的峰峰间隔分别为3.91 GHz和1.25 GHz.在风场观测试验中,通过多次测量同一方向上径向风速得到,91%的测量方差小于4 m/s,在水平风场观测中,该系统白天探测高度为13 km,夜间可达17 km,并与探空气球进行对比,从1.5 km至10 km范围内二者吻合较好.

Doppler wind measurement lidar system based on Fabry-Perot etalon was developed.The laser emission wavelength is 532 nm.The 300 mm diameter telescope is used to receive the echo signal,which can simultaneously detect the wind field from the boundary layer to the top of the troposphere in China.In order to improve the accuracy of Fabry-Perot etalon transmittance curve scanning,the three-channel Fabry-Perot etalon spectrum is directly scanned by pulsed light on the basis of strict installation and adjustment of the receiver optical path.The pulse signal is collected by high-speed acquisition card,and the accurate pulse signal intensity is obtained by fitting integration method.Using nonlinear least squares fitting method,the spectral widths of FPI-1,FPI-2 and FPI-L are 1.20 GHz,1.22 GHz,and 1.18 GHz,respectively.The peak transmittance of FPI-1,FPI-2 and FPI-L is 0.817,0.807,0.768,respectively.The peak-to-peak spacing of FPI-1 and FPI-2 is 3.91 GHz and the peak-to-peak spacing of FPI-1 and FPI-L is 1.25 GHz.In the wind field observation test,the radial wind speed was measured multiple times in the same direction.91%of the measurement variance was less than 4 m/s.In horizontal wind field observation,the system has a detection height of 13 km during the day and 17 km at night.Compared with the air balloon,the agreement is good from 2 km to 10 km.