车载式1 064 nm和532 nm双波长米散射激光雷达

Mobile dual-wavelength Mie lidar

新近研制的车载式双波长米散射激光雷达可用于1064nm和532nm两个波长对白天与夜晚对流层气溶胶消光系数垂直分布进行的探测。该激光雷达由激光发射单元、接收光学和后继光学单元、信号探测和采集单元以及系统运行控制单元组成,后继光路之间采用光纤导光、高低层分层探测等关键技术。该激光雷达使用1064nm和532nm的两个波长,其单发脉冲能量分别为400和300mJ,重复频率都为20Hz,光束发散角小于0.5mrad;望远镜接收视场为1～3mrad,滤光片的中心波长为1064nm和532nm,带宽1nm。分别使用R3236及H7680的PMT和VT120及Phillips777的放大器对两个波长的信号进行探测;对532nm波长用3A/D采集卡、1064nm波长用了光子计数卡。给出了双波长测量对流层气溶胶消光系数垂直分布的结果,该激光雷达可以探测10-5～1之间的消光系数,探测高度可达10km以上。

A mobile dual-wavelength Mie lidar (DWL) is introduced. The DWL can be used to measure the aerosol extinction coefficient profiles at 1064 nm and 532 nm wavelength. The DWL system is composed of a transmission unit, a signal receiving unit, a signal acquiring unit and a processing control unit. Some main specifications of the DWL system are presented, which include laser with 1064 and 532 nm wavelengths and 400 and 300 mJ pulse energy, 20 Hz repetition rate and less 0.5 mrad divergence, telescope with 1-3 mrad FOV, two different PMT R3236 and H7680 and two different amplifier VT120 and Phillips777 for 1064 and 532 nm signal detecting, filters with 1064 and 532 nm center wavelength and 1 nm bandwidth, even different data acquiring cards and so on. The fundamental principles and key techniques of each unit are explained. Preliminary observation shows that the DWL system is reliable to obtain vertical aerosols profiles of total troposphere, namely about 10 km in height, and to detect aerosols extinction coefficients of 10-5 to 1.