粒子退偏比测量拉曼-米偏振激光雷达系统设计与仿真

Design and Simulation of Raman-Mie Polarization Lidar System for Particle Depolarization Ratio Measurement

针对米-偏振激光雷达回波信号受大气分子信号影响而只能测得体退偏比的问题,设计了一种可以测量粒子退偏比的纯转动拉曼-米偏振激光雷达.仿真了其回波信号与信噪比,结果表明系统夜晚最大探测距离可达12km,验证了系统的可行性.利用拉曼信号校正米-偏振信号得到气溶胶和云的粒子退偏比,通过对比不同天气状况下的退偏比廓线,得出该系统更适用于高空卷云和浓度较小但退偏比较大的气溶胶粒子的退偏比测量.

In order to solve the influence of atmospheric molecular signal on the echo signal of Mie-polarization lidar,a pure rotational Raman-Mie polarization lidar was designed for particle depolarization ratio measure.The echo signal and the SNR simulation results show that,the maximum detection distance can reach 12 km at night,verifying the feasibility of the system.The particle depolarization ratio profile was calculated by correcting the polarization signal with Raman signal.Comparing the depolarization ratio profiles in different weather conditions,it was found that this system was more suitable for the measurement of high altitude cirrus clouds and aerosol particles with smaller concentration but larger depolarization.