全天时大气温度探测的纯转动拉曼激光雷达系统设计与仿真

Design and Simulation of Pure Rotational Raman Lidar System for Daytime Detection of Atmospheric Temperature

提出了一种全天时大气温度探测的纯转动拉曼激光雷达系统,选用Nd\:YAG脉冲激光器的四倍频输出266.0 nm作为激励波长,避开了强烈的太阳背景光对系统探测大气温度的影响。设计了一种新型三次衍射式双光栅多色仪作为激光雷达的分光系统。仿真结果表明,双光栅多色仪可实现Stokes与Anti-Stokes高低量子数通道转动拉曼谱线的有效提取,对米-瑞利弹性散射信号的抑制率可达到60～70 dB。充分考虑臭氧吸收和荧光对系统探测性能的影响,所设计的日盲紫外纯转动拉曼激光雷达采用模拟探测模式可在12 min的积分时间内实现2.2 km高度范围内大气温度的全天时探测。

A pure rotational Raman lidar for measuring atmospheric temperature on daytime is proposed.The quadruple frequency of 266.0 nm of Nd\:YAG pulsed laser is selected as the transmitter wavelength,which avoids the effect of solar background light on the detection of atmospheric temperature.A new type of triple-diffraction double grating polychromator is designed as the spectroscopic system of lidar.Simulation results show that the designed double grating polychromator can achieve the extraction of Stokes and Anti-Stokes pure rotational Raman signals from high and low quantum number channels.The suppression rate of the Mie-Rayleigh scattering signals is up to 60-70 dB.Meanwhile,considering the effects of the ozone absorption and fluorescence on the detection performance of the system,the designed solar-blind ultraviolet pure rotational Raman lidar system with the analog detection mode can detect atmospheric temperature in the range of 2.2 km in 12 minutes′integration time.