全天时绝对测温激光雷达的多通道纯转动拉曼分光系统  

Multichannel Pure Rotational Raman Spectroscopic System for Absolute-Probing Temperature Lidar Throughout a Day

作　　者：李仕春[1,2] 王旭 张鹏辉 辛文辉 华灯鑫[1,2] 胡向龙 宋跃辉[1,2] Li Shichun;Wang Xu;Zhang Penghui;Xin Wenhui;Hua Dengxin;Hu Xianglong;Song Yuehui(School of Mechanical and Precision Instrument Engineering,Xi'an 710048,Shaanxi,China;Collaborative Innovation Centre for Modern-Equipment Environmentally-Conscious Manufacturing,Xi'an 710048,Shaanxi,China)

机构地区：[1]西安理工大学机械与精密仪器工程学院,陕西西安710048 [2]陕西省现代装备绿色制造协同创新中心,陕西西安710048

出　　处：《中国激光》2022年第13期125-134,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金(62175199,61875162,41627807,61308106);陕西省自然科学基金(2020JM-445);陕西省教育厅自然科学基金(20JY048)。

摘　　要：为实现大气温度廓线的全天时绝对探测,基于N_(2)分子的精细纯转动拉曼谱线结构,本课题组提出并设计了多通道纯转动拉曼激光雷达分光系统。采用F-P干涉仪(FPI)作为频率梳滤波器,考虑FPI膜层损耗和镜面缺陷,精细匹配N_(2)分子anti-Stokes分支的纯转动拉曼谱线,实现了FPI结构及性能参数的优化,并有效滤除了太阳背景噪声及邻近谱线信号;结合衍射光栅和光纤线阵列,通过两级光谱滤光对弹性散射信号实现了约60 dB的抑制率,有效提取了8通道偶转动量子数(J=6~20)的拉曼光谱信号,以直接反演大气温度;基于标准大气模型,对8通道纯转动拉曼分光系统的信号功率及信噪比进行了仿真,并分析了全天时绝对测温激光雷达的探测性能。结果表明,在累积时间为17 min时,该系统实现白天信噪比优于10的探测高度可达到1.8 km,反演温度1 K偏差对应的高度达0.8 km,可实现全天时大气温度廓线的无校正探测。Objective Atmospheric temperature is an important meteorological parameter in atmospheric physics,weather forecasting,and environmental monitoring.Because of the advantages of high temporal and spatial resolution,atmospheric temperature lidar has become a research hotspot.Because of the influence of aerosols at the bottom of the atmosphere,pure rotational Raman and Rayleigh high optical spectral lidars have become important equipment for observing atmospheric boundary layer temperature profiles.Among them,the pure rotational Raman lidar with a medium optical spectral resolution has particularly developed rapidly.However,it still has problems such as daytime detection capability and system stability,which have become critical factors in limiting its application.Based on the current application status of these optical spectroscopic bulk optics in the pure rotational Raman lidar,particularly the application of F-P interferometer(FPI)in the temperature relative detection technique of pure rotational Raman lidar,a multichannel pure rotational Raman lidar spectroscopic system is proposed and designed by combining with the research progress of our research group in the field of absolute-probing temperature lidar.Methods Considering the influence of the atmospheric fluorescence signal,the pure rotational Raman signal of the anti-Stokes branch is selected in the pure rotational Raman fine spectral-line structure of nitrogen molecules in the atmosphere to retrieve the atmospheric temperature.The FPI is used as a frequency comb filter to configure the primary pure rotational Raman spectroscopic system to effectively filter the daytime solar background noise and the pure rotational Raman spectral signals of other gas components such as oxygen molecules,which are distributed between the pure rotational Raman spectral signals of nitrogen molecules.A secondary pure rotational Raman spectroscopy system is constructed using the advantages of a low-order diffraction grating for spatial spectroscopy combined with a precise and unif

关 键 词：遥感 激光雷达 纯转动拉曼绝对测温 F-P干涉仪 精细拉曼谱结构 无校正探测 

分 类 号：TN958.98[电子电信—信号与信息处理] P423.5[电子电信—信息与通信工程]