Mie散射垂直扫描激光雷达近场信号校正及反演技术  

Near-Field Signal Correction and Retrieval Technique for Mie Scattering Vertical Scanning Lidar

作　　者：李仕春[1,2] 任腾 张鹏辉 高迎春 华灯鑫 王玉峰[1,2] 宋跃辉 高飞[1,2] Li Shichun;Ren Teng;Zhang Penghui;Gao Yingchun;Hua Dengxin;Wang Yufeng;Song Yuehui;Gao Fei(School of Mechanical and Precision Instrument Engineering,Xi'an University of Technology,Xi'an 710048,Shaanai,China;Shaanai Collaborative Innovation Center for Modern Equipment Green 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：《光学学报》2023年第18期337-348,共12页Acta Optica Sinica

基　　金：国家自然科学基金(62175199,61875162);陕西省自然科学基金(2020JM-445);陕西省教育厅自然科学基金(20JY048);陕西省大学生创新创业训练计划项目(S202210700104)。

摘　　要：激光雷达近场信号的重叠因子校正和盲区问题一直制约着激光雷达的实用化进程,在假设水平大气均匀的情况下,提出了Mie散射激光雷达的近场信号垂直扫描校正方法和多角度反演算法,实现了大气状态自适应控制遥感。从散射型激光雷达方程出发,构建了激光雷达近场的重叠因子和盲区的模型,结合研制的二维扫描激光雷达参数,仿真分析了重叠因子和盲区的特征。利用Fernald气溶胶反演算法,提出了基于信噪比的多仰角扫描控制与校正方案,以实现不同大气状态的自适应扫描控制。融合多角度扫描遥感数据,并以水平探测的Collis法反演的结果作为地面消光系数,获得了大气气溶胶消光系数无盲区廓线,验证了方案的有效性。数据分析结果表明,在静稳天气时水平能见度优于18km的情况下,以信噪比20为阈值,通过7个仰角约15min观测,可实现激光雷达重叠因子的自适应校正,获得的重叠因子校正曲线与水平校正法的平均相对偏差约20%,两组扫描校正的重叠因子的平均相对误差为4.2%,可实现大气气溶胶的无盲区反演。Objective Mie scattering lidar is a remote sensing instrument with a high spatial and temporal resolution,and it has received extensive attention in research since it has successfully been applied in the fields such as atmospheric aerosol observation,cloud and fog characteristic analysis,and pollution emission monitoring.However,most of these groundbased lidars belong to the monostatic structure with the same transmitting and receiving sites.While they are been utilized to detect tropospheric or boundary layer,the transmitting and receiving coaxial systems(limited by the reflective telescope structure)or the transmitting and receiving systems with different axes(also known as off-axis)are almost affected by the near-field blind area and overlap factor,which results in the loss of near-field signals of the lidar or the reduction of accuracy.Therefore,the data of near-field point-type probing instruments(such as horizontal visibility meter,PM2.5 meter,and particle spectrometer)are usually required for data correction,compensation,or verification in these applications of lidar.However,the near-field atmospheric characteristics are usually essential data in meteorological,environmental,and other fields,which greatly limits the engineering and application process of the lidar.Therefore,overlap factor correction of lidar near-field signals and blind area have always restricted the practical process of lidar.Methods Based on the assumption of horizontal atmosphere uniformity,a multi-angle scanning near-field signal adaptive correction method for lidar is proposed using the vertical scanning function of the developed two-dimensional scanning lidar system.Firstly,according to the overlap factor model of an off-axis lidar system,the influence of laser beam divergence angle,telescope field angle,optical axis distance,and optical axis angle on the overlap factor is analyzed.Secondly,using the Fernald aerosol retrieval algorithm and taking the advantage of lidar vertical scanning,a multi-elevation angle correction scheme depe

关 键 词：传感器 激光雷达 近场信号校正 大气消光系数 垂直扫描 

分 类 号：TN958.98[电子电信—信号与信息处理] TP217[电子电信—信息与通信工程]