摘要
提出了一种稳定的拉曼激光雷达重叠因子计算和校正算法,适用于含有拉曼散射通道的激光雷达系统的重叠因子校正。此算法基于大气气溶胶光学参数的拉曼反演算法,通过分析消光系数和后向散射系数的反演特点,发现后向散射系数在过渡区中不受重叠因子的影响。用后向散射系数和激光雷达比的乘积对消光系数缺失信号进行初步校正,进而正演出初步校正后的拉曼散射回波信号,将实际拉曼散射回波信号与正演的拉曼散射回波信号相除即可得到重叠因子廓线。对回波信号和气溶胶光学参数进行了过渡区信号校正和盲区信号补充。分别用单组和连续的激光雷达实验观测数据进行了重叠因子的计算和校正,并与能见度仪观测的近地面数据进行了对比,呈现良好的一致性。结果表明,此算法对重叠因子计算较为稳定。
Lidar has been widely used in the field of atmospheric detection,with the advantages of high spatial-temporal resolution and high detection sensitivity.The overlap factor of lidar system arises from the incomplete overlap between the laser beam and the receiver’s field of view,resulting in distortion of the received backscattered signal in the near-field range.The accurate observation of aerosol optical parameters near the ground is important for the monitoring of the atmospheric environment,air quality,and atmospheric visibility.The overlap factor at a certain distance is defined as the ratio of the beam energy entering the receiving field of view to the actual backscattering energy.In general,the overlap factor is estimated by either theoretical methods or experimental methods.The theoretical methods are to calculate the overlap factor according to the structural parameters of the lidar system.However,some parameters are often rather difficult to accurately obtain in practice or in theory,such as the performance of the optical elements,and the beam divergence and direction.The experimental methods are to calculate the overlap factor with the experimental observation data.Some use the deviation between Raman solution and Fernald solution of backscattering coefficient to calculate the overlap factor.The main limitation is that the Fernald method of aerosol backscattering coefficient requires the assumption of lidar ratio or boundary conditions,which will introduce great errors.Besides,the experimental methods strongly depend on accurate estimation of the atmospheric conditions.Thus,it is necessary to propose a stable algorithm for the overlap factor to correct the signal and aerosol optical parameters in the near-field range.An experimental method for the overlap factor of Raman-Mie lidar is proposed in this paper,which is applicable for the lidar system with Raman scattering channel.The method is based on the Raman inversion method for aerosol optical parameters.By analyzing the inversion characteristics of ae
作者
王欣红
狄慧鸽
王娅娅
尹珍珍
袁云
杨涛
闫庆
李仕春
辛文辉
华灯鑫
Wang Xinhong;Di Huige;Wang Yaya;Yin Zhenzhen;Yuan Yun;Yang Tao;Yan Qing;Li Shichun;Xin Wenhui;Hua Dengxin(School of Mechanical and Precision Instrument Engineering,Xi’an University of Technology,Shaanxi 710048,Xi’an,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2023年第6期83-93,共11页
Acta Optica Sinica
基金
国家自然科学基金(61875163,42130612,41627807)。
