High Precision Inversion Of Aerosol Parameters In Ground-based Raman-Mie Lidar Combining Polarization Data

Atmospheric environment is closely related to human life,especially aerosol particles affect human health and even life safety,so it is a focus to learn more about aerosol particles today.As an active remote sensing equipment with technologies of mechanism,hydraulic pressure and electronics,lidar has been widely used in the detection of atmospheric environment and the study of aerosol characteristics.Firstly,in this paper,the significance of atmospheric detection is introduced systematically,from aerosols concept,origin,classification and influence of the heat balance of the earth,influence of the earth’s environment.Then,the interaction between laser and atmosphere,the basic structure of the lidar,different work modes of detection is expounded.The current observation of ground-based lidar networks which are put into used and spaceborne lidar system are introduced.At the same time,this paper discusses the detection research status of atmospheric aerosol lidar inversion algorithm.Secondly,it’s a comprehensive introduction of the experimental equipment to be used in this paper.The foundation structure of the rotational Raman-Mie Lidar and the polarization Lidar of the Laser Radar Laboratory at Beijing Institute of Technology are discussed in detail.And the simulation analysis of the rotational Raman-Mie Lidar system is carried out.The widely used Lidar equation and the polarization Lidar equation are introduced.Thirdly,using the data detected from the e rotational Raman-Mie Lidar of the Laser Radar Laboratory at Beijing Institute of Technology on January 8,2018 to invert aerosol extinction coefficient by the several classic inversion algorithms.And analyze the results of different inversion algorithm and select out the near-field and far-field algorithm.With correlation coefficient as the criteria for joining together the results of two algorithms,compose a combined the advantages of near field and far field of the new inversion results.The core of the new algorithm is "splicing",discussing and using experimental data to verify the advantages of new algorithm splicing method.In order to prove the viability of the new algorithm,selecting the data of different weather conditions,sunny conditions(on January 8,2018),cloudy conditions(on December 12,2017),the condition of fog(on March 13,2018),they all show the superiority of inversion results of the new algorithm.Finally,the detection data of the ground polarization lidar if the Laser Radar Laboratory at Beijing Institute of Technology is processed.The theory basis of polarization lidar calibration and the BIT polarization Lidar system calibration process and the calibration results are introduced in detail.In order to ensure the accuracy of the calibration results,for two consecutive days(on April 11,2018,April 12,2018)do calibration experiments for many times.Using detection data of after-calibration polarization Lidar system inverts atmospheric total depolarization ratio,and combines with atmospheric depolarization ratio sets up aerosol depolarization ratio mathematical model,and then invert the backscattering coefficient of the refined classification.On April 11 2018,in the Laser Radar Laboratory at Beijing Institute of Technology at the same time using the of rotational Raman-Mie Lidar and the polarization Lidar to detect the atmospheric,invert the atmospheric extinction coefficient,atmospheric total depolarization ratio,aerosol depolarization ratio and refine the classification of backscattering coefficient.