The Retrievals Of Aerosol Backscattering Ratio From Lidar Data

With the improvement of people’s living standard, human living environment isalso receiving more and more widespread concern. As an important part of the loweratmosphere, aerosol is closely related to the degree of atmospheric drying andcleanliness as well as climate changes. Serious aerosol pollution would bring greatharm to human health. Real-time, multi-site and long-time detection of aerosoldistribution has become the difficulty which has to be overcome.Lidar makes the study of atmospheric aerosol get rapid development with itsadvantages of high temporal and spatial resolution, high sensitivity and accuratedetection. The thesis mainly introduces the experimental analysis of the troposphereaerosol by using a Raman lidar system-inversing atmospheric aerosol extinctioncoefficient and backscattering ratio over Qingdao.The thesis describes the development of aerosol lidar at home and abroad indetail and lists the site distribution as well as relevant data of aerosol lidar networkswhich are relatively perfect in the world presently. What is more, it focuses onanalyzing the history and development status at home and abroad of detecting aerosoldata by using Raman lidar as well as the mature Raman lidar products on theinternational. It gives an in-depth study of atmospheric molecules and aerosolscattering mechanism especially the principles and characteristics of Ramanscattering.By Fernald method and iodine molecular filter high spectrum method, aerosolbackscattering ratio Rb can be inversed from the data that accessed in Doppler lidarexperiment carried out in the southern suburbs of Beijing in April2011, and then thethesis discusses the advantages and disadvantages of the two methods. For theinadequacies of the Doppler wind lidar developed by Ocean University of China, Raman real-time inversion method of aerosol backscattering ratio is proposed.The thesis simply introduces the experimental system of Raman lidar from thelaser emission system, the receiving system and information collection system.Raman signal is obtained by grating. The experiment results show that the inversionof vertical profiles of aerosol backscattering ratio with Raman lidar is viable. Itsdetection height by direct inversion process can be up to ten kilometers. Meanwhile, itis capable of acquiring the aerosol extinction coefficient, lidar ratio and so on byderivation inversion process.