Retrieval Of High-resolution Aerosol Optical Depth By Synergetic Use Of TERRA MODIS And AQUA MODIS Data Over Land

The increasingly prominent global ecological environment problems pose a serious threat to human daily life,among which the air pollution problem is particularly severe.How to carry out accurate air quality monitoring has become a hot spot in society at home and abroad.As an important parameter to evaluate the level of air pollution,aerosol optical depth（AOD）information is very important for atmospheric environmental quality monitoring and pollution control.Using satellite remote sensing to extract aerosol continuous observation information from global scale is an effective mean to obtain air quality data.However,the current aerosol products provided by satellite sensors are concentrated in low and medium spatial resolutions,and only for the limited ground surface types,which cannot meet the fine environmental monitoring at a specific regional scale.In this thesis,GF-1 satellite Multispectral Wide Field of View（WFV）camera data,TERRA and AQUA satellite MODIS data were used as data sources to collaboratively retrieve high-resolution AOD over land.In addition,we explored the AOD distribution and its related applications.The main research results are as follows:1).Research on scale conversion method based on Mutual Information algorithm.To obtain high-resolution AOD information,based on mutual information algorithm,this thesis uses GF-1 WFV data to downscale MODIS data and adjusts parameters to obtain the maximum mutual information entropy between matching data.After downscaling,the MODIS data at100m spatial resolution retains the original image information and contains more texture features and ground details,which effectively improves the spatial resolution.In addition,the pixel scale of AOD results with different resolutions is explored according to the land use type map,and the pixel scale conversion law is summarized.2).High resolution aerosol optical depth retrieval.The surface is constructed as Lambert body,and the atmospheric radiative transfer equation is only considered in the case of single scattering.On the premise that the surface characteristics and aerosol types and properties remain unchanged during the transit of two satellites.Using the characteristic that the scale coefficient of surface reflectance in the same area is independent of wavelength for different phases,the atmospheric radiative transfer model based on TERRA and AQUA MODIS data is solved to obtain the high resolution AOD data set at 100m spatial resolution over land in Beijing.Compared with MODIS AOD products,the correlation coefficient was 0.79 and the root mean square error was 0.11;Compared with AERONET data,the correlation coefficient is0.88 and the root mean square error is 0.15.The verification results show that the algorithm has high reliability and stability.3).Analysis of temporal and spatial distribution of high-resolution AOD and its retrieval application.The AOD distribution of different weather conditions in Beijing is analyzed by using the retrieval results of 2020（a total of 47 scenes）.The high-resolution AOD application research was carried out in Xuzhou.The spatial distribution of inhalable particulate matter concentration(PM_2.5/PM₁₀)was estimated by using the spatiotemporal weighted geographical regression model,and the identification of pollution hotspots and comprehensive analysis of atmospheric pollution in Xuzhou were carried out combined with various atmospheric parameters.