Retrieval Of Aerosol Optical Depth Using Remotely Sensed Data Of Chinese GF-1 WFV

The increasingly serious air pollution problem can affect the stability of the ecological environment,and cause serious damage to public health.Studying the air pollution problem and comprehensively grasping the temporal and spatial distribution characteristics of air pollution are of great significance for improving the environment and comprehensive regional governance.Aerosol Optical Depth(AOD)is an important physical quantity for characterizing atmospheric turbidity.It can estimate the content of particulate matter or the degree of air pollution in the atmosphere according to the degree of weakening of solar radiation by particles in the whole atmosphere,so as to obtain the pollution of continuous distribution at the regional scale.As one of the important means of AOD observation,remote sensing has been increasingly used to air quality monitoring,regional pollution incident analysis and emergency requirements.The most widely used operational aerosol remote sensing is the Moderate Resolution Imaging Spectrometer(MODIS).Domestic satellites especially operational aerosol products based on high resolution satellite loads are less.Based on the Gaofen-1(GF-1)wide-field-of-view(WFV)data,solving cloud identification and surface reflectance problems and using the Deep Blue(DB)algorithm to retrieve the Aerosol Optical Depth(AOD)are developed in this study,which reflecting the application value of GF-1 data in atmospheric environment detection.Includes the following aspects:1)A cloud recognition method suitable for GF-1 WFV is proposed based on the band threshold,variation among bands and the space conversion of bands.Moreover,the independent points and cloud edges are effectively processed,which is more conducive to the identification of thin clouds and cloud edges.2)Using MODIS reflectance products,the surface reflectance of blue band in every month of MODIS with 500 m was constructed by using the Minimum Reflectance Technology(MRT)and the Optimal Reflectance Technology(ORT).Based on the channel response function of MODIS and WFV to establish the conversion relation.Converted to GF-1 WFV blue band surface reflectance database for each month3)For GF-1 WFV data,Deep Blue algorithm was used for AOD retrieval,and the Beijing-Tianjin-Hebei region was selected as the demonstration area to verify the retrieval results.The following conclusions can be drawn from the inversion results: The AOD retrieval result based on ORT is better than the AOD retrieval result based on MRT to construct surface reflectance.The correlation coefficient can reach more than 0.8,and the retrieval results are very similar to other satellite data AOD both in spatial distribution and comparative verification.The use of gf-1 satellite data can effectively monitor AOD.Using GF-1 data can effectively monitor AOD.