The Dual-angle Retrieval Algorithm Study On Aerosol Opacity From AATSR Satellite Radiometer

Issue of global climate change has become a hot topic during the last 20 -30 years. Atmospheric aerosols radiative forcing plays an important role in global climate change. In the meantime, the atmospheric correction of remote sensing image and urban air pollution all need large-scale information of atmospheric aerosols, even at a global scale.The aerosol opacity retrieval using satellite instruments is an effective means of obtaining aerosol information. With the emergence of multi-spectral and multi-angle satellite sensors, such as AATSR and MISR, it provides a new multi-angle method for aerosol opacity retrieval.Compared to traditional Dense Dark Vegetation(DDV) method, it can preferably differentiate the contribution of the surface and the atmosphere, and also applicable to bright and desert surface.Based on the theory of radiative transfer in the atmosphere, the following research in aerosols retrieval algorithm has been performed:(1) Review recent researches on aerosol opacity retrieval from multi-angle satellite radiometers and several algorithms.(2) Based on AATSR dual-angle data ,we develop two aerosols retrieval algorithms:Combined MODIS BRDF/Albedo Product, we developed an aerosol opacity retrieval algorithm using prior knowledge of surface reflectance.Based on the assumption that the variation of the surface reflection with angles is independent of the wavelength , we developed a retrieval algorithm using the ratio of dual view radiance.(3)Using 6S model and four aerosol model to build Look-Up-Table(LUT).(4)These two algorithms all use LUT multi-spectral optimization technique.(5)It also gives the preliminary result of AOT temporal and spatial distribution in Chinese northwest area by using AATSR data. Recently, the study of aerosol remote sensing using multi-angle algorithms is in its infancy. Due to the diversity of surface and aerosol type, it's difficult to inverse aerosol opacity accurately. The dual-angle retrieval algorithm study on aerosol opacity in China from AATSR satellite radiometer is just the beginning. In order to improve the algorithm, more tests and verifies should be in progress. We hope this paper could be a reference to the study of multi-angle aerosol opacity retrieval.