Aerosol optical thickness retrieval over non-Lambertian land surface with synergistic use of AATSR radiance measurements and MODIS derived Albedo Model Parameters |
| |
| Authors: | Yong Xue Jianping Guo Xiaoye Zhang |
| |
| Institution: | 1. Centre for Atmosphere Watch and Services, Chinese Academy of Meteorological Sciences, China Meteorological Administration, Beijing 100081, China;2. Department of Computing, London Metropolitan University, 166-220 Holloway Road, London N7 8DB, UK;3. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University, Institute of Remote Sensing Applications, Chinese Academy of Sciences, PO Box 9718, Beijing 100101, China;4. Graduate University of Chinese Academy of Sciences, Beijing 100049, China;1. College of Resource and Environmental Science, Hunan Normal University, Changsha, 410081, China;2. Hunan Industry Polytechnic, Changsha, 410208, China;3. School of Public Policy and Urban Affairs, Northeastern University, Boston, MA 02115, USA;1. Urban Studies and Planning Program & National Center for Smart Growth Research and Education, University of Maryland, United States;2. Urban Studies and Planning Program, University of Maryland, United States;1. Civil Engineering Department, Zhejiang University, Hangzhou 310058, China;2. Center for Real Estate Studying, Zhejiang University, Hangzhou 310058, China;1. LREIS, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;2. University of Chinese Academy of Sciences, Beijing 100049, China;1. School of Economics and Management, Zhejiang University of Science and Technology, Hangzhou 310023, China;2. College of Economics and Management, Zhejiang University of Technology, Hangzhou 310023, China |
| |
| Abstract: | Various algorithms have recently been developed in order to retrieve the aerosol optical thickness (AOT) at continental scales. However, they are, to some extent, subject to large uncertainties resulting from some necessary physical assumptions on land surface anisotropy and level of brightness. In fact, disentangling aerosol and surface signals contained in the top of atmosphere (TOA) radiance received at the satellite level are a matter of difficulty because a single sensor itself cannot gather all required spatial, temporal, spectral and angular information. In particular, each instrument yields limited scanning configuration due to its platform's orbital characteristics. In this regard, a synergetic approach is presented which merges Advanced Along-Track Scanning Radiometer (AATSR) TOA radiances and the MODerate resolution Imaging Spectroradiometer (MODIS) Bi-directional Reflectance Distribution Function (BRDF)/Albedo Model Parameters Product for the retrieval of AOT at 0.55, 0.66, and 0.87 µm wavelengths over non-Lambertian land surface at a 5 km spatial resolution. In this approach, BRDF products serve to assess the surface reflectance in the AATSR geometry as a boundary layer. The peculiarity of the approach is that no specific assumption is required about the spectral characteristics of land surface, thus allowing for a quantitative retrieval of aerosol particles over any arbitrary land unit in virtue of combining forward and nadir AATSR observations. We obtain on average differences within 0.1τ compared to in situ AErosol RObotic NETwork (AERONET) measurements and 36 retrievals corresponding to 27 January, 12 February, 16 March, 28 May, 26 June, and 21 July 2006, respectively, over the city of Beijing in China. Pearson's correlation coefficient is 0.94 and 0.96 for nadir and forward AATSR, respectively. These suggest that AOT retrieval over land is indeed feasible by taking benefit of the validated MODIS BRDF. Besides, the first results indicate that the AATSR retrievals might be used to evaluate the spectral behaviour of the AOT. |
| |
| Keywords: | Aerosol AOT AATSR BRDF MODIS |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
