Preliminary Evaluation of Sentinel-2 Bottom of Atmosphere Reflectance Using the 6Sv Code in Beijing Area

In this study, the Sentinel-2A Bottom Of Atmosphere (BOA) reflectance imageries over Beijing area from Dec 2016 to Nov 2017 were generated by the Sen2Cor processor and evaluated using the AERONET measurements and the 6SV code. The result shows a poor correlation between the Sen2Cor retrieved AOT and the ground data with R = 0.289 possibly because of the limitation of the AOT algorithm. The errors of Sen2Cor retrieved AOT and water vapor pressure have a great effect on the BOA reflectance and spectral indices such as NDVI. The highest relative uncertainty of the Sen2Cor BOA reflectance is 37.76% for B01 and the lowest correlation is 0.859 for B09. The result also shows that a high-accuracy atmospheric correction is still crucial and urgent for the Sentinel-2A data.