A Surface Reflectance Model for Aerosol Remote Sensing over Land

Aerosol remote sensing over land is based on the use of pixels covered by vegetation. Because of the absorption of the photosynthesis pigments, these pixels are quite dark in the blue and in the red. This consideration led to introduce the concept of DDV pixels. Initially, 11 DDV models have been selected from the POLDER 1 imagery. ARVI, atmospherically resistant vegetation index, has been used to detect these pixels. A clear limitation to the initial process was the limited spatial coverage of DDV pixels. That the reason why, the DDV concept has been extended to include less dark pixels for the aerosol remote sensing. First, an extensive archive of MERIS images has been fully corrected from the atmosphere, including the aerosols. Second, a simple linear regression can be applied to the surface reflectance versus the ARVI in the MERIS band used for aerosol remote sensing. We answer to the question: how far we can go using less dense vegetation? A validation of this concept is reported from MERIS, SeaWiFS and MODIS data. This work is the fundamental basis for the last MERIS reprocessing on the aerosol product over land. The pixel identification is based on the use of the ARVI.