With regard to the pre-processing, five steps are concerned by the Round-Robin:
• the pixel identification, which should result in the “best” identification of pixel status (i.e. land, water, snow and ice, cloud, cloud shadow and invalid);
• the aerosol retrieval, which should result in the “best” aerosol properties estimation;
• the atmospheric correction, which should result in the “best” surface directional reflectance (SDR) products (i.e. in surface reflectance products which are not BRDF-corrected);
• the BRDF correction, which should result in the “best” surface reflectance products;
• the compositing algorithm, which should minimize the compositing length while maintain the composite quality in terms of space and time consistency.
The figure below illustrates the whole pre-processing chain in highlighting in red the steps (and the associated results) that are tested in this Round-Robin.
