DLR
EOC
Satellite
Earth Observation
Imagery
Germany
Cloud-Free
Mosaic
Monthly
Surface Reflectance
MAJA
MACCS-ATCOR Joint Algorithm
WASP
Weighted Average Synthesis Processor
Copernicus
Sentinel-2
L3A
Sentinel Level 3A for Germany is a monthly, cloud-free surface reflectance syntheses produced at the DLR Earth Observation Center using the WASP processor.
The Level 3A product provide a weighted average of the non-clouded observations obtained over a 45-day synthesis period, based on the Level 2A MAJA product.
Conventional methods for creating time syntheses often use the "best available pixel" method, which selects for each pixel the date for which the best acquisition conditions are available. Best available pixel mosaics are prone to artifacts on the boundary lines between the different dates selected for each pixel. The weighted average method minimizes these artifacts by merging the different dates without clouds, but depends on good cloud masks, which are provided by the MAJA L2A processor.
References:
- Olivier Hagolle, Mireille Huc, Camille Desjardins, Stefan Auer, & Rudolf Richter. MAJA Algorithm Theoretical Basis Document (Version 1.0, 2017, December 7) Link
- Olivier Hagolle, David Morin, & Mohamed Kadiri. (2018, August 21). Detailed Processing Model for the Weighted Average Synthesis Processor (WASP) for Sentinel-2 (Version 1.4) Link
Items:
Monthly surface reflectance synthesis for all 10 and 20 m Sentinel 2 bands
Bitwise classification map: Bit 0: No Data, Bit 1: Cloud, Bit 2: Snow, Bit 3: Water, Bit 4: Land.
Weighted average of the dates used by the synthesis, as number of days since January 1st, 2018.
