3.5.4. Sentinel-2 Processing levels

Last modified by Wai-Tim Ng on 2018/08/30 07:53

 Index

  • Sentinel-2 Level-1C
  • Sentinel-2 Level-2A
A Sentinel-2 Level-1C product is composed of 100x100 km tiles. The Level-1C product results from using a Digital Elevation Model (DEM) to project the image in cartographic geometry. Per-pixel radiometric measurements are provided in Top Of Atmosphere (TOA) reflectances along with the parameters to transform them into radiances. Level-1C products are resampled with a constant Ground Sampling Distance (GSD) of 10, 20 and 60 m depending on the native resolution of the different spectral bands. The products include Cloud Masks and ECMWF (European Centre for Medium-Range Weather Forecasts) data (total column of ozone, total column of water vapour and mean sea level pressure).

The Sentinel-2 Level-2A product provides Bottom Of Atmosphere (BOA) reflectance images derived from the associated Level-1C products. Each Level-2A product is composed of 100x100 km tiles in cartographic geometry (UTM/WGS84 projection). This correction was performed by applying the SEN2COR alogrithm and uses two main auxiliary data: the Radiative Transfer Look-Up Tables and the Digital Elevation Model (DEM). The algorithm includes cloud detection and scene classification followed by the retrieval of the Aerosol Optical Thickness (AOT) and the Water Vapour (WV) content from the L1C image. The Figure below compares both Sentinel-2 level 1C (left) and Level 2A (right) images.

atmocorr.JPG