MERIS FR Level 2 is a Full-Resolution Geophysical product for Ocean, Land and Atmosphere. Each MERIS Level 2 geophysical product is derived from a MERIS Level 1 product and auxiliary parameter files specific to the MERIS Level 2 processing.
The MERIS FR Level 2 product has Sentinel 3-like format starting from the 4th reprocessing data released to users in July 2020.
The data package is composed of NetCDF 4 files containing instrumental and scientific measurements, and a Manifest file which contains metadata information related to the description of the product. A Level 2 product is composed of 64 measurement files containing: 13 files containing Water-leaving reflectance, 13 files containing Land surface reflectance and 13 files containing the TOA reflectance (for all bands except those dedicated to measurement of atmospheric gas - M11 and M15), and several files containing additional measurement on Ocean, Land and Atmospheric parameters and annotation.
The Auxiliary data used are listed in the Manifest file associated to each product.
The Level 2 FR product covers the complete instrument swath. The product duration is not fixed and it can span up to the time interval of the input Level 0/Level 1. Thus the estimated size of the Level 2 FR is dependent on the start/stop time of the acquired segment.
During the Envisat mission, acquisition of MERIS Full Resolution data was subject to dedicated planning based on on-demand ordering and coverage of specific areas according to operational recommendations and considerations. See yearly and global density maps to get a better overview of the MERIS FR coverage.