220.127.116.11.7 Annotation data set
Annotation data provided in the Level 2 product are identical to those of the Level 1b product.
All annotation data will be provided at equally spaced tie points every 16 by 16 pixels in Reduced Resolution and every 64 by 64 Full Resolution pixels, which is equivalent to a 19km by 19 km grid on ground.
The following meteorological data provided by ECMWF will be resampled to the tie point grid: :
· Mean sea level atmospheric pressure
· Surface wind speed
· Relative Humidity
· Total column ozone
The following geographical information will be provided with respect to the Earth reference model WGS84:
· Latitude, Longitude
· Altitude and topographically corrected localisation
The following geometrical information will be provided with respect to the Earth reference model WGS84 :
· Solar illumination zenithal angle
· Solar illumination azimuthal angle
· Viewing zenithal angle
· Viewing azimuthal angle
The annotation data povided in the near real time products will consist of meteorological forcasts and, geographical and geometric information computed using a predicted satellite orbit state vector.
The annotation data povided in the off-line (consolidated) products will consist of meteorological analysis data and, geographical and geometric information computed using a restituted satellite orbit state vector.
For further details regarding the MERIS Level 2 data products see Product Spreadsheets.
2.8 MERIS-Specific Topics
MERIS is operated with a fixed set of bands, recommended by the Science Advisory Group (SAG) and frozen before launch. The Level 2 ESA products have been developed and are validated for this set of bands.
It is possible to use alternative band sets for experimental campaigns of a few weeks duration. Initial requirements for such campaigns can be submitted through the Announcement of Opportunity.
MERIS measurements are always taken in full resolution (FR). These are averaged onboard to reduced resolution (RR). RR and FR data from areas, which are not in the visibility need to be recorded onboard. The capacity of the onboard recorder for FR data is limited to 20 min.
The background mission defines which data is stored and transmitted to the receiving station. The background mission foresees that RR data is available from every location worldwide, while FR data are available from European land surfaces and all coastal areas, but not from open ocean areas. Requests for FR data can be submitted to mission planning and overwrite the background mission.
2.9 Auxiliary Files