The SLSTR Level-2 WST product respects the Group for High Resolution Sea Surface Temperature (GHRSST) L2P specification, and includes a single SST field derived from the best performing single-coefficient SST field in any given part of the swath, plus a number of supporting data fields providing context for the SST fields.
Each SST, previously generated during the SLSTR Level-2 algorithm or contained in the Level-2 WCT product, is atmospherically smoothed. The "best" product for the local conditions is then forwarded to the output field.
All the variables are gathered in one measurement file, called the 1 km L2P SST measurement dataset, generated on a wide 1 km measurement grid.
This file, indexed by across track and along track dimensions and by reference time, provides for each thermal SLSTR channel:
- the latitude and longitude coordinates of each pixel
- the SST value
- the SST time deviation from reference time and from analysis field
- the Single Sensor Error Statistic (SSES) bias and standard deviation estimate
- several contextual parameters (wind speed at 10 m, the fractional sea-ice contamination, the aerosol contamination indicator for each pixel) with the time difference between the SST and these data measurements
- a quality flag (gathering information about sensor and surface type, geographical contamination, problems during processing, Level-1B flags) and a quality indicator (from 0, default value unknown quality, 1, excellent quality to 3, extremely suspect) for SST.
- satellite zenith angle of each pixel and each reference time
- associated Top Of Atmosphere (TOA) Brightness Temperature (BT)
- associated TOA noise equivalent BT
- SST total uncertainty.