Minimize Level-2 WST

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 following the AATSR model. 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.

Some parameters are also included in this file if a user-dependent switch, included in the SLSTR Level-2 configuration file, is set to '1'. These are:

  • 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.