"sea_surface_temperature_tx" band in level 1 Sentinel 3 data


Sentinel 3 level 1 datasets have a “sea_surface_temperature_tx” band that can be opened using SNAP. I have not been able to find information online about how data in this band is generated. Is there somewhere I can find this information?

There are level 2 WST (water surface temperature) products which give the skin surface temperature of the sea using GHRSST specifications. I assume the level 2 temperature will differ from the “sea_surface_temperature_tx” band in the level 1 data, I just don’t know how. Any information on this topic would be appreciated.

You can start by reading the tutorials of SLSTR.
Level 1 data must be brightness temperature, and Level 2 surface temperature (K) after atmospheric correction or other calibrations.

I am more interested in the specific processing that is used to produce this particular surface temperature band. There are many ways to convert from brightness temperature to surface temperature (e.g. single window, split window). Without knowing how “sea_surface_temperature_tx” is created it is difficult to judge if it is suitable for a particular task.

More to the point, opening the “sea_surface_temperature_tx” band in SNAP, it looks like it is lower resolution than Sentinel 3 SLSTR and gap-filled, suggesting that the band may be a level 3 or 4 product, not level 2 as you suggest above.

Just to add a bit more information to this post, within the file “met_tx.nc” contained in a Sentinel 3 dataset, the “sea_surface_temperature_tx” band has the following properties:

Name: sea_surface_temperature_tx
dimensions: ('t_single', 'rows', 'columns')
size: 156000
type: dtype('float32')
_FillValue: nan
long_name: 'Sea surface temperature'
model: 'ECMWF_F'
parameter: '34'
standard_name: 'sea_surface_temperature'
units: 'K'

The relevant part is “model: ‘ECMWF_F’”. ECMWF is the European Centre for Medium Range Weather Forecasts. Therefore, I believe that the sea_surface_temperature_tx band is from a weather forecasting model and not derived explicitly from other satellite or in situ measurements.