The European Space Agency has developed their Sentinel-3 World Fires Atlas Prototype product over the southern countries of the ESA member states, using as input the Sentinel-3A and Sentinel-3B SLSTR Level 1b data containing two dedicated channels (F1 and F2) for fire and high temperature event monitoring capable of detecting fires up to ~650 K without saturation.
The Prototype aims to provide continuity to ESA ATSR World Fire Atlas which has operated from June 1995 to March 2012, taking on board all the improvements of Sentinel-3 SLSTR instrument.
The processing chain is based on ESA SNAP and GDAL routines hosted in the ONDA Copernicus DIAS.
Two different algorithms, derived from a simplification of the work of Wooster et al. 2012, for day and night time have been developed, implemented and adapted to S3 SLSTR L1b NRT processing constraints.
Day-Time algorithm
For all valid pixels over land is applied an algorithm based on:
Brightness Temperature of Sentinel-3 Fire channels acquired at nadir (F1_BT_in and F2_BT_in)
Skin Temperature – auxiliary data provided by ECMWF [defined as the temperature of the surface at radiative equilibrium. It forms the interface between soil, snow or ice and the atmosphere]
Contextual filters*, mean & standard deviation on 5×5 window, are applied in order to prevent false alarms
Night-Time algorithm
For all valid pixels over land is applied an algorithm based on:
Brightness Temperature of Sentinel-3 Fire channels acquired at nadir (F1_BT_in and F2_BT_in)
Contextual filters* (mean & standard deviation on 5×5 window) are applied in order to prevent false alarms
*Contextual filters derived from a simplification of the work of Wooster et al. 2012
ESA is providing two dedicated viewers to users:
Near Real Time viewer
To visualise fire events occurred in the last 24, 48 or 72 hours on the map and their relative information available here. In addition, a further option will be available from May 2019 allowing users to receive notifications for new fire events detected in a given area of interest
Archive viewer
To visualise, define a time range, etc, fire events which have occurred over the southern countries of the ESA member states from 1st of January 2019 onwards is available here. These results are based on Sentinel-3 SLSTR Level 1b Non Time Critical products.
ESA intends to systematically process all acquired Sentinel-3A and Sentinel-3B SLSTR Level 1b data from April 2019 onward over the southern countries of the ESA member states (Latitude range 34°N to 60°N; Longitude range 12°W to 31°E) and operate the prototype service up to end of summer.
Jeremy Parkin
Yorumlar