The AATSR World Fire Atlas (WFAA) is being processed in Near Real Time since the beginning of February 2006. The transfer to the new system improves considerably the delivery time of the WFAA.

The processor has been completely re-coded with the same algorithms than the ones used to process the years 1995 to 2005:

• Algorithm 1 selects the record having a brightness temperature in the 3.7 micron channel above 312K (= -5 saturated value);
• Algorithm 2 selects records above 308K.

The data are now loaded directly from two rolling archives that give access the ENVISAT products approximately 6 hours after their acquisition onboard the satellite. The data are then processed for hot spot detection and the output file containing the coordinates of the hot spots is merged immediately with the other hot spots detected since the beginning of the current month.
The updated file is then uploaded by the Ionia server via FTP and made available to the user. The hot spots detected are available typically 6 to 12 hours after the satellite pass over a region, depending on availability of the file on the rolling archive.

The user should be aware of some change in the processing chain in order to improve his confidence in the WFAA data:

• The initial AATSR products are not exactly the same than the one used before because the rolling archive hosts the ENVISAT unconsolidated data. This cannot be a source of inconsistency;
• A new feature has been added to check if the WFAA data are not duplicated. This allows eliminating the possible redundancy of the WFAA output;
• Thanks to the use of the BEAM library in the NRT processor, the geographical coordinates retrieved are more accurate than previously;

Archive
Once a full month has been processed, it is moved to the archived data repository, and made available to registered users. The monthly product is consolidated at the end of the following month (to cover occasional late availability of files on the rolling archive) and the corresponding statistics are published on Ionia (missing data, total coverage etc...).
Please note that at present, the coverage indicated (as a percentage) concerns only days for which data is available. Missing days are not taken in consideration for the data coverage.

Glossary

AATSR	Advanced Along Track Scanning Radiometer
WFAA	World Fire Advanced Atlas
WFAA_NRT	World Fire Advanced Atlas Near Real Time
NRT	Near real time
RL	Rolling archive