GOES Fire Detects from the Wildfire Automated Biomass Burning Algorithm (WF_ABBA)
The WF-ABBA product was developed by Elaine Prins
(NOAA/NESDIS/ORA) in collaboration with the Cooperative Institute for
Meteorological Satellite Studies (CIMSS) at the University of Wisconsin.
For details
about the algorithm, users are referred to the
Biomass Burning Monitoring web
page at
CIMSS.
The WF-ABBA system runs operationally at the Satellite Services
Division. The product
is run half-hourly upon receipt of GOES-East or West imagery.
The algorithm uses multi-spectral GOES imagery (visible, 3.9 and 10.7
microns).
Users should note:
- This data is generated by an automated algorithm and is placed on
the web page in near-realtime. It has not been quality controlled.
For a quality controlled product, users are referred to the
Hazard Mapping System (HMS) product created
by SSD satellite analysts.
- In the raw WF-ABBA product, a large number of false detects were noted
around sunrise and sunset
due to reflection off clouds. The product available through this site has been
filtered against detects noted in the past 12 hours. A
new detect is held until it is seen at least twice by either satellite.
This has greatly reduced the number of false fires.
- False detects are also noted during summer when surface temperatures can
reach extreme values. This problem is worse for GOES-10 (in the west)
due to the lower saturation temperature of that instrument. Extra land
surface filtering is done in this case.
- Fire locations represent the approximate location of the fire pixel
and do not represent the actual fire size. The GOES instantaneous
field of view at nadir is 4x4 km, which is quite large, but the fire phenomena
is usually much smaller than that.
Studies at CIMSS have shown that the minimum detectable fire size at the
sub-satellite point, and smoldering at 450K, is approximately .5 to 1 acre
in size in relatively non-cloudy conditions. The WF-ABBA is able to
identify hot spots through smoke.
(Prins and Menzel, 1996).
- GOES data comes in every 15 minutes. Sometimes there are no fires detected.
These "empty" files are not placed on the server.
The SSD product is a reformatted version of the product
available on the CIMSS website.
The reformatting of the WF-ABBA product consists of removing the lowest
probability fires (category 5), as validation at CIMSS has shown that many of
the low possibility fires are not fires. The fields fire size and temperature
have been removed as they are very rough estimates of
the average instantaneous sub-pixel fire(s) size and temperature, and
are not meant to be used for wildfire diagnosis. The header is
simplified and the table is put into comma-delimited form so that it can
be easily read into a Geographic Information System (GIS) as table data.
Each fire is described by a single line, specifying longitude, latitude,
4 micron (channel 2) temperature, 11 micron (channel 4) temperature,
ecosystem category, and a
fire flag.
The ecosystem category (see table of definitions)
is determined by the
GLOBAL LAND COVER CHARACTERISTICS DATA BASE.
The fire flag is defined as:
- 0 indicates a processed fire pixel (A fire was identified and
conditions were favorable to allow for sub-pixel instataneous estimation of
fire size and temperature.)
- 1 indicates a saturated fire pixel
- 2 indicates a cloud-contaminated fire pixel
- 3 indicates a high possibility fire pixel
- 4 indicates a medium possibility fire pixel
- 5 indicates a low possibility fire pixel (at this time, all
5's have been removed to minimize false detects).
The most recent WF-ABBA detects, as well as the
other layers that make up the HMS Fire and Smoke Product,
can best be viewed through our
SSD Fire Web-GIS page.
Here are plots of the latest GOES-East and West data we have processed and the
composite of all the fires so far from today and all the fires from yesterday
(both satellites). For the daily plots, the cutoff is 0 GMT (8 pm EDT).
The red "X's" are hot spots that are flagged 0-4 and have been temporally
filtered (as described above) to minimize false detects.
Contact Address: SSDFireTeam@noaa.gov
