Remote Sensing Fires
Remote sensing instruments, specifically satellite and radar, provide
imagery which can be quite useful for fire detection. Smoke plumes from fires can be
viewed with weather surveillance radars and visible channel satellite imagery
while the shortwave infrared (3.9 micron) satellite channel can literally sense
heat associated with fires.
Meteorologists most
often use longwave (10.7 micron) infrared satellite imagery in weather forecasting.
This case study will demonstrate the utility of surface observations and remote sensing,
in the detection of fires. While visible channel satellite
imagery can detect smoke emanating from fires, the shortwave infrared (3.9 micron)
satellite channel can literally sense heat associated with fires.
The brightness temperature of the 10.7 micron channel gives more accurate surface or
cloud top temperatures than that of the 3.9 micron channel, since the temperature
uncertainty of the shorter wavelength channel increases sharply with decreasing
temperature. The properties of the 3.9 micron channel, however, make it valuable
for detecting hot spots associated with fires. Blackbody radiance in the 3.9 micron
channel increases more rapidly with temperature than the radiance in the 10.7 micron
channel. Therefore, the 3.9 micron channel is more sensitive to sub pixel hot spots
then the 10.7 micron channel, and is resultantly better suited for fire detection.
Visible Satellite Imagery from 1815Z, December 15, 2006
The image below shows a subtle smoke plume emanating from a fire in Richmond
County. Also notable are the surface weather observations at Mackall U.S. Army
Airfield, which reported smoke (FU) with a visibility of 1 mile in
otherwise clear skies during the middle of the afternoon.
A visible satellite loop
shows the smoke plume much more clearly. The loop shows the rapid dissipation of fog,
evident as shrinking bright white areas at the beginning of the loop.
This smoke plume was referenced in the Satellite
Service Division product from 02 UTC 16, December
3.9 Micron Satellite Imagery from 1815 UTC, December 15, 2006
The image below shows prominent hot spots in Richmond County, near the Yadkin
River on the Davidson and Rowan County border, and in Chesterfield County, SC.
Web-based image from the Satellite Services Division Fire Product Web Page
A web page has been developed that allows visitors to interactively
view data from the trained satellite analysts in the Satellite Analysis Branch (SAB),
within the Satellite Services Division (SSD), to manually integrate data from
various automated fire detection algorithms with GOES and polar
(Advanced Very High Resolution Radiometer (AVHRR), Moderate Resolution
Imaging Spectroradiometer Fire Algorithm (MODIS) and Defense Meteorological
Satellite Program/Operational Linescan System (DMSP/OLS) satellite images.
The result is a quality controlled display of the locations of fires
and significant smoke plumes detected by meteorological satellites.
The image below shows the detected hot spots and smoke plumes as analyzed by
integrated datasets on the Satellite Services Division Fire Product web page.
Real time fire detection and smoke analysis data can be found
here.
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