The Fire Information for Resource Management System (FIRMS) is a NASA system that distributes near real-time satellite active fire detections for the whole globe. Its points come from the MODIS instrument on the Aqua and Terra satellites and the VIIRS instrument on Suomi NPP, NOAA-20 and NOAA-21.
Where it came from and how it works
FIRMS was developed by the University of Maryland with funds from NASA's Applied Sciences Program and the United Nations Food and Agriculture Organization.
A U.S. and Canada version, FIRMS US/Canada, is a joint effort of NASA and the USDA Forest Service.
NASA's near real-time processing system handles the detections with the standard MODIS fire algorithm and the VIIRS 375 m fire and thermal anomaly algorithm. MODIS stands for Moderate Resolution Imaging Spectroradiometer, and VIIRS stands for Visible Infrared Imaging Radiometer Suite.
How fast it is
Globally, FIRMS makes the data available within 3 hours of a satellite observation on a best effort basis. For the United States and Canada, it says active fire detections are available in real time.
Fast delivery is not continuous coverage. Each polar-orbiting satellite sees a location only at certain times of day, so a fire can start and end between passes.
Reading the points carefully
Each point marks the center of a pixel about 1 km across for MODIS or 375 m for VIIRS. NASA says it cannot determine the exact location or size of the fire inside, only that at least one fire is there.
FIRMS advises using its confidence field with caution because its meaning can vary from one part of the world to another. Clouds, smoke and tree canopy can hide fires, and some points come from gas flares or volcanoes rather than vegetation fires.
Where it fits
FIRMS is a detection feed, not an incident record. Fire names, mapped perimeters and containment come from fire agencies through interagency services such as Wildland Fire Interagency Geospatial Services (WFIGS).