Map Layer Information:  MODIS Fire Detection

This layer displays information on fire locations from Moderate Resolution Imaging Spectroradiometer (MODIS) fire detection data.  MODIS fire detection data for the current year are compiled Terra and Aqua MODIS fire and thermal anomalies data. The MODIS instrument images the entire surface of the Earth every two days (daily in northern latitudes), making observations in 36 co-registered spectral bands at moderate spatial resolutions (250, 500, and 1000 meters). Thermal information is collected at 1000-meter spatial resolution. The collected thermal information is converted to ellipse-shaped vector polygons. These collections are processed through the MODLand Rapid Response System using the algorithm described by the MOD14 Users Guide. The thermal MODIS data is shown by the color of the symbol on the map. This thermal data is collected twice a day, at 2:00 PM EST and again at 12:00 AM EST and are then processed and merged into a single map, which is available by 3:00 AM EST.

The currency of the thermal MODIS data is shown by the color of the symbol on the map.

Map Legend

Thermal MODIS Map Legend

Identification of a MODIS pixel as "fire" in this layer does not necessarily mean that the entire area represented by the pixel is on fire. The identification of a fire can be the result of a hot fire in a relatively small area, or a cooler fire over a larger area. At this time, there is no way to discriminate between these two possibilities. The geolocation of the centroid of the fire pixel is within one-half of one pixel (500-meters) of the location shown on the map.

The Thermal MODIS layer is updated every two hours. However, there may be gaps in daily coverage as explained below. If we have received no new data, the "expired" layers are not replaced. The layer is replaced as soon as we receive an updated file.

The thermal information is collected at a 1 km spatial resolution and converted to ellipse-shaped vector polygons. The geolocation of the centroid of each polygon is within one-half of one pixel (500-meters) of the location shown on the map. These collections are processed by the MODLand Rapid Response system and merged into a single file.

This fire location data is compiled by the USDA Forest Service Remote Sensing Applications Center in cooperation with NASA Goddard Space Flight Center, the National Interagency Fire Center and the USDA Forest Service Missoula Fire Sciences Laboratory.