Remote Access
Strategic decisions regarding fire suppression resource allocation are based on a variety of available information sources. Timely, consistent and accurate information is important to develop an overall understanding of the current regional and national fire situation. One such piece of information is the daily Incident Management Situation Report produced by the National Incident Coordination Center at the National Interagency Fire Center. The situation report is a text-based summary characterizing current wildland fire activity and the allocated resources within designated geographic areas across the nation as well as at individual large wildfire incidents.
Although comprehensive, the situation report doesn't adequately portray this information within a geospatial context. Valuable geospatial information that could help decision-makers may include: Where has a particular wildland fire already burned? Where is it actively burning now? What is the proximity of current wildland fires to one another? How close are current wildland fires to communities?
In an effort to facilitate the decision-making process of regional and national fire managers, the USDA Forest Service, NASA Goddard Space Flight Center, the University of Maryland and the National Oceanic and Atmospheric Administration have collaborated to develop a comprehensive, near real-time fire detection system. The system uses daily, synoptic-view satellite imagery collected by the Moderate Resolution Imaging Spectroradiometer, or MODIS. Additionally, to facilitate the use of fire detection data and imagery products, the Forest Service has developed a complementary program to generate value-added geospatial products for fire detection and monitoring. These products are updated frequently and portray the current extent and activity of wildland fires at regional and national scales.
As a result, the products provide a geospatial component to the situation report and other information available to wildland fire managers and also serve as a decision support tool for strategic planning.
The MODIS sensor flies onboard the Terra satellite platform launched by NASA in December 1999. In May 2002, NASA launched a second MODIS sensor on the Aqua mission. Both Terra and Aqua platforms have multiple sensors onboard and are part of a constellation of NASA satellites known as the Earth Observing System.
The MODIS sensor is designed to monitor and provide integrated measurements of Earth's land, ocean and atmospheric processes. A particular phenomenon that MODIS is specifically designed to monitor is fire. MODIS has several characteristics that facilitate its ability for daily global satellite fire detection. Each of the MODIS sensors has a field of view of 2,330 kilometers and orbits the Earth several times daily. With their field of view and orbit configuration, each MODIS sensor can view nearly the entire planet daily — once during the day and once nightly. As a result, the combination of both modis sensors provide the opportunity to detect fire activity across the globa four times each day.
MODIS also has a broad spectral resolution measuring reflected and emitted energy from the visible to thermal infrared wavelengths. These measurements are collected at one of three spatial resolutions: 250 meters, 500 meters and 1 kilometer. MODIS thermal image data are used to detect fire activity on both the daytime and nighttime observations. The fire detection locations resolved from MODIS thermal image data are compiled at a spatial resolution of 1 kilometer; however, in favorable conditions the sensor can identify fire activity covering just a fraction of the sampled 1 square kilometer area.
During the 2000 fire season, remote-sensing analysts at the Forest Service Remote Sensing Applications Center investigated the utility of MODIS to support the Forest Service and other agencies in the management of wildland fires in the western United States. A major hurdle encountered by RSAC in using MODIS data was the time lag between acquisition of MODIS imagery and its subsequent availability. At the time, the procedure for accessing MODIS imagery and derived products from NASA could take several days to weeks. Since the availability of current information is critical for operational wildland fire support, this delay in obtaining MODIS data was a significant limitation to overcome.
RSAC's requirements for rapid access to MODIS data for wildland fire support led to a collaboration between RSAC and MODIS scientists at GSFC and the University of Maryland. In early 2001, GSFC and the University of Maryland developed a specialized data-processing system to derive fire detection data and imagery datasets from MODIS image data. The system, known as Rapid Response, is located at GSFC and leverages access to the standard MODIS data stream provided by NOAA. The data stream contains daily MODIS imagery collected for the entire globe.
The GSFC Rapid Response configuration facilitates near real-time access to MODIS data. That are routed from the EOS Data and Operation System receiving station in White Sands, N.M., to the NOAA Near Real Time Processing System. At this point in the data stream, NOAA subsequently relays these data to GSFC for processing by the Rapid Response system. The entire procedure takes approximately a few hours from the image acquisition by the respective MODIS instruments to data processing by the GSFC Rapid Response system.
To facilitate the use of MODIS fire detection data and imagery derived from Rapid Response, in 2001 RSAC developed a geospatial data-processing and mapping program called the Forest Service MODIS Active Fire Mapping Program. Near real-time MODIS fire detection data and selected imagery for North America generated by GSFC are continually transferred to RSAC year round, 24 hours a day.
The MODIS Active Fire Mapping Program automatically processes these data every hour and maintains fire detection geospatial datasets for the continent. The program uses the fire detection locations and imagery to compile a series of value-added geospatial products and Web-based applications for the continental United States and Alaska. In 2004, at the request of several provinces and territories in western Canada, the MODIS Active Fire Mapping Program expanded to provide a similar suite of value-added products and applications for all of Canada.
RSAC also has initiated steps to further minimize the latency period between acquiring MODIS image data and providing derived fire products to users. Each MODIS sensor has the unique capability to broadcast the data it collects in real-time to specialized ground stations designed to receive the broadcasted MODIS data signal as the sensor orbits overhead. RSAC completed construction of a MODIS ground station at its Salt Lake City facilities in time for the 2002 fire season.
With this capability, RSAC collects daily image data in real time from both MODIS sensors. The geographic location of the RSAC ground station facilitates the acquisition of real-time MODIS image data for the majority of the United States, southern Canada and northern Mexico.
To process MODIS data acquired by the RSAC ground station, RSAC coordinated with GSFC and the University of Maryland to implement the Rapid Response system on site. As a result, MODIS imagery and derived fire detection data are generated by RSAC within an hour of acquisition. The rapid availability of these data further reduces the time required to provide current fire information for the western states.
Real-time data for the western United States provided by RSAC augments the comprehensive, near real-time data provided by GSFC. RSAC, GSFC and the University of Maryland also actively coordinate with other MODIS ground station facilities in Alaska and the continental United States. Rapid Response fire detection data derived from this network of ground stations are also continuously compiled and processed at RSAC. As a result, the MODIS Active Fire Mapping Program can provide real-time coverage for all the fire-prone areas of the United States and Canada.
The Forest Service MODIS Active Fire Mapping Program provides a suite of active fire-mapping geospatial products, data and Web-based applications. These products are provided unrestricted from the MODIS Active Fire Mapping Program Web site at http://activefiremaps.fs.fed.us. Canadian active fire mapping products are available at http://activefiremaps.fs.fed.us/canada/.
The cornerstone products of the program are the MODIS Active Fire Maps, a series of poster-sized maps that cover 37 predefined geographic areas within the continental United States, Alaska and Canada. The maps are updated several times daily as fire activity warrants in individual geographic areas. Maps typically are published following both the daytime and nighttime observations of respective geographic areas by each MODIS instrument. The maps depict MODIS active fire detections occurring within the last 12 and 24 hours of the time of map publication. Cumulative MODIS fire detections for the current calendar year also are displayed. The maps are provided in PDF and JPEG formats and are rendered on a topographic base together with political boundaries, urban areas, major transportation routes, hydrographic features and the names of current large wildfires.
MODIS active fire detection data also are available in interactive, Web-based map applications. Individual map viewers are provided for the continental United States, Alaska and Canada. These applications allow users to view recent and cumulative fire detections at user-defined scales and map extents with various cartographic layers and satellite imagery. Key fire-related geospatial data layers are included, such as National Fire Danger Rating System observed and forecasted data and fire regime condition class data. In addition, advanced very high-resolution radiometer and geostationary operational environmental satellites fire detection data provided by NOAA also are available.
To support analysis and custom mapping needs of users, the MODIS Active Fire Mapping Program also provides downloadable geospatial data. Daily georeferenced, multi-spectral image subsets are available for current large wildland fires greater than 10,000 acres in the western United States. These MODIS image subsets include the spectral bands covering the visible, near-infrared and short-wave infrared wavelengths and can be manipulated to characterize smoke conditions and assess the extent of burned areas. The subsets are generated daily from MODIS direct-broadcast data acquired via the RSAC ground station and are provided in JPEG, GeoTiff and generic binary formats.
In addition to MODIS image subsets, annual MODIS fire detection GIS data sets are provided for each year since 2001. These data sets contain MODIS fire detection data for North America provided by Rapid Response processing at GSFC, RSAC and selected MODIS ground station facilities. The fire detection data set for the current calendar year is updated hourly.
The program also offers analytical summaries of current MODIS fire detections. Additional GIS analyses are conducted to provide detailed information about each fire detection within the United States and Canada over the last 24 hours. Hourly maps and geospatial summaries are provided for each detection describing the latitude and longitude; time and date of detection; intersecting county, state and National Forest; and the distance to the nearest city or town.
Wildland fire managers throughout the United States and Canada use MODIS active-fire mapping products. The products provide a comprehensive assessment of wildland fire activity in a geospatial context at any given time, and serve as a decision support tool for strategic planning and resource allocation.
Although not intended for tactical assessment, MODIS products augment airborne assets used to observe and assess fire activity. Available airborne assets may not provide coverage for all fires due to the number and distribution of fires, remote locations of fires, or safety hazards posed by heavy smoke conditions. In addition, MODIS active-fire mapping products are a valuable public information tool. They provide a source of current fire information for the general public, particularly for communities threatened by fire.
The Rapid Response Project and the Forest Service MODIS Active Fire Mapping Program are a result of collaboration between the Forest Service, NASA-GSFC, the University of Maryland and NOAA. These complementary programs provide value-added fire geospatial products intended for strategic wildland fire management in the United States and Canada. By leveraging the availability of real-time MODIS data from RSAC and other MODIS ground station facilities, delivered products provide a current characterization of wildland fire activity at regional and national scales.
The successful implementation of these programs serves as a model for supporting wildland fire management with future satellite missions.
Brad Quayle is a remote-sensing/GIS specialist for the USDA Forest Service Remote Sensing Applications Center based in Salt Lake City. He may be contacted at bquayle@fs.fed.us.
Keith Lannom formerly served as the operations program leader at the USDA Forest Service Remote Sensing Applications Center. He currently is the district ranger for the Tellico District of the Cherokee National Forest in Tellico Plains, Tenn. Lannom can be contacted at klannom@fs.fed.us
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