US firefighters and land managers are using NASA satellite data provided by the Moderate-resolution Imaging Spectroradiometer (MODIS) instrument. The device on the Terra satellite provides a view of fires across the entire United States, which helps fire experts manage fires more effectively, both during and after wildfire events. The effort is a collaboration between NASA, NOAA, the University of Maryland and the USDA Forest Service.
The Terra satellite beams daily images of western US wildfires to NASA within a few hours of the time that it passes over the region. These images, showing the locations of active fires, are transmitted to the Forest Service. When the Forest Service's own direct broadcast receiving stations are completed in October, this will reduce the transmission time to minutes. Images from Terra's Moderate-resolution Imaging Spectroradiometer (MODIS) instrument will become a regular part of the Forest Service�s fire monitoring toolkit.
“NASA remains deeply committed to working cooperatively with its sister agencies to monitor and combat wildfires across the nation. Our investment in the Terra Earth Observing System is starting to pay tremendous dividends to the American taxpayer,” said Ghassem Asrar, NASA's associate administrator for the Office of Earth Science.
In order to use MODIS data to tackle forest fires, researchers must maintain a complex communications network between NASA, the University of Maryland, and the Forest Service. The three institutions are integrated under the Rapid Response Project. Rob Sohlberg at the University of Maryland's Department of Geography in College Park, MD, leads the Rapid Response Project with Jacques Descloitres at NASA�s Goddard Space Flight Center in Greenbelt, MD. This program was created in response to the 2000 fire season, with its extensive wildfires in Idaho and Montana.
By October 2001, the Forest Service will have the capability to produce its own MODIS fire images within minutes of a Terra overpass. “The Active Fire Maps offer the potential for understanding the big picture when working on resource allocations decisions,” said Alice Forbes, deputy director for Forest Service Fire and Aviation Operations at the National Interagency Fire Center (NIFC). “The maps can also help the public understand where the fires are located, and give them a look at the burned areas after fire season.”
The University and NASA developed all of the needed software, which will be installed at the Forest Service�s data receiving station. The Forest Service developed corresponding software that creates the Active Fire Maps from the Terra data using standard mapping techniques.
The Forest Service�s Remote Sensing Applications Center (RSAC) in Salt Lake City, Utah, provides development, support and application of remote sensing technologies and techniques. Currently, the Forest Service is building a MODIS processing center in Salt Lake City to generate near-real-time images of western wildfires. However, the Forest Service will still receive imagery of the eastern U.S. from the University and NASA.
Keith Lannom, the Operations Program Leader at RSAC, stated, “The University of Maryland sends MODIS images and active fire location information daily to RSAC staff who are overlaying state boundaries and topographical features on the images to best determine where fires are occurring. These maps show current active fire areas in near real time on the Internet.”
The maps show daily active fires, and areas that were burned during previous days. These maps will be used for strategic asset allocation when fighting wildfires. Advanced products to assist the Burned-Area Emergency Rehabilitation (BAER) teams are also being developed from Terra data. The BAER team consists of soil scientists, hydrologists, wildlife specialists and other scientists. They use burn-severity maps derived from satellite and ground measurements to help them take measures that will prevent further erosion, soil loss and adverse impacts to water quality. It is anticipated that Terra data will provide a quick look, which can then be refined on the ground. The maps will also help scientists identify critical wildlife habitat affected by the fire and facilitate reforesting an area.
Wei Min Hao, the Project Leader of the Fire Chemistry Project at the Forest Service's Fire Science Laboratory in Montana, is developing a MODIS aerosol product to track smoke dispersed by wildfires, and to determine the impact that it has on regional air quality. Hao said, “During fires where there are large amounts of smoke, reconnaissance planes that normally map fires can't fly into an area, but MODIS can provide those pictures from space.” Dr. Yoram Kaufman from NASA is working with Dr. Hao on these products.
The Terra spacecraft is part of NASA's Earth Science Enterprise, a long-term research effort being conducted to determine how human-induced and natural changes affect our global environment.
About MODIS
The MODIS instrument provides high radiometric sensitivity (12 bit) in 36 spectral bands ranging in wavelength from 0.4 �m to 14.4 �m. The responses are custom-tailored to the individual needs of the user community and provide exceptionally low out-of-band response. Two bands are imaged at a nominal resolution of 250 m at nadir, with five bands at 500 m and the remaining 29 bands at 1000 m. A ±55-degree scanning pattern at the EOS orbit of 705 km achieves a 2,330-km swath and provides global coverage every one to two days.
The Scan Mirror Assembly uses a continuously rotating double-sided scan mirror to scan ±55-degree driven by a motor encoder built to operate at 100 percent duty cycle throughout the 6-year instrument design life. The optical system consists of a two-mirror off-axis afocal telescope which directs energy to four refractive objective assemblies; one for each of the VIS, NIR, SWIR/MWIR and LWIR spectral regions covering a total spectral range of 0.4 to 14.4 �m.
A high-performance passive radiative cooler provides cooling to 83K for the 20 infrared spectral bands on two HgCdTe Focal Plane Assemblies (FPAs). Photodiode-silicon readout technology for the visible and near infrared provides unsurpassed quantum efficiency and low-noise readout with exceptional dynamic range. Analog programmable gain and offset and FPA clock and bias electronics are located near the FPAs in two dedicated electronics modules, the Space-viewing Analog Module (SAM) and the Forward-viewing Analog Module (FAM) . A third main electronics module (MEM) provides power, control systems, command and telemetry, and calibration electronics.
In addition, the system includes four on-board calibrators as well as a view to space: a Solar Diffuser (SD), a v-groove Blackbody (BB), a Spectroradiometric calibration assembly (SRCA), and a Solar Diffuser Stability Monitor (SDSM).