The first full year of Landsat-7 operations under joint U.S. Geological Survey (USGS) and NASA Landsat Program Management was very successful. The USGS assumed responsibility from NASA for flight operations for the Landsat 7 satellite, expanding the long-standing role of the USGS in the Landsat program that includes processing, archiving, and distributing data from Landsats 1 through 7. Since its launch in April 1999, Landsat 7 has carried out the mission objective of building a seasonal global archive of data by capturing more than 300,000 scenes of Earth for the U.S. and a growing network of 14 ground stations operated by 8 international cooperators. Landsat 7 extends an important long-term record of Earth’s land and near-shore areas for environmental research and applications such as forestry, agriculture, geology, land cover classification, and geographic research.

At the end of FY 2000, NASA and USGS were assessing four funding and management options for the follow-on to Landsat 7, known as the Landsat Data Continuity Mission (LDCM). As specified by the Land Remote Sensing Policy Act of 1992, these options were private-sector owned and operated; a U.S. Government-private sector cooperative effort; a U.S. Government-owned and -operated system (Landsat-7 model); and an international consortium. NASA and USGS drafted and distributed for public review a specification that defines the characteristics of data that would be expected from any LDCM operator, no matter which funding/management option is chosen.

The USGS Earth Resources Observation Systems (EROS) Data Center Earth Observing System (EOS) Distributed Active Archive Center (DAAC), which is funded by NASA, began receiving data successfully from the Terra satellite during FY 2000. Data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensors were processed by systems at the NASA-Goddard Space Flight Center and in Japan, respectively, and then sent to the EROS Data Center DAAC. MODIS data were released to the public in early spring 2000.

The USGS and Satellite Pour l’Observation de la Terre (SPOT) Image Corporation agreed to make more than 700,000 historical SPOT satellite images acquired over the United States from 1986 through 1998 available to other Federal agencies. These data are being permanently archived at the USGS EROS Data Center, where they will be distributed to Federal research and operational users at the cost of reproduction, plus a royalty fee paid to SPOT Image Corporation. SPOT data complement the USGS Landsat archive by substantially increasing the number of available low-cloud-cover images and by filling gaps in Landsat coverage. SPOT data are used for applications such as environmental research, forestry, agriculture, geology, and land-cover mapping.

DoI personnel continued to use both the DoD Navstar GPS Precise Positioning Service (PPS) and augmented differential GPS for real-time positioning in wildland areas. DoI assisted the DoT and DoD in their efforts to expand the Nationwide Differential GPS (NDGPS) by identifying project areas that are out of reach of current differential GPS methods. DoD turned off the Selective Availability feature that limited the accuracy of the Navstar Standard Positioning Service (SPS) signal in May 2000, making higher accuracy positioning available to all civil users. Now, DoI GPS coordinators are seeking suitable civilian GPS equipment that take advantage of this change in GPS signal access. At the end of FY 2000, tests were underway to determine if PPS performance is needed in areas of heavy vegetation cover and steep terrain.

The U.S. Fish and Wildlife Service (FWS) and the Federal Highway Administration continued to develop a digital baseline inventory of all public-use roads in the FWS National Wildlife Refuge System. The Refuge System explored ways to use GPS units to standardize some of the inventory and monitoring functions carried out on all refuge units. Remotely sensed data are not used as widely as other inventory and monitoring tools due both to cost and inconsistent availability, but the Pacific Islands were exploring the use of Landsat 7 and other new satellite data to define critical habitats for endangered species. Remotely sensed data may offer the only current method to collect data to designate critical habitat for over 200 species, many of them on inaccessible islands.

The National Park Service (NPS) used Landsat and SPOT satellite data, along with conventional aerial photography, Light Detection and Ranging (LIDAR), and digital orthophotography to map and monitor land cover, vegetation, cultural features, and other specific features in many national parks. The USGS continued to collaborate with NPS to map the vegetation and obtain uniform baseline data on the composition and distribution of vegetation types for 235 U.S. national park units. Vegetation mapping was completed at Devils Tower National Monument, Mount Rushmore National Memorial, Scotts Bluff National Monument, and Tuzigoot National Monument. In 2000, the program expanded its coverage to include two FWS National Wildlife Refuges in the Western United States. Approximately 400 GPS units were used to support NPS mapping and navigation needs for a variety of resource management and maintenance applications.

The Office of Surface Mining Reclamation and Enforcement (OSM) continued to use GPS technology in FY 2000 for project work and training. Restoration of Western U.S. surface mine topography has been field verified for GPS use. The Mountaintop Removal Environmental Impact Statement Task Force used GPS to classify and map ephemeral streams in surface mining areas of Appalachia. OSM personnel used GPS to map the location of monitoring points and subsidence features to support a project to monitor the hydrologic impacts of mine subsidence above underground longwall mining in southwestern Pennsylvania.

OSM continued prototyping the use of 1-meter IKONOS panchromatic data to map mine infrastructure, water features, active mining areas, and reclaimed land acreage. Stereo IKONOS data were used to generate digital elevation models, measure slopes, and create three-dimensional spatial databases of active surface coal mines. OSM also continued using the IKONOS 4-meter multispectral data to map vegetation health and vigor in reclaimed areas and to monitor water depth and sediment content.

The Bureau of Reclamation (BOR) used new remote-ensing technologies to develop inundation maps and emergency response plans for different scenarios of operational water releases from BOR dams and releases caused by potential dam failures. BOR scientists used LIDAR data acquired from aircraft to generate digital elevation models with submeter vertical accuracy to allow for precise modeling of flood boundaries and flood water depths. BOR personnel continued research to determine the feasibility of using high-resolution Space Imaging Corporation. IKONOS satellite imagery to classify land use and land cover for potentially flooded areas, thus providing better estimates of loss of life and property.

BOR staff used commercial Earth Search Sciences Inc. Probe 1 hyperspectral and IKONOS imagery to map the extent of the invasive plant species purple loosestrife at Winchester Wasteway, Washington, to monitor biological control efforts at that location. BOR and USGS personnel also collected ground spectral data of another invasive plant, leafy spurge, in Theodore Roosevelt National Park, North Dakota, in preparation for detailed large-scale mapping using Airborne Visible Infrared Imaging Spectrometer (AVIRIS), Earth Observing-1 Hyperion, IKONOS, and Compact Airborne Spectrographic Imager (CASI) data. BOR continued to use Landsat Thematic Mapper (TM), Indian Remote Sensing Satellite multispectral and panchromatic imagery, as well as USGS digital orthophoto quarterquads, to map agricultural crops in the Colorado River basin. Scientists used irrigation status and crop type data with crop water use coefficients and locally varying climate data to calculate agricultural consumptive water use.

The Minerals Management Service used GPS to assist in determining baseline points used to delineate offshore boundaries in the U.S. Virgin Islands. Accurate boundaries were needed to support Territorial Submerged Lands jurisdictions as well as a proposed national monument for protection of coral reefs around St. Thomas and St. Croix.

The Bureau of Indian Affairs (BIA) used remote sensing and GPS to support BIA and tribal initiatives to map land use, inventory natural resources, and conduct environmental assessments. Scientists used digital orthophotography, National Aerial Photography Program (NAPP) aerial photography, National Elevation Dataset (NED) data, and Digital Raster Graphics (DRG) as backdrops to model potential flood inundation zones caused by the failure of BIA-managed dams. BIA used these datasets with GPS and digital cameras to map irrigation structure condition on irrigated agricultural lands within BIA irrigation districts on Indian reservations in the Western United States. The BIA also expanded the applications of both civilian and military (encrypted) GPS receivers in natural resource planning, inventory, and mapping.

The Bureau of Land Management (BLM) used remotely sensed data from satellites and aircraft sensors, and GPS technology, to support 47 Bureauwide land- use planning programs during FY 2000. These technologies were used in conjunction with Geographic Information Systems (GIS) to address increased energy and mineral demands, competing resource demands from urban growth, and other changing resource conditions on the public lands. Scientists continued to use data from traditional and digital aerial cameras and multispectral and hyperspectral sensors with GIS technology to support inventory, assessment, modeling, and monitoring efforts associated with wildlife habitat, wilderness, recreation, rangeland, timber, fire, minerals, and hazardous materials.

The USGS and BLM used Landsat-7, RADARSAT, and European Remote Sensing Satellite (ERS)-2 synthetic aperture radar (SAR) images to investigate glacier dynamics at Bering Glacier, Alaska. The potential failure of the ice dam that impounds water in Berg Lake threatens to inundate large areas of Native American lands that are important wildlife habitat, used for subsistence hunting, popular for numerous recreational uses, and contain mineral resources that may soon be developed. Hence, lives as well as economic development are at risk from this unpredictable hazard.

The USGS, the French Space Agency (CNES), and NASA developed a dynamic algorithm to determine snow depth from passive microwave observations obtained by the Special Sensor Microwave Imager (SSM/I) on the Defense Meteorological Satellite. USGS and NASA planned to use the new algorithm to improve measurements of global snowpack. USGS and CNES also developed a new technique to map snow depth using radar altimeter observations from the ERS-2 satellite that is based on attenuation of the radar pulse by the snow pack.

The USGS also worked with scientists at the University of Washington to improve snow-melt runoff forecasts using SSM/I passive microwave observations. Investigators continued to develop techniques to combine hydrology models with a microwave snow-pack scattering model to determine the distribution of snow water equivalent for test basins in the Upper Rio Grande River, Colorado, and the upper Salmon River, Idaho. This technique has yielded greatly improved snow- water equivalent estimates when compared to conventional microwave techniques based solely on the satellite observations.

The year 2000 wildland fire season was quite active in the United States; almost 80,000 fires burned some 6,940,000 acres. The USGS EROS Data Center responded by providing spatial technologies and research experience to support wildfire management. Landsat-7 data acquired before and after the Jasper Fire in the Black Hills National Forest of South Dakota illustrated the change in green biomass caused by the fire, and demonstrated the capability for mapping the fire perimeter and the severity of burn. The Black Hills National Forest staff and the governor of South Dakota used these data to make a rapid assessment of the Jasper Fire. National Forest staff also used the data to map fire severity and model tree mortality. The NPS determined that these products could be of value as the tool for the national yearly mapping of the extent of wild land fires.

The BLM, BIA, and U.S. Forest Service (USFS) continued to work with the USGS to validate the utility of the Fire Potential Index (FPI), a fire ignition predictive tool developed by USGS and USFS scientists. The FPI characterizes relative fire potential for forests, rangelands, and grasslands both regionally and locally, using NOAA AVHRR multispectral satellite data with information from vegetation maps and daily weather information to generate 1-km resolution fire potential maps. The FPI is updated daily to reflect changing weather conditions and is posted by the USFS and the Alaskan Fire Service on their Web sites. Fire management staffs in Alaska, Arizona, California, Oregon, Montana, Nevada, and Wyoming continued to use the FPI in their daily decisionmaking process to supplement traditional information sources for establishing priorities for prevention activities to reduce the risk of wildland fire ignition and spread, and for allocating suppression forces to improve the probability that initial attack will control fires occurring in areas of high concern. Scientists tested the FPI in Argentina, Chile, Mexico, and Venezuela with the support of the Pan American Institute for Geography and History. The Joint Research Center for Remote Sensing in Ispra, Italy, worked with the USGS to test and implement the FPI for all of Europe.

The regional component of the interagency Multi-Resolution Land Characterization Project (MRLC) was completed in FY 2000 with release of the National Land Cover Data (NLCD) set. These data were derived from Landsat TM data acquired in the early 1990’s and shows the distribution of 21 categories of land cover across the conterminous 48 United States. The NPS became a member of the MRLC consortium this year, joining USGS, EPA, NASA, NOAA, and other agencies. In FY 2000, researchers began work on NLCD 2001, which will cover all 50 United States and Puerto Rico using current data.

The USGS carried out a study of ground-water flooding in the Puget Sound Basin, Washington, using RADARSAT SAR data. Ground-water flooding occurs in the complex glacial geologic framework of the region when the water table rises above low-lying land surfaces as a result of above-average precipitation. This flooding lasts for several weeks until the water table lowers. Groundwater flooded areas were identified by comparing SAR images from dry periods with images from wet periods.

USGS developed a field spectral radiometer for rapid, frequent remote monitoring of turbidity in the Colorado River in the Grand Canyon. The instrument measured the brightness and color of river water every 30 minutes from August 1999 to September 2000. The measurements were highly correlated to turbidity and total suspended sediment concentration measured from water samples collected during part of this time period, thus confirming the value of the method. Because of access restrictions within national parks and the high cost of monitoring remote areas such as the Grand Canyon, this system offers frequent, noninvasive remote monitoring of such areas. Near real-time monitoring is possible if the measurements are telecommunicated directly to an office for recording and analysis.

USGS scientists used Interferometric Synthetic Aperture Radar (InSAR) data from the ERS-1 and ERS-2 satellites to detect an uplift of several centimeters that occurred during the first half of 1993 in the San Bernardino groundwater basin of Southern California. This uplift correlates with unusually high runoff from the surrounding mountains and increased groundwater levels in nearby wells. The deformation of the land surface is used to identify the location of faults that restrict groundwater flow, map the location of recharge, and suggest the actual distribution of fine-grained aquifer materials. The results demonstrated that naturally occurring runoff and resultant recharge can be used with InSAR deformation mapping to help define the structure and important hydrogeologic features of a groundwater basin. This approach may be particularly useful to investigate remote areas having limited ground-based hydrogeologic data.

The USGS used digitized aerial photographs and airborne digital Scanning Hydrographic Operational Airborne LIDAR Survey (SHOALS) laser bathymetry data to map coral reef environments on the Hawaiian island of Molokai. The laser bathymetry and aerial photography images show information to a depth of approximately 35 and 20 meters, respectively. Researchers used digitized aerial photographs collected in September 1993 and January 2000 to detect changes in the amount of sea grass and sand cover on the inner and fore reef areas.

The USGS cooperated with NOAA and the United Kingdom Royal Aircraft Establishment National Remote Sensing Council to produce a 1:5,000,000-scale map of the Antarctic continent using NOAA Advanced Very High Resolution Radiometer (AVHRR) satellite data. The USGS also printed six image maps at 1:250,000-scale around Ross Island using Landsat Multispectral Scanner (MSS) data. Using Landsat data, the USGS also produced satellite image maps of South Florida and the Chesapeake Bay watershed. Numerous agencies involved in environmental restoration programs used these products.

In FY 2000, the USGS Volcano Disaster Assistance Program (VDAP) responded to the eruptions at Guagua Pichincha and Tungurahua volcanoes in Ecuador. For the first time, VDAP personnel combined classified reconnaissance data of the volcanoes acquired through the National Civil Applications Program with field-based and aerial observations of eruption features to assess the nature and magnitude of danger to people and property in the area. This project represented a new collaboration between the USGS Volcano Hazards Program and NCAP personnel.

In cooperation with university research groups and the National Science Foundation, the USGS assisted in the expansion of the network of continuously operating permanent GPS stations to measure crustal deformation in tectonically active areas in the western United States, Alaska, Hawaii, and the South Victoria land region of the Transantarctic Mountains (near McMurdo, Antarctica). Data continued to be transmitted to analysis centers for processing and analysis to produce highly accurate estimates for horizontal and vertical changes in Earth’s crust. The study area in Antarctica involves measuring crustal rebound resulting from changes in ice sheet mass balance. These measurements may contribute information for investigations of global sea-level changes.

The USGS cooperated with universities in Southern California to establish a large array of GPS receivers to make continuous measurements between stations that bridge known faults. Immediately following a major earthquake, new dual- frequency geodetic receivers are deployed on stations in the affected region to measure postearthquake rebound. Using advanced GPS data processing software and coordinated data, baseline vectors are determined to a few millimeters in each component. In FY 2000, technicians upgraded GPS networks at Mt. St. Helens in Washington and at Augustine Volcano in Cook Inlet, Alaska, to better monitor deformation at those hazardous volcanoes.

GPS use continued to expand to meet a wide range of USGS water resources applications. Researchers performed high-accuracy GPS surveys to prepare highly accurate digital elevation models of levees along the Mississippi and Missouri Rivers in areas that were flooded during 1993. Researchers continued to use this information to modify flood plain management practices to reduce damage from major floods in the future. High-accuracy differential GPS surveys provided elevation data at the few centimeter (cm) level for surface water flow modeling in the South Florida Ecosystem Restoration Initiative where extremely low relief requires elevation accuracies of at least 15 cm to be achieved over wide areas. Traditional differential leveling methods could not meet this requirement because it is much too expensive and time-consuming. In Puerto Rico, the public benefitted from use of GPS surveying techniques to help manage water resources. Researchers used GPS measurements to accurately map reservoir depth and reveal that the storage capacity of the Lago Dos Bocas reservoir had been reduced by over 40 percent due to sedimentation during the last 52 years.

USGS scientists regularly used GPS technology in a variety of projects in the Great Lakes region in FY 2000. Scientists used GPS receivers and aerial photographs to determine sample locations, provide geographic reference for GIS data sets and assist in navigation during wetland restoration projects on FWS National Wildlife Refuges. GPS technology supported side-scan sonar surveys conducted in several Great Lakes and habitat mapping projects in the Detroit River to locate sample sites and provide geographic reference for biological data. Researchers used GPS to guide sampling procedures and simplify navigation in open water for studies of larval fish habitat preference in Lake Erie. GPS was also used as part of native clam research in several national parks in Michigan.

USGS developed a GPS database of accurate locations of 16,000 bridges for the State of Pennsylvania. This engineering application will benefit public safety through assessment of the condition of bridges that are located on rivers with unstable channels and high scour potential where countermeasures are necessary to protect bridges from possible damage.