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Figure 3. – Digital cartographic
mapping. A, Status of digital line graph production. B, Status of digital elevation model production.
Production of color infrared and simulated natural color orthophotoquads during fiscal year 1983 included areas in Delaware, North Carolina, and Washington at scales of 1:24,000 and 1:25,000. The Geological Survey is also preparing a series of simulated natural color image maps at 1:25,000 scale of the United StatesMexico international boundary in cooperation with the Customs Service, U.S. Department of the Treasury.
During fiscal year 1983, the National Mapping Division, in cooperation with the Minerals Management Service, completed 25 Landsat 1:250,000-scale black-andwhite image maps for the Alaskan North Slope above the 68th parallel. These products will be used to help support the management of the Federal Government's oil and gas program in that area. Plans are being made to publish the Landsat image maps as part of standard Alaskan map coverage. Other Landsat image maps are under consideration.
The Survey also has been evaluating Side-Looking Airborne Radar for use in topographic and geologic mapping. Twelve controlled 1:250,000-scale quadrangle image mosaics of the Aleutian Island Arc in Alaska are being prepared from radar imagery acquired in 1982. Six of the mosaics will be printed back-to-back with updated line maps; the remaining mosaics will be printed without line maps.
duplication among depository systems, thereby cutting costs, several map depository programs (including the Geological Survey and Defense Mapping Agency programs) are being consolidated within the larger Congressional depository system. The consolidated, but expanded, program will be administered by the Government Printing Office under the policy direction of the Joint Committee on Printing. The program will be implemented in early 1984, following a survey by the Government Printing Office to determine which products each depository library wishes to receive. The Geological Survey will then make monthly mailings to the libraries of the Survey and Defense Mapping Agency maps.
In the area of product distribution, a computer-based system has been installed to track the various types of Survey maps and books that are stored for public sale and distribution. Major Survey warehouses in Arlington, Virginia, Alexandria, Virginia, and Denver, Colorado, have been equipped with terminals that communicate over telephone lines with the host computer, which contains descriptive information about each product, its storage location, and its stock quantity. In 1984, an additional capability to handle and track the thousands of orders received each year will be developed.
To meet the increasing need for earth science data, the Survey is considering the development of a cooperative information service that will coordinate the existing information services of the Geologic, Water Resources, and National Mapping Divisions. As part of this service, the Survey has linked its Public Inquiries Office and National Cartographic Information Center public access points via a computer-based network and plans to exchange and share information with other Interior bureaus and selected State offices. The network, referred to as the Earth Science Information Network, will help to provide the public and other Government agencies with the earth science data stored in various major data bases, to develop the flow of information among public access points, and, when necessary, to bring information together quickly to focus attention on national problems.
The National Cartographic Information Center's network of State affiliates continued to grow during the year. Newcomers to the network include the States of Idaho, Massachusetts, and Rhode Island. Since the initial affiliate agreement with the State of Texas in April 1976, 36
The Geological Survey disseminates much of the Nation's earth science information through its Public Inquiries Offices, National Cartographic Information Centers, and Earth Resources Observation Systems Data Center. The National Mapping Division operates these public access points for the Survey and sells the Survey's maps, books, photographs, and machinereadable tapes. Four areas where significant advances have been made in providing improved service to the public are in the map reference library program, the product-inventory distribution system, the cooperative information service system, and the National Cartographic Information Center's State affiliate network.
The Geological Survey's map reference library network has been an important extension of the Survey in many communities across the country. At present, there are over 500 libraries that house collections of Geological Survey topographic and scientific maps. To provide access to a greater number of citizens and to eliminate
States have become linked with the National Cartographic Information Center. The State affiliates handle cartographic and geographic data, distribute pamphlets, brochures, and topographic indexes, and sell maps of their respective States.
Research, Investigations, and Developments
Vegetation-Land Cover Classification in Alaska
The National Mapping Division has cooperated during the past 3 years with several State and Federal resource management agencies in Alaska to produce vegetation and land cover classifications to support comprehensive planning, research, and management mandates of the 1980 Alaska National Interest Lands Conservation Act and inventory requirements of the Forest and Rangeland Renewable Resources Planning Act of 1974.
The vegetation-land cover classifications have been derived from Landsat digital data and digital elevation data using standard digital processing techniques. With few exceptions, the analysis procedures (including field data collection) and classification descriptions follow a standard format. By the end of fiscal year 1983, approximately 110 million acres of Alaska were classified for vegetation-land cover. Projects in progress will complete an additional 80 million acres by the middle of fiscal year 1984. At that time, over half the State will have detailed land cover classifications. The primary use of these data is for estimates of land cover acreages and for producing habitat suitability models for various wildlife species.
circular includes technical standards for applying digital line graph techniques (a way to represent line map information in digital form) for the Public Land Survey System and a description of digital elevation models (collections of elevation values stored on a computer). Work is essentially complete on technical standards for digital line graphs for hydrography and for 1:100,000-scale maps. These standards will be included as additional chapters of the circular.
The Survey recognized that other public groups and individuals who use its products should be involved in the development of digital cartographic standards and actively supported the work of the National Committee for Digital Cartographic Data Standards. The goal of the committee, established under the auspices of the American Congress on Surveying and Mapping, is to provide a professional forum for Federal, State, and local agencies, private industry, and professional individuals to share their opinions, assessments, and proposals on digital cartographic data standards. After the standards are formulated, they will be subjected to extensive review. When the Survey is confident that the standards are acceptable, they will be submitted to the National Bureau of Standards for application throughout the Federal Government.
Petroleum Resource Assessment of Undeveloped Federal Lands
Digital Cartographic Data Standards
As a part of the development of a national digital cartographic data base, the Survey also develops technical standards that govern the information that is stored in the data base. An agreement between the National Bureau of Standards and the Geological Survey assigns the Survey the responsibility to develop and maintain the standards for computer-based and graphic information for the earth sciences.
The Survey is preparing technical standards for the various types of cartographic information in the national data base. Interim standards are being published as Geological Survey Circular 895, which currently consists of seven chapters. The
The Survey has prepared a series of maps and associated statistics to support an assessment of petroleum potential in undeveloped Federal lands in 11 Western States. These undeveloped lands include wilderness areas and other lands being considered for wilderness designation. Administrative and legal boundary information on these areas was compiled using computer-assisted techniques developed by the National Mapping Division. Resource boundaries of potential petroleumyielding areas and geologic basins were compiled in the same way.
Additional computer programs were developed to provide a geographic analysis of the combined boundary information. By using these programs, the National Mapping Division prepared maps that combined the areas that have petroleum potential with the various categories of Federal lands. The potential of the petroleum areas was classified from low to high, and the size of these areas was also calculated.
Satellite image maps are highly useful as multipurpose base maps for various types of geological, glaciological, and geophysical data. The National Mapping Division used a 1:500,000-scale Landsat image mosaic of the Amery Ice Shelf, Antarctica, as the base map for compilation of 1- and 5-meter contours derived from Seasat radar altimeter data. Division scientists have also collected data for preparation of a 1:5,000,000-scale digital mosaic of Antarctica using National Oceanic and Atmospheric Administration very high resolution radiometer images. The mosaic will be unique because it will be the first cartographically and geometrically accurate image base of the entire continent made from one data source. It will be used as the basis for a new map of the continent and for maps on specialized topics.
can be used to produce a three-color map. After examining many of these combinations, bands 2, 3, and 5 were selected to produce the final map.
Each band was processed to achieve the optimum density, or brightness, for processing. A digital edge enhancement technique was used to accent the boundaries between different areas on the images. The map developed from the Thematic Mapper images was printed on the reverse of a standard line map. Both the Las Vegas and Dyersburg maps incorporate a Universal Transverse Mercator grid so that each can be cross-referenced to its companion line map.
Rolla Conterminous United States Mineral Assessment Program Activity
Image Map Research
The Geologic Division, the Earth Resources Observation Systems Data Center, and the Missouri Geological Survey developed and tested a digital geologic data base for mineral resource assessment of the Rolla, Missouri, 1° by 2° quadrangle. The data base consisted of 20 numerically encoded layers of surface and subsurface geological, geochemical, and geophysical data that were digitized from 1:250,000-scale maps compiled as part of the Conterminous United States Mineral Assessment Program. Using defined geological and geochemical characteristics, two additive numerical models were developed and applied to the data base to identify and rank favorable areas for the occurrence of Mississippi River valley-type lead-zinc mineralization.
Federal Mineral Land Information System
Since the launch of Landsat 1 in 1972, the Survey has published a variety of experimental image maps based on the multispectral scanner data. The 80-meter picture element data of the multispectral scanner, when properly processed, can provide resolution, geometric accuracy, and content comparable to a 1:250,000scale line map.
Early in 1982, the Las Vegas 1:250,000-scale quadrangle was selected to test a newly developed geometric registration capability together with advanced digital image processing techniques available at the Earth Resources Observation Systems Data Center. The Las Vegas area was selected because of the diversity of features-urban areas, desert, mountains, lakes, rivers, and irrigated agriculture. Four Landsat scenes were required to cover the map area. The final product was a conventional color-infrared image map with a standard line map printed on the back.
The area around Dyersburg, Tennessee, located along the Mississippi River in the northwestern part of the State, was the first area to be mapped (scale 1:100,000) with data from the Landsat 4 Thematic Mapper. The process used to develop the Dyersburg map laid the groundwork for future uses of Thematic Mapper data. The Thematic Mapper has a picture element size of 30 meters and produces data on seven bands. By combining and manipulating this data, numerous color combinations
The Federal Mineral Land Information System is being designed as a tool to develop land management and policy objectives for the Nation's strategic and critical minerals and energy resources. Central to this objective is the creation of a data base on Federal surface ownership, subsurface mineral rights, Federal restrictions to mineral development, and mineral occurrence and potential. These types of information will be compiled and analyzed using a geographic information system currently under development.
A pilot project, based on questions which might be asked of an operational system by national policymakers, was conducted on the Medford, Oregon, 1:250,000-scale quadrangle. The Medford
quadrangle was selected because a Conterminous United States Mineral Assessment Program report was available, as well as other mineral deposit and occurrence data. Surface mineral management status maps were also available at 1:100,000 scale. Results of the pilot project have been analyzed and a report has been prepared outlining the potentials and limitations of using a digitized approach for national level data bases.
which items can be retrieved by specifying latitude-longitude coordinates of an area of interest, or by entering an index number for a particular lake.
The lake surface area and any other lake attribute (such as depth, water quality, or temperature) that has been entered into the file will be listed. In addition, the computer can sort and display lakes by size classes (5-10 acres, 10-50 acres, and over 50 acres) and summarize surface area by lake classes. The lake inventory has been completed for nine quadrangles within the National Petroleum Reserve. Work on six additional quadrangles on the North Slope is underway.
Arctic Lake Digital Data Base Project
The National Mapping Division has cooperated with the Water Resources Division to develop a digital data base containing the geographic location, acreage, and other attributes for lakes greater than 5 acres on the North Slope of Alaska. The data will be used by the Bureau of Land Management in its onshore oil and gas assessment and leasing program.
The basic information for the project is the water categories derived from a digital land cover classification of the National Petroleum Reserve in Alaska. The classification was originally performed by National Mapping Division personnel at Moffett Field, California, using Landsat digital data. The product is a computer file from
Fuel Mapping and Monitoring for Wildlife
The National Mapping Division, the Bureau of Land Management, and the National Oceanic and Atmospheric Administration jointly evaluated the use of advanced very high resolution radiometer data for mapping wildland fire fuels and monitoring the growth of grasslands and biomass accumulation of over 9 million acres of public lands in northwestern Arizona. Bureau of Land Management fire managers require a low-cost, effective means of mapping fire