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Maps Of An Emerging Nation

By John H. Wittmann

A special-edition map sheet was prepared to commemorate the bicentennial of the signing of the United States Constitution. The special edition includes, on one side, a map of the young Nation at about the time of the signing of the Constitution and, on the reverse side, a series of maps portraying the country's territorial development up to the present time.

U.S. Geological Survey researchers reviewed several historical maps in the collection of the Library of Congress' Geography and Map Division and sought recommendations from eminent historical cartographers for the most appropriate map to portray the

young Nation. The map published in 1784 by Abel Buell was chosen, primarily because it is the first map of the fledgling United States that was produced by an American. Only a few copies of Buell's water-colored map survive. The version selected for reproduction is in the collection of the New Jersey Historical Society.

A series of 14 maps recently produced as part of the USGS National Atlas was chosen to illustrate the territorial growth of the Nation. The maps show the extent of the British colonies and the expansion of the United States, its possessions, and outlying areas for selected years between 1775 and 1987. A depiction of the flag of the United States appropriate to each year was added to the chronological series.

The special-edition map sheet was granted recognition by the Commission on the Bicentennial of the United States Constitution as a project of exceptional merit with national significance and substantial educational and historical value. It serves as the Survey's proud contribution to the celebration of this milestone in American history.

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Satellite Data
Acquisition and
Processing System
Becomes Operational

By Wayne A. Miller

The U.S. Geological Survey, together with the National Oceanic and Atmospheric Administration (NOAA), has developed a system to receive, process, and archive Advanced Very High Resolution Radiometer (AVHRR) data acquired from NOAA's series of polar-orbiting meteorological satellites. Located at the Survey's facility in Sioux Falls, South Dakota, the AVHRR Data Acquisition and Processing System became operational on May 15, 1987, and

has been routinely acquiring and processing AVHRR data over the conterminous United States to support a variety of Federal research activities. The system can provide data that are screened for cloud cover, registered to various map projections, calibrated for brightness level and temperature, processed to calculate a greenness index, merged with other data or user-supplied line work, and shipped in digital form within 1 to 2 working days after acquisition and in photographic form within 7 to 10 working days after the data set is produced. All data acquisitions are archived temporarily for 90 days. A selected data set is permanently archived to support future research efforts.

Survey scientists have been investigating various applications of AVHRR data to support a variety of Department of the Interior resource management and planning activities, such as fire-fuels mapping, image mapping, rainfall monitoring,

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and vegetation monitoring. The results of these studies have shown that analyses of AVHRR data can be used for monitoring seasonal changes in vegetation over large areas. AVHRR data have also been used successfully to map different types of fire fuels in support of the Bureau of Land Management's national fire management program. Investigations being conducted with the Bureau of Indian Affairs show that AVHRR-derived data of rangelands in the southwestern United States can be grouped into categories related to herbage production. In other studies, research conducted with the Nebraska Forest Service found that AVHRR data can be used for computing fire-danger ratings to aid in fire prevention at the county or fire-district level. AVHRR data also have been useful in monitoring food and fiber production on range and agricultural lands in Montana and in monitoring floods in eastern South Dakota. In each of these research investigations, the AVHRR data were merged with other types of data, such as USGS digital line graph data, arc-second digital terrain data, and other digitized map data.

A satellite-image mosaic of the conterminous United States (fig. 3) has been prepared using portions of 15 NOAA AVHRR images acquired over a 2-year period, 1984-1986. Large-area mosaicking software and a set of 200 ground-control points automatically generated for each image were used to digitally mosaic and register all 15 images to a 1,500-meter Albers Equal Area Grid. After the image was registered, mosaicked, smoothed, and enhanced, it was merged with a map collar containing the State boundaries and produced on film using a color-film recorder at a scale of 1:25,000,000. This effort has helped to define techniques for using AVHRR data for other continentwide image maps at scales of less than 1:2,000,000 and to guide future AVHRR research activities.

The system will continue to provide the Survey and other Federal agencies with ready access to AVHRR data for use in monitoring the growth of vegetation, mapping snow cover, producing enhanced image maps, and conducting time-series analysis to support a wide variety of geologic, hydrologic, and land management applications.

Advanced

Cartographic System Developments

By Paul E. Needham

The advent of the computer has changed the focus of mapping requirements in the United States. For more than 40 years, the U.S. Geological Survey has provided map users with primary topographic quadrangle map coverage of the United States at 1:24,000 scale in the lower 49 States and at 1:63,360 scale in Alaska. By the end of fiscal year 1987, primary quadrangle maps and related map products were available for about 93 percent of the country. Initial national coverage of these graphic map products is scheduled for completion by 1990. In recent years, however, it has become apparent that we must also produce digital versions of these graphic products to support the needs of our computer-oriented society.

In 1979, the Survey received funding appropriations that formally initiated the National Mapping Division's Digital Cartography Program. More recently, the Division began a major new development effort called Mark II that will implement both advanced cartographic technologies and production procedures to satisfy National Mapping Program requirements through the year 2000. By 2000, the National Digital Cartographic Data Base (NDCDB) is scheduled to contain digital data representing the content of the primary map series and other smaller scale series. This data base will serve two major functions: a central archive for the dissemination of digital data to the user community for information systems analysis, and a working data base for production of standard graphic map products. As initial coverage of the Nation at 1:24,000 scale approaches completion and the need for map revision and digital cartographic data increases, the traditional National Mapping Program is in transition. With this transition come the attendant problems of implementing new technologies and developing appropriate hardware and software to meet the mapping needs of the next century.

To achieve the digital data base goal by the year 2000, a number of development tasks must be accomplished. The Survey will need to expand and improve mass digitizing capabilities; modify data structures to support increased content and access requirements; develop digital revision capabilities; develop the capability to generate standard, derivative, and digital products; improve quality control; and support advanced analysis and applications.

Specific requirements for the NDCDB contents and related production processes were also identified. These requirements cover sources of data, categories of data, levels of data integration, data revision, data quality, and both digital and graphic products to be produced from the NDCDB.

To evaluate the existing systems and to facilitate the identification of new and improved capabilities, Mark II was divided into four functional components, each addressing a specific part of the production process. Each of the four components was further divided into a series of modules designed to develop a specific part of the production system.

The data-production component addresses all phases of data collection, editing, data processing, and quality control prior to entry into the NDCDB. The database component is designed to develop two levels of data bases: an operational data base to support ongoing mapping center production and product-generation requirements and an archival data base to provide a central repository for data to support the operational data bases. The product-generation component is designed to provide the cartographic products required to support the National Mapping Program, as well as to provide an interface between the production system and geographic information systems. The production-management component is designed primarily as an interface between the production system and the National Mapping Program requirements and authorization systems.

Implementation of digital revision and maintenance of primary quadrangle mapping through digital techniques will require major changes in the National Mapping Program production process. An overall production strategy has been developed, and efforts are now underway to meet identified goals.

Developing Digital
Cartographic Data
Standards

By Frank J. Beck

The U.S. Geological Survey has been developing digital techniques to collect, manipulate, analyze, and display cartographic and geographic data. Part of this development effort has included defining and implementing digital standards. Standards-related activities can be separated into two general types, those internal to the Survey or to other Federal agencies, and those at the national level affecting the public as well as government sectors.

The Survey established and published digital standards for cartographic data several years ago as separate chapters in a circular (U.S. Geological Survey Circular 895, 1983) that described various aspects of the digital cartography program and types of data being gathered, processed, stored, and distributed. The information contained in these chapters is being updated and separated into two distinct yet related series of documents. Information on data standards and specifications is being included in the Survey's National Mapping Division "Manual of Technical Instructions." Information on data characteristics or applications is being converted into a series of seven data users guides.

A Data Standards Committee within the USGS considers earth science data standards suggested by USGS divisions or other agencies. Standards adopted by the Survey are submitted to other standards groups, such as the National Bureau of Standards and the American National Standards Institute, for their consideration. A Survey standard, "Representation of Geographic Point Locations for Information Interchange," for example, has been recently adopted by both of these organizations.

The definition and application of digital standards for cartographic data within the Survey has had a significant impact on the map user community as well. A major effort to coordinate standards within the Federal government is underway in the Federal Interagency Coordinating Com

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