The National Map

Topographic Mapping

for the 21st Century

Final Report

November 30, 2001

Cooperative Topographic Mapping Program

U.S. Geological Survey

Mail Stop 511

Reston, VA 20192

http://nationalmap.usgs.gov

U.S. Department of the Interior

U.S. Geological Survey
The National Map ii Final Report

Any use of trade, product or firm names is for descriptive purposes only and does not 

imply endorsement by the U.S. Government.

The following is the recommended bibliographic citation for this publication:

U.S. Geological Survey, 2001, The National Map: Topographic Mapping for the 21st

Century: Reston, Va., Office of the Associate Director for Geography, 

U.S. Geological Survey.
The National Map iii Final Report

Preface

The report The National Map describes the vision by which the U.S. Geological Survey 

(USGS), working with partners, will provide the Nation with current, accurate, and 

nationally consistent basic spatial data, including digital data and derived topographic 

maps, and deliver spatial information that is current. Issues discussed include the form 

USGS maps and spatial data will take, ways that lag time between changes on the ground 

and corresponding updates in data and on maps can be reduced, and means by which the 

USGS can create and maintain these data and maps.

To develop the report, the USGS interviewed key individuals familiar with the 

development and use of spatial data. The individuals were from the USGS; associations 

of professionals and organizations, Federal, State, and regional agencies, and private 

companies. USGS personnel also reviewed the documents listed in the Selected 

References section. From this information, the USGS drafted a vision statement and 

released it for public review during the spring of 2001. On the basis of the 130 comments 

received from across the spatial data community, the USGS revised the report. Scientists 

from other USGS disciplines and representatives of selected professional organizations 

and interest groups validated the revisions.

The report recommended the development of The National Map to meet needs and take 

advantage of technological and other developments. The National Map is proposed as a 

database of basic spatial data that will provide a starting point for users to extend and 

enhance and to which users can tie additional data to meet their individual needs. The 

National Map concept is the unifying construct that incorporates all geography programs 

of the USGS: Cooperative Topographic Mapping, Land Remote Sensing, and Geographic 

Analysis and Monitoring. The USGS will provide the leadership needed to develop and 

continuously maintain The National Map through partnerships linking Federal, State, 

local, and tribal governments, the private sector, other organizations, and the general 

public.

USGS invites partners, customers, and the public to contribute to achieving the goals of 

The National Map. Suggestions can be sent by electronic mail to: 

nationalmap@usgs.gov.

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Contents

Preface.................................................................................................................................iii

Contents ...............................................................................................................................v

Executive Summary: The National Map............................................................................ 1

Choices About the Future – Being Made Today ................................................................ 5

Vignette 1: Status Quo ................................................................................................... 5

Vignette 2: Common Action Enabled Through a Common Set of Basic Spatial Data . 5

The Needs of the Federal Government, and the Nation, for a Common Set of Basic 

Spatial Data ......................................................................................................................... 7

The USGS’s Role in Meeting These Needs........................................................................ 7

Changing Needs for Spatial Data, and Opportunities for Meeting These Needs ............... 9

The National Map ............................................................................................................. 10

Data Characteristics ...................................................................................................... 11

Development, Maintenance, and Operations ................................................................ 14

Access and Use ............................................................................................................. 15

Organizational Issues and Strategies................................................................................ 16

Roles of the USGS ........................................................................................................ 16

Roles of Partners........................................................................................................... 18

Needed Research and Development ................................................................................. 19

Next Steps......................................................................................................................... 20

Selected References .......................................................................................................... 23

Glossary ............................................................................................................................ 25

Appendix 1. The Changing Needs for Spatial Data, and Opportunities for Meeting These 

Needs................................................................................................................................. 29

Appendix 2. Research and Development Needed to Support The National Map ........... 33
Executive Summary: The National Map

This report defines a vision for The National Map, a database of continuously maintained 

base geographic information for the United States and its territories that will serve as the 

Nation’s topographic map for the 21st century. Improvements will include greatly 

increased attention to keeping the information current, seamless national digital data 

coverage to avoid problems now caused by map boundaries, higher resolution and 

positional accuracy to better support user requirements, thorough data integration to 

improve the internal consistency of the data, and dramatically increased reliance on 

partnerships and commercially available data.

Governments depend on a common set of base information that locates and describes the 

Earth’s surface and features as a tool for land and natural resource management, 

economic and community development, and health and security services. Federal 

functions ranging from land management to emergency management and defense to 

environmental protection require this information. Private industry, nongovernmental 

organizations, and the general public also create and use these geographic data. Spatial 

information underpins an increasingly large part of the Nation’s economy.

The National Map will serve as a foundation for integrating, sharing, and using spatial 

data easily and consistently and will provide a new approach to provide more current 

information while retaining and improving other valued characteristics, such as positional 

accuracy and content completeness.

Under the leadership of the U.S. Geological Survey (USGS), and through partnerships 

with other Federal agencies, State and local governments, the private sector, academia, 

libraries, and the public, The National Map will provide data and operational capabilities 

that include the following:

• High-resolution digital orthorectified imagery. Imagery will provide some of the 

feature information content now symbolized on topographic maps.

• High-resolution surface elevation data, including bathymetry.

• Vector feature data for hydrography, transportation (such as roads, railways, and 

waterways), structures, and boundaries of government units and publicly owned 

lands.

• Geographic names, such as those for physical and cultural features.

• Land cover data classifying the land surface.
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The USGS will continue to provide a standard set of digital data products and highquality paper topographic maps derived from The National Map. Customers also will be 

able to create their own maps by defining a geographic area of interest, selecting unique 

combinations of data, and printing their maps at home or at kiosks.

Changes to The National Map will be captured in near real-time, rather than during 

cyclical inspection and revision. Currentness will be measured in days and months. The 

ultimate goal is that changes will be recorded within 7 days of a change on the landscape. 

Near-term expectations are for significant currentness improvements for most data 

themes compared with data now available from the USGS. Features will be represented 

in their entirety and consistently classified. This will enable users to extract data for 

geographic areas such as counties or watersheds and will allow improved computer 

analysis of the information. Data resolution and completeness will vary depending on 

geographic area and need. Positional accuracy will be sufficient to align features from 

different data themes.

The initial version of The National Map will be based primarily on existing available 

data. As the initial version is improved, emphasis will shift to maintaining data 

currentness through continuous updating. Potential data sources include State and local 

governments, private industry, and trained and certified local volunteers.

The National Map will be accessible continuously through the Internet. The vision calls 

for data to be in the public domain, which will require the negotiation of unlimited 

distribution and use rights for data from commercial sources.

Users will be able to combine data from The National Map with spatial information 

available from other organizations, such as cadastral information from the Bureau of 

Land Management and demographic data from the Bureau of the Census. The National 

Map will be the foundation of a USGS enterprisewide geographic information system to 

which other organizations can add or reference their information, such as land use data, 

school district boundaries, or wildlife census information.

The success of The National Map will depend heavily on sustainable partnerships. The 

USGS will lead the development and maintenance of The National Map by being the 

(1) guarantor of national data completeness, consistency, and accuracy, (2) organizer 

responsible for awareness, availability, and utility of The National Map, (3) catalyst and 

collaborator for creating and stimulating partnerships, (4) integrator and certifier of data 

from participants, (5) owner and data producer when no other sources for needed data 

exist, and (6) leader in the development of geospatial data standards.

The USGS will seek partnerships and business arrangements with other organizations to 

develop and operate The National Map. USGS staff will be located across the Nation to 

work directly with partner Federal, State, or other public organizations, private industry, 

and universities. Federal agencies would identify needs and develop and execute plans 

for collaborative data development and maintenance. The role of the USGS in these 
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relationships could range form being the organizer of consortia to working with other 

agencies to support the inclusion of their data in The National Map. State, regional, and 

local partners would coordinate or undertake area-specific geographic data development 

to meet their needs and, where interests align, to maintain and operate The National Map

for their areas. Private organizations would provide analysis and visualization tools, 

develop standards-based, open technology and processing standards, and provide data 

under contract or license. The USGS will work with university faculty on relevant 

research topics. Libraries will support public access to The National Map. The USGS 

will encourage volunteers to help detect and report changes to maintain The National 

Map.

The USGS will maintain a 5-year plan for the Cooperative Topographic Mapping 

Program to implement The National Map. This plan will define objectives, data 

architecture, business methods, and an annual program of work goals necessary to 

establish the program structure and to measure progress toward full realization of The 

National Map vision.
Choices About the Future – Being Made Today

The National Map will underpin the mission activities of Federal agencies, as well as 

other public and private organizations. The proposed continuously maintained, nationally 

consistent set of basic spatial data will provide a starting point and organized means for 

integrating, sharing, and using spatial data easily, consistently, and quickly.

The following vignettes, set in the year 2010, offer ideas of the consequences of no

action, and of how The National Map could benefit the Nation.

Vignette 1: Status Quo

FAIRVIEW, August 15, 2010 – It had been a long 

fire season, and it wasn’t going to let up soon. 

Local, State, and Federal firefighting crews were 

being augmented by military units.

The commander of a newly arrived unit entered 

the command post. “Where do you want us?” he 

asked the Ops Chief.

“Come here and I’ll show you,” replied the Ops 

Chief. On a table were maps updated and

annotated by hand using a rainbow of colored 

pencils. Stacked around these maps were USGS 

and other maps, aerial and satellite photos, and 

plots from computer files. Even a few tourist maps 

peeked from the pile, and the commander swore 

one looked like the map on the placemat from a 

local diner. “What’s this?” he asked.

“We use the maps to plan fire lines,” the Planning 

Section Chief said half-apologetically. “We get 

whatever base maps are available. They’re often 

not current, and we update them with whatever 

information we can get. This probably is the first 

time most of this information has been pulled 

together. The information often doesn’t fit well, 

but we do the best we can in the time we have.”

“Isn’t there anything better available?” asked the 

commander. The Planning Section Chief noted 

that, as a result of local interest and resources, there 

were good integrated digital base maps available 

for limited areas. “They’re great to use, but they’re 

often not available or don’t contain the topographic 

information we need” he noted. “And where they 

are available, they usually stop at a county or forest 

boundary. Unfortunately, fires aren’t too picky 

about crossing boundaries. There are less detailed 

satellite and other data that cover larger areas. 

They’re great for getting an overall view, but they 

don’t help much in the field. As for base maps for 

tactical firefighting, USGS topographic maps are

available, but they’re often out of date. No one 

pulls existing data together, fills in the gaps, and 

keeps the information current, so we make do.”

The Ops Chief pointed to an area on the map. 

“We need your people to establish a fire break here. 

We’re trying to protect some homes further up the 

mountain.” “Where are the buildings?” the

commander asked. “I don’t see them on the map.” 

“They’re out there,” the Planning Section Chief

replied. “But we don’t know exactly where, and so 

we can’t plot them on the map.”

“Hell of a way to fight a fire,” the commander 

muttered as he left the command post.

Vignette 2: Common Action Enabled Through a Common Set of 

Basic Spatial Data

MIDWAY, July 4, 2010 – After years of cleanup 

efforts, the river was open to swimmers. On a hot, 

muggy Fourth of July, people were drawn to the 

river–swimming, tubing, boating, and fishing. 

They had no idea of how exciting their vacations 

were about to become.

Upriver, a containment pond had given way, and 

thousands of gallons of caustic sediment were

pouring into the river. The skeleton staff at the 

plant alerted the emergency spill center, which

swung into action.

Their first priority was public safety and health. 

Using The National Map developed and maintained 

by the USGS and other organizations, they located 

on recent digital aerial photos and river and lake 

data the place where the spill entered the river, and 

they identified the area and facilities downstream 

that the spill was most likely to affect. Water

utilities with intakes in the area were ordered to 

stop pumping. The media broadcast warnings to 

stay clear of the contaminated water; however,

officials were concerned that people on the river 
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might not receive the warning in time. In a flash of 

inspiration, they remembered that personal

electronic devices had been equipped with Global 

Positioning System receivers for years. Using The 

National Map to outline an area that included the 

river and land within 100 yards of the shore, they 

identified all the devices in the area and sent them a 

simple message – “HAZARDOUS SPILL –

LEAVE THE RIVER NOW.” People headed for

shore as the river came alive with the chirping of 

cell phones, pagers, and personal digital assistants.

The center also warned Federal and State natural 

resource and environmental agencies of the spill. 

The agencies, with partners from industry and nongovernmental organizations, had been linking

information about water quantity and quality, the 

shape and makeup of the riverbed, and aquatic

plants and animals to The National Map for years. 

The agencies used these spatially referenced data to 

plan actions to minimize damage and start cleanup 

operations. “At least it won’t get much worse,” 

said one chemist after using the data to determine 

that the spill was unlikely to interact with other 

naturally occurring chemicals in the river. Using 

The National Map, scientists pinpointed wetlands 

and alerted field personnel to place barriers to 

protect this productive habitat.

Having issued the warning, the center

concentrated on predicting the likely extent of the 

spill. By analyzing real-time river flow

information, elevation and land cover data, and 

weather forecasts, they estimated the rate of the

spread of the spill and produced maps showing 

impacted areas and access routes for remediation 

teams. “How about that,” one official exclaimed, 

“we might get ahead of the spill before it reaches 

the Mississippi.”
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The National Map

The Needs of the Federal Government, and the 

Nation, for a Common Set of Basic Spatial Data

Governments are inherently geographic. All governments need spatial data that locate 

and classify lands and waters, describe the distribution of peoples, economic activities, 

infrastructure, and natural resources, and document the products of their domains. The 

National Academy of Public Administration (1998) identified 12 broad Federal functions, 

ranging from economic and community development to emergency management and 

defense to environmental protection, that require spatial data. The report summarized the 

Federal Government’s role in spatial data functions as “one in which Government is 

expected to help ensure public safety, manage the public lands for multiple uses, preserve 

the Nation’s resources for future generations, and help meet the basic needs of an 

expanding economy.” 

Spatial data required by the Federal Government are also created and used by State, 

regional, local, and tribal governments, private industry, nongovernmental organizations, 

and individual citizens. Paper maps and digital forms of spatial data underpin an 

increasingly large segment of the Nation’s economy. The economic multiplier of freely 

available public domain geographic data is substantial. Entire industries are built around 

these data. Base geographic data should be considered and supported as part of the 

Nation’s infrastructure. A 1997 National Research Council report concluded that:

Spatial data have helped form a foundation for commercial enterprises, such as 

delivery services, and have also led to enhanced market analyses. At the same 

time, the use of spatial data has reduced costs and increased efficiencies in a wide 

variety of areas where it is necessary to manage large networks of geographically 

dispersed facilities, most notably in the utility industries, transportation, and local 

governments. Policies and practices of open and affordable access to spatial data 

have contributed to U.S. leadership in the world markets of spatial data 

technologies and applications.

The USGS’s Role in Meeting These Needs

A common set of current, accurate, and consistent basic information that describes the 

Earth’s surface and locates features is the starting point for most geographic activities. 

The National Map will be a composite of continuously maintained basic spatial data for 

the United States and its territories and will serve as the Nation’s topographic map for the 
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21st century. It will be a data foundation that could be extended and enhanced, and to 

which additional data, both public and private, could be tied. It will contain sufficient 

detail to support national, regional, and local activities. Guaranteed availability of The 

National Map will allow Federal agencies to concentrate on data unique to their mission 

needs and to avoid expending resources to find, develop, and integrate basic spatial data 

each time they are needed. Within the U.S. Geological Survey (USGS), The National 

Map will be one of many data sets accessible through the USGS Gateway portal and will 

be the organizing mechanism for spatially referenced scientific information, as the 

foundation data of an enterprisewide geographic information system.

The USGS has a mandate to provide base topographic information to the Nation,

including the needs of its own scientific programs and those of other Federal agencies. 

This mission is consistent with the Office of Management and Budget Circular A-16, 

“Coordination of Surveying, Mapping, and Related Spatial Data Activities.” 

The most widely known form of topographic information is the USGS primary series of 

topographic maps,1 which gives a complete and consistent picture of our Nation’s lands. 

The maps, complemented by digital forms of the mapped information and aerial and 

satellite imagery, support numerous government activities, including saving lives and 

property in natural disasters, aiding other bureaus of the Department of the Interior in 

carrying out their stewardship and regulatory responsibilities, and providing a 

cornerstone for other USGS science programs. These spatial data also have been used 

widely by State, regional, and local governments, the private sector, and other 

organizations. Citizens use the maps in educational, recreational, environmental, and 

conservation activities, and to explore and understand natural resource issues. The maps 

help people connect with the Earth through the power of place and geography.

Developing and maintaining basic, standardized spatial data for the Nation have required 

and will continue to require a significant national commitment and engineering effort. To 

give a sense of the scope of the effort, the USGS primary topographic map series includes 

more than 55,000 unique map sheet, and 220,000 digital orthorectified images2 to cover 

the United States. Although one form of these spatial data, the paper map, once was 

sufficient, other needs evolved over the last 20 years with developments in computer 

technology. The USGS responded to these changing needs by providing basic spatial 

data in a number of digital forms in addition to the paper map form. While these maps 

and related digital data are considered by many to be a national treasure, they are rapidly 

becoming less valuable as they age. For example, the average age of the primary 

 

1

 The primary topographic map series subdivides the United States into four-sided figures called 

quadrangles, which are bounded by lines of latitude and longitude. Topographic maps present the 

horizontal and vertical positions of represented features. The maps show relief (elevations and 

depressions), water features, roads and railroads, structures, boundaries, names, and other information. The 

most widely known maps in the series are the 71⁄2-minute quadrangles, most of which are published at a 

map scale of 1:24,000 (1 inch on the map represents 2,000 feet (24,000 inches) on the ground). For Alaska, 

most quadrangles are 15 minutes in latitude and from 20 to 36 minutes in longitude and are published at a 

scale of 1:63,360 (1 inch on the map represents 1 mile (63,360 inches) on the ground). 

2

 An orthorectified image is an aerial photograph or satellite image from which displacements caused by 

terrain and other factors have been removed. The resulting image has the image characteristics of a 

photograph and the geometric qualities of a map.
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topographic series maps is 23 years. Although historical base geographic information is 

vital for many governmental, commercial, and academic purposes, showing where 

changes have occurred on the landscape, the maps no longer portray conditions 

accurately. Complementary digital images often are more current; however, maintaining 

the currentness of the data provided by the USGS, while retaining other valued 

characteristics, such as positional accuracy and completeness, is a challenge, especially 

for areas of rapid development.

As the Nation’s largest civilian mapping agency, the USGS has the responsibility to 

organize and lead partnerships and activities that provide basic spatial data needed by all 

national sectors. Clearly a new approach is needed to keep up with rapid changes on the 

landscape and to provide current, accurate, consistent, and useful basic spatial data.

Changing Needs for Spatial Data, and 

Opportunities for Meeting These Needs

The rapid pace of improvements in digital technologies and plunging unit costs for these 

technologies are changing the way information is made available and used. The use of 

spatial data has been affected radically by these trends. Computerized systems to use 

spatial data, such as geographic information systems, and to acquire the position of 

features and events, such as the Global Positioning System, are changing the spatial data 

needs of organizations and individuals and are providing new opportunities to meet those 

needs. 

Major current and developing spatial data needs, and the implications of new capabilities, 

include the following:

• Data: There continues to be an unmet need for a common set of nationally 

consistent, basic spatial data. For some places, considerable data are available; 

for others, there is very little data. These data must be current and useful for any 

arbitrarily defined geographic area. Both digital and paper forms of basic spatial 

data are needed.

• Technology: Technology will continue to evolve and will provide new ways to 

collect, maintain, access, and use basic spatial data. For example, the 

convergence of personal digital devices, Global Positioning System capabilities, 

and wireless communications is stimulating numerous location-based services that 

provide access to geospatial data by users at remote sites and will make possible 

the real-time collection and updating of data by those same users.

• Partnerships: Common needs and interests offer opportunities for partnerships to 

collect, maintain, access, and use basic spatial data among Federal agencies and 

with other public organizations, notably State and regional organizations. Private 

sector investments in the collection, maintenance, access, and use of basic spatial 

data provide opportunities to meet national needs. Volunteers may be an 

untapped source of information needed to maintain basic spatial data. 
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• Federal leadership: Federal leadership and commitment are needed to ensure 

that nationally consistent, basic spatial data are available to support Federal 

agencies in accomplishing their missions. The USGS has the mission to lead in 

the development and maintenance of a common set of basic spatial data, although 

a new approach is needed. USGS leadership and participation in current 

interagency data development programs, as well as in activities of the Federal 

Geographic Data Committee, provide starting points and contexts for developing 

and maintaining basic spatial data.

Appendix 1 contains a summary of these changing needs and opportunities.

The National Map

The proposal for The National Map sketches the initial concept and way of moving 

forward to meet national needs for basic spatial data. The goal of The National Map is to 

provide a nationally consistent set of integrated, current topographic information that 

supports those needs. The resolution of the data will vary depending on geographic area 

and availability (for example, more detailed and accurate elevation data for flood plain or 

coastal areas). In no case will the resolution of the best available data in The National 

Map be lower than that associated with USGS primary series topographic maps for an 

area. 

Information Content 

The National Map will consist of several themes of spatial data; this is the initial set:

High-resolution digital orthorectified imagery. An orthorectified 

image is an aerial photograph or satellite image from which most 

displacements caused by terrain relief and sensor geometry have been 

removed. The result combines the image characteristics of a 

photograph with the geometric qualities of a map. Images will be 

collected using the most efficient and effective combination of 

aircraft- and satellite-based remote sensing capabilities. In addition 

to providing the high-resolution imagery, The National Map will also serve seamless 

Landsat satellite imagery to provide intermediate-resolution national coverage.

High-resolution elevation data, including offshore bathymetric data 

maintained by the National Oceanic and Atmospheric 

Administration. At a minimum, these data will have sufficient detail 

to yield contours for primary series topographic maps, to support the 

geometric correction of imagery, to support three-dimensional 

perspective views and fly-throughs, and, in areas of subtle relief 

variation such as flood plains and coastal areas, to support hydrologic 

and other modeling. (Data courtesy of Intermap Technologies, Inc.)
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Vector feature data for the themes of hydrography, transportation 

(especially roads, but also including railroads and waterways), 

structures, boundaries of governmental units, and administrative 

boundaries of publicly owned lands. These data will have unique 

feature identifiers and minimal associated descriptive information. In 

most cases, the information content will include simple classification 

information (for example, “stream/river” and “lake/pond”) and a 

geographic name. Feature-based linear referencing systems required to link other data to 

The National Map will also be included. Examples include reach codes for hydrography 

data that support operations of the U.S. Environmental Protection Agency, U.S. Forest 

Service, and USGS, and street addresses that support operations of the Bureau of the 

Census.

Geographic names. These names include those for physical and 

cultural geographic features needed to support the U.S. Board on 

Geographic Names, and other names, such as for highways and 

streets. Names will be associated with their corresponding features, 

and the locational accuracy of names not associated with a feature 

specifically represented in The National Map, such as a locale or a 

ridgeline, will be improved.

Land cover information. These data classify the land surface into 

categories, such as open water, perennial ice/snow, evergreen forest, 

and high-density residential. The data satisfy the need for nationally 

consistent content for topographic mapping applications. Land cover 

data are developed from a combination of aircraft- and satellite-based 

remote sensing sources, supplemented by ground-truth information.

Data Characteristics

The National Map data will have the following characteristics: 

• Currentness. Content will be updated on the basis of changes in the landscape 

instead of the cyclical inspection and revision cycles now in use. Currentness will 

be measured in days and months, not years. The ultimate goal is that new content 

be incorporated within 7 days of a change in the landscape. Currentness will vary 

depending on the data theme, local characteristics (for example, rate of change), 

user requirements, source availability, technology, and resources. Data expected 

to be significantly more current in the near future include imagery, elevation 

(depending on the applicability of new remote sensing technologies), and features 

for which surrogate indicators of change are available (such as construction or 

occupancy permits).

• Seamlessness. Features will be represented in their entirety and not interrupted by 

arbitrary edges, such as 7.5-minute map boundaries.
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• Consistent classification. The type of feature, such as “road” and “lake/pond,” 

will be identified the same way throughout the Nation.

• Variable resolution. Data resolution, or pixel size, may vary among imagery of 

urban, rural, and wilderness areas. The resolution of elevation data may be finer 

for flood plain, coastal, and other areas of low relief than for areas of high relief. 

A tool will be provided to generalize data of varying resolution within a specified 

geographic area. Reduced-resolution, internally consistent representations may be 

precomputed and stored or generated on the fly, depending on the complexity of 

the data and size of area selected.

• Completeness. Data content will include all mappable features (as defined by the 

applicable content standards for each data theme and source). Content will not be 

generalized (for example, features deleted or aggregated) as may be required for 

graphic representation. Tools will be provided to support data generalization and 

symbolization for graphic display. 

• Consistency and integration. Content will be delineated geographically (that is, in 

its true ground position within the applicable accuracy limit) to ensure logical 

consistency between related features. For example, the terrain surface will be 

accurately depicted by the combined elevation and hydrography data, such that 

streams and rivers consistently flow downhill; each structure will be located 

correctly in relation to other local features, such as roads and other buildings.

• Variable positional accuracy. Positions will be based on locations on the ground 

and will not have offsets, generalizations, or other adjustments that are made to 

improve legibility on paper maps. The minimum positional accuracy will be that 

of the current primary topographic map series for an area. Actual positional 

accuracy will be reported in conformance with the Federal Geographic Data 

Committee’s “Geospatial Positioning Accuracy Standard.” Relative accuracy will 

be achieved through attention to logical consistency and data integration. 

• Spatial reference systems. The coordinates for spatial data in The National Map

will be based on defined horizontal and vertical datums and will be encoded in a 

defined coordinate system. Tools will be provided to integrate data that are 

mapped using different datums and referenced to different coordinate systems, 

and to reproject data to meet user requirements.

• Standardized content. The content of The National Map will conform to 

appropriate Federal Geographic Data Committee, other national, and/or 

international standards.

• Metadata. At a minimum, metadata will meet Federal Geographic Data 

Committee standards to document the content and characteristics of The National 

Map data, such as lineage, positional and attribute accuracy, completeness, and 

consistency. Metadata will be maintained at the feature level when applicable. 

The metadata will be published over the Internet, using standard Web protocols, 

such as the National Spatial Data Infrastructure Clearinghouse, to enable users to 

find and evaluate the reliability and usefulness of data for their unique 

applications.
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• Temporal dimension. To facilitate the tracking of changes over time, the USGS 

will ensure that The National Map content is permanently archived by retaining 

versions of data sets or feature-based transactional information. Existing paper 

topographic map archives will also be preserved.

For many areas, The National Map will contain data that surpass standards for the current 

primary topographic map series and related digital spatial data.

Figure 1 illustrates the importance of the proposed data characteristics. Seamless and 

consistently classified data allow similar views to be generated for any area. Consistent 

and integrated data ensure that, when combined, data from the various themes register 

well. Currentness ensures that the data accurately represent the ground. These qualities 

are important for maps and other displays of data. They are also essential to ensure 

accurate results from automated analyses of the data.

Figure 1. Computer-generated image for an area west of Denver from data such as those 

proposed for The National Map. A shaded, three-dimensional perspective view has been 

generated from elevation data; orthorectified image, transportation (roads in red), and 

hydrography (in blue) data are draped over the view.
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Development, Maintenance, and Operations

The initial version of The National Map will largely be based on available data. Sources 

of data will include current holdings of the USGS and other participating organizations. 

When needed, new data will be obtained primarily through contracts with the private 

sector and purchases of data available in the marketplace. The initial version will not 

achieve all the characteristics described in the previous section, but data will be improved 

and replaced over the next decade as the emphasis shifts to maintaining data currentness 

through continual updating.

When a change on the landscape occurs, database updates will be made through 

transactions in which only the needed changes to the data will be processed. These 

updated data will be made available immediately. The processing of transactions will 

require ensuring the integrity of the resulting change with similar data for surrounding 

areas (for example, making sure new roads fit into the existing road network) and with 

related data from other themes in the same area (for example, making sure changes in 

hydrography data match the elevation data). The USGS will develop an archive strategy 

for The National Map that will include time-specific versions and feature-based change 

information, as appropriate.

Critical to success is a robust means of knowing about changes when they occur and of 

receiving spatial data that faithfully represent those changes for inclusion in The National 

Map. The ideal sources for information about a change and for new data that represent 

the change are those close to the change, such as local governments, local offices of other 

public and private organizations, or trained and certified local volunteers. The preferred 

approach would be for these organizations or persons to “push” updates to The National 

Map when changes occur on the landscape. Another approach is for public and private 

sector organizations that have reporting relationships with local organizations or 

individuals to act as intermediaries for providing updates. A third approach would be for 

the USGS to detect changes from imagery or from notifications of changes provided by 

others, and so directly acquire the data needed to update The National Map. The 

approach used for an area will depend on the commitment of partners and the relative 

costs of available approaches.

Computing and telecommunications technologies will allow numerous options for 

sharing responsibilities. The National Map may develop as a networked, distributed 

collection of databases, operated by public or private sector organizations that, as data 

stewards, agree to provide basic spatial data that meet common standards and levels of 

service. Although the data archive may be distributed among many sites, the data in The 

National Map will appear seamless to users. The National Map will follow relevant 

national and international standards that are supported by industry. 

To continue to be relevant, it is important that The National Map be developed and 

improved in response to users’ needs, as well as to changing technical and organizational 

requirements. There must be a means to obtain feedback from users and to respond to 

reported deficiencies and changing needs.
The National Map 15 Final Report

Access and Use

The National Map will provide around-the-clock access through the Internet to basic 

spatial data; access will be based on user-specified combinations of data and geographic 

area of coverage. Views of the data and transfers of reasonable amounts of data through 

the Internet will be provided at no cost. Access to large volumes of data may require a 

fee to pay for media and other distribution costs. The USGS will review data distribution 

charges periodically to ensure compliance with Federal pricing policy. 

The USGS is committed to ensuring that The National Map content remains in the public 

domain and is made accessible over the World Wide Web through multiple Web-based 

services, including an image service (Web mapping), feature services (data streaming in 

support of location-based services and metadata browsing), and data extract (feature 

access and spatial data transfer). All services will use industry-supported, open, 

standards-based protocols, as appropriate, to allow these data to be accessed easily and 

readily, for maximum utility to all users. Unrestricted and immediate access to The 

National Map is of vital importance to public and private organizations for emergency 

and disaster response. To ensure access for these and other critical needs, The National 

Map will be designed with redundant servers, sufficient bandwidth, and around-the-clock 

operational support. In cases where rights to data are held by private organizations, the 

negotiation of appropriate distribution and use rights will be required.

The National Map will also provide means of accessing and using other data from 

Federal agencies and other organizations, using open, standards-based technology and 

processing methods, such as those being developed through the Open GIS Consortium 

and the Federal Geographic Data Committee. One method will be use of The National 

Map as a reference base to link to additional attribute information, such as detailed USGS 

scientific data. Another method will be the combination of displays of The National Map

data with themes available from other organizations, such as geodetic control data from 

the National Oceanic and Atmospheric Administration, cadastral information from the 

Bureau of Land Management and State agencies, soils data from the Natural Resources 

Conservation Service, or demographic data from the Bureau of the Census. Similarly, 

data from local agencies, such as zoning, school, or watershed protection data, could be 

displayed in combination with data from The National Map. In addition, The National 

Map could provide access to more detailed data or value-added 

services available for a fee from public or private organizations.

The USGS will also provide a standardized set of high-quality paper 

topographic maps and digital data created from The National Map. 

This view of The National Map will be a continuation of the USGS 

primary topographic map series and complementary digital data. 

Imagery may carry some of the information content now encoded 

with map symbols; for example, an image might substitute for 

symbols used to portray structures. Customers will have the 

flexibility to define map boundaries and to select different 

combinations of data to produce maps that best suit their needs. In 

addition, USGS business partners may develop kiosks that provide 

customized maps on demand through a distributed retail network (for 
The National Map 16 Final Report

example, at gas stations, convenience stores, coffee shops, recreational stores, State or 

local government offices, bookstores, libraries, and post offices).

Organizational Issues and Strategies

The success of The National Map will depend on the participation and support of many 

organizations. To ensure success, the USGS must lead, develop, and sustain mutually 

beneficial relationships with other organizations. These issues will be among the most 

challenging to be addressed in developing and maintaining The National Map. 

Roles of the USGS

The USGS will provide the national leadership to develop and maintain The National 

Map. This leadership includes being the (1) guarantor of national data completeness, 

consistency, and accuracy, (2) organizer responsible for awareness, availability, and 

utility of The National Map, (3) catalyst and collaborator for creating and stimulating 

partnerships, (4) integrator and certifier of data from other participants, (5) owner and 

data producer of content for The National Map when no other suitable and verifiable 

source for those data exist, and (6) leader in the development and implementation of 

national geospatial data standards. The USGS will also ensure the quality of The 

National Map data through standards development, by devising and implementing quality 

assurance procedures, and by promoting process certification criteria for content 

providers.

Within the USGS, the responsibility for The National Map is vested in the Associate 

Director for Geography. Program priorities and commitments are being aligned with 

financial and personnel resources to accomplish this responsibility. Priorities for the 

development and operation of The National Map will be reviewed and endorsed annually 

to update the long-term strategy, to define intermediate goals, and to establish an annual 

operating plan. Standards for currentness and strategies for maintenance and operations 

will be reviewed annually to consider new geographic, societal, and programmatic 

priorities (for example, regional patterns of wildland fire, coastal erosion activity, disease 

diffusion trends, and other requirements, including national security). Because the USGS 

will depend on partners to develop and operate The National Map, program staff will 

concentrate on the agreements needed to meet the goals of the program.

Because the ability to meet Federal needs is central to the success of The National Map, 

the USGS will provide liaison staff to Federal agencies to help understand their evolving 

needs and to identify opportunities to work with agencies that produce spatial data that 

could contribute to National Map maintenance. For similar reasons, substantial numbers 

of employees will be located in area maintenance offices to work with other USGS 

offices, partner organizations, and a volunteer workforce. These offices will analyze 

requirements, develop partnerships, and identify data for The National Map. They will 

provide data acquisition, evaluation, integration, and applications expertise to partners 

and users. When fully implemented, these offices will be responsible for ensuring that 

The National Map meets user needs in their areas. The USGS will also encourage 
The National Map 17 Final Report

rotational assignments of staff among USGS offices and in university and private 

industry settings.

In addition to having area maintenance offices, the USGS will have field centers with 

responsibilities for The National Map to provide primary management, technical, and 

administrative support, including the following:

• Providing leadership by monitoring and responding to national trends in spatial 

data development and use, developing and managing standards, and providing 

independent technical expertise in the application of spatial technologies and data.

• Providing a core production workforce to maintain subject matter proficiency and 

to provide the technical underpinning to The National Map.

• For times when a surge capability is needed, such as during hazards and disaster 

response and recovery operations, supporting data “swat teams” to meet 

immediate needs for geographic information and applications.

• Addressing needs for cartographic and geographic information and general 

information science research.

• Staffing systems development, administration, and support activities.

• Providing product-generation operations, including those needed for standard 

USGS digital and paper map products.

To date, the USGS has organized, led, and participated in interagency data development 

activities to pool resources and make needed data available to Federal agencies and 

others. For example, The National Atlas of the United States ® is a partnership between 

government and business that delivers small-scale maps and data. A component of The 

National Map, the National Atlas is led by a network of Federal collaborators. It adheres 

to existing and emerging standards and uses the latest technologies. Its products are 

offered online. Integrated National Atlas data provide a reliable framework for regional, 

national, and global studies. 

There are other examples. The USGS leveraged Federal and State resources over the last 

decade to provide coverage of digital orthorectified imagery through the National Digital 

Orthophoto Program. First-time coverage is nearly complete for 49 States. Similarly, the 

USGS worked with the U.S. Environmental Protection Agency to provide initial national 

coverage of the National Hydrography Dataset and is working with Department of the 

Interior Bureaus, the U.S. Forest Service, the U.S. Environmental Protection Agency, and 

States to develop more detailed data. Through the National Digital Elevation Program, 

the USGS leads a consortium of Federal and State organizations that require elevation 

data. Partnerships also exist for land cover data and for geographic names. The USGS 

participates on State geographic information development activities and provides 

leadership for themes of data in the Federal Geographic Data Committee. This 

experience will guide new partnerships needed to develop The National Map.

To realize the full potential of The National Map, the USGS will investigate a legislative 

initiative, patterned on the National Cooperative Geologic Mapping Act. Such legislation 

would clarify Federal responsibilities and support partnerships with State, regional, and 
The National Map 18 Final Report

local governments, academic organizations, and the private sector. Advice and 

concurrence on this issue will be sought as The National Map implementation progresses.

Roles of Partners

Partnerships are the key to the success of The National Map. Among the roles of partners 

are identifying needs; budgeting, developing, and executing plans for collaborative data 

development and maintenance; organizing consortia; providing access to data; and 

conducting research.

To provide overall guidance, a proposed Federal advisory committee, consisting of 

representatives from the USGS and other Federal organizations, participating State and 

regional organizations, the private sector, and academia, would make recommendations 

on evolving requirements, approaches to data maintenance and processing, systems and 

technology development and implementation, and skill enhancements that contribute to 

The National Map.

Federal partners. The USGS will work with other Federal agencies to identify needs 

and to develop and execute plans for collaborative data development and maintenance to 

ensure that The National Map meets these needs. The role of the USGS in these 

relationships could range from being the organizer of collaboration to working with 

Federal agencies to support the inclusion of their data in The National Map. In addition 

to strengthened cooperation within the USGS for hydrography and elevation data, 

examples of potential partners among Federal agencies include Bureaus in the 

Department of the Interior and the Forest Service (basic data needed to manage Federal 

lands), Bureau of the Census (roads and boundaries), Environmental Protection Agency 

(hydrography and land cover), Federal Emergency Management Agency (elevation), the 

Department of Agriculture (imagery), the National Oceanic and Atmospheric 

Administration (bathymetry and links to the Nation’s geodetic control data network), and 

the National Imagery and Mapping Agency (data required for national defense). Other 

potential partners include the National Aeronautics and Space Administration, 

Department of Housing and Urban Development, Federal Communications Commission, 

Federal Aviation Administration, and Centers for Disease Control and Prevention.

State, regional, and local partners. The USGS will strengthen its coordination 

with State and regional consortia to develop partnerships with State, county, city, and 

other local organizations for high-resolution data for The National Map. When 

partnership arrangements can contribute to The National Map and meet Federal needs, 

the USGS will participate in and support State and regional consortia, such as State 

geological surveys, State GIS councils, or Implementation Teams, which coordinate areaspecific spatial data development to respond to local issues. When data held at State and 

local levels can contribute to The National Map, partnerships may be formed to develop 

methods and business relationships to extract data for The National Map from more 

detailed local holdings. 

USGS participation will include providing national and multistate program perspectives, 

coordinating leadership as appropriate, and offering guidance and expertise on data 

development and maintenance strategies. Participation may include developing strategies 

for data collection and maintenance, and pooling funding, expertise, and other resources. 
The National Map 19 Final Report

Area maintenance offices will develop business relationships needed to receive public 

reports of events (for example, building permits and road construction) that identify 

changes and trigger data maintenance efforts. Building on successes such as that of the 

Texas Natural Resources Information System, the USGS will encourage similar 

comprehensive State mapping capabilities. Where State and regional organizations share 

the goals of The National Map, they may develop, maintain, and operate The National 

Map, including distributing data and products, for their geographic areas. In these cases, 

the USGS will support their activities through cooperative agreements.

Private industry partners. The USGS will partner with private organizations that 

develop and supply geographic information analysis and visualization tools for broad 

public access, for research on cartographic technologies and issues, and for open 

technology and processing standards needed to take advantage of new computing and 

telecommunications technologies. The USGS will also procure data for The National 

Map from the private sector when the data and related licensing provisions support broad 

access to and use of the data. These procurements could be single purchases or 

subscriptions to updating services. When data are not available for an area, the USGS 

will contract with the private sector for data production and processing. For the 

derivation of products from The National Map beyond standard Internet-based displays 

and paper topographic maps, the USGS will rely on the private sector to provide valueadded output capabilities for public access, including meeting the demands for 

customized paper maps.

Academic and library partners. On cartographic, geographic, and general 

information science topics relevant to The National Map, the USGS will work with 

universities by supporting research and by rotating assignments of staff. The USGS will 

continue to rely on the Federal Depository Library Program as a vehicle for ensuring 

public access to The National Map and for providing feedback about geospatial 

information needs. The USGS also will work with the library community on issues 

relating to information archival and distribution of The National Map.

Partnerships with the public. Taking advantage of the anticipated widespread 

availability of Global Positioning System capabilities in personal electronic devices, the 

USGS will certify and encourage the participation of groups (such as the Appalachian 

Trail Club), scouting organizations, and private citizens to serve as a volunteer force for 

maintaining and validating The National Map. These persons will be trained through a 

virtual “volunteer academy.” Area Maintenance Offices will interact routinely with 

volunteers to ensure adequate training and data quality. The USGS will partner with 

private industry to support this large, semi-public activity and to ensure the widespread 

availability of low-cost techniques that integrate the Global Positioning System, wireless 

and broadband communications, high-resolution displays, and mass data storage 

technology. 

Needed Research and Development

The near-term technical functions needed to accomplish this vision will be met using 

commercially available capabilities. Development will be required to integrate these 
The National Map 20 Final Report

capabilities and to configure them to aid in the development and maintenance of The 

National Map.

To satisfy mid- and long-term goals, work is needed in applied topics in cartography, 

geographic information science, remote sensing, and general information science. In 

addition, issues such as new models for partnership relationships, the value of and 

business processes for sharing base geospatial information, and the relationship between 

intellectual property rights and public domain information needs must be investigated. 

These investigations will be focused first on needs that must be met in the next 5 years 

and will be pursued with partners from government, academia (including consortia such 

as the University Consortium for Geographic Information Science), and private industry. 

Appendix 2 contains a partial list of topics that require investigation.

Next Steps

The USGS plans to conduct the following activities to refine and implement The National 

Map:

• Conduct an ongoing review of the concept to evolve the vision. 

o Support a review of The National Map concept by the Mapping Sciences 

Committee of the National Research Council. This study will review the 

goals for The National Map and evaluate the approaches described for 

meeting those goals, the potential benefits of The National Map to the 

Nation, and the role of the USGS as the proposed leader for this effort.

o Identify topics that require more formal study and support investigations 

in these areas.

o Revise and add clarity to the concept on the basis of comments and the 

results of pilot projects, implementation activities, and research. 

• Align USGS activities with the vision.

o Complete a 5-year plan for the USGS Cooperative Topographic Mapping 

Program that identifies the goals for the Program and the steps necessary 

to achieve The National Map vision. The 5-year plan will include details 

about data architecture, operations concept, and annual goals and 

timelines. The goal for full implementation of The National Map by 2010 

is part of the vision. However, significant accomplishments must be 

programmed for the fiscal year 2002-06 timeframe and defined in the 5-

year plan. Implementation of The National Map will be accomplished in 

phases, and timeframes will differ for various data components and 

capabilities.

o Develop a business model and funding mechanisms for implementing The 

National Map.

o Identify and make needed changes in business practices.
The National Map 21 Final Report

o Identify characteristics of the workforce required to implement the 

concept and address deficiencies.

o Evaluate existing USGS and partner data holdings to understand their 

currentness and other characteristics in light of The National Map vision 

and to identify in more detail the information content to be captured in The 

National Map.

o On a pilot basis, expand selected current State liaison activities to assess 

the potential contributions of area maintenance offices. 

o Identify needs for a legislative initiative as implementation progresses.

• Forge relationships with organizations interested in The National Map vision.

o Identify organizations that use an approach similar to that proposed and 

work with them to identify key steps required to implement the concept.

o Evaluate the characteristics of other organizations’ holdings of basic 

spatial data and techniques for collecting and maintaining these data to 

understand what their value may be to The National Map.

o Work with key Federal agencies to understand their needs for spatial data 

and how their plans will coincide with implementation activities for The 

National Map.

o Work with interested State, regional, and local agencies to test and 

demonstrate aspects of the concept and to assess their interest in 

participating in The National Map.

o Implement data stewardship agreements that define ownership and 

responsibilities for The National Map components, and develop other 

business and cooperative data partnerships.

o Work with all sectors to identify the role of commercially provided data in 

The National Map and to resolve licensing issues such that the national 

interests for public domain data are served.

o Seek and secure funding to encourage and sustain State, local, and private 

sector data maintenance and dissemination activities.

o Identify priority research topics and opportunities for working with the 

academic and private sectors to undertake these investigations.

o Identify priority technology developments needed to implement The 

National Map and opportunities to work with standards and other 

organizations to understand and influence these developments.

o Assess how volunteers can best aid the development and maintenance of 

The National Map and identify and work with interested volunteer groups.

The National Map 23 Final Report

Selected References

Asche, H., 1998, Mapping and map use in the age of information technology: LIBER 

quarterly, v. 8, no. 2. 

Blanchard, K., Waghorn, T., and Ballard, J., 1997, Mission possible: becoming a worldclass organization while there’s still time: New York, McGraw-Hill.

Christensen, C.M., 1997, The innovator’s dilemma: Boston, Harvard Business School 

Press.

Collins, J., and Porras, J., 1997, Built to last: successful habits of visionary companies: 

New York, HarperBusiness.

Corbin, C., 2000, Great leaders see the future first: taking your organization to the top in 

five revolutionary steps: Chicago, Dearborn Financial Publishing, Inc.

Croswell, P., 2000, Information technology trends and challenges: URISA News, 

November/December 2000.

Federal Geographic Data Committee, 1995, Development of a national digital geospatial 

data framework: Washington, Federal Geographic Data Committee.

Federal Geographic Data Committee, 1997, Framework introduction and guide: 

Washington, Federal Geographic Data Committee.

Independent Commission on the National Imagery and Mapping Agency, 2000, The 

information edge: imagery intelligence and geospatial information in an evolving 

national security environment: Washington, Independent Commission on the 

National Imagery and Mapping Agency.

National Academy of Public Administration, 1998, Geographic information for the 21st

century: building a strategy for the Nation: Washington, D.C., National 

Academy of Public Administration.

National Research Council, 1995, A data foundation for the National Spatial Data 

Infrastructure: Washington, D.C., National Academy Press.

National Research Council, 1997, The future of spatial data and society: Washington, 

D.C., National Academy Press. 

National Research Council, 1999, Distributed geolibraries: spatial information resources: 

Washington, D.C., National Academy Press.

National Research Council, 2001, Future roles and opportunities for the U.S. Geological 

Survey: Washington, D.C., National Academy Press.

National States Geographic Information Council, 2000, Undaunted courage: a history of 

exploration and mapping: United States Geological Survey leadership in the 

development of a sustainable framework [resolution] from National States 

Geographic Information Council 2000 business meeting.

Neidig, C.A., Davis, S., Benjamin, C., and Sewash, J., 1999, State caucus report to the 

1999 USGS Mapping Workshop: [unpublished report].
The National Map 24 Final Report

Office of Management and Budget, 1990, Coordination of surveying, mapping, and 

related spatial data activities (Circular A-16).

Office of Management and Budget, 2000, Geospatial information roundtable, summary 

of proceedings: [unpublished report].

Strategy, Research & Action, 1999, Research is helping to develop the market across 

North America: market research report [transcript] from 1999 International Map 

Trade Association Convention.

Tosta, N., 2001, Licensing data and people: Geospatial Solutions, February 2001.

Turner, A.K., 1999, Putting the user first: implications for the geolibrary in National 

Research Council, 1999, Distributed geolibraries: spatial information resources: 

Washington, D.C., National Academy Press.

Urban Logic, Inc., 2000, Financing the NSDI: National Spatial Data Infrastructure: New 

York, Urban Logic, Inc.

U.S. Geological Survey, 1987, Primary mapping economic analysis (phase 1): 

[unpublished report].

U.S. Geological Survey, 1988, Primary mapping economic analysis (phase 2): 

[unpublished report]. 

Wacker, W., and Taylor, J., with Means, H., 2000, The visionary’s handbook: New 

York, HarperCollins Publishers, Inc.

Worster, D., 2001, A river running west: the life of John Wesley Powell: New York, 

Oxford University Press.
The National Map 25 Final Report

Glossary

accuracy – the closeness of observations to true values or values accepted to be true. 

Accuracy relates to the quality of a result and is distinguished from precision, which 

relates to the quality of the operation by which the result is obtained.

area – a generic term for a bounded, continuous, two-dimensional object that may or 

may not include its boundary.

attribute – a defined characteristic of a feature. For example, “name” is an attribute 

for a feature “road.”

attribute value – a specific quality or quantity assigned to an attribute for an 

occurrence of a feature. For example, “Spring Street” is the attribute value for the 

attribute “name” for an occurrence of the feature “road.”

bathymetry – the science of determining depths of oceanic or other deep waters.

cadastral information – the geographic extent of the past, current, and future 

rights and interests in real property, including the spatial data needed to describe that 

geographic extent.

completeness – the relationship between the objects represented and the abstract 

universe of all such objects; in particular, the exhaustiveness of a set of features.

contour – an imaginary line on the ground, all points of which are at the same 

elevation.

coordinates – a set of numeric quantities that describe the location of a point in a 

geographic reference system.

database – a collection of information related by a common fact or purpose.

datum – any quantity, or set of such quantities, that may serve as a reference or basis 

for calculation of other quantities; especially a set of quantities that serve as a 

reference for the calculation of positions. A horizontal datum is the set of constants 

specifying the coordinate system to which horizontal coordinates are referred. A 

vertical datum is a set of constants specifying the coordinate system to which 

elevations are referred. In a linear referencing system, the datum serves as the basis 

for locating the linear referencing system in the real world and consists of a connected 

set of anchor sections that have anchor points at their junctions and termini. 

digital – a description of data that are stored or transmitted as a sequence of discrete 

symbols from a finite set; most commonly this means binary data that are processed 

by computers.

digital orthorectified image – a digital representation of an orthorectified 

image. The digital image is composed of pixels whose dimensions define the 

minimum unit of resolution (expressed in distance on the ground). 

elevation – the vertical distance from a datum to a point or object on the Earth's 

surface.

feature – a real world phenomenon of a given type, such as a “road.”

Federal Geographic Data Committee – an interagency committee 

established by Office of Management and Budget Circular A-16 to promote the 
The National Map 26 Final Report

coordinated development, use, sharing, and dissemination of spatial data, and to 

coordinate the development of the National Spatial Data Infrastructure.

generalization – reduction in detail in geographic data representation; for 

example, resampling elevation or image data to a larger spacing or reducing the 

number of points in a line. 

geodetic control – a network of geodetic control points, or a set of known 

reference positions, used as a basis for obtaining positions of other features. 

geographic information system (GIS) – a computer system for the input, 

editing, storage, maintenance, management, retrieval, analysis, synthesis, and output 

of spatial information. In the most restrictive usage, the term refers only to hardware 

and software. In common usage, it also includes data, and sometimes the people and 

procedures involved in operations. 

Global Positioning System (GPS) – a satellite-based navigation system 

deployed by the Department of Defense and used to determine locations on the 

Earth’s surface.

governmental units – the geographic extent of units of government, including the 

Nation, States, counties, incorporated places and consolidated cities, functioning and 

legal minor civil divisions, such as towns and townships, Federal- or State-recognized

American Indian reservations and trustlands, and Alaskan Native regional 

corporations. 

hydrography – surface water features, such as streams and rivers, lakes and ponds, 

canals and ditches, and oceans.

Implementation Team (I-Team) – a collaborative group organized to build 

portions of the National Spatial Data Infrastructure for a geographic area, such as a 

State or region. Participants may include local, State, Federal, and tribal 

organizations, private sector companies, and other organizations. A team prepares a 

comprehensive plan for compiling, maintaining, and financing a spatial data 

infrastructure for a geographic area. The planning includes alignment of participants’ 

needs and resources, identification of participants’ responsibilities, and development 

of milestones. Planned activities must adhere to National Spatial Data Infrastructure 

principles and include the development, testing, and use of standards.

integration – the processes required to compile a consistent set of data from 

different sources of data. In horizontal integration, sets of data of the same theme for 

adjoining areas are processed to remove gaps, overlaps, spurs, and other 

inconsistencies along their common edge. In vertical integration, sets of data of 

different themes for the same area are processed to ensure that, where features have 

the same alignments on the ground, the data that encode the features also have the 

same alignments. In semantic integration, sets of data that express a common theme 

or meaning in different ways are processed to express the theme or meaning in a 

consistent way.

line – a one-dimensional directed and nonbranching sequence of nonintersecting line 

segments.

linear referencing method – a mechanism for finding and stating the 

location of any point along a network by referencing it to a known point. Linear 
The National Map 27 Final Report

referencing methods consist of traversals and associated traversal reference points 

that together provide a set of known points, a metric, and a direction for referencing 

the locations of unknown points. 

linear referencing system – a set of datums, networks, and linear referencing 

methods, whereby each point along a network can be identified uniquely by 

specifying the direction and distance from any known point on the network.

metadata – data about data; data about the content, quality, condition, and other 

characteristics of data. 

National Spatial Data Infrastructure (NSDI) – the technology, 

policies, standards, and human resources necessary to acquire, process, store, 

distribute, and improve the use of spatial data. The NSDI is an umbrella under which 

organizations and technology interact to foster activities for using, managing, and 

producing geographic data. Federal responsibilities for the NSDI are coordinated 

through Office of Management and Budget Circular A-16 and Executive Order 

12906.

orthorectified image – an aerial photograph or satellite image from which most 

displacements caused by terrain relief and sensor geometry have been removed. The 

result combines the image characteristics of a photograph with the geometric qualities 

of a map. 

pixel – a two-dimensional picture element that is the smallest nondivisible element of 

a digital image.

point – a zero-dimensional object that specifies a location.

raster data – spatial data in which locations are represented using an array of 

cells, pixels, or points that hold values for attributes.

reach – a continuous unbroken stretch or expanse of surface water.

reach code – a numeric code that uniquely identifies a reach. 

referencing system – a set of datums and rules by which the location of points 

can be identified uniquely. 

relief – elevations and depressions of the land or sea bottom.

resolution – the measurement of the finest detail distinguishable.

spatial data – information that identifies the geographic location and 

characteristics of natural or constructed features and boundaries on the Earth. The 

information may be derived from, among other things, remote sensing, mapping, and 

surveying technologies.

structure – something, such as a building, that is constructed.

theme – a topic or subject.

topographic map – a map that presents the horizontal and vertical positions of 

represented features, such as elevations and depressions of the land surface (relief), 

water features, roads and railroads, structures, boundaries, names, and other themes.

topography – the configuration (relief) of the land service; a representation or 

portrayal of that configuration.
The National Map 28 Final Report

transaction – a unit of processing activity that accomplishes a specific purpose, 

such as a retrieval, an update, a modification, or a deletion of one or more data 

elements.

transportation – features used to move people and goods from place to place, 

such as roads, trails, railroads, ports, airports, and waterways, and related features 

such as bridges and tunnels. 

vector data – spatial data in which locations of features are represented using 

points, lines, and areas.
The National Map 29 Final Report

Appendix 1. The Changing Needs for Spatial 

Data, and Opportunities for Meeting These Needs

During the development of the concept, the USGS interviewed key individuals familiar 

with the development and use of spatial data from Federal, State, and regional 

government agencies, the private sector, the academic community, and professional 

organizations. In addition to doing the interviews, the USGS reviewed a number of 

documents listed in the Selected References section.

The following are current and developing spatial data needs and the implications of new 

capabilities identified during the development of the report:

• There continues to be an unmet need for a common set of basic spatial data. The 

Federal Government, other public and private organizations, and individuals need 

a common set of basic spatial data that they can expand and enhance to meet their 

mission, business, or individual needs. Not only must these data be developed, 

but they must also be maintained. These data would provide an enterprise level of 

spatial data for the Federal Government. 

• For some places, large amounts of data are available; for others, very little. For 

areas for which spatial data exist, the data developed by different jurisdictions are 

not consistent. For other areas, little data, or data of unknown or poor quality, 

exist. Existing data should be used as a starting point for areas for which they are 

available. Investment is needed where data are lacking.

• A standing collection of basic spatial data is needed. There is a need to develop 

and maintain a standing inventory of these data. In spite of improvements in 

remote sensing and other technologies, a capability to develop all basic spatial 

data “just in time” is unlikely. The need to analyze changes in the landscape 

through time also requires an inventory of data.

• These data must have the following characteristics:

o Currentness. Natural and human processes change even the most 

“timeless” features, such as elevations, and some features, such as a 

network of roads, can change very quickly. Data must accurately reflect 

the current state of the landscape. Reasons to maintain currentness range 

from ensuring correct results from analyses to gaining the confidence of 

those using the data. Continual maintenance is needed to ensure that the 

data typically are current in terms of days or months, not years.

o Usefulness for any arbitrarily defined geographic area. Public and 

private organizations use spatial data to meet mission and business needs, 

and these needs often have different “footprints” on the landscape. For 

example, census data concern the geographies of census and political 

units, work on water resource problems often concerns watersheds, and 

responses to natural disaster concern the area affected. For the Federal 

Government, these areas may be as small as individual farms or fields, or 

as large as ecosystems (and sometimes the entire Nation). The data must 

have a consistent classification and minimum criteria for completeness 
The National Map 30 Final Report

and positional accuracy. Inconsistencies must be resolved among data 

collected over different areas or by different jurisdictions, as must 

inconsistencies among different themes of data.

• Both digital and paper forms of basic spatial data are needed; paper maps should 

be derived from a master set of digital data. Much as word processing and other 

office productivity software have not eliminated paper documents, basic spatial 

information in the forms of both digital data and paper maps will continue to be 

needed. Data portrayed on maps must be consistent with those provided in digital 

form and should be derived from those digital data. 

• Technology will continue to evolve and will provide new ways to collect, 

maintain, access, and use basic spatial data. There will be few technical 

limitations to meeting needs for spatial data; indeed, the future promises an 

expanding number of possibilities for spatial data collection, maintenance, access, 

and use. Advances in computing hardware and broadband and wireless 

communications will provide the basic ability needed to store, process, and 

communicate data. The trend of including Global Positioning System and 

“locationally aware” technologies in cell phones and other personal electronic 

devices promises increased use of spatial data and intriguing new ways of 

collecting and maintaining these data. Standards, including those for open 

geographic information technology and processing methods, will be key to 

capitalizing on these technologies. For the foreseeable future, it appears likely 

that human intervention will be required to interpret features such as roads and 

buildings from remotely sensed data.

• The Internet will continue to provide new ways for disseminating and using 

spatial data. The Internet will be the enabling technology that will increase the 

public and private sectors’ and individuals’ use and awareness of spatial data. 

Evolving from a means to view content and purchase products, the Internet will 

encourage the development of more holistic spatial services, stand-alone devices, 

specialized applications, customized spatial queries, and interactive capabilities. 

The result of these changes will be a proliferation of specialized devices that 

require spatial data accessed over the Internet to operate. The business models for 

providing these services will result in a number of new funding models.

• Common needs and interests offer opportunities for partnerships to collect, 

maintain, access, and use basic spatial data among Federal agencies, and with 

other public organizations, notably State and regional organizations. Although 

the missions of Federal agencies vary, and often are different from those of State, 

regional, local, and tribal governments, there are overlapping needs and interests 

in a common set of basic spatial data. Common needs can be met more quickly 

by pooling resources. The challenge of organizing these resources is substantial.

• Private sector investments in capabilities to collect, maintain, access, and use 

basic spatial data, and in the development and maintenance of data, provide 

opportunities to meet Federal needs. The private sector currently collects, under 

contract, basic spatial data that meet Federal specifications. Moreover, some 

privately held data developed and maintained for other markets could meet 
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Federal needs. It is worth noting, however, that some private sector business 

models are new and evolving and it is too early to predict the long-term success of 

these approaches.

• Volunteers may be an untapped means of maintaining basic spatial data. With 

the advent of “locationally aware” capabilities in cell phones and other personal 

electronic devices, volunteers knowledgeable about changes in their locales could 

be a useful source of information needed to maintain basic spatial data.

• The National Spatial Data Infrastructure provides the context for developing and 

maintaining basic spatial data. The National Spatial Data Infrastructure is the 

technologies, policies, and people necessary to promote sharing of geospatial data 

throughout all levels of government, the private and nonprofit sectors, and the 

academic community. The goals of the National Spatial Data Infrastructure are to 

(1) reduce duplication of effort among agencies, (2) improve quality and reduce 

costs related to geographic information, (3) make geographic data more accessible 

to the public, (4) increase the benefits of using available data, and (5) establish 

key partnerships with States, counties, cities, tribal nations, academia, and the 

private sector to increase data availability. Under Executive Order 12906, the 

Federal Geographic Data Committee coordinates the Federal Government’s 

development of the National Spatial Data Infrastructure. The National Spatial 

Data Infrastructure encompasses policies, standards, and procedures for 

organizations to cooperatively produce and share geographic data. The 17 

Federal agencies that are members of the committee cooperate with organizations 

from State, local, and tribal governments, the private sector, and the academic 

community to develop the National Spatial Data Infrastructure. The USGS 

participates in the committee and leads several of its activities. The National Map

concept aligns with the goals of, and is one of several USGS activities that 

contribute to, the National Spatial Data Infrastructure. 

• Policies and other rules for accessing and sharing basic spatial data, such as 

licenses, must allow the data to flow as needed to meet Federal mission needs. 

The Federal Government needs basic spatial data only as much as these data help 

meet mission needs. The trend for the Federal Government to carry out programs 

and evaluate results by working with State and other public entities, the private 

sector, nongovernmental organizations, and the public will continue to grow. 

Basic spatial data must be available for use by those carrying out programs and 

for reuse by different combinations of organizations for follow-on work and longterm understanding of change. The ability to share data widely also increases the 

opportunities for partnerships to fund data collection and maintenance. Therefore, 

licenses and other policies for basic spatial data use must allow for data sharing 

among partners that carry out, monitor, or evaluate Federal activities.

• Federal leadership and commitment are needed to ensure that basic spatial data 

are available to support Federal agencies in accomplishing their missions. 

Without leadership, agencies are likely to expend funds in areas outside their 

mission responsibilities to obtain these data. A coordinated approach to 

developing and maintaining these data would reduce duplication and expense.
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• As the Nation’s largest civilian mapping agency, the USGS mission is to lead in 

the development and maintenance of this common set of basic spatial data. A new 

approach is needed. The current approach of irregular cycles of updates and 

independent lines of digital data and paper maps will not meet the needs of the 

Federal Government. USGS leadership and participation, such as that 

demonstrated in interagency data development efforts for orthorectified imagery, 

elevation, hydrography, land cover, and geographic names data, are needed to 

foster partnerships and approaches to provide needed basic spatial data.
The National Map 33 Final Report

Appendix 2. Research and Development Needed 

to Support The National Map

Applied cartographic, geographic, and general information science research and 

development will be required to implement The National Map. Using mechanisms such 

as cooperative research and development agreements with the private sector, grants to 

universities, and interdisciplinary collaborative teams, the USGS will conduct applied 

research and development in the following representative areas:

Database Design 

• Evaluation of alternative representation models, with the goal of selecting for 

each theme a single optimal model that will support a small, defined set of 

applications and product requirements. 

• Design of seamless data organization methods that support incremental and 

transactional updates.

• Exploration of variable (not multiple) resolution models.

• Understanding of how to represent and propagate uncertainty.

Database Population Strategies

• Development of data conflation techniques (similarity indicators, multimode 

approaches).

• Identification of surrogates for permanent feature identifiers, and methods for 

using them.

• Identification of strategies for data integration (registration, constraints to logical 

intertheme relationships).

Data Maintenance Approaches

• Development of practical transaction-based update strategies.

• Development of means for providing temporal updates.

• Development of methods to improve the resolution and accuracy with which a 

feature is represented.

• Development of Internet-based change notification capabilities to take advantage 

of a citizenry empowered with Global Positioning System and other “locationally 

aware” technology.

• Development of new techniques for detecting change.

Product Generation

• Development of user-defined product generation options, including variable 

footprint, time-slice, resolution, reference system, feature/theme content, and 

representation models.
The National Map 34 Final Report

• Deployment of techniques for generalization, symbolization, name placement, 

overlay and transparency levels, and collar generation. 

• Exploration of new format and media options, including those that support printon-demand.

• Development of predefined product templates, especially those needed to support 

on-the-fly generation of traditional products, such as the maps of the primary 

topographic series. 

Accessibility

• Development of interactive data access methods that comply with open 

geographic information technology and processing standards, as well as other 

Internet standards.

• Understanding of the technical aspects of data access licensing arrangements 

proposed by the private sector.

Related longer-term research needs include the following:

• Investigations of multidimensional data models to support the integration and 

application of other USGS scientific data holdings with The National Map.

• Understanding of the application of sensor technologies now being developed, 

including new techniques for sensing the landscape remotely and on the 

ground.

• Exploration of synchronization approaches for distributed data holdings and 

architectures.

• Exploiting of wireless devices and technology linked to the Global Positioning 

System for updating data.

• Understanding of mappings and transforms among different data models

• Investigations of cognition and visualization of spatial data.

• Investigations of topics related to models of institutional arrangements, the 

value of sharing data, and intellectual property.