| |
Introduction
The National Map comprises a variety of products and services that
provide the Nation with access to base geospatial information to describe
the landscape of the United States and its territories. The
National Map
supports data download, digital and print versions of topographic maps,
geospatial data services, and online viewing. Customers can use geospatial
data and maps to enhance their recreational experience, make life-saving
decisions, support their scientific missions, and for countless other
activities. Nationally consistent geospatial data from The National Map
enable better policy and land management decisions and the effective
enforcement of regulatory responsibilities.
The National Geospatial Program (NGP) of the
U.S. Geological Survey (USGS) manages The National Map and
The National Atlas of the United States of America®. Partners
and other organizations produce and maintain a vast array of
high-quality geospatial data. A significant objective of the
NGP is to leverage these assets through mutually beneficial
partnerships that ensure the ongoing availability of current data.
National Geospatial Program Mission
The National Geospatial Program:
- Organizes, maintains, publishes, and disseminates
the geospatial baseline of the Nation's topography, natural
landscape, and built environment through The National Map,
a set of basic geospatial information provided as a variety
of products and services.
- Fosters a richer understanding of America's places and
people through the National Atlas of the United
States®.
- Increases the efficiency of the Nation's geospatial
community by improving communications about geospatial
data, products, services, projects, needs, standards, and
best practices.
The National Map Online Data
The National Map includes eight datasets and three products and services. The
geospatial data available from The National Map include boundaries, elevation,
geographic names, hydrography, land cover, orthoimagery, structures, and
transportation.
|
Boundaries
Dataset - The boundary data layer represents major civil
areas including States, counties, Federal and Native American
lands, and incorporated places such as cities and towns. |
|
Sample boundaries data.
|
National
Elevation Dataset - The National Elevation Dataset (NED)
is a seamless raster image dataset at multiple resolutions.
NED data can be used to portray landscape elevation and shape.
|
|
Color shaded relief from elevation data.
|
Geographic
Names Dataset - The USGS maintains the Geographic Names
Information System, which is the authoritative database of
official U.S. geographic names and is developed in cooperation
with the U.S. Board on
Geographic Names.
|
|
Sample of geographic names data.
|
National
Hydrography Dataset - The National Hydrography Dataset
(NHD) provides mapping coverage of the surface waters of the
United States consisting of 7.5 million miles of rivers and
streams and 6.5 million lakes and ponds. The NHD provides a
complete network that supports the analysis of any type of
movement by surface waters.
|
|
Sample hydrography data.
|
The National
Land Cover Database - The National Land Cover Database
(NLCD) provides consistent land cover data for all 50 States
from the Landsat satellite for 2001 and 2006. Sixteen classes
of land cover are included, such as imperviousness and percent
tree canopy.
|
|
Sample land cover data.
|
Orthoimagery
Dataset - Through cooperative partnerships, the USGS
acquires and disseminates high-resolution digital aerial
photography data that have the accuracy and reliability of
a base map. The resolution of the imagery in the USGS digital
orthoimagery dataset varies from one meter to one foot or finer.
|
|
Sample orthoimagery data.
|
Structures Dataset - USGS data portray selected
structures (buildings) data, including the function,
name, location, and physical form from best available
sources including
citizen
volunteers.
|
|
Sample structures data.
|
| Transportation
Dataset - Transportation data consist of airports, railroads,
roads, and other features associated with the transportation of
people or commerce. |
|
Sample transportation data.
|
Map Products and Online Services
In 1879, the USGS was entrusted with the responsibility for mapping the country and has been the primary civilian mapping agency of the United States ever since. More than 200,000 USGS topographic maps have been published in paper form in scales primarily ranging from 1:20,000 to 1:250,000. The best known USGS maps are the 1:24,000-scale topographic maps, also known as 7.5-minute quadrangles. The 7.5-minute map series was officially completed in 1992, and only minor revisions have been made to the printed product in recent years. While the NGP is converting all the historic topographic map products to a digital format, hard copy maps are available for sale through the online and business partner retailers. The NGP began releasing digital topographic (US Topo) maps in October 2009.
| Digital Topographic Maps - US Topo maps can be downloaded
for free from the USGS Store or The National Map Viewer.
The output of US Topo is a georeferenced map in GeoPDF
format that has the look and feel of the historic
1:24,000-scale topographic map but includes slightly
different content in digital format. US Topo maps
include elevation contours, geographic names, hydrography,
orthoimagery, and roads. As many as 100 US Topo maps are
produced daily. |
|
Portion of 2010 US Topo Map of Renovo West, Pennsylvania, without orthoimagery.
Source: USGS
|
Historic Topographic Maps - All scales and editions of the maps published by the USGS since the inception of the topographic mapping program in 1884 are being scanned and made available in GeoPDF format. As physical and cultural features changed over time, the topographic maps were updated and revised, and new editions were printed. These maps are often useful to environmentalists, genealogists, historians, scientists, and others
researching a particular geographic location.
|
|
Engraving for U.S. Topgraphic Maps.
Source: USGS
|
| National Map Viewer - The online user interface of The National Map is the Viewer which allows a user to interactively view National Map data as a map, customize the view, print a map, and download the data for use in geographic information systems (GIS). The Viewer allows geospatial data to be downloaded directly or viewed with Open Geospatial Consortium (OGC) Web mapping services (WMS) and keyhole markup language (KML). |
|
The National Map viewer.
Source:USGS
|
|
Introduction
The National Map Online Data
