USGS - science for a changing world
Logo and link to The National Map

The National Map


Skip Links


This is a formatting graphic.

Elevation

The National Elevation Dataset (NED) is a seamless raster product primarily derived from USGS 10- and 30-meter Digital Elevation Models (DEMs), and, increasingly, from higher resolution data sources such as light detection and ranging (lidar), interferometric synthetic aperture radar (ifsar), and high-resolution imagery. NED data are available from The National Map Viewer as 1 arc-second (approximately 30 meters) for the CONUS, and at 1/3 and 1/9 arc-seconds (approximately 10 and 3 meters, respectively) for parts of the United States. NED resolution for Alaska is primarily 2 arc-seconds (approximately 60 meters) but is rapidly being replaced with 5-meter resolution ifsar data State-wide and lidar over select areas. Lidar point cloud data is available for download from Earth Explorer.

In response to growing needs for high-quality topographic data and for a wide range of other three-dimensional representations of the Nation's natural and constructed features, the National Geospatial Program has introduced the 3D Elevation Program (3DEP) initiative, the goal of which is to systematically collect enhanced elevation data in the form of high-quality lidar data over the conterminous United States (CONUS), Hawaii, and the U.S. territories. Ifsar data will be collected over Alaska, where cloud cover and remote locations preclude the use of lidar over much of the State. The 3DEP initiative will result in higher resolution and more accurate data as well as new products in the future.


Data: documentation and downloads

National Elevation Dataset - Spatial Metadata
NED Data Dictionary, Release Notes, and ESRI shapefiles...

The National Map Viewer - download elevation data
Select the 'Elevation' theme within the 'Download Data' tool....see detailed instructions...

EarthExplorer - lidar point cloud data
An extensive user guide is available (PDF)...

USGS Center for Lidar Information Coordination and Knowledge (CLICK)
The CLICK is a portal for lidar information, discussion, and data. Its primary mission is to support scientific research on lidar point data.

 
Image of an 'all-return lidar point cloud' featuring the EROS Data Center in Sioux Falls, SD.
Image of an 'all-return lidar point cloud' featuring the USGS Earth Resources Observation and Science (EROS) Center in Sioux Falls, SD.

Note: Lidar data of the USGS' National Geospatial Program (NGP) will no longer be available for download from the CLICK as the NGP transitions its elevation datasets from the EROS Data Center to the National Geospatial Technical Operations Center (NGTOC). During this transition period, users can discover and access lidar data from the USGS Earth Explorer (EE). That tool provides users the ability to query, search, and order lidar data as well as satellite images, aerial photographs, and cartographic products from several sources.


 
Status graphic and link to NED recent updates

 

 

Status & highlights

Latest National Elevation Dataset Update

The February, 2014 update of the National Elevation Dataset (NED) 1, 1/3 and 1/9 arc-second collections was released on February 4, 2014. This marks the 76th update of the 1 arc-second layer since bi-monthly revisions began in June, 2000. This update is the largest release of new light detection and ranging (lidar) data into the NED 1/9 arc-second layer, incorporating 57,794 square miles of new data. The NED 1 and 1/3 arc-second layers also set high marks with 70,668 square miles of migrated high-resolution source data and 2265 square miles of 5-meter Interferometric Synthetic Aperture Radar (IFSAR) source data over Alaska. All NED data are available via The National Map Viewer: htp://viewer.nationalmap.gov/viewer/.

The status graphic on the left (click for larger version) is one of several contained in the NED Release Notes for February, 2014 (PDF), which is published on a bi-monthly basis.

 
 
NED topobathy status map
   
TopoBathy

The August, 2012 NED release marked the addition of the first set of topobathymetric data, Mobile Bay, into the NED. The June, 2013 NED release featured the San Francisco Bay topobathymetric dataset. This 6023 square mile dataset is centered over San Francisco Bay, California and dramatically illustrates many prominent geophysical features of the area: the seafloor of the Golden Gate Strait separating San Francisco and Marin County; the San Andreas Fault, and the Farallon Islands and Escarpment to name a few.

Topobathymetric data are created by merging topography (land elevation) and bathymetry (water depth) into a seamless elevation product useful for applications such as modeling sea level rise and storm surge. Presently there are three topobathy datasets available through the The National Map Viewer: http://viewer.nationalmap.gov/viewer/, shown in the status graphic. They are Mobile Bay, North Carolina and San Francisco Bay. Additional topobathymetric databases are being prepared for southern Louisiana and the Hurricane Sandy impact area, and will be used by the USGS and others to advance research on coastal change processes and hazard vulnerability in those regions.

Hightlight: South Dakota Lidar

Recently, 16,303 square miles of eastern South Dakota elevation data has been updated in the NED. This lidar collection was a collaboration between Natural Resources Conservation Services (NRCS) and the State of South Dakota. The lidar data were acquired in 2012 and are replacing source data ranging from 1951 through 1972.

The image pair below shows land change in an area in northeast South Dakota near Waubay. The lakes in this area have been increasing in size due to flooding from substantial rainfalls over the last decade. This lake growth has reclaimed land that was once prime farmland during the dry cycles of the 1970s and has limited or eliminated access to many areas.

Comparison of 1970 DEM data and 2012 lidar source data.

The South Dakota lidar also brings a vast improvement in the quality of the NED elevation data. The previous NED data was old, lacking in detail, and riddled with star artifacts as the before and after lidar examples of the northeast corner of Brookings, South Dakota and Interstate 29 illustrate in the set of images below:

Comparison of 10-meter DEM data and 2012 1-meter lidar source data.

 


Publications

National Requirements for Enhanced Elevation Data
USGS Open-File report 2013-1237

The 3D Elevation Program - Summary of Program Direction
USGS Fact Sheet 2012-3089

National Enhanced Elevation Assessment at a Glance
USGS Fact Sheet 2012-3088

Lidar Base Specification Version 1.0
USGS Techniques and Methods 11-B4; August 2012

The National Map - Elevation
USGS Fact Sheet 2009-3053

The National Map - Elevation
USGS Multimedia Gallery (video); May 1, 2012

Creation of Digital Contours That Approach the Characteristics of Cartographic Contours
USGS Scientific Investigations Report 2012-5167

Mount St. Helens lidar    (cover: ····>)
USGS General Information Product 116; November 2010

Thumbnail image and link to USGS GIP 116, Mount Saint Helens lidar
High-resolution lidar image of Mount St. Helens, Washington

Graphic representation of topo-bathymetric data for Mobile Bay, Alabama.
Graphic representation of topo-bathymetric data for Mobile Bay, Alabama

Frame from video of lidar imagery used in detecting ground features
Frame from lidar imagery video identifying the Mt. Tallac Fault, California.

 

Applications and examples

TopoBathy—merging topography (elevation) and bathymetry (water depth) into a seamless elevation product
The initial dataset (left) is centered over Mobile Bay, Alabama and was constructed using a combination of 71 disparate topographic and bathymetric datasets from the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), and the U.S. Army Corps of Engineers (USACE)

The National Atlas: Topographic Maps Illustrating Physiographic Features
Demonstrates how many map features are recreated on topographic maps using contours

Treatment of Hydrographic Features in lidar data (PPT; 5.6MB)
Interactively (see slide 8) displays techniques used to adjust lidar data anomalies over surface water areas

USGS Topographic Science
Research and applications that facilitate the development and use of integrated national and global topographic datasets

Using bare-earth lidar imagery to reveal the Tahoe-Sierra frontal fault zone, Lake Tahoe, California
A video demonstrating how airborne lidar imagery can penetrate dense forest cover to reveal an active fault line not detectable with conventional aerial photography.


  Thumbnail and link to lidar-dem hydro treatment presentation
Hydrography treatments of lidar-dem data (links to ppt; 5.6mb)
 Free document viewers: Adobe Reader | Microsoft Word | Microsoft Excel | Microsoft Powerpoint
 

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://nationalmap.gov/elevation.html
Page Contact Information: The National Map
Page Last Modified: Tuesday, 13-May-2014 08:56:33 EDT