Identification_Information:

Citation:

Citation_Information:

Originator: U.S. Geological Survey (USGS)

Publication_Date: 2009

Title: National Elevation Dataset (NED)

Edition: 2

Geospatial_Data_Presentation_Form: raster digital data

Publication_Information:

Publication_Place: Sioux Falls, SD

Publisher: U.S. Geological Survey

Online_Linkage: http://nationalmap.gov

Online_Linkage: http://seamless.usgs.gov

Description:

Abstract:

The National Elevation Dataset (NED) is the primary elevation data product produced and distributed by the USGS. The NED provides the best available public domain raster elevation data of the conterminous United States, Alaska, Hawaii, and territorial islands in a seamless format.  The NED is derived from diverse source data, processed to a common coordinate system and unit of vertical measure.  All NED data are distributed in geographic coordinates in units of decimal degrees, and in conformance with the North American Datum of 1983 (NAD 83).  All elevation values are provided in units of meters, and are referenced to the North American Vertical Datum of 1988 (NAVD 88) over the conterminous United States.  The vertical reference will vary in other areas.  NED data are available nationally at resolutions of 1 arc-second (approx. 30 meters) and 1/3 arc-second (approx. 10 meters), and in limited areas at 1/9 arc-second (approx. 3 meters).  At present, the bulk of Alaska is only available at a 2 arc-second (approx. 60 meters) resolution, owing to a lack of higher resolution source data, though some areas are available at resolutions of 1 and 1/3 arc-second with plans for significant upgrades of the state over the next five years.  The NED is updated on a nominal two month cycle to integrate newly available, improved elevation source data.

Purpose:

The NED serves as the elevation layer of The National Map, and provides basic elevation information for earth science studies and mapping applications in the United States.  The data are utilized by the scientific and resource management communities for global change research, hydrologic modeling, resource monitoring, mapping and visualization applications.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 19990201

Ending_Date: 20090201

Currentness_Reference: 20090201

Status:

Progress: In work

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

bounding_Coordinates:

West_Bounding_Coordinate: -90.00055555556

East_Bounding_Coordinate: -88.99944444444

North_Bounding_Coordinate: 30.00055555556

South_Bounding_Coordinate: 28.99944444444

Keywords:

Theme:

Theme_Keyword_Thesaurus: National Elevation Dataset (NED)

Theme_Keyword: NATIONAL ELEVATION DATASET

Theme_Keyword: NED

Theme_Keyword: ELEVATION

Theme_Keyword: GRID

Theme_Keyword: LIGHT DETECTION AND RANGING

Theme_Keyword: LiDAR

Theme_Keyword: LIDAR

Theme_Keyword: HIGH RESOLUTION

Theme_Keyword: EARTH SCIENCE

Theme_Keyword: LAND SURFACE

Theme_Keyword: TOPOGRAPHY

Theme_Keyword: LANDFORMS

Theme_Keyword: DRAINAGE AREA

Theme_Keyword: HYDROLOGY

Theme_Keyword: HYDROLOGIC

Theme_Keyword: HYDROLOGIC MODELING

Theme_Keyword: TERRAIN ELEVATION

Theme_Keyword: 1-DEGREE DEM

Theme_Keyword: 2-ARC-SECOND DEM

Theme_Keyword: 7.5-MINUTE DEM

Theme_Keyword: CARTOGRAPHY

Theme_Keyword: DEM

Theme_Keyword: DIGITAL ELEVATION MODEL

Theme_Keyword: DIGITAL MAPPING

Theme_Keyword: DIGITAL TERRAIN MODEL

Theme_Keyword: EROS

Theme_Keyword: GEODATA

Theme_Keyword: GIS

Theme_Keyword: MAPPING

Theme_Keyword: RASTER

Theme_Keyword: USGS

Theme_Keyword: U.S. GEOLOGICAL SURVEY

Place:

Place_Keyword_Thesaurus:

U.S. Department of Commerce, 1995, Countries, dependencies, areas of special sovereignty, and their principal administrative divisions, Federal Information Processing Standard 10-4,): Washington, D.C., National Institute of Standards and Technology

Place_Keyword: NORTH AMERICA

Place_Keyword: UNITED STATES

Place_Keyword: UNITED STATES OF AMERICA

Place_Keyword: US

Access_Constraints:

None.  Any downloading and use of these data signifies a user's agreement to comprehension and compliance of the USGS Standard Disclaimer.  Insure all portions of metadata are read and clearly understood before using these data in order to protect both user and USGS interests.

Use_Constraints:

There is no guarantee or warranty concerning the accuracy of the data.  Users should be aware that temporal changes may have occurred since this data set was collected and that some parts of this data may no longer represent actual surface conditions.  Users should not use this data for critical applications without a full awareness of its limitations.  Acknowledgement of the originating agencies would be appreciated in products derived from these data.  Any user who modifies the data is obligated to describe the types of modifications they perform.  User specifically agrees not to misrepresent the data, nor to imply that changes made were approved or endorsed by the U.S. Geological Survey.  Please refer to http://www.usgs.gov/privacy.html for the USGS disclaimer.

Original statement:

None.  Acknowledgement of the originating agencies would be appreciated in products derived from these data.

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method:

Raster

Raster_Object_Information:

Raster_Object_Type: Pixel

Bits_Per_Pixel: 32

Vertical_Count: 1

Row_Count: 10812

ColumnCount: 10812

Spatial_Reference_Information:

Horizontal_Cooordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.00001

Longitude_Resolution: 0.00001

Geographic_Coordinate_Units: Decimal Degrees

Planar:

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: Row and Column

Coordinate_Representation:

Abscissa_Resolution: 0.0000925925926

Ordinate_Resolution: 0.0000925925926

Geodetic_Model:

Horizontal_Datum_Name: North American Datum of 1983

Ellipsiod_Name: Geodetic Reference System 80

Semi-major_Axis: 6378137.000000

Denominator_of_Flattening_Ratio: 298.257222

Vertical_Coordinate_System_Definition:

Altitude_System_Definition:

Altitude_Datum_Name: North American Vertical Datum of 1988

Altitude_Resolution: 1.000000

Altitude_Distance_Units: Meters

Altitude_Encoding_Method: Implicit Coordinate

Distribution_Information:

Distributor:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Customer Service Representative

Contact_Organization U.S. Geological Survey

Contact_Address:

Address_Type: mailing and physical address

Address:

USGS Earth Resources Observation & Science (EROS) Center

47914 252nd Street

City: Sioux Falls

State_or_Province: SD

Postal_Code: 57198-0001

Country: USA

Contact_Voice_Telephone: 605-594-6151

Contact_Voice_Telephone: 1-800-252-4547

Contact_Facsimile_Telephone: 605-594-6589

Contact_Electronic_Mail_Address: webmapping@usgs.gov

Hours_of_Service: 0800 - 1600 CT, M - F (-6h CST/-5h CDT GMT)

Resource_Description: National Elevation Dataset (NED)

Distribution_Liability:

Although these data have been processed successfully on a computer system at the U.S. Geological Survey, Earth Resources Observation & Science (EROS) Center, no warranty, expressed or implied, is made by either regarding the utility of the data on any system, nor shall the act of distribution constitute any such warranty.  The USGS will warranty the delivery of this product in computer-readable format and will offer appropriate adjustment of credit when the product is determined unreadable by correctly adjusted computer peripherals, or when the physical medium is delivered in damaged condition.  Requests for adjustments of credit must be made within 90 days from the date of this shipment from the ordering site.

Metadata_Reference_Information:

Metadata_Date: 2009

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Customer Service Representative

Contact_Organization: U.S. Geological Survey

Contact_Address:

Address_Type: mailing and physical address

Address:

USGS Earth Resources Observation & Science (EROS) Center

47914 252nd Street

City: Sioux Falls

State_or_Province: SD

Postal_Code: 57198-0001

Country: USA

Contact_Voice_Telephone: 605-594-6151

Contact_Voice_Telephone: 1-800-252-4547

Contact_Facsimile_Telephone: 605-594-6589

Contact_Electronic_Mail_Address: webmapping@usgs.gov

Hours_of_Service: 0800 - 1600 CT, M - F (-6h CST/-5h CDT GMT)

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998