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 paucity 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: -121.0005555556
East_Bounding_Coordinate: -119.9994444445
North_Bounding_Coordinate: 40.00055555556
South_Bounding_Coordinate: 38.99944444444
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
Row_Count: 10812
ColumnCount: 10812
Vertical_Count: 1
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