Identification_Information: Citation: Citation_Information: Originator: U.S. Geological Survey (USGS), EROS Data Center Publication_Date: 1999 Title: National Elevation Database Edition: 1 Geospatial_Data_Presentation_Form: raster digital data Publication_Information: Publication_Place: Sioux Falls, SD Publisher: U.S. Geological Survey Online_Linkage: http://edcnts12.cr.usgs.gov/ned/ned.html Description: Abstract: The U.S. Geological Survey has developed a National Elevation Database (NED). The NED is a seamless mosaic of best-available elevation data. The 7.5-minute elevation data for the conterminous United States are the primary initial source data. In addition to the availability of complete 7.5-minute data, efficient processing methods were developed to filter production artifacts in the existing data, convert to the NAD83 datum, edge-match, and fill slivers of missing data at quadrangle seams. One of the effects of the NED processing steps is a much-improved base of elevation data for calculating slope and hydrologic derivatives. Purpose: Geospatial elevation data are utilized by the scientific and resource management communities for global change research, hydrologic modeling, resource monitoring, mapping, and visualization applications. Supplemental_Information: Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19990201 Ending_Date: Unknown Currentness_Reference: publication date Status: Progress: In work Maintenance_and_Update_Frequency: As needed Spatial_Domain: bounding_Coordinates: area1 West_Bounding_Coordinate: 109.125 East_Bounding_Coordinate: 103.000 North_Bounding_Coordinate: 37.000 South_Bounding_Coordinate: 35.000 Keywords: Theme: Theme_Keyword_Thesaurus: GCMD Parameter Keywords Theme_Keyword: EARTH SCIENCE Theme_Keyword: LAND SURFACE Theme_Keyword: TOPOGRAPHY Theme_Keyword: LANDFORMS 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: EDC Theme_Keyword: EROS Theme_Keyword: GEODATA Theme_Keyword: GIS Theme_Keyword: MAPPING Theme_Keyword: RASTER Theme_Keyword: USGS Place: Place_Keyword_Thesaurus: GCMD Location Keywords Place_Keyword: NORTH AMERICA Place_Keyword: UNITED STATES Place_Keyword: UNITED STATES OF AMERICA Access_Constraints: None Use_Constraints: None. Acknowledgement of the originating agencies would be appreciated in products derived from these data. Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Raster Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Customer Services Representative Contact_Organization: EROS Data Center Contact_Address: Address_Type: mailing and physical address Address: U.S. Geological Survey EROS Data Center City: Sioux Falls State_or_Province: SD Postal_Code: 57198 Country: USA Contact_Voice_Telephone: 605-594-6151 Contact_Facsimile_Telephone: 605-594-6589 Contact_Electronic_Mail_Address: custserv@edcmail.cr.usgs.gov Resource_Description: National Elevation Database (NED) Distribution_Liability: Although these data have been processed successfully on a computer system at the U.S. Geological Survey, EROS Data 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 warrant 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: 19990211 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Customer Services Representative Contact_Organization: EROS Data Center Contact_Address: Address_Type: mailing and physical address Address: U.S. Geological Survey EROS Data Center City: Sioux Falls State_or_Province: SD Postal_Code: 57198 Country: USA Contact_Voice_Telephone: 605-594-6151 Contact_Facsimile_Telephone: 605-594-6589 Contact_Electronic_Mail_Address: custserv@edcmail.cr.usgs.gov Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Description of source data: NED tiles are stored as arc/info grids. Each tile covers a 1x1 degree area of the earth's surface. Example grid name: dem10148 10148 refers to the longitude (-101) and latitude (48) of the upper-left (northwest) corner of the grid. Example Grid information: dem10148 Cell size: one arc-second Data type: Floating Point Number of rows: 3600 Number of columns: 3600 Projection: Geographic Datum: NAD83 Units: Decimal Degrees Zunits: Meters Spheroid: GRS1980 Example of CD contents: The root directory of the CD contains one or more subdirectories. Each subdirectory includes a readme file with specific area information. CD root ----| |---area - Arc/Info workspace directory. |---demgrid.bil - Arc/Info "GRIDIMAGE" output .bil image format. |---demgrid.blw - World ASCII text file. |---demgrid.hdr - Header ASCII text file. |---demgrid.prj - Projection ASCII text file. |---demgrid.stx - Statistics ASCII text file. |---info - Arc/Info "info" directory. |---metadata - Arc/Info coverage of polygon-based metadata. |---readme - The readme ASCII text file. VIEWING Tiles: No software for viewing NED tiles are included on this disc. Free software for viewing other USGS digital cartographic data are available at the following internet sites: dlgv32 is Windows95/NT software for viewing a variety of USGS geospatial data including GeoTIFF Tiles. http://mcmcweb.er.usgs.gov/viewers/dlg_view.html Arc Explorer is a free lightweight GIS data explorer developed by ESRI. http://www.esri.com/software/arcexplorer/index.html PCI Freeware Handler is an application for viewing, enhancing and examining remotely sensed imagery such as LANDSAT, SPOT, RADARSAT, ERS-1, NOAA AVHRR, aerial photography. The Freeware Handler is freeware, and is offered by PCI to the remote sensing community as a public service. http://www.pcigeomatics.com/downl.html#FREEWARE