Elevation Derivatives for National Applications (EDNA) Data Dictionary Active

 

Compressed File Size

• Field Definition:  The compressed size of the data file in megabytes. Raster products have large files that may time out during file transfer. Please contact custserv@usgs.gov for additional options of receiving data.

 

Coordinates Decimal Degrees

• Field Definition:  The latitude and longitude are provided in decimal degrees for the following fields:
  
  Format:
  Latitude Format Decimal Degrees: -90.000 through 90.000
  Longitude Format Decimal Degrees: -180.000 through 180.000
  
  Number of decimal places will vary by dataset – check collection in EarthExplorer.
  
  Values:
  Coordinates in decimal degrees for the following fields:
  
  Scene Center Latitude and Longitude
  Northeast (NE) Corner Latitude and Longitude
  Northwest (NW) Corner Latitude and Longitude
  Southeast (SE) Corner Latitude and Longitude
  Southwest (SW) Corner Latitude and Longitude

 

Coordinates Degrees, Minutes, Seconds

• Field Definition:  The latitude and longitude are provided in degrees, minutes, and seconds for the following fields:
  
  Format:
  Latitude Format:
  DDMMSS.SSH
  DD = Degree(s) with a range of 0 through 90
  MM = Minutes(s) with a range of 0 through 59
  SS.SS = Second(s) with a range of 0 through 59.99
  H = Hemisphere with N for north and S for south
  
  Note: Number of decimal places will vary by dataset – check collection in EarthExplorer.
  
  Values:
  Scene Center Latitude and Longitude
  Northeast (NE) Corner Latitude and Longitude
  Northwest (NW) Corner Latitude and Longitude
  Southeast (SE) Corner Latitude and Longitude
  Southwest (SW) Corner Latitude and Longitude

 

Data Format

• Field Definition:  The EDNA database contains both raster and vector layers. Raster (grid) data are available in ArcMap format and vector (point, line, and polygon) are available in Esri shapefile format.

 

Ellipsoid

• Field Definition:  The reference ellipsoid used to map the data.

 

Entity ID

• Field Definition:  The naming convention of each file is based on the data set name, region, and layer.

 

Horizontal Datum

• Field Definition:  The horizontal reference system associated with the data.

          Values:

          NAD83 = North American Datum of 1983 (Conterminous US and Hawaii)

          NAD27 = North American Datum of 1927 (Alaska)

 

Layer Name

• Field Definition:  The EDNA database includes the following topographically derived hydrologic data layers:

          Values:

          Aspect

         Cataloging Units*

         CTI (Compound Topographic Index)

         DEM (Digital Elevation Model)

         Flow Accumulation

         Flow Accumulation High Values (Conterminous US only)

        Flow Direction

        Reach Catchments

        Shaded Relief

        Sinks

        Slope

        Synthetic Streams

       *Catalog units are not available for Hawaii. Each island is a separate polygon and has not been sub-divided into smaller units.

 

Map Projection

• Field Definition:  The reference system used to represent the 3-dimensional surface of the earth.

           Values:

           Albers Conical Equal Area

Production Begin Date

• Field Definition:  The begin and end date are used to indicate the production date range for the EDNA database. The begin date is the first day of production.

          Format:

          YYYY/MM/DD

          YYYY = Year

          MM = Month

          DD = Day

Production End Date

• Field Definition:  The begin and end date are used to indicate the production date range for the EDNA database. The end date is the last day of production.

          Format:

          YYYY/MM/DD

          YYYY = Year

          MM = Month

          DD = Day

Region

• Field Definition:  The geographic area covered in the database.

          Values:

          AK = Alaska

          HI = Hawaii

          US = United States (Conterminous)

 

Resolution

• Field Definition:  The distance on the ground represented by each pixel.

 

Uncompressed File Size

• Field Definition:  The uncompressed size of the data file in megabytes. Files are compressed for data delivery.

 

Units

• Field Definition:  The unit of measure associated with the resolution.

 

Vertical Datum

• Field Definition:  The vertical reference system from which elevation values are determined.

          Values:

          NAVD88 = North American Vertical Datum of 1988