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Elevation-Derived Hydrography Data Acquisition Specifications: Spatial Reference System Requirements

By NGP Standards and Specifications

Elevation-Derived Hydrography Data Acquisition Specifications

Spatial Reference System Requirements

Return to EDH Data Acquisition Specifications Table of Contents

Spatial Reference System

Datums

 

Spatial Reference System

Final products shall be in the reference systems defined below. If a collection area is composed of multiple sources of elevation data, all elevation data shall be processed to one common coordinate reference system prior to elevation-derived hydrography compilation.

The digital elevation model used to create the Elevation-derived hydrography shall be:

  • Comprised of the best available 3DEP lidar source data or other accepted lidar source data,
  • Seamless within the final hydrography defined project area (DPA) boundary,
  • Completely encompasses the DPA, plus at least 250 meters outside the DPA, as needed to derive hydrography.

Associated digital elevation model deliverables:

  • If 3DEP hydroflattening breaklines are available for the selected elevation datasets, they shall be provided with the elevation derived hydrography delivery as one dataset.
  • A spatial metadata layer that describes the source lidar data used.

All geospatial products must meet the following requirements:

  • In EPSG:6350 coordinate reference system for CONUS.
  • In EPSG:3338 coordinate reference system for Alaska.
  • For American Samoa, Commonwealth of the Northern Mariana Islands, Guam, Hawaii, Puerto Rico, U.S. Virgin Islands, and other U.S. territories, the following guideline applies:
    • USGS National Geospatial Program and all collection partners shall agree to and specify horizontal and vertical datums, ellipsoids, and geoids in advance of data collection.
Datums
  • For the conterminous United States, unless otherwise specified by the user and agreed to in advance by the U.S. Geological Survey (USGS) National Geospatial Program, the following guidelines apply:
    • The horizontal datum for latitude and longitude and ellipsoid heights will be the North American Datum of 1983 (NAD 83) using the most recent National Geodetic Survey published adjustment (currently NAD 83, epoch 2010.00, realization of 2011).
    • The vertical datum for orthometric heights will be the North American Vertical Datum of 1988 (NAVD 88).
    • The geoid model used to convert between ellipsoid heights and orthometric heights will be GEOID18.
  • For Alaska, American Samoa, Commonwealth of the Northern Mariana Islands, Guam, Hawaii, Puerto Rico, U.S. Virgin Islands, and other U.S. territories, the following guideline applies:
    • USGS National Geospatial Program and all collection partners shall agree to and specify horizontal and vertical datums, ellipsoids, and geoids in advance of data collection.