As many of you already know, the National Geodetic Survey (NGS)–an office of the National Oceanic and Atmospheric Administration (NOAA)–is planning to replace the North American Datum of 1983 (NAD 83) and the North American Vertical Datum of 1988 (NAVD 88) with new datums in 2022.
Approximate horizontal change in
coordinates when new reference
frame is adopted.
Source: National Geodetic Survey
The new reference frame will:
- be geo-centric
- rely primarily on Global Navigation Satellite Systems (GNSS) such as the Global Positioning System (GPS)
- rely on active control — Continuously Operating Reference Stations (CORS) — rather than passive control
- incorporate a time-tracked geoid model with plate-fixed coordinates, to account for change in the x, y and z coordinates of points over time
- adopt a US-specific reference frame with temporal coordinates using International Terrestrial Reference Frame (ITRF) coordinates and velocities
- include a new vertical datum based on precise gravity measurements
The NGS hosted a Geospatial Summit in April 2015 to share updates and receive feedback on the planned 2022 release of the new datums.
The Presentations and webinar videos from the event are available through the NGS 2015 Geospatial Summit Website.
The NGS website also contains useful information about the coming transition, including more videos and tutorials.
The replacement of NAD 83 and NAVD 88 is a significant undertaking requiring years of planning. The NGS website, videos, and tutorials provide a good starting point for getting introduced to some of the complexities of the process. Stay tuned for more information as this initiative takes shape over the next few years.