The National Spatial Reference System (NSRS), managed by the National Geodetic Survey (NGS), is a coordinate system that includes latitude, longitude, elevation, and other values. The NSRS consists of a National Shoreline, the NOAA CORS Network[1] (a system of Global Positioning System Continuously Operating Reference Stations), a network of permanently marked points, and a set of models that describe dynamic geophysical processes affecting spatial measurements. The system is based on the datums NAD 83 and NAVD 88.[2]
In 2024 or 2025, the NSRS will be modernized with a focus on Global Navigation Satellite Systems (GNSS) and geoid use. It will use the following four frames of reference, each representing a tectonic plate:[3] [4]
The North American-Pacific Geopotential Datum of 2022 (NAPGD2022) is a new geodetic datum set to be produced by the U.S. National Geodetic Survey in 2024–2025 to improve the National Spatial Reference System (NSRS).[5] [6] It will replace the North American Datum of 1983 (NAD 83) and the North American Vertical Datum of 1988 (NAVD 88) with a new geometric reference frame and geopotential datum.[7] In association with this release, a new, time-dependent geoid model, GEOID2022, will also be released.[8] The release date for both of these was initially planned to be 2022, hence the names, although they have been delayed.
The new reference frames will rely primarily on GNSS, such as the Global Positioning System (GPS), as well as on a gravimetric geoid model resulting from NGS' Gravity for the Redefinition of the American Vertical Datum (GRAV-D) Project. These new reference frames are intended be easier to access and to maintain than NAD 83 and NAVD 88, which rely on physical survey marks that deteriorate over time.
Attribution: contains public domain material copied from ngs.noaa.gov