The U.S. government is closed. This site will not be updated; however, NOAA websites and social media channels necessary to protect lives and property will be maintained. To learn more, visit commerce.gov.
For the latest forecasts and critical weather information, visit weather.gov.
*Please note: Some Funding Opportunities offered under the Bipartisan Infrastructure Law are open and can be applied for during the partial government shutdown.
A geodetic datum or reference frame is an abstract coordinate system with a reference surface (such as sea level) that serves to provide known locations to begin surveys and create maps.
NGS defines the official geodetic datums for all federal mapping activities in the U.S. and its territories (see Table 1) as part of the National Spatial Reference System (NSRS). However, NGS will be defining “new datums” to replace these datums.
TABLE 1: Current Datums of the United States and Territories
A Terrestrial Reference frame provides a set of coordinates of some points located on the Earth's surface. NGS contributes to International bodies that define globally consistent reference frames, and to some other frames that are used to define a national coordinate system or datum (see Table 2).
TABLE 2: International Reference Frames
