Datums and Reference Frames | Datums | National Geodetic Survey

International Terrestrial Reference Frame (ITRF)

The current global standard reference frame. NGS New datums will align with the current ITRF.

World Geodetic System 1984 (WGS 84)

Defined by the U.S. Department of Defense. Commonly used within civilian GPS software.

Geodetic Reference System 1980 (GRS 80)

Geodetic reference system consisting of a global reference ellipsoid and a gravity field model. Basis for NAD 83 and related datums.