Earth-centered, Earth-fixed coordinate system

For broader coverage of this topic, see Spatial reference system.

The ECEF coordinates (x, y, z) shown in relation to latitude and longitude
Geodesy
Fundamentals
Concepts
Technologies
Standards (history)
NGVD 29 Sea Level Datum 1929
OSGB36 Ordnance Survey Great Britain 1936
SK-42 Systema Koordinat 1942 goda
ED50 European Datum 1950
SAD69 South American Datum 1969
GRS 80 Geodetic Reference System 1980
ISO 6709 Geographic point coord. 1983
NAD 83 North American Datum 1983
WGS 84 World Geodetic System 1984
NAVD 88 N. American Vertical Datum 1988
ETRS89 European Terrestrial Ref. Sys. 1989
GCJ-02 Chinese obfuscated datum 2002
Geo URI Internet link to a point 2010

The Earth-centered, Earth-fixed coordinate system (acronym ECEF), also known as the geocentric coordinate system, is a cartesian spatial reference system that represents locations in the vicinity of the Earth (including its surface, interior, atmosphere, and surrounding outer space) as X, Y, and Z measurements from its center of mass.[1][2] Its most common use is in tracking the orbits of satellites and in satellite navigation systems for measuring locations on the surface of the Earth, but it is also used in applications such as tracking crustal motion.

The distance from a given point of interest to the center of Earth is called the geocentric distance, R = (X2 + Y2 + Z2)0.5, which is a generalization of the geocentric radius, R0, not restricted to points on the reference ellipsoid surface. The geocentric altitude is a type of altitude defined as the difference between the two aforementioned quantities: h′ = R − R0;[3] it is not to be confused for the geodetic altitude.

Conversions between ECEF and geodetic coordinates (latitude and longitude) are discussed at geographic coordinate conversion.

  1. ^ Leick, Alfred (2004). GPS Satellite Surveying. Wiley.
  2. ^ Clynch, James R. (February 2006). "Earth Coordinates" (PDF). Archived from the original (PDF) on April 18, 2015.
  3. ^ Chobotov, V.A. (2002). Orbital Mechanics. AIAA Education Series. American Institute of Aeronautics & Astronautics. p. 72. ISBN 978-1-60086-097-3. Retrieved October 24, 2021.