1) Relating to, measured from, or with respect to the center of the Earth.
geocentric coordinate system
râžmân-e hamârâhâ-ye zamin-markazi
Fr.: système de coordonnées géocentriques
A coordinate system which has as its origin the center of the Earth.
Geocentric Coordinate Time (TCG)
zamân-e hamârâ-ye zamin-markazi
Fr.: Temps coordonné géocentrique
The proper time experienced by a clock at rest in a coordinate frame co-moving with the center of the Earth, i.e. a clock that performs exactly the same movements as the Earth but is outside the Earth's gravity well. TCG was defined in 1991 by the International Astronomical Union as one of the replacements for Barycentric Dynamical Time (TDB).
keyhân-šenâsi-ye zamin-markazi (#)
Fr.: cosmologie géocentrique
A model of the Universe in which the Earth is centrally located and the Sun, planets, and stars revolve around the Earth.
Fr.: latitude géocentrique
The angle between the geocentric location vector and the → geodetic equator.
Fr.: longitude géocentrique
The same as → geodetic longitude.
Fr.: parallaxe géocentrique
The difference between the direction of an object as seen from a point on the surface of the Earth and the direction in which it would be seen from the Earth's center. Also known as → diurnal parallax.
Fr.: système géocentrique
An ancient model of the Universe whereby all the celestial bodies travel around the Earth in circular orbits. Eudoxus of Cnidus (c. 390- c. 337 BC), one of Plato's pupils, maintained that all objects in the sky are attached to moving crystalline spheres, with the Earth at the centre. This model is often named → Ptolemaic system after its most famous supporter, the Greco-Roman astronomer Ptolemy.