The instant that the gravitational correction started to be applied serves as the epoch for Barycentric Coordinate Time ( TCB ), Geocentric Coordinate Time ( TCG ), and Terrestrial Time ( TT ).

Difficulties were recognized, which led to these being in turn superseded in the 1990s by time scales Terrestrial Time ( TT ), Geocentric Coordinate Time GCT ( TCG ) and Barycentric Coordinate Time BCT ( TCB ).

TT was formally defined in terms of Geocentric Coordinate Time ( TCG ), defined by the IAU on the same occasion.

TT differs from Geocentric Coordinate Time ( TCG ) by a constant rate.

where TT and TCG are linear counts of SI seconds in Terrestrial Time and Geocentric Coordinate Time respectively, L < sub > G </ sub > is the constant difference in the rates of the two time scales, and E is a constant to resolve the epochs ( see below ).

The present definition of TT is a linear scaling of Geocentric Coordinate Time ( TCG ), which is the proper time of a notional observer who is infinitely far away ( so not affected by gravitational time dilation ) and at rest relative to the Earth.

* Geocentric Coordinate Time

For the calculation of ephemerides, TDB was officially recommended to replace ET, but deficiencies were found in the definition of TDB ( though not affecting T < sub > eph </ sub >), and these led to the IAU defining and recommending further time scales, Barycentric Coordinate Time ( TCB ) for use in the solar system as a whole, and Geocentric Coordinate Time ( TCG ) for use in the vicinity of the Earth.

* Geocentric Coordinate Time ( TCG ) is a coordinate time having its spatial origin at the center of Earth's mass.

) After the difficulties were appreciated, in 1991 the IAU refined the official definitions of timescales by creating additional new time scales: Barycentric Coordinate Time ( TCB ) and Geocentric Coordinate Time ( TCG ).

* Geocentric Coordinate Time

Geocentric Coordinate Time ( TCG-Temps-coordonnée géocentrique ) is a coordinate time standard intended to be used as the independent variable of time for all calculations pertaining to precession, nutation, the Moon, and artificial satellites of the Earth.

de: Geocentric Coordinate Time

* Geocentric Coordinate Time

* Geocentric axial dipole, a hypothesis that Earth's magnetic field dipole component is in roughly 10, 000-year average aligned to rotation axis

* Geocentric model, the astronomical model in which the Earth is at the center of the universe

Geocentric coordinate systems used in geodesy can be divided naturally into two classes:

* Geocentric Solar Ecliptic System, a Cartesian coordinate system with center in the earth, X-axis pointing towards the sun and Z-axis parallel to the ecliptic pole

** Geocentric, a model of the universe that places the earth at its centre

The obsolete Geocentric model of the universe places the Earth at the centre.

As late as 1650, P. Schirleus has produced a Geocentric planetarium showing the sun as a planet with Mercury and Venus moving around it as moons.

Geocentric coordinates are an Earth-centered system of locating objects in the solar system in three-dimensions along the Cartesian X, Y and Z axes.

* Barycentric Coordinate Time

Barycentric Coordinate Time is a coordinate time scale at the center of mass of the solar system, which is called the barycenter.

* Barycentric Coordinate Time ( TCB ) is a coordinate time having its spatial origin at the solar system barycenter.

In popular GIS software, data projected in latitude / longitude is often represented as a ' Geographic Coordinate System '.

Coordinate systems can specify a position in 3-dimensional space, or merely the direction of the object on the celestial sphere, if its distance is not known or not important.

Coordinate dimensioning was the sole best option until the post-World War II era saw the development of geometric dimensioning and tolerancing ( GD & T ), which departs from the limitations of coordinate dimensioning ( e. g., rectangular-only tolerance zones, tolerance stacking ) to allow the most logical tolerancing of both geometry and dimensions ( that is, both form and sizes ).

TDB is now ( since 2006 ) defined as a linear scaling of Barycentric Coordinate Time ( TCB ), and a feature that distinguishes TDB from TCB is that TDB, when observed from the Earth's surface, has a difference from Terrestrial Time ( TT ) that is about as small as can be practically arranged with consistent definition: the differences are mainly periodic, and overall will remain at less than 2 milliseconds for several millennia.

Barycentric Coordinate Time ( TCB, from the French Temps-coordonnée barycentrique ) is a coordinate time standard intended to be used as the independent variable of time for all calculations pertaining to orbits of planets, asteroids, comets, and interplanetary spacecraft in the Solar system.

Barycentric Coordinate Time ( TCB ) is the equivalent of TCG for calculations relating to the solar system beyond Earth orbit.

* Coordinate notation is similar to algebraic notation except that no abbreviation or symbol is used to show which piece is moving.

The discrete Laplacian is defined as the sum of the second derivatives Laplace operator # Coordinate expressions and calculated as sum of differences over the nearest neighbours of the central pixel.

Based on the definition of Neumann, Heinrich Streintz ( 1883 ) argued that if gyroscopes don't measure any signs of rotation, then one can speak of inertial motion which is related to a " Fundamental body " and a " Fundamental Coordinate System ".

He is commonly credited with proposing the idea of Coordinate Remote Viewing, a process in which viewers would view a location given nothing but its geographical coordinates, which was developed and tested by Puthoff and Targ with CIA funding.

The Coordinate system # Coordinate surface | coordinate surfaces of the Cartesian coordinates ( x, y, z ).

* Display Coordinate System, the coordinate system where objects are transformed to before being displayed in CAD systems.

Coordinate descent does a line search along one coordinate direction at the current point in each iteration.

* Barycentric Coordinate Time ( from the French temps-coordonnée barycentrique ), a coordinate time standard in the Solar system

Founded in 1937, New Haven County has a county-wide fire-protection agency called " New Haven County Fire Emergency Plan " based in Hamden to " Coordinate Mutual Aid-Radio Problems, assist members of county at major incidents if requested, provide training ".

* Coordinate and collaborate with other credible sources.

:: Coordinate conjunction ( C ), determiner ( D ), negation ( Neg ), particle ( Par ), preposition ( P ) and prepositional phrase ( PP ), subordinate conjunction ( Sub ), etc.

Coordinate systems fixed with respect to the rotating axles are defined as having their x-axis unit vectors ( and ) pointing from the origin towards one of the connection points.

Coordinate dimensioning involves defining all points, lines, planes, and profiles in terms of Cartesian coordinates, with a common origin.

Coordinate data from ACME Mapper.

The coordinates were speedily sent out as an International Astronomical Union ( IAU ) and Gamma-ray burst Coordinate Network Circular.

< Coordinate point =" 0 0 0 1 0 0 0. 5 1 0 "/>

Practical examples include the International Atomic Time standard and its relationship with the Barycentric Coordinate Time standard used for interplanetary objects.