25 relations: Astrometry, Astronomical object, Barycenter, Barycentric celestial reference system, Catalogues of Fundamental Stars, Circular motion, Earth, Earth orientation parameters, Epoch (astronomy), Extragalactic astronomy, Frame of reference, General relativity, Gravity, Inertial frame of reference, International Astronomical Union, International Celestial Reference System, International Earth Rotation and Reference Systems Service, International Terrestrial Reference System, Ionosphere, Mean squared error, Minute and second of arc, Noise floor, Quasar, Solar System, Very-long-baseline interferometry.
Astrometry is the branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies.
An astronomical object or celestial object is a naturally occurring physical entity, association, or structure that exists in the observable universe.
The barycenter (or barycentre; from the Ancient Greek βαρύς heavy + κέντρον centre) is the center of mass of two or more bodies that are orbiting each other, which is the point around which they both orbit.
The Barycentric celestial reference system (BCRS) is a coordinate system used in astrometry to specify the location and motions of astronomical objects.
The Catalogue of Fundamental Stars is a series of six astrometric catalogues of high precision positional data for a small selection of stars to define a celestial reference frame, which is a standard coordinate system for measuring positions of stars.
In physics, circular motion is a movement of an object along the circumference of a circle or rotation along a circular path.
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
In geodesy, earth orientation parameters (EOP) are a collection of parameters that describe irregularities in the rotation of the Earth.
In astronomy, an epoch is a moment in time used as a reference point for some time-varying astronomical quantity, such as the celestial coordinates or elliptical orbital elements of a celestial body, because these are subject to perturbations and vary with time.
Extragalactic astronomy is the branch of astronomy concerned with objects outside the Milky Way galaxy.
In physics, a frame of reference (or reference frame) consists of an abstract coordinate system and the set of physical reference points that uniquely fix (locate and orient) the coordinate system and standardize measurements.
General relativity (GR, also known as the general theory of relativity or GTR) is the geometric theory of gravitation published by Albert Einstein in 1915 and the current description of gravitation in modern physics.
Gravity, or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward (or gravitate toward) one another.
An inertial frame of reference in classical physics and special relativity is a frame of reference in which a body with zero net force acting upon it is not accelerating; that is, such a body is at rest or it is moving at a constant speed in a straight line.
The International Astronomical Union (IAU; Union astronomique internationale, UAI) is an international association of professional astronomers, at the PhD level and beyond, active in professional research and education in astronomy.
The International Celestial Reference System (ICRS) is the current standard celestial reference system adopted by the International Astronomical Union (IAU).
The International Earth Rotation and Reference Systems Service (IERS), formerly the International Earth Rotation Service, is the body responsible for maintaining global time and reference frame standards, notably through its Earth Orientation Parameter (EOP) and International Celestial Reference System (ICRS) groups.
The International Terrestrial Reference System (ITRS) describes procedures for creating reference frames suitable for use with measurements on or near the Earth's surface.
The ionosphere is the ionized part of Earth's upper atmosphere, from about to altitude, a region that includes the thermosphere and parts of the mesosphere and exosphere.
In statistics, the mean squared error (MSE) or mean squared deviation (MSD) of an estimator (of a procedure for estimating an unobserved quantity) measures the average of the squares of the errors—that is, the average squared difference between the estimated values and what is estimated.
A minute of arc, arcminute (arcmin), arc minute, or minute arc is a unit of angular measurement equal to of one degree.
In signal theory, the noise floor is the measure of the signal created from the sum of all the noise sources and unwanted signals within a measurement system, where noise is defined as any signal other than the one being monitored.
A quasar (also known as a QSO or quasi-stellar object) is an extremely luminous active galactic nucleus (AGN).
The Solar SystemCapitalization of the name varies.
Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy.