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In geodesy and astrometry, earth orientation parameters (EOP) describe irregularities in the rotation of planet Earth.EOP provide the rotational transform from the International Terrestrial Reference System (ITRS) to the International Celestial Reference System (ICRS), or vice versa, as a function of time.
The Sub-bureau for Rapid Service and Predictions of Earth Orientation Parameters of the IERS, located at the United States Naval Observatory, monitors the Earth's rotation. Part of its mission involves the determination of a time scale based on the current rate of the rotation of the Earth. Other services of IERS are at the Paris Observatory.
Constructed with input data under the form of time series of station positions and Earth Orientation Parameters. [5] This version introduces extra parameters to describe the year-periodic motion of the stations: A (amplitude) and φ (phase) per-axis. This sort of seasonal variation has an amplitude of around 1 cm and is attributed to non-tidal ...
The basic coordinate system is the ITRF reference frame, which is related to the ICRS celestial inertial system by means of very precise Earth Orientation Parameters (EOPs), containing polar coordinates, Earth rotation and nutation parameters. The ITRF data set is revised every 3–5 years, the actual accuracy is in the millimeter area.
Earth's rotation period relative to the Sun (solar noon to solar noon) is its true solar day or apparent solar day. [26] It depends on Earth's orbital motion and is thus affected by changes in the eccentricity and inclination of Earth's orbit. Both vary over thousands of years, so the annual variation of the true solar day also varies.
Geodesy or geodetics [1] is the science of measuring and representing the geometry, gravity, and spatial orientation of the Earth in temporally varying 3D.It is called planetary geodesy when studying other astronomical bodies, such as planets or circumplanetary systems. [2]
Models representing the ever-changing orientation of the Earth in space are available from the International Earth Rotation and Reference Systems Service. Examples include: J2000: One commonly used ECI frame is defined with the Earth's Mean Equator and Mean Equinox (MEME) at 12:00 Terrestrial Time on 1 January 2000.
Tiếng Việt; Walon; ... Pages in category "Earth" The following 57 pages are in this category, out of 57 total. ... Earth orientation parameters; Earth's rotation; S.