European Terrestrial Reference System 1989
Encyclopedia
The European Terrestrial Reference System 1989 (ETRS89) is a ECEF
(Earth-Centered, Earth-Fixed) geodetic
Cartesian reference frame
, in which the Eurasian Plate
as a whole is static. The coordinates and map
s in Europe based on ETRS89 are not subject to change due to the continental drift
.
The development of ETRS89 is related to the global ITRS
geodetic datum, in which the representation of the continental drift is balanced in such a way that the total apparent angular momentum
of continental plates is about 0. ETRS89 was officially born at the 1990 Florence
meeting of EUREF
, following its Resolution 1, which recommends that the terrestrial reference system to be adopted by EUREF will be coincident with ITRS at the epoch 1989.0 and fixed to the stable part of the Eurasian Plate. According to the resolution, this system was named European Terrestrial Reference System 89 (ETRS89). Since then ETRS89 and ITRS diverge due to the continental drift at a speed about 2.5 cm per year. By the year 2000 the two coordinate systems differed by about 25 cm.
The 89 in its name does not refer to the year of solution (realization), but rather the year of initial definition, when ETRS89 was fully equivalent to ITRS. The solutions of ETRS89 correspond to the ITRS solutions. For each ITRS solution, a matching ETRS89 solution is being made. ETRF2000, for example, is an ETRS89 solution, which corresponds to ITRF2000. ETRS89 is realized by EUREF through the maintenance of the EUREF Permanent Network (EPN) and continuous processing of the EPN data in a few processing centres. Users have access to ETRS89 via EPN data products and real-time streams of differential corrections from a set of public providers based on the EPN stations.
The transformation from ETRS89 to ITRS is time-dependent and was formulated by C. Boucher and Z. Altamimi
ETRS89 is the EU
-recommended frame of reference for geodata for Europe. It is the only geodetic datum to be used for mapping
and surveying
purposes in Europe.
It plays the same role for Europe as NAD-83 for North America. (NAD-83 is a datum in which the North American Plate
as a whole is static, and which is used for mapping and surveying in the USA, Canada, and Mexico.) ETRS89, as well as WGS-84 and NAD-83, is based on the GRS80 ellipsoid
.
ECEF
ECEF stands for Earth-Centered, Earth-Fixed, and is a Cartesian coordinate system, and is sometimes known as a "conventional terrestrial" system. It represents positions as an X, Y, and Z coordinate. The point is defined as the center of mass of the earth, hence the name Earth-Centered...
(Earth-Centered, Earth-Fixed) geodetic
Geodesy
Geodesy , also named geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth, including its gravitational field, in a three-dimensional time-varying space. Geodesists also study geodynamical phenomena such as crustal...
Cartesian reference frame
Cartesian coordinate system
A Cartesian coordinate system specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances from the point to two fixed perpendicular directed lines, measured in the same unit of length...
, in which the Eurasian Plate
Eurasian Plate
The Eurasian Plate is a tectonic plate which includes most of the continent of Eurasia , with the notable exceptions of the Indian subcontinent, the Arabian subcontinent, and the area east of the Chersky Range in East Siberia...
as a whole is static. The coordinates and map
Map
A map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....
s in Europe based on ETRS89 are not subject to change due to the continental drift
Continental drift
Continental drift is the movement of the Earth's continents relative to each other. The hypothesis that continents 'drift' was first put forward by Abraham Ortelius in 1596 and was fully developed by Alfred Wegener in 1912...
.
The development of ETRS89 is related to the global ITRS
International Terrestrial Reference System
The International Terrestrial Reference System describes procedures for creating reference frames suitable for use with measurements on or near the Earth's surface. This is done in much the same way that a physical standard might be described as a set of procedures for creating a realization of...
geodetic datum, in which the representation of the continental drift is balanced in such a way that the total apparent angular momentum
Angular momentum
In physics, angular momentum, moment of momentum, or rotational momentum is a conserved vector quantity that can be used to describe the overall state of a physical system...
of continental plates is about 0. ETRS89 was officially born at the 1990 Florence
Florence
Florence is the capital city of the Italian region of Tuscany and of the province of Florence. It is the most populous city in Tuscany, with approximately 370,000 inhabitants, expanding to over 1.5 million in the metropolitan area....
meeting of EUREF
Regional Reference Frame Sub-Commission for Europe
Regional Reference Frame Sub-Commission for Europe is the sub-commission of the International Association of Geodesy , part of the Sub-Commission 1.3 , under IAG Commission 1 ....
, following its Resolution 1, which recommends that the terrestrial reference system to be adopted by EUREF will be coincident with ITRS at the epoch 1989.0 and fixed to the stable part of the Eurasian Plate. According to the resolution, this system was named European Terrestrial Reference System 89 (ETRS89). Since then ETRS89 and ITRS diverge due to the continental drift at a speed about 2.5 cm per year. By the year 2000 the two coordinate systems differed by about 25 cm.
The 89 in its name does not refer to the year of solution (realization), but rather the year of initial definition, when ETRS89 was fully equivalent to ITRS. The solutions of ETRS89 correspond to the ITRS solutions. For each ITRS solution, a matching ETRS89 solution is being made. ETRF2000, for example, is an ETRS89 solution, which corresponds to ITRF2000. ETRS89 is realized by EUREF through the maintenance of the EUREF Permanent Network (EPN) and continuous processing of the EPN data in a few processing centres. Users have access to ETRS89 via EPN data products and real-time streams of differential corrections from a set of public providers based on the EPN stations.
The transformation from ETRS89 to ITRS is time-dependent and was formulated by C. Boucher and Z. Altamimi
ETRS89 is the EU
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
-recommended frame of reference for geodata for Europe. It is the only geodetic datum to be used for mapping
Cartography
Cartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.The fundamental problems of traditional cartography are to:*Set the map's...
and surveying
Surveying
See Also: Public Land Survey SystemSurveying or land surveying is the technique, profession, and science of accurately determining the terrestrial or three-dimensional position of points and the distances and angles between them...
purposes in Europe.
It plays the same role for Europe as NAD-83 for North America. (NAD-83 is a datum in which the North American Plate
North American Plate
The North American Plate is a tectonic plate covering most of North America, Greenland, Cuba, Bahamas, and parts of Siberia, Japan and Iceland. It extends eastward to the Mid-Atlantic Ridge and westward to the Chersky Range in eastern Siberia. The plate includes both continental and oceanic crust...
as a whole is static, and which is used for mapping and surveying in the USA, Canada, and Mexico.) ETRS89, as well as WGS-84 and NAD-83, is based on the GRS80 ellipsoid
Reference ellipsoid
In geodesy, a reference ellipsoid is a mathematically-defined surface that approximates the geoid, the truer figure of the Earth, or other planetary body....
.