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Content of description of European Coordinate Reference Systems


The system was established for the users of geospatial data.

It contains:

  • the description of national CRS of mostly countries in Europe and
  • the description of pan-European CRS (ETRS89 / EVRF2000 / EVRF2007) for position and height
  • the transformation parameters for a 7-parameter Helmert transformation from national to pan-European CRS with an accuracy of 1...3 m (GIS accuracy) for position
  • the transformation parameters for transformation of gravity-related heights from national height systems to pan-European height systems
  • verification data to compare and verify own transformation computations
  • a website for online-transformation of single points

    • for position: from national ellipsoidal CRS to ETRS89 in ellipsoidal coordinates, Cartesian coordinates and plane coordinates (ETRS89_TM<zn>) and also conversion to national plane and Cartesian coordinates
    • for height: from national gravity-related height to pan-European height systems EVRF2000 and / or EVRF2007 at the position of height point
  • links to the National Mapping Agencies (NMA) of European Countries

The NMAs or comparable institutions / organisations provided the information for the descriptions of the national Coordinate Reference Systems and for the transformation parameters between the national Coordinate Reference Systems and the pan-European Coordinate Reference Systems.These information were edited, homogenised and verified by computations with test coordinates. For the height the transformation parameters were calculated by UELN Data Center at Bundesamt für Kartographie und Geodäsie (BKG).

This information system is based on the convention of ISO 19111 Spatial referencing by coordinates standard.

Coordinate Reference Systems

Each Coordinate Reference System has a CRS Identifier which contains:
<Country Identifier>_< Datum Identifier> / <Coordinate System Identifier >

e.g. ES_ED50 / UTM for position

IdentifierValueDescription
Country IdentifierESSpain
Datum IdentifierED50European Datum 1950
Coordinate System IdentifierUTMUniversal Transverse Mercator



or ES_ALIC / OH for height

IdentifierValueDescription
Country IdentifierESSpain
Datum IdentifierALICtide gauge Alicante
Coordinate System IdentifierOHOrthometric heights


Special cases for Coordinate System / Operation Identifier are:
 

IdentifierDescription
UTMUniversal Transverse Mercator as special United States and military specification of Transverse Mercator Projection
GK_3Gauss-Krüger-System as special German specification of Transverse Mercator Projection (zones of 3 degrees width)
TM_6Transverse Mercator similar to Gauss-Krüger-System but with zones of 6 degrees width

For pan-European CRS no <Country Identifier> is in use and the names of the identifiers are not components of the standard.

Remark: The description of coordinate systems in CRS-EU are a general description. If identifier will be used to manage coordinates data sets e.g. for web services some further declarations are neccessary. These declarations like the order of coordinate values or coordinates with / without zone numbers are not explicit components of identifier in CRS-EU. For these usage the EPSG codes are valid.

Transformation to pan-European Coordinate Reference Systems

The transformation parameters are valid for the whole country or for different areas of the country. Concerning the purpose of geo-referencing for Geoinformation the accuracy of coordinates, provided by the transformation parameters, are 1...2 m in general. The digits of transformation parameters values are adjusted to this fact. Exceptions of accuracy are marked in the descriptions or in the quality field.

If no ellipsoidal heights are available and only the horizontal position is of interest, it is possible to perform the computations with gravity-related heights or also with height 0. But keep in mind, that the accuracy is a little bit lower and only available for the horizontal position.

To give the possibility to compare or verify own computations for all countries with transformation parameters verification data for the published parameters in the point "Description of Transformation" were computed by BKG. The data based on 2...3 fictive points of the transformation area.
For position ellipsoidal coordinates of mostly diametrically opposed points in national CRS were transformed in ETRS89 and for the height points with the national CRS height 100.00 m to EVRF2000 and EVRF2007.

Onlinetransformation

The online-transformation is a tool to transform single points from national CRS to pan-European CRS with the described transformation parameters.

Position:

At present the user have the possibility to input ellipsoidal coordinates in the notation degree minutes seconds in national datum. The tool compute all other CRS of national datum (corresponding plane coordinates e.g. Transverse Mercator and Cartesian coordinates) by conversion and by transformation the coordinates in pan-European datum ETRS89 in the different coordinate systems plane coordinates ETRS89-TM<zn> (zn...zone number), ellipsoidal coordinates and Cartesian coordinates.

Normally the input of ellipsoidal heights and not gravity-related height are necessary.
But if only the horizontal position is of interest, it is possible to perform computations with gravity-related heights or also with height 0. Be aware that then the Cartesian coordinates in both datums and the heights in pan-European datum are not correct. Accurately viewed horizontal position is also not correct if gravity-related heights instead of ellipsoidal height are used, but in the accuracy level of transformation there is no difference.

Height:

The user have the possibility to transform national gravity-related heights to pan-European CRS EVRF2000 or EVRF2007. Besides the value of height the position of point in ellipsoidal coordinates must be input. In the result fields also an information about the accuracy of transformation will be shown (RMS from computation of transformation parameters).

 

How to navigate to get the information

To get the information for a CRS of an European country do the following:

  • choice menu national CRS
  • choice a country in the list or in the map
  • a list of CRS for the country divide in position and height will be displayed
  • for each CRS choice on of the button for description of CRS or for transformation parameters to pan-European CRS or for online transformation (three colums on the right hand site)
  • if more than one transformation for the CRS exist a choice of the transformation is necessary

For the pan-European CRS only choice menu pan-European CRS. In the list with the CRS press button for description of CRS . Naturally no more buttons for description of transformation and online transformation exist.

Remark: Please use for navigation on step back the links "< back" inside website and not back button of the browser.



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© CRS-EU 2014