European Petroleum Survey Group Geodesy

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The European Petroleum Survey Group Geodesy ( EPSG ) was a working group of European oil and gas exploration companies. It was founded in 1986 and is based in London . In 2005 she was replaced by the Surveying and Positioning Committee of the International Association of Oil & Gas Producers ( OGP ). The EPSG became known through its system of unique key numbers for geodetic data sets ( EPSG codes ).

EPSG code

The EPSG code is a system of globally unique, 4 to 5-digit key numbers ( SRIDs ) for coordinate reference systems and other geodetic data sets, such as reference ellipsoids or projections . It will be continued under the same name by the successor organization OGP. The information on the EPSG codes is available in an online database.

In addition to coordinate reference systems, other geodetic information such as conversions between different reference systems, geodetic data, areas of validity and units are provided with code numbers. The keys are only unique in the respective category.

The individual objects refer to each other hierarchically. For example, the projected coordinate reference system EPSG: 31466 ( Gauß-Krüger , Zone 2) consists of the geodetic datum EPSG: 6314 ( German main triangle network ) and the map projection EPSG: 16262. The date is again based on the Bessel ellipsoid (EPSG: 7004). The projection is determined by specifying the algorithm EPSG: 9807 (transversal Mercator projection ) and corresponding parameters such as false easting and central meridian .

Examples

code Coordinate reference system comment
4326 WGS-84 / Geographic Coordinates worldwide system for GPS devices, OpenStreetMap database
25832 ETRS89 / UTM Zone 32N from 6 ° E to 12 ° E - area: Germany (W + M) + Austria (W) + Switzerland
25833 ETRS89 / UTM Zone 33N from 12 ° E to 18 ° E - area: Germany (E) + Austria (M + E)
31466 DHDN / Gauß-Krüger Zone 2 Area: Germany - west of 7.5 ° E
31467 DHDN / Gauß-Krüger Zone 3 Area: Germany - from 7.5 ° E to 10.5 ° E
31468 DHDN / Gauß-Krüger Zone 4 Area: Germany - from 10.5 ° E to 13.5 ° E
31469 DHDN / Gauß-Krüger Zone 5 Area: Germany - from 13.5 ° E to 16.5 ° E
3857 WGS 84 / Pseudo-Mercator Google Maps, OpenStreetMap and other map providers on the net.

Germany

The Gauß-Krüger zones 2 to 5 of the German main triangle network, which are common in Germany, have the EPSG codes 31466 to 31469.

In the new federal states, the Gauß-Krüger coordinate system and the Krassowski ellipsoid were used . The EPSG codes are EPSG: 2398 for Gauß-Krüger (4th strip Krassowski 3 degrees) and EPSG: 2399 for Gauß-Krüger (5th strip Krassowski 3 degrees).

The UTM zones of the European Terrestrial Reference System ETRS89 32N and 33N have the EPSG codes 25832 and 25833.

The EPSG code 3034 is used for the location-based data records for the test reference years (TRY) of the German weather service .

In Germany, the state surveying offices have made the transition to the UTM system with reference to the ETRS89 (system) with the GRS80 ellipsoid since the 1990s . In mid-2015, Saxony was one of the last federal states to make the change. Other EPSG codes must be used accordingly.

WGS 84 (EPSG: 4326)

The most frequently used EPSG code is 4326 for the World Geodetic System 1984 (WGS 84), a worldwide geodetic reference system on the basis of which the Global Positioning System (GPS) also works.

WGS 84 / Pseudo-Mercator (EPSG: 3857)

A simple and efficient projection method with a certain inaccuracy was spread through Google Maps (the ellipsoid is ignored and the Mercator projection is applied to the raw WGS-84 coordinates). For a while there was no established name or code number for this. To specify the Tile Map Service which led OSGeo key OSGEO: 41001 one. It was further from the OpenLayers the name EPSG project: spread the 900,913th

Eventually the EPSG saw the need for an official key number. The first specification EPSG: 3785 turned out to be faulty (a sphere was assumed to be the starting ellipsoid) and was therefore replaced by the now official key EPSG: 3857 .

application

Many applications have implemented the EPSG codes, making it easier to use geodetic data. The format of PROJ.4 and the WKT format are known .

The following two details are synonymous, they describe the Swiss national coordinates , EPSG: 2056 in PROJ.4 format: 

+init=epsg:2056 +no_defs

+proj=somerc +lat_0=46.95240555555556 +lon_0=7.439583333333333 +k_0=1 +x_0=2600000 +y_0=1200000
+ellps=bessel +towgs84=674.374,15.056,405.346,0,0,0,0 +units=m +no_defs

Here is an example for EPSG: 2007 “St. Vincent 1945 "in WKT format: 

PROJCS[„St. Vincent 45 / British West Indies Grid“,
GEOGCS[„St. Vincent 1945“,DATUM[„St_Vincent_1945“,
SPHEROID[„Clarke 1880 (RGS)“,6378249.145,293.465, AUTHORITY[„EPSG“,„7012“]],
TOWGS84[195.671,332.517,274.607,0,0,0,0], AUTHORITY[„EPSG“,„6607“]],
PRIMEM[„Greenwich“,0, AUTHORITY[„EPSG“,„8901“]],UNIT[„degree“,0.01745329251994328,
AUTHORITY[„EPSG“,„9122“]],AUTHORITY[„EPSG“,„4607“]],UNIT[„metre“,1,
AUTHORITY[„EPSG“,„9001“]],PROJECTION[„Transverse_Mercator“],
PARAMETER[„latitude_of_origin“,0],PARAMETER[„central_meridian“,-62],
PARAMETER[„scale_factor“,0.9995],PARAMETER[„false_easting“,400000],
PARAMETER[„false_northing“,0],AUTHORITY[„EPSG“,„2007“],
AXIS[„Easting“,EAST],AXIS[„Northing“,NORTH]]

Web links

Individual evidence

  1. ↑ EPSG Projection 31466 - DHDN / 3-degree Gauss-Kruger zone 2. Spatial Reference, accessed February 4, 2015 .
  2. ↑ EPSG Projection 31467 - DHDN / 3-degree Gauss-Kruger zone 3. Spatial Reference, accessed February 4, 2015 .
  3. ↑ EPSG Projection 31468 - DHDN / 3-degree Gauss-Kruger zone 4th Spatial Reference, accessed February 4, 2015 .
  4. ↑ EPSG Projection 31469 - DHDN / 3-degree Gauss-Kruger zone 5th Spatial Reference, accessed February 4, 2015 .
  5. ↑ Test reference years (TRY). Retrieved October 4, 2017 .
  6. ↑ New official position reference system ETRS89_UTM33 (change since July 2015). landesvermessung.sachsen.de, accessed on June 27, 2019 .
  7. ^ Message from the AdV office dated October 9, 2012
  8. ^ Tile Map Service Specification on OSGeo -Wiki
  9. ↑ SphericalMercator ( Memento of the original from July 27, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. on OpenLayers Wiki @1@ 2Template: Webachiv / IABot / trac.osgeo.org
  10. ↑ Google Projection: 900913 on crschmidt.net
  11. ↑ http://www.epsg-registry.org/report.htm?type=selection&entity=urn:ogc:def:crs:EPSG::3785&reportDetail=short&style=urn:uuid:report-style:default-with-code&style_name= OGP% 20Default% 20With% 20Code & title = EPSG: 3785
  12. ↑ EPSG Geodetic Parameter Dataset Version: 8.2.4 EPSG: 3857 on EPSG Geodetic Parameter Registry