EPSG Geodetic Parameter Dataset
EPSG Geodetic Parameter Dataset is a public registry of geodetic datums, spatial reference systems, Earth ellipsoids, coordinate transformations and related units of measurement, originated by a member of the European Petroleum Survey Group in 1985. Each entity is assigned an EPSG code between 1024 and 32767, along with a standard machine-readable well-known text representation. The dataset is maintained by the IOGP Geomatics Committee.
Most geographic information systems and GIS libraries use EPSG codes as Spatial Reference System Identifiers and EPSG definition data for identifying coordinate reference systems, projections, and performing transformations between these systems, while some also support SRIDs issued by other organizations.
Common EPSG codes
- EPSG:4326 - WGS 84 datum ensemble for 2D coordinates with 2 meter accuracy, used by the Global Positioning System among others.
- EPSG:3857 - Web Mercator projection of WGS 84, used for display by many web-based mapping tools, including Google Maps and OpenStreetMap.
- EPSG:9989 - International Terrestrial Reference Frame 2020 for 3D coordinates with subcentimeter accuracy, used for monitoring continental drift among others.
History
In 2005, the EPSG organisation was merged into International Association of Oil & Gas Producers, and became the Geomatics Committee. However, the name of the EPSG registry was kept to avoid confusion. Since then, the acronym "EPSG" became increasingly synonymous with the dataset or registry itself.