Greenwich meridian
The Greenwich meridian is the zero-degree line of longitude that passes through the Royal Observatory Greenwich in London. It serves as the global reference for measuring longitude and defining time zones worldwide.
IAG as part of the IUGG
IAG Related Organisations
IAG collaborates closely with numerous organizations within geodesy and beyond. See the list for details.
This website is provided by the IAG Secretariat and the GGOS Coordinating Office, which are hosted by the BEV – Federal Office of Metrology and Surveying (Bundesamt für Eich- und Vermessungswesen) in Vienna, Austria.