INTERMAGNET (the International Real-time Magnetic Observatory Network) is a world-wide consortium of institutes operating ground-based magnetometers recording the absolute level of the Earth's time-varying magnetic field, to an agreed set of standards. INTERMAGNET has its roots in discussions held at the Workshop on Magnetic Observatory Instruments in Ottawa, Canada, in August 1986 and at the Nordic Comparison Meeting in Chambon La Foret, France, in May 1987. A pilot scheme between USGS and BGS was described in the sessions of Division V of the International Association of Geomagnetism and Aeronomy at the 19th General Assembly of the International Union of Geodesy and Geophysics in Vancouver, Canada, in August 1987. This scheme used the GOES East satellite to successfully transfer geomagnetic data between the two organisations. INTERMAGNET was founded soon after in order to extend the network of observatories communicating in this way. 62 different institutes are now members of the INTERMAGNET consortium, and, since 1991, data have been contributed to INTERMAGNET from approximately 150 observatories. INTERMAGNET is a member of the World Data System of the International Science Council, and it is closely associated with the International Association of Geomagnetism and Aeronomy. INTERMAGNET (the International Real-time Magnetic Observatory Network) is a world-wide consortium of institutes operating ground-based magnetometers recording the absolute level of the Earth's time-varying magnetic field, to an agreed set of standards. INTERMAGNET has its roots in discussions held at the Workshop on Magnetic Observatory Instruments in Ottawa, Canada, in August 1986 and at the Nordic Comparison Meeting in Chambon La Foret, France, in May 1987. A pilot scheme between USGS and BGS was described in the sessions of Division V of the International Association of Geomagnetism and Aeronomy at the 19th General Assembly of the International Union of Geodesy and Geophysics in Vancouver, Canada, in August 1987. This scheme used the GOES East satellite to successfully transfer geomagnetic data between the two organisations. INTERMAGNET was founded soon after in order to extend the network of observatories communicating in this way. 62 different institutes are now members of the INTERMAGNET consortium, and, since 1991, data have been contributed to INTERMAGNET from approximately 150 observatories. INTERMAGNET is a member of the World Data System of the International Science Council, and it is closely associated with the International Association of Geomagnetism and Aeronomy. INTERMAGNET is organised into an Executive Council, formed of representatives of its founding members (NRCan - Canada, IPGP - France, BGS - United Kingdom, USGS - United States of America), and an Operations Committee, formed of members from many institutes concerned with geomagnetism and with operating magnetic observatories. The Operations Committee handles applications for membership of INTERMAGNET, implements updates to the technical manual. and oversees the maintenance of standards and the annual publication of data. Intermagnet operational standards and other technical information are summarized in the technical manual.