Useful Links
Magnetometer Chains and Organizations:
Geomagnetic Observation using the Magnetometer Network (210 Magnetic Data)
Arctic and Antarctic Research Institute (AARI)
The Geophysical Institute Magnetometer Array (GIMA)
Magnetometer Array for Cusp and Cleft Studies (MACCS)
Canadian Array for Realtime Investigations of Magnetic Activity (CARISMA)
Canadian Space Science Data Portal
Greenland magnetometers operated by DMI and SPRL
International Monitor for Auroral Geomagnetic Effects (IMAGE)
International Real-time Magnetic Observatory Network (INTERMAGNET)
Space Physics Research Group at Virginia Tech
Geomagnetic data from Tromsų Geophysical Observatory
SAMBA (South American Meridional B-field Array)
SAMNET - The UK Sub-Auroral Magnetometer Network
Sino-Magnetic Array at Low Latitudes (SMALL)
USGS National Geomagnetism Program
British Antarctic Survey (BAS)
Other:
List of Ground-Based Observing Instruments
National Geophysical Data Center
IGRF/DGRF Model Parameters and Corrected Geomagnetic Coordinates at SPDF
Magnetic fields in near-Earth and near-Mars space
World Data Centre for Geomagnetism (Kyoto)
World Data Centre for Geomagnetism (Edinburgh)