We are involved in the ESA satellite mission Swarm, which observes the geomagnetic field since November 2013. The mission consists of three identical, low-Earth orbiting satellites and also measures ionospheric and atmospheric parameters.
Many satellites carry magnetometer as part of its attitude orbit control system (AOCS). The magnetometer does not belong to the scientific payload of the mission. However, after postprocessing the satellites magnetometer data, information on the geomagnetic field and on electric currents in near Earth space can be derived. Platform Magnetometer on ISDC webpage: isdc.gfz-potsdam.de/platform-magnetometer/
CHAMP (CHAllenging Minisatellite Payload) was a German small satellite mission for geoscientific and atmospheric research and applications, managed by GFZ. With its highly precise, multifunctional and complementary payload elements and its orbit characteristics CHAMP generated highly precise gravity and magnetic field measurements simultaneously for the first time and over a 10 years period.
A global network of geomagnetic observatories is the backbone of studies concerning the field sources in the Earth's core, ionosphere and magnetosphere. Moreover, the data are used for models and maps with practical applications, and the determination of magnetic activity indices for space weather monitoring.