French Global Network of Geomagnetic observatories

The Bureau Central de Magnétisme Terrestre (BCMT) is a French organization founded in 1921 and attached to the Institut de Physique du Globe de Paris (IPGP). Two French institutions are involved in BCMT operations: IPGP and École et Observatoire des Sciences de la Terre de Strasbourg (EOST). The primary mission of the BCMT is to provide ground geomagnetic observations of the highest quality to the scientific community, in France and abroad. To achieve its mission, the BCMT operates a network of magnetic observatories distributed worldwide, including the National Magnetic Observatory located at Chambon-la-Forêt, France. Each observatory is equipped with two types of magnetometers: A three-axis vector magnetometer and an absolute scalar magnetometer. Calibration measurements are made regularly by an operator at each magnetic observatory. Vector data, scalar data and calibration data are gathered to obtain fully calibrated set of definitive values of the magnetic field vector at the observatory position along time. BCMT data are available on its website (www.bcmt.fr) and on Intermagnet’s website (www.intermagnet.org). The data are under license CC BY-NC 4.0.