The Bureau Central de Magnétisme Terrestre (BCMT) is a French
organisation founded in 1921 and attached to the Institut de physique
du globe de Paris (IPGP). It is also a national service
of observation recognised by the CNRS-INSU. 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 and variometer stations,
including the National Magnetic Observatory located at
Chambon-la-Forêt, France. Each observatory or station is
equipped with two types of magnetometers for continuous
data acquisition: A three-axis vector magnetometer and an
absolute scalar magnetometer. Distributed data include
variation data, quasi-definitive and definitive data, that are
provided with a sampling rate of 1 Hz and also
as averages over 1 minute..
