The geomagnetic observatory in Dourbes, (IAGA code: DOU), in operation since 1953 and following on the previous century-old tradition of magnetic observations in the Brussels area (Rasson, 2007), consists of variometers for measuring the variations of the field components about the baseline and magnetometers for the absolute measurements needed to establish the baseline values (Verhulst et al., 2014).
Real-time measurements from the observatory are used for estimation of the local magnetic activity (Stankov et al., 2011). For the purpose, 1-min vector magnetic field measurements, as obtained directly from the FLV1/A Triaxial Fluxgate Variometric Magnetometer, are used. FLV1/A is a high-resolution instrument capable of accurately measuring the changes of the geomagnetic field vector by recording its total field modulus (F) and its orientation in space—the magnetic declination (D) and inclination (I). The current cadence is 1 s for time, with a precision of 0.1 nT for the induction and 0.001° for both, the declination and the inclination.
Rasson, J.L. (2007): Observatory instrumentation. In: Gubbins, D., Herrero-Bervera, E., (Eds.), Encyclopedia of Geomagnetism and Paleomagnetism, Springer, 725–726.
Verhulst, T., Stankov, S., Rasson, J. (2014): The geomagnetic field—an actively changing global phenomenon. KBVE Review E Tijdschrift—Journal of the Royal Belgian Association of Electrical Engineers (KBVE), 130 (2), 1–6.
Stankov, S.M., Stegen, K., Warnant, R. (2011): K-type geomagnetic index nowcast with data quality control. Annals of Geophysics, 54 (3), 285–295.