For pratical use and scientific research, Belgium must know the value of continuous variations and the geomagnetic field.This is one case for magnetic declination: it is used to find the direction of north with the compass. This is done using the Magnetic Observatories of Dourbes and Manhay. A complete measure of geomagnetic vector is recorded every minute.
In addition to themeasurements done in an observatory, there are frequently measurements done on the field all over Belgium. Upon request, field measurements can be requested outside Belgium. Everything is reported using the International System of Units (SI) and magnetic measurements are accomplished with a precision of 0.1nT for magnetic inductions and 0.001° for angles. The Observatory at Dourbes disposes of a diverse range of geomagnetic instrumentations. We develop, realize, test and calibrate small series of geomagnetometers: optically pumped magnetometer, proton and fluxgate variometer DIDD, Difluxes (automatic) and North Seekers.
The magneticnon-polluted environment at Dourbes makes it into the ideal place to test the amagnetism of materiels that can be used in industrial or research products.
On a regularly base, the Earth's magnetic field is calculated and published in annual reports. These results are recorded in international databases and at the RMI. They are also available online in quasi real time on the INTERMAGNET site. Besides the permanent record of the earth magnetic field, we calculate and publish also the magnetic activity indices on the ISGI site.
Chef de section - Dr. Jean Rasson