German Repeat Station Surveys
The German geomagnetic repeat station network currently consists of 45 points out of a denser network from former ground vector surveys. Regular repeat station surveys started in 1992 and were carried out every 4 years. The measurements are taken by a fluxgate theodolite (D, I) and a proton magnetometer (F). A variometer close to the point of observation is used for proper data reduction to the epoch. The measurements and production of magnetic charts has been a joint task of the three German Geomagnetic Observatories Niemegk, Wingst (both Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum) and Fürstenfeldbruck (Ludwig-Maximilians-Universität München). With the adoption of Wingst observatory by GFZ in 2000 these tasks have been overtaken by Niemegk observatory. The measurements are taken by a fluxgate theodolite (D, I) and a proton magnetometer (F). A variometer close to the point of observation is used for proper data reduction to the epoch.
German repeat station and ground vector surveysParticularly the declination, the angle between geographic and magnetic north, is of practical interest for navigational purposes. Repeat station or ground vector surveys are the basis for magnetic charts.
The charts have to be updated every few years as the geomagnetic field is changing constantly. This so-called secular variation cannot be predicted. Therefore every few years repeat station surveys are carried out to measure secular variation in detail and update the charts.
German regional magnetic surveys since 1950
To illustrate the the results of the Repeat station surveys you can go to the map galleries: