Geomagnetic field measurements: instrument calibration and data processing

Abstract

In the field of geophysics, the time variations in the electric and magnetic fields are used to study solar activity and the geomagnetic field, and to characterise the electrical properties of the subsurface. It is important to know the operational range and limitations of the sensors and the data logger used for the data digitalization. Time series processing allows converting the recorded signals to the frequency and to calculate the transfer functions. The objective of this work is to compare the time series and geomagnetic transfer functions obtained with two different instruments and with the ones obtained using data from the Ebre Observatory. As the data were registered at similar latitudes as the observatory, a comparison can be conducted with integrity. The results show some similarities and discrepancies between both the time signals and the transfer functions. It is also notable that none of the tested instruments performed better than the other in the collective outcome.