A Total Field Fluxgate Magnetometer

Sayyadual Arafin

doi:10.1071/eg984075

Hungarian repeat station survey, 2010

Annals of Geophysics ◽

10.4401/ag-5450 ◽

2013 ◽

Vol 55 (6) ◽

Author(s):

Péter Kovács ◽

András Csontos ◽

Balázs Heilig ◽

András Koppán

Keyword(s):

Fluxgate Magnetometer ◽

Total Field ◽

Geophysical Observatory ◽

Repeat Station ◽

Magnetic Elements ◽

Technical Details ◽

Temporal Correction

<p>The last Hungarian repeat station survey was completed between October 2010 and February 2011. Declination, inclination and the total field were observed using one-axial DMI fluxgate magnetometer mounted on Zeiss20A theodolite and GSM 19 Overhauser magnetometer. The magnetic elements of the sites were reduced to the epoch of 2010.5 on the basis of the continuous recordings of Tihany Geophysical Observatory. In stations located far from the reference observatory, the observations were carried out in the morning and afternoon in order to decrease the effect of the distant temporal correction. To further increase the accuracy, on-site dIdD variometer has also been installed near the Aggtelek station, in the Baradla cave, during the survey of the easternmost sites. The paper presents the technical details and the results of our last campaign. The improvement of the accuracy of the temporal reduction by the use of the local variometer is also reported.</p>

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A new method of fluxgate signal extraction

Information extraction and processing ◽

10.15407/vidbir2017.45.083 ◽

2017 ◽

Vol 2017 (45) ◽

pp. 83-89

Author(s):

A.A. Marusenkov ◽

Keyword(s):

High Frequency ◽

Second Harmonic ◽

Excitation Frequency ◽

Low Noise ◽

Measuring System ◽

Signal Extraction ◽

Fluxgate Magnetometer ◽

New Approach ◽

Average Value ◽

The Time Domain

Using dedicated high-frequency measuring system the distribution of the Barkhausen jumps intensity along a reversal magnetization cycle was investigated for low noise fluxgate sensors of various core shapes. It is shown that Barkhausen (reversal magnetization) noise intensity is strongly inhomogeneous during an excitation cycle. In the traditional second harmonic fluxgate magnetometers the signals are extracted in the frequency domain, as a result, some average value of reversal magnetization noises is contributed to the output signals. In order to fit better the noise shape and minimize its transfer to the magnetometer output the new approach for demodulating signals of these sensors is proposed. The new demodulating method is based on information extraction in the time domain taking into account the statistical properties of cyclic reversal magnetization noises. This approach yields considerable reduction of the fluxgate magnetometer noise in comparison with demodulation of the signal filtered at the second harmonic of the excitation frequency.

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