Measurement experiences with FluxSet digital D/I station

Abstract

Abstract. Geomagnetic observatories use classical theodolites equipped with single-axis flux-gate magnetometers known as declination–inclination magnetometers (DIM) to determine absolute values of declination and inclination angles. This instrument and the measurement method are very reliable but need a lot of handwork and experience. The authors developed and built a non-magnetic theodolite which gives all measurement data in digital form. Use of this instrument significantly decreases the possibility of observation errors and minimises handwork. The new instrument is presented in this paper together with first measurement results in comparison to the classical DIM.

Analysis of Several Years of DI Magnetometer Comparison Results by the Geomagnetic Network of China and IAGA

“…Note that considerable effort has been directed toward the development of new observation technology (Auster et al, 2003;Rasson et al, 2011). Recently, some automatic DIMs have been realized and are performing some observations (Gonsette et al, 2017;Hegymegi et al, 2017;Brunke et al, 2018). In the future, the automatic instruments would allow completely unattended magnetic observatory operation.…”

Vector Overhauser magnetometer POS-4: experience and prospects of application

“…AutoDIF and GyroDIF magnetometers have been developed and are already being used in observational practice, completely new devices with an automatic laser binding system to a remote reference point, a sensor rotation system and high-precision positioning [2,3]. In addition, there are DIflux based on standard non-magnetic theodolites, in which manual manipulations and visual reading of the scale readings are performed automatically [4]. Together with a scalar magnetometer, an automatic or semi-automatic system for measuring the full field vector is obtained.…”

The operator difference in absolute geomagnetic measurements

“…These elements are different in different coordinates: they may be expressed by X (north component), Y (eastern component) and Z (vertical component) in Cartesian coordinates; described by H (horizontal component), D (declination) and Z in cylindrical coordinates; or represented by D, I (inclination) and F (total field) in spherical coordinates. Nowadays, D, I and F are extensively adopted in most geomagnetic observatories around the world (Bitterly et al, 1984;Jankowski et al, 1996).…”

“…Usually, a set of at least three major instruments is used to measure the geomagnetic field at most observatories: a variometer, an absolute scalar magnetometer and a fluxgate theodolite (Gonsette et al, 2017a). The variometer can record the continuous variations of the geomagnetic field components; as the variometer usually works as a near-zero sensor, the recording is not an absolute value but a relative value, and its measurement range is usually within ±3000 nT, although it may be as great as ±4000 nT at high latitudes (Jankowski et al, 1996). Therefore, to obtain the continuous absolute geomagnetic field components of tens of thousands of nanotesla, a reference value or "baseline" should be added to these relative values.…”