Absolute magnetic measurements require the vertical and the geographic north as reference directions. We present here a novel system able to measure the direction of the magnetic field and of the vertical and true north. A design of a north seeker is proposed that takes into account sensor bias as well as misalignment errors. Different methods are derived from this model and measurement results are presented. A measurement test at high latitude is also shown.

In this paper, we give some background on calibration and verification of our automatic DI-flux instrument and then compare the automatic absolute magnetic measurements with the human-made and discuss the advantages and disadvantages of automatic measurements.

We present a novel method for calibrating magnetic observatories. We show how magnetometer baselines can highlight a possible calibration error. We also provide a method based on high-frequency automatic absolute measurements. This method determines a transformation matrix for correcting raw data suffering from scale factor and orientation errors. We finally present a practical case where covered data have been successfully compared to those coming from a reference magnetometer.

Commercial solutions for an automated DI-flux are practically reduced to the AutoDIF and the GyroDIF. We analyze the pros and cons of both in terms of suitability at the Livingston Island geomagnetic observatory, Antarctica. We conclude that the GyroDIF is more suitable for harsh conditions due to its simpler infrastructure. We also show the instrument housing design and its control electronics. Our experiences can benefit the geomagnetic community, which often faces similar challenges.

In geomagnetism, geodesy and in general disciplines requiring orientation on Earth, accurately finding the direction of true north is a challenge. This paper describes a method to do so using a traditional theodolite and the proposed apparatus: an electro-optical add-on. The details of the concepts, design and operation of the add-on are explained.