Absolute magnetic measurements, methods, and instrumentation

Abstract

Summary Absolute geomagnetic measurement is an accurate determination of magnetic declination D and inclination I at a given location and time on the Earth. These quantities are essential to monitor the long-term baseline changes and calibration parameters of variometers in observatories and repeat station surveys. Methods and the instrumentation are tightly coupled to this kind of measurement. Since all the relevant methods based on the usage of a classical theodolite equipped with one-axis magnetometer known as declination inclination magnetometer (DIM). DIMs have several difficulties. Measurement process is carried out manually. Difficult to use DIM for I observation in equatorial region because the microscope cannot be read in nearly vertical position even with diagonal eyepiece. The computation of magnetic meridian is calculated by the operator during the measurements. To overcome this problem at MinGeo company we developed a cable-less, digital, non-magnetic DIM instrument, named as FluxSet Declination Inclination Digital Station (DS), which was designed to facilitate the absolute magnetic measurements. The aim of this presentation to asses the accuracy and precision of the absolute magnetic measurements, which were measured by some reference DIMs and DS instrument using null and this new proposed method.