The analysis of baselines for different fluxgate theodolites of geomagnetic observatories

Abstract

This paper analyzes the baselines of 8 geomagnetic observatories in the China Magnetic Observatory Network. The baselines of similar variometers were measured by two different fluxgate theodolites during the same time period. The results demonstrate that two baseline values measured by two independent absolute instruments did not completely coincide for the same components even though the differences between pillars and instruments had been corrected. The baseline values were still not smooth, and there existed obvious wave variations for the D, H, and Z components. The causes of this inconsistency might be the differences between the two pillars installed with two independent absolute instruments and instrument problems in some of the observatories. In other words, the difference in the geomagnetic field between two points in the same observational area is not a constant.