Development and Application of Proton Magnetometers in Marine Geomagnetic Diurnal Variation Observatories

The core function of a marine geomagnetic diurnal variation observatory is to continuously collect geomagnetic diurnal variation data at a fixed ocean depth, and the quality of such data directly determines the accuracy of marine magnetic survey results. In the absence of this data, marine magnetic data cannot be precisely corrected, which in turn leads to significant errors in data processing and ultimately impairs the reliability of magnetic exploration outcomes.

At present, the Sentinel series geomagnetic diurnal variation observatories based on the Overhauser principle are widely adopted in China's marine magnetic survey sector. This paper presents a novel marine geomagnetic testing system developed on the basis of proton precession magnetometers, which offers three key advantages: first, it fills the domestic gap in independently developed products for marine geomagnetic diurnal variation observatories; second, it is designed with 6,000-meter ocean-specific glass floats, making it suitable for deep-sea deployment requirements; third, it achieves substantial improvements in both instrument performance and operational stability. The findings of this study provide an important reference for the technological iteration and application expansion of marine geomagnetic diurnal variation observatories.