Measurement and analysis of earth´s magnetic field based on low-magnetic field standards

The Cheongyang (CYG) observatory has been built to measure earth´s magnetic field and to study prediction of earthquake and space weather. The equipments of the CYG observatory are a 3-axis fluxgate magnetometer, an overhauser effect proton magnetometer, a declination/inclination magnetometer and a data logger. A Cs-⁴He atomic magnetic resonance magnetometer was used to correct the measured data obtained by the proton magnetometer. All the measurement equipments were calibrated using magnetic field standard system maintained at KRISS. The Measurement results show a variation of the baselines less than 5 nT within one year, which is the most critical requirement criteria for joining the INTERMAGNET (International Real-time Magnetic Observatory Network).