High precision magnetometer for geomagnetic exploration onboard of the China Seismo-Electromagnetic Satellite

The China Seismo-Electromagnetic Satellite (CSES) is the first platform of China's earthquake observation system in space and the first satellite of China's geophysical field detection missions. The high precision magnetometer (HPM), which contains two fluxgate sensors and a coupled dark state magnetometer (CDSM), measures the vector of the Earth's magnetic field with a bandwidth from DC to 15 Hz. The two fluxgate sensors are in a gradiometer configuration in order to reduce satellite interferences. Additionally, the CDSM sensor measures the scalar value of the magnetic field with higher accuracy and stability. Several data processing and calibration methods have been prepared to get accurate vector magnetic field data. This includes the calibration of each of the three sensors, the absolute vector correction algorithm, the spacecraft magnetic interference elimination and the coordinate transformation method. Also the instrument performances based on ground calibration activities are shown in this article.