First in-orbit results of the vector magnetic field measurement of the High Precision Magnetometer onboard the China Seismo-Electromagnetic Satellite

Abstract

The High Precision Magnetometer (HPM) is one of the main payloads onboard the China Seismo-Electromagnetic Satellite (CSES). The HPM consists of two Fluxgate Magnetometers (FGM) and the Coupled Dark State Magnetometer (CDSM), and measures the magnetic field from DC to 15 Hz. The FGMs measure the vector components of the magnetic field; while the CDSM detects the magnitude of the magnetic field with higher accuracy, which can be used to calibrate the linear parameters of the FGM. In this paper, brief descriptions of measurement principles and performances of the HPM, ground, and in-orbit calibration results of the FGMs are presented, including the thermal drift and magnetic interferences from the satellite. The HPM in-orbit vector data calibration includes two steps: sensor non-linearity corrections based on on-ground calibration and fluxgate linear parameter calibration based on the CDSM measurements. The calibration results show a reasonably good stability of the linear parameters over time. The difference between the field magnitude calculated from the calibrated FGM components and the magnitude directly measured by the CDSM is just 0.5 nT (1σ) when the linear parameters are fitted separately for the day-and the night-side. Satellite disturbances have been analyzed including soft and hard remanence as well as magnetization of the magnetic torquer, radiation from the Tri-Band Beacon, and interferences from the rotation of the solar wing. A comparison shows consistency between the HPM and SWARM magnetic field data. Observation examples are introduced in the paper, which show that HPM data can be used to survey the global geomagnetic field and monitor the magnetic field disturbances in the ionosphere.

Initial scalar lithospheric magnetic anomaly map of China and surrounding regions derived from CSES satellite data

“…On-ground prelaunch test showed that the remaining magnetic interference of the platform at the center of the CDSM sensor is lower than 0.33 nT [24]. After temperature correction, absolute value correction and elimination of platform interference, the accuracy of the magnetic field intensity observations was estimated to be within 0.5 nT [25,26].…”

CSES High Precision Magnetometer Data Products and Example Study of an Intense Geomagnetic Storm

“…(2018), B. Zhou et al. (2018, 2019), and Pollinger et al. (2020).…”

On the Magnetosphere‐Ionosphere Coupling During the May 2021 Geomagnetic Storm

“…Figure 5a shows CSES (China Seismo Electromagnetic Satellite) (Shen et al., 2018) magnetic observations (Zhou et al., 2019) along the North‐South ( B N ‐ left panel), East‐West ( B E —Central panel) and Vertical ( B C —Right panel) direction, respectively, from 11 May to 14 May 2021, after removing the internal and crustal contributions to the Earth's magnetic field by use of the CHAOS‐7 model (Finlay et al., 2020). CSES is a Chinese satellite launched on 2 February 2018, hosting a fluxgate magnetometer, two Langmuir probes, an electric field detector and two particle detectors out of eight payloads.…”