The South Korean meteorological and environmental satellite GEO-KOMPSAT-2A (GK-2A) was launched into geostationary orbit at $128.2^{\circ}$ East on 4 December 2018. The space weather observation aboard GK-2A is performed by the Korea Space Environment Monitor. It consists of three particle detectors, a charging monitor and a four-sensor Service Oriented Spacecraft Magnetometer (SOSMAG). The magnetometer design aims for avoiding strict magnetic cleanliness requirements for the hosting spacecraft and an automated on-board correction of the dynamic stray fields which are generated by the spacecraft. This is achieved through the use of two science grade fluxgate sensors on an approximately one meter long boom and two additional magnetoresistance sensors mounted within the spacecraft body. This paper describes the instrument design, discusses the ground calibration methods and results, presents the post-launch correction and calibration achievements based on the data which were acquired during the first year in orbit and demonstrates the in-flight performance of SOSMAG with two science cases. The dynamic stray fields from the GK-2A spacecraft, which was built without specific magnetic cleanliness considerations, are reduced up to a maximum factor of 35. The magnitude of the largest remnant field from an active spacecraft disturber is 2.0 nT. Due to a daily shadowing of the SOSMAG boom, sensor intrinsic offset oscillations with a periodicity up to 60 minutes and peak-to-peak values up to 5 nT remain in the corrected data product. The comparison of the cleaned SOSMAG data with the Tsyganenko 2004 magnetic field model and the magnetic field data from the Magnetospheric Multiscale mission demonstrates that the offset error is less than the required 5 nT for all three components and that the drift of the offsets over 10 months is less than 7 nT. Future work will include a further reduction of the remaining artefacts in the final data product with the focus on lessening the temperature driven sensor oscillations with an epoch based identification and correction.

中文翻译：

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GEO-KOMPSAT-2A上的空间天气磁强计

韩国气象和环境卫星 GEO-KOMPSAT-2A（GK-2A）于 2018 年 12 月 4 日以 128.2 美元 ^{\circ}$ 东部发射到地球静止轨道。 GK-2A 上的空间天气观测由韩国航天局进行环境监测器。它由三个粒子探测器、一个充电监视器和一个四传感器服务导向航天器磁力计 (SOSMAG) 组成。磁力计的设计旨在避免对承载航天器的严格磁清洁度要求以及对航天器产生的动态杂散场进行自动机载校正。这是通过在大约一米长的吊臂上使用两个科学级磁通门传感器和安装在航天器体内的两个附加磁阻传感器来实现的。本文介绍了仪器设计，讨论了地面标定方法和结果，展示了基于在轨第一年获得的数据的发射后校正和标定成果，并通过两个科学案例展示了 SOSMAG 的飞行性能。GK-2A 航天器的动态杂散场在建造时没有考虑特定的磁清洁度，最大降低到 35。来自有源航天器干扰器的最大残余场的大小为 2.0 nT。由于 SOSMAG 繁荣的每日阴影，具有高达 60 分钟的周期性和高达 5 nT 的峰峰值的传感器固有偏移振荡保留在校正数据产品中。将清理后的 SOSMAG 数据与 Tsyganenko 2004 磁场模型以及来自磁层多尺度任务的磁场数据进行比较表明，所有三个分量的偏移误差都小于所需的 5 nT，并且偏移量的漂移超过 10 个月小于 7 nT。未来的工作将包括进一步减少最终数据产品中的剩余人工制品，重点是通过基于纪元的识别和校正来减少温度驱动的传感器振荡。