标题： 先进天基太阳天文台（ASO-S）上全盘磁像仪（FMG）的磁场标定 显示英文标题

标题： The Magnetic Field Calibration of the Full-Disk Magnetograph onboard the Advanced Space based Solar Observatory (ASO-S/FMG)

摘要： 全日面磁像仪是先进太阳观测卫星（ASO-S/FMG）上的主要科学载荷，通过Stokes参数观测来测量矢量磁场。 磁场值的准确性是检验FMG磁场测量质量的一个重要方面。 根据FMG的设计，弱场近似下的线性定标方法是磁场定标的主要方案。 然而，航天器轨道速度会影响观测光谱线的位置，进而导致偏振信号强度的变化。 因此，磁场受到航天器轨道速度的调制。 本文通过FMG与HMI（太阳动力学天文台上的日震与磁成像仪）之间的交叉定标，研究了航天器轨道速度对磁场定标系数的影响。 通过比较考虑航天器轨道速度辅助参考的FMG和HMI磁场，获得了依赖于轨道速度的修正线性定标系数。 用修正后的定标系数校正的FMG磁场将更加准确，并适合用于科学研究。 显示英文摘要

摘要： The Full-disk magnetograph is a main scientific payload onboard the Advanced Space based Solar Observatory (ASO-S/FMG) that through Stokes parameter observation to measures the vector magnetic field. The accuracy of magnetic-field values is an important aspect of checking the quality of the FMG magnetic-field measurement. According to the design of the FMG, the linear calibration method under the weak-field approximation is the preferred scheme for magnetic-field calibration. However, the spacecraft orbital velocity can affect the position of observed spectral lines, then result in a change of the polarization-signal strength. Thus, the magnetic field is modulated by the orbit velocity of the spacecraft. In this article, through cross calibration between FMG and HMI (Helioseismic and Magnetic Imager onboard the Solar Dynamic Observatory), the effects of spacecraft orbital velocity on the coefficient of magnetic-field calibration are investigated. By comparing the magnetic field of FMG and HMI with spacecraft orbital velocity as an auxiliary reference, the revised linear-calibration coefficients that depend on spacecraft orbital velocity are obtained. Magnetic field of FMG corrected by the revised calibration coefficients removing the effect of spacecraft orbital velocity will be more accurate and suitable for scientific research.