基于边缘探测器的FMG稳像探测研究

全日面矢量磁像仪(Full-disk vector Magnetograph, FMG)是先进天基太阳天文台(Advanced Space-based Solar Observatory, ASO-S)卫星的主要载荷之一,为确保其可获得高空间分辨率的全日面太阳矢量磁场图, FMG配备了一套高精度稳像控制系统.FMG稳像系统采用边缘探测器对太阳入射倾斜偏差进行测量.基于FMG望远镜的太阳像仿真数据分析边缘探测器在太阳像能量分布下的输出特性以及太阳像尺寸与边缘探测器量程和灵敏度的关系.最后,在实验室搭建了一套验证系统对FMG稳像系统边缘探测器进行了相关性能验证实验.实验结果与理论分析一致,太阳像尺寸越大,边缘探测器量程越大,边缘探测器灵敏度越低.

Research on the Limb Sensor for the FMG Image Stabilization System

The Full-disk vector Magnetograph (FMG) is one of main payloads onboard the Advanced Space-based Solar Observatory (ASO-S). In order to measure the photospheric magnetic fields of the entire solar disk with high spatial resolution, FMG is equipped with an image-stabilization system with high accuracy. The limb sensor, one of the key components in the image-stabilization system, is used to detect the tip/tilt jitter. Based on the simulated data of the solar image on FMG, the measurement range and detection sensitivity of the limb sensor are theoretically analyzed and discussed while the size of the solar image varies. Finally, a suit of test system is set up in the lab to verify the performance of the limb sensor of the FMG image stabilization system. The experimental results are in good agreement with the theoretical analyses. The larger the size of the solar image, the greater the measurement range of the limb sensor, and the smaller the detection sensitivity of the limb sensor.