太阳X-EUV成像望远镜的移动补偿系统

卫星帆板转动和自身颤动会导致太阳X射线-极紫外射线(X-EUV)成像望远镜的成像质量下降.用移动补偿系统控制相机的CCD驱动器,使势阱转移到相邻相的位置上,转移的方向正好与图像在传感器上移动方向一致,使得图像的每个光子在移动后仍然落入传感器的同一个势阱内,补偿由于帆板移动造成的图像偏移.CCD相移沿列的方向进行,而CCD的列平行于东西向.高精度太阳敏感器使用两轴直角坐标来定位太阳的位置.移动补偿系统只使用其中一个轴向数据,由于南北指向误差远远小于东西指向,因此不对南北指向补偿.该移动补偿系统利用高精度太阳敏感器构成半闭环控制系统,通过偏移CCD势阱来实现一个方向上的移动补偿.该方案可以在不增加成本的前提下,消除长时间曝光过程中的太阳的平移和帆板颤动对图像质量造成的影响,扩大动态观测范围. 

Jitter compensation system in solar X-EUV imaging telescope

The constant attitude control motions of the satellite often result in a platform that is not stable enough for mounting a high-resolution telescope.The jitter compensation system commands the CCD camera to shift one phase in the appropriate direction so that light from a point of the sun will continue to fall into the same CCD potential well.The CCD pixels phase shift along the detector's columns which are aligned parallel to east-west.The high accuracy sun sensor(HASS) uses two reticles,which one is for each axis to determine the relative position of the sun.Only one axis of the HASS data is used for motion compensation.The north-south pointing errors are significantly smaller then the east-west errors,and are not compensated for by the system.The jitter compensation system incorporates HASS that is used in a semi-closed loop system to shift the CCD potential wells in order to compensate for jitter in one dimension.The motion compensation system can remove the solar "drift" and the solar array jitter during the exposure,and the X-ray imaging performance will be improved.