太阳米粒组织目标特性对望远镜相关跟踪系统的影响

Influence of Solar Granulation Characteristics on Correlation Tracker of Space Solar Telescope

研究太阳目标特性对太阳望远镜相关跟踪图像稳定系统的影响,采用Hinode太阳光学望远镜的观测数据,对以2min为时间间隔采样的5幅太阳米粒组织图像进行相关计算.针对国家天文台正在研制的空间太阳望远镜(SST)主光学望远镜(MOT)相关跟踪图像稳定系统,分析了太阳米粒组织随时间衍化对相关跟踪系统图像移动计算精度的影响以及米粒组织动态变化对望远镜曝光时间的影响.仿真结果表明,更换参考图像时间不能大于2min,并且在保证算法实时性的情况下,选用参考图像的尺寸与相关跟踪系统定位精度成正比.

To research the influence of solar characteristics on space solar telescope（SST）＇s correlation tracker,the observed data of the solar optical telescope（SOT） aboard the Hinode satellite was used,the correlation calculation for five images with sampling interval time of 2 minutes was implemented,and the evolution of solar granulation with time was found.For the correlation tracker image stabilization system of SST being developed in the National Astronomical Observatories,Chinese Academy of Sciences,the influences of granulation evolution on calculation accuracy of image movement of the correlation tracker system and telescope exposure time were analyzed.The results indicate that the time to replace the reference image should not longer than 2 minutes.By comparing the correlation coefficient of the images with different sizes,it is found that using larger reference images could improve the positioning accuracy of the correlation tracking system.This research could provide some advices for the development of the correlation tracker system of SST.