1m红外太阳望远镜镜面位置误差致光轴偏移分析

摘要

Taking the 1 m new vacuum solar telescope(NVST) of the Yunnan Observatories as an example, this paper analyzed quantitatively the maladjustment of the optical imaging components(such as the primary mirror and the secondary mirror) on the optical axis deviation. The influence of the decentration or tilt of the secondary mirror on the optical axis and the field of view is discussed and the allowable deviation of the optical axis of the NVST is analyzed under the combination of the two factors. We noticed that decentration and tilt can sometimes compensate each other, mitigating damage of telescope imaging quality. When the limit offset reaches 4.5 mm and 0.392, the optical axis offset is 0.392, which is far larger than the design field of view of telescope. It is concluded that the optical axis stability is a necessary index to test the results of large telescope alignment.%定量分析了云南天文台1 m新真空红外太阳望远镜（简称NVST），副镜失调误差对主光轴偏移的影响。以格里高利双反射系统为例，在综合像质达到衍射极限的前提下，分析了副镜的离心和倾斜误差分别对光轴带来的影响，然后分析了两种因素综合作用下，NVST光轴的可能的偏移量。模拟结果表明当副镜离心和倾斜单独存在且分别小于0.121 mm和0.01时，像质可达衍射限。当副镜离心与倾斜同时存在且耦合，离心4.5 mm倾斜0.392时，像质仍可达到衍射限，光轴已偏移0.392，远大于望远镜设计视场0.083。因此光轴稳定性是大型望远镜装调的一项必检指标。