应用天文研究组知识库

1m新真空太阳望远镜在连续观测时，太阳辐射导致的温度变化使其光机结构产生热变形，主要表现为焦点实时变化，产生离焦像差，影响观测数据的质量。为解决这一问题，基于焦点扫描探测算法并结合望远镜的系统结构设计了一个焦点探测系统。首先分析了1m新真空太阳望远镜焦点变化并设计了焦点探测系统的总体结构；然后进行软硬件系统的详细设计和实现，重点对系统的重复精度和焦点探测精度进行测试，表明系统能满足望远镜的焦点探测精度要求；最后给出了焦点探测系统在望远镜上3个月的运行结果：系统能实时监测望远镜的焦点变化，根据焦点的变化量进行调焦，能得到优先的观测数据。

During the continuous observation in 1-meter New Vacuum Solar Telescope，the solar radiation changes the temperature of the telescope surface，resulting in the thermal deformation on the optical and mechanical structure of the telescope． This results in real-time variation of the telescope focus，which produces the defocus aberration in the observation data． Thus it is of importance for the observation to detect and correct the defocus． This paper describes the design and implementation of a defocus-detect system，based on the optical and mechanical structure of this telescope，and the scanning defocus-detect algorithm is used． Firstly， the variation of defocus causing by temperature change is analyzed and the overall design of the defocus-detect system is given． Then the detailed design and implementation of its hardware and software system is described，subsequently the test results of the repeat position precision and detect error show that this defocus-detect system meets the requirement of the observation． At the last part of this paper，the performance of this system on the telescope with 3-months continuous observation is displayed． And it shows that this system can detect and correct the real-time variation of the telescope defocus，and has a positive influence on the quality of the observation data．