Bai Yang, Li Jianlin, Zha Rongwei, Wang Ying, Lei Guangzhi
Institute of Photonics and Photon-Technology, National Key Laboratory of Photoelectric Technology and Functional Materials (Culture Base), Northwest University, Xi'an 710127, China.
Space Optical Technology Research Department, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China.
Sensors (Basel). 2020 Sep 25;20(19):5501. doi: 10.3390/s20195501.
The optical system is one of the core components for star sensors, whose imaging quality directly influences the performance of star sensors for star detection, thereby determining the attitude control accuracy of spacecrafts. Here, we report a new type of optical system with a catadioptric structure and a large entrance pupil diameter for a 15-magnitude star sensor. It consists of an improved Cassegrain system (R-C system), an aperture correction spherical lens group and a field of view correction spherical lens group. By embedding the secondary mirror of the R-C system into the output surface of the negative spherical lens of the aperture correction spherical lens group, the blocking of incident light is eliminated from the secondary mirror holder. After the structure optimization, the catadioptric optical system (COS) had a spectral range of 450 nm-950 nm, an entrance pupil diameter of 250 mm, a half-diagonal field of view of 1.4° and a focal length of 390 mm. By using theoretical calculations and experimental measurements, it was verified that the COS, with the ability to correct astigmatism, lateral color and distortion, can fulfill the detection of 15-magnitude dark stars.
光学系统是星敏感器的核心部件之一，其成像质量直接影响星敏感器的星探测性能，进而决定航天器的姿态控制精度。在此，我们报道了一种用于15等星敏感器的新型折反射式光学系统，该系统具有折反射结构和较大的入瞳直径。它由改进的卡塞格伦系统（R-C系统）、孔径校正球面透镜组和视场校正球面透镜组组成。通过将R-C系统的副镜嵌入孔径校正球面透镜组负球面透镜的出射面，消除了副镜支架对入射光的遮挡。经过结构优化后，该折反射光学系统（COS）的光谱范围为450 nm - 950 nm，入瞳直径为250 mm，半对角线视场为1.4°，焦距为390 mm。通过理论计算和实验测量验证，该COS能够校正像散、横向色差和畸变，可实现15等暗星的探测。
