卡塞格林式星敏感器杂散光分析

Analysis of Stray Light in Cassegrain Star Sensor

卡塞格林系统是新型星敏感器的光学系统,具有口径大、体积小的优点,但外界杂散光对卡塞格林系统的影响很大。介绍了一种焦距为425mm,口径为102mm的卡塞格林系统,考虑轴外渐晕的影响,给出星敏感器主遮光罩以及主、次遮光罩的设计方法。这种设计方法相比于其他方法更加便捷和精准。并用Tracepro对系统进行杂散光分析。计算得到点源垂直照度透射比(Point Source Transmittance,PST)曲线。分析结果表明,当杂散光入射角大于临界角30°时,PST值小于10-8量级,满足系统使用要求。证明设计方法是可行的。

As a new form of optical structure in star sensor, the Cassegrain system maintains the advantages of large caliber,Small volume. This paper introduces The system had an effective focal length of 425 mm,an F-Number of F/4.3,and Diameter is 102mm. taking account of vignette of Cassegrain system. the design method of the outer baffle of the Cassegrain star sensor and primary and secondary lens hoods was given. This design approach is more convenient than other methods and precision.This paper also systematically analyzes the stray light with Tracepro and gets the Point Source Transmittance curve. The results show that the system meets the requirements of operation, when the light source off-axis angle is 30 degrees greater than the critical angle of incidence and the PST value is less than 10-8order of magnitude. Proven design approach is feasible.