基于LCOS拼接的高精度高动态星模拟器设计

Design of high-precision and high-dynamics star simulators based on LCoS splicing

为了满足基于硅基液晶(LCOS)拼接的动态星模拟高精度与高动态的要求,对传统的拼接方法及修正方法进行了提升与优化。提出了将拼接系统的一块偏振分光棱镜(PBS)拆分为三块PBS的方法进行光学拼接。针对新的拼接结构,设计了长出瞳距,低畸变、消色差目镜系统,并进行了像质评价。重点阐述了像差对动态星模拟器星点位置的影响,详细论述了一种基于星模拟器光学系统位置像差的修正方法。结果表明:光学系统在12°×12°的视场范围内,相对畸变小于0.035%,且在奈奎斯特频率为v=60lp/mm时,全视场的MTF不小于0.8。新的拼接结构提高了两片LCOS显示对比度的一致性,加强了动态星模拟器在星敏感器动态测试中的可识别率。新的修正方法提高了星图的显示精度,经测试其星间角距误差小于7″,符合设计要求。

In order to meet the design requirements of high-precision and high-dynamics star simulators based on Liquid Crystal on Silicon（LCoS）splicing,the traditional splicing method and correction method were improved and optimized.A method of splitting apolarizing beam into three components was proposed to perform optical splicing.Based on the new splicing structure,a system with large papillary distance,low distortion,and an achromatic lens was designed,and the image quality was evaluated.The impact of aberration on the star position in dynamic star simulator was elaborated.A method to correct the position aberration based on the star simulator optical system was presented in details.Results show that,when an optical system is within a 12°×12°field of view,the relative distortion is less than 0.035%.In addition,when the Nyquist frequency is v= 60lp/mm,the fullfield of MTF is no less than 0.8.The new splicing structure can improve the consistency of the contrast ratio between the two pieces of LCoS,and enhance the recognition rate of dynamic star simulator in a dynamic test of the star sensor.The new correction method can improve the accuracy of a star map display.The angular distance error is less than 7？after testing,which is in good agreement with the design requirements.