通过理论及数值仿真分析拼接式望远镜中子镜的平移误差、倾斜误差和子镜间隙对系统成像质量的影响。理论推导了存在不同误差时拼接式望远镜点扩散函数(PSF)及远场光斑斯特列尔比(S.R,用RS.R 表示)的表达式,建立了三种误差对拼接式望远镜PSF 和远场光斑RS.R 的影响的仿真模型,分析了三种误差分别对拼接式望远镜成像质量的影响。分析结果表明:当子镜存在平移误差时,拼接式望远镜成像质量随着子镜平移误差标准差δ 增加逐渐变差,当δ<λ/20 时,拼接式望远镜远场光斑RS.R>0.9;当子镜存在倾斜误时,拼接式望远镜成像质量随着波前相位均方差(RMS,用erms 表示)增加逐渐变差,当erms<0.3 rad 时,拼接式望远镜远场光斑RS.R>0.9;当子镜间存在间隙时,拼接式望远镜成像质量随着间隙因子w 增大逐渐变差,当w<0.025 时,拼接望远镜远场光斑RS.R>0.9。

The impact of segmented telescope piston error, tip-tilt error and gap on image quality by theoretical and numerical simulation was analyzed. Different error segmented telescope Point-spread-function (PSF) and the far-field spot Strehl Ratio (S.R) expression were derived theoretically. Then, set up simulation model about three kinds of error effect on segmented telescope PSF and far-field spot S.R, and analyzed three kinds of error influence on imaging quality of splicing telescope. Analysis results show that: when the segmented mirror exist piston error, segmented telescope image quality with piston error standard deviation δ increasing gradually becomes poor; when δ < λ/20 segmented telescope, the far field spot RS.R >0.9;when the segmented mirror exist tip-tilt error, the segmented telescope imaging quality with the wavefront phase RMS increases gradually worse, when eRMS<0.3 rad, the far-field spot of the segmented telescope RS.R>0.9; when the segmented mirror exist gap, its imaging quality with the gap factor w increases gradually becomes poor, and when w<0.025, a segmented telescope far-field spot RS.R>0.9.