本文根据衍射光学理论和几何光学理论, 利用已得到的拼接望远镜的理论解析表达式和建立的数值仿真模型, 对拼接望远镜光学系统的远场特性进行了分析计算, 包括系统的理论衍射光斑直径、点扩散函数、斯特列尔比以及光学传递函数等。并根据仿真模型分析了拼接主镜中分块镜平移误差和倾斜误差对拼接望远镜系统远场的影响。分析结果表明, 拼接主镜的平移误差和倾斜误差都影响系统的点扩散函数、斯特列尔比和光学传递函数, 并使远场成像模糊; 其中分块镜倾斜误差会额外引入平移量, 如果补偿掉平移量对望远镜系统的远场性能有很大提高。

Based on optical diffraction theory and geometry optical, such as diameter of diffraction spot, Point Spread Function (PSF), Strehl Ratio, Modulation Transfer Function (MTF), etc., were analyzed using theoretical analytical expression and numerical simulation of segmented telescope in the paper. The effect of sub-segmented mirrors’ Piston error and Tip-tilt error on far-field was calculated. The results show that both Piston error and tip-tilt error affect system’s Strehl Ratio and MTF and blurred far field image. Tip-title error can cause the generation of piston error. The compensation for the Piston error would highly improve the far field imaging characteristics.