为了能够准确测量同轴三反相机中次镜的倾斜量变化, 提出一种新的角度测量方法, 即用大口径干涉仪与经纬仪相结合进行测量。以主镜为测量基准, 两镜相对倾角较小时, 使用大口径干涉仪同时测量两镜的干涉条纹, 相对倾斜角度过大时次镜无干涉条纹, 加入一台经纬仪分别自准直于干涉仪和次镜, 间接测量两镜相对夹角。通过模拟计算与实验验证表明, 对于次镜组件倾角测量误差可以控制在0.5″以内。结果表明, 该检测方法具有通用性强, 测量精度高等特点, 克服了传统检测方法测量精度不足的问题。

In order to accurately measure the tilt amount of the secondary mirror in coaxial three reverse camera, a new method for measuring angle was proposed , which used the combination of a large-aperture interferometer and a theodolite. Taking the primary mirror as the measuring reference ,while the included angle of two mirrors was small, the large-aperture interferemeter was used to measure the interference fringes of two mirror simultaneously . While the included angle was too large and the secondary mirror did not involve the interference fringes , a theodolite was added for autocollimation from the interferometer and secondary mirror to measure the included angle of two mirrors indirectly. Examples and analog computations show that for the secondary mirror tilt angle, its measuring error can be within 0.5″. The results indicate that the measurement method has the characteristics of strong universality and high precision,and can overcome the problem of insufficient measurement accuracy of traditional detection method.