Optimal analysis for segmented mirror capture and alignment in spaceoptics system

摘要

A great deal segmented mirror errors consisting of piston and tip-tilt exist when space large aperture segmented optics system deploys. These errors will result in the departure of segmented mirrors images from the view. For that, proper scanning function should be adopted to control actuators rotating the segmented mirror, so that the images of segmented mirror can be put into the view and placed in the ideal position. In my paper, the scanning functions such as screw-type, rose-type, and helianthus-type and so on are analyzed and discussed. And the optimal scanning function principle based on capturing images by the fastest velocity is put forward. After capturing, each outer segmented mirror should be brought back into alignment with the central segment. In my paper, the central and outer segments with surface errors have the different figure, a new way to control the alignment accuracy is present, which can decrease the bad effects from mirror surface and position errors effectively. As a sample, a simulation experiment is carried to study the characteristics of different scanning functions and the effects of mirror surface and position errors on alignment accuracy. In simulation experiment, the piston and tip-tilt errors scale and the ideal position of segmented mirror are given, the capture and alignment process is realized by utilizing the improved optics design software ZEMAX, the optimal scanning function and the alignment accuracy is determined.