Design Of Space Pose Test System For Segmented Mirror

Optical telescope plays a very important role in modern astronomical observation,and the angular resolution is determined by the aperture of telescopes.In the development of astronomical telescopes,astronomers continuously expand the aperture of the telescope to obtain stronger light collecting ability and higher angular resolution.However,the large weight of large-aperture telescope will lead to higher manufacturing cost,more support systems,transportation and installation difficulties,etc.These problems will directly lead to the deformation of the mirror structure and the decline of optical quality.In order to solve the above problems,It is an important trend to use segmented mirror active optics to conduct astronomical observation in the future.In the system of active optics,the wavefront sensor is used to detect the distorted wavefront,the wavefront restoration algorithm is used to compensate phase,and the relative pose of mirror is controlled by feedback system.Finally,each sub-mirror reaches the state of co-focus and co-phase.In this paper,an active optics experimental system based on three spherical mirrors is constructed,the detection and adjustment of the co-focus statement of segmented mirror is analyzed and studied in detail,Experimental results show that the Tip-tilt error of segmented mirror is better than 0.018"rms,the defocus error detected by S-H sensor is about 0.02?,the value of PV is better than 0.06? rms.The main research content and innovation of this paper include:1.Based on the S-H wavefront sensor,an optical test system for adjusting the relative position and pose of segmented mirror was constructed,and an adjustable truss supporting structure was designed based on the segmented mirror diameter and radius of curvature.2.Based on the active optical system of three segmented mirrors,the relationship between different error terms of sub-mirror and image quality of optical imaging is established by using the independent error term control method,and the range of error is described by simulation,which provide theoretical model for experimental detection and control.3.The corresponding relationship between the relative pose of three segmented mirrors and the actuator displacement of support system was established.The error transfer mechanism of sub-mirror spatial pose testing system was analyzed by S-H wavefront sensor,and successfully realized the relative pose correction of segmented mirror.4.The method of multi-frame sampling was used to correct the random error caused by air disturbance,and the wavefront information detected by the sensor was processed.The rationality and feasibility of the active co-focus experiment were verified by optical test system.