Research on the Posture Error of Cassegrain Optical System

This paper studies the calibration error of a spatial pointing measuring instrument with a Cassegrain optical system. The influences of the position and attitude error of the secondary mirror on the calibration accuracy were analyzed. We simulated the posture error of the secondary mirror in the Cassegrain-type optical system model. The simulated imaging quality of the calibration-grid star map and the calibration accuracy were presented. An experimental setup was constructed and the results consisted well with the simulation, which offered a reference in the assembling of the optical system to deliver high resolution images.