Full Scan of The Best Focal Plane and Defocus Compensation for Space Camera
Tao Yu, Shuyan Xu, Kefei Song · Journal of Convergence Information Technology · 2013
Satellite launching and space environments cause the space camera defocus and make the focal plane outside the correct position range. In order to recognize the best focal plane, compensate the defocus correctly and guarantee the imaging quality, a method of full scan of the best focal plane and defocus compensation for space camera is proposed. Firstly, the method is divided into four stages which consist of preparation, full scan of focal plane, calculation of the best focal plane and adjustment of the best focal plane, and then the handling strategies of four stages are introduced in detail. Secondly, according to the method, the system structures and operating principles are introduced. Finally, the method is implemented and verificated. Experimental results show that the best focal plane is recognized with once full scanning of focal plane which needing 7.613s, the adjusting error of focal plane is less than 1.3 um, and the controlling results satisfy the requirements of system design index. The method provides a viable option for space camera under the conditions in which thermal control has faults or the camera’s best position of focal plane in-orbit has big deviation comparing to the best position scaled on the ground. Experiments prove that the method is feasible and effective and meets the requirements of defocus compensation.