航天相机快速定焦的关键参数  

The Key Parameters for Rapid Focusing of Space Camera

作　　者：钟卉[1] 郭悦[1] 贾馨[1] ZHONG Hui GUO Yue JIA Xin(Beijing Institute of Space Mechanics ＆ Electricity, Beijing 100094, China)

机构地区：[1]北京空间机电研究所,北京100094

出　　处：《航天返回与遥感》2017年第4期82-89,共8页Spacecraft Recovery & Remote Sensing

摘　　要：在航天相机的装调中,焦平面的位置是影响航天相机的成像质量的关键因素,如何准确且快速地在实验室环境中预置相机的焦平面是体现光学装调水平的重要指标。通过深入研究定焦原理,建立光学模型进行理论推导和光学仿真,发现了定焦过程中平行光管焦面的离焦量与相机焦面组件的偏移量之间的定量关系,提出了离焦放大率的定义并将其作为定焦关键参数进行定焦的方法,克服了传统定焦方法中应用恒定值的轴向放大率定焦而需要反复迭代的缺陷。实验结果表明:装调实例的装调效率较传统装调方法提高了约3倍。由于对焦平面的精度要求主要取决于镜头的焦深大小,因此大相对孔径短焦的相机对焦面偏移量更为敏感,使用该关键参数指导装调,可以快速准确地确定最佳焦面位置,降低反复拆装焦面组件的风险,尤其适用于短焦相机的定焦,能大大节省工作量,提高装调效率。同时,由于离焦放大率和平行光管焦面的离焦量成线性关系,也有利于进行多个具有相同光学参数的相机的快速定焦。Focusing is a very important part in the alignment of space camera.How to place the focal plane of the camera accurately and quickly in laboratory environment is an important index of optical alignment.Based on the study of the principle of focusing and the optical modal,an efficient way of focusing based on defocusing magnification is proposed through theoretical analysis and optical simulation.This method overcomes the drawback of the traditional way of focusing,which takes the longitudinal magnification as a fix value and needs repeated iteration.Experimental results show that the efficiency of the adjustable instance is increased by about 3 times than traditional method.Because the accuracy of the position of the focal plane mainly depends on the focal depth of the lens,the short focal length lens with large relative aperture is more sensitive to the offset of the focal plane.The defocusing magnification is helpful to locate the optimal position of focal plane quickly and accurately.The focusing workload could be greatly reduced and the risk of repeated disassembly focal plane is decreased.This method is perfect for short focal length lens.In addition,because of the linear relationship between the defocusing amount and defocusing magnification,multiple cameras which have the same optical parameters could be rapid focused.

关 键 词：快速定焦 轴向放大率 航天相机 

分 类 号：TP705[自动化与计算机技术—检测技术与自动化装置]