空间相机平台时间同步误差分析与改进研究  

Research on Analysis and Improvement of Platform Time Synchronization Errors of Space Camera

作　　者：魏君成[1,2] 武星星[1] 刘金国[1] 周怀得[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,长春130033 [2]长春理工大学,长春130022

出　　处：《计算机测量与控制》2014年第4期1294-1296,共3页Computer Measurement &Control

基　　金：国家自然科学基金项目(61108066);吉林省科技发展计划资助项目(20130101028jc)

摘　　要：时间同步误差是影响空间相机平面定位精度的重要因素,为了提高系统的可靠性,在星基导航授时失效时需要使用航天器的平台时间进行时间同步;详述了使用航天器平台时间进行时间同步的原理,在分析使用航天器平台时间进行时间同步时相机时间同步误差的各种影响因素的基础上,建立了平台时间同步误差模型;提出了减小航天器数管计算机和相机主控制器对平台时标转发延迟误差、采用低频差晶振、减小关中断时间、减小中断服务程序执行时间、缩短行同步计数器的查询周期等软件和硬件改进方法;最后通过实验对比了使用GPS高精度时间和使用航天器平台时间进行同步时所能达到的时间同步精度;实验结果表明,经过改进后使用航天器平台时间进行时间同步时,相机时间同步误差绝对值≤3.34ms,满足技术指标要求。Time synchronization errors have important influences on location precision of space camera. In order to improve reliability of the system, spacecraft platform time should be used as satellite based navigation time synchronization doesn~ t work. Principle of time syn chronization using platform time was detailed. Factors that influence time synchronization errors of space camera using platform time were an- alyzed and improved methods were put forward. The improved methods include reducing transmitting delays of platform time flag by space- craft data managing computer and the primary camera controller, adopting precise crystal oscillator, reducing time of disabling interrupts, de creasing execution time of interrupt service routines and shortening inquiry cycles of row synchronization counters. Finally time synchroniza- tion precision using GPS high precision time and time synchronization precision using spacecraft platform time were compared through experi- ments. Results of experiments indicated that as spacecraft platform time was used for time synchronization, time synchronization errors were no more than 3.34 ms and met the demand of qualification.

关 键 词：空间相机 平台时间 时间同步 

分 类 号：TP336[自动化与计算机技术—计算机系统结构]