第22卷第11期 2014年11月
文章编号
1004-924X(2014)11-3074-07
光学精密工程
Optics and Precision Engineering
Vol.22No.11
Nov.2014
基于星图识别的空间目标快速天文定位
张磊，，何听，魏仲慧，郭敬明
（中国科学院长春光学精密机械与物理研究所，吉林长春130033）
摘要：本文提出了一种基于星图识别的快速定位算法用于加快空间目标的定位速度和提高定位精度，首先，采集当前图像的拍摄时刻和编码器角度值，运用天文定位三角形建立的地平坐标系与地馈坐标系的转换关系，计算设备视轴在地惯坐标系中的指向；然后，由视轴指向所在的天区，提取出该天区所有的导航星与特征库；结合有初始指向的局部星图识别建立图像中背景恒量星像与导航星的对应关系。最后，根据小孔成像原理，通过已识别的背景参考恒星以角距离匹配的方式对空间目标进行相对定位。对4×4"视场、分辨率为1024×1024的实际图像的试验结果表明，因定位过程中引人了天文定位三角形模型和星图识别，大大加快了空间目标的定位速度，初始定位速度平均约为400ms;又因采用相对定
位的方式排除了影响定位精度的因素，空间目标的定位精度优于2°。关键调：空间目标；星图识刻；天文定位；最小二乘法
中图分类号：V556；TP391
文献标识码：A
doi;10,3788/OPE.20142211.3074
Fastcelestialpositioningforspaceobjectsbasedonstaridentification
ZHANG Lei', HE Xin, WEI Zhong-hui, GUO Jing-ming(Changchun Institute of Opties,FineMechanicsand Physics ChineseAcademyof Sciences,Changchun 130033,China)
*Correspondingauthor，E-mail:zlrrl@tom.com
Abstract: A fast celestial positioning method based on star identification was proposed to improve positioning accuracy and reduce positioning time. Firstly, the photographic time and angular values were acquired, and the pointing direction of boresight in geocentric inertial coordinate system was calculated by transforming a horizontal coordinate system into a geocentric inertial coordinate system with an astronomical triangle model. Then, all navigation stars and patterns in the area that the boresight pointed were extracted, and the corresponding relationship between stars in images and in the sky was established by a region star match. Finally, the celestial positioning for a space object was completed relatively by reference stars in a background according to pinhole imaging model. The experiment for an imagewith a FOV of 4°X4°and a resolution of 1 o24X1 o24shows that thecourse of the positioning for the space object has been greatly accelerated due to the introduction of astronomical triangle model and region star match, and the positioning speed is approximately 4oo ms. On the other hand, the positing accuracy of a space target is better than 2" because the relative positioning method eliminates a lot of factors effecting the accuracy.
Key words: space-object; star identification; celestial positioning; least square
收稿日期：2013-11-13修订日期：2014-01-13，
基金项目：中国科学院知识创新工程领域前沿项目