高轨空间碎片图像定心算法的比较  

A comparison of digital centering algorithms for high Earth orbital space debris

作　　者：孙荣煜[1,2] 赵长印[1,2] 朱听雷 鹿瑶[1,2,3] 

机构地区：[1]中国科学院紫金山天文台,南京210008 [2]中国科学院空间目标与碎片观测重点实验室,南京210008 [3]中国科学院大学,北京100049

出　　处：《中国科学：物理学、力学、天文学》2014年第6期656-664,共9页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金资助项目(批准号:11033009;11125315)

摘　　要：数字图像定心算法的使用对天体测量的最终精度有着重要的影响.高轨空间碎片的光学观测中,受观测方法影响,目标星像存在较严重的退化,影响了星像质心的计算.针对常用的四种图像定心算法:修正矩方法、一维Gauss拟合、二维Gauss拟合和中值法,利用空间碎片的实测图像进行了实验.通过比较天文定位结果与精密星历参考值,分析了不同方法的计算精度,以及不同阈值对结果的影响.实验表明,对于高轨空间碎片的退化星像,中值法计算的赤经位置精度最好,其余三种方法计算的赤纬精度较高,对于Gauss方法,无阈值能获得比较好的计算精度.The applications of digital centering algorithms have a major impact on precise astrometry. In optical observations of space debris, due to the observing strategies and methods, the image degradation is distinct, which affects the centroid computing of CCD images. Adopting the four widely-used centering algorithms, including modified moment, one-dimensional Gaussian fit, two-dimensional Gaussian fit and median, tests are made on raw CCD images of space debris. With the observation positions obtained by astronomical calibration and the reference ones from ephemeris, the precision of variable algorithms and the influence of different threshold settings are acquired. The results indicate that the median reveals performs best for right ascension coordinates and others reveals a better results for declination coordinates. For Gaussian fit, no threshold may improve the centering precision.

关 键 词：空间碎片 天体测量 图像处理 

分 类 号：P123.3[天文地球—天体测量]