星点中心高精度质心定位算法  

High-Accuracy Centroid Algorithm of Star Points

作　　者：原玉磊[1] 郑勇[1] 杜兰[1] 

机构地区：[1]信息工程大学测绘学院,河南郑州450052

出　　处：《测绘科学技术学报》2012年第2期122-126,共5页Journal of Geomatics Science and Technology

基　　金：国家自然科学基金项目(10878025)

摘　　要：质心法是星点中心计算的常用算法。为提高质心法的精度,对其进行了深入研究。在分析3种质心法形式的基础上提出了质心法的统一模型,并指出模型中的参数阈值T和灰度加权指数k对于质心法的最终精度有很大影响。采用模拟星点和实测星点对质心法精度与参数T和k的关系进行了分析,得出了相同的结论。随着T和k的增加,质心法精度先升高后降低,存在极值点;在极值点处,T为背景灰度,k为2.0;为保证信息量,T不能过高,但增加k可以获得增加T同样的精度效果;通过调节T和k,可以使质心法精度提高25%以上。Centroid algorithm is common used in star point centers calculation.An in-depth study was made to improve the accuracy of the centroid algorithm.The universal model of centroid algorithm was proposed based on 3 different formulae of centroid algorithm.And two parameters in this model the threshold T and the exponent of gray-weighted k could greatly influence the accuracy of centroid algorithm.The relationship between the accuracy of centroid algorithm and the parameters T and k was analyzed with both simulated and actual star images,and the same conclusions were obtained.When T and k increasing from 0,the centroid error went down in first and then up.With T and k being background gray and 2.0 respectively,the minimum centroid error was obtained.T cannot be set too big to reserve enough information,but the same high-accuracy purpose could be reached through increasing k.The accuracy could increase more than 25% using the appropriate T and k.

关 键 词：星点中心 质心法 统一模型 阈值 灰度加权 

分 类 号：P228[天文地球—大地测量学与测量工程]