一种用于白天星敏感器的星点质心提取方法  

Method of star centroid extraction used in daytime star sensors

作　　者：胡晓东[1] 胡强[1] 雷兴[1] 魏青[1] 刘元正[1] 王继良[1] 

机构地区：[1]中国航空工业集团西安飞行自动控制研究所,西安710065

出　　处：《中国惯性技术学报》2014年第4期481-485,共5页Journal of Chinese Inertial Technology

基　　金：航空基金支撑项目(61901060301)资助课题

摘　　要：从星空图像中提取星点质心是星敏感器工作的重要基础,针对白天星敏感器所获取的星空图像噪声情况复杂的特点,应用高斯点分布函数为数学模型,提出了一种能够获取高精度星点质心位置的基于帧累加的星点质心提取方法。首先通过多帧迭代优化目标星像灰度,消除随机噪声的影响,提高信噪比,再利用平方加权质心法计算星点质心的位置,从星空图像中提取星点质心。仿真实验结果表明:该方法具有较强的抗干扰能力和稳定性,且质心提取精度随迭代帧数的增加而提高,当迭代次数达到100次时平均定位精度可达0.1像素,适用于低信噪比条件下的质心定位计算。该算法简单易行,运算量小,能够实现对视频图像信息的实时处理,且有效地提高质心的定位精度,可以满足白天星敏感器的应用需求。Star centroid extraction from object image in center of mass is the important basis of star sensor. For the star image obtained by daytime star sensors under complicated circumstances, a method of star centroid based on multiframe incremental is proposed by using the mathematical model of Gaussian point distribution function. By optimizing the multi-frame iterative image gray scale, the influence of random noise is eliminated and the signal-to-noise ratio is improved. Then, by utilizing weighted squared centroid algorithm, the star centroid is calculated to extract the star centroid from the star image. The simulation experimental results show that the method has excellent anti-interference ability and stability, and the centroid extraction precision is increased with the iteration frames. When the number of iterations reaches 100 times the extraction precision is increased with the increasing of iteration number and could approach 0.1 pixel, which is suitable for low signal-to-noise ratio. This algorithm is simple, less computations, and can achieve real-time processing of video image information. It can effectively improve the positioning precision, and satisfy the application requirements of daytime star sensors.

关 键 词：图像处理 质心提取 亚像素定位 帧累加 信噪比 

分 类 号：O436[机械工程—光学工程]