摘要
恒星质心的确定对天文导航起着至关重要的作用,白天拍摄的近红外恒星图像,由于极强的天空背景,信噪比极低,恒星目标基本被淹没在背景中,给质心定位带来极大的麻烦。传统的一阶矩法、加权质心法计算简单但是误差较大,尤其在低信噪比条件下。高斯曲面拟合法虽然定位精度较高,但计算复杂。分析恒星成像时能量的分布,提出基于多步长最小能量差的质心定位方法,该方法使用线性叠加缩小质心区域,利用恒星能量分布的对称性,基于试探性质心寻找,求取能量差值的最小值进行质心位置计算,并采用模拟星图验证比较,实验表明,该方法定位精度可达0.001 pixel,对低信噪比条件下的质心计算具有较好的效果。
We analyzed the energy distribution in stellar image,and proposed a star target centroid location method based on multi-step minimum energy difference.This method uses the linear superposition to narrow down the centroid area,tries to find the centroid by using the symmetry of the stellar energy distribution,and determines the centroid location when the minimum energy difference appears.And it is compared with the simulated star images.Experiments show that the positioning accuracy of the method is up to 0.001 pixel.It has good effect in calculating the centroid under low SNR conditions.
出处
《激光与红外》
CAS
CSCD
北大核心
2013年第5期518-521,共4页
Laser & Infrared
关键词
能量分布
多步长
最小能量差
亚像素
质心计算
energy distribution
multi-step
minimum energy difference
sub-pixel
centroid calculation
