基于高斯分布的星点图像亚像元定位算法研究

应用高斯点分布函数为数学模型,提出了一种新的获取高精度恒星质心位置的方法.由于入射到星像点邻域内像元中的光子能量呈近高斯分布,因此利用成像邻域内像元强度的比值,将高斯点分布函数展开成为关于质心位置的多项式,可将质心位置在x、y轴方向分别计算出来,并利用从星图中提取出的多星对角距误差的统计值来间接验证提出的算法.试验结果...

Research of sub-pixel location algorithm for star image based on Gaussian distribution

A novel centroid algorithm is proposed to acquire better stars centroid performance in star image based on Gaussian point spread function(PSF).As photons incident on pixels of stars presents the near Gaussian distribution,therefore,the centroid locations in x and y axis are calculated respectively utilizing the pixel intensity ratio and expand the Gaussian PSF to be polynomials with respect to the centroid location.The statistic of angular separation error between star pairs is used to indirectly verify the proposed algorithm.The result clearly shows that the centroid accuracy achieves 1/33 of a pixel and improves about 2 times than the moment method,which indicates the proposed algorithm is effective and convenient.Furthermore,the relation between the centroid position and the attitude accuracy is analyzed.The test result shows that the proposed centroid algorithm can improve the attitude accuracy of the camera significantly.