低信噪比星象质心定位算法分析

High Accuracy Centroid Calculation of Low SNR Star Image

对于星空观测CCD图像,为了对低信噪比目标星象进行天文定位,精确的提取目标星象的质心是至关重要的。首先,系统地推导了CCD星象质心定位误差产生的原因,分析得出提高星象质心定位精度的途径;然后,分别从星象插值和增强两个方面研究了提高星象质心定位精度的方法,通过仿真得出不同的插值算法和插值步长对星象质心定位的影响,并总结得出最佳的插值方法,另外,系统地分析了增强算法对质心定位精度的影响;最后,总结得出低信噪比星象质心提取的最佳方法,为星象的天文定位奠定了基础。

For the star-sky observation CCD images, in order to improve the positioning precision of low SNR space target orbit, high precision target centroid location method is of great importance. First of all, the paper makes detailed analysis on the factors which influence centroid location accuracy. Then, from the aspects of image interpolation and enhancement, the centroid location improving methods are investigated. Through a variety of simulation research, centroid location precision of different algorithm is validated. At last, the paper sums up the best centroid location method. It provides a good basis for space target astronomical orientation.