天文导航中星体高精度细分定位方法研究

介绍了一种从星体图像中高精度提取恒星位置的方法.这种方法把星光成像看成是高斯点扩散函数模型,利用线性内插和最小二乘法拟合得到高斯曲面参数,从高斯曲面模型中得到亚像素级的恒星位置.由于直接进行高斯曲面拟合计算非常复杂,将二维曲面拟合转化为两个方向上的一维曲线拟合,分别得到不同的曲面系数.仿真结果表明当信噪比小于0.05时,定位精度能达到1/20像素,与质心法比较,高斯曲面拟合法精度高,抗噪声能力强.

High Precision Subdivided Locating Method of Star Image

A new algorithm to extract the star position from star image was presented. The algorithm regards the star imaging pattern as Gauss point spread function model. The coefficient of Gauss curved face function was obtained using the combination of linearity interpolation method and least squares method. From the Gauss curved face function, the sub-pixel position of star was obtained. The calculation of the direct Gauss curved interpolation is very complex, for reducing calculation, the curved face divided method was used in imaging point adjacent, and the different coefficients of Gauss curved was obtained individually. The simulation calculation results show that the locating precision is less than 1/20 pixel and the error of star magnitude is less than 5% when the signal-to-noise ratio is 0. 05. The extracted precision using Gauss curved method is higher than using traditional centroid method.