一种星图识别的星体图像高精度内插算法

介绍了一种从星敏感器成像中高精度提取恒星位置和星等的方法.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方法,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和恒星星等.理论研究表明,曲面拟合法提取的星体位置精度高于传统的质心法.由于直接进行高斯曲面拟合计算非常复杂,为了简化计算,利用了星体成像点附近x,y方向的非线性插值方法,分别得到不同的曲面系数.仿真结果显示,在信噪比小于0.05时,定位精度小于1/20像素,星等误差小于5%.

High precision interpolation algorithm for star pattern

To extract the star position and star magnitude, a new algorithm was developed. The algorithm regards the star imaging pattern as Gauss point spread function model. The coefficient of Gauss curved face function was getted using the combination of linearity interpolation method and least squares method. From the Gauss curved face function, the sub-pixel position of star and its star magnitude were obtained. Theoretical research indicates that the extracted precision using Gauss curved method is higher than using traditional centroid method. The calculation of the direct Gauss curved interpolation is very complex, for reducing calculation, the x, y direction nonlinear interpolation method was used in imaging point adjacent, and the different coefficients of Gauss curved was getted individually. The simulative calculation results show that the locating precision less than 1/20 pixel and error of star magnitude less than 5% when the signal-to-noise ratio is 0.05.