基于三次样条拟合插值的高精度质心定位方法

High Precision Centroid Location Algorithm Based on Cubic Spline Fitting and Interpolation

通过对质心法、曲面拟合法两类质心定位算法的优劣势进行分析,提出结合两类定位算法优势的基于三次样条拟合插值的高精度质心定位算法,并指出其实现双重定位误差抑制的原理。通过仿真实验,对比不同信噪比下传统质心法与所提算法的定位误差,发现基于三次样条拟合插值的质心定位误差均明显小于传统质心法。当信噪比为20 dB时,基于三次样条拟合插值的质心定位误差方均根误差仅为0.003 pixel。通过真实仪器测量的星点图像,再次验证了所提算法的有效性。基于三次样条拟合插值的高精度质心定位算法可有效抑制定位误差,具有较好的抗噪性,不依赖特定星点模型,适用范围较广。

In this paper,we proposed a high-precision centroid location algorithm based on cubic spline fitting and interpolation combining the advantages of centroid algorithms and surface fitting algorithms.Besides,the principle behind its double error suppression was given.The simulation showed that the location error of the proposed algorithm at different SNRs was significantly smaller than that of traditional centroid algorithms.When the SNR was 20 dB,the root-mean-square error of the proposed algorithm was only 0.003 pixel.Furthermore,the star images from real instruments verified the effectiveness of this algorithm once again.In summary,this algorithm can effectively suppress the location error and has strong noise resistance,which can be widely applied without requiring specific star models.