基于改进的Ly算子的快速星图质心确定方法

Ly算子是摄影测量中应用较多的一种点特征提取算子,它的解算速度快、抗噪能力强,但精度较低;而质心法是星图质心确定中比较具有代表性的方法,但它对噪声敏感,星图较大时,效率不高。根据Ly算子特点,本文在对Ly算子改进的基础上,提出了基于改进的Ly算子的快速星图质心确定方法,实验结果表明,该方法在信噪比较低、星图较大的情况下,较传统质心法解算速度更快、定位精度更高、抗噪能力更强;较带阈值的质心法,解算精度相当,但解算速度更快。

Rapid centroid calculation for star image based on improved Ly operator

Ly operator is a popular operator of point feature extraction in photogrammetry.The rate of resolution by this operator is fast,and its noise restraining ability is really strong,but the precision is low.The centroid algorithm is a representative way to make sure the centroid of star image.But it is always affected by noise,and if the star image is larger,the resolution rate will drop down quickly.Considering with the character of Ly operator,in this paper,Ly operator was applied for the centroid of star image,and made use of centroid algorithm to improve Ly operator.The result of experiments showed that the centroid algorithm for star image based on improved Ly operator is better than other methods in the instance of low SNR and big star image.Compared with traditional centroid algorithm,the rate is faster,fixed position accuracy is more precise,and noise restraining ability is stronger.Compared with centroid algorithm with threshold,when fixed position accuracy is same,the rate is faster.