Sub-pixel Location with Phase Transfer Function for Star Tracker
Star tracker has been widely used as a precise and reliable device for the attitude measuring of a spacecraft.The accuracy of star location will affect the accuracy of star identification and finally the accuracy of attitude measurement.This paper proposed a novel method to locate the star position with the phase transfer function (PTF).The numerical expressions are deduced with the diffraction model of the star point in 1-D and given directly in 2-D.Then calculation is performed and the accuracy is better than 2.1% pixels (SNR=20) with a 3×3 window of airy disk,which is higher than the traditional centroid method.Different sizes of the airy disk from 3 to 6 are simulated with PTF method and we find that the optimal window size is 3 to 5.Finally the Additive Gaussian Noise with SNR from 2 to 40 is introduced to evaluate the novel method and compare it with the traditional centroid method.The accuracy of the new method can reach better than 2.5% pixels and it is much robust than the traditional centroid method,which proves that the method we proposed has a good performance under the noise environment.
Star Tracker Sub-pixel Diffraction Model Phase Transfer Function
Jiangbo Xi Zongxi Song Wei Gao
Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences;Graduate School of th Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences
国际会议
2012第八届精密工程测量和仪器仪表国际研讨会(ISPEMI2012)
成都
英文
1-7
2012-08-08（万方平台首次上网日期，不代表论文的发表时间）