基于星图匹配脱靶量标定的移动测站望远镜指向修正技术  

Pointing correction technology of telescope of mobile tracking station based on star pattern matching deviation calibration

作　　者：柳鸣 杨文波[1] 刘德龙 孙建南[1] 康喆[1] 李振伟[1] Liu Ming;Yang Wenbo;Liu Delong;Sun Jiannan;Kang Zhe;Li Zhenwei(Changchun Observatory,National Astronomical Observatories,Chinese Academy of Sciences,Changchun 130117,China)

机构地区：[1]中国科学院国家天文台长春人造卫星观测站,吉林长春130117

出　　处：《红外与激光工程》2023年第5期330-338,共9页Infrared and Laser Engineering

基　　金：国家自然科学基金(12103071)。

摘　　要：目前,移动测站以其高机动性正逐步成为空间目标监测网络重要的系统组成,应用于空间目标的共视观测与精密跟踪。针对移动测站光电望远镜由于工况的不稳定性以及装调过程中存在的指向误差,文中提出了一种基于星图匹配脱靶量标定的指向误差修正方法。首先,根据编码器轴系定位筛选出定标星群并进行资料归算;其次,采用面向脱靶量标定的快速星图匹配算法识别出与测量恒星相匹配的定标星坐标,并作为理论位置;最后,将多颗测量恒星坐标带入脱靶量标定指向修正数学模型对望远镜的指向进行拟合与标定。实验结果证明:采集一组序列图像对光心指向进行修正,单帧图像的修正周期约为2.2 s,从第10帧后修正量基本趋于稳定。对全天区典型分布的一批子天区进行指向修正,指向误差均值由修正前的124.24″提高至4.97″,标准差从41.50″提高至4.76″。综上所述,基于星图匹配脱靶量标定的指向误差修正方法对于提高测站望远镜的指向精度效果显著,且该方法的修正过程与望远镜机架结构无关,因此也可适用于不同机架结构的望远镜指向修正。Significance At present,the mobile tracking station,with its advantages of high mobility,high flexibility,wide observation range and low networking cost,is gradually becoming an important system component in the space target monitoring network and is widely used for common-view observation and precision tracking of spatial objectives.The rapid angular velocity motion of the space debris causes the dynamic axis of the telescope to become unstable during tracking,resulting in a dynamic bias in the telescope's pointing.In particular,the operating conditions of the mobile station are complex and frequently changing,leading to deviations in the pointing accuracy provided by the telescope's encoder.However,precise pointing accuracy is a prerequisite for astronomical positioning and target identification by optoelectronic telescopes,so dynamic pointing errors in mobile stations must be corrected to ensure the accuracy of space target positioning.To address the dynamic pointing errors caused by the above factors,a pointing error correction method based on star pattern matching deviation calibration is provided.Methods Firstly,the acquired images are processed by extracting the centroid coordinates of the measured stars,filtering the catalogue of calibration stars,and converting the stellar position coordinates.The Source-Extractor software is used to perform threshold segmentation,contour extraction and centroid coordinate extraction of the measured stars on the acquired images(Fig.2).The catalogue of calibration stars is filtered by the rough pointing provided by the telescope's encoder to determine the population of calibrated stars at the current pointing and the field of view.The SOFA package is called to perform a coordinate transformation of the coordinates of the calibration stars,transforming the flat position of the filtered calibration star at J2000 to the apparent position of the station,i.e.the azimuth and elevation of the calibration stars(Fig.4);Secondly,a rapid star pattern matching algorithm for star devi

关 键 词：光电望远镜 指向误差 星图匹配 空间目标 

分 类 号：TH751[机械工程—仪器科学与技术] P123.46[机械工程—精密仪器及机械]