Abstract
天体测量定标是高精度位置测量的基础。空间望远镜图像的天体测量定标是我国计划于2024年发射空间站望远镜需要突破的关键技术。本文以“卡西尼” (Cassini)飞行器窄视场照相机 (Narrow Angle Camera,NAC)拍摄的图像为例,探究了CCD图像天体测量定标技术,希望为拓展应用到我国即将发射的空间站望远镜提供有益的参考。具体地,本文选取了NAC在五个历元 (2006,2008,2010,2014,2016)拍摄的具有不同指向和取向观测密集星场的图像,探究了空间图像高精度天体测量的归算方法,求解出了各历元的CCD扭曲模型。相比目前其他学者的归算结果,本文在恒星的位置测量精度上有较大的提高。对于在2.6秒曝光时间11~12星等 (Gaia-G星等)的恒星,平均(O-C) (The Observed Minus Computed)的标准差在x和y坐标方向分别为约0.04像素 (约提高0.5倍)和0.03像素 (约提高1倍)。通过分析各历元图像的扭曲模型,本文发现在飞行器执行任务期间CCD图像的扭曲保持了良好的稳定性。在1024×1024像素尺度下,几何扭曲的最大值、中值、最小值分别为0.184 ± 0.023,0.038 ± 0.005和0.007 ± 0.003像素。根据求解扭曲的平均模型,本文提供了模型的数值表达式及改正方法。
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: SCIENTIA SINICA Physica, Mechanica & Astronomica
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.