赤道式望远镜指向精度分析

Analysis of Pointing Precision for Equatorial Telescope

赤道式望远镜因其跟踪测量的简单性和可靠性,在中小口径的望远镜中得到广泛的应用,本文介绍了赤道式望远镜的特点,建立了赤道式坐标系,并阐述了赤道式望远镜的跟踪测量原理。望远镜在制造、装配和安装过程中会产生视轴与纬轴不垂直、纬轴与极轴不垂直和极轴指北高度偏差等误差,这些误差严重影响望远镜的指向精度,文中利用球面三角形在赤道式坐标系中推导出制造、装配和安装误差引起的赤道式望远镜指向误差,此结果可用于实时测量的误差修正,也可用于结构设计中的误差分配。

Equatorial telescope is applied broadly in small and middle aperture telescope for its simplicity and reliability.The feature of equatorial telescope is presented.The equatorial coordinate is established and the measure principle for equatorial telescope is discussed.The pointing precision for equatorial telescope is severely affected by many errors which are brought in manufacture and assembly process such as non-perpendicularity between optical axis and latitude axis,non-perpendicularity between polar axis and latitude axis and so on.The pointing precision is deduced by the method of spherical triangle based on the equatorial coordinate.The result can be used not only for correction of actual measurement but also for design of equatorial telescope.