A new telescope with three fields of view to measure the orientation parameters of the Moon and terrestrial planets

For lots of scientific questions about lunar physics deep inside the Moon,in-situ observation on lunar physical libration is one of the most potential ways.In this paper,we propose a brand new optical telescope functioned with simultaneously observing multiple(here there are three)fields of view(FOVs)for in-situ observation of lunar physical libration.The telescope can be placed at any place with any attitude on the Moon and do not require manned install,control or operation.It passively,continuously and simultaneously observe stars in three FOVs along with rotation of the Moon.Libration is to be measured and studied from celestial motion of the directions of three FOVs from image processing.The concept and design of this telescope are firstly introduced in this paper.The principle and feasibility of the method of insitu observation are also demonstrated.From simulation,precision of the determined lunar physical libration is expected to be several milliarcsecs,about two orders of magnitude better than the current precision of libration by lunar laser ranging observation.Libration data with milliarcsec precision level can play a valuable role in the study of the physics and dynamics of the interior of the Moon.This telescope can also be applied to observe the rotation of other terrestrial planets like Mars.     

行星(月球)自转监测望远镜的原理样机地面验证实验

类地行星(月球)自转监测望远镜的科学目标是在行星(月球)表面现场测量行星(月球)自转并研究其内部结构和物理性质.为了验证全新的观测原理和资料处理方法,项目团队设计制造了一套原理样机,在一台商用天文望远镜的光路前端增加3面反射镜组,使其具有同时观测3个视场的能力.自2017年起在地面上开展了观测实验,获得了混合有3视场星象的图像.通过计算星象在前后图像上的位移实现了归属视场识别,使得观测效果与分视场独立观测等同,证明了用一台设备同时观测多视场的可行性.处理图像并通过3个视场中心的指向变化归算地球自转轴的空间指向,与理论值比较偏差平均约1′′,证明了观测原理和数据处理方法有效.对各种观测误差来源进行了分析,包含大气折射、仪器热稳定性和光学分辨能力的影响等,指出采用更长焦距的望远镜可以提高空间分辨率,优化形变控制可以提高观测稳定性.改进多视场同时观测中的光学设计也有助于精度的提高.