基于1.2m望远镜的月球及中继星深空激光测距关键技术研究

In order to realize the detection of gravitational waves, Sun Yat-Sen University proposes the “Tian Qin” plan. The high-precision lunar and relay-satellite laser ranging is the precondition of this plan. The super-disturbance laser ranging of lunar and relay-satellite, makes the design of control system and weak signal processing be very challenging for the telescope. Especially, the far distance and low brightness of the relay-satellite, and the small observation angle is only about 1.5 degree between the earth and the lunar, which also make the search for the relay-satellite very challenging. Therefore, this research proposes an acceleration feedback control strategy, which is based on the internal mode approach, to improve the tracking accuracy of the telescope and suppress the tracking jitter; furthermore, a multi-modes control method is proposed to satisfy the requirement of the relay-satellite searching, which is the stepping–searching angle less than 0.1 second; finally, a weak signal processing method, which is based on the empirical mode decomposition, is proposed to improve the detection capacity of the echo photon of the lunar and relay-satellite. All the above strategies will carry out based on the 1.2m telescope, which is owned by the Yunnan Observatory of the Chinese Academy of Sciences. This research will not only provide technology foundation for super-disturbance laser ranging of “Tian Qin” plan, but also significantly improve the scientific research capabilities and international influence of our country, on the lunar and deep space-satellite laser ranging and the deep space-satellite orbit determination.

为实现空间引力波探测实验，中山大学提出了“天琴计划”。利用月球和嫦娥四号中继星开展高精度深空激光测距技术验证是保障该计划顺利开展的前提。超远距离的月球及中继星激光测距对望远镜本身的跟踪抖动和弱信号处理提出新的挑战，特别是中继星，其亮度低、距离远，地面观测角度与月球仅差1.5度左右，在月光的影响下，搜索发现和测距难度极大。本项目以云南天文台1.2m激光测距望远镜为平台，提出基于内模方法的加速度反馈策略，以提高望远镜的跟踪精度，从而降低抖动的影响；提出基于多模控制方法的快速搜索、定位策略，以满足对中继星的步进搜索步长优于0.1角秒；提出基于经验模态分解法的弱信号检测技术，以提高对月球/中继星回波光子的探测能力。通过本项目的研究，为“天琴计划”所需的深空激光测距奠定技术基础；同时，该项目的研究成果将显著提升我国在月球、深空卫星激光测距和定轨方面的科研实力和国际影响力。

为实现空间引力波探测实验，中山大学提出了“天琴计划”。利用月球和嫦娥四号中继星开展高精度深空激光测距技术验证是保障该计划顺利开展的前提。超远距离的月球及中继星激光测距对望远镜本身跟踪抖动和弱信号处理提出新的挑战，特别是中继星，其亮度低、距离远，地面观测角度与月球仅差1.5度左右，在月光的影响下，搜索发现和测距难度极大。本项目以云南天文台1.2m激光测距望远镜为平台，提出基于内模方法的加速度反馈策略来提升望远镜跟踪精度、降低抖动影响；提出基于多模控制方法的快速搜索、定位策略，通过对月球跟踪，精密跟踪精度优于1角秒。通过该项研究，为“天琴计划”所需的深空激光测距奠定技术基础；同时，研究成果将显著提升我国月球、深空卫星激光测距和定轨能力的科研实力和国际影响力。