月球激光测距中的角反射器月面布置指向优化  

Corner Retroreflector Direction Optimization for Lunar Laser Ranging

作　　者：杨永章 伏红林[1] 孙尚彪 翟东升[1] 李祝莲[1] 李语强[1] Yang Yongzhang;Fu Honglin;Sun Shangbiao;Zhai Dongsheng;Li Zhulian;Li Yuqiang(Yunnan Observatories,Chinese Academy of Sciences,Kunming,Yunnan 650216,China;State Key Laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan University,Wuhan,Hubei 430072,China)

机构地区：[1]中国科学院云南天文台,云南昆明650216 [2]武汉大学测绘遥感信息工程国家重点实验室,湖北武汉430072

出　　处：《中国激光》2022年第6期73-80,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(12103087,12033009,U2031124)、国家重点研发计划(YFA20210715101)、中国科学院月球与深空探测重点实验室开放基金(LDSE202004)、武汉大学测绘遥感信息工程国家重点实验室开放课题(21P02)。

摘　　要：为了进一步提高地月激光测距精度,新部署单体大孔径的激光角反射器是下一代月球角反射器的主要选择,由于单口径角反射器相比阵列式反射器面积要小,反射器指向要求更高。针对这一问题,本文在不含二面角误差的理想角反射器前提下,通过数值模拟的方法分析了角反射器的有效衍射区域随激光光束入射条件的变化规律。在忽略大气影响的简化条件下模拟了地面3个激光测月台站对新布置角反射器的观测情况,通过LevenbergMarquardt方法优化了角反射器的指向。结果表明,选择合适的指向可以将反射器有效衍射面积提高到80%以上,同时得到低纬度地面台站比高纬度台站更有利于观测的结论,提示我国应当充分利用已建成的两个低纬度激光测月台站,以期在未来地月激光测距和地月科学研究中发挥更大的作用。Objective Lunar laser ranging has made outstanding contributions to maintaining the earth-moon reference frame,understanding the earth-moon system,and testing general relativity theory.However,due to the influence of the moon’s apparent libration,the array corner retroreflector installed on the moon 50years ago could not determine the corner retroreflector that reflected the photons,which would introduce cm-level errors.To overcome this problem,the newly deployed single large-aperture laser corner retroreflector is the leading choice for the next generation of lunar corner cube retroreflectors(CCR).Since the single-aperture corner retroreflector has a smaller reflection area than the array type,the CCR has higher requirements for directing.In this study,we analyze the effective diffraction region of the next-generation CCR and the relationship with the laser beam incident conditions employing numerical simulation.Ignoring the influence of atmospheric and dihedral errors,the observation situation of the newly-arranged CCR by three ground stations is simulated.The CCR pointing is optimized using the Levenberg-Marquardt method.We hope that our basic strategy and findings can be helpful in the deployment of the new CCR on the lunar surface in the near future.Methods In this study,a mathematical model with an effective diffraction region(EDR)is developed first for a retroreflector based on its geometrical structure and vector form of reflection-refraction law.Through numerical simulation,the regularity of change for EDR is analyzed.Then,we select three typical areas as the locations of the new CCR in the future,i.e.,the Chang’E-3landing area,Mare Nectaris area,and Shacklten Crater area.In terms of ground stations,three places such as GRASSE,APOLLO,and YNAO,are selected for observation.The minimal angle between the normal direction of the CCR and laser emitted by the ground station is taken as the optimizing objective.The optimization process is performed using the Levenberg-Marquardt method.In addition,the observa

关 键 词：测量 月球激光测距 角反射器 有效衍射区域 视天平动 

分 类 号：O436[机械工程—光学工程]