联合多源探测数据的月球极区控制网构建方法研究

Future human exploration of the moon will likely rely on the establishment of permanent lunar base and the utilization of moon resources to enable long duration lunar missions. Lunar poles have already greatly inspired all countries’ exploration enthusiasm because there is water ice in this area for human future long duration lunar exploration. In recent years, many science and engineering researches about lunar poles such as early lunar tectonic activity, distribution and content of water ice, and selection of safe landing areas all require the support of fine lunar polar terrain data. Therefore, an uniform, standard and high-precision geographic reference, which means a high precision lunar polar control network, is urgent to be established. However, because of the shortcomings such as less connection points, large overlaps, high correlation relationship, low precise exterior orientation elements involved in current lunar poles remote sensing images, high precision coordinates of control points can’t be obtained under traditional photogrammetric methods. On the other hand, reasonable layout of the control network will be affected by the permanently shadowed region in lunar poles. Based on this background, this program will research an combined processing method for the construction of lunar polar control network by Chang’E-1 laser altimeter data, image data, Chang’E-2 image data and other lunar exploratory data. Key technical problems such as data organization, extraction of auxiliary control points in the shadowed areas, multi-resolution image matching, bundle block adjustment of multi polar exploration data, distribution of lunar polar control network will be discussed. Finally, a high-precision lunar polar control network with control points’ position accuracy and image information will be given. It will provide important theoretical methods and techniques for China’s future lunar exploration missions such as soft landing in poles and establishing permanent lunar base.

月球极区由于存在水冰，能够满足人类未来在月球上建立永久性基地、开发利用月球资源的探测需求，极大鼓舞了各国的探测热情。目前月球早期构造活动、水冰含量及分布、安全着陆区选取等月球极区科研和工程任务均需要精细的月面地形数据予以支持，迫切需要建立统一、标准的高精度极区地理基准，即构建月球极区控制网。然而，极区遥感影像存在连接点少、重叠度大、相关性高、外方位元素精度低等问题，传统摄影测量法难以解算高精度的控制点坐标，永久阴影区也将严重影响极区控制网的布设。针对以上现状，本项目拟研究基于嫦娥一号激光测高数据、影像数据、嫦娥二号影像数据等多源月球极区探测数据的联合处理方法，解决数据组织、辅助控制点提取、多分辨率影像匹配、多源探测数据联合区域网平差、控制网布设等关键问题，构建高精度的月球极区控制网，给出控制点的位置和影像信息，为我国未来实施月球极区软着陆、开展月球长期探测等探月任务提供理论依据和技术支持。

高精度月球极区控制网是开展月球早期构造活动、水冰含量及分布、安全着陆区选取等月球极区科研和工程任务的地理基准，构建月球极区控制网主要数据源是月球轨道器获取的遥感影像数据和激光高度计测距数据等，目前月球探测任务获取的极区遥感影像存在连接点少、重叠度大、相关性高、外方位元素精度低等问题，传统摄影测量法难以解算高精度的控制点坐标，永久阴影区也将严重影响极区控制网的布设。针对以上现状，本项目在系统调研CE-1三线阵相机影像、CE-2两线阵相机影像、CE-1激光测高数据、以及CE-1/CE-2的轨道数据、姿态数据等多源探测数据的特征和精度情况的基础上，重点研究了CE-2全月球地形数据产品（CE-2TMap2015）的生产方法，解决了探测器轨道优化、不同分辨率的影像匹配、影像数据全球平差、月球空间坐标系精确转换等关键技术，结合极区地形数据和激光高度计探测数据开展了极区光照条件分析，定位了永久阴影区位置，最终成功构建了月球极区控制网，其中北极区域控制点193个，南极地区控制点180个，共计373个高精度月球极区控制点，精度分析结果表明利用该控制网能够实现CE-2TMap2015与美国LOLA DEM数据等国际月球极区地形数据的无缝镶嵌。本项目构建的月球极区控制网，将为我国后续月球极区探测工程任务和相关的科学研究应用提供高精度的位置基准，作为月球极区预选着陆点选取，着陆区高精度影像图制作，月球极区地形和地貌类型单元划分，撞击坑的形态、大小和密度统计，月球极区表面年龄计算，月球极区表面坡度和粗糙度计算等应用的地理基准使用，发挥重要的基础支撑作用。