High-Resolution Terrain Analysis for Lander Safety Landing and Rover Path Planning Based on Lunar Reconnaissance Orbiter Narrow Angle Camera Images: A Case Study of China's Chang'e-4 Probe
High-Resolution Terrain Analysis for Lander Safety Landing and Rover Path Planning Based on Lunar Reconnaissance Orbiter Narrow Angle Camera Images: A Case Study of China's Chang'e-4 Probe
复制标题
基于探月轨道器窄角相机图像的着陆器安全着陆和月球车路径规划高分辨率地形分析——以中国嫦娥四号探测器为例
DOI：
10.1029/2018ea000507
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发表时间：
2019-03-01
影响因子：
3.1
通讯作者：
Yao, Peiwen
中科院分区：
文献类型：
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作者：
Li, Bo;Yue, Zongyu;Yao, Peiwen
中国嫦娥四号（CE-4）探测器将于2018年底对南极-艾特肯盆地进行探测。其预选着陆区位于冯卡门陨石坑的东南底部。由于月球背面地形较为崎岖，中国嫦娥三号探测器的着陆经验可能无法直接应用于CE-4任务。此外，由于尺度依赖性和平滑效应，以往基于分辨率较低的数字高程模型数据得出的地形研究无法表征米尺度的地形特征。由于月球图像的时间和空间复杂度较低，图像分割算法特别适合识别月球特征。我们基于双阈值Otsu方法将窄角相机（NAC）马赛克图像分为三部分：暗区、亮区和平坦区。前两个部分对应于起伏区域（正地形和负地形）。然后计算历次成功登月任务（包括嫦娥三号、阿波罗、测量者、月球系列）的平坦面积百分比（Fap），得出月球安全着陆的Fap阈值（>0.6）。根据CE-4预选着陆区的Fap图（类似于每像素1.5 m），划分的大小为0.01度的正方形网格可分为安全网格（Fap>0.6）和不安全网格（Fap>0.6）和不安全网格（Fap>0.6）。
China's Chang'e-4 (CE-4) probe will explore the South Pole-Aitken basin in late 2018. Its preselected landing area is located on the southeastern floor of the Von Karman crater. Landing experience of China's Chang'e-3 probe may not be applied to CE-4 mission directly because the topography of lunar farside is more rugged. Moreover, due to scale dependence and smooth effects, the previous topographic studies derived from digital elevation model data with lower resolution cannot represent the meter-scale topographic features. Because of low time and space complexities in lunar images, image segmentation algorithm is especially suitable for recognizing lunar features. We divided the narrow angle camera (NAC) mosaic image into three parts: dark area, bright area, and flat area, based on a double-threshold Otsu method. The first two parts corresponded to the undulating areas (positive and negative terrains). And then we calculated the flat area percentage (Fap) of the previous successful lunar landing missions (including Chang'e-3, Apollo, Surveyor, and Luna series) and obtained the Fap threshold (>0.6) for lunar safe landing. According to Fap map (similar to 1.5 m per pixel) of CE-4 preselected landing area, the divided square grids with a size of 0.01 degrees can be classified into safe grids (Fap > 0.6) and unsafe grids (Fap