High‐resolution digital terrain models (DTMs) generated from the Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Cameras (NACs) provide an opportunity to study surface roughness of the Moon at meter scale. In this study, we mapped and investigated meter‐scale topographic roughness over 462 regions of the Moon using NAC DTMs. Our results show that, at meter to hectometer scales, there are obvious differences in median bidirectional slope, root‐mean‐square (RMS) height, and median absolute slope between maria and highlands. In terms of the median value, ratios of the bidirectional slope, RMS height, and median absolute slope within the maria and highlands are 1: 2.4, 1: 3.0, and 1: 2.7, respectively. However, up to a baseline of ∼0.2 km, no discernible differences in the Hurst exponent and median differential slope exist between the maria and highlands. The Hurst exponent varies from 0.7 to 0.95, with a median value of 0.9 within both the maria and highlands. To identify potential factors affecting meter‐scale roughness of the Moon, we compared the maria with volcanic features on Earth and Mars, as well as the lunar highlands with simulated cratered terrains. We found that the Hurst exponents within the lunar maria are much larger than those of the volcanic features on Earth and Mars, mainly because the lunar maria accumulated more impact craters with diameters smaller than 1 km. The Hurst exponents within the highlands are consistent with those of the simulated cratered terrains, whose surface roughness depends primarily on crater shape, number density, and stratigraphic age. All these results indicate that lunar surface roughness at meter to hectometer scales is mainly controlled by small degraded impact craters.

中文翻译：

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米级月球地形粗糙度：小型撞击坑的影响

由月球侦察轨道照相机（LROC）窄角照相机（NAC）生成的高分辨率数字地形模型（DTM）提供了研究米尺月球表面粗糙度的机会。在这项研究中，我们使用NAC DTM绘制和调查了月球上462个区域的米级地形粗糙度。我们的研究结果表明，在米到公顷的尺度上，玛丽亚和高地之间的双向平均坡度，均方根（RMS）高度和绝对绝对坡度存在明显差异。就中值而言，玛丽亚州和高地地区的双向斜率，RMS高度和中值绝对斜率之比分别为1：2.4、1：3.0和1：2.7。然而，到基线〜在0.2公里处，玛丽亚和高地之间的赫斯特（Hurst）指数和中值差异坡度没有明显差异。赫斯特（Hurst）指数从0.7到0.95不等，玛丽亚和高原地区的中位数为0.9。为了确定影响月球米级粗糙度的潜在因素，我们将玛丽亚与地球和火星上的火山特征以及模拟火山口地形的月球高地进行了比较。我们发现月球玛丽亚内部的赫斯特指数比地球和火星上的火山特征大得多，这主要是因为月球玛丽亚累积了更多直径小于1 km的撞击坑。高地中的赫斯特指数与模拟火山口地形的指数一致，其表面粗糙度主要取决于火山口的形状，数量密度，和地层时代。所有这些结果表明，米到百米尺度上的月球表面粗糙度主要由小的退化的撞击坑控制。