| 摘要: |
| 雷达是探测火星次表层结构和属性的重要手段。火星勘测轨道飞行器（Mars Reconnaissance Orbiter，MRO）搭载的SHARAD（Shallow Radar）在过去的近20年间已基本实现了对整个火星的环绕探测，为探索火星提供了大量宝贵数据。然而，当前针对SHARAD数据的反演和解释研究主要针对其中包含次表层反射的部分，占比最多的表面反射数据没有得到充分利用。2021年，美国“毅力号”火星车和我国“祝融号”火星车先后成功着陆在Jezero撞击坑和乌托邦（Utopia）平原南部。两者均搭载了探地雷达设备并采集了大量数据，为SHARAD表面反射数据的标定提供了关键依据。本文首先对SHARAD数据进行处理，剔除电离层、卫星姿态和地面粗糙度的影响。然后对“祝融号”上搭载的火星次表层探测雷达（Mars Rover Penetrating Radar，RoPeR）低频通道雷达数据进行处理和反演，用于标定SHARAD数据的表面反射功率。最后，基于SHARAD表面反射功率反演了火星乌托邦平原南部的介电常数分布图。结果表明乌托邦平原南部表面物质的相对介电常数较为均匀（3.5~4.5），但其南部高地的介电常数值略高于北部低地。本研究提出了一种联合SHARAD和RoPeR的数据处理与反演方法，有助于提高火星雷达大范围数据处理和解释能力，深化火星表面性质和演化历史的认识。 |
| 关键词: 火星 SHARAD雷达 火星次表层探测雷达 反演 介电常数 |
| DOI：DOI:10.3969/j.issn.1672-2337.2025.05.011 |
| 分类号:TN959.7 |
| 基金项目:国家自然科学基金（No.52179126， 52379099）； 广东省基础与应用基础研究基金项目（No.2024A1515010934） |
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| Permittivity Map of the Southern Utopia Planitia on Mars Inverted from SHARAD and RoPeR |
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DUAN Diwen， MENG Xu， LIU Hai， LI Jianhui， LIU Chao， WANG Xiangyu
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School of Civil Engineering and Transportation, Guangzhou University, Guangzhou 510006, China
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| Abstract: |
| Radar is a crucial tool for detecting subsurface structures and properties on Mars. The shallow radar （SHARAD） aboard the Mars reconnaissance orbiter （MRO） has conducted almost comprehensive orbital surveys of Mars over the past two decades, which provides a lot of valuable data for detection of Mars. However, the current research on the inversion and interpretation of SHARAD data mainly focuses on the part containing subsurface reflection, and the surface reflection data, which accounts for the largest proportion, has not been fully utilized. In 2021, the US “Perseverance” rover and China’s “Zhurong” rover successfully landed in Jezero Crater and southern Utopia Planitia, respectively. Both rovers were equipped with ground-penetrating radar systems and collected a large amount of data, providing crucial references for calibrating SHARAD surface reflection data. Firstly, the SHARAD data is processed to eliminate the influence of ionosphere interference, satellite attitude and ground roughness. Then, the low-frequency channel radar data from Mars rover penetrating radar （RoPeR） on “Zhurong” rover are processed and inverted to calibrate the surface reflection power of SHARAD data. Finally, a permittivity distribution map of the southern Utopia Planitia is generated based on the processed SHARAD surface reflection power. The results indicate that the permittivity map in southern Utopia Planitia is relatively uniform, ranging from 3.5 to 4.5, but the permittivity values in the southern highland are slightly higher than those in the northern lowland. A data processing and inversion method by combining SHARAD and RoPeR is proposed in this study, which can help improve the large-scale data processing and interpretation capabilities of Mars radar and enhance the understanding of Mars surface properties and evolution history. |
| Key words: Mars SHARAD RoPeR inversion permittivity |
