The Mars Global Digital Dune Database (MGD³) contains information on Martian dune fields and prepared manually from the Thermal Emission Imaging System (THEMIS; 100 m/pixel) images. Although the MGD³ outlines dune fields, it overlooks the recognition of smaller dune forms. This paper aims to identify individual dunes from a semiautomated object‐based image analysis technique and characterize dune materials at Hargraves crater, Mars. MGD³ would benefit to be updated for an improved understanding of the Martian surface and its atmospheric mechanisms at a local scale. An object‐based image analysis technique was applied here to the Context Camera (CTX; 6 m/pixel) data set to extract dune data in a more efficient, reliable, and accurate fashion. This study is a test case in validating a remote sensing method that has wide applicability to the entire Martian surface resulting in an update to the dune database at a higher spatial resolution—providing a better understanding of surface and atmospheric behavior of Mars at the local scale. We also explored the wind flow and dune stability—presenting an insight into the dune modification mechanism—within the crater. The prevailing wind inside the crater flows to the west‐northwest. The dunes are labeled as active (stability index of 2) and do not appear to have been influenced by subsurface water ice or volatiles. We emphasize that the technique used here has a wide prospect in temporal monitoring of dune sediment flux, dune migration or erosion rates, improving near‐surface airflow modeling, and dune stability analysis.

中文翻译：

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火星Hargraves陨石坑的沙丘半自动识别和表征

火星全球数字沙丘数据库（MGD ³）包含有关火星沙丘场的信息，并且是根据热发射成像系统（THEMIS; 100 m / pixel）图像手动准备的。尽管MGD ³概述了沙丘场，但它忽略了较小沙丘形式的识别。本文旨在通过一种基于对象的半自动图像分析技术来识别单个沙丘，并在火星的Hargraves火山口表征沙丘的材料。MGD ³将有利于进行更新，以便在局部范围内更好地了解火星表面及其大气机制。此处将基于对象的图像分析技术应用于上下文摄像机（CTX; 6 m /像素）数据集，以更有效，可靠和准确的方式提取沙丘数据。这项研究是一个验证适用于整个火星表面的遥感方法的测试案例，从而以更高的空间分辨率更新了沙丘数据库，从而更好地了解了当地火星的表面和大气行为。我们还研究了火山口内的风流和沙丘稳定性，从而了解了沙丘的变质机理。火山口内的盛行风向西北偏西流动。沙丘被标记为活动沙丘（稳定性指数为2），似乎不受地下冰水或挥发物的影响。我们强调，这里使用的技术在沙丘沉积物通量，沙丘迁移或侵蚀速率的时间监测，改善近地表气流模型以及沙丘稳定性分析方面具有广阔的前景。