River valleys have been observed on Titan at all latitudes by the Cassini‐Huygens mission. Just like water on Earth, liquid methane carves into the substrate to form a complex network of rivers, particularly stunning in the images acquired near the equator by the Huygens probe. To better understand the processes at work that form these landscapes, one needs an accurate digital terrain model (DTM) of this region. The first and to date the only existing DTM of the Huygens landing site was produced by the U.S. Geological Survey (USGS) from high‐resolution images acquired by the DISR (Descent Imager/Spectral Radiometer) cameras on board the Huygens probe and using the SOCET SET photogrammetric software. However, this DTM displays inconsistencies, primarily due to nonoptimal viewing geometries and to the poor quality of the original data, unsuitable for photogrammetric reconstruction. We investigate a new approach, benefiting from a recent reprocessing of the DISR images correcting both the radiometric and geometric distortions. For the DTM reconstruction, we use MicMac, a photogrammetry software based on automatic open‐source shape‐from‐motion algorithms. To overcome challenges such as data quality and image complexity (unusual geometric configuration), we developed a specific pipeline that we detailed and documented in this article. In particular, we take advantage of geomorphic considerations to assess ambiguity on the internal calibration and the global orientation of the stereo model. Besides the novelty in this approach, the resulting DTM obtained offers the best spatial sampling of Titan's surface available and a significant improvement over the previous results.

中文翻译：

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土星最大卫星泰坦上的惠更斯着陆点的新数字地形模型

卡西尼-惠更斯飞行任务已在所有纬度的泰坦上观测到河谷。就像地球上的水一样，液态甲烷也进入基质，形成复杂的河流网络，这在惠更斯探测器在赤道附近获得的图像中尤为惊人。为了更好地了解形成这些景观的工作流程，需要一个该区域的准确数字地形模型（DTM）。惠更斯着陆点的第一个也是迄今为止唯一的DTM是由美国地质调查局（USGS）根据惠更斯探测器上的DISR（下降成像仪/光谱辐射仪）摄像机获取的高分辨率图像并使用SOCET制作的SET摄影测量软件。但是，此DTM会显示不一致，这主要是由于观看几何形状不佳以及原始数据的质量不佳，不适合摄影测量重建。我们研究了一种新方法，这得益于最近对DISR图像进行的重新处理，从而校正了辐射和几何畸变。对于DTM重建，我们使用MicMac，这是一种基于自动开源的“运动定型”算法的摄影测量软件。为了克服数据质量和图像复杂性（异常的几何配置）等挑战，我们开发了一条特定的管道，本文对此进行了详细记录。特别是，我们利用地貌因素来评估立体模型的内部校准和全局方向上的歧义。除了这种方法的新颖性之外，获得的DTM还提供了可用的泰坦表面的最佳空间采样，并且比以前的结果有了显着改进。