Pfeiffer Jan, Rutzinger Martin, Spötl Christoph
Department of Geography University of Innsbruck Innsbruck Austria.
Institute for Interdisciplinary Mountain Research Austrian Academy of Sciences Innsbruck Austria.
Photogramm Rec. 2023 Mar;38(181):6-21. doi: 10.1111/phor.12437. Epub 2022 Dec 29.
Perennial ice deposits in caves are an underexplored component of the cryosphere preserving a largely untapped archive of long-term changes in landscape and climate whose existence is threatened by climate change. This study demonstrates how terrestrial laser scanning (TLS) can be used to fully and accurately (registration accuracy < 1 cm standard deviation of point differences) assess the geometry of an ice-bearing cave in the Eastern Alps (Tyrol, Austria). Three TLS campaigns and 255 scan positions were used to acquire point clouds with a high sampling density (2 cm average point spacing) in order to minimise shading effects and to assure a precise and highly resolved 3D documentation of the cave. A semi-automated registration and point cloud-processing approach adapted to the site-specific demands ensured a complete and error-minimised assessment of the cave's geometry serving as a solid basis for future quantifications of snow and ice content dynamics. Dominant cave surface structures were investigated by performing a multiscale principal component analysis (PCA) to identify a detailed and computationally efficient basis for future airflow modelling tasks.
洞穴中的常年冰沉积物是冰冻圈中一个未被充分探索的组成部分，它保存了大量尚未开发的景观和气候长期变化档案，而其存在正受到气候变化的威胁。本研究展示了如何利用地面激光扫描（TLS）来全面且准确地（配准精度 < 1厘米点差标准差）评估东阿尔卑斯山（奥地利蒂罗尔州）一个含冰洞穴的几何形状。通过三次TLS测量和255个扫描位置，以高采样密度（平均点间距2厘米）获取点云，以尽量减少阴影效应，并确保对洞穴进行精确且高分辨率的三维记录。一种根据特定场地需求调整的半自动配准和点云处理方法，确保了对洞穴几何形状进行完整且误差最小化的评估，为未来雪冰含量动态的量化提供了坚实基础。通过进行多尺度主成分分析（PCA）来研究洞穴的主要表面结构，以确定未来气流建模任务的详细且计算高效的基础。
