Sedimentological characterization of Antarctic moraines using UAVs and Structure-from-Motion photogrammetry
Sedimentological characterization of Antarctic moraines using UAVs and Structure-from-Motion photogrammetry
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DOI：
10.3189/2015jog15j086
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发表时间：
2015-11
影响因子：
3.4
通讯作者：
M. Westoby;S. Dunning;J. Woodward;A. Hein;S. Marrero;Kate Winter;D. Sugden
中科院分区：
文献类型：
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作者：
M. Westoby;S. Dunning;J. Woodward;A. Hein;S. Marrero;Kate Winter;D. Sugden
冰川环境中冰雹的粒度分析提供了对碎屑成因、运移历史、沉积机制和改造过程的深入了解。传统的粒度分类方法劳动强度大、物理干扰大，且仅限于斑块尺度(1m2)的观测。我们开发了基于新兴的高分辨率地面和无人驾驶飞行器的“运动结构”(UAV-SfM)摄影测量技术，以恢复南极洲遗产山脉冰原表面的颗粒尺寸信息。SFM数据产品与使用地面激光扫描获得的同等数据集进行了基准比较，发现对于斑块和场地规模的建模，其精度分别在1.7 mm和50 mm以内。颗粒大小分布是通过对斑块尺度的SfM正射影像进行数字颗粒分类或“照片筛选”获得的。与来自干筛的对照分布相比，光筛分布的精确度为2 mm。将斑块尺度的中值颗粒尺寸与当地地面高度的标准差之间的关系应用于现场尺度的无人机-SfM模型，以促进放大和制作0.3平方公里范围内的中值颗粒尺寸的空间连续地图。这种用于现场规模沉积学表征的高度自动化的工作流程消除了许多与传统方法相关的主观性，并为随后的冰川过程解释和分析奠定了坚实的基础。
In glacial environments particle-size analysis of moraines provides insights into clast origin, transport history, depositional mechanism and processes of reworking. Traditional methods for grain-size classification are labour-intensive, physically intrusive and are limited to patch-scale (1m2) observation. We develop emerging, high-resolution ground- and unmanned aerial vehicle-based ‘Structure-from-Motion’ (UAV-SfM) photogrammetry to recover grain-size information across an moraine surface in the Heritage Range, Antarctica. SfM data products were benchmarked against equivalent datasets acquired using terrestrial laser scanning, and were found to be accurate to within 1.7 and 50mm for patch- and site-scale modelling, respectively. Grain-size distributions were obtained through digital grain classification, or ‘photo-sieving’, of patch-scale SfM orthoimagery. Photo-sieved distributions were accurate to <2mm compared to control distributions derived from dry sieving. A relationship between patch-scale median grain size and the standard deviation of local surface elevations was applied to a site-scale UAV-SfM model to facilitate upscaling and the production of a spatially continuous map of the median grain size across a 0.3 km2 area of moraine. This highly automated workflow for site scale sedimentological characterization eliminates much of the subjectivity associated with traditional methods and forms a sound basis for subsequent glaciological process interpretation and analysis.