Sequential digital elevation models of active lava flows from ground-based stereo time-lapse imagery
Sequential digital elevation models of active lava flows from ground-based stereo time-lapse imagery
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DOI：
10.1016/j.isprsjprs.2014.08.011
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发表时间：
2014-11-01
影响因子：
12.7
通讯作者：
Robson, S.
中科院分区：
文献类型：
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作者：
James, M. R.;Robson, S.
我们描述了一个框架，用于推导序列的数字高程模型（DEM）的分析活动的熔岩流使用倾斜立体对延时成像。由于设备成本低、便携性高和网络扩展能力强，基于照片的技术比基于激光的替代技术更受青睐，数码单反相机可以在长达几个小时的时间内拍摄前进水流的图像。然而，在典型的场尺度场景下，相对相机取向不能被严格地保持（例如，通过使用立体声条），从而防止使用标准的立体缩时处理软件。因此，我们尝试半自动DEM序列工作流程，能够处理小的相机运动，可变的图像质量和有限的摄影测量控制，导致在远程和危险场所的数据收集的实用性。实现的图像处理工作流程要么链接单独的近景摄影测量和传统的立体匹配软件，要么集成在基于运动恢复结构（SfM）的单个软件包中。我们应用这些技术对比的案例研究，从基拉韦厄火山，夏威夷和埃特纳山，西西里，不同的规模，持续时间和图像纹理。在基拉韦厄，薄的液态熔岩瓣的前进方向很难预测，妨碍了控制的良好分布。因此，通过不同的工作流程计算出的体积变化相差10%左右的DEM（超过30米（2）），每分钟捕获一次，持续37分钟。在埃特纳火山中，更厚、更粘稠的熔岩的更可预测的推进（类似于3小时，类似于3英里/小时（-1））允许部署强大的控制，体积变化结果通常在5%以内（超过类似于500 m（2））。总的来说，综合SfM软件使用起来更简单，在有利的条件下，产生的结果与近景摄影测量管道的结果相当。然而，在摄影测量控制选项有限的条件下，基于SfM的表面中的误差可能难以检测。(C)2014年国际摄影测量与遥感学会（摄影测量和遥感学会）。Elsevier B. V.出版，保留所有权利。
We describe a framework for deriving sequences of digital elevation models (DEMs) for the analysis of active lava flows using oblique stereo-pair time-lapse imagery. A photo-based technique was favoured over laser-based alternatives due to low equipment cost, high portability and capability for network expansion, with images of advancing flows captured by digital SLR cameras over durations of up to several hours. However, under typical field scale scenarios, relative camera orientations cannot be rigidly maintained (e.g. through the use of a stereo bar), preventing the use of standard stereo time-lapse processing software. Thus, we trial semi-automated DEM-sequence workflows capable of handling the small camera motions, variable image quality and restricted photogrammetric control that result from the practicalities of data collection at remote and hazardous sites. The image processing workflows implemented either link separate close-range photogrammetry and traditional stereo-matching software, or are integrated in a single software package based on structure-from-motion (SfM). We apply these techniques in contrasting case studies from Kilauea volcano, Hawaii and Mount Etna, Sicily, which differ in scale, duration and image texture. On Kilauea, the advance direction of thin fluid lava lobes was difficult to forecast, preventing good distribution of control. Consequently, volume changes calculated through the different workflows differed by similar to 10% for DEMs (over similar to 30 m(2)) that were captured once a minute for 37 min. On Mt. Etna, more predictable advance (similar to 3 mh(-1) for similar to 3 h) of a thicker, more viscous lava allowed robust control to be deployed and volumetric change results were generally within 5% (over similar to 500 m(2)). Overall, the integrated SfM software was more straightforward to use and, under favourable conditions, produced results comparable to those from the close-range photogrammetry pipeline. However, under conditions with limited options for photogrammetric control, error in SfM-based surfaces may be difficult to detect. (C) 2014 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS). Published by Elsevier B.V. All rights reserved.