气候变化领域集成服务门户(CCPortal): Technical Note: Flow velocity and discharge measurement in rivers using terrestrial and unmanned-aerial-vehicle imagery

CCPortal

DOI	10.5194/hess-24-1429-2020
	Technical Note: Flow velocity and discharge measurement in rivers using terrestrial and unmanned-aerial-vehicle imagery
	Eltner A.; Sardemann H.; Grundmann J.
发表日期	2020
ISSN	1027-5606
起始页码	1429
结束页码	1445
卷号	24 期号:3
英文摘要	An automatic workflow to measure surface flow velocities in rivers is introduced, including a Python tool. The method is based on particle-tracking velocimetry (PTV) and comprises an automatic definition of the search area for particles to track. Tracking is performed in the original images. Only the final tracks are geo-referenced, intersecting the image observations with water surface in object space. Detected particles and corresponding feature tracks are filtered considering particle and flow characteristics to mitigate the impact of sun glare and outliers. The method can be applied to different perspectives, including terrestrial and aerial (i.e. unmanned-aerial-vehicle; UAV) imagery. To account for camera movements images can be co-registered in an automatic approach. In addition to velocity estimates, discharge is calculated using the surface velocities and wetted cross section derived from surface models computed with structure-from-motion (SfM) and multi-media photogrammetry. The workflow is tested at two river reaches (paved and natural) in Germany. Reference data are provided by acoustic Doppler current profiler (ADCP) measurements. At the paved river reach, the highest deviations of flow velocity and discharge reach 4% and 5%, respectively. At the natural river highest deviations are larger (up to 31%) due to the irregular cross-section shapes hindering the accurate contrasting of ADCP-and image-based results. The provided tool enables the measurement of surface flow velocities independently of the perspective from which images are acquired. With the contactless measurement, spatially distributed velocity fields can be estimated and river discharge in previously ungauged and unmeasured regions can be calculated, solely requiring some scaling information. © 2020 Author(s).
语种	英语
scopus关键词	Antennas; Discharge (fluid mechanics); Doppler effect; Flow velocity; Object detection; Rivers; Unmanned aerial vehicles (UAV); Acoustic doppler current profiler; Automatic approaches; Contactless measurement; Discharge measurements; Flow charac-teristics; Irregular cross-sections; Particle tracking velocimetry; Structure from motion; Velocity; Acoustic Doppler Current Profiler; automation; cross section; flow velocity; image analysis; imagery; river discharge; unmanned vehicle; videography; Germany
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159463
作者单位	Eltner, A., Institute of Photogrammetry and Remote Sensing, Technische Universität Dresden, Dresden, 01069, Germany; Sardemann, H., Institute of Photogrammetry and Remote Sensing, Technische Universität Dresden, Dresden, 01069, Germany; Grundmann, J., Institute of Hydrology and Meteorology, Technische Universität Dresden, Dresden, 01069, Germany
推荐引用方式 GB/T 7714	Eltner A.,Sardemann H.,Grundmann J.. Technical Note: Flow velocity and discharge measurement in rivers using terrestrial and unmanned-aerial-vehicle imagery[J],2020,24(3).
APA	Eltner A.,Sardemann H.,&Grundmann J..(2020).Technical Note: Flow velocity and discharge measurement in rivers using terrestrial and unmanned-aerial-vehicle imagery.Hydrology and Earth System Sciences,24(3).
MLA	Eltner A.,et al."Technical Note: Flow velocity and discharge measurement in rivers using terrestrial and unmanned-aerial-vehicle imagery".Hydrology and Earth System Sciences 24.3(2020).