Results 111 to 120 of about 163 (140)

Augmenting LSPIV Surface Current Measurement with Drifting ASVs

2018 OCEANS - MTS/IEEE Kobe Techno-Oceans (OTO), 2018
Large Scale Particle Image Velocimetry (LSPIV) has been successfully used in the field to gather water surface flow data, which is critical to understanding complex geomorphic, hydrologic, and ecological river processes. Its success, however, depends on lighting conditions and adequate flow seeding with trackable debris or visual features, that can be ...
Christopher Tomaszewski, Paul Scerri, John Dolan   +2 more
openaire   +1 more source

River surface target enhancement and background suppression for unseeded LSPIV

Flow Measurement and Instrumentation, 2013
Abstract Large-Scale Particle Image Velocimetry (LSPIV) is an image-based technique for nonintrusive streamflow monitoring, where the visibility of flow tracers is one of the main limitations to its application in field conditions. Based on the target characteristics of flow tracers as well as the optical environment of river surface, the paper ...
Tanghuai Fan, Lizhong Xu
exaly   +2 more sources

Reducing the operator effect in LSPIV image-based discharge measurements

2023
The operator effect is a prominent error source in image-based velocimetry methods. The LSPIV method is known to be sensitive to the parameters and choices of the user, as shown in the literature and emphasized by the results of a video gauging intercomparison, the Video Globe Challenge 2020 (VGC2020) (Le Coz et al., 2021).
Guillaume Bodart, Jérôme Le Coz, Magali Jodeau, Alexandre Hauet   +3 more
openaire   +1 more source

Design of online open channel flow monitoring system based on LSPIV

2020 5th International Conference on Communication, Image and Signal Processing (CCISP), 2020
With the change of global climate in recent years, the risk and harm of flood disasters are gradually increasing. Long-term monitoring for prediction and assessment of them open channels is very necessary. Nowadays, hydropower stations often bear more flood discharge costs to help the downstream avoid risks, but there is a lack of a scientific method ...
Xincheng Liu, Yongjian Wang, Jiegang Peng   +2 more
openaire   +1 more source

Integrating unmanned aerial systems and LSPIV for rapid, cost-effective stream gauging

Journal of Hydrology, 2018
Abstract Quantifying flow in rivers is fundamental to assessments of water supply, water quality, ecological conditions, hydrological responses to storm events, and geomorphological processes. Image-based surface velocity measurements have shown promise in extending the range of discharge conditions that can be measured in the field.
Quinn W Lewis, Bruce L Rhoads
exaly   +3 more sources

Application of LSPIV to measure supercritical flow in steep channels with low relative submergence

Flow Measurement and Instrumentation, 2020
Abstract Measuring flow discharge has always been one of the most important concerns of water experts. To measure discharge in streams using velocity-area method it is necessary to quantify average velocity of the flow. It is not feasible to measure velocity by contact approaches like current meters under certain conditions such as in flood periods ...
Josef Schneider
exaly   +2 more sources

Comparison of macroturbulence measured using decomposition of PIV, ADV and LSPIV data

Journal of Hydraulic Research, 2011
Visualization and length-scale estimates are provided for turbulence in open channel flow over a gravel-bed. Results obtained using the digital particle image velocimetry (PIV) followed by post-processing with proper orthogonal decomposition showed higher and lower velocity regions aligned along a stagnation plane extending from the bed at ...
James F. Fox, Brian J. Belcher
openaire   +1 more source

Quantifying the operator effect in LSPIV image-based velocity and discharge measurements

2022
<p><span>The operator effect is a prominent error source in image-based velocimetry methods. Video sampling, ortho-rectification parameters, motion analysis parameters and filters can strongly impact velocity and discharge measurements. This has been reported in the literature (e.g.
Guillaume Bodart, Jérôme Le Coz, Magali Jodeau, Alexandre Hauet   +3 more
openaire   +1 more source

IP camera-based LSPIV system for on-line monitoring of river flow

2017 13th IEEE International Conference on Electronic Measurement & Instruments (ICEMI), 2017
To improve the real-time performance and robustness of the existing Large-Scale Particle Image Velocimetry (LSPIV) system, an IP camera-based LSPIV system has been developed for on-line monitoring of river flow. The camera was refitted to support NIR imaging to enhance the contrast between flow tracers and water surface.
Zhang Zhen, Zhou Yang, Li Yuchou, Ye Youjie, Li Xurui   +4 more
openaire   +1 more source

Application of an automated LSPIV system in a mountainous stream for continuous flood flow measurements

Hydrological Processes, 2016
AbstractAn imaging‐based automated large‐scale particle image velocimetry (LSPIV) system for flash flood monitoring is developed and deployed in a mountainous stream in the Longchi Catchment, Chengdu, China. This system is built from a low‐cost Raspberry Pi board‐level computer with a camera module, which can acquire continuous images/videos ...
Qian Liao, Mengyao Wang
exaly   +2 more sources