TY - JOUR
T1 - A preliminary assessment of the use of drones to quantify current velocities at tidal stream sites
AU - Fairley, Iain A.
AU - Williamson, Benjamin
AU - McIlvenny, Jason
AU - Lewis, Matt
AU - Neill, Simon
AU - Masters, Ian
AU - Williams, Alison J.
AU - Reeve, Dominic E.
N1 - Funding Information:
This work has been conducted as part of the Selkie Project. The Selkie Project is funded by the European Regional Development Fund through the Ireland Wales Cooperation programme. The authors would also like to acknowledge the financial support of the EPSRC Supergen ORE Hub (EP/S000747/1) funded V-SCORES project.
Funding Information:
This work was conducted as part of the Selkie Project. The Selkie Project is funded by the European Regional Development Fund through the Ireland Wales Cooperation programme. The financial support of the EPSRC Supergen ORE Flexible Fund V-Scores project is also acknowledged.
Publisher Copyright:
© European Wave and Tidal Energy Conference 2021.
PY - 2021
Y1 - 2021
N2 - Whenever considering new tidal stream sites; information on current characteristics is of paramount importance. This contribution describes a methodology to measure surface currents at tidal stream sites using drones and provides initial validation of the approach against velocities measured by GPS surface drifters. Drones have the potential to measure surface currents at high spatial resolution and low cost. An open-source toolbox, PIVlab, is used to apply particle image velocimetry (PIV) to nadir imagery that is georectified based on GPS position and gimbal heading information. The technique shows potential when PIV derived velocities are compared to velocities measured by the surface drifters. For drifter velocities over 0.8ms-1, there is reasonable correlation, although substantial variance, with mean absolute errors between 0.12ms-1 and 0.24ms-1. There is a poorer match with drifter velocities below 0.8ms-1; mean absolute errors are between 0.33ms-1 and 0.34ms-1, which considering the smaller velocities, give large percentage errors. It is hypothesised that improved image pre-processing would reduce these errors.
AB - Whenever considering new tidal stream sites; information on current characteristics is of paramount importance. This contribution describes a methodology to measure surface currents at tidal stream sites using drones and provides initial validation of the approach against velocities measured by GPS surface drifters. Drones have the potential to measure surface currents at high spatial resolution and low cost. An open-source toolbox, PIVlab, is used to apply particle image velocimetry (PIV) to nadir imagery that is georectified based on GPS position and gimbal heading information. The technique shows potential when PIV derived velocities are compared to velocities measured by the surface drifters. For drifter velocities over 0.8ms-1, there is reasonable correlation, although substantial variance, with mean absolute errors between 0.12ms-1 and 0.24ms-1. There is a poorer match with drifter velocities below 0.8ms-1; mean absolute errors are between 0.33ms-1 and 0.34ms-1, which considering the smaller velocities, give large percentage errors. It is hypothesised that improved image pre-processing would reduce these errors.
KW - Drones
KW - Particle Image Velocimetry
KW - Surface Currents
KW - Tidal Stream Energy
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M3 - Conference article
AN - SCOPUS:85120042889
SN - 2706-6932
SP - 2018-1-2018-10
JO - Proceedings of the European Wave and Tidal Energy Conference
JF - Proceedings of the European Wave and Tidal Energy Conference
T2 - 14th European Wave and Tidal Energy Conference, EWTEC 2021
Y2 - 5 September 2021 through 9 September 2021
ER -