Details
Original language | English |
---|---|
Pages (from-to) | 150-165 |
Number of pages | 16 |
Journal | Coastal Engineering |
Volume | 83 |
Publication status | Published - 1 Jan 2014 |
Abstract
Simulating swash zone morphodynamics remains one of the major weaknesses of beach evolution models. One of the reasons is the limited availability of data on morphological changes at the temporal scales of individual swash events. This paper sets out to present a new hybrid system, consisting of 2D/3D laser scanners and several video cameras, which was designed to monitor swash zone topographic change on a wave-by-wave basis. A methodology is proposed consisting of sensor calibration and several data processing steps, allowing a fusion of different sensors. Such an approach can improve the performance of several field/laboratory, optical technique applications for nearshore hydro- and morpho-dynamic measurements. Digital Elevation Models from a 3D scanner were used in the extrinsic camera calibration procedure and reduced the geo-rectification errors from 0.035m<RMSE<0.071m to 0.008m<RMSE<0.013m. The 2D scanner provided instantaneous measurements of the water and dry beach surface elevation along a 10m cross-shore section, and comparison with ultrasonic sensor measurements resulted in RMS errors within the 1.7cm<RMSE<3.2cm range. The combination of 2D scanner and video data (i) reduced geo-rectification errors by more than one order of magnitude; and (ii) made 2D laser point cloud processing easier and more robust. The hybrid monitoring system recorded the morphological change of a replenished beach-face on a wave-by-wave basis, during large-scale, physical modeling experiments and the observations showed that individual swash events could result in elevation changes up to dz=±10cm. The sediment transport direction and intensity of the monitored swash events was relatively balanced and sediment transport rates ranged between -3.5kgm -1s -1>Q t>3.5kgm -1s -1. Extreme transport swash events became rarer as the morphology was reaching equilibrium.
Keywords
- Coastal erosion, Coastal video monitoring, Remote sensing, Sediment transport, Swash zone, Terrestrial LIDAR
ASJC Scopus subject areas
- Environmental Science(all)
- Environmental Engineering
- Engineering(all)
- Ocean Engineering
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In: Coastal Engineering, Vol. 83, 01.01.2014, p. 150-165.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - The role of combined laser scanning and video techniques in monitoring wave-by-wave swash zone processes
AU - Vousdoukas, MI
AU - Kirupakaramoorthy, T
AU - Oumeraci, H.
AU - De La Torre, M
AU - Wübbold, Frauke
AU - Wagner, Bernardo
AU - Schimmels, Stefan
N1 - Funding information: The principal author acknowledges funding from the European Community Seventh Framework Programme , under the Integrated Infrastructure Initiative Hydralab IV , Contract no. 261520 . We are also grateful to Matthias Kudella, Hernan Fernandez and all the other colleagues at Forschungszentrum Küste for their invaluable support during the experiments.
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Simulating swash zone morphodynamics remains one of the major weaknesses of beach evolution models. One of the reasons is the limited availability of data on morphological changes at the temporal scales of individual swash events. This paper sets out to present a new hybrid system, consisting of 2D/3D laser scanners and several video cameras, which was designed to monitor swash zone topographic change on a wave-by-wave basis. A methodology is proposed consisting of sensor calibration and several data processing steps, allowing a fusion of different sensors. Such an approach can improve the performance of several field/laboratory, optical technique applications for nearshore hydro- and morpho-dynamic measurements. Digital Elevation Models from a 3D scanner were used in the extrinsic camera calibration procedure and reduced the geo-rectification errors from 0.035m<RMSE<0.071m to 0.008m<RMSE<0.013m. The 2D scanner provided instantaneous measurements of the water and dry beach surface elevation along a 10m cross-shore section, and comparison with ultrasonic sensor measurements resulted in RMS errors within the 1.7cm<RMSE<3.2cm range. The combination of 2D scanner and video data (i) reduced geo-rectification errors by more than one order of magnitude; and (ii) made 2D laser point cloud processing easier and more robust. The hybrid monitoring system recorded the morphological change of a replenished beach-face on a wave-by-wave basis, during large-scale, physical modeling experiments and the observations showed that individual swash events could result in elevation changes up to dz=±10cm. The sediment transport direction and intensity of the monitored swash events was relatively balanced and sediment transport rates ranged between -3.5kgm -1s -1>Q t>3.5kgm -1s -1. Extreme transport swash events became rarer as the morphology was reaching equilibrium.
AB - Simulating swash zone morphodynamics remains one of the major weaknesses of beach evolution models. One of the reasons is the limited availability of data on morphological changes at the temporal scales of individual swash events. This paper sets out to present a new hybrid system, consisting of 2D/3D laser scanners and several video cameras, which was designed to monitor swash zone topographic change on a wave-by-wave basis. A methodology is proposed consisting of sensor calibration and several data processing steps, allowing a fusion of different sensors. Such an approach can improve the performance of several field/laboratory, optical technique applications for nearshore hydro- and morpho-dynamic measurements. Digital Elevation Models from a 3D scanner were used in the extrinsic camera calibration procedure and reduced the geo-rectification errors from 0.035m<RMSE<0.071m to 0.008m<RMSE<0.013m. The 2D scanner provided instantaneous measurements of the water and dry beach surface elevation along a 10m cross-shore section, and comparison with ultrasonic sensor measurements resulted in RMS errors within the 1.7cm<RMSE<3.2cm range. The combination of 2D scanner and video data (i) reduced geo-rectification errors by more than one order of magnitude; and (ii) made 2D laser point cloud processing easier and more robust. The hybrid monitoring system recorded the morphological change of a replenished beach-face on a wave-by-wave basis, during large-scale, physical modeling experiments and the observations showed that individual swash events could result in elevation changes up to dz=±10cm. The sediment transport direction and intensity of the monitored swash events was relatively balanced and sediment transport rates ranged between -3.5kgm -1s -1>Q t>3.5kgm -1s -1. Extreme transport swash events became rarer as the morphology was reaching equilibrium.
KW - Coastal erosion
KW - Coastal video monitoring
KW - Remote sensing
KW - Sediment transport
KW - Swash zone
KW - Terrestrial LIDAR
UR - http://www.scopus.com/inward/record.url?scp=84887387834&partnerID=8YFLogxK
U2 - 10.1016/j.coastaleng.2013.10.013
DO - 10.1016/j.coastaleng.2013.10.013
M3 - Article
VL - 83
SP - 150
EP - 165
JO - Coastal Engineering
JF - Coastal Engineering
SN - 0378-3839
ER -