Accuracy of sand beach topography surveying by drones and photogrammetry
Elisa Casella
Jan Drechsel
Christian Winter
Markus Benninghoff
Alessio Rovere
Abstract
Beaches are characterized by high morphodynamic activity, and high-frequency measurements are needed to understand their states and rates of change. Ideally, beach survey methods should be at once accurate, rapid and low-cost. Recently, unmanned aerial systems (drones) have been increasingly utilized to measure beach topography. In this paper, we present a review of the state of art in drones and photogrammetry for beach surveys and the respective achieved measurement quality (where reported). We then show how drones with a minimal configuration and a low-cost setup can meet the high accuracy and rapidity required for beach surveys. To test a minimal drone and ground control point configuration, we used consumer-grade equipment to perform the same flight path with different cameras and at different altitudes. We then used photogrammetry to produce digital elevation models of the beach. Using a GNSS-RTK system, we collected 2950 independent control points to evaluate the accuracy of the digital elevation models. Results show that, once a few potential sources of uncertainties in the final digital elevation model are taken into account, the average RMSE(z) of the digital elevation models was ~5 cm, with a survey efficiency of ca. 3 m2 min−1. Digital elevation models taken at different times were used to calculate the before–after sediment budget following a storm that hit a sandy coast in Sylt Island at the German North Sea coast.
Casella E., Drechsel J., Winter C., Benninghoff M. and Rovere A. (2020) Accuracy of sand beach topography surveying by drones and photogrammetry. Geo-Marine Letters 40: 255-268. 10.1007/s00367-020-00638-8
@article{Casella2020,
Title = {Accuracy of sand beach topography surveying by drones and photogrammetry},
Author = {Casella, Elisa and Drechsel, Jan and Winter, Christian and Benninghoff, Markus and Rovere, Alessio},
Editor = {},
Journal = {Geo-Marine Letters},
Year = {2020},
Pages = {255-268},
Volume = {40},
Doi = {10.1007/s00367-020-00638-8},
Abstract = {Beaches are characterized by high morphodynamic activity, and high-frequency measurements are needed to understand their states and rates of change. Ideally, beach survey methods should be at once accurate, rapid and low-cost. Recently, unmanned aerial systems (drones) have been increasingly utilized to measure beach topography. In this paper, we present a review of the state of art in drones and photogrammetry for beach surveys and the respective achieved measurement quality (where reported). We then show how drones with a minimal configuration and a low-cost setup can meet the high accuracy and rapidity required for beach surveys. To test a minimal drone and ground control point configuration, we used consumer-grade equipment to perform the same flight path with different cameras and at different altitudes. We then used photogrammetry to produce digital elevation models of the beach. Using a GNSS-RTK system, we collected 2950 independent control points to evaluate the accuracy of the digital elevation models. Results show that, once a few potential sources of uncertainties in the final digital elevation model are taken into account, the average RMSE(z) of the digital elevation models was ~5 cm, with a survey efficiency of ca. 3 m2 min−1. Digital elevation models taken at different times were used to calculate the before–after sediment budget following a storm that hit a sandy coast in Sylt Island at the German North Sea coast.},
}
TY - JOUR
AU - Casella, Elisa
AU - Drechsel, Jan
AU - Winter, Christian
AU - Benninghoff, Markus
AU - Rovere, Alessio
TI - Accuracy of sand beach topography surveying by drones and photogrammetry
T2 - Geo-Marine Letters
PY - 2020
SP - 255-268
VL - 40
DO - 10.1007/s00367-020-00638-8
AB - Beaches are characterized by high morphodynamic activity, and high-frequency measurements are needed to understand their states and rates of change. Ideally, beach survey methods should be at once accurate, rapid and low-cost. Recently, unmanned aerial systems (drones) have been increasingly utilized to measure beach topography. In this paper, we present a review of the state of art in drones and photogrammetry for beach surveys and the respective achieved measurement quality (where reported). We then show how drones with a minimal configuration and a low-cost setup can meet the high accuracy and rapidity required for beach surveys. To test a minimal drone and ground control point configuration, we used consumer-grade equipment to perform the same flight path with different cameras and at different altitudes. We then used photogrammetry to produce digital elevation models of the beach. Using a GNSS-RTK system, we collected 2950 independent control points to evaluate the accuracy of the digital elevation models. Results show that, once a few potential sources of uncertainties in the final digital elevation model are taken into account, the average RMSE(z) of the digital elevation models was ~5 cm, with a survey efficiency of ca. 3 m2 min−1. Digital elevation models taken at different times were used to calculate the before–after sediment budget following a storm that hit a sandy coast in Sylt Island at the German North Sea coast.
ER -
