%0 Journal article
%A Casella, Elisa
%A Drechsel, Jan
%A Winter, Christian
%A Benninghoff, Markus
%A Rovere, Alessio
%T Accuracy of sand beach topography surveying by drones and photogrammetry
%R 10.1007/s00367-020-00638-8
%J Geo-Marine Letters
%V 40
%N 2

%I Springer Berlin Heidelberg
%X 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.
%U http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10713
%~  FID GEO-LEO e-docs