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Orthophotos were obtained concurrently with photogrammetric DEMs. They were derived from Unmanned Aerial Vehicle (UAV) imagery processed using Structure-from-Motion photogrammetry (survey method PHO).
Hydrographic surveys have been conducted using small boats of the Institut Universitaire Européen de la Mer (https://www.flotteoceanographique.fr/en/Facilities/Vessels-Deep-water-submersible-vehicles-and-Mobile-equipments/Station-vessels/Albert-Lucas), which can be equipped with a range of sensors for data acquisition in the nearshore zone. For each survey, we prepared a Digital Elevation Model (DEM) at a fixed sampling distance of 0.5 m.
DEMs covering both subaerial and subtidal domains were created by fusing topographic and bathymetric DEMs collected concurrently. Fusion DEMs provide an overview of sedimentary bedforms across the air-water interface. Comparison of measured topographic and bathymetric elevations at the overlap provides means for additional data verification.
In order to facilitate capturing three-dimensional beach change, full surveys of the subaerial beach have been conducted starting in 2004 using RTK-GNSS (survey method GPS), Unmanned Aerial Vehicle (UAV) imagery processed using Structure-from-Motion (SfM) photogrammetry (survey method PHO) and terrestrial laser-scanning (survey method TLS). For each survey, we prepared a Digital Elevation Model (DEM) at a fixed sampling distance of 0.5 m.
Continuous hourly time-series of inshore waves spanning the period 2000-2019 are provided alongside topo-bathymetric and tide datasets. The wave dataset starts three years before topographic observations to provide antecedent conditions for morphodynamic modelling purposes. Wave parameters were derived from existing databases furnished by external organisations.
Continuous tidal levels spanning the period 2000-2019 are provided alongside topo-bathymetric and wave datasets. The astronomical tide dataset starts three years before beach morphological observations. Tidal levels were derived from existing databases furnished by external organisations.
The archived multi-sensor dataset detailed here presents the results of topographic and bathymetric surveys at Porsmilin, a macrotidal pocket (embayed) beach situated in Brittany, in northwest France. The Porsmilin beach survey program was launched in January 2003 by the Institut Universitaire Européen de la Mer (IUEM/Univ. Brest) and is continuing today in the framework of the French coastal observation service SNO-DYNALIT. The dataset contains over 16 years of beach profile surveys and a large collection of recurring high-resolution subtidal and subaerial digital elevation models (DEMs) obtained using various survey methods. The dataset is accompanied by time-series of inshore waves and water levels, and enriched metadata, that will facilitate its future reuse in coastal research. The dataset is structured as follows, with separate metadata (child records) for 1) beach profiles, 2) topographic DEMs, 3) bathymetric DEMs, 4) fusion DEMs, 5) orthophotos, 6) inshore waves and 7) astronomical tides.
Beach profiling using RTK-GNSS (survey method GPS) represents one of the most convenient method for frequent resurveys. Since 2003, profile surveys have been (approx.) weekly for the first year, fortnightly between January 2004 and June 2005, and near-monthly thereafter, with occasional gaps in the data due to equipment misfunctioning and maintenance. Trimble 5700/5800 and Topcon Hiper V GPS systems were used for data acquisition.