UAV photogrammetry monitoring of La Palue and Lostmarc'h embayed beaches (Crozon, France)
UAV flights (DJI Phantom 4 RTK) and GNSS surveys are performed quarterly during spring low tides over La Palue and Lostmarc’h embayed beaches in Crozon peninsula (Brittany, France). Image blocks are processed using Structure-from-Motion (SfM) photogrammetry to produce georeferenced orthophotographs and Digital Elevation Models (DEMs) at 0.1 m and 1 m spatial resolution.
Simple
- Date (Publication)
- 2021-11-20
- Citation identifier
- https://portail.indigeo.fr/geonetwork/srv/metadata/092918bf-dfb1-4d8e-805b-6bd420158160
- Credit
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UMR 6538 Geo-Ocean
- Status
- On going
- Point of contact
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Organisation name Individual name Electronic mail address Role UMR 6538 Geo-Ocean
Bertin Stéphane
Author UMR 6538 Geo-Ocean
Ammann Jérôme
Author
- Theme
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Beach profile
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Digital Elevation Model
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Coastal monitoring
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Orthoimage
- Place
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Brittany
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Finistere
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Crozon
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GEMET - INSPIRE themes, version 1.0
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Orthoimagery
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Elevation
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- Access constraints
- Other restrictions
- Other constraints
- No limitations to public access
- Use limitation
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Free use subject to mentioning the source (at least the name of the producer) and the date of its last update
- Use constraints
- Other restrictions
- Other constraints
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Supplier partner is not able to guarantee the accuracy, update, integrity, completeness of data and in particular that they are free of errors or inaccuracies, including location, identification or qualification. No warranty as to the fitness of the data for a particular purpose is made by the supplier partner. Users use the data under their full responsibility, without recourse against the supplier partner whose liability can be incurred due to damage resulting directly or indirectly from the use of this data. In particular, it is up to users to decide, on their own responsibility: the opportunity to use the data; File compatibility of their computer systems; adequacy of the data to their needs; that they have sufficient competence to use the data. The partner supplier is in no way responsible for external elements including data analysis tools, hardware, software, networks ... used to view and / or process data. The user ensures verify the timeliness of the information provided is compatible with the use of it.
- Spatial representation type
- Grid
- Spatial representation type
- Text, table
- Distance
- 1 m
- Language
- Français
- Character set
- UTF8
- Topic category
-
- Geoscientific information
))
- Begin date
- 2020-09-17
- End date
- 2022-06-14
- Unique resource identifier
- RGF93 / Lambert-93 + NGF-IGN69 height (EPSG:5698)
- Distribution format
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Name Version ASC
1.0
GeoTIFF
1.0
- Distributor contact
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Organisation name Individual name Electronic mail address Role INDIGEO
Publisher
- OnLine resource
- Hierarchy level
- Dataset
Conformance result
- Date (Publication)
- 2010-12-08
- Explanation
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Article 7, paragraph 1, of Directive 2007/2 / EC corresponds to the technical procedures for interoperability: this is the regulation on interoperability: regulation n ° 1253/2013 of 21 October 2013 amending and supplementing Regulation n ° 1089/2010 of 23 November 2010
- Pass
- Yes
- Statement
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Data are referenced according to the French coordinate system: RGF93-Lambert93 horizontal and NGF-IGN69 vertical. Three geodetic marks (cast iron nails) have been implanted into bedrock on Kerdra point. Two geodetic marks are used as fixed positions with known coordinates to install the GNSS base station (Topcon Hiper V) and the drone mobile station for image geolocation (DJI RTK2). The other mark is used for RTK-GNSS georeferencing evaluation, showing sub-centimetric standard error in rapid static mode (four acquisitions over a seven-month period; GNSS rover mounted onto a pole set at 2 m with 10 s averaging).
- Description
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UAV data acquisition: Images are collected from an altitude of ~100 m above the beach. Images are geolocated in RTK mode using the drone mobile station. Several flights with a small alongtrack overlap are necessary to cover the survey area. Each flight consists in a simple photogrammetric block with a forward/side overlap of 80/70 %, respectively. The camera (20Mpixel 1’ CMOS sensor) is tilted forward with a 6° angle during image acquisition. The ground sampling distance (GSD) on the beach is approximately 2.6 cm.
- Rationale
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UAV data acquisition
- Description
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GNSS surveys: Ground photogrammetric targets, visible on aerial images, are measured using RTK-GNSS in rapid-static mode. Targets are used either as ground control points (GCPs) during photogrammetric reconstruction or as verification points (ChkPts).
- Rationale
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GNSS surveys
- Description
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Photogrammetric processing: Aerial images are processed using SfM photogrammetry embodied in Agisoft Metashape ( https://www.agisoft.com/ ). Camera self-calibration and model georeferencing are performed using both image exif information (position and attitude) and GCPs. Interpolated DEMs/orthophotographs are prepared with a final spatial resolution of 0.5/0.1 m, respectively. Raster coverage (2500 x 600 m) is kept constant throughout acquisitions (Easting = 139350 - 139950 m, Northing = 6814700 – 6817200 m).
- Rationale
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Photogrammetric processing
- Description
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Quality verification: Photogrammetric quality is evaluated using independent verification data (ChkPts) measured using RTK-GNSS. Results demonstrate the absence of bias in data and centimetric global precision (RMSE along XYZ ~GSD).
- Rationale
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Quality verification
Metadata
- File identifier
- 092918bf-dfb1-4d8e-805b-6bd420158160 XML
- Metadata language
- Français
- Character set
- UTF8
- Hierarchy level
- Dataset
- Hierarchy level name
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Parent
- Date stamp
- 2022-09-08T14:37:49
- Metadata standard name
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ISO 19115
- Metadata standard version
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1.0
- Metadata author
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Organisation name Individual name Electronic mail address Role UMR 6538 Geo-Ocean
Bertin Stéphane
Point of contact
- Other language
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Language Character encoding English UTF8 French UTF8
Overviews
Spatial extent
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