Geodaysit 2023

The paper describes the integrated survey operations carried out on the Redisole dam (S.Giovanni in Fiore, southern Italy), on the surrounding area and on the internal and external parts of the artifact. The dam reservoir is not yet filled, so that some elements usually not visible (spillway, bottom outlet) could be surveyied and mapped.
This survey has involved the integration of different geomatic techniques, which can be summarized as follows:
- Georeferencing of the dam, by means of the survey of fixed landmarks with triple frequency differential GPS, in the RDN-ETRF2000 network;
- Quadcopter drone flight for the acquisition of stereoscopic images for photogrammetric use for a surveyed area of about 25 hectares; the same drone has been used for obtaining close-up images for the inspection of the bituminous surface of the dam. To this aim, GCP have been positioned and their coordinates have been acquired acquisition with differential GPS and Total Station;
- Survey by long range Terrestrial Laser Scanner of the artifact, of its components and of the surrounding area (up to 500 m from the dam); the fixed landmarks and some Ground Control Points have been used, also surveyied by drone photogrammetry.
- Scanning of the tunnels, of the surface and bottom outlets as well as of the shaft, with a series of static scans conducted with a high precision, medium range Terrestrial Laser Scanner.
- Registration of the point clouds obtained and of DTM and DSM (provided by the Italian Ministry for the Environment) with 1m spacing
- Registration by the Persistent Scatterers (PS) provided by the Italian Ministry for the Environment.
The products obtained are:
- External planimetry of the dam, plano-altimetric rendering (elevated points and contour lines) in vector format, manageable in CAD environment.
- Map, profiles and quoted sections of the tunnels, of the bottom and surface outlets, as well as of the shaft.
- 3D textured model of the entire site;
- Orthophoto of the whole site with 5 cm/pixel resolution;
- High resolution orthophoto projected on the dam wall, for the visual search of the critical points of the surface.
The future activities include:
- The accurate identification of the PS present in the area and the measurement of their movements for the identification of any displacements of the building and/or of the entire area;
- PS monitoring through periodic measurement via GNSS and TLS and comparison of relative movements with those obtained via Differential Interferometric Synthetic Aperture Radar.