Page 31: of Marine Technology Magazine (March 2026)

A Carefully Managed Mission Model (DTM). Conclusions and Future Prospects

The mission required adherence to Comparing LiDAR data with topo- The operation in Palavas-les-Flots, numerous parameters. The Navigator graphic surveys acquired using a GNSS combining a new methodology and a system needed a drone capable of car- rod (GCP) demonstrated centimeter- baseline assessment before develop- rying a 4 kg payload. The ? ight scenario level accuracy. This precision is essen- ment, validated the operational capabil- chosen was S1, due to the drone’s to- tial for detecting sandbank movements ity of the Navigator. This tool effective- tal weight. The mission utilized a DJI and any changes or displacements of ly ? lls gaps in bathymetric data while

M600, a drone proven for bathymetric future UpBlock structures or existing ensuring the continuity of topographic

LiDAR missions. breakwaters. data with centimeter precision.

Given the urban context and the pres- Terrasolid software was thenused to The ? ight protocol, approved by au- ence of an air corridor, ? ight autho- overlay the processed data. Lineup thorities, will serve as a reference for rizations were obtained, and all legal Ocean had conducted photogrammetric future operations. The next data ac- requirements were followed. Palavas- modeling in April 2025, while LiDAR quisitions will occur during the instal- les-Flots, a popular seaside resort near acquisition took place in June 2025. The lation of a demonstrator segment of an airport, also presented logistical observed differences in the beach pro- UpBlock modules and after the ? rst challenges. To minimize disruptions, ? le were attributed to seasonal changes, storm, to measure sandbank move- the mapping was conducted at sunrise, such as winter storms. Fixed structures ments on the site. YellowScan will par- with support from the municipal police and breakwaters served as reference ticipate in these operations as a techni- to secure the area. points, showing that the beach pro? le cal partner.

To create a comprehensive carto- had evolved between April and June. YellowScan thanks the Lineup Ocean graphic baseline, data density was cru- The LiDAR acquisition revealed a level team for their trust and openness to cial. The plan involved covering the drop of nearly 20 cm in some areas of new technologies, as well as the mu- 8-hectare experimental site in less than the emerged beach, a phenomenon at- nicipality of Palavas-les-Flots and the 20 minutes, at an altitude of 50 meters tributed to the establishment of a “sum- Directorate General of Civil Aviation and a speed of 5 m/s. In practice, the mer pro? le” by the Lineup Ocean team. for their support.

protocol was adapted with three dis- tinct takeoff and landing zones to main- tain the maximum allowed distance be- tween the drone and the pilot.

Throughout the operation, the drone pilot, LiDAR operator, and members of the Lineup Ocean and YellowScan teams ensured the smooth execution of the ? ights. Pedestrians, athletes, and residents were informed about the

SURFREEF project and the ongoing mission.

Data Processing

The point clouds generated by the Nav- igator were processed and classi? ed, then cross-checked with control points (GCP) and, for the terrestrial part, with photogrammetry data. Given the nature of the project and the mapped area, half a day was allocated for data processing.

The topo-bathymetric LiDAR point cloud was processed automatically us- ing YellowScan CloudStation software.

The point density underwater was at least 20 points/m². This software was used for classi? cation and ? ltering to export the seabed as a Digital Terrain www.marinetechnologynews.com 31

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