Description du sujet de thèse

We are looking for a PhD student to develop an underwater centimeter positioning system associated with underwater photogrammetric surveys. The overall objective of the project is to develop an operational solution for accurate underwater photogrammetric surveys for seabed exploration and monitoring. The research proposed to the candidate will consist in defining and implementing a methodology allowing the centimetric positioning of acoustic beacons on the seabed that will serve as a control point for the photogrammetric survey. The principle of underwater positioning is based on the measurement of return travel time between acoustic sources carried by surface drones (USV Unmaned Surface Vehicle) and transponder beacons placed previously on the bottom whose position is sought to know. The USV are located by kinematic GPS, allowing to determine the coordinates of the beacons by tri-lateration.
The PhD student will develop the precise positioning system based on GNSS measurements for the dynamic positioning of surface drones and acoustic signals to underwater beacons. We are looking for a candidate with strong geodesy skills, good development ability and able to implement new methods. The candidate must also be able to train in underwater positioning. Finally, he must have a taste for measuring and organizing experience at sea.

Contexte de travail

The context is that of the DEEP-C project funded by BPI-France. This project is supported by the start-up DEESS and CNRS research laboratories, including Geoazur located in Sophia-Antipolis. The Géoazur laboratory is a multidisciplinary research unit composed of geophysicists, geologists, and astronomers federating themselves around major scientific issues: telluric hazards (seismic, gravity and tsunami) and associated risks, the dynamics of the lithosphere and the imagery of the Earth, the geodesy-metrology of the Earth and the nearby Universe. The laboratory is composed of about 170 researchers and teacher researchers and structured into 6 thematic teams. The successful candidate will join the laboratory's earthquake team, and will work under the responsibility of Jean-Mathieu NOCQUET,

Contraintes et risques

The student will make regular stays at Ifremer in Seyne-sur-Mer where the project is developed. He will interact directly with DEESS engineers and researchers involved in the project. The PhD student will have to carry out short sea campaigns, typically one day to carry out the experiments of his project.