EGU22-11454, updated on 10 Jan 2024
https://doi.org/10.5194/egusphere-egu22-11454
EGU General Assembly 2022
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Contribution of Direction-of-Arrival Observations for Geodetic Seafloor Positioning Using an Unmanned Surface Vehicle

Pierre Sakic1,2, Clémence Chupin3, Valérie Ballu3, Thibault Coulombier3, Pierre-Yves Morvan4, Paul Urvoas4, Mickael Beauverger5, Edgar Lenhof5, and Jean-Yves Royer5
Pierre Sakic et al.
  • 1GeoForschungsZentrum GFZ, Space Geodesy Section 1.1, Potsdam, Germany
  • 2Institut de Physique du Globe de Paris, University of Paris, Paris, France
  • 3Littoral Environnement et Sociétés, CNRS and University of La Rochelle, La Rochelle, France
  • 4iXBlue, Acoustic Positioning Division, Brest, France
  • 5Laboratoire Géosciences Océan, CNRS and University of Brest, Brest, France

Precise underwater geodetic positioning remains a challenging operation. Measurements combining surface positioning (GNSS) with underwater acoustic positioning are usually performed from research vessels. We present an alternative approach using a small Unmanned Surface Vehicle (USV) equipped with a compact GNSS/Acoustic experimental configuration, which is more cost-effective and easier to deploy. The positioning system included a GNSS receiver mounted above an Ultra Short Baseline (USBL) module integrated with an inertial system (INS) to correct the USV movements. The experiment conducted in the shallow waters (40 m) of the Bay of Brest, France, provided a data set to derive the coordinates of individual transponders from two-way-travel times and direction of arrival (DOA) of acoustic rays from the transponders to the USV. We tested different acquisition protocols (box-in circles around transponders and two static positions of the USV). Using a least-squares inversion, we show that DOAs improve single transponder positioning both in box-in and static acquisitions. From a series of short positioning sessions (20 min) over two days, we achieved repeatability of ~5 cm in the locations of the transponders. Post-processing of the GNSS data also significantly improved the two-way-travel times' residuals compared to the real-time solution.

How to cite: Sakic, P., Chupin, C., Ballu, V., Coulombier, T., Morvan, P.-Y., Urvoas, P., Beauverger, M., Lenhof, E., and Royer, J.-Y.: Contribution of Direction-of-Arrival Observations for Geodetic Seafloor Positioning Using an Unmanned Surface Vehicle, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11454, https://doi.org/10.5194/egusphere-egu22-11454, 2022.

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