2023_programme: Ocean acoustics experiments in environments of high frequency hydrological dynamics

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  • Session: 11. Prospective underwater acoustics : at-sea experiments
    Organiser(s): Jean-Pierre Sessarego, Dominique Fattaccioli and Gaultier Real
  • Lecture: Ocean acoustics experiments in environments of high frequency hydrological dynamics [invited]
    Paper ID: 2009
    Author(s): KINDA G. Bazile, Le Courtois Florent, Réal Gaultier, Dellong David, Lajaunie Myriam
    Presenter: Kinda G. Bazile
    Abstract: The understanding of oceanographic processes is a major issue for underwater acoustic propagation. Indeed, unstable phenomena such as thermal or thermohaline fronts create complex modeling conditions and low-resolution numerical models of the environment are not always adequate to estimate in situ acoustic properties.\n\nThree Acoustic campaigns have been conducted for this purpose between 2019 and 2022, in collaboration between the Shom and the DGA Naval Systems (French Defense Procurement Agency). These campaigns were focusing on different fronts and aimed at characterizing the impact of high frequency hydrological phenomena on underwater acoustic propagation. \n\nThe experimental protocol consisted of an exploratory phase to characterize the physical environment as accurately as possible, to determine a configuration for the deployment of a set of acoustic sources and receivers. In general, acoustic sources are either moored (bandwidth 1kHz - 14 kHz) or towed (bandwidth 50 Hz - 2200 Hz). The receivers consisted in two moorings: one of two autonomous hydrophones and the other of a 6-hydrophones array. These acoustic moorings were completed, in some cases, by hydrological moorings to monitor environmental fluctuations between the sources and receivers. One of the campaigns also used two oceanographic and acoustic payload gliders to ensure spatial sampling, mainly the right-of-way of the fixed moorings. The propagation ranges lie between 18 km and 50 km in various sections crossing the fronts.\n\nResults in terms of underwater acoustics propagation (temporal and spatial evolution of the impulse response and of the transmission loss) associated with the fluctuations in the frontal zone of the environment will be presented.
  • Corresponding author: Dr G. Bazile KINDA
    Affiliation: Shom
    Country: France
    e-mail:

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