UACE2023: JEAN-PIERRE HERMAND: AN INNOVATOR IN OCEAN ACOUSTIC EXPERIMENTATION



  • Session: 01. Memorial Session for Jean-Pierre Hermand
    Organiser(s): Chapman Ross
  • Lecture: JEAN-PIERRE HERMAND: AN INNOVATOR IN OCEAN ACOUSTIC EXPERIMENTATION [invited]
    Paper ID: 914
    Author(s): Siderius Martin
    Presenter: Siderius Martin
    Presentation type: oral
    Abstract: Jean-Pierre Hermand was a pioneer in large scale ocean experiments. I met Jean-Pierre when I came to work for NATO at the SACLANT Undersea Research Centre (now the Centre for Maritime Research and Experimentation). I was assigned to work for Jean-Pierre and this began my education into ocean acoustic experiments and the complexities of working with field data. In the mid 1990’s Jean-Pierre designed and led a series of novel ocean acoustic experiments. These included the Yellow Shark experiments in the fall of 1994 and spring of 1995. These experiments were remarkably comprehensive in that they included a massive collection of acoustic, oceanographic and geophysical data. The measurements were extensive, taken over several weeks with both ship and shore based instruments and source-receiver separations of up to 55 km. Jean-Pierre chose the location of the Yellow Shark experiments based, in part, on the interesting clay and silt layers that strongly influence the acoustic propagation. The site is in the Giglio basin off the west coast of Italy just south of Elba Island. Over the propagation tracks there exists a clay layer of varying thickness of between 3 and 10 m with a sound speed less than the water column. The clay layer is above a more consolidated and higher sound speed silt. For certain source-receiver geometries, the layering causes a strongly frequency dependent filtering of the transmission loss data. Using the detailed measurements of bathymetry and geo-acoustic properties of the seabed the effect could be reproduced in simulations showing the underlying cause of the filtering. In this paper, the experimental work of Jean-Pierre will be described along with a description of some of the resulting analysis and discoveries. His ground-breaking research into geo-acoustic inversion methods and the model-based matched filter will also be discussed.\n
  • Corresponding author: Prof Siderius Martin
    Affiliation: Portland State University
    Country: United States
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