%0 Journal Article %T Shallow-water waveguide acoustic analysis in a fluctuating environment %+ École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne) %+ Service Hydrographique et Océanographique de la Marine (SHOM) %+ DGA %A Pinson, Samuel %A Quilfen, Victor %A Le Courtois, Florent %A Real, Gaultier %A Fattaccioli, Dominique %< avec comité de lecture %@ 0001-4966 %J Journal of the Acoustical Society of America %I Acoustical Society of America %V 152 %N 3 %P 1252-1262 %8 2022-09 %D 2022 %R 10.1121/10.0013831 %Z Engineering Sciences [physics]/Acoustics [physics.class-ph]Journal articles %X The Acoustic Laboratory for Marine Applications (ALMA) is a deployable and autonomous acoustic system, designed by DGA Naval Systems, to address problems in underwater acoustics, such as sound propagation in fluctuating environments. In this article, data from the ALMA-2016 at-sea campaign are used to analyze the ocean fluctuation's influence on sound propagation in a shallow-water waveguide. The experiment took place on the continental shelf of the island of Corsica in November 2016. A source and a receiver array were 9.3 km apart in a nearly constant water depth of 100 m. The source emitted a variety of signals from which the chirp (1–13 kHz) is used to extract the waveguide eigenrays. To do so, a time-domain beamforming is performed on the match-filtered received signals with an automatic detection of local maxima in the time of arrival/direction of arrival (TOA/DOA) domain. A 2 min acquisition period of more than 13 h duration shows significant fluctuations in eigenray TOAs/DOAs. Qualitative comparisons with synthetic signals obtained from simulations in two and three dimensions permit reproduction of the observed eigenray fluctuations without including range dependence of the sound-speed profile. %G English %L hal-03808840 %U https://ensta-bretagne.hal.science/hal-03808840 %~ ENSTA-BRETAGNE