Acoustic noise interferometry for remote sensing of the ocean

Abstract: In a wide range of frequencies spanning from below 1 mHz to hundreds of kHz and encompassing acoustic, gravity, and infragravity waves, ocean waves create pressure fluctuations, which can be harnessed to interrogate the ocean and measure physical parameters of the water column, ice cover, and the seabed. Noise interferometry replaces signals due to a powerful, compact wave source with averaging extensive datasets comprising contributions of multiple spatially distributed random sources. By cross-correlating the pressure or particle acceleration fluctuations at different locations, interferometry of diffuse noise retrieves approximations to Green’s functions of various waves, which then serve as the input data for passive ocean remote sensing. The success of seismic interferometry is well documented. Achievements of acoustic noise interferometry are more modest but include passive measurements of current velocity in the Straits of Florida, acoustic thermometry of the ocean, passive acoustic tomography of the water column, characterization of the geoacoustic parameters of the seabed at various sites, and characterization of the sound speed profile variations on sub-seasonal time scales on continental shelf. 
In this presentation, I will discuss the theoretical underpinnings and current implementation of acoustic and gravity wave interferometry in the ocean as well as emerging opportunities for ocean monitoring that stem from combination of wave interferometry with distributed acoustic sensing of underwater fiber-optic cables. 

‼️ Le séminaire peut être suivi en ligne suivant le lien : https://univ-amu-fr.zoom.us/j/96895258758?pwd=oTjg71WEYYQnzs95yn19hk7Mp4sE3o.1

Le mardi 21 octobre 2025 à 11h00 / Amphithéâtre François Canac, LMA

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