 |
Article dans une revue
Passive geoacoustic inversion with a single hydrophone using broadband ship noise
Abstract : An inversion scheme is proposed, relying upon the inversion of the noise of a moving ship measured on a single distant hydrophone. The spectrogram of the measurements exhibits striations which depend on waveguide parameters. The periodic behavior of striations versus range are used to estimate the differences of radial wavenumber between couples of propagative modes at a given frequency. These wavenumber differences are stacked for several frequencies to form the relative dispersion curves. Such relative dispersion curves can be synthesized using a propagation model feeded with a bottom geoacoustic model. Inversion is performed by looking for the bottom properties that optimize the fit between measured and predicted relative dispersion curves. The inversion scheme is tested on simulated data. The conclusions are twofold: (1) a minimum 6 dB signal to noise ratio is required to obtained an unbiased estimate of compressional sound speed in the bottom with a 3m s 1 standard deviation; however, even with low signal to noise ratio, the estimation error remains bounded and (2) in the case of a multi-layer bottom, the scheme produces a single depthaverage compressional sound speed. The inversion scheme is applied on experimental data. The results are fully consistent with a core sample measured around the receiving hydrophone.
https://hal-ensta-bretagne.archives-ouvertes.fr/hal-00690412
Contributeur : Annick Billon-Coat <>
Soumis le : lundi 23 avril 2012 - 14:31:38
Dernière modification le : jeudi 19 novembre 2020 - 12:59:41
Contributeur : Annick Billon-Coat <>
Soumis le : lundi 23 avril 2012 - 14:31:38
Dernière modification le : jeudi 19 novembre 2020 - 12:59:41
Lien texte intégral
