Marine mammal's directivity in geoacoustic inversion scheme - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2014

Marine mammal's directivity in geoacoustic inversion scheme

Résumé

Gervaise & al 2011 and Barazzutti & al 2013 described the general structure of a scheme to estimate the nature of superficial sediment in shallow waters using marine mammal's whistles and a single receiver. The multipath structure of calls given by a spectrogram is used to estimate the source characteristics and the superficial sea bottom features. A field application of this method was presented in [11] using controlled signals similar to marine mammal's vocalizations in a shallow water environment on a sandy bottom. However, contrary to the source used during that experiment, marine mammals are directive sources and the directivity loss underwent by the multipath must be taken into account in our inversion process. Indeed, the directivity is a function of frequency and emission angle (sound-source azimuth), and impacts each path differently. Thus the bottom path, once corrected from transmission loss, must be corrected from directivity loss before being used to estimate the bottom features. The emission angle can easily be geometrically related to the arrival angle and a specific unknown angle we called attitude (source orientation in space during the emission). However, the directivity patterns of marine mammals are not well studied yet, especially for vocalizations (e.g. directivity model assumption - Au 1993[4], directivity pattern measurement - Au & al 2012[9], etc.) and contrary to other mammals the unknown "attitude" parameter is not that easy to observe (e.g. Dantzker & al 1999). Our communication aims at describing different methods to estimate the "attitude" angle and the directivity loss for marine mammals. Their performances and limits are evaluated using simulated data.
Fichier principal
Vignette du fichier
236._Marine_mammala_s_directivity_in_geoacoustic_inversion_scheme.pdf (715.54 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-01021409 , version 1 (09-07-2014)

Identifiants

  • HAL Id : hal-01021409 , version 1

Citer

Amélie Barazzutti, Cedric Gervaise, Jerome I. Mars. Marine mammal's directivity in geoacoustic inversion scheme. UA 2014 - 2nd international conference and exhibition on Underwater Acoustics, Jun 2014, Rhodes, Greece. pp.1557-1562. ⟨hal-01021409⟩
212 Consultations
113 Téléchargements

Partager

Gmail Facebook X LinkedIn More