title: Estimation of modal group velocities with a single receiver for geoacoustic inversion in shallow water.
abstract: Due to the expense associated with at-sea sensor deployments, a challenge in underwater acoustics has been to develop methods requiring a minimal number of sensors. This paper introduces an adaptive time-frequency signal processing method designed for application to a single source-receiver sensor pair. The method involves the application of conjugate time-frequency warping transforms to improve the SNR and resolution of the time-frequency distribution (TFD) of the measured field. Such refined knowledge of the TFD facilitates efforts to extract tomographic information about the propagation medium. Here the method is applied to the case of modal propagation in a shallow ocean range independent environment to extract a refined TFD. Given knowledge of the source-receiver separation, the refined TFD is used to extract the frequency dependent group velocities of the individual modal components. The extracted group velocities are then incorporated into a computationally light tomographic inversion method. Simulated and experimental results are discussed.
authors: GIPSA-Laboratory/DIS, Grenoble Institute of Technology, 961 rue de la Houille Blanche, 38402 Grenoble, France. julien.bonnel@gipsa-lab.inpg.fr
authors: Julien
authors: J
authors: Bonnel
authors: Barbara
authors: B
authors: Nicolas
authors: Jérome I
authors: JI
authors: Mars
authors: Shane C
authors: SC
authors: Walker
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D003198:Computer Simulation; D004867:Equipment Design; D005844:Geology / Q000295:instrumentation*; D008962:Models, Theoretical; D009038:Motion; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D013018:Sound Spectrography; D013997:Time Factors; D014159:Transducers