title: Shallow-water acoustic tomography from angle measurements instead of travel-time measurements.
abstract: For shallow-water waveguides and mid-frequency broadband acoustic signals, ocean acoustic tomography (OAT) is based on the multi-path aspect of wave propagation. Using arrays in emission and reception and advanced array processing, every acoustic arrival can be isolated and matched to an eigenray that is defined not only by its travel time but also by its launch and reception angles. Classically, OAT uses travel-time variations to retrieve sound-speed perturbations; this assumes very accurate source-to-receiver clock synchronization. This letter uses numerical simulations to demonstrate that launch-and-reception-angle tomography gives similar results to travel-time tomography without the same requirement for high-precision synchronization.
authors.affiliation: Unité Mixte de Recherche 5216 CNRS, Grenoble Institut National Polytechnique, Université Joseph Fourier, Université Stendhal, 11 Rue des Mathématiques, Grenoble Campus, BP46, F - 38402 Saint Martin d'Hères Cedex, France Florian.Aulanier@gipsa-lab.grenoble-inp.fr, Barbara.Nicolas@gipsa-lab.grenoble-inp.fr, Jerome.Mars@gipsa-lab.grenoble-inp.fr.
authors.forename: Florian
authors.initials: F
authors.lastname: Aulanier
authors.forename: Barbara
authors.initials: B
authors.lastname: Nicolas
authors.forename: Jérôme I
authors.initials: JI
authors.lastname: Mars
authors.forename: Philippe
authors.initials: P
authors.lastname: Roux
authors.forename: Romain
authors.initials: R
authors.lastname: Brossier
mesh_terms: D000162:Acoustics; D003198:Computer Simulation; D009038:Motion; D009716:Numerical Analysis, Computer-Assisted; D009791:Oceanography / Q000379:methods*; D009792:Oceans and Seas; D015203:Reproducibility of Results; D012623:Seawater; D012815:Signal Processing, Computer-Assisted; D013016:Sound; D013018:Sound Spectrography; D013997:Time Factors