Shallow-water acoustic tomography from angle measurements instead of travel-time measurements.

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.

[1]  M. D. Collins.  A split‐step Padé solution for the parabolic equation method , 1993 .

[2]  J. Virieux,et al.  Travel-time tomography in shallow water: experimental demonstration at an ultrasonic scale. , 2011, The Journal of the Acoustical Society of America.

[3]  Carl Wunsch,et al.  Ocean acoustic tomography: a scheme for large scale monitoring , 1979 .

[4]  A. Devaney.  Geophysical Diffraction Tomography , 1984, IEEE Transactions on Geoscience and Remote Sensing.

[5]  Sensitivity kernel for surface scattering in a waveguide. , 2012, The Journal of the Acoustical Society of America.

[6]  Sergio M. Jesus,et al.  An experimental demonstration of blind ocean acoustic tomographya) , 2006 .

[7]  K. Metzger,et al.  Stability and identification of ocean acoustic multipaths , 1980 .

[8]  Per Christian Hansen,et al.  Analysis of Discrete Ill-Posed Problems by Means of the L-Curve , 1992, SIAM Rev..

[9]  Guust Nolet,et al.  Three-dimensional waveform sensitivity kernels , 1998 .

[10]  P. Roux,et al.  Time-angle sensitivity kernels for sound-speed perturbations in a shallow ocean. , 2013, The Journal of the Acoustical Society of America.

[11]  Robert C. Spindel,et al.  Ocean acoustic tomography: Mesoscale velocity , 1987 .

[12]  Dianne P. O'Leary,et al.  The Use of the L-Curve in the Regularization of Discrete Ill-Posed Problems , 1993, SIAM J. Sci. Comput..

[13]  W. Kuperman,et al.  The structure of raylike arrivals in a shallow-water waveguide. , 2008, The Journal of the Acoustical Society of America.

[14]  Albert Tarantola,et al.  Inverse problem theory - and methods for model parameter estimation , 2004 .

[15]  Travel-time sensitivity kernels in ocean acoustic tomography , 2004 .

[16]  Barbara Nicolas,et al.  Target detection and localization in shallow water: an experimental demonstration of the acoustic barrier problem at the laboratory scale. , 2011, The Journal of the Acoustical Society of America.

[17]  P. Williamson,et al.  A guide to the limits of resolution imposed by scattering in ray tomography , 1991 .

[18]  Simulations of acoustic tomography array performance with untracked or drifting sources and receivers , 1985 .

[19]  W. Kuperman,et al.  Analyzing sound speed fluctuations in shallow water from group-velocity versus phase-velocity data representation. , 2013, The Journal of the Acoustical Society of America.

[20]  Barbara Nicolas,et al.  Double formation de voies pour la séparation et l'identification d'ondes : applications en contexte fortement bruité et à la campagne FAF03 Double Beamforming for wave separation and identification : robustness against noise and application on FAF03 experiment , 2008 .

[21]  J. Virieux,et al.  Shallow-Water Acoustic Tomography Performed From a Double-Beamforming Algorithm: Simulation Results , 2009, IEEE Journal of Oceanic Engineering.

[22]  F. A. Dahlen,et al.  Resolution limit of traveltime tomography , 2004 .

[23]  Sergio M. Jesus,et al.  Physical limitations of travel-time-based shallow water tomography , 2000 .