This volume contains the collection of papers from the second workshop on Experimental Acoustic Inversion Techniques for Exploration of the Shallow Water Environment. Acoustic techniques provide the most effective means for remote sensing of ocean and sea floor processes, and for probing the structure beneath the sea floor. No other energy propagates as efficiently in the ocean: radio waves and visible light are severely limited in range because the ocean is a highly conductive medium. However, sound from breaking waves and coastal shipping can be heard throughout the ocean, and marine mammals communicate acoustically over basin scale distances. The papers in this book indicate a high level of research interest that has generated significant progress in development and application of experimental acoustic inversion techniques. The applications span a broad scope in geosciences, from geophysical, biological and even geochemical research. The list includes: estimation of geotechnical properties of sea bed materials; navigation and mapping of the sea floor; fisheries, aquaculture and sea bed habitat assessment; monitoring of marine mammals; sediment transport; and investigation of natural geohazards in marine sediments. Audience This book is primarily intended for physicists and engineers working in underwater acoustics and oceanic engineering. It will also be of interest to marine biologists, geophysicists and oceanographers as potential users of the methodologies and techniques described in the book contributions. CD Rom containing full color images which are printed in black and white in the book. TOC:On the assessment of geoacoustic parameters in shallow water environments.- Bayesian inversion of seabed reflection data.-Backpropagation techniques in ocean acoustic inversion: time reversal, retrogation and adjoint modelling - a review.- Acoustic inversion at low kHz frequencies using an active, vertical line array.- Dispersion of broadband acoustic normal modes in the context of long sediment tomography.- Characterization of local seabed properties using synthesized horizontal array data.-Characterization of a range-dependent environment from towed array data.- Accounting for bias in horizontal wavenumber estimates due to source motion.- Acoustic clutter from burried submarine mud volcanoes.- Nonlinear acoustical methods in the detection of gassy sediments.- Acoustic scattering from submerged and buried objects.- High-frequency bistatic scattering experiments using proud and buried targets.- A sediment probe for the rapid assessment of seabed characteristics.- Continuous acoustic monitoring of physiological and environmental processes in seagrass prairies with focus on photosynthesis.- Shallow water tomography in a highly variable scenario.- Inversion of reflection loss measurements of a smooth water/sand interface.-Estimation of transmissions loss and its uncertainty.- A forward model for geoacoustic inversion based on ray tracing and plane-wave reflection coefficients.- Inversion of the propeller harmonics from a light aircraft for the geoacoustic properties of marine sediments.- Inversion of shallow water ambient noise data by means of differential evolution as a global search method.- Reflection Loss and Sub-bottom Profiling with Ambient Noise.- Inversion of geoacoustic model parameters using ship radiated noise.- Matched-field processing of humpback whale song off eastern Australia.- Inversions of horizontal and vertical line array data for the estimation of geoacoustic model parameters.- Issues of environmental variability in inverse problems in ocean acoustics. Thisvolume contains thecollection of papers from the second workshop on Expe- mental Acoustic Inversion Techniques for Exploration of theShallow Water Environment. Theworkshopthemefollowedtheoriginalconceptofthe rstworkshop, heldinCarvoeiro, Portugal, in 1999, i.e., to focus on experiments and experimental techniques for acoustic sensing in the shallow ocean. More than forty leading international scientists were invited to meet in the picturesque town of St. Angelo on the island of Ischia, in June 2004, to discuss progress in the application of new experimental techniques for exploration and assessment of shallowwater environments. Acoustic techniques provide the most effective means for remote sensing of ocean and sea oor processes, and for probing the structure beneath the sea oor. No other energy propagates as ef ciently in the ocean: radio waves and visible light are severely limited in range because the ocean is a highly conductive medium. However, sound from bre- ing waves and coastal shipping can be heard throughout the ocean, and marine mammals communicate acoustically over basin scale distances. Preface xi Acknowledgements xiii On the assessment of geoacoustic parameters in shallow water environments 1(16) Jean-Claude Le Gac Yann Stephan Thierry Garlan Nicholas Weber Bayesian inversion of seabed reflection data 17(12) Stan E. Dosso Charles W. Holland Backpropagation techniques in ocean acoustic inversion: time reversal, retrogation and adjoint modelling-A review 29(18) Matthias Meyer Jean - Pierre Hermand Acoustic inversion at low kHz frequencies using an active, vertical line array 47(10) Paul C. Hines Matt Coffin Dispersion of broadband acoustic normal modes in the context of long range sediment tomography 57(16) Gopu Potty James Miller Characterization of local seabed properties using synthesized horizontal array data 73(14) Peter L. Nielsen Mark Fallat Christopher Harrison Characterization of a range-dependent environment from towed array data 87(12) Mark Fallat Peter Nielsen Stan E. Dosso Martin Siderius Accounting for bias in horizontal wavenumber estimates due to source motion 99(10) Kyle M. Becker Acoustic clutter from buried submarine mud volcanoes 109(16) Charles W. Holland Anthony L. Gerig Piero Boni Nonlinear acoustical methods in the detection of gassy sediments 125(12) Jaroslaw Tegowski Zygmunt Klusek Jaromir Jakacki Acoustic scattering from submerged and buried objects 137(18) Ilkka Karasalo Patrik Skogqvist High-frequency bistatic scattering experiments using proud and buried targets 155(16) Philippe Blondel Peter F. Dobbins Nic Jayasundere Mario Cosci A sediment probe for the rapid assessment of seabed characteristics 171(12) John Osler Arnold Furlong Harold Christian Continuous acoustic monitoring of physiological and environmental processes in seagrass prairies with focus on photosynthesis 183(14) Jean-Pierre Hermand Shallow water tomography in a highly variable scenario 197(16) Cristiano Soares Sergio M. Jesus Emanuel Coelho Inversions of reflection loss measurements of a smooth water/sand interface 213(20) Marcia J. Isakson Tracianne Neilsen Andrew Worley Estimation of transmission loss and its uncertainty 233(8) Peter Gerstoft Chen-Fen Huang William Hodgkiss A forward model for geoacoustic inversion based on ray tracing and plane-wave reflection coefficients 241(16) Jens M. Hovem Hefeng Dong Xiukun Li Inversion of the propeller harmonics from a light aircraft for the geoacoustic properties of marine sediments 257(8) Michael J. Buckingham Eric M. Giddens Fernardo Simonet Inversion of shallow water ambient noise data by means of differential evolution as a global search method 265(16) Dick G. Simons Camiel van Moll Chris H. Harrison Reflection loss and sub-bottom profiling with ambient noise 281(8) Chris Harrison Inversion of geoacoustic model parameters using ship radiated noise 289(14) N. Ross Chapman Reza M. Dizaji R. Lynn Kirlin Matched-field processing of humpback whale song off eastern Australia 303(6) Aaron Thode Peter Gerstoft Melania Guerra M. Dale Stokes Michael Noad Douglas C. Cato Inversions of horizontal and vertical line array data for the estimation of geoacoustic model parameters 309(12) Dag Tollefsen Michael J. Wilmut Ross Chapman Issues of environmental variability in inverse problems in ocean 321(8) David P. Knobles Mason Gray Robert A. Koch Adam Cook Author Index 329(2) Subject Index 331