PROGRESS IN UNDERWATER ACOUSTICS PROGRESS IN UNDERWATER ACOUSTICS Edited by HAROLD M. MERKLINGER Defence Research Establishment Atlantic Dartmouth, Nova Scotia, Canacla PLENUM PRESS • NEW YORK AND LONDON Library of Congress Cataloging in Publication Data Associated Symposium on Underwater Acoustics (1986: Halifax, N.S.) Progress in underwater acoustics. "Proceedings of the Twelfth International Congress on Acoustics Associated Sym· posium on Underwater Acoustics, held July 16-18, 1986, in Halifax, Nova Scotia, Canada" - T.p. verso. "Sponsored by the Canadian Acoustical Association" - Pref. Includes bibliographical references and indexes. 1. Underwater acoustics-Congresses. I. Merklinger, Harold, M. II. Associated Symposium on Underwater Acoustics (1986: Halifax, N.S.) III. Canadian Acoustical Association. IV. Title. QC242.A87 1986 621.389'5 87·11020 ISBN-13: 978-1-4612-9043-8 e-ISBN-13: 978-1-4613-1871-2 DOl: 10.1007/978-1-4613-1871-2 Proceedings of the Twelth International Congress on Acoustics Associated Symposium on Underwater Acoustics, held July 16-18, 1986, in Halifax, Nova Scotia, Canada © 1987 Plenum Press, New York Softcover reprint of the hardcover Ist edition 1987 A Division of Plenum Publishing Corporation 233 Spring Street, New York, N.Y. 10013 All rights reserved No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher FOREWORD IMAGE TRACKS AT HALIFAX by L.B. Felsen All living kind much effort spend Some model modes, some model rays, To cope with their environment Some feel that spectra all portrays. Some use their eyes, some use their nose Then there are those who with despatch, To sense where other things repose. Take refuge in the ocean wedge. For one group, nothing's more profound Than to explore the world with sound. If things get messy, randomize. These audio diagnosticians What's partly smooth, determinize. Go by the name of acousticians. You ponder, is it this or that? And wish you were a lowly bat They regularly meet to check Whether their sonogram's on track. The meeting's hosts did treat us well. With images stored in their packs, They let the climate cast its spell. This year they came to Halifax. No weath'ry hope was placed in vain. There they combined with ocean types We were exposed to wind and rain, And each could hear the other's gripes. We glimpsed blue sky through clouds dispersed. A meeting naturally does start But rainy sequence was reversed: Reviewing present state of art. The ocean types would like it wet What we found out is where it's at: Yet they got stuck with sun instead. We cannot hope to match the bat Each confrence has the same refrain: Computer printouts by the reams It has been fun to meet again. Oocument new inversion schemes. May Nova Scotia long survive Each wiggle gets processed with care And let the ocean addicts thrive. To image what is actually there. To our hosts who labored hard, The ill-posed problem gives us grief, I offer thanks, ere we depart. It's science laced with strong belief. The lowly bat has no such doubt: Ill-posed or not, it sorts things out. After two days of imagery, The sonic thrusters went to sea. The ocean bottom, smooth or rough, Makes tracking sonic signal tough. Halifax, Nova Scotia, 14-18 July 1986. v PREFACE This book contains the proceedings of the 12th ICA Associated Symposium on Underwater Acoustics held at the Chateau Halifax hotel in Halifax, Nova Scotia Canada, 16- 18 July 1986 .. The proceedings is not quite complete, 98 papers were presented, 94 of these are contained in this book. The 12th International Congress on Acoustics (lCA) itself was held in Toronto during the period 24-31 July 1986. It and the several associated symposia were sponsored by the Canadian Acoustical Association. About three years ago, in 1983, the community of acousticians in Halifax agreed to organize two of these associated symposia under a single organizing committee. The 15th in an annual series of symposia on Acoustical Imaging was one of these, and Prof. Hugh Jones of the Technical University of Nova Scotia took on the management of the technical program. Prof. Leif Bj !1lrn!1l of Denmark pressed us to include more emphasis on underwater acoustics and, in the end, I agreed to look after the technical program for a separate symposium for Underwater Acoustics. I was not alone in this task of organizing the symposium. Assisting immeasurably were Academician L.M. Brekhovskikh (USSR), Prof. Leif Bj!1lrn!1l (Denmark), Dr. R.P. Chapman (Canada), and Dr. W.A. Kuperman (USA), the members of our Technical Committee. Local arrangements were the responsibility of a Local Organizing Committee chaired by Prof. Jones and co-chaired by myself. Other members were Mr. H.W. Kwan, Dr. L.J. Leggat, Mr. David M.F. Chapman, Dr. D.O. Ellis, Dr. N.A. Cochrane and Ms. S. Robertson, with Ms. L. Buckly, Ms. S. Forbes and Mr. R. Raven helping with respect to the hotel. The original call-for-papers proposed the following technical areas for special attention: • Underwater Acoustic Imaging • Acoustic Propagation (Deep water, Shallow water, Slope water) • Scattering of Rough Ocean Boundaries • Acoustic Signal Processing and Beamforming • Inverse Methods; and • Acoustics in the Offshore Industry: Petroleum and Fishing. During the interval between the call-for-papers and the symposium, the falling price of oil on the world market resulted in a noticeable decline of activity in the offshore petroleum industry. This change in emphasis, I believe, 'carried over to our symposium. The greatest emphasis -in terms of papers submitted -was on sound propagation, with a healthy respect paid to the interaction of sound with the ocean bottom. In the event, 106 papers appeared in the program and, of these, 98 were presented. The authors are to be commended on the quality of their presentations. And the Chairmen did a fine job managing the discussion and keeping to the published'schedule. Over two hundred delegates representing 22 countries attended the symposium. The papers held the attention of delegates to the very end; even the two final afternoon sessions were very well attended. vii The organization of this proceedings does not conform precisely with that of the Symposium itself. The constraints imposed by scheduling two parallel sessions around mealtimes and social functions forced certain groupings that were not based entirely on subject matter. A proceedings is not so constrained, and so the papers are grouped under the following general classifications: • Sound Scattering from Ocean Boundaries • Sound Scattering from Biological and Other Objects • Acoustic Characterization of the Ocean and Ocean Floor • Sound Propagation in the Ocean a) General b) Shallow Water c) Slope Water • Transducers, Radiation and Instrumentation • Signal Processing and Beamforming. It may be noted that there is no Underwater Acoustic Imaging classification. Most of the papers presented under the imaging classification will appear in the proceedings of the 15th Symposium on Acoustical Imaging, a companion to this volume. The three imaging papers slated for inclusion in the underwater acoustics proceedings fit equally well under one of the above classifications. Within each classification, the order of the papers is essentially the same as for the oral presentations. Many people assisted in the process of editing this proceedings. Mary Jo Delaney did most of the checking while Linda Kenney did most of the corrections. Assisting with the editing were David Chapman, Dale Ellis, Joe Farrell, Garry Heard, Phil Staal, John Stockhausen and Jim Theriault Thank you all. Harold M. Merklinger Halifax, Nova Scotia Canada October 1986 N01E: All rights of the editor have been assigned to The Canadian Acoustical Association, P.O. Box 3651, Station C, Ottawa, Ontario, Canada K1Y 4J1. ACKNOWLEDGEMENT The preparation of this book was supported in part by the Nova Scotia Department of Development. viii CONTENTS OPENING Opening Address •......................................•.............................................. 1 D. Schofield SOUND SCATTERING FROM OCEAN BOUNDARIES Acoustical Visualisation of the Ocean Bottom ......•.......•...................................... 7 L.M. Brekhovskikh, V. V. Krasnoborodko and V.Ch. Kiriakov The Sea Bottom Backscattering of Sound (The llistory and Modem State) .................. 15 Yu. Yu. Zhitkovskii A Unified Description of Wave Scattering at Boundaries with Large and Small Scale Roughness .......••.••....•..••.......................•................... 25 A.G. Voronovich Validity of the Bom and Rytov Approximations ..•.•••••....••.•.•...•............•.•........... 35 S. Leeman, P. Chandler, LA. Ferrari and DA. Seggie Multiple Scattering at Rough Ocean Boundaries ................................................. 43 John A. DeSanto Rough Surface Scattering and the Kirchhoff Approximation ................................... 51 Diana F. McCammon and Suzanne T. McDaniel lligh Frequency Scattering from Rough Bottoms and the Second Bom Approximation ....................................•.......................................... 57 Stanley A. Chin-Bing and Michael F. Werby Statistical Characteristics of Acoustic Fields Scattered at the Sea Surface: A Helmholtz-Gulin Model ................................................................. 65 Jerald W. Caruthers, Stanley A. Chin-Bing and Jorge C. Novarini The Importance of Hybrid Ray Paths, Bottom Loss, and Facet Reflection on Ocean Bottom Reverberation ................•.......................................... 75 Dale D. Ellis and J.B. Franklin ix SCATTERING BY BIOLOGICAL AND OTHER BODIES The Study of Sound Backscattering from Microinhomogeneities in Sea Water ..................................................................................... 85 VA. Akulichev and VA. Bulanov Scaring Effects on Fish and Harmful Effects on Eggs, Larvae and Fry by Offshore Seismic Explorations .................................................... 93 John Dalen and Geir Magne Knutsen Fish Stock Assessment by a Statistical Analysis of Echo Sounder Signals ................. 103 P. N. Denbigh and J. Weintroub Processing of Fish Echo-Signals for Classification Purpose .................................. 113 Didier Vray and Gerard Gimenez Broadband Acoustical Scattering by Individual Fish ........................................... 121 LeifB jpr,,; and Niels Kjaergaard Multichannel False Color Echograms as a Biological Interpretative Tool .................... 129 NA. Cochrane andDD. Sameoto Study of the Pseudo-Lamb Wave So Generated in Thin Cylindrical Shells Insonified by Short Ultrasonic Pulses in Water ................................ 137 Maryline Talmant and Gerard Quentin Scattering of an Acoustic Wave by a Transmission-Loss Tile ................................ 145 Richard J. Brind Frequency Dependence of the Interaction of Ultrasound with Suspended Sediment Particles .......................................................................... 153 A.S. Schaafsma and AJ. Wolthuis Sound Scattering in Aqueous Suspensions of Sand: Comparison of Theory and Experiment .................................................................... 161 J. Sheng and AE. Hay ACOUSTIC CHARACTERIZATION OF THE OCEAN AND THE OCEAN FLOOR A Combined Seismic Reflection Profiler and Sidescan Sonar System for Deep Ocean Geological Surveys ..................................................... 169 DJ. Dodds and G.BJ. Fader Signal Processing of Ocean Acoustic Tomography Data ...................................... 181 Duncan Sheldon and G. Clifford Carter Seismic Profiling with a Parametric, Self-Demodulated Ricker Wavelet .................... 189 T.G. Muir, RJ. Wyber, J.B. Lindberg, and L.A. Thompson Remote Acoustic Mapping of a Submarine Spring Plume ..................................... 207 E. Colbourne and A.E. Hay Acoustic Remote Sensing of the Waveheight Directional Spectrum of Surface Gravity Waves .................................................................... 215 Steven H. Hill A Pattern Recognition Approach to Remote Acoustic Bottom Characterization ............................................................................. 225 Thomas L. Clarke and John R. Proni x Comparative Numerical Study of VLF Signal Propagation Characteristics for Ocean Bottom and Marine Borehole Arrays. . .. . .. . . . . . . . . . . .. . .. 231 G.J. Tango, H.B. Ali, and M.F. Werby Application of Acoustic Waves and Electrical Conductivity for the Determination of Mechanical Characteristics of Marine Sediments ................... 239 J.P. Longuemard and J M. Daupleix The Estimation of Density, P-Wave, and S-Wave Speeds of the Top-Most Layers of Sediments ........................................................... 247 S. Levy, J. Cabrera, K. Stinson, D. Oldenburg and NR. Chapman ETL Reflectivity as a Feature for Recognition of Top-Layer Marine Sediments ................................................................................... 265 Jinsheng Meng andDinghua Guan Inversion of Ocean Subbottom Reflection Data ................................................. 271 David J. Thomson An Inverse Method for Obtaining the Attenuation Profile and Small Variations in the Sound Speed and Density Profiles of the Ocean Bottom .......... 279 Subramaniam D. Rajan and George V. Frisk A Perturbative Inverse Method for the Determination of Geoacoustic Parameters in Shallow Water ............................................................. 287 James F. Lynch, Subramaniam D. Rajan and George V. Frisk A Synthetic Aperture-Array Technique for Fast Approximate Geobottom Reconnaissance ................................................................ 295 M.F. Werby, GJ. Tango and HE. Ali Buried Target Reflectivity Evaluation Through an Array of Sensors ......................... 303 R. CarbO Fite and C. Ranz Gue"a Reflectivity of a Layer With Arbitrary Profiles of Density and Sound Velocity ...................................................................................... 311 P. Cobo, C.RanzandR. CarbO Sound Speed Profile Inversion in the Ocean .................................................... 319 Unda Boden and John A. DeSanto A Technique for Modeling the 3-D Sound Speed Distribution and Steady State Water Velocity Field from Hydrophone Data ............................ 329 PD. roung SOUND PROPAGATION IN THE OCEAN a) General A New Form of the Wave Equation for Sound in a General Layered Fluid ................. 337 OA.Godin Phase Space Methods and Path Integration: The Construction of Numerical Algorithms for Computational Acoustics ................................... 351 Louis Fishman Predicting Convergence Zone Formation in the Deep Ocean .................................. 361 John J. Hanrahan xi A New Approximate Solution Valid at Turning Points ........................................ 371 Guan Ding-hua and Ling Hui The Sound Intensities Near the Conjugate Turning Points in an Underwater Sound ChanneL .............................•................................ 379 ZhangRenhe Modeling Acoustic Waves by Transmutation Methods ........................................ 389 RobertP. GilbertandDavidH. Wood Beyond What Distance are Finite-Amplitude Effects Unimportant? .......................... 395 Frederick D. Cotaras, David T. Blackstock and Christopher L. Morjey Attenuation of Low-Frequency Sound in the Sea: Recent Results ........................... 403 David G. Browning and Robert H. Mellen On the Calculation of Acoustic Intensity Fluctuations Caused by Ocean Currents ............................................................................. 411 J.S. Robertson, M J. Jacobson and W L. Siegmann Quick Nonnal Mode Type Starting Fields for Parabolic Equation Models .................. 419 E. Richard Robinson, Hue B. Tran and David H. Wood A Posteriori Phase Corrections to the Parabolic Equation ..................................... 425 DJ. ThomsonandD.H. Wood Perturbation Modeling for Ocean Sound Propagation .......................................... 433 MarkD.Duston, GhasiR. VermaandDavidH. Wood Fast Computation of Perturbed Nonnal Modes ................................................. 439 Dominic Y. Savio andDavidH. Wood Omnidirectional Ambient Noise Measurements in the Southern Baltic Sea During Summer and Winter ......................................................... 445 RA. Wagstaff and J. Newcomb Ambient Noise over Thickly Sedimented Continental Slopes ................................. 453 DR. Del Balzo, M J. Authement and D A. Murphy b) Shallow Water Some New Challenges in Shallow Water Acoustics ........................................... 461 E.C.Shang Propagation of Seismic and Acoustic Waves in Horizontally Stratified Media with Stochastically Rough Interfaces ............................................ 473 Henrik Schmidt The Effect of Variable Roughness of a Granite Seabed on Low-Frequency Shallow-Water Acoustic Propagation .....•.............................................. 485 Philip R. Staal, David M F. Chapman and Pierre Zakorauskas Ocean Seismo-Acoustic Propagation ............................................................. 493 Tuncay Akal and Finn B. Jensen Measurements of Wind Dependent Acoustic Transmission Loss in Shallow Water Under Breaking Wave Conditions ..................................... 501 P. Wille, D. Geyer, L. Ginzkey and E. Schunk xii
Description: