ACKNOWLEDGEMENTS 



These proceedings record the first plenary session of the 

 International Workshop on Low Frequency Propagation and Noise, 

 sponsored by the Director, Antisubmarine Warfare Programs of the 

 U. S. Navy Chief of Naval Operations staff. Scientists from six 

 nations--Australia, Canada, New Zealand, Norway, the United Kingdom, 

 and the United States- -participated. The Workshop was conducted 

 by the Chief of Naval Research. The executing agency was the Maury 

 Center for Ocean Science; Director, Dr. J. B. Hersey. Commander A. G. 

 Brookes, Jr., USN, coordinated the conduct of the symposium which 

 was held at the Woods Hole Oceanographic Institution, Quisset Campus, 

 Woods Hole, Massachusetts. The Office of Naval Research is indebted 

 to the Institution for its excellent hosting of this meeting and in 

 particular to Mr. Charles S. Innis for his conspicuous efficiency 

 and skill in making all local arrangements. All participants in 

 the Workshop made substantial contributions either by preparing the 

 papers listed in the Table of Contents or by chairing various sessions. 

 These proceedings were recorded in detail by Ace Federal Reporters, 

 Inc. The completeness and quality with which the proceedings were 

 recorded are much appreciated and have made possible the level of 

 detail these proceedings contain. The proceedings were edited 

 primarily by the authors themselves and by Mr. F. P. Diemer in the 

 Office of Naval Research and Commander A. G. Brookes, Jr., USN. The 

 final editing and preparation of these proceedings were performed by 

 Science Applications, Inc., under contract to the Office of Naval 

 Research. Technical editing was performed by Drs . J. Czika, J. S. 

 Hanna, and R. C. Cavanagh under the direction of C. W. Spofford, 

 all of Science Applications, Inc. 



The illustration on the title page displays iso-loss contours in range and depth generated 

 by the Parabolic Equation Model of Dr. F.D. Tappert. Regions of heaviest shading correspond 

 to losses of less than 80 dB re 1 yard, lighter shading to losses between 80 and 90 dB, and 

 lightest shading to losses greater than 90 dB. The calculation is for a constant (pressure) 

 gradient sound-speed profile in water 16,000-feet deep overlying a highly absorbing bottom. 

 The source is at a depth of 8,000 feet, the acoustic frequency is 50 Hertz, and the maximum 

 range is 50 nautical miles. 



Details on the technique and more examples are contained in Dr. Tappert's paper entitled 

 "Selected Applications of the Parabolic-Equation Method in Underwater Acoustics" found in 

 Volume I of these Proceedings. 



Title page was designed by Frank Varcolik, SAL 



