North Pacific Acoustic Laboratory (NPAL) - Towed Array Measurements

North Pacific Acoustic Laboratory (NPAL) - Towed Array Measurements
Author:
Publisher:
Total Pages: 7
Release: 2009
Genre:
ISBN:

The long-term goal of this research is to understand deep-water propagation, with particular emphasis placed on the passive quiet target detection problem. Focus is on the spatial/temporal structure of acoustic paths for moving sources and moving receivers. Propagation paths are separated into two classes: bottom interacting and refracted/surface-reflected (non-bottom interacting). This research seeks to understand the impact that mid-ocean variability (internal waves, mixed layer variability) and seafloor scattering have on the detection problem.

Springer Handbook of Acoustics

Springer Handbook of Acoustics
Author: Thomas Rossing
Publisher: Springer
Total Pages: 1280
Release: 2015-01-15
Genre: Science
ISBN: 1493907557

Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience and others. Here is an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents spanning: animal acoustics including infrasound and ultrasound, environmental noise control, music and human speech and singing, physiological and psychological acoustics, architectural acoustics, physical and engineering acoustics, medical acoustics and ocean acoustics. The Springer Handbook of Acoustics reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest research and applications are incorporated throughout, e.g. computer recognition and synthesis of speech, physiological acoustics, psychological acoustics, thermoacoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. This new edition of the Handbook features over 11 revised and expanded chapters, new illustrations and two new chapters covering microphone arrays, acoustic metamaterials and acoustic emission. These improvements will make the handbook even more useful as a reference and a guide for researchers and students in every branch of acoustics. Praise for the first edition: "This treatise is a successful attempt to cover in one book the diverse field of acoustics, which ranges from physics to music and from formal mathematics to technological applications. ... It is this reviewer's opinion that a handbook like Rossing's, which covers the whole field of acoustics, serves a real purpose because it not only gives one a chance to see how one's specialty is covered but it also permits one to make a quick survey of other acoustical areas." (Leo Beranek, American Journal of Physics, Vol. 77 (12), December, 2009) "The Springer Handbook of Acoustics falls into that exceptional list. ...every physics department should have a copy available." (John L. Hubisz, The Physics Teacher, Vol. 48, March, 2010) "This handbook is an excellent addition to the acoustics literature. ... The handbook nicely covers both basics and advances in several areas of acoustics. Several chapters provide good mathematical depth, making the handbook useful as a research and technical resource. ...Overall, a very useful educational and research resource. Summing Up: Recommended. Upper-division undergraduates through professionals." (M. G. Prasad, CHOICE, Vol. 45 (5), January, 2008) "This book covers a wide range of topics and the inclusion of musical acoustics, computer and electronic music appeal to me (singer, song-writer, performer and recording studio co-owner). This handbook is probably well suited for an undergraduate-level introduction to an acoustics course. ... The wide range of topics, inclusion of music-related chapters, eye-pleasing presentations and other useful features make this a very good book to have on your shelf." (Tim Casey, International Journal of Acoustics and Vibration, Vol. 13 (1), 2008) "The Springer Handbook of Acoustics comprises 28 chapters written by 33 authors. The Handbook of Acoustics is useful as a source book for anyone who needs or wants to become familiar with the jargon and issues related to a specific subfield of acoustics ... ." (Robert I. Odom, Siam Review, Vol. 50 (3), 2008) The Springer Handbook of Acoustics reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest research and applications are incorporated throughout, e.g. computer recognition and synthesis of speech, physiological acoustics, psychological acoustics, thermoacoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. This new edition of the Handbook features over 13 revised and expanded chapters, new illustrations and 3 new chapters covering microphone arrays, acoustic metamaterials and acoustic emission. These improvements will make the handbook even more useful as a reference and a guide for researchers and students in every branch of acoustics.

Sound Propagation Around Underwater Seamounts

Sound Propagation Around Underwater Seamounts
Author: Joseph J. Sikora (III.)
Publisher:
Total Pages: 242
Release: 2005
Genre: Seamounts
ISBN:

This thesis develops and utilizes a method for analyzing data from the North Pacific Acoustic Laboratory's (NPAL) Basin Acoustic Seamount Scattering Experiment (BASSEX). BASSEX was designed to provide data to support the development of analytical techniques and methods which improve the understanding of sound propagation around underwater seamounts. The depth-dependent sound velocity profile of typical ocean waveguides force sound to travel in convergence zones about a minimum sound speed depth. This ducted nature of the ocean makes modeling the acoustic field around seamounts particularly challenging, compared to an isovelocity medium. The conical shape of seamounts also adds to the complexity of the scatter field. It is important to the U.S. Navy to understand how sound is diffracted around this type of topographic feature. Underwater seamounts can be used to conceal submarines by absorbing and scattering the sound they emit. BASSEX measurements have characterized the size and shape of the forward scatter field around the Kermit-Roosevelt Seamount in the Pacific Ocean. Kermit-Roosevelt is a large, conical seamount which shoals close to the minimum sound speed depth, making it ideal for study. Acoustic sources, including M-sequence and linear frequency-modulated sources, were stationed around the seamount at megameter ranges. A hydrophone array was towed around the seamount to locations which allowed measurement of the perturbation zone. Results from the method developed in this thesis show that the size and shape of the perturbation zone measured coincides with theoretical and experimental results derived in previous work.

Springer Handbook of Acoustics

Springer Handbook of Acoustics
Author: Thomas Rossing
Publisher: Springer Science & Business Media
Total Pages: 1179
Release: 2007-06-21
Genre: Science
ISBN: 0387304460

This is an unparalleled modern handbook reflecting the richly interdisciplinary nature of acoustics edited by an acknowledged master in the field. The handbook reviews the most important areas of the subject, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest research and applications are incorporated throughout, including computer recognition and synthesis of speech, physiological acoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. An accompanying CD-ROM contains audio and video files.

Seventy Years of Exploration in Oceanography

Seventy Years of Exploration in Oceanography
Author: Klaus Hasselmann
Publisher: Springer Science & Business Media
Total Pages: 151
Release: 2010-04-08
Genre: Science
ISBN: 3642120873

It all began with Markus Jochum approaching one of us (HvS) – “when you guys are doing interviews with senior scientists from oceanography and related sciences, why are you not doing Walter Munk?” Indeed, why not? Walter Munk, an icon in oceanography, had just given a wonderful talk in a symposium in honor of his 90th birthday, sweeping a grand circle from his earliest work with Chip Cox on airborne measurements of ocean surface roughness to the latest satellite data – not simply a review, but the struggle of an active scientist opening up new perspectives – as inspiring and stimulating as when one of us (KH) rst met him at the Ocean Waves Conference in Easton in 1961 (Fig. I. 1). Walter immediately agreed to share with us his recollections on the nearly seventy years of his path-breaking contributions in a sheer amazing range of topics, from ocean waves, internal waves, ocean currents, tides, tsunamis, sea level, microseisms and the rotation of the earth to ocean acoustic tomography. With “you guys” Markus was referring to HvS and the various partners HvS had 1 invited to join him in conducting a series of interviews of retired colleagues.