Coastal Acoustic Tomography


Book Description

Coastal Acoustic Tomography begins with the specifics required for designing a Coastal Acoustic Tomography (CAT) experiment and operating the CAT system in coastal seas. Following sections discuss the procedure for data analyses and various application examples of CAT to coastal/shallow seas (obtained in various locations). These sections are broken down into four kinds of methods: horizontal-slice inversion, vertical-slice inversion, modal expansion method and data assimilation. This book emphasizes how dynamic phenomena occurring in coastal/shallow seas can be analyzed using the standard method of inversion and data assimilation. The book is relevant for physical oceanographers, ocean environmentalists and ocean dynamists, focusing on the event being observed rather than the intrinsic details of observational processes. Application examples of successful dynamic phenomena measured by coastal acoustic tomography are also included. Provides the information needed for researchers and graduate students in physical oceanography, ocean-fluid dynamics and ocean environments to apply Ocean Acoustic Tomography (OAT) to their own fields Presents the benefits of using acoustic tomography, including less disturbance to aquatic environments vs. other monitoring methods Includes the assimilation of CAT data into a coastal sea circulation model, a powerful tool to predict coastal-sea environmental changes







High Frequency Ocean Acoustics


Book Description

All papers were peer-reviewed. Sound in the ocean is as fundamental as light in theatmosphere. The high-frequency acoustic band has been little studied in the past; however, new applications such as mine hunting, marine mammal tracking, and communications (the undersea internet) have generated tremendous interest. These peer-reviewed proceedings include 8 invited papers by leading experts in particular areas and collectively survey all aspects of current research in high-frequency acoustics.




High-Frequency Seafloor Acoustics


Book Description

This book is a research monograph on high-Frequency Seafloor Acoustics. It is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. It provides a critical evaluation of the data and models pertaining to high-frequency acoustic interaction with the seafloor, which will be of interest to researchers in underwater acoustics and to developers of sonars. Models and data are presented so as to be readily usable, backed up by extensive explanation. Much of the data is new, and the discussion in on two levels: concise descriptions in the main text backed up by extensive technical appendices.







Sound Images of the Ocean


Book Description

Sound Images of the Ocean is the first comprehensive overview of acoustic imaging applications in the various fields of marine research, utilization, surveillance, and protection. The book employs 400 sound images of the sea floor and of processes in the sea volume, contributed by more than 120 marine experts from 22 nations.







In Situ High-frequency Acoustic Propagation Measurements in Marine Sediments in the Santa Barbara Shelf, California


Book Description

Measurements were made of sound speed and attenuation in marine sediments at 15, 30, and 60kHz by means of in situ acoustic probe instrumentation in conjunction with CURV II. These experiments were conducted in silty sand and sandy silt Continental Shelf areas of the Santa Barbara Channel, California. The main conclusions are: (1) attenuation was found to be about 3, 10, and 20 dB per meter at 15, 30, and 60 kHz, respectively; (2) for the attenuation equation, alpha = K(f to the nth power) (where alpha is sound attenuation in dB per meter, K is a dimensional material parameter, and f is frequency in kHz), the exponent, n, was found to be about 1.2, and K varied from approximately 0.1 to 0.2; (3) no significant sound-speed dispersion was found, in agreement with many other investigations; and (4) individual acoustic measurements made in close proximity to one another in a nominally homogeneous bottom can vary appreciably, although their average values may be in close agreement. (Author).