Accession Number:

ADA537376

Title:

Bubble Field Characterization Using the Ambient Sound Field

Descriptive Note:

Annual rept.

Corporate Author:

WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB

Personal Author(s):

Report Date:

1998-09-30

Pagination or Media Count:

3.0

Abstract:

The ambient sound field contains information about the processes generating the sound and the intervening media modifying the sound. This research seeks to demonstrate measurement of useful geophysical processes using passive measurements of the ambient sound field. This will allow passive monitoring of environmental conditions from simple and robust sensors, namely hydrophones. The ambient sound field measured at a point consists of the sound generated by a distributed sound source after transmission through the media to the measurement point. In the ocean, one feature of the intervening media are ambient bubbles. These bubbles attenuate sound principally at their resonant frequency. Thus, measurement of frequency dependent sound attenuation along known transmission paths can be used to measure the ambient bubble size distribution. If the distributed sound sources are known, through measurement or prediction, then passive monitoring of the sound field away from these sources can be used to measure the ambient bubble size distributions.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE