Article

 

Acoustic backscattering by Hawaiian lutjanid snappers. II. Broadband temporal and spectral structure Público Deposited

Contenido Descargable

Descargar PDF
https://ir.library.oregonstate.edu/concern/articles/w9505199r

Descriptions

Attribute NameValues
Creator
Abstract
  • The characteristics of acoustic echoes from six species of deep-dwelling (up to 400 m) Hawaiian Lujanid snappers were determined by backscatter measurements at the surface. A broadband linear frequency-modulated signal and a short dolphinlike sonar signal were used as the incident signals. The fish were anesthetized and attached to a monofilament net that was attached to a rotor so echoes could be collected along the roll, tilt, and lateral axes of each fish. The temporal highlight structure of broadband echoes was determined by calculating the envelope of the cross-correlation function between the incident signal and the echoes. The echo waveforms were complex with many highlights and varied with the orientation of the fish. In the tilt plane, the strongest echoes occurred when the incident signal was perpendicular to the long axis of the swimbladder. The number of highlights was the fewest at this orientation. The number of echo highlights and the length of echoes increased as the fish was tilted from this orientation. The highlight structure of the echoes resulted in the transfer function being rippled, with local maxima and minima that changed with fish size and species. The echo structures in both the time and frequency domains were generally consistent within species and were easily distinguishable between species.
  • Keywords: structural acoustics, backscatter, underwater acoustic propagation, echo, sonar signal processing, bioacoustics, acoustic field
Resource Type
DOI
Fecha Disponible
Fecha de Emisión
Journal Title
Journal Volume
  • 114
Journal Issue/Number
  • 5
Declaración de derechos
Funding Statement (additional comments about funding)
  • This work was supported by the Hawaii State Department of Land and Natural Resources.
Publisher
Peer Reviewed
Language
Replaces
ISSN
  • 0001-4966

Relaciones

Parents:

This work has no parents.

Elementos