Multiview Acoustics

Posted Sat, 07/11/2009 - 03:53 by paul
Project Goals: 

The multiple angle acoustics project is focused on applying sound scattering measurements made at multiple angles in order to estimate biophysical parameters of marine animals such as size, shape, orientation, and taxa. This is an emerging area of bioacoustics which departs from the more traditional backscatter paradigm in an effort to improve the specificity of acoustic systems beyond remote sensing of volume backscatter.

There are two major components to this research. The first, is the construction and evaluation of a multiple angle scattering apparatus, while the second is the development of algorithms for learning how to relate the multiple angle acoustic scatter to important bio-physical parameters. The laboratory setting allows us to compare the estimates produced by the algorithms to video data of the scatters during insonification. This provides a method for characterizing the performance of the system on live subjects.

General Specifications: 

The multiple angle scattering apparatus is composed of a variety of acoustical and optical imaging systems:

Technical Drawing                        3D Tank Drawing

The drawings above show the major components and their relative location in the observation tank. The system is made up of a transducer array, a large (14x10x8ft) chilled seawater tank, two high sensitivity video cameras on adjustable pan and tilt mounts, and a rigid frame to hold everything together inside the tank.

A single transducer is used as the source of sound, while the other elements of the array receive only. This multistatic configuration allows for multiple angles of scatter to be acquired simultaneously. The stereo video system allows us to infer the size, shape, orientation, and taxa of the scatterer during insonification.

The system is powered by two computers running Windows XP, one using LabVIEW and the other using the Matrox Imaging Library. Panametrics broadband preamps are used for signal enhancement prior to digitization. An ENI AP400B power amplifier to used to power the sound source.

Detailed Specifications: 
application/vnd.ms-excel icon
multi-view-det-specs.xls
People: 
  • Principal Investigators: Jules S. Jaffe
  • Gaduate Students: Paul L. D. Roberts
  • Development Support: Marine Science Development Shop
  • Technical Consultants:  Robert Glatts, Benjamin Maurer, Fernando Simonet, Eddie Kisfaludy.
Pictures and Data: 

Preamps, Power amp, acoustic and video computers, signal generator.Side view cameraTransducer arrayTransducer array and tank wall

Sponsors: 

California Sea Grant

Publications: 

[1] [2]

References

  1. Roberts, PLD, Jaffe JS.  2008.  Classification of live, untethered zooplankton from observations of multiple-angle scatter. Journal of the Acoustical Scoienty of America. 124(2):796-802.
  2. Roberts, PLD, Jaffe JS.  2007.  Multiple angle acoustic classification of zooplankton. Journal of the Acoustical Society of America . 121:2060-2070.
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2pAOa4-Acoustics08.pdf1.5 MB
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