Acoustic Observation of Zooplankton Using High Frequency Sonar
Abstract: Underwater acoustic
sampling techniques provide an advantage over traditional net-sampling for
zooplankton research. The research presents a methodology for extracting both
biological and physical information from high frequency sonar. These methods
can easily provide the information that will improve our understanding of the spatial
and temporal distribution of zooplankton. Measured acoustic data converted into
biological organisms and numerical physics-based scattering models were used in
this research. The numerical backscattering process was modeled using the
Distorted-Wave Born Approximation (DWBA) to predict the amount of sound
scattered by a weakly scattering animal. Both acoustic measurement and DWBA
modeled scattering patterns showed that acoustic scattering levels are highly
dependent on zooplankton orientation. The acoustic backscattering from zooplankton
depends on the material properties (i.e. the sound speed and density of the
zooplankton), the shape and size, and the orientation relative to the incident
acoustic wave. DWBA model significantly improve the accuracy and precision of
zooplankton acoustic surveys. Zooplankton data measurement and DWBA model analysis
provide a basis for future acoustical studies.
Aurthor: Henry M. Manik
Journal Code: jpperikanangg150008
