Advances on modelling, simulation and signal processing of ultrasonic scattering responses from phytoplankton cultures.

P. BOS; I. PRARIO; M. CINQUINI; S. BLANC

Congreso; 22nd International Congress on Acoustics 2016; 2016

The International Commission for Acoustics (ICA) and the Ibero-american Federation of Acoustics (FIA)

High-frequency acoustic techniques provide remote sensing capability for plankton biomass estimation. While these techniques have been widely used to investigate zooplankton with frequencies below 1 MHz, few acoustical studies have been reported for phythoplanktonic organisms. Phytoplankton belongs to the lowest trophic level in the aquatic food  chain and plays an important role in the marine ecosystem. There are some species that can be used as biological indicators of polluted waters  while others produce harmful algae blooms affecting anthropogenic  activities. Acoustically monitoring of phytoplankton is potentially useful  for real time estimation of its numerical abundance. Quantitative  measurements of scattering from phytoplankton are difficult to perform  due to the weak scattered intensity. Moreover, unmasking the acoustic response from spurious scattering generated by bubbles, suspended  particles and other organisms in mixed plankton populations is necessary. Advances on analysis and signal processing of acoustic  scattering responses by phythoplankton are presented. At-lab   measurements were performed by insonification of Skeletonema pseudocostatum cultures using a 5 MHz narrowband transducer driven  by a pulse-receiver system. Backscattering cross-section of individual  scatterers were computed using theoretical models for further signals  simulation. Good agreement was obtained when comparing simulation  results with acoustic measurements.