UNIDEF   23986
UNIDAD DE INVESTIGACION Y DESARROLLO ESTRATEGICO PARA LA DEFENSA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Advances on analysis and signal processing of acoustic scattering responses by phythoplanktonic species.
Autor/es:
MARIANO CINQUINI; PATRICIO BOS; IGOR PRARIO; SILVIA BLANC
Lugar:
Praga
Reunión:
Congreso; 26 th IUGG General Assembly; 2015
Institución organizadora:
International Union of Geodesy and Geophysics (IUGG)
Resumen:
Acoustically monitoring phytoplankton scatterers living either within aqueous culture media or in seawater samples may be an interesting technique feasible to be applied in detection of harmful algae blooms or biological indicators of polluted sea areas. Very few measurements on acoustical responses of phytoplankton have been reported since the first ones were published in 1998. First results of biomass estimations using acoustical measurements on phytoplankton cultures have encouraged the improvement of the initially proposed methodology. Further improvements to assure repeatability during at-lab essays with several phytoplankton species at different ultrasonic frequencies are presented here. The complexity involved in measuring the scattering contribution due to phytoplankton presence leads to deal with the task of unmasking the acoustic response of those organisms from spurious scattering generated by bubbles and suspended particles. Signal processing techniques for attenuating the undesirable scattering contribution to the total backscattered power will be described in this presentation. At-lab measurements were performed by insonification of Skeletonema pseudocostatum, Chlamydomonas reinhardtii and Euglena gracilis cultures using 2.25, 3.5 and 5 MHz narrowband transducers. Additionally, Skeletonema pseudocostatum cultures were used to determine the Volume Backscattering Strength by two independent methods: experimental determination of the backscattered acoustic intensity to incident intensity ratio and application of theoretical scattering models combined with optical counting and culture media image analysis. The comparison of both methods provided encouraging results. Moreover, simulations for estimating algae cultures acoustic responses will be discussed.