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Ref.: in Proc. of Meetings on Acoustics (POMA), Acoustical Society of America, no.17,
070052, January 2013.
Abstract:
Acoustic prediction for future time frames usually suffer from uncertainties in ocean forecasts, due to the
extreme sensitivity of acoustic propagation to the ocean environment. The current work assesses the feasibility
of combining a Feature-Oriented Regional Modelling System (FORMS) with acoustic inversion outcomes, for acoustic
prediction in the Cabo Frio (Brazil) coastal area. First, the oceanographic prediction model is tested for
acoustic applications. Two numerical acoustic simulations were performed, with an acoustic model having as
input two different initial fields: i) in situ hydrographic data from the OAEx10 sea trial, and ii) the
oceanographic modelling system outputs. The simulations were compared in terms of transmission loss (TL),
detection probability and impulse response. The second stage of this work concerned acoustic data-model
comparison, for OAEx10. Experimental impulse responses correlated fairly well with modelled ones corresponding
to the forecasts, with values between 0.72 and 0.89. In an attempt to increase these values, the acoustic
data was inverted, for the basement compressional speed, whose estimates led to increased impulse response
correlations of as high as 0.96. In summary, the prediction of the acoustic field can be well accomplished
by combining a FORMS technique with an acoustic inversion scheme.