Model‐based seafloor identification with parametric sonar data: Experimental results

A method is proposed to estimate the geoacoustic parameters of the uppermost seafloor strata using normal‐incidence backscattered acoustic data obtained with a parametric sonar in the 4–12 kHz frequency range. A model‐based identification approach has been pursued. The time‐domain backscattering model BORIS [Bergem et al., SACLANTCEN Memorandum SM‐328 (1997)] has been selected as a forward model. A specific wavelet transform has been defined in order to obtain a significant measure of the discrepancy between data and model predictions in the wavelet‐transformed domain. This discrepancy is minimized as a function of the bottom parameters. The technique has been tested on experimental data gathered in different locations in order to assess its perfomance on different bottom types. Identification results have been compared with independent ground truth collected by core analysis and video camera inspection. The comparison shows excellent agreement between acoustically determined parameters and ground truth. ...