Angular dependence of statistical distributions for backscattered signals: modelling and application to multibeam echosounder data

Hellequin et al. (2003) showed that backscattered signal statistics, obtained from an acoustical imaging system, present a strong angular dependence. This paper deals with an extension of the proposed models to describe the intensity statistics fluctuations according to sonar resolution. Thus, the proposed model takes into account a wider variety of seabeds to provide an estimate of the order parameter of the K-law. Experimental data recorded by the EM1000 multibeam echosounder in shallow water provide the way to compare the different models on four different seafloors (mud, muddy sand, fine sand, coarse sand and a zone colonized by a bivalve population).