The strength of correlations between geotechnical variables and acoustic classifications

Seabed grain size, shear strength, bearing strength, and porosity were measured at 15 sites, all in bays and harbours around southern Vancouver Island. Sounder echoes at 38 and 200 kHz from the same sites were classified using the QTC VIEW/sup TM/ technology. This approach uses a feature set generated from the direct echoes by a set of algorithms and then reduced by multivariate analysis, with similar acoustic responses put into the same class. Canonical correlation analysis was used to uncover correlations between two data sets: the frequency of occurrence of each acoustic class, and the four geotechnical variables. Bearing strength was found to be the major contributor to the first geotechnical canonical variable, which correlated with classes from the 38-kHz echoes with a coefficient of 0.94.