ACOUSTICAL CLASSIFICATION OF BOTTOM SEDIMENTS IN SOUTHERN BALTIC USING FRACTAL DIMENSION

摘要

We present a single-frequency, narrow beam method of acoustical identification and classification of marine bottom sediments. The method is based on the assumption that layers of bottom sediments have fractal structure, which is transferred onto the shape of acoustic echo. The fractal dimension of the bottom echo is combined with backscattering strength and duration of the echo, and used for bottom type classification in the neural network algorithm. The obtained results show that for the Gdansk Bay region as well as the whole area of Polish Economical Zone in Southern Baltic, the Hausdorff dimension of echo envelope describes well the bottom sediments structure. The proposed classification method, which involves just three echo parameters, may be a useful tool for sediment identification. The obtained accuracy is comparable to other, more complex methods.