“…Forsgren et al (1993) used the acoustic signal patterns of the echogram to differentiate between fine-and coarse-grained sediment bottoms according to four criteria: roughness of the line surface, line thickness, occurrence of white line and echo. Investigations by Clay and Leong (1974), Dunsinger et al (1981) and Cochrane and Dunsinger (1983) showed that inhomogenities in the sediment cause scattering of acoustic signals. They also showed that with increased roughness of the sediment surface the scattering component of the acoustic signals increased.…”