Roughness

Bed roughness is measured using a special sensor which is dragged across the sediment inside a measuring tube. The friction between sediment and the measuring tube generates sound which is recorded with a special microphone. Obstacles like shells or debris will produces more friction sound than a smooth bed. These variations in friction sound are recorded and linked to their position by means of GPS. With the results a two dimensional map of the roughness of the top layer of the sediment can be produced.

This information can be used to reveal the presence of obstacles. Useful in for example dredging works or locating shells.