Seabed characterization with multi-band interferometric sonar

Mapping of the seabed is important for numerous applications, including the detection of buried objects such as cables, pipelines, unexploded ordnance (UXO), off-shore engineering, and soil remediation. This paper introduces multi-band interferometric sonar as a technique to map a volume of the seabed. It uses a high- frequency interferometric side scan sonar to map the sea surface, whereas lower frequencies are used to map the interior of the seabed. The combination of these two techniques enables the detection and localization of objects or features of interest, including accurate estimates of the depth of burial. This has been demonstrated on data acquired in the Haringvliet, the Netherlands. It is shown that the multi-band interferometric sonar system has the capability to detect buried objects and to map the thickness of a soft sediment layer (mud) in an efficient fashion.