SAS Processing results for the detection of buried objects with a ship mounted sonar

In September 2002, TNO-FEL and GESMA carried out a sea experiment with a low frequency (20 kHz) sonar mounted on a mine hunter. To our knowledge, it is the first time the synthetic aperture sonar technique has been implemented on board an operational mine hunter for the purpose of buried mines detection. The collected data set is mainly made up of sonar runs in several SAS geometries (side scan, squinted, spotlight and tomographic configuration). This paper presents preliminary results that have been obtained after synthetic aperture processing of the sonar data, with or without using additional non-acoustic data for motion correction and geo-referencing. It is concluded that targets that are not too deeply buried can be detected. In addition, the technique has also been evaluated on non-military data for the purpose of surveying shipwrecks.