Synthetic Aperture and 3D Imaging for Mine Hunting Sonar

Modern mines have become very stealthy. Sonar designed to face this threat must use enhanced classification process. The classification decision process corresponds to the discrimination between Mines and Non Mine Bottom Objects (NOMBO). The need for enhanced classification is due to the increasing number of non-mine objects detected at the first step of the mine hunting operation. The classification must have a reduced ambiguity factor if a good performance is expected. The best way to overcome this difficult classification challenge in common operation conditions is to obtain high resolution and multiple aspects views of the object to be classified. These performance can be obtained by the use of new techniques now available for various existing systems as hull mounted sonar and unmanned underwater vehicles : synthetic aperture imaging and 3D object reconstruction. Some results obtained at sea are shown.