Detection of Buried Objects : The MUD Project

The aim of the Mine Underwater Detection (MUD) project at TNO is to experimentally investigate the acoustic and magnetic detection of explosives underwater, buried in a soft sediment layer. This problem is relevant for the protection of harbors and littoral assets against terrorist attacks and for the detection of underwater unexploded ordnance (UXO). The present article focuses on the acoustic part of the project. An experimental system, referred to as ‘MUD system’, has been developed for the purpose. The design and development of this vessel-deployed system focuses on modularity in order to be able to test different system configurations (tilt angle, depth, bandwidth etc.). The system has been tested in a trial conducted in close collaboration with the Royal Netherlands Navy (RNLN). The trial was situated in the Haringvliet, an estuary in the Netherlands with water depth up to 20 m. The trial results include comparison of sidescan and Synthetic Aperture Sonar (SAS) images for different configurations of the MUD system, a study of the detection performance and a comparison of the MUD system with detections done by a REMUS Autonomous Underwater Vehicle (AUV), equipped with a high frequency sonar. The results show that all the trial test objects have been detected by both systems, suggesting that the objects were not completely buried. A firm conclusion on the possibility to detect explosives buried in a mud layer can therefore not be drawn at this stage, although several features in the examined data indicate that this is the case. A new trial incorporating the knowledge acquired in the MUD project will be performed in 2011 using an upgraded version of the MUD system.