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AUV seafloor tracking for MCM operations

The use of autonomous underwater vehicles has greatly reduced the time it takes to search large areas of seafloor in mine countermeasures operations. Efforts have now turned toward automating the identification of mine-like objects found, which requires the vehicle to navigate very close to the object in question if optical sensors are used. Many altitude-keeping mechanisms only consider the seafloor underneath the vehicle: a danger when altitude is low and the bottom profile changes rapidly. We have developed and tested a prototype sensor for seafloor tracking and obstacle avoidance based on a forward-looking sonar. This sensor tracks the seafloor ahead of the vehicle, with the intent of allowing it to take action earlier and avoid collisions even when navigating at a very low altitude.