AUV-Based Sonar Registration of Seafloor Features and Objects

In support of future U.S. Navy mine-hunting and surveillance systems, Imaging Microsensors Inc. (IMI) proposes an innovative acoustic method for identifying and locating seafloor features and objects that had been previously detected. The ability tore-acquire an object in sonar images, at arbitrary times and aspect angles, is critical to many applications involving underwater operations, including the reacquisition of a target, station keeping, maneuvering relative to stationary objects, mapping, andnavigation by landmarks.IMI has developed extensive SAS imaging computer simulation software. The imaging software will be adapted to include realistic assumptions, made using a modern sonar modeling software package currently in use at ARL,UT-Austin, about target strength andbackground reverberation. The SAS imaging software will also be adapted to produce images at different aspect angles of the simulated targets and the associated shadowing effects for the purpose of developing image registration algorithms and evaluatingtheir performance.Phase I will model the acoustic response of seafloor features and objects, determine important system requirements, develop basic registration algorithms, and identify sonar systems capable of supporting the algorithms. In Phase II, engineering developmentof sensor and measurement technology will be carried out leading to a laboratory demonstration on a Navy representative vehicle. There is private sector interest in underwater navigation and station-keeping relative to the seafloor, particularly in the growing sonar and autonomous underwater vehicle (AUV) sector. Applications include oil drilling, underwater mining, andsalvage/recovery. They all could benefit from this technology.