High Resolution Multibeam Sonar Mapping of the Lost City Hydrothermal Site with the Autonomous Benthic Explorer

The Autonomous Benthic Explorer (ABE) of the Woods Hole Oceanographic Institution (WHOI) collected high-resolution multibeam sonar bathymetry of the Atlantis Massif and the Lost City vent site in May 2003. A Simrad Mesotech SM 2000 multibeam sonar has been fully integrated into the vehicle for this purpose. The challenging topography of the Lost City site demanded careful AUV survey planning, but also afforded the opportunity to try new survey techniques, particularly side-looking surveys along steep slopes. The quality of post-processed navigation has been improved with the addition of a model-based smoother. To aid in processing the large volume of sonar data generated during surveys, we have developed a high-level user interface in the form of a MATLAB GUI that allows users to inspect sonar images and the corresponding bathymetry concurrently. Using these techniques, bathymetric maps gridded on 2 m regular grids are visually free of trackline artifacts.