Development of AUV MONACA - Hover-Capable Platform for Detailed Observation Under Ice -

The melting of ice and changes in ocean currents in Antarctica must be investigated to understand global climate change. In this regard, the volume changes of sea ice and ice shelves, bathymetry, and ocean currents in the Antarctic Ocean must be measured in three dimensions. Therefore, the use of autonomous underwater vehicles (AUVs), which can directly observe under ice, is being considered. The authors developed an AUV named Mobility Oriented Nadir AntarctiC Adventurer (MONACA) to observe sea ice and the lower region of the ice shelf in the Antarctic Ocean. Herein, we describe MONACA and its basic autonomous navigation methods (altitude control, depth control, and waypoint tracking), as well as report the results of a sea experiment conducted in Shimoda Bay, Japan. During the 5-day sea trial, the MONACA successfully measured bathymetry by tracking 15 waypoints in sequence, switching the control criteria in the -axis direction between 3 m depth and 3 m altitude.