Autonomous drifter for sea measurements. Design and hydrodynamic issues.

The aim of this thesis is the design of an autonomous drifting buoy. The whole design of the device is done within an open source philosophy. This means that: i)the hardware and software tools used are, when available, open source; ii)the results of the design procedure as well as the procedure itself will be made freely available. Drifting buoy is a Lagrangian device used for measurement of the ocean currents, sea temperature, wind conditions and wave sea state. Because it is a single point measurement system, it is usually used in multiple configuration, i.e. as a buoy fleet, to map the ocean area of interest. However, a drifting buoy is a passive device, i.e. the main issue consists in its placement at the beginning and recovery at the end of the mission; moreover, they are often lost. With the objective to overcome these issues, present work thesis focuses on the design of a hybrid buoy, i.e. passive during the measurement stage and autonomous during the cruise stage. The latter is a novel requirement which enables the buoy to reach the area of interest from home and vice-versa in autonomous way, avoiding human intervention.