Acoustic Positioning System for the Deep-Sea ANTARES Neutrino Telescope

The ANTARES collaboration is currently deploying a large underwater neutrino telescope at a depth of 2500 m in the Mediterranean Sea. The first detection line was connected in March 2006 and five of such lines are now currently operated. The spatial reconstruction of the detector is mainly based on an acoustic positioning system. This contribution presents the architecture and performances of this acoustic system, as well as first results obtained by the analysis of several months of data taking.