The positioning system of the ANTARES Neutrino Telescope

The ANTARES neutrino telescope, located 40km off the coast of Toulon in the Mediterranean Sea at a mooring depth of about 2475m, consists of twelve detection lines equipped typically with 25 storeys. Every storey carries three optical modules that detect Cherenkov light induced by charged secondary particles (typically muons) coming from neutrino interactions. As these lines are flexible structures fixed to the sea bed and held taut by a buoy, sea currents cause the lines to move and the storeys to rotate. The knowledge of the position of the optical modules with a precision better than 10cm is essential for a good reconstruction of particle tracks. In this paper the ANTARES positioning system is described. It consists of an acoustic positioning system, for distance triangulation, and a compass-tiltmeter system, for the measurement of the orientation and inclination of the storeys. Necessary corrections are discussed and the results of the detector alignment procedure are described.
Bibliographic reference
ANTARES Collaboration Aguilar Sánchez, Juan Antonio Bigongiari, C. Dornic, Damien Emanuele, U. Gómez González, Juan Pablo Hernández Rey, Juan José Mangano, Salvatore Real Máñez, Diego Ruiz-Rivas Onsés, Joaquín Salesa Greus, Francisco Toscano, S. Yepes Ramírez, Harold Zornoza Gómez, Juan de Dios Zúñiga Román, Juan 2012 The positioning system of the ANTARES Neutrino Telescope Journal Of Instrumentation 7 8 T08002-1 T08002-20