1 BUILDING THE SYNTHETIC “MAC SYSTEM”: AN ANALYTICAL INTEGRATION OF MAGNETIC AND ACOUSTIC SUBSYSTEMS FOR PORT PROTECTION SCENARIOS. Faggioni O. (1,2) , Soldani M. (1,2) , Zunino R. (3,2) , Leoncini D. (3,2) , Di Gennaro E. (4) , Gabellone A. (5) , Maggiani P.V. (6) , Falcucci V. (7) and Michelizza E. (7) 1 – Istituto Nazionale di Geofisica e Vulcanologia, Via Pezzino Basso 2, 19025 Fezzano (SP), Italy 2 – Defence Geophysics Group, University of Genoa, DIBE, SEA Lab, Via All’Opera Pia 11a, 16145 Genova, Italy 3 – University of Genoa, DIBE, Via All’Opera Pia 11a, 16145 Genova, Italy 4 – Italian Navy, Naval Logistic Inspectorate, Piazza della Marina 4, 00196 Roma, Italy 5 – Italian Navy, CSSN ITE “G. Vallauri”, Viale Italia 72, 57127 Livorno, Italy 6 – Italian Navy, COMFORDRAG, Viale Giovanni Amendola 1, 19122 La Spezia, Italy 7 – WASS, Via di Levante 48, 57124 Livorno, Italy e-mail: osvaldo.faggioni@ingv.it Abstract In order to obtain a preliminary overview on the effectiveness of the underwater anti-divers magnetic-acoustic “MAC System”, we have developed a synthesis between the results coming out from the two different subsystems (magnetic and acoustic), based on two different models, during two different test sections. The section covered by the magnetic component, measured near the NURC dock (La Spezia, Italy) in very noisy port condition, has been remodeled on the sea bottom profile of the access channel to the Italian Navy Base in La Spezia, which presents environmental electromagnetic noise compatible with the NURC’s one. In this entrance way has been executed an acoustic port protection experiment, too. The two different covered sections (magnetic and acoustic) have been merged to obtain an integrated synthetic model of the accuracy of the MAC System. The results have pointed out a remarkable increase of the anti- divers covering effectiveness, in particular in the boundary zone of the access way to be protected: the confidence of the MAC System can be considered quite 1 and higher in respect to the sum of the confidence of the two subsystems. Rationale During the last five years, 2004-2008, underwater intruders’ detection systems for port protection have been developed according to two independent approaches, based respectively on acoustic principles and magnetic effects. The analysis and comparison of the performances of the two approaches highlight their peculiarities: acoustic barriers guarantee optimum volumetric control but exhibit some limitations in peripheral surveillance; on the other hand, magnetic arrays achieve high peripheral security but partially fail at volumetric control. These operational features suggest the integration of both detection approaches into a dual system.