1. G. Larosa, M. Ardid (for the KM3NeT Consortium) Institut d’Investigació per a la Gestió Integrada de les Zones Costaneres - Universitat Politècnica de València Frontier Detectors for Frontier Physics 12 th Pisa meeting on advanced detectors La Biodola, Isola d’Elba (Italy) May 20 – 26, 2012

2. KM3NeT  a future underwater neutrino telescope Compact package of the DU Flexible tower The compact package of the DU allows a fast and efficient way for deploying the detector. The DU unfurls once it is placed on the seafloor.

3. Acoustic Positioning System (APS) Key elements for the Acoustic Positioning System:  Auto-calibrating Long Baseline of acoustic transceivers anchored in known and fixed positions. They define the reference frame.  Array of acoustic sensors (hydrophones) in the Detection Unit mechanical structure.  Auxiliary devices: tiltmeters and compasses, CTDs, sound celerimeters, sea current metres (ADCPs).  Data acquisition and transmission system.  Data analysis system on-shore. Hydrophones will be sampled continuously at a rate of about 200 kHz and a continuous stream of data will be sent to shore for positioning and acoustic monitoring studies. Measurement and Analysis Technique: 1.T Rec (Hydro) – T Em (Beacon)  Distance 2. Geometrical Triangulation  Position Measurement and Analysis Technique: 1.T Rec (Hydro) – T Em (Beacon)  Distance 2. Geometrical Triangulation  Position All elements have been tested in lab, and will be tested in situ In NEMO-Phase II (2012) and in the KM3NeT Pre-Production Model. Scheme of the Acoustic Positioning System

4. Acoustic Positioning System (APS) for KM3NeT Acoustic receivers and electronics Piezo and preamp Acoustic transceiver Sound Emission Board (SEB) FFRSX30 transducerSEB Diagram SMID hydrophone KM3NeT Acouboard Electronics inside the DOM Piezo in the DOM (external view)  Emission frequency :25 kHz÷45 kHz.  LBL transcievers and hydrophones phased and synchronous.  Acoustic signal amplitude can be set from shore.  All data to shore. Power consumption: 100 mA @+5 VDC 1 mA @+12 VDC Piezo dimensions: 18 mm x 12 mm Sensor dimensions: 21 mm x 30 mm