1. The Instrumentation Unit of The KM3NeT Calibration Unit
KickOff Feder, 21/06/2017

2. The Calibration Unit
Independant line dedicated to the calibration of the detector
Particularity of the line: inductive line in order to save money
Needed for the Calibration in time and in position :
Calibration in time : inter DU time calibration with the use of laser light emission
Calibration in position : acoustics emitter/receiver for the relative acoustic positioning system
Calibration in position : measurements of oceanographic parameters to know the sound velocity
+ sea current measurement

3. The Calibration Unit Global sketch of the Calibration Unit : CU CPPM
APC
- Laser : time calibration
- Acoustics : relative positioning

4. The Instrumentation Unit (IU) for the Calibration Unit
Inductive Instrumentation Unit directly inspired of the Albatross line
The IU is composed by one inductive Instrumentation Line (IL) and one titanium Instrumentation Base container (IB)
The IL hosts all the oceanographic instruments linked to the line via an inductive interface that communicate with inductive modem (SeaBird, rate 1200 bauds)
The instruments are autonomous in terms of energy using internal batteries
The IU is recoverable in order to change the batteries and to calibrate some of the instruments that need recalibration periodically (about once every 2 years)
The IU will be connected to the electric interlink cable with a ROV via the IB wet matable connector

5. The instruments for the CU
The IU is linked to the Calibration Base of the CU via one 50 m electric serial cable using RS422 serial communication for the data transfert :
4 electrical points for the RS422 link
2 electrical points for the 12V power (supplied by CB)
The configuration of the IL in order to intrument the full water column of the KM3Net detector for the ORCA version (vertical height 200m) is the following :
3 CTD probe (Conductivity, Temperature, Depth)
theses parameters are used to calculated the sound water speed with the Chen&Millo empiric formula
3 currentmeter : measures the sea current
3 SV : Sound velocimeter : direct measurement of the sound velocity
 One measurement of each instrument every 20 minutes, transmitted in «real time» to the CB

6. The instruments of the IU
- CTD from SeaBird : (SBE 37IMP-ODO-1b) Inductive instrument
Initial Accuracy
Conductivity
± S/m 
Temperature °C
± (-5 to 35 °C);
Oxygen
± 2% of saturation
Pressure
± 0.1% of full scale range
- Sound Velocimeter from Valeport MiniSVS :
Range: m/s
Resolution: 0.001m/s
Accuracy: theoretical max error from ±0.017m/s to ±0.02 m/s depending on sensor size.
Non Inductive instrument and non powered : need an extra serial/inductive interface
- Currentmeter : Aquadopp6000 from Nortek :
Local measurement of the sea current
Range: ± 3m/s
Accuracy: 1% of measured value ± 0.5 cm/s
Non Inductive instrument : need an extra serial/inductive interface
Could be replaced by ADCP : Acoustic Doppler Current Profiler (current profile on the water column)

7. Status of the IU Test bench operationnal in CPPM :
Simul. Inductive cable
Simul. IU Manager (CB)
IMM : inductive modem
Simul. Inductive cable coupler
UIMM serial/inductive adapter : to interface Aquadopp currentmeter
all instruments (CTD, currentmeter, celerimeter) are now correctly interfaced and configured via inductive modem.
Launch of measurement and retrieve of the data are operational

8. Status of the IU Mechanics : Global mechanics design almost completed
Global deployment steps defined  Full detailed deployment procedure under redaction