Underwater communication link

1. Inductive modem

The Aqualog Profiler can accommodate an inductive SBE IMM modem to transfer the data and the telemetric information.

The inductive SBE IMM modem with cable coupler installed on the Aqualog profiler

Data is transferred real-time to the subsurface flotation by using inductive modems. Then the tether transmits the information from the subsurface flotation to the surface buoy. The wire rope, in contact with seawater at each end, conducts electrical signals in a loop, where seawater is the electrical return path. IM devices couple to this loop inductively along the insulated (jacketed wire) part of this loop without direct electrical connection. The coupling is achieved using a toroid transformer in which the mooring wire and seawater return form a single winding. Since there is only one current path, only one device can transmit at a time (half-duplex).

2. Acoustic modem

The Aqualog Profiler can accommodate a hydroacoustic Benthos ATM modem to transmit the data and the telemetric information

Teledyne Benthos Acoustic telemetry modem 903 transducer

Data is transferred real-time to the subsurface flotation by using inductive modems. Then the tether transmits the information from the subsurface flotation to the surface buoy. 

3. Evologics S2CR 7/17 modem

The underwater acoustic modems S2CR 7/17, produced by EvoLogics GmbH, are currently being considered for integration into the data communication system of the Aqualog profiler. Reliable operation below the seasonal  thermocline at the distances up to 4 km.

Evologics S2CR 7/17 modem

Evologics S2CR 7/17 modem

Air communication link

1. GPRS (mobile telemetry) buoy

The GPRS buoy  serves for the data and command exchange between the mooring and a user via Internet.

GPRS (mobile telemetry) buoy

GPRS (mobile telemetry) buoy

2. The radio buoy

The radio buoy transmits the observational data and telemetry information from the mooring to the coastal station. In return, it receives commands from the coastal station.

The radio buoy

The radio buoy

The radio buoy specification