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This bi-directional and interactive system
comprises an acoustic link from the bottom station to a surface buoy and then a
satellite link (Inmarsat miniM) from the buoy to the shore. The satellite
transmission may be doubled by a radio link whenever the experiment site is not
too far from a coast.
The system operation is managed by an
electronic unit installed on the buoy. From land one is able through a PC
interface to send commands to the station and to recover hourly summaries of the
data records and the station operating parameters.
The Inmarsat miniM transmission operates with
a geostationary satellite toward which the buoy antenna must be directed. The
servo controlled antenna positioning is an energy consuming process which cannot
be run permanently. So the buoy electronic unit activates periodically the
antenna for a limited time duration, typically a quarter of an hour every day,
during which the dialogue with the station can be established. At this occasion,
the operator has the possibility if needed to modify the periodicity and
duration of the next dialogue time windows.
The communication system equipment is housed
in two interconnected watertight containers, one for the electronics and
satellite antenna and the other for the batteries.
This system has been developed with he
contribution of ORCA instrumentation (Brest, acoustic transmission), SYSTEME G
(Lannion, electronic unit) and KENTA ELECTRONIC (Ergué-Gabéric, VHF radio link).
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Technologie Marine
- Marine Technology
