On board Polarstern there are three different antennas available, which can be used alternatively but not at the same time.
First antenna is flush and permanently mounted in ships keel at ca. 11m11 meter depth. The antenna is protected by window, which against ice sheets. The window can be opened during operation, but during open window and ice covered situation the ship must not be driven.
Second antenna namedis a deployable antenna is loweredby means of lowering through the moon pool.
Third antenna from Thomson Marconi is fixed mounted aton a device carrier forto be lowered through moon pool.
If an antenna is lowered through moon pool in ice covered areas, the ship must not be driven.
Active antenna is connected to electronic device named USBL-Box in room E-525a. The control and operation of the system is performed via web-Interface.
For Typically Posidoniathe system are two transponders of type Oceano ET861 and two releasers of type Oceano RT 861 B1S (RT2500 S-Side Bar) on board available. The maximum depth amounts to 6000m.
System IXSEA TT801 (SN 002) is operated from laptop on the bridge by laboratory electronic engineer.
Online data stream of Posidonia is broadcasted via UDP, which can be used by alternative visualisation tools (e.g. PosiView) or for seperately logging.
Mobile system IXSEA Oceano TT801 can alternatively be used to send release commands.
Online data stream of Posidonia is broadcasted via UDP, which can be used by alternative visualisation tools (e.g. PosiView) or for seperately logging
For Posidonia system are two transponders of type Oceano ET861 and two releasers of type Oceano RT 861 B1S (RT2500 S-Side Bar) on board available. The maximum operation depth of these devices is 6000 meter. | 
