Preface The expedition ARK XIX/3 with the German icebreaking RV ...

schools and academic institutions in order to promote and enhance interest in Marine
Sciences, or simply, distant learning. Communications will be via satellite as this is the
only available means currently for such a transmission to be feasible on board a
vessel.
This project is on its initial stage hence the requirement to collect as much data on the
factors governing such a transmission.
Several tests were already carried out a few weeks earlier on the research vessel
Belgica and further testing were planned on this expedition on board the FL
Polarstern.
An Overview of Satellite Communication
Satellite communications may be classified into three types, according to their orbits:
1) Geostationary earth orbit – GEO
2) Mid-Eath Orbit – MEO
3) Low Eath Orbit – LEO
GEO satellites are located about 36,000 km in space, with MEO and LEO situated
around 10,000 km and less than 1,000 km altitude respectively. Unlike terrestrial
transmission, signals transmitted cannot be refreshed along the way in order to
maintain the signal integrity hence the transmission system for satellite communication
has high power consumption. Systems can only withstand a finite power and excess
power will burn a system out. This same fact also applies to satellite transmission
systems; therefore, with the lack of signal refresh along the signal path, satellite
signals are generally weak when received. This weak signal and the noise that is
picked up along the way, degrading the signal even further, and the earlier factors,
make satellite link an expensive means of communication and is also generally
considered as unreliable.
The development of internet access via terrestrial optical fibre has enabled high data
transmission but in the case of satellite communication, access to the internet via
satellite is still a relatively new development hence access is still slow as problems
have to be overcome. High speed optical transmission by optical fibre has also led to
the development of video streaming. However, to perform such an operation via a
satellite link will require a need to optimize transmission to overcome the slow speed
and weak signals.
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