Oceanographic Tools: SeaNeT
SeaNet is a new communications
system developed in 1995 to extend the Internet to ships at sea.
in the middle of the ocean, thousands of miles from shore, oceanographers
aboard research ships have been cut off from the fiber-optic-based
transmission lines that link the rest of the land-based world to
the Internet. But in 1995, a new communications system called SeaNet
was developed to extend the Internet to ships at sea.
SeaNet greatly expands the number of scientists and students that can participate
on research cruises. It gives them access to shipboard data, images and information
as they sit at their computer terminals in shore-based laboratories or schools.
SeaNet was developed by a group of engineers and marine technicians at Woods
Hole Oceanographic Institution (WHOI), Lamont-Doherty Earth Observatory (LDEO),
and the Scripps Institution of Oceanography (SIO) with support from the National
Science Foundation. The system takes advantage of high-speed satellite, cellular,
and other communications technology, as well as specialized software and hardware
tools developed by the SeaNet engineering group, to provide affordable, high-speed
data transmission to and from shore.
Affordable was a key obstacle, because the primary communication
links to ships are satellites, which cost about $10 per minute to use. To overcome
this, SeaNet engineers created Data Pipes, which allow data files
to be transferred easily and without errors between the ship and any computer
on shore connected to the Internet. Data files containing information or images
are first combined together into one batch. Then they are compressed, so
that they dont take as much time (and money) to be transmitted via satellite.
Then they are put into a computer holding bin. Several times a day, a technician
on board ship establishes a connection to a satellite and the batch of compressed
files is transferred. To maximize the amount of data transferred during each
active satellite link, data files are transmitted to and from the ship simultaneously.
The files are also transferred at high speed-about 64,000 bytes per second. This
fast, two-way transfer makes the system very cost-efficient.
While it is possible now to bring up a communication link and go live on
the Internet using SeaNet, the cost of satellite communications prohibits doing
this often or for long periods of time. However, when the cost of satellite time
decreases and computer compression software is improved, routine online access
to the Internet from ships will become feasible.
SeaNet now operates on six UNOLS (University National Oceanographic Laboratory
System) ships. They are: RV Melville (SIO), RV Atlantis (WHOI), RV Ewing (LDEO),
RV Seward Johnson (Harbor Branch Oceanographic Institution), RV Pelican (Louisiana
University), and RV Knorr (WHOI).