Dive and Discover : Oceanographic Tools: SeaNeT

SeaNeT
SeaNet is a new communications system developed in 1995 to extend the Internet to ships at sea.

Out 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 don’t 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).