Dec 9, 2010 10:58 GMT  ·  By

One of the most interesting experiments aboard the International Space Station (ISS) is the Norwegian Automatic Identification System (NORAIS), a detector capable of keeping track of ships sailing on the world's oceans for months on end. The system was activated on June 1, 2010.

Experts operating the experiment say that the instrument has been able to track the routes of individual ships for as much as six months without break. Some 60,000 ships were tracked thus far, they add.

The tool is installed on the ISS Columbus research module, which is operated by the European Space Agency (ESA). It works be capturing Automatic Identification System (AIS) signals ships traveling the oceans are required by law to emit.

Usually, these signals are monitored by coast guard and port authorities in countries around the world, given that the officials can form a clear picture of what ships are at which location in their path.

The companies operating the ships can also keep track of their crews' progress, and use the data to build more efficient and faster trading routes. The NORAIS instrument is purely experimental for now.

According to ESA, all international vessels, passenger carriers and cargo ships have to carry AIS VHF-radio transponders if they exceed 300 tonnes.

“AIS messages are designed to be used only on a local basis, with a range of 50 [kilometers] or so to the horizon,” says Norwegian Defense Research Establishment (FFI) expert Torkild Eriksen.

The organization was responsible for building the NORAIS receiver, in collaboration with scientists from the Kongsberg Seatex, also in Norway.

“Instead, we are picking them up from 350 [kilometers] in orbit, when they might have traveled up to 2000 km. Our receiver, therefore, had to be designed for extreme sensitivity to detect such weak signals,” the scientist goes on to say.

The NORAIS instrument is just one component of a larger project championed by space agencies involved in constructing the $100 billion ISS, for using the station as a platform for various types of planetary monitoring studies.

“Operating from space, we have been able to track ships for long periods as they cross the ocean,”adds FFI expert Andreas-Nordomo Skauen. In four months, NORAIS recorded some 30 million AIS messages, from about 60,000 vessels.

The instrument's range covers 95 percent of Earth's surface, and reaches polar latitudes as well.

“Over the four-month period, we watched one ship travel from the western Pacific to Argentina then over to Europe and down to Africa, picking up its AIS signal from two to seven times per day, depending on latitude,” Skauen adds.

“So we can reveal exactly where a vessel has been in the marine environment, information that would be very useful to port, fisheries and marine authorities,” he concludes.