ARLA/CLUSTER: Tecnologia que remonta à II Guerra Mundial volta a ser usada para apoiar os sistemas de GPS

[João Costa > CT1FBF]

GPS back-up: World War Two technology employed

Technology developed during World War Two is to be used as a back-up for GPS.

The General Lighthouse Authorities (GLA) have announced that they have
installed a system called eLoran in seven ports across Britain.

The GLA say many critical instruments on ships use Global Navigation
Satellite Systems, and if they fail the consequences could be
disastrous.

The new system, which is ground rather than satellite-based, is
designed to be used in the event of a GPS failure.

"All vessels that sail today are massively dependent on GPS, " Martin
Bransby, research and radio navigation manager for the General
Lighthouse Authorities of the UK and Ireland, told the BBC's
technology programme Click.

"It is their primary means of navigation - and a massive number of
instruments rely on it too.

"If you don't have it, you are dead in the water."

Testing for eLoran has taken place in Felixstowe, the busiest
container port in the UK.

Each year, three million containers are brought in on some of the
biggest ships in the world.

Safely manoeuvring these vessels in this packed waterway is vital, and
currently the only way to do this is with the help of GPS.

Onboard the Galatea, a ship that is 80m (260ft) long, the GLA have
been finding out what happens if the satellite system goes wrong.

Martin Bransby demonstrates a GPS failure by pulling the plug on the
ship's receiver.

Within a few seconds, alarms start to sound on the bridge as one by
one the instruments stop working.

"This is the gyrocompass - it steers the ship - you can see it
starting to fail," says Mr Bransby.

"If we walk over here, this is the radar, and that's not working
either. This is the dynamic positioning: it holds the ship's position,
that's not working.

"The electronic chart display becomes unusable. Even the ship's clock
stops working."

In a series of tests, the GLA have found that almost every bit of kit
on the boat uses GPS - even the onboard satellite entertainment
system.

Mr Bransby says: "You can imagine standing watch on this ship, it's
the middle of the night, it's dark, it's foggy, you are in the English
Channel, and then this happens.

"What do you do? You're in a right mess, basically."

Read the full BBC News story at:
http://www.bbc.co.uk/news/science-environment-29758872