Alice: Hello, I'm Alice.

　　Stephen: And I'm Stephen.

　　Alice: And this is 6 Minute English! This week we’re talking about sat navs.

　　Stephen: Sat navs – that’s short for satellite navigation systems.

　　Alice: They’re the gadgets people put in their cars to help give them directions.

　　Engineers have been asking if we’re becoming too reliant on them. Before we

　　find out more, here’s a question for you, Stephen:

　　Stephen: Ok – I’m ready and waiting.

　　Alice: When we talk about ‘satellite navigation’ in English, there is an abbreviation

　　we use called GPS. Do you know what it stands for? I’ll give you some choices.

　　Is it:

　　a) greater place signal

　　b) global positioning signal, or

　　c) global positioning system

　　Stephen: I’m pretty sure I know the answer – but I won’t spoil it for everyone else. I’ll

　　tell you at the end of the programme.

　　Alice: That’s fine. Sat navs using GPS have become very popular in recent years. But

　　they can sometimes get people into trouble. The BBC News website has lots of

　　examples about people driving into rivers or getting stuck on roads which are

　　too narrow. This woman is talking about the lorries which keep getting stuck

　　under a 15th century stone archway in her town because they’re following

　　directions on their sat navs.

　　Insert 1: Woman

　　The amount of lorries that we see nearly every day - they get to that point and there’s no

　　signs anywhere. At the bottom of the road, it doesn’t say: “Don’t go down there - there’s

　　a bridge.” And they get to this point here and every one of them have to reverse - and

　　there’s cars everywhere. It’s just absolute mayhem.

　　Alice: Oh dear – she says it’s mayhem. Lorries either get stuck under the bridge or

　　they cause lots of problems trying to turn around - or to go backwards, to

　　reverse - on a very narrow road. She says it’s absolute mayhem.

　　Stephen: Mayhem – chaos.

　　Alice: In another incident, a car got stuck on the edge of a steep hill when its sat nav

　　directed it down a path which wasn’t suitable for vehicles any more. Antony

　　Chmarny, who works for a satellite navigation manufacturer, says the gadgets

　　should only be used as an aid to driving:

　　Insert 2:

　　Sat nav voice: Turn around when possible – then turn right.

　　Antony Chmarny: If it doesn’t look suitable, don’t drive down it, don’t drive down a

　　one-way street the wrong way if a sat nav tells you to do that.

　　Alice: I think he means, use your common sense – don’t drive down a one-way street

　　the wrong way even if a sat nav tells you to do it!

　　Stephen: I like the sat navs which you can programme with different voices – so you can

　　have your favourite singer or actor with you in the car as your navigator!

　　Alice: What a good idea! Let’s hear now from an engineer who is worried that we’re

　　becoming too reliant on sat nav and GPS technology. Professor Martyn

　　Thomas from the Royal Academy of Engineering says the weak radio signal it

　　uses can easily be messed up.

　　Stephen: Messed up – that’s interfered with, or destroyed.

　　Insert 3:

　　Professor Martyn Thomas: You can get interference – either deliberate or accidental

　　interference, because it is a very weak radio signal.

　　BBC interviewer Justin Webb: Yes, it’s quite easy, isn’t it, to mess it up?

　　Professor Martyn Thomas: Oh, extremely, yes. The radio signal is about the strength…

　　in light terms, it’s like looking at a 100 watt bulb from 12,000 miles away.

　　Justin Webb: So someone who really wanted to put out a large area – satellite

　　navigation systems, could do so?

　　Professor Martyn Thomas: Yes, you could. It would essentially have to be

　　jammed line-of-sight, so you’d have to do it from high ground.

　　Alice: Researchers were able to interfere with GPS signals on a ship using a

　　transmitter on high ground.

　　Stephen: A transmitter produces radio signals or interference - signals which, if strong

　　enough, can block other signals.

　　Alice: Professor Martyn Thomas said all kinds of things went wrong with the onboard

　　equipment on the ship.

　　Stephen: Without saying anything was wrong – incorrect – the ship reported that it was

　　travelling ten miles inland and moving faster than the speed of sound:

　　Insert 4: Professor Martyn Thomas

　　All kinds of things went wrong. The onboard equipment, that was reporting where they

　　were, at one point said that they were ten miles inland and moving faster than the speed

　　of sound. But more alarmingly, quite often the onboard systems, without saying

　　anything was wrong, was reporting their position as being just subtly wrong. And of

　　course, the onboard systems would broadcast that position and information to other

　　ships.

　　Alice: Professor Martyn Thomas from the Royal Academy of Engineering who thinks

　　we should be careful about becoming too reliant on GPS and sat navs, because

　　they can be interfered with. Apparently some people buy blocking gadgets to

　　put on their sat navs in company cars, so their employers won’t know where

　　they’ve been! Well, before we go, Stephen, can you tell us about the

　　abbreviation ‘GPS’?

　　Stephen: So, does it stand for global positioning system?

　　Alice: Yes, well done. So, before we go - a chance to hear some of the words and

　　phrases we’ve heard in the programme today: would you mind, Stephen?

　　Stephen: Sure.

　　satellite navigation systems

　　gadgets

　　abbreviation

　　mayhem

　　to reverse

　　aid

　　common sense

　　navigator

　　messed up

　　interfere with

　　Alice: Thanks, Stephen.

　　Stephen: You’re welcome.

　　Alice: Well, that’s all we have time for today. We’ll have more 6 Minute English next

　　time.

　　Both: Bye!