【一起听英语】卫星导航系统

驾车的朋友深有体会，有了卫星导航系统，去哪里都不用愁。

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 1 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. 

6 Minute English © bbclearningenglish.com 2011

Page 2 of 6

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 2, to

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

Stephen: Mayhem – chaos 3.

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. 

6 Minute English © bbclearningenglish.com 2011

Page 3 of 6

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 5 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 6 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 7 have to be

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

Alice: Researchers were able to interfere 4 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. 

6 Minute English © bbclearningenglish.com 2011

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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 8 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 

6 Minute English © bbclearningenglish.com 2011

Page 5 of 6

 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!