Q&A: what would happen if GPS failed?

I'd pull out the map I have next to my seat.

By therebbe on 8 Mar 2011

Drama queens ahoy

Seriously?! If GPS failed a ship would not run aground. It would notice said GPS had failed and stop or seek guidance. When my SatNav fails I don't drive blindly with no idea where I am going. Gotta love drama queen analysts making work for their jobs.

By drummerbod on 8 Mar 2011

Not so, there have already been examples of ships' GPS failing and the systems have fallen back to dead reckoning/gyros without any alarm being generated. Admittedly, these were usually on 1st gen systems, but there are hundreds - if not thousands of those systems still afloat.

By Ex_Sailor on 8 Mar 2011

Ships

According to the interview on the Today programme this morning, the problem with ship GPS is that the failure mode of some GPS receivers is to fail silently. Instead of indicating a problem, a receiver could start to show the ship as being on a different heading and at a slightly different position and at an incorrect speed. The ship would then rebroadcast its position to other vessels, unaware of the inaccuracy.
Could cause chaos crossing busy shipping lanes.

By 959ARN on 8 Mar 2011

"
because instead of being guided they’d have to look where they are, and so on, and that’s likely to cause a traffic jam and it may cause accidents" - WHAT? So because a driver has to LOOK WHERE HE IS AND WHERE HE'S GOING, it's more likely to cause accidents? Okay, I can accept that failure of satnav might force me to drive round a bit more to get where I need to go, or pull over to look at a map or (heaven forfend) ask for directions, which could contribute to jams, but as a general rule I tend to look where I'm going anyway when I'm driving, rather than naively follow the satnav's on-screen display.

I'm not saying that a widespread failure of GPS wouldn't be catastrophic, just that the failure of consumer grade satnav shouldn't lead to increased road accidents.

By flyingbadger on 8 Mar 2011

That was an interesting article, but, in line with the other posters, I'm inclined to think that the consumer-level scenarios are basically little more than scaremongering.

Failure of car sat-navs may slow traffic up, and may slow deliveries of the local Tesco/Argos/etc vans, but cause more accidents? I find the logic in that a bit '2+2=22' myself.

Worrying (if true) about a lack of GPS throwing out radar though - I really would have thought they were purposely totally independent systems. That certainly needs looking into.

Also a little staggered to hear that banking relies on GPS. What numpty came up with that idea?

By Mr_John_T on 8 Mar 2011

They're not saying that if one person's sat-nav failed it would bring about carnage, they're saying that if we reach a point where most people routinely use sat-nav, and are happily driving about being told where to go when someone jams signals across a large and busy area, there will be chaos.

As for ships, far more worrying than their GPS/RADAR failing is when someone spoofs the GPS signals to make the ship think it's somewhere it's not. It can be used to cause accidents, aid piracy and do other nasty things. It's not widespread yet but it does happen.

By nelviticus on 8 Mar 2011

Trucks

Already happens to trucks. Hijackers uses jammers to stop trucks from being tracked before they do what they do with the drivers...

By 959ARN on 8 Mar 2011

Worst Case Scenario

@drummerbod

You're obviously the kind of person that thinks most ships are fitted with state-of-the-art equipment, captained by people with the navigational skills of Captain Bligh. Which, unfortunately is far from the truth. Just look at the Herald of Free Enterprise disaster - I'd have thought checking the water-tight doors were closed before setting off was basic common-sense, let alone a mandatory safety procedure.

The report is talking about wide-scale disruption from loss of GPS services. Either through equipment or software failure, naturally-occurring interference, or deliberate disruption.

These are real and worrying threats. particularly to the emergency services, who are increasingly reliant on their own Sat Nav systems, as more and more local ambulance stations are shut down, and large regional centres are staffed with people who don't have the local knowledge.

Hell, recently I had to call an ambulance for myself, and had to stagger out to them as I could see they couldn't find my house. And the nearest ambulance station is a literally 3 minute drive up the road from me.

I do wonder whether that "Diplomatic Team" recently dropped into Libya were a bit too reliant on their Sat Navs to notice they were about to be captured...

By Penfolduk01 on 8 Mar 2011

I see GPS failures all the time

And they do cause immediate local accidents! Here in Zone 1, one of the key signs that the car in front of you is an out-of-towner is the glowing square of a cheapo bargain basement GPS, right below the rear-view mirror. As a cyclist, spotting these things is bloody important, because cheap satnavs lose their signals in built up areas, very easily.

This appears to happen most often in the middle of a junction, as the antenna is rotated with the car. You can see the driver stop paying attention to the road, and switch to the misbehaving nav. Some reach up to touch or hit it. At that point, their next move is anyone's guess, and that's how accidents happen.

By Steve_Cassidy on 8 Mar 2011

Timing is more important than navigation

The article misses the most important use of GPS. Although it mentioned timing for financial transactions it is a relativley minor aspect of how GPS is used for timing.

Practically every data link is kept in sync by using GPS. I am not sure about 3G GSM but every single CDMA base station needs a GPS timing receiver. All TV outside broadcast vehicles need GPS to sync the video signals.

One way or another data comms today would be pretty screwed without GPS.

By juliand2 on 8 Mar 2011

...or not.

clearly this 'expert' is roughly between 7 and 12 years old, or is otherwise suffering from terrible retrograde amnesia.

For anyone else that CAN remember a time more than 5 years ago when consumer sat navs were for the high end consumer only and often proceeded to engage in activities no more useful than barking 'make a u turn' at you every 30 seconds, we can reassure ourselves that actually there wasn't a crashed car every 100 yards, and the apocalypse did not descend on the M25 at half 5 on a friday for 5 days a week.

I do not have a satnav. I am perfectly capable of driving. This is because I am not a retard. I would not have passed my driving test otherwise.

By MarcosGTS on 9 Mar 2011

what drama

Get out the map and use road signs. Ship Captains have to have a certain level of competency as well, including how to navigate.

The world survived before it, the world will survive without it

By Bunnyman on 9 Mar 2011

Its about unexpected simultaneous multiple failures

Seriously?! If GPS failed a ship would not run aground. It would notice said GPS had failed and stop or seek guidance. When my SatNav fails I don't drive blindly with no idea where I am going. Gotta love drama queen analysts making work for their jobs.

By drummerbod

I think you missed the point. The point is not that GPS failure would bring down sat-nav, with all that entails. The point is that multiple systems would fail simultaneously since they all depend on GNSS. So systems which people did not realise were interlinked actually prove to share a common failure mode, bringing them all down together, unexpectedly.
So in this case not only is navigation lost, but so is your suggested "common-sense" back-up: communication systems.
Likewise yourself, if you tried, say, to phone for directions, would find that your mobile phone no longer worked - becasue sat nav had gone down. Oo'd uv thunk it? That is the point. Nobody thunk it, until now.
Oh yes, and try making a ship 'stop', as in stay in a fixed position, without sat nav.

By martindaler on 9 Mar 2011

@nelviticus "As for ships, far more worrying than their GPS/RADAR failing is when someone spoofs the GPS signals to make the ship think it's somewhere it's not. It can be used to cause accidents, aid piracy and do other nasty things. It's not widespread yet but it does happen."

Yup, that happens all the time. I saw it in a documentary a few years ago. I think it was called "Tomorrow Never Dies" or something like that :D

@MarcosGTS "I am perfectly capable of driving. This is because I am not a retard. I would not have passed my driving test otherwise."

I'm quite sure you are perfectly capable of driving, and that you are not a retard, but the possession of a valid driving licence certainly doesn't prove either of these things, as the prevalence of drivers who are clearly either retarded or incapable of driving (or both) demonstrates!

By flyingbadger on 9 Mar 2011

Ship = plane = car?

There's a lot of people here who seem to think that passing their driving test qualifies them to talk about navigation at sea.

By steviesteveo on 9 Mar 2011

iBus

All the buses in London are coordinated by a system called iBus which takes its data from the GPS receivers in every bus.
Were GPS to fail, the countdown displays at bus stops would cease to be of any use.
More importantly though, iBus warns drivers of low bridges - especially important in the case of new drivers, unfamiliar with a route, or any bus on a diversion from their normal route.
Bus times would probably be affected too, because currently iBus regulates the bus' position to a seven minute window.
iBus is a Transport For London system, search for - "london bus information gps".

By Klobba on 10 Mar 2011

Don't forget aircraft, too

Aircraft use GPS for navigation and precision (landing) approaches.

I regret the final demise of Loran last year as a redundant, independent system.

It is especially worrisome as the Chinese have already demonstrated they could quickly take out GPS satellites if it strikes their fancy.

By GopherBaroque on 12 Mar 2011