Could the Americans switch off GPS ?

[lustyd]

Will existing GPS receivers be able to use Galileo satellite signals, or will we all have to buy new receivers ( when the existing GPS satellites die, rather than being switched off, which is unlikely)

Current systems can generally receive the US and Russian signals. Very current systems (within the last year or so) have the chip but maybe not the antenna to get the EU signals. Brand new systems can do all three but may not have the software (firmware) to make use of it. Within the next year almost all will be able to fully utilise all three.

 

[Heckler]

They would need some serious justification to ground the world's commercial airline fleet and dock the world's merchant navy...

Hang on, when I bought my Garmin 12, 13 yrs ago, the Yanks could and did make it less accurate than it is today. I have in the garage a gizmo that used to pick up radio signals to make the thing accurate. Bill Clinton made them switch on the accuracy thing and it has been like that since.
They could switch it again now if they wanted to.
Stu

 

[Buck Turgidson]

So you're saying planes used to crash when it was cloudy? I'm pretty sure any reasonable pilot would have a good plan even in fog to avoid their own demise.

Did I say they crashed when it was cloudy? Well actually quite a few did. But more importantly they didn't fly. Ground based nav aids are being removed all over the place. NDBs and even VORs are being shut down as the navigation policy changes. Billions have been invested in PBN and the introduction of GNSS and SBAS/GBAS based systems and procedures.

Many of the remote fields in Northern Canada/Central Australia and other places rely on GNSS to remain open. These fields and the businesses they serve (oil/gas/mineral mining) would be severely effected by switching off GPS. Something which US policy forbids. What they can do is Jam the service over an area. This is what would be done in case of the home made GPS missile scenario posited earlier in this thread. All the info is available on the GPS web site.

 

[geoid96]

Hang on, when I bought my Garmin 12, 13 yrs ago, the Yanks could and did make it less accurate than it is today. I have in the garage a gizmo that used to pick up radio signals to make the thing accurate. Bill Clinton made them switch on the accuracy thing and it has been like that since.
They could switch it again now if they wanted to.
Stu

See: http://www.gps.gov/systems/gps/modernization/sa/

 

[lustyd]

Did I say they crashed when it was cloudy? Well actually quite a few did. But more importantly they didn't fly. Ground based nav aids are being removed all over the place. NDBs and even VORs are being shut down as the navigation policy changes. Billions have been invested in PBN and the introduction of GNSS and SBAS/GBAS based systems and procedures.

Many of the remote fields in Northern Canada/Central Australia and other places rely on GNSS to remain open. These fields and the businesses they serve (oil/gas/mineral mining) would be severely effected by switching off GPS. Something which US policy forbids. What they can do is Jam the service over an area. This is what would be done in case of the home made GPS missile scenario posited earlier in this thread. All the info is available on the GPS web site.

I'm pretty sure I've misread something here. Planes fly all the time on cloudy days and always have done even before GPS. Clouds are quite high (I'm not a pilot...) so surely when below the cloud the pilot just looks for the runway and asks over the radio which direction to approach from then aims for it using instruments for altitude and direction etc?

 

[Buck Turgidson]

I'm pretty sure I've misread something here. Planes fly all the time on cloudy days and always have done even before GPS. Clouds are quite high (I'm not a pilot...) so surely when below the cloud the pilot just looks for the runway and asks over the radio which direction to approach from then aims for it using instruments for altitude and direction etc?

"Clouds are quite high"

;-)

 

[photodog]

The yanks don't need to turn it off for military purposes... They are quite practiced at Jamming the signals when they need to... Most here will have seen the notices telling us of excercises In the uk doing that... I also believe that they have the ability to degrade the signals on a wider regional basis as well...

 

[l'escargot]

Hang on, when I bought my Garmin 12, 13 yrs ago, the Yanks could and did make it less accurate than it is today. I have in the garage a gizmo that used to pick up radio signals to make the thing accurate. Bill Clinton made them switch on the accuracy thing and it has been like that since.
They could switch it again now if they wanted to.
Stu

Nothing in my post suggests they couldn't...just that now it is so established they would need some serious justification to do so

 

[Buck Turgidson]

Nothing in my post suggests they couldn't...just that now it is so established they would need some serious justification to do so

GPS III satellites no longer have the SA capability so as the new sats go into service they will lose the ability that they have stated they will not use.

 

[Sgeir]

Hang on just a minute. They not only have the capacity to shut down civilian GPS, something I thought that we already knew anyway, but, more to the point, haven't they already done that? I'm sure that they have selectively closed down GPS in conflict zones. Closer to home, and perhaps I'm wrong, but haven't we had coastguard warnings over the past three or four years about temporary selective shutdown in some UK waters?

 

[NorthUp]

Close- it is selective jamming, in the Minch during Exercise Joint Warrior, and other areas round the coast where the military play.
In the Minch the transmitters were at Loch Ewe and Cape Wrath

http://stakeholders.ofcom.org.uk/spectrum/gps-jamming-exercises/

 

[Seajet]

Buck,

I couldn't agree more, I'm sure you're well aware the term is ' Controlled Flight Into Terrain ' - CFIT - when pilots flying blind went straight into hills and mountains while seeking a runway.

A helluva lot of good people have gone this way, GPS gives altitude which we yotties ignore ( ' sea level ' is usually a good bet ) but there are other terrain mapping devices such as TIRPROM, where the landscape has been digitally mapped very accurately and can give a display and audio warnings.

The main thing nowadays is there will hopefully be a Notice To Mariners if something pointy is going to come someone's way, and a compass and chart are still useful.

 

[nimbusgb]

Wow, what a load of *******s there is in this thread!

Gps III satellites are not even fitted with selective availability capability so how can you turn on something that is not there?

An act of congress specifically prohibits anyone from 'turning off' gps.

Do people really think that the US military relies solely on GPS to the extent that they would even consider turning it off. It would be a pretty thick military that made a navigation system freely available and then relied on it completely!

The service is under the JOINT control of the National Executive Committee for Space-Based Positioning, Navigation, and Timing and is not solely controlled by the military.

And the biggie ............

If there is a global conflict on the scale you lot believe is neccessary to 'turn off' GPS who will give a **** where they are? You certainly wont be wandering about sailing or flying or perhaps even driving for pleasure. We will all be hiding under our kitchen tables waiting for the flash!

It really is hilarious to think people are concerned that when two superpowers start talking about lobbing thermonuclear devices around the globe, or an alien life form has invaded earth or some other box office megacatastrophe has occurred you lot are worrying about finding your way to a mooring in the dark after a pleasant days sailing!

Go back to the pub and worry about something realistic for pitys sake!

 

[Pete R]

You don't really need the Americans to switch it off as there are numerous items on the market that will allow you to do it yourself. All legal to buy in the UK BUT illegal to use.
http://www.guardian.co.uk/technology/2013/feb/13/gps-jammers-uk-roads-risks

Some of the basic ones that plug into a cigarette lighter operate at a distance of a couple of metres, just enough to prevent a tracker on a vehicle from working if you have just nicked it or if an errant spouse or VIP doesn't want to be followed.

Some of the bigger ones are enough to cover a building and just in case anyone here is friendly with the Russians you can even get the range to mess up an airport or two.
http://arstechnica.com/information-...pumps-up-the-gps-jamming-in-week-long-attack/

 

[MASH]

Nimbus, they've been told again and again, it's a waste of breath.
What's even more hilarious is that some people imagine in a conflict that big switching GPS off would have any effect, as if military platforms bigger than jeeps rely on GPS.

Still, the nasty, machiavellian Great Satan is an soft target for all the conspiracy-theory victims with non-precision arguments...

 

[Sandy]

It's not just an aid to navigation in the aviation world. There are categories of approach which are only available using GPS. ICAO have mandated that those approaches should be available for every runway by 2016 and they are already implemented in many many remote places as the only approach. For en-route navigation it would restrict many areas of airspace and the entire airbus fleet would be restricted in how they are operated due to their GPS primary architecture. The EGPWS system which helps prevent CFIT will not work without GPS. So you would be sending aviation back 20+ years. Ronnie made GPS available to civvy operators because of the Korean Airlines shoot down. Subsequently the yanks have declared that they will not degrade the system which is why transport systems have been developed which rely on it.


http://www.gps.gov/policy/

I bow to your greater knowledge of the aircraft world.

 

[glashen]

In the early days of GPS the Americans did use ' selective ability ' to degrade the accuracy for civilians or knobble it entirely when the Gulf Wars were going on; there were stories of yachts being surprised to read that they were doing 400 knots at 10'000 feet !

However I understand that since GPS became so popular and a major safety aid, the U.S. put out an official statement a few years ago saying they will not spoof the system.

Having said that, I know what I'd do if I was in Washington with news that an amateur GPS guided terrorist missile was heading my way !

I was told the opposite was true during the first Gulf war SA was turned off because there were not enough military receivers and civilian receivers were being used. I heard at least one south coast marine electronics firm did a roaring trade to soldiers who wanted to know where their vehicle was. As other have said the likelihood of GPS being turned off now is virtually zero I wouldn't speculate on the economic cost but I'm sure it would be enormous, I doubt many realise just how many application rely on a GPS and particularly the timing signal.

 

[prv]

I doubt many realise just how many application rely on a GPS

I read an article somewhere which said that the doors on some railway carriages used GPS and a database of station locations to decide where to unlock.

Pete

 

[nortada]

The short answer is yes but they won’t, at least not yet, because they need it for their own military purposes.

Why would the US want to switch off a system they introduced?

 

[nortada]

Visual approaches are only useful in visual conditions. GPS or more accurately GNSS approaches are used in Instrument Metrological Conditions. i.e. when it's cloudy ;-)

ILS, GCA or internal aids could all be used in IMC conditions. Could increase break-off heights unless the aircraft had auto land. Finally, don't understate visual approaches, in many places because of a good weather factor they are the norm & can really shorten the approach for even big aircraft & thereby increase airfield utilization.

Quickest way to get back on the ground - ask any fighter pilot!