Are we about to lose GPS - post this Br***t mess? Very worrying

[JumbleDuck]

Yes, it is a bit simplistic. All the satelites are visible at different times everywhere in the world; the orbits aren't geostationary (and GPS wouldn't work if they were). To deny access to a part of the world means very clever programming of the system to deny signals useful in certain places, and I doubt it can be done with any sort of precision.

SA allowed deliberately wrong positions to be derived over defined areas, so perhaps similar technology would allow no position at all to be found.

 

[Mark-1]

The loss of GPS in places like the West of Scotland is achieved by jamming, not by fiddling with the system itself.

I'm sure you're right but do you have a link?

 

[Mark-1]

SA allowed deliberately wrong positions to be derived over defined areas

Google is silent on this but that is my recollection.

 

[Mark-1]

They can: https://www.wired.com/2001/10/u-s-could-deny-gps-to-taliban/

 

[Topcat47]

I am delighted to report my sextant still works and as long as I have led in my pencil can do the sums.

I take an interest all the electronic gizmos due to my interest in digital comms and usually fall about laughing when the politicians/media talk and report on something that they have no understanding of.

I'm no sae green as I may seen. D'ye think I'm saft as candy........

 

[Topcat47]

God! don't you just hate autocorrect.....

 

[Blue Sunray]

Presumably both of you voted in the referendum To be so ignorant of basic facts surrounding GPS which as sailors is probably your prime means of navigation doesn't say a great deal about the understanding of issues surrounding Brexit. And people wonder why it is inadvisable to hold referenda and why the UK is is in such a mess, if anything demonstrates it it is the OPs post.

That frankly a bit of an odd post. I'm not sure that there is any necessity to understand the technicalities of how GPS works to use it effectively and to somehow extrapolate from that lack of understanding to understanding of the politico-economics of BREXIT probably says more about your prejudices than about the OP, who whilst he might be ignorant of the facts, is at lest asking questions to correct that situation.

"The presence of those seeking the truth is infinitely to be preferred to the presence of those who think they’ve found it." Terry Pratchett

 

[NormanS]

I'm sure you're right but do you have a link?

The relevant Nav Warnings always refer to the jamming of GPS.

 

[Kukri]

There was a major - and I mean major - GPS spoofing in the Black Sea not so long ago. Numerous ships found themselves sailing across hillsides and down suburban streets. Part of the ongoing Russia/Ukraine cyber war, like the Notpetya virus, intended to cripple the Ukrainian financial system, that actually shut down Maersk Line - who, very luckily had a power cut in their Accra office at the time, so they had one intact hard drive, and could get going in a couple of days, at a cost of a mere US$300million.

 

[Poignard]

I hope that you also have your sextant and sight tables to get your Lat and Long to plot on your chart!

Afraid not. I now only sail in the Bay of Biscay so if I get lost I can just head east until I see land (hopefully before I hit it).

 

[Blue Sunray]

I imagine 'jagged area of the UK' would be tricky but the USA can certainly turn GPS off on a regional basis. For instance, they periodically turn off GPS in the area West of the West Coast of Scotland for military exercises and I'm sure they turned off GPS in and around Iraq during the Gulf War. They don't want the enemy using civilian GPS.

...but that's GPS & the OP was asking about Galileo. I've no idea what ability Galileo has to be limited by geographical area or even if they have a concept of Military/Civilian use.

All academic though. If we lose one GNNS provider the other 3 will all work fine. The only way I can see GNNS completely ceasing to work in the UK is a war where the USA/China/Russia started destroying all the GNNS SVs to deny GNNS to the others and under those circumstances finding my way to St Vaast for Moule Frites wouldn't be a big priority.

WRT to Galileo: In the same way than none of us noticed GNNS getting better when Galileo was switched on, none of us would notice GNNS getting worse if it were switched off.

I was going to say that is pretty much nonsense but I see Antarctic Pilot got there first, you might have rescued a little bit of credibility if you could have got the abbreviation correct (GNSS).

 

[Fr J Hackett]

USA controls Galileo and apparently Europe is getting a system of its own - but both may be denied to GB boats.

This I heard from a neighbour last evening, one who seems to know what he is talking about - but I don't in this case.

So, post Br***t, might Europe deny this vital facility to GB sailors/fishermen/CG/commercial vessels etc etc ?
Or at least might we have to "pay through the nose" by way of licence fees, usage tariffs etc?

What a horrifying thought, if true.

Anybody any advice, thoughts, knowledge on this?

That frankly a bit of an odd post. I'm not sure that there is any necessity to understand the technicalities of how GPS works to use it effectively and to somehow extrapolate from that lack of understanding to understanding of the politico-economics of BREXIT probably says more about your prejudices than about the OP, who whilst he might be ignorant of the facts, is at lest asking questions to correct that situation.

"The presence of those seeking the truth is infinitely to be preferred to the presence of those who think they’ve found it." Terry Pratchett

Those first two lines say it all, confusing the European GNSS with the US one then "he seems to know what he was talking about" patently didn't. Then goes on to bring it all into the Brexit sphere. The extrapolation is made as I pointed out on the basis that GPS has been about for a long time and there are the 3 common systems and sailors are increasingly reliant on GNSS as a prime navigating tool so one would expect them to have at least a rudimentary knowledge of who owns the systems and selective availability. If they had they wouldn't have made such fatuous comments and assumptions then linked them to Brexit. So is it any wonder that someone can question their thought processes.

 

[macd]

It ought to be pretty obvious that any system called "Galileo" has a European provenance. The US system (or rather the administration that owns it), can't possibly be Galilean since it's pre-Copernican. For traditionalists, sextants don't work very well in that universe, either.

 

[Mark-1]

The loss of GPS in places like the West of Scotland is achieved by jamming,

The relevant Nav Warnings always refer to the jamming of GPS.

Thanks both.

<polite cough> GNSS: Global Navigation Satellite System

Thanks for spotting that, and I'm afraid you got Lakesailored in my corrections!

 

[Mark-1]

GPS is US owned and controlled, it broadcasts an unencrypted signal for public use and an encrypted signal for use by whoever the USA grant access.

You are about 15 years out of date.

I think he's right:

https://www.quora.com/Is-there-any-...y-GPS-data-and-civilians-in-terms-of-accuracy

The military have a few more toys to play with, in addition to C/A on L1, and L2C on L2, they also have access to the encrypted P(Y) data being sent on both the L1 and the L2 frequencies. And this allows them to perform ionosphere correction as mentioned by other answers. Since 2005, the military also get access to their new M-code signals being transmitted on both L1 and L2, which will increase accuracy and reliability further.

Also:
https://www.news24.com/Columnists/GuestColumn/could-the-us-switch-off-our-access-to-gps-20171222

There are two different GPS signals – military and civilian. The military GPS signal is encrypted while civilian GPS is not.




I recall long after they turned off SA there was some kind of SOG & Altitude limit on Civilian GPS to stop people guiding missiles with Civilian GPS. I very much doubt F14s lost their fix when the went too fast or too high! Possibly that's redundant with Drones (slow low flying) and SBAS, or maybe the limitation is still there.

 

[lw395]

......
I recall long after they turned off SA there was some kind of SOG & Altitude limit on Civilian GPS to stop people guiding missiles with Civilian GPS. I very much doubt F14s lost their fix when the went too fast or too high! Possibly that's redundant with Drones (slow low flying) and SBAS, or maybe the limitation is still there.

I'm not sure how you could stop GPS working above a certain altitude or SOG?
The satellites essentially only know thier own trajectory and the time.
If you can resolve your position at 5 knots on the ground, you can do it at mach 10 in the stratosphere.
Maybe the limitation is in commercially available receivers?
Might even just be the NMEA sentence structure?

 

[Robert Wilson]

So is it any wonder that someone can question their thought processes.

Sir,
I am somewhat bemused by the attack on my knowledge and understanding of the satellite positioning systems used by many, includingmyself, to navigate at sea; and how my post attracted harsh criticism of my political awareness. For the life of me, I fail to see the link between those two matters.
To help me, I would be grateful if you would kindly answer “yes”or “no” to the following questions so that I may understand the reason(s) for your criticism.
My questions may seem incongruous and vague, but please bear with me.
1. Do you read a Daily Newspaper (British orotherwise)?
2. Are you, or were you, a “man of the cloth”?
3. By your using “Fr” before your name, am I correctin assuming you are, or were, of the Catholic faith?
4. Do you know the extended method by which news is gleaned, reported, printed and distributed to your door up to seven days each and every week?
5. Do you rely for veracity on that which you read in your chosen newspaper, or do you make your own decision based on what you read – from one or more sources?
6. Do you accept the system of development overtime of various life-forms on earth?
Gratefully,
Robert Wilson

 

[Mark-1]

I'm not sure how you could stop GPS working above a certain altitude or SOG?
The satellites essentially only know thier own trajectory and the time. Maybe the limitation is in commercially available receivers?

I can't fault any of that logic, and yet I'm only aware of it because I encountered the issue when I was working on a GPS stack - and we hadn't added that limitation. Also what would be the point in relying on designers to add the limitation because someone building a missile in an hollowed out volcano would just ignore it. So either my memory is wrong or the clever
folk who designed GPS have done something clever that you and I haven't thought of. Neither would surprise me.

 

[JumbleDuck]

I'm not sure how you could stop GPS working above a certain altitude or SOG?

Early Garmin receivers limited displayed speed to 99kt, but that was only because they sold "aviation" ones for much more. Or you could cut the single circuit board link which implemented the limit.

 

[DipperToo]

I had heard somewhere that the Galileo system needed ground stations - and several of these are on UK territory in the South Atlantic (Falklands and Ascension)? How does that work if the EU wish to deny the UK access as we are not EU members? Will this only affect the South Atlantic area?