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Old 19-09-2018, 13:03   #1
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Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

Various threads on celestial navigation, emergencies, etc., have touched on GPS outages. While the usual focus is on failure of the equipment on board, there is some possibility, however remote, that the GPS and GLONASS constallations on which these devices depend could fail.


Possible failure causes could include:
* Electromagnetic interference due to space weather, making it difficult or impossible for receivers to receive the signal from satellites (https://www.bc.edu/research/isr/spac...ereffects.html).
* Loss of satellites due to debris. There is some concern that a single particularly serious collision could produce a debris cloud large enough to damage other satellites leading to a chain reaction that could render the all geosynchronous orbits unusable. https://physicsworld.com/a/space-deb...nderestimated/
* Deliberate shutdown or degradation of service by the nations responsible for operating these systems.
* Physical loss of satellites due to hostile action.
* Loss of control of satellites due to hostile compromise (hacking) of command and control systems or the satellites themselves.


It is my view that these scenarios are unlikely but possible, and that the prudent mariner may wish to maintain the ability to carry on with a voyage without reliance on these external systems, through use of dead reckoning, pilotage, celestial navigation, and an accurate on-board source of time.
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Old 19-09-2018, 13:15   #2
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

If you are unlucky enough to find yourself in the general area where the US military are planning an attack, you are very likely to find the GPS signals to be blocked or even spoofed. How likely is this to happen? Well, we did invade Greneda.
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Old 19-09-2018, 13:27   #3
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

Jammer, I think it was Arthur C. Clarke who back around 1960 pointed out that all it takes is a handful of buckshot, let go (not even fired, just let go) in a retrograde orbit, to wipe out pretty much everything it encounters. So yes, it is cheap and easy to wipe out satellites. the Chinese test that destroyed one of their own "obsolete" sateliites maybe 5 years ago left something like 4000 debris particles large enough to be tracked--as dangers to everything else out there.

The UK and EU were just recently talking about potential hostilities in space, the Donald is gaga for the Thunderbirds, er, Space Force, and our own Air Force had their ultra-secret re-usable vehicle up there for something like two years on a classified mission. There's no doubt that sooner or later, one of the more and more common players in the orbital game will do something totally deniable. Or, accidentally and callously create 4000 more bits of debris.

The Brits have been putting together some type of "net" to launch to test the idea of cleaning up debris. And whether anything important (phone lines or GPS or wx satellites, whatever) is actually armored...that's classified too. The electronics in satellites are routinely chosen and protected against cosmic rays. Which supposedly will cause four memory errors in the average sea-level computer each year. But a really good solar pulse event?

Yeah, the little that is known about the last ones, says that there may be no practical way to protect anything up there.
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Old 19-09-2018, 13:37   #4
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

Apart from electromagnetic issues or debris or similar, there is a high level of redundancy in these systems. Within each system there are spare satellites.

And there are several separate systems offering more or less the same.

GPS (=US), GLONASS =(Russia), Galileo (=Europe), Beidou (=China) , maybe more, not sure.

Many receivers support all of the above. My phone does for example.

Of course there is no guarantee that there are no possibilities to switch of reception for one or all of these.
Still in my eyes it's pretty unlikely that all these systems fail at once.
If there is such a failure, there are most likely a lot of other issues to deal with too.
In a worst case, follow sun and compass until you hit land somewhere.
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Old 19-09-2018, 13:52   #5
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

For navigation if I lost GPS for future voyaging, I have a copy of The Barefoot Navigator onboard along with my two Suunto Handheld Compasses. (I use the compasses now when I have everything powered down except the autopilot)

I've read the book several times and it has some great info.

Orion comes up here now before 4am or so and I like to check the belt star for East. Hopefully, I can do that this weekend and compare to compass and GPS

https://www.amazon.com/Barefoot-Navi.../dp/1574092324
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Old 19-09-2018, 14:20   #6
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

There is a USB puck GM-3N, available on ebay.uk: https://www.ebay.co.uk/itm/GM-3N-GNS...-/281305628065
about £50. I have an older one that reads all systems.
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Old 19-09-2018, 22:28   #7
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

I launched my sail boat in 1987 and sailed up and down the coast of Western Australia until about 1999 without a GPS. It's really not so long ago that we stumbled about and managed to pretty well stay off the rocks without GPS and electronic chart plotters.

If you are really feeling paranoid about the loss of the GPS system you should probably buy a radar. If you are off the east coast of the US just travel west until you can see land on the radar then travel N or S until you recognize some place.
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Old 19-09-2018, 23:26   #8
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

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If you are really feeling paranoid about the loss of the GPS system you should probably buy a radar. If you are off the east coast of the US just travel west until you can see land on the radar then travel N or S until you recognize some place.
Thats where the list of lights comes in, and a chart with basic details like lighthouses. It's often much easier to recognise a coastline from the lighthouses at night.
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Old 20-09-2018, 06:46   #9
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

As I posted in the celestial nav thread, if you really believe that there's any chance that the entire GPS constellation will be taken out you would never step foot on an airplane since we can and do rely on GPS for both en-route and approach phase navigation in instrument meteorological conditions. Come to think of it, if you believe that the GPS constellation being taken out is a threat you wouldn't even walk around outside and would lock yourself in a concrete bunker resistant to an aircraft crash on any cloudy day, given that all those aircraft constantly flying over you are depending on GPS. Just want to make sure we're being consistent here, it's either a clear and present danger or it's not, so if you truly believe it is you would want all your actions to be consistent with that belief, not just what you do on your boat.
I spent 20 years rescuing people at sea. Not a single one was due to loss of GPS signal. Lots and lots of them were due to much more boring reasons. If you're going to focus on a something to increase your safety at sea, may I humbly suggest this isn't the lowest hanging fruit. That said, any attempt to make yourself a better navigator, especially improving your pilotage or dead reckoning skills is a great idea. I have had to rescue people who wouldn't have had the pleasure of interacting with us given better basic pilotage skills. And learning celestial navigation for its own sake, because it's a neat, historical skill, is certainly worth doing if you're interested. Just don't do it to prepare for something that is vanishingly unlikely while neglecting the hundreds of things that actually do kill sailors every year.
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Old 20-09-2018, 08:23   #10
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

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Originally Posted by 14murs14 View Post
As I posted in the celestial nav thread, if you really believe that there's any chance that the entire GPS constellation will be taken out you would never step foot on an airplane since we can and do rely on GPS for both en-route and approach phase navigation in instrument meteorological conditions.......
And if you really believe the only way you as a cruiser could loose your GPS fix is all the satellites fail simulataneously........ never mind, taking arguments to the extreme rarely ends in meaningful insights.
As I mentioned above, a scenario where you find yourself near a military invasion is more probable and the signals are jammed or spoofed. Think the Greneda invasion.
Losing electronics onboard due to lightning is pretty common, although with the shear number of GPS enabled devices onboard it is unlikely that they all will be fried.
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Old 20-09-2018, 09:20   #11
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

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Originally Posted by 14murs14 View Post
As I posted in the celestial nav thread, if you really believe that there's any chance that the entire GPS constellation will be taken out you would never step foot on an airplane since we can and do rely on GPS for both en-route and approach phase navigation in instrument meteorological conditions. Come to think of it, if you believe that the GPS constellation being taken out is a threat you wouldn't even walk around outside and would lock yourself in a concrete bunker resistant to an aircraft crash on any cloudy day, given that all those aircraft constantly flying over you are depending on GPS.

I've flown in IMC. As you are no doubt aware, there are multiple backups for GPS although capacity would suffer. There are VORs. Even without an airborne VOR receiver, there's vectors from surveillance radar operators. And there's still ILS.



Quote:
I spent 20 years rescuing people at sea. Not a single one was due to loss of GPS signal. Lots and lots of them were due to much more boring reasons. If you're going to focus on a something to increase your safety at sea, may I humbly suggest this isn't the lowest hanging fruit. That said, any attempt to make yourself a better navigator, especially improving your pilotage or dead reckoning skills is a great idea. I have had to rescue people who wouldn't have had the pleasure of interacting with us given better basic pilotage skills. And learning celestial navigation for its own sake, because it's a neat, historical skill, is certainly worth doing if you're interested. Just don't do it to prepare for something that is vanishingly unlikely while neglecting the hundreds of things that actually do kill sailors every year.

I think that the threat environment in orbit has changed and will continue to change. The fact that the GPS has had no substantive, widespread outages for many years does not guarantee that it will remain so reliable in future.



I think this is useful stuff to think about, not only from a safety standpoint, but from a standpoint of continuing the voyage. If GPS disappeared tomorrow, how would you sail? What happens to the usability of chartplotters as a reference source when they lose GPS capability? How can we, the sailing community, improve OpenCPN so that it better supports non-gps operation -- for example, using compass and paddlewheel inputs to pan the chart using DR.



To your point about skills, yes, disciplined navigation is a valuable skill whether the GPS is working or not. Meaning, being able to maintain positional awareness at all times, using a log, or by knowing the coast. DR and pilotage are valuable skills. I've never had radar, but I would imagine that using radar as a means of navigation is also a valuable skill.
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Old 20-09-2018, 09:30   #12
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

As Director of National Intelligence Dan Coates told the Senate Select Committee on Intelligence:

"The global threat of electronic warfare (EW) attacks against space systems will expand in the coming years in both number and types of weapons. Development will very likely focus on jamming capabilities against dedicated military satellite communications (SATCOM), Synthetic Aperture Radar (SAR) imaging satellites, and enhanced capabilities against Global Navigation Satellite Systems (GNSS), such as the US Global Positioning System (GPS)."

All of the GNSS systems are extraordinarily susceptible to jamming, both in a localized attack and large-area attack from jamming satellites. Russia has jammed GPS multiple times in the Black Sea, and North Korea has jammed GPS to such an extent the South Korean fishing fleet has had to return to harbor. Spoofing is also an issue. Iran got its hands on a spiffy US drone that way. An attacker may choose to transmit bogus GPS data instead, and users depending exclusively on GPS would have no way of determining that something's wrong.

The alternative is Enhanced LORAN: eLORAN, which is based on high power ground based transmitters, is highly resistant to jamming. Europe is well along to developing its eLORAN system. Here in the States, we have no backup to GPS. We abandoned the old LORAN system and tore down its infrastructure duriing the Obama administration, and political resistance will only allow a semi-privatized eLORAN system - pay for play - or you're lost at sea.

"The tragedy of the commons:" why pay for something that benefits everyone? It reminds me of an old joke: "How do you know you are walking in a Republican neighborhood? There are no sidewalks."

If you're headed out to sea, I recommend keeping your skills up in celestial navigation. The US Navy still practices with sextants. So should you.

By the way, WWV/WWVH, which you'll need at sea for determining the status of the GPS constellation and for precise time in determining longitude by sextant, are scheduled to be shut down in 2019 in order to save $6 million. Those stations have survived all political agendas since the 1920s, but not the current crop of politicians. If the current politicians have their way, you're going to have to pay to get the time of day. They haven't yet figured out how to charge tolls on the wind, but I'm sure they're working on it.
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Old 20-09-2018, 09:54   #13
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

Quote:
Originally Posted by Jammer View Post
Various threads on celestial navigation, emergencies, etc., have touched on GPS outages. While the usual focus is on failure of the equipment on board, there is some possibility, however remote, that the GPS and GLONASS constallations on which these devices depend could fail.


Possible failure causes could include:...

Add to the list the much more likely event of a lightning strike taking out the electronics.



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Old 20-09-2018, 09:59   #14
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

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If you are unlucky enough to find yourself in the general area where the US military are planning an attack, you are very likely to find the GPS signals to be blocked or even spoofed. How likely is this to happen? Well, we did invade Greneda.
USA invasion of Grenada was in 1983, since then USA has invaded:
Panama 1989
Iraq 1991
Haiti 1994
Afghanistan 2001
Back to Iraq 2003
Syria 2015
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Old 20-09-2018, 10:00   #15
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Re: Scenarios for losing GPS/GLONASS/Galileo constallations: are they plausible?

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I've flown in IMC. As you are no doubt aware, there are multiple backups for GPS although capacity would suffer. There are VORs. Even without an airborne VOR receiver, there's vectors from surveillance radar operators. And there's still ILS.






I think that the threat environment in orbit has changed and will continue to change. The fact that the GPS has had no substantive, widespread outages for many years does not guarantee that it will remain so reliable in future.



I think this is useful stuff to think about, not only from a safety standpoint, but from a standpoint of continuing the voyage. If GPS disappeared tomorrow, how would you sail? What happens to the usability of chartplotters as a reference source when they lose GPS capability? How can we, the sailing community, improve OpenCPN so that it better supports non-gps operation -- for example, using compass and paddlewheel inputs to pan the chart using DR.



To your point about skills, yes, disciplined navigation is a valuable skill whether the GPS is working or not. Meaning, being able to maintain positional awareness at all times, using a log, or by knowing the coast. DR and pilotage are valuable skills. I've never had radar, but I would imagine that using radar as a means of navigation is also a valuable skill.
As a Coast Guard pilot I mostly flew offshore and in fact there were no VORs or ILS or radar. We used GPS exclusively. And a good chunk of the flights in the world are in fact offshore. You can use GPS as primary nav for en-route and approach flying IFR, so essentially the aviation experts of the world have determined that you can fly at 450 knots from NYC to Lisbon using GPS. I'm gonna say you're pretty safe sailing that same route at 5 knots using GPS.
Again, if you want to engage in esoteric thought experiments there is a non-zero chance of the GPS constellation going out. It is a far smaller chance than literally every other thing that has killed the hundreds of people who have died on ships over the past decade. So if you're really concerned about safety, focus on those things, not the highly unlikely eventuality.

And to the other posters, no, DoD didn't turn of the then non-existent GPS constellation for Grenada and in fact the last time they fiddled with it during a war was during Desert Storm when they made it more accurate for everyone, not less. DoD isn't going to cause thousands to potentially die in aircraft crashes to prosecute a war, and if we're in a situation where they decide that is the prudent course you've got far more to worry about in life than your celestial navigation skills! And find me a lightening strike that will take out my 2 installed GPS receivers, the one in my In-Reach stored in a cabinet, the one in my tablet, the one in my wife's tablet, the one in my cell phone, the one in my wife's cellphone, the one in my laptop, and in my wife's laptop, and if they're aboard the one in my kid's tablet and phone? Seriously folks, if you've ever peed off the side of your boat you've put yourself in far graver danger from an actual risk based on actual deaths than you'll ever be in from relying on GPS.
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