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Comment by olig15 | Hacker News Reader

The high precision offered by Galileo was one of the reasons why the Pentagon rejected the system in the first place. There were fears that adversaries of NATO or of other allies could use it for military purposes. However, engineers have found a solution to that problem: should a serious crisis arise, the military can jam a certain part of the broadcasting spectrum. This would cut off civilian use, but still retain the functions that are reserved for allied military purposes.

This seems like quite a big issue; If any of the EU states go to war, then planes and other civilian things relying on Galileo would stop working? Would they fall back to GPS?

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It appears that most civilian receivers are going to use all of the various constellations at the same time.

Here's an article from 2014 talking about production chipsets that do GPS/Galileo/Glonass/BeiDou.

http://gpsworld.com/quad-constellation-receiver-gps-glonass-...

This. The combination gives higher accuracy, faster fix, independence from a single political entity, and overall higher reliability by redundancy.

...and higher power usage.

which is why being practical, you would use only one and fallback to the others on failure-to-fix.

This only applies to battery-powered GPS devices. Navigation systems on boats or aeroplanes can afford the higher power consumption and hence use multiple systems simultaneously. Additionally, even battery-powered systems can use multiple systems for a short period at first to get a faster lock, then fall-back to one to lower power consumption.

I'm not sure you got the point right. Originally Galileo was supposed to use frequencies very close to GPS. For technical reasons. But this would deprive USA from military advantage they have: they couldn't jam Galileo signals without jamming signals of their own system, GPS. (Maybe I should point out that GPS isn't something that "just works" for everyone: primitively speaking, USA can turn encryption on anytime, making these signals essentially useless for everyone but them.) It isn't about fairness or civilian convenience, it is about USA having an advantage in case of war. So, USA basically threatened to blow Galileo satellites up if EU goes with it. Unfortunately, they can, so EU backed off and changed the frequency spectrum of Galileo so that USA can retain their advantage. Yeah.

So, no, Galileo users aren't supposed to fall back to anything. That's the point.

The article was a little unclear. Originally Galileo was supposed to use the same frequency band as GPS which would prevent the US from jamming it without also affecting GPS.

It still does on the primary civilian signal.

http://www.navipedia.net/index.php/GNSS_signal

> If any of the EU states go to war, then planes and other civilian things relying on Galileo would stop working?

That's the point of projects like these, working together and relying so much on each other that European countries waging war against each other simply stops making sense.

But the same thing would happen if a non-eu country attacked a Galileo using country, right?

With systems like these it would always be possible to selectively degrade availability/accuracy over defined country-sized areas, yea.

Any life safety system should definitely not be designed to rely on GPS/Galileo/Glonass - they are RF systems that can be jammed by anyone with any interest in doing so.

Practically all life safety systems (boats, cars, climbing etc.) are based on radio.

I certainly wouldn't want to trust my life to the integrity of a -130 dBm strength signal. Particularly if I'm traveling in a tunnel, or heck, deep forest.

I think, though, that if the alternative is to trust my instincts (which I don't have), then I'd rather trust that -130 dBm strength signal. I think that my instincts are the secondary factor when I get lost in the forest, not the first factor. If I have no reason to think the GPS system is deceiving me, I would trust it.

What should they use instead for positioning?

For critical functions - combination of inertial navigation systems, mapping, radar, and plain old visual recognition of the location - after all, you need to have a sophisticated visual recognition system anyways to scan for all of the dynamic activity, why not extend it to be more broadly used? GPS is okay for gross navigation and tracking, just don't design any critical life-safety system to rely on it. I'd be very surprised if there were any boats/cars/planes that absolutely required GPS to be functioning for safe operation beyond the higher level navigation functions. Very disappointed as well.

Most commercial planes (and certainly almost every civilian airliner?) have an inertial reference system that is backed up by GPS.

The inertial reference system is a physical unit that cannot be externally manipulated, but it has less accuracy. If the plane's flight management computer detects that the GPS significantly disagrees with the IRU, it will warn the pilots, and may automatically disable the GPS unit.

Planes can also obtain position data via 2 VOR radials, or a single VOR-DME radial, or such. There are many options.

To provide redundancy, there are usually 2 or 3 IRUs.

Chips that support multiple systems are fairly inexpensive. I picked a couple up on an indie gogo for $15 each. And it does GPS/Glonass/Beidou https://www.indiegogo.com/projects/navspark-arduino-compatib...

Assuming, for example, commercial delivery drones were to use this, I can only imagine there would be some sort of notice of termination giving enough time to ground things.. Maybe that would put them out of service? If GPS 15m accuracy isn't enough, falling back won't help.

Here's hoping sanity prevails and there's no sudden cutoff leading to things falling from the sky.

Here's an example of prior notification and a disagreement about the effects of GPS jamming on popular model of small jet:

http://www.usatoday.com/story/news/2016/06/08/embraer-gps-te...

It's obscene that the US has such control over foreign infrastructure installations in the name of "security". GPS accuracy limits and ITAR/COCOM GPS export restrictions are a farce anyway; even a third-world basement laboratory could construct a GPS receiver sufficiently fast and accurate for missile controls these days.

The only thing these laws accomplish is to inconvenience civilians. I know some people in the high-altitude balloon community who are frequently frustrated by scared manufacturers not wanting to run afoul or ITAR and restricting GPS units so they can't even be used for balloons. Who knows what sort of cool location-based technology we could have today if the US hadn't intentionally held back civilian GPS for decades.

I hate to point this out, but we (the americans) paid for it, why shouldn't we have control over it? If you don't like it, you're always welcome to build your own.

.. and if we don't let you win you're taking your football and going home?

Perhaps some in USA might consider benefit to humankind to be a worthy end? I think it was Franklin who pointed out that ownership of resources by a limited elite wasn't due to a natural right but was a consequence of past "violence".

Your answer is the one rich people give as to why poor people don't deserve water, "I paid for that water, buy your own it you want to drink". GPS isn't a need like water, but the sentiment and ethic appears to derive from the same logic, lack of empathy, and lack of humanity.

You asked why.

You are missing the point. It isn't about USA being able to shut GPS down for Europeans. They already can, and that's pretty natural, because it's their military system in the first place. It isn't about being able to shut Galileo down as well. It is about EU knowingly building the system (using their money) that can be used by anyone, but can be shut down without shutting down GPS (which is capable of limiting availability to USA military forces only, should they wish so), because one particular aggressive country threatened to use violence otherwise.

As I understand, it's not that America can call Europe and say "Shut down the GPS", it's that America wants to be able to jam GPS (which is reciprocal, BTW. Europe can go to war now and jam GPS signals).

It's quite reasonable that if a third-party is supplying weapons to an enemy, it gets caught up in the cross-fire.

The EU did, and the US threatened to just shoot down the EU satellites unless they get the ability to turn off GALILEO.

>The EU did, and the US threatened to just shoot down the EU satellites unless they get the ability to turn off GALILEO.

In times of war.

Not just in times of "war between EU and US", but in times of "war between US and anyone else".

This is not something that's in any way acceptable.

Americans did not pay for Galileo. The EU paid for it.

Americans did pay for GPS, which is why we should have full access to its capabilities as taxpayers.

Couldn't the other military jam the military GPS/Gallieo/etc bands too?

As long as they have their own constellation that stays unjammed.

This is already an issue with GPS: https://news.ycombinator.com/item?id=11856131

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