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Galileo navigation satellite system goes live (dw.com)
411 points by vezycash on Dec 17, 2016 | hide | past | favorite | 160 comments

Galileo's actual value has always been murky. It's use case has changed a lot over the years. Originally it was meant to be a navigation system free of GPS's Selective Availability "feature" that diluted precision for civilian use. The Clinton administration effectively killed SA (http://www.gps.gov/systems/gps/modernization/sa/) in 2000. Galileo was sold as a higher precision civilian alternative that was going to be commercially viable and make money. A few years later the US made improvements to the GPS ephemerides and effectively increased precision of GPS, making the benefits less obvious. The new block of GPS satellites offers even better precision and a lot of the Galileo features (like multiple civilian frequencies). It's honestly quite hard to compete with a free alternative that the US government throws billions of dollars at. Still, GPS can't hit sub-meter accuracy any time soon, so there's a real potential use case emerging for autonomous cars and aircraft.

If you're excited and interested in Galileo it's really worth reading up on how GPS works and was built. The first satellite was launched almost forty years ago and it was operational in the 1980s. It's truly one of the coolest and most amazing things made by humans.

Selective Availability was replaced by regional denial capabilities with the GPS III satellites, i.e. instead of fuzzing the signal the US can now turn off GPS for entire countries[1].

It's strategically foolish for the major economies like the EU, Russia & China to depend on the US's goodwill in maintaining a system that drives a huge part of their economy, GPS is used pervasively for everything, and that's only increasing.

Trump wants NATO countries to pay their fair share, how long until he gets the idea that all countries around the world should pay a GPS licensing fee least GPS regional denial be turned on?

Those are the sort of reasons for why it makes sense to develop a GPS alternative, even if you're only aiming for feature parity, or even less than that.

1. https://www.faa.gov/about/office_org/headquarters_offices/at...

>>> It's strategically foolish for the major economies like the EU, Russia & China to depend on the US's goodwill in maintaining a system that drives a huge part of their economy, GPS is used pervasively for everything, and that's only increasing.

Exactly. For this same reason, India recently deployed its own satellite navigation system NAVIC[1][2].

[1] https://en.wikipedia.org/wiki/Indian_Regional_Navigation_Sat...

[2] http://www.isro.gov.in/irnss-programme

Indeed. In the India-Pakistan Kargil war of 1999, USA sided with Pak and turned off GPS for Indian troops. That led to the creation of NAVIC


seriously, WTF is wrong with US and their attitude towards India/Pakistan. India is democracy, never attacked anybody out of blue from 1947 when it was created (unlike its neighbors Pakistan and China who attacked it numerous times).

Yet US sides with dictatorship which doesn't even control its own secret service which creates its own terrorist organizations (laskar-e-taeba).

It's a political philosophy sometimes called 'realpolitik' that basically says never mind morality, just do what is in the interests of your own country. It has a certain emotional appeal, but when you take a cold and practical look at the history of decisions made on that basis, they tend to end up doing more harm than good to the interests of the country that made them, quite apart from everyone else.

India was part of the 'non-aligned' block and at various times has been keen on building ties with the Russians, buying lots of arms from them. In contrast, Pakistani leaders have been firmly in the US camp. Hence, in '71 it was a no-brainer for Nixon which side the US would support. It is bizarre the Nixon continued supporting Pakistan during the Bangladesh Genocide, but that's Nixon for you.

Also, India did invade and annex Goa in '62.

>> Also, India did invade and annex Goa in '62.

... because Goa is an historically Indian territory, and Republic of India just got it back from foreign invaders!?

Not just dictatorships. Islamist dictatorships (Pakistan, Saudi Arabia). A lot of western (not just US) diplomacy is horribly short sighted.

> never attacked anybody out of blue from 1947 when it was created

India "attacked" East Pakistan in the Bangladesh Liberation War [1]. Whether or not you or I feel it was justified is besides the point: it violated the sovereignty of another nation (similar to the U.S. in Iraq and Russia in Crimea).

[1] https://en.wikipedia.org/w/index.php?title=Bangladesh_Libera...

Your linked article reads

"India joined the war on 3 December 1971, after Pakistan launched preemptive air strikes on North India."

which doesn't sound out of the blue to me.

I think they're worried the Pakistani islamists will give nukes to the international jihadi islamists if we aren't somewhat supportive.

You must be new here. It's not about democracy, it's what's more convenient for the US interests. Welcome to HN.

Russia's GLONASS too, antennas for which have been built into iPhones since the 4S. https://en.wikipedia.org/wiki/GLONASS

Most smartphones designed in the past few years support GLONASS. Russian law requires GLONASS support to be sold there, so manufacturers have generally added it across their model lines since that's easier than producing different SKUs for sale in Russia.

I've never seen an authoritative reference for any area denial capability in block III. Can you provide one?

There is an enhanced footprint signal boost capability for the military but that's the opposite of what you describe.

I think the FAA is an authoritative reference, and I linked to their claims about GPS III regional denial in my original post.

Ah, I see where the misunderstanding arises. The reference to regional denial on that page is not a feature of any GPS satellite.

The military has airborne and surface-based electronic warfare platforms that can be used to jam GPS. That's what is referenced on that page.

The FAA is not considered an authority for GPS, with the exception of certifying that WAAS is in-service for aircraft when it is meeting FAA specifications. For civilian information purposes the appropriate agency is the US Coast Guard NAVCEN.

The Air Force Space Command is the holds primary developmental, specification, and operational responsibility.

Yes I'm pretty sure you're right. I wrote most of my comment from memory and just dug up a reference, knowing the FAA doesn't operate GPS, but figured their FAQ was summarizing the satellite features.

But I've searched around and can't find anything that indicates that this is a feature of the satellites themselves, rather it's just as you say, the US military has replaced SA with the general ability to jam local radio traffic, including GPS. E.g. [1] is another source for that.

So it does look like the US can't block GPS for entire countries anymore, I take that back.

I must say though, I think any public commentary about GPS capabilities should be taken with a huge grain of salt. It's a military system, they're very likely lying or not telling the full truth about what it's really capable of. E.g. I find the claim that the new generation can't do SA by design dubious, surely just fuzzing the signal by some offset is a rather trivial change.

1. https://web.archive.org/web/20050921115614/http://ngs.woc.no...

If SPACECOM can't tell the Navstar satellites to turn on selective availability for specific areas I will eat my hat. Much effort is being expended to provide over the air crypto re-key, increase anti-jam margin and improve signal authentication [1]. Would you really disable the SA feature when military consumer platforms now have the features to re-key, obviating the main drawback of SA?

[1] http://www.dote.osd.mil/pub/reports/fy2011/pdf/af/2011gps.pd...

It takes a fair amount of magical thinking to believe that GPS can do area denial from space. Consider how many satellites are above the horizon for a given location at any moment - somewhere around 8-12 at any moment, or more.

Each of those satellites in view would have to be implementing this scheme you suggest in order for it to be effective.

Since the satellites only have a single transmitter for each signal their entire receiving area would be affected by whatever modifications are made to implement SA. This means that to turn SA on for a single area more than half the globe would be getting a degraded signal from 1 or more satellites, which ones being undetectable.

I'm afraid SA is an all-or-nothing idea. Area denial (jamming) by surface and airborne transmitters is a much more workable approach. One could imagine jamming from space, but not using the GPS satellite vehicles.

Is it 'magical thinking' that the NSA would build a system with the capability to intercept every VPN session traversing the US, and spend ~$500 million to break the DH groups with the mother of all rainbow tables?

So, to GPS. In the original GPS SA it is certainly true that many satellites would have to be using degraded mode to guarantee degradation for a specific point. However, the newer satellites have an additional directional antenna. While primarily for transmitting M-code to a specific region, it could equally be used for transmitting a self-jamming signal.

Actually US can still jam Gallileo. US "asked" EU to patch it so that it can be controlled(turned off) by the US in case of war with Russia or China.

The "patch" was changing to a different frequency band, allowing anyone to block only one system without affecting the other [1]. This is very much different from being able to turn it off.

[1] https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)...

I think OP meant jam. I believe at some point in the discussions about the Galileo frequencies that the US threatened that they may need to use an ASAT weapon on Galileo spacecraft if they believe the system was being used against them. That would have been the only way to maintain GPS and stop Galileo. So Galileo switched to a different frequency than GPS.

>>Trump wants NATO countries to pay their fair share, how long until he gets the idea that all countries around the world should pay a GPS licensing fee least GPS regional denial be turned on?<<

Now now, do not insert political commentary into this discussions. I got yelled at for doing that. [1]


I don't think this is unwarranted political comentary, the reasons to build the alternative to gps are largely political according to GP

I am largely with you, however the direct Trump referencing is unwarranted - it is the institution he will represent, not the man, which is involved in this political battleground.

EDIT: to wit, the institution is the most powerful military force, active across the globe https://en.wikipedia.org/wiki/List_of_wars_involving_the_Uni...

He doesn't represent the administration, he leads it.

It seems perfectly fair and reasonable reason to mention the power the president has in the situation given some of the president elect's statements.

The benefits of Galileo are very clear for me as an EU taxpayer.

Don't rely on GPS because it is controlled by a single country and that country can shut it down whenever it likes.

No country is your friend forever, you only have to look at the Trump administration. It takes 1 election and everything can swing in the wrong direction.

Completely agree.

GPS is so essential, that is becoming more and more a "single point of failure" for our civilization.

Without having any data, I have the intuition that the cost of deploying our own GPS system may be worth just as an "insurance".

To all who are writing that the EU Galileo system is "insurance" against the US's regional denial capability, it appears you haven't thought through how they would do that.

It would not be by turning off or fuzzing the US GPS signal. It would be by deploying vessels with jammers.

Galileo was originally designed to be on an independent frequency, and the US has pushed to have it so close to the US GPS frequency that jamming will effectively kill both.

Not great insurance.


> Galileo was originally designed to be on an independent frequency, and the US has pushed to have it so close to the US GPS frequency that jamming will effectively kill both.

This (as I wrote in another comment) is the exact opposite of what actually happened [1].

Edit: Added a reference.

[1] https://en.wikipedia.org/wiki/Global_Positioning_System#Rest...

Ok, you are correct.

Galileo was originally designed to use the same frequencies as GPS.

Now they use different enough frequencies that Galileo can be jammed without jamming GPS. Of course, jamming both is also possible.

I wonder if we've gotten to the point were attempting to turn it off would harm us (United States) directly as much as anyone else, even if we only do it in certain sections of the world.

Turing off GPS would not have to be binary. There is a seperate, encrypted, GPS frequency that the US government can continue using even in places that they shut down GPS for everyone else. Additionally, they can degrade the accuracy of civilian GPS (also in a targeted area if they wanted).

During the Iraq war everyone kept trying to find these magic encrypted GPS devices that used military only frequencies. I never saw one, or heard of anyone using one.

Even SEALs are issued the same Garmin Foretrex 401 you can get at Best Buy.

I believe that they're considered classified material and are also big, clunky and expensive, which is why the military just ends up using standard civilian GPS equipment a lot of the time.

Government fab and production tech can't compete with the stuff on the open market. From GPS to crypto hardware, civilian stuff is almost always smaller and more usable. I suspect most hardware using the encrypted GPS channels is in munitions.

The GPS clearly only works at certain speeds and heights, there's another level...

If this doesn't exist then those missiles don't work...

A GPS receiver is not supposed to work at an altitude greater than 60000 feet or while travelling at over 1000 knots, but the system itself does not in any way enforce this restriction [1].

[1] https://en.wikipedia.org/wiki/Global_Positioning_System#Rest...

A friend in Houston was telling me in the early 2000s about working on a NASA JSC project to use an off the shelf GPS receiver on the space shuttle. It took a few iterations on the firmware to handle 18,000 mph, etc., but he said the vendor eventually converged on firmware that worked in orbit.

To be clear, it's not that a receiver couldn't work, but that it shouldn't.

A civilian receiver is meant to deactivate under certain conditions lest it be suitable for use in things that go very fast and fly very high, e.g. missiles.

So as you say, you may be able to change the firmware to disable these restrictions, just don't try and take them out of the US...

Or buy a receiver from outside the US that's ITAR-free.

you're describing 'Selective Availability'.

...and that was removed quite a few years ago now.

Having an alternative to GPS in mission critical systems is enough of a case to justify the existence of Galileo in the first place. Things like drones or self driving cars are not just about accuracy, but also reliability, and civilian GPS is not bulletproof (especially not in urban area). We're already seeing triple band GPS implementations with Galileo, GPS and GLONASS (the Russian alternative).

Depending on the device SoC, you may see 4 different constellations, as China has their own.


Also QZSS, if you're in the right part of the world

While I agree with the principle in your point, does Galileo operate on a different enough set of frequencies to avoid interference that would knock out GPS?

This is not correct. The primary civilian signal for both Galileo and GPS have the same frequency on L1, 1575.42 MHz. Their modulation schemes and encoding are coordinated to not interfere. [1]


Galileo's actual value has always been murky.

Not even remotely. GNSS is far too important to be left up to one or two militaristic providers whose interests (to put it mildly) may not always coincide with your own.

If anything we need more systems up there.

And more satellites are good for everyone, at least so long as all these systems remain open for use. It means more accuracy, and some redundancy never hurts, either.

> Still, GPS can't hit sub-meter accuracy any time soon

GPS has had sub-millimeter survey grade accuracy for quite some time. However, these require post-processing which takes maybe a day, read that as not realtime.

WAAS+GPS currently gives 2-3 meters.

>sub-millimeter survey grade accuracy

Could you provide some links to read? I just can't imagine how it's possible.


(full disclosure: I work for Leica Geosystems.)

With real-time kinematic service, our GPS receivers give you 8mm horizontally and 15mm vertically. And you will get 3mm hz and 4mm vertical with post processing.

Does Galileo change this at all? Or is it just more better GPS,GLONASS,...

It is achievable with static post-processing of GPS data, kinematica claims 8mm. For real time requirements, there's consumer level products that offer accuracy of a few centimeters.



Sub-millimeter is a little tricky.

Very high (few centimeter) resolution can be done in real-time, in fact, under some limitations. Keyword: real-time kinematic.

One important component is using a reasonably short baseline: you have a receiver at a known location somewhat nearby (in many places there are networks of stations run by the relevant governments), and you compute difference between your solution and the station's solution. Most of the errors are common between the two and so they cancel.

Another important component is carrier phase tracking: The receiver processes the signal to recover the carrier phase. This boosts the resolution from the code timing to a level determined by the carrier frequency (and signal bandpass). Unfortunately, it leaves an integer ambiguity-- you know you are 'something' + 0.233 cycles from the sat, you need to solve for the 'something'; you can do this by collecting enough data as the sats move around or by starting at a known position and moving while holding a lock.

Another component is multiple frequency operation. There is a set of GPS signals on the L2 band some 350MHz lower in frequency. If you imagine the lattice of integer solutions in 3D space for two different frequencies you can observe the the integer solutions coincide very infrequently, leaving few options to choose between. Dual frequency operation also allows for correction of ionospheric effects.

Another component is semi-codeless tracking: The L1 and L2 GPS signals have a military P-code signal which is encrypted. The P code signal runs at 10x the speed and has a much longer repeat interval, this increases the accuracy of code tracking and improves multipath resistance. The L2 signal has historically only had the P-code stream. The encryption would be a barrier except it's kind of broken: The codestream is 10MHz but the stream cipher runs at only 500KHz and the same signal is sent on L1 and L2. Because of the first property you can still range against the P-code and because of the second you can find the phase offset between L1 and L2 quite precisely. (Trade name for this kind of codeless tracking is "Z-tracking"). --- this is hopefully becoming less necessary now with new civilian (unencrypted) signals on L2 and L5. The new signals also have better anti-multipath properties.

Any survey receiver worth the name implements these techniques and many more. For realtime (non-postprocessed) output using the above, accuracy is 2cm +/- 2ppm (of the distance to your reference station) or so.

What postprocessing does is lets you use very accurate orbital and ionospheric data which is available for download some hours later, built based on observations by many known-position ground stations. (I believe the Galileo sats even have retro-reflectors for laser based ranging, though I don't know if they're used yet.) ... plus using many hours of observations as the sats move through the sky.

So like any modern technology, the state of the art result isn't given by any one technique but by many combined.

Thank you for your thorough but not overcomplicated explanation.

Isn't carrier phase tracked off the 1 PPS transition?


I think I overstated but still it is possible. Millimeter survey grade is commercial.

what is murky about 10x more precision?? Sounds like sour grapes. Sure GPS is amazing. Now there's something better. Just because it isn't American doesn't mean its value is questionable. Nothing is being taken away here. Choice is being added.

Perhaps the Europeans are concerned that if the USA gets into a shooting war with China or Russia in a few decades, our GPS satellites will be the first casualties.

There's no question that GPS satellites will be a high-value target in the next super-regional conflict. The system was a primary reason why Saddam was defeated (temporarily!) in Desert Storm. The Iraqis were used to getting lost in the trackless desert from their war with Iran, and assumed that the coalition forces would be just as lost. GPS allowed the famous "left hook" that cut the Republican Guard off.


and perhaps that is a legitimate concern for more than just Europeans, and that includes Americans, and perhaps it's not just about war, but about competition, trade, and fair global access to a technology not being beholden to a single administration (especially in the new age of "America first").

Is there a good, wide-ranging treatment of the history of GPS? Something like Rhodes' Making of the Atomic Bomb but for electronic navigation?

> It's honestly quite hard to compete with a free alternative that the US government throws billions of dollars at.

Yes, but it's not a commercial venture. Surely there is equivalent value in having a satellite system that European governments throw billions of euros at, no?

I like living in Europe most of the time. And I'm sure if we could get over a lot of petty, cultural, differences, we could build more amazing things and innovate at a much faster speed then we have been so far.

Well nowadays it seems like EU is not going to survive as it is. Countries in the east seem to be more and more opposed to the idea of EU (some 1/4 - 1/3 of people IIRC). These are countries that most benefit from the EU, not only financially (funds and markets), but also need the external control to prevent the come-back of mafia, corruption, etc.

Russia is playing a huge role in this, modern information warfare. They want the people in countries that suffered for some 20 plus years last decade to again love the motherland. They play on nationalism (Slavs) mostly (thanks to refuge crisis, in which Russia is involved directly), and that most media are owned by the west (and thus lie), and only alternative media will tell you the truth. About Ukraine, about USA, about Syria, about everything. There are different levels for everyone to choose from, be it Jews being responsible for everything, or just plain Brussel Dictatorship.

This sounds like a wild conspiracy, but it's scary as fuck to see it. At first it seemed like a joke, or a way to make some money (like regular conspiracy websites would do), but I'm now convinced there are external motives and financing. And people are eating it up. Loving Russia and all. Country which is far worse off than any of the EU members.

I'm not sure where you got the impression that the EU is less popular in the east; according to these [1] surveys, Poland is the only large EU country where EU approval ratings have held up lately, while Hungarians also have quite good feelings on the subject - despite their governments' very public disputes with the EU on the erosion of democracy in those countries. The correlation is weak, but they're also less into decentralisation than others. And Spain and Italy are also relatively pro-Eu; their populist movements have been left-wing and pro-EU.

It's rich Northwestern states (and, understandably, Greece) that have big problems on the popular level with the EU.

[1] http://www.pewglobal.org/2016/06/07/euroskepticism-beyond-br...

It's actually quite the opposite: the eastern states are the most supportive while the Western states(i.e. UK, Holland and few others) are more pessimistic. It's usually because the richer states subsidize the poorer ones. There is also a doze of populism and lack of EU cohesion.

As a European living in the US I believe what is holding Europe back more than anything is the fragmentation. Companies like Google and Apple come out of the US because of the pro-business policies. However, I believe the gigantic, relatively homogenous market is by far the biggest advantage. If Europe spoke predominantly a single language and had largely the same regulations Europe could stand a much better chance. That's too often overlooked and the lack of a European Google or Apple is just blamed on socialism.

If market size is more important, we'd expect most European startups to come out of the largest countries, even after weighting by population, right? And if entrepreneurial culture or socialism was more important, we'd expect some metric for those to be correlated, right? Really curious as to whether this analysis has been done in an authoritative way.

One reason that's often put forward for why Sweden breeds a disproportionate amount of successful companies is that the Swedish market is so small that they have to quickly learn to expand and navigate the global market. Meanwhile in "big enough" markets like Germany and France there's enough room for expansion without going global. So it could go both ways.

Another reason that has been put forward is social welfare. It's easier to start a business if you can afford failing.

Market size enables huge companies. That's why Google isn't European. If you look at the list of largest companies by revenue, it's dominated by America and China. https://en.wikipedia.org/wiki/List_of_largest_companies_by_r...

The list would be dominated by American and Chinese companies even if each person on the planet had an equal chance of founding a huge company. The question is whether big countries like the US and China would be overrepresented per capita. And looking at that list, it's not at all clear. UK, Switzerland, Germany, and South Korea all have companies near the top.

Yeah, I've long suspected the same, that the big market is a significant advantage. It's easier to grow in a big market, that's why the US has (seemingly) more big companies like Google, Facebook, Microsoft, McDonalds.

Don't worry, in face of the challenges that are ahead, we will be forced by circumstances to set aside our cultural differences to cooperate and find solutions.

Climate change, resources depletion, crops failing, famine, sea rising, environmental degradation, etc. These challenges are not for one nation only, but for the whole world.

It takes a crisis to wake you up from your illusions. It will be the same for humanity.

Don't worry, in face of the challenges that are ahead, we will be forced by circumstances to set aside our cultural differences to cooperate and find solutions.

If that happens, it will be the first time in the history of Planet Earth. Localized resource scarcity doesn't usually lead to peaceful cooperation. It leads to war.

It can lead to war, absolutely. Will we be wise enough to avoid it? I certainly hope so.

Couldn't you say that for just about anywhere?

No. I don't think I'd like living just about anywhere, tbh.

Not many places/regions are as advanced and have as a high quality of life and high percentage of educated citizens as Europe, so no. At this moment in time, not really.

OK maybe I was more glib than was fair but Syria, Israel and Iran are all full of smart people. Imagine if there were no cultural differences dividing the region. (I realize they're not neighbours.)

What is "smart" anyway? Lots of countries are filled with untapped demographic potential. To tap into that resource you need a highly advanced school system and a high quality of life (so that you don't suffer from brain drain). Syria is of course a no-no, I don't know much about Iran to comment on their school system but I don't think the quality of life in Iran is as good as say, in Italy.

Could say that for everywhere, all at once!

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?

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.


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.


> 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:


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

> Using GPS, private users can navigate with a precision of up to 15 meters (m). Galileo offers a precision of up to 4m for its fully open service.


> Real-world data from the FAA show their high-quality GPS SPS receivers attaining better than 2.168 meter horizontal accuracy, 95% of the time.

It seems even better than that. My phone can tell me which side of a small road (2m accuracy) I am on 95% of the time. Maybe it uses a WiFi database and dead reckoning to improve on pure GPS.

Phones generally use the WiFi database (plus cell tower info) to bootstrap GPS startup, but that's not useful for fine positioning.

AGPS is designed to give a quicker Time-To-First-Fix (TTFF) but the accuracy is unchanged.

The application here (driving) constrains the solution to 2D (i.e. known altitude from the map), and hence can since that variable is known quite accurately it can improve the accuracy of the other variables.

Receivers tend to be built with augmentation systems. This uses a network of ground stations that measure the variation in the GPS signal and transmit corrections over an additional satellite. This helps the device account for atmospheric interference.


GPS and location systems designed for driving will 'snap' to the correct side of the road.

They're aware of what they're being used for and optimise for that. Similarly, because driving is 2D solution instead of 3D, the altitude will be used derived from the map, not the signal.

Which is why GPS systems designed for driving are fundamentally not suitable for use in (say) planes which need a true 3D solution.

Your phone also probably augments with the Russian GLONASS

Another thing to note on the accuracy front is that the US is about to start launching the next GPS IIIA generation, which has higher resolution than the current generation.


While the features of IIIA are nice, it will be a while until all the existing ones are replaced by IIIA.

The more immediate nice thing about the IIIA launches are that it adds more satellites that can transmit the L2 signal. Currently there are 18 healthy IIR-M and IIF satellites which can transmit L2. I believe you need about 24 minimum for full coverage.

Once we have full L2 and we get civilian dual band L1/L2 receivers it will get rid of one of the biggest sources of inaccuracy which is ionospheric delay. A dual band L1/L2 receiver will be able to measure ionospheric delay directly. This means the delay calculated will be for that specific point instead of the area covered by a WAAS ground station. Plus you won't need a direct view of the WAAS satellites.

How long does the GPS receiver have to stay in the same place to attain that accuracy? What was the percentage for the numbers in the article?

It is easy to end up comparing apples to oranges with this sort of stuff.

Survey grade receivers using differential GPS can achieve cm-level accuracy most of the time.

My dedicated Garmin GPS (no supplementary GLONASS) unit has 3 meter accuracy.

As long as you have an unobstructed view of the equator. To get 2-4m accuracy with commercial GPS you must use WAAS. The sattelites that tansmit the WAAS signal are geostationary.

So if you have buildings, hills or mountains blocking your view you're back to 7-15m accuracy. It gets worse thr furer north you go as your angle to the WAAS sattelites gets closer to he ground.

Plus it's North America only. Not sure if Garmin units support EGNOS which is the system in Europe.

EGNOS and WAAS use the same frequencies and same protocol. They're essentially two implementations of the same thing. As far as a receiver is concerned, they are identical. My Garmin eTrex 20 receives both without issue.

Thanks, nice to know.

Are GPS systems just plug and play, or does the software also have to be compatible. e.g. Could I just replace the GPS receiver in my car to one that supports Galileo (even though I don't think any are on the market yet)?

No, they aren't usually.

However there are some devices that are already capable of using Galileo. Recent Qualcomm chips and tomtom devices are I think.

Yep, but I'm not aware of any automobiles using them yet. And I'm also not aware of any cars that allow you to swap out the navigation hardware either. Feel free to interject if you know of any!

My car's headunit just has a GPS input in the back, my GPS sits under the windshield.

The article contained a strange word "eparated". It took me a few seconds to realize it meant "separated". I tried Googling the word to check how good its spelling correction was - but instead it came back with no correction and real results about automobiles. It seems to have parsed the word as "EPA rated", alluding to fuel efficiency.

Any guess when devices will start using Galileo? I'm thinking about dropping some coin in a Garmin Fish Finder & chartplotter for my boat. Currently sell models that use GPS & GLONASS.

There are some already capable, but they'll need a firmware upgrade. Recent Qualcomm chips for phones do at least.

With the new Trump/Putin alliance NATO will be threatened. It makes sense for Europe to develop independent military infrastructure and to ramp up military spending.

Galileo is a civilian project, though. It has features that are limited to police, border security, military, etc but it's an EU project. The EU doesn't have an army (its member states do, but the EU doesn't).

The EU does have a coast and border guard, though, which is a paneuropean military entity.

Can you be more specific? I live few kilometers from EU outer border with a hostile country, but have never seen or heard of such paneuropen guards. AFAIK paneuropean is only a law which requires every country to guard all their borders, and only non-national military we have is NATO.

Frontex (http://frontex.europa.eu), its more of a co-ordination agency, but it does I believe have its own staff on secondment to it.

It was established in July 2016 to replace Frontex and national border guards, as response to the refugee crisis:


Now that there's a second player in this world, maybe we can standardize the hardware? Great the satellites are online...but how many devices have been manufactured with the requisite hardware?

Also wonder how many devices this network can support. I'm sure there is sufficient capacity but I'm just curious how the capacity is calculated!

Galileo isn't second, its 4th or 5th in the market. Depending on how you read the table on this page [1].

>Also wonder how many devices this network can support. I'm sure there is sufficient capacity but I'm just curious how the capacity is calculated!

Satellite navigation systems broadcast signals on a specific frequency. Anyone listening, should be able to pick up the signal. Therefore I assume infinite capacity.


Do we know when Galileo-compatible chips are expected to be deployed widely?

Europe is really late to the party. GPS has been here for a long time. China's Bei Dou has been operational for a few years and is entering the 3rd generation.

The first GPS satellite was launched almost 40(!) years ago (https://en.wikipedia.org/wiki/GPS_satellite_blocks#Block_I_s...)

Where do they get off claiming Ariane 5 has a perfect record? It's explosion is one of the classic stories of software failure.

Indeed, I was surprised to read that too. Probably mistake on author's part.

This 1996 failure was not a "production" flight but a "test" flight (the very first test flight in fact). I guess the article implicitly claims all "production" flights were flawless.

But that too would be an overstatement. There was a second (and last) failure in 2002 for the first test of the ECA configuration of Ariane 5. (ECA, Évolution Cryotechnique type A, is an improved Vulcain 2 first-stage engine with a longer nozzle with a more efficient flow cycle and denser propellant ratio.)

All ~75 launches since 2002 have been flawless.

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