Galileo navigation satellite system goes live
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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.
https://en.wikipedia.org/wiki/BeiDou_Navigation_Satellite_Sy...
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...
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...
http://timesofindia.indiatimes.com/home/science/How-Kargil-s...
Yet US sides with dictatorship which doesn't even control its own secret service which creates its own terrorist organizations (laskar-e-taeba).
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...
"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.
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!?
Now now, do not insert political commentary into this discussions. I got yelled at for doing that. [1]
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...
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.
There is an enhanced footprint signal boost capability for the military but that's the opposite of what you describe.
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.
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...
[1] http://www.dote.osd.mil/pub/reports/fy2011/pdf/af/2011gps.pd...
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.
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.
[1] https://en.wikipedia.org/wiki/Galileo_(satellite_navigation)...
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.
Could you provide some links to read? I just can't imagine how it's possible.
I think I overstated but still it is possible. Millimeter survey grade is commercial.
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.
(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.
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.
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.
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".
Even SEALs are issued the same Garmin Foretrex 401 you can get at Best Buy.
If this doesn't exist then those missiles don't work...
[1] https://en.wikipedia.org/wiki/Global_Positioning_System#Rest...
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...
...and that was removed quite a few years ago now.
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.
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...
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.
https://www.scientificamerican.com/article/gps-and-the-world...
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?
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.
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.
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.
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...
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?
Here's hoping sanity prevails and there's no sudden cutoff leading to things falling from the sky.
http://www.usatoday.com/story/news/2016/06/08/embraer-gps-te...
Here's an article from 2014 talking about production chipsets that do GPS/Galileo/Glonass/BeiDou.
http://gpsworld.com/quad-constellation-receiver-gps-glonass-...
which is why being practical, you would use only one and fallback to the others on failure-to-fix.
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.
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.
Americans did pay for GPS, which is why we should have full access to its capabilities as taxpayers.
In times of war.
This is not something that's in any way acceptable.
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.
It's quite reasonable that if a third-party is supplying weapons to an enemy, it gets caught up in the cross-fire.
So, no, Galileo users aren't supposed to fall back to anything. That's the point.
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.
http://www.gps.gov/systems/gps/performance/accuracy/
> 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.
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.
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.
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.
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.
It is easy to end up comparing apples to oranges with this sort of stuff.
https://en.wikipedia.org/wiki/European_Border_and_Coast_Guar...
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!
>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.
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.