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GPS vs. Galileo; Where Are They Headed?
ben_ writes "This keynote speech from the recent European Navigation Conference talks about the history between the US military's GPS and the proposed EU Galileo system, as well as where they're both going. Interested in how you know where you are and what's going to happen to those satellites?"
The correct links for the US-administered GPS satellite constellation, known as NAVSTAR:
NAVSTAR GPS Joint Program Office - responsible for operational maintenance of NAVSTAR GPS equipment, services, and infrastructure
Interagency GPS Executive Board - executive management of NAVSTAR GPS
GPS fact sheet - US Air Force facts about NAVSTAR GPS
US Naval Observatory NAVSTAR GPS home page
Further information:
FAS GPS background info
Global Security GPS background info
Most GPS receivers are able to switch between metric and imperial modes...all the satellite does is send a timing signal which the receiver interprets according to it's relative doppler shift...the satellite does not transmit *your* position based upon its own calculations, the receiver performs these calculations and displays them in whatever measurement you desire
For more information look at the Article featured on Slashdot about 6 months ago.
:)
Galileo System To Include Jamming Capability
+++ MELON MELON MELON +++ Out of Cheese Error +++ redo from start +++
Uh, no.
irb(main):001:0>
The paper says that by necessity, the two systems need be compatible on several fronts. OK, that is good, saves everyone money, too, by not obsoleting all your GPS hardware when the EU system goes live.
The EU system will also provide "additional commercial services, on a user-pays basis." That could be good too, but the basic "where am I now" function of GPS works fine for me. I'm leery of a govt body stacking commercial features on to a pretty well proven system.
"Galileo thus requires US cooperation for its commercial success, while at the same time apparently threatening US national security and industrial advantage!" To which I say Bah! Unless the US has really been dragging its heels in cooperating, I say, build your nav sat system and go for it! Our (the US) present obsession with security is mostly the work of a paranoid few. Let the US take care of itself and power to the EU for whatever they can do.
Sure, there may be a few Pentagon types who might drag their feet, but the timing and communications methods aren't rocket science... and even the rocket science part can be easily handled.
They're in on Galileo: see here
Here is a technical comparison. They seem more alike than different to me.
I know of a few very high-powered geologists who cross-check GPS with GLONASS. Having a third system would seem to only help.
Update. The GPS and Galileo L1 bands overlap others do not. More information here: http://www.gpsworld.com/gpsworld/article/articleDe tail.jsp?id=61244
You're mostly correct. Selective Availibility can be done region by region (I don't know the resolution of this), and the signal can be degraded with rather fine-grained control (the whole world was degraded to 200meter-ish accuracy until the late 90s). SA does not effect military recievers; when supplied with the days proper P(Y) code, they are as accurate as the GPS spec allows (~1 meter resolution, best case).
So the US can degrade the signal in a fine grained way, without affecting military / government systems.
--
Phil
It can be turned off selectively. Furthermore, as I understand it, "turned off" only means that the unencrypted data stream is gone. The military has the keys to the encrypted stream, so their GPS units still work.
I have also heard of GPS jammers, but anyone could use those, so that would effectively negate the US's GPS advantage.
GPS jammers are nearly useless. They are only powerful enough to cover a small area, so their only use is to protect a stationary target from attack by GPS guided bombs. Unfortunately, as demonstrated in the Iraq war last year, they don't even do that effectively. All six of the Russian-made GPS jammers fielded by Iraq were destroyed in short order, some of them by GPS guided missiles!
If a job's not worth doing, it's not worth doing right.
Just like China wanting to be independent technologically, the EU also does not want to be dependant on the USA.
Read the FAQ where it says one of the objectives is just that:
2bits.com, Inc: Drupal, WordPress, and LAMP performance tuning.
HUH? are you nuts?
the GPS system CAN be turned off or rendered pretty much useless for anyone except the US troops. the DOP can be adjusted from zero to insanely high for non-military units. (DOP is dilution of Precision) I work with a guy that just came back from NORAD and his main job was dealing with the GPS systems. (Luetenant who is back only to gather his things and return back to full active duty due to an offer from the military he could not refuse)
the non-classified things he was able to tell me is that the DOP can be adjusted a very wide range to the point that even DGPS can be rendered pretty useless unless both recievers were in very close proximity.
if anyone ever thought that a military system would not have the ability to be disabled for all but military use they are horribly mistaken. the lives of the service men on the ground and the sucess of a mission is much more important than some businesses using it for navigation.
SA can be turned back on at any time if it is needed.
Do not look at laser with remaining good eye.
In spite of the advantage that SA theoretically gave us, it was turned off in both Iraq Wars. First time, because not enough milspec GPS receivers were available, second time because it had been turned off years before by Clinton, and it was no longer practical to disable it.
Note further that differential GPS was developed specifically to overcome the limitations imposed by SA. Most commercial-grade GPS receivers support it. Even if they didn't, it isn't so difficult a concept that it couldn't be reinvented if it were needed by a potential belligerent.
"I do not agree with what you say, but I will defend to the death your right to say it"
Also, DGPS only works when the L1 frequency is on. This frequency could conceivably be turned off by NAVSTAR over a region (it hasn't happened to date, but the US has never fought an enemy that had GPS-guided bombs). Another point: if the DOP is set high enough on SA, it could really restrict the range that DGPS could work over.
So you're not counting GLONASS? As far as I know, the Russian system is a perfectly acceptable alternative to GPS.
Heard of the European Rapid reaction force? Still in the planning stages but they just set up a headquarters. It's been seen a nascent European Army.
It's not really a question of bigger militaries, but some people/countries do want to see a unified (and therefore more powerful) force independent of the US.
As for political pressure, you can always rely on Rumsfeld for a quote, or here's another link I imagine there's quite a lot going on behind the scenes though. Understandably the US are worried about losing control of EU actions.
2)"Arabs" are not the enemy.
3)I seem to remember France invading the Barbary coast and turning it into a colony, in time, because of its piracy. They intended that to be a short stay, to sort out the terrorism, but somehow they ended up staying much longer, till the eventual nightmare of the Algerian war. Does this sound familiar?
4)"Europe" IS NOT A COHESIVE ENTITY. Any more than these "Arabs" are. You'll find many European nations (in particular the so-called ex-Stalinist Eastern European, and labour governed UK, oh and Spain till it burned them, and Italy, supported the US in this recent conflict. And some nations did not. That's because "Europe" does not exist a cohesive, American hating state except in your ignorant and jingoistic head.
5)It's not an "ideology driven by hatred and revenge" to realise that the USA has a different foreign policy ambition, and Europe another. It's being realistic.
Thank you and good day, loony.
Look at how many commerical GPS units there are, and how many military ones.
That's quite true. I've seen $99 yellow Garmin devices that were used to call down JDAM strikes on Taleban targets. The US Army had this elaborate "21st Century Force Digitization" plan in the works, but they're pulling back from it because the men are creating better capability on their own from civilian COTS electronic gear.
Factoid 2: Today, all US warfighter pilots have GPS build into their avionics (and augmented by inertial navigation). But in the first Gulf War, many planes on bombing missions carried handheld GPS in the cockpit to find their targets.
Factoid 3: Remember the "Saving Private Lynch" made-for-TV rescue? Her unit was lost and overwhelmed because not one of them had even a civilian-level GPS handheld. I don't think the Army will make that mistake again.
Even in a war zone, most of the commercial GPSes in use are those ofUS soldiers.
That may be true today, but probably not in a few decades. We must assume that civilian GPS will become more and more common until all phones and 50% of wristwatches include it. Eventually, the OPFOR will have more civilian GPS recievers than they do troops. But at the same time, maybe someday the US Army will get its act together enough to give each soldier a military GPS unit. When that happens, they may once again feel safe about degrading the signal.
It all depends on your confidence in the Army's logistical ability to supply 100,000 units of a $300 machine. Sure, they haven't managed in the past 15 years, but there's always next time.
It looks like plane 2 is entire empty. And the slots in plane 1 and 3 are each only half full.
Unless they launch a whole bunch more, it's no longer a GPS alternative.
'SBEMAIL!' is better than a goat!!