back to article New GPS sats to lack Selective Availability

The US military announced yesterday that it will no longer procure Global Positioning System (GPS) satellites with the capability for worldwide civil sat nav degradation. In a release dated yesterday, the Pentagon confirmed that "this capability, known as Selective Availability (SA), will no longer be present in the next …


This topic is closed for new posts.
  1. Keith Martin


    Galileo presumably won't include SA, so if the US went ahead with SA, then Galileo would whip them. Even if Galileo ends up not going ahead (and that decision will probably rest on whether the US system still has SA or not, because that's Galileo's competitive advantage), the US basically has to drop SA for everything except very extreme situations.

  2. Svein Skogen

    Sure, they won't OFFICIALLY have SA in them. Do we KNOW?

    Sure, the US military that is launching them, controlling all aspects of them, and designing and paying for them, SAY they won't have SA built in. Will the public have any other "proof" of this than their word?

    I'm asking this, because the current Washington DC regime isn't exactly known for it's honesty regarding facts. (Has anybody found Saddam's WMDs?)

    It's strange how this statement comes at the same time the EU is considering the go-ahead for Galileo. Especially given past statements from the US military regarding Galileo (The "If you make them that accurate, we'll shoot them down!" line of arguments, from the same source that now stops using SA)

    Maybe the SA issue will resurface as soon as they have talked the EU into stopping the Galileo project?



  3. Tom Chiverton

    Who cares if Galileo has SA or not ?

    If the US doesn't like it, they'll jam it (locally, as they do GPS) or just shoot down the sats.

    This isn't an excuse to waste billions of European tax dollers.

  4. Ash

    Shooting down European satellites

    Hate to point out the obvious (to me), but I'm pretty sure that this isn't an option for our very good friends over the pond, mostly because we (Europe, not just the UK) might get a little bit peeved at them firing weapons at our property, especially when it's only active over Europe.

    Am I giving them too much credit? Answers on a postcard (Or posted below).

  5. Matt


    We don't use dollars in Europe, we use the worlds largest currency, Euros. From my point of view Gallileo is money well spent just to be rid of US interference, if nothing else.

  6. Iain Gilbert

    Re: Shooting down EU Sats

    Especially as countries like France aren't particularly pro-US (Thankfully someone's got sense) and have their own weapons that aren't US controlled.

    After all do you think we could really nuke anyone without the US's say so?

  7. joe K

    GPS competitive advantage?

    @Keith Martin...

    You make it sound like GPS is run by Nokia trying to prepare for a backlash by newly released Sony Ericcson rival product...While I'm sure the US DOD runs the GPS system on as economical a financial plan as possible, seeing as they don't profit from it, its hard to see why they'd consider themselves 'in competition' with Galileo..... Its a free service, you don't like it, you don't use it, they don't need to entice you to use it.....

  8. Glen Turner

    @Joe K

    The US and EU are competing. Most of the manufacturers of GPS equipment are based in the US. The US government sees Galileo as presenting a threat to US dominance in that industry, much the same as occurred with Airbus and Ariane.

    The US DoD gains strategic advantage from operating the only satellite positioning system.

    1) With one one signal specification, the US DoD can jam the civilian GPS signal. Once there are multiple systems in the same spectrum then jamming all of the civilian signals and opposing military signals whilst not jamming your own military signal is complex.

    2) DoD's ownership of GPS give US forces the unique ability to deploy GPS-guided munitions with certainty. All other forces accept that their GPS guided munitions may fail should the US choose to jam its civilian GPS signal. That's not an acceptable situation to a number of military forces in EU members.

  9. Andrew Moore

    SA or not SA

    Does not really matter if the next batch of Navstar satellites (which have been put on indefinite hold I've been told) are SA free as a quick firmware upgrade would soon reinstall it...

  10. RRRoamer

    So you REALLY think that EU GPS guilded weapons use the civilian signal???


    The impact of SA had NOTHING to do with the Europe's military hardware. They are using the military signal anyway. SA would only impact all the civilian GPS users, including commercial aviation. The whole point of SA was to degrade the accuracy of "rogue states" that were forced to use the civilian signal for their GPS guided "stuff".

    Of course, there are a couple of reasons why SA really isn't an option anymore: 1) GPS use has been far more critical to world wide commerce (aviation, survey, land navigation, etc.) than it was originally expected, 2) Commercial GPS receivers are MUCH more accurate even with a SA signal than the military ever expected. The advancements in cheap, small and POWERFUL digital signal processing along with super accurate clocks allowed much of the noise to be removed from the SA signal. And 3) differential GPS is wide spread and it almost always covers a VERY large area right around any major area that the "bad guys" would want to hit anyway, they can STILL get cm level accuracy in many target areas even with SA turned on.

    SA's time has simply passed. Technology has rendered it pretty much useless at this point.

  11. Anonymous Coward
    Anonymous Coward

    US interference?

    "We don't use dollars in Europe, we use the worlds largest currency, Euros. From my point of view Gallileo is money well spent just to be rid of US interference, if nothing else."

    WTF are you talking about?

    The US didn't build GPS to interfere with the Europe. We built it to navigate. Then we gave it to the rest of the world. For free.

    The GPS system is one of the most marvelous technical systems ever created. And it's free to all the people of the world. And the appreciation and thanks the US gets is "we need to spend the money on a system just to be rid of US interference" Great. Build Gallileo. But do me a favor, turn off your existing GPS units until it's done.

  12. Tony

    To those who seem to have a gripe about US control over the US GPS system.

    Stop using it. Pay the US (and us taxpayers) for all of your past use. Absolve yourself of your sins. Use someone else's system. Build your own system. Go back to LORAN.

  13. Tony

    And another thing

    If the US did restrict GPS data in Europe for some emergency it would only be for free, civilian use. Apart from a declaration of war by US allies in Europe there is no chance of our allies losing access to GPS.

  14. Anonymous Coward
    Anonymous Coward

    To the Americans:

    The question is not that the “world” is not grateful for GPS, the question is that the world now relies on accurate positioning, and fears that should any “troubles” were to start, and US will decide to encrypt GPS signals, a European (and Russian, forgotten in these comments) systems would come in handy.

    Strategically speaking, having accurate positional data is quite important, I am more than positive that US has a way of rendering GPS signals useless during war time. It is most probably classified, and I would not be at all surprised if US military receivers have hidden firmware settings to switch to a different frequency and protocol, if the main GPS signal goes dead.

    What I have always wanted to know, however, is how the old ICBMs navigated, before satellite positioning...

  15. Arif Rashid

    American Government are liars

    The American Goverment doesnt have a good track record on things and they are especially good at backtracking and changing the rules at any moment when it suits them. So its quite possible the Bush administration might turn around and stop anyone it doesnt like from using the system and it could (in theory) even send out a wrong signal...

    Given the reliance on SatNav these days it makes perfect sense to have more than one system. For one it means that if (in the unlikely event) the GPS system goes down (and it has done, albeit only once if memory serves) there is another system to use instead.

  16. Anonymous Coward
    Anonymous Coward

    RE: And another thing

    "Apart from a declaration of war by US allies in Europe there is no chance of our allies losing access to GPS."

    What if the US did declare war on Europe? If you don't control it, you can't trust that you'll always have access to it.

    In response/addition to other comments: It's not necessarily an economical advantage that the US owns and controls the only GPS-like system, it's a strategic military advantage. Who cares about the US companies? It's all about control. If the US military controls it, it can mess with it all it wants. And if the US wanted the UK's military to stop using the "Military Channel", it could just disable their keys.

This topic is closed for new posts.