Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
Communications Media Television Wireless Networking United States Hardware Technology

Global Positioning Without GPS 82

Posted by kdawson
from the where-we-are dept.
GadgetMike sends word of an award to Boeing for work on a Robust Positioning System that could make use of cell signals, television transmissions, and other clues to provide position information when GPS is unavailable. (Wonder if they've heard about Skyhook Wireless, which does a similar job based on Wi-Fi hotspots, for 2500 US cities and towns.) The work is being sponsored by the US military, so it's not surprising that they don't want to rely on upcoming GPS enhancers or replacements from France, China, and Russia. Here is the Boeing press release.
This discussion has been archived. No new comments can be posted.

Global Positioning Without GPS

Comments Filter:
  • by 5, Troll (919133) on Saturday April 21, 2007 @01:42PM (#18825501) Journal
    Reminds me of that near-field locater thingy they had in Aliens...

    Hudson: This signal's weird...must be some interference or something. There's movement all over the place...

    Hudson: Nine meters. Eight...!

    Ripley: Can't be. That's inside the room!

    Hudson: It's readin' right. Look!

    Hicks: Well you're not reading it right!
  • by zappepcs (820751) on Saturday April 21, 2007 @01:46PM (#18825519) Journal
    Pilots have used VOR http://en.wikipedia.org/wiki/VHF_omnidirectional_r ange [wikipedia.org] for a long time. Knowing the lat/lon position of other radio beacons and being able to detect them is (IIRC) something that was experimented with for robotic vehicles.

    Using geo-data and good state of the art receivers, it would be possible to locate your position reasonably accurately if you have many landmark transmitting beacons. The trouble is making those receivers small enough to be useful. Of course, this might not work too well in the middle of a desert but would function well enough for many problems.
    • This idea seems pretty flimsy..

      If you are incorporating known, ground based beacons/signals to provide positioning data wouldn't it be easy enough for the enemy to emulate those beacons/signals from some location near to the real one to create multiple signatures and distort positioning data? Wouldn't this confuse the proposed system?

      All it would require is transmitting eq that you could fit into a small, mobile (cargo van type) container. Now you have to a: track down the false signatures & have resp
      • by zappepcs (820751) on Saturday April 21, 2007 @03:15PM (#18825973) Journal
        Well, if you were relying on single source beacons, that might be true. But think of all the commercial beacons that are available, from TV and radio stations, to emergency radio towers, ham radio repeaters, VOR beacons... there are hundreds of radio beacons around you, no matter where you live in the civilized world. All of these, when incorporated into a positioning scheme, become more or less redundant sources of triangulation that would have to be disabled in some form or another to stop this from working. It would take a lot of effort to disable such a system as they do not rely on the same infrastructure or control systems.
        • Re: (Score:2, Informative)

          An excellent point when considering developed countries.

          What about use in Afghanistan, though? Even Iraq in the months directly following the invasion when power and basic utilities were scarce? The number of measurable signals would have been cut harshly and the ability to confuse such a system would have increased.

          I have no doubt about the viability of the signal/location system in good circumstances. I remember navigating on flight-sims using the system.

          I am worried about more military money going in
          • by mazarin5 (309432)
            Well, number one is that this is a backup in case the satellites are unavailable.
            Number two is that in the case of absolute failure, they're no worse off than they are today.
      • This idea seems pretty flimsy... If you are incorporating known, ground based beacons/signals to provide positioning data wouldn't it be easy enough for the enemy to emulate those beacons/signals from some location near to the real one to create multiple signatures and distort positioning data? Wouldn't this confuse the proposed system?

        This technology could have other military applications. You could use it to send homing missiles to target specific signals. The Russians have already killed a Chechnen le
    • Re: (Score:3, Interesting)

      by drix (4602)
      I think this is a new idea. It sounds like they want to construct a radionavigation system that doesn't require any new hardware outlay, based instead on the known locations of various cell towers and TV transmitters. When you consider that the investment in equipment and maintenance in GPS runs into the tens of billions of dollars, this approach is nothing short of revolutionary.

      Second, there's really no issue with acquiring a GPS lock in an airplane, since you have unobstructed access to no less than 10 s
  • Alright, so let me see if I have this straight: If some other country tries to fire a missle at the United States, and we want to deprive them of accurate positioning, the United States would have to blow up a bunch of cell towers in the United States. Right?

    • by cduffy (652) <charles+slashdot@dyfis.net> on Saturday April 21, 2007 @02:15PM (#18825687)
      This is more a matter of removing the motive for $OTHER_COUNTRY to try to confuse the US's offensive infrastructure by destroying disabling our GPS satellites. It works both ways, obviously, if $OTHER_COUNTRY is using similar technology -- but any missile which is going to do really significant damage will be able to get close enough to where it needs to be using inertial guidance, so the example you give isn't a serious concern.

      Moreover, disabling GPS is really an asymmetric threat -- it's easy to do (if you're China, for whom the necessary technology is already a sunk cost), and has an impact on your opponent far greater than its marginal cost. Avoiding unfavorable asymmetric threats is a Good Thing.
      • by ozbird (127571)
        This is more a matter of removing the motive for $OTHER_COUNTRY to try to confuse the US's offensive infrastructure by destroying disabling our GPS satellites.

        1) Why destroy when jamming is easier and cheaper?
        2) How much of this is a genuine survivability requirement than just hubris about using someone else's system (or everybody else's systems together)?

        • by cduffy (652)

          1) Why destroy when jamming is easier and cheaper?

          I left out a key word there, but my intended phrasing was "destroy or disable"; jamming falls into the latter category. That said, jamming is more of a local defensive measure than an asymmetric attack; it doesn't have the same impact on civilian or commercial operations and other interests (ie. ability to wage war in theaters other than that in which the immediate conflict is taking place).

          2) How much of this is a genuine survivability requirement than just

    • by PPH (736903)
      Look at that the other way around. When we invade a country, the first thing we do is take out all of their telecommunications infrastructure. Good thinking, folks.

      In reality, this might be useful outside of conflict areas if something or someone takes out the GPS system. But in a country under attack, they can just initiate blackout measures for broadcast systems. Critical communications can be done with portable equipment (truck mounted cell towers, for example) which render them useless as navigation aid

  • by Anonymous Coward on Saturday April 21, 2007 @01:59PM (#18825597)
    Before the patent wars begin, there's prior art out here: I think it is called a "map" or something.
  • robust mess? (Score:2, Informative)

    by Anonymous Coward

    Robust navigation? From a jumble of tv/mobile signals? I don't think so. For absolute position VOR+DME is pretty good and ILS/MLS around terminal areas. Relative collision avoidance is handled by S-mode transponders and TCAS.

    Use existing systems. ATC could gather all the TCAS negotiation information via the s-mode datalinks and use that to make a more accurate picture of the traffic than the survaillance radar alone can provide and broadcast that back to the planes. All that the planes really need anyway

    • Robust navigation? From a jumble of tv/mobile signals? I don't think so. For absolute position VOR+DME is pretty good and ILS/MLS around terminal areas. Relative collision avoidance is handled by S-mode transponders and TCAS.

      Use existing systems. ATC could gather all the TCAS negotiation information via the s-mode datalinks and use that to make a more accurate picture of the traffic than the survaillance radar alone can provide and broadcast that back to the planes. All that the planes really need anyway

      • ATC could gather all the TCAS negotiation information via the s-mode datalinks and use that to make a more accurate picture of the traffic than the survaillance radar alone can provide and

        Thats effectively what ADSB does. Works a treat in Australia

        broadcast that back to the planes.

        Why? TCAS already got that information the first time around. Why create a dependency on ground hardware when you don't need it?

  • LORAN (Score:5, Informative)

    by Cyberax (705495) on Saturday April 21, 2007 @02:13PM (#18825663)
    We've had http://en.wikipedia.org/wiki/LORAN [wikipedia.org] since WWII. It works fairly well for ships and airplanes, I'm sure it will be quite enough to guide airplanes to nearest aerodrome in case of aliens knocking off GPS satellites.
    • Re: (Score:2, Insightful)

      by Lumpy (12016)
      If the pilot is even slightly competent he can fly and find his airport and LAND without GPS,LORAN, or other navigation system. A compass or even dead reckoning works quite well and last I knew you had to learn it.

      But then we had a story a couple moths ago how military pilots could not fly because their GPS's failed.

      If you cant fly with your entire instrument cluster dead, then you have no business being in the cockpit of an aircraft.
      • by Ralgha (666887)
        Go jump in an airplane and find your way to an airport, without crashing, using no instruments and having an overcast cloud layer at 200 feet with the tops at 20k. When you accomplish that, you can come back here and repeat your statement. You'll die first though.
        • by Lumpy (12016)
          Since you do not know how to fly an airplane, I'll enlighten you.

          to get your Advanced Instrument rating you have to do just that. and a 200 foot ceiling is really easy to deal with. First you either pick a different airport that does not have the visibility problem,(typically low ceiling is localized within a 50 mile radius) You also can find where you are easily by listening to the beacons on your portable and watching your HSI needle (sandel makes a nice one). I can tell you without looking out that wi
          • by Ralgha (666887)
            I don't know how to fly an airplane huh? I captain a Brasilia for a large regional airline. Try again. There is no such thing as an "Advanced Instrument Rating", there is only an "Instrument Rating", unless you're referring to the ATP, which replaces the instrument rating, and is actually easier to get. If you are in the clouds, and you lose all your instruments, you are dead. It's that simple. If you are not in the clouds, and you have the fuel to make it somewhere that does not have low ceilings, th
          • by Ralgha (666887)
            Forgot to add, I taught instrument ratings for a few years, and it's not required anywhere to navigate without any instruments. Escape methods are good to know, and all my students learned them, but it's not required knowledge. If you're in the clouds and you lose all navigation capability (handheld is cheating, you didn't say that was available in your first post), then you're dead unless you get really lucky.

            If you happen to be somewhere flat, like the midwest, you might be able to make that luck by k
    • by Ralgha (666887)
      While LORAN is good (I've used it), it requres a specific receiver, which most airplanes do not have, thus rendering it useless for all but the few that have the necessary equipment.
  • Well, the blackbird used astral navigation.
    • Re: (Score:3, Informative)

      by calidoscope (312571)

      Well, the blackbird used astral navigation.


      To be precise, the Blackbird used an astro-inertial navigation system originally developed for the Skybolt missile. This used the position of the sun or other selected stars to refine the position estimates given by the inertial nav system. A related guidance system is used in the Trident II missile.

      • To be precise, the Blackbird used an astro-inertial navigation system originally developed for the Skybolt missile. This used the position of the sun or other selected stars to refine the position estimates given by the inertial nav system. A related guidance system is used in the Trident II missile.
        Looks like we've got a G-man here... :)
  • How about not relying on things around you having power? For example, wouldn't the "enemy" want to take out your power grid? Wouldn't that then significantly change the picture from the signals around you? Heck, even WE could do that to ourselves if we needed to divert power to some military purpose and might have to turn off some civilian transmitters.

    We recently saw some tech news (damn; can't remember where now) where two satellites in close tandem were making incredibly detailed gravity maps of the w
  • And all this time I thought one only required a sextant and a way of reliably telling time.
  • I always imagined that the GPS network must be very vulnerable to attack, any nation as industrialized as say china could probabbly fill orbit with enough shrapnel bombs to destroy the bulk of the satellites around the planet if they put the resources into it. what did people do before GPS? Well theirs a few things, but most of them don't fit in your pocket. land navigation is extreamly difficult, I spent a good part of my child hood/early teens practiceing land navigation, and I wouldn't ever want to re
    • Sure they could put shrapnel up there, but they'd screw themselves over. Destroying satellites is the absolutely last thing you wanna do. One satellite destroyed is one more object in space (likely multiple pieces) to worry about. Not to mention small pieces of shrapnel can destroy anything, and the US can't even track any debris thats smaller than a baseball. It's a mutually assured destruction kind of thing. You leave our stuff alone, or it'll invariably damage/destroy something else of yours in the 20 so
      • Destroying satellites is the last thing you want to do, IF you depend on satellites. A country with little need for permanent presence in space (North Korea maybe?) could easily use the threat of knocking out a satellite. The problem is that a country knocking out a US (or other country's) satellite could easily cause damage to third party nations' satellites. Is it worth having multiple countries mad at you?
    • Also celestial navigation relies on a unubstructed horizon and clear weather obviously

      But I wonder what you could accomplish today with a PDA equipped with a camera and an accurate clock? If it could resolve stars and (say) the Moon and/or Venus and the horizon in one or two images could it work out your location on the ground?

      Might be hard in the city but if you have some kind of disaster where city lights are lost celestial navigation might become possible again.

    • I always imagined that the GPS network must be very vulnerable to attack,

      Many slashdot readers imagine all manner of ludicrous things. Sometimes the even remember them when they sober up or the high wears off.
  • Sounds an awful lot like Intel's PlaceLab [placelab.org] to me.
  • Stars (Score:3, Funny)

    by tsa (15680) on Saturday April 21, 2007 @03:57PM (#18826221) Homepage
    I read somewhere that you can use the stars as well for global positioning at night. That's an interesting and novel idea. Maybe they should do some more research on that.
  • When I was 12, the Boy Scouts taught me to triangulate my position with a map and a compass. Oh, and something to draw the lines with.
  • Oh come now, You must be referring to Galileo system that is being buid for the EU and ESA (European Space Agency) by European Satellite Navigation Industries. So it's basicly european system not French. Get your facts straight.

    More on subject:
    The EU site for the Galileo project http://ec.europa.eu/dgs/energy_transport/galileo/i ndex_en.htm/ [europa.eu]
    The wikipedia site: http://en.wikipedia.org/wiki/Galileo_positioning_s ystem/ [wikipedia.org]

"In the face of entropy and nothingness, you kind of have to pretend it's not there if you want to keep writing good code." -- Karl Lehenbauer

Working...