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Global Positioning Without GPS
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.
Pilots have used VOR http://en.wikipedia.org/wiki/VHF_omnidirectional_r ange 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.
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Before the patent wars begin, there's prior art out here: I think it is called a "map" or something.
We've had http://en.wikipedia.org/wiki/LORAN 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.
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.
They got lost. Ships hit rocks and aircraft hit mountains. Google Earth has an interesting feature where you can overlay old maps on the current images. There you can see how inaccurate the old map makers were.
From the military point of view, GPS means less bombs hitting civilians. During WWII and the Korea war it was normal to drop hundreds of bombs, flattening several city block or even entire villages, just to hit one bridge. Today when a bomb hits anything other than the intended target it's considered a major fuck-up.
The smarter technology gets around us, the more efficient we get. We need to make sure we have a fallback system in case the new technology fails, of course, but we are still much better off with the smarter systems than with the old tech solutions.
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.
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