Hmm, the GPS signal the military uses is supposed to be encrypted and un-spoofable.
I wonder if Iran cracked it. If so, can the US reset the key easily?
I wonder if Iran cracked it. If so, can the US reset the key easily?
I hope it was not that insecure.
Simply jamming something should not by-pass an authentication mechanism.
There should be a time component in the signal that wouldn't match the internal clock, but maybe enough satellites saying the same thing would trigger a self correction... or it would disregard all GPS data.
1) the location of satellites. You can probably get it from the commercial signal.
2) transmission system, which overpowers signals from satellites. Many amateurs have it too.
3) location of the receiver you want to distract. I have no idea, how this works, but apparently it is possible.
4) program that calculates right delays for each signal so that plane will locate itself incorrectly.
Maybe the droid was programmed so, that GPS overrides other locationing devices, if it is working and the droid thought that GPS was working.
As jgrahamc says: "I realize that as a Westerner I shouldn't be rooting for the Iranians but if they did spoof GPS, jam the rest of the communications and get this thing to land thinking it was at its home base then it's at least a neat hack."
When commercial GPS-devices begin to locate themselves, they need four satellites for the process: Three for the coordinates and one for time. I believe, that military system works the same way. If you cut down the signals for a while, the droid will, when the signal (delayed one) comes back, maybe adjust it's clock a couple of 1/10000ths of second to get GPS-locationing back in business. And after that the signal transmitter decides, where the droid will fly.
Many guesses here, but this is just one suggestion free for discussion, how the system might work...
unless it also has frequency hopping when it senses a jam.