Hi Setting up the signals for any time / location on earth is simply matter of a few mouse clicks with any of a number of packages. No need to do anything more than that to get the data.
Bob > On Aug 14, 2017, at 3:02 PM, Graham / KE9H <ke9h.gra...@gmail.com> wrote: > > Remember the military drone that the Iranians tricked into landing in Iran > a few years ago? > > The best explanation I heard of how they did it was that they knew that if > it lost its command channel, that it would return to the airport where it > took off. > > So, what they did was spoof the GPS with a signal that said it was 150 > miles further east than it actually was, then jam the control channel, and > it set down nicely on the airport it came from, except that it was the > desert in IRAN with a few rocks that ripped up its landing gear, and not > its home runway. > > Would this spoof be as easy as recording the real signal and playing it > back (louder) delayed by about 120 seconds? (Assuming you want to shift > things to the East.) (Also assume you have a relatively unsophisticated GPS > nav receiver.) > > --- Graham > > == > > On Mon, Aug 14, 2017 at 1:41 PM, Bob kb8tq <kb...@n1k.org> wrote: > >> Hi >> >>> On Aug 14, 2017, at 2:13 PM, Chris Albertson <albertson.ch...@gmail.com> >> wrote: >>> >>> The trouble with spoofing location is that in theory every ship is using >>> more than one method of navigation. They would notice their GPS is >> acting >>> up and turn it off. >> >> In most cases the “other method” is dead reckoning. That’s actually being >> generous. There are a *lot* of cases every year where the answer is that >> the vessel is on GPS autopilot with nobody at all on watch. Yes the >> results of >> breaking the law are fairly predictable. Actually having a competent >> navigator >> on duty all the time running “alternate” data, that costs money ….. >> >> Bob >> >>> >>> I'm far from a professional but I've taken the six week class and I'm >>> reasonably certain I could find a place on the other side of the pacific >>> ocean with no GPS. The GPS is far easier to use and more accurate but >> no >>> one uses just GPS alone, they alway compare several methods. >>> >>> On Mon, Aug 14, 2017 at 10:12 AM, Clint Jay <cjaysh...@gmail.com> wrote: >>> >>>> I guess it would depend on the level of infrastructure available to the >>>> attacker, clock distribution is a reasonably well solved problem isn't >> it? >>>> >>>> There would, I suppose also be the issue of receiver swamping, you could >>>> monitor received signal levels as it's my understanding that the signals >>>> from the satellites are weak enough that they're indiscernible from >> noise >>>> floor without some rather complex processing? >>>> >>>> Authentication via signing could be another feasible way to prevent >>>> spoofing except we are potentially talking about interference from state >>>> actors who may even be the very people who run one of the satellite >>>> networks >>>> >>>> On 14 Aug 2017 5:51 pm, "Attila Kinali" <att...@kinali.ch> wrote: >>>> >>>>> On Mon, 14 Aug 2017 12:09:43 -0400 >>>>> Tim Shoppa <tsho...@gmail.com> wrote: >>>>> >>>>>> I think if you are only trying to spoof a single receiver it would be >>>>>> possible to walk a spoofed time/space code in a way that time moved >>>>> without >>>>>> so obvious of a discontinuity. I'm sure there would be effects a >>>> time-nut >>>>>> could notice still. >>>>> >>>>> Not really. Unless you have a multi-antenna setup (see jim's email), >>>>> you have nothing to compare the signal to. Even an ideal reference >>>>> clock in your GPS receiver does not help, as the attacker could be >>>>> tracking you in such a way that you will never see a discontinuity >>>>> in time or position and that all the other sanity checks you do >>>>> still don't show anything. >>>>> >>>>> With a two antenna setup, you can already check whether the phases >>>>> add up to what you expect them to be, given your position relative >>>>> to the satellites position. You do not need 3 antennas as a potential >>>>> attacker can spoof the phase of some satellites correctly, but not >>>>> of all at the same time. This at least gives you a spoof/no-spoof >> signal. >>>>> >>>>> With an antenna array you can do some masking of spoofers (ie placing >>>>> a null where the spoofer comes from). But this increases the cost and >>>>> complexity of the system super-linear with the number of antennas. >>>>> Maybe one way to do it, would be to use a single receiver with a stable >>>>> reference clock and switch between antennas in short succession. Ie >>>> similar >>>>> to how the early single channel GPS receivers worked, but for antennas >>>>> instead of SVs. But I have no idea how easy/difficult this would be >>>>> to do and how well it would work against spoofers. >>>>> >>>>> Attila Kinali >>>>> -- >>>>> It is upon moral qualities that a society is ultimately founded. All >>>>> the prosperity and technological sophistication in the world is of no >>>>> use without that foundation. >>>>> -- Miss Matheson, The Diamond Age, Neil Stephenson >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to https://www.febo.com/cgi-bin/ >>>>> mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to https://www.febo.com/cgi-bin/ >>>> mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>> >>> >>> >>> -- >>> >>> Chris Albertson >>> Redondo Beach, California >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to https://www.febo.com/cgi-bin/ >> mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/ >> mailman/listinfo/time-nuts >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
