> > > With one tower, you're down to describing an arc along which
> > > the phone is probably located; still pretty good when it comes to finding
> > > someone.
> >
> > He seemed to imply that they could get it within 25m, even with one
> > phone. Like I said, I don't understand how, but I didn't question his
> > ability. Plus, he knows alot more about the stuff than I do.
>
> Well, assuming they have 100% antenna overlap (not unlikely) you could
> just do phase comparisons between the antennae getting the squirt. If
> these guys are as smart as you say (and I have no doubt at all about
> that), 25m at near distance is probably not unrealistic.
True. Up close, you can triangulate.
> Ask him if they can still do it at 35km out (the outer limit for a normal
> GSM cell). That'd really spook me. 8)
He wasn't interested in talking about it when I started asking about
single cell towers, so I never pressed him on the issue. Maybe he was
afraid that the 100m accuracy claim would be found out to be un-doable,
but the Feds claim 'it must be that accurate', and they aren't
interested in spending the $$ for GPS receivers in the handhelds.
Or, he's got it figured out, and is applying for a patent on it and
didn't want to reveal his secrets. :)
Nate
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