> This makes it quite possible to detect this kind of simple
> spoofing by using two or more GPS antennas located a known distance from
> each other and checking to see that the positions computed from the
> signal out of each one differ by the known distances.
Sounds like some interested parties should take some GPS gear and some
radio receiving and test gear to one of the spots where the millatree
is warning airmen that "for the next two weeks, GPS doesn't work
here", and see just what sort of jamming they are using...
John
