On 12/27/2011 8:48 PM, [email protected] wrote: > Danny Mayer <[email protected]> wrote: >> On 12/24/2011 8:10 PM, [email protected] wrote: >>> John Hasler <[email protected]> wrote: >>>>> The open sky nearest the OPERA detector is straight up through 1400m of >>>>> rock. >>>> >>>> Jim Pennino writes: >>>>> And the easiest open sky to get to is horizontally down the tunnel to >>>>> the entrance which is next to a freeway. >>>> >>>> Yes, the entrance is next to a freeway. The entrance to the LNGS >>>> facility where the OPERA detector is located is near the middle of the >>>> 10 km long Gran Sasso highway tunnel. >>> >>> The bottom line is that the only thing that is relevant is how easy it is >>> to get to a GPS antenna with an open view of the sky. >>> >>> Everything else is bloviation. >> >> GPS is not used for this kind of thing, they are too inaccurate, so it >> doesn't matter. They use atomic clocks. >> >> Danny > > How do you measure distance with an atomic clock? > >
That's a complex question. GPS (even the military version) is not accurate enough. Danny _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
