That small hemispherical antenna could also have been 900mhz. I have one here @ home that is a combined gps/900mhz antenna from an ambulance tracking system.
On Jun 10, 2011, at 22:01, Hal Murray <[email protected]> wrote: > > [email protected] said: >> There's an enormous amount of gear out there that gets timing off of GPS. > > That's an interesting claim. Does anybody have any data on the usage of GPS > for timing? > > I assume there is one in every cell tower and one in every 911 call center. > Are there other large categories of users? > > What would it cost to replace all of it? If you wanted to do something like > that, what would "it" cover? How about people like us running old recycled > gear? (Z3801A, ThunderBolt, ...) > > > I think I saw one last week. It was on a river level measuring station on > the Sacramento River. It was a small block building. There was an antenna > pointing up into the sky. I assume there is a satellite up there. There was > also a small (~3 inch dia) hemisphere antenna. I assume it was GPS. (They > had power going into the building (no solar panels) so it should have been > simple to get a phone line too.) > > I'm not sure why they need GPS at the recording house. They know where it is > so timing is the only use I can think of. But they could also get that at > the receiving end. Millisecond accuracy isn't helpful. Second level > accuracy might be interesting if something breaks and you want to know when > the wave got to downstream stations. The risetime is probably over a second. > > > -- > These are my opinions, not necessarily my employer's. I hate spam. > > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
