It's usually a manual setting of antenna delay on receivers I've used, and based on assumed delay in the particular cable & connectors. You can tweak things closer if you have a good 1PPS to compare with.
Rob K -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Pierpaolo Bernardi Sent: 08 September 2010 11:36 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] What position is measured? On Wed, Sep 8, 2010 at 02:16, jimlux <jim...@earthlink.net> wrote: > Mark J. Blair wrote: >> On Sep 7, 2010, at 6:30 AM, jimlux wrote: > Yes.. except that the cable's physical and electrical length *do* vary > with temperature, so if you're looking at the gnat's eyelash sort of > thing, you need to take that into account. Maybe 10 ppm/degree, so a > 20 meter run will change a bit less than a millimeter. That's down in > the fractional picoseconds time-wise. > > It's an issue if you're doing things like interferometry at higher > frequencies.. Would be possible for the receiver to take into account automatically the delay of the antenna cable, by measuring the delay of an echo of a signal it sends towards the antenna? Do such receivers exists? _______________________________________________ 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.
