> -----Original Message----- > From: time-nuts-boun...@febo.com > [mailto:time-nuts-boun...@febo.com] On Behalf Of Ralph Smith > Sent: Tuesday, March 17, 2009 12:05 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Loran-C & French Clocks > > Not exactly the case. Radio components of the ADS-B system > require 100 ns accuracy. Multilateration systems also > require very precise timing between components. The > navigation and communications systems are most definitely not > looking at the hands of a mechanical watch. > > Ralph > > On Tue, March 17, 2009 9:06 am, Lux, James P wrote: > > The latter is probably because air traffic control is > basically done > > at a resolution of 1 minute (e.g. "Hold at SADLE > intersection, expect > > release at 32[minutes after the hour]") so the several > second offset > > between UTC and GPS is immaterial. You're looking at a mechanical > > watch in any case. > > > > Jim > >
Oh, yes, if you consider ATC to include navigation functions. But the "flight control" kinds of things are done on a substantially coarser time scale. I suppose as automated flight control (collision avoidance, for instance) becomes more common, then tighter timing is required. _______________________________________________ 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.