Tony Hoyle wrote: > How do you find out it's better though? You have to rely on the fact > ntpd knows the time to some accuracy to calculate the time1 value for > the GPS device - so it's a catch-22.
No, you don't. Four GPS satellites can tell you your position and the current time. You have four unknown quantities (latitude, longitude, elevation, and time; the position of the satellite is known --- it is broadcast by the satellite). Those quantities are all related, and plugging in measurements from the four satellites gives a system of equations to solve. If you know your current position (latitude, longitude, elevation), you only have one unknown, and this only need one satellite. Google will no doubt provide all the details. _______________________________________________ timekeepers mailing list [email protected] https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers
