On 2014-03-18 02:59, Martin Burnicki wrote:
All depends on how accurate and precise you can get your timestamps, and this is probably easier with network packet timestampers at both sides of a cable than with a wireless time transfer method like GPS which usually suffers from delays which can't easily be measured, like ionospheric delays. And yes, I know that this can be improved if you receive 2 GPS frequencies instead of only the L1. ;-)
Problem with PTP accuracy is how do you set and discipline your GM? WithNTP probably. NIST site has a paper on TWSTFT stating that some of the delays cancel and others can be measured or estimated so that on commercial sat channels they can get uncertainties between two stations down to 0.1-1ns, which is better than they can get with common view even using L1+L2 freq and P code. BIPM monthly national TAI/UTC comparisons show uncertainties up to 10-20ns. -- Take care. Thanks, Brian Inglis _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
