Hal Murray wrote: > In article > <485551ee-a847-45b6-a040-624dc80ce...@s38g2000prg.googlegroups.com>, > cjc <[email protected]> writes: > >> We have some time servers with GPS clocks. One of their uses is in >> operations centers where satellites are being flown. The satellites >> use >> GPS (as opposed to UTC) internally, so we want the computers on the >> ground also to use GPS (rather than UTC). The time servers speak NTP >> and hand out GPS time as if it were UTC. The ground computers think >> they are on UTC, but it's really GPS. >> >> But we'd like some of the computers to really be on UTC. I really >> haven't >> been able to think of a good way to have computers use the GPS time >> given out by the time servers as a source, but then to actually offset >> their own time by the GPS-UTC difference. Some quick Googling hasn't >> turned anything up. Anyone have some suggestions on how to manage >> something like this? Or are we just going to have to live 15 seconds >> ahead of the rest of the world? >> > > The GSS satellites also tell you the offset from GPS time to UTC. > Most of the (low cost) GPS receivers tell you UTC rather than GPS. > > Things get interesting around leap seconds. Other than that, > UTC via GPS works pretty well. > > What type of GPS clock/receivers are you using? > I would also bring up the issues with L1 GPS being so easily spoofed from a trust-anchor standpoint L1 is almost worthless - if you need to prove the source of the time then you need an AutoKEY based relationship with some reliable provider.
Todd Glassey > > > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.0.238 / Virus Database: 270.12.18/2096 - Release Date: 05/04/09 > 17:51:00 > > _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
