This may be a dumb question, but I am new to using LadyHeather with my Thunderbolt (previously it had been slaved to driving a clock display but that broke, which made me get around to installing a serial card in my linux box)...
Are these "events" something I should be able to see in LH? If so what should I be looking for? I see a pair of off-setting events in the graphs (a sharp negative spike in DAC Voltage & PPS, followed later by a sharp positive spike of the same magnitude), but not sure if I am seeing what I want to see, of if this is actually what I am looking for. Off to study the LH Manual some more! 73, Brian KD4UYP On Wed, 2016-01-27 at 01:15 +0100, Magnus Danielson wrote: > Hi, > > On 01/26/2016 11:46 PM, Martin Burnicki wrote: > > Paul Boven wrote: > > > Hi everyone, > > > > > > Has anyone else seen GPS time jump by -13.7 usec today? > > > I just heard from several geographically quite distributed radio > > > observatories that they have seen their GPS receiver(s) jump > > > compared to > > > their in-house standards. > > > > We were able to track this down today at Meinberg. > > > > The problem was that some satellites were sending invalid UTC > > correction > > parameters. The UTC correction parameter set not only contains > > current > > leap second information but also coefficients (A0, A1, WNt, tot) > > for a > > polynomial used to compensate the fractional difference between GPS > > time > > and UTC(USNO). > > > > Normally A0 (the constant offset) is very small, close to 0. WNt > > and tot > > give the week number (truncated to 8 bits) and second-of-week for > > which > > A0 is valid, i.e. the reference time for the time correction > > parameters. > > WNt is currently about 89. > > > > Today the faulty satellites sent about 13.7 microseconds for A0, > > and WNt > > as well as tot were both 0. So when the GPS receiver updated its > > UTC > > correction parameters from a faulty satellite the UTC correction > > jumped > > from close to 0 to about 13.7 microseconds, which let the UTC time > > step, > > and when the GPS receiver received the UTC parameter set from a > > healthy > > satellite the UTC time stepped back. > > > > We have recorded a few of the faulty subframe words. If someone is > > interested I can provide more detailed information. However, I'm > > currently out of the office and don't have the information here > > right now. > > You know I want more details. ;-) > > I did see the report you guys sent to the USCG, good work there and > good > report. > > I also some another report showing issues with other SVNs. > > Cheers, > Magnus > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
