Re: [time-nuts] GPS jump

2014-10-12 Thread Magnus Danielson
of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 09, 2014 4:43 PM Subject: [time-nuts] GPS jump Folks, We look after 5 separate hydrogen masers spread all over Australia and we collect tic phases between the masers and the GPS. On around ~Oct 7 we have

Re: [time-nuts] GPS jump

2014-10-11 Thread Hal Murray
gign...@gmail.com said: Is it actually possible to phase lock two oscillators together cross the distance from DC to Colorado Springs? (2400 kilometers or so). ? I think so - if your clocks are stable enough. There is probably a simple rule for PLL stability based on round-trip-time and

Re: [time-nuts] GPS jump

2014-10-11 Thread Brian Inglis
On 2014-10-11 00:49, Hal Murray wrote: gign...@gmail.com said: Is it actually possible to phase lock two oscillators together cross the distance from DC to Colorado Springs? (2400 kilometers or so). ? I think so - if your clocks are stable enough. There is probably a simple rule for PLL

Re: [time-nuts] GPS jump

2014-10-11 Thread Jim Palfreyman
measurement time-nuts@febo.com Sent: Thursday, October 09, 2014 4:43 PM Subject: [time-nuts] GPS jump Folks, We look after 5 separate hydrogen masers spread all over Australia and we collect tic phases between the masers and the GPS. On around ~Oct 7 we have noticed that the normal

Re: [time-nuts] GPS jump

2014-10-11 Thread Bob Camp
Hi On Oct 10, 2014, at 11:20 PM, Brian Inglis brian.ing...@systematicsw.ab.ca wrote: On Oct 9, 2014, at 7:43 PM, Jim Palfreyman jim77...@gmail.com wrote: We look after 5 separate hydrogen masers spread all over Australia and we collect tic phases between the masers and the GPS. On

Re: [time-nuts] GPS jump

2014-10-11 Thread Magnus Danielson
Hal, On 10/11/2014 08:49 AM, Hal Murray wrote: gign...@gmail.com said: Is it actually possible to phase lock two oscillators together cross the distance from DC to Colorado Springs? (2400 kilometers or so). ? I think so - if your clocks are stable enough. There is probably a simple rule

Re: [time-nuts] GPS jump

2014-10-11 Thread Bob Camp
Hi To the extent that anything *is* locked, it’s been done for a lot longer than the 1980’s. Long before common view GPS, Loran-C observations (and corrections via clock trips) were used. You can look at it as a PLL, just a *very* fancy one with *very* long time constants. Bob On Oct 11,

Re: [time-nuts] GPS jump

2014-10-11 Thread Jim Lux
On 10/11/14, 8:08 AM, Bob Camp wrote: Hi To the extent that anything *is* locked, it’s been done for a lot longer than the 1980’s. Long before common view GPS, Loran-C observations (and corrections via clock trips) were used. You can look at it as a PLL, just a *very* fancy one with *very*

Re: [time-nuts] GPS jump

2014-10-11 Thread Bob Camp
Hi The interesting thing about keeping ensembles of primary standards in line is that the boundary between “post processing” and “real time” blurs quite a bit. Looking at the papers, in many cases they are looking at all of what’s gone on over the last year or two and guessing at what will

Re: [time-nuts] GPS jump

2014-10-10 Thread Brian Inglis
On Oct 9, 2014, at 7:43 PM, Jim Palfreyman jim77...@gmail.com wrote: We look after 5 separate hydrogen masers spread all over Australia and we collect tic phases between the masers and the GPS. On around ~Oct 7 we have noticed that the normal steady straight line (with standard daily noise)

Re: [time-nuts] GPS jump

2014-10-10 Thread Neil Schroeder
I'm trying to determine semantics and I was likely mistaken. They regularly update them both a variety of technologies - TWTCC and others. Then DC of course sends to COS. Is it actually possible to phase lock two oscillators together cross the distance from DC to Colorado Springs? (2400

Re: [time-nuts] GPS jump

2014-10-10 Thread Neil Schroeder
No. They don't directly if that's what you mean. They do regular time transfers, likely more regularly than most due to accessibility to a common view and common interest. The GPS consolation is actually a sub-(sub?)-scale of UTC(USNO_MC) called i think USNO_OSC? Have to check. They have been

[time-nuts] GPS jump

2014-10-09 Thread Jim Palfreyman
Folks, We look after 5 separate hydrogen masers spread all over Australia and we collect tic phases between the masers and the GPS. On around ~Oct 7 we have noticed that the normal steady straight line (with standard daily noise) took a noticeable downward turn - on all 5 masers. Did anyone

Re: [time-nuts] GPS jump

2014-10-09 Thread John C. Westmoreland, P.E.
Hello Jim, I am just a novice here - but, when you say noticeable, can you please tell us how noticeable? What is a small downturn vs. a noticeable one? I just put up an outdoor GPS antenna. If there is anything I can do to possibly help, please give me instructions. I do not have direct

Re: [time-nuts] GPS jump

2014-10-09 Thread Bob Camp
Hi GPS is steered by the Air Force last time I checked. A really good place to check is the NIST Time and Frequency pages that show both real time and historical data for each GPS sat compared to NIST time: http://www.nist.gov/pml/div688/grp40/gpsarchive.cfm Hopefully it’s accessible via

Re: [time-nuts] GPS jump

2014-10-09 Thread mike cook
Le 10 oct. 2014 à 03:09, Bob Camp a écrit : Hi GPS is steered by the Air Force last time I checked. A really good place to check is the NIST Time and Frequency pages that show both real time and historical data for each GPS sat compared to NIST time: