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 building out the timescale ensemble at Schriever significantly over yhe last 5 or so years. They were up to 26 references planned last i spoke with anyone back home - the delta being primarily H-masers. I think that's a good move. Despite Timefreq being just about 2 hours away, that master clock's survivability was never certain. Shipping the timescale to Colorado Springs from Wisconsin Ave/Bethesda did contain risk, and they are mitigating it. I was once told - total anecdote and certainly 15 years ago - that despite proximity and willingness they rarely exchange views or collaborate experimentally between Colorado Springs and Boulder. Silly in my mind but it is an a active weapons platform and the logistics may not be conducive. NS On Friday, October 10, 2014, Brian Inglis <[email protected]> wrote: > On Oct 9, 2014, at 7:43 PM, Jim Palfreyman <[email protected]> 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) took a noticeable downward turn - on all 5 masers. >>>> >>> > On 2013-10-03 05:33, Jim Palfreyman wrote: >>>> >>> > Noticed an above average bump in our H-Maser vs GPS graphs - from sites >>>>> all over Australia. >>>>> >>>>> Recent coronal mass ejection or US government shutdown not updating >>>>> GPS? >>>>> Anyone else seen it? >>>>> >>>> > drop out gap between about 04.21-04.26 UTC? >>>> clockstats.20131003: >>>> 56568 15684.876 127.127.20.4 $GPRMC 042124 A ... >>>> 56568 16004.862 127.127.20.4 $GPRMC 042644 A ... >>>> peerstats.20131003: >>>> 56568 15684.876 127.127.20.4 961a -0.000002270 ... 0.000005344 >>>> 56568 16004.862 127.127.20.4 961a -0.000013150 ... 0.000015721 >>>> loopstats.20131003: >>>> 56568 15684.876 -0.000002270 0.899 0.000007071 0.000070 4 >>>> 56568 16004.862 -0.000013150 0.898 0.000008830 0.000114 4 >>>> >>> > >>>> Did anyone else who tracks H-masers notice this as well? >>>> >>>> Is it JPL making corrections? >>>> >>> > Le 10 oct. 2014 à 03:09, Bob Camp a écrit : >> > > 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 that link from a variety of locations. >>> Since the NIST data is independent of the steering (two different >>> outfits involved) it should not be vulnerable to a “our ground segment >>> broke and we steered everything to match” sort of error. >>> >> > On 2014-10-09 23:06, mike cook wrote: > >> I remember Jim reported a similar issue back in october last year: >> > > That dates are close enough to make you wonder if it is not part of >> some cycle. >> > > From: http://www.usno.navy.mil/USNO/time/gps/gps-info > GPS SYSTEM TIME > GPS system time is given by its Composite Clock (CC). > The CC or "paper" clock consists of all operational Monitor Station and > satellite > frequency standards. GPS system time, in turn, is referenced to the Master > Clock > (MC) at the USNO and steered to UTC(USNO) from which system time will not > deviate > by more than one microsecond. The exact difference is contained in the > navigation > message in the form of two constants, A0 and A1, giving the time > difference and > rate of system time against UTC(USNO,MC). > > Page also gives links to GPS time data ftp://tycho.usno.navy.mil/pub/ > gps/utcgps30.dat > which shows a 2ns jump in UTC(USNO)-GPS smoothed over 2 days from Oct 7-8, > but that > appears normal; the <1ns differences from Oct 2-7 appear anomalous. > > Looking at the NIST 10 min data, from Oct 3-8 the gap between GPS samples > and NIST > closed about 1.5ns/day, dropping now to about .5ns/day: the graph shows > the values > sliding down to the right, and now levelling off about zero. > > So are NIST and USNO steering each other? > > -- > Take care. Thanks, Brian Inglis > _______________________________________________ > 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.
