![arXiv:2003.03596v2 [astro-ph.HE] 29 Apr 2020a near-weekly cadence, with some daily observations, until MJD 57723. From that point, it was observed nearly ev-ery day through MJD 57843.](https://static.fdocuments.us/doc/165x107/5f9ee26c4f00201b6e5b0eea/arxiv200303596v2-astro-phhe-29-apr-2020-a-near-weekly-cadence-with-some-daily.jpg)
Recent Time and Frequency Activities at PTBX-Band 15-minute means, one point per hour Sigma of...
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6th M eeting ofrepresentatives oflaboratories contributing to TAI,2004/03/31 TW STFT between USNO andPTB: Recentcalibration Results USNO •Time linksbetweenUSNO andPTB •TWSTFT X-band /Ku-band •Recentcalibration exercises
Transcript of Recent Time and Frequency Activities at PTBX-Band 15-minute means, one point per hour Sigma of...
6th M eeting of representatives of laboratoriescontributing to TAI, 2004/03/31
TW STFT betw eenUSNO and PTB:
Recent calibration Results
USNO
•Tim e links betw een USNO and PTB
•TW STFT X-band /Ku-band
•Recent calibration exercises
Time LinksUSNO
CalibrationUSNO
4 calibrationexercises usingFly-away X-band station from USNO:
June 2002January 2003July 2003March 2004
CalibrationUSNOJune 2002Determination ofCALR value
January 2003Perfect agreement with previous calibration result
July 2003No results
March 2004Preliminary evaluationshows agreement at 1 ns level.
TWSTFT X-band PerformanceUSNOX-band MC2 - HM(PTB)nominal 24 sessions/dayduration 15 min/session
Sample data Jan- Feb 2004
TWSTFT USNO(MC2) - H4(PTB)X-Band 15-minute means, one point per hourSigma of individual measurement results STDev of observations around daily linear regression
MJD53010 53030 53050 53070
σ / n
s
0.0
0.2
0.4
0.6
0.8
1.0
MJD_Xobs vs Sigma_indiv MJD_Day vs STDev_Day
USNOKu-bandschedule: daily4 points/day
X-band7 points/weekmidpoint of dailylinear regression
TWSTFT Results
Ku X
Jan. 2004 Feb 2004
USNO TWSTFT Results
Double difference
daily points:
mean: 0.26 nssigma: 0.82 ns
equivalent to0.6 ns foreach link
03/2003 01/2004
Calibration ExerciseUSNOUSNO TWSTFT X-band fly away station at PTB
Calibration March 2004USNO
Ku-band X-band
Fly-away
Session
Calibration March 2004USNO
Ku
X
Summary of CalibrationsUSNO
Calibration failed
IntelsatSatellitechange
ConclusionUSNO
Intelsat satellite change had caused interruption of US -EU link,X-band link interrupted because of hardw are failure
G PS CV TAIP3 link used to bridge the IS gap (Piester, PTTI2003).
M arch 2004 calibration successful,
Final results and determ ination of a new CALR value after closure m easurem ents, i.e. w hen FX is back at USNO
Apparent error of the currently applied CALR about1-2 ns.
Further analysis: Stability of TAI P3 link and G PS CV link
• USNO A. M cKinley, P.W heeler, A.Sm ith, E.New m an, G . Luther, D. M atsakis
• VSL G . de Jong (support during satellite change)
• BKG U. Hessels (operation of geodetic G PS)
• BIPM G . Petit (TAI P3 processing)
• PTB D. Piester, J. Becker, T. Polew ka
AcknowledgementsUSNO
