TWSTFT

1
TWSTFT
USNO
TWSTFT between USNO and PTB
TWSTFT Working Group Meeting 14-15 October
2004 Tokyo Dirk Piester
2
TWSTFT
USNO
TWSTFT between USNO and PTB
USNO Angela McKinley, Eric Newman, Blair
Fonville, Alan Smith, Demetrios
Matsakis PTB Jürgen Becker, Thomas Polewka,
Andreas Bauch, Dirk Piester
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TWSTFT
USNO
number of sessions per day nominal 24 mean 2002 2
2.3 2003 19.6 2004 20.4 total 20.2 standard
deviation around daily linear regression mean 2002
0.514 ns 2003 0.314 ns 2004 0.241
ns total 0.310 ns
X-band link USNO-PTB
4
USNO
TWSTFT
Two USNO calibration exercises at PTB in 2004
First exercise 8-10 March Five sessions with
different setup configurations UTC(PTB) -
MC2(USNO) X-band - trav. st. 1.2 ns Ku-band -
trav. st. 1.7 ns
Ku-band
X-band
trav. st.
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USNO
TWSTFT
USNO calibration exercises at PTB in 2004
Second exercise 20-21 September (preliminary
results) UTC(PTB) - MC2(USNO) X-band - trav. st.
1.3 ns Ku-band - trav. st. 16.1 ns
Ku-band const.
X-band
trav. st.
6
USNO
TWSTFT
USNO calibration exercises at PTB in 2004
Second exercise 20-21 September (preliminary
results) UTC(PTB) - MC2(USNO) X-band - trav. st.
1.3 ns Ku-band - trav. st. 16.1 ns
X-band
trav. st.
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USNO
TWSTFT
USNO calibration exercises at PTB in 2004
March 2004 Sept. 2004 Difference X-band -
trav. st. 1.2 ns 1.3 ns 0.1 ns Ku-band - trav.
st. 1.7 ns 16.1 ns 14.4 ns
X-band link calibration verified below one
nanosecond Ku-band link recalibrated
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USNO
TWSTFT
Transponder change on the transatlantic Ku-band
link
Ku-band calibration recoverable UTC(PTB) -
MC2(USNO) UTC(PTB) - MC2(USNO) - 14.4
ns Right graph shows effect of the 14.4 ns on
NIST/PTB data.
9
USNO
TWSTFT
Long term comparison of Ku-band with X-band
Since 2002 four successful transatlantic
calibration campaigns were performed by USNO.
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USNO
TWSTFT
Long term comparison of Ku-band with X-band
X-band bridged with TAIP3
annual periodicity visible in double difference
Ku-band - X-band peak-to-peak amplitude 1.1
ns periodicity 359 days
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USNO
TWSTFT
H-maser and link stability
Relative frequency instability derived from
X-band raw data and double difference Ku-band -
X-band MC2(USNO) - UTC(PTB) in the period from
December 2003 until September 2004