First Science Run at Livingston LIGO Observatory: Data calibration and stability

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"First Science Run at Livingston LIGO
Observatory Data calibration and stability"

• Gabriela González
• Louisiana State University

LIGO-G020503-00-Z
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S1 run Aug 23-Sept 9
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Lots of data
Triple coincidence 96 hours
http//www.phys.lsu.edu/faculty/gonzalez/S1LockSta
ts/
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Looking farther than ever before
P. Suttons SenseMonitor
Ed Daws cascaded histograms
Segment in Upper Limits Playground
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Looking for gravitational waves, finding
glitches
D. Browns inspiral event viewer
event rate
events SNR
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How far? Depends on calibration
?????
Power in the arms
Sideband power in the PRC
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Calibration? What calibration?
Seismic noise, Calibration lines, Gravitational
waves!
Interferometer!
Digital filters
Pendulums
Open Loop Gain
Calibration of AS_Q
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A simple DARN model
Rana Adhikaris Simulink model
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Why does calibration matter?
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Control room calibration
Calibration lines
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Why would calibration change?
We can get information about a from changes in
the amplitude of known displacements we push
the mirrors with sine waves, or calibration
lines.
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How much did the calibration change?
Optimal gain
possible gains
alignment
loop design
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Range, histograms, calibration
all related, but all the same?
50 kpc
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Not really gain is not the only indicator of
noise (or even a good one)
redgtblack
blackgtred
Bilinear couplings V. Chickarmane, R. Adhikari
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Conclusions

• Theres a lot of work to do!
• Understand the noise
• Dominant sources
• Not-so-dominant sources
• Model comparison
• Find out a good tracking calibration method
• Keep the alignment controlled so that the
  calibration does not change!
• Find good criteria to evaluate performance in
  REAL TIME