Martin Hewitson

1
Overview of DC work

• Martin Hewitson

2
DC work

• Noise characterisation
• Noise projections, noise sources, noise couplings
• Calibration
• Production of h(t) and validation
• Detector operation
• Environmental effects, losses of lock, drifts and
  alignment control studies, long term effects
• Data characterisation
• Glitch rates, glitch coincidences
• Sensitivity fluctuations
• Non-stationarity
• Source sensitivity

3
Noise characterisation

• Noise projections
• Try to understand limiting noise sources
• Noise sources
• Lines, broad-band features
• Do these limit CW searches?
• Noise couplings
• Transfer functions from signal X to detector
  output
• Time-variable? Significant?
• Leads to instrumental vetoes (see previous talks
  by Ken)

4
Calibration

• Production of h(t)
• See calibration talk not repeated here
• Validation
• Validation group
• Need independent ESD calibration
• Need study of subtle artifacts
• From inverse optical-response filtering
• From up/down-sampling
• Can the c2 help as a data quality indicator?

5
Detector operation

• Environmental effects
• Temperature dependences, seismic noise, wind
• Studying losses of lock
• Operation and understanding of monitors
• Control room monitors
• GEO Summary pages
• Operational tasks
• Daily checks during science runs
• Are alignment drifts near end of range?
• Is sensitivity normal?

6
Data characterisation

• Glitch rates and coincident glitches
• Is the glitch rate too high for effective burst
  searches?
• Time and frequency variance of glitch rate
• Sensitivity fluctuations
• Non-stationary behaviour
• Do we have a measure/monitor for this? Who cares?
• (Gaussianity of individual frequency bins)
• Source sensitivity
• Monitors for each search
• We have inspiralMon only do we need others?

7
Summary

• DC work remains important
• Need task-driven DC work
• Answer questions that exist
• Clearer understanding of who should do which work
• Detector group work, analysis group work, or
  both?
• More involvement/feedback from analysis groups (?)