1. LIGO-G05????-00-Z Detector characterization for LIGO burst searches Shourov K. Chatterji For the LIGO Scientific Collaboration 10 th Gravitational Wave Data Analysis Workshop University of Texas at Brownsville 2005 December 14

2. LIGO-G05????-00-Z Shourov Chatterji - GWDAW10 - 2005 December 14 2 Detector characterization tasks Monitor a large number of auxiliary interferometer and environmental channels Near real time feedback for control and commissioning Histograms of trigger significance Measures of detector non-stationarity Trigger rates as a function of time Develop event based vetoes based Time lag correlation studies of veto efficiency Use simulated burst injections to test for veto safety Reject epochs of poor data quality Detailed time and frequency domain studies of interesting events

3. LIGO-G05????-00-Z KleineWelle trigger generator Identifies statistically significant clusters of signal energy in the dyadic wavelet transform of a whitened timeseries. For S4, triggers were generated for ~50 interferometer and environmental channels at each LIGO site. Online trigger production provided daily feedback for data quality investigations. Study correlation between triggers and candidate bursts to develop safe and effective event based vetoes Evaluate effect of epoch vetoes based on data quality flags (dust, enhanced seismic activity, etc.)

4. LIGO-G05????-00-Z KleineWelle daily statistics

5. LIGO-G05????-00-Z Tests for correlated triggers

6. LIGO-G05????-00-Z Event based vetoes Identify channels that show a statistically significant correlation with the gravitational-wave channel triggers Avoid false rejection by studying simulated bursts that are physically injected into the detector Unsafe channelSafe channel

7. LIGO-G05????-00-Z Data quality epoch vetoes Reject periods of anomalous detector behaviour Require a minimum epoch duration to prevent false rejection Based on kleineWelle, BurstMon, and many other studies For S4, a number of epoch vetoes were applied One of the two Hanford detectors not in lock 30 seconds before the end of each lock segment Increased seismic noise at the resonant frequency of the seismic isolation system High wind velocities at Hanford Injection of simulated gravitational wave signals For S4, repository of data quality flags maintained on-line For S5, moving to a database solution

8. LIGO-G05????-00-Z Shourov Chatterji - GWDAW10 - 2005 December 14 8 BurstMon Implementation of WaveBurst algorithm for rapid detector characterization Near real-time figure of merit for detector non-stationarity Fraction of detected events consisting of more than two time-frequency pixels:

9. LIGO-G05????-00-Z Shourov Chatterji - GWDAW10 - 2005 December 14 9 Event display Permits a detailed study of a large number of interferometer and environmental channels around the time of interesting events Results published on-line as html reports Displays lock segment information Displays time series and time-frequency spectrograms Incorporates parameter estimation for candidate events Applied to candidate events Applied to simulated burst injections For S5, automatically applied to study the most significant events on a daily basis Incorporating multiresolution Q transform spectrograms

10. LIGO-G05????-00-Z Shourov Chatterji - GWDAW10 - 2005 December 14 10 Event display

11. LIGO-G05????-00-Z Shourov Chatterji - GWDAW10 - 2005 December 14 11 Q spectrograms

12. LIGO-G05????-00-Z End

13. LIGO-G05????-00-Z Shourov Chatterji - GWDAW10 - 2005 December 14 13 Automated line-finding