1. LIG O HW S Introduction to Bicoherence Monitors: BicoViewer & BicoMon Steve Penn (HWS)

2. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z2 Why use BicoViewer? Noise Investigations »Step 1: Power Spectral Density (PSD) investigation, done in DTT –Tells you the frequency and power of the noise –If the noise is a “known” source, then you are done »Step 2: Coherence investigation, done in DTT –Tells you the phase correlation between two channels –This gives an indication of the physical coupling between these channel source »Step 3: Bicoherence investigation, done in BicoViewer –Tells you the phase correlation phase correlation at different frequencies, possibly different channels –Indicates the coupling either in the physical system or in the sensing

3. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z3 Statistics (1) “1D” Statistics: (2 nd Order Cumulants, 1 st Order Spectra) »Correlation: »Power Spectral Density: »Coherence: –Tells us power and phase coherence at a given frequency

4. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z4 Statistics (2) “2D” Statistics: (3rd Order Cumulants, 2nd Order Spectra) »Bicumulant: »Bispectral Density: »Bicoherence: –Tells us power and phase coherence at a coupled frequency

5. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z5 Why Higher Order Statistics? For a Gaussian process: For independent processes: Allows for isolation of nonGaussian processes »Visual check of frequency coupling and phase noise »Statistical test for the probability of gaussianity and linearity »Iterative process to reconstruct nongaussian signal from the higher order cumulants

6. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z6 BicoViewer (Foreground Monitor) Plots Bicoherence (auto- or cross-) & PSD’s of input channels Proper decimation, Optimized windowing, Vectorized FFT User selects: (Channels, Frequency Range, Frequency resolution, Data Span, Overlap) Outputs GIF files. Script to make video. Table of Current and New Parameters with Accuracy & Time Estimates Plot Countdown clock Text File Output Faster Smoothing Routine Heterodyning Strip Chart for Monitoring Bicoherence of certain ROI Output calculation parameters as configuration for BicoMon

7. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z7 Current Version

8. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z8 Current Version (2)

9. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z9 H1:LSC-AS_I movie

10. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z10 H1:LSC-AS_Q movie

11. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z11 Online Demo (requires X windows) On Fortress: > /export/home/spenn/BicoViewer new version soon in DMT

12. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z12 BicoMon: Current Version Monitor integrates bicoherence over specified frequency ROI Calculates bicoherence for multiple channel combinations Integrates bicoherence over multiple specified ROI Integrates bicoherence over entire unique area (Gaussianity) Trends Data and sends to DMTviewer. Included proper decimation with filtering rather than rebinning Tests for Operational State

13. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z13 3 30 C 2 H1:LSC-AS_Q16384 H1:SUS-ITMX_OPLEV_PERROR 2048 2561.00.564 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_ALL 0 0 0 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_60_2_2 60 2 2 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_60_10_2 60 10 2 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_60_38_2 60 38 2 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_60_50_2 60 50 2 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_120_2_2 120 2 2 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_120_10_2 120 10 2 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_120_38_2 120 38 2 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_120_50_2 120 50 2 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_180_2_2 180 2 2 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_180_10_2 180 10 2 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_180_38_2 180 38 2 M Bico:H1:AS_Q-ITMX_OPLEV_PERROR_180_50_2 180 50 2 C 2 H1:LSC-AS_Q16384 H1:SUS-ITMY_OPLEV_PERROR 2048 2561.00.564 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_ALL 0 0 0 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_60_2_2 60 2 2 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_60_10_2 60 10 2 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_60_38_2 60 38 2 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_60_50_2 60 50 2 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_120_2_2 120 2 2 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_120_10_2 120 10 2 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_120_38_2 120 38 2 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_120_50_2 120 50 2 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_180_2_2 180 2 2 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_180_10_2 180 10 2 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_180_38_2 180 38 2 M Bico:H1:AS_Q-ITMY_OPLEV_PERROR_180_50_2 180 50 2 C 1 H1:LSC-AS_Q16384 2561.00.564 M Bico:H1:AS_Q_ALL 0 0 0 M Bico:H1:AS_Q_120_2_2 120 2 2 M Bico:H1:AS_Q_120_10_2 120 10 2 M Bico:H1:AS_Q_120_38_2 120 38 2 Configuration File Calculation Parameters Measurement Parameters

14. LIG O HW S LSC Meeting August 2004LIGO DCC G040410-00-Z14 Conclusions Bicoherence monitors could be a useful tool for analyzing data for glitches, gaussianity, upconversion, and chirps. We are now at sensitivity where up-converted data can be seen BicoMon operational. BicoViewer works (Beta Testers Needed). Beta Test Need: Now that the IFO is at/near a sensitivity to see bicoherence, we need people to use monitor and make bicoherence an analysis tool on par with PSDs or coherence.