Data Analysis of Correlated Channels in CLIO:
Hilbert-Huang Transform View
Edwin J. Son, John J. Oh, SangHoon Oh (KGWG-NIMS) and Young-Min Kim (KGWG-PNU) In collaboration with KAGRA-detchar group
7th Korea-Japan Workshop on KAGRA 19-20 Dec. 2014 at U. of Toyama
A Brief Introduction to Hilbert-Huang Transfrom[Ref. N.E.Huang and S.S.P.Shen, Hilbert-Huang Transformation and Its Applications]
Hilbert transform [wikipedia.org]
• In mathematics and in signal processing, the Hilbert transform is a linear operator which takes a function, u(t), and produces a function, H[u](t), with the same domain.
• Complexify:
• Relationship with the Fourier transform:
Hilbert transform examples
A problem of traditional Hilbert transform
[Courtesy: Norden E. Huang]
Empirical Mode Decomposition (EMD)
[Courtesy: Norden E. Huang]
“Sifting”
[Stoppage criterion]
Intrinsic Mode Function(IMF)
[Courtesy: Norden E. Huang]
[Hilbert transform on an IMF]
Comparison between FFT and HHT
• FFT:
• HHT:
Power Spectral Density
Trigger Generation• [Ref. CISME1(2)1-6 (2011)]
• A: amplitude in a given segment
• j: index of IMFs
• M: mean value of the amplitude
• X: peaks (extrema) of amplitude
• s: index for threshold
• When amplitude exceeds the threshold, a trigger candidate is reported.
ApplicationAnalyses on CLIO data
CLIO Data Used [Courtesy: H. Yuzurihara] Operation check using CLIO’s channel data
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・CLIO detector data recorded at September 2012 two channel data : GW channel accelerometer channel・search for correlation between GW channel and accelerometer channel
Accelerometer is located near front mirror of X-arm.
http://www.icrr.u-tokyo.ac.jp/gr/GWPOHPe/clio-e.html
Interesting Data [Courtesy: H. Yuzurihara] spectrogram of each channel data
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→ → → → →→
Black arrow in right figure show hardware injection equivalent (shock chamber directly)⇒ There is this disturbance in GW channel? We search correlation using developed correlation monitor.
accelerometer channel 4~8sec
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1000
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GW channel accelerometer channel
CLIO GW Channel at 1034657664
CLIO SEI Channel at 1034657664
Thank you!
