Details
| Original language | English |
|---|---|
| Article number | 102006 |
| Number of pages | 9 |
| Journal | Physical Review D |
| Volume | 101 |
| Issue number | 10 |
| Publication status | Published - 26 May 2020 |
Abstract
Longitudinal control signals used to keep gravitational wave detectors at a stable operating point are often affected by modulations from test mass misalignments leading to an elevated noise floor ranging from 50 to 500 Hz. Nonstationary noise of this kind results in modulation sidebands and increases the number of glitches observed in the calibrated strain data. These artifacts ultimately affect the data quality and decrease the efficiency of the data analysis pipelines looking for astrophysical signals from continuous waves as well as the transient events. In this work, we develop a scheme to subtract one such bilinear noise from the gravitational wave strain data and demonstrate it at the GEO 600 observatory. We estimate the coupling by making use of narrow-band signal injections that are already in place for noise projection purposes and construct a coherent bilinear signal by a two-stage system identification process. We improve upon the existing filter design techniques by employing a Bayesian adaptive directed search strategy that optimizes across the several key parameters that affect the accuracy of the estimated model. The scheme takes into account the possible nonstationarities in the coupling by periodically updating the involved filter coefficients. The resulting postoffline subtraction leads to a suppression of modulation sidebands around the calibration lines along with a broadband reduction of the midfrequency noise floor. The observed increase in the astrophysical range and a reduction in the occurrence of nonastrophysical transients suggest that the above method is a viable data cleaning technique for current and future generation gravitational wave observatories.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physics and Astronomy (miscellaneous)
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In: Physical Review D, Vol. 101, No. 10, 102006, 26.05.2020.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Bilinear noise subtraction at the GEO 600 observatory
AU - Mukund, N.
AU - Lough, J.
AU - Affeldt, C.
AU - Bergamin, F.
AU - Bisht, A.
AU - Brinkmann, Marc
AU - Kringel, V.
AU - Lück, H.
AU - Nadji, S.
AU - Weinert, M.
AU - Danzmann, K.
N1 - Funding information: We thank the GEO collaboration for the construction of GEO 600, and Walter Graßfor his work in keeping the interferometer in a good running state. N. M. expresses thanks to Denis Martynov and Gautam Venugopalan for their valuable suggestions on the filtering scheme. Special thanks go to Sumit Kumar and Bhooshan Gadre for their insights on Bayesian parameter estimation. The authors are grateful for support from the Science and Technology Facilities Council (STFC) Grant No. ST/L000946/1, the University of Glasgow in the United Kingdom, the Bundesministerium für Bildung und Forschung (BMBF), and the State of Lower Saxony in Germany. This work was partly supported by the DFG grant SFB/Transregio 7 Gravitational Wave Astronomy. This document has been assigned LIGO document number LIGO-P1900350.
PY - 2020/5/26
Y1 - 2020/5/26
N2 - Longitudinal control signals used to keep gravitational wave detectors at a stable operating point are often affected by modulations from test mass misalignments leading to an elevated noise floor ranging from 50 to 500 Hz. Nonstationary noise of this kind results in modulation sidebands and increases the number of glitches observed in the calibrated strain data. These artifacts ultimately affect the data quality and decrease the efficiency of the data analysis pipelines looking for astrophysical signals from continuous waves as well as the transient events. In this work, we develop a scheme to subtract one such bilinear noise from the gravitational wave strain data and demonstrate it at the GEO 600 observatory. We estimate the coupling by making use of narrow-band signal injections that are already in place for noise projection purposes and construct a coherent bilinear signal by a two-stage system identification process. We improve upon the existing filter design techniques by employing a Bayesian adaptive directed search strategy that optimizes across the several key parameters that affect the accuracy of the estimated model. The scheme takes into account the possible nonstationarities in the coupling by periodically updating the involved filter coefficients. The resulting postoffline subtraction leads to a suppression of modulation sidebands around the calibration lines along with a broadband reduction of the midfrequency noise floor. The observed increase in the astrophysical range and a reduction in the occurrence of nonastrophysical transients suggest that the above method is a viable data cleaning technique for current and future generation gravitational wave observatories.
AB - Longitudinal control signals used to keep gravitational wave detectors at a stable operating point are often affected by modulations from test mass misalignments leading to an elevated noise floor ranging from 50 to 500 Hz. Nonstationary noise of this kind results in modulation sidebands and increases the number of glitches observed in the calibrated strain data. These artifacts ultimately affect the data quality and decrease the efficiency of the data analysis pipelines looking for astrophysical signals from continuous waves as well as the transient events. In this work, we develop a scheme to subtract one such bilinear noise from the gravitational wave strain data and demonstrate it at the GEO 600 observatory. We estimate the coupling by making use of narrow-band signal injections that are already in place for noise projection purposes and construct a coherent bilinear signal by a two-stage system identification process. We improve upon the existing filter design techniques by employing a Bayesian adaptive directed search strategy that optimizes across the several key parameters that affect the accuracy of the estimated model. The scheme takes into account the possible nonstationarities in the coupling by periodically updating the involved filter coefficients. The resulting postoffline subtraction leads to a suppression of modulation sidebands around the calibration lines along with a broadband reduction of the midfrequency noise floor. The observed increase in the astrophysical range and a reduction in the occurrence of nonastrophysical transients suggest that the above method is a viable data cleaning technique for current and future generation gravitational wave observatories.
UR - http://www.scopus.com/inward/record.url?scp=85085977715&partnerID=8YFLogxK
U2 - 10.48550/arXiv.2001.00242
DO - 10.48550/arXiv.2001.00242
M3 - Article
AN - SCOPUS:85085977715
VL - 101
JO - Physical Review D
JF - Physical Review D
SN - 2470-0010
IS - 10
M1 - 102006
ER -