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Improving signal-to-noise ratios of ambient noise cross-correlation functions using local attributes
  • Bin He,
  • Hejun Zhu,
  • David E Lumley
Bin He
University of Texas at Dallas
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Hejun Zhu
University of Texas at Dallas

Corresponding Author:[email protected]

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David E Lumley
University of Texas at Dallas
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Abstract

For seismographic stations with short acquisition duration, the signal-to-noise ratios (SNRs) of ambient noise cross-correlation functions (CCFs) are typically low, preventing us from accurately measuring surface wave dispersion curves or waveform characteristics. In addition, with low-quality CCFs, it is difficult to monitor temporal variations of subsurface physical states or extract relatively weak signals such as body waves. In this study, we propose to use local attributes to improve the SNRs of ambient noise CCFs, which allows us to enhance the quality of CCFs for stations with limited acquisition duration. Two local attributes: local cross-correlation and local similarity, are used in this study. The local cross-correlation allows us to extend the dimensionality of daily CCFs with computational costs similar to global cross-correlation. Taking advantage of this extended dimensionality, the local similarity is then used to measure non-stationary similarity between the extended daily CCFs with a reference stacking trace, which enables us to design better stacking weights to enhance coherent features and attenuate incoherent background noises. Ambient noise recorded by several broadband stations from the USArray in North Texas and Oklahoma, the Superior Province Rifting EarthScope Experiment in Minnesota and Wisconsin and a high-frequency nodal array deployed in the San Bernardino basin are used to demonstrate the performance of the proposed approach for improving the SNR of CCFs.
29 Nov 2023Submitted to ESS Open Archive
01 Dec 2023Published in ESS Open Archive