An investigation of time-frequency domain phase-weighted stacking and its application to phase-velocity extraction from ambient noise's empirical Green's functions

Guoliang Li, Fenglin Niu*, Yingjie Yang, Jun Xie

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)
30 Downloads (Pure)

Abstract

The time-frequency domain phase-weighted stacking (tf-PWS) technique based on the S transform has been employed in stacking empirical Green's functions (EGFs) derived from ambient noise data, mainly due to its superior power in enhancing weak signals. Questions such as the induced waveform distortion and the feasibility of phase-velocity extraction are yet to be thoroughly explored. In this study, we investigate these issues by conducting extensive numerical tests with both synthetic data and USArray transportable array (TA) ambient noise data. We find that the errors in the measured phase velocities associated with waveform distortion caused by the tf-PWS depend largely on the way of how the inverse S transform (IST) is implemented. If frequency IST is employed in tf-PWS, the corresponding errors are generally less than 0.1 per cent, sufficiently small that the measured phase velocities can be safely used in regular surface wave tomography. On the other hand, if a time IST is used in tf-PWS, then the extracted phase velocities are systematically larger than those measured from linearly stacked ones, and the discrepancy can reach as much as ~0.4 per cent at some periods. Therefore, if tf-PWS is used in stacking EGFs, then frequency IST is preferred to transform the stacked S spectra back to the time domain for the stacked EGFs.

Original languageEnglish
Pages (from-to)1143-1156
Number of pages14
JournalGeophysical Journal International
Volume212
Issue number2
DOIs
Publication statusPublished - 1 Feb 2018

Bibliographical note

This article has been accepted for publication in Geophysical Journal International ©: 2017 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

Keywords

  • Time-series analysis
  • Seismic noise
  • Seismic tomography
  • Surface waves and free oscillations

Fingerprint

Dive into the research topics of 'An investigation of time-frequency domain phase-weighted stacking and its application to phase-velocity extraction from ambient noise's empirical Green's functions'. Together they form a unique fingerprint.

Cite this