Train traffic has been recognized as a useful noise source for subsurface imaging using seismic interferometry method. Compared with other ambient noise, train traffic has a striking feature of sharp equidistant spectral lines in a broadband spectrum. However, little attention has been paid to this characteristic during seismic wave retrieval. The aim of this study is to investigate the influence of the train traffic characteristics on the seismic interferometry method. After analyzing the cross correlation of the train-induced vibrations at two receivers, we find that the train traffic noise introduces cross terms that are non-negligible for reflection wave retrieval, but can be suppressed for direct wave, scattered wave and refraction wave retrieval. Field data validate these findings. We further demonstrate that the retrieved surface wave can be used to estimate near-surface velocities and the retrieved scattered surface wave can be used to locate near-surface heterogeneous bodies.
Presentation Date: Monday, October 12, 2020
Session Start Time: 1:50 PM
Presentation Time: 2:40 PM
Presentation Type: Oral