Inproceedings,
Automatic S-phase arrival determination of seismic signals using nonlinear filtering and higher-order statistics
Geoscience and Remote Sensing Symposium 2000, Proceedings IGARSS 2000, 1, page 292--294. IEEE, (July 2000)
DOI: 10.1109/IGARSS.2000.860496
Abstract
Automatic seismic P- and S-phases arrival identification has been
a challenging scientific goal for the last two decades for seismologists,
as it provides them with important seismological information. Based
on recent bibliography, various approaches result in efficient P-phase
identification, while S- phase identification is still an open problem,
since there is an overlap of the S- phase arrival and the P- phase
coda. They usually employ simple energy ratio criteria, the linear
seismic wave polarity assumption, neural networks or heuristic methods
based on seismologists' experience, but they seem to have moderate
performance, especially for noisy cases. The proposed method uses
a Wavelet Transform-based filtering technique that separates the
STationary from the NonSTationary parts of a mixed signal, namely
the WTST-NST filter, combined with Higher-Order Statistics (HOS).
Initially, the WTST-NST filter is used to remove the undesired P-phase
coda (given the P-phase arrival) and the background noise from the
seismic data. Then, the HOS are applied on the de-noised signal to
detect the S-phase arrival at the location of the maximum value of
HOS. The method has been applied on real seismic data recorded in
Greece, characterized by human experts as highly noisy cases. Experimental
results indicate that the proposed method identifies the S-phase
arrival efficiently, since evaluation analysis proves high identification
accuracy, when compared to the analysts' findings and due to its
low computational complexity, real-time implementation is feasible.
