HR: 1340h
AN: S33A-0300    [Abstracts]
TI: New Frequency-Dependent Coherence Measure for Noise Suppression in Seismic Array Data
AU: * Schimmel, M
EM: schimmel@ija.csic.es
AF: Institute of Earth Sciences Jaume Almera - CSIC, lluis Sole i Sabaris, S/N, Barcelona, 08028 Spain
AU: Gallart, J
EM: jgallart@ija.csic.es
AF: Institute of Earth Sciences Jaume Almera - CSIC, lluis Sole i Sabaris, S/N, Barcelona, 08028 Spain
AB: We introduce and discuss a new filter for seismic signal enhancement through incoherent noise attenuation. Our processing tool is designed for densely spaced arrays to identify signals by their frequency-dependent lateral phase coherence. This attribute is based on the instantaneous phases which we obtain from local spectra for the data of neighboring stations. It is used to attenuate incoherent components in the time-frequency representations of the seismic records. The final coherence filtered traces are obtained from a back transform to the time domain. This way we construct a data-adaptive filter which enhances coherent signals in single-component multi-channel data sets. In our approach, no waveforms are averaged to maintain local amplitude informations. We outline the method and show results for theoretical test data, an OBS record section from NW-Spain, and a tele-seismic event registered at Spanish broadband stations.
DE: 0910 Data processing
DE: 3270 Time series analysis (1872, 4277, 4475)
DE: 7200 SEISMOLOGY
DE: 7203 Body waves
SC: Seismology [S]
MN: Fall Meeting 2005