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NOTICE!!! THIS PROGRAM COMES WITH NO WARRANTY, TO THE EXTEND PERMITED BY LAW!

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ABC: AmBient noise and Coda

• To extract empirical green's funcions(EGFs) from seismic ambient noise or coda with seismic interferomatry method.
• Actually, it's to compute cross-correlation time functios of one station-pair.

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:one: Here is given raw data with 86400 seconds long (one day) and sampling rate of 5 Hz.

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:two: Cut coda from 10k - 40k seconds after event time.

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:three: Execute band-pass filtering with period range of 15 - 50 seconds.

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:four: Temporal normalization with run-absolute-mean method

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:five: Spectral whitening with run-absolute-mean method

results in time domain

 -

results in frequency domain

• 

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:six: Compute cross-correlation time function

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Denpendencies

• Linux or Mac OS platform;
• FFTW3 (Fast Foureier Transform in the West) ;

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Usage

abc_egf file.lst

• file.lst: sac1 sac2 year mon day hour min sec start0 cut_npts cor_name lag_time

| parameter | meaning | | --------- | -------- | | sac1 | SAC file1| | sac2 | SAC file2| | year | year of seismic event happening| | mon | month of seismic event happening| | day | day of seismic event happening| | hour | hour of seismic event happening| | min | minute of seismic event happening| | sec: | second of seismic event happening| | start0 | time of after seismic event happening| | cut_npts | points number of cutting| | cor_name | name of cross-correlation| | lag_time | lag time of cross-correlation|

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Contribution

• Author: Xuping Feng
• Email: geophydogvon@gmail.com

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Reference

Bensen, G. D., et al. "Processing seismic ambient noise data to obtain reliable broad-band surface wave dispersion measurements."  -
Geophysical Journal International 169.3 (2007): 1239-1260.