Questions about time range settings for linear fk analysis.

[shandou]

Hey guys,

I am trying to apply a varying time window on time series that are used for surface wave dispersion analysis. The ideal operations in my head would be to have a window with fixed duration T and different starting time t0. t0 can be arrival time of Rayleigh wave for each signal, or any other arrival time that I can play with, and these t0 values would have been picked on the fly in the graphic viewer, or have been written in the input file headers.

I have two questions here:

(1) Does the geopsy option on "linear f-k analysis for active experiments" allow such varying window settings described above?

(2) If I used SEGY input format, what are the header items that can be recognized by geopsy as such arrival times?

Thank you very much!

[admin]

I cannot see any standard SEGY header field that contains arrival picks. But I may be wrong. Other suggestions?

Yes, you can pick arrival times in geopsy and use these picks as the starting time of your MASW processing window. You can do it in "Pre-processing" tab, in the "Taper" parameters. After picking the beginning of the time window with time picks, start "Active linear FK" and select the beginning of taper window to be "Timepick" and its number. Probable that the best second limit for the taper window is "during".