geopsy.org

I am trying to use geopsy to process MASW data; I open 10 signals (shots) with 24 geophones each and when I try to open the Noise reduction module to stack the signals and I get the following message:

"More than one signal per receiver detected. Make sure that the time reference is different for all individual shot. Suggestion: set preferences for loading signals to "No common time reference" and "Set "Rxxx" as name".

Well, I already checked and the suggestions are done and each shot has a different time reference... Do you have any idea why I can't open the toolbox?

Hi,

You probably get this message because the name of signals is the same for all receivers. Before importing your signals, make sure that you switch to the correct settings suitable for refraction experiments and MASW data:

• "No common time reference (leave T0 as is)"
• Set "Rxxx" as name where xxx is the receiver number"

If you do not want to re-import your signals, you can also fix it with menu "Edit/Set header" using this formula: Note that stacking in time domain for MASW is not recommended. When stacking in time you have to ensure a good trigger time. This is the reason for the "Noise Reduction" module with tab "Adjust T0". Small differences are likely to corrupt a little your waveforms. The best option is to stack in frequency domain where differences in reference time have no influence.

So process all shots separately within the MASW module: put all shots in one graphic window and run the module. Before picking the dispersion curves, choose "Stack" in "Tools" menu from the graphical results and pick it on the stacked plot (added at the end). By comparison you can pick all shots individually and average the curves. Differences might not be so significant.

Thank you! I will try it.

Hi,

I am starting to use geopsy and probably I am doing something wrong. But I have done what you told me and even used the code you sent and it keeps giving me errors. Now also when trying fk processing.

It happens also when I have only one signal opened.

Please see the attached files.

Thank you.

Good afternoon,

I keep having the same problem. Does someone know how to help me?

Thank you very much.

Hi,

Can you do the following:
- select all files as you did in the figures sent here above
- drag them to a table
- click on File/Export
- select "Table" format
- post the exported file on this forum.

Thanks

Marc