Re: Getting dispersion from a soil profile?

Pourya · Post by **Pourya** » Wed Nov 02, 2022 8:58 pm

Hi Marc,

I was wondering if it is possible in geospy/dinver to define a soil profile (different layers with different velocities) and then get its dispersion? I am working on a borehole data and have calculated the velocities based on it. however, want to get the first idea of its dispersion before running the goopy procedure based on the receivers

Pourya · Post by **Pourya** » Fri Nov 04, 2022 4:12 pm

Hi Marc,

I noticed that I can use gpdc to get the dispersion curve out of my own 1D soil profile. This is the txt file that i use (I attached it here); basically, i want two layers over half space (3 layers overall) with these data:
# depth vs vp density
2 200 400 2500
3 400 800 2500
0 2000 1000 2500
when i use the command "gpdc < test.model | figue -c" , this is the result:

result.PNG: (53.37 KiB) Not downloaded yet

What do the Y and X axis show? it should be the phase velocity vs frequency but it is nonsense to me. The y axis does not represent the phase velocity!

Post by **admin** » Mon Nov 07, 2022 10:22 am

Hi,

The dispersion curve calculated by gpdc is in slowness versus frequency. figue takes these values without any transformation. If you want to plot velocity versus frequency, you can change the axis scales (item "Properties" in context menu, right click). Usually, I use log scale for X and inverse log for Y.

Best regards,

Marc

Pourya · Post by **Pourya** » Mon Nov 07, 2022 3:15 pm

Thank You Marc