f-k and phase velocity-wavelength graph in Geopsy/DINVER

[Aniket19061990]

Hello.
I am using Geopsy and DINVER 3.3.6. For active MASW, I can generate image between Rayleigh wave phase velocity and frequency. However, I also want to get the frequency-wavenumber image and the phase velocity-wavelength image and also want to extract curve (data points) in frequency-wavenumber image and the phase velocity-wavelength domain in both Geopsy and DINVER, just as we extract (pick/auto-pick) dispersion curve from the dispersion image. How to do that?

Thanks in advance.
Aniket desai

[admin]

Hi,

For passive FK, it is possible to plot results with various formats (gphistogram). However, for MASW, this would require an additional option for the output plots. I keep your suggestion in mind.

For the inversion. not simply plotting but computing the misfit in velocity-wavelength would require an in depth re-writing. This not straight forward because the frequency is the primary parameter for computing a theoretical dispersion. The core dispersion computation could be also based on wavelength but the current algorithm for dispersion computation is complex (modal separation) and it is now stable and validated after years of adjustments. I'm not going to touch it in the next years. So currently, I cannot answer to the question, "What is the theoretical velocity at a wavelength of X m?", without an iterative process: bracket the wavelength between two frequency values and refine.

Everything is possible, but it needs time. The source code is open, everybody can explore and develop his/her own options.

Best regards,

Marc