I am trying to do ambient noise tomography and I am quite confused on how to perform time-frequency analysis (FTAN) as shown in figure 13b and 13d of this paper by Bensen et al.. I am using Python and Obspy to do analysis. The closest I can find is time-frequency representation from Obspy but I'm not sure if they show the same thing. My question is how can I make similars FTAN figures from a signal?
Any help would be appreciated. Thank you.