I had a look at this particular tutorial on ObsPy regarding Beamforming FK analysis. I had a few questions regarding the same.
- The output of the FK analysis algorithm is the Slowness,the back-azimuth and the corresponding power. This tells us the angle at which the source is present taking the center of the array geometry as the origin and the velocity of the wave which was received on site. My question is that, how to convert the Slowness vs Backazimuth plot to a X distance vs Y distance color map?
- Where do we use the information that there are surface waves too since we only look at the vertical components and not the radial ones of the seismometer?
Any help, clarification or resource provision would be highly appreciated! Forgive me for my insufficient knowledge about the topic since this isn’t my major.
Thank you 
Link : https://docs.obspy.org/tutorial/code_snippets/beamforming_fk_analysis.html