Hello Alex and thank you for your question. The pos files I created were purely to easily visualise the data in Homer2 and did not have any physiological meaning. Sometimes displaying the optode array is not compatible with easily interpreting the data until you superimpose the optode locations onto a head or brain using an atlas viewer. If you have meaningful location data you may be better off going straight to the visualisation on the head/brain as the "demo" pos files are really just for people without the ability to measure locations of optodes. I hope this helps!

Rebecca