So, I found a way to calculate the numbers for prematching. It was actually in front of me because I made some excel documents with some stuff already.
Well this was in fact pretty obvious, if you know the GSD and the width and hight in pixels of your sensor you can easily calculate this distance. If you got an overlap of 50% and the width on the ground is 40 meter then theres 40 meters between the center of the first image to the next.
So if you got an overlap of 80% how many neighbours does an image have. 100/(100-80)=5 and 5*5-1=24. 24 isn’t totally correct but it’s pretty close, the corner overlap hasn’t been taken into account here.
If someone else has a better way to calculate it I would love to hear it!