We are doing a project in which we are detecting (using YOLOv4) runway debris using a fixed camera mounted at a pole on the side of the runway. We want to find out the position of the object with respect to the runway surface. How can we find out the distance of the object from the runway sides?
I would recommend using reliable sensors such as "light curtains" to make sure there is no debris on a runway. AI can fail, especially if things are hard to see.
As for mapping image coordinates to world coordinates on a plane, look into "homography". OpenCV has getPerspectiveTransform. it's easiest if you pick a big rectangle of known dimensions in your scene (runway), mark the corners, find them in your picture, note those points too, and those four pairs you give to getPerspectiveTransform. now you have a homography matrix that will transform coordinates back and forth (you can invert it).
check out the tutorials section in OpenCV's documentation for more on homographies.