That would be if it were straight overhead, intersecting tangentially with another sphere. Realistically they're not overhead, but if two satellites are 30 degr

That would be if it were straight overhead, intersecting tangentially with another sphere. Realistically they're not overhead, but if two satellites are 30 degrees apart, the line of intersection between their spheres will move twice the distance one of the spheres moves. The magnifying factor is 1/sin(angle between the satellites from the observer).