I had an ally quest to go here and get a scanner upgrade. I assumed it was going to be on the roof but it looks like the marker is telling me to go below the floor of the main room. I don’t see the way down here. There is no stairway going down to get here.
You should be a me to find it from the ground floor. There should be two sets of double doors. One brings you outside and the other down a hall where you will eventually find the stairs down the basement