Radio altimeters work on the principle of bouncing radio waves off the ground to get the actual height above ground.
So say, there's a huge building that's a few hundred metres wide and say 50 metres high( like a hangar or a factory) and under the approach path of the a/c below 2500 feet, would the RA reading be affected ? I don't think it does as i've seen a/c approach paths over such buildings, but why ?
