From the roof of a 25 floor building in New Brunswick, NJ, I get Philadelphia stations like locals from 65 miles away, New York stations are very strong 25 miles away. A 50000 watt station from Delaware, 100 miles away, comes in consistently. I can see the Empire State Building from the roof. A 50000 watt station 20 miles away overloads my radio. 98.1 from Philly comes in well, despite a 98.3 from New Brunswick just a mile away. On the ground, only 98.3 overloads my radio, but on top, lots more stations overload my radio. A Class A 40 miles away comes in well, and it doesn't come in at all on the ground except during tropo. I can get my 10 watt high school station from 25 miles away on top of that building, and that station fades out on the ground after 3 miles and is gone at 7 miles.
There's a wireless router on a top floor, and I can get wireless internet half a mile away. A 1 watt station on top of this building would go very far.
When the tropo hits, I can get several stations on each frequency, all of them strong. However, e-skip is better heard on the ground because the skip comes from the sky and the local stations are weaker on the ground.
In a 11-floor parking garage, there is no reception on the 1st floor, not even the strongest station. On the 11th floor, the reception is impressive.