For both television and FM radio stations, the most significant factor affecting coverage after power is Height Above Average Terrain, or HAAT (pronounced ``hat''). Because VHF and UHF signals normally travel only in a straight line, they do not follow the curvature of the Earth but are instead radiated out into space. If a station wants to reach over the horizon and cover a large area, the easiest way to do so is to put the transmitting antenna up high, so that more of the Earth is ``visible'' to the antenna. As a result, mountain peaks and the tops of tall buildings are the favored spots for VHF and UHF broadcasting. (Some non-broadcast UHF facilities, like cellular telephone base stations, are designed to serve only a local area and don't benefit from being up high, which is why the cell antennas are typically well below the level of the FM bays on a tower that's shared by both services.)
The FCC database does not provide HAAT information for low-power TV stations. The database does give height above mean sea level for such stations, and that's what we show in the new TV dial pages, but be aware that these numbers are not directly comparable with the numbers for full-power stations. (The new dial pages are the ones which show low-power stations in a separate section. If everything is in one table, you're looking at an old dial page.)