Values for antenna height above average terrain (commonly abbreviated "HAAT") can be calculated using this form. Two terrain databases are available here: the FCC's legacy 30-second terrain database, and the GLOBE 1 km Base Elevation database from the National Geophysical Data Center. Using GLOBE, HAAT values can be calculated for any location on Earth, given coordinates and an antenna radiation center height above mean sea level (usually correlating to the physical center of the antenna). More about HAAT below the form.
For more information on AM and FM radio broadcasting, please visit the Audio Division website, and the Broadcast Radio Links page.
For more information on Television broadcasting, please visit the Video Division website.
FCC > Media Bureau > Audio Division, (202) 418-2700, and Video Division, (202) 418-1600.