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EHAAT
Height above average terrain (HAAT), or (less popularly) effective height above average terrain (EHAAT), is the vertical position of an antenna site is above the surrounding landscape. HAAT is used extensively in FM radio and television, as it is more important than effective radiated power (ERP) in determining the range of broadcasts ( VHF and UHF in particular, as they are line of sight transmissions). For international coordination, it is officially measured in meters, even by the Federal Communications Commission in the United States, as Canada and Mexico have extensive border zones where stations can be received on either side of the international boundaries. Stations that want to increase above a certain HAAT must reduce their power accordingly, based on the maximum distance their station class is allowed to cover (see List of North American broadcast station classes for more information on this). The FCC procedure to calculate HAAT is: from the proposed or actual anten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of North American Broadcast Station Classes
This is a list of broadcast station classes applicable in much of North America under international agreements between the United States, Canada and Mexico. Effective radiated power (ERP) and height above average terrain (HAAT) are listed unless otherwise noted. All radio and television stations within of the US-Canada or US-Mexico border must get approval by both the domestic and foreign agency. These agencies are Industry Canada/Canadian Radio-television and Telecommunications Commission (CRTC) in Canada, the Federal Communications Commission (FCC) in the US, and the Federal Telecommunications Institute (IFT) in Mexico. AM Station class descriptions All domestic (United States) AM stations are classified as A, B, C, or D. * A (formerly I) — clear-channel stations — 10 kW to 50 kW, 24 hours. **Class A stations are only protected within a radius of the transmitter site. **The old Class I was divided into three: Class I-A, I-B and I-N. NARBA distinguishe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
