Height above average terrain

Height above average terrain (HAAT), or (less popularly) effective height above average terrain (EHAAT), is a measure of how high 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 antenna site, either 12 or 16 radials were drawn, and points at 2, 4, 6, 8, and 10 miles (16 km) radius along each radial were used. The entire radial graph could be rotated to achieve the best effect for the station. The altitude of the antenna site, minus the average altitude of all the specified points, is the HAAT. This can create some unusual cases, particularly in mountainous regions—it is possible to have a negative number for HAAT (the transmitter would not be located underground, but rather in a valley, with hills on both sides taller than the transmitter itself, for example).

The FCC has divided the Contiguous United States into three zones for the determination of spacing between FM and TV stations using the same frequencies. FM and TV stations are assigned maximum ERP and HAAT values, depending on their assigned zones, to prevent co-channel interference.

US FM broadcast zones
FM broadcast zones in the U.S.

The FCC regulations for ERP and HAAT are listed under Title 47, Part 73 of the Code of Federal Regulations (CFR).

FM

Zones I and I-A

  • Maximum HAAT: 150 metres (492 ft 2 in)
  • Maximum ERP: 50 kilowatts (47dBW)
  • Minimum co-channel separation: 241 km (150 mi)

Zones II and III

  • Maximum HAAT: 600 metres (1,968 ft 6 in)
  • Maximum ERP: 100 kilowatts (50dBW)
  • Minimum co-channel separation: 290 km (180 mi).

TV

In all zones, maximum ERP for analog TV transmitters is as follows:

  • VHF 2-6: 100 kilowatts (50dBW) (analog); 45 kilowatts (46.5dBW) (digital)
  • VHF 7-13: 316 kilowatts (55dBW) (analog); 160 kilowatts (52dBW) (digital)
  • UHF: 5,000 kilowatts (67dBW) (analog); 1,000 kilowatts (60dBW) (digital)

Maximum HAAT

  • Zone I: 305 metres (1,000 ft 8 in)
  • Zones II and III: 610 metres (2,001 ft 4 in)

Minimum co-channel separation

Band Zone I Zone II Zone III
VHF 272.7 km
(169.5 miles)
304.9 km
(189.5 miles)
353.2 km
(219.5 miles)
UHF 248.6 km
(154.5 miles)
280.8 km
(174.5 miles)
329.0 km
(204.5 miles)

Zone layouts

Zone I (the most densely populated zone) consists of the entire land masses of the following states: Connecticut, Delaware, Illinois, Indiana, Maryland, Massachusetts, New Jersey, Ohio, Pennsylvania, Rhode Island, and West Virginia; in addition to the northern and eastern portions of Virginia; the areas of Michigan and southeastern Wisconsin south of 43° 30' north latitude; the coastal strip of Maine; the areas of New Hampshire and Vermont south of 45° north latitude; and the areas of western New York south of 43° 30' north latitude and eastern New York south of 45° north latitude. In addition, Zone I-A (FM only) consists of all of California south of 40° north latitude, Puerto Rico and the U.S. Virgin Islands (If the dividing line between Zones I and II runs through a city, that city is considered to be in Zone I.).

Zones I and I-A have the most "grandfathered" overpowered stations, which are allowed the same extended coverage areas that they had before the zones were established. One of the most powerful of these stations is WBCT in Grand Rapids, Michigan, which operates at 320,000 watts and 238 meters (781 ft) HAAT.

Zone III (the zone with the flattest terrain) consists of all of Florida and the areas of Alabama, Georgia, Louisiana, Mississippi, and Texas within approximately 241.4 kilometers (150.0 mi) of the Gulf of Mexico.

Zone II is all the rest of the Continental United States, Alaska and Hawaii.

See also

External links

CKQM-FM

CKQM-FM is a Canadian radio station, broadcasting at 105.1 FM in Peterborough, Ontario. Owned by Bell Media, the station airs a country music format branded as Country 105. The station was launched in 1977 and is a sister station of CKPT-FM.

On March 24, 2009, CKQM-FM received approval by the CRTC to decrease the effective radiated power from 50,000 watts to 7,500 watts, and increasing height above average terrain from 91.5 to 277.5 meters. In FM Broadcasting effective radiated power is Inversely proportional to antenna height.

On May 28, 2019, CKQM-FM and many other Bell Media owned country music radio stations rebranded as "Pure Country."

KAJE

KAJE (107.3 MHz, "My Country 107.3") is a commercial FM radio station licensed to Ingleside, Texas. The station serves the Corpus Christi metropolitan area with a classic country radio format. The station is currently owned by John Bushman through licensee ICA Radio, Ltd. The station carries the syndicated "Big D and Bubba" morning show based in Nashville.

KAJE's studios and offices are located on North Upper Broadway in Corpus Christi. The transmitter is off Avenue B in Ingleside. The station broadcasts at 14,000 watts effective radiated power from a tower 446 feet in height above average terrain.

KBYN

KBYN (95.9 FM) is a radio station broadcasting a Regional Mexican format. Licensed to Arnold, California, United States, the station serves the Modesto area. The station is currently owned by La Favorita Radio Network, Inc.On December 30, 2014 KBYN was granted a Federal Communications Commission construction permit to move to a new transmitter site, change the community of license to City of Angels, California (aka Angels Camp), decrease the effective radiated power to 240 watts and increase the height above average terrain to 488 meters.

KCOB-FM

KCOB-FM (95.9 FM) is a commercial radio station that serves the community of Newton, Iowa. The station primarily broadcasts a country music format, but also provides local and national news, weather and sports. KCOB is owned by Alpha Media, through licensee Alpha Media Licensee LLC.

The station also broadcasts the St. Louis Cardinal baseball games, as well as the Newton High School football and basketball games.

The transmitter and broadcast tower are located north of Newton. According to the Antenna Structure Registration database, the tower is 93 metres (305 feet) tall with the FM broadcast antenna mounted at the 89 metres (292 feet) level. The calculated Height Above Average Terrain is 108 metres (354 feet). The tower is also used as the antenna system for its sister station, KCOB (AM).

KDFR

KDFR (91.3 FM) is a radio station that serves the Des Moines, Iowa and central Iowa area. The station broadcasts a Religious format & is licensed to Family Stations, Inc.

The transmitter and broadcast tower are in east Des Moines near the intersection of NE 23rd Ave and NE 44th Court. According to the Antenna Structure Registration database, the tower is 153 m (502 ft) tall with the FM broadcast antenna mounted at the 146 m (479 ft) level. The calculated Height Above Average Terrain is 136 m (446 ft).

The station airs a mix of Christian ministry programmes from noted teachers like R.C. Sproul, Alistair Begg, Ken Ham, John F. MacArthur, Dennis Rainey, John Piper, & others as well as music by Sovereign Grace Music, Keith & Kristyn Getty, The Master's Chorale, Fernando Ortega, Chris Rice, Scott Krippayne, & others.

KEFX

KEFX is a radio station broadcasting from Twin Falls, Idaho, United States, and airing a Christian Rock format. The station operates on a frequency of 88.9 MHz FM with an effective radiated power of 100 kW at 302 meters height above average terrain and is owned by The River Christian Fellowship, formerly Calvary Chapel of Twin Falls. KEFX is the flagship station of Effect Radio, and its broadcast is sent to two other full powered stations and 53 translators across the United States. It is a sister station to KAWZ, which is the flagship station of the more widely distributed CSN International.

KEMP

KEMP (99.3 MHz) is a commercial FM radio station broadcasting a Top 40 music format. Licensed to Payson, Arizona, United States, the station is currently owned by Kemp Broadcasting & Digital Media.The station has a construction permit to increase it signal strength to 50,000 watts effective radiated power (ERP) and increase its tower height above average terrain (HAAT) to 459 feet (140 meters).

KIAI

KIAI (93.9 FM) is a commercial radio station that serves the areas of Mason City, Iowa and Austin–Albert Lea, Minnesota. The station broadcasts a Country format. KIAI is owned by Alpha Media, through licensee Digity 3E License, LLC, which owns several other radio stations in Iowa and Minnesota.

The station was originally licensed as KNIQ on April 9, 1985 but changed callsigns to KIAI on October 4, 1991.The transmitter and broadcast tower are located 4 miles east of Mason City along 280th Street. According to the Antenna Structure Registration database, the tower is 244 m (801 ft) tall with the FM broadcast antenna mounted at the 229 m (751 ft) level. The calculated Height Above Average Terrain is 241 m (791 ft).

KICD-FM

KICD-FM (107.7 FM) is a radio station licensed to serve the community of Spencer, Iowa. The station broadcasts a country music format. KICD is licensed to Saga Communications of Iowa, LLC.

The studio, transmitter and broadcast tower are located on the north side of Spencer along U.S. Route 71. According to the Antenna Structure Registration database, the tower is 120 m (394 ft) tall with the antenna array mounted at the 102 m (335 ft) level. The calculated Height Above Average Terrain is 87 m (285 ft). The tower is also used by its sister station KICD (AM).

KLFG

KLFG (89.5 FM) is a radio station that serves the Fort Dodge, Iowa area. The station broadcasts a Contemporary Christian music format airing Educational Media Foundation's K-Love network programming.

The transmitter and broadcast tower are located four miles north of Badger, Iowa along Hwy P52. According to the Antenna Structure Registration database, the tower is 183 m (600 ft) tall with the FM broadcast antenna mounted at the 113 m (371 ft) level. The calculated Height Above Average Terrain is 111 m (364 ft).

On May 29, 2015, Family Stations, Inc. filed an application to sell the then-KIFR, KEAF and four translators to Educational Media Foundation. KIFR would air EMF's K-Love network. Educational Media bought the six licenses for $553,750.The station changed its call sign to the current KLFG on November 20, 2015, coincident with the consummation of the sale to EMF.

KLQP

KLQP is a 25,000 watt commercial FM radio station which operates on 92.1 mhz with an antenna 91 meters height above average terrain from Madison, Minnesota (with a remote studio in Dawson, Minnesota). The station was put on the air on January 31, 1983 by Maynard Meyer and Terry Overlander who still own and operate the station as Lac Qui Parle Broadcasting Co., Inc. KLQP, also known as "Q-92" serves a 5-county area in western Minnesota and part of eastern South Dakota.

KSKS

KSKS (93.7 MHz) is a commercial FM radio station located in Fresno, California. The station is owned by Cumulus Media and it airs a country music radio format branded as "Kiss Country". Its studios are located at the Radio City building on Shaw Avenue in North Fresno and its transmitter is off Auberry Road in Meadow Lakes, California. 93.7 Kiss Country has local DJs during the day and in the evening runs the syndicated Nash Nights with Shawn Parr from Nash FM, a subsidiary of Cumulus Media.

KSKS is licensed to broadcast in the HD (digital hybrid) format. As one of the oldest FM stations in the Fresno media market, the station is considered a grandfathered superpower station. Its effective radiated power is 68,000 watts at a height above average terrain of 580 meters (1,903 feet). Stations at that height in Central California should run less than 3,000 watts, according to current Federal Communication Commission rules for Class B regions. But KSKS went on the air in 1946, founded before the rules were put in place.

KSPE

KSPE (94.5 FM, "La Musical 94.5 FM") is a commercial radio station that is licensed to Ellwood, California, a district of Goleta in Santa Barbara County. It is owned by Rincon Broadcasting and broadcasts a classic regional Mexican music format. The KSPE studios and offices are on East Cota Street in Santa Barbara and the transmitter is located on West Camino Cielo in the Los Padres National Forest. While the station's effective radiated power is only 810 watts, the tower is 2,949 feet (899 m) in height above average terrain, making KSPE a Class B FM station covering the Santa Barbara radio market and parts of Ventura-Oxnard.

WBXA-CD

WBXA-CD is a low-power, Biz Television-affiliated television station licensed to Birmingham. Owned by L4 Media Group, it broadcasts a standard definition digital signal on UHF channel 24 from a transmitter located along Golden Crest Drive atop Red Mountain in southern Birmingham. The height above average terrain for WBXA-CD is 380 feet.

WDEN-FM

WDEN-FM (99.1 MHz, "#1 Country FM 99 WDEN") is a commercial radio station licensed to Macon, Georgia. The station is owned by Cumulus Media and the broadcast license is held by Cumulus Licensing, LLC. WDEN airs a country music radio format. The studios and offices are on Mulberry Street.

WDEN-FM has an effective radiated power (ERP) of 100,000 watts, the maximum permitted for non-grandfathered FM stations. It uses a tower that is 177 meters (581 feet) in height above average terrain (HAAT). The transmitter is off Ocmulgee East Boulevard (Route 87), near Interstate 16 in Macon.

WKSB

WKSB (102.7 FM, "Kiss 102.7") is a commercial FM radio station licensed to serve Williamsport, Pennsylvania. The station is owned by iHeartMedia, Inc., through licensee Clear Channel Broadcasting Licenses, Inc., and broadcasts a Hot Adult Contemporary format. Its broadcast tower is located on Bald Eagle Mountain south of Williamsport at (41°11′24.7″N 76°58′46.2″W).WKSB is a grandfathered “superpower” station. The station’s effective radiated power (ERP) exceeds the maximum limit allowed for a Class B FM station, and is also far above the maximum allowable ERP for its antenna height above average terrain (HAAT) according to current FCC rules.

WPCV

WPCV (97.5 FM, "97.5 WPCV") is a country music station owned and operated by Hall Communications. WPCV is licensed in Winter Haven, Florida, with studios in Lakeland, and transmitting facilities east of Haines City.

While the station predominantly covers Polk County, WPCV also serves listeners in the greater Orlando area, as well as many parts of the Tampa Bay area. With its transmitter located in the central part of Florida, broadcasting at 100,000 watts effective radiated power at 310 meters height above average terrain, WPCV is one of very few radio stations in Central Florida to reach both Atlantic and Gulf coasts.

WPCV has operated a country music format under its current calls since 1975. Previous to that, the station played beautiful music as WHFL, and prior to that the station was known as WINT-FM and WXKL.

WRTO-FM

WRTO-FM (98.3 MHz "Mix 98.3") is a commercial FM radio station licensed to Goulds, Florida, and serving the Miami-Fort Lauderdale-Hollywood radio market. The station airs a tropical music radio format, broadcasting in Spanish. It is owned by Univision Radio under the name Univision Radio Illinois, Inc.WRTO-FM's studios and offices are in Coral Gables and the transmitter is off Coconut Palm Drive (SW 248th Street) in Homestead. WRTO-FM is a Class C FM station with an effective radiated power (ERP) of 100,000 watts from a tower at 1407 feet (429 m) in height above average terrain (HAAT). The signal reaches from north of Fort Lauderdale to Marathon Key.The station also broadcasts using the HD radio format. Its logo looks similar to WKAQ-FM in San Juan, Puerto Rico and KBBT in San Antonio, Texas.

WYFL

WYFL (92.5 FM) is a noncommercial radio station broadcasting a religious format. Located near Henderson, North Carolina, United States, it serves the Raleigh-Durham, North Carolina area. The station is owned by Bible Broadcasting Network.

The transmitter and broadcast tower are located about ten miles southeast of Henderson. According to the Antenna Structure Registration database, the tower is 293 m (961 ft) tall with the FM broadcast antenna mounted at the 284 m (932 ft) level. The calculated Height Above Average Terrain is 311 m (1,020 ft). The FM antenna array is a FM10/8 manufactured by SWR.

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