The Air Route Surveillance Radar is a long-range

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

system. It is used by the

United States Air Force The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...

and the

Federal Aviation Administration The Federal Aviation Administration (FAA) is a Federal government of the United States, U.S. federal government agency within the United States Department of Transportation, U.S. Department of Transportation that regulates civil aviation in t ...

to control airspace within and around the borders of the United States. The ARSR-4 is the FAA's most recent (late 1980s, early 1990s) addition to the "Long Range" series of radars. It is a solid state Westinghouse system with a range. The ARSR-4 features a "look down" capability that enables the radar to detect aircraft attempting to elude detection by flying at low altitudes, advanced clutter reduction via hardware and software post-processing, and enhanced poor-weather object detection. A beacon system, the ATCBI-6M (a monopulse system), is installed along with each ARSR-4. However, since the ARSR-4 has 3D capabilities, it can determine altitude independently of its associated beacon (albeit less accurately). ARSR-4 systems are installed along the borders and coastal areas of the contiguous United States,

Guantanamo Bay Naval Base Guantanamo Bay Naval Base (), officially known as Naval Station Guantanamo Bay or NSGB, (also called GTMO, pronounced Gitmo as jargon by the U.S. military) is a United States military base located on of land and water on the shore of Guant ...

in Cuba, the municipality of

Yigo Yigo, Guam (; ) is the northernmost village of the United States territory of Guam, and is the location of Andersen Air Force Base. The municipality of Yigo is the largest village on the island in terms of area. It contains a number of populated pl ...

Guam Guam ( ; ) is an island that is an Territories of the United States, organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. Guam's capital is Hagåtña, Guam, Hagåtña, and the most ...

, and a training site at the FAA's

Mike Monroney Aeronautical Center Mike Monroney Aeronautical Center is a regional office of the United States Federal Aviation Administration on the grounds of Will Rogers Airport in Oklahoma City. With around 7,500 direct federal employees, the Aeronautical Center is one of the ...

Oklahoma City Oklahoma City (), officially the City of Oklahoma City, and often shortened to OKC, is the List of capitals in the United States, capital and List of municipalities in Oklahoma, most populous city of the U.S. state of Oklahoma. The county seat ...

. They are generally unmanned, and are equipped with remote monitoring of both the radar data and the status of the radar's health and environment. It has expanded to additional sites throughout the entire contiguous US (or CONUS).

History

Raytheon Raytheon is a business unit of RTX Corporation and is a major U.S. defense contractor and industrial corporation with manufacturing concentrations in weapons and military and commercial electronics. Founded in 1922, it merged in 2020 with Unite ...

introduced ARSR-1 in 1958 operating in the

L-band The L band is the Institute of Electrical and Electronics Engineers (IEEE) designation for the range of Frequency, frequencies in the radio spectrum from 1 to 2 gigahertz (GHz). This is at the top end of the ultra high frequency (UHF) band, at t ...

. At that time it had a maximum range of . ARSR-2 was developed in the 1960s, also with a 200-mile range. From a user perspective, the ARSR-1 and ARSR-2 function nearly identically. Components that had proved troublesome in the ARSR-1 were redesigned in order to improve reliability. Existing ARSR-1 systems were retrofitted with the more reliable ARSR-2 components. All ARSR-1/2 systems have been upgraded with modern Common ARSR systems (CARSR).

Vacuum tubes A vacuum tube, electron tube, thermionic valve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. It ...

were still in use nationwide prior to the upgrade. All ARSR-1/2s were replaced by Common ARSR by the end of 2015. CARSR has a range, and shares transmitter components and software with the FAA's new airport surveillance radar, the ASR-11. Like the ASR-11, CARSR is completely solid state. Westinghouse built ARSR-3. ARSR-3 and 3D search radar were used by the FAA in the Joint Surveillance System (JSS). The radar operated in the L-band at 1250 to 1350 MHz and detected targets at distances beyond . The D model had height-finder capability. Westinghouse also built ARSR-4 3-D air surveillance radar in the 1990s for the JSS. By the late 1990s, this radar had replaced most of the 1960s-vintage AN/FPS-20 variant search radars and a number of ARSR-3 search radars under the "FAA/Air Force Radar Replacement" (FARR) program.

References

;Further reading
ARSR-1,2,3,4 @ radomes.org
{{Aerospace Defense Command, state=collapsed Ground radars Military air traffic control Military radars of the United States Radars of the United States Air Force Aviation in the United States Air traffic control in North America