PAVE PAWS is a complex Cold War early warning radar and computer system developed in 1980 to "detect and characterize a sea-launched ballistic missile attack against the United States". The first solid-state phased array deployed used a pair of Raytheon AN/FPS-115 phased array radar sets at each site to cover an azimuth angle of 240 degrees. Two sites were deployed in 1980 at the periphery of the contiguous United States, then two more in 1987–95 as part of the United States Space Surveillance Network. One system was sold to Taiwan and is still in service.
An active electronically scanned array (AESA) is a type of phased array antenna, which is a computer-controlled array antenna in which the beam of radio waves can be electronically steered to point in different directions without moving the antenna. In the AESA, each antenna element is connected to a small solid-state transmit/receive module (TRM) under the control of a computer, which performs the functions of a transmitter and/or receiver for the antenna. This contrasts with a passive electronically scanned array (PESA), in which all the antenna elements are connected to a single transmitter and/or receiver through phase shifters under the control of the computer. AESA's main use is in radar, and these are known as active phased array radar (APAR).
Duga was an over-the-horizon radar (OTH) system used in the Soviet Union as part of its early-warning radar network for missile defense. It operated from July 1976 to December 1989. Two operational duga radars were deployed, with one near Chernobyl and Chernihiv in the Ukrainian SSR, and the other in eastern Siberia.
Over-the-horizon radar (OTH), sometimes called beyond the horizon radar (BTH), is a type of radar system with the ability to detect targets at very long ranges, typically hundreds to thousands of kilometres, beyond the radar horizon, which is the distance limit for ordinary radar. Several OTH radar systems were deployed starting in the 1950s and 1960s as part of early warning radar systems, but airborne early warning systems have generally replaced these. OTH radars have recently been making a comeback, as the need for accurate long-range tracking becomes less important with the ending of the Cold War, and less-expensive ground-based radars are once again being considered for roles such as maritime reconnaissance and drug enforcement.
Clear Space Force Station is a United States Space Force radar station for detecting incoming ICBMs and submarine-launched ballistic missiles to NORAD's command center and to provide Space Surveillance data to the United States Space Force. Clear's AN/FPS-123 Upgraded Early Warning Radar is part of the Solid State Phased Array Radar System (SSPARS) which also includes those at Beale AFB, Cape Cod Space Force Station, RAF Fylingdales and Thule Site J. The "historic property" was one of the Alaska World War II Army Airfields and later a Cold War BMEWS site providing NORAD data to Colorado's BMEWS Central Computer and Display Facility (CC&DF).
Radiolocation, also known as radiolocating or radiopositioning, is the process of finding the location of something through the use of radio waves. It generally refers to passive uses, particularly radar—as well as detecting buried cables, water mains, and other public utilities. It is similar to radionavigation, but radiolocation usually refers to passively finding a distant object rather than actively one's own position. Both are types of radiodetermination. Radiolocation is also used in real-time locating systems (RTLS) for tracking valuable assets.
The Jindalee Operational Radar Network (JORN) is an over-the-horizon radar (OHR) network that can monitor air and sea movements across 37,000 square kilometres (14,000 sq mi). It has a normal operating range of 1,000 kilometres (620 mi) to 3,000 kilometres (1,900 mi). It is used in the defence of Australia, and can also monitor maritime operations, wave heights and wind directions.
Point Arena Air Force Station is a closed United States Air Force General Surveillance Radar station. It is located 3.7 miles (6.0 km) east of Point Arena, California. It was closed in 1998 by the Air Force, and turned over to the Federal Aviation Administration (FAA).
A wind profiler is a type of weather observing equipment that uses radar or sound waves (SODAR) to detect the wind speed and direction at various elevations above the ground. Readings are made at each kilometer above sea level, up to the extent of the troposphere. Above this level there is inadequate water vapor present to produce a radar "bounce." The data synthesized from wind direction and speed is very useful to meteorological forecasting and timely reporting for flight planning. A twelve-hour history of data is available through NOAA websites.
Mount Hebo Air Force Station is a closed United States Air Force General Surveillance Radar station. It is located 5.2 miles (8.4 km) east-southeast of Hebo, Oregon, located at the top of 3,154-foot (961 m) Mount Hebo. It was closed in 1980.
Ground Equipment Facility J-33 is a Federal Aviation Administration (FAA) radar station of the Joint Surveillance System's Western Air Defense Sector (WADS) with an Air Route Surveillance Radar (ARSR-4). The facility was previously a USAF general surveillance radar station during the Cold War.
Terence James Elkins is an Australian-born American physicist. In 1960, he participated in an expedition from Mawson Station which conducted the first geological surveys of the Napier Mountains in Antarctica. The highest of this group of mountains, Mount Elkins, was subsequently named after him. In 1979, he received the Harold Brown Award, the Air Force's highest honour for research and development, for research he conducted that contributed to the development of the AN/FPS-118 over-the-horizon backscatter (OTH-B) air defence radar system. This system, consisting of six one-megawatt transmitters and their associated horizontal linear phased array antennas, is currently the largest radar system in the world.
Ajo Air Force Station is a closed United States Air Force General Surveillance Radar station. It is located 6.4 miles (10.3 km) northwest of Ajo, Arizona. It was closed in 1969 by the Air Force, and the radar site turned over to the Federal Aviation Administration (FAA).
The 776th Radar Squadron is an inactive United States Air Force unit. It was last assigned to the Northeast Air Defense Sector, Air Combat Command, stationed at Bangor Air National Guard Base, Maine, where it was inactivated on 6 September 1991.
The 777th Radar Squadron is an inactive United States Air Force unit. It was last assigned to the Northwest Air Defense Sector, Tactical Air Command, stationed at Mountain Home Air Force Base, Idaho. It was inactivated on 15 September 1991.
Columbia Falls Air Force Station is a closed United States Air Force radar station in Washington County, Maine. Located 16.0 miles (25.7 km) northwest of Machias, Maine and 10.0 miles (16.1 km) north of Columbia Falls, it went operational in 1990 but was closed in 1997 and placed in "warm storage" with minimal maintenance. It was deactivated and placed in "cold storage" in 2002.
Moscow Air Force Station is a closed United States Air Force radar station in Somerset County, Maine. Located 6.0 miles (9.7 km) northeast of Moscow, Maine, it went operational in 1990 but was closed in 1997 and placed in "warm storage" with minimal maintenance. It was deactivated and placed in "cold storage" in 2002.
Bangor Air National Guard Base is a United States Air National Guard base. Created in 1927 as the commercial Godfrey Field, the airfield was taken over by the U.S. Army just before World War II and renamed Godfrey Army Airfield and later Dow Army Airfield. It became Dow Air Force Base in 1947, when the newly formed U.S. Air Force took over many Army air assets.
Eglin AFB Site C-6 is a United States Space Force radar station which houses the AN/FPS-85 phased array radar, associated computer processing system(s), and radar control equipment. Commencing operations in 1969, the AN/FPS-85 was the first large phased array radar. The entire radar/computer system is located at a receiver/transmitter building and is supported by the site's power plant, fire station, 2 water wells, and other infrastructure for the system. As part of the US Space Force's Space Surveillance Network its mission is to detect and track spacecraft and other manmade objects in Earth orbit for the Combined Space Operations Center satellite catalogue. With a peak radiated power of 32 megawatts the Space Force claims it is the most powerful radar in the world, and can track a basketball-sized object up to 22,000 nautical miles (41,000 km) from Earth.
Container (29B6) radar is the new generation of Russian over-the-horizon radar, providing long distance airspace monitoring and ballistic missile detection. The first radar, near Kovylkino, Mordovia, Russia, became operational in December 2013 and entered combat duty on 1 December, 2019. Another Container radar is planned to be deployed in Kaliningrad.
United States Air Force 
