Radar is a radiolocation system that uses radio waves to determine the distance (ranging), angle (azimuth), and radial velocity of objects relative to the site. It is used to detect and track aircraft, ships, spacecraft, guided missiles, and motor vehicles, and map weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna and a receiver and processor to determine properties of the objects. Radio waves from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds.
Signals intelligence (SIGINT) is intelligence-gathering by interception of signals, whether communications between people or from electronic signals not directly used in communication. Signals intelligence is a subset of intelligence collection management. As classified and sensitive information is usually encrypted, signals intelligence in turn involves the use of cryptanalysis to decipher the messages. Traffic analysis—the study of who is signaling whom and in what quantity—is also used to integrate information again.
Electronic warfare (EW) is any action involving the use of the electromagnetic spectrum or directed energy to control the spectrum, attack an enemy, or impede enemy assaults. The purpose of electronic warfare is to deny the opponent the advantage of—and ensure friendly unimpeded access to—the EM spectrum. EW can be applied from air, sea, land, and/or space by crewed and uncrewed systems and can target communication, radar, or other military and civilian assets.
This is an index of articles relating to electronics and electricity or natural electricity and things that run on electricity and things that use or conduct electricity.
Measurement and signature intelligence (MASINT) is a technical branch of intelligence gathering, which serves to detect, track, identify or describe the distinctive characteristics (signatures) of fixed or dynamic target sources. This often includes radar intelligence, acoustic intelligence, nuclear intelligence, and chemical and biological intelligence. MASINT is defined as scientific and technical intelligence derived from the analysis of data obtained from sensing instruments for the purpose of identifying any distinctive features associated with the source, emitter or sender, to facilitate the latter's measurement and identification.
Direction finding (DF), or radio direction finding (RDF), is – in accordance with International Telecommunication Union (ITU) – defined as radio location that uses the reception of radio waves to determine the direction in which a radio station or an object is located. This can refer to radio or other forms of wireless communication, including radar signals detection and monitoring (ELINT/ESM). By combining the direction information from two or more suitably spaced receivers, the source of a transmission may be located via triangulation. Radio direction finding is used in the navigation of ships and aircraft, to locate emergency transmitters for search and rescue, for tracking wildlife, and to locate illegal or interfering transmitters. RDF was important in combating German threats during both the World War II Battle of Britain and the long running Battle of the Atlantic. In the former, the Air Ministry also used RDF to locate its own fighter groups and vector them to detected German raids.
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).
The Kolchuga passive sensor is an electronic-warfare support measures system developed in the Soviet Union and manufactured in Ukraine. Its detection range is limited by line-of-sight but may be up to 800 km (500 mi) for very high altitude, very powerful emitters. Frequently referred to as Kolchuga Radar, the system is not really a radar, but an ESM system comprising three or four receivers, deployed tens of kilometres apart, which detect and track aircraft by triangulation and multilateration of their RF emissions.
Electronic counter-countermeasures (ECCM) is a part of electronic warfare which includes a variety of practices which attempt to reduce or eliminate the effect of electronic countermeasures (ECM) on electronic sensors aboard vehicles, ships and aircraft and weapons such as missiles. ECCM is also known as electronic protective measures (EPM), chiefly in Europe. In practice, EPM often means resistance to jamming. A more detailed description defines it as the electronic warfare operations taken by a radar to offset the enemy's countermeasure.
A low-probability-of-intercept radar (LPIR) is a radar employing measures to avoid detection by passive radar detection equipment while it is searching for a target or engaged in target tracking. This characteristic is desirable in a radar because it allows finding and tracking an opponent without alerting them to the radar's presence. This also protects the radar installation from anti-radiation missiles (ARMs).
Passive radar is a class of radar systems that detect and track objects by processing reflections from non-cooperative sources of illumination in the environment, such as commercial broadcast and communications signals. It is a specific case of bistatic radar – passive bistatic radar (PBR) – which is a broad type also including the exploitation of cooperative and non-cooperative radar transmitters.
Radar jamming and deception is a form of electronic countermeasures that intentionally sends out radio frequency signals to interfere with the operation of radar by saturating its receiver with noise or false information. Concepts that blanket the radar with signals so its display cannot be read are normally known as jamming, while systems that produce confusing or contradictory signals are known as deception, but it is also common for all such systems to be referred to as jamming.
The VERA passive radar is an electronic support measures (ESM) system that uses measurements of time difference of arrival (TDOA) of pulses at three or four sites to accurately detect and track airborne emitters. It is reportedly able to detect military "invisible aircraft". The manufacturer is ERA a.s., based in Pardubice.
The AN/FPS-17 was a ground-based fixed-beam radar system that was installed at three locations worldwide, including Pirinçlik Air Base in south-eastern Turkey, Laredo, Texas and Shemya Island, Alaska.
Radiofrequency MASINT is one of the six major disciplines generally accepted to make up the field of Measurement and Signature Intelligence (MASINT), with due regard that the MASINT subdisciplines may overlap, and MASINT, in turn, is complementary to more traditional intelligence collection and analysis disciplines such as SIGINT and IMINT. MASINT encompasses intelligence gathering activities that bring together disparate elements that do not fit within the definitions of Signals Intelligence (SIGINT), Imagery Intelligence (IMINT), or Human Intelligence (HUMINT).
Radar MASINT is a subdiscipline of measurement and signature intelligence (MASINT) and refers to intelligence gathering activities that bring together disparate elements that do not fit within the definitions of signals intelligence (SIGINT), imagery intelligence (IMINT), or human intelligence (HUMINT).
Electro-optical MASINT is a subdiscipline of Measurement and Signature Intelligence, (MASINT) and refers to intelligence gathering activities which bring together disparate elements that do not fit within the definitions of Signals Intelligence (SIGINT), Imagery Intelligence (IMINT), or Human Intelligence (HUMINT).
Signals intelligence operational platforms are employed by nations to collect signals intelligence, which is intelligence-gathering by interception of signals, whether between people or between machines, or mixtures of the two. As sensitive information is often encrypted, signals intelligence often involves the use of cryptanalysis. However, traffic analysis—the study of who is signalling whom and in what quantity—can often produce valuable information, even when the messages themselves cannot be decrypted.
Countersurveillance refers to measures that are usually undertaken by the public to prevent surveillance, including covert surveillance. Countersurveillance may include electronic methods such as technical surveillance counter-measures, which is the process of detecting surveillance devices. It can also include covert listening devices, visual surveillance devices, and countersurveillance software to thwart unwanted cybercrime, such as accessing computing and mobile devices for various nefarious reasons. More often than not, countersurveillance will employ a set of actions (countermeasures) that, when followed, reduce the risk of surveillance. Countersurveillance is different from sousveillance, as the latter does not necessarily aim to prevent or reduce surveillance.
The AN/ALQ-218 is an American airborne electronic warfare system, found on Northrop Grumman EA-6B Prowler and Boeing EA-18G Growler military aircraft.
