Synthetic-aperture radar (SAR) is a form of radar that is used to create two-dimensional images or three-dimensional reconstructions of objects, such as landscapes. SAR uses the motion of the radar antenna over a target region to provide finer spatial resolution than conventional stationary beam-scanning radars. SAR is typically mounted on a moving platform, such as an aircraft or spacecraft, and has its origins in an advanced form of side looking airborne radar (SLAR). The distance the SAR device travels over a target during the period when the target scene is illuminated creates the large synthetic antenna aperture. Typically, the larger the aperture, the higher the image resolution will be, regardless of whether the aperture is physical or synthetic – this allows SAR to create high-resolution images with comparatively small physical antennas. For a fixed antenna size and orientation, objects which are further away remain illuminated longer – therefore SAR has the property of creating larger synthetic apertures for more distant objects, which results in a consistent spatial resolution over a range of viewing distances.
The Euroradar Captor is a next-generation mechanical multi-mode pulse Doppler radar designed for the Eurofighter Typhoon. Development of Captor led to the Airborne Multirole Solid State Active Array Radar (AMSAR) project which eventually produced the CAESAR, now known as Captor-E.
An active electronically scanned array (AESA) is a type of phased array antenna, which is a computer-controlled antenna array 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).
Imaging radar is an application of radar which is used to create two-dimensional images, typically of landscapes. Imaging radar provides its light to illuminate an area on the ground and take a picture at radio wavelengths. It uses an antenna and digital computer storage to record its images. In a radar image, one can see only the energy that was reflected back towards the radar antenna. The radar moves along a flight path and the area illuminated by the radar, or footprint, is moved along the surface in a swath, building the image as it does so.
Inverse synthetic-aperture radar (ISAR) is a radar technique using radar imaging to generate a two-dimensional high resolution image of a target. It is analogous to conventional SAR, except that ISAR technology uses the movement of the target rather than the emitter to create the synthetic aperture. ISAR radars have a significant role aboard maritime patrol aircraft to provide them with radar image of sufficient quality to allow it to be used for target recognition purposes. In situations where other radars display only a single unidentifiable bright moving pixel, the ISAR image is often adequate to discriminate between various missiles, military aircraft, and civilian aircraft.
The AN/MPQ-64 Sentinel is an X-band electronically steered pulse-Doppler 3D radar system used to alert and cue Short Range Air Defense (SHORAD) weapons to the locations of hostile targets approaching their front line forces. It is currently produced by Raytheon Missiles & Defense.
The AN/APG-66 radar is an X-band solid state medium range pulse-Doppler planar array radar originally designed by the Westinghouse Electric Corporation for use in early generations of the F-16 Fighting Falcon. Later F-16 variants use the AN/APG-68 or the AN/APG-83. This radar was employed in all domestic and export versions of the F-16A/B models throughout the production. Subsequent upgrades have been installed in many varying aircraft types including the U.S. Customs and Border Protection's C-550 Cessna Citation, US Navy P-3 Orion, and Piper PA-42 Cheyenne II's.
The AN/APG-68 radar is a long range pulse-dopple radar designed by Westinghouse to replace AN/APG-66 radar in the General Dynamics F-16 Fighting Falcon. The AN/APG-68 radar is now currently being replaced on US Air Force F-16C/D Block 40/42 and 50/52 by the AN/APG-83 AESA radar.
The AN/APG-76 radar is a pulse Doppler Ku band multi-mode radar developed and manufactured by Northrop Grumman.
COSMO-SkyMed is an Earth-observation satellite space-based radar system funded by the Italian Ministry of Research and Ministry of Defence and conducted by the Italian Space Agency (ASI), intended for both military and civilian use. The prime contractor for the spacecraft was Thales Alenia Space. COSMO SkyMed is a constellation of four dual use Intelligence, surveillance, target acquisition, and reconnaissance (ISR) Earth observation satellites with a synthetic-aperture radar (SAR) as main payload, the result of the intuition of Giorgio Perrotta in the early nineties. The synthetic-aperture radar was developed starting in the late nineties with the SAR 2000 program funded by ASI.
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).
The KLJ-7, also referred to as the Type 1478, is an X band airborne fire-control radar (FCR) developed by Nanjing Research Institute of Electronic Technology (NRIET), also known as the China Electronics Technology Company's (CETC's) No. 14 Research Institute. In December 2010, Pakistan Air Force's Air Chief Marshal Rao Qamar Suleman announced that KLJ-7 radar will be built at Pakistan Aeronautical Complex (PAC), in Kamra, north of Islamabad.
The AN/APG-67 is a multi-mode all-digital X band coherent pulse doppler radar originally developed by General Electric for the Northrop F-20 Tigershark program of the early 1980s. It offers a variety of air-to-air, air-to-ground, sea-search and mapping modes, and compatibility with most weapons used by the US Air Force in the 1980s.
Airborne ground surveillance (AGS) refers to a class of military airborne radar system used for detecting and tracking ground targets, such as vehicles and slow moving helicopters, as opposed to Airborne early warning and control, whose primary role is detecting and tracking aircraft in flight. Antenna beam width should be very small to enhance resolution. This antenna size limitation demands high frequency of operation, to be operated in this mode. AGS radar is typically a medium or low power radar. It includes both maritime and land surveillance. Today, UAVs perform this operation, which often uses optical aids for surveillance.
Irbis-E is a Russian multi-mode, hybrid passive electronically scanned array radar system developed by Tikhomirov NIIP for the Sukhoi Su-35 multi-purpose fighter aircraft. NIIP developed the Irbis-E radar from the N011M Bars radar system used on Sukhoi Su-30MKI aircraft.
The AN/APS-154 Advanced Airborne Sensor (AAS) is a multifunction radar installed on the P-8 Poseidon maritime patrol aircraft. The radar is built by Raytheon as a follow-on to their AN/APS-149 Littoral Surveillance Radar System (LSRS).
High Resolution Wide Swath (HRWS) imaging is an important branch in synthetic aperture radar (SAR) imaging, a remote sensing technique capable of providing high resolution images independent of weather conditions and sunlight illumination. This makes SAR very attractive for the systematic observation of dynamic processes on the Earth's surface, which is useful for environmental monitoring, earth resource mapping and military systems.
The AN/APS-4, originally known as ASH is an early military air-to-air and air-to-surface radar used by American and British warplanes during World War II.
