Four Norwegian F-16 fighters are crossing the sky from the Lofoten Islands, after taking off to meet a call interception against targets moving toward Air Base Andoya. The F-16 was equipped with an IRST AN/AAS-42.
Flying below the formation of condensation trails (30,000 feet), the Norwegian pilots soon found six "targets." Su-27 fighters were approaching from the front at the same altitude, flying a fighter sweep pattern of type "wall Flanker" and projecting their large envelope search radar ahead. Presumably, a group of attack would come close behind.
The F-16 had their radars off and reduced engine power not to be seen by the Su-27 IRST, which is suspected to operate in the 3-5 m band, optimized to detect signatures of afterburners. As the sensor AN/AAS-42, which works in the band 8-12 mM detects the signature of air friction on the fuselage, the F-16 were able to detect and classify the approach of Su-27 before being detected. The Norwegians made ​​a stealthy ambush and defeated the Su-27 with AMRAAM firing at maximum reach.
This graphic demonstration of the potential offered by fighters equipped with IRST was made ​​by Lockheed Martin Tactical Aircraft Systems in Fort Worth, Texas, in simulated air to air scenarios. The increasing performance of thermal imaging sensors has allowed IRST rivaling the radar as the sensor of choice for many applications in air-air fighter and surveillance aircraft.
See what can not be seen is characteristic of modern warfare. The current weapons can easily destroy targets, air or land after detected and identified. The ideal is to detect and locate enemy without being detected in the process. Although radar is an effective sensor, its fundamental weakness is you need to illuminate the target with energy. When you do that will identify and report their position and can still be jammer. Heat sensors and electro do not have this disabled by being passive.
The FLIR was first used in 1967 during the the Vietnam War. It proved a hit with the heat of enemy troops and equipment denouncing its position with the heat emitted. The FLIR (Forward Looking InfraRed) became a generic term for a wide range of imaging equipment heat. The FLIR first appeared in 1964 produced by Texas Instruments experience using infrared scanners used in the first linear recognition of cocoons.
The IRST, or the Search and Screening Systems Infra-Red (Infrared Search and Track) is a passive sensor, which uses the heat emitted by the target to generate data for the weapon system of an aircraft (or other platform to ship or anti-aircraft battery).
The passive operation of the IRST has the advantage of concealment. The advantage of forming high-resolution imaging also aids in visual identification (VID) over long distances. The loss of accuracy in the information range can be partially overcome with the integration of a laser rangefinder or laser radar (LADAR).
The use of sensors that detect heat to search for targets for combat aircraft is so
old as the use of these sensors for missile guidance. The first models had limited performance, since the target image is not formed. USAF aircraft of the 50s and 60s as the F-101B Voodoo, F-102 Dagger, F-104 Starfighter, F-106 Delta Dart, F-8 Crusader and F-4B Phantom were already equipped with these sensors, but with little practical use.
The IRST interceptors were installed mainly in whose targets were Bear and Bison bombers with a large IR signature flying at high altitude in clear sky and a cold setting in northern Cadaná. They could also be used to point heat-seeking missiles like the Sidewinder and Falcon. By acting the IRST passively give little warning to the target and the radar jammer could not. Soviet bombers had powerful jammers at the time.
The IRST USAF were adopted by the U.S. Navy F-4B-4 AAA sensor mounted in the nose IRST to point the AIM-9B. Were removed in later versions used for air superiority and attack.
The F-4C was equipped with an IR detector Hughes S-71N (AN/AAR-4) radome under the radar, but that He was replaced by an antenna warning radar in F-4D models. The Swedish JAS-35F Draken was also equipped with AAR-4 in the 60's.
An AAS-15 IR sensor was installed in most F8U-2N Crusader in 1960, appearing as a horn in front of the cockpit of the aircraft.
The Russians have a longer history and consistent use of IRST. IRST copied the Russians and Americans settled in their Mig-25 and Mig-23 air defense from the 60's. The Mig-23 had a heat seeker TP-23 TP-23-1 or PT-23M (MiG-23ML) under the nose can detect an F-16 or 35-40 km similar to TP-26 or an appointed back with a range of 60 km. The data are shown on the HUD. The TP-26 is used to aim missiles R-60 and R-23T. The MiG-23P with computer and digital datalink 23SML Lazur-interception capacity was completely autonomous in the early 80's.
IRST The first of the J-35A Draken was very ineffective and short-range and differs greatly in format in later versions used in the J-35F. The sensor was manufactured by Hughes and had a range of 25km. It was appropriate for the icy regions of the Nordic countries.
The first models of the F-14 Tomcat was equipped with an IR detector AN/ALR-23 movable under the nose, which could be targeted by radar or used independently to sweep areas not monitored by radar. The indium antimonate detector was cooled by a cryogenic system Stirling cycle independent. In practice, the AN/ALR-23 was ineffective and was replaced by Northrop AN/AXX-1 Television Camera Set (TCS).
The pilots of the F-14 Bombcat realized that the LANTIRN FLIR sensor was more efficient to check targets at long range that the TCS. The FLIR has zoom 4, 10 and 20 times and can be pointed 150 degrees off axis of the aircraft. With datalink FTI, the image of the FLIR can be transmitted over long distances along with images of TARPS reconnaissance pod and TCS.
The first were simply IRST FLIR cameras with a simple system of tracking and accuracy. Recent projects have increased capacity, including a great deal of searching, acquiring autonomous distant targets, accurate tracking of multiple targets, rate of false warning of targets very low in all conditions, passive distance estimation, comparable image quality to cameras High Definition TV, and integration with other sensors and weapons onboard.
The ability of the IRST varies according to operating frequency. For example, operating in the band of 2 microns the sensor detects only taskmasters rocket afterburner and the cavity of the turbine. In the band of 4 microns and detects the aforementioned hot parts of the fuselage and the band of 8 microns for all the above and to the turbulence.
The difference between a FLIR and IRST is one that shows the latest data from sources of heat in the same format as a radar screen can also inform the distance using a laser rangefinder or estimate. The FLIR is a heat sensor that forms the front images to be displayed to the pilot and use in navigation and target acquisition in a narrow FOV. The IRST today are capable of forming high-resolution images can be used to purchase with a narrow FOV and visual identification.
