Decoys
Decoys - also more common countermeasures called - are ejectable loss body that almost exclusively of military platforms such as land , air and sea vehicles are used mostly approaching missiles to draw on the decoys themselves or distract from the actual target, thereby protecting the original goal . El Al is the only civil airline to equip its aircraft with decoys.
Deployment tactics
Decoys can be used preventively ( preemptive ) or reactively.
In the case of preventive use, the main task of a decoy is to reduce the scene contrast required for target acquisition and target tracking to a level that is no longer usable for the respective weapon system sensor.
In reactive use, the decoy is supposed to imitate the electromagnetic signature of the already selected, illuminated ( marked ) target in order to steer the weapon system sensor from the target to the decoy ( break lock ). In this case, the decoys should represent the “more attractive” target.
aviation
The first use of swap bodies was in World War II . Since the 1970s at the latest, primary combat aircraft and helicopters have been equipped with one or more decoys. In combat aircraft, the launchers are mostly aerodynamically embedded in the fuselage, in helicopters they are often mounted outside of the fuselage as a result of retrofitting. Some retrofits also include aerodynamic tanks equipped with sensors and decoys. Decoys have a rectangular shape, which is why the launchers have a honeycomb structure inside. A basic distinction must be made between infrared and radar decoys in aircraft.
IR decoys
Infrared decoy flare are used to defend against IR-controlled anti-aircraft missiles or air-to-air missiles and are automatically ejected in preset sequences depending on the suspected threat. The decoys are principally strong flares whose IR radiation is intended to simulate or cover the spectral range of the hot engine exhaust gases emitted by the aircraft. Here, infrared is understood to mean wavelengths of 1 - 5 µm and 8 - 14 µm.
Radar decoys
Aircraft use so-called chaff decoys to defend themselves against radar-guided missiles . Chaff (engl. Chaff ) are for example aluminum or silver-coated glass fibers or nylon fibers having lengths corresponding to an integer multiple of half the wavelength to be expected in accordance with the radar transmit frequencies. Air force radar systems work in the frequency range 3 - 30 GHz (corresponding to wavelengths of 100 - 10 mm). A countermeasure to this is the MTI system, a so-called “fixed-character suppression”, which fades out the quasi-static, slowly tumbling chaff in the target evaluation and continues to precisely depict the moving target as the only one.
Radar disruptors
Conventional chaff has been replaced in part by radar jamming systems that can be dropped, particularly in American combat aircraft. With the help of small batteries and integrated circuits, these actively generate interference signals. These are intended to prevent target acquisition and tracking by enemy radar systems as effectively as possible. Other types try to actively generate the largest possible radar cross-section in coordination with enemy radar emissions in order to deflect approaching guided missiles. Throwable jamming devices have two main advantages over Düppel: They cannot be reliably detected by either MTI or HOJ operating modes and they actively disrupt the hostile radar system instead of passively. The models of the American armed forces can be integrated into existing countermeasure launchers without any further configuration effort. Due to the small size, however, the radiation power and transmission time of the disruptive bodies are very limited, so that they cannot completely replace large and complex disruptive systems.
The US Air Force currently has two detachable radar jamming systems : Primed Oscillator Expendable Transponder (POET) and GENeric eXpendable (GEN-X).
Decoys launcher
The launcher units for decoys are usually very similar with niches or holes for the decoy cartridges and the sequencers that trigger the volleys themselves. While western throwers mainly group rectangular decoys together in a grid shape, eastern throwers mostly use circular decoys. Below is a selection of well-known throwing units:
- Russia
- Artem ASO-2W (32 × 26mm flare cartridges)
- Artem ASO-3 (96 × 26mm flare cartridges)
- APP-50 (96 × 50mm decoy cartridges)
- BVP-30-26M (30 × 26mm decoy cartridges)
- BVP-50-30 (30 × 50mm decoy cartridges)
- United States
- AN / ALE-29A
- AN / ALE-39
- AN / ALE-40
- AN / ALE-45
- AN / ALE-47
- AN / ALE-50
- AN / ALE-55
- Europe
- Saab BOP-B / C
- Saab BOL
- Saab BOX-9
- Bofors BOZ-101 / -102 / -107
- MBDA Saphir-M
Bait drones
In addition, unmanned aerial vehicles (drones) are also used as decoys in aviation . As radar bait drones, they imitate aircraft and thus generate decoy targets to weaken the enemy air defense. Until the 1970s, the McDonnell ADM-20 was an effective decoy to protect the Boeing B-52 ; this described flight maneuvers that corresponded to a real B-52. In addition, the electromagnetic radiation and the radar cross-section also corresponded to that of a B-52.
The Miniature Air Launched Decoy (MALD) radar bait drone , which has a so-called Signature Augmentation System (SAS), which is able to increase the radar cross-section of the drone many times over, is under development. Furthermore, MALD should be able to simulate the exact radar profile of any combat aircraft or bomber.
shipping
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Against attacking aircraft or missiles, means are used by ships that are comparable to those used by aircraft, in particular also flares and chaff to defend against anti-ship missiles .
In order to ward off target-seeking enemy torpedoes , target-representing counter- torpedoes or towing decoys (e.g. AN / SLQ-25 Nixie ), which simulate one or more decoy targets, usually with a very strong electromagnetic and / or a coordinated acoustic frequency spectrum (to represent screw noise ). Attacking torpedoes then almost always switch to the stronger decoy target (so-called lock on ) and allow the attacked person to temporarily withdraw from the threatening situation.
There are also purely acoustic decoys for submarines, which are ejected through a special decoy ejection system or the garbage hatch and release large amounts of gas. This creates a "gas bubble" for opposing sonar devices in and behind which they cannot locate (e.g. Bold ). Such systems were already used on German Class XXI submarines during World War II .
Used ship-based decoy systems are u. a .:
- NATO
- Russia
ICBMs
Decoys are also used in the warheads of modern ICBMs , often with multiple warheads, to divert defense weapons from the effective warheads or even to saturate the defense so that statistically a sufficient number of effective missiles can penetrate through a defense shield.
Web links
Individual evidence
- ^ CNN.com: Missile defense for El Al fleet. Retrieved May 2, 2011 .