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Decoys are an integral component of current ship self-defense efforts. Decoy employment is used primarily to defend against anti-ship missiles which have avoided detection and penetrated to the terminal-defense area that represents an imminent threat to ownship. Deployed in conjunction with electronic warfare systems and passive countermeasures, chaff and infrared distraction decoys are an effective adjunct to hard kill weapons.

A decoy is a device which is designed to present an appearance which is indistinguishable from that of a true target when viewed by a specified sensor, so that deception of the sensor or its operator can be accomplished. The degree to which the decoy must resemble the true target, in terms of all of its measurable characteristics, depends upon the attributes of the sensor. For example, a sensor which measures both the signature and motion characteristics of its target cannot be reliably deceived by a decoy which differs significantly from a true target in either respect.

Decoys have been in use since the earliest days of radar. The ways in which decoys can be used to defeat weapons correspond to the sequence of operations of weapon targeting. During World War II, for example, chaff decoys were used by the allies against German air defenses in two ways: corridor chaff was employed to mask entire flights of bombers to deny Information on the number of aircraft involved; chaff was also used to degrade the tracking capabilities of the German gun-laying radars.

Currently, decoys are being developed to counter antiship missiles (ASMs). The decoy must be indistinguishable from a true target in the sense that the victim sensor cannot reject the decoy on the basis of received data. The decoy's position is important because sensors accept only those signals which emanate from the volume of space where true targets are expected to be. Decoy effectiveness against a particular ASM depends upon the decoy placement geometry and also upon the performance characteristics of the decoy (e.g., its radar cross section). Consequently, it is possibl e to determine decoy effectiveness only through consideration of both performance and placement.

Used to launch both chaff and infrared decoys, the MK 36 decoy launching system is the primary decoy launcher in the fleet today. The MK 36 decoy launching system is found on the following ship classes: LSD 41/49, LHD, LPD 4, LHA, FFG 7, DD 963, DDG 47, CG 47, and AOE 1/6.

The MK 36 Super Rapid Bloom Offboard Countermeasures (SRBOC) Chaff and Decoy Launching System is an evolutionary development of the RBOC family with enhanced capability. The MK 36 is a deck-mounted, mortar-type countermeasure system that may be used to launch an array of chaff cartridges against a variety of threats. The purpose of the system is to confuse hostile missile guidance and fire control systems by creating false signals. The launching system is controlled from the Combat Information Center and is dependent on information provided by the detection and threat analysis equipment on the ship.

The DLS MK 36 Mod 12 is a morter-tube launched decoy countermeasures system that projects decoys aloft at specific heights and ranges. Each DLS launcher includes six fixed-angle (elevation) tubes: four tubes set at 45 degrees and two tubes set at 60 degrees. Decoy selection and firing is controlled from either the EW console of the bridge launcher control. The DLS launches the following types of decoys: SRBOC - which uses chaff to deceive RF-emitting missiles/radars, NATO Sea Gnat - which is similar to SRBOC but with extended range and a larget payload of chaff, and TORCH - which uses heat to deceive infrarad-seeking missiles.

The MK 36 is combat proven, fully supported, highly reliable, and cost effective. The system has been deployed throughout the world and is in service with at least 19 navies. The MK 36 consists of the MK 137 launcher, the MK 158 Mods 1 and 2 master launcher control, the MK 164 Mods 1 and 2 bridge launcher control, the MK 160 Mod 1 power supply, the MK 5 Mod 2 or Mk 6 Mod 0 ready service lockers, and a range of munitions. The Mk 137 launcher has six 130-mm fixed tubes arranged in two parallel rows at angles of 45 and 60 degrees. The firing circuits employ electromagnetic induction to initiate the propelling charges in the cartridges. Near each launcher is a deck locker with up to 20 MK 5 or 35 MK 6 rounds for quick reload.

Both the MK 214 and 216 rounds release propellant which scorches tubes and leaves behind a coating which some ships mistakenly believe is teflon coating from the launcher tubes. The MRC 18M-1R requires that launch tube components be cleaned after each shoot, which should eliminate the residue. The use of the MK 214 and the MK 216 impose a heavy maintenance burden for post firing clean up.

The existing Mk 36 Decoy Launching System is being modified to support Nulka launches. After the Nulka equipment is installed, the system is redesignated as a Mk 53 DLS. The DLS MK 53 retains all capabilites of the DLS MK 36 Mod 12. The MK 137 SRBOC Launcher is required to receive overhaul on average once every 48-72 months.

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Page last modified: 03-06-2018 19:25:13 ZULU