Editing Electronic countermeasure

{{Short description|Electronic device for deceiving detection systems}}

[[File:Two airmen inspect an electronic countermeasures pod.jpg|right|thumb|250px|Inspecting an AN/ALQ-184 Electronic Attack Pod.]]

An '''electronic countermeasure''' ('''ECM''') is an electrical or electronic device designed to [[countermeasure|trick or deceive]] [[radar]], [[sonar]], or other detection systems, like infrared (IR) or lasers. It may be used both offensively and defensively to deny targeting information to an enemy. The system may make many separate targets appear to the enemy, or make the real target appear to disappear or move about randomly. It is used effectively to protect [[aircraft]] from [[guided missile]]s. Most [[air force]]s use ECM to protect their aircraft from attack. It has also been deployed by military ships and recently on some advanced tanks to fool laser/IR guided missiles. It is frequently coupled with stealth advances so that the ECM systems have an easier job. Offensive ECM often takes the form of [[Radar jamming|jamming]]. Self-protecting (defensive) ECM includes using [[blip enhancement]] and jamming of [[missile guidance|missile terminal homers]].

== History ==
The first example of electronic countermeasures being applied in a combat situation took place during the [[Russo-Japanese war]]. On July 13, 1904, Russian [[wireless telegraphy]] stations installed in the [[Lüshunkou|Port Arthur]] fortress and on board Russian light cruisers successfully interrupted wireless communication between a group of Japanese battleships. The spark-gap transmitters in the Russian stations generated senseless noise while the Japanese were making attempts to coordinate their efforts in the bombing of a Russian naval base.  [[Germany]] and [[United Kingdom]] interfered with enemy communications along the western front during [[World War I]] while the [[Royal Navy]] tried to intercept German naval radio transmissions.<ref name="proceedings">Polmar (1979), p. 121.</ref>  There were also efforts at sending false radio signals, having shore stations send transmissions using ships' call signs, and jamming enemy radio signals.<ref name="proceedings" /> On the other hand, there were also attempts by the Ottoman side to jam Allied wireless communications during the [[Gallipoli campaign]].<ref>{{cite book | language = tr | title = Tevfik Rıza Bey | url = https://canakkalesavaslariansiklopedisi.com/content/tevfik-riza-bey/ | author = Vahibe Türkan Doğruöz | access-date=6 December 2023 | publisher = Çanakkale Savaşları Ansiklopedisi | year = 2022 | isbn = 978-605-80897-7-8}}</ref>

[[World War II]] ECM expanded to include dropping [[Chaff (countermeasure)|chaff]] (originally called Window), jamming and spoofing radar and navigation signals.<ref name="proceedings" /> German bomber aircraft navigated using radio signals transmitted from ground stations, which the British disrupted with spoofed signals in the [[Battle of the Beams]]. During the RAF's night attacks on Germany the extent of electronic countermeasures was much expanded, and a specialised organisation, [[No. 100 Group RAF]], was formed to counter the increasing German [[night fighter]] force and radar defences. [[Cold War]] developments included [[anti-radiation missile]]s designed to home in on enemy radar transmitters.<ref name="proceedings" />

In the 2007 [[Operation Orchard]] Israeli attack on a suspected Syrian nuclear weapons site, the [[Israel Air Force]] used electronic warfare to take control of Syrian airspace prior to the attack.<ref>{{Cite news |title=And they struck them with blindness |author=Yaakov Katz |work=The Jerusalem Post |date=2010-09-29 |access-date=2025-03-16 |url= https://www.jpost.com/Magazine/Features/And-they-struck-them-with-blindness}}</ref> Israeli electronic warfare (EW) systems took over Syria's air defense systems, feeding them a false sky-picture while Israel Air Force jets crossed much of Syria, bombed their targets and returned.<ref>[http://aviationweek.com/awin/israel-shows-electronic-prowess Israel Shows Electronic Prowess] Nov 26, 2007, David A. Fulghum and Robert Wall, Aviation Week & Space Technology</ref>

== Radar ECM ==
{{Main|Radar jamming and deception}}

[[File:Radar jamming.jpg|thumb|Simulated radar screen in US Navy training exercise showing simulated jamming (triangular white area lower right)]] 
Basic radar ECM strategies are (1) radar interference, (2) target modifications, and (3) changing the electrical properties of air.<ref name="proceedings" />  Interference techniques include jamming and deception.  Jamming is accomplished by a friendly platform transmitting signals on the radar frequency to produce a noise level sufficient to hide echos.<ref name="proceedings" />  The jammer's continuous transmissions will provide a clear direction to the enemy radar, but no range information.<ref name="proceedings" />  Deception may use a transponder to mimic the radar echo with a delay to indicate incorrect range.<ref name="proceedings" />  Transponders may alternatively increase return echo strength to make a small decoy appear to be a larger target.<ref name="proceedings" />  Target modifications include radar absorbing coatings and modifications of the surface shape to either "stealth" a high-value target or enhance reflections from a decoy.<ref name="proceedings" />  Dispersal of small aluminium strips called [[Chaff (radar countermeasure)|chaff]] is a common method of changing the electromagnetic properties of air to provide confusing radar echos.<ref name="proceedings" />

== Communications ECM ==
{{Main|Radio jamming}}
[[File:1st_Squadron,_3rd_Cavalry_Regiment,_operate_the_Drone_Defender.jpg|thumb|Drone counter measures (1st Squadron, 3rd Cavalry Regiment of the US Army drill with the Battelle DroneDefender, 30 October 2018, Iraq.)]]

Radio jamming or communications jamming is the deliberate transmission of radio signals that disrupt communications by decreasing the signal-to-noise ratio to the point where the target communications link is either degraded or denied service.

== Aircraft ECM ==
[[File:AGM-88 and AIM-9 on Tornado.jpg|thumb|German [[Panavia Tornado|Tornado ECR]] ]]
ECM is practiced by nearly all modern military units—land, sea or air. Aircraft, however, are the primary weapons in the ECM battle because they can "see" a larger patch of earth than a sea or land-based unit. When employed effectively, ECM can keep aircraft from being tracked by search radars, or targeted by [[surface-to-air missile]]s or [[air-to-air missile]]s.  An aircraft ECM can take the form of an attachable underwing pod or could be embedded in the airframe. Fighter planes using a conventional electronically scanned antenna mount dedicated jamming pods instead or, in the case of the US, German, and Italian air forces, may rely on electronic warfare aircraft to carry them. ECM pods vary widely in power and capability; while many fighter aircraft are capable of carrying an ECM pod, these pods are generally less powerful, capable and of shorter range than the equipment carried by dedicated ECM aircraft, thus making dedicated ECM aircraft an important part of any airforce’s inventory.

=== Future airborne jammers ===
The [[Next Generation Jammer]] is being developed to replace the current [[AN/ALQ-99]] carried on the E/A-18G electronic warfare plane. Planned for adoption around 2020, it will use a small AESA antenna divided into quadrants<ref>{{Cite web|url=https://www.flightglobal.com/news/articles/in-focus-us-navy-next-generation-jammer-proceeds-b-371742/|title = IN FOCUS: US Navy Next Generation Jammer proceeds, but F-35 integration deferred indefinitely}}</ref> for all around coverage and retain the capability of highly directional jamming.

[[DARPA]]'s Precision Electronic Warfare (PREW) project aims to develop a low-cost system capable of synchronizing several simple airborne jamming pods with enough precision to replicate the directionality of an electronically scanned antenna, avoiding collateral jamming of non-targeted receivers.<ref>[https://www.fbo.gov/download/f3d/f3d24a4cc17130af66971e0d897baa87/PREW_BAA_24_Aug_09.pdf Broad Agency Announcement Precision Electronic Warfare (PREW) STRATEGIC TECHNOLOGY OFFICE DARPA-BAA 09-65]</ref>

An expendable active decoy that uses [[Digital radio frequency memory|DRFM]] technology to jam RF based threats has already been developed by [[Selex ES]]<ref>{{cite web|url=http://www.uk.leonardocompany.com/-/britecloudlaunch|title=New Selex ES expendable active decoy 'britecloud' selected by saab for gripen fighter – DETAIL – Leonardo|work=uk.leonardocompany.com|access-date=2016-07-20|archive-url=https://web.archive.org/web/20160816132819/http://www.uk.leonardocompany.com/-/britecloudlaunch|archive-date=2016-08-16|url-status=dead}}</ref> (merged into [[Leonardo S.p.A.|Leonardo]] new name of Finmeccanica since 2017). The system, named [[BriteCloud]], is self-contained within a small canister that is similar to a standard flare cartridge. The 55&nbsp;mm format of the system has undergone flight trials with the [[Gripen]] aircraft and the development of a 218 variant is at an advanced stage.<ref>{{cite web|url=http://www.uk.leonardocompany.com/-/britecloud-gripen-trials|title=Finmeccanica – Selex Es to hold britecloud trials with Gripen – DETAIL – Leonardo|work=uk.leonardocompany.com|access-date=2016-07-20|archive-date=2016-08-16|archive-url=https://web.archive.org/web/20160816165034/http://www.uk.leonardocompany.com/-/britecloud-gripen-trials|url-status=dead}}</ref>

=== Dedicated ECM aircraft ===
* [[Douglas A-3 Skywarrior|EA-3 Skywarrior]]
* [[Douglas B-66 Destroyer|EB-66 Destroyer]]
* [[EC-130H Compass Call]]
* [[EA-6 Prowler|EA-6B Prowler]] equipped with ALQ-92 communications jammer, ALQ-100 multi-band track breaking system, and five ALQ-99 tactical jammer pods.<ref name="p2">Polmar (1979), p. 122.</ref>
* [[EA-18G Growler]]
* [[EA-37B Compass Call]]
* [[EF-111A Raven]]
* [[Panavia Tornado|Tornado ECR]]
* [[Shenyang J-16|J-16 D]]
* [[Sukhoi Su-24|Su-24MP]]
* [[Yakovlev Yak-28|Yak-28PP]]
* [[Mil Mi-8|Mi-8PP]]

== Shipboard ECM ==
The ULQ-6 deception transmitter was one of the earlier shipboard ECM installations.<ref name="p2" />  The [[AN/SLQ-32 Electronic Warfare Suite|Raytheon SLQ-32]] shipboard ECM package came in three versions providing warning, identification and bearing information about radar-guided cruise missiles.<ref name="p2" />  The SLQ-32 V3 included quick reaction electronic countermeasures for cruisers and large amphibious ships and auxiliaries in addition to the RBOC (Rapid Blooming Off-board Chaff) launchers found on most surface ships.<ref name="p2" />  The BLR-14 Submarine Acoustic Warfare System (or SAWS) provides an integrated receiver, processor, display, and countermeasures launch system for submarines.<ref name="p2" />

== Infrared and acoustic analogies ==
{{See also|Acoustic quieting}}
[[File:BAE Hot Brick.jpg|thumb|BAE Hot Brick infrared jammer]]
[[Infrared homing]] systems can be decoyed with [[Flare (countermeasure)|flares]]<ref name="proceedings" /> and other [[infrared countermeasure]]s. [[Acoustic homing]] and detection systems used for ships are also susceptible to countermeasures.  [[United States]] warships use Masker and PRAIRIE (propeller AIR Ingestion and Emission) systems to create small air bubbles around a ship's hull and wake to reduce sound transmission.<ref name="proceedings" />  Surface ships tow noisemakers like the [[AN/SLQ-25 Nixie]] to decoy homing torpedoes.<ref name="proceedings" />  Submarines can deploy similar acoustic device countermeasures (or ADCs) from a 3-inch (75-mm) signal launching tube.<ref name="proceedings" />  United States ballistic missile submarines could deploy the Mark 70 MOSS ([[Mobile submarine simulator]]) decoy from torpedo tubes to simulate a full size submarine.<ref name="proceedings" /> Most navies additionally equip ships with decoy launchers.<ref>{{cite web |url=http://www.terma.com/media/118849/skws_022007.pdf |title=Terma SKWS Decoy Launching System |archive-url=https://web.archive.org/web/20130426191854/http://terma.com/media/118849/skws_022007.pdf |archive-date=2013-04-26 |url-status=dead }}</ref>

== See also ==
{{Portal|Electronics}}
* [[AN/MSR-T4]]
* [[Electronic warfare]]
** [[Electronic warfare support measures]]
** [[Electronic counter-countermeasure]]
* [[Khibiny (electronic countermeasures system)]]
* [[Krasukha (electronic warfare system)]]
* [[No. 100 Group RAF]]
* [[Samyukta electronic warfare system]]
* [[Starshel]] rounds

== References ==
{{Reflist}}

=== Sources ===
{{refbegin}}
* Polmar, Norman: "The U. S. Navy Electronic Warfare (Part 2)", ''United States Naval Institute Proceedings'', November 1979.
* [https://web.archive.org/web/20090226192655/http://www.spectrumsignal.com/publications/Electronic_Counter_Measures.pdf Electronic Counter Measures (PDF)] (Lee Pucker)
* [http://www.ug.ru/issues/?action=topic&toid=1267&i_id=15 A Down of Electronic Counter Measures]- in Russian
* [http://www.computer-museum.ru/connect/reb100.htm 100 years of ECM]- in Russian
{{refend}}

[[Category:Electronic countermeasures| ]]
[[Category:Military communications]]
[[Category:Weapons countermeasures]]