An
electronic countermeasure (
ECM) is an electrical or electronic device designed to trick or deceive
radarRadar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
,
sonarSonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
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
aircraftAn aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
from
guided missileGuided Missile is a London based independent record label set up by Paul Kearney in 1994.Guided Missile has always focused on 'the underground', preferring to put out a steady flow of releases and developing the numerous GM events around London and beyond....
s. Most
air forceAn air force, also known in some countries as an air army, is in the broadest sense, the national military organization that primarily conducts aerial warfare. More specifically, it is the branch of a nation's armed services that is responsible for aerial warfare as distinct from an army, navy or...
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 jamming. Defensive ECM includes using
blip enhancementBlip enhancement is an electronic warfare technique used to fool radar. When the radar transmits a burst of energy some of that energy is reflected off a target and is received back at the radar and processed to determine range and angle...
and jamming of missile terminal homers.
History
One of the first examples of electronic countermeasures being applied in a combat situation took place during the
Russo-Japanese warThe Russo-Japanese War was "the first great war of the 20th century." It grew out of rival imperial ambitions of the Russian Empire and Japanese Empire over Manchuria and Korea...
. On April 15, 1904, Russian
wireless telegraphyWireless telegraphy is a historical term used today to apply to early radio telegraph communications techniques and practices, particularly those used during the first three decades of radio before the term radio came into use....
stations installed in the
Port ArthurLüshunkou is a district in the municipality of Dalian, Liaoning province, China. Also called Lüshun City or Lüshun Port, it was formerly known as both Port Arthur and Ryojun....
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.
GermanyGermany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
and
Great BritainGreat Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
interfered with enemy communications along the western front during
World War IWorld War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
while the
Royal NavyThe Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
tried to intercept German naval radio transmissions. There were also efforts at sending false radio signals, having shore stations send transmissions using ships' call signs, and jamming enemy radio signals.
World War IIWorld War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
ECM expanded to include dropping chaff (originally called Window), jamming and spoofing radar and navigation signals. German bomber aircraft navigated using radio signals transmitted from ground stations, which the British disrupted with spoofed signals in the
Battle of the BeamsThe Battle of the Beams was a period early in the Second World War when bombers of the German Air Force used a number of increasingly accurate systems of radio navigation for night bombing. British "scientific intelligence" at the Air Ministry fought back with a variety of increasingly effective...
. During the RAF's night attacks on Germany the extent of electronic countermeasures was much expanded, and a specialised organisation,
No. 100 Group RAFNo. 100 Group was a special duties group within RAF Bomber Command.It was formed on 11 November 1943 to consolidate the increasingly complex business of electronic warfare and countermeasures within one organisation. The group was responsible for the development, operational trial and use of...
, was formed to counter the increasing German
night fighterA night fighter is a fighter aircraft adapted for use at night or in other times of bad visibility...
force and radar defences.
Cold WarThe Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...
developments included
anti-radiation missileAn anti-radiation missile is a missile which is designed to detect and home on an enemy radio emission source. Typically these are designed for use against an enemy radar, although jammers and even radios used for communication can also be targeted in this manner.- Air-to-Ground :Most ARM designs...
s designed to home in on enemy radar transmitters.
Radar ECM
Basic radar ECM strategies are (1) radar interference, (2) target modifications, and (3) changing the electrical properties of air. 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. The jammer's continuous transmissions will provide a clear direction to the enemy radar, but no range information. Deception may use a transponder to mimic the radar echo with a delay to indicate incorrect range. Transponders may alternatively increase return echo strength to make a small decoy appear to be a larger target. 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. Dispersal of small aluminum strips called
chaffChaff, originally called Window by the British, and Düppel by the Second World War era German Luftwaffe , is a radar countermeasure in which aircraft or other targets spread a cloud of small, thin pieces of aluminium, metallized glass fibre or plastic, which either appears as a cluster of secondary...
is a common method of changing the electromagnetic properties of air to provide confusing radar echos.
Aircraft ECM
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 missileA surface-to-air missile or ground-to-air missile is a missile designed to be launched from the ground to destroy aircraft or other missiles...
s or
air-to-air missileAn air-to-air missile is a missile fired from an aircraft for the purpose of destroying another aircraft. AAMs are typically powered by one or more rocket motors, usually solid fuelled but sometimes liquid fuelled...
s. On aircraft ECM can take the form of an attachable underwing pod or could be embedded in the airframe.
Active Electronically Scanned ArrayAn Active Electronically Scanned Array , also known as active phased array radar is a type of phased array radar whose transmitter and receiver functions are composed of numerous small solid-state transmit/receive modules . AESAs aim their "beam" by broadcasting radio energy that interfere...
(AESA) radars like those mounted on the F-22, MiG-35, Su-35BM or the
F-35The Lockheed Martin F-35 Lightning II is a family of single-seat, single-engine, fifth generation multirole fighters under development to perform ground attack, reconnaissance, and air defense missions with stealth capability...
can also act as an ECM device to track, locate and eventually jam enemy radar. Previous radar types were not capable of performing these activities due to:
- the inability of the antenna to use suboptimal frequencies
- the processing power needed
- the impossibility to practically intermix or segment antenna usages
Future Airborne Jammers
The Next Generation Jammer will be carried on the E/A-18G and F-35 fighters and use AESA technologies in side mounted pods to provide all around coverage with highly selective directional jamming.
DARPA's Precision Electronic Warfare (PREW) project aims to combine AESA with
Synthetic aperture radarSynthetic-aperture radar is a form of radar whose defining characteristic is its use of relative motion between an antenna and its target region to provide distinctive long-term coherent-signal variations that are exploited to obtain finer spatial resolution than is possible with conventional...
spread over multiple platforms for very tightly focused jamming.
The
Air Force Research LaboratoryThe Air Force Research Laboratory is a scientific research organization operated by the United States Air Force Materiel Command dedicated to leading the discovery, development, and integration of affordable aerospace warfighting technologies; planning and executing the Air Force science and...
is exploring the concept of a Cognitive Jammer to deal with Dynamic Spectrum Access technologies.
Examples of dedicated electronic countermeasures aircraft
- EC-130H Compass Call
-See also:- External links :* * * * * *...
- EA-6B Prowler
The Northrop Grumman EA-6B Prowler is a twin-engine, mid-wing electronic warfare aircraft modified from the basic A-6 Intruder airframe. The EA-6B has been in service with the U.S...
equipped with ALQ-92 communications jammer, ALQ-100 multi-band track breaking system, and five ALQ-99 tactical jammer pods.
- EA-18G Growler
The Boeing EA-18G Growler is an American carrier-based electronic warfare aircraft, a specialized version of the two-seat F/A-18F Super Hornet. The EA-18G will replace the Northrop Grumman EA-6B Prowlers in service with the United States Navy. The Growler's electronic warfare capability is...
- Tornado ECR
The Panavia Tornado is a family of twin-engine, variable-sweep wing combat aircraft, which was jointly developed and manufactured by the United Kingdom, West Germany and Italy...
Shipboard ECM
The ULQ-6 deception transmitter was one of the earlier shipboard ECM installations. The Raytheon SLQ-32 shipboard ECM package came in three versions providing warning, identification and bearing information about radar-guided cruise missiles. 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. The BLR-14 Submarine Acoustic Warfare System (or SAWS) provides an integrated receiver, processor, display, and countermeasures launch system for submarines.
Heat and Sound Analogies
Infrared homing systems can be decoyed with flares. Sound detection and homing systems used for ships are also susceptible to countermeasures.
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
warships use Masker and PRAIRIE (PRopellor AIR Ingestion and Emission) systems to create small air bubbles around a ship's hull and wake to reduce sound transmission. Surface ships tow noisemakers like the
AN/SLQ-25 NixieThe AN/SLQ-25 Nixie and its variants are towed torpedo decoys used on US and allied warships. It consists of a towed decoy device and a shipboard signal generator...
to decoy homing torpedoes. Submarines can deploy similar acoustic device countermeasures (or ADCs) from a 3-inch (75-mm) signal launching tube. United States ballistic missile submarines could deploy the Mark 70 MOSS (MObile Submarine Simulator) decoy from torpedo tubes to simulate a full size submarine.
See also
- Electronic warfare
Electronic warfare refers to any action involving the use of the electromagnetic spectrum or directed energy to control the spectrum, attack an enemy, or impede enemy assaults via the spectrum. The purpose of electronic warfare is to deny the opponent the advantage of, and ensure friendly...
- Electronic warfare support measures
In military telecommunications, the terms Electronic Support or Electronic Support Measures describe the division of electronic warfare involving actions taken under direct control of an operational commander to detect, intercept, identify, locate, record, and/or analyze sources of radiated...
- Electronic counter-countermeasures
Electronic counter-countermeasures is a part of electronic warfare which includes a variety of practices which attempt to reduce or eliminate the effect of electronic countermeasures on electronic sensors aboard vehicles, ships and aircraft and weapons such as missiles. ECCM is also known as...
- No. 100 Group RAF
No. 100 Group was a special duties group within RAF Bomber Command.It was formed on 11 November 1943 to consolidate the increasingly complex business of electronic warfare and countermeasures within one organisation. The group was responsible for the development, operational trial and use of...
- Starshel
R-045/R-046 Starshel is a type of electronic countermeasures ammunition, fired by 122 mm or 152 mm artillery guns, respectively...
rounds