Electronic countermeasure
An electronic countermeasure (ECM) is an electrical or electronic device designed to 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 missiles. Most air forces 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. Self-protecting (defensive) ECM includes using blip enhancement and jamming of missile terminal homers.
History[edit]
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 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.[1] There were also efforts at sending false radio signals, having shore stations send transmissions using ships' call signs, and jamming enemy radio signals.[1] On the other hand, there were also attempts by the Ottoman side to jam Allied wireless communications during the Gallipoli campaign.[2]
World War II ECM expanded to include dropping chaff (originally called Window), jamming and spoofing radar and navigation signals.[1] 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 missiles designed to home in on enemy radar transmitters.[1]
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.[3] 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.[4]
Shipboard ECM[edit]
The ULQ-6 deception transmitter was one of the earlier shipboard ECM installations.[9] The Raytheon SLQ-32 shipboard ECM package came in three versions providing warning, identification and bearing information about radar-guided cruise missiles.[9] 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.[9] The BLR-14 Submarine Acoustic Warfare System (or SAWS) provides an integrated receiver, processor, display, and countermeasures launch system for submarines.[9]