“Next War will be won by the side that best exploits the Electromagnetic Spectrum.” – Admiral Sergei Gorshkov
The electromagnetic (EM) spectrum has been employed for more than 100 years, starting with wireless telegraphy. With technological advances, the width of the Electromagnetic spectrum has been increasing exponentially for employment in communication, sensor technology, data dissemination, navigation, targeting and other fields. During the Russo Japanese War in 1904, which is considered as the first incidence of electronic warfare (EW), when probably for the first time that Russian radio operators started jamming Japanese stations, which were directing artillery fire onto Port Arthur in Manchuria. The importance of communication intelligence and the need to have secure communication was amply demonstrated. Even after a lapse of more than a century, lack of secure communication once again influenced the outcome of the engagement during the aerial engagement in Op Swift Retort after recent Balakot strike. It is, therefore, considered important to trace the evolution of Electronic Warfare and highlight the lessons that are as relevant today as they were in the past.
World War I.
The First World War saw the employment of airplanes and airships as the instrument of military power, reconnaissance, and liaison. The em spectrum was exploited for communication amongst friendly field formations. Most of the Air Forces of the world were born during this period either as independent service as a part of the Army Wing. To avoid monitoring by hostile forces, encryption was introduced in wireless telegraphy by means of cryptography. The next spiral was the application of goniometric principle of direction finding that led to locating the transmitting stations by triangulation.
World War II.
Due to the advent of Radio Navigation and Radar during World War II, there were rapid advances in the field of EW during this period. To aid in accurate navigation by the British and the German Air Forces, radio navigation techniques were exploited copiously. However, the opposing forces mostly came up with countermeasures to ‘Bend the Beams’ and render the radio navigation inaccurate and ineffective. This ‘Wizard War’ of Electronic Beams raged during the period brought home the need to ensure resilience and redundancy in the navigational systems. The same lesson was learnt during the First Gulf War in 1991, when the NATO Forces used the GPS navigation system extensively and the Iraqi Forces were able to counter them by simple interference, during later part of the campaign. Today, the GPS signals can be easily spoofed, and the GPS receivers jammed. Therefore, all nations are developing more robust and resilient GPS systems with redundancy and with use of broader frequency spectrum, to null the jamming/spoofing effects. The lessons are being re-learned.
During the Battle of Britain, in 1941 the Germans deployed a Radar named Freya (Scandinavian Goddess of beauty, love and fertility) with a Range of 120 miles operating at a frequency range of 120-130 Mhz. By 1942, the British Forces started experiencing high attrition due to successful interceptions by the German fighters. The Britishers came out with a ‘Mandrel’ jammer and escorted the strike force successfully.
The Germans then deployed a new 3D narrow beam Radar called Wuerzburg-Riese, operating at 565 Mhz, beyond the capability of the British Mandrel jammer. The Britishers detected the radar through aerial reconnaissance and physically picked up the radar for analysis and came out with ‘Carpet’ Jammer to tackle the radar. The Israeli Forces also physically picked up the P 12 series Radar, SA 6 SAM and Shilka AA Gun System to devise effective countermeasures during the 1973 Yom Kippur War. Acquisition of weapons or sensors employed by adversaries, has been resorted to, by many countries to arrive at the best countermeasure techniques and tactics. In 1943, The Germans re-introduced a multi frequency Radar, ’Neptune’ operating at six frequencies in 158-189 Mhz Range, which was unaffected by Jammers and chaff. This is the typical spiral of EW in which the countermeasures catch up with the Radar technology only to find the Radars employing technology beyond the capability of the Jammers. The Radar operating frequency ranges have been increasing since then and now the radars operate in Ku band and beyond. However, the jammers have been keeping pace with the advances and are capable of much wider frequency coverage.
WW II Lesson
The Countermeasures development needs to move from ‘Reactive’ to ‘Proactive’ and preemptive capability. The jammers need to be capability based and not specific threat based. While the Radar Warning Receivers (RWR) were introduced to warn the submarines and aircraft of being painted by radar transmissions, the Germans introduced RWRs in an offensive manner by employing the ‘Naxos’ RWR to detect the H2S radar onboard pathfinder Force of the RAF and intercept them successfully with night fighters. They also employed ‘Flensburg’ RWR to detect tail warning Radar ‘Monica’ of the British Bombers and to literally catch these night Bombers ‘by the tail’. Such innovations always tip the balance towards a win. The IAF employed handy cams to record the target details during Kargil Operations to gain better intelligence.
Integrated Air Defence System (IADS). Having experienced the jamming and other countermeasures against Radars, the Germans pioneered the concept of ‘Integrated Air Defence System’. Each Cell comprised of one Freya, two Wurzburg, Airborne Radar equipped night fighters, Command and Control Network, Antiaircraft Guns, and searchlights. With overlapping radar coverage and different types of weapon systems, the Germans put up a tough and improved Air Defence network. This proved quite effective against the hostile bombers. The concept of IADS was forgotten during the Fifties and Sixties, before it regained importance in the Seventies. The IADS concept was operational in 1942 and it is equally relevant today. Integrated Air Defence set up ensures effective protection against different types of air threats including ballistic Missiles, cruise missiles, Fighters, helicopters, and UAVs. The networked AD ensures better resilience due to diverse, multi spectral employment and resilience against hostile EW action.
On 24 Jul 1965, the US F4 Phantom fighter was shot down by SA2 SAM, the first kill by a SAM during hot war. The US lost 160 aircraft to the SAMs by the end of 1965. During early 1966 the US fielded Jammers and maneuvers to counter the SAM. As ECM became effective the SAM frequencies were changed from S (2965-3060) to C Band (5010-5090). The US later developed Anti-Radiation Missile (ARM) AGM 45 Shrike, to counter the SA2. The Vietnamese started deploying dummy SA2 transmitters on known strike routes and the US Forces exhausted their ARMs on dummy transmitters before they reached the target area. Low level strikes remained vulnerable to terminal defences. That is when, Laser and TV guided precision bombs were inducted to keep the attacking Forces safe from terminal defences at low levels.
The USAF also inducted dedicated Standoff Jammer aircraft EA6B and RPV for Elint missions. Employment of Command and Control Airborne Aircraft was also effectively employed during this campaign. Use of digital and programmable RWR and ASPJs capable of noise and deception jamming were introduced for all fighters and bombers including the B 52. The US Forces attrition Rate reduced from 14% to 1.4% once the ECM measures were put in place. Hunter Killer operations, that involved ‘hunter’ aircraft equipped with ESM sensors to locate the SAM/ Radar sites and the Killer force to attack the sites were effectively employed. Lesson from Vietnam was that Self-protection suites are must for all aerial platforms. No platform should be designed without including the integrated and embedded self-protection armour. While the LCA Mk I missed it, the LCA Mk II must have it included at the design stage itself.
1973 Yom Kippur Arab Israeli War
On 06 Oct 1973, the Israelis were surprised by the Egyptians and Syrians as they simultaneously crossed the border and carried out aerial strikes. When the Israeli pilots went in to attack the Egyptian advancing Armoured columns, they suffered heavy losses as they did not receive any warning on RWRs and got shot down by the modern SA 6 Gainful SAM system that used CW transmissions and Shilka AAA Gun control Radar operating in Ku Band, that was beyond the frequency range of the RWRs. There were no countermeasures against the IR guided SAM 7 Missiles. The Egyptians also moved their SAMs during the night and deployed them at different locations, to avoid destruction. The Israeli Air Force prioritized support to the Army and counter air operations against the airfields, without attacking the SAM sites. This resulted in heavy attrition. Modern ECM Eqpt had to be requisitioned extremely fast and the Israeli pilots had to devise effective tactical maneuvers in the meantime. The spiral went in favour of the SAMs during this Conflict. The Lesson from the Conflict was the need forcontinuous intelligence of the Electronic Order of Battle is important to avoid technological surprises. The EW systems must be upgradable programmable and with open architecture.
The Bekaa Valley Conflict 1982
During the intervening period after the Yom Kippur War, the Israeli Air Force modernized itself well with modern fighters F 15 and F 16 with look down shoot down capability and with modern EW equipment. The Israeli Defence Industry developed more capable PGMs, UAVs, Airborne Command and Control Systems and acquired ARMs. The Israeli campaign commenced with the launch of Decoys that stimulated the AD network. The Israeli Air Force commenced electronic jamming of all Radars, SAMs and communication networks. This was followed by PGM and ARM strikes. The entire operation was coordinated by E2C Hawkeye Airborne control aircraft. This campaign changed the way the wars were planned and executed post the Bakaa Valley Campaign. The entire world took note of the importance of Electronic Warfare, PGMs, ARMs and UAVs. The aircraft and ECM regained superiority over the SAMs. Lesson from Bekaa Valley was that EW would continue to play an important role in deciding the outcome of operations. However, the competition between the SAMs and aircraft would continue unabated. Post 1982 Bekaa Valley Conflict, the operational concepts changed rapidly and technological advances in sensor technology, propulsion systems, computer power and networked operations brought in quantum advances in the fields of Radars and EW.
Present Operational Scenario
Technological advances have been imbibed in the military field with tremendous force multiplying impact. As the em spectrum gets exploited by the military as well as for civil communication and networking, the em environment has become more congested, contested and overlapping than before. Normal means of spectrum analysis, threat identification and countermeasure techniques are insufficient in such congested environment, and they require much more advanced technological applications and exploitation. It is, therefore, important to analyse the present operational scenario and look at the way ahead for the EW, to remain effective.
Computational Power. On 20 Jul 1969, when Niel Armstong landed on the moon, the Apollo Guidance Computer had 2 Mhz CPU speed and 4 Kb RAM. Normal smart watch today has 1 GHz CPU speed and 512 MB RAM. Floating operations per second have increased a trillion folds in the last 60 years. Supercomputing continues to hit new milestones. This has facilitated major advances in all systems, in terms of computing speed, solutions, latency, tasking and operational capabilities. Digital EW systems have much better capabilities due to high computing power.
Communication Systems. Data flow rates have increased tremendously as the em spectrum employment has shifted from HF VHF, UHF to EHF and even the Laser regime.
Sensor Technology. Modern RF sensors are much more powerful as well as more sensitive. IR sensors have graduated to Imaging IR sensors with much better resolution and resistance to IR countermeasures. Python and MICA (IR) AAMs are such examples that employ IIR seekers. EO sensors have added another layer of em spectrum, which generates much more complexities as they are passive and more capable of target identification and resistant to usual means of jamming (Sky Spotter system). Due to miniaturisation, the weapon systems can employ multiple sensor seekers for better resilience and performance under various atmospheric and electromagnetic environments. Multi seeker options onboard AAMs and SAMs (David Sling) ensures better resistance to countermeasures.
AESA Technology. Active Electronic Steering Array Technology has revolutionised the capability of the Radars and other sensors. It facilitates electronic steering of the antenna with power being generated by Trans Receiver Modules (TRM). As there is no mechanical steering of the antenna, the transmission beams are shaped and beamed electronically. Therefore, they can scan extremely fast, with prioritised dwell times and vast scan volumes. The radar can undertake interleaved multiple modes of operations in air, ground, and mapping modes. Ground based Radars are capable of programmable and auto controlled transmissions with due consideration to the prevailing em environment and they can avoid intentional or unintentional interference. Better processing power, better use of EM Spectrum, much wider bandwidths, more powerful sensors and AESA technology have revolutionized the radar capabilities.
Ground Based Air Defence.
Integrated Air Defence. The present AD Systems are all networked with deployment of multi-spectral, multi-layered radars with very wide frequency bands. Multi-static radars and counter stealth radars in V/UHF bands provide much improved capability against all types of threats including cruise missiles, UAVs, stealth fighters and even terminal weapons like smart bombs and missiles. The ground-based sensor network has achieved wide diversity by including EO sensors that have much better detection and identification capability (Sky Spotter of Rafael). Other passive sensors that are capable of geolocating ground based as well as airborne threat (RFeye AD System of CRFS). They have also achieved operational capabilities and operate silently without any warning to the attacker force. Even the stealth fighters are no more silver bullets than they used to be in the past, due to advances in radar technology.
SAM Capabilities. The fighters are presently capable of delivering precision guided munition at greater standoff ranges, targeting multiple targets simultaneously. This evolutionary spiral has prompted the Forces to field long range SAMs like S 400, capable of shooting the intruders at ranges up to 400 km. Due to significant advances in multi pulse propulsion, miniaturisation and guidance technologies, the SAMs are capable of much better endgame capability against even the manoeuvring and high speed targets. Multi layered Air Defence system comprises various types of SAMs to engage low-level pop-up threats, low RCS low speed targets as well as fast manoeuvrable and stealth fighters.
Current Trend in the EW Field.
Fighter EW Programmes. While all the present fighters have integrated self-protection suites like RWRs, Self-Protection Jammers, passive countermeasure dispensing systems, more and more fighters are now adding on Missile Approach Warning Systems, Laser warning Receivers and towed decoys to improve end game survivability. RWRs are capable of geolocating ground based radars more accurately for hard kill. The core technologies employed are ultra-wideband digital receivers and digital radio frequency memory DRFM) devices, Gallium Nitride (GaN) solid state active electronically scanned array (AESA) jammer transmitters and interferometric direction-finding systems. Integration of onboard sensors like AI Radar, EO sensors, IRST scanners and RWRs significantly improve situational awareness to counter the threat more effectively.
Escort Jammers. Escort Jammers are again gaining importance as the typical IADS has a large number of multi band Radars. Saab’s EW Business unit has been working on developing an Escort jammer using AESA, DRFM and Interferometry technologies to counter radar threat in L and S bands, with the option to jam radars in V/UHF Bands as well. On similar lines, the EuroDASS Consortium comprising of Leonardo, Electronica, Indra and Hensholdt are in the process of finalizing Electronic Combat Role (ECR) concept which will provide the Eurofighter with capability of passive threat location, active electronic jamming of all threats and a modular configuration for SEAD/DEAD missions. BAE Systems has recently been nominated to upgrade the AN/ASQ 239 self- protection system to Block IV configuration of the F 35 fighter aircraft. The system would corelate with the onboard AN/APG 81 AI Radar and AN/ASQ242 Communication, navigation, and Identification System to generate better situational awareness.
The US Navy is also moving ahead to upgrade its dedicated EW aircraft EA 18G Growler with better ESM suite that would employ data linked integration with other EA 18Gs or E2D AEW&C to produce a high quality geolocation of threat. The EW pods onboard would be capable of handling even the VHF band radars employed with S400 and HQ class of SAMs. RAAF has inducted 11 EA 18G Growlers to support all the three services in EW. The aircraft EW pods would be upgraded with Low band, Mid band and High band jamming capabilities with the modern AN/ALQ 249(V1) jamming Pods.
Future Trends in EW
The EW systems would exploit all the technological advances to counter the modern digital multi spectral sensors. AESA technology has been adapted by the Jammers to counter multiple threats simultaneously with much higher Effective Radiated Power. Cognitive EW systems would employ Artificial Intelligence to better identify threats and generate optimum jamming techniques, especially against new and unknown threats. Networked and data linked operations would ensure faster and more accurate mapping of the EOB and the ASPJs would be able to receive new jamming techniques online, as more inputs on efficient jamming techniques are obtained by central EW Control Center. The EW systems would need to be more adaptable to emerging threats by upgrading the hardware, software, and firmware, as no force can afford to discard the EW systems when a new threat emerges. For fast upgrades, the systems would need to have open architecture to plug in the new capabilities. Simulation tools would play an important role in better system evaluation and training.
Stand-in jamming would prove more effective by employment of dedicated UAVs or through Manned-unmanned teams of fighters and UAVs. Anti- Radiation Missiles have been improved to counter more complex targets from stand-off ranges and against mobile sensors and SAMs.
EW Aspects: India China Standoff.
Both India and China have Integrated Air Defence Systems operational with various types of Radars, other sensors, SAMs and AWACS(KJ2000/KJ200). PLAAF is known to have dedicated EW aircraft, Y8 and TU 154. PLAAF is also known to have Kh31 Anti-Radiation Missile (ARM) integrated with the Su 30 MKK, configured with Zhuk AI Radar and ESM system. The PLAAF has inducted BM/KG 3000 series of ECM equipment onboard the fighters. There are a large number of Ground based EW Regiments with powerful jammers operational with the Chinese Ground Forces. Both the Air Forces would have ASPJ systems integrated on all fighters.
The IAF has gained considerable experience in generating effective active ECM techniques, as the IAF has Fighters, Radars and SAM systems of diverse origins including the Russian, Western and the Indigenous ones. The PLAAF has most of the weapons systems like the Russian systems, with which the IAF would have exercised quite often and refined the jamming techniques. The IAF is, therefore, more experienced in operating in the realistic EW environment, and should employ its EW assets more effectively. The IAF has also trained with many Air Forces, including its participation in the Red Flag Series of Exercises.
From the perspective of em spectrum management, the IAF and PLAAF have some common fighters of the Russian origin. The SU30 MKK of the PLAAF is known to have two variants of the AI Radars viz NO001VEP and the ZHUK MS. The Russian origin AI radars may have some overlapping Radar parameters amongst the SU 30 variants. It would, therefore, be prudent to judiciously analyse and differentiate between its own AI Radar signatures onboard SU 30 MKI, MiG 29, MiG 21 Bison and the Red Force Su30. For hard kill, the IAF has excellent standoff precision air launched weapons that could be employed effectively. However, the present SAMs systems can be redeployed at a new location in less than six minutes (S 400) as compared to the old SAM systems (HQ 2J) that required nearly six hours. For faster reaction, the IAF may consider employing a fighter aircraft by simultaneous carriage of Reconnaissance pod and the standoff PGMs. This would minimize the sensor to shooter reaction while at the same time effectively exploit the fighter capability. The IAF Chief has rightly prioritised networked centric operational capability for induction. Considering its diverse inventory of fighters, transport aircraft and helicopters, the IAF must ensure a common and secure data link on all airborne platforms to achieve better situational awareness and effective employment of the forces. Henceforth, all inductions in the IAF and other Armed Forces must have interoperability of communication systems and compatibility with the IAF Air Network.
Electronic Warfare has evolved over the years. Most of the lessons learnt nearly 100 years back are equally relevant today. There has been continuous competition between the Air Defence systems and the EW systems, each gaining upper hand over the other at some time or the other. This evolutionary spiral would continue in future as well. With employment of a much wider and denser em environment, the complexity of EW engagement would require application of artificial intelligence and cognitive systems. The EW systems can no longer be reactive in this game, they would need to be pre-emptive and adaptive to the future threats. EW protection has gained high importance in the present electromagnetic environment. Even the stealth fighters require EW support to remain effective. As the systems get more and more data linked, their security and ‘invisibility’ would be the most important requirement of future wars.
Author: Air Marshal Daljit Singh (Retd) is a former Air Officer Commanding-in-Chief of an Operational Command of Indian Air Force. Electronic Warfare was his area of specialisation. The views expressed are the author’s own.
Lead Picture Credit: Wikipedia