Home / Technology / Electronics & EW / Militaries require next generation ESM /ELINT systems to counter sophisticated LPI, agile, Ultrawideband, VHF long-range early warning Radar threats

Militaries require next generation ESM /ELINT systems to counter sophisticated LPI, agile, Ultrawideband, VHF long-range early warning Radar threats

Electronic Warfare EW, encompasses, in all battle phases, military actions involving the use of EM energy to determine, exploit, reduce or prevent hostile use of EM spectrum and the actions, which retain friendly use of the EM spectrum. EW consists of three related sectors, viz., Electronic Protection (EP), Electronic Attack (EA), and Electronic Support (ES).


ES sensors allow the passive detection of emissions from radar systems and can be used to classify and geo-locate radar systems operated by an adversary. ES is responsible for supplying intelligence and threat recognition that are necessary for EA and EP to function effectively. In the context of radar, ES consists of two divisions: Electronic Intelligence (ELINT), and Electronic Support Measures (ESM). Although ELINT is technically a subset of SIGINT or Signals Intelligence, ELINT specifically deals with radar signals, whereas SIGINT is often associated only with Communication or data link signals.


ESM receivers are linked with radar warning system or radar countermeasure systems in order to react to encountered threats. Hence, time is a critical factor in ESM. Ideally, an ES system on an aircraft, for example, should be able to recognise the transmissions from a threat radar system, associate it with a hostile platform and weapon system, discern the operating mode it is using, whether that be search and track or weapon guidance, and hand the information off to, for example, a Defensive Aids Suite (DAS) controller to deploy countermeasures and issue the pilot with appropriate manoeuvre advice. It might also hand the information off to a data link for sharing over a tactical network.


ELINT’s purpose, on the other hand, is to receive, locate and identify and sometimes measure and analyse radar signals. The goal of ELINT, in contrast, is to create threat databases that are used by ESM (among other users), and to update the Electronic Order of Battle (EOB) which is concerned with movements, location updates, and the readiness of adversary emitters. Electronic Warfare heavily relies on Electronic Intelligence (ELINT) and the data it provides including radar operating parameters, waveform details, geo-location, and other pertinent information.With advances in digital hardware technology, it becomes possible (and it is sometimes preferred) to use the same hardware (i.e. receiver) for both ESM and ELINT.

Threat Challenges

Technical ELINT then deals with interception, collection, analysis identification and recording, and documentation of emitter radiations or signatures. Although often non-real time in the past it is becoming forced to be more real-time to keep pace with the modern battlefield.


ELINT/ES systems exploit signals intercepted from target radars that are continually evolving and becoming more complex. They process high and low power signals from the same bandwidth and as well as advanced radar waveforms. EW systems are evolving due to employment of Spread spectrum technology in communication, proliferation of pulse Doppler, multimode, and low probability of intercept (LPI) radars and stealth technology. The extension of EM spectrum coverage is extended to millimeter wave and optical wave lengths.


The surveillance platforms are becoming more diverse like Aerostats, AEW&C, aircrafts, unmanned air vehicles (UAV) and Satellites. The miniaturisation of receivers and processing equipment has made the use of ESM systems practical on more platforms, with UAVs and other unmanned systems prominent among them, so that their information gathering capabilities now permeate the battlespace.


Today’s state-of-the-art radars feature either Passive Electronically Scanned Array (PESA) or Active Electronically Scanned Array (AESA) antenna/transceiver systems, signals with very complex modulations, unpredictable scan patterns and the ability to use different scan patterns simultaneously, multiple beams and multiple frequencies simultaneously.


Their RF signal sources, increasingly, exploit solid-state gallium arsenide (GaAs) technology, which is difficult, bordering on impossible to fingerprint and can extend radar frequencies beyond 18GHz. Furthermore, a growing number of modern radars, such as Frequency Modulated Continuous Wave (FMCW) sets, operate at very low power levels, making them harder to detect.


The future looks even more challenging. The resurgence of VHF long-range early warning radar with anti-stealth capabilities continues, while more short range – and therefore hard to intercept – gun and missile control radars exploit the 33 to 36GHz K-band window. Low power and solid-state radars proliferate along with radars that use advanced and hard to unravel modulation techniques such as polyphase coding. What the effect of exotica such as artificially intelligent cognitive radar will be is, as yet, unknown.


Electronic Support System

Antennas, receivers, processors and – crucially – databases are key components of an ESM suite, which is essentially a radio receiver that measures signals and compares them against a database containing previously analysed signatures. Requirements include 360 degree hemispherical or for aircraft spherical coverage, high sensitivity to detect lowpower signals, sufficient selectivity to separate the signals it wants from those that it doesn’t, and a high Probability of Intercept (PoI).


A full 360 degree of coverage is typically provided through the use of multiple staring antennas with overlapping coverage volumes. A PoI of 100 percent is routinely claimed by suppliers, but rarely defined. In a nutshell it is the probability that the ESM system will detect a particular threat signal between the time it reaches the system and the time at which it is too late for the system to do its job.


ES utilizes special receivers to intercept electromagnetic (EM) emissions of radars. Such EM emissions of radars are mostly formed (modulated) in the shape of pulsed signals. In order to gather useful information, the characteristic parameters of intercepted signals are measured.


Some parameters of radar signals can be obtained from a single pulse, whereas other parameters can only be obtained from a greater number of pulses. Radio Frequency (RF), Pulse Width (PW), Time of Arrival (TOA), Angle of Arrival (AOA), and Pulse-Amplitude (PA) are common examples of parameters obtained from a single pulse. This set of parameters is referred to herein as a Pulse Parameter Vector (PPV). Each measured pulse, therefore, is represented by a single PPV.


Practically, parameters that require a greater number of pulses in order to be measured make use of multiple PPVs in the measurement process; they are referred to as derived parameters. Some of the derived parameters are pulse-repetition-interval (PRI), and the antenna scan period (ASP), which is measured by utilizing multiple PPVs.


The environment, where the interception takes place, usually consists of many emitters. it becomes important to separate (sort) interleaved emitters’ pulses (PPVs) into distinctive groups. This sorting process is called de-interleaving. De-interleaving allows for further analysis of emitter parameters, particularly for the measurement of inter-pulse parameters, which (in addition to PPV parameters) are important for classification of an emitter.


In order to distinguish radars of the same class from each other, an identification task should take place. More parameters are required in order to perform the identification process. These parameters are usually related to imperfections in the manufacturing process of radar components, such as local oscillator, power amplifiers, etc. Pulse rise-time, and phase coherency with time are examples of parameters that can be used in identification.


Trends in Electronic support systems

EW techniques need to become more sophisticated as adversarial threats become more agile and advanced. New concepts that provide improved intelligence and intentions and warning are required to meet this challenge. High sensitivity digital receivers coupled with strong signal analyzers & feature extraction techniques are the trends in communication EW. Digital Receiver Technologies employ direct RF Sampling from Antenna, System On Chip including  processor & Display. With the increasing miniaturization of electronic components and the increasing efficiency of the cooling technology, the Radio Frequency systems will get better and the performance of the sensors will also improve.


Historically, ELINT/ES systems used instantaneous frequency measurement typically providing a capability between 2-18 GHz. Such systems have a relatively low sensitivity, around -55dBm one result is they are blocked by high energy signals.


A solution to this problem could be the use of narrowband receivers to increase sensitivity and selecting specific targets of interest from the spectrum avoiding high-power transmissions. However, some modern threat radar systems use wide transmission bandwidths, modern radars are capable of transmitting over bandwidths wider than 1 GHz. Narrowband intercept systems will not always able to collect the complete signal as they are bandwidth limited.


Other features of modern threat radars is that they can use pseudo-random radio frequency (RF) agility transmitting on multiple frequencies simultaneously. This can cause a pulse-on-pulse problem for the interception receiver. When a number of radar pulses are received simultaneously, the pulse that has the highest energy at an instant in time is processed. This causes pulse collisions or “dropouts” in the collection system. When this happens, incorrect emitter processing is often the result.


This effect increases when a number of radars of the same type are found in the same operating area—such as in a maritime task group. Not only do these radars have a high duty cycle, but the pulses they transmit are long high-energy pulses. In some instances, the energy in the, received pulses is enough to overdrive the analog to digital converter in sensitive intercept receivers. When the receiver is overdriven, the spectrum is destroyed and the ELINT/ES system cannot detect target transmissions.


This is not the only challenge faced by modern ELINT/ES systems. It has become apparent in recent years that there has been a significant increase in low probability of intercept (LPI) radars. LPI can be used to describe a radar that an intercept receiver cannot detect or process for any number of reasons, not just due to low transmission power, it is possible to detect and process both solid-state radars and FMCW radars with a modern digital narrowband receiver.


The real challenge for ELINT/ES receivers occurs when a high-power radar is found in the same bandwidth as a low-power radar. When this happens, the high-power radar can overdrive the receiver, this is compensated for by adding attenuation. The result is that as the dBs are added, the noise floor rises and the low-power signal is lost in the noise and cannot be processed.


It is essential that ELINT/ES systems contain powerful analysis tools that are not only capable of handling long, complex RF/ pulse repetition interval (PRI)/partial discharge (PD) patterns associated with modern radars, but also the waveforms associated with FMCW radars. Modern pulsed radars can use very long cyclic lengths or long frame structures. Within these structures, it is not unusual for a radar to use interleaved PRI waveforms where dwell/switch patterns or long periods of a constant PRI are regularly interleaved with stagger sequences.


The use of long complicated PRI structures has also been accompanied by PD agility and changes in intrapulse modulation types. Radar systems now use a variety of non-linear waveforms, which are difficult to identify. Binary phase-shift keyed pulses (BPSK) are still relatively common, but some radars are now increasing their use of quadrature phase shift keying (QPSK). As the capability, complexity and diversity of modern radars increases, it naturally follows that the intercept and processing capability of ELINT/ES systems has to improve.


Equipment like the Krasukha-4 or the Turkish KORAL ground-based jammer can generate very high power output over a broadband of frequencies that can be effective at distances up to 300km, which is a big jump from the previous generation of jammers that had limited ranges and effectiveness while in broadband jamming mode. Truly multi-role aircraft operating in high threat AD environment will be more effective than single mission electronic attack legacy aircraft. The advanced EW systems being used for military applications, which can effectively disrupt and paralyze the operations of the enemy, are however, likely to see a greater reliance on non-standard protocols, non-standard modulation schemes, and proprietary waveforms.


BAE Systems to develop next-generation full spectrum electronic warfare technology

The US Office of Naval Research (ONR) has awarded $11m contract to BAE Systems for developing next-generation electronic warfare (EW) technology that will quickly detect, locate, and identify emitters of radio frequency signals over all threat bands and from all directions. Known as the Full-Spectrum Staring Receiver (FSSR), this technology will enable near-instantaneous full-scale battlespace situational awareness, emitter identification and tracking, threat warning and countermeasure & weapon cueing.  Conventional situational awareness systems are not able to deliver the high level of coverage and responsiveness that FSSR will provide. The ONR programme aims to develop and display a range of next-generation EW systems that prevent adversaries from tapping into the electromagnetic spectrum while ensuring unrestrictive usage to the nation’s allies.


Digital ELINT sensor completes demo onboard MQ-9 Predator

General Atomics Aeronautical Systems Inc (GA-ASI) and Raytheon Deutschland have tested a recently developed Electronic Intelligence (ELINT) sensor. The advanced radar detection system (ARDS) sensor was integrated into a wing-mounted pod and test-flown on the GA-ASI medium-altitude, long-endurance (MALE) MQ-9 Predator B remotely piloted aircraft system (RPAS). Developed by Raytheon Deutschland, ARDS is a fully digital, high-precision radar-detection sensor.


The sensor is said to be a platform-independent, follow-on development of the digital emitter location system (ELS) currently in use on German Luftwaffe Tornado electronic combat / reconnaissance (ECR) version. The demonstration involved flight testing against ground radar targets, which included testing of the system’s processing speed and geolocation precision. Other than sensor performance, the companies also demonstrated the use of aircraft datalink and ground station elements. The tests proved the system’s precision direction-finding and radar identification capabilities. GA-ASI noted that the system supported downlinking the data in real-time to the MQ-9 aircraft’s ground control station.


R&S ELINT systems

Rohde & Schwarz ELINT systems feature highly sensitive, multi-channel ELINT processors as well as powerful analysis software and digital I/Q recording solutions. Rohde & Schwarz offers what it describes as a cutting edge digital ELINT system with market leading sensitivity (-85dB has been achieved), one that uses IQ data processing techniques for accurate identification and measurement of contemporary modulation techniques. A compact system that integrates the receiver, digitiser and analyser components, it is designed to provide both high sensitivity and a large dynamic range;

the former enabling it to detect and process very faint signals and the latter allowing it to cope with both faint and powerful signals at the same time.


Rockwell Collins CS-3045 Airborne ELINT/ESM Subsystem

The CS-3045 is 0.5 to 40 GHz system that can address both electronic intelligence (ELINT) and electronic support measures (ESM) mission requirements for airborne missions. The non-blocking architecture, flexible radio frequency (RF) distribution and powerful software provide the flexibility for a wide range of tasking. Adding a second pulse analyzer or high probability of intercept receiver allows ELINT collection and ESM situational awareness simultaneously.


Agilent Ultra Wideband Digital Receivers

Ultra wideband signals are widely present in applications such as SAR or UWB radar, ECM/ESM and SIGINT/ ELINT, and in some wireless applications. The conventional design approach for narrow band receivers tends to minimize the RF analog front-end by transposing RF processing in the digital domain as much as possible. However, this approach can appear less appropriate for ultra-wideband systems because of bandwidth constraints and consequently the required sampling and processing frequencies.

Agilent Acqiris signal analyzer solutions can solve that issue for SAR, UWB radar, ECM/ESM and SIGINT/ELINT, and wireless applications where wideband capability, good dynamic range, and low-level signal accuracy are key requirements.


USAF Seeks Better Ways to Process Electronic Intelligence

The Air Force is looking for new ways to process electronic intelligence signals used to detect threats in support of its reconnaissance platforms, according to a broad agency announcement released in Sep 2020.


The overall technical objectives of this BAA are to employ existing and emerging technologies to develop and demonstrate automated, real-time signal detection, processing, exploitation, and reporting capabilities of existing and emerging Electronic Intelligence (ELINT) signals in support of Intelligence, Surveillance, and Reconnaissance (ISR) platforms. Technology applications include, but are not limited to: (1) the enhancement of ELINT signal processing software and hardware to address the increased complexity and volume of the ELINT battlespace; (2) the enhancement of collection system efficiency for single and multi-platform collection optimization and management; (3) the development of technology for the detection and exploitation of emerging ELINT signals and systems,(4) the enhancement of effectiveness of databases that use existing multi-source, multi-platform, real-time collection systems, and (5) the development of capabilities to improve the timeliness and accuracy of post-mission ELINT intercept processing in support of analysis enhancements.


Detailed scope and definition of problems are as follows: (1) ELINT emitter detection, identification, geolocation, and tracking: Battlefield management depends heavily on ELINT assets to provide current threat analysis and assessment for successful war-fighting planning and resource management: a need for real-time detection, identification, geolocation, tracking, and reporting is required to prosecute existing and emerging ELINT systems that employ short-up-time tactics in Anti-Access Area Denial (A2AD) regions; (2) Automated signal collection, identification and first level processing: emerging ELINT systems employ advanced modulation, Low Probability of Intercept (LPI) signals that dictate the need for automated, dynamic collection using both on-board / off-board assets; (3) Enhanced digital ELINT processing: Environment complexity, as well as advanced collection hardware technology, demands growth in the digital ELINT processing arena; (4) Multi-sensor/multi-processor collection management; (5) enhanced generation of ELINT emitter models using various adaptive/machine learning techniques.


Market Growth

According to the current analysis by Reports and Data, the global Electronic Warfare market was USD 25.813 Billion in 2018 and is projected to grow at a CAGR of 4.58% from 2019 to 2026. The electronic warfare market is projected to grow  to USD 30.32 Billion by 2022.

Electronic Warfare can be defined as the warfare conducted using electromagnetic spectrum. Electronic Warfare usually employs radio waves or laser light to confuse or disable the enemy’s electronics. It can involve listening to or collecting the enemy’s radio signals or sensing the radar of an incoming missile. Advanced electronic attack solutions are used to deliver non-kinetic and digital effects, while still providing a cloak of protection for the platforms.


Increasing transnational and regional instability is the primary factors responsible for the growth of the market. Another major factor for the growth of the market is the increasing focus on Cognitive electronic warfare technology, which will spur the demand for Electronic Warfare over the forecast period. However, the high cost of equipment will be a significant factor obstructing the growth of the market over the forecasted period.


With the rise in the tensions politically across nations or regions, the instability is increasing, which is the primary factor these countries are increasingly investing in upgrading their military capabilities. The U.S. is at the stage of expanding its Electronic Warfare research, development, test and evaluation funding and procurement by over 9.5% and 7.1% respectively. The market is increasingly diversified across almost every area of defense spending.


The increasing rate of electronic, cyber, and optical domains will require a perceptible shift in warfighting techniques. Since the avenues of technological advancement in these fields are limitless, new generations of equipment will emerge at a rapid rate. The challenge would be to integrate them into the physical domain of warfighting and achieve the desired effect on the adversary. The relatively new field of Quantum Computing has the potential of creating a new generation of satellites. Trends like these will help drive the market further over the forecast period.

The growing drone industry, the demand for Electronic Warfare will further rise over the forecast period of 2019-2026. Aerial Platform is predicted to be the second-largest segment in the market, with a global market share of over 30% in 2026. Increasing investments being carried out in the segment by the leading market players will be the main factor driving the growth of the segment. The electronic warfare market has been segmented on the basis of platform, product, capability, and region. Electronic warfare segment is projected to grow the fastest over the forecast period due to the increasing procurement of equipment in military ships and aircraft.


Key participants include Honeywell International (U.S.),Lockheed Martin (US), Thales Group (France), SAAB (Sweden), Boeing (US), Bosch (Germany), Northrop Grumman Corporation (U.S.), Kvh Industries (U.S.), Moog, Inc.(U.S.), BAE Systems (UK), Rockwell Collins (U.S.), Fairchild Semiconductors (U.S.), Analog Devices (U.S.), Xsens (Netherlands), Sensonor AS (Norway), and VectorNav Technologies (U.S.).






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