Contents of publications

Design concept of aircraft individual protection against guided missile weapons

the product line of the company 'Defense Initiatives' features:

— the airborne defense suite for aircraft individual protection 'Talisman';

— the airborne defense suite for helicopter individual protection 'Amulet';

— the missile approach warning system 'Aura'.

All the above-mentioned products (systems) belong to the equipment for individual protection, with their design, based on a game-changing concept of EW (electronic warfare) — the concept of providing individual protection for air platforms against guided missile weapons.

the brand new concept is strikingly different from any existing methods and means employed in EW. Let us consider those in detail.

Capabilities of existing methods and tools of EW for protection of air platforms against guided missile weapons

Prior to characterizing the capabilities of existing systems for EW and those under development, we suggest to elaborate on the radar design of modern and advanced air defense radio-electronic weapon control systems and those of aircraft missile intercept systems (AMIS).

By 2000 popular radio-electronic weapon control systems of air defense and aircraft missile intercept systems had passed another milestone in their development, constantly surpassing and outstripping the one of EW methods and tools. the key features of the given milestone are as follows:

1. the coherent processing of radar signals, widely used in the first place for the selection of moving targets in terrain clutter, for monopulse angle measurement, autocorrelated and basic correlated compensation of jamming signals, received in the main and side lobes of the antenna pattern (ML and SL of AP).

2. the multichannel capability of REE of weapons control (target attack radars) when tracking targets in angular points due to the application of phased antenna arrays with electronic beam steering, thus making it possible to track-while-scan multiple targets, perform multibeam probing, generate 'nulls' in the side lobes of antenna pattern in the bearing of escort jammers, etc.

3. the aplication of digital receiver-processors with fast Fourier transformation (FFT), including their application in radar seekers of SAMs and guided aircraft missiles (GAM), providing multichannel tracking of the target in range and velocity, which stultifies the application of all types of range-gate and velocity-gate pull-off jamming.

4. the application in REE WC of a few types of probe signals, a pulse signal with LFM and phase-code modulation (PCM) and pulse-Doppler signals.

5. the application of signals with extensive (high) time-bandwidth product of up to 30 dB and higher, which allows either to reduce the radar peak power, or increase the radiation energy by as much as the above-mentioned value, while preserving the same peak power.

6. Energy-related breakaway from EW systems: with REE of weapons control reaching peak potential of 80...100 dBW, and onboard radars of AMIS reaching peak potential of 70...80 dBW, with radiation energy of up to 40...60 dB J, with the simultaneous descent of SL level of antenna pattern of up to -30 dB and lower.

7. Final switch to monopulse angle measurement in electronic weapons control systems and radar seekers of SAM and GAM.

8. the change (from probing to probing) of the probe signal parameters, in the first place, the carrier frequency agility (pulse-by-pulse) and pulse repetition interval wobbling.

9. the wide diversification of information sources on target data for SAM and GAM guidance (homing), requiring the EW equipment to provide jamming coverage of multiple interacting radars, operating in different frequency ranges.

10. the equipment of majority of SAM and GAM with semi-active radar seekers (SARS) and onboard radio direction finders, providing high accuracy of aiming (up to a direct hit) towards noise and deception jammers, with transition to self-guidance in the terminal phase, occurring just a few seconds before collision with the target, which toughens the requirements for the response time of EW complexes.

11. the active implementation of active radar seekers (ARS) on SAM and GAM with homing support during the missile guidance to the ARS coverage area, provided by inertial systems with radio correction for the implementation of the 'fire and forget' principle.

12. SAM guidance with no use of information on the target range:

— in SAM-systems: due to triangulation between the target attack radars of neighbouring fire weapon systems (between the target attack radar and the onboard radio direction finder of the missile);

— in AMIS: due to inter-aircraft triangulation and the so-called kinematic triangulation methods for target range estimation with the help of one aircraft only.

13. the development and implementation of the whole armoury of anti-jam systems and methods against traditional and advanced digital jamming types.

What do EW-systems have to offer in contrast?

the increase of signals' time-bandwidth product of new radio electronic weapons control systems (REWCS) while preserving peak potential equal to the one of earlier REWCS and energy breakaway from EW analogue systems, related to that, set the task of coordination and matching the jamming spectrum with the one of probe signal, which was achieved with the advent of DRFM-based EW systems.

Herewith the energy power balance between EW and radar stations was partially regained, however, in all other respects the digital EW systems failed to offer any substantial advantage in the effectiveness of jamming REWCS, since the older analogue EW systems as well as new digital active jamming stations possessed only deception and masking jamming against the channels of detection, range and Doppler velocity measuring. For the suppression (jamming) of angle channels with monopulse direction finders those jamming stations did not possess any self-protection tools. As means for collective and mutual protection, there was employed either cover jamming (air defense terminology) or stand-off jamming (aviation terminology), or jamming for collective protection: blinking countermeasures of various types from the group of jammers, unresolved in range and velocity. Low effectiveness of blinking countermeasures has been proved by a number of flight tests and military exercise.

the preservation of specific capabilities in jamming the distance and Doppler channels of electronic systems was well compensated by the above mentioned firing modes with no 'range data' employed. For quite a few SAM-system types, it may be considered common practice to do firing with no range data available, or at least such firing does not present the biggest challenge to them. With no range data available, a SAM-system either employs the mode of prior range or a well-known 'line-of-sight' method, which does not require the target range at all.

Thus, frequency spot noise masking countermeasures, generated by digital active jammers, definitely, complicate and hinder the REWCS combat operation, however, after the launch of the missile with a radar seeker, the probability of killing a jammer, generating such countermeasures, is substantially higher than the kill probability of a 'jam-free' target.

High expectations laid on deception countermeasures, i.e. those, generating likely false marks (against target attack radars), 'moving' along realistic trajectories (though, only in the reference system 'range-velocity'), were ruined once REWCS (target attack radars) adopted and implemented an ability to change many parameters of the probe signal: carrier frequency, pulse repetition interval, pulse width, type of interpulse and inter-pulse-burst modulation, up to the change of polarization of probe and received signals.

Digital jamming equipment cannot possibly catch up with the pulse-to-pulse frequency hopping of the jammed radar. False marks at best can appear only 'behind' the jammer, i.e. at a longer range. In the fixed-frequency probing mode, the stability of false marks, generated by digital deception countermeasures, is destroyed by simple wobbling of repetition frequency, transforming deception jamming into relict asynchronous pulse (fruit pulse) one.

Moreover, the existing active jammers and those under development, which implement the distance - Doppler concept, including the world's top systems, fail to provide effective protection of air platforms against self-homing missile weapons when in modes of collective (group) and mutual protection and are extremely dangerous when used for individual protection.

the existing EW systems are not capable of competing and counteracting contemporary REWCS. Effective and reliable EW calls for brand new principles, methods and ways of counteraction.

the  EW systems, developed by the company 'Defense Initiatives', employ the game-changing EW concept that shall provide effective radio electronic protection of any types of air platforms with no application of any special measures in the reduction of radar cross section (RCS) of the protected platform.

Key Principles of the Concept:

— individual protection of the carrier as top priority;

— only REWCS shall be exposed to jamming;

— stealthiness of applied countermeasures;

— versatility of jamming effect;

— invariance of the system for individual protection;

— continuous effect on REWCS;

— no restrictions on throughput capacity;

— no restrictions on combat tactics of the carrier;

— electromagnetic compatibility with the onboard electronic equipment (avionics) of the carrier.

Let us consider the key principles of the concept in detail.

1. Individual protection of the carrier as top priority

Only individual protection of air platforms may be effective. As for collective protection, i.e. the generation of masking jamming from the air patrol zone (standoff jamming), it is tactically feasible only when applied against strike aircraft and may serve only as a supplement to individual protection. the application of aircraft close formation (unresolved in angle, range and velocity) is tactically reasonable only in terms of complicating and impeding the operation of attacking SAMs and GAMs. That is why collective protection (the protection of similar-type aircraft in close formations) makes sense only with no effective individual protection available.

the partial or even complete rejection of collective and group protection is accounted for the inability to provide any effective protection of co-operating carriers against REWCS with monopulse angle measurement. Moreover, the rejection of group protection is determined by the following conditions:

— group reciprocal protection, in principle, shall only be possible for those air platforms, used in close air formation. Even though in a number of cases the group application of air platforms, for instance, strategic cruise missiles, is possible; however, it calls for special technical measures aimed at missiles' formation in the area of expected attacks by air defense systems;

— group protection imposes heavy restrictions on the tactics of air platforms;

— even if we assume that SAM and GAM radar seekers possess angular strobing (gating) as a means of protection against blinking countermeasures, then even with a standard number of SAM (GAM) to fire an individual target (2 missiles), the protection effectiveness of one of the co-operating carriers is, in essence, provided at the sacrifice of the second carrier. This is connected with the fact, that when hitting one of the carriers with the first missile from the salvo or volley, the probability of killing the second carrier (the point source of any types of countermeasures against the range finding and Doppler systems of the seeker) is maximum and, as a rule, higher than the one of the 'jam-free' target.

As for collective protection (standoff jamming), i.e. the protection of air platforms through affecting the side lobes of antenna pattern from the EW aircraft, then, while providing certain protection from SAM (GAM) retargeting, the given method requires the high sensitivity of ELINT receiver and calls for the peak potential of the active jammer or the one beyond reachable scope.

Please, note the following highly significant advantage of individual protection. Individual protection provides for jamming effect only on the main lobes of EWCS antenna pattern, which saves 15...35 dB of AJ potential relative to the methods of distance-Doppler concept, requiring the preemptive effect on REWCS antenna pattern SL in order to exclude any lock-on. In fact, the switch to individual protection does not tackle the problem of AJ potential deficit, but at least it offers solution to it, thus making it solvable. the same is true for the problem of sensitivity deficit of AJ receive paths, isolation between receive and transmit antennae.

Individual protection shall be understood to mean the jamming impact only on the antenna pattern main lobe of the suppressed electronic system.

Transition to individual protection provides:

— saving of 15...35 dB of the AJ potential, when compared to effecting the side lobes of antenna pattern;

— solution to the problem of sensitivity deficit of receive paths;

— solution to the problem of isolation between receive and transmit antennae;

— light weight and small dimensions;

— low power consumption.

2. REWCS only shall be subject to jamming

According to the new concept, the jamming shall be applied only against the radio electronic systems, directly controlling self-guided and TV-guided missile weapons and gunfire of air defense systems. Under the new concept, the following systems shall be referred to REWCS:

— target attack radars of long-range and medium-range SAM-systems;

— onboard radars of fighter-interceptor aircraft;

— active and semi-active radar seekers of SAMs and GAMs;

— radars for guidance of mobile short-range SAM-systems and antiaircraft artillery system.

One thing is sure: all new is well forgotten old. the concentration of EW efforts right on the terminal homing phases of guided missile weapons has been repeatedly declared as the EW principle, making it possible to dramatically reduce the AJ frequency range, lower the required jamming potentials, etc. However, the principle, lacking the support of the effective system (method), being able to suppress REWCS and, in the first place, radar seekers, is nothing but wishful thinking.

the contemporary, so-called, systematic or integrated approach in EW, i.e. the suppression of all radio-electronic systems, united and incorporated in the air defense system at the earliest phase of radar contact - detection - happens to be the result (or rather masking (concealment) of missing effective methods for individual protection of platforms against radar seekers. For the Air Forces of the USSR and USA of the 80-90s of the 20th century the given approach was acceptable, since it was possible to provide protection of strike aircraft with involvement of special EW aircraft and helicopters, loitering (patrolling) outside the effective area of air defense systems, in combat formations, the so-called 'reinforced (with EW means) aircraft'. But as of the present, in the overwhelming majority of countries the Air Forces cannot possibly afford to implement the 'integrated' approach in the foreseeable future due to insuperable financial and economic difficulties. Let alone tactical difficulties related to the coordination of protection zones (cover zones) covered by combat formations of aircraft and helicopters of collective protection (EW) when protecting strike aircraft.

Let us elaborate only on the key advantages, resulting from the implementation of the given point of concept:

— the reduction of the frequency range of suppressed radio-electronic systems. the effective protection against GAM suffices the frequency range of around two GHz in a frequency range of 8.5…10.5 GHz. the protection against SAMs requires a frequency span from 6 to 12 GHz. the protection against target tracker of short-range SAM-systems requires a span from 12 to 18 GHz. the exclusion of 10-cm and decimetric wave bands even for smaller carriers presents an invaluable advantage, offered by the new concept.

— the reduction of real power potential to the level that can be actually attained in each class of carrier, even if the suppressed RES were jammed in the side lobes of antenna pattern. the decisive gain in potential is connected with refusal to perform jamming in the side lobes of antenna pattern;

— the exclusion of  the carrier's early disclosure through jamming generation until the detection of the carrier. For the carriers, employing the signature reduction measures (RCS reduction) (Stealth), this is the only way to retain those advantages that had been achieved by such costly means. Standard requirements for the electronic intelligence of modern active jammers provide for the detection of signals of jammed RES not less than at a 1.2*Ddet (detection range) of the carrier or at a 1.8 of the maximum killing range and immediate jamming generation for the break (exclusion) of acquisition and lock-on of the carrier. There is hardly any logic when the aircraft designer manages to reduce RCS one order less compared to the previous modification of the same class, and then the designer of AJ for this very aircraft implements the concept under which the hostile onboard radar locates this very aircraft with high probability by the signal from AJ long before any hostile RES REWCS (target attack radars) will be able to detect it by the airframe echo signal.

3. Stealthiness of applied countermeasures

the application of jamming shall not be disclosed or detected by standard means and tools for the analysis of electronic environment of both the suppressed RES and those RESs, interacting with them. the jamming application, covert in terms of signal and spectrum, or stealthy EW methods, form the backbone of the future EW effectiveness, and make up the key conceptual principle of the new radio electronic protection.

the epoch of noise countermeasures was marked by the open and overt application of EW means and tools with no attempts on any masking, since the primary task was to effect suppression. That, naturally, resulted in the mobilization of all ECCM resources, which the suppressed RES featured; the increase of number of missiles assigned for attacking the jammer, the allocation of additional firing channels, the concentration of firing on the jammer by several SAM-systems or AMIS aircraft and the like measures, let alone the fact that when in combat environment jamming was easily detectable by elementary automation facilities and tools.

the concept of DRFM-based deception jamming laid the groundwork for the covert application of countermeasures. It suggested the generation of stable likely false targets, with the mark from the real target to be entirely indiscernible. However, any hopes for covert application of digital deception countermeasures shall be abandoned for indefinite time due to the insuperable challenge connected with providing the stability of marks in range and Doppler velocity when changing the parameters of target probing and the virtually random nature of such marks in angular coordinate even with stable single-frequency probing.

the give-away features of deception jamming for Doppler RES (in case of short-number digitization of the probe signal) consist in specific spectral 'tails', allowing RES operating crews to securely discern and single out the target mark.

the overt jamming application contributes to the reasons for permanent EW crisis. the application of EW tools shall not provoke and instigate the suppressed RES to the employment of the whole range of ECCM or at least it shall postpone this mobilization of ECCM resources of RES for the later phase of their combat performance. Theoretically, up to the very end of jamming effect, i.e. up to the flight of SAM (GAM) at a safe distance from the carrier, there shall be maintained the illusion of RES operation against a 'jam-free' target.

the realization of this very point, i.e. 'covert jamming', tackles the problem of counteraction against the measures of the so-called 'counter-EW'.

the transition from electronic jamming to electronic protection presents a highly significant feature of the concept.

4. Versatility of jamming effect

the system of individual protection shall focus on the use of only fundamental characteristics of hostile REWCS.

It is totally unacceptable to design a self-defense system, based on the employment of particular design errors and defects of the specific REWCS.

95% of all REWCS in their design are based on monopulse direction finding. A number of target attack radars may miss a range finder or lack a Doppler velocity meter, but there are no contemporary REWCS with missing monopulse angle measurement equipment.

Out of four radar coordinates, such as range, velocity and two angular points, the first two register the target position on the beam (a straight line), the other two - the position on the contracting (expanding) sphere. In terms of the set theory, the power of the two sets is the same and equal to the power of continuum. However, in the supplement to the guidance task of guided, let alone, self-guided missile weapons, the accurate indication of angular points almost fully tackles the tasks, assigned to the weapons control system. And in this sense the 'power' (capacity) of the angular protection system is incomparably higher than the one of EW distance-Doppler systems.

A rather categorical choice of the data link channel, to be jammed in the first place, shall not be considered as a sign of some inherent imperfection and incompleteness of the new concept ('we jam what we can'). In fact, it results from the fact that nowadays the proposed solution (concept) deems it necessary and sufficient to concentrate efforts on jamming RES monopulse direction finders only.

the system of individual protection shall affect the hostile RES direction finders and negate (disrupt) their operation.

5. Invariance of self-defense systems

the system, providing the carrier's individual protection and implementing the new concept, shall be invariant to all existing and expected (in the near future) ECCMs, including the change of all parameters of  RES probe signal and, first of all, the agility of the signal's carrier frequency.

In other words, the system for individual protection, adopting the new concept, shall fully neutralize the key anti-jam tool of new generation RES, which is the change of probe signal parameters.

6. Continuous effect on REWCS

According to the new concept the impact on REWCS shall be maintained at all the stages of their operation:

— target surveillance (search) (repeated search — in case of external target designation);

— target acquisition and lock-on;

— radio guidance of the guided missile to the coverage area of the radar seeker;

— target illumination for guided missiles with semi-active radar seekers;

— operation of the guided missile radio proximity fuse.

Certainly, effective jamming at the stage of tracking, resulting in the automatic track loss of the target, covered by the EW system, may be considered an almost sufficient means of electronic protection. But it is only 'nearly sufficient' since the track loss may occur, for example, when the radar seeker of SAM (GAM) has already locked on the target, etc. With regard to highly automated onboard radars, the application of effective jamming at the surveillance stage may even decide the combat of two fighters. Therefore the effective action of EW system shall be provided and maintained at all the stages of REWCS combat operation.

7. No restrictions on throughput capacity

One of the main provisions of the new concept states that the number of simultaneously jammed REWCS is not limited.

8. No restrictions on combat tactics of the carrier

the system of individual protection, implementing the new concept, shall not restrict the capabilities of aircraft when maneuvering or in combat formations. No restrictions shall be laid on types of combat formations, flight altitude, levels, etc.

9. Electromagnetic compatibility with the carrier's onboard radio electronic equipment

According to the new concept, the system for individual protection shall provide complete electromagnetic compatibility (EMC) with the onboard radio electronic equipment (avionics) of the carrier and shall not affect a neighbouring aircraft in the formation.

To blank the emissions of EW systems, as well as onboard radar, navigation, communication and other systems, as the main technique for providing ECM, is unacceptable. In doing so, it is not possible to provide EMC of new EW systems with the onboard radio electronic equipment of the carrier by blanking the operation of the onboard radar and ELINT of the carrier, what is common for existing EW systems.

the protection effectiveness should not be affected or lowered in the course of independent operation of EW equipment of the nearest neighbouring aircraft in combat formation.

the requirement for 'ecological compatibility' in terms of EMC 'purity' of the protection complex is evident. the independent application of the carrier's EW even in the closest combat formations constitutes the key requirement for the tactical isolation of carriers. In present day air combat or when penetrating into the air defense effective zones, the freedom of group maneuvering as well as the one of individual aircraft within a group offer an invaluable tactical advantage.

the implementation of the above-mentioned principles of the new EW concept made it possible to develop the electronic protection equipment, making up the integral part of the airborne defense suites 'Talisman' and 'Amulet'.

Below there are listed the key advantages of the electronic protection equipment, implementing the new EW concept.

— the sci-tech solutions, applied in the given radio electronic protection equipment, provide the unattainable for any other means protection of aircraft against guided missile weapons, being resistant to any known ECCM (anti-jam) methods and tools and having no match in terms of  'effectiveness/value'.

— the covert and non-provocative nature, inherent in the application of new electronic protection solutions, allows to avoid any accusations of aggressive actions when flying in border areas in the conditions of continuous radar contact with REE of AMIS of neighbouring states.

— Weight-size parameters, power consumption and additional RCS, inserted by the antenna assemblies (systems) of electronic protection equipment, are appreciably lower than the one of currently designed AJ.

— the new equipment for radio electronic protection is applicable for the protection of every single type of operational and military transport aircraft and may be used for protection against terroristic or unauthorized application of guided missile weapons in the missions of civil and VIP aircraft, both in the local area and any other regions of the world.

In conclusion it shall be pointed out that:

the traditional jamming methods can be fully defined as the methods employed for the radio electronic SUPPRESSION of radio electronic equipment. the military forms of EW, resulting in the inevitable extensive forms of EW development happen to reflect a futile attempt to 'cover' all the frequency range of radar systems, all REE types, at all phases of radar contact, etc. Therefore the military EW approach shall give way to the game-changing form of EW. the given form may be naturally termed as RADIO ELECTRONIC PROTECTION of carriers. In other words, there is implied the new quality of jamming impact, but not the quantitative growth of potential and jamming frequency range expansion. the supporters of classical military EW have plans to adopt megawatt and even gigawatt levels of wideband countermeasures, radio electronic bombs, and similar tools and methods. It should be noted that almost insolvable problems of EMC in home REE already occur at levels of 40…50 dBW.

the exclusion of any provocative and preventive application of jamming from the new concept as well as the change of suppression for protection allow the new concept of jamming development to come in line with the defense doctrine.

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