Self-Protection Task for Surface Ships

Self-Protection Task, as part of Electronic Attack, contributes to Platform Immunity (or Platform Survivability) by decreasing or cancelling Platform Susceptibility to ensure the full mission capability in the battlefield for the entire duration of the engagement.

This task is accomplished by giving to the platform the capability to interfere with the kill chain of the opponent weapon system according to the following steps:

1. Not to be seen: ability not to be detected by the opponent weapon system.
2. Not to be tracked: ability not to be classified, identified, tracked by the opponent weapon system.
3. Not to be engaged: ability not to be detected, discriminated, tracked by the launched weapon (terminal threat).
4. Not to be hit: the ability to escape from the terminal weapon avoiding being hit (combination of range/velocity/angle deception and platform manoeuvres).
5. Not to be damaged: this is not included in EA task.

Following this approach the mission of EA can be seen as a whole with a combination of both Offensive and Defensive EA whose global task can be divided in two phases:

• Phase 1 is performed by Offensive EA and represents steps a and b above.

Figure 1: Susceptibility and Immunity [1]

• Phase 2 is performed by Self Protection (Defensive EA) and represents steps c and d above): to deny the target detection and tracking to a victim radar or missile seeker (terminal threats) up to the minimum distance possible (burn-through range).
  Target of this phase are Target Trackers (TT), Fire Control Radars (FCR) and missile seekers that are tackled with Range/Velocity/Angle Gate Pull-Off to seduce/deceive range, Doppler and angle tracking with the cooperation of platform manoeuvers.

Figure 2: Example of Engagement scenario

• The role of Electronic Warfare in Anti-Ship Missile Defence (SMD).
  Active radar seekers have gained wide applications in the terminal phase of missile guidance to provide hit-to-kill capability.
  They are the most popular in all the current missile programs (NATO, non-NATO) owing their flexibility of design and implementation to suit almost every mission requirement, apart from their intrinsic all-weather capability.
  This is primarily due to the choice of waveform design, optimization of receiver and adaptability and flexibility offered by the digital signal processing techniques in vogue.
  With the advances in ECM techniques, stealth technology and modern vessel operational performance, such as maneuverability and speed, new requirements are considered for seeker design:

• Low peak power for reduced vulnerability of detection as well as less demanding power supply

• High power-aperture product for increased range

• Optimum waveform design for advanced ECCM features

• Wide bandwidth operation to provide frequency agility (pulse-to-pulse, batch-to-batch, pseudo-random fashion)

• Multi-sensor data fusion being implemented through double-seeker (i.e. radar and IR/TV)/dual-band seeker (i.e. Ku and Ka)/datalink/INS-GPS

• Faster signal processing for large data handling and also for imaging

• Low radar cross section detection and tracking capability to meet stealth technology advancements

• Low weight/low volume/high-density packaging and efficient thermal management for miniaturization

• Use of commercially-off-the-shelf (COTS) components for the development of low cost seeker (as seeker costs 70% of missile just for a price of kill)

The above requirements have pushed the radar seeker technology to adopt entirely newer concepts and has led to the development of new architectures, such as millimeter wave (MMW) Pseudo random code seekers.

Electronic Warfare have a key place.

Provision of missile defence to a ship, or a group of ships, involves multiple skills and capabilities that are often required to be executed within a relatively compressed timescales during period of high threat alert, where personnel and system performance factors will have a significant influence on outcomes.
Coordination of these skills and capabilities, along with insight into the threat, are essential components of success, which can only be realized through comprehensive analysis, modelling, simulation and training to develop robust tactics, techniques and procedures (TTPs) for the efficient proactive and reactive use of integrated hard-kill and soft-kill effectors.
These all must be used with cognizance of the operating environment, including meteorological and geographical impacts on weapon and sensor systems. Good Anti-Ship Missile Defence (ASMD) seeks to bring all these factors together in a measured and coherent manner to break the Anti-Ship Missile (ASM) kill chain (Find, Fix, Target, Track, Engage and Assess processes, F2T2EA) in one or more stages
The combined and coordinated use of on-board and off-board (passive and active) countermeasures is emerging as the route to achieve this goal:

• on board active countermeasures are dedicated to the weapon system and are devoted to (a) negate the access to the spectrum (b) degrade the use of the spectrum (c) delay the firing and/or the coordination of multiple weapon systems (d) force the designation towards a false target

• off-board passive/active countermeasure perform seduction and angular deception towards the terminal threat

Although existing soft-kill offers solutions against a large proportion of currently fielded ASMs, further decoy development beyond which exists today will be required to evolve solutions, especially against MMW seekers.
This is in progress with such programs as the US Surface Electronic Warfare Improvement Program (SEWIP), with the Advanced Off-Board Electronic Warfare (AOEW) jammer system, developed by Lockheed Martin.
The AOEW system will provide MH-60 helicopters with enhanced electronic warfare surveillance and countermeasure capabilities against anti-ship missile (ASM) threats.

The AOEW AMP AN/ALQ-248 can work independently or with the ship’s on-board electronic surveillance sensor, SEWIP Block 2 AN/SLQ-32(V) 6, to detect an incoming missile and then evaluate where it is going. AOEW then uses radio frequency countermeasure techniques to deter the missile.
Other nations are developing advanced corner reflectors and K-band chaff cuts to counter the MMW seekers.
Development of a decoy’s performance against a seeker, expressed in terms of Probability of Escaping Hit (PEH) will be determined by its payload with regard to persistence of effect, its specific size and type to counter the threat (will it have enough payload of the right type to protect a given type of ship?) and do so affordably.

Optimizing the PEH of a decoy payload is directly linked to its placement in relation to the inbound threat, and will likely increasingly become a key feature in defeating a seeker’s counter-countermeasure logic. In MMW band, the seeker’s field of view is very narrow and this increases its capability to discriminate the target and the decoy. Furthermore, the ability to light on the seeker very close to the target dramatically compress the timeframe useful to deploy the decoy itself.
Equally, manoeuvring a ship to optimize the launch of decoys may compromise other ASMD solutions available (for example, minimizing radar cross section is essential to optimize the seduction effect of RF decoys) as well as influencing the use of other effectors both for AMD and other warfare domains in a multi-threat environment.

Tactical UAVs, flying around the ship during the engagement phase, equipped by active countermeasure systems and cued by the on-board EW Management System, seem to offer the necessary versatility and capability to contribute effectively to ASMD against the mentioned emerging threats.
These emerging tactics, when unmanned items are teamed with manned/supervised item, has been recently indicated as Manned-Unmanned Teaming (MUT), inside the modern more general approach known as “Collaborative EW”.
In the following, an example of possible Anti-Ship Missile (ASM) kill chain (F2T2EA) Engagement

Figure 3: example of possible Anti-Ship Missile (ASM) kill chain (F2T2EA) Soft Engagement

Phases and stages of countermeasures in future scenarios.

• The role of Electronic Warfare in countering asymmetric IR-guided threats.
  The multirole capability required to modern vessels enhances their exposure to asymmetric scenarios, especially when roles such convoy protection or humanitarian support make those assets a target for modern piracy.
  Infrared-guided missiles have been among the most deadly threats in all recent conflict. They are primarily air-to-air missiles and surface-to-air missiles and include small shoulder-fired weapons. Man-Portable Air Defense System MANPADS have been widely used against airplanes and helicopters.
  Platform engines and exhaust gases feature have high temperatures and consequent strong IR emissions. The skin of an aircraft is warm in contrast against the sky background and reflects radiation from the sun and from the earth. These direct emissions and reflections enable detection and tracking, make aircrafts and helicopters vulnerable to a wide proliferation of IR-guided missiles and search/track systems.
  Advanced IR-guided missiles (so-called 4th and 5th generation) are currently being developed and deployed in operational theatre and are available to NATO’s countries Armed Forces. However, BRICS countries are developing their own advanced weapon systems and soon will be able to include them in their defense policy.
  In the meantime, (MANPADS) represent a significant threat to both military and civilian aviation since they are also available to “non-state” organizations.
  The basic – and incremental – elements of platform defence are:

• Suppression of the platform’s IR signature to reduce missile acquisition range

• Situational awareness and identification of an appropriate defence strategy

• Manoeuvring

• Activation of countermeasures: decoys (such as flares) and also active jammers.

• Active Countermeasure solutions have been developed in US, Israel, UK and Italy and their effectiveness in defending helicopters and large body aircrafts against MANPADS has been demonstrated in trials.

ecently there have been news about MANPADS effectively employed by piracy in the maritime environment, against humanitarian convoys and commercial vessels.

Figure 4: Examples of IR guided Threats for Surface Ships

Capitalizing the experience matured in defending air platforms, studies have been conducted in maritime environment.

Challenges related to the effective employment of active IR countermeasure in maritime environment are:

• Platform signature, much more than an helicopter of even an aircraft, which could require huge levels of generated power

• Reflections from the sea surface, amplification of sun effects

• Propagation and other atmospheric effects inducted by the sea surface

• The role of Electronic Warfare in countering mini-drones.
  Small, mini, micro UAVs have drastically widespread in the last years and should continue to improve in both performance and overall functionalities.
  Technology advancements in power storage, avionics miniaturization, materials and design methodologies, together with the availability on open market of SW applications, will enable new missions to be performed by increasingly smaller, lower cost platforms.
  Anti-Drone Capability protection against Class I mini and micro UAV (manually controlled or autonomous) in a maritime environment requires:

• Multi-sensor and multi-domain architecture for detection, classification and identification of hostile drones

• Drones neutralization through traditional AND smart jamming using library based techniques

• Jamming to radio-links and/or to navigation systems

• 24/7 in operation with human supervision/decision making

Captured operational modes are:

• Completely autonomous operation.

• Coordinated activity with on-board communications and CMS interface.