Naval Warships now faces wide spectrum of threats from hypersonic missiles, ballistic and cruise missiles, cavitating torpedoes, rail guns, lasers and UAVs. Anti-Ship Missiles are guided missiles most of them of the sea skimming variety, and many use a combination of inertial guidance and active radar homing. A good number of other anti-ship missiles use infrared homing to follow the heat that is emitted by a ship; it is also possible for anti-ship missiles to be guided by radio command all the way.
Hard kill counter measures include long-range surface-to-air missiles, like the American SM-6 or the British Sea Viper. Next up are medium-range SAMs like the Evolved Sea Sparrow, Aster 15 or SA-N-12 Grizzly. These will be joined by the main guns from the battle group’s cruisers and destroyers firing proximity-fused AA shells (or, with some very new guns, beam-riding guided shells). If the missiles made it through those defenses, or were fired closer, the shipboard Close-In Weapons System, the rapid-firing autocannon-based weapons would engage it.The US uses one called Phalanx, the Dutch use one called Goalkeeper, the Russians have one called Kashtan.
Hard kill options dominate the doctrinal thinking of shipboard missile defense. Papers have been written modeling the value of various engagement doctrines, the optimal load out of long, medium, and short range missiles, and much more, all of it focused on how to kill missiles before they can reach the ship. Much less has been written, doctrinally, about not expending limited missiles in the first place.
Soft countermeasures include decoys that are designed to emit fake radar signatures, to sucker the missiles away from the warships . Modern Warships have launchers for a variety of decoys including basic chaff (metal strips to confuse radar) and flares to decoy infra-red sensors. Royal Navy’s Type 45 and 23/26 also have launchers for floating decoys designed to simulate a ship’s radar signature. With seconds to react it takes considerable skill to select which type of decoy to use and where to position it.
The concept of using chaff to defend against AShMs was first proven at the Battle of Latakia in 1973, where Israeli missile corvettes rendered the SS-N-2 ‘Styx’ missiles of the Syrian Komar and Osa class missile boats all but useless through competent use of chaff and jamming. By modern standards this is not that impressive as the Styx had a fantastically simple and rudimentary radar seeker, but the destruction of three enemy missile boats without taking a single hit speaks well to the importance of ship launched chaff. It is also important to note that the Israeli corvettes had no hard kill capabilities. If they had not been able to decoy and jam the incoming missiles, they would have likely suffered heavy losses.
Soft Kill methods have their own advantages . Hard kill methods have a firm upper limit as to how many incoming missiles they can defend against. Once you run out of missile and bullets, you have no more hard kill capability. Overwhelming majority of ships can only carry, at the outside, a few interceptor missiles at maximum load, whereas chaff and flare launcher reloads can be carried by the hundreds. Jammers such as SLQ-32 don’t run out of ammunition, only electricity or processing power. Floating decoys such as SLQ-49 can theoretically distract as many missiles as lock onto it, as the decoy has the Radar cross-section (RCS) of a 500ft+ long ship, but the size of a mid-range sedan. It is unlikely the decoy will take a direct hit, and is an incredibly difficult thing to sink even after multiple near misses. Chaff clouds, depending on the weather, can remain in place for tens of minutes if not more than an hour.
Low observable anti-ship weapons like LRASM and the forthcoming Block V Tomahawk will reduce the probability of kill for individual interceptor missiles such that uneven quantities will need to be used per inbound missile killed. Even with the large VLS cell numbers on the new Type 055 destroyers, it is unlikely that the task force will have enough interceptors to shoot down every incoming missile, especially with the low detection times that low observable missiles like LRASM and Naval Strike Missile allow for.
All of this means that against the theoretical worst-case, thousand-missile salvos an adversary may launch at US fleets in the future, decoying and forcing misses will be critical to keeping the fleet intact, as it will run out of interceptor missiles before the adversary runs out of AShMs. Even with revised engagement doctrines, such as shoot-look versus shoot-shoot-look, hard kill measures do not have the depth to keep fleets safe for repeated engagements. Naval ships employ integrated combination of soft-kill countermeasures, that make incoming missiles miss, and hard-kill countermeasures, that destroy incoming missiles.
Soft kill technology
There several types of soft kill measures that deserve to be explored in greater detail. First among them are jammers. Shipboard jammers are, naturally, very similar to their airborne counterparts in function. However, they can leverage significantly higher power levels to achieve greater capabilities.There are a variety of forms of jamming, whether its noise, deception, distraction or other, less well known forms, it is a critical aspect of soft kill defenses.
Chaff and flare rockets are the cheapest form of soft killing an inbound missile. Almost every combat ship in the world has a chaff launcher of some description, as they are mechanically simple and thus affordable. At their simplest, chaff rocket launchers are simply tubes with electrical connections at their base to initiate the rocket motor. However, simply firing chaff into the air on the engaged side of a ship is no longer sufficient to force a miss from a modern missile. Specific patterns of chaff are required now to blind the seekers of modern missiles. This has led to the rise of trainable chaff and flare launchers. Every major naval power has their own variant, but all achieve the same basic goal. Many launchers can also fire infrared blinding flares, highly similar in concept to the flares fired by combat aircraft.
Proper decoys are the final category of soft kill systems. These are systems like the Mk. 53 Nulka or SLQ-49 Chaff Buoy Decoy System. More expensive than simple chaff filled rockets, but far cheaper than an SM-2 or Aster 30, decoys usually have longer active time than other defensive means. They’re purpose is also different, though synergistic, than that of the expendable rocket. While chaff is meant to force a miss by confusing the inbound missile, decoys aim to present a more attractive target than the ship they are protecting. Combined with ever shrinking radar cross sections, this will likely become an ever more potent form of missile defense in the future.
As the weapons become sophisticated the soft kill technology also advances to keep pace. For example modern sea-skimming ASCM types, employed increasingly complex RF seekers with very narrow range gates and various electronic counter-countermeasures processing techniques. These threats were the catalyst to the development of increasingly automated soft-kill systems, improved chaff payloads, rapid response corner reflector decoys, and a new breed of active off-board countermeasures devices.
They’ll also activate jammers to blind the missiles’ radar and radio command links, spoofing and even cyber warfare techniques as defence against missiles. Softkill methods are more cost efficient, the most decoys can be replenished at sea and can be a cost factor of 100 times less than a missile, it may be more viable to launch multiple decoys vice one guided weapon.
The emergence of guidance methods and seeker technologies exploiting other parts of the electromagnetic spectrum has similarly resulted in the development of matching soft-kill responses. These include infrared (IR) decoys to seduce IR seekers, and multispectral obscurant payloads designed to counter electro-optical (EO) guidance systems.
Another defense is emergence of Electromagnetic weapons both ultra wideband and high power microwave type that can destroy, intercept or jam approaching enemy missiles, drones, rockets or aircraft at much lesser cost than firing an interceptor missile which can cost up to hundreds of thousands of dollars. This tactic would both force enemies to spend money on expensive weapons while decreasing the offensive and defensive weaponry costs to the U.S., therefore advancing a “cost-imposing” strategy.
Navies must focus on auto EW systems to survive hypersonic missiles
Paul Bradbeer, a former Royal Air Force air electronics engineer, and now electronic warfare operational support technical sales manager for MASS Consultants, presented a paper in EW Europe 2017 exploring three themes: a detailed analysis of the kill chain itself; the application of artificial intelligence to automate and compress the decision cycle; and the merging of traditional EW practices with modern cyber techniques.
“Good ASMD should address this by integrating hard-kill and soft-kill solutions with a dynamic threat evaluation weapon allocation [TEWA] tool embedded in combat management systems both at the unit and task group level,” he said. “This TEWA function should present the operator with an automated solution, able to be vetoed where necessary [‘man-on-the loop’] as the man direct ‘in-the-loop’ will no longer be able to cope when faced with multi-axis, multitype, multithreat scenarios.
Future hypersonic weapons engagements will present scant warning cues to platforms, and will be delivered so fast that traditional man-in–the-loop responses will be unable to cope, according to Paul Bradbeer, the electronic warfare operational support sales manager at MASS, a leading British company in the field.
Bradbeer noted that as a general guide, some “future hypersonic missiles may be seven times faster than the threats we have dealt with in the past, and engaging from twice the distance.” IISS’ Barrie said the threat to high-value targets is further exacerbated by the possible attack profile of these new cruise weapons. “Some of these cruise missiles could fly at 80,000 feet or more, an altitude most naval radars traditionally don’t bother to look [at],” Barrie said.
According to Bradbeer, the detect-to-engage sequence – today still largely based on manual drills, decisions, and actions executed by the command team – needs to be automated through the exploitation of artificial intelligence methods, specifically machine learning. “[If] a defending platform thoroughly understands the threat kill chains in the local environment, and if that platform can sense and locate exactly where it is on an aggressor’s kill chain, the defending platform can make appropriate responses and deploy countermeasures, hopefully long before the end game of trying to hard kill or soft kill a weapon that has already been launched,” he said.
“In fact, a series of machine learning-based awareness chains takes the general concept of a well-drilled, highly experienced operations room team, but applies it with machine-like rigour and speed, addressing more kill-chain options than is humanly possible, and operates on seemingly unconnected fragments, which may easily be missed by even the most experienced and diligent of human operators.
This, he’s to say, maximizes such defensive capabilities by exploiting every piece of information available to the platform: establishing and filling platform information gaps, using data to locate your position in another’s kill chain, and then taking effective action to disrupt the kill chain. “In future, we will need machines to interpret these indicators and assess the likely sequence of events. The response could involve machine-led reconfiguration of combat systems and initiation of countermeasures,” Bradbeer said,
Bradbeer’s third theme explored the convergence of EW and cyber, and echoed Hogben’s call for a ‘left shift’ in kill-chain targeting. “If we consider typical ‘platform protection’ ECM, used by a defending platform against an attacker, the scope and penetration of that technique is actually quite limited… affecting predominantly the attacking platform’s sensors and weapons,” he said. “Using a stand-off ECM approach, we could assert that we are reaching further back in to the kill chain [by] targeting sensors and C2 systems of supporting and co-ordinating platforms. However, there are still many parts of the kill chain that are not targeted by traditional [soft kill], and of course, traditional countermeasures tend to address the ‘end game’.
Cyber, Bradbeer argued, offers a different mechanism by which to target the kill chain. “There is the potential to disrupt the data, processes, decision making, support infrastructure and C2 systems. For example, corrupting data before it can be made in to effective mission data sets or disrupting the supply chain of critical items. By incorporating cyber techniques… it will be possible to attack further up the chain [i.e. earlier] and attack elements and components of the kill chain that traditional countermeasures just cannot reach.”
ONR working on a new electro-optical defense for Navy ships
Office of Naval Research has planned, “ The Combined EO/IR Surveillance and Response System, or CESARS,” program, intended primarily to defend against optically guided anti-ship missiles and fast attack crafts, with unmanned aerial vehicles seen as a secondary threat, according to a presolicitation issued by ONR.
There are two distinct functions that constitute CESARS: Shipboard Panoramic EO/IR Cueing and Surveillance System (SPECSS) and Multispectral EO/IR Countermeasures for Advanced Threats (MEIRCAT). The primary function of SPECSS is to perform wide field-of-view target detection and tracking, with subsequent cueing of MEIRCAT high-resolution sensors.
The functions of the MEIRCAT system are target re-acquistion, tracking, classification/identification, 3-D ranging, threat assessment, CM execution and CM effectiveness monitoring (CMEM). Multi-band capability against multiple targets in a single engagement is required for MEIRCAT. MEIRCAT should be able to provide multiband capability against multiple targets at a time.
The overall CESARS system therefore must provide the following basic capabilities:
•Wide field-of-view (WFOV) situational awareness across multiple wavebands
•Automated multi-target detection, tracking, and cueing algorithms
•Video data acquisition, dissemination, recording, processing, and display
•High resolution classification, identification and tracking in multiple wavebands
•Integrated, precise, and real-time, active-and-passive fine tracking (including range) in multiple wavebands
•Enhanced CM capability against current and advanced multi-band EO/IR threats
•Provide precise 3_D ranging and CMEM information to the shipboard combat system
MEIRCAT high-resolution target identification and tracking cameras: MERICAT comprises high resolution LWIR, MWIR, and visible spectrum sensors. MEIRCAT sensing shall include a multi-band, high-resolution, high-frame-rate capability to support the target classification/identification, active and passive tracking, and CMEA functions.
MEIRCAT Beam Control, Pointing and Processing system includes turret/gimbal, optical bench, and window(s). The contractor shall supply Inertial Measurement Unit(s) required for tracking ship motion so that the target tracking is maintained.
The MEIRCAT software shall include countermeasure processing, transceiver to gimbal control, and system control processing. The MEIRCAT software must maintain relative coordinates of both imaging systems and targets in the ship coordinate system and provide high repetition rate line-of-sight (LOS) angular and range data for potential targets to Fire Control.
US Navy continuous upgrades for shipboard electronic warfare system
The U.S. Navy’s Surface Electronic Warfare Improvement Program (SEWIP) is a series of evolutionary development “block” upgrades for Raytheon’s legacy AN/SLQ-32(V) electronic warfare system, designed to provide incremental capability enhancements to enable its ships to continue to outpace threats. Introduced in the late 1970s, the original AN/SLQ-32 electronic warfare system’s mission was to provide early detection, signal analysis, threat warning, and protection from anti-ship missiles. The integrated shipboard combat system is equipped with a full suite of electronic warfare capabilities that can be managed and controlled manually from a console either semi-manually or automatically by the host combat management system, according to the Navy.
Surface Electronic Warfare Improvement Program (SEWIP) Block 3
The US Navy (USN) is exploring options to compete the production of hardware for its next-generation Surface Electronic Warfare Improvement Program (SEWIP) Block 3 electronic attack (EA) system. SEWIP Block 3 is designed to provide USN surface ships with expanded EA capabilities based upon the architecture of the AN/SLQ-32(V)6/SEWIP Block 2 system. As well as jamming targeting radars and missile seekers, the Block 3 increment will also introduce a soft kill co-ordination system to provide direction and scheduling for both onboard and offboard ‘soft-kill’ effectors.
Northrop Grumman was awarded a $267m contract by the US Navy to develop and manufacture the next-generation SEWIP Block 3 system. SEWIP Block 3 will provide Electronic Attack (EA) capability improvements required for the AN/SLQ-32(V) system to keep pace with the threat. The SEWIP Block 3 solution features active and passive arrays, and electronic warfare and communications functions with continuous 360° coverage. Designed to easily interact with the combat management system, the system’s multi-mission technology provides unprecedented situational awareness to detect, track and engage threats in high-clutter environments.
In contrast to traditional systems designed to operate in a narrow range of frequencies against known threats, “SEWIP Block 3 brings active electronic attack across a wider frequency range…with digital processing that will facilitate new ‘intelligent’ EW processing that will enable the system to react to signals it has never seen before,” said retired Navy commander Bryan Clark, now with the Center for Strategic and Budgetary Assessments. “SEWIP Block 3’s AESA array enables it to be a passive sensor, communication array, or a radar,” he added. “It could also confuse or obscure aircraft and ship radars” as part of the Navy’s new “electromagnetic maneuver warfare” concept.
Traditionally, ships try to shoot down incoming missiles with their own interceptor missiles at the longest possible range, Clark says, but long-range interceptors are expensive and bulky, and ships can’t carry enough — nor can the Navy afford enough — to fend off a Chinese or Russian-style mass salvo. That puts a premium on “non-kinetic” systems that can keep shooting as long as they have electrical power, like the Navy’s prototype laser or the SEWIP Block 3 jammer.
The General Dynamics Advanced Information Systems’ AN/SSX-1 is an electronic warfare system that supports a variety of missions including maritime interdiction operations against weapon, chemical and drug smuggling. The AN/SSX-1 collects precision electronic parametric data and correlates it to specific transmissions from ships and aircraft searching for potential matches. It was designed for the US Navy’s Surface Electronic Warfare Improvement Program (SEWIP) which is an upgrade to the AN/SLQ-32 electronic warfare anti-ship missile defense system. The US Navy in collaboration with Northrop Grumman successfully completed the preliminary design review (PDR) for the next-generation AN/SLQ-32 shipboard electronic warfare system.
The SEWIP Block 3 enhancements for the shipboard AN/SLQ-32 will be provided through a series of upgrades that will involve the addition of new technologies and capabilities for early detection, signal analysis, threat warning and protection from anti-ship missiles. SEWIP Block 4 is a future planned upgrade that will provide advanced electro-optic and infrared capabilities to the AN/SLQ-32(V) system.
Integrated Warfare Systems (PEO IWS) programme executive officer rear admiral Jon A Hill said: “This ensures that the cutting-edge preliminary design is on track to meet necessary technology improvements to the AN/SLQ-32 family of electronic warfare systems through specific enhancements to threat identification, prioritisation, defensive systems optimal assignment, and active engagement.” The upgraded version of current AN/SLQ-32(V)6 systems will offer enhanced, fully integrated, threat detection and active radar-jamming capability, in addition to critical enhancements in coordinated electronic warfare defence.
Nulka Active Missile Decoy
Developed in cooperation with Australia, Nulka can be used for stand-alone ship protection, or as part of a multi-layer defense system. It is intended to counter a wide spectrum of present and future radar-guided Anti-Ship Missiles (ASMs). After launch, the Nulka decoy radiates a large, ship-like radar cross section while flying a trajectory that lures ASMs away from their intended targets. Australia developed the hovering rocket while the U.S. developed the electronic payload. The system is effective over a full 360 degrees around the defended ship. The effectiveness of the decoy is wholly independent of ship maneuvers even in the most extreme environmental conditions.
This decoy weapon system can be commanded automatically or manually by the ship’s EW system or weapons control system. On receiving an ASM threat warning, the relative missile(s) angle of arrival and ship’s positional data are used to preprogram the decoy via the Decoy Launch Processor (DLP). The DLP computes the best launcher to use and an optimized flight path for the selected decoy. The flight path data is communicated to the decoy Flight Control Unit prior to launch. At launch, the decoy payload immediately begins to engage the ASM seeker.
Our Nulka Countermeasures system adds yet another layer to a ship’s layered self-defense system against radio-frequency anti-ship missile attacks. The Nulka decoy simulates the radar return from a large ship overlapping the target signal. To an enemy radio-frequency anti-ship missile, it’s a more attractive target instead. For U.S. and allied ships, it’s the smartest and most reliable way to draw missile fire away from our fleet and defeat the threat.
Rheinmetall’s Multi Ammunition Softkill System (MASS)
Rheinmetall has developed Multi Ammunition Softkill System, or MASS. supplied the MASS for the Royal Canadian Navy Halifax-class frigate upgrade program. To date, more than 200 MASS systems have been supplied to 14 nations on five continents, including 34 to Canada.
MASS is naval countermeasure system, protecting ships from most modern anti-ship-missiles as well as asymmetric threats in the littoral environment. To complete the defense of the full spectrum of naval Anti Air Warfare threats, MASS provides new capabilities as millimetre wave (MMW)-Decoy capability, MMW-Sensor SME100+ for MMW anti-ship missile detection as well as the off-board corner reflector.
Rheinmetall also offers the MASS variant MASS_ISS (ISS stands for “Integrated Sensor Suite”) that features integrated radar ESM systems and laser warning systems.
Threat analysis conducted by Rheinmetall shows that the threat to seagoing vessels in littoral waters from small weapons such as guided missiles (i.e. asymmetric threats) is basically undetectable using current shipboard sensor systems. In order to bridge this capability gap, Rheinmetall is cooperating with the Israeli company Elta to integrate its NavGuard technology into MASS. NavGuard is a radar-based projectile warning system capable of detecting even small incoming threats. MASS has already undergone successful live-fire testing in combination with NavGuard
Conclusion
Future conflicts will likely require a dramatic reorganization of doctrine to survive repeated instances of very large missile salvos between opportunities to replenish ship’s magazines. This will mean that interceptors must only be used for those missiles that either can not be decoyed in time, or can not be decoyed by virtue of technological superiority. Soft-kill options must be considered to be equal in importance to hard kill capabilities in the future, or everyone is going to be losing a lot more ships than expected.
References and Resources also include:
- http://edition.cnn.com/2016/10/10/politics/yemen-us-navy-targeted/
- http://www.popularmechanics.com/military/weapons/a23325/yemen-uss-mason-navy-destroyer-defense/
- https://www.overtdefense.com/2019/08/05/behind-a-tin-foil-shield-the-importance-of-soft-kill-measures-in-shipboard-missile-defense/
- http://taskandpurpose.com/us-destroyer-responds-someone-shoots/
- http://www.janes.com/images/assets/919/73919/Breaking_the_kill_chain_Rethinking_soft_kill_in_anti-ship_missile_defence.pdf