Self-defense systems are vital to the survival of ships in combat. The Italian Navy is making great advances in hard-kill and soft-kill systems, making both point defense and area defense possible for its ships and task forces.
Self-defense is one of the crucial requirements for Italian naval operations. In a hostile environment—where ships must operate within the envelope of potential hostile weapons—reaction time and effectiveness of self-defense assets and confidence in their performance are not only keys to survival but also the elements that can make a mission feasible with acceptable risk.
Self-defense is even more important when such factors as investments in personnel and training, impact of media scrutiny, and ship costs are considered. The role of the media is of particular concern: any damage, injury, or loss of personnel or assets hardly can be silenced—or even understated—today.
For a ship, self-defense represents an ability to carry out assigned missions without depending on others for her own survival and to defeat an attack before sustaining damage. It is the sine qua non of mission success.
Only a careful balance between a ship’s self-defense capability and main weapons can guarantee complete freedom of action and mission accomplishment; confidence in both is required for a ship to reach her full potential.
From this perspective, self-defense forms the core of a ship’s combat system, around which all other weapons are gathered. Since no unique system is able to counter all possible threats, self- defense is realized by integrating all available resources on board in a coherent way to oppose specific threats, sequentially or simultaneously.
Self-defense systems do not limit their usefulness to the hot phase of reaction to incoming threats; they also have to deal with situations that can deteriorate quickly into open conflict. In most cases ability to react—and also assume a de-escalatory posture—must coexist.
It is necessary to have the ability to warn a potential enemy, making clear that any further action will be interpreted as a hostile act. To this aim, the identification process is extremely important and cannot be based on IFF (identification friend or foe) equipment alone, because many targets either will not cooperate or will lack any means to respond. Electro-optic sensors can partially fill the gap, but imaging capability also is needed at long distances. Electronic support measures (ESM)—both radar and communications emissions—through a number of signal-analysis techniques such as fingerprinting, are key elements in the identification process. ESM can anticipate the intentions of a hostile target, revealing through emissions analysis whether and when an engagement is going to begin.
These are significant advantages that can be exploited, like electronic countermeasures (ECM), to send a firm warning—similar to firing a shot across the bow, but more discreet. Things are different with hard-kill systems; their use always conveys, even in case of a decoy launch, the impression of an hostile act in progress.
A target indication system (TIS) fitted with an active radar sensor offers significant advantages. Radar provides detection beyond the maximum weapon engagement range, but is normally detectable by ESM from even longer distances, giving the enemy a chance to back away if he so chooses. Systematic, manifest use of a radar TIS to keep enemy assets well clear of the ship actually gives both sides the ability to consider each action carefully and assess the risk involved.
The careful and rational use of these resources allows responses to be tailored to the circumstances, therefore, self-defense systems must not only be adequate to their main role, but also be able to provide—especially in crisis situations—the means to exercise deterrence and tailored reaction within the framework of the rules of engagement.
Air defense at sea is based on the defense-in-depth principle, which postulates a layered, integrated defense around a naval force, attained through two ways: area defense and self defense. This is a well-known concept.
Area defense is ensured by specialized units—ranging from air, surface, and submarine platforms to the full capability of the naval force as a whole—where ships fitted with medium-range surface-to-air missile systems are intended primarily to counter the threat represented by aircraft and cruise missiles.
Self-defense is essential for individual ship survival. It must counter the close- in threat, mainly consisting of sea-skimming or high-diving missiles that may have penetrated area-defense assets.
On board every fighting ship, self-defense is provided by two different systems:
- Point-Defense Missile System
- Inner-Layer Defense System
The point-defense missile system (PDMS) should guarantee the ship a high probability of continuing her mission after engaging several omnidirectional waves of multiple targets attacking the ship simultaneously under severe environmental and ECM conditions. Moreover, exploiting a range advantage from its own point-defense capability, PDMS should provide an extended self-defense umbrella for nearby smaller naval vessels or escorted merchant ships.
Self-defense systems are to operate given the situation, in a fully automatic mode from detection to kill, while the PDMS operator continuously monitors the process, maintaining veto capability. Manual intervention should be limited to correct or stop the action if necessary, keeping the operator in an “observer” position, out of any direct involvement, when not otherwise required.
A careful selection of either active or passive sensors is essential to provide early warning time. The availability of appropriate sensors, operating in different bands of the electromagnetic spectrum ensures not only the highest probability of detection at a given distance but also the most precise localization of the target. High-frequency-band (X, K) tracking radars searching at 360° over the horizon and surface-surveillance radars combine effectively in detecting small tar gets—even those approaching at very low altitude, which frequently are barely detectable by traditional surveillance radars.
A pure electro-optic passive sensor surely is an important asset in this regard, but it cannot be considered the main sensor for self-defense because of its lower detection performance, especially under certain weather conditions. Moreover, it cannot provide three-dimensional target position, having to rely on other sensors for range data.
On the other hand, sensors operating in the infrared or visible field provide operators with an essential tool to carry out their task of supervising the system in a proper way. The availability of a multisensor suite permits operations under all weather conditions, with higher precision and fewer tracking errors.
SAAM (Surface-to-Air Antimissile)
SAAM is the point-defense missile system under development since 1990 by the Italian Navy inside the FSAF (future surface-to-air-family) Franco-Italian program and is designed to be installed in all new surface combatants, from escort vessels to aircraft carriers.
The basic elements of SAAM are:
- EMPAR multifunction radar based on a phased-array type rotating antenna operating in the G band, which performs in one revolution (1 sec) volumetric search at long range, low attitude and high elevation coverage, environmental map updating, jammer localization, threat preevaluation, and tracking of all targets, including our own missiles
- Up-link transmitter of the data for the missile in flight by means of radar antenna
- Computing section that incorporates dramatically reduced reaction time, threat evaluation, intercept calculations, salvo consistency, launch-sequence optimization, and own-missile guidance functions
- Vertical launching system capable of simultaneous omnidirectional
- Two-stage, “Aster 15” missile (complete ammunition in the container)
The modular design of the SAAM allows a natural evolution toward different roles besides self-defense, such as local area and medium-range defense, which altogether are covered by the system that is sought for the new Horizon frigates as ship principal antiair missile system (PAAMS). This system, which will be developed within a cooperative program— independent of Horizon—shared by Italy, France, and the United Kingdom, will operate in the following priority:
- Self Defense
- Local Area Defense
- Medium-Range Defense
The Horizon program, which also involves Italy, France, and the United Kingdom, was launched in 1994 to study, define, develop, produce, and support a new antiair warfare frigate. The Italian Navy is interested in acquiring six ships of this class, beginning in 2003.
Inner-Layer Defense System
Depending on the number of attacking missiles, the probability of an attack breaking through the PDMS barrier can not be discounted. The inner-layer defense system (ILDS) therefore must be designed to counter antiship missiles that might leak through PDMS within a range of three to four kilometers. A fully coordinated PDMS/ILDS reaction is needed, with automatic-target-handover and kill-assessment capabilities.
Foreseeable solutions are based either on missile or artillery options. Artillery solution are based either on proximity- fuse ammunition or on kinetic-energy projectiles. One of the proximity solutions the Italian Navy is interested in uses a course correction shell (CCS) for 76-mm guns, which can alter its trajectory in response to incoming missile maneuvers. This provides current gun systems improved effectiveness against most modem missiles. New-generation microwave fuses will enhance the overall performance. The ability of the CCS to vary trajectory in flight increases the engagement area of each round. In fact, by injecting discrete codes in CCS rounds just before firing, each shell’s course can be altered independently of others in flight, even those fired from other guns and aimed at the same target.
The most advanced antiship missile radar seekers generally use monopulse target-tracking techniques. At present, there is no effective countermeasure for these techniques, at least for ships. Chaff is not always adequate, and violent maneuvering has no useful application in ship-versus-missile engagements. Today, the truly effective countermeasures are based on hard-kill weapons. However, this may not be the case forever.
Cross Eye is a new false-target-generation technique based on active phased- array antenna. It has unlimited false-target repetition, all-weather capability, is invulnerable to electronic counter-countermeasures (owing to its design), and can cope with multiple, simultaneous threats by relying on near-zero reaction time. Cross Eye is well suited for shipboard installation.
In practice, two echoes (true and false targets) no longer exist. Only one echo, the virtual one, exists. Cross Eye allows the generation of as many “virtual” ships as needed—each one located in a different position with respect to the real ships.
Finally, this type of jamming by its very nature allows missiles to pursue a steady approach path, resulting in more favorable engagement conditions for hard-kill weapons, increasing the overall defensive capability of ships.
The same general principles of self- defense also apply to underwater threats for all ships whose integrity may be essential to the maritime mission. The underwater defense concept appears to be similar to an above-water layered-defense concept; and tries to neutralize potential launchers through surveillance and advanced detection and prosecution means.
The primary contribution to antitorpedo self-defense is expected from the ships’ detection and prosecution systems, which must allow preventive action against submarines (40,000-yard range is a baseline requirement for hull-mounted sonars).
Since preventive action may fail, inner-layer defense against incoming torpedoes is necessary, particularly for ships that lack ASW systems. Effective defense against submarine-launched torpedoes can be provided only by systems capable of automatic detection, classification, and reaction. This is because of the inherently short ranges at which surface units may reasonably expect to detect any attacking torpedo.
Present technologies appear to encourage the development of systems based on soft-kill countermeasures, but their integration with effective hard-kill countermeasures also should be sought—and this could become available in the medium term. Several nations are engaged in programs to develop torpedo self-defense systems (TSDS), and the Italian Navy has promoted significant national effort, particularly in the field of soft-kill countermeasures. The plan is to cooperate in order to face effectively the important technological and financial implications of fielding an effective TSDS for surface combatants by the beginning of the next decade.
The threat posed by modern (and less- modern) mines ranges from depths of hundreds of meters to the surf zone and affects a wide variety of conceivable naval missions. The availability of specialized mine countermeasures vessels to carry out explorative operations cannot be taken for granted. Consequently, even token mine fields may attain remarkable sea-denial results unless ships are equipped with adequate mine-avoidance systems. Sonar technology applications to hull-mounted and remote-control systems may be able to attain an effective capability in the near-to-medium term, if adequate priority is given to this requirement. The Italian Navy is exploring all realistic development programs to acquire effective mine-avoidance systems for generic ships. These systems should possibly be of a portable, remote-control nature, to minimize cost while remaining able to provide the right mix of systems for each operation.
Finally, it might be unrealistic to dream of scenarios in which surface combatants may be subject to attacks by undersea special forces. Nevertheless, it is conceivable that ships could be exposed to such attacks in some cases, and be particularly vulnerable to remote-controlled weapons that could be used during latent- crisis and time-of-tension situations.
Systems that can guarantee adequate alert and reaction times are not available at present, and then would be required to counter such a threat. Nevertheless, the same technology that is slated to cover important requirements in the areas of hard-kill antitorpedo defense and mine avoidance, may well provide the key to effective defense against this sometimes more-than-marginal threat.
Self-defense must be stressed in operations where confined sea areas, an omnidirectional threat, a high operational tempo, an unusual tactical situation, and a variety of cooperating assets characterize the scenario. Such operations are proving themselves useful even though widely diffused among the present hot spots of the world.
Most of them have erupted in the recent past and are not unlike those of the near future in the Mediterranean, where the Italian Navy has developed self-defense solutions based on its experience attained in this unique theater of operation. These solutions also have proved effective outside of the Mediterranean, where Italian Navy ships operated in multinational task forces.
Captain Leonardi commanded the corvette Airone and the guided-missile destroyer Impavido. He is the Project Horizon coordinator on the Italian Navy General Staff in Rome.