Anti-Ship Missile Defence

When the history of the ANZAC ships is written, it is highly likely that the success and utility of the Commonwealth’s original approach since the frigates have required minor and major upgrades to enhance their anti-submarine warfare [ASW] and anti-surface warfare [ASuW] capabilities, but not their capability to prosecute an attack.

1st Jul 2009


Anti-Ship Missile Defence

When the history of the ANZAC ships is written, it is highly likely that the success and utility of the Commonwealth’s original approach since the frigates have required minor and major upgrades to enhance their anti-submarine warfare [ASW] and anti-surface warfare [ASuW] capabilities, but not their capability to prosecute an attack. This is a consequence of the “fitted for, but not with” philosophy behind the original procurement strategy.

However, the ANZAC ships, once modified under other projects and SEA 1448, will become a vital component of the Royal Australian Navy’s [RANs] warfighting inventory, as they will outlast the four FFGs, and provide a gap-filler to support the three AWDs until the ANZAC ship replacement program emerges – now being studied in Defence. This is unlikely to happen much before 2025. Like the Navy’s Type 23 frigates, the ANZAC ships will remain operational well beyond the time originally contemplated.

Background

As built to the Blohm+Voss Meko 200 design, the eight ANZAC class ships were specified to have modest ASuW, ASW and self-defence capabilities, appropriate to the class identification of being frigates, but accepted to be inadequate for modern naval warfare, such as high density littoral combat. As built, the ANZAC ship included AAW capabilities, as follows:-

*The locally developed CelsiusTech 9LV Mk3 command management system [CMS], extensively based on the Swedish product.
*Weapon direction capability provided by the Ericsson Sea Giraffe fire control radar, with electro-optical augmentation locked to the director for gun and missile direction, which provides only a single channel of fire for ship-launched weapons (gun and missile). This meant that the gun and missile could not be fired simultaneously at different threats. Simultaneous firing of the missile and the gun at two targets required a second and independent channel of fire.
*The Raytheon AN/ SPS-49 (V) L-band long range surface search radar as the primary radar sensor.
*The elementary “Sceptre” ESM (electronic support measures), which was later extensively modified.
*The self-defence system that comprised NATO RIM-7 Sea Sparrow, a United Defence 127mm rapid-fire gun, that is not really designed for AAW, Nulka and RF decoys. RIM-7 SeaSparrow was replaced by NATO’s Evolved Sea Sparrow missile [ESSM], using the Mk41 VLS, during construction. The system was declared operational in 2004.

ESSM uses a new target continuous wave, Illuminator, developed and supplied by CEA Technology. Selected under competition, the Illuminator became the standard for all NATO’s ESSM installations.

The MK41 VLS is a modular, flush deck-mounted system that is available in structurally integrated “nests” of four, eight, 16, 24 or 32 individual cells in which missiles are housed ready for launch. Four ESSMs are stowed in a single cell. It is understood that the Mk41 VLS for the ANZACs is configured for 32 ESSMs and eight harpoon Block II anti-ship missiles (16-cell installation). Harpoon was installed during the period 2004-2008. The Mk41 VLS is also installed on the FFGs, configured for the standard missile SM-2 configuration and is ordered for the AWDs with the standard missile SM-2/3 configuration.

Nulka and a passive decoy system are installed.

*Link 11 and Satcom communications were installed, with MILSATCOM (military satellite communications) yet to be fitted.

The combat management system [CMS] design, as implemented, had a number of shortcomings including the inability to track supersonic missile threats, and that the Sea Giraffe radar provided only a single channel of fire and was initially configured for NATO RIM-7 SeaSparrow (a short range air defence missile). No other short range weapons were fitted apart from the autonomous Phalanx added on a campaign basis.

Other programs have been implemented to improve the ships’ ASW and ASUW capabilities.

It could be reasonably concluded that the ANZAC, as built, was a good-looking ship that was short on capability.

ANZAC Warfighting Improvement Program

During the ship construction program, studies on improving the warfighting capability of this class were carried out by the RAN, with a consensus reached that by mid-life the capability of the ships would be significantly less than that of contemporary ships of its class. This brought about the proposal to implement the ANZAC warfighting improvement program [WIP].

During 1998, a large industry team was assembled to study how a WIP might be developed and implemented. Companies supporting the RAN in the WIP study included Tenix Defence, CelsiusTech, BAE Systems, SMA and CSC. Advanced radar systems evaluated included the US Navy’s AN/SPY-1F, Thales’ APAR, BAE Systems’ Sampson and CEA Technologies’ developmental CEAFAR. CelsiusTech’s command management system would require significant development to process data from any of these systems.

Importantly, Australian Marine Technologies carried out ship structural, hydrodynamic and services studies along with Blohm and Voss (the designer of the Meko 200 ship design adopted for the ANZAC) and a number of its subcontractors.

The WIP study continued for about nine months until 1999, at which time it was terminated when it became apparent that the implementation costs would be unacceptably high and the ship modification activities would take too long with attendant loss of ship availability.

In retrospect, this program was simply too ambitious and expensive, as it proposed the almost complete replacement of the ship’s combat system, plant and machinery, crew facilities and other affected services by more capable systems and in that process would almost certainly have required a large plug to be fitted in the hull to provide the required space for new systems.

But the lessons learned would be incorporated in a far more modest project, the objective of which was to improve the ship’s self-defence capability against air and surface missile threats – anti-ship missile defence [ASMD].

ANZAC Anti-ship Missile Defence Project

With a $500 million initial cap, the project was announced in December 2003 as two serial and discrete Phases, 2A and 2B. It was essentially a case of – “What can you do for $500m?” The two-phase approach was adopted to isolate lower and higher risk aspects of the project. Project management was vested in an alliance comprising the RAN, Tenix Defence (now BAE Systems) and CelsiusTech (now Saab Systems). This alliance was formed in 2001 to provide a complete through-life support capability for the ships.

Awarded in May 2005, Phase 2A was considered to be a low risk activity, as it is based on using modified and new extant systems, including:-

*An upgraded CMS (SaabSystems’ 9LV453 Mk3E) derived from the original ANZAC CMS with performance, improvements – closely related to the Mk3E CMS installed on the Swedish Visby stealth corvettes (including the adoption of COTS technology). Noteworthy is the design by AMT, of an isolation platform on which CMS consoles are mounted to attenuate shock and vibration from damaging COTS components
*The SAGEM Vampir NG IRST (infra-red search and track) fielded in the French and Italian navies.

It is understood that this phase originally included a short range self-defence gun system which was cancelled.

Phase 2B is significantly based on the adoption of:-

*The CEA Technologies’ CEAFAR phased array radar, which at that time was under development.
*The integration of the CEA Technologies’ CEAMount, a solid state X-band CW Illuminator used to illuminate a selected target using the reflections from which to provide a guidance signal for the ESSM semi-active homing missile until the missile’s homing capability provided autonomous terminal guidance, comprising active radar and active electro-optics sensors.
*The adoption of the new Kelvin Hughes solid-state radar, which included a high power RF amplifier rather than a magnetron.

Extensive use is being made of land-based test facilities, established for the original ANZACs, and modified for the ASMD capability to be followed by a ship installation in 2010. The program timescale then schedules the first ship under this program to begin its initial operational capability in mid 2011, with a scheduled duration of 12 months, prior to committing the capability to other ANZACs, assuming success. It appears possible that all ships could be upgraded by 2016, assuming adequate preparation, forward ordering of materiel and ship availability.


A Quick Look at the Technologies involved in Phase 2A

Existing fire control radar

The Ericsson Sea Giraffe, the fire control radar now fitted on the ANZAC ships, is a 2D radar optimised for fire control. It uses a conventional rotating antenna and an optronic sensor integral with the radar antenna, which is not capable of independent movement for improved target resolution. As a necessary add-on, this radar also carries the antenna associated with the CEA Technologies’ CEAMOUNT ESSM continuous wave X-band target illuminator. The Sea Giraffe radar will not be replaced by a radar with more modern technology, but its range and detection capabilities will be improved to enhance detection of anti-ship missiles. In this process, the E-O sensor will be replaced by an improved capability E-O sensor.

Command Management System

The Saab Systems’ 9LV 453 MK 3 CMS has been continuously developed by the company, because of its wide involvement in naval and army use in Sweden and Australia. The improvements include a higher system data processing rate (through the adoption of open architecture), LAN-based communications and modern digital processors. Improvements in the man-machine interface are provided by the adoption of the Windows NT© applications software, advanced colour workstations and the use of COTS-based hardware throughout the system – to reduce cost, optimise system growth and life.

Adoption of COTS brings with it necessary minor modifications to the ship’s structure by installing shock and vibration isolation platforms on which the CMS is installed. One of these systems is being installed on ANZAC ship 10 for evaluation. Following successful completion of the event, this CMS will become the standard for the ASMD program and applied to all RAN’s ANZAC ships.

Infra-Red Search and Track

IRSTs are designed to detect and track the mid-IR and/or long wave IR band thermal radiation emitted by supersonic sea-skimming missiles, as they appear over the horizon on an approach course. Due to the presence of aerosols immediately above the sea surface, these threats might not be detectable by radar as well as degrading thermal detection. An IRST system is also capable of tracking larger, slower flying missiles and aircraft.

IRSTs are specified in almost all cases to provide detection and tracking over 360 degrees in azimuth and, because they are designed to detect and track missiles appearing over the horizon, they look only at low angles of elevation. IRSTs do not conventionally directly measure target range. The requirement to continuously cover an azimuth angle of 360 degrees with minimal loss of timely detection involves high speed rotation of the horizon stabilised optics, typically at 60-90rpm to provide a target update rate of at least 1Hz or less. To obviate the effects of wooding by the ship’s superstructure, installation of the ‘antenna’ at masthead is an important requirement.

The optics are designed so that acquired imagery is directed onto a focal plane array [FPA] assembly optimised for the system’s performance. The small size of a target, at long range results in images detected by the FPA, are typically less than one half pixel in size. This presents a huge processing demand, especially if there are multiple targets present and a number of other factors, including: low and variable intensity of a target’s thermal emissions; relative to the ambient background thermally noisy radiation; the presence of aerosols immediately above the surface of the sea that attenuate threat emissions; glint; possible reflections from land objects; and target smearing caused by the rotating optics. These issues are addressed by using filtering algorithms that are applied to a detector element processor to resolve a target. All these factors add up to a probability of extremely rapid detection, tracking and unambiguous declaration of a target of perhaps no better than 60-80% for existing systems. And there are very few of those available.

Future systems might use static arrays comprising thousands of detector elements assembled into matrices like a modern static multi-face radar array, or the adoption of a different approach to the sensor head movement.

After a long evaluation of the technology and equipment performance, the Sagem VAMPIR NG (third generation) system was selected and ordered for the ASMD project in July 2005.

The VAMPIR NG is claimed to improve the survivability of a ship against any (Sagem statement) air threats, in particular anti-ship missiles. It is also claimed to be effective against asymmetric threats (undefined) present in coastal areas. It is understood that this system has also been selected for the AWDs and LHDs. The ability to detect floating surface mines and swimmers under 24 hour operating conditions is not known.

A Quick Look at the Technologies involved in Phase 2B

Phase 2B will predominantly be associated with the inclusion of CEA Technologies’ CEAFAR radar and the integration of the CEAMOUNT target illuminator, both with the CMS.

CEAFAR

This fourth generation 3D active phased array radar is the result of a long and dedicated development by CEA Technologies, located in Canberra.

Features of the radar include:-

*Size and power scalability to accommodate a wide range of ship applications and the operational performance of the radar;
*High degree of freedom of the location of the planar array antenna elements to provide 360 degree, azimuth and high angle elevation coverage;
*Inherent system flexibility to meet changing operational requirements;
*Individual transmit/receive modules are software controlled to establish an antenna polar diagram to provide surveillance and target tracking as required by the CMS;

*The number of modules required in an antenna element is a function of the requirement specification;

*Extremely accurate and simultaneous tracking of a large number of targets;
*Simultaneous 3D volume and surface surveillance capability;
*Advanced target classification capability;
*High level of immunity to active jamming;
*A significant feature of the radar is that it generates verified target tracks that are output to a CMS, thereby reducing the processing load on that system;
*High reliability, high damage resistance, automatic operation and redundant design.

An operational example of the radar was installed on HMAS Arunta under SEA 1448 Phase 1D and subjected to a range of performance qualification trials to measure the at-sea performance of the radar. The formal trials were completed in March 2004, but the evaluation of its future applicability continued for some time.

A second set of trials was carried out on HMAS Perth, with specified aircraft tracking trials as part of the Commonwealth’s risk mitigation strategy. Although very successful, a model of the radar was also tested at the company’s premises in November 2008 using first production deliverables. On 1 December 2008, Parliamentary Secretary for Defence Procurement, announced that the at-sea trials of CEAFAR had been successfully demonstrated.

CEAMOUNT

CEA Technologies’ CEAMOUNT Target Illuminator is a major component of NATO’s ESSM system. It provides continuous wave illumination of a selected target, the reflections from which are detected by an ESSM following its launch. The missile homes on these reflections until it detects the target using its own embedded homing system. The missile’s homing system uses both radar and E-O sensors, with automatic selection of the sensor that provides the best tracking data.

The CEAMOUNT radiating element comprises a narrow angle antenna that is directed by the CEAFAR radar. The original Illuminator installed on the ANZAC ships was mounted directly on the trainable Sea Giraffe director, as this director provided the ship’s target tracking capability. Phase 2B will combine the functions of CEAFAR and CEAMOUNT to provide combined scalability, modularity and operational flexibility of the radar and the Illuminator.

SharpEye™ radar

Developed by Kelvin Hughes, this radar breaks new ground in naval navigation radars by using a solid state transmitter/receiver module, in which the transmitter is a high power RF amplifier and not a conventional modulator and magnetron combination. Operating in the I or F-band, the power amplifier outputs only 170W (peak power) with a 10% duty cycle – compared with an equivalent magnetron-based radar that typically outputs 25-30 kW (peak power) with a 0.05% duty cycle. The power amplifier provides longer range and also lower probability of intercept performance than magnetron-based covert radar systems.

The radar also employs a monostatic pulse doppler, solid state receiver using the doppler effect to measure target velocities and pulse compression to process received data into velocity bands – allowing accurate separation of valid targets from clutter.

The radar incorporates a performance monitoring system in which critical performance parameters are continuously measured and the results of any degradation of these are output to an operator, thereby eliminating routine maintenance.

Colour radar video is output to a compatible colour tactical data system.

The radar meets IMO mandatory requirements for safe navigation and collision avoidance.

What’s missing in the ASMD?

There are several components of a ship’s ASMD that are considered to be critically important. Not in any order of priority, but they include:-

*Adoption of the US Navy’s cooperative engagement capability [CEC] that will result in ships fitted with the capability being operationally force-centric. This will be a major determinant in their ability to contribute to the establishment of a force protection “umbrella.” Without CEC, ships remain essentially operationally ship-centric and isolated from a common situational awareness presentation essential for force operations.
*Adoption of a close-in weapon system, such as a gun or a missile. ESSM has a short range capability to engage airborne targets, but not surface targets. It is also an expensive missile and the ANZAC’s full load capacity is only 32 of same. There is therefore a very strong argument to install a short range gun capable of engaging surface and air targets (such as Typhoon or Phalanx) or an autonomous missile to engage air targets (such as Mistral or RAM). These systems typically have maximum engagement ranges of 2km for a gun and 5km for a missile. Noteworthy is that most guns fire 20mm ammunition which are not fuzed, thus placing a demand for higher accuracy of the weapon and engagement at a range when the trajectory is flat.
*A general purpose electro-optical sensor system [EOSS] capable of continuous 24 hour operation. This providing long range, horizon stabilised, automatic or operator controlled surveillance, detection, tracking, ranging and threat type classification of a wide range of air and surface threats. Also, this type of system contributes to ship navigation, station keeping, shore bombardment, and search and rescue. These systems typically carry a single bandwidth IR camera, a daylight visible band colour camera, a long range eye-safe laser range finder – all aligned on a common optical boresight In some cases these systems are also capable of directing a gun system and providing pointing data to a missile system. RAN’s FFGs are fitted with a system of this capability, excluding direct weapon control. A contract was also recently awarded to provide two EOSS for each of the AWDs. The AWD system is essentially similar to the proven system installed on the Navy’s Type 45 destroyer. The systems are supplied by Ultra Electronics Command and Control Systems, United Kingdom.

Conclusion

The ASMD project will not upgrade the ANZAC Class ships to a level of capability that is common in many other ships of this class in other navies, but it will greatly improve its chances of survival in a limited multiple threat air attack. However, this will be insufficient in an intense littoral air and surface warfare environment, particularly if the ships are not part of an integrated force.

Like most Australian defence projects, absolute superiority is considered to be unaffordable. This project is ‘tuned’ to a lesser level of capability, commensurate with the perceived low density operational environment considered likely to emerge during their remaining life.

APDR at a glance