Early warning and long-range naval surveillance radars

The Royal Netherlands Navy De Zeven Provinciën air defence and command frigate has been the first of four class ships to be equipped with the new Thales Nederland SMART-L MM/N long range surveillance radar. © NATO/US Navy

By Luca Peruzzi

By Luca Peruzzi The increasing number of air breathing and ballistic missiles and the addition of hypersonic weapons in the naval domain pushed worldwide naval forces and industries to develop more potent long-range surveillance radars capable to provide necessary information for a successful engagement of such challenging threats. Naval ballistic missile defence (BMD) early warning sensors registered high interest in the last years, although they received scarce resources within the current national and alliance territorial and expeditionary defence concepts. Hereafter a short analysis on European and Israeli industries new products.

Thales

In May 2021, during the US-led NATO At-Sea Demonstration/Formidable Shield 21 (ASD/ FS 21) Integrated Air and Missile Defence (IAMD) exercise, the US Navy’s Paul Ignatius Arleigh Burke Flight IIA class destroyer used data from Thales’ SMART-L MM/N long range surveillance radar and upgraded combat system of the Royal Netherlands Navy (RNLN) De Zeven Provinciën air defence and command frigate (Luchtverdedigins en commandofregat – LCF) to conduct a “Launch on Remote” firing of a Raytheon Standard Missile 3 (SM-3) and guide it to intercept a non-separating ballistic missile well outside the earth’s atmosphere.

This major milestone in fielding a BMD longrange surveillance and track capability is the

The SMART-L MM/N radar represents a substantial upgrade and re-architecture of the existing SMART-L model, introducing a series of hardware, software, and operating mode enhancements, including a new high-power AESA antenna, a huge uplift in processing and the patented Extended Long Range waveform. © Thales Nederland

culmination of a long roadmap which started in the mid-1990s, well before the announcement by the Netherlands government plans to upgrade the four De Zeven Provinciën-class frigates in November 2011 as part of its national contribution to NATO’s BMD capability and consistent with the alliance’s Smart Defence initiative. This was followed in June 2012 by the contract award to Thales Nederland for the development of the new SMART-L MM/N and the manufacture of the four series-production radars. The starting point of the latter solution is the existing SMART-L L-band (NATO D-band) 3D volume search radar capable of automatic detection, track initiation and tracking of up to 1,000 air targets at ranges up to 400 km. In addition to RNLN’s four LCFs, the SMART-L also equips the German Navy’s three F 124 AAW frigates and the three Danish Navy’s Iver Huitfedlt-class frigates and South Korean Navy’s Dokdo LPH. A modified variant called S1850M is installed on board the four French and Italian navies’ Horizon air defence platforms, the UK Royal Navy’s six Type 45 destroyers and two Queen Elizabeth-class aircraft carriers.

The SMART-L MM/N is designed to detect air, surface, and high-speed exo-atmospheric targets such as ballistic missiles and space objects, the latter here depicted, respectively out to an instrumented range of 480, 60 and 2,000 km. © Thales Nederland

Leonardo developed the fully-digital Kronos Power Shield early warning radar for tactical ballistic missile surveillance and defence. The system has been developed for the Italian Navy and procured for the Qatar Emiri Naval Forces. © Luca Peruzzi

The new system represents a substantial upgrade and re-architecture of the existing SMART-L, introducing a series of hardware, software, and operating mode improvements, including a new high-power active electronically scanned array (AESA) antenna based on Gallium Nitride (GaN) transmit/ receive modules (TRMs), a huge uplift in processing and the patented Extended Long Range (ELR) waveform extensively tested in different campaigns and exercises, enabling the detection and tracking of fast-moving objects through space.

The resulting SMART-L MM/N is designed to detect air, surface, and high-speed exo-atmospheric targets such as ballistic missiles and space objects out to an instrumented range of 2,000 km. The new radar autonomously detects ballistic missile type of targets and following fast track initiation, these targets track is maintained up to zenith. With same SMART-L dimensions and a 9 tonnes antenna, the system has an instrumented range of respectively 480 and 60 km against air and surface targets, while tracking capacity reaches 1,000 tracks. Combining dual-axis multi-beam with instantaneous monopulse accuracy in azimuth and elevation, and instantaneous Doppler processing for the full range azimuth and elevation coverage with the patented ELR waveform, the SMART-L MM is designed to operate in four different modes: standard air surveillance; air surveillance and BMD mixed;

The Kronos Power Shield, here depicted on the Italian Navy new Trieste LHD, has an instrumented range of respectively 400 and 1,500 km against air-breathing and ballistic missile targets. © Giorgio Arra

A key feature of the Kronos Power Shield is a rotating antenna structure with lateral doors enabling personnel to conduct maintenance completely indoor. © Luca Peruzzi

air surveillance and BMD sector; and BMD staring. In rotating modes, the radar updates every five seconds, while in the dedicated BMD staring mode the update rate can be set at either two or five seconds. The new radar is also software programmable, allowing new capabilities to be added during the lifecycle, making the radar future-proof for evolving requirements.

During the ASD/FS 21 exercise, the first LCF upgraded not only with the new radar but also with the combat management system (CMS), alongside the introduction of a new Tecnobit LINPRO link processor, allowed the US destroyer to intercept the exo-atmospheric flying target based on SMART-L MM/N data without seeing the surrogate ballistic missile when the SM-3 missile was launched. Once it came under US ship radar coverage, the latter switched to its own data to neutralize the threat. Thanks to this and to the validation of the BMD chain, the SMART-L MM/N has been declared initial operational capable (IOC). The second frigate (Tromp) already equipped with the new radar is planned to participate in a similar NATO exercise in mid-2023 to validate new functionalities after which, if successful, the SMART-L MM/N will achieve full operational capability. The third frigate (De Ruyter) upgrade is in full swing while the fourth (De Evertsen) is expected to follow only in 2024 during planned maintenance and upgrading activities. The SMART-L MM/F land-based version was ordered for the to the Royal Netherlands Air Force in two systems, the first of which already delivered.

Leonardo

The Italian Navy challenging operational requirements, and in particular the demanding threat represented by the ballistic missiles, have taken Leonardo to develop under contract a new generation of L-band (NATO D-band) long-range surveillance radar to replace the current RAN-40L model.

Leveraging RAT-31/FADR L-band longrange land-based radar developments, the participation to ATBMD NATO activities, the technologies already proven through in-service EMPAR passive phase array and Kronos family of AESA multifunction radars which dates back to the early 1990s, as well as the latest developments in radar technologies, Leonardo developed the fully-digital D-band Kronos Power Shield early warning radar for tactical ballistic missile surveillance and defence. Conceived for both naval and land applications, the Kronos Power Shield is the first Leonardo’s fully digital radar using state-of-the-art digital beam forming (DBF) technology, latest micro-electronics and GaN TRMs developments providing more emitting power, higher work duty and efficiency among other enhancements. The core block of the new digital antenna is the DAT (Digital Active Tile), which implements a full radar chain for each single radiating element, starting from the waveform generation up to the broadband analogue-to-digital converter. More than 1,000 radiating elements grouped in DATs provide a completely distributed architecture controlled at single element level. This, according to Leonardo, brings increased performance, new functionality and the ability to implement a wide range of radar scanning

architecture required to match current and future challenging operational requirements. The fully digital architecture provides, according to the manufacturer, excellent tracking accuracy thanks to bi-dimensional digital monopulse capability, high range resolution (wide band) to discriminate tactical ballistic missile (TBM) booster from TBM reentry vehicles, advanced ECCM (Electronic Counter Counter Measures) capabilities and clutter/multipath suppression by means of adaptive digital beamforming, in addition to stared antenna mode for radar performance extension. A key feature of the new radar is the capability to conduct maintenance completely indoor thanks to a 7 tonnes rotating antenna structure with lateral doors that allow personnel to access and conduct activities inside.

The Kronos Power Shield covers the full spectrum of BMD capabilities that modern complex scenarios require for an early warning radar (EWR), says Leonardo. With a 15 rotation-per-minute and a respectively 4 seconds (rotating) and 1 second (staring) update time, 360° or sector search volume, an elevation coverage of respectively 70° and 90° in search and tracking modes and electronically scanned beam coverage of ±45° in azimuth and 0°-90° in elevation, the new radar can simultaneously track over 1,000 targets and has an instrumented range of respectively 400 and 1,500 km against airbreathing and TBM targets. Funded within the 2015 Naval Law, the first radar went through all test and qualification activities and was installed in 2022 on board the Italian Navy’s Trieste LHD platform, which is currently planned to be delivered in 2023. The second radar is currently conducting functional and performance qualification and acceptance activities at Pratica di Mare Leonardo facilities near Rome; these are planned to be completed by late 2022 after which the Kronos Power Shield will be declared ready for service. The new radar has so far been acquired in one system for the Italian Navy and one for the Qatar Emiri Naval Forces (QENF). According to Leonardo, the Kronos Power Shield together with the C-band Kronos Grand Naval rotating AESA multifunction 3D radar can deal with ballistic missiles up to 600 km range, while the new system together with the C-band four fixed faces Kronos Quad AESA radar can manage ballistic missiles with ranges up to 1,300 km with re-entry vehicles.

In August 2021, Hensoldt and IAI received a contract for the supply of four new long-range air surveillance radars to be installed on in-service German Navy’s three F124 Sachsen-class air defence frigates and at a land centre. © Hensoldt/IAI

The new AESA long-range radars by Hensoldt and Israel Aerospace Industries will have a range of more than 400 km for air targets and up to 2,000 km for objects in earth orbit. © Hensoldt/IAI

Hensoldt/IAI

In August 2021, the Bundesamt für Ausrüstung, Informationstechnik und Nutzung der Bundeswehr (BAAINBw), Germany’s Federal Office for Bundeswehr Equipment, Information Technology and In-Service Support, awarded Hensoldt and Israel Aerospace Industries (IAI) a contract for the supply of four new long-range air surveillance radars to enhance the anti-air warfare (AAW) capabilities of in-service three F124 Sachsen-class air defence frigates of the German Navy as part of the “F124 ObsWuF ” programme. This followed a similar deal signed the previous month between the same parties to provide the same type and number of radars to the German Air Force under the “Hughes Air Defence Radar Nachfolgesystem” (HADR NF) programme. Approved by the German Parliament in June 2021, these programmes will support the German Armed Forces in establishing a national BMD capability in addition to the protection of the air space within the “Territorial Missile Defence” concept for national and Alliance defence. The latter represents the national overall architecture for protection against any missile threat, integrated into the NATO IAMD. The cooperation agreement between the two companies sees IAI/ELTA as design authority and Hensoldt as prime contractor for the joint development and delivery to the customer of both projects, where the German company, as a long and established partner of the German Armed Force, will bring in the knowledge of certification and specific requirement fulfilment, alongside long-term supply and support together with training.

Under the “F124 ObsWuF” programme, the Hensoldt-IAI/ELTA industrial team will manufacture, deliver and install four radars of which three on the Sachsen class air defence frigates and one at the test reference and training (TRT) facility at the German Navy’s Naval School of Technology in Parow. Having received the TRS-4D/LR ROT designation by the BAAINBw, the new long-range radars for air and sea space surveillance will replace current SMART-L systems on the three frigates from 2025. The additional radar will be installed at the land facility as early as in 2023. The latter will not only enable training for users and service technicians, but also will

allow further developments to be tested on land prior to onboard installation.

The Israeli company leverages its experience in air surveillance and BMD radar systems developed in the last decade, including the Spectra, Multi-Mission Radar (MMR) and Iron Dome, together with the MF-STAR in the maritime domain, based on fully digital architecture, high-power radar modules with GaN technology and slew-to-cue software developments, to satisfy the German Navy and Air Force with a proven capability already fielded. Hensoldt, which equips major German Navy ships with its radars, will manufacture the core components and completely assemble the radars. No further details were provided about technologies, technical description and capabilities, but according to the BAAINBw statement, thanks to the AESA technology the new radars will be able to detect and track very small and manoeuvrable targets, with a range of more than 400 km for air targets and up to 2,000 km for objects in earth orbit. According to plans, the first sensor will not be released for integration on the first frigate until the TRT facility’s test and evaluation in conjunction with a derivative of the on board combat management system module, won’t be successfully completed. The Hessen frigate will receive the new radar during its scheduled maintenance period in 2024 and overall activities on the three naval units will be completed in 2028.

The current first phase (Stage 1) of the programme, will be followed by a second one (Stage 2) centred on the implementation of the sensors’ basic capability for early warning and slew-to-cue in support of other platforms and effectors for ballistic missile defence. The F124 class frigates will not be equipped with a shooter capability to engage ballistic missiles. The BMD capability will require adjustments to the combat management system and the communication suite. Stage 2 will be aimed at developing and incorporating in the F124 command management system a separate BMD Module to reduce integration risks to a minimum, alongside a database for the specific threat classification.

The new long range sensor for German Navy’s F124 air defence frigates leverages on IAI and Hensoldt experience in air surveillance and BMD radar systems, support, training and customers requirement fulfilment. © Bundeswehr