Naval 3D multifunction radars

By Luca Peruzzi

The family of ARTISAN 3D S-band multibeam radars is being offered for a wide range of missions and platforms, from the OPVs and support ships to corvettes and frigates. © BAE Systems Maritime Services.

European and Israeli radar houses exploit latest technologies to improve the performances of their maritime surveillance radar families. While advanced high-power multifunction radars based on fixed phased-array antennas have increasingly become the norm for specialist anti-air warfare frigates and destroyers, most surface combatants continue to rely on rotating radars for 3D short to medium range air and surface surveillance, threat detection, and target indication/ weapon support. Thanks to weight and footprint reduction alongside enhanced capabilities, the new or upgraded 3D radars are expanding the platform portfolio towards Offshore Patrol Vessels (OPVs), support ships and smaller platforms.

BAE Systems ARTISAN

BAE Systems Maritime Services offers its family of ARTISAN 3D (Advanced Radar Target Indication Situational Awareness and Navigation) S-band multibeam radars that was developed to meet the UK Royal Navy’s requirement for replacement medium-range radar. Designated as Radar Type 997 by the service, the ARTISAN 3D is today in service with Type 23 frigates, Queen Elizabethclass aircraft carriers, Albion-class LPDs and is planned to equip the Type 26 Global Combat Ship. The Brazilian MoD selected a version of the ARTISAN 3D to initially equip the new Tamandaréclass corvettes. The ARTISAN 3D is however

already in service with the Brazilian Navy on the Atlantico multipurpose helicopter carrier, secondhand procured from the UK MoD. BAE Systems currently offers a family of 3D radars, ARTISAN 100, 200 and 300, where the less-capable 100 model for OPVs, amphibious and support ships and mine counter measures vessels, can be brought to 200 and 300 model standards through hardware and software upgrade. According to BAE Systems, the ARTISAN 100 shares technologies with the same company’s SAMPSON back-to-back AESA (Active Electronically Scanned Array) MultiFunction Radar (MFR) to provide electronically stabilized 3D performances at low cost. Key technical features include a 16-element solid-state transmitter housed in the antenna, a waveform generator essentially identical to that in Sampson, digital front-end receivers from Sampson, and a signal processing architecture derived from BAE Systems’ Commander long-range land radars. Capable of 3D air surveillance with fast target alerts, secondary navigation surface surveillance, gun control support, jammer suppression and surveillance thanks to digital adaptive beam forming, digital pulse compression and Doppler processing, the ARTISAN is capable to operate in any of the following modes, all at 30 rotation per minutes (rpm), providing fully automatic detection and tracking: long-range, littoral-water defence, open-water and air traffic management. The ARTISAN 100 has a maximum instrumented range of over 200 km and maximum elevation coverage of over 70°, with a 3D tracking capacity (air and surface) of over 1,000 targets. With an antenna featuring a less than 730 kg weight design, the radar has a declared track range of over 110 km against maritime aircraft and over 35 km against missiles. The more capable ARTISAN 200 has a 3D accuracy allowing to cue active missile systems and differs mainly for a heavier antenna complex (less than 760 kg) and declared tracking range (over 135 and over 45 km respectively against maritime aircraft and missiles).

Elta/IAI STAR-X and ALPHA

Israel Aerospace Industries/Elta Systems offers its new STAR-X (ELM-2238X) compact shipborne surveillance radar system specially designed for Offshore Patrol Vessels (OPVs), but capable also to serve as secondary search radar for larger naval vessels. Operating in X-band and implementing AESA digital beam forming technology in elevation, the radar performs 3D simultaneous surface and air surveillance, offering superior detection, tracking and classification capabilities

Elta’s latest naval rotating radar development is the EL/M-2258 Alpha, a multirole solid-state S-band radar using a single rotating AESA face that leverages the same technologies applied to the company’s EL/M-2248 MF-STAR fixed-faces multifunction radar. © IAI Elta.

The GEM Elettronica new Columbus X-band 3D radar offers simultaneous short to medium-range air and surface target surveillance and tracking, alongside with weapon system target designation, with a low-weight design in mind for smaller naval platform applications. © Luca Peruzzi.

of surface vessels as well as aerial threats such as jet fighters, helicopters, and low RCS targets (i.e. drones and missiles), according to Elta. Also, capable to support surface gun fire control with splash detection, the configurable software-defined radar that allows adaptation to emerging future threats also features low probability of intercept (LPI) as well as advanced ECCM capabilities. The system employs advanced algorithms to accurately discriminate threats when operating in dense and cluttered electromagnetic environments.

The radar employs GaN (Gallium-Nitride) solidstate transmit modules to achieve a compact lightweight design that adheres to Size, Weight and Power (SWaP), with high reliability thanks to graceful performance degradation. With a radar antenna package weighing less than 350 kg and capable of 6, 15, 30 and 60 rpm with a 0°-70° elevation and electronic stabilization, the STAR-X has a 150 km maximum instrumented range, and a detection range of over 25 km against low flying attacking missiles and over 60 km versus high flying attacking fighter aircraft. With a tracking capacity of over 1,000 targets and three fire control windows for gunfire support, the STAR-X can be seamlessly integrated to the vessel’s CMS and air defence system.

Elta’s latest naval rotating radar development is the EL/M-2258 Alpha (Advanced Lightweight Phased Array), a multirole solid-state S-band radar using a single rotating AESA face that leverages the same technologies applied to the company’s EL/M-2248 MF-STAR fixed-faces multifunction radar. In service with the Israeli

The GEM Elettronica Columbus 3D multifunction radar is installed on the Italian Navy’s first-of-class Vulcano LSS (Logistic Support Ship) and one Comandanti-class OPV, and has been sold abroad in a new version to the Lithuanian Ministry of Defence. © Luca Peruzzi.

Navy, the Alpha has been recently selected to equip the new corvettes for the Philippine Navy to be provided by Hyundai Heavy Industries. The EL/M-2258 main features include 2-D electronic beam steering (scanning at elevations up to 70°), very high tracking update rate, automatic splash detection and measurement for gunnery support, and advanced beamforming techniques for multipath suppression and ECCM. In the baseline configuration with 200 km instrumented range, Alpha’s antenna unit weighs 880 kg, with below deck equipment cabinets adding 1,400 kg.

GEM Elettronica Columbus

Derived from the research, development and demonstration MFRAD (Multi-Function RADar) programme jointly funded by the Italian Ministry of Defence and GEM Elettronica, the new Columbus 3D radar develops from the latter company’s proven and state-of-the-art technologies and was purposely designed for shipborne and coastal surveillance applications, fulfilling the role of primary and secondary air/surface search radar respectively for offshore patrol vessels (OPVs), corvettes and medium combatant platforms. The new X-band 3D multifunction radar offers simultaneous short to medium-range air and surface target surveillance and tracking, as well as with weapon system target designation, and has been conceived with a low-weight design, electronically stabilized antenna complex without the need of radome and includes the option for a co-mounted IFF interrogator antenna. Weighing less than 400 kg (less than 450 kg with the IFF interrogator), the antenna complex - sided by the air-cooling unit, elevating the overall on top weight to less than 550 kg - includes a lower flat aperture for surface surveillance, target designation and navigation, together with a higher-placed and larger sloping antenna for same purposes in the air domain, capable of a programmable 10-to-60 rpm. With solid-state transmitter/receiver modules (TRMs) and power management in surface mode for LPI operations, digital beam forming in elevation together with digital pulse compression with fully coherent pulse processing for clutter elimination, frequency diversity-agility and PRF variation, the Columbus radar is air cooled and has demonstrated a maximum instrumented range of over 120 km with a maximum elevation coverage of over 60°, alongside a 3D tracking capability (air and surface) of more than 300 targets. Characterized by six operational surface and air main modes, the new radar’s digital signal processing is conducted undercover through fibre-optic connection and with the capability to elaborate and display either air, surface or both target types simultaneously on combat management system operator consoles. The initial Mk 1 system iteration has been selected and is installed on the Italian Navy’s first-ofclass Vulcano LSS (Logistic Support Ship) and one Comandanti-class OPV, while an already available evolved Mk 3 model is characterized by a system thermal optimisation, eliminating the need for the air-cooling unit, without reducing radar performances. The Mk 2 model was developed to further reduce the antenna complex weight to less than 200 kg this version lacking the navigation function, EDR Magazine understood. The latter model, according to the Lithuanian Ministry of Defence, was selected and a contract awarded in October 2021 to Leonardo - which today has a 30% stake of GEM Elettronica - to supply the 3D Columbus radar to equip the flotilla of platforms based on transferred Flyvefisken-class patrol vessels in service with the Lithuanian Navy, in addition to training and system integration. The equipment is planned to be delivered and all services provided by the end of 2023.

Hensoldt

The South African branch of Hensoldt developed the new generation Quadome 3D naval air and surface surveillance radar equipped with the latest AESA technology. According to the company it provides rapid response and high precision, at excellent price-performance ratio. The solid-state softwaredefined C-band 3D features AESA stacked beam elevation scan with electronic stabilization up to 70° maximum elevation, and a 360° mechanical continuous rotation with an azimuth scan period of 4 and 2 seconds. With a maximum-instrumented range of 200 km and a track capacity of over 1,000 air and surface targets, the Quadome has an above-deck and below-deck mass of respectively less than 850 kg each with two cabinets. Aimed at

The higher-end 3D rotating radar proposed by Hensoldt and employing the latest GaN AESA sensor technology belongs to the C-band TRS-4D family of systems. The TRS-4D Rotator equips the US Navy’s Freedom-class variant of the Littoral Combat Ship, here depicted. © Hensoldt.

the global market of OPVs, corvettes, light frigates and support vessels, the Quadome features two main operational modes that simplify operator’s interaction and reduce operator’s workload. The surveillance mode is used for general surface and air surveillance, while the self-defence mode is employed for high-threat situations and target engagement, with helicopter support continuously available in either mode.

The higher-end 3D rotating radar proposed by Hensoldt and employing the latest GaN AESA sensor technology belongs to the C-band TRS-4D family of systems. The software-defined TRS-4D Rotator is quoted to feature flexible electronical multi-beam scanning, high sophisticated dual mode operation, 3D air volume surveillance with fast target alert and high range resolution surface surveillance, in addition to fire control support, surface gun fire control with splash detection, helicopter control, cued search with enhanced detection performance for a dedicated sector, cued track with high-priority target tracking for missile guidance and automatic target classification.

The South African branch of Hensoldt developed the new generation Quadome 3D naval air and surface surveillance radar that, according to the company, provides rapid response and high precision, at excellent price-performance ratio. © Hensoldt.

The Kronos Naval radar is a multifunction 3D radar employing Gallium Arsenide AESA technology to provide situational awareness, point defence, and missile and gunfire support to ships. Leonardo has developed a new more capable HP (High Power) version. © Leonardo.

With an instrumented maximum and minimum ranges of 250 km and less than 100 meters, an elevation coverage of -2°/+70° and -2°/+90°, a target detection capability in term of RCS equal to 0.01 m2, the TRS-4D Rotator features a tracking 3D capacity of over 1,000 targets and four windows for gun fire support. Hensoldt declares a tracking range performance of over 14 and 100 km respectively for small surface and maritime patrol aircraft targets, and limited by horizon for supersonic sea skimmers. The TRS-4D features a GaN AESA electronically stabilized antenna with integrated IFF antenna (three channels) weighing less than 900 kg, with a mechanical rotation speed of 30 and 15 rpm. The TRS-4D has obtained both national and international success having been procured by the German MoD to equip so far the second batch of K130 corvettes together with the same company’s MSSR 2000 ID IFF. On the international market, the TRS-4D was selected by the US Navy to equip the Freedom-class variant of the Littoral Combat Ships (LCSs), starting from the Indianapolis (LCS 17) platform, which has received the AN/SPS-80 US Navy designation, being the first AESA rotating radar aboard a US Navy ship according to Hensoldt.

Leonardo

Drawing on technology previously embodied in the EMPAR passive multifunction radar, but introducing a new antenna architecture with AESA array, advanced technologies and operational software derived from the active Kronos MFRA (Multi-Function Radar) installed initially on board Italian Navy FREMM frigates, alongside the capability to manage various shorter range

Although Leonardo does not provide information on customers, EDR Magazine learned that the Kronos Naval HP has been acquired by Qatar to equip the new Musherib-class OPV here depicted, alongside Saudi Arabia and UAE naval platforms. © Fincantieri.

Originally developed by Saab to provide the Visby-class corvettes with a lightweight, multirole 3-D radar capable of air surveillance and tracking, surface surveillance, target indication, and gunfire support, the Sea Giraffe AMB has been sold worldwide. © Saab.

The US Navy equips with the Sea Giraffe AMB (AN/SPS-77 designation) the Independence-class LCSs, together with variants for the Expeditionary Sea Base ships, US Coast Guard Offshore Patrol Cutters as well as in a derivative known as AN/SPN-50, to meet the air traffic control needs for the US Naval Sea System Command. © Saab.

weapon systems, Leonardo developed the smaller naval variant of its Kronos family of 3D C-band radars, which secured its first order in 2009. The Kronos Naval is a multifunction radar employing gallium arsenide (GaAs) AESA technology to provide situational awareness, point defence, and missile and gunfire support to ships down to 400 tonnes. Unlike traditional 3D radars, the Kronos Naval automatically schedules and performs any activity classified as a priority within the current tactical scenario by scanning the beam in both azimuth and elevation, while mechanically rotating at 60 rpm. The system antenna provides electronic elevation coverage up to 70° in surveillance and 85° in tracking mode (electronic scanning provides for beam steering up to +/-45° in azimuth, and up to +/-60° in elevation). With a maximum surveillance range of 250 km and a tracking update rate of up to one second, the system is capable of managing up to 300 air and surface tracks with an above deck weight of 970 kg including the IFF. The Kronos Naval has found initial success in the Middle East and South American regions being respectively acquired and in service with the UAE and Peruvian navies. Today the Kronos Naval is marketed in the HP (High Power) version which EDR Magazine understood features an AESA active electronically scanned array antenna equipped with a higher number of transmitter/receiver modules based on GaAs technology, compared to the original baseline model of Kronos family radars. This allows providing enhanced performances as well as higher availability and improved graceful degradation capacity. The new version has already found international success and although Leonardo

A lightweight X-band radar, weighing less than 150 kg (topside weight is 100 kg), the Sea Giraffe 1X is designed as a primary 3D surveillance radar for smaller vessels such as patrol craft and offshore patrol vessels, and secondarily as an adjunct surveillance/ target indication sensor for larger vessels. © Saab.

does not provide information on customers, EDR Magazine learned the system is in service with Qatar Emiri Naval Forces on board the Musheribclass OPVs and has been installed on board the Al Jubail-class corvettes being delivered by Navantia of Spain to the Royal Saudi Navy. The Kronos Naval HP has also been contracted to equip the Falaj-3 class OPVs to be built by Abu Dhabi Ship Building (ADSB) for the UAE Navy.

Saab Sea Giraffe 1X and Sea Giraffe AMB

The latest iteration of the Saab Giraffe family of radars, exploiting the latest technologies to perform with a very limited footprint, is the Sea Giraffe 1X. A lightweight X-band radar, it is designed as a primary 3D surveillance radar for smaller vessels such as patrol craft and offshore patrol vessels, and secondarily as an adjunct surveillance/target indication sensor for larger vessels. Weighing less than 150 kg (topside weight is 100 kg), the Sea Giraffe 1X covers the entire search volume every second and provides accurate 3D data for all air targets in the search volume. The operating X-band offers higher resolution that, together with the refresh rate, is key for the detection and discrimination of low-radar cross section threats. The Sea Giraffe 1X found initial success in Europe: as part of the combat system delivery and integration to new Pohjanmaa-class corvettes of the Finnish Navy, Saab will deliver the Sea Giraffe Multi Sensor Solution package, which includes the Sea Giraffe 1X and a fixed-face version of the Sea Giraffe 4A. The X-band radar is also a main sensor component of the combat system overhaul for the German Navy’s F123 frigates, for which Saab is prime contractor.

The Swedish group continues promoting its existing C-band Sea Giraffe AMB short- to medium-range surveillance stacked beam 3D radar. Originally developed by Saab to provide the Visby-class corvettes with a lightweight, multirole 3-D radar capable of air surveillance and tracking, surface surveillance, target indication, and gunfire support, the Sea Giraffe AMB has been sold worldwide, being procured by the Polish Navy (Orkan-class fast patrol craft), UAE Navy (Baynunah-class corvettes), Royal Australian Navy (Canberra-class multipurpose amphibious ships), the Republic of Singapore Navy (Victory-class missile corvettes), Algerian Navy (Erradii-class Meko A-200AN frigates) frigates, Thai Navy (for different platforms including the Bhumibol Adulyadej-class frigate) and the US Navy for equipping the Independence-

class LCS (with AN/SPS-77 designation), together with variants for the Expeditionary Sea Base ships, US Coast Guard Offshore Patrol Cutters as well as in a derivative known as AN/SPN-50, to meet the air traffic control needs for the US Naval Sea System Command, alongside foreign military sales. The Sea Giraffe AMB has also been contracted for the Royal Canadian Navy to equip its new Protecteurclass joint support ships and upgrade the Sea Giraffe 180 antenna package on board Halifaxclass frigates. The system is now into its third iteration - Mod C - reflecting a series of hardware and software uplifts. Transmission is performed in a wide elevation beam, with radar returns in multiple receive beams. Reception beams are digitally formed, and signals processed in several parallel processing channels. With a 30 or 60 rpm rate, air surveillance (scanning up to 70° in elevation) is performed automatically in parallel moving target indication (MTI) and non-MTI processing channels to optimize performances in heavy clutter.

Thales NS50

In January 2021, Thales announced to have been awarded by Kership, the joint venture between Naval Group and Piriou, a contract for the supply of its new NS50 radar to equip the 12 new generation Mine Counter Measures Vessels (MCMVs) for the navies of Belgium and the Netherlands. According to Thales Nederland, the NS50 is the world’s first compact multi-mission 4D AESA radar available on the market for smaller vessels offering both air and surface surveillance with missile and gun fire control. The “4D” radars, according to the same company, not only provide bearing, range and elevation (3D) information, but also provide indepth analysis of the target’s Doppler signature and 10 times more time on target (the 4th dimension) by applying dual-axis multi-beam processing. The NS50 is an X-band software-defined dual-axis multi-beam 4D sensor that features modular and scalable hardware architecture, allowing it to be installed on OPVs, MCMVs, auxiliaries and various other platforms, including combat boats. The NS50 provides accurate 4D target information for rapid acquisition to fire control systems, for fire control of short-range ‘fire and forget’ surface-to-airmissile systems and for fire control of shipborne artillery against surface targets. The NS50 radar consists of a 2.5 meters high and 2.5 meters wide AESA antenna, protected by a radome, with a 15 or 60 rpm rate, featuring GaN TRMs and an integrated IFF antenna with an overall weight of 750 kg and two below deck cabinets for additional 680 kg. With a maximum instrumented range of respectively 180 and 80 km against air and surface targets, and an elevation coverage of 70°, the NS50 has a tracking capacity of 1,000 targets and a three windows for gun fire support. In addition to the simultaneous air and surface targets detection and tracking thanks to the dual axis multi-beam capability, alongside fire control, the NS50 features IFF data handling, jammer detection and tracking, provision of surveillance video, high availability and graceful degradation.

The navies of Belgium and the Netherlands have become the launch customers of the Thales NS50 4D AESA radar, after the latter was procured to equip the 12 new generation Mine Counter Measures Vessels (MCMVs) being built for the two services by Kership, the joint-venture between Naval Group and Piriou. © Thales. The NS50 is an X-band software-defined dual-axis multibeam 4D sensor that features a modular and scalable hardware architecture, allowing to be installed on OPVs, MCMVs, auxiliaries and various other platforms, including combat boats. © Thales.