Saab Grintek Defence (SGD) is evolving its naval electronic support measures (ESM) solutions with its new third generation U/SME-400 wideband digital ESM family. The U/SME-400 is the company’s flagship naval radar warning/electronic support measures system and will be displayed for the first time at the Euronaval exhibition in Paris that takes place between 4 and 7 November.
Emphasising the importance of ESM systems for naval applications, Saab notes that navies still rely on ESM systems as primary sensors when operating in radar silence. The company’s first- and second-generation systems have been integrated onto Greek, Portuguese, and South Korean submarines, amongst others – fifteen solutions are in service with three NATO navies. The ESM and ELINT (electronic intelligence) range comprises the SME-50 ESM receiver, SME-150 ESM system with ELINT functionality, and SME-250 ESM receiver with digital ELINT receiver – the latter covers the .5-18 GHz range while the SME-50 and SME-150 cover the 2-18 GHz range. The SME designation is used for surface vessels and UME for subsurface vessels.
These systems can be integrated with the NLWS (Naval Laser Warning System), MASS (Multi Ammunition Softkill System) or other decoy systems, active electronic countermeasures (ECM) systems, and Saab CRS-8000 communications ESM system (Saab Deutschland offers the CRS series of naval communications intelligence [COMINT] and communications ESM [C-ESM] solutions).
What distinguishes the new U/SME-400 from previous generations is a shift to a fully digital system with a wideband receiver. According to Francois Raubenheimer, Business Development and Marketing Executive at Saab Grintek Defence, some of the advantages of going digital are enhanced signal processing, faster processing, better classification and tracking of complex signals especially in crowded environments with overlapping signals, resilience to interference, and easy adaptation to new signal types without hardware changes, making it possible to react quickly to new tactics developed by adversaries.
Other advantages are greater accuracy and sensitivity, including improved detection of weak and low power signals. Raubenheimer pointed out that radars are becoming stealthier and use lower power, making them more difficult to detect.
The U/SME-400 series is being developed in three main variants: U/SME-410 (2-18 GHz with 16 GHz instantaneous bandwidth [IBW] acquisition and .5 GHz instantaneous bandwidth direction finding [DF]); U/SME-420 (1-18 GHz with 16 GHz IBW acquisition and 8 GHz IBW DF); and U/SME-450 (1-18 GHz with 16 GHz IBW acquisition and 16 GHz IBW DF). These are able to intercept, detect, and identify modern wideband radars including low probability of intercept (LPI) frequency modulated continuous wave (FMCS) radars at long ranges. The U/SME-420 and U/SME-450 are both also available with an option to cover Ka-band.
Development of the U/SME-400 series is still underway, with about a year to go before production ready status, but Saab is already promoting the system as naval vessel programmes take years to be completed. Sea trials are expected in the next year or so, and the company has already offered it to prospective customers.
SGD has built its naval business tremendously over the last quarter of a century, with one of its other key naval products being its Naval Laser Warning System (NLWS), which can be either a standalone system or fully integrated into a vessel’s combat system. It includes a laser waring system for surface vessels and a Light Detection and Ranging (LIDAR) blue-green laser sensor for sub-surface applications. Sensors are placed around a vessel to ensure adequate coverage, with the number of sensors determined by the size of the vessel. The system, which interfaces with the vessel’s combat management system and ESM, can provide the bearing, laser classification and identification information required to deploy the necessary countermeasures.
The NLWS features the NLWS 310 laser warning sensors, which in LWS 310 guise is also used in Saab’s IDAS defensive aids suite for aircraft, and operates across the .5-1.7 nm wavelength to provide threat classification and direction of arrival for laser rangefinders, designators and missile guidance lasers. The LWS series has gone through several versions, namely Mk I, II, and III, with a new high accuracy sensor (LWS-700) launched in 2023.
The new LWS 700 allows for the automated detection, classification, and identification of laser-based weapons. It is capable of classifying and identifying laser threats such as target designators or laser rangefinders. With a 1° bearing and elevation accuracy, the sensor is able to support countermeasures, specifically the deployment of hard-kill counter fires. This is a much-improved version to the LWS 310, which offers a bearing accuracy of 7.5°.
SGD’s NLWS is in service with several nations, including with the United Arab Emirates Navy (Baynunah class corvettes), German Navy, and New Zealand Navy and on order, 5+ nations. For German Mine Sweepers, Saab’s radar ESM and laser warning systems are used in combination with Rheinmetall’s Multi Ammunition Softkill System (MASS) decoy system, which guards against both radar and laser-guided threats.
SGD’s naval products are somewhat unique in that they are used in air, land and sea applications as they share common building blocks. Saab Grintek Defence has for many years manufactured laser warning and missile approach warning sensors, with previous generations being the LWS-310 and MAW 300 respectively. The company recently launched its next generation MAW 400 and LWS-330 for airborne platforms, now in production, with a European customer the first to take these new products.
In addition, Saab Grintek Defence is producing a LEDS 50 MK 4 system with the LWS-700 sensors, which is a 1-degree sensor for land applications. (Land Electronic Defence Systems, or LEDS, is an integrated, modular, active protection system consisting of laser warning sensors, an active defence controller, human-machine-interface and an effector control segment that can launch smoke or cue jammers).
Saab’s laser and missile approach warning systems form part of its integrated defensive aids suite (IDAS) for helicopters, transport aircraft and combat aircraft. IDAS warns against radar, laser and infrared guided threats and automatically deploys appropriate countermeasures such as chaff and flares. IDAS is operational on 30+ aircraft types in more than 15 countries.
