In a media briefing on 23 October, Francois Raubenheimer – business development and marketing executive at Saab – said naval platforms rely on ESM capability as a primary sensor when operating in ‘radio silent’ mode while scouting for and approaching potential targets. ESM systems are used to detect radar signals from such targets; Raubenheimer explained that contemporary radar systems are smarter, which in turn drives the need for enhanced ESM capability.
More broadly, he added, ESM systems use the electromagnetic spectrum to contribute to the maritime situational awareness picture.
The U/SME-400 system series can be fitted to surface and underwater systems, both crewed and uncrewed; surface system designation is SME-400; the sub-surface system is UME-400. Essentially, the system and software are common across both variants, with the configuration adaptable to meet platform fit requirements.
Three sizes are available, to equip different platform types: U/SME-450, for corvettes and frigates; U/SME-420, for patrol ships, mine warfare vessels, and small submarines; and U/SME-410, for uncrewed surface vessels (USVs) and uncrewed underwater vehicles (UUVs). While all three variants provide 16 GHz of instantaneous bandwidth for target acquisition, the differentiator between the sizes includes total GHz of bandwidth available.
For U/SME-410 and uncrewed platforms, the concept of operation effectively is electronic intelligence-gathering, with information downloaded and processed upon returning to base, Raubenheimer explained.
Compared to previous generations, this third-generation series brings a particular capability step-up. “The big change … is to have a fully digital system, a wideband digital receiver architecture,” said Raubenheimer. ‘Going digital’ brings several advantages, he added, including: improved detection, classification, and tracking of complex signals, especially in crowded electro-magnetic environments featuring multiple overlapping signals; resilience to interference like jamming or spoofing, in increasingly hostile EW environments; faster and more precise signals processing; and improved adaptability and flexibility, enabling system updates to tackle adversaries’ new signal types and tactics but without requiring significant hardware changes.
“We now have a wideband digital ESM system; it provides for a very wide, instantaneous frequency coverage,” Raubenheimer continued. Standard coverage for the 450/420 is 1-18 GHz; 410 standard coverage is 2-18 GHz. Options exist to extend to 24-40 GHz. The bandwidth coverage means that “every signal that’s active will be seen immediately by the system, ensuring a very high probability of intercept,” he added.
Francois Raubenheimer, Business Development and Marketing Executive at Saab
“This wideband instantaneous bandwidth for both acquisition and direction-finding functions provides us with the ability to really quickly put the tactical picture together,” said Raubenheimer.
The improved, digital-based system sensitivity and accuracy also provides capability to process signals in for example smaller frequency bands. “[This] leads to improved detection of weak- and low-power signals, which is one of the main developments on the radar side: they are getting more stealthy, more low power, and more difficult to detect because of these low-power emissions,” Raubenheimer explained.
The U/SME-400 system comes with an interface bridge to the platform’s respective combat management systems (CMSs), and data library management and post-mission analysis tools. It also brings design focus on improved ease of operation at the human/machine interface.
Saab intends to display U/SME-400 at the Euronaval exposition in Paris in November. With the system set to be ready for production towards the end of 2025 following sea trials, customer deliveries are scheduled to be available from 2028, Raubenheimer explained.
