As naval surveillance and engagement requirements grow, so naval EO/IR systems developers are accelerating their use of new technology to keep track of the threat.
On 19 October 2023, while sailing in the Red Sea off the coast of Yemen, the US Navy (USN) DDG 51 Arleigh Burke-class guided-missile destroyer (DDG) USS Carney shot down three land-attack missiles and several unmanned systems.
At a media briefing that day, the US Department of Defense’s (DoD) Pentagon press secretary Brigadier General Pat Ryder said: “This action was a demonstration of the integrated air and missile defence [IAMD] architecture that we built in the Middle East and that we are prepared to utilise whenever necessary to protect our partners and our interests in this important region.”
Carney’s engagement reflected what are now becoming more routine ‘threat-and-response’ activities in today’s complex maritime domain. The contemporary naval operating environment mirrors the often-used maxim that modern military battlespaces are ‘cluttered, congested, and contested’. For Western naval forces, the threats in their operating environment encompass the spectrum of operational tasks. This ranges from non-state actors using remote-controlled unmanned systems in the air or on the surface to swarm around naval or commercial ships operating at sea, right up to high-value assets being at risk of attack at sea, including from both traditional and emerging technologies. Such traditional technologies include long-range anti-ship cruise missiles (ASCMs), with the emerging technological threat including unmanned surface vessels (USVs) that can operate at distance across open seas.
Examples of such risks and technology developments are now commonplace. USN warships, as well as commercial shipping, have been targeted by remotely operated rigid-hull inflatable boats (RHIBs), shore-based anti-ship missiles (ASMs), and unmanned aerial systems (UASs) when sailing in the Gulf of Aden, through the Bab-al-Mandeb Strait maritime choke point, or in the southern Red Sea. The most recent incident there occurred on 15 November 2023, when the USN Arleigh Burke-class DDG USS Thomas Hudner shot down a UAS that was heading in the direction of the ship as it sailed in the Red Sea off the Yemeni coast. Commercial ships sailing in the Straits of Hormuz have been harassed by Iranian fast attack craft (FACs) operating in swarms. In May 2023, the USN released a video screenshot of what it stated were Iranian Islamic Revolutionary Guards Corps Navy FACs swarming a Panama-flagged oil tanker, Niovi, in the Straits of Hormuz. In the Russia-Ukraine war, both parties to the conflict have been operating USVs across the Black Sea, including to target coastal infrastructure. At the top end of the spectrum, the Russian Federation Navy Slava-class cruiser and Black Sea Fleet flagship Moskva was hit and sunk by a pair of Ukrainian Neptune ASCMs.
All this points to a need for navies to be able to surveil the naval operating environment at distance, accurately identify ships, aircraft, missiles, and unmanned systems against the cluttered, congested backdrop, and then track, classify, and – if needed – target any threat.
Carney was reported in US Naval Institute News to have used Raytheon Standard Missile (SM)-2 weapons as effectors to take down the incoming missiles. However, prior to engaging targets with effectors, a warship will need to generate surveillance, identification, and tracking capability in order to respond to the prospective threat. Primary capabilities for meeting this requirement are electro-optical and infra-red (EO/IR) sensor systems. Such capabilities sit at the centre of any navy’s networked IAMD capability.
Navies use EO/IR systems and capabilities for two primary purposes: first, to provide persistent, 24/7 surveillance of the maritime battlespace to detect, track, and visually identify air and surface targets; and second, should any such targets be classified as a threat, to provide the fire control capability for precision engagement of the target by gunnery or other weapon systems, should the decision be taken to engage.
Eagle Eye
One company providing such capabilities through its portfolio of EO/IR systems is the UK-based Chess Dynamics. Part of the Cohort group, Chess Dynamics is a systems house that develops surveillance and fire control systems for the land and maritime domains.
For the naval operating environment, the company produces Sea Eagle, a family of systems that offers EO/IR capability in two primary strands.
First, the Sea Eagle EOSS (electro-optical surveillance system) provides 24/7 surveillance though high-performance IR and TV camera sensors. It also provides wide-area surveillance through sector scanning and automatic detection. An enhanced version of Sea Eagle EOSS is fitted with a laser range-finder (LRF) sensor. Overall, the function of the Sea Eagle EOSS system is to provide air and surface surveillance to generate platform navigation and maritime situational awareness (MSA).
Second, the Sea Eagle Fire Control Electro-Optical system (FCEO) provides 24/7 long-range target detection, tracking, and identification using IR, TV, and LRF sensors. The system generates automatic detection, precision tracking, and target classification. The enhanced Sea Eagle FCEO Mk II version adds digital high-definition (HD) IR and colour daylight TV (DLTV) sensing capability. Overall, the function of the Sea Eagle FCEO system is to provide fire control in anti-surface, anti-air, and naval gunfire support engagements.
The Sea Eagle EOSS and Sea Eagle FCEO family of systems is in service or entering service with 12 international navies, including five European, four Indo-Pacific, and two Middle Eastern navies, and one South American navy, Dr Mark Byfield, Chess Dynamics’ vice president for Strategic Business Development, told Armada International. Over 100 systems have been installed to date, and over 25 are on order.
An integrated EO and radar fire control system (Sea Eagle FCRO) also is in development, along with a Laser Directed Energy Weapon (LDEW) beam director.
The Sea Eagle family is built around a design that is digital and modular, with a fit onboard a ship that includes just power and ethernet connections incoming, and an outgoing link to the ship’s combat management system (CMS). The modular design offers several benefits, including ease of ability to swap out or re-fit the system at sea (the latter enabled, for example, by a modular software architecture). This reduces the engineering burden onboard.
The design also brings particular focus on reducing the operator burden onboard. The Sea Eagle’s in-built automatic tracking system means that the operator, rather than having to move a joystick to keep the system’s camera pointed at an object, can simply click a track box around the object and the camera will track it automatically. This can be done even with fast-moving, agile objects like a UAS, helicopter, or jet ski.
Eyes on the Target
In two interview discussions with Armada International – at the Defence and Security Equipment International (DSEI) exhibition in London in September, and at a pre-DSEI media briefing held by the Cohort group in London in July – Byfield explained the role of EO/IR capability, and new developments in both core EO/IR technologies and Chess Dynamics’ specific systems. EO/IR capability “is like the eyes of the ship,” said Byfield.
“An EO/IR system typically includes a thermal imager, to give you the night vision, and a colour TV camera. Most of our systems have one or both of those fitted,” said Byfield. “Thermal imagers will give you the black-and-white view; TV will give you the colour view, which allows you during daytime probably to make quicker sense of what you’re looking at.”
“Often, the LRF is the third sensor, to give you the range of what you’re looking at,” he explained. The LRF uses a laser ‘ping’ to gauge range to the target.
“What’s new is increasingly powerful cameras,” Byfield continued. “We’ve gone to HD; eventually we’ll go to 4K [resolution] …. This gives you more pixels on your target, and a better chance of identifying a small target at long range.” 1080 HD Thermal and HDTV camera technology is now used routinely.
Looking at a target warship or other platform using a low-resolution camera may give a blurred image, including when zooming in. “If you’ve got lots and lots of pixels like an HDTV screen, you’ve got more clarity of information. So that means you can identify the target at further range,” said Byfield. “It’s all about knowing what you’re dealing with. A ship comes over the horizon, you might have the intel to say it’s a hostile ship …. If you’ve got a very good, high-resolution camera, you can zoom in on that ship and get a lot of clarity on the image.”
“As the camera technology improves and we’re feeding in the latest generation cameras, that means you can prosecute a target further away from the ship,” Byfield added.
EO/IR systems are already cued onto a target by a ship’s radar. However, further integration with the radar system can provide options for maintaining a track on a target, David Eldridge – Chess Dynamics’ sales director – told Armada International. “An FCEO system still has the problem of, if a target goes behind a cloud, you can’t see it,” he explained. Chess is already working with radar system companies to further integrate radar and FCEO technologies.
Byfield explained that EO/IR system outputs typically are measured, in range terms, through three metrics: detection range; recognition range; and identification range. These are known collectively as DRI. Here, EO/IR cameras will be used to detect an object at range, then recognise whether it is a warship or another type of ship, and then (if it is a warship) identify the type and class. “In general rules of engagement terms, you can’t prosecute the target – fire on it, or designate it for a hit from a missile – until you’ve identified it,” said Byfield. “Basically, with advanced cameras, you’re pushing those DRI ranges further out.”
“That’s the massive value of giving your own forces the ability to advance their MSA,” Byfield added.
As regards FCEO capability, the ability to better detect, track, and identify targets at greater range with greater clarity enhances operator output once more. For example, following a cue onto a potential target – typically, from the ship’s surveillance radar – the Sea Eagle FCEO system will track and identify the target, and continuously feed its precise, real-time geo-coordinates (bearing, elevation, and range) into the ship’s CMS. The CMS will use stored ballistics information (specific to ammunition type and gun characteristics), in conjunction with local meteorological data and the live target coordinates from the FCEO, to compute the gun trajectory, intercept angle, and flight-time requirements required to accurately prosecute the target. “We’re effectively telling the ship precisely where to point its gun if it wants to intercept the target,” said Byfield.
Within the Sea Eagle family, perhaps the state-of-the-art EO/IR system is the Sea Eagle FCEO Mk 2 version.
“That’s an all-digital design,” said Byfield. “We’ve replaced all the analogue technology for the latest digital electronics. It means it’s easy to upgrade, to add in new software capabilities.”
“It’s picking up targets at greater range. We’ve improved the dynamic performance, so it can cope with swarms of drones moving around,” Byfield added. “It’s got the latest artificial intelligence (AI)-based trackers for robust, reliable tracking of a whole range of targets. In the maritime environment, it could be surface, it could be air,” he continued. “We’ve got a target classifier, which helps reduce the operator burden: an operator can keep an eye on a couple of consoles, but the system will [send an] alarm automatically to the operator if it picks up an unknown object.”
Artificial Enhancement
To further improve the effectiveness of core EO/IR technologies, other areas of capability development focus include advanced tracking technologies and target classification, software enhancements, and the use of AI-based technologies like machine learning. These individual new technologies and approaches also can be combined, in order to further enhance EO/IR outputs.
To support target classification, technology automation such as the use of AI-based technologies can provide more automated initial assessment of what is a potential target and what is not, thus reducing the operator burden. Software developments, such as in data processing, are also speeding up operator decision making. “You’re gaining time to make a decision whether to open fire, because [the technology] is … either sounding an alarm to alert you, or giving you information on what the type of target is,” Byfield explained. “Is it a fishing boat, or is it two people on a jet ski with an RPG?”
Summarising the net effect of such technological developments, Byfield explained “You’re enabling the crew to fire reliably at known targets further away from the ship.”
Future Capability
The arrival of unmanned systems is driving EO/IR technology suppliers to develop their products to both counter the threat posed by unmanned systems and to provide capability that can be fitted onboard such systems.
In a further demonstration of how technology integration can provide enhanced capability, EO/IR technology suppliers are already looking at how their systems can be integrated with USVs.
EO/IR capability requirements for USVs currently include navigation, collision avoidance, intelligence, surveillance, and reconnaissance (ISR), and wider MSA, Eldridge explained. Many current USVs (although not all) are smaller than crewed platforms carrying the EO/IR systems in question. Thus, companies are looking to develop EO/IR systems with reduced size, weight, and power (SWP) requirements, he added.
With unmanned systems emerging as a valuable technology for all operators – as demonstrated in the Russian and Ukrainian USV campaigns in the Black Sea – EO/IR system suppliers are also already developing their products with the technology to counter unmanned systems.
“UAS have come along in the last five to 10 years. Our EO/IR heads are able to track them, and move with agility,” said Byfield.
Tackling targets coming in at speed – whether vessels or missiles – is an increasingly important requirement for EO/IR capability. Reacting to the speed of an incoming hypersonic system is a particular challenge for navies in the contemporary operating environment. “We are cognizant of the emergence of hypersonics, but it’s all pushing in the same direction for us: picking up targets further away, identifying them, and tracking them,” said Byfield. Here, he underlined the importance of radar capability in picking up the incoming hypersonic threat.
by Dr. Lee Willett
