EO/IR sensors

EO/IR systems such as Controp’s iSea-20HD can be complementary to radars; while the latter provides range and direction to a target, the former are better suited to target classification. (Photo: Controp)

Rising to the challenge

EO/IR sensors have a wide range of applications in the naval domain. Whilst manufacturers continue developing these systems to keep up with changing operational requirements, they also need to keep prices in check.

Gerrard Cowan

EO/IR sensors support a range of roles for surface ships, from building a tactical picture to fire control. Experts highlight a number of focus areas for technological development, notably in interpreting and displaying the increasing amounts of data that the sensors process.

EO/IR has a wide range of naval applications, said a spokesperson for Elbit Systems, which produces a number of such sensors, including the SPECTRO XR multispectral payload. The sensor was recently part of a contract win with an unnamed navy in Southeast Asia. Such technology is used for collision avoidance and SAR, detection and identification, fire control and as a navigation aid, the spokesperson said.

While addressing such demanding missions, the equipment must be capable of handling the harsh visual and environmental challenges of seaborne systems, the spokesperson added, including salt, corrosion, high temperatures and exposure to the sun for long periods of time, as well as the complexity of maintenance at sea.

Advanced processing

Norman Friedman, a naval analyst and author who contributes to the US Naval Institute, noted that EO/IR systems provide greater resolution than radar and can have particular uses in areas like force protection or fire control. He also highlighted the growing use of the systems in identifying small boats, although he noted that this is more a developing use of the technology rather than a novel technological development.

However, he said that as the sensors grow more advanced, ‘the amount of information increases immensely – the question is, what do you do with it?’ It is important to consider the way in which data is processed and presented to operators, he said, to ensure that they can fully comprehend what they are seeing without being overwhelmed.

This is a growing area of focus for companies in the domain. Steve Schultz, director of business development for ISR systems at Raytheon Intelligence & Space – which develops a range of sensors that can be used in multiple domains – said the company is looking to AI and machine learning to provide advanced processing and automated sensor control functions in EO/IR sensors’ software. This technology ‘will help reduce operator workload, while still enabling crews to search wide areas with greater surveillance and targeting accuracy’.

The use of this technology would complement two other developments in the sensors themselves, Schultz added. He said that advances in digital focal plane arrays enhance the sensitivity of the sensor, improving multiband performance. This will increase the sensor’s capability to detect, classify and track targets at greater range and help discriminate targets from background clutter.


🜂 Controp points to the use of EO/IR sensors for countries with long coastlines, in areas like border protection and countering illegal immigration. (Photo: Controp)


Additionally, Schultz said Raytheon is tracking electronics miniaturisation, which will provide increased mission capability with reduced SWaP. Miniaturisation is enabled by advances in node size, integrated wafer-level packaging and photonic integrated circuits. ‘These contribute to the powerful processing needed to support larger-format focal plane arrays.’

He said these advances would enhance the use of EO/IR as an essential asset for safe navigation around the world. ‘The technology enables the captain and crew to see at night and in adverse weather by assisting with navigation as well as aiding in [missions including] search and rescue and threat detection,’ Schultz emphasised.

Joe Ottaviano, business development director for Lockheed Martin Rotary and Mission Systems, said that advances in the development of very large focal plane array technology would provide significant increases in IR sensor performance, allowing for better ISR and range detection performance in the future.

The company – which focuses on integrating EO/IR into a range of programmes, such as the Shipboard Integrated Electro-optic Defense System and the Multispectral EO/IR Countermeasures for Advanced Threats function of the Combined EO/IR Surveillance and Response System programme – is focusing on ‘maturing the EO/IR technology that offers low risk, low cost and fast delivery with a capability that can be evolved and easily upgraded’, said Ottaviano.

Complex missions

While surface ship configurations vary widely, there are growing efforts to have scalable commonality between installed systems – such as EO/IR and radar – while using a modular open system architecture path to better maintainability and serviceability, Ottaviano noted. ‘Additionally, emerging systems include requirements to detect and track smaller objects in brighter and/or dimmer environments at militarily significant ranges,’ he added.

A spokesperson for Controp – manufacturer of the iSea range of systems – highlighted in particular the use of EO/IR sensors for countries with long coastlines, in areas like border protection and countering illegal immigration. ‘They are in search of electro-optical systems to assist in these complex missions,’ the spokesperson said.


There are growing efforts to have scalable commonality between installed systems.


EO/IR systems are complementary to radar, said the Controp spokesperson. While the latter provides range and direction to a target, the former are better suited to target classification, supporting decision-making for the ship’s commanding personnel.

‘The ability of a well-designed and -built EO system to provide the required information by day or night is greatly dependent on the balanced matching of its constituent sensors and their characteristics, as well as the overall system level design, tailored to satisfy a known set of requirements, be it ranges for detection, recognition and identification of targets, classification of targets, threat detection, etc,’ they added.

New features and capabilities are being added to EO/IR sensors as they become available, the spokesperson said, pointing in particular to the growing use of short-wave IR (SWIR) sensors and cameras and the enhancement of medium-wave IR resolution from VGA to HD format. The spokesperson also pointed to the introduction of more advanced algorithms for video and image processing and enhancement, among other developments.

Alex Riahi, director and head of marketing and business development in Israel Aerospace Industries’ (IAI’s) TAMAM division, said that efforts by both navies and coastguards to address human trafficking and illegal immigration had underscored the importance of EO/IR systems, particularly their applications at night, when much of this activity occurs. This had led to an increased demand for EO/IR sensors in border protection roles, he said, though it also remains steady ‘for the classical naval applications’.

Changing demands

The nature of demand is changing in other ways, Riahi said. There is a growing demand for integration with other sensors, such as radars, as well as the provision of computing and C2 and associated services. This has been seen not just for larger vessels, but increasingly for smaller ships, he noted.

‘We need now to propose not only the payload, the EO/IR, as we did in the past for navies, but to give a full solution, including the software, the computer, etc, to enable shipyards to be able to give the complete solution to their customers,’ he said.

The company is working on improving digital interfaces to help support this integration, making it simpler for operators to exploit the information provided from a series of integrated sensors, including EO/IR, radar or automatic identification systems and other maritime sensors.


🜂 IAI has a range of sensors suited to naval work, like the MOSP3000, pictured here. (Photo: IAI)


Riahi underlined the need for gyro-stabilisation in the cameras when used on all platforms, although this is particularly important in the naval context due to the potential impact of heavy seas. This is also necessary to improve detection range, he said.

A spokesperson for FLIR, which recently released the SeaFLIR 280-HDEP shipboard multispectral surveillance system, said that higher-performance sensors are continuously requested, along with 360° situational awareness. Distributed-aperture, wide-field-of-view systems – such as those found in fifth-generation aircraft – are in development and will become increasingly important for shipboard applications, the spokesperson added. Finally, they highlighted a growing market for EO/IR in USVs, ‘which are increasing in the inventory’.

The Elbit spokesperson noted that there has been an increasing need for EO/IR systems in both smaller vessels and in larger platforms like frigates. The spokesperson also highlighted the applications of HD multispectral sensors as well as improvements in video analytics such as automatic target recognition and classification. The company will implement such technology – along with data fusion capabilities between different sensors – increasingly in the coming years, the spokesperson added, while it will also focus on implementing advanced analytics in smaller-sized payloads.

Finding a balance

In terms of technological evolution, Riahi said that naval platforms are seeing much of the same advances that have been seen in airborne systems and other domains. HD systems are advancing, he said, as users ‘want a better resolution with better performance – they want better optics all the time, so we need to develop and improve it’. He also pointed to the demand for SWIR, notably for operating over longer ranges. SWaP constraints are less demanding for large naval ships than they would be for a smaller platform – such as a helicopter – but they must still be considered, he added.

Riahi said the major strength of EO/IR is in identification, rather than detection: in analysing threats, for instance. On this level, the company is working to improve the ability of the sensors to automatically identify particular objects, people, etc.

The second area of technological development the company is focusing on for the coming years is on the analytics side, he added. Depending on the sophistication of the computer that can be placed on a ship (ie if there are few limitations around size or power consumption), it is increasingly possible for the system to conduct automatic target recognition, for example. This could be continuously updated, he added.

‘If they are looking for navy systems with a lot of different armaments, for example, we want to be able to automatically give the user updates about the things they are looking for,’ he noted. This would be supported through integration with other sensors, he added, something that IAI TAMAM is working to expand in the coming years.

Finally, Riahi noted that all of this must be achieved while keeping prices much the same, particularly given the likely budgetary context of the post-COVID-19 world. ‘It’s like in the car market, where the price is almost the same as it was ten years ago, but the level of security and electronics and engine performance is far greater,’ he said. ‘You need all the time to develop new technologies, to improve the capabilities of the systems and, at the same time, be competitive in price.’