Why signature analysis is crucial for combat survival
You know how your tanks and troop carriers look to the naked eye. But how do they look to the advanced sensors being used by your opponents? Analysing the electromagnetic signature of your deployed assets can help you improve camouflage, delivering a major tactical advantage.
In a desert somewhere in the Middle East, a mobile military unit has just begun settling in for the night. With darkness falling and a conventional camouflage net over their camp, the soldiers are reasonably confident of not being disturbed before morning.
But, not far off, an enemy using a thermal sensor has detected the distinctive heat radiation patterns emitted by the group’s recently driven vehicles and the bodies of the soldiers. Within an hour, the group is under deadly attack.
The situation is a classic example of how the electromagnetic signature of military assets can reveal their presence to the enemy. Without adequate protection, electromagnetic radiation, including reflected light, infrared radiation and radio waves and emitted thermal radiation, can be picked up by sensors, turning the most powerful of deployed assets into sitting ducks.
The scenario also demonstrates why ‘signature analysis’ – the process of actively assessing how military assets will appear on sensors – is so important for the effectiveness of camouflage solutions. By better understanding how the enemy will view groupings of assets in the field, camouflage providers like Saab and armed forces can work together to create solutions that work better.
By better understanding how the enemy will view groupings of assets in the field, camouflage providers like Saab and armed forces can work together to create solutions that work better.
Electromagnetic radiation and signatures
So, how is signature analysis undertaken? And how effective can it be at reducing an object’s visibility to sensors?
The problem at the heart of all signature analysis work is the way that deployed military assets – and all other objects in our world – interact with electromagnetic radiation (EMR). Electromagnetic waves are a natural part of our environment and include light waves, which allow us to see objects, and waves not visible to human beings without sensors, such as radio waves. The surface characteristics, composition and movement patterns of an object all interact with these waves in a predictable manner.
For example, the reflected light from an uncamouflaged main battle tank rolling along 100 metres in front of a soldier creates a distinctive impression on his or her retinas that is interpreted by the brain. An object of that size, shape and colour moving at that speed is very likely to be a tank. Infrared sensors and radars use other parts of the spectrum to identify objects with equal speed and certainty.
Camouflage solutions such as those provided by our Barracuda range seek to manage these electromagnetic signatures and to manipulate them in ways that confuse enemy sensors.
How camouflage works
At the simplest visual level, camouflage netting that matches the colour of the surrounding environment will make it harder for the enemy to spot an embedded asset, such as a command post, with their naked eye. More sophisticated solutions used exclusively in the Barracuda range include multispectral camouflage nets with advanced particles and pigments to make it far harder for infrared sensors and radar to identify deployed assets.
The importance of avoiding detection by the enemy can’t be overstated. Being able to advance through the field of combat without being observed by the enemy provides troops with a decisive tactical advantage. By avoiding detection and destruction, a tactical unit can approach close enough to the enemy to unleash a devastating attack, potentially changing the course of the battle and the conflict. While sometimes undervalued by military strategists, camouflage can be more valuable than ballistic armour in achieving mission objectives. If an asset is never discovered, it has no need for heavy armour.
Signature analysis in product development
Signature analysis is a key part of our product development process. New materials and camouflage concepts are developed in the company’s labs using complex physics and chemical models. While modelling provides an excellent picture of how such materials should behave in real-world environments, there is no substitute for testing them in the field.
The first step is to travel to the environment in which the camouflage is intended to be used. Our technicians travel the globe, conducting trials in climates ranging from tropical jungles to snow-swept Arctic environments. They are familiar with most of the world’s distinct desert types, from the Sahara in Africa to the Thar Desert between India and Pakistan and the Atacama in Chile, and they understand that no two deserts are exactly the same.
In the case of testing, say, an innovative mobile camouflage system for a vehicle, our technicians will typically take two identical vehicles into the field. One will be camouflaged using the prototype solution, while the other will be uncamouflaged and serve as the control. The vehicles might be positioned close to the tree line to help them blend in with their surrounds.
A barrage of tests are then conducted using the types of sensors the vehicle is likely to encounter in combat situations. Thermal sensors are used to assess how much heat radiation is escaping from the camouflage and how exhaust gases are being distributed. Would enemy sensors be able to detect the camouflaged vehicle and, if so, could they identify it? The camouflage is assessed from a visual perspective. How does it appear to the naked eye? How does it appear when viewed with the benefit of near and short-wave infrared sensors that can be used to enhance the visual spectrum? Radar satellites or mobile radars may be used to assess how the vehicles interact with radio waves.
For some tests, a team of observers, each member equipped with a different sensor, will approach the test object from different directions, each recording the reaction of their sensor as they draw closer. This is known as an observer trial.
The collective results of such tests, including any weaknesses in sensor protection, are used to tweak and improve the prototype camouflage. Pigments with coatings might be adapted or changed, with repeated field tests helping to further fine tune the resulting product.
Signature analysis for deployed assets
Another key use for signature analysis is in determining how the collective camouflage systems of armed forces work together when their various assets are deployed in the field.
Individual Barracuda systems are thoroughly tested both individually and in combination with other camouflage solutions before being sold. However, each country’s armed forces uses a unique combination of military hardware, electronics and camouflage solutions. It’s crucial to know how these different assets and their signatures will interact with each other and the combined effect they will have on enemy sensors. Such interactions are particularly important when forces are combined in coalitions. It’s possible that the combination of two groups of deployed assets will have unexpected consequences on signatures. Or that while one armed forces has effectively managed its signatures, its partner has not. In a combat situation, weak signature management by one partner could result in both groups of soldiers being detected and attacked.
To analyse the signature of deployed assets, our technicians typically attend exercises staged by the customer in the target terrain. A full array of sensors are then used to collect information on the emitted signatures. Because this work is conducted during exercises, Saab analysts are able to observe the camouflage in near real-combat conditions. It may emerge that a proposed camouflage solution restricts the use of a weapon and tweaks can be made. Or that the customer has a distinct and unexpected way of using equipment that was not anticipated during the design process. Again, changes can be made.
Signature analysis at this level may also be undertaken before a major purchase of new camouflage solutions. By understanding the baseline situation and all the variables involved, a customer can make an informed decision on what is required to achieve effective camouflage not just across their tank fleet but the entire brigade.
A recent innovation in this field has been for Saab to train armed forces to conduct their own signature analysis work. Our willingness to share knowledge means we are able to provide engineers with the methodologies and tools for independently assessing the effectiveness of camouflage solutions. This can help in cases where Saab has conducted the initial analysis, but then a new item of equipment is added to the mix of deployed assets, changing the overall signature configuration. Or if a new tactical approach is being trialled, using soldiers and assets in previously untried combinations. Ensuring that deployed units are able to keep their signatures to a minimum can prove crucial to mission success.
Optimisation of signatures
In some cases, signature analysis and management can help armed forces approach zero signature. However, in the majority of cases natural physical limits on signature management apply. Customers may use signature analysis to tweak and improve their camouflage against those sensor threats that pose the greatest risk, while consciously paying less attention to others. For example, it may be that visual and infrared detection is a low risk, while radar detection is a major challenge. In such a case, the capability of the camouflage to evade radar sensors could be maximised, even if doing so is slightly to the detriment of visual and infrared detection. In many cases, the customer goal is not to be entirely invisible to the enemy, but to remain undetected and unidentified long enough to be able to achieve their mission objectives.
A solution for every situation
Our Barracuda range contains a wide range of multispectral camouflage solutions that can be adapted to meet the needs of customers.
For armed forces seeking a dependable 2D solution, our Advanced Reversible Camouflage Screen (ARCAS) provides a solution for fast-changing environments. While a step-down from a 3D solution, each side of an ARCAS net has different multispectral properties, allowing it to be flipped, for example when snow falls, and to continue delivering high levels of sensor protection. The system can be supplemented with telescopic supports that help change the shape profile of the netting, eliminating sharp edges.
Our 3D Ultra-Lightweight Camouflage Screen (ULCAS) meanwhile, delivers unparalleled senor protection qualities while reducing up to 80 percent of solar loading on vehicles, shelters, tents and containers. ULCAS’s 3D surface structure is made up of two layers of textiles. A garnish layer is quilted on a backing to give the net non-snagging properties. This facilitates rapid deployment and redeployment. The system delivers radar-absorbing properties not seen in any other camouflage net and protects against radar reconnaissance and homing missiles in the 1-100 GHz range. In the visual and near-infrared range, the choice of patterns, colours and pigments helps the system to blend in with its surrounds. Thermal properties, meanwhile, are reduced to obstruct reconnaissance using thermal sensors.
Protection for individual soldiers and vehicles
It’s not just large assets that need sensor protection. Individual soldiers have more skin in the game than anyone else. Our personal net is light, water repellent, non-snagging and easy to use. It delivers visual, near-infrared and thermal sensor protection, helping soldiers to turn the surrounding environment into their wingman. The Barracuda Soldier Net, meanwhile, is a perfect mix of camouflage net and uniform. It is designed to cover an individual’s load carriage system, shielding both soldier and equipment from view. The Soldier Net weighs less than 1.5 kilograms and its water repellent fabric ensures that it maintains this ultra-lightness even in humid or wet conditions.
Our Break Away System allows vehicles to be concealed from sensors one moment and rapidly deployed the next. The system allows vehicles to be driven almost immediately without the need to take down camouflage. It was developed in cooperation with US Special Forces and its colours and patterns can be adapted for any terrain.
So, the new is good for armed forces looking to conceal themselves from the explosion in enemy sensors. With the right camouflage products and a considered approach to signature analysis and management, you stand an excellent chance of deceiving your opponents and achieving mission success. And we at Saab are ready to stand by you on your camouflage journey.
Article authors
Johan Jersblad
is a Senior Development Engineer specialized in Signature Management at Saab. He joined Saab in 2003 working with radar absorbing materials for ground vehicles. Today, he is working with Signature Management in the whole electromagnetic spectra, from UV to RADAR. Focus is both on material development and measurement methodology. He participates in numerous international collaborations focused on Signature Management within both NATO and EDA. Jersblad holds a Ph.D. in Laser Cooling from Stockholm University.
Niklas Ålund
joined Saab´s Bussiness Unit Barracuda 2010. Responsible for Strategy, Doctrine generation and Business Development on our 20+ market and main B2B partners. Degrees in physics and military science. 20 years in the Swedish Army; leader on platoon to battalion level in Infantry Brigade Combat Team, Armored Brigade Combat Team and Combat Engineering. From 2004-2007 serving as the joint system manager for deception and signature management at the joint HQ.