GriffinsRule
SENIOR MEMBER
- Joined
- Nov 18, 2015
- Messages
- 3,394
- Reaction score
- 7
- Country
- Location
The art of avoiding detection
By Air Marshal (ret’d) Greg Bagwell CB CBE
Airforces Monthly, Sept 2019
The idea of stealth aircraft is now firmly set in the public imagination. Yet, we are still some way off from the Harry Potter-like ‘cloak of invisibility’. Firstly, stealth capability today is about reducing radar signature in relatively narrow bands of the spectrum; rather than making aircraft totally undetectable. But, invariably they are able to reduce detection ranges to such a degree that a stealthy aircraft can either fly through the now larger gaps created in radar coverage, or get close enough to target the very thing trying to detect them.
But even stealth aircraft have Achilles’ heels. Noise, heat, visual signature and even certain angles or aircraft configuration allow some chance of detection. Moreover, modern surface-to-air missile (SAM) systems and even airborne radars are looking at new slices of the electronic spectrum to use frequencies that render current stealth designs less effective or even defunct. So, the evolution of the airborne cat-and-mouse game continues. But, while we have seen major air powers each pursue their own versions of stealth aircraft, the greatest advances have perhaps been in the development of detection and interception technologies, so maybe aircraft are losing this ‘arms race’.
Of course, stealth aircraft still only form a fraction of even very modern and wealthy air forces, so what are the other tools and tactics available to crews in today’s battlespace? Well quite simply, the rules of the game are rather straightforward and involve a combination of physics and cunning. Let’s start with the technical bit first – the physics boils down to three simple techniques: stay outside detection range, blank out the other side’s detection capability or deceive it to look elsewhere.
Staying outside detection range is what stealth characteristics aim to achieve. By reducing detection range, you can actually decrease standoff and, in extremis, penetrate an enemy’s defence system. It goes without saying, that knowing where systems are is a vital element in staying out of detection range, and long-term surveillance is aimed at gathering both system locations and electronic signatures to enable this. Of course, even more critical are missile flyout and engagement ranges – respectively, the weapon’s ‘legs’, before it loses kinetic energy, and the practical envelope at which it can shoot down a target. Historically, these have been much lower than the detection ranges, but new systems are increasingly able to shoot over the horizon and this is forcing strategic assets such as surveillance platforms further away from the front line.
Jamming and spoofing
Standoff or even self-protection ‘noise’ jamming is the next simple technique that aims to deny or at least disrupt detection; it does this by swamping hostile equipment – creating so much ‘electronic noise’ within an operating system that its users have to de-tune it to such an extent that detection ranges drop dramatically, or are even totally shut down. However, this technique has a few drawbacks in that it requires significant power for an air platform to overcome a ground-based system with greater generation capacity; moreover, it can actually act as a beacon for enemy sensors able to home in on a jamming signal. Finally, it needs to be able to match the operating frequency of the targeted hardware, and today’s air defence systems are increasingly able to hop frequency incredibly quickly, which needs an equally agile jamming signal or ‘barrage’ jamming of a wide spectrum band, which again demands significant power.
And so, the final technique is one of deception rather than avoidance, and this requires an electronic signal that can decoy, distract or divert detection methods. These are more prevalent in modern systems and can include the use of standoff, supporting or deployable decoys. Indeed, much of the recent hype about swarming drones hints towards this use for cheaper, expendable platforms that can act as a diversion for other more valuable platforms.
I have, of course, grossly oversimplified some rather sophisticated physics and technologies, but the basic principles hold good for radar-guided systems. Of the other detection measures, increased performance in sensors and processors is making the broader spectrum (visual, infrared and noise) increasingly exposed and cannot be discounted as a growing vulnerability in the coming years.
Clever tactics
So much for the science, what about the art form known as cunning. There is an old fighter pilot adage that ‘if you’re not cheating, you’re not trying’, and nowhere is this more true than in the tactics employed to avoid detection. SAM battery operators are trained to spot patterns or assume certain behaviours. There have been numerous recent examples, in relatively benign circumstances, where air defence weapon systems have engaged friendly aircraft that either weren’t exhibiting certain behaviours or became confused with nearby platforms that were hostile. Saturating a defensive system or creating a complex or conflicting picture can buy precious time to decrease detection or at the very least decrease reaction time to engage; and in this case anything goes to try to create maximum confusion. The rest, my friend, is classified, but let your imagination run wild, the less predictable the better.
I hope I have painted a rather more nuanced picture of a battle to reduce detection times to such an extent that any reaction is too slow to carry out a successful interception. Rarely will this result in a totally one-way fight. The history of air power is littered with surprising shoot-downs of platforms that were considered immune to attack, and these will not be the last. Control of the air remains a key foundation of air power doctrine, but what was once largely a battle between aircraft is now a far more complex equation, but one where ‘he who sees first wins’ still holds as valid today as it did over the battlefields of World War One.
By Air Marshal (ret’d) Greg Bagwell CB CBE
Airforces Monthly, Sept 2019
The idea of stealth aircraft is now firmly set in the public imagination. Yet, we are still some way off from the Harry Potter-like ‘cloak of invisibility’. Firstly, stealth capability today is about reducing radar signature in relatively narrow bands of the spectrum; rather than making aircraft totally undetectable. But, invariably they are able to reduce detection ranges to such a degree that a stealthy aircraft can either fly through the now larger gaps created in radar coverage, or get close enough to target the very thing trying to detect them.
But even stealth aircraft have Achilles’ heels. Noise, heat, visual signature and even certain angles or aircraft configuration allow some chance of detection. Moreover, modern surface-to-air missile (SAM) systems and even airborne radars are looking at new slices of the electronic spectrum to use frequencies that render current stealth designs less effective or even defunct. So, the evolution of the airborne cat-and-mouse game continues. But, while we have seen major air powers each pursue their own versions of stealth aircraft, the greatest advances have perhaps been in the development of detection and interception technologies, so maybe aircraft are losing this ‘arms race’.
Of course, stealth aircraft still only form a fraction of even very modern and wealthy air forces, so what are the other tools and tactics available to crews in today’s battlespace? Well quite simply, the rules of the game are rather straightforward and involve a combination of physics and cunning. Let’s start with the technical bit first – the physics boils down to three simple techniques: stay outside detection range, blank out the other side’s detection capability or deceive it to look elsewhere.
Staying outside detection range is what stealth characteristics aim to achieve. By reducing detection range, you can actually decrease standoff and, in extremis, penetrate an enemy’s defence system. It goes without saying, that knowing where systems are is a vital element in staying out of detection range, and long-term surveillance is aimed at gathering both system locations and electronic signatures to enable this. Of course, even more critical are missile flyout and engagement ranges – respectively, the weapon’s ‘legs’, before it loses kinetic energy, and the practical envelope at which it can shoot down a target. Historically, these have been much lower than the detection ranges, but new systems are increasingly able to shoot over the horizon and this is forcing strategic assets such as surveillance platforms further away from the front line.
Jamming and spoofing
Standoff or even self-protection ‘noise’ jamming is the next simple technique that aims to deny or at least disrupt detection; it does this by swamping hostile equipment – creating so much ‘electronic noise’ within an operating system that its users have to de-tune it to such an extent that detection ranges drop dramatically, or are even totally shut down. However, this technique has a few drawbacks in that it requires significant power for an air platform to overcome a ground-based system with greater generation capacity; moreover, it can actually act as a beacon for enemy sensors able to home in on a jamming signal. Finally, it needs to be able to match the operating frequency of the targeted hardware, and today’s air defence systems are increasingly able to hop frequency incredibly quickly, which needs an equally agile jamming signal or ‘barrage’ jamming of a wide spectrum band, which again demands significant power.
And so, the final technique is one of deception rather than avoidance, and this requires an electronic signal that can decoy, distract or divert detection methods. These are more prevalent in modern systems and can include the use of standoff, supporting or deployable decoys. Indeed, much of the recent hype about swarming drones hints towards this use for cheaper, expendable platforms that can act as a diversion for other more valuable platforms.
I have, of course, grossly oversimplified some rather sophisticated physics and technologies, but the basic principles hold good for radar-guided systems. Of the other detection measures, increased performance in sensors and processors is making the broader spectrum (visual, infrared and noise) increasingly exposed and cannot be discounted as a growing vulnerability in the coming years.
Clever tactics
So much for the science, what about the art form known as cunning. There is an old fighter pilot adage that ‘if you’re not cheating, you’re not trying’, and nowhere is this more true than in the tactics employed to avoid detection. SAM battery operators are trained to spot patterns or assume certain behaviours. There have been numerous recent examples, in relatively benign circumstances, where air defence weapon systems have engaged friendly aircraft that either weren’t exhibiting certain behaviours or became confused with nearby platforms that were hostile. Saturating a defensive system or creating a complex or conflicting picture can buy precious time to decrease detection or at the very least decrease reaction time to engage; and in this case anything goes to try to create maximum confusion. The rest, my friend, is classified, but let your imagination run wild, the less predictable the better.
I hope I have painted a rather more nuanced picture of a battle to reduce detection times to such an extent that any reaction is too slow to carry out a successful interception. Rarely will this result in a totally one-way fight. The history of air power is littered with surprising shoot-downs of platforms that were considered immune to attack, and these will not be the last. Control of the air remains a key foundation of air power doctrine, but what was once largely a battle between aircraft is now a far more complex equation, but one where ‘he who sees first wins’ still holds as valid today as it did over the battlefields of World War One.
