Do You know the Salient Features of Rafale Fighter Jet?

How do active cancellation techniques of Rafale work against advanced Radar?

Indian airforce: The first, five #1AF#Rafales have taken off from Dassault Aviation Facility, Merignac, #France today morning. These 5 include 3 single-seater and 2 twin-seater aircraft. The ferry is planned in two stages & is

being undertaken by IAF pilots.

Air to Air Refuelling planned during the first leg of the ferry will be undertaken by dedicated Tanker support from French Air Force. The aircraft is likely to reach AF Stn Ambala on 29 Jul 20. No 17 Sqn, 'The Golden Arrows', is being raised at #Ambala with #Rafale aircraft.

Cost of Rafale for India

Cost: India had signed an inter-governmental agreement with France in September 2016 for procurement of 36 Rafale fighter jets at a cost of around Rs 58,000 crore.

Name of the crew team members who have been brought the Rafale fighter jet from France to India:-

Group Captain:  Harkirat Singh & R Kataria

 Wing Commanders:

1. Abhishek Tripathi

2. MK Singh 

3. Siddhu

4. Arun

5.  Manish Singh

Salient Features of Rafale Fighter Jet:

 

Rafael is a scalp missile and this missile can hit 600 km from the air to the ground. Rafale is a two-engine fighter aircraft, which is the first choice of Indian airforce and can be sent for all kinds of missions. Rafale can reach a height of 60 thousand feet in a minute. Its fuel capacity is 17 thousand kilometres. This fighter aircraft is capable of carrying a weight of up to 24,500 kg and can fly for an extra 40 hours. Rafael can fly at a speed of 2,223 kilometres per hour.

 

Kashmir's Hilal Ahmad became the first Indian pilot to fly Rafale 

Watch the video to know the salient features of Rafale Jet:

1. What is Active Cancellation:

 It is often argued in defence forums that Rafale may not have shape stealth-like F-35 but it can elude enemy radars by so-called active cancellation technique. Another emphasis is made on the ability of RBE-2 radar to create false targets for the enemy. Apparently good Electronic Warfare systems can produce Phantom echoes that can look like aircraft where there's none. I'm just taking the example of Rafale but it is equally well claimed for other 4++ Gen aircraft as well.  Then, the Russian doctrine of stealth also lays overwhelming emphasis on Radio Frequency Memory Jamming instead of cost-intensive shape stealth and thick coatings of RAM paints as practised by Americans.

2. Theory of Active Cancellation:

Active cancellation as a theory is very simple. You just need to provide a mirror image of the incoming wave (received from adversary aircraft radar) - a phase shift - and they will cancel each other out. But mind you if you match your signal with the echo it will become twice as strong. So with a sufficiently fast computer and a sufficiently strong emitter you can stand in front of the radar and it won't see a thing. 

But there are few ifs with regards to active cancellation technique. The idea of active cancellation may have been theorised for decades now, but even today it is just not possible out of ideal lab conditions. 

One of the biggest reasons why it cannot work is that an aircraft is a complex shape. Try as you might, but cancelling the waveform hitting your jamming pod will do nothing for the waveforms hitting elsewhere on the aircraft, say your wings. Worse still, it may, in fact, do the opposite just as easily and result in you constructively interfere with incoming waveforms hitting other parts of your plane, and actually boost the return signals. So against a modern digital radar, attempting this technique will actually increase its ability to detect you, as they are capable of using the delayed echoes as diversity gain. 

Now in theory, if you are able to cover your aircraft skin with tiny jamming modules that can send out directional radiation, then we might be able to get a working one. But nobody is at that point yet. An attempt in this regard is being made in Rafale F4 which will boast of multiple arrays of radar on its airframe. 

In layman's language, it is called Repeater jamming and is commonly done nowadays by systems with radio frequency memory. But the point I want to make is that Radiofrequency memory jamming is far more limited than commonly believed. First, unless it's World War 2 era pulse radar, jammers cannot anticipate the keyed modulation sent by modern digital radars like AN/APG-81( Advanced radars like AN/APG-81 can emit a background noise like a signal to avoid detection by adversary radar. It is actually generated by a cryptographically keyed pseudo-random number generator with a bunch of other processing in the mix). Since the jammer cannot anticipate keyed modulation, it has to listen and repeat. This means it's only capable of creating phantom images (false targets) at a further range than the jamming platform, plus some additional minimum distance due to latency within the jammer. That implies that even if a Rafale or a Typhoon creates a phantom image farther than itself to waylay the adversary radar, the actual aircraft is nearer for the approaching missile than the phantom image created by it. 

Even yet worse, if there is any form of multi-static radar or passive EW multi alteration, the deception fails entirely. But even short of this due to geometric constraints, the first image of the aircraft as seen by say AN/APG-81 radar, is the correct image. 

Tejas Mark1 aircraft, on the other hand, employs passive jammers as there is not sufficient volume to incorporate an integrated active jammer. Passive jamming - flooding all frequencies with noise is almost trivially detectable. (You just tune a radio/other detectors to an unused band and wait for the noise level to spike.) Flooding a single band or set of bands (emitted by saying F-35's AN/APG-81 radar) with noise is also relatively simple to detect because the noise will swamp out the signal and become obvious. Imagine someone playing the violin (F-35 Radar) being drowned out by a jet engine (Passive Jammer of Tejas)- you can easily tell the jet engine is there. You can't tell whether the violin is being played or where it is, but you know something is going on, and by moving towards the sound (i.e. moving in the direction that makes the engine louder) you can figure out where it is. 

In either case, even if Tejas Mark1 is flying with its radar off, once you detect the jamming signals you can then use triangulation to pinpoint the source (In a group of three planes, when one detects a signal from a source, the other two can also listen for the same signal, all three measuring the amount of time taken for transmissions to travel from the source to each aircraft to triangulate the location). 

More granular active jamming, in theory, is much more difficult to detect if done correctly - which is a big if as I explained above- because essentially what the jammer is doing is emitting the exact same waveform it's receiving...except inverted. So the incoming radar wave gets reflected back...and the target emits a wave that is the exact opposite of that wave, cancelling it out. From the radar's point of view, there's no return, exactly as if the radar wave didn't hit anything at all. There's also no obvious jamming signal to detect since the only wave that is being emitted is being cancelled out nearly perfectly by the radar signal. Imagine wearing noise-cancelling headphones while listening while someone playing the violin - the headphones are simply playing a "sound" whose wave is the exact opposite of the sound of the violin, making you unable to tell whether the violin is being played or not, and without giving you any other signal that funny business is occurring. 

But also this second form of jamming is only effective versus predictable signal structures like that of World War 2 style radars. Any form of keyed modulation as employed by AN/APG-81 radar forces the use of repeater jamming which is inherently limited by latency, the speed of light, and the geometric constraints resulting from the same. The example of sound was just to explain the theory, but 1D examples of sound do not generalise to electromagnetic waves radiating in 3D. The situation in 3D with EM signals is not in any way analogous to acoustic interference patterns. Sound is a scalar wave. EM is a vector field. Huygens-Fresnel is not equivalent to Maxwell's laws.

So in a nutshell, active cancellation might be theoretically possible in the future but isn't possible right now. Especially not with jamming pods. 

We won't see the real potential of active EW until wingman drones with EW systems working as a network come into service. Fleets of non-existent aircraft popping in and out of existence all over the battlefield as real aircraft or drones - usually operating stealthily - attempt to penetrate enemy defences.