ECM 2.0

[Frostie]

One way to derail a thread is when the pot starts calling the kettle black, wrong forum for this sort of nonsense. :D

[MoGas]

It bugs me when people suggest it should be like this in Lockon because it is in Falcon, they forget that Falcon is just a game and its actually not real. Yeah the buttons do the right thing but the radar logic is no better if not worse than lockon's.

 

:thumbup: those stupid blowmac flyer's all the time, should learn from falcon...:joystick:

[Renato71]

(sorry for late reply)

I should imagine IRL the jammer automatically combats the radar and the radar combats the jammer, the radar for a contact and the jammer to deny a contact. What happens in LO when blinking occurs is just the jammers part of attack without the radar automatically fighting back, so this can be concluded as totally unrealistic.

 

Is there any difference when trying to lock a blinking target at 20, 50 and 100 km?

[GGTharos]

In LO? Yes. In reality? Depends on the technique. You'll likely burn through an angle jammer at some point ... probably not so much against a range jammer until you're dangerously close to the bubble.

 

Is there any difference when trying to lock a blinking target at 20, 50 and 100 km?

[RedTiger]

Unrelated to blinking but about "burn-through":

 

Q: Has the AIM-120B/C performance been improved?

A: Yes in regards to range, speed, fuze ranges, and counter-counter measure effectiveness. Other missiles have also been improved. In a related manner, ECM burn-through ranges have been moved significantly out (based on aircraft type) and a 15 second ECM warm-up time has been added to address ECM blinking online.

 

This sounds like you'll cut through the jamming earlier than you used to and be able to lock-up a solid return sooner than you could before, based on aircraft type.

 

Isn't this backwards from reality? I could have sworn that I read a discussion here where someone did the math using an equation from a well-known radar technician's text book showing that generally any "burn-through" by a fighter's radar on another fighter using ECM would be so close as to be almost negligible, something like 400 meters. I know this is VERY general (what radar? what fighter? what ECM? etc.), but I remember it just being used to debunk the idea of burn-through.

 

I'm not a big Falcon fan, but I used to think this was an area where Falcon excelled. ECM effectively jammed your radar until you were VERY close, well into Rmax. It was/is impossible to lock up a jamming strobe from 250km away and launch HOJ when you get the range from AWACS or you use something gamey like the Beryoza to estimate the distance. In Falcon, you have to be crafty to survive and even then, you have to be willing to buy the merge and duke it out WVR.

[GGTharos]

This is what ECCM is all about ;)

 

Just because falcon has it doesn't mean it's right. It might be right in SOME cases - nor is it necessary for you to be unable to lock up the jamming strobe - heck, you might not even realize you're being jammed, nor will your radar with some techniques. It all depends.

[RedTiger]

This is what ECCM is all about ;)

 

Just because falcon has it doesn't mean it's right. It might be right in SOME cases - nor is it necessary for you to be unable to lock up the jamming strobe - heck, you might not even realize you're being jammed, nor will your radar with some techniques. It all depends.

 

Right so, in other words, there isn't any such absolute. So if a sim deveoper says "here's the way our simulation handle's ECM" we should all just nod and smile since for all we know, they could be right..or completely wrong...but most won't know for sure and the ones that do aren't talking.

[GGTharos]

Pretty much. There exist well known techniques etc, but we don't really know what the guts of a jammer do, and especially what an ECCM system does to degrade the jammer.

[Vekkinho]

That's probably the most classified intel. Imagine the battlefield with no chance of locking an airborne target and you know there's more than hundred of them up there...Many believed their onboard radars and warning systems died that very moment but radars would work properly in the HAS on the day after if only they made it thru the night!

 

;)

[Vekkinho]

Indeed, my last post was reflection of how often things get misinterpreted, lots of YuAF pilots and airmen who participated in '99 Allied Force campaign over Balkans often mention how their onboard radars deteriorate because of bad or no maintenance over years. They also fail to mention the technical supremacy of their opponents at that time and draw the line between certain facts. So it's not only embargo and lack of spares that made MiG-29 underdog with radars suddenly less effective. It's either working or not and radar being less effective can only point to heavy ECM clutter over the battlefield!

[A.S]

Its not a super difficult topic at all. The techniques instead are ultra classified. You can read very accurate material like Modern Missile Guidance by Rafael Yanushevsky or Radar System Analysis and Design by Bassem R. Mahafza - which both i have - but you dont need to in order to understand the principles.

 

Very simple demonstrated:

 

Imagine a signal-emitter (radar) which is emitting rays out to get the "ping" or reflection back in order to "locate" postions and/or closure and more data etc etc....

Those rays can be in conventional understanding sine-waves, but its a little bit more complex. The signals sent out have a very unique frequence, amplitute, singnature AND/OR patterns.

The reciever (the bandit) of course detects those rays noticing that he "is searched for".

Now what basically happens if we speak about "ECM-jamming" is that the reciever reads out those signals and uses those to sent back a distracting

countersignal....think about interferences, phases, polarities, ghost images -stuipid analogy- but helps understanding ....reality is -as always- little bit more comlex, somtimes even carrier signals and spoting signals in cooperation from your wingy and other sources ....anyways.

This "radar fights ECM, ECM fights back radar game" is a massive process and one reason why modern jets have calculation power in their systems cracking easily the terrabyte range. The days of ole motorola chips are gone.

The basic idea is to deny a save lock as long as possible or to distract a "carrier signal", no matter if it is the radar of the jet or the the missile seeker.

 

I know this is very simple explained, but gives a picture for the difficulty about the quesiton "now, how do we simulate this ?".

What global variables do/can/will matter, which ones can be implemented in simplistic ways in the game code (remember, we dont have supercomputers) and so on. As much more variables or details can be implemented in a efficient way...as better it is, but in certain points you have to make "assumptions" to set some variables. F4AF does that pretty neet in my humble opinion.

Having them all dynamic calculated all the time would just exceed the cpu power.

But then again...those "assumptions" and the question "why are they made in certain ways" ..and "how are they implemented"...are important!

Are they based on unpractical reality-copy efforts, are they totally "wild assumptions" or DO they represent the fundamentel basic concepts in an acceptable fashion so it permits a BVR combat scenario in a proper, or should i say book-style or classic understanding.

The art of simulation, copying the nature in simplified ways, but same results :)

 

PS: and no, i dont wanna lock the Jamming background-noise-guy 300nm away. :D

Edited December 1, 2009 by A.S

[thaFunkster]

One thing that any sim is going to have a problem with is ECM modeling.

 

It's alot more than just "jamming a radar". There's different ypes of jamming. It does alot more than just create noise.

 

Here is one technique. It's called RGPO or Range Gate Pull Off

 

 

 

The ECM system receives the target emitter, then duplicates and amplifies the signal. It's a synthesizer at it's basic element. It then creates an offset. In the example above, the target signal is a Bravo Scan. aka Horizontal scanning radar. When the target radar receives the signal, it sees the target as being on a different azimuth (bearing from origin). The ECM system "walks" this offest out to a predefined limit, resets, and repeats the process. The goal of RGPO is to pull an incoming missile off it's course.

 

In the case of a missile homing radar, that horizontal window is going to be VERY narrow. RGPO is designed to open up that window. Get the missile to fly off course so you can evade (if in an aircraft) or get a hard kill with CIWS (if on a ship).

 

Now, there's many more techniques and not every technique is used the same. It depends on the radar. The "what technique to use and how to use it" are all defined in the software of the ECM system.

 

Now, throw in HOJ (Home On Jam) and you have to employ this technique in a tactical manner. Pull the missile off course with RGPO until the ECM system detects a change in operation of the seeker. Then it will disengage ECM or go to another technique. This causes the HOJ to shut off and the seeker to go active again.

 

Alot of missiles have an active seeker, are locked before they leave the rail, have chaff discrimination, and HOJ all in one convenient, high speed, death delivering package.

 

Here's why flight sim develoeprs cannot get this realistically modeled into the game: Everything about ECM techniques against specific emitters is classified. They get their hands on that and then put it into the game, then that can put them into a sticky situation.

 

In the case of LockOn, a 15 second warm up time is a good decision. Putting in this warmup time will get rid of the ECM On/Off/On/Off (repeat) exploit.

 

While realistically, pulsing ECM techniques definitely exists, the aircraft targeting and seeker radar models in LockOn, Falcon, etc etc are all modeled incomplete. Making a pulsing of ECM an exploit instead of realistic. If it were realistic, then the seekers and targeting radars would have the ways to combat the technique built in. It would take the power of the entire engine just to model the targeting and seeker radars, ECM techniques, radar cross section of chaff types, Infrared signatures, and overall radar propogation.

 

Hope this all makes sense :)

 

Great thanks again Total.

 

Question though: We are not really dealing so much with EW aircraft here, but with inbuilt ECM on fighters and strike aircraft. Does that narrow down what we need to model, and simplify the types of jamming involved?

 

.....Sometimes i really wonder, if real Pilots also have such a huge ego like virtual ones=?....

 

Of course they do! ;)

[weasel75]

I really enjoy all the tech-talk in this thread, and it truly helps to understand what EW is all about - computational power vs. computational power, algorithms and probability as counter-measures to a RL-thread.

To sum it up: in order to be efficient, modern EW-systems draw their own conclusions in order to react to signals in the most optimal way - EW-systems do assumptions about the world around them, a world measured by sensors. A world measured by (limited) sensors leads to a simulated world.

 

For a "simulation" like LOMAC/FC that would mean: try to simulate a computer, that simulates a world based on his sensors (which are simulated), in order to react to threats (which are simulated) that emit simulated radar-impulses.

 

Mhmmm.... so somewhere in this chain some assumptions will be made, some short-cuts taken, etc. ... and then ... well ... then I start thinking ... why all that fuzz, why trying to "really" model such details, if they all can just fall short?

 

Maybe it is easier to just give a feeling of how it would be.

After all, even the Mark I - eyeball is just another simulation, a pixel on a monitor is a poor resemblance of the real thing (seen by a real pilot)......

 

Anyway, thx for all the technical revelations in this thread - it is always a pleasure to read such details - Thank you! :)

[Total]

EW has come a very LOOOONG way.

 

One of the first ECM systems palced aboard ships had a mode called Decoy. It's purpose: make a frigate seem larger than a carrier so the missile would come at it instead of the carrier. Talk about sticking it to the little guys lol!