About ECM and HOJ

[355th_Xantris]

Cause of the increased importance in v1.1 of HOJ due to later burn through I have some questions about ECM and HOJ cause it isn't clear to me.

 

-If amraam is fire and forget in HOJ mode, what happens with amraam fired from 15 nm when target switches ECM off just after the shot was fired? I know it's guess work for the target cause he doesn't hear launch warning but is it able to find the target itself then?

-If amraam is fired in normal mode at a non ECM using target and the target switches ECM on during the Amraam's flight, does it immediatly goes active then and is it able to home in on the target?

-If I, in for example Su 27, fire a R27ER in HOJ mode and during the flightpath, target switches off ECM, does it still be able to reach the target?

-And reversed: what happens if Su 27 fires an ER in normal mode against non ECM using target and during the flight target switches on ECM? Can it still home and how?

[GGTharos]

1) The missile will go active once it loses the jammer (or it could be active all the time, I don't know) and it'll look fo rht etarget itself.

 

2) Not sure of wether it goes active right away or not, dependson the programmed missile logic. I'd imagine that it does go active right away, attempting to ping the target.

 

3) Yes, and if you lock onto the plane after it drops ECM, the missile will home. (so I hear)

 

4) I don't think so, but that's for the Beta Testers to answer. Against a noise jammer it -should- home since the signal will be even stronger (you have to understand that a noise jammer looks like a very bright reflection of the self-same radar that was guiding the missile)

[emenance]

what is hoj ?

 

why do people say if ecm is on to wait for a bit after f15 has fired then switch ecm off and watch the f15 missles lose lock and fly away . I am still not understanding the proper use of ecm :(

[GGTharos]

HoJ is 'Home on Jam'.

Basically if you turn on ECM the missiles can be locked onto your ECM.

 

If the missile being launched at you is SARH, it may well completely lose lock (especially if you deny the F-15 a radar lock) and miss by a mile.

 

Alternatively it may fire an AIM-120 which whill jsut use its own radar to acquire you once you drop ECM (and it'll home in on your ECM all the way if you do keep it on)

[S77th-GOYA]

I was under the impression that a HOJ target doesn't hear a warning other than that they are being spiked by someone's radar until the ARH missle itself reaches burn-through range. Is this correct?

 

And is the burn-through range for the 120 shorter than the 15's radar?

 

So as not to cause confusion, I'm talking about in LOMAC, not reality.

[GGTharos]

You're going to get a missile warning from the moment the HOJ AMRAAM goes active, which I believe happens when it leaves the rail, unless it homes in silently - I can't be certain how this is modelled.

 

The burn through range on the AIM-120 is going to be much much shorter, since it has a rather incredibly puny radar compared to the F-15.

[emenance]

HoJ is 'Home on Jam'.

Basically if you turn on ECM the missiles can be locked onto your ECM.

 

If the missile being launched at you is SARH, it may well completely lose lock (especially if you deny the F-15 a radar lock) and miss by a mile.

 

Alternatively it may fire an AIM-120 which whill jsut use its own radar to acquire you once you drop ECM (and it'll home in on your ECM all the way if you do keep it on)

 

ill admit reading the read me for 1.02 is now on my short list but as your were saying ......i understand that they can lock on my ecm ......my problem is understanding the priciples in useing it in the first place and how to use it effectivly in battle. My first impression after reading your post is to not even think about useing ecm but it must be good for something? :?:

[GGTharos]

It's good for denying the enemy range, speed, and vector information.

 

You can for example turn on ECM, notch his radar and turn it back off. Net result, you dissapear from Rada and he doesn't know where you went.

 

Also if a missile is fired at you - a SARH one - from long range, you can blink the ECM on/off and lose the lock, I think - you may have to combine it with a notching maneuver though.

[SwingKid]

The exact effectiveness of ECM in Lock On depends on the version - 1.0, 1.01, 1.02 or (soon to be) 1.1, but one thing to look for is the missile trajectory. A HOJ missile will generally use a less efficient lead/loft trajectory when flying to the target. This can reduce the maximum range or maneuverability of the missile and make it easier to defeat by target beaming and maneuvering. How much less efficient - this appears to change from version to version, but turning on ECM after being detected by radar is generally modelled to be slightly more of a help than a disadvantage. OTOH keeping it on all the time can get you detected at a longer range.

 

-SK

[355th_Xantris]

1) The missile will go active once it loses the jammer (or it could be active all the time, I don't know) and it'll look fo rht etarget itself.

 

2) Not sure of wether it goes active right away or not, dependson the programmed missile logic. I'd imagine that it does go active right away, attempting to ping the target.

 

3) Yes, and if you lock onto the plane after it drops ECM, the missile will home. (so I hear)

 

4) I don't think so, but that's for the Beta Testers to answer. Against a noise jammer it -should- home since the signal will be even stronger (you have to understand that a noise jammer looks like a very bright reflection of the self-same radar that was guiding the missile)

 

When target switches off ECM, after an amraam missile has been fired in HOJ mode, does he hear a launch tone at that moment ?

And would he hear a launch tone too when SARH missile has been fired in HOJ mode and ECM has been switched down after the launch in this mode?

[SAM-Smasher]

With the AMRAAM I believe a launch tone would be heard, because the missile is actively painting his aircraft, and turning off ECM would make the RWR aware of the attack, thus an initial launch warning would be given, I cant say 100% with-out testing this somehow, but thats how I believe it to be.

 

With a SARH missile, there would be no launch tone after downing ECM, because the missile has already been launched and is riding a beam, so the only tone would be the lock warning produced by your radar holding his aircraft in lock. If you see what I mean :wink:

 

Hope this helps, I apologise if I have made any error in my statement :?

[S77th-GOYA]

What exactly does the targeted RWR look for to sound a launch warning? I'm sure it differs according to which missle is launched and in which mode.

[GGTharos]

What exactly does the targeted RWR look for to sound a launch warning? I'm sure it differs according to which missle is launched and in which mode.

 

Techncially, a SARH launch shouldn't give you a warning tone any more (it use to because the radar waves would switch characteristics after a launch on), with current AC all you shoudl get is the lock-on tone. The RWR may be able to pick up the datalink, in which case it could give you a warning the moment it picket it up, but this could be potentially iffy.

 

FOr an AMRAAM, it loosk fo rthe missile's radar characteristics and once it picks those up, you know you're in trouble.

[S77th-GOYA]

Techncially, a SARH launch shouldn't give you a warning tone any more (it use to because the radar waves would switch characteristics after a launch on), with current AC all you shoudl get is the lock-on tone. The RWR may be able to pick up the datalink, in which case it could give you a warning the moment it picket it up, but this could be potentially iffy.

 

FOr an AMRAAM, it loosk fo rthe missile's radar characteristics and once it picks those up, you know you're in trouble.

 

In LOMAC, not IRL. I know LOMAC is different from this explaination because I get launch warnings from 33s all the time

[GGTharos]

In LOMAC you'll get the warning the moment someone pulls the trigger AFAIK, unless it's an IR or HoJ missile shot.

[AlphaWhiskey]

why dontcha just get online w/ eachother and do some experiments?!?

 

 

:lol:

[emenance]

bump

 

if you fly the su27 or 33 how are you useing ecm and what have been your results.?

 

I am very interested in learning how to use ecm in the f15 also but at this time only fly the 27 and 33

 

thanks :)

[SAM-Smasher]

if you fly the su27 or 33 how are you useing ecm and what have been your results.?

 

I am very interested in learning how to use ecm in the f15 also but at this time only fly the 27 and 33

 

thanks

 

I have taken to flying and practicing in these aircraft alot recently, and I use ecm only after I have recieved a launch warning, there is no point increasing your profile in these aircraft until it is necessary to dodge an incoming missile, also due to aircraft using HOJ, you want to prevent them using this ability to launch their missiles, this is very important when attacked by AMRAAM capable aircraft.

 

You can use your ecm when you are in a HOT SAM area to reduce pk from lock to launch, it is possible that you may not recieve a launch warning, but a SAM launch is usually quite easy to spot, so with practice and plenty of SA this should not be a problem to you.

 

( you may want to re-think your use of ecm in SAM zones when you know there are enemy planes around, but then should you have entered a SAM engagement zone when there are air threats around?? )

 

Hope this is useful :D

[emenance]

bump

 

 

if you fly the su27 or 33 how are you useing ecm and what have been your results.?

 

I am very interested in learning how to use ecm in the f15 also but at this time only fly the 27 and 33

 

thanks

 

I have taken to flying and practicing in these aircraft alot recently, and I use ecm only after I have recieved a launch warning, there is no point increasing your profile in these aircraft until it is necessary to dodge an incoming missile, also due to aircraft using HOJ, you want to prevent them using this ability to launch their missiles, this is very important when attacked by AMRAAM capable aircraft.

 

You can use your ecm when you are in a HOT SAM area to reduce pk from lock to launch, it is possible that you may not recieve a launch warning, but a SAM launch is usually quite easy to spot, so with practice and plenty of SA this should not be a problem to you.

 

( you may want to re-think your use of ecm in SAM zones when you know there are enemy planes around, but then should you have entered a SAM engagement zone when there are air threats around?? )

 

Hope this is useful :D

[Iron Legionnaire]

In LOMAC you'll get the warning the moment someone pulls the trigger AFAIK, unless it's an IR or HoJ missile shot.

 

What about a shot while in TWS?

[GGTharos]

In LOMAC you'll get the warning the moment someone pulls the trigger AFAIK, unless it's an IR or HoJ missile shot.

 

What about a shot while in TWS?

 

AFAIK you should get the warning only when the AMRAAM goes active.

[crazyleggs]

When a SARH missile is launched against you in its normal mode you will always get an audio and visual launch indication on your RWR. When the SARH missile leaves the rail, the supporting radar (i.e. shooter's AI radar) switches modes to provide the missile seeker head with homing info. The RWR picks up that radar mode change and it's parameter library figures out that the radar is in a missile support mode. It is not picking up the data link per say, just the radar mode. That's why you get a launch indication.

 

In a HOJ mode, you will not get a launch indication. You might get a lock indication if the shooter locks your jamming strobe close to your actual range. That is why you shouldn't drone around with ECM on all the time. Eventually, you will get a missile right in the face without warning. ECM comes in handy with maneuvres to defeat lock ons and shots.

 

As far as TWS goes, you're SOL. If you listen to your RWR (Russian) carefully, you can tell if the offender (F-15) is in TWS or RWS. (I think it is modeled in the sim, but not sure). So if you know he's in TWS and you know his range, take appropriate action to try to defeat any shots that might be in the air because if he shoots an AMRAAM in TWS, you won't know it's coming at you till it goes active. That's bad.

 

My comments pertain to real life and the sim. ED has done a good job making it real while keeping systems fairly simple IMHO. The only thing I find is too simplyfied is the ECM. It seems to be noise only (dumb jamming) and not a full SPJ suite. But on the other hand, if SPJ was truly simulated it would be much harder to get a kill.

 

Thanks, can't wait for 1.1 !

[S77th-GOYA]

Somehow I missed this post by crazyleggs. It seems to answer a few questions. But there is one question that I'm not sure of: Timeframe.

The types of jamming being discussed here are relevent to the early 90's or not?

[crazyleggs]

Timeframe is not really an issue. Deliberate noise jamming against radar has been around since early 40s and deception jamming a little later on.

 

The important thing is that a modern day fighter SPJ will use both noise and deception jamming depending on the situation. Also, the techniques generated and the parameters the SPJ uses are kept up to date based on current threats. So your techniques might be old school but if the parameters are correct, you will be effective.

 

Hope this helps.