AIM-120 Still Too Easy to Notch?

[DCS FIGHTER PILOT]

Been doing some testing lately and it still seems like the AMRAAM (and other ARH missiles) can get notched too easily. As mentioned by others, part of this problem comes from the fact that the RWR's of most planes in game are too accurate. Still, even in planes like the F-14 (where the RWR is much less accurate), notching these missiles is still pretty easy. Another problem that seems to contribute to this is that once active, the missile appears to ignore guidance data from the shooters radar (provided they are still tracking/locking the target), even if the missiles radar loses track. From what I understand (and please correct me if I am wrong), even if the missile loses lock, the shooter should still be able to guide it in until impact (if in STT) or until the missile reacquires the target again. Thoughts? 

 

Also out of curiosity , in game, what is the current velocity gate on the AIM-120 as I would like to do some very basic calculations with this information. 

 

Track Descriptions:

Track One: AIM-120C loses lock and misses F-18 at medium altitude. No chaff or ECM is used in the defense. Additionally, once missile is "notched" missile launch tone terminates providing positive feedback to pilot that "notch" was successful. 

Track Two: AIM-120C loses lock and misses F-18 at low altitude. No chaff or ECM is used in the defense. Additionally, once missile is "notched" missile launch tone terminates providing positive feedback to pilot that "notch" was successful. 

Track Three: AIM-120C loses lock and misses F-14 at low altitude. No ECM is used in the defense. Missile launch tone persistent even while in the "notch". 

Notch One.trk Notch Two.trk Notch Three.trk

Edited December 16, 2023 by DCS FIGHTER PILOT

[GGTharos]

49 minutes ago, DCS FIGHTER PILOT said:

Been doing some testing lately and it still seems like the AMRAAM (and other ARH missiles) can get notched too easily. As mentioned by others, part of this problem comes from the fact that the RWR's of most planes in game are too accurate. Still, even in planes like the F-14 (where the RWR is much less accurate), notching these missiles is still pretty easy. Another problem that seems to contribute to this is that once active, the missile appears to ignore guidance data from the shooters radar (provided they are still tracking/locking the target), even if the missiles radar loses track. From what I understand (and please correct me if I am wrong), even if the missile loses lock, the shooter should still be able to guide it in until impact (if in STT) or until the missile reacquires the target again. Thoughts? 

RWR's being 'too accurate' isn't the problem, it's a truly minor part of the problem which you've already demonstrated by mentioning the cat's RWR, so why mention it at all?  You're not offering a solution, and you're not offering any reasoning with respect to how easy/hard it should be notch, so your report as is leads to 'there's nothing to do here'.

As for the last, no, there's no 'guiding an AMRAAM', it guides itself to impact, period.  Best you can do is give it target position updates, but those are nowhere near as accurate as homing guidance and you shouldn't be hoping to fly the missile to a lethal pass (otherwise, what's the homing guidance for?  It's expensive)

49 minutes ago, DCS FIGHTER PILOT said:

Also out of curiosity , in game, what is the current velocity gate on the AIM-120 as I would like to do some very basic calculations with this information.

You should be able to calculate this by flying a bunch of experiments.  I don't recall the numbers which is why I'm not quoting them.

[Hobel]

vor 3 Stunden schrieb DCS FIGHTER PILOT:

Also out of curiosity , in game, what is the current velocity gate on the AIM-120 as I would like to do some very basic calculations with this information. 

~25knots

 

Tested with and without ground clutter.  

This applies to an Aim120 that is in search mode, if it has a track it could be slightly different

I determined this value a few weeks ago, but it should still be up to date.

Edited December 16, 2023 by Hobel

[DCS FIGHTER PILOT]

2 hours ago, GGTharos said:

RWR's being 'too accurate' isn't the problem, it's a truly minor part of the problem which you've already demonstrated by mentioning the cat's RWR, so why mention it at all?  You're not offering a solution, and you're not offering any reasoning with respect to how easy/hard it should be notch, so your report as is leads to 'there's nothing to do here'.

Forgive me but I am really not understanding the need for this border line hostility. Perhaps you failed to read the title which had a question mark in it. My goal here was to get feedback from the community, not to outright claim something. Granted perhaps my choice of words in some areas revealed my bias towards thinking the current in game AMRAAMs are too easy to notch. Supporting this line of thinking, I have routinely observed defenders successfully “notch” several inbound AMRAAMs all coming in from different aspects. The next time I see and capture this behavior, I will be sure to post it. Though perhaps the solution here is to move this post to another section since I am not officially claiming something is broken at this time. I suppose that is for the moderators to decide. 

[DCS FIGHTER PILOT]

1 hour ago, Hobel said:

~25knots

 

Tested with and without ground clutter.  

This applies to an Aim120 that is in search mode, if it has a track it could be slightly different

I determined this value a few weeks ago, but it should still be up to date.

 

So if my understanding is correct, given a target traveling at 700 knots roughy off the nose of an inbound AMRAAM, they would have to fly within an arc spanning approximately 4 degrees in order to notch it. From what I have observed in game, the AMRAAM gets notched well outside of these parameters. For example (as mentioned above) I often observe high speed defenders (700 knots plus) “notch” several inbound missiles all coming in from different aspects. 

Edited December 16, 2023 by DCS FIGHTER PILOT

[GGTharos]

12 minutes ago, DCS FIGHTER PILOT said:

Forgive me but I am really not understanding the need for this border line hostility. Perhaps you failed to read the title which had a question mark in it. My goal here was to get feedback from the community, not to outright claim something. Granted perhaps my choice of words in some areas revealed my bias towards thinking the current in game AMRAAMs are too easy to notch. Supporting this line of thinking, I have routinely observed defenders successfully “notch” several inbound AMRAAMs all coming in from different aspects. The next time I see and capture this behavior, I will be sure to post it. Though perhaps the solution here is to move this post to another section since I am not officially claiming something is broken at this time. I suppose that is for the moderators to decide. 

Fair question - the irony is that I agree with you, but the catch is this:  What good is the community opinion  (1) ?  Maybe you believe this is harsh, but the fact is, most of the community doesn't know, those who know don't talk and those who have a better idea of what's going on without fear of spilling the beans so to speak are far and few inbetween but they are around.

So, I think the goal here is to ask the right questions and get the right information, eg:

What does it mean that the missile is too easy to notch?  A couple of tracks is neat but doesn't mean anything, ie. 'works as designed' within the context of the game - closure < 25kts (as reported above) = break-lock.

So, are we now going to talk about a target recovery attempt?  It has been done in this game before.  it was successful and guess what ... (1) people complained the 120 was 'too good' now, you actually had to stay in the notch and execute very accurately to make the thing stop hounding you.  So ED turned that feature off.

But suppose this comes back - now what?  How do we deal with ECM and countermeasures, because obviously the missile could/should be affected (sometimes positively!)?

Basically, saying 'it's too easy to notch' is stating a gut feeling without offering what it should be, never mind how it should be.

3 minutes ago, DCS FIGHTER PILOT said:

So if my understanding is correct, given a target traveling at 700 knots roughy off the nose of an inbound AMRAAM, they would have to fly within an arc spanning approximately 4 degrees in order to notch it. From what I have observed in game, the AMRAAM gets notched well outside of these parameters. For example (as mentioned above) I often observe high speed defenders (700 knots plus) “notch” several inbound missiles all coming in from different aspects. 

 

One problem is that the notch works if you merely fly through it.  Another problem is that if you go hot to cold aspect, it's possible (not certain but possible) that the in-game doppler tracker will give up.  Essentially 'blinking' through the notch may constitute a break-lock.   The simulation used to be much simpler than it is today, but some simple effects appear to remain.  Without any debug prints though (which we will not be getting) it's really hard to judge what's going on any more.

[Hobel]

vor 7 Minuten schrieb DCS FIGHTER PILOT:

So if my understanding is correct, given a target traveling at 700 knots roughy off the nose of an inbound AMRAAM, they would have to fly within an arc spanning approximately 4 degrees in order to notch it. From what I have observed in game, the AMRAAM gets notched well outside of these parameters. For example (as mentioned above) I often observe high speed defenders (700 knots plus) “notch” several inbound missiles all coming in from different aspects. 

 

There could be different things that play into it, in a clean environment I come up with this number.    Otherwise can you show a track/tacview so that we are all talking from the same point of view. 

 

EDIT: sorry will look tracks later.

Edited December 16, 2023 by Hobel

[DCS FIGHTER PILOT]

2 minutes ago, Hobel said:

There could be different things that play into it, in a clean environment I come up with this number.    Otherwise can you show a track/tacview so that we are all talking from the same point of view. 

 

EDIT: sorry will look tracks later.

 

Okay let’s be a bit more lenient and say the velocity gate is plus or minus 50 knots. At this point, a 700 knot defender would have to fly within an arc spanning 8 degrees. Again from the examples I witnessed, at least one of the missiles should still be able to track the target. 

[Ramius007]

Are You awere that you are trying to make undoubtly best A2A missile in game even better without any data relevance on this part?

[GGTharos]

That's a poor argument.   Although this complaint is specifically about the 120, anything that came out of it could/should apply to any 80's missile and probably a bunch of 70's ones, to include SAMs as well.

[DCS FIGHTER PILOT]

28 minutes ago, GGTharos said:

Fair question - the irony is that I agree with you, but the catch is this:  What good is the community opinion  (1) ?  Maybe you believe this is harsh, but the fact is, most of the community doesn't know, those who know don't talk and those who have a better idea of what's going on without fear of spilling the beans so to speak are far and few inbetween but they are around.

So, I think the goal here is to ask the right questions and get the right information, eg:

What does it mean that the missile is too easy to notch?  A couple of tracks is neat but doesn't mean anything, ie. 'works as designed' within the context of the game - closure < 25kts (as reported above) = break-lock.

So, are we now going to talk about a target recovery attempt?  It has been done in this game before.  it was successful and guess what ... (1) people complained the 120 was 'too good' now, you actually had to stay in the notch and execute very accurately to make the thing stop hounding you.  So ED turned that feature off.

But suppose this comes back - now what?  How do we deal with ECM and countermeasures, because obviously the missile could/should be affected (sometimes positively!)?

Basically, saying 'it's too easy to notch' is stating a gut feeling without offering what it should be, never mind how it should be.

One problem is that the notch works if you merely fly through it.  Another problem is that if you go hot to cold aspect, it's possible (not certain but possible) that the in-game doppler tracker will give up.  Essentially 'blinking' through the notch may constitute a break-lock.   The simulation used to be much simpler than it is today, but some simple effects appear to remain.  Without any debug prints though (which we will not be getting) it's really hard to judge what's going on any more.

Understood.

Like you mentioned, it appears as if all one has to do in order to notch an inbound AMRAAM is to merely “hit” the notch. After that the missile seems to rarely recover. It’s as simple as rolling left or right until you find the sweet spot and then boom, missile trashed. This (along with the missile appearing to just give up tracking for no apparent reason on a hot to cold target) is the most frustrating part of this behavior. 

Edited December 16, 2023 by DCS FIGHTER PILOT

[DCS FIGHTER PILOT]

I think this video basically sums up the current state of the game (intended or not) 

 

[Hobel]

vor 1 Stunde schrieb DCS FIGHTER PILOT:

Okay let’s be a bit more lenient and say the velocity gate is plus or minus 50 knots. At this point, a 700 knot defender would have to fly within an arc spanning 8 degrees. Again from the examples I witnessed, at least one of the missiles should still be able to track the target. 

I'll just rate your tracks now.

 

in "Notch2" loses the missle exactly at the point where you reach the 48kmh/25.9knots

"notchone" the same, 48kmh/25.9knots

 

 

 

 

 

In "notch3" the difference is already bigger, but you are also very close to the ground here, there is also a report on this, which could be related to this
Edit: maybe the chaff also falsify it, doesn't the Rio also activate the ECM automatically in the F14 or something?

And to check the figures again.

Here is a Tacview with the parameters in a very clean environment.

the left helicopter flies 55kmh TAS is always hit
Right helicopter 53kmh TAS and is not hit.

these are exactly the areas we see in the track above One and Two, 3 could have additional reasons

Tacview-20231217-003954-DCS.zip.acmi

Edited December 16, 2023 by Hobel

[okopanja]

37 minutes ago, Hobel said:

in "Notch2" loses the missle exactly at the point where you reach the 48kmh/25.9knots

48 km/h 25.9 knots is the Doppler filter speed for AMRAAM seeker?

[Xhonas]

RWRs being too precise plays a big factor in this perception, and also the fact that missiles appear on the RWR when they are still too far from the defending jet, giving it plenty of time to think and defend in the notch. There are a lot of online references on how RWRs should work and EW in general, if ED used available data in our RWRs this perception would be very different.  I wont send it here to avoid breaking any rules, but i believe that ED is aware of these references.

Aside from fixing some problems with the Aim-120 terminal guidance, i don't think there is a lot more they can change to improve tracking targets that are in the notch.

[Hobel]

vor 10 Stunden schrieb Xhonas:

RWRs being too precise plays a big factor in this perception, and also the fact that missiles appear on the RWR when they are still too far from the defending jet, giving it plenty of time to think and defend in the notch. There are a lot of online references on how RWRs should work and EW in general, if ED used available data in our RWRs this perception would be very different.  I wont send it here to avoid breaking any rules, but i believe that ED is aware of these references.

Aside from fixing some problems with the Aim-120 terminal guidance, i don't think there is a lot more they can change to improve tracking targets that are in the notch.

btw

How the RWR reacts to Missles or Aim120 has changed slightly.

As an example
Aim120 whose target an F16 goes at 10nm active, then RWR of the F16 gives a warning between ~6-7nm.

in the past you always got a warning at exactly 8nm in this scenario

vor 10 Stunden schrieb okopanja:

48 km/h 25.9 knots is the Doppler filter speed for AMRAAM seeker?

the way it looks,

Or rather, ~53km/h

 

Edited December 17, 2023 by Hobel

[DCS FIGHTER PILOT]

17 hours ago, Hobel said:

I'll just rate your tracks now.

 

in "Notch2" loses the missle exactly at the point where you reach the 48kmh/25.9knots

"notchone" the same, 48kmh/25.9knots

 

 

 

 

 

In "notch3" the difference is already bigger, but you are also very close to the ground here, there is also a report on this, which could be related to this
Edit: maybe the chaff also falsify it, doesn't the Rio also activate the ECM automatically in the F14 or something?

And to check the figures again.

Here is a Tacview with the parameters in a very clean environment.

the left helicopter flies 55kmh TAS is always hit
Right helicopter 53kmh TAS and is not hit.

these are exactly the areas we see in the track above One and Two, 3 could have additional reasons

Tacview-20231217-003954-DCS.zip.acmi 56.63 kB · 6 downloads

 

Thanks for the review. Would you be able to tell me whether or not I stayed in the notch or did I eventually come out of it? As you can see in the tracks, the missiles never reacquired and missed. 

[Ramius007]

I also see bug, missiles in DCS always go of rails, missile engine always ignite, radar/ seeker/ proximity fuze always work... This coin have 2 sides, i dont see anybody raporting dark side of the coin

[GGTharos]

10 minutes ago, Ramius007 said:

I also see bug, missiles in DCS always go of rails, missile engine always ignite, radar/ seeker/ proximity fuze always work... This coin have 2 sides, i dont see anybody raporting dark side of the coin

This is not a bug.

[Ramius007]

9 minutes ago, GGTharos said:

This is not a bug.

If RL have bugs and game not simulate this, then it is a bug. On more sirious note regarding specific OP topic, just simple variance added to how doppler work in missile would work, it's proapbly most realistic way to do this, given we lack classified info what exactly is needed to beat missile

[GGTharos]

No, what is a bug is programming something and it doesn't work as intended.  This is not a bug.

[Hobel]

vor 3 Stunden schrieb DCS FIGHTER PILOT:

Thanks for the review. Would you be able to tell me whether or not I stayed in the notch or did I eventually come out of it? As you can see in the tracks, the missiles never reacquired and missed. 

Difficult to say, I would also have questions about.

in Tacview one you are briefly in a notch, the missle loses track, then it searches for you and although in my eyes the approach speed is more than high enough and the plane is in Missle  FOV but doesn't see it, why?

I don't know

 

basically this moment

 

Edited December 17, 2023 by Hobel

[ruxtmp]

Im pretty sure once the missile loses lock, in this case due to notch, it goes dumb and just flies off on a ballistic trajectory. I have never seen a missile in DCS an air to air missile re-acquire a target even if it was inside seeker FOV.

[GGTharos]

This capability had been put in and was later removed.   Or perhaps there exist other bugs causing issues here, or incomplete features regarding the behavior of the range and doppler gates which are simulated for at least the 120 and I believe the 7 as well.

[ruxtmp]

Not sure why they would add it then remove it. Does the real missile not have the capability to re-engage a target inside its seeker FOV? Seems like a pretty basic thing to have but Im not a missile engineer.