fixed AIM-120 HOJ incapable of hitting manoeuvring targets

[Default774]

The AIM-120 HOJ issues have been split up in a number of threads, so I figured I'd compile the issues together in one thread.

When the target is jamming, the AIM-120 is completely incapable of hitting manoeuvring targets. The missile can be defeated by a level 2G turn or a 2g climb. All of this ultimately culminates in that the AIM-120 has practically a 0% Pk against jamming targets. You might as well not bother firing an AIM-120 if the target is jamming and they're not flying perfectly straight.

Description of tracks and what situation they depict:

• clht - Turn from beaming back into the target, missile misses 100% of the time
• manv - Generic manoeuvring, ranging from level 2-3g turns, 2g climbs, and random turns, missile misses 100% of the time.
• hot - High G climb slightly before the missile hits you, missile misses 100% of the time.
• beaming - slight vertical pull when beaming the missile, missile misses 100% of the time.
• ai_hoj&ai_nohoj - Ace AI vs AIM-120s, with the AI being allowed to jam and not allowed to jam respectively.

Additionally, I would like to raise some questions about the implementation of HOJ in the AIM-120. As it currently stands, the implementation of HOJ on the 120 is perplexing at best. 

• Does the missile not use datalink updates for determining range to target when the target is jamming? For example, even if the parent aircraft has burnt through the jammer and has resolved range, the missile still does not loft or carry out the midcourse phase normally. Additionally, can the missile not utilize datalink updates from the parent aircraft during terminal guidance for resolving the targets closure and range? 
• Does the missile ever attempt to use its own radar against jamming targets? If yes, why does the missile not burn through the jammer at closer ranges?

120hoj.zip

[Default774]

Issue mentioned in first post is now fixed, but you are still able to dodge 120s in any situation by pulling a high G manoeuvre one or two seconds before impact. This is probably an inherent issue of HOJ guidance, but that brings me back to the points I made in the main post. Why does the missile not burn through the jammer as it gets closer to the target?

Hopefully we can get some sort of insight from ED on why HOJ is implemented the way it is for 120s. For a modern missile to be able to be defeated by pulling a simple high g pull is a bit ridiculous in my opinion.

120_hhg_2.trk 120_hhg_3.trk 120_hhg_4.trk 120_hhg_1.trk 120_hhg_4.acmi 120_hhg_3.acmi 120_hhg_2.acmi 120_hhg_1.acmi

[Default774]

Small and not entirely unrelated sidenote. Setting the proximity fuse distance to equal that of the killDistance attribute like every single other missile in the game, hhg1&3 will both hit their target.

[Pavlin_33]

15 hours ago, Default774 said:

Why does the missile not burn through the jammer as it gets closer to the target?

 

120_hhg_2.trk 51.28 kB · 0 downloads 120_hhg_3.trk 49.69 kB · 0 downloads 120_hhg_4.trk 54.54 kB · 0 downloads 120_hhg_1.trk 52.7 kB · 0 downloads 120_hhg_4.acmi 20.39 kB · 0 downloads 120_hhg_3.acmi 14.09 kB · 0 downloads 120_hhg_2.acmi 17.26 kB · 0 downloads 120_hhg_1.acmi 20.25 kB · 0 downloads

What makes you thing it has enough power to "burn through" the jammer.

120 in HOJ does not use its own radar, BTW - it does but in passive mode.

[Default774]

1 minute ago, Pavlin_33 said:

What makes you thing it has enough power to "burn through" the jammer.

Thats exactly what im trying to establish here. Considering its at a very close distance to the target and its a modern missile why should it not be able to burn through? For arguments sake, the missile wont even burn through extremely outdated jammers like on the mig21(i know dcs only has three jammer types)

4 minutes ago, Pavlin_33 said:

120 in HOJ does not use its own radar, BTW - it does but in passive mode.

If this is the case, why does the missile give me an RWR launch warning when guiding onto me in HOJ?

https://streamable.com/fzb6dh

[okopanja]

4 minutes ago, Default774 said:

Thats exactly what im trying to establish here. Considering its at a very close distance to the target and its a modern missile why should it not be able to burn through? For arguments sake, the missile wont even burn through extremely outdated jammers like on the mig21(i know dcs only has three jammer types)

This is actually very simple to understand: HOJ mode is made with idea to fire at jamming target which denies normal ranging information in the first place. The drawback of this approach is that guidance law is based only on angular coordinates, but huge benefit is that it is passive from the point of shooter, meaning it will not give a warning to the victim. Your idea to burn-through is essentially negating the HOJ mode in the first place.

[Pavlin_33]

55 minutes ago, Default774 said:

Thats exactly what im trying to establish here. Considering its at a very close distance to the target and its a modern missile why should it not be able to burn through? For arguments sake, the missile wont even burn through extremely outdated jammers like on the mig21(i know dcs only has three jammer types)

If this is the case, why does the missile give me an RWR launch warning when guiding onto me in HOJ?

https://streamable.com/fzb6dh

The entire ECM topic is a bit out if my competences, but in DCS:

1. I guess burn through for AIM120 is the same as the pitbill distance

2. 120 in HOJ does not emit any radiation so if you had RWR indication, it was not fired in HOJ

Edited February 18, 2023 by Pavlin_33

[Default774]

1 hour ago, Pavlin_33 said:

1. I guess burn through for AIM120 is the same as the pitbill distance

 

the aim120 never burns through any jammer

1 hour ago, Pavlin_33 said:

2. 120 in HOJ does not emit any radiation so if you had RWR indication, it was not fired in HOJ

Except that it quite literally does. There is as far as I know no situation where the AIM120 will passively guide onto a jamming target without giving an RWR warning.

https://streamable.com/ol0rcr

Missile is fired in BVR, as you can see the missile is clearly in HOJ as it doesn't loft. And as you would expect, I get a missile warning from the missiles radar. As the missile is closing in I start toggling my ECM, and you can see the missile start twitching as it starts switching from HOJ to normal PN.

https://streamable.com/rythpd

Here you can see me toggling ECM while defending the missile. As I toggle ECM on and off you can see the missile switching from HOJ to PN guidance repeatedly.

Can you show me an example of an AIM-120C being fired in HOJ and not giving an RWR warning to its target?

[Pavlin_33]

1 hour ago, Default774 said:

the aim120 never burns through any jammer

...

Can you show me an example of an AIM-120C being fired in HOJ and not giving an RWR warning to its target?

To be honest I don't know. My ECM knowledge is limited to FC3. You said you were toggling the jammer on/off - I guess the 120 switches its radar on after the ECM are switched off. What happens if you keep the jammer on and the 120 is fired at you otside the attackers burn through distance? Does it still go active?

[Default774]

1 hour ago, Pavlin_33 said:

To be honest I don't know. My ECM knowledge is limited to FC3. You said you were toggling the jammer on/off - I guess the 120 switches its radar on after the ECM are switched off. What happens if you keep the jammer on and the 120 is fired at you otside the attackers burn through distance? Does it still go active?

I showed that exact scenario in this video(AI set to fire at max range), the missile still goes active. As far as I can see, the missile always keeps its radar on, even in HOJ.

https://streamable.com/ol0rcr

Edited February 18, 2023 by Default774

[Pavlin_33]

1 hour ago, Default774 said:

I showed that exact scenario in this video(AI set to fire at max range), the missile still goes active. As far as I can see, the missile always keeps its radar on, even in HOJ.

https://streamable.com/ol0rcr

 

Any idea what range that was? Burn through distance is the same for all fighters in DCS, so it should be easy to tell.

[BIGNEWY]

Hello all, 

this issue is an older one that was addressed in a previous patch.

If you still think it is an issue we would require new track replays from the latest open beta. 

I have closed this report as not to mix it with any future reports. 

thank you