bvr FOX 3: An Overview of ARH Missiles & BVR Combat

[tripod2008 594]

14 minutes ago, Faster_Boiiiii said:

. And no you don't need MWSs for radar guided missile warnings

I'm not seeing how that would work, assuming that it isn't simply a "launch" / guidance warning that you are talking about, but a "proper" missile awareness system;

For example and AIM-7 gets launched at a target; the CW illuminator / Radar's PRF changes (in order to support missile's guidance via the onboard systems), which gives away the "launch", the Sparrow doesn't emit or receive (conventional) guidance commands so the RWR would only be able to tell where the Shooter is via strength comparison of the RWR's antenna array, which tells you nothing about where the missile actually is located in space is isn't usefully since they often pull lead so stay in the same spot in space (CBDR / "pursuit" "geometry") where the "Shooter" isn't bound as such and may well be performing defensive maneuvers which move them quite a distance from the "missile".

 

Similarly most Fox-3's are SARH for the first stages of transit downrange so would look the same as a Fox-1 until some point (often they are told to go active by the "Shooter's" radar / manually, which also keeps tabs on the location of the missile) when they go active then you get angular data, though there are ways to estimate the range to the missile it's just guess work based off known characteristics, or measured Doppler shift  / received power, and as such aren't perfect and provide varying levels of spatial resolution which are very much worse than the standards set by IR systems (some have multiple cameras in a quadrant so can perform parallax calculations, or have a Laser rangefinder integrated to resolve distances with a much greater degree of accuracy).

8 minutes ago, MythicPi said:

Pretty sure theyre reworking missile trails this patch actually?

Looking at was was on dev they are thoroughly on the "Shrike" (AGM-45) side of things and would need to be toned down somewhat, the current crop of (common) missiles shouldn't be too much more noticeable than "high altitude" contrails that already exist, and should spread "faster", though take longer to dissipate in comparison.

[Faster_Boiiiii 753]

20 minutes ago, tripod2008 said:

I'm not seeing how that would work, assuming that it isn't simply a "launch" / guidance warning that you are talking about, but a "proper" missile awareness system;

For example and AIM-7 gets launched at a target; the CW illuminator / Radar's PRF changes (in order to support missile's guidance via the onboard systems), which gives away the "launch", the Sparrow doesn't emit or receive (conventional) guidance commands so the RWR would only be able to tell where the Shooter is via strength comparison of the RWR's antenna array, which tells you nothing about where the missile actually is located in space is isn't usefully since they often pull lead so stay in the same spot in space (CBDR / "pursuit" "geometry") where the "Shooter" isn't bound as such and may well be performing defensive maneuvers which move them quite a distance from the "missile".

 

Similarly most Fox-3's are SARH for the first stages of transit downrange so would look the same as a Fox-1 until some point (often they are told to go active by the "Shooter's" radar / manually, which also keeps tabs on the location of the missile) when they go active then you get angular data, though there are ways to estimate the range to the missile it's just guess work based off known characteristics, or measured Doppler shift  / received power, and as such aren't perfect and provide varying levels of spatial resolution which are very much worse than the standards set by IR systems (some have multiple cameras in a quadrant so can perform parallax calculations, or have a Laser rangefinder integrated to resolve distances with a much greater degree of accuracy).

what i'm looking for is not MWS. Its proper RWR with the appropriate missile warnings. Basically I want to know, whether or not the RWR contact is a missile or not(for fox-3s) and whether or not the locking radar has fired a missile or not. I know how this works

[DSplayer 271]

I'm just going to tack on with info that I've gathered from this latest dev server on the AIM-54.

The AIM-54A in WT is closer to a Mk60 variant than a Mk47 motor variant (17000N of thrust, 30 second burn time) while the AIM-54B in the files is just a copy-paste AIM-7F (and the AIM-54B never got produced either). It's current implementation in the first dev server is rather poor imo. It doesn't act like a Fox-1 when launched in PD-STT (TRK PD) and has pretty poor tracking overall which isn't helped by the weird WT radar thing when you're close to the ground. I've also had problems where the AIM-54 can't tell what target it should hit when its coming across a bomber formation so it'll just do a wavy flight pattern until it detonates near one of the planes (and the proximity fuse seems too short of a distance). Also the AIM-54's drag seems to be pretty high atm compared to Heatblur's CFD data resulting in a missile that loses its speed after the motor burns out pretty quickly along with it takes a longer time to get up to speed.

All of this is compounded by the current AWG-9 implementation (lack of TWS Auto, weird and incorrect radar azimuth and bar settings, the weird detection range it has now, etc.) which leave the F-14 a mess to play in WT compared to DCS. It also doesn't help when you can't exactly use DCS as a reference in bug reports.

Edited May 30, 2022 by DSplayer

[Gatsby_WT 136]

16 minutes ago, DSplayer said:

I'm just going to tack on with info that I've gathered from this latest dev server on the AIM-54.

The AIM-54A in WT is closer to a Mk60 variant than a Mk47 motor variant (17000N of thrust, 30 second burn time) while the AIM-54B in the files is just a copy-paste AIM-7F (and the AIM-54B never got produced either). It's current implementation in the first dev server is rather poor imo. It doesn't act like a Fox-1 when launched in PD-STT (TRK PD) and has pretty poor tracking overall which isn't helped by the weird WT radar thing when you're close to the ground. I've also had problems where the AIM-54 can't tell what target it should hit when its coming across a bomber formation so it'll just do a wavy flight pattern until it detonates near one of the planes (and the proximity fuse seems too short of a distance). Also the AIM-54's drag seems to be pretty high atm compared to Heatblur's CFD data resulting in a missile that loses its speed after the motor burns out pretty quickly along with it takes a longer time to get up to speed.

All of this is compounded by the current AWG-9 implementation (lack of TWS Auto, weird and incorrect radar azimuth and bar settings, the weird detection range it has now, etc.) which leave the F-14 a mess to play in WT compared to DCS. It also doesn't help when you can't exactly use DCS as a reference in bug reports.

Russian Devs over at RU forum said it's going to get fixed also it will have lofting, that's all good news.

[shanrocks1 383]

15 minutes ago, DSplayer said:

All of this is compounded by the current AWG-9 implementation (lack of TWS Auto, weird and incorrect radar azimuth and bar settings, the weird detection range it has now, etc.) which leave the F-14 a mess to play in WT compared to DCS. It also doesn't help when you can't exactly use DCS as a reference in bug reports.

What did Heatblur use to model the F-14 in regards to its radar, 54 and its modes? Is there any way that someone could get ahold of the material to hopefully make bug reports?

[DSplayer 271]

27 minutes ago, shanrocks1 said:

What did Heatblur use to model the F-14 in regards to its radar, 54 and its modes? Is there any way that someone could get ahold of the material to hopefully make bug reports?

Well HB probably used a mix of SMEs along with some documentation that they got a hand on but didn't tell us what documentation that was.

[Gatsby_WT 136]

Well Aim-54A MK.60 received new changes in the latest DEV update:
It got datalink, also new variables for range, quite low, maybe range for its own radar seeker? it could make sense (in DCS World, you can select target size, which affects at what time and range Phoenix goes pitbull), well take a look yourself: 
https://github.com/gszabi99/War-Thunder-Datamine/blob/master/aces.vromfs.bin_u/gamedata/weapons/rocketguns/us_aim_54a.blkx

Edited May 30, 2022 by PhantomRiderWT
The new changes are on right side of the screenshot

[Faster_Boiiiii 753]

14 minutes ago, PhantomRiderWT said:

It got datalink, also new variables for range, quite low, maybe range for its own radar seeker?

thats what it looks like to me. a range at which the onboard radar activates itself and a link to the mothership for rough guidance

[spacenavy90 1,402]

Important developer post regarding radar cross sections among other things for future reference.

 

[spacenavy90 1,402]

Some missiles got their own dedicated and in-depth forum topics, check them out here:

 

 

 

 

Edited June 17, 2022 by spacenavy90

[Sky_King7 102]

@spacenavy90

great post! lots of good info. 

Do you happen to know why in the current implementation of the AWG-9, AIM-54, AIM-7F why in the world we cannot get a solid lock in NORMAL search mode from the rear (trailing the target) aspect? I understand HIGH PRF radars have limited rear aspect capability, but i though this limitation only existed while in PD modes... not just normal search. As it sits right now, the F14 can only use these missiles in head in engagements regardless of altitude

 

[spacenavy90 1,402]

1 hour ago, gordoniemorrow said:

@spacenavy90

great post! lots of good info. 

Do you happen to know why in the current implementation of the AWG-9, AIM-54, AIM-7F why in the world we cannot get a solid lock in NORMAL search mode from the rear (trailing the target) aspect? I understand HIGH PRF radars have limited rear aspect capability, but i though this limitation only existed while in PD modes... not just normal search. As it sits right now, the F14 can only use these missiles in head in engagements regardless of altitude

 

 

In pulse doppler mode, the 'zero doppler filter' limitation exists where you cannot see a stationary target (relative to you). If someone is flying away from you at roughly +-100kts they would be invisible to your radar. In pulse mode, assume ground clutter was not an issue you would have no problem seeing a target from behind like this and in look-up situations.

As for why you can't launch radar missiles from behind, I am not sure.

[Sky_King7 102]

33 minutes ago, spacenavy90 said:

 

In pulse doppler mode, the 'zero doppler filter' limitation exists where you cannot see a stationary target (relative to you). If someone is flying away from you at roughly +-100kts they would be invisible to your radar. In pulse mode, assume ground clutter was not an issue you would have no problem seeing a target from behind like this and in look-up situations.

As for why you can't launch radar missiles from behind, I am not sure.

Exactly! in normal search mode, its simply a radar cross section issue verses ground clutter... the idea of the zero doppler shift, side lobes of the radar, high/medium PRF shouldn't matter as we are simply measuring radar return...

I cannot describe how frustrating this is lol! Are you aware of any bug reports on this issue? I find a few instances talking about this in the forums, but no direct address by admins. 

[Flame2512 3,386]

9 hours ago, spacenavy90 said:

As for why you can't launch radar missiles from behind, I am not sure.

 

The AIM-7 is guided using CW radar, which have the same issues (zero doppler and side lobe clutter) in the rear hemisphere as High PRF Pulse Doppler radar. In my opinion Gaijin are over-stating the effect somewhat, but the AIM-7 did perform poorly when launched from behind due to the inability to filter out sidelobe clutter in the rear aspect.

[nighthawk2174 80]

It should also be a matter of closure rate not aspect.  If your target is flying away from you at 300kts and your at 800kts that's the same as a target closing on you at 500kts.  I'm not sure if WT simple uses aspect angle or actually looks at closure rate.  But it should be closure rate dependent.  Additionally you just get reduced range against retreating targets not no detection.  We have test data for the first model of APG-63 on the F15A test flights.  And head on look-down detection was about 60% higher but for radars like the AWG-9 this would still be 50-60NMi of detection in look down.   This reduction would be compensated somewhat irl by higher RCS in the rear hemisphere as well.  Additionally if your in STT your constantly illuminating the target and this has the effect of increasing integration time to be essentially infinite.  giving a large boost to S/N ratio and as such increasing the range at which you can track a target over just search. 

[Flame2512 3,386]

1 hour ago, nighthawk2174 said:

It should also be a matter of closure rate not aspect.  If your target is flying away from you at 300kts and your at 800kts that's the same as a target closing on you at 500kts.

 

In terms of high PRF Pulse Doppler and CW radar those situations are not the same, aspect absolutely matters due to the way clutter works in those types of radars. I have explained it in detail here. Using your example lets say we have the following situations:

1. You're flying 200 kts and the enemy is flying 300 kts directly head on to you.
2. You're flying 800 kts and the enemy is flying 300 kts directly away from you.

In both of those situations you are closing on the target at 500 kts, but a high PRF PD / CW radar will perform far better at detecting the target in scenario 1 than it would in scenario 2. To show why this is the case I'll draw the target return on the doppler spectrum for each scenario (if you are not familiar with this graph then I would recommend reading the post I linked above, before continuing with this one). Note: This graph is only approximate and not to scale.

 

Here is the graph for scenario 1. You can see that the clutter region stretches from -200 kts to 200 kts (the groundspeed of your aircraft). The target's closing velocity of 500 kts is outside the clutter region meaning that the radar (or radar receiver in a missile) can see it without any ground clutter.

By comparison here is the graph for scenario 2. You can see that in this instance the clutter region stretches from -800 kts to 800 kts (as the size of the clutter region is directly tied to the aircraft's ground speed). This means that the target's closing speed of 500 kts puts it within the sidelobe clutter region. This means that the target will be partially obscured by clutter making it hard for the radar to see it.

This is what the F-4J Tactical manual says about targets in the clutter region: 

Quote

The probability of target detection is limited in the clutter region.

 

If the target aircraft is flying away from you then the closing velocity between you and target will always be lower than your groundspeed, so the target will always be in the clutter region. Likewise if the target is flying towards you then the closing velocity will always be higher than your groundspeed, so the target return will always be outside of the clutter region. This is why aspect matters a lot for HPRF PD / CW radars. It is not the closure rate which is important, it is the closure rate relative to your own speed (which depends entirely on aspect).

Edited June 19, 2022 by Flame2512

[nighthawk2174 80]

1 hour ago, Flame2512 said:

 

In terms of high PRF Pulse Doppler and CW radar those situations are not the same, aspect absolutely matters due to the way clutter works in those types of radars. I have explained it in detail here. Using your example lets say we have the following situations:

1. You're flying 200 kts and the enemy is flying 300 kts directly head on to you.
2. You're flying 800 kts and the enemy is flying 300 kts directly away from you.

In both of those situations you are closing on the target at 500 kts, but a high PRF PD / CW radar will perform far better at detecting the target in scenario 1 than it would in scenario 2. To show why this is the case I'll draw the target return on the doppler spectrum for each scenario (if you are not familiar with this graph then I would recommend reading the post I linked above, before continuing with this one). Note: This graph is only approximate and not to scale.

 

Here is the graph for scenario 1. You can see that the clutter region stretches from -200 kts to 200 kts (the groundspeed of your aircraft). The target's closing velocity of 500 kts is outside the clutter region meaning that the radar (or radar receiver in a missile) can see it without any ground clutter.

By comparison here is the graph for scenario 2. You can see that in this instance the clutter region stretches from -800 kts to 800 kts (as the size of the clutter region is directly tied to the aircraft's ground speed). This means that the target's closing speed of 500 kts puts it within the sidelobe clutter region. This means that the target will be partially obscured by clutter making it hard for the radar to see it.

This is what the F-4J Tactical manual says about targets in the clutter region: 

 

If the target aircraft is flying away from you then the closing velocity between you and target will always be lower than your groundspeed, so the target will always be in the clutter region. Likewise if the target is flying towards you then the closing velocity will always be higher than your groundspeed, so the target return will always be outside of the clutter region. This is why aspect matters a lot for HPRF PD / CW radars. It is not the closure rate which is important, it is the closure rate relative to your own speed (which depends entirely on aspect).

You are correct here good explanation, I was making a visualization error in regards to the Doppler spectrum I'd forgotten about the ground speed return.

Edited June 19, 2022 by nighthawk2174

[spacenavy90 1,402]

@nighthawk2174 @Flame2512

 

Just wanted to say I appreciate the illustrative insight on how these systems work.

[Sky_King7 102]

On 19/06/2022 at 16:24, Flame2512 said:

 

In terms of high PRF Pulse Doppler and CW radar those situations are not the same, aspect absolutely matters due to the way clutter works in those types of radars. I have explained it in detail here. Using your example lets say we have the following situations:

1. You're flying 200 kts and the enemy is flying 300 kts directly head on to you.
2. You're flying 800 kts and the enemy is flying 300 kts directly away from you.

In both of those situations you are closing on the target at 500 kts, but a high PRF PD / CW radar will perform far better at detecting the target in scenario 1 than it would in scenario 2. To show why this is the case I'll draw the target return on the doppler spectrum for each scenario (if you are not familiar with this graph then I would recommend reading the post I linked above, before continuing with this one). Note: This graph is only approximate and not to scale.

 

Here is the graph for scenario 1. You can see that the clutter region stretches from -200 kts to 200 kts (the groundspeed of your aircraft). The target's closing velocity of 500 kts is outside the clutter region meaning that the radar (or radar receiver in a missile) can see it without any ground clutter.

By comparison here is the graph for scenario 2. You can see that in this instance the clutter region stretches from -800 kts to 800 kts (as the size of the clutter region is directly tied to the aircraft's ground speed). This means that the target's closing speed of 500 kts puts it within the sidelobe clutter region. This means that the target will be partially obscured by clutter making it hard for the radar to see it.

This is what the F-4J Tactical manual says about targets in the clutter region: 

 

If the target aircraft is flying away from you then the closing velocity between you and target will always be lower than your groundspeed, so the target will always be in the clutter region. Likewise if the target is flying towards you then the closing velocity will always be higher than your groundspeed, so the target return will always be outside of the clutter region. This is why aspect matters a lot for HPRF PD / CW radars. It is not the closure rate which is important, it is the closure rate relative to your own speed (which depends entirely on aspect).

awesome summary, i was going to make the same point as well that the clutter region shifts depending on your own groundspeed, but you illustrated it beautifully! 

Edited June 22, 2022 by gordoniemorrow

[oom1992 649]

On 18/06/2022 at 06:13, spacenavy90 said:

Some missiles got their own dedicated and in-depth forum topics, check them out here:

 

 

 

 

I was really looking forward new topic of AIM-120 AMRAAM series 

Edited June 22, 2022 by oom1992

[spacenavy90 1,402]

9 hours ago, oom1992 said:

I was really looking forward new topic of AIM-120 AMRAAM series 

 

We may see the AIM-120A/B in game sooner than some people realize.

I'll throw together a specific topic on the series of missiles if no one else is already working on it.

 

Edit:

 

Edited June 23, 2022 by spacenavy90

[oom1992 649]

I'm realizing something,  spacenavy90 need you take add update data for Vympel R-33/R-33S and Vympel R-37

[spacenavy90 1,402]

21 hours ago, oom1992 said:

I'm realizing something,  spacenavy90 need you take add update data for Vympel R-33/R-33S and Vympel R-37

 

Thank you for noticing, I have added those missiles.

[InterFleet 359]

Taiwan also have their own TC-2 missile and China have PL-15, although informations are quite limited for those missiles

[spacenavy90 1,402]

I predict that the upcoming December update will be a heavily top-tier aircraft focused update, and as such we may see some of the things listed in the OP that have been wish-listed for a while.

Such as a long overdue RWR overhaul, larger air maps for top tier, and drop tanks that have been teased for a while.