AIM-54 launch in PD STT = no active guidance? (@ DEVS)

Making a separate thread for this question as it got lost in the larger AIM-54 Guidance mega-thread:

AIM-54 Guidance

Deleted that post and also clarified some points below.

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Single Target Track: In this mode the AWG-9 maintains track on one target and may launch a AIM-54 in Semi-active mode while the AWG-9 illuminates the target. The AWG-9 will also send track data and steering commands to the missile via coded messages in the radar pulse.(just as I speculated) As per the document, the missile will not ever go active in this mode of operation.

If I understand the above thread and the nice included summary provided by Beamscanner here correctly, AIM-54 guidance is either:

a) LONG RANGE (50nm to 20nm): TWS = guidance from PD then commanded active. Guidance always transmitted in-case seeker fails to find target.

b) MEDIUM RANGE(20nm to 10nm): PD STT = SARH only and will never be commanded to go active i.e. effectively long range AIM-7?!

c) SHORT RANGE (<10nm): P STT / ACM modes = active at launch (maddog) but if WCS track available, AIM-54 will launch along track, otherwise launch along ADL

EDIT: Seems like 'PH ACT' is automatically commanded if AIM-54 launched < 6nm cold target or < 10nm hot target

Please correct any of the above statements.

So some follow-up questions:

1. If PD guidance is being utilized for TWS and then subsequently commanded active, why is an active command not sent during PD STT? It seems a waste to guide an AIM-54 in PD STT that can never be commanded to go active especially if the PD STT lock is lost.
    
   
2. Post-launch switch from PD STT to P STT should lose lock, as mode is set at launch, but I believe has been stated by Naquaii that it is not modeled REF LINK. And P STT allows for maddog launch at WCS target track. But if PD STT cannot command the AIM-54 active and P STT can only maddog launch in the general vicinity towards WCS tracked target, doesn't that leave a massive mid-range gap in the ability to guide the AIM-54 to specific target then command it active, without utilising TWS (less tracking)?
    
   
3. If a target is low then it seems more beneficial to utilise PD STT over P STT to avoid ground interference. However, as discussed above, PD STT will never command the AIM-54 active. What happens if you launch an AIM-54 on a PD STT target but the RIO has set 'MSL OPTIONS' to 'PH ACT'? Does this allow a maddog launch towards a PD STT tracked target?
    
   
4. If guidance is always sent during a TWS launch in-case an active AIM-54 loses track of the target, does this mean the AIM-54 is constantly switching from active to PD guidance? I still don't understand that if guidance mode it set at launch, then why can the AIM-54 switch between PD guidance and active guidance in TWS, but not PD STT.
   

Again please correct any of the above assumptions if incorrect. However after reading through the HB manual, the ED forums, watching a lot of the available videos, I still don't have a clear understanding of the best way to utilize the AIM-54 at medium ranges.

But to me so far, it seems like I would never want to launch the AIM-54 in PD STT. At most, lock in PD STT, transition to P STT, then launch.

If possible, I would appreciate answers that distinguish what is modeled in-game as opposed to what happens in real-life.

EDIT: My testing seems to confirm this i.e. PD STT > AIM-54 launch > immediately turn cold > AIM-54 never tracks

1. This is just the way the AWG-9/AIM-54 was designed as far as we know.

2. It does, if you switch out of pulse-doppler before the active command is sent the missile is effectively lost.

3. Setting the MSL OPTIONS to PH ACT tells the AIM-54 to go active along sensor LoS just as in a pure pulse mode with reduction in range as per those modes.

4. IRL the missile would track actively but fall back to pulse doppler if it loses track.

PD STT is advantageous over TWS in that it has longer range and that you have more control over the specific target track, i.e. less risk of attack the wrong target. It's also much easier to loose a target in TWS.

That said, a lot of this is still not modelled in DCS as this is kinda the first more detailed active missile in the sim. At launch the AIM-54 behaves much like the AIM-120 in the sim and the first step will be adding more control over the seekerhead and the lofting. This will more or less correctly model the AIM-54 not going active in PD-STT.

Thanks for the answers Naquaii!

As an overall, are you able to detail how much of what you've described is modelled in-game and if not modelled, are there plans to model it?

Not trying to hold yourself or HB to task on anything, and indeed I'm certainly fine with any best laid plans not coming to fruition.

However it's difficult to discern at the moment the best tactics in the F14 when there is:

a) Guidance that is modeled and in-game

b) Guidance that is not modeled but there is plans for it to be e.g. matching what is stated in the official manual and external sources

c) Guidance that is mis-understood i.e. a lot of players believe the AIM-54 should go active in PD STT

d) Guidance that cannot be modeled but a stop-gap has been introduced in the interim e.g. AIM-54 behaving like AIM-120s

A specific example of this confusion in relation to what you wrote above would be that:

5) An AIM-54 being guided in PD STT should never be commanded active. However as AIM-54 guidance is behaving much like the AIM-120 at the moment, is the AIM-54 in DCS currently able to go active in PD STT?

Some more specific follow-up questions:

2) By your comment "out of pulse-doppler before the active command is sent", is this again implying that an active command is currently sent to the AIM-54 due to it currently being modeled on the AIM-120, but it shouldn't and will not be in the future? My understanding from your previous comments in other threads was that PD STT to P STT switch should lose the lock within itself, but it's not currently modeled.

3) By 'sensor LoS' do you mean that the AIM-54 will fire in the vector of the PD STT tracked target, much like P STT with the ACM modes, or the AIM-54's own sensor? I ask this as again, this seems a way to circumvent the lack of active command being given to a PD STT tracked target, but perhaps restricted by the AIM-54s own sensor range and coverage if you meant the latter.

Some other questions:

6) Do the ACM modes, P STT, PD STT + PH ACT all command the AIM-54 to not loft?

Again, please correct any of the assumptions included in the above questions and I would appreciate a distinction between what is, isn't and planned in regards to modeling.

Thanks!

Thanks for the answers Naquaii!

 

As an overall, are you able to detail how much of what you've described is modelled in-game and if not modelled, are there plans to model it?

 

Not trying to hold yourself or HB to task on anything, and indeed I'm certainly fine with any best laid plans not coming to fruition.

 

However it's difficult to discern at the moment the best tactics in the F14 when there is:

a) Guidance that is modeled and in-game

b) Guidance that is not modeled but there is plans for it to be e.g. matching what is stated in the official manual and external sources

c) Guidance that is mis-understood i.e. a lot of players believe the AIM-54 should go active in PD STT

d) Guidance that cannot be modeled but a stop-gap has been introduced in the interim e.g. AIM-54 behaving like AIM-120s

 

A specific example of this confusion in relation to what you wrote above would be that:

 

5) An AIM-54 being guided in PD STT should never be commanded active. However as AIM-54 guidance is behaving much like the AIM-120 at the moment, is the AIM-54 in DCS currently able to go active in PD STT?

 

Some more specific follow-up questions:

 

2) By your comment "out of pulse-doppler before the active command is sent", is this again implying that an active command is currently sent to the AIM-54 due to it currently being modeled on the AIM-120, but it shouldn't and will not be in the future? My understanding from your previous comments in other threads was that PD STT to P STT switch should lose the lock within itself, but it's not currently modeled.

 

3) By 'sensor LoS' do you mean that the AIM-54 will fire in the vector of the PD STT tracked target, much like P STT with the ACM modes, or the AIM-54's own sensor? I ask this as again, this seems a way to circumvent the lack of active command being given to a PD STT tracked target, but perhaps restricted by the AIM-54s own sensor range and coverage if you meant the latter.

 

Some other questions:

 

6) Do the ACM modes, P STT, PD STT + PH ACT all command the AIM-54 to not loft?

 

Again, please correct any of the assumptions included in the above questions and I would appreciate a distinction between what is, isn't and planned in regards to modeling.

 

Thanks!

I think the vast majority of your concerns can be explained rather simply as HB has control over only a very very small section of the missile code to work with that basically covers aerodynamics, rocket motor performance, seeker head gimbal limits and loft behavior while ED keeps tight control over the guidance programming and anything that a third party user could tweak to gain an unfair advantage.

HB has always maintained a desire for 100% accuracy but has to work directly with ED on the more "advanced" limitations for missile performance and seeker head performance. Hence why the Phoenix operates like a AIM120 in game with insane range.

I've got absolutely no problems/concerns, and completely understand the positions/limitations of both ED and HB.

My aim is really just clarify how it works in real-life, what is modeled and what may come, purely for educational purposes. Nothing more.

There are so many nuances to the way the AIM-54 can be launched. I'm making an F14 Kneeboard for distribution and want to ensure that what's written is accurate. There are also some gaps in the official manual, as has been expressed in other threads.

Thanks for the answers Naquaii!

 

As an overall, are you able to detail how much of what you've described is modelled in-game and if not modelled, are there plans to model it?

 

Not trying to hold yourself or HB to task on anything, and indeed I'm certainly fine with any best laid plans not coming to fruition.

 

However it's difficult to discern at the moment the best tactics in the F14 when there is:

a) Guidance that is modeled and in-game

b) Guidance that is not modeled but there is plans for it to be e.g. matching what is stated in the official manual and external sources

c) Guidance that is mis-understood i.e. a lot of players believe the AIM-54 should go active in PD STT

d) Guidance that cannot be modeled but a stop-gap has been introduced in the interim e.g. AIM-54 behaving like AIM-120s

 

A specific example of this confusion in relation to what you wrote above would be that:

 

5) An AIM-54 being guided in PD STT should never be commanded active. However as AIM-54 guidance is behaving much like the AIM-120 at the moment, is the AIM-54 in DCS currently able to go active in PD STT?

 

Some more specific follow-up questions:

 

2) By your comment "out of pulse-doppler before the active command is sent", is this again implying that an active command is currently sent to the AIM-54 due to it currently being modeled on the AIM-120, but it shouldn't and will not be in the future? My understanding from your previous comments in other threads was that PD STT to P STT switch should lose the lock within itself, but it's not currently modeled.

 

3) By 'sensor LoS' do you mean that the AIM-54 will fire in the vector of the PD STT tracked target, much like P STT with the ACM modes, or the AIM-54's own sensor? I ask this as again, this seems a way to circumvent the lack of active command being given to a PD STT tracked target, but perhaps restricted by the AIM-54s own sensor range and coverage if you meant the latter.

 

Some other questions:

 

6) Do the ACM modes, P STT, PD STT + PH ACT all command the AIM-54 to not loft?

 

Again, please correct any of the assumptions included in the above questions and I would appreciate a distinction between what is, isn't and planned in regards to modeling.

 

Thanks!

Basically the current AIM-54 works exactly like the AIM-120 in DCS. It will go active on it's own within a certain distance to the target regardless of mode and will do so even in PD-STT.

It will receive updates just like the AIM-120 as long as the launching aircraft track the target.

The first improvement we plan to add is control of the missile seeker, meaning that we can then control when it goes active in TWS and have it not do so at all if you loose track in addition to enabling the pure SARH mode that's used in PD-STT.

5: Yes, it will currently go active in PD-STT as we have no control over the seeker yet.

2: Currently the missile decides to go active on it's own as per how the AIM-120 works. When the above is implemented we will change this.

3: Sensor LoS is related to radar in P-STT and TCS in which case the AIM-54 will launch active along that sensors line of sight.

6: Correct, due to the short seeker range (within 20nm) all active modes do not loft and while we currently do not set this specifically it shouldn't do anyway due to the short range. We will set to a hard no lofting as soon as we can though, probably at the same time as the seeker update is implemented.

Fantastic! Thanks for the clarification Naquaii. Makes a lot more sense now.

It still baffles me that the AIM-54 guidance in real-life has what seems to be a massive gap in mid-range guidance in that AIM-54 cannot be commanded active in PD STT, but can switch between PD and active guidance in TWS. If anybody can explain this design decision, please do.

Basically the current AIM-54 works exactly like the AIM-120 in DCS. It will go active on it's own within a certain distance to the target regardless of mode and will do so even in PD-STT.

 

It will receive updates just like the AIM-120 as long as the launching aircraft track the target.

 

The first improvement we plan to add is control of the missile seeker, meaning that we can then control when it goes active in TWS and have it not do so at all if you loose track in addition to enabling the pure SARH mode that's used in PD-STT.

Side question if possible, will the "track hold function" still give the 54 mid course corrections to active point, based on saved track data? or will it need an active TWS return to conduct that function?

And does this apply to both the A and C? from what i heard the C operates the same way as the 120 missile "active at x range"

Side question if possible, will the "track hold function" still give the 54 mid course corrections to active point, based on saved track data? or will it need an active TWS return to conduct that function?

 

And does this apply to both the A and C? from what i heard the C operates the same way as the 120 missile "active at x range"

The track hold function was actually enabled automatically for targets under missile attack for this reason, when we get control over the seeker we'll look at adding this if possible. If so that would make the missiles go towards calculated track position and then go active as long as the AWG-9 is looking at that position in space.

In regards to the C, we don't have that much info as our manuals are older than the -C. If you have any info feel free to share! :-)

The track hold function was actually enabled automatically for targets under missile attack for this reason, when we get control over the seeker we'll look at adding this if possible. If so that would make the missiles go towards calculated track position and then go active as long as the AWG-9 is looking at that position in space.

 

In regards to the C, we don't have that much info as our manuals are older than the -C. If you have any info feel free to share! :-)

Thank you for the answer, but why would the awg-9 have to look at the held track position if the data is sent from the "held track"?

On the C I saw that statement mentioned on the forums, from what I gather the 120 was derived functionally from the 54c. documentation however AFIK will be tough to come by. but all and all worth considering to look into.

Thank you for the answer, but why would the awg-9 have to look at the held track position if the data is sent from the "held track"?

 

On the C I saw that statement mentioned on the forums, from what I gather the 120 was derived functionally from the 54c. documentation however AFIK will be tough to come by. but all and all worth considering to look into.

The AWG-9 would have to be sweeping over or looking at the calculated track position to be able to send the active command to the missile. The AWG-9 antenna is used to transmit commands to the missile.

We're always on the lookout for additional information, we'd need some kind of source to be able to realistically use the information though.

The AWG-9 would have to be sweeping over or looking at the calculated track position to be able to send the active command to the missile. The AWG-9 antenna is used to transmit commands to the missile.

Of course that makes sense!

I am sure I saw some source on the similarity of the 120 to 54C functions some time ago on some forum far away. ill set some time this weekend and try and look for it and even if its worth it as a data point source and not some forum speculation.

The track hold function was actually enabled automatically for targets under missile attack for this reason, when we get control over the seeker we'll look at adding this if possible. If so that would make the missiles go towards calculated track position and then go active as long as the AWG-9 is looking at that position in space.

 

In regards to the C, we don't have that much info as our manuals are older than the -C. If you have any info feel free to share! :-)

C include command inertial guidance system. What different C and A on active command？

We're always on the lookout for additional information, we'd need some kind of source to be able to realistically use the information though.

sent you a PM with what i found due to rules 1.16 cant post it here.

sent you a PM with what i found due to rules 1.6 cant post it here.

What you found?:thumbup:

What you found?:thumbup:

Not much to be honest but enough information to state that the 54C seems to operate more like the 120 than the A basically.

search for Forecast International Inc. Missile Forecast November, 1997

Not much to be honest but enough information to state that the 54C seems to operate more like the 120 than the A basically.

 

search for Forecast International Inc. Missile Forecast November, 1997

Used google book search the key world of AIM-54C command inertial, you will found some Interesting Things.:)

So currently Aim 54 in STT is working as a Fox 1 and never goes active with its own radar?

Read previous posts. Opposite. It shouldn't go active but it does because at the moment as it's modeled after the AIM-120 until HB can get access from ED to model it all properly.

C include command inertial guidance system. What different C and A on active command？

As we have no hard data on the -C we'll model it as the -A until we find data to the contrary.

Read previous posts. Opposite. It shouldn't go active but it does because at the moment as it's modeled after the AIM-120 until HB can get access from ED to model it all properly.

Correct, this is in the works.

In regards to the C, we don't have that much info as our manuals are older than the -C. If you have any info feel free to share! :-)

I think there's technically enough info to try to implement some difference between them (DCS permitting, of course).

https://forums.eagle.ru/showpost.php?p=2890020&postcount=125

https://www.forecastinternational.com/archive/disp_old_pdf.cfm?ARC_ID=1066

So, if I understand correctly, during the mid-course phase, the AIM-54A will periodically get messages from the AWG-9 on where to look for the reflected SARH signal and then adjust its course towards the target directly. Not sure at which interval these messages are sent, but I guess the missile will burn more energy because it will keep readjusting itself towards the target until the terminal phase where it switches either to ARH homing or SARH with PN. The interval is also different in case ARH (less frequent) or SARH terminal homing (more frequent) is used (or basically TWS or PD-STT).

For the AIM-54C on the other hand, it apparently has a digital inertial system with an autopilot so it can fly towards an optimal intercept point calculated by the AWG-9 on launch and then updated directly in case the target changes its trajectory.

I think there's technically enough info to try to implement some difference between them (DCS permitting, of course).

 

https://forums.eagle.ru/showpost.php?p=2890020&postcount=125

 

https://www.forecastinternational.com/archive/disp_old_pdf.cfm?ARC_ID=1066

 

So, if I understand correctly, during the mid-course phase, the AIM-54A will periodically get messages from the AWG-9 on where to look for the reflected SARH signal and then adjust its course towards the target directly. Not sure at which interval these messages are sent, but I guess the missile will burn more energy because it will keep readjusting itself towards the target until the terminal phase where it switches either to ARH homing or SARH with PN. The interval is also different in case ARH (less frequent) or SARH terminal homing (more frequent) is used (or basically TWS or PD-STT).

 

For the AIM-54C on the other hand, it apparently has a digital inertial system with an autopilot so it can fly towards an optimal intercept point calculated by the AWG-9 on launch and then updated directly in case the target changes its trajectory.

Problem is that both missiles have these systems, they're just implemented differently, and compared to our data on the -A a lot of the -C stuff is conjecture. In any case we're not at a stage where this makes any difference in DCS apart from numbers for countermeasure rejection and seeker performance.

Problem is that both missiles have these systems, they're just implemented differently, and compared to our data on the -A a lot of the -C stuff is conjecture. In any case we're not at a stage where this makes any difference in DCS apart from numbers for countermeasure rejection and seeker performance.

Both systems have the same purpose in the end, but if e.g. my simplified understanding is generally correct, the AIM-54C would normally burn less speed during the mid-course phase and thus would have more available on the final (which would match those claims that it has some optimizations against more maneuverable targets).

In that case, perhaps some drag values could be adjusted so that on average it ends up with somewhat more energy?

I mean, what's the point of having the C in the game if it's modeled exactly the same as A is?

I'm sure HB could make a reasonable educated guess based on the data available and give it a somewhat improved performance.

Both systems have the same purpose in the end, but if e.g. my simplified understanding is generally correct, the AIM-54C would normally burn less speed during the mid-course phase and thus would have more available on the final (which would match those claims that it has some optimizations against more maneuverable targets).

 

In that case, perhaps some drag values could be adjusted so that on average it ends up with somewhat more energy?

 

I mean, what's the point of having the C in the game if it's modeled exactly the same as A is?

 

I'm sure HB could make a reasonable educated guess based on the data available and give it a somewhat improved performance.

AIM-54C include the command inertial system, but don't active command is from command message or inertial.

Both systems have the same purpose in the end, but if e.g. my simplified understanding is generally correct, the AIM-54C would normally burn less speed during the mid-course phase and thus would have more available on the final (which would match those claims that it has some optimizations against more maneuverable targets).

 

In that case, perhaps some drag values could be adjusted so that on average it ends up with somewhat more energy?

 

I mean, what's the point of having the C in the game if it's modeled exactly the same as A is?

 

I'm sure HB could make a reasonable educated guess based on the data available and give it a somewhat improved performance.

Our -C already has different flight parameters and range compared to the -A in addition to slightly different seeker performance.

If we find reasonably trustworthy data on other paramaters which we could feasably implement we'll ofc do that.