correct as is Maverick (D+H) VIS mode for JHMCS - seeker movement not visible in JHMCS (or HUD) until TMS up short - different to previous OB

[darkman222]

As shown in the video by Grim Reapers (31.12.2021), the Maverick seeker heads movement is visible in the JHMCS and HUD.

This is not the case any more in DCS 2.8.6.41363 Open Beta.

Reproduction:

-AG mode

-Select Maverick (VIS mode)

-go to WPN page

-look out of the cockpit with JHMCS

-TMS up long

-Seeker visibly moves on the MFD, but not shown on the JHMCS or on the HUD

-TMS up short seeker, stops at current position and shows in JHMCS

 

-TMS down, seeker continues visible in JHMCS too now.

 

Looks like a bug to me, because it makes more sense how it used to work in the Grim Reapers video. Issue was already in a few OB versions earlier before I decided to post it.

Does not matter what Maverick variant ( D or H)

Track:

https://www.dropbox.com/s/x66hefdcj0rpyz6/mavD v2.trk?dl=0

Video:

 

Edited June 23, 2023 by darkman222

[Lord Vader]

Hi @darkman222

The video you used as reference is a bit old and reflects a previous state of the maverick/HMCS logic.

We currently have an accurate representation of the AGM-65 operation using VIS mode for both the HUD and JHMCS operation based on documentation for our F-16C Block 50 CCIP tape. The steps are the following:

Setup:

- AG Master Mode
- AGM-65 Power ON
- VIS mode selected
- WPN format on MFD

Procedure:

- HUD to SOI
- TMS forward long to cage TD box to HMCS
- Designate via HUD or HMCS (TMS long) and ground stabilize
- LOS symbology is shown cued to TD box on HUD and HMCS
- DMS aft to move SOI to WPN page
- Refine target and TMS forward to lock
- Fire within MLE range
- Profit

Hope this helps, happy flights.

[_SteelFalcon_]

@Lord Vader

Your description does not precisely match that of manuals regarding HMCS operation for EO VIS Mav employment.

-> TMS fwd LONG will move TD Box to HMCS

But to the OPs Bug report:

A reference can be found in a manual, that the LOS of the missile is shown when she's slewing or tracking

And if the TD Box is on the HMCS, it is clearly visible on the WPN page that the missile is slewing. Yet the Mav LOS circle is missing in DCS at the moment.

Same applies when I'm not using HMCS but HUD only. slewing the TD box without designating has the Mav LOS circle currently missing.

AGM65D_VIS.trk

Edited June 24, 2023 by _SteelFalcon_

[darkman222]

On 6/23/2023 at 1:51 PM, Lord Vader said:

- LOS symbology is shown cued to TD box on HUD and HMCS

This is what I am talking about.

 

The difference to my procedure only was as follows:

-(after TMS up long) DMS down short to refine target.

 

The result is the same, that the LOS symbology is NOT shown on HUD or JHMCS. Thus the pilot has no reference in the HUD or JHMCS where the LOS seeker of the Maverick is looking. Also not knowing if the seeker is still slewing to the TD box in the JHMCS if he is looking outside of the cockpit and not glancing with the eyes on the MFD. Because if you look at the MFD with your head the TD box will be moved away from target and so will the LOS seeker of the Maverick, which of course not intended if you want to assingn a target via JHMCS.

Please see new video  and track with the procedure you suggest @Lord Vader

https://www.dropbox.com/s/0p6y0o06svd9hyx/mavD vis LOS not showing.trk?dl=0

 

 

[Hobel]

vor 3 Stunden schrieb darkman222:

This is what I am talking about.

 

The difference to my procedure only was as follows:

-(after TMS up long) DMS down short to refine target.

 

The result is the same, that the LOS symbology is NOT shown on HUD or JHMCS. Thus the pilot has no reference in the HUD or JHMCS where the LOS seeker of the Maverick is looking. Also not knowing if the seeker is still slewing to the TD box in the JHMCS if he is looking outside of the cockpit and not glancing with the eyes on the MFD. Because if you look at the MFD with your head the TD box will be moved away from target and so will the LOS seeker of the Maverick, which of course not intended if you want to assingn a target via JHMCS.

Please see new video  and track with the procedure you suggest @Lord Vader

https://www.dropbox.com/s/0p6y0o06svd9hyx/mavD vis LOS not showing.trk?dl=0

 

 

there is a kind of work around, i am not at home right now so here is a hint from memory:
if you switch back and forth once with the DGFT override switch then the MAV LOS Circle appears.
I may have forgotten another step, but maybe it helps for now

[darkman222]

@Hobel It kinda does. What needs to be done beforehand is a TMS up, it will show the LOS circle anyway then. If you go DGFT on and off it will break the lock / ground stabilisation and the TD box is free again, with the LOS circle chasing it.

@Lord Vader Can you please have another look at this issue? Although I am not a fighter pilot my senses are that this cant be correct and is also very impractical and very inconsistent.

[BIGNEWY]

Hi, 

we will ask the team to check again, but for changes in behaviour we would need public unclassified evidence before making a change, we can not do it on feelings alone. 

thank you

[Lord Vader]

On 6/24/2023 at 1:11 PM, _SteelFalcon_ said:

@Lord Vader

Your description does not precisely match that of manuals regarding HMCS operation for EO VIS Mav employment.

-> TMS fwd LONG will move TD Box to HMCS

Yes, this is correct, the correct phrase is "TMS-forward >0.5 sec." I mistakenly only read the 0.5 seconds part for some reason, and went for "short".
I have corrected my original text to make sure it doesn't lead anyone in error.
Thanks for this, @_SteelFalcon_.

[darkman222]

@BIGNEWYThank you. I am not saying that it should be changed. I am just saying that the way when the LOS circle was shown before serveral updates makes more sense in practical way. If it is only shown when pressing TMS up, it gives a less useful information instead of when the LOS circle is shown already while its travelling to the TD box (visible in left MFD). But if thats the way it works in the real jet, sure, no complaints.

On 6/23/2023 at 1:51 PM, Lord Vader said:

- Designate via HUD or HMCS (TMS long) and ground stabilize
- LOS symbology is shown cued to TD box on HUD and HMCS

Also what @Lord Vader says (in his updated post) is not the case. Please watch the second video I posted again. The LOS symbology is NOT shown after these steps. Which is another indication that something might be wrong here.

 

Edited June 27, 2023 by darkman222

[Lord Vader]

This is the video I did using my checklist.
I do have to revise something again on one of the steps. 

Procedure:

- HUD to SOI
- TMS forward long to cage TD box to HMCS
---> - Designate via HUD or HMCS (TMS short) and ground stabilize <---
- LOS symbology is shown cued to TD box on HUD and HMCS
- DMS aft to move SOI to WPN page
- Refine target and TMS forward to lock
- Fire within MLE range

[darkman222]

@Lord Vader Please consider two things in your video: Your off-boresight angle youre showing is not very high. So you have the MFD always in the corner of your eye. Also consider that the FOV of your "camera" is from a 2D monitor. The FOV is significantly less in VR (but also more realistic). So the issue is not too apparent the way you show it.

I have made a replay right from my VR headset. Please note that the seeker takes some time to slew to its outer boundaries. If you look about 25 degrees off to one side, you cant glimpse at the MFD showing the maverick seeker to make sure that the seeker has reached its final position at the TD box, before pressing TMS up. If you wanted to look at the MFD you'd need to move your head, which would move the TD box away from where you'd want to assign it. By just looking at the target you'd have to guess when the maverick seeker has finished slewing to the TD box.

If the estimated time was too little when pressing TMS up, you'll stop the Maverick LOS symbology on half the way to the TD box, which true location becomes visible only at once you press TMS up.

On 6/27/2023 at 12:14 PM, Lord Vader said:

- TMS forward long to cage TD box to HMCS
---> - Designate via HUD or HMCS (TMS short) and ground stabilize <---

At this point in your checklist you still need to be looking right on the target. You cant look on the MFD as this will move the (invisible) LOS of the Maverick away from the target. There is no way to verify that the LOS of the Maverick has reached the TD box. Also a real pilot as well as VR users need to hold their heads still (due to unintentional natural head movements) for a short amount of time before pressing TMS up, which can only be timed correctly when the LOS is visible catching up the TD box.

As you can see in my video it takes some time, depending on where the seeker of the Maverick was previously looking. You can imagine that this seems highly unpractical in a fast paced combat environment. Not saying that this is wrong, it just does not seem plausible for an aircraft that is very pilot friendly in many other aspects of sensor usage.

Also the "workaround" @Hobel suggests, which works like, when the seeker is locked to a target, will be unlocked going DGFT and then back to normal (->A-G) mode, brings the LOS symbology back to chasing the TD box. I dont show it in my video because this is not the issue I am reporting. But it shows that the functionality once was there already.

Track:

https://www.dropbox.com/s/c6dwg30fdro5k15/mav LOS visible when stopped.trk?dl=0

Edited June 28, 2023 by darkman222

[BIGNEWY]

Dear all,

we have checked and we are happy with the behaviour regarding the LOS Circle not being visible in EO-VIS mode prior to designation with the TD Box.

When EO-VIS is entered, the AGM-65 seeker is Slaved to the TD Box. Once the TD Box is used to designate a target location, the SOI is automatically moved to the WPN SOI and the AGM-65 enters Slew mode. The LOS Circle" representing the seeker line-of-sight appears when the AGM-65 seeker is in Slew or Track mode, which only occurs after a designation is made using the TD Box. Before a designation is made, the seeker is in a Slave mode. 

The above was concluded when reading the manuals that refer to the exact version of the F-16C Block 50 CCIP variant we're trying to replicate.
We've been trying to refine the model to represent an accurate simulation of the real life operation. And we feel we've reached a fairly accurate representation from the available information.

We understand you may have a "preference" for previous states like the ones portrayed in the shared GR video, but it does represent a previous state that was not really accurate.

thank you

 

[darkman222]

Thanks for checking and verifying the conditions when the seeker LOS will appear.

My question also points to if the LOS circle will be stuck/set to the random place where it is while it is travelling to the TD box, or if it will continue to the TD box after designation.

The question is justified because with the LOS symbology still travelling invisibly to the TD box there is no way you can tell where it is going to stop (because you can simply not see it) nor will the location where it stops be the desired one, as you want the LOS symbol to go to the TD box and not stop somewhere in the middle.

Given the fact that you wont see the left MFD when looking to the right out of the cockpit, there is no way to tell if the LOS symbol is still moving without turning the head away from the target on the right side back to the MFD, which again will make the LOS move.

I would kindly ask not to close the case too soon, before it is not clear that the LOS symbol will be stuck in the middle or if it will continue to go on to the TD box after designation instead.

Edited June 28, 2023 by darkman222

[BIGNEWY]

We have highlighted some other issues with the EO-VIS mode, related to the logic of how the Maverick should behave with regard to TMS commands and SOI selection. 

But the issue in this thread is correct as is, we have seen no evidence that would suggest we need to change it.

thanks

[darkman222]

Okay, understand. What I am referring to now is:

32 minutes ago, BIGNEWY said:

We have highlighted some other issues with the EO-VIS mode, related to the logic of how the Maverick should behave with regard to TMS commands and SOI selection. 

...which is a different topic. Looking forward to see the further development of the Mavericks for the Viper regarding that.

Thanks for reviewing the particular issue in this thread and making the Viper the most accurate possible.

[_SteelFalcon_]

@BIGNEWY / @Lord Vader

thanks for looking into this.

i struggle with understanding the feature in the following part:

On 6/28/2023 at 9:15 PM, BIGNEWY said:

The LOS Circle" representing the seeker line-of-sight appears when the AGM-65 seeker is in Slew or Track mode

Good.

but then:

On 6/28/2023 at 9:15 PM, BIGNEWY said:

which only occurs after a designation is made using the TD Box. Before a designation is made, the seeker is in a Slave mode. 

Now my struggle with this is:

when I dms down to make the wpn page SOI without prior designation, I can slew the mav. Is that now Slew mode or Slave? Because I am clearly slewing the weapon around however no LOS circle shows.

I can understand the behavior if VIS mode is active, the TD box has not been moved and is sat on the FPM. Then it makes sense to be slaved and not having the missile LOS as to not cramp too many things over eachother on the FPM making it hard to see through.

but moving the TD box with HUD (TDC slew) or with HMCS entered by pressing TMS Fwd Long, we are now clearly slewing the TD box. We can clearly see the maverick seeker move around on the WPN page too -> the missile seeker is therefore slewing. So if the LOS is shown when Slewing OR Tracking, it should show up, regardless of a designation has yet been made, as described by you and by manuals that mention LOS to show when slewing or tracking.

edit:

this generally brings me to the question of „what does it mean when it says ‚is slaved to the hud td box‘?“

does it mean the missile will try to match los with the td box at all times also while slewing?

is „slaved to“ and „slewing“ in this context mutually exclusive or do they co-exist?

as in:

If i slew the TD box and the missile is SLAVED to that box, does the missile, which is moving around when the TD box moves due to trying to match LOS, in fact SLEW? Or is that not considered slewing?

Edited June 30, 2023 by _SteelFalcon_

[Moonshine]

On 6/28/2023 at 9:15 PM, BIGNEWY said:

The LOS Circle" representing the seeker line-of-sight appears when the AGM-65 seeker is in Slew or Track mode, which only occurs after a designation is made using the TD Box. Before a designation is made, the seeker is in a Slave mode

First and foremost, I would like to address the point where you mention that "Slew mode" only becomes active when the TD box is designated. In fact, this is a contradiction.

SLAVE means that the sensor, in this case, the MAV seeker line of sight, is forced to follow another sensor, in this case, it is the TGP or the TD box that is Sensor of Interest (SOI) and provides a System Point of Interest (SPI).

in Short:
Sensor management is based on a single line-of-sight concept where all sensors are slaved to a common aimpoint, referred to as the System Point-of-Interest (SPI).

Therefore, we should use DMS aft to make the MAV seeker the SOI and then manually move the MAV-seeker-LOS. In this case, it is no longer in SLAVE because we detach the MAV-seeker-LOS from SLAVE by slewing it through movement. However, in one of the videos provided here, the Missile-LOS-Circle does not appear.

 

Let's move on to point 2.

Slave mode and slewing are not mutually exclusive. The MAV seeker LOS can be in a Slave mode to the TD box but must slew with every movement of the TD box to maintain this state.

As mentioned before, SLAVE means that one sensor is bound to another and tries to follow it. In our case, the Maverick seeker LOS is in slave mode by using the HMCS, which is SOI and provides the TD-Box/SPI, and therefore tries to follow the TD-Box/SPI.

However, for the MAV seeker LOS to follow, it must move, and movement essentially involves slewing. Therefore, every time the MAV seeker LOS moves, a LOS Circle should appear, and once it reaches the TD-box-LOS and stops slewing, the seeker-LOS-Circle should disappear, which does not happen in the provided example.

In this example, with the help of the workaround (enter and leave dogfight mode), we can observe a part of the correct behavior. The movement with the head/HMCS is faster than the MAV seeker head can slew. By slewing alone, the seeker LOS Circle should appear. Only when it reaches the TD box LOS and stops slewing should the seeker LOS disappear, which doesn't happen in the example.

LOS.webm

An excerpt from the ED F16 manual (pages 400/402):

Quote

 

"When handing off targets from the TGP, the missile boresight correlator (MBC) compares the image from the targeting pod with the image from the missile seeker head and slews the missile seeker head until the images match. The MBC is only active when in A/G mode with an AGM-65 selected, and the TGP is sensor of interest (SOI).

• S: Slave (MBC has not been commanded to slew the missile)
• 1: Slew 1 (MBC is slewing to match missile LOS to TGP LOS)
• 2: Slew 2 (MBC is slewing to match missile video to TGP video)"

 

These 2 examples clearly explain that even when the TGP is the SOI, the term "slewing" is used to describe the movement of the MAV LOS. Furthermore, there are publicly available documents that provide further evidence that equates MAV LOS movement with slewing.

From the explanation in the documents, "seeker line-of-sight appears when the AGM-65 seeker is in Slew or Track," a LOS Circle should appear with every movement, which is equivalent to slewing.

Finally, it should be noted that this logic supports the pilots, especially when using HMCS. They need to know when the MAV seeker LOS matches the TD box; otherwise, it can lead to input errors.

 

Edited July 1, 2023 by Moonshine

[Raptor9]

2 hours ago, Moonshine said:

snip Furthermore, there are publicly available documents that provide further evidence that equates MAV LOS movement with slewing.

From the explanation in the documents, "seeker line-of-sight appears when the AGM-65 seeker is in Slew or Track," a LOS Circle should appear with every movement, which is equivalent to slewing.

There is a specific distinction between the the process of "slewing" and the state of being "in Slew mode". The difference may seem inconsequential, but it is distinct.

"seeker line-of-sight appears when the AGM-65 seeker is in Slew or Track,"
"seeker line-of-sight appears when the AGM-65 seeker is slewing or tracking,"

2 hours ago, Moonshine said:

An excerpt from the ED F16 manual (pages 400/402):

As for the DCS F-16C Early Access guide, that will of course receive any necessary revisions to be more clear to describe the accurate behavior.

As BigNewy stated above, we are investigating the logic of EO-VIS mode as a whole to identify any required refinements of the behavior, but in the case of the OP's topic within this thread, we have determined that the current implementation to be accurate.

[_SteelFalcon_]

13 minutes ago, Raptor9 said:

There is a specific distinction between the the process of "slewing" and the state of being "in Slew mode". The difference may seem inconsequential, but it is distinct.

"seeker line-of-sight appears when the AGM-65 seeker is in Slew or Track,"
"seeker line-of-sight appears when the AGM-65 seeker is slewing or tracking,"

the manuals are rather clear about that and state "slewed or is tracking"

They dont mention a specific "slew-mode".

and since they state "slewed", i'd expect the LOS to appear when manually selecting WPN page as SOI and SLEWING the mav seeker, even prior to designating anything. Yet in DCS no LOS is showing.

And since the parts on page 400/402 in the EA manual is basically word for word out of a specific manual, I'd be curious as to what you'd wanna change about that when reviewing it to be honest.

Edited July 1, 2023 by _SteelFalcon_

[Raptor9]

1 hour ago, _SteelFalcon_ said:

the manuals are rather clear about that and state "slewed or is tracking"

They dont mention a specific "slew-mode".

I think I know which document you are pulling that from, and that statement is from a larger paragraph that is describing the events, in sequence, that occur when EO-VIS is being used. The designation is performed, and then the LOS circle appears. Further, the figures that immediately follow that paragraph distinctly display the LOS circle in the post-designate state, but not in the pre-designate state. There is a specific Slew mode, even if not described in that document; others are worded differently and are annotated as "in Slew".

1 hour ago, _SteelFalcon_ said:

And since the parts on page 400/402 in the EA manual is basically word for word out of a specific manual, I'd be curious as to what you'd wanna change about that when reviewing it to be honest.

The MBC is a function of the TGP (not the AGM-65) that is active when performing handoffs in EO-PRE. When this is occurring, the TGP is commanding movement of the AGM-65 seeker LOS while the TGP is SOI (WPN is not SOI, AGM-65 seeker is in Slave mode). The MBC is commanding movement of the AGM-65 seeker, just like the TD Box is commanding movement of the AGM-65's seeker while in pre-designate EO-VIS.

So again, our interpretation of the logic of the LOS circle is already as it is within DCS. I understand others have a different interpretation or opinion of what should or should not be in DCS F-16C, but we are confident that the current implementation is accurate.

[Moonshine]

can you explain why, when i manually select the WPN page and start moving the mav around, it isnt considered "slew" according to your statement and hence no missile LOS circle is displayed in the HUD?

[Raptor9]

9 minutes ago, Moonshine said:

can you explain why, when i manually select the WPN page and start moving the mav around, it isnt considered "slew" according to your statement and hence no missile LOS circle is displayed in the HUD?

As was already stated by BigNewy and myself, EO-VIS as a whole is being looked at to identify any inaccuracies within the logic. However, I will state once again that the OP's topic of this thread is already determined to be correct as is. Your specific circumstance will be looked at during the review, but as for the original topic of discussion (which we have since departed), it has been determined to be correct-as-is.

[Moonshine]

got it, thanks for your time!

[_SteelFalcon_]

41 minutes ago, Raptor9 said:

When this is occurring, the TGP is commanding movement of the AGM-65 seeker LOS while the TGP is SOI (WPN is not SOI, AGM-65 seeker is in Slave mode).

sorry if off topic, but since we're talking about the same manual, please consider this part in that manual again precisely, specifically line 2 under the EO delivery with TGP part of what exactly the MBC does take control of. something something missile SLEW...

 

And if the MBC is the only thing that can take control of the seeker, why does VIS description state that missile is slaved to the TD box?
- if nothing can take command of the missile seeker in VIS prior to designation, how does the LOS magically sync with the TD box upon designation?
- if nothing can take control of the missile seeker in VIS prior to designation, why is it moving on the WPN page instead of staring straight ahead?
- and if it should be moving prior to designation, why is no LOS circle displayed on the HUD"

Edited July 1, 2023 by _SteelFalcon_

[NineLine]

OP has been answered, closing this thread.