[FIXED] Command-guided missiles fly to actual target location instead of last reported contact pos (Full Version)

All Forums >> [New Releases from Matrix Games] >> Command: Modern Operations series >> Tech Support



Message

Zanthra -> [FIXED] Command-guided missiles fly to actual target location instead of last reported contact pos (3/7/2019 12:52:06 PM)

The Tomahawk variants with datalinks and similar missiles, while in terminal phase (without a course) knows where it's target is without any detection of that target. If you select a tomahawk and clear it's path, it will enable any seekers it has, start transmitting the information picked up by it's IIR seeker, and also home in on the target far out of seeker range. This can be employed to attack an ambiguous target by using bearing only launch, then re-targeting the tomahawk with F1, after it has it's new target clearing the path will cause it to home in directly on the target.

I have attached a scenario with two destroyers, after detection and missile launch (6 tomahawk MMT and 2 LRASM) I used the editor to move the enemy destroyer to another location. If you select any of the missiles, and clear their course by pressing F3 and escape, the missiles will turn and fly towards the new location, even though it's new location is not identified by that side. Alternatively, once the missiles reach the old target coordinates, they will go to terminal phase and turn around to home in on the destroyers current location.



doabliptnk -> RE: Tomahawk Missiles can home without detection in terminal phase. (3/8/2019 8:51:56 AM)

I can confirm the above behavior. This is probably a bug.



michaelm75au -> RE: Tomahawk Missiles can home without detection in terminal phase. (3/8/2019 12:34:10 PM)

Not sure if your test is valid.
The enemy contact has been identified and the missiles are assigned to attack the contact (not the location where it was unless it was a BOL). Moving the contact somewhere else probably isn't going to 'un-contact' it from the side.



Zanthra -> RE: Tomahawk Missiles can home without detection in terminal phase. (3/8/2019 4:39:47 PM)

The issue is not that they home in on the contact, it's that if their course is cleared, by selecting a missile and pressing F3, and then escape (or just letting them fly all the way to the original detection), they turn to the contact's current location without the side having any indication of where the target is currently. In practice, this means that a Block IV tomahawk can home in on ground units or ships that have long since vacated the location they were detected at.

A more natural scenario would have been to have the other destroyer sailing away from the contact point and maneuvering, but I wanted to magnify the demonstration having the missile course change substantially to make it clear they were not just predicting the target motion, or picking the target up on their seeker when they get close.

The expected behavior is that if the missile course is cleared, the missile continues to fly to the contact's last known location, updated via the datalink. Upon reaching that location, if the missile does not detect it's target, it begins a search pattern.



Whicker -> RE: Tomahawk Missiles can home without detection in terminal phase. (3/8/2019 5:56:54 PM)

are you able to do this on something other than the unit that you moved? I don't quite understand the issue, but see what Michael is saying, the moved unit is not a good test case as the game is not going to treat you moving it in a graceful manner most likely.



Zanthra -> RE: Tomahawk Missiles can home without detection in terminal phase. (3/8/2019 9:24:32 PM)

quote:

ORIGINAL: Whicker

are you able to do this on something other than the unit that you moved? I don't quite understand the issue, but see what Michael is saying, the moved unit is not a good test case as the game is not going to treat you moving it in a graceful manner most likely.


Yes. Anything a datalinked tomahawk has targeted, if it has no current course it "knows" where the target currently is and will home to that point, regardless of what the tomahawk, the unit controlling the datalink, or the side in general has information about.

A tomahawk on the final leg still has a course, as indicated by the plotted course line, and the final leg is updated due to the datalink, this omniscient seeking only happens once it reaches the terminal phase, when it gets close to the datalink provided location and turns on it's own seeker, or the course is cleared manually.



doabliptnk -> RE: Tomahawk Missiles can home without detection in terminal phase. (3/9/2019 4:48:59 AM)

Attached is my modified scen (using Zanthra's scen) to better illustrate the point:

- Play the scen and wait a bit
- The E-3G detects SKUNK#2 (North West of the DDG 96)
- Shoot 1 RGM-109I toward SKUNK#2 (create crazy plot course)
[img]https://i.imgur.com/9wAE3HY.jpg[/img]
- Turn off E-3G's radar
- (OPTIONAL) play in editor mode, switch side and change SKUNK#2 course
- Wait until SKUNK#2's AOU gets significantly bigger
[img]https://i.imgur.com/3NPhNYm.jpg[/img]
- Clear RGM-109I's course (F3 then ESCAPE)
- The missile goes straight for the target



templar42 -> RE: Tomahawk Missiles can home without detection in terminal phase. (3/9/2019 7:29:06 PM)

This is definitely a bug IMHO. However, it's very difficult to illustrate without editing during play.

The attached file illustrates the bug in a completely naturalistic way. The MMTs infallibly point themselves to a target that is around 70nm away from the target area they have been given.

From my scenario description:

This scenario is designed to illustrate the "psychic" powers of the Tomahawk MMT in the simplest possible way without editing the scenario whilst the missiles are inflight, thus excluding the possibility that the anomaly is a product of unrealistic editing. This bug may be a variant of the R-27 ARM bug which I highlighted last year.

The Blue player should simply start the scenario and needs only to watch with appropriate acceleration. The long range launch is designed to exclude the possibility that the missiles got lucky and detected the ship on their own.

The scenario starts with a P-8A about to lose contact with an OSA-II traveling north. 3 RGM-109I have been allocated via Shift-F1 and will launch as soon as the scenario is started. Their course involves one way point halfway to the target producing a roughly straight course from their launch ship. Unknown to the Blue side, the OSA-II is about to reverse course. The plotted course of the P-8 ensures that this will never be known to the Blue side as it is about to fly out of its radar coverage and is too far away to use its FLIR.

The missiles travel to the last known position of the OSA-II exactly as they should, incorporating its known course at the time of launch. However, when they reach it, they change course to travel directly towards its new position, despite the Blue side having no awareness of the ship's course change or current position, and the OSA-II being well outside the IIR and ARH acquisition limit of the missiles, and steaming under EMCON Alpha. The Red side is set to not ignore EMCON when under attack, so there is no chance that the OSA-II is detecting the active seekers, going active itself, and then drawing the missiles toward it through their passive seekers.

A surprise then happens when the missiles close. The OSA-II defends itself poorly, as expected, firing its AK-230. Instead of impacting, however, the surviving missiles are listed as missing by ~70nm, despite being close enough to be engaged by the CIWS and heading straight towards the ship!

My best guess as to the source of this bug is that the code that determines what the missiles do when they reach the predicted target area has a mistake such that the missiles are given the real position of the target as opposed to being given the Blue side's best estimate of the position of the target. The miss by ~70nm is bizarre, and not knowing Command's internals I can't speculate on this.



Zanthra -> RE: Tomahawk Missiles can home without detection in terminal phase. (3/10/2019 4:57:41 AM)

The seeking behavior also affects other missiles with datalinks. Including and probably not limited to, Harop, SLAMER, LRASM.

Also, it looks like if the weapon seeker is the only detection of a moving target, the impact point is one pulse of movement +- CEP. So for a car moving at 30 knots, that's 50 feet per second, and attacking with a tomahawk with 2m (about 6 foot) CEP will miss by 44 feet to 56 feet. If running in high fidelity mode at less than 15x speed, since the pulse length is 0.1 seconds that's reduced to 5 feet +- 6 feet, and is very likely to take out the target. If there is another source of detection for the target, it can hit mobile targets fine it seems.

If the target is never seen by the seeker, such as in heavy fog, the impact point is actually at the point the contact was last seen, even though the missile flies to the current location. It can damage units in the explosion that were near where the contact was lost, and far far from where the missile was when it explodes. When it says it missed by 70 nm, it means that the explosion was 70 nm from where the target currently is (and where the weapon was).

I figure the reason this does not show up all that much is due to the fact that there are not a lot of mobile units that tomahawks are used against (actually moving, there are many mobile SAM units that tomahawks are used against, but they rarely actually move). Add to that the fact that it needs to be out of recon for long enough that the missile does not see the target on it's seeker when it gets there.

PS: I discovered this seeking when using tomahawks to locate and identify mobile units in the Reds CoW bonus scenario as the resources for safe recon below cloud level and in close proximity to the USSR SAMs are limited. I was chasing a group of mobile units across the battlefield with tomahawks loitering around and occasionally clearing their course to get sensor updates. The PRC mobile units usually stay still, but they can shuffle to reorganize around a new group lead if the last one dies. If the new lead dies while the next in line is still shuffling into position, the group takes on the speed and direction of the new lead, and the group runs off in that direction.



Dimitris -> RE: Tomahawk Missiles can home without detection in terminal phase. (4/21/2019 2:12:04 PM)

Thanks, logged as major and we'll definitely investigate.



Dimitris -> RE: Tomahawk Missiles can home without detection in terminal phase. (4/22/2019 10:22:24 AM)

Tested this now, using both Zanthra's OP scenario and templar42's superb test example. Version used is Build 1009.27.9.

In the first scenario, I manually teleported the target DDG off the west. In the second one I didn't have to intervene thanks to the Osa setup.

In both scenarios, upon reaching the target area the Tactoms activated their seekers and maintained their course, searching for targets. They did NOT automagically locate their intended targets.

I re-ran both scenarios, this time clearing the course on the missiles early, instead of just letting them run. In this case, too, they ran straight out without any indication of hidden knowledge of their target's true location.

So it looks like one of our recent updates fixed this.

Can anyone give this a try and confirm?



Zanthra -> RE: Tomahawk Missiles can home without detection in terminal phase. (4/22/2019 9:20:13 PM)

It looks like the missiles loose the datalink as soon as they don't have a course now, either by reaching the end of the last leg or having the course cleared. So no sensor data sent back to the launching unit for missiles with BDII like Tomahawk or SLAM-ER, and no further re-targeting or course corrections. The game must be paused before changing the course of a missile now, since the tick after you hit F3 to specify the new course, you lose the datalink and can't give it the new course. Although this change is not limited to just cruise missiles. It seems that AIM-120Ds lose the datalink during terminal engagement as well now, meaning there is no indication of the target being acquired by the AIM-120D in the recent detections list of the target. Wire Guided torpedoes and command guided missiles like the Gabriel II on the other hand do maintain their datalinks.

It looks like the seeking behavior is still a problem with Gabriel and Gabriel II missiles which are command guided and maintain the datalinks. If they have no course, they will home in without detection. Although without detection it's subject to the issue of missing a moving target while it's out of recon, but only after flying to the point where the unit currently is. Attached is an example



templar42 -> RE: Tomahawk Missiles can home without detection in terminal phase. (4/23/2019 3:44:43 PM)


quote:

ORIGINAL: Dimitris

Tested this now, using both Zanthra's OP scenario and templar42's superb test example. Version used is Build 1009.27.9.

So it looks like one of our recent updates fixed this.

Can anyone give this a try and confirm?


Thank you for your kind word about my scenario! I just ran it twice in 1009.27.9. The missiles no longer turn towards the OSA and behave exactly as expected. It must have been fixed by a recent update as you suggest.



Dimitris -> RE: Tomahawk Missiles can home without detection in terminal phase. (4/27/2019 9:28:12 AM)

I examined this now.

quote:

ORIGINAL: Zanthra
It looks like the missiles loose the datalink as soon as they don't have a course now, either by reaching the end of the last leg or having the course cleared. So no sensor data sent back to the launching unit for missiles with BDII like Tomahawk or SLAM-ER, and no further re-targeting or course corrections. The game must be paused before changing the course of a missile now, since the tick after you hit F3 to specify the new course, you lose the datalink and can't give it the new course. Although this change is not limited to just cruise missiles. It seems that AIM-120Ds lose the datalink during terminal engagement as well now, meaning there is no indication of the target being acquired by the AIM-120D in the recent detections list of the target. Wire Guided torpedoes and command guided missiles like the Gabriel II on the other hand do maintain their datalinks.


You are correct. The underlying issue is that the missile evaluates the "go autonomous?" (and sever datalinks in the process) question based on whether it has a plotted course or not. The absence of the plotted course may be the result of the missile reaching its activation point, or the player manually clearing the course; the weapon is unaware of the reason.

If you consider this a major issue please open a separate thread so that we can track it independently. Thanks!

quote:


It looks like the seeking behavior is still a problem with Gabriel and Gabriel II missiles which are command guided and maintain the datalinks. If they have no course, they will home in without detection. Although without detection it's subject to the issue of missing a moving target while it's out of recon, but only after flying to the point where the unit currently is. Attached is an example


I tried your test scenario, using B1009.27.13. The Gabriel guidance seemed to work as expected both "positive" (ie. the FAC tracked the destroyer via radar, and the missiles were correctly command-guided to impact) and "negative" (the FAC lost track, the destroyed was teleported out of the way and the missiles literally splashed into the target's last reported location).

Am I missing something?



Zanthra -> RE: Tomahawk Missiles can home without detection in terminal phase. (4/27/2019 5:12:36 PM)

Here is a screenshot illustrating what I was seeing with the Gabriel II missiles. The missiles fly to the current location of the target (which they should not know about), then when they get there, spawn an explosion at the last known location of the target, possibly multiple nm away from where they were. I had erroneously thought it was the same thing that caused Mavericks to miss while the target was out of recon, but that was fixed without affecting this.

This matches the behavior I noted previously in this thread if tomahawks were unable to see their target due to heavy fog (at the time they maintained their datalink until impact):

quote:


If the target is never seen by the seeker, such as in heavy fog, the impact point is actually at the point the contact was last seen, even though the missile flies to the current location. It can damage units in the explosion that were near where the contact was lost, and far far from where the missile was when it explodes. When it says it missed by 70 nm, it means that the explosion was 70 nm from where the target currently is (and where the weapon was).


For most missiles though, the change where the missiles drop their datalinks when the seeker activates is concealing this bug, so I would be watchful of reoccurance if datalink behavior is changed.

[image]local://upfiles/62189/2864AA990F5C4376A5B48D901DC11607.jpg[/image]



Dimitris -> RE: Tomahawk Missiles can home without detection in terminal phase. (6/18/2019 5:15:32 PM)

quote:

ORIGINAL: Zanthra
Here is a screenshot illustrating what I was seeing with the Gabriel II missiles. The missiles fly to the current location of the target (which they should not know about), then when they get there, spawn an explosion at the last known location of the target, possibly multiple nm away from where they were. I had erroneously thought it was the same thing that caused Mavericks to miss while the target was out of recon, but that was fixed without affecting this.


Thanks, the save was very illuminating for this. Fixed for the next update release.



Page: [1]

Valid CSS!




Forum Software © ASPPlayground.NET Advanced Edition 2.4.5 ANSI
1.25