Slew on saved datalink target don't work

[Hajime]

Hey I noticed, that the Ka-50 Datalink does not work properly (SP & MP).

When I save a target (air start) and want to slew back to the target there is always a big offset to the right.
This also happens with shared targets in MP.

Edit: As I watched the track. It feels odd, that the Skval is not pointing directly on the vehicles as I locked them. I'm 100% sure i locked the vehicle itself and not the ground next to it.

 

Ka-50-Track.trk

Edited December 16, 2022 by Hajime

[Hajime]

I tested the same thing with the BS3-Module.
It is the same.

Even with Cold start, normal aligmnent and "realistic INS" disabled.
QFE ist set.

The problem cannot be attributed to INS drift, Aligment errors etc.

If you make your prober coldstart, alignment etc. and you just hover directly over your starting position (so that your LAT LONG Position is the same apart from the altitude).
Then you lock a target. With your laser ranger you get a offset position (range and bearing) relative to your position. The flight computer is calculating the position of the locked target from your position + the offset (range and bearing).

So if you now call up that datalink position a short time after (e.g. 10s). The Shkval has to slew to the same position, regardless of a eventual faulty INS position at the time you reccord that datalink position. There could only be a big error between the stored and called position if there is a position drift in that 10s.
That can't make sense from a technical point of view.
@BIGNEWY@NineLine

Edited December 19, 2022 by Hajime

[Sneethe]

I thought I was doing something wrong while learning Volk's tutorials, tried everything to fix it but I had the weird feeling it might be bugged, please acknowledge the issue and take a look at it.

[SnuggleFairy]

On 12/16/2022 at 1:56 AM, Hajime said:

Hey I noticed, that the Ka-50 Datalink does not work properly (SP & MP).

When I save a target (air start) and want to slew back to the target there is always a big offset to the right.
This also happens with shared targets in MP.

Edit: As I watched the track. It feels odd, that the Skval is not pointing directly on the vehicles as I locked them. I'm 100% sure i locked the vehicle itself and not the ground next to it.

 

Ka-50-Track.trk 199.78 kB · 6 downloads

 

sorry your track isn't playing properly for me. On my screen it looks like you're trying to save targets far in the water.

Spoiler

I just made this yesterday:

Spoiler

 

 

[Sneethe]

Thank you, I tried it again and it works for the Black Shark 2, Black Shark 3 still broken however. Accidentally thought this was the Bug forum for 3 when I saw the thread, at least BS2 still works.
 

 

5 hours ago, SnuggleFairy said:

sorry your track isn't playing properly for me. On my screen it looks like you're trying to save targets far in the water.

  Reveal hidden contents

I just made this yesterday:

  Reveal hidden contents

 

 

 

 

Edited January 12, 2023 by Sneethe

[Hobel]

Am 12.1.2023 um 18:28 schrieb SnuggleFairy:

sorry your track isn't playing properly for me. On my screen it looks like you're trying to save targets far in the water.

  Versteckten Inhalt anzeigen

I just made this yesterday:

  Inhalt verstecken

 

 

After the last update, there were some improvements regarding the data linkPoints.
 

 

however, one question remains that he mentions

Am 18.12.2022 um 17:42 schrieb Hajime:

So if you now call up that datalink position a short time after (e.g. 10s). The Shkval has to slew to the same position, regardless of a eventual faulty INS position at the time you reccord that datalink position. There could only be a big error between the stored and called position if there is a position drift in that 10s.
That can't make sense from a technical point of view.

what do you think about that?

Edited January 27, 2023 by Hobel

[Akiazusa]

7 hours ago, Hobel said:

what do you think about that?

 

I have a feeling that this position difference is not due to INS position drift,but because of INS heading drift. It seems that when the system record the target heading,it is using the heading output from the INU, but when it turns the Shkval,it won't use the same heading source. I tried a few times and the system just simply turns that aircraft to the REAL heading of the recorded INU heading no matter how wrong the INS heading have already been messed up.

For example,when saving target it records a target at 5km in a wrong drifted heading of 78°(but the target is actually at 5km in a real heading of 76°),then you uncage the Shkval,the Shkval will try to point to a position at 5km in the REAL heading of 78°

As a result,any difference between the INU heading and real aircraft heading can make the Shkval pointing to a different position.

You could intentionally input a wrong heading to the INU(by messing the MH/gyro/MAN switch),then save a data link target and see the result.

 

By the way anyone noticed the target point elevation is no longer effect by altimeter setting after the update?

Edited January 27, 2023 by Akiazusa

[Hobel]

vor 2 Stunden schrieb Akiazusa:

I have a feeling that this position difference is not due to INS position drift,but because of INS heading drift. It seems that when the system record the target heading,it is using the heading output from the INU, but when it turns the Shkval,it won't use the same heading source. I tried a few times and the system just simply turns that aircraft to the REAL heading of the recorded INU heading no matter how wrong the INS heading have already been messed up.

For example,when saving target it records a target at 5km in a wrong drifted heading of 78°(but the target is actually at 5km in a real heading of 76°),then you uncage the Shkval,the Shkval will try to point to a position at 5km in the REAL heading of 78°

As a result,any difference between the INU heading and real aircraft heading can make the Shkval pointing to a different position.

You could intentionally input a wrong heading to the INU(by messing the MH/gyro/MAN switch),then save a data link target and see the result.

 

By the way anyone noticed the target point elevation is no longer effect by altimeter setting after the update?

 

Very interesting point!

so I tested that directly

 

I created a Fixpoint 3 to cause a deliberate drift 1km away from me.
so if it drifts the INU HDG i should be pretty much on the secured target after saving?
as far as i understood you.

But what happens is that the saved point gets twice the deviation.
1km drift suddenly becomes 2
each drift always causes double for saved points
 

EDIT: And another thing, why is the Point drifting towards me, I would expect it to drift further away from me in the scenario?
but the point comes closer.

 

vor 2 Stunden schrieb Akiazusa:

By the way anyone noticed the target point elevation is no longer effect by altimeter setting after the update?

yes and that is a good thing

 

Edited January 27, 2023 by Hobel

[Akiazusa]

 

(please ignore this...I accidentally post the same reply twice..)

Edited January 28, 2023 by Akiazusa

[Akiazusa]

14 hours ago, Hobel said:

Very interesting point!

so I tested that directly

 

I created a Fixpoint 3 to cause a deliberate drift 1km away from me.
so if it drifts the INU HDG i should be pretty much on the secured target after saving?
as far as i understood you.

But what happens is that the saved point gets twice the deviation.
1km drift suddenly becomes 2
each drift always causes double for saved points
 

EDIT: And another thing, why is the Point drifting towards me, I would expect it to drift further away from me in the scenario?
but the point comes closer.

 

yes and that is a good thing

 

 

Hi, I did some additional tests...

But the result is odd to me.........

It seems that when you saving the target point via DL,it compares the difference/Delta1 between the aircraft INU position and the Shkval aiming point on ABIRS(the yellow leg),then adds this difference/Deta1 to the aircraft ABRIS/GPS position to create a new target point.

And when uncaging the Shkval,it compares the difference/Delta2 between the aircraft INU position and the target point position,then adds this difference/Delta2 to the aircraft ABRIS/GPS position to create a Shkval aiming point,then steers the Shkval to it....

It could explain why there is a 2 km shorter in distance,but it makes no sense to me to be honest.....

 

Also if the target point is crated via PVI800 keyboard,the Shkval will just points to the 0 ASL now, it could be pretty hard to find targets via coordinate if there is no way to input target altitude,especially when your mission is in high elevation area.

I also wonder how the system knows the exact altitude of my aircraft.Even if I turn off the ABRIS/GPS,it can still points to an elevation of 0 ASL,and changing the weather settings doesn't affect it neither.

[Hobel]

vor 22 Minuten schrieb Akiazusa:

Hi, I did some additional tests...

But the result is odd to me.........

It seems that when you saving the target point via DL,it compares the difference/Delta1 between the aircraft INU position and the Shkval aiming point on ABIRS(the yellow leg),then adds this difference/Deta1 to the aircraft ABRIS/GPS position to create a new target point.

And when uncaging the Shkval,it compares the difference/Delta2 between the aircraft INU position and the target point position,then adds this difference/Delta2 to the aircraft ABRIS/GPS position to create a Shkval aiming point,then steers the Shkval to it....

It could explain why there is a 2 km shorter in distance,but it makes no sense to me to be honest.....

 

Also if the target point is crated via PVI800 keyboard,the Shkval will just points to the 0 ASL now, it could be pretty hard to find targets via coordinate if there is no way to input target altitude,especially when your mission is in high elevation area.

I also wonder how the system knows the exact altitude of my aircraft.Even if I turn off the ABRIS/GPS,it can still points to an elevation of 0 ASL,and changing the weather settings doesn't affect it neither.

something that summarises the whole thing well, if something is unclear in the video please say so, I will have a closer look at your post later, I don't have that much time at the moment.

 

 

I have created a Fixpoint 3 to simulate a 1km drift, the results are as follows:

1. the waypoint is 1km north, as you would expect.

2. The target point, however, is 2km south.

 

Edited January 28, 2023 by Hobel

[SnuggleFairy]

8 hours ago, Akiazusa said:

I also wonder how the system knows the exact altitude of my aircraft.Even if I turn off the ABRIS/GPS,it can still points to an elevation of 0 ASL,and changing the weather settings doesn't affect it neither.

There are mentions on the forum here and there, that it's dependant on the QFE setting on the altimeter, so that's how it knows your altitude. That's how it should work i guess, but that's not how it works in DCS. No matter where the QFE is set, the datalink saves and ingresses on targets at exactly the same point

Edited January 28, 2023 by SnuggleFairy

[Taz1004]

Regardless of the reason or whether it's realistic or not, these inaccuracies in DL makes wingman commands "Engage Datalink Target" useless because the AI doesn't know which target I'm talking about.

[Candiru89]

According to my observations its not about slewing in to wrong position, but saving the target in to the wrong position. 

Its quite annoying, DL is a very useful function. I would even go back to BS2 if there was no MWS in 3.

[Hobel]

@Candiru89@Taz1004 @Akiazusa

 

This behaviour has been fixed with today's update.

[Akiazusa]

7 hours ago, Hobel said:

This behaviour has been fixed with today's update.

 nice to know that,seems it was forgotten by the changelog,I'm gonna try it out

[Candiru89]

On 3/10/2023 at 8:05 PM, Hobel said:

@Candiru89@Taz1004 @Akiazusa

 

This behaviour has been fixed with today's update.

Are you sure? I tried it yesterday(after the patch, MT) and it wasnt fixed.

[Hobel]

vor 5 Stunden schrieb Candiru89:

Are you sure? I tried it yesterday(after the patch, MT) and it wasnt fixed.

Yes see

Behaviour 1:
In the video I save a target point at the beginning, then i create a 1km northern drift.

The target point is now shifted 1km north as you can see.

Before the patch, the shkval slewed 2km south for reasons.

2.
after the 2 section in the video I save another point, after I call it up immediately afterwards the point is exactly where I saved it a moment before, before the patch it was also an extreme drift, although there was no drift between saving and re-selecting.

Before the patch you always had double the drift, a 500m drift is not so bad in itself but if it doubles every time and shifts in the wrong direction it is dramatic, but that is no longer the case.

Otherwise, post a track and we'll see what happens to you?

[tekrc]

far as I can tell (my best guess. not claiming fact here), its fine in those examples because youre doing it still on and around the pad just after scenario start. but after flying around for not even 10 mins the ins drift has gotten so bad coordinate entry is useless and as a result, so is datalink. still have to rely on marks saved by yourself on the dl panel and cant use a nav tgt or target sent to you past referencing the abris. even saving your own they dont stay good for very long as drift error drags them out pretty quickly.

in my case if I do start and takeoff or just scenario start hot, fly out to a target area (in this case target is a building at an airfield 10km away) and then try to pull up a target I had saved as a nav tgt. it looks fine on the abris but shkval is way off when it is uncaged (always tries to slew down almost to where the heli is it feels like). NOTE: if I grab the nav tgt position from the shkval it works fine. I believe this is because of referencing own navigation instead of from coordinate but I didnt do a position comparison here

finding the target manually with the shkval, storing it, recalling it works fine just nothing coming from another aircraft or stored through pvi coordinate entry goes to the right place for me. makes me think its related to drift error because its only really noticed when using references from outside your own nav system after being in transit for a bit

NAV TGT track.trk

Edited March 12, 2023 by tekrc

[Hobel]

Am 12.3.2023 um 18:31 schrieb tekrc:

far as I can tell (my best guess. not claiming fact here), its fine in those examples because youre doing it still on and around the pad just after scenario start. but after flying around for not even 10 mins the ins drift has gotten so bad coordinate entry is useless and as a result, so is datalink. still have to rely on marks saved by yourself on the dl panel and cant use a nav tgt or target sent to you past referencing the abris. even saving your own they dont stay good for very long as drift error drags them out pretty quickly.

in my case if I do start and takeoff or just scenario start hot, fly out to a target area (in this case target is a building at an airfield 10km away) and then try to pull up a target I had saved as a nav tgt. it looks fine on the abris but shkval is way off when it is uncaged (always tries to slew down almost to where the heli is it feels like). NOTE: if I grab the nav tgt position from the shkval it works fine. I believe this is because of referencing own navigation instead of from coordinate but I didnt do a position comparison here

finding the target manually with the shkval, storing it, recalling it works fine just nothing coming from another aircraft or stored through pvi coordinate entry goes to the right place for me. makes me think its related to drift error because its only really noticed when using references from outside your own nav system after being in transit for a bit

NAV TGT track.trk 12.65 MB · 0 Downloads

 

Thx for the feedback.

 

I take later a look

[Hobel]

Am 12.3.2023 um 18:31 schrieb tekrc:

its fine in those examples because youre doing it still on and around the pad just after scenario start. but after flying around for not even 10 mins the ins drift has gotten so bad coordinate entry is useless and as a result, so is datalink. still have to rely on marks saved by yourself on the dl panel and cant use a nav tgt or target sent to you past referencing the abris. even saving your own they dont stay good for very long as drift error drags them out pretty quickly.

This is not the only type of test I have done, it just illustrates the basic principle of where the error did or did not occur.

 

 

Am 12.3.2023 um 18:31 schrieb tekrc:

in my case if I do start and takeoff or just scenario start hot, fly out to a target area (in this case target is a building at an airfield 10km away) and then try to pull up a target I had saved as a nav tgt. it looks fine on the abris but shkval is way off when it is uncaged (always tries to slew down almost to where the heli is it feels like). NOTE: if I grab the nav tgt position from the shkval it works fine. I believe this is because of referencing own navigation instead of from coordinate but I didnt do a position comparison here

As I see it, your procedure is also wrong, you make precise aligment and fly off after a few minutes?

You should actually wait 20 or at least 10 minutes for this procedure with the engines switched off on the ground.

 

 

Here is an example, I run the Auto start which performs a Quick Aligment.
After this is done I could have waited another 2-5 minutes for the diss, but I decided to take off right away so that it would "start up" faster, so I hover for a moment so that I don't accumulate too many errors, now that the DISS was on I could fly.

and when I was in the finish area, the shkval jumped close to the point I had created.
The inaccuracy is due to the fast aligment and the fact that I didn't do it very cleanly.
 

But let me say that the fast aligment is not intended for combat missions anyway, standard or precision are absolutely necessary for combat missions!

 

 

[okopanja]

Interstingly I do not manage to use PVI target point in my own mission to slew skhval. Either from AIR or on ground hot take off. It does move but does not point to target, but simply drifts. Relative movement between 2 target points works, but off course behaves the same.

In contrast ED's instante free flight works perfectly.

Any cue on what am I doing wrong?

[Candiru89]

On 3/12/2023 at 1:07 PM, Hobel said:

Yes see

 

Now I tested and it seems it slewing works as intended now, but the icon on the abris is far off.

https://youtu.be/joc-vzJj78c

Not recorded, but I observed what tekrc said, after 10 mins drift is so big its barely usable. I understand its more realistic and you should use precision alignment, but its quite annoying to wait 12 minutes just for the ins alignment at every start up, especially in multiplayer.

[Hobel]

vor 26 Minuten schrieb Candiru89:

Now I tested and it seems it slewing works as intended now, but the icon on the abris is far off.

https://youtu.be/joc-vzJj78c

Not recorded, but I observed what tekrc said, after 10 mins drift is so big its barely usable. I understand its more realistic and you should use precision alignment, but its quite annoying to wait 12 minutes just for the ins alignment at every start up, especially in multiplayer.

The video does not show the status of your INU navigation system, if the system is drifting it is normal even on the ABRISS the point is way off.

 

vor 33 Minuten schrieb okopanja:

Interstingly I do not manage to use PVI target point in my own mission to slew skhval. Either from AIR or on ground hot take off. It does move but does not point to target, but simply drifts. Relative movement between 2 target points works, but off course behaves the same.

In contrast ED's instante free flight works perfectly.

Any cue on what am I doing wrong?

track?

[Candiru89]

11 minutes ago, Hobel said:

The video does not show the status of your INU navigation system, if the system is drifting it is normal even on the ABRISS the point is way off.

Ok, I feel stupid now. How do I check the status of the INU?