reported earlier jdam still inaccurate beyond the 5m CEP

[TobiasA]

vor 1 Stunde schrieb Hobel:

  

 

 

Why don't you test it yourself and then share the results?

 

I did, it was different and now I am wondering if it was coincidence or not.

I will try again.

It looks like this here. Approach was from right to left. Too long, too short, too short, too short, way too short so the last approach is even further off.
Attack height 25k.

So even worse with the last approach being closest release, but hits further away.

Edited January 6, 2023 by TobiasA

[TobiasA]

Here is one more, same approach.

null

It is left, long, very short, very short this time. Track is attached.

F-16_JDAM.trk

[TobiasA]

Next run, 6500ft:

Way more precise, but still no reliable deviation. Hits about where it is supposed to hit. About. Static tanks do not care.

Also with track.

This shows: The error depends largely on altitude. And probably on release technique. Maybe. If not, my results would not differ that much.

 

F-16_JDAM_6500.trk

Which ultimately leads to the conclusion that the JDAM hits where is is supposed to hit, but the TGP's precision is most probably not good enough to guarantee a hit...

[TobiasA]

If you place precision waypoints on top of every tank in that mission, you will be even further off, and CEP will be considerably larger even if you drop on exactly that steerpoint without touching the TGP.

Fun thing is that TGP and tank do not align in that case.

[_SteelFalcon_]

1 hour ago, TobiasA said:

If you place precision waypoints on top of every tank in that mission, you will be even further off, and CEP will be considerably larger even if you drop on exactly that steerpoint without touching the TGP.

Fun thing is that TGP and tank do not align in that case.

Can you post the miz that you use for the tests? I‘d like to have a go at it.

[AstonMartinDBS]

1 hour ago, TobiasA said:

If you place precision waypoints on top of every tank in that mission, you will be even further off, and CEP will be considerably larger even if you drop on exactly that steerpoint without touching the TGP.

I can confirm this behaviour.

 

1 hour ago, TobiasA said:

Fun thing is that TGP and tank do not align in that case.

Indeed, there is a huge offset to the targets, when the TGP is pointing at the four WPs (all four WPs have been set to ground level).

WP1/TGT1:

WP2/TGT2:

WP3/TGT3:

WP4/TGT4:

 

3 minutes ago, _SteelFalcon_ said:

Can you post the miz that you use for the tests? I‘d like to have a go at it.

You can use this mission for testing (extracted from @TobiasA's Track): CA F-16C Test GBU38.miz

 

Edited January 6, 2023 by AstonMartinDBS

[Hobel]

vor einer Stunde schrieb TobiasA:

If you place precision waypoints on top of every tank in that mission, you will be even further off, and CEP will be considerably larger even if you drop on exactly that steerpoint without touching the TGP.

Fun thing is that TGP and tank do not align in that case.

damn I hadn't thought about the height.

i tested on flat levels.

ME waypoints have always landed in the 5m CEP
TGP marked targets mostly missed by a long way.

thanks for the tests!

[TobiasA]

vor 2 Minuten schrieb _SteelFalcon_:

Can you post the miz that you use for the tests? I‘d like to have a go at it.

It's always the same mission, I just edited position and altitude for different tests. It should be attached to this message.

JDAM_test.miz

[Hobel]

As far as I can tell, 2 things are happening here.

Once it is the CEP from the bomb itself. which in some cases goes slightly beyond 5m.
and I got similar results in the A10C 2 with the GBU38 when the aiming points were placed perfectly in the ME.

Whether it is really due to the height must be tested again more precisely. @TobiasA
hint here under 10.000 feet it could rather come to inaccuracies and everything beyond that leads to better CEP

 

The second thing is the F16 TGP offset, If you use it, you get an additional offset, and the bomb can hit far off target (+10m)because of this

 

this 2 things must be tested and assessed independently of each other, even if both are related to each other.

[AstonMartinDBS]

8 hours ago, Hobel said:

this 2 things must be tested and assessed independently of each other

Should I create a new thread for the TGP offset issue?

[Moonshine]

maybe its in one of those already:

both of these have something to do with the pod being inaccurate 

 

 

[Hobel]

 

vor 4 Stunden schrieb AstonMartinDBS:

Should I create a new thread for the TGP offset issue?

I would have said this is more about the Tgp offset, because the thread creator points out the difference in the first post.

[AstonMartinDBS]

7 hours ago, Hobel said:

I would have said this is more about the Tgp offset, because the thread creator points out the difference in the first post.

I've done some further testing. Since the same problem with the TGP offset occurs in the Hornet and in the Hog (A-10C II) as well, it might be a problem with the core.

There's no problem in the Hornet & Hog, see next answer.

Edited January 7, 2023 by AstonMartinDBS

[AstonMartinDBS]

5 hours ago, AstonMartinDBS said:

Since the same problem with the TGP offset occurs in the Hornet and in the Hog (A-10C II) as well, it might be a problem with the core.

I think we've found the source of this issue. There might be a problem by transferring the elevation from the ME to the planes.

Sorry, my bad. By copying the original F-16C to the F/A-18C and A-10C II for testing purposes the original WP elevation of 36 has changed to 136 in the Hornet and Hog - and sadly I didn't double check this on the other planes. There are no issues with the TGP in the Hornet or Warthog.

Edited January 7, 2023 by AstonMartinDBS

[_SteelFalcon_]

the problem seems to be the TGP. if you drop JDAMs on a waypoint (that you place in the ME DIRECTLY on  a tank, ground level) it hits. but if you use the pod, area track on the waypoint without slewing the pod at all, it misses by quite a bit, despite the target being in the exact same place. Even worse if you CZ the pod before the drop.

and same goes for MK 84. if you CCRP on the steerpoint without the pod, it drops within 5m of the target. if you use the pod to designate the target, it misses by quite a bit.

[Moonshine]

in todays patch it was listed that the JDAM now have the correct 5m CEP.

while this might be true, they all still fall short of the designated target in all cases, and on top of that they have a 5m CEP.
so while that CEP is correct, why does a bomb not fall 5m long or left/right? in the attached tracks you can see the aiming point from my TGP, and the impact point afterwards. this looks like way more than 5m.

the measured distance from the desired impact point to the true impact point is around 30ft which in my books is closer to 10m than to 5. tested in Point track and area track

JDAM_inaccurate.trk JDAM_inaccurate_2.trk

[BIGNEWY]

we are aware and more tweaks are coming

thanks

[codyj007]

I am noticing at that with gbu-38s,ONLY in the F16, that they are falling short of target. I believe to have followed the correct procedure to drop this weapon and to create a valid point with my TGP. I have had no issue with the accuracy of the gbu-38 in the F18 and they are pinpoint accurate to the crosshair.

1.Master Arm 2. Power ON JDAM 3. When JDAM is ready, point track a ground target 4. Pickle JDAM when in parameters.

That sequence is similar to some online tutorials i've seen.

 

dcs.log TNN_release-2.0.63-20230131-162122.trk

[VarZat]

I believe that the JDAMs are quite inaccurate right now, which is probably the issue.

[MagicALCN]

Title speaks for itself, I'm trying to use the JDAMs but it never hits. Coordinates are good.
F-16 alignement is also good, INS NORM, hit enter on LAT and LONG, back to NAV when at 10.

Mission is in 2016, US faction. On Persian Gulf Singleplayer and Multiplayer

Gif linked of what is happening during the alignement (It's sped up ofc).

I tried PRE and VIS using the TGP, always missing by a huge margin.

 

Edited March 7, 2023 by MagicALCN

[BIGNEWY]

Please add a short as possible track replay example showing the issue. 

Please ensure you confirm your start position during a cold start in the DED. 

thanks

 

[Moonshine]

@BIGNEWYnot again, all needed evidence is here, there are also links to other threads that include trackfiles related to the JDAM accuracy error, the TGP inaccuracies etc.

 

 

Edited March 7, 2023 by Moonshine

[BIGNEWY]

I'm aware of those reports, I could easily dismiss this report as the same but its always best to check with a track replay if a new report is made, then I know to merge them or not as already reported. 

thank you

[MagicALCN]

1 hour ago, BIGNEWY said:

Please add a short as possible track replay example showing the issue. 

Please ensure you confirm your start position during a cold start in the DED. 

thanks

 

Here's a track file, from cold start to JDAM hitting the ground. The alignment stops at A04, and the bombs seems to have hit 10m-20m off the target even tho the actual point made by the TGP was ahead of the target so at the total opposite of where the bomb hit.

Jdam-problem.trk

[BIGNEWY]

thank you I will check it