investigating Maverick BGST & JDAM PPT Still broken post patch.

[Shibiswag]

Wanted to see if the JDAMS worked, not to my surprise they do not.
Bombs are still falling way past target for PPT attacks.
Idk why ED is focused more on "Cosmetics" then actually fixing bugs for the 16.
We don't need a pilot model, we need the systems to be functional.
This has been a bug for what the past couple of months now, said it was being worked on internally and fix would be in "Next Update"
Well it's the next update and they are still broken.
Same with the Mavricks BSGT still broken.

So now how long are we going to have to wait for these to be fixed? Another 2-3 months?
Was actually hoping to hop back in the 16 after all this time, but I guess Ill just shelf it until it's fixed.
No sense in using a plane where the primary purposes that I love to use it for don't even work.

 

JDAMMissing.trk MavBSGT.trk

[Lord Vader]

Regarding JDAM, it has been stated previously that with Pre Planned targets it is expected the bomb accumulate INS errors introduced by the aircraft's MMC. For that reason, at least until we refine the weapon self guidance features (WIP), you are required to acquire targets with on board sensors (FCR, TGP, HUD) to guarantee a precise hit. 

As for the Mavericks, I will take a look at your track and will address it if necessary.

[BIGNEWY]

7 hours ago, Shibiswag said:

Wanted to see if the JDAMS worked, not to my surprise they do not.
Bombs are still falling way past target for PPT attacks.
Idk why ED is focused more on "Cosmetics" then actually fixing bugs for the 16.
We don't need a pilot model, we need the systems to be functional.
This has been a bug for what the past couple of months now, said it was being worked on internally and fix would be in "Next Update"
Well it's the next update and they are still broken.
Same with the Mavricks BSGT still broken.

So now how long are we going to have to wait for these to be fixed? Another 2-3 months?
Was actually hoping to hop back in the 16 after all this time, but I guess Ill just shelf it until it's fixed.
No sense in using a plane where the primary purposes that I love to use it for don't even work.

 

JDAMMissing.trk 8.28 MB · 3 downloads MavBSGT.trk 11.41 MB · 5 downloads

Hi, 

Just to touch on some of your points, first please don't turn this thread into a discussion of product management and dev time, it helps no one when reporting issues. Artist's don't fix bugs, Devs work on code and you can see they have been from our change logs.    

Again please do not derail this report, if you wish to please PM me. 

thank you

[Moonshine]

so bottom line (despite it working previously) it now requires direct line of sight, bomb on coordinates is no longer valid as unless you try to hit a massive building, you wont hit anything. sad to see it changed that way and stays that way until its refined. hope it wont take months until that. its a rather core part of using those weapons in adverse weather conditions with no LOS

[Lord Vader]

Hello again @Shibiswag

I've reviewed your track with the AGM-65D Maverick and saw that you are attempting to boresight the missiles establishing targets closer than desired for a proper alignment. As previously stated several times, boreshighting these missiles should be above 3nm (at least) to guarantee there is no introduction of parallax errors. There will never be an engagement of an AGM-65 at the distances you performed on you track. The best advice is to boresight the missiles mid-air, enroute to the mission area, guaranteeding proper ranges.

Regarding the previous error that was corrected, it had to do with an improper alignment mid air and completely offset from the intended alignment. That has been fixed in this newest DCS version as you say by being able to observe on your track. 

If you still feel this is a bug, let me know what I missed. 

 

[Shibiswag]

6 hours ago, BIGNEWY said:

Hi, 

Just to touch on some of your points, first please don't turn this thread into a discussion of product management and dev time, it helps no one when reporting issues. Artist's don't fix bugs, Devs work on code and you can see they have been from our change logs.    

Again please do not derail this report, if you wish to please PM me. 

thank you

apologies BIGNEWY.
I wrote this out of frustration which I realize was in error on my part.
It will not happen again, if you want, I will delete this post/topic.

6 hours ago, Moonshine said:

so bottom line (despite it working previously) it now requires direct line of sight, bomb on coordinates is no longer valid as unless you try to hit a massive building, you wont hit anything. sad to see it changed that way and stays that way until its refined. hope it wont take months until that. its a rather core part of using those weapons in adverse weather conditions with no LOS

yeah, I can directly hit targets just fine with the 18 and 15E JDAMS fall right where they are supposed to.
Just not with the 16.
So I don't understand how it can work for some but not others.
I'm going to try another test and input coordinates just shy of the target and see if that will result in a hit.
The Strike eagle uses the 00.00.000 format as well in terms of GPS, so I can hit those same 4 targets dead on with the 15E in my mission.
Yet with the 16 that uses the same 00.00.000 format bombs always fall past the target.
So it has to be a bug with the INS somewhere still.

[Shibiswag]

6 hours ago, Lord Vader said:

Regarding JDAM, it has been stated previously that with Pre Planned targets it is expected the bomb accumulate INS errors introduced by the aircraft's MMC. For that reason, at least until we refine the weapon self guidance features (WIP), you are required to acquire targets with on board sensors (FCR, TGP, HUD) to guarantee a precise hit. 

As for the Mavericks, I will take a look at your track and will address it if necessary.

Thank you.

5 hours ago, Lord Vader said:

Hello again @Shibiswag

I've reviewed your track with the AGM-65D Maverick and saw that you are attempting to boresight the missiles establishing targets closer than desired for a proper alignment. As previously stated several times, boreshighting these missiles should be above 3nm (at least) to guarantee there is no introduction of parallax errors. There will never be an engagement of an AGM-65 at the distances you performed on you track. The best advice is to boresight the missiles mid-air, enroute to the mission area, guaranteeding proper ranges.

Regarding the previous error that was corrected, it had to do with an improper alignment mid air and completely offset from the intended alignment. That has been fixed in this newest DCS version as you say by being able to observe on your track. 

If you still feel this is a bug, let me know what I missed. 

 

okay thank you, I will try in an flight allignment for the mavricks.
Also thank you for you're response for the JDAMs, though in question, The JDAM "Miss" only seems to be in the Viper.
I have played that same mission with both the Strike Eagle as well as the Hornet.
Both planes hit all 4 targets with PPSPT dead on.
So this has to be limited to the 16 especially since the 15E uses the same 00.00.000 GPS format as the 16.

[Shibiswag]

On 5/24/2024 at 3:17 AM, Lord Vader said:

Hello again @Shibiswag

I've reviewed your track with the AGM-65D Maverick and saw that you are attempting to boresight the missiles establishing targets closer than desired for a proper alignment. As previously stated several times, boreshighting these missiles should be above 3nm (at least) to guarantee there is no introduction of parallax errors. There will never be an engagement of an AGM-65 at the distances you performed on you track. The best advice is to boresight the missiles mid-air, enroute to the mission area, guaranteeding proper ranges.

Regarding the previous error that was corrected, it had to do with an improper alignment mid air and completely offset from the intended alignment. That has been fixed in this newest DCS version as you say by being able to observe on your track. 

If you still feel this is a bug, let me know what I missed. 

 

attempted bsgt from the air, still did not work.
Mavericks are still offset and Auto TGP handoff will not autolock due to the maverick being offset.
Please let me know if I am doing anything in error.

MavBSGT-1.trk

[Lord Vader]

Hi @Shibiswag

You are attempting boresighting in very hasty situations, resulting in an imprecise alignment. Here are a few tips:

• Choose target areas between 3 to 4 nm for boresight alignment, stabilize the plane.
• Don't pick large buildings or low contrast objects as targets to boresight. Try to pick vehicles or other high contrast objects, even stationary scenery cars can be used.
• Use the TGP zoom as well as FOV feature to get the most precise target zone to boresight.

However, in your track you're trying to re-boresight a hot airplane. Even though it's rearmed, this is a hot started plane and since the last update we've added an "auto-alignment" feature in DCS for Hot started planes. See here in the changelog:

• Added Maverick and HMCS Auto-Boresight, automatic for hot starts. Cold starts require manual boresight.

As you can see, you're trying to boresight align and already aligned plane. So I picked this mission of yours, edited it with a cold start plane and applied the tips above. The result is a good alignment on both stations and a good handover. Here's the track: MavBSGT-correct.trk

Hope this helps you and others struggling with this feature.

[Shibiswag]

4 hours ago, Lord Vader said:

Hi @Shibiswag

You are attempting boresighting in very hasty situations, resulting in an imprecise alignment. Here are a few tips:

• Choose target areas between 3 to 4 nm for boresight alignment, stabilize the plane.
• Don't pick large buildings or low contrast objects as targets to boresight. Try to pick vehicles or other high contrast objects, even stationary scenery cars can be used.
• Use the TGP zoom as well as FOV feature to get the most precise target zone to boresight.

However, in your track you're trying to re-boresight a hot airplane. Even though it's rearmed, this is a hot started plane and since the last update we've added an "auto-alignment" feature in DCS for Hot started planes. See here in the changelog:

• Added Maverick and HMCS Auto-Boresight, automatic for hot starts. Cold starts require manual boresight.

As you can see, you're trying to boresight align and already aligned plane. So I picked this mission of yours, edited it with a cold start plane and applied the tips above. The result is a good alignment on both stations and a good handover. Here's the track: MavBSGT-correct.trk

Hope this helps you and others struggling with this feature.

Actually, I have tested that. regarding the hot start auto-boresight.
It only seems to work if the plane is pre-loaded in the mission editor, then yes, the mavericks are bore sighted correctly.
Though not in the track file that with just a hot start and arming the plane, the mavericks are not automatically bore sighted and are still slewed off and not matching the TGP.

[Strannix]

On 5/24/2024 at 11:29 AM, Lord Vader said:

Regarding JDAM, it has been stated previously that with Pre Planned targets it is expected the bomb accumulate INS errors introduced by the aircraft's MMC. For that reason, at least until we refine the weapon self guidance features (WIP), you are required to acquire targets with on board sensors (FCR, TGP, HUD) to guarantee a precise hit. 

As for the Mavericks, I will take a look at your track and will address it if necessary.

Hi, Why the bomb is accumulate INS error from the aircraft MMC. In preplanned mode the coordinate entered in the bomb are far the most accurate because they are coming from the editor. The JDAM has his own guidance that's completely independent from the aircraft INS, so why it's affect the accuracy of the bomb?
INS of the aircraft is used for coordinate extraction with a TGP or FCR/HUD, and in that case you will have bad location if your INS has drift at the opposite of the preplanned grid that have been generated preflight.   

[Sinclair_76]

15 hours ago, Strannix said:

Hi, Why the bomb is accumulate INS error from the aircraft MMC. In preplanned mode the coordinate entered in the bomb are far the most accurate because they are coming from the editor. The JDAM has his own guidance that's completely independent from the aircraft INS, so why it's affect the accuracy of the bomb?
INS of the aircraft is used for coordinate extraction with a TGP or FCR/HUD, and in that case you will have bad location if your INS has drift at the opposite of the preplanned grid that have been generated preflight.   

It's because the JDAM GPS can't get a good/sustained fix below the wing. So before the release coordinates are transferred as a starting point. After release the JDAM needs 28 seconds before the error is identified. Then depending on the sub-mode it rejects the error or implements is as a bias.

 

 

Edited June 1, 2024 by Sinclair_76

[Strannix]

44 minutes ago, Sinclair_76 said:

It's because the JDAM GPS can't get a good/sustained fix below the wing. So before the release coordinates are transferred as a starting point. After release the JDAM needs 28 seconds before the error is identified. Then depending on the sub-mode it rejects the error or implements is as a bias.

 

 

 

28 sec to fix error? The thing i'm trying to highlight is the non sense of the advise to use inboard sensors instead of pre planned coordinates. Pre planned coordinate will never change because they are generate from high accuracy geographical imagery and loaded in aircraft with DTC. In DCS it's done by create WPT in the editor.
For exemple with a TGP if you try to extract grid from a target with INS drift, you will accumulate error from your own location + TGP capacity (TLE cat) and in this manner you can't have better coordinate.
To sum up, if with got errors in pre planned from own INS, it must be worth with inboard sensors.  

[Hobel]

vor 16 Minuten schrieb Strannix:

28 sec to fix error? The thing i'm trying to highlight is the non sense of the advise to use inboard sensors instead of pre planned coordinates. Pre planned coordinate will never change because they are generate from high accuracy geographical imagery and loaded in aircraft with DTC. In DCS it's done by create WPT in the editor.
For exemple with a TGP if you try to extract grid from a target with INS drift, you will accumulate error from your own location + TGP capacity (TLE cat) and in this manner you can't have better coordinate.
To sum up, if with got errors in pre planned from own INS, it must be worth with inboard sensors.  

As far as I understand it, this part is still WIP.  This means that the GPS bomb will land exactly on its PP coordinates in the future.   No matter if the f16 drifts 10-30m inaccurately.  

However, I wonder how TGP designations will work in the future if the f16 always has 10-30m drift, if you then make an exact designation on the target you give the bomb the drift of the f16 with + the bombs ~5m cep.

Does this depend on the sub mode?

[Strannix]

2 minutes ago, Hobel said:

As far as I understand it, this part is still WIP.  This means that the GPS bomb will land exactly on its PP coordinates in the future.   No matter if the f16 drifts 10-30m inaccurately.  

However, I wonder how TGP designations will work in the future if the f16 always has 10-30m drift, if you then make an exact designation on the target you give the bomb the drift of the f16 with + the bombs ~5m cep.

Does this depend on the sub mode?

With JDAM, it's not designation, you're extracting coordinate and put this into the bomb navigation unit. So you've got few meters error from your own INS/GPS, the TGP will use his LRF for ranging (few more meters of errors). So you've got more errors accumulation with TGP than using high accuracy coordinate from specific imagery. Keep in mind that the farthest your are from the target, you will put more errors from the TGP, it's an angular thing.
IRL there is targeting cel to prepare coordinate for preplanned strike. If using fighter aircraft sensors would be better, we will use them instead of.

CEP are not simulated in DCS.

I'm IRL JTAC so we've got same trouble has aircraft to extract good grids. A TGP his not accurate has you thing to give you good grids that you can fill inside a JDAM especially the one we've got in DCS (LITENING II).

[Hobel]

vor 7 Minuten schrieb Strannix:

CEP are not simulated in DCS.

Can you be more specific?

[Strannix]

13 minutes ago, Hobel said:

Can you be more specific?

From my test with GBU 38 every time my impact were long from the target instead of be around and respecting CEP pattern. I don't even talk about Vertical Error who has been more important for GPS weapons. My last tests from yesterday just show that JDAM doesn't even use elevation of waypoint and still can succeed to hit the target... My TGT elevation was 443ft and i tried 443, 2000ft and 5000ft and it was no difference in the POI.
Another exemple is the PWY 2 bombs who are able to pinpoint the TGT every time but even an LGB has CEP and it's not 1 meter.
From public sources and my own IRL experience the good CEP characteristics i found:
-GBU 38 with only INS is 30m and with INS/GPS is 13m
-PWY II is 6m

To much people things that a guided bomb GPS or laser one is a magic thing who always pinpoint and in DCS do to the fact that military effects of ammunitions are completely out of something realistic they need to ask for something not good like a GBU 38 who have a CEP of 2m.   

[Hobel]

vor 38 Minuten schrieb Strannix:

From my test with GBU 38 every time my impact were long from the target instead of be around and respecting CEP pattern. I don't even talk about Vertical Error who has been more important for GPS weapons. My last tests from yesterday just show that JDAM doesn't even use elevation of waypoint and still can succeed to hit the target... My TGT elevation was 443ft and i tried 443, 2000ft and 5000ft and it was no difference in the POI.
Another exemple is the PWY 2 bombs who are able to pinpoint the TGT every time but even an LGB has CEP and it's not 1 meter.
From public sources and my own IRL experience the good CEP characteristics i found:
-GBU 38 with only INS is 30m and with INS/GPS is 13m
-PWY II is 6m

To much people things that a guided bomb GPS or laser one is a magic thing who always pinpoint and in DCS do to the fact that military effects of ammunitions are completely out of something realistic they need to ask for something not good like a GBU 38 who have a CEP of 2m.   

What you describe is what I mean, the "too long" comes from the jet(in dcs) , the bomb lands around the actual coordinate in a cep that pretty much matches your experience "~13m"  

Also altitude actually plays an important role in dcs.

 

 

For example, everything around the center.

GBU38

Edited June 1, 2024 by Hobel

[Strannix]

35 minutes ago, Hobel said:

What you describe is what I mean, the "too long" comes from the jet, the bomb lands around the actual coordinate in a cep that pretty much matches your experience "~13m"  

Also altitude actually plays an important role in dcs.

 

 

For example, everything around the center.

GBU38

So it's just take the best CEP because that must be more spread. A given CEP is for 50% of impact inside the radius but i understood the problem coming from the jet.
And tested again, elevation don't do anything on the impact point for jdam. I put 2000ft elevation on 443ft TGT and it was direct hit. Because in the editor i can't put elevation below the ground, i did it inside the aircraft with 0ft and still hitting the TGT instead of hitting short for a big offset. 

[Hobel]

vor 5 Minuten schrieb Strannix:

elevation don't do anything on the impact point for jdam. I put 2000ft elevation on 443ft TGT and it was direct hit.

Hm ok will have a look.

I'll come back to this later.  

Can you send me a track of it so I can see your procedure?

[Strannix]

14 minutes ago, Hobel said:

Hm ok will have a look.

I'll come back to this later.  

Can you send me a track of it so I can see your procedure?

Here it is. already try the same with A10C.
Cheers guys, I dont want to be boring but i'm really concerne about the refine of ammunitions effects and i hope it will be taking seriously by ED. So CEP is a less problem than damage modeling.
Thx

jdam elevation trouble.trk

[Hobel]

vor 16 Stunden schrieb Strannix:

Here it is. already try the same with A10C.
Cheers guys, I dont want to be boring but i'm really concerne about the refine of ammunitions effects and i hope it will be taking seriously by ED. So CEP is a less problem than damage modeling.
Thx

jdam elevation trouble.trk 1.19 MB · 1 Download

You're right, somehow altitude has no influence, the bomb hits the target.

 

[Shibiswag]

On 5/31/2024 at 2:27 AM, Lord Vader said:

Hi @Shibiswag

You are attempting boresighting in very hasty situations, resulting in an imprecise alignment. Here are a few tips:

• Choose target areas between 3 to 4 nm for boresight alignment, stabilize the plane.
• Don't pick large buildings or low contrast objects as targets to boresight. Try to pick vehicles or other high contrast objects, even stationary scenery cars can be used.
• Use the TGP zoom as well as FOV feature to get the most precise target zone to boresight.

However, in your track you're trying to re-boresight a hot airplane. Even though it's rearmed, this is a hot started plane and since the last update we've added an "auto-alignment" feature in DCS for Hot started planes. See here in the changelog:

• Added Maverick and HMCS Auto-Boresight, automatic for hot starts. Cold starts require manual boresight.

As you can see, you're trying to boresight align and already aligned plane. So I picked this mission of yours, edited it with a cold start plane and applied the tips above. The result is a good alignment on both stations and a good handover. Here's the track: MavBSGT-correct.trk

Hope this helps you and others struggling with this feature.

 

@Lord Vader
Please see new track file I have attached regarding my previous statement regarding despite hot start, manual re-arming of mavricks are not BSGT from hot start.
This is from a hot start - loaded Mav's on the ground via ground crew rearming, not in mission editor.
I have done no attempt to BSGT in game as I did in the previous statement, as you can see targets are even 70+ miles away.
When I near the target area you can clearly see the Mavrick seaker is not BSGT to the target pard and is slewed off to the right of the target.
Only time Mavricks are actually BSGT to the TGP is as I previously stated only done when plane is loaded via mission editor onto a hot start, then yes they are BSGT and work correctly.

MavBSGT-2.trk

[Strannix]

@HobelHi, will you forward the elevation issue with the JDAMs to the dev team or i need to create a new thread?

[Swift.]

On 6/1/2024 at 2:48 PM, Strannix said:

With JDAM, it's not designation, you're extracting coordinate and put this into the bomb navigation unit. So you've got few meters error from your own INS/GPS, the TGP will use his LRF for ranging (few more meters of errors). So you've got more errors accumulation with TGP than using high accuracy coordinate from specific imagery. Keep in mind that the farthest your are from the target, you will put more errors from the TGP, it's an angular thing.
IRL there is targeting cel to prepare coordinate for preplanned strike. If using fighter aircraft sensors would be better, we will use them instead of.

CEP are not simulated in DCS.

I'm IRL JTAC so we've got same trouble has aircraft to extract good grids. A TGP his not accurate has you thing to give you good grids that you can fill inside a JDAM especially the one we've got in DCS (LITENING II).

With JDAM, you have to remember that Absolute targeting and Relative targeting are a thing.

Absolute being what you describe where you program known coordinates into the bomb and it will fly to those exact coordinates as best it can (ie using the alignment transfer from the jet until it can get its own GPS fix, where it will correct any offset).

Relative is what we have in DCS, where you use an aircraft sensor to generate coordinates to feed the bomb. The bomb will then in effect fly to that location (relative to the aircraft, hence the name). And wont correct any offset at GPS, but will maintain it (ie not allowing any more drift).

 

They are both 'correct' and both have their uses. We are just missing the Absolute mode from DCS currently, so we experience the pain of having the INS errors carrying over the alignment transfer and causing issues on preplanned coordinates.

 

In viper the mechanization should be Relative when CZ is shown (ie cursor slew has been applied), and Absolute when CZ is removed (ie no cursor slew).