Jump to content

Recommended Posts

Hi guys,

I am sorry to bother you, but I really don´t understand why my JDAMs are so inaccurate. They work perfect at the other platforms (Hornet, A10, AV8B,...), but I am not able to hit anything via F16. I am trying different methods, lasing the target prior making Markpoint for better accuracy, via Markpoints, or steerpoints (for multi targets), in PRE mode. I tried to drop all JDAMs at the one location, but all four went to different places (as seen on the attached video). Sometimes they hit, but it´s like 1 drop from 15. What I am doing wrong. Thank you for your help.


 

MSI Z370 GAMING PLUS, i5 8600K, MSI GTX 1080 GamingX, 16 GB DDR4 3000MHz, 500 GB M2 SSD, 1 TB SSD

Link to comment
Share on other sites

It would help to see your SMS page to verify the alignment quality of the JDAM. You want an "A01" alignment quality figure. And yes, CZ but the fact that TGP is slaved directly at the target suggests that's not an issue. Also he did lase during the mark point so that's not an issue. You can simply compare the TGP displayed coordinates (or the mark DED page) against the target actual coordinates. Nor would a targeting error cause a large dispersion.

But when testing it's best to eliminate as many extraneous variables as possible. Why include TGP, marks, etc. when testing if a weapon is accurate or not? I just put a waypoint at the target and delivered bombs against the waypoint. No extra sensors, no marks, no cold start, no alignments.

From 26,000' M0.9 heart of the LAR delivered 4x GBU-38 rapid fire against the Senaki TACAN antenna. Bomb craters (small) are the impact locations. The last bomb has yet to explode for scale.

image.png

The TACAN antenna disappeared between the 2nd and 3rd explosions but it was in the middle of the craters shown above. This suggests that under certain conditions 4x JDAM can have very small dispersion, about 3m on average and good accuracy. Why the other bombs were at a higher dispersion and/or lower accuracy would have to be discovered by changing one variable at a time to isolate the cause.

  • Thanks 1
Link to comment
Share on other sites

Guys, when I tick in the Mission editor (MISSION OPTIONS) "Unrestricted SATNAV", JDAM drops are now way more accurate. I didn´t know about this option.

Edit: I was trying to hit two targets at the same time now.

 


Edited by lukynoo92

MSI Z370 GAMING PLUS, i5 8600K, MSI GTX 1080 GamingX, 16 GB DDR4 3000MHz, 500 GB M2 SSD, 1 TB SSD

Link to comment
Share on other sites

JDAMs, despite the common nickname of "GPS weapon" are more accurately "INS weapon with optional GPS assistance". GPS availability is going to improve JDAM accuracy by a significant amount. This comes from two effects: keeping the host platform INS more accurate so transferred alignment is better and allowing the bomb itself to refine its position midflight.

I'm guessing your F-16 was on REDFOR faction which would have either no GPS or reduced-accuracy GPS. The "unrestricted" option would mean that GPS availability isn't restricted based on faction.

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

Mission date is 2016 and playing for a redfor as seen on the video. I agree, that option should be on by default. It brought to me a lot of troubles to solve this problem and find the reason why I cannot drop JDAMs preciselly. 

MSI Z370 GAMING PLUS, i5 8600K, MSI GTX 1080 GamingX, 16 GB DDR4 3000MHz, 500 GB M2 SSD, 1 TB SSD

Link to comment
Share on other sites

  • 1 year later...
On 1/30/2022 at 7:39 PM, Frederf said:

It would help to see your SMS page to verify the alignment quality of the JDAM. You want an "A01" alignment quality figure. And yes, CZ but the fact that TGP is slaved directly at the target suggests that's not an issue. Also he did lase during the mark point so that's not an issue. You can simply compare the TGP displayed coordinates (or the mark DED page) against the target actual coordinates. Nor would a targeting error cause a large dispersion.

But when testing it's best to eliminate as many extraneous variables as possible. Why include TGP, marks, etc. when testing if a weapon is accurate or not? I just put a waypoint at the target and delivered bombs against the waypoint. No extra sensors, no marks, no cold start, no alignments.

From 26,000' M0.9 heart of the LAR delivered 4x GBU-38 rapid fire against the Senaki TACAN antenna. Bomb craters (small) are the impact locations. The last bomb has yet to explode for scale.

image.png

The TACAN antenna disappeared between the 2nd and 3rd explosions but it was in the middle of the craters shown above. This suggests that under certain conditions 4x JDAM can have very small dispersion, about 3m on average and good accuracy. Why the other bombs were at a higher dispersion and/or lower accuracy would have to be discovered by changing one variable at a time to isolate the cause.

Hmm. Seems that CBU-105 goes over with tpod pointtrack even lased pretty much same kind that my JDAM´s do. I would eliminate the tpod for sure if I had targets on the waypoints without searching 🙂  The very basis for me the problem here is, that JDAM´s and CBU-105´s are not dropping where I pointtrack on pre mode (and yes I laze the targets etc.) CBU-105 has a reported bug. Dunno if that has something to do with tpod as my jdams seem to go pretty much either over or under the target. Or has this been solved yet, with JDAM´s. With hornet I really have ZERO problems with em. Even with pretty crazy DLZ situations. (only ofc normal driftting of the tpod.) But with f-16 the drift seems not be the case. BTW: as I am pretty new to f16, compared to many other planes-> Does pointtrack (or areatrack etc) make that point Spi / (or JDAM target in this case), or what was that about pressing the CZ. Does it always want a Spi on waypoint (the Jdam)? But still my prob is that with tpod they are inaccurate, in a way that seems to repeat itself more or not. Have to make a test range without any winds etc, but still big difference to hornet. Is this a reported bug also?

Link to comment
Share on other sites

On 1/23/2024 at 3:11 PM, Wiggo said:

Hmm. Seems that CBU-105 goes over with tpod pointtrack even lased pretty much same kind that my JDAM´s do. I would eliminate the tpod for sure if I had targets on the waypoints without searching 🙂  The very basis for me the problem here is, that JDAM´s and CBU-105´s are not dropping where I pointtrack on pre mode (and yes I laze the targets etc.) CBU-105 has a reported bug. Dunno if that has something to do with tpod as my jdams seem to go pretty much either over or under the target. Or has this been solved yet, with JDAM´s. With hornet I really have ZERO problems with em. Even with pretty crazy DLZ situations. (only ofc normal driftting of the tpod.) But with f-16 the drift seems not be the case. BTW: as I am pretty new to f16, compared to many other planes-> Does pointtrack (or areatrack etc) make that point Spi / (or JDAM target in this case), or what was that about pressing the CZ. Does it always want a Spi on waypoint (the Jdam)? But still my prob is that with tpod they are inaccurate, in a way that seems to repeat itself more or not. Have to make a test range without any winds etc, but still big difference to hornet. Is this a reported bug also?

also keep in mind that you have to point TGP at the bottom of target. depending on slant angle to target you could be getting a SPI that is not on the target. higher the altitude, better the coordinates.

nevermind. in your video you were slewed to the bottom. but i never saw you designate. not sure if that matters. i think it does. how else would the JDAM know to put itself on the target.


Edited by silverdevil
  • Like 1

AKA_SilverDevil AKA Forums My YouTube

“It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt.” — Mark Twain

Link to comment
Share on other sites

On 1/28/2024 at 6:18 PM, silverdevil said:

also keep in mind that you have to point TGP at the bottom of target. depending on slant angle to target you could be getting a SPI that is not on the target. higher the altitude, better the coordinates.

nevermind. in your video you were slewed to the bottom. but i never saw you designate. not sure if that matters. i think it does. how else would the JDAM know to put itself on the target.

 

Ok thanks. (btw, it was not my vid.. ) 🙂 I just joined the conv. as I had pretty much the same prob with few ordinant types. (JDAM, CBU-105 atleast). I have also wondered though, that does the JDAM "program" its target only if i push tpod -> point tranck (TMS up) OR does it update it also from area track? After which press does for example jdam designate itself? Does it always need TMS up (to designate). Or is it always just where the tpod is pointing before the drop? (in f16 ofc) Is there any page i can see in which point the ordinant is programmed (like in hornet the MSN page of JDAM). Would be nice to see in which coords for example it designates itself. It always drops to the SPI, but for example: Is there a way in f-16 i could move the tpod after designating the jdam, before dropping it, without jdam designating itself again? Does the SPI always move where the tpod is lookin? This might sound stupid, but yes I am pretty new to f-16. My english is not very good, hope you get hold on something from my typing 😄


Edited by Wiggo
Link to comment
Share on other sites

On 1/28/2024 at 5:18 PM, silverdevil said:

nevermind. in your video you were slewed to the bottom. but i never saw you designate. not sure if that matters. i think it does. how else would the JDAM know to put itself on the target.

As far as I know in F-16 you don't have to designate, where ever you move your sensor that spot becomes sensor point of interest (SPI) and all your other sensors are slewed there.

As long as you aim for the bottom of the target you are good to go, be sure to lase for 2 or 3 sec prior to releasing JDAM for better accuracy.

  • Thanks 1
Link to comment
Share on other sites

43 minutes ago, Furiz said:

As far as I know in F-16 you don't have to designate, where ever you move your sensor that spot becomes sensor point of interest (SPI) and all your other sensors are slewed there.

As long as you aim for the bottom of the target you are good to go, be sure to lase for 2 or 3 sec prior to releasing JDAM for better accuracy.

Ok thanks! Yeah watched Deephacks short vid "jdam ripple with f-16". Solution for my question is more or less ofc make markspnts  /wpnts of the targets (if want to wobble other stuff before drop etcetc), and then just drop the JDAM´s to wpnts / marks. Yeah..  this can be little confusing ofc after hornet, where the designation system is pretty much different. Designate system i maby like more, but f-16 makes it simple though. (as in many other things too, which ofc is not a bad thing always.. ). Now when I start to get hold of that spi system, everything gets more clear, and also in future more clear in other planes also (a-10, apache etc all use similar spi system etcetc..) After hornet i look many times some way to do things  in f-16, while the solution is REALLY usually much more simpler. 🙂 But yeah. Thanks. 


Edited by Wiggo
Link to comment
Share on other sites

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...