J-dam bomb misses laser designated targets

[Ramstein]

J-dam bomb misses (LGB) laser designated targets. When I use the laser to paint a target, building or vehicle, most often, the bomb totally misses the target... why? Also, once you paint a target, doesn't the J-dam variety stay on target even if you move away with the aicraft? Mayybe other laser guided need a constant laser lock from your aircraft to hit target, forcing you to hold pickle until hit is finished? I am confused why most often my bombs miss bt a large distance, say hundreds of feet...

 

I try to lase and drop from at least 15,000 feet...

 

thnx..

:joystick:

Edited February 6, 2012 by Ramstein
clear up confusion between lgb and laser guided

[Ghanja]

JDAMs don't need a laser to find their target. You only need to lase the target to get the exact distance and coordinates (you don't have to but it helps). Are you sure you are creating a valid SPI for the JDAM to hit?

[MTFDarkEagle]

What type of bomb? GBU-1X or GBU-3X? Like above the GBU-3X (I.e. JDAM) does NOT need laser. If you are indeed using GBU-1X: At what time are you lasing?

[Depth]

The bomb leaves the aircraft in an arc, carrying its momentum forward until it starts dropping. If the laser is active before the bomb is out of this first glide it'll try to "cut a corner" and take a path straight to the target by entering a very steep angle. As it doesn't have wings it'll start dropping faster than it's going forward untill it stalls and falls short.

 

There was a very good picture illustrating this floating around a while back but I can't find it. If you don't get the idea I can make a new one but I'm limited to Paint so it wouldn't even be medium quality :P

[Ramstein]

What type of bomb? GBU-1X or GBU-3X? Like above the GBU-3X (I.e. JDAM) does NOT need laser. If you are indeed using GBU-1X: At what time are you lasing?

 

what time am I lasing? I thought when you lock the target you can hit the insert key which set the laser for some countdown, on how much time it lases.. whatever default it.. so when you approach, say the countdown starts at 10.... and you start at 6... wouldn't that be ok? I just don't understand what the minimum distances are and times to hit soem buttons, I though there was a window wher is says maually drop and you pickle, holding it in manual mode.. auto mode hasn't worked for me either, but i thought I would save that for later.. when I did more reading about it..

 

If you pick a target, choose a bomb, lock the target with the crosshairs, and then hit 'Ctrl+up' = Lock slected target, whatever it's called when the crosshairs have have locked on and have a square... then it says maual drop on the left side of the hud.. there is also a countdown... to '0' then back up in negative numbers as you pass the target..

 

either way, I thought it locked the coordinate, and any bomb with eithe rlaser or gpu type of guidance would just stay locked on the target locked by your crosshairs..

 

I also saw the laser timing adjustmnet in the profile..... so I tried to mess with that and set it so the laser would stay on longer.. but it didn't help.

 

Yes, I am talking about at least two different types of bombs and guidanve systems, laser and gpu, but both of them confuse me on why they miss...

 

I guess I have to go back and read some stuff...

 

Maybe soemone can either explain it clearly for my burned out brain or point me to the right manual? Maybe a video for training too?

 

thanx..

:joystick:

Edited February 5, 2012 by Ramstein

[159th_Viper]

If you post a track we'll be able to tell you what's wrong.

[kylania]

Here's a video I made a while ago that shows how to configure and drop a GBU-12 laser guided bomb and a GBU-38 JDAM.

 

[Ramstein]

This sounds very convoluted. Personally I like using Auto Lase, but even manual Lase works fine. You should be flying straight level towards your target and the laser should fire around 10 seconds before it hits the target. If you last it too soon or too late the bomb may under or over shoot your target.

 

You want to see how easy it can be to fire a GBU-12, select one of the DSMS, click Profile, change from CCIP to CCRP, hit the CHG SET button, turn auto lase on, set the time to 10, save, find a target, set your SPI, fly straight and level, release weapon ease off target gently, watch it get obliterated...

 

your bombs should never appear to be trying to cut corners. That just sounds like you're dropping them like a crazy person, and I would expect routine misses to be normal.

 

 

That'as what I wanted to hear, the 'set the lase to 10', maybe that's my problem then...

 

In the past I never added a number, or changed it, or I made the number wrong... so I wil try '10' and see if that fixes it.. and btw, I setup targets froma long distance, but that didn't help. and I have tried to wait a minute, make a you turn and line up again... or just went on to the next target,, I just needed or need answers that make sense that all...

 

now it sounds really simple and I missed some very easy step..

 

 

thanx..

:joystick:

Edited February 6, 2012 by Ramstein

[FreeFall]

And after releasing the bomb, be sure to maneuver your aircraft so that the target will be lased unobstructedly.

[Ghanja]

I still find the topic title a little bit "irritating" since it actually discusses issues with a LGB. In the sim that would be GBU-10 and GBU-12.

A JDAM or IAM does not use a laser to strike a designated target - it uses an inertial guidance system (and also a GPS system) to destroy targets. In the sim that would be GBU-31 and GBU-38.

I don't want to pe picky - just wanted to clear things up ... :)

As far as using the auto-lase feature I have had the best results using time periods around 13 seconds.

[Ramstein]

I still find the topic title a little bit "irritating" since it actually discusses issues with a LGB. In the sim that would be GBU-10 and GBU-12.

A JDAM or IAM does not use a laser to strike a designated target - it uses an inertial guidance system (and also a GPS system) to destroy targets. In the sim that would be GBU-31 and GBU-38.

I don't want to pe picky - just wanted to clear things up ... :)

As far as using the auto-lase feature I have had the best results using time periods around 13 seconds.

 

I will try to correct the wording.. sorry, but they all seem to involved some laser when locking on a target and dropping these.

[Jona33]

Using all bombs you lase the target beforehand to get an accurate drop.

Using a GBU-10/12 you use a laser to guide the bomb to the target.

Using a GBU-31/38 you drop the bomb and then you can break off, do whatever/get drunk. :P

[MagnumHB]

Strictly speaking, it is not necessary to use the laser when dropping GBU-38/31, although it can increase accuracy in certain situations.

[Tailgate]

How long do you leave the laser on to get the slant range? In RL, I would assume you don't want it lasing for very long if you don't need it for JDAMS. It's also probably the reason for the 8 to 10 second autolase value for LGB's.

[kylania]

To get range I lase for 2 seconds or so, basically one long hold of the NWS button.

 

The reason for the 8-10s autolase is to retain energy for the bomb to correct itself. An average drop seems to be 20-30 seconds or so of fall time so if you start to try to maneuver the bomb from the start of that it'll use up it's energy and drop short. So you only lase for the last few seconds off the drop.

[Ramstein]

To get range I lase for 2 seconds or so, basically one long hold of the NWS button.

 

The reason for the 8-10s autolase is to retain energy for the bomb to correct itself. An average drop seems to be 20-30 seconds or so of fall time so if you start to try to maneuver the bomb from the start of that it'll use up it's energy and drop short. So you only lase for the last few seconds off the drop.

 

see, these are the type of posts that help point me in the right direction..

I have no excuse for my dead brain cells, I am just trying to enjoy what's left..

:doh:

[Speed]

so if you start to try to maneuver the bomb from the start of that it'll use up it's energy and drop short. So you only lase for the last few seconds off the drop.

 

This is incorrect, at least in DCS for the A-10. You can lase right from the moment the bomb is dropped, and it will never miss due to you lasing too early.

 

This might hold true for aircraft that fly faster, in theory, but the A-10 flies slow. Since a bomb dropped from the A-10 starts with such a low initial velocity, it is falling more-or-less straight down by the time it gets its nose down far enough to even see the laser. So this concern about "don't lase too early" is irrelevant in DCS: Warthog. Save it for when we get DCS: Strike Fighter. Quite often, this false concern about not lasing too early makes people miss moving targets they would have hit if they had just lased the target from the time that the bomb was released.

 

So go ahead, lase from the time the bomb leaves the rack. The one side effect (perhaps) is that since you are a little bit less efficient, your bomb flies just a little bit slower, and the countdown timer (time to impact) will hit zero about 1 second earlier than the bomb impacts... then again, I may see this happen with JDAMs too, so maybe this is a slight bug in the game.

Edited February 7, 2012 by Speed

[S77th-konkussion]

Seems to be the most relevant thread. Is there a new step modeled for engagement w/ LGB's?(12's) ? I am following the same procedure that I used to (worked every time) But now- Nuttin. Not hitting a thing 100% of the time. Lased at 12 seconds, lased at 25 seconds.. always from angels 9 or higher.. Perfectly stable and level.. perfect alignment of HUD reticles... bombs release right on time... everything seems OK- except it totally misses.

 

I've been away for a while- and I don't see anything "ah-HA" on the forum... Need to set laser code manually or something?

[Nu-NRG]

Seems to be the most relevant thread. Is there a new step modeled for engagement w/ LGB's?(12's) ? I am following the same procedure that I used to (worked every time) But now- Nuttin. Not hitting a thing 100% of the time. Lased at 12 seconds, lased at 25 seconds.. always from angels 9 or higher.. Perfectly stable and level.. perfect alignment of HUD reticles... bombs release right on time... everything seems OK- except it totally misses.

 

I've been away for a while- and I don't see anything "ah-HA" on the forum... Need to set laser code manually or something?

Few things that come to mind:

Laser missmatch but you would get that as warning ...

Laser is on?

Did laser fire? Latch on/off, manual lase, auto lase?

 

To be totally honest, mine went after the laser 100%

[S77th-konkussion]

Yes on all counts. No warnings displayed- as in mismatch. I'll post a track.

[S77th-konkussion]

:doh: It was the LATCH setting. Move along people ...nothing to see here...

 

(I swear the latch was ON by default previously)

[WildBillKelsoe]

JDAMS are GPS/INS guided. Just set your SPI to TGP, designate tgt using TMS fwd long, and release, laser off..

 

LGB's on da otter hand need lazzerrr...

[Harzach]

This is incorrect, at least in DCS for the A-10. You can lase right from the moment the bomb is dropped, and it will never miss due to you lasing too early.

 

This might hold true for aircraft that fly faster, in theory, but the A-10 flies slow. Since a bomb dropped from the A-10 starts with such a low initial velocity, it is falling more-or-less straight down by the time it gets its nose down far enough to even see the laser. So this concern about "don't lase too early" is irrelevant in DCS: Warthog. Save it for when we get DCS: Strike Fighter.

 

I know this is an old post, but are you suggesting that munitions with higher initial energy will lose all of that energy faster than munitions with lower initial energy? That doesn't really make any sense.

[lubey]

I think he's saying that the munitions with higher initial energy will be dropped earlier/further out by the aircraft in order to hit the same target with a ballistic trajectory. So they also have more distance to cover using their energy.

[Arclight]

The problem is the amount of time the bomb is actively guiding.

 

Dropped from an A-10 at relatively low speed it takes a while for the bomb to tip over far enough for the seeker to actually "see" the laser reflection. Even if the target is designated from launch, the seeker will not pick up the target untill somewhere in the last half of the bomb's flight, so the time spend actively guiding is short.

 

Dropping at higher speed, the seeker can "see" the target much earlier. The bomb would spend most of its flight actively guiding, thereby bleeding a lot of energy (bang-bang guidance is rather ineffecient).