Hey all, I wonder if anyone can help me clear this up. I always seem to be a good twenty yards off with my LGB impacts... any idea why? I originally releasing them as follows:

- No options set up in DSMS, simply selected GBU-12
- TGP Latch ON
- Lase target and set TGP look point as SPI
- Turn off laser
- Ensure HUD is in CCRP mode
- Line up on target, wait for countdown
- Hold down Weapon Release button at the 5 second mark
- Immediately lase again and keep TGP on target

Using this I kept being just a bit off, so I went and did the relevant training mission (one of the few I'd neglected) and did the following:

- DSMS profile page
- AUTO LASE set to ON, 10 seconds from impact
- Save profile
- Set TGP look point as SPI (no lase)
- Ensure HUD is in CCRP mode
- Line up on target, wait for countdown
- Hold down Weapon Release button at the 5 second mark
- No manual lase during fall

With this method I was spot on first time around, but then my second try yielded the same disappointing impact two-dozen or so yards from the practice target. Any ideas where I'm going wrong?

One final note: I originally wondered whether the "flashlight effect" was meaning that my SPI was actually designated some distance behind the target when I didn't lase, but my final attempt last night saw the bomb fall short of the target... I'm a bit stumped!

Thanks all!

Try lasing for 15 sec.

Watch the bomb as it falls. If it wiggles, it's tracking. If it doesn't, it's not.

If it tracks for 5+ seconds and then doesn't hit what the TGP is pointed at then there's something marginal about your delivery like low altitude or something.

If using the laser manualy you should wait a couple of seconds after release to start lasing the target. I use to lase until impact is confirmed by TGP.

(HJ)

In the first test you have the Laser on for the whole drop and that is not recommended. (I just remember that it is not, can't tell you why w/o further research.)

In the second test you did not SPI with the Laser so your elevation is off and it should overshoot.

I will drop and wait for the countdown to reach 13-11 seconds and then manually lase it in to impact.

Another option is to use GBU-38's which are drop and forget, and can be used with multiple Mark Points. I prefer these GBU-38s and -31s when I'm out on my own. The laser GBUs 10s and 12s are great for buddy lasing.


Wrecking Crew

Because the guidance type is bang-bang (yes, that is what it's called), which means the controls are fully deflected to achieve a correction, than a smooth, proportional correction. This wastes energy. In addition, lasing too early may cause the bomb to dive too soon.

What you did not mention was your altitude at release.

From my experience, the LGB needs at least 1,000-2,000 feet of free fall before the "guidance" kicks in and starts bang-bang guidance. Drop from at least 7,000 feet. The flashlight effect is only significant when you are marking targets or making SPI --- ie, IAMs. Since you are dropping LGBs, it does not matter what your SPI is, your bomb will track the laser.

Lastly, make sure you are not masking your TGP -- as noted by the "M" symbol on the TGP display. If you lose your laser, your bomb will miss.

Hope that helps.

Not quite correct. It matters very much what your SPI is, unless of course you drop in CCIP, break away and let your buddy lase for you. For a CCRP drop from altitude you need to designate the targeting coordinates, ie SPI, to ensure that the ordinance drops into the weapons-basket, only then picking up the laser reflection on target.

Yep, you can drop blind CCIP, or have a SPI that is "in the vicinity of the target" and as long as the weapon has enough "energy" (ie height), it can make it to the target. The accuracy of the laser pointer is more important, and that the laser isn't masked.

IAMs however, are very much more reliant on SPI... if your SPI was off by 20 meters, the bomb hits grass and not armor.

The Paveway II "basket" is very large from substantial height. If you lase early enough you can be very sloppy with the delivery. By SPI doesn't matter, it means guidance is not based on SPI. Delivery may be based on SPI, but if the bomb hits just matters laser energy on target and the physical delivery unlike WCMD/JDAM.

IRL there's an delay in activating the guidance package on the MAU. Also the nose seeker is unlikely to have the target in view initially before the bomb rotates. The flashlight effect is not modeled in DCS. Unless terrain blocks LOS, the seeker will see the dot, even on the backside of an object.

I think all of the advice here has helped me understand what I was doing wrong - particularly lasing too soon and wasting course correction energy since, as GrayGhost and Wrecking Crew said, it's "bang-bang" correction (I remember that from the manual now that you've mentioned it). I'll give it a few more tries tonight, making sure I'm at a higher altitude and probably taking GrayGhost's initial advice to auto-lase 15 seconds from impact. Thanks everyone!

I prefer 38's as well really, especially since not having to keep the laser trained makes breaking off easier. Plus, don't modern tanks have sensors and alarms to tell them they're being lased? Not much they could do about it in their last fifteen seconds I guess though

Little something about lasers: http://www.marcorsyscom.usmc.mil/sites/fss/Documents/Presentation/04_LASERTHEORY_Presentation.pdf

I doubt all these effects are modeled into the sim, but it may be interesting to some to understand some of the real-world physics, and the difference between the flashlight effect and the podium effect!

Interesting read, thanks! It never occurred to me that laser energy might diverge so much over range.

Not very useful for moving targets.



That depends ... if they're near cover, and the engine is on, and they realize that it's an airborne attack, they can do a few things. But yeah ... it depends.

They aren't. I doubt there's even beam divergence - basically those effects are not really needed in the sim, but I think if there was an opportunity to do so, they ought to make it happen

Also, similar things are missing from radio and IR simulation. The problem is that once you introduce multi-path problems, you have to start introducting multi-path solutions to your radars, missiles, etc.

Actually, the GBU-12 comes up in CCIP mode in the DSMS by default. When you select the GBU-12, go to the Profile page and change from CCIP to CCRP, then click SAVE, then return to the main page. I don't think that your HUD mode will change the weapon profile and I'm not in a place where I can test it, but I'm sure someone will correct me if I'm wrong.

Also, if you select another weapon before releasing your -12, and then come back to the -12, you will have to set it up again. Unless, you go in and edit the profile from the ... uh, my memory is failing me here. Inventory page? Search these forums and you will certainly find it.

Good hunting!

No, the HUD mode won't change the weapon profile, but it will change the release method. It's like a manual override. You select GBU-12, master mode to CCRP and you're done, no need to mess with DSMS.

The DSMS PROF CCIP/CCRP is the initial HUD mode option. Picking a profile with a CCIP option and manually cycling to CCRP (or the reverse) is functionally identical to picking a profile that is set to CCRP initially. It's just a time saver. A nice time saver, but just that.