JDAM implementation.

[DmitriKozlowsky]

Despite that JDAM implementation is , well I dunno. It is kind of hard to use, and confusing. It does keep the aircraft out of AAA and IR SR/MANPADS SAMs engagement dome.

I just experienced that if INS craps out in-flight, so does JDAM, and I could not find a backup ballistic mode and use it as MK-82.

[kengou]

I'm happy to help if you're confused about the implementation in DCS. It's somewhat confusing to load in mark points from the map, for sure.

 

 

As to your concerns, I can't say I've ever had the INS "crap out" in the Harrier, but even if it does, isn't that what the GPS system is for, to correct for INS drift? I doubt this is a big concern in real life and it should be no concern at all in DCS. In any event, there is a backup bomb sight for most bombs, haven't checked if it's implemented in JDAM yet, I believe it's the "SITE" toggle on the Stores MFD when the bomb is selected.

[Captain Orso]

It really isn't very difficult at all, maybe just a bit... different and maybe incomplete.

 

Check this video

. I've found it tells you everything you need to know.

 

The only real tips other than this video might be...

 

- If you are using F10 to mark units on targets on the map, zoom in until you are certain you are zoomed all the way in, before positioning a marker.

- Place a dummy marker first named T00 (tee zero zero). Please ignore Cap's "tee oh one" and "tee oh two", because it's not "oh" it's "zero" and he's a real dummy in this case.

- You'll have to zoom in and out for each target you designate. It's a tad time-consuming, but I've seen worse too.

 

The very first time I loaded the JDAM's I setup 2 groups of 3 targets and 4 individual targets. The two groups of three, I dropped all three bombs in one pass and hit all three targets of each group without a problem. Going after the other 4 targets was also no big issue.

 

The only thing that confused me at first was in going after targets from 20k+ feet. At that height the max-LAR ring is already at around 15nm so it might not even show when going to A/G and selecting the GBU-38's. It depends on how close of far you are from your target.

[Hawkeye_UK]

Its actually really simple to be fair once have gone through the process once - and also very very fast!

 

One thing i have noticed though, unless its just me, is that i cannot import whilst inflight in multiplayer.

 

This is not representational and needs to be looked at if its reliant or set to WOW.

 

Also just to check - can we have the 9 line edit for input, in fairness coordinates only would be surely simple to implement and give us what we need.

[Hawkeye_UK]

Orso - in fairness the first mark point i dont name as T00 just leave it blank and the T01 , T02 still import fine.

 

Zoom is critical as you say!

[kengou]

Also just to check - can we have the 9 line edit for input, in fairness coordinates only would be surely simple to implement and give us what we need.

Zeus has said this will be implemented.

[Captain Orso]

Its actually really simple to be fair once have gone through the process once - and also very very fast!

 

One thing i have noticed though, unless its just me, is that i cannot import whilst inflight in multiplayer.

 

This is not representational and needs to be looked at if its reliant or set to WOW.

 

Also just to check - can we have the 9 line edit for input, in fairness coordinates only would be surely simple to implement and give us what we need.

 

IIRC Wags said in his video that using the F10 method was designed to only work with wheels on the ground, maybe also only with engine off, like some of the other things which work through the special Harrier kneeboard pages.

 

For inflight I guess until nine-line is implemented only TOO will work.

[Captain Orso]

Orso - in fairness the first mark point i dont name as T00 just leave it blank and the T01 , T02 still import fine.

 

Zoom is critical as you say!

 

I honestly haven't played around to see the limits of what works and what doesn't. I just wanted to post what I knew works ;)

[DmitriKozlowsky]

I have the F10 marks process, partially , trained. As long as NAV system has at least one steer or way point.

Have autopilot fly the aircraft.

Go to F10 map, select own aircraft.

Place target marks. Name the first one XX, as it is ignored. But rename subsequent marks TO1, TO2, etc..

Hold down Right SHIFT+Right ALT + 8, and marks are sent to NAV system.

Back in cockpit, got Menu/CAS/RCALL page and the marks will be there.

 

OK, at this point , I get stumped. THough it may be RTFM, none of FMs I have describe how to display target coords on HUD to que the TPOD or DMT TDC.

 

So for now, I manually guide the TPOD or DMT TDC to point on ground.

Place HUD in Air-Ground mode.

Hold down WAYPOINT NEXT switch for one second. Release hold, and depress again for second.

Hopefully this gives a release circle with numerical CIP. When CIP is around 90, release JDAM.

 

However the above is not consistent. Sometimes it works, many other it does not. If HUD shows a double circle with CIP, then it is working. But often I get single circle with NO. A negative solution, and I do not know why. EHSD map also shows release parameters. If a double circle is drawn on MAP then its good. But often I get a single circle on MAP, with no solution.

Obviously I do not know this works in real life with real AV-8B HOTAS. But in DCS, the process is confusing , unreliable, and inconsistent.

There is one limitation, also present in A-10C, that should not be in AV-8B JDAM. In both modules, JDAM can only be released when target is ion front of aircraft. In RL, JDAM can be released with target in rear hemisphere. Weapon is GPS guided, it can follow a non-ballistic trajectory to target.

Fun fact. Field Artillery version of JDAM is Excalibur 155mm round. Excalibur negates the need for precise laying of gun. As long as gun and target are in range weapon can be fired almost straight up. It will then guide itself to target. There is also MLRS rocket variant with GPS guidance. ATACMS is GPS/Inertial guided.

[solidGad]

I have the F10 marks process, partially , trained. As long as NAV system has at least one steer or way point.

Have autopilot fly the aircraft.

Go to F10 map, select own aircraft.

Place target marks. Name the first one XX, as it is ignored. But rename subsequent marks TO1, TO2, etc..

Hold down Right SHIFT+Right ALT + 8, and marks are sent to NAV system.

Back in cockpit, got Menu/CAS/RCALL page and the marks will be there.

 

OK, at this point , I get stumped. THough it may be RTFM, none of FMs I have describe how to display target coords on HUD to que the TPOD or DMT TDC.

 

So for now, I manually guide the TPOD or DMT TDC to point on ground.

Place HUD in Air-Ground mode.

Hold down WAYPOINT NEXT switch for one second. Release hold, and depress again for second.

Hopefully this gives a release circle with numerical CIP. When CIP is around 90, release JDAM.

 

However the above is not consistent. Sometimes it works, many other it does not. If HUD shows a double circle with CIP, then it is working. But often I get single circle with NO. A negative solution, and I do not know why. EHSD map also shows release parameters. If a double circle is drawn on MAP then its good. But often I get a single circle on MAP, with no solution.

Obviously I do not know this works in real life with real AV-8B HOTAS. But in DCS, the process is confusing , unreliable, and inconsistent.

There is one limitation, also present in A-10C, that should not be in AV-8B JDAM. In both modules, JDAM can only be released when target is ion front of aircraft. In RL, JDAM can be released with target in rear hemisphere. Weapon is GPS guided, it can follow a non-ballistic trajectory to target.

Fun fact. Field Artillery version of JDAM is Excalibur 155mm round. Excalibur negates the need for precise laying of gun. As long as gun and target are in range weapon can be fired almost straight up. It will then guide itself to target. There is also MLRS rocket variant with GPS guidance. ATACMS is GPS/Inertial guided.

 

Did you assign each bomb to a target and then select which targets you want to bomb?

[DmitriKozlowsky]

In UK, some people use vocal O as numerical ZERO. Some in States also. Which is why NATO military and sciences fields use numerical ZERO , and train that way. I noticed that sciences in civilian applications, are starting to use NATO phonetic and numerical notation.

 

I've made some progress in my self training for JDAM usage in Harrier.

After good start up, with nav system working, and having waypoints. Either sitting on ramp or in-flight.

1. Go to F10 map view.

2. Select own aircraft and place markers. Named with T00 , T01, T02... Note those are ZERO.

3. Presh/hold for 1 sec LeftSHIFT+LeftALT+8. This will send target markers to CAS/RCALL page. Marker locations become target waypoints. Scroll through them using Next Waypoint button. Nav system will first cycle through waypoints then through target points. Target points appear on HUD (in NAV mode) as circles. With distance and bearing to target.

4. Approach target, and guide TPOD or DMT/ARBS TDC to the target circle. Designate.

5. Switch to AG master mode and prosecute target.

 

There are still things to learn, with JDAM sub-modes.

[kengou]

The tpod is not needed at all once the target points are in the system. On the cas page, hit the use button and select a number using the ufc. This enables it as a target point. Then, when you select jdams, the option screen shows the targets you can select from. Selecting those targets for the JDAM correspond to the target points from the f10 map and will let you drop jdams on the selected targets right away. That’s all you need to do.

[MarvK]

Hey guys,

 

I’ve been relatively successful in employing and delivering JDAM’s so far. Welcome addition to the Harrier. :thumbup:

 

I know that it’s still a work in progress, but when I return to base, I’d like to reload another round and go out after another set of targets. Has anyone found a way to remove,or delete the old targets off the CAS page? Deleting the marks off the map doesn’t seem to do it. Adding new marks just adds to the list. Re-loading the plane is the only way I’ve found so far.

[solidGad]

loving the JDAM's and have had good success. Last night there was a weird little issue. Was heading towards the target area and I had the big circle and things were looking good. then before i got within the big circle it turned into a little circle that was barely as big as the target area. not sure why that happened.

[Captain Orso]

That's normal. Practically when you touch the big circle the bubble pops and you only have the small circle left on the MMAP. Press on and drop your eggs, Mommy wants an omelette :D

[LastRifleRound]

loving the JDAM's and have had good success. Last night there was a weird little issue. Was heading towards the target area and I had the big circle and things were looking good. then before i got within the big circle it turned into a little circle that was barely as big as the target area. not sure why that happened.

 

This is because the circle isn't correct symbology for an LAR. The circle represents the max range of the bomb for given parameters assuming the current bearing to the target.

 

If you are not flying at the target, and instead are flying to one side or the other, the closer you get, the smaller the circle gets, until it retracts past your aircraft. This means if you have multiple targets selected with dispersion, and head to their overlap point's center, by the time you get there you will find you have an invalid solution.

 

IRL, when your nose is within +/- 15 degrees of the target (or target centroid if more than one is selected) a fan shaped LAR appears that is the acceptable LAR of release to hit that target, or all targets selected simultaneously if more than one is selected. The steering dot, when placed in the middle of the ASE, is supposed to guide you there, but those two HUD elements are static and not really useful.

 

In fact, when more than one target is selected, the range circles aren't displayed at all. Instead, diamonds representing the targets are displayed, and a triangle representing the centroid, and then the fan-shaped LAR when your attitude is +/- 15 degrees of the centroid. There are other restrictions if terminal parameters are selected, but those aren't modeled so are irrelevant to this discussion.

 

This is probably really confusing sounding, so:

 

TL:DR; the circle you see on the EHSD at any given moment represents the LAR assuming you maintain the same bearing to the target. If you are flying to side of the target, the bearing will change, and so will the LAR. The LAR should be fan-shaped, even without a terminal heading, because that shape represents and actual usable "fly-to" point.

Edited January 8, 2020 by LastRifleRound

[solidGad]

good info! thanks LastRifleRound!

[Captain Orso]

I don't know from where you are taking your information, LRR, but in my direct experience in DCS there are 2 LAR circles, the max range and the min range, and I've seen them both for one target at the same time. When passin the edge of the max LAR, shortly afterwards, it disappears, leaving only the min LAR.

 

Also, with 3 targets close to each other, I had 1 max LAR and 3 min LAR. AFAIK there is no centroid calculated. Only the closest target is referenced for the hit probability designated be the sequence of target numbers in the HUD with the current target digit being visibly enlarged.

 

The LAR is a circle, because it gives a clear, easy to understand and recognize queue illustrating the max and mid drop ranges at 0° bearing (B), your ground speed (S), and your current height above target (H). Nothing else would make sense.

[LastRifleRound]

I don't know from where you are taking your information, LRR, but in my direct experience in DCS there are 2 LAR circles, the max range and the min range, and I've seen them both for one target at the same time. When passin the edge of the max LAR, shortly afterwards, it disappears, leaving only the min LAR.

 

Also, with 3 targets close to each other, I had 1 max LAR and 3 min LAR. AFAIK there is no centroid calculated. Only the closest target is referenced for the hit probability designated be the sequence of target numbers in the HUD with the current target digit being visibly enlarged.

 

The LAR is a circle, because it gives a clear, easy to understand and recognize queue illustrating the max and mid drop ranges at 0° bearing (B), your ground speed (S), and your current height above target (H). Nothing else would make sense.

 

Right, DCS does it wrong.

 

Centroid is calculated. Here's an easy test. Make 2 targets 10nm apart from one another perpendicular to your flight path. Select them both as TGT for JDAMs. AV8 will show 2 target circles, and an additional diamond between them. Your HUD diamond cue and heading bug refer to this particular point, not either of the targets.

 

EDIT: I also want to add that the calculation of the centroid for a QTY release is correct behavior, but the IZLAR is missing. Also, if your targets were close together, you probably didn't notice the centroid. Try my example and put the targets further away from each other. JDAMS on strike can be used on targets 2nm apart in practice, and further in theory.

Edited January 9, 2020 by LastRifleRound

[Zeus67]

Hello folks,

 

Now you can engage up to 10 targetpoints with the JDAMs. Number of targets is limited by bomb count on the aircraft.

 

 

 

[Zeus67]

Right, DCS does it wrong.

 

Centroid is calculated. Here's an easy test. Make 2 targets 10nm apart from one another perpendicular to your flight path. Select them both as TGT for JDAMs. AV8 will show 2 target circles, and an additional diamond between them. Your HUD diamond cue and heading bug refer to this particular point, not either of the targets.

 

EDIT: I also want to add that the calculation of the centroid for a QTY release is correct behavior, but the IZLAR is missing. Also, if your targets were close together, you probably didn't notice the centroid. Try my example and put the targets further away from each other. JDAMS on strike can be used on targets 2nm apart in practice, and further in theory.

 

You are correct.

 

With two or more selected targetpoints, all steering cues on the HUD are towards the centroid, not the targets. The EHSD shows centroid and selected targets, but the distance is so small that they usually show as a single point.

[tom1502]

Hi all,

 

Loving the JDAM implementation, but I seem to have an issue. I can ripple off the first three but the fourth seems to crash DCS. I don't know why this is but it is a repetitive issue as soon as I press the weapon release on the fourth JDAM (when rippling) I get the blue box telling me that DCS has crashed.

 

Is this unique to me or is it a bug that is being examined?

 

Thanks,

 

Tom

[MarvK]

Hello folks,

 

Now you can engage up to 10 targetpoints with the JDAMs. Number of targets is limited by bomb count on the aircraft.

 

Welcome addition! :thumbup:

 

But, can we remove/delete old targets from the cas page, or do we have to reload a new plane?

[Marsvinet]

Hi all,

 

Loving the JDAM implementation, but I seem to have an issue. I can ripple off the first three but the fourth seems to crash DCS. I don't know why this is but it is a repetitive issue as soon as I press the weapon release on the fourth JDAM (when rippling) I get the blue box telling me that DCS has crashed.

 

Is this unique to me or is it a bug that is being examined?

 

Thanks,

 

Tom

It is a known bug that is fixed. While waiting fo ED to release the next patch, you can follow this. It does not prevent you from playing multiplayer.

[tom1502]

It is a known bug that is fixed. While waiting fo ED to release the next patch, you can follow this. It does not prevent you from playing multiplayer.

 

Brilliant, thank you!

Edited January 10, 2020 by tom1502