investigating Bombing solution seems to use Barometric Altitude only

[UWBuRn]

Yeah, i always used metric units in russian birds, not really used to knots/feets with them. I switched to english pit as it's easier to learn the controls as i don't speak russian, now that i'm familiar with all the switches it will be the same. If i have some time today i will try it.

[CrazyGman]

5 hours ago, UWBuRn said:

@BIGNEWY, track are in the above post, sorry, i forgot to page quote you.

@CrazyGman, are you using english or russian cockpit? I'm guessing if this can be a factor? Personally i'm using english pit + metric units.

Using Russian and metric. 

Edited October 24 by CrazyGman

[ldnz]

I tried in a fresh mission without any DTC setup (single waypoint placed, airstart, bombing mozdok) and it looked very accurate. Tried an old mission (pre patch) and its still falling short.. resaved that mission and I think we're ok now.

I'll do some more testing later

 

[UWBuRn]

Pit language makes no difference (thankfully).

After some more testing, to my understanding LR aiming works as long as you don't input any point in the DTC. By points i mean the first tab, not waypoints or A/D, even if without points you can't of course have waypoints.

As soon as you input a point in the DTC, the TargetPoint in the Weapon tab is assigned and it reverts to the behavior of relying on DTC altitude + correct baro reference.

Not sure if it's working as intended, probably not. I guess that, either:

• TargetPoint should have an option to be left unassigned
• TargetPoint altitude + bar reference only make sense for TOSS mode

[AeriaGloria]

TOSS should still work, it uses same calculations as CCRP launch. After laser ranges and pitch up, the gyros remember long enough for the maneuver, or atleast, combat manual does not claim it functions any different and idk why it would need to. 
 

I would like to see if backup radar altimeter ranging works, but this seems to get in the way. 

[YoYo]

I've found a rather interesting method that I think works well even if the target isn't saved in the DTC. Of course, we need to know the target's location (altitude), which is easy to determine by hovering the mouse cursor over the map (F10) where the target should be (even if it's hidden).

Example:

STEP 1: target height 299m.

STEP 2: we divide the height by 8 = 37 (we round it)

STEP 3:  we subtract it from the standard QNH = 1013-37 = QFE is 976

So: target elevation in meters / 8 = X and 1013 - X = QFE for target location for MiG.

STEP 4: pressure Unit Conversion Between Hectopascals (hPa) and Millimeters of Mercury (mmHg)

QFE for target location for MiG x 0,75 = Y mmHg (set it on the altimeter)

Example: QFE 976 x 0,75= 732 (set it on the altimeter)

I once recorded something like this for Viggen, but here we have to be at the airport:

 

Edited Sunday at 09:21 PM by YoYo

[AeriaGloria]

Interesting, how far up does it go? The altimeter doesn’t seem to adjust up much. 

[YoYo]

I don't know if there's a bug here. The target's QFE doesn't always work either. For example, here's the map of Afghanistan. My calculations are accurate, but they do contain a small error. If all 250kg bombs are dropped at once, the area is so large that those few mmHg are completely irrelevant.

The target is at an altitude of 597 meters (no DTC).

Following my example: 597/8=75.  1013-75=938hPa.  938x0,75=704mmHg.

It's almost consistent with this screenshot. When I aimed the plane and reset the altimeter, I had 708mmHg, so the difference doesn't matter much.

However, the bombs in pre-destination and with the laser rangefinder activated fell probably 500 meters earlier than the target, I was at 2000 m, the altimeter being set on 704mmHg.

Everything behaves well at lower altitudes, but at 600 meters (1970 ft) the difference is enormous. I need to run some more tests, but something seems off.

Btw. A (different) but similar counting principle worked perfectly in Viggen.

Edited Monday at 10:21 PM by YoYo

[AeriaGloria]

I’m done with bombs falling short, just gonna use the rocket bombs for now (S-24) 

[Ornithopter]

This is really getting confusing to me.  I think for a developer, or somebody who knows how it's actually supposed to be, this is your magic moment to explain it.

Quote

I’m done with bombs falling short, just gonna use the rocket bombs for now (S-24) 

p.s, I'm done with CCRP, just gonna use pre-desig CCIP to sink moving World War II aircraft carriers for now (FAB-500)

Edited yesterday at 01:28 AM by Ornithopter

[IvanK]

When using the DTC to set a Target elevation and reading the Target Altitude from the MB map be aware that the altitude is AMSL so is QNH referenced. That means you aircraft needs to be using QNH as well not QFE. (This is different to the method implied in the R.Wise flight manual excepts which use a Delta H value and therefore would mean everything is QFE based)

I have been testing on the Nevada map QNH760mm Take off Toonopah Test range elev 1687m AMSL. Target on a Mountain top elev 2780m AMSL derived from MB map. I set 2780m in the DTC on the target Waypoint. Then flew the sortie flying a level pass in CCRP no Laser ranging no pre designation , nil wind. Altimeter set to 760mm QNH. Target selected as the active waypoint.  I am achieving consistent direct hits 500KG LD bombs.

 

The available documentation on all of this ranging issue is next to non existent. It would be really nice to get some definitive documentation on just how the MIG29 does its ranging when the laser is not available.

 

Edited yesterday at 05:48 AM by IvanK

[YoYo]

1 hour ago, IvanK said:

When using the DTC to set a Target elevation and reading the Target Altitude from the MB map be aware that the altitude is AMSL so is QNH referenced. That means you aircraft needs to be using QNH as well not QFE. (This is different to the method implied in the R.Wise flight manual excepts which use a Delta H value and therefore would mean everything is QFE based)

I have been testing on the Nevada map QNH760mm Take off Toonopah Test range elev 1687m AMSL. Target on a Mountain top elev 2780m AMSL derived from MB map. I set 2780m in the DTC on the target Waypoint. Then flew the sortie flying a level pass in CCRP no Laser ranging no pre designation , nil wind. Altimeter set to 760mm QNH. Target selected as the active waypoint.  I am achieving consistent direct hits 500KG LD bombs.

 

The available documentation on all of this ranging issue is next to non existent. It would be really nice to get some definitive documentation on just how the MIG29 does its ranging when the laser is not available.

 

Are you suggesting this means that in very undulating terrain, the only option in DCS is to set everything in DTC? That sounds a bit absurd, because it means the pilot and player be completely deprived of the ability to drop dumb bombs.

[AeriaGloria]

1 hour ago, IvanK said:

When using the DTC to set a Target elevation and reading the Target Altitude from the MB map be aware that the altitude is AMSL so is QNH referenced. That means you aircraft needs to be using QNH as well not QFE. (This is different to the method implied in the R.Wise flight manual excepts which use a Delta H value and therefore would mean everything is QFE based)

I have been testing on the Nevada map QNH760mm Take off Toonopah Test range elev 1687m AMSL. Target on a Mountain top elev 2780m AMSL derived from MB map. I set 2780m in the DTC on the target Waypoint. Then flew the sortie flying a level pass in CCRP no Laser ranging no pre designation , nil wind. Altimeter set to 760mm QNH. Target selected as the active waypoint.  I am achieving consistent direct hits 500KG LD bombs.

 

The available documentation on all of this ranging issue is next to non existent. It would be really nice to get some definitive documentation on just how the MIG29 does its ranging when the laser is not available.

 

 

20 minutes ago, YoYo said:

Are you suggesting this means that in very undulating terrain, the only option in DCS is to set everything in DTC? That sounds a bit absurd, because it means the pilot and player be completely deprived of the ability to drop dumb bombs.

This makes so much sense Ivan! I can’t wait to try it and see if it’s why I have trouble with bomb dropping online! If I can finally CCRP from over 5 km away online and bomb without risking my butt to any MANPAD or AAA……….

 

Yo-yo, to me what this means is that whether you do CCIP or CCRP bombs. Laser on or off, it will only be truly accurate for one altitude/target area. Which, the MiG-29 and all Soviet tactical aviation was designed to only attack one location at a time anyways. 
 

Which should still be wrong for laser assisted CCIP……. But atleast this means we can choose our target and be accurate, we just won’t have the ability to CCIP bombs wherever we want………

Which how odd would it be if Mikoyan said “let’s use set target deltaH for bombing CCRP and CCIP wether the laser  turns on or not.”

Edited yesterday at 07:12 AM by AeriaGloria

[IvanK]

No yoyo. It means for non laser range deliveries only you need target area altitude for an accurate delivery. Since it would seem (in DCS anyway) that baro ranging is all you get if the laser is not available.

if you want to ensure laser ranging is available get some decent dive angle going. Chances are this will also result in a CCIP delivery anyway. 
 

I dont think target altitude in the DTC is required  ( or even used )if you have laser ranging. It would be good practice however to set it in case you dont get laser ranging.

[AeriaGloria]

I have been having misses lately using laser ranging in CCIP in multiplayer, consistently. Making sure my laser was on also. If I destroy the target it’d only be from splash damage. I’m gonna try matching up QFE and see if that makes a difference. 

1 hour ago, IvanK said:

No yoyo. It means for non laser range deliveries only you need target area altitude for an accurate delivery. Since it would seem (in DCS anyway) that baro ranging is all you get if the laser is not available.

if you want to ensure laser ranging is available get some decent dive angle going. Chances are this will also result in a CCIP delivery anyway. 
 

I dont think target altitude in the DTC is required  ( or even used )if you have laser ranging. It would be good practice however to set it in case you dont get laser ranging.

Mission I tested in had QFE same as briefing. So that’s why I saw difference not in MP. I set my QFE +30 and bomb went quite long with laser on CCIP

 

EDIT: I just tried CCIP and CCRP in the online server that I’ve been having short bomb impacts in, matched QNH to briefing. And the impacts were PERFECT on both CCIP and CCRP now! You figured out bombing!!!!!!  

Edited yesterday at 09:34 AM by AeriaGloria

[BIGNEWY]

 

Good to hear, so I can mark this issue correct as is as it does seem to be working as intended. 

 

[YoYo]

4 minutes ago, BIGNEWY said:

 

Good to hear, so I can mark this issue correct as is as it does seem to be working as intended. 

 

Not yet pls, we need more tests.

[YoYo]

1 hour ago, AeriaGloria said:

EDIT: I just tried CCIP and CCRP in the online server that I’ve been having short bomb impacts in, matched QNH to briefing. And the impacts were PERFECT on both CCIP and CCRP now! You figured out bombing!!!!!!  

Did you also test in mountainous terrain, start (hot) in the air too?

[AeriaGloria]

22 minutes ago, BIGNEWY said:

 

Good to hear, so I can mark this issue correct as is as it does seem to be working as intended. 

 

While we have figured out how it works In game, it still does not make sense according to documentation which says it should be using laser range when the laser is on and within range of ground (3.5 km). And I can confirm with my tracks in the “bombing short” thread that this altitude error does occur with the laser on and in range.  
 

So the behavior we should see 

1. laser on in CCIP, bombs drop accurately no matter the “target altitude setting” (this is the part that does not seem correct as it’s still using target altitude)

2. target altitude and QFE must be set for CCRP (this part works and is seemingly correct) 

The whole reason for this discussion is that people are confused by the laser being on and ranging yet not being utilized by the aircraft, and you can see similar comments in the Russian forums 

11 minutes ago, YoYo said:

Did you also test in mountainous terrain, start (hot) in the air too?

I tested both air and land start. I didn’t feel the need to test in mountains becuase this “setting QFE” technique by its nature will only work for targets at a specific barometric altitude. 

Edited yesterday at 10:37 AM by AeriaGloria

[Кош]

46 минут назад, BIGNEWY сказал:

 

Good to hear, so I can mark this issue correct as is as it does seem to be working as intended. 

 

It's correct as it is if laser ranging is not performed. AKA like in MiG-21 with radar off. How exactly do you calculate the solution with the laser so you still need target elevation? null

Edited yesterday at 11:01 AM by Кош

[YoYo]

16 minutes ago, AeriaGloria said:

I tested both air and land start. I didn’t feel the need to test in mountains becuase this “setting QFE” technique by its nature will only work for targets at a specific barometric altitude. 

Right, I check it out a bit later and let me know what the effect is.

[Кош]

@BIGNEWYKOLS Lase is literally equal, albeit much much more precise, to (own altitude - target elevation)*sin(pitch angle). Also SME said target elevation was just never necessary in IRL operation. How your AG modes work is a math\logic bug.

[swartbyron]

I cant understand why the end users are having to solve this problem?

Surly the Fulcrum Dev guys know exactly how bombing has been simulated and have already had this double checked by SMEs?

All that is necessary is for us to be told how its meant to work and to be given the correct procedure?

End users can then confirm that this works as intended, report it if not and if necessary, challenge it if it differs from publicly available information.

 

[YoYo]

13 minutes ago, Кош said:

@BIGNEWYKOLS Lase is literally equal, albeit much much more precise, to (own altitude - target elevation)*sin(pitch angle). Also SME said target elevation was just never necessary in IRL operation. How your AG modes work is a math\logic bug.

Looks like. Yes, even logically.

[AeriaGloria]

It is one thing that needs added, laser range added to WCS info in bombing modes. It already does this for rocket and gun which work perfect. 
 

When laser sees no ground it uses target elevation. I assume the fact that this “switch” between the two ranging methods is just what needs to be done. 
 

I have not checked rocket/gun use with the laser turned off though…….If that works off target altitude also, it is a matter of adding the same process to bombing mode. 
 

Another interesting aspect of target altitude, the laser has two conditions to auto turn on 

range to target alt is less then 3.5 km and nose below 10 degrees elevation. Therefor is target alt was off by a lot. You may need to activate it early 

Edited yesterday at 01:08 PM by AeriaGloria