LASTE, WIND and Dumb Bombs in 1.2.4

[gusanako]

No tracks are needed.:doh:

It's as simple as creating a mission with wind and A-10c with dumb bombs. The dumb bombs will never reach the point of impact of the reticle.

Four months later and two versions of DCS: world since the thread was created and no tester or administrator has said nothing to the topic.

shameful.....:mad:

Edited August 30, 2013 by gusanako

[Angel101]

I played these tracks:

without laste: i saw you aiming about one width of the runway right of the tanks and the impacts were almost spot on (about 2-3 meters right of the tanks)

with laste: i saw you aiming along the edge of the runway and the impacts were exactly there, too.

 

I suppose when you flew in 1.2.3, you had the pipper spot on along the tanks?

 

 

Ok, Something wrong with traks, PIPPER stay in diferent position replaying in 1.2.3.9871 than in 1.2.5.16508. Bombs Still missing from far away where I put the Pipper at least in the track using LASTE correction... (in 1.2.3.9871 all bombs hit where the pipper was, and also hit the tanks in both traks)

 

Replay

Ver. 123.9871

 

 

 

 

Same moments in 125.16508

 

 

 

You can see the difference between tracks.

 

-------------------------------------

 

But your answer let roll my mind.

 

--EDITED---

 

False alarm! Still broken! Just some bombs hit where pipper was but I tried a different angles and bombs still falling very far from computed impact point.

Edited August 31, 2013 by Angel101
images editing

[Flagrum]

:doh: I don´t know why tracks aren´t reliables

Tracks record mainly only the input of the pilot. If the calculations of the simulation now change between versions, the same track gets different results.

 

I actually find it this way quite nice. As seen in this case, they are good tools for repeatable tests.

[Flagrum]

At this moment releases in CCIP seems correct. :music_whistling:

I can't hit sh*t in my own test mission.

 

I set the first layer and the second layer each to 20 m/s (about 40 knots) and direction set to be the same for both, too.

 

I fly a 30° dive beginning at 20000 and release at about 9000 ft, wind coming from the left. My bombs miss by about 100 ft too far right. NO MATTER IF I SET UP LASTE WINDS OR NOT...

 

Then I measured the actual wind in game:

 

What I find disturbing: the wind speed near the ground - 60 knots? seriously? or would/should laste take this into account, i.e. is that incorporated in the wind model laste uses?

[gusanako]

I can't hit sh*t in my own test mission.

I set the first layer and the second layer each to 20 m/s (about 40 knots) and direction set to be the same for both, too.

I fly a 30° dive beginning at 20000 and release at about 9000 ft, wind coming from the left. My bombs miss by about 100 ft too far right. NO MATTER IF I SET UP LASTE WINDS OR NOT...

 

+1

I reinstalled "dcs: world" with the module of "a-10c" in case it was problem of the installation and follow these errors, the bombs deviate by much.

In this video I show how the wind deviates the dumb bomb, the installation is new and the mission created from zero.

 

 

The Wind in the mission is:

Sea level--> 6 m/s 143º

2000m --> 8 m/s 104º

8000m --> 12m/s 116º

 

I wonder why testers no says nothing about this ....:cry:

Edited August 31, 2013 by gusanako

[PFunk1606688187]

+1

I reinstalled "dcs: world" with the module of "a-10c" in case it was problem of the installation and follow these errors, the bombs deviate by much.

In this video I show how the wind deviates the dumb bomb, the installation is new and the mission created from zero.

 

 

The Wind in the mission is:

Sea level--> 6 m/s 143º

2000m --> 8 m/s 104º

8000m --> 12m/s 116º

 

I wonder why testers no says nothing about this ....:cry:

 

Yea that video is pretty unmistakable. Whats really convincing is the fact that the second bomb landed exactly the same distance right of the target as the first. If you were a sniper that'd be the start to a pretty decent grouping.... :doh:

 

I really do want a tester to comment on this. Did the recent patch to LASTE effectively ruin unguided CCIP delivery?

[Flagrum]

Yea that video is pretty unmistakable. Whats really convincing is the fact that the second bomb landed exactly the same distance right of the target as the first. If you were a sniper that'd be the start to a pretty decent grouping.... :doh:

 

I really do want a tester to comment on this. Did the recent patch to LASTE effectively ruin unguided CCIP delivery?

 

+1

 

I can't even hit without any wind at all. I think, this was already mentioned by someone else in this (or that other) threat: the mk-82 always fall short, about 30 ft. But I can't swear that I haven't induced any pilot errors - dumb boms are a new terrain for me :o). So I'd like to see that someone performs some convincing tests. This is a freaking complex matter ... but with "convincing" I mean that all relevant aspects are taken into account, like ...

 

1. CCIP / CCRP

2. no wind / wind (single layer) / wind (several layers)

3. with and without LASTE wind entry (they DO have an affect on the pipper ... dunno how that relates to the statement [by Eddie?] that this is not implemented!?)

4. all relevant bomb types

 

these are quite a few test cases already ... but I am willing to help - if we can settle to common and comparable test and environment settings.

[Angel101]

OK, We performed a lot of delivery´s with dumb bombs with 4 friends more, used A10C and A10A with Mk-82 and Mk-84.

 

Nobody was able to hit a target.

 

Winds used:

10m/s sea lvl.

15m/s 2000m.

22m/s 8000m.

 

I want to remark that A10A also suffers the same problem.

 

The point that I don´t understand is why other A-10c squadrons doesn´t say nothing about it. They are using only guided ammunitions? aren´t using wind settings in their missions?

 

What I missed?

[IdleBoards]

From the descriptions given here, it sounds like there is a legitimate issue with the IFFCC wind calculations - especially if you're not seeing any difference when entering winds vs. not entering winds.

 

However, I wonder if you might be expecting too much. A miss distance of 100ft when releasing at 9, 000ft is perfectly normal...especially when you're testing with 40-60 knots of wind. I don't mean to be condescending, but they're called dumb bombs for a reason. You can't expect to hit point targets with dumb bombs when using a medium altitude delivery.

 

I'd be careful which test cases you use when trying to quantify the error. The pics posted by Angel are compelling.

[Angel101]

From the descriptions given here, it sounds like there is a legitimate issue with the IFFCC wind calculations - especially if you're not seeing any difference when entering winds vs. not entering winds.

 

However, I wonder if you might be expecting too much. A miss distance of 100ft when releasing at 9, 000ft is perfectly normal...especially when you're testing with 40-60 knots of wind. I don't mean to be condescending, but they're called dumb bombs for a reason. You can't expect to hit point targets with dumb bombs when using a medium altitude delivery.

 

I'd be careful which test cases you use when trying to quantify the error. The pics posted by Angel are compelling.

 

Well, the fact is from DCS:warthog 1.1.1.2 until DCS:world 1.2.3.9871 dumb bombs hit on target or nearly the target in windy conditions. (check screenshoots in different ver.)

 

From 1.2.4.xxx to now (few months between patch) is broken.

 

I understand that some delivery´s are less precisse but at this moment are very very imprecise.

 

Feels like going in the Mustang droping dump bombs... Whats the point of CCIP in modern fighters?

 

About expecting to much, in my Test I´m dropping at 5.000fts with around 20 knots and missing about one runway width. I think ins´t to much wind.

 

Regards.

 

edit: Also i like to remark this video

 

made by Gusanako, in HD you can see the great job that he is doing and how bombs missed the target like if the pipper was from a WWII plane.

Edited September 1, 2013 by Angel101

[Eddie]

It does indeed seem there is something not quite right with the IFFCC at the moment. I'll take a look and report as needed, as and when I have time over the next couple of weeks.

 

But, as said above, I think you guys are expecting far too much from the IFFCC wind correction. In light winds, and using low level/high angle releases, yes it should be able to compensate for winds. But with 40+ knots of wind, a medium altitude release is never going to be all that accurate.

 

Well, the fact is from DCS:warthog 1.1.1.2 until DCS:world 1.2.3.9871 dumb bombs hit on target or nearly the target in windy conditions. (check screenshoots in different ver.)

 

In previous versions of DCS the wind correction was too good, as it was near perfect in any winds. It shouldn't be like this. But equally it should be a bit better than it currently appears to be.

 

But it's hard to say if there is a real problem or not without performing some proper deliveries and looking at the results.

 

 

Whats the point of CCIP in modern fighters?

 

Try performing a manual delivery using nothing other than the depressible pipper. Then you'll quickly find the answer to your question.

 

About expecting to much, in my Test I´m dropping at 5.000fts with around 20 knots and missing about one runway width. I think ins´t to much wind.

 

As I said, without knowing the release parameters (dive angle, airspeed, ToF, etc.) is hard to say. But for s slow, shallow release with such high winds that isn't a far off as you might think.

 

So in summary, there may well be a bug, but it's not as drastically off as you may think. I'll say this much, during my normal flying I haven't noticed any significant reduction in weapon accuracy.

Edited September 1, 2013 by Eddie

[Angel101]

Thanks Eddie to have a look when you got time. :thumbup:

[Laud]

Any news on this? Still an issue?

[Flagrum]

Any news on this? Still an issue?

 

-->

It does indeed seem there is something not quite right with the IFFCC at the moment. I'll take a look and report as needed, as and when I have time over the next couple of weeks.

[Eddie]

Ok guys, I've done some testing this afternoon and the short of it is, everything is fine and working exactly as it should.

 

I've performed around 40 deliveries in both still air, and high winds both with and without manually entered wind data. And in every situation the weapons landed on target.

 

I've done these tests in the current test version, and confirmed the results in 1.2.6 with the same outcome.

 

My thoughts on the issue are as follows:

 

1. You guys are perhaps not appreciating how inaccurate dumb bombs can be

 

It gets said a lot, but remember PGMs were developed for a reason. Scoring a "hit" on a point target such as a single tank is not easy, especially in high winds and from high altitudes. There is a reason that an impact within 100 ft is considered a hit in real world training.

 

2. By not performing deliveries correctly (dive angle, release altitude, CCRP/CCIP, etc. you are performing inherently inaccurate deliveries.

 

Shallow dive angles, low release airspeed, and long weapon time of flight, all reduce accuracy and by quite a significant amount. If you want an accurate delivery you need at least a 30 degree dive, if not 45 degree and it needs to be a dive bomb with a release altitude of around 4000 feet. Even a 45 degree high altitude dive bomb will have a release altitude below 8000 feet.

 

3. You are expecting 500lb bombs to do more damage to hard targets than they should.

 

The "lethal" blast radius of a Mk-82 is only around 75 feet (depending on terrain and fusing) in the real world, and DCS does a reasonable job of simulating that. Don't expect an impact more than 50 feet away to kill a tank.

 

Anyway, those are my thought and results. It may not be what some of you were expecting, or wanted to hear, but that's how it is. I've attached 3 of my test tracks in case anyone wants to take a look, there were recorded in the internal test build, but seem to work ok in 1.2.6.

82 45HADB - No Wind.trk

82 45HADB - Auto Wind Correction.trk

82 45HADB - Manual Wind Entry.trk

[Threshor]

Thanks Eddie,

 

Viewed your tracks.

 

Just realized I had my winds to/from backwards when inputing in the pit from your tracks. Hit dead on on the one I built.

 

What is this auto correction one, is that a different way to set up winds?

[Eddie]

What is this auto correction one, is that a different way to set up winds?

 

Auto correction is just letting the IFFCC do its thing. It seems that people keep missing (or sometimes it appears ignoring) the fact that IFFCC corrects for wind all the time, even if you don't enter wind data. When doing so it uses the measured wind speed and direction (as shown in the CDU) and applies an algorithm that assumes the wind speed drops to zero at -4000 ft. This is adequate correction in most cases.

 

You only need to enter wind data if you're flying in/dropping through wind layers that vary greatly in terms of speed and/or direction. In most cases manual wind data entry is simply not necessary.

[Threshor]

In most cases manual wind data entry is simply not necessary.

 

Just did a simple test with this. I had 3 wind layers same direction but slightly different speeds and no manual data entry, bombs where right on.

 

Then with winds in different directions and speeds and bombs where off target.

[howie87]

Auto correction is just letting the IFFCC do its thing. It seems that people keep missing (or sometimes it appears ignoring) the fact that IFFCC corrects for wind all the time, even if you don't enter wind data. When doing so it uses the measured wind speed and direction (as shown in the CDU) and applies an algorithm that assumes the wind speed drops to zero at -4000 ft. This is adequate correction in most cases.

 

You only need to enter wind data if you're flying in/dropping through wind layers that vary greatly in terms of speed and/or direction. In most cases manual wind data entry is simply not necessary.

 

Thanks Eddie. Great info and glad to hear everything is working as intended. Now... If they could just get round to fixing those ILS steering bars ;)

[Hansolo]

Thanks Eddie for taking the time to check this :thumbup: Much appreciated

 

Cheers

Hans

[MaverickF22]

I did some more testing of this issue and I came up with interesting results. It appears that the issue is not a problem with LASTE calculations, but rather with wind implementation as it is defined in the editor. I usually practice my CCIP deliveries by placing a hefty, medium sized wind at constant headings and speeds per altitude interval.

 

In the editor, I define the wind parameters as 5 m/s or about 10 knots at every altitude interval.

 

...

 

At altitude, the wind is how I defined it, though the "288" is very strange. This number should read "115".

 

...

 

When I descend to sea level, the wind speed picks up. If you set the wind speed at higher settings, this "amplification" effect appears to increase exponentially.

 

...

 

From these results, it appears that the LASTE is in fact computing an accurate solution given the wind conditions at a specific altitude, but different wind speeds at different altitude intervals are causing the bombs to miss the target as wind speed picks up with lower altitude. This is a normal result, but the winds do not match the behavior specified in the editor.

 

Habu

 

You found it right..., there is a problem between the mission editor's values and those that are seen in-game, and not due to the problem that the wind's direction in the editor (which tells you were the wind is actually going/heading) is 170 degrees (instead of 180, that should be...) more or less than that read by the CDU, because the CDU actually tells you the direction from where the wind comes and not where it goes (as in mission editor), while the speed is read in knots!

 

So now we can presume that the LASTE (i thought it also had problems) isn't the problem..., as it tries to correct the pipper's position accordingly and perhaps it does it very good..., but the problem is where from does the LASTE actually get the wind data and what are the values within it?

 

Someone did actually make some airspeed measurements, using the CDU, by flying with the A-10C between the first two layers of altitude that were set in the mission editor (0 and 2000 meters) and had a surprise to see that the airspeed read by the CDU wasn't the one written in the editor, so there is a problem between the data within the editor and the actual gameplay!

 

Here's the data showing the difference:

 

http://forums.eagle.ru/showthread.php?t=112577

Edited September 9, 2013 by MaverickF22

[MaverickF22]

...e.g enter Wind in ME as 360deg (that is the wind is actually blowing from 180). Then fly a pass with an attack direction

of 270deg. See where the bomb impacts Left or Right of the target. If the 180ambguity is resolved in the solution an impact should occur if the bomb impacts Left of the target then the ambiguity has not been resolved.

 

In fact the direction is +-170 or +-190 degrees from that of the mission editor's, although it's a 10 degrees error, but it might have some similarity with the high variation between the wind's level in ME and that one in-game!

Edited September 9, 2013 by MaverickF22

[Flagrum]

In fact the direction is +-170 or +-190 degrees from that of the mission editor's, although it's a 10 degrees error, but it might have some similarity with the high variation between the wind's level in ME and that one in-game!

Wind direction in the ME is "blowing to" as the small compas-control is used everywhere else for setting the heading of something. The value is the true heading.

 

The CDU expects "blowing from" - as this is the common way to express wind directions in RL. But beware, the A-10C operates with magnetic heading which is, i think, 6 or 7 degrees (to the west, if i am not mistaken) off of the true heading.

[MaverickF22]

T

A-10C operates with magnetic heading which is, i think, 6 or 7 degrees (to the west, if i am not mistaken) off of the true heading.

 

Copy, you might be right about that divergence between the true (used by CDU) heading and the magnetic one, difference which depends on the aircraft`s geographical position!

 

The LASTE seems to correctly listen to it`s given data (the data being the problem), so it can be taken out of the discussion.

 

The CCRP`s failing to correctly calculate (the CCIP calculates perfectly though) the release point for any bomb type, still remains a problem to solve, especially when releasing bombs from a dive or a climb attitude!

 

My personal suggestion, would be that every problem or accomplishment should be more closely linked to a visual proof as a video or a track (as i`ve always provided when i was reffering to something), and less likely pictures/screenshots where the ambiguity could be high (somewhat masking the truth).

 

I`ve provided videoes and tracks (in my earlier posts about CCRP, LASTE AND MK-82AIR problems) showing what isn`t right and some possible ways to get around them, so in the same manner i wish to to thank to all the others (an example is "Eddie") who are providing visual proofs for what should be done or what could be the correct techniques that need to be applied, in order to obtain the right and expected results.

 

 

A good day everyone!

[IvanK]

Regarding variation and wind. The convention in pretty much all Nav systems is to enter wind direction in TRUE. The Nav system then if required applies the Variation by way of a MAGVAR table (or internal calculation). Though given the variation is pretty small in the area its probably not that significant

Edited September 15, 2013 by IvanK