False ship data?

[nazaka]

Hi,

I had a problem in play.
During an attack, I took my measurements for the RAOBF disc, and I got this:
https://i.imgur.com/it28Zo5.png

If I look at the result correctly, in X6, with a height of 7.5 (1200m) and a length of 23, I get an AOB of 52.5 .
Since the ship has a leaking heading, the true AOB would be 180-52.5=127.5°.
This is totally false.

To the eye we can see that the AOB does not exceed 105/110°.

Only erroneous data can give such results.
The mast height and/or length of the vessel must be wrong.

Am I getting the wrong idea, or am I correct?

[nazaka]

Nobody?

[vdr1981]

Nobody?

There is indeed a possibility that not all the values from the recognition manual are 100% correct. Unfortunately there is no 100% valid way in the game to measure ships length, height and other values...

[nazaka]

May be a conversion error between units of measurement (feet/metres)...

Could someone with the feet version be able to give us the values he has?

[hauangua]

Hi,

I had a problem in play.
During an attack, I took my measurements for the RAOBF disc, and I got this:
https://i.imgur.com/it28Zo5.png

If I look at the result correctly, in X6, with a height of 7.5 (1200m) and a length of 23, I get an AOB of 52.5 .
Since the ship has a leaking heading, the true AOB would be 180-52.5=127.5°.
This is totally false.

To the eye we can see that the AOB does not exceed 105/110°.

Only erroneous data can give such results.
The mast height and/or length of the vessel must be wrong.

I calculated the 102 ° AOB with the "Gegnerlage Berechnungstabelle" ...
:salute:

[nazaka]

I've decided to take a different approach to checking this ship's values.
I created a mission with the ship AOB 90° at 2000m.

I was able to determine the values at once:
Height: 5.5 ticks for 2000m corresponds to a height of 27.6m
https://i.imgur.com/PfaFijh.png





length: 17.4 ticks for an AOB from 90° to 2000m gives us a length of 86.9m
https://i.imgur.com/bvL4GLj.png


So there are a lot of wrong values in this identification book. I hope there aren't too many, it would be really stupid to miss out on it.

Thank you for your help.

[nazaka]

For info, with the values of 7.5 ticks of height and 23 ticks of length, I find an AOB of 104-105°. :Kaleun_Cheers:

[nazaka]

I calculated the 102 ° AOB with the "Gegnerlage Berechnungstabelle" ...
:salute:
What have you use to calculate this?


I can't find anything on the forum about "Gegnerlage Berechnungstabelle."

[hauangua]

What have you use to calculate this?


I can't find anything on the forum about "Gegnerlage Berechnungstabelle."
https://i.postimg.cc/KjbwZNc6/IMG-20200327-195951.png (https://postimg.cc/62HYcCvc)

[hauangua]

For info, with the values of 7.5 ticks of height and 23 ticks of length, I find an AOB of 104-105°. :Kaleun_Cheers:

delete

[nazaka]

Why did you delete my message?

You miscalculated.
Did you take the values from my screenshot?

On the ship's identification book, we have a height of 22.6m and a length of 86.9m

That gives us this theoretical aspect ratio: 86.9/22.6=3,485

Now, the observed aspect ratio in ticks: 23/7.5=3.067

ratio observed aspect / theoretical aspect ratio X 100= 3.067/3.485 X 100 = 88% X 100 = 88

If we go back to the Gegnerlage Berechnungstabelle:
https://i.imgur.com/SdsS4ph.jpg

We're getting an AOB of 63°
And since the ship is fleeing: 180-63=117°

[hauangua]

Why did you delete my message?

You miscalculated.
Did you take the values from my screenshot?

On the ship's identification book, we have a height of 22.6m and a length of 86.9m

That gives us this theoretical aspect ratio: 86.9/22.6=3,485

Now, the observed aspect ratio in ticks: 23/7.5=3.067

ratio observed aspect / theoretical aspect ratio X 100= 3.067/3.485 X 100 = 88% X 100 = 88

If we go back to the Gegnerlage Berechnungstabelle:
https://i.imgur.com/SdsS4ph.jpg

We're getting an AOB of 63°
And since the ship is leaking: 180-63=117°

Forgive me but i delete MY answer before..but yess i (bit) miscalculate because I was in a hurry, you right

True 86.9/22.6=3,4

Relat 24**(12x2)/7.5=3.2

3.2/3.4=0,94--->94%---.>72

180-72=108

**
I had read in an old tutorial,
better multiply x2 tick towards the bow (in our case 12, and not 12 (bow) +11 (stern) .. and no take more decimal...the aob is still approximate
I feel comfortable using this method
Forgive my bad english
:Kaleun_Salute:

[nazaka]

Okay, but did you get a good look at my test at 2000 meters?

It clearly indicates that the ship's I.D. is incorrect for this vessel.

If we quickly recalculate with the corrected height (27.6m instead of 22.6m), we get:
Theoretical ratio: 86.9/27.6=3.149
observed ratio: the same as before, 3.067 (if we take your approximation of 3.2, we are higher than the theoretical value, not top but comprehensive)

3.067/3.149 X 100=97.4%

And we obtain with the Gegnerlage Berechnungstabelle: 77°.
Let a real AOB of 103

Anyway, all this to say that maybe we should check the values in the ship's identification book.


PS: my english is pretty bad too, I can thank DeepL for the translation

[hauangua]

Okay, but did you get a good look at my test at 2000 meters?

It clearly indicates that the ship's I.D. is incorrect for this vessel.

If we quickly recalculate with the corrected height (27.6m instead of 22.6m), we get:
Theoretical ratio: 86.9/27.6=3.149
observed ratio: the same as before, 3.067 (if we take your approximation of 3.2, we are higher than the theoretical value, not top but comprehensive)

3.067/3.149 X 100=97.4%

And we obtain with the Gegnerlage Berechnungstabelle: 77°.
Let a real AOB of 103

Anyway, all this to say that maybe we should check the values in the ship's identification book.


PS: my english is pretty bad too, I can thank DeepL for the translation

Hi Nazaka
In your test mission ship is
- 2000 m
- 90 aob
Right?... If so really wrong ID book..
Which test mission you play?

[nazaka]

I created him.

If you want to check it out:
https://drive.google.com/open?id=1M2nG8vpO9AIr36tKLJDKzxoz5AHcNPCZ


all you have to do is put it in the "SingleMissions" folder.

You'll find it easily, it's the one without a name (I don't know why).

[bstanko6]

Just to chime in here, you seem to have a handle on this.

The attack wheel on your scope has limitations. Once a ship passes the 90deg range AOB... the markings on the wheel do not align. It's hard to explain without showing. When a ship is going away from you, you will have negative or as you say "erroneous" results. With practice you can still get accurate shots, but the numbers will be in the negatives range.

Good luck!

[nazaka]

Negative value?



no, as the AOB exceeds 90°, the result obtained must be subtracted from 180.


A.3 [In cases when ship is moving AWAY from you] AOB when exceeding 90 Degrees.

1. If the ship is moving away exceeding 90 degrees, use formula:
180 Minus Determined AOB from the steps taking in A.2.


source: https://steamcommunity.com/sharedfiles/filedetails/?id=1541073853&searchtext=disc


bstanko6 (https://www.subsim.com/radioroom/member.php?u=337477), I checked the ship that I had a problem with, and it was an error in notation of mast height that was the cause of it

[bstanko6]

Ah ok. But the problem you named is common. Glad you figured it out.

[hauangua]

I created him.

If you want to check it out:
https://drive.google.com/open?id=1M2nG8vpO9AIr36tKLJDKzxoz5AHcNPCZ


all you have to do is put it in the "SingleMissions" folder.

You'll find it easily, it's the one without a name (I don't know why).

thanks i will try to test and let you know

[nazaka]

Ah ok. But the problem you named is common. Glad you figured it out.


If it's a known concern, why hasn't anyone made a subject to list it?

I just modified the CFG file for the ship in question. And that was accounted for by the ship's identification book.

https://i.imgur.com/j8FHAnn.png

I'm testing most of the ships, I'll give you a summary of the ships to be modified if you wish.

[vdr1981]

I'm testing most of the ships, I'll give you a summary of the ships to be modified if you wish.
That would be very useful...:yep: Thanks!

[hauangua]

If it's a known concern, why hasn't anyone made a subject to list it?

I just modified the CFG file for the ship in question. And that was accounted for by the ship's identification book
But you you have TWoS installed ..? Or other Mod?

[nazaka]

yes, i have TWOS and this list:
https://i.imgur.com/00nyJQA.png

[vdr1981]

yes, i have TWOS and this list:
https://i.imgur.com/00nyJQA.png
Hmm...I'd say with that kind of mod soup you can expect larger problems than just a few incorrect mast height /length values from the rec. manual. Happy (bug) hunting!:salute:

[nazaka]

all my mods are either optional TWOS mods, or translation mods (FRA=French), or the addition of tool to draw (the last EQuaTool)


Thanks, you too :Kaleun_Salute:

[propbeanie]

Look at the dates of some of your FRA mods though nazaka, and they pre-date TWoS... you might also have some you do not really need. There is no harm in removing some of the mods to see if the game then runs better or more reliably on your computer.

The mast height "issue" was there in the rec manuals issued to all submarine skippers, no matter their nationality or the battle fought. There is always erroneous data, no matter the application. This is one of several things the devs did correctly. Also, the game pulls data from more than just the cfg files. Some comes from the sim file, but my mind cannot recall which is which... :salute:

[nazaka]

Hello propbeanie,

I have just made a test by uninstalling the mods different from TWOS, even the translations.

I reinstalled them one by one, and I looked at the files which was modified for each of them. NONE modifies the ships folder ("Sea" folder)

And yes, I'm willing to have 1-meter uncertainties, but when I see certain values, it's scary.

The most telling example is the hospital ship.
Mast height before modification: 33m
Height of mast after verification: 39.5m

If you want to keep playing with such a mistake, no worries.
I don't.

[propbeanie]

Those aren't necessarily "mistakes" is what I'm saying about the mast height figures. Pre-war, the merchant marine of various nations had information on their own, and other nations ships, generally freely available from various sources. After the war started, the merchant marine of a given nation would think to themselves "how can I make it more difficult for a submarine to target my ships accurately?" So they would cut the height of the masts, or add more to them. Thinking further, if they would paint geometric shapes of various colors on the side of their ships, that would also "break the lines" of the ship as you were viewing it in the periscope at a distance, such that it might look much further away than it was, or much closer. Add a fake stack to alter the outline, or with a fake bow splash painted on, it would change the appearance of its speed. There were various "tricks" they used in attempts to make it to where the submarine skipper would miss a particular ship more often than not, if they weren't able to get in close and at a 90° track to their target, such that none of that matters. You just basically point and shoot then... but with "unreliable" targeting information, such as in the game's recognition manual, it is more like what a kaleun actually had to deal with... ??

By the same token, I also understand your desire for reliable information. It is a real bother to track a convoy for 12 hours or longer, waiting for dark, maybe rougher seas - some rain would be good, get your boat on a good intersect course, split through the escorts, only to be off several hundred yards on your track and the range is 1200 and not 900 meters, and then miss with three torpedoes behind, in spite of corrections... Perfect line-up and spread, other than the mast height was off by 6.5 meters, or whatever... :salute: