An explanation is needed for the AOF finder re Aob

[I'm goin' down]

I do not play SH3. I play ATO (SH4.) I am posting here because not many captains post in the ATO forum.

I am famailiar with the AOBF, and use it always. I have read the tutorial by kazarmozovnew, and am familiar with it. In the tutorial example, he determines the Aob of a German Battleship. Because the periscope is set to 6x zoom, the Aob for the Battleship, per the example, is 52 degrees (i.e. your multiply the reticules for the battleship's length (13) by 4.) The AOBF calibrates to 50 degrees which is astride the verticle line on the top of the wheel, and he determines the 52 degrees mark on the 'wheel' via logarithims (his tutorial says that the scale is "logarithmic.") He provides no other explanation or examples. I do not understand the concept and how it fits into the using the wheel.

I just had an encounter with a target moving away from my boat, where the wheel readings where far in excess of the reading on the vertical line on wheel, and frankly, I lacked the expertise to calculate the Aob. Is there an explanation somewhere? I am not sure where to look. Someone who is familiar with the wheel and with karamozovnew's tutorial would be the person who might be able to give me a thorough response. I could not copy the relevant pages of his tutorial, which are unnumbered, as it is in Adobe format.

[postalbyke]

If a ship is moving away from you, use the AOBF the same way, but when you receive your answer (it should be a small number, right?), subtract it from the 180' mark with the appropriate aob side.

Wait...

What precisely do you mean by the wheel readings being in excess of the markings on the... umm... word?

On second thought, let me look at the KMN AOBF as I use the Makman AOBF... (which is based on someone elses...)(edit: no, it's makman's)

[I'm goin' down]

take a look at karamazovnew tutorial. then read my post. Otherwise, you may be analyzing a different mod.

[postalbyke]

Round 2!
Okay, if the number is too big to fit on your RAOBF, the "logarithmic" is how to Figure this out.
Word.
You'll notice that the numbers go up to a certain point (say 300 or so), then the next number is like... 4, right? (or in this case (from what I glimpsed), 5)
that number is actually doing double-duty now. It not only means "5," it also means "500." The logarithmic scale of the circle (math-talk) allows the small numbers to accurately represent large numbers, also! It's the same with the inner scales, so "scale as appropriate!"

Am I speaking english?... Someone fix both of us.

[I'm goin' down]

I think I need someone to post the wheel and provide examples. In the abstract, I am not able to visualize it.

[Pisces]

Can you post the link to the tutorial? I can't seem to find it. I'll try to clarify later today.

[I'm goin' down]

The KIUB Users Guide is one of the "Support" files in the "OMEGU_v300_pkg" download. This download link can be found in the ATO forum in either the OM or OMEGU thread (perhaps both threads?) When you open the download, you will see a Support folder. It contains the KIUB Users Guide.

The KIUB Users Guide explains how to use the wheel. First it discusses range, then target speed, then Aob. It is the discussion of Aob, with the Bismark moving away, where kasmarovnew breifly discusses logarithims.

Here is the link to the download. http://www.subsim.com/radioroom/downloads.php?do=file&id=1336&act=down

Here is the link to OMEGU. http://www.subsim.com/radioroom/showpost.php?p=1211610&postcount=1

[Pisces]

I do not play SH3. I play ATO (SH4.) I am posting here because not many captains post in the ATO forum.

I am famailiar with the AOBF, and use it always. I have read the tutorial by kazarmozovnew, and am familiar with it. In the tutorial example, he determines the Aob of a German Battleship. Because the periscope is set to 6x zoom, the Aob for the Battleship, per the example, is 52 degrees (i.e. your multiply the reticules for the battleship's length (13) by 4.) The AOBF calibrates to 50 degrees which is astride the verticle line on the top of the wheel, and he determines the 52 degrees mark on the 'wheel' via logarithims (his tutorial says that the scale is "logarithmic.") He provides no other explanation or examples. I do not understand the concept and how it fits into the using the wheel.Well, that 52 isn't the AOB. That 52 is the amount of horizontal marks the Bismark would measure up to in 6x view. (from bow to middle) And it isn't even degrees, or 2 degrees per mark, despite what the manual says. The (green) mark spacing is actually 1.55 degrees in 6x view, and 6.22 in 1.5x view. If that range of 2700m and 57m height is correct anyway. So, if you can't get the numbers to match what the naked eye would see, then that may be why.

The 52 points to the AOB, on the smallest wheel scale. The 52 points to the AOB because the range (2700m) was previously aligned with Bismark's actual length (251m). What happens here is Logarithm Magic. (wiki ;) ) (http://en.wikipedia.org/wiki/Slide_rule) Those scales are aligned in a certain way to start a series of multiplications and divisions with those numbers. (divisions are the opposite of multiplications)

By aligning 251m length with 27 (hundred meter range) you set the ratio 9.3 into the device. (251/27=9.3) For example: start looking to 251 on the outside scale, jump across to the adjacent scale to 27, go counterclockwise to 1(00), and back across you'll find the 93-ish mark on the most outer scale. (the scales are probably skewed a bit due to graphical editing) Anywhere along the circle you'll find the same ratio, if you divide the opposing numbers the same way. The amount you turned the wheel represents the multiplication or division factor. One full turn of the wheel make a multiplication by 100, ... or 0.01 if you go the other way. One half lap of the wheel is a multiplication of 10, or 0.1 if you go in reverse. Notice how 10 is opposite the 100 on the two outer scales. Those are pure logarithmic scales.

The two scales on the inside contain different mathematical functions, aswel as being stretched according to logarithm magic. The AOB scale (smallest wheel) contains the sine function (trigonometry). The smallest of the middle wheel is sort of a tangent function (trigonometry function again). There is also a built-in multiplication factor in the middle wheel. The scales on it are shifted against eachother.

Ultimately, the alignment of numbers points to a mark on the AOB scale (smallest scale) that is the end result. This point along the AOB scale is really a number that is division of length_in_view by length_true, corrected for range. (also a sort of multiplication/division) The sine function in that wheel turns it into degrees again.

But there is actually another hidden ratio in this particular mod's wheels. Notice how the 90 degree mark isn't exactly on top! In the original mod, 90 would be at the top, since the sine of 90 degrees is 1. The same place as the mark for 1 or 100m length or height. The mod maker must have rotated this wheel to correct for screen resolution differences. Now 64 degrees is on top, the sine of it is 0.9. This prevents me to explain why exactly certain lines line up to make the AOB calculation, since I don't know the specifics of the formula behind it in this one.

Sorry about that. I hope the Wiki is better at explaining this Logarithmic magic.

[I'm goin' down]

thanks for the tutorial, which I did not understand by the way. (not a sufficient math background on this end, but I guess the Navy needed all the captains they could get.) All I want to know is how to read the no. of degrees on the degree scale when the reading on the spinning dial exceeds 50 degrees per the example in the tutorial. You can use the settings for the Bismark to provide some examples, and if you can provide screen shots that would be helpful. Once I understand it, then I can try different scenarios and see if I understand the concept.

[Pisces]

... All I want to know is how to read the no. of degrees on the degree scale when the reading on the spinning dial exceeds 50 degrees per the example in the tutorial. ...Ok, in a nutshell: just move the decimal dot of the 'degrees' value 2 steps left. (divide by 100) That's all there is to it. The mark for i.e. 55 would be at the exact same spot as the one for 0.55. The screenshot you want is already in the manual on page 6. The manual writer added the red numbers 60 and 55 to identify the marks they are equivalent to. 60 would be at the 0.6 'degree', and 0.55 is the mark for 55 'degrees'. 0.7 is 70.

Why? Because in this circular logarithmic scales a full lap clockwise makes numbers exactly 100 time bigger, or in reverse direction 100 times smaller. Writing both numbers at the same mark would just make things crowded. Whoever made those wheels, decided to start the scale at 0.5 and go to 50. But it could just as easily be starting at 1 and ending at 99.999999.

The mark for 52, or 0.52, isn't there, so you have to guesstimate where it falls in between 0.5 and 0.55. The red number 2 points to where it is.

The AOB is just across it on the smallest wheel.

[I'm goin' down]

In the example in the tutorial, what you seem to be saying is the marks on the inner dial on the wheel are spaced apart by 5 degrees once you pass the 50 degree setting? Is this correct?

Assuming it is, are you also saying that in every situation using the wheel, the marks are 5 degrees apart? If so, great. If not, how do I determine the number of degrees that is appropraite in a particular situation?

[Pisces]

In the example in the tutorial, what you seem to be saying is the marks on the inner dial on the wheel are spaced apart by 5 degrees once you pass the 50 degree setting? Is this correct?

Assuming it is, are you also saying that in every situation using the wheel, the marks are 5 degrees apart? If so, great. If not, how do I determine the number of degrees that is appropraite in a particular situation?First of all, they are not degrees! Becarefull with that name, it's going to mess up your mind and sense of direction. They are the number of marks in the reticule. It's a kind of angle, but they are not 360 degrees in a circle.

If you look closely you see tall and shorter marks on that scale. Between 0.5 and 1 the larger marks are in steps of 0.1, with the smaller marks in between at the 0.05 intervals.

But between 1 and 1.5 the marks all look alike. So you have to count them, and see what number-space they they encompass. There are 10 spaces between 1 and 1.5. So this means these marks are in steps of 0.05 .

Beyond 1.5 it's in steps of 0.1 again.

http://members.home.nl/rico.v.jansen/AOBF_Inner_marks.png

Between 3 and 5 it's in steps of 0.2.

After that the step size repeats the same as on the opposite side of the wheel. Only, it is in a relative sense. 0.5 is followed by small mark 0.55. 5 on the opposite side is followed by small mark 5.5. They both are the same number of pixels appart on the scale, but value-wise the step is 10 times larger.

With logarithm scales the relative sizes of the numbers matter, not the absolute differences.