Quote:
Originally Posted by 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.
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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 
) 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.