Mathematical View of AoB

[rgrlee71]

Hi,

I am a noob to submarine sims as a whole (sh4 is my first). I am however versed at trig, but wasn't understanding "where" the AoB was coming from. I kept thinking that the bow of your sub was taken into account and that somehow intersected your targets heading to create the angle. It seems that, in these forums, that the AoB comes up a lot and even the video tutorials don't explain where the angle really comes from. So I spent a few minutes in the Nav map and came up with a visual representation of "what" the AoB really is. I turned on autotargeting to see what the angle the computer set for the target, then used the drawing tools to map it out.

Many of you probably know this, but for those who don't and may want to plot it here are the images.




1) With the compass and protractor you can see that if you draw your normal target course line and a line from the center of your sub to the center of your target, the intersecting angles are about 22 degrees.




2) This image is what the auto-targeting computed.





So, incase there are those that are confused about where this angle comes from, you now have a graphical representation of AoB.

[XLjedi]

I drew these last year to help explain AoB, perhaps they might be useful here...





Just a quick (and mathematical) way to calculate AoB if you know your sub course is on a 90° beam to the target true course.

Now you shouldn't need the auto-target to compute it.

[rgrlee71]

aaronblood,

Thanks for the addition. I'm just starting to do manual targeting, but I plan on leaving contact updates on. It's fun playing with the plotting tools to find the angles, makes it a little more immersive, even if the auto-updating is semi-cheating

[SteamWake]

Originally Posted by aaronblood

I drew these last year to help explain AoB, perhaps they might be useful here...





Just a quick (and mathematical) way to calculate AoB if you know your sub course is on a 90° beam to the target true course.

Now you shouldn't need the auto-target to compute it.

Thats some nice stuff right there... nice job !

[I'm goin' down]

excellent graphical representation. (I make my son wear a copy pasted to his forehead, so I am sure not to forget it.) the AOB concept is important to understand on a theoretical level and these examples make understanding it quite easy. it goes hand in hand with Hitman's tutorial on manual targeting, and makes attacking with the SCAF mod much easier to understand.

[Nisgeis]

If you want to know conceptually what the AoB is, then think of yourself standing on the bow of the ship you are targetting. Look to port or starboard until you can see the attacking submarine. That relative bearing to the submarine is the ship's AoB.

I have seen AoB poorly explained, because they use very simplified set ups that give you the impression that the AoB is something that it is not, by using examples of only 'ship due east of you sailing towards you at AoB 0' and 'ship sailing due west away at AoB of 180'.

Hope that helps you visualise what it is you are working out.

[cleverusername]

AOB is basically your position relative to the target ship. Or, pretend you're on target ship and you're looking at ownship. What is its bearing? That's AOB.

[XLjedi]

Originally Posted by cleverusername

AOB is basically your position relative to the target ship. Or, pretend you're on target ship and you're looking at ownship. What is its bearing? That's AOB.

That's only true if ownship's bearing is to starboard. If ownship is to port then you have to subtract 270° from the bearing.

[Frame57]

Bow to bow. The WW2 skippers and officers and quartermasters had to be so good at this, they could just look and determine AOB with great accuracy. using the bearing marker and line of sight to the targets bow brings it in resonably accurate for me. Of course i am always second guessing myself...

[I'm goin' down]

My key point was that it was an good graphical representation. There are several ways to learn: Seeing, reading, and hearing are key techniques to aid thinking. The post involveses visualizing AOB. For someone who is just being introduced to the concept it makes understanding it easier. Nisgeis post is also a good description, but does not contain a grahpical representation. The benefit of graphics is that it displays the various angles that are in play

To understand the importance of AOB applied in an attack scenrio is another issue, and Hitman's tutorial, where aspect ratio is manually calculated and converted to AOB is another ball game, but is useful as a next step because you have the oppurtunity to appreciate its relationship to torpedo attack schematics. Hitman's tutorial culminates in brilliant fashion with a screen shot of Attack Map displaying the results of his tutorial, i.e. the target's Range and projected course pegged to perfection by the TDC with a white "x" and directional line. That screen shoot is follwed by another showing the aftermath of his labors (i.e. the torpedoes' impact). I used his tutorial until I was comfortable with the method, and then moved on to the SCAF mod, which eliminates the need for doing the math he prescribes.

[XLjedi]

Originally Posted by rgrlee71

...It's fun playing with the plotting tools to find the angles, makes it a little more immersive...

If you like the math, graphing, and so forth, you might like using the electronic maneuvering board that I used. It's free you know.

[Rockin Robbins]

Originally Posted by aaronblood

If you like the math, graphing, and so forth, you might like using the electronic maneuvering board that I used. It's free you know.

Sheesh aaronblood, you can't bring yourself to promote your brainchild to save your own life! OK, guys, his program is MoBo: the electronic maneuvering board and Christmas cookie maker. You got me, I made up the part about the cookies, but it's almost that good. Now here's how you do it.

The Link

Now quit being so darn modest and get these people some help!

[XLjedi]

Actually, I'm just sneaky...

[Nisgeis]

Originally Posted by cleverusername

AOB is basically your position relative to the target ship. Or, pretend you're on target ship and you're looking at ownship. What is its bearing? That's AOB.

That's what I said

[Rockin Robbins]

Actually if you're a German U-Boat, your bearing from the target is all that needs to be said because the Germans measured the bearing as 0 to 180 from the starboard or port bow. They'd say the target bears 45º port.

The American bearing system is a 360º system to avoid confusing starboard and port. The German bearing 45º port would be 360-45 or bearing 315º.

That's why I've been caught saying that angle on the bow is nothing more than your bearing from the target using the German system. No graphs necessary.