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Old 04-01-07, 04:19 PM   #1
aso544
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Default Angle Of Bow.......Quick Question

What is AOB based on? The bow /heading of my sub to the target or the bearing from my TDT/Periscope to the target?

What is the best way to plot my sub and my target to determine the AOB? Can i use my attack map?

Sorry, slightly struggling on the manual TDT although the video really helped minus this one areas.
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Old 04-01-07, 04:43 PM   #2
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AoB is the bearing of your sub as seen from the target, i.e. you must take the position of the target's skipper who is looking at your sub. If the target is heading straight at you, the AoB is 0, if it is showing his entire broadside to you the AoB is 90.

AoB can be estimated by sight or plotted on the map (draw course of the target and measure the bearing to your sub)
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Old 04-01-07, 08:12 PM   #3
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If he is heading straight toward me that AOB is "0", but what if he is heading to my starbord side (90 degrees)? Is the AOB still zero or does my bow heading factor into this equation as well?
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Old 04-01-07, 08:35 PM   #4
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No, your bow heading doesn't matter. As LST said, all angle on bow means is where you are in relation to his bow. Think of it this way, if the other ship's watch crew spotted your submarine, they would call out "Submarine spotted, bearing ___" That number would be the AOB.
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Old 04-01-07, 11:06 PM   #5
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I think mainly why people get confused about AOB is because most people write it out as "Angle of Bow" or "Angle on Bow." It's actually "Angle Off Bow" which, if you think about it in relation to the target, makes a whole lot more sense (at least to me).
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Old 04-02-07, 12:50 AM   #6
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Quote:
Quote:
Originally Posted by mookiemookie
No, your bow heading doesn't matter. As LST said, all angle on bow means is where you are in relation to his bow. Think of it this way, if the other ship's watch crew spotted your submarine, they would call out "Submarine spotted, bearing ___" That number would be the AOB.
Not quite. AOB (Angle on the Bow) has to include Port or Starboard--the target's port or starboard side as seen by the sub. AOB can therefore never be numerically greater than 180 degrees. In your example it would be possible for the submarine to be bearing 270 relative, and thus give an AOB of 270 (without port or starboard, which renders it incorrect too.) An AOB of 270 isn't possible.

AOB is taught in USN Sub School (the real one, not the one in the game <g>) using vectors. The Line-of-Sight (LOS) is an imaginary line extending from the center of the observer's vessel (sub) through the center of the target. The vector is the target's course (AOB results) and speed (length of vector.) If the target's bow is to the right of the LOS it's a starboard AOB; left it's a port. Broadside is a 90 AOB, either port or starboard, etc. The AOB is the angle between the LOS and the TARGET'S bow.
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Old 04-02-07, 06:53 AM   #7
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Originally Posted by Snowman999
Quote:
Quote:
Originally Posted by mookiemookie
No, your bow heading doesn't matter. As LST said, all angle on bow means is where you are in relation to his bow. Think of it this way, if the other ship's watch crew spotted your submarine, they would call out "Submarine spotted, bearing ___" That number would be the AOB.
Not quite. AOB (Angle on the Bow) has to include Port or Starboard--the target's port or starboard side as seen by the sub. AOB can therefore never be numerically greater than 180 degrees. In your example it would be possible for the submarine to be bearing 270 relative, and thus give an AOB of 270 (without port or starboard, which renders it incorrect too.) An AOB of 270 isn't possible.

AOB is taught in USN Sub School (the real one, not the one in the game <g>) using vectors. The Line-of-Sight (LOS) is an imaginary line extending from the center of the observer's vessel (sub) through the center of the target. The vector is the target's course (AOB results) and speed (length of vector.) If the target's bow is to the right of the LOS it's a starboard AOB; left it's a port. Broadside is a 90 AOB, either port or starboard, etc. The AOB is the angle between the LOS and the TARGET'S bow.
D'oh! Forgot to mention that part about it being relative to port or starboard. Ah well, I knew someone would come along and explain it better than me.
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Old 04-02-07, 07:40 AM   #8
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Concur with snowman999. As a current instructor at Naval Submarine school I can backup snowman's claim. Also, as for the term angle off the bow...that is incorrect...we here at subscol have an impressive array of references...and believe it or not one of our more important ones I am going to share with you right now...we would appreciate it if you didn't share this with any Navies foreign.

www.google.com

Don't get me wrong...we have bowditch and notice to mariners as well as some other instructions and what not...but before we crack open a book...most of the time I google it due to the fact some nice soul out there has taken the info and put it on the internet. Hope I didn't bust anyone's bubble by letting the reference out.

Anyhow, with a little bit of ingenuity I googled angle on the bow and came out with the following:

Angle on the bow -- Relative bearing of submarine from the target ship measured to starboard or port from the target ship's head from 0° to 180°. (ref: http://www.history.navy.mil/library/online/ss-doc-4.htm )

Also looked through this link only because of all the different fleet boat terminology which was cool: http://www.maritime.org/fleetsub/chap2.htm

This one is a good link that some guy converted over into SH3 terminology and images and posted on the subsim forum: http://images.google.com/imgres?imgu...%3Den%26sa%3DN

This one has a great illustration...treat the arrows as your sub and all you have to determine is whether your seeing the port side or the starboard side of the ship so for the example given those are all starboard angle on the bows except for the 0 and 180 degrees: http://www.sailingusa.info/current_deviation.htm

You could go on and on looking for stuff if you like.

I hope this helps you and good hunting and remember...if you got a 90 degree angle on the bow at 1000yards or less...let them fish fly and send them japs to the bottom.
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Old 04-02-07, 08:27 AM   #9
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Quote:
Originally Posted by Tieg
This one is a good link that some guy converted over into SH3 terminology and images and posted on the subsim forum: http://images.google.com/imgres?imgu...%3Den%26sa%3DN
That "some guy" is "Onkel" Neal Stevens, webmaster of Subsim. :rotfl:
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Old 04-02-07, 08:40 AM   #10
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Webmaster??? as in God???

Only 2 things come from Texas....

Webmasters and ..... well lets just leave it at webmaster...don't want to get excused from the website
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Old 04-02-07, 09:50 AM   #11
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Quote:
Originally Posted by mookiemookie
Quote:
Originally Posted by Tieg
This one is a good link that some guy converted over into SH3 terminology and images and posted on the subsim forum: http://images.google.com/imgres?imgu...%3Den%26sa%3DN
That "some guy" is "Onkel" Neal Stevens, webmaster of Subsim. :rotfl:
Dang, I wish SH4 had the same tools for computing / plotting the AOB. The post in this thread did help me in figuring out AOB though.....hopefully!

Thanks guys!!!
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Old 04-02-07, 10:31 AM   #12
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Not an expert here by any measure....but this is what I usually do.

If you have a plot line for the target's course just use the angle tool on the map. It takes three clicks. The first one is just out in front of your target along its course, the second click is at the bow of the target ship. The third click is back on your sub. The angle displayed should be the AOB value, then you just need to notice whether his port or starboard is presenting to you and Yahtzee. Pretty quick and painless if you have a good idea of the target's course and has been working well for me.

-happy hunting
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Old 04-02-07, 01:02 PM   #13
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Concur with snowman999. As a current instructor at Naval Submarine school I can backup snowman's claim.
Thanks. I graduated SOBC in 1981; it's been a while.
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Old 04-02-07, 01:12 PM   #14
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If you have a plot line for the target's course just use the angle tool on the map. It takes three clicks. The first one is just out in front of your target along its course, the second click is at the bow of the target ship. The third click is back on your sub. The angle displayed should be the AOB value, then you just need to notice whether his port or starboard is presenting to you and Yahtzee. Pretty quick and painless if you have a good idea of the target's course and has been working well for me.
I don't have the game, so I don't know how the plots work yet, but the problem with this idea is that the AOB is HOW you determine target course. And it has to be assessed by the Approach Officer from a couple of grainy, watery looks. You can't take three bearings, connect them, and call it a course because bearings are the result of relative motion--you're on a moving observation platform. You also don't know the target's speed (yet) and bearing presentation is affected by speed. A close, fast contact will have little bearing change if it has a narrow AOB; a distant, slow, broad contact will show the same bearing change. One is a collision, the other a pretty picture.

The AOB is critical. It establishes the target course--the "track"--which gives the distance-to-the-track, which gives the optimal approach course and speed, and ultimately, gyro angle. Unlike speed (sonar) and range (stadimeter), AOB depends on the skill of the Approach Officer and years of practice.
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Old 04-02-07, 02:22 PM   #15
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I don't have the game, so I don't know how the plots work yet, but the problem with this idea is that the AOB is HOW you determine target course. And it has to be assessed by the Approach Officer from a couple of grainy, watery looks. You can't take three bearings, connect them, and call it a course because bearings are the result of relative motion--you're on a moving observation platform. You also don't know the target's speed (yet) and bearing presentation is affected by speed. A close, fast contact will have little bearing change if it has a narrow AOB; a distant, slow, broad contact will show the same bearing change. One is a collision, the other a pretty picture.

The AOB is critical. It establishes the target course--the "track"--which gives the distance-to-the-track, which gives the optimal approach course and speed, and ultimately, gyro angle. Unlike speed (sonar) and range (stadimeter), AOB depends on the skill of the Approach Officer and years of practice.
In real life, perhaps, and for the manual purist who wants to do it like they did it. I'm not pretending to be an expert as I indicated in my first post, but I have found that I can get a pretty good solution using the method I described.

To clarify, I'm not talking about taking three bearings, the way to angle tool works on the map requires three clicks in quick succession. Like I stated the first click out in front of the target along it's projected course, another click at the target bow and the last click on your sub will draw an angle on the map which represents the AOB (at least roughly). In my limited experience a decent way of getting an AOB value in a relative hurry at a single point in time when you have a pretty good idea of the target's course (map updates on, or through visual contact, or sonar contacts over time).

For example, make visual contact with target, mark location on map. Make another mark in 3 minutes. You can use this to get a rough idea of speed and if you a draw a line through those two marks you get a pretty good estimate of course. You can then use the angle tool to grab a AOB measurement. Go to Scope and take bearing and distance and enter speed and AOB and you should have a decent solution that usually requires a tweak here or there. I'm not claiming that this is the offical way to do it, but the original poster asked for ways to calculate AOB and I offered one way that works for me in the game.

-happy hunting

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