Confusion in AOB

[cmdr_loslos]

Ok so here I have 3 screenshots while doing the tutorial mission in wolfpack.
The below is a pic of type 12:
Screenshot (17).jpg

This one is also the same ship taken showing the front of the sub:
Screenshot (18).jpg

And this one is taken on the map:
Screenshot (16).jpg

I want to start by saying I am finding it really difficult to find aob by imagining myself on target ship so, I was trying to find the aob by using the map and plotting my bearing at which I saw the ship and the range the ship was at so that (maybe) I could find aob using some simple geometry but the pickle was that I didn't know the target ship's course. (Also in the last pic it shows that type 12 is headed on a course making an obtuse angle but in the first 2 pics it seems like the course of type 12 is a straight line which also is really confusing) So is there any other way I could try to find aob or do I just have to imagine myself on the target ship to find it?

[derstosstrupp]

Check the first 2 slides here (basic plotting, and deriving course/AOB), these should help.

https://drive.google.com/drive/folde...dAroe9botffqR_

[Pisces]

Unfortunately the screenhots you showed get reduced in size, so it is very hard to see it. Jpeg compression doesn't make it better either. (there are site to which you can upload the images for a limited time and it shows them in better quality. like imageur.com, postimage.org, imgbb.com)

But if you look at the map image then you'll see that they, all three of them, are showing about the same AOB: around 135 left/port. With a bit of effort because of the image-quality I notice that I can look into the backside of the front structure, and not to the front of the back structure.

(On second thought, my draughtsman eye suggests it is closer to AOB 120 left.)

Can this be refined or narrowed down or proved? With more experience for certain. But as a rough first guess you can take it as it is. You see it has 2 sets of kingpost masts. Meaning 2 times side-by-side masts. If you set the bearing tracking selector to this (attack) periscope, then set the AOB to 135 left. Turn the attack periscope about 45 degrees left to get the AOB needle to point down to 180. Then notice the angle at the bottom. Turn to that course to go parallel. (Or what we think is parallel) When you are surfaced and moving faster than it then you will see those masts converge. And when they do you know the AOB if 90 degrees. And you can refine the AOB setting in the TDC for more accuracy. After that you can try to look at the ships from different positions (as you move around it) and see how those relate to the TDC AOB dial at that moment. That helps you learn to distinguish AOB better.

It also helps to compare its shape with the recognition manual. In your imagination try to match the size of the recognition manual side-on view to the actual view. And see how much it looks shorted. 25% the side-on length indicates an AOB of 15 (or 165) degrees. Halve the size of side-on indicates AOB of 30 (or 150). 70% of side on indicates (45 or 135) degrees. 90% indicates 65 (or 115) degrees. The above does suggest there is a mathematical relationship between the length and height ratios of observed versus true size. It's by the law of sines. But it will go quicker if you learn to do this by eye rather than spend minutes measuring and calculating it.

[cmdr_loslos]

Originally Posted by Pisces

Unfortunately the screenhots you showed get reduced in size, so it is very hard to see it. Jpeg compression doesn't make it better either. (there are site to which you can upload the images for a limited time and it shows them in better quality. like imageur.com, postimage.org, imgbb.com)

But if you look at the map image then you'll see that they, all three of them, are showing about the same AOB: around 135 left/port. With a bit of effort because of the image-quality I notice that I can look into the backside of the front structure, and not to the front of the back structure.

(On second thought, my draughtsman eye suggests it is closer to AOB 120 left.)

Can this be refined or narrowed down or proved? With more experience for certain. But as a rough first guess you can take it as it is. You see it has 2 sets of kingpost masts. Meaning 2 times side-by-side masts. If you set the bearing tracking selector to this (attack) periscope, then set the AOB to 135 left. Turn the attack periscope about 45 degrees left to get the AOB needle to point down to 180. Then notice the angle at the bottom. Turn to that course to go parallel. (Or what we think is parallel) When you are surfaced and moving faster than it then you will see those masts converge. And when they do you know the AOB if 90 degrees. And you can refine the AOB setting in the TDC for more accuracy. After that you can try to look at the ships from different positions (as you move around it) and see how those relate to the TDC AOB dial at that moment. That helps you learn to distinguish AOB better.

It also helps to compare its shape with the recognition manual. In your imagination try to match the size of the recognition manual side-on view to the actual view. And see how much it looks shorted. 25% the side-on length indicates an AOB of 15 (or 165) degrees. Halve the size of side-on indicates AOB of 30 (or 150). 70% of side on indicates (45 or 135) degrees. 90% indicates 65 (or 115) degrees. The above does suggest there is a mathematical relationship between the length and height ratios of observed versus true size. It's by the law of sines. But it will go quicker if you learn to do this by eye rather than spend minutes measuring and calculating it.

I get what you are trying to say. One question tho, how do you know the aob is 135/120 port(without the map) because to me ship's course looks completely horizontal to me which therefore makes an angle <90 for me? This is the only thing that I have been getting stuck on everytime.

[blackswan40]

Hi cmdr_loslos this may help some i have these printed and laminated

[stellaferox]

To me the pics (though small) make perfect sense. The ship is on a port course and you can see the masts are separated in perspective with a direction away from you, so the AOB MUST be in between 90-180 port. A bit of experience is needed to guesstimate the course at about 130 deg (without seeing the map). I had trouble with this too and started using the sub buddy app which you can use to train yourself in the AOB. I now rarely have more then 5 deg difference from the real course.

BTW: don't use the perspective from the target. Just use your common geometric sense which you learn at school to estimate the angle from your own viewpoint.

[Pisces]

Originally Posted by cmdr_loslos

I get what you are trying to say. One question tho, how do you know the aob is 135/120 port(without the map) because to me ship's course looks completely horizontal to me which therefore makes an angle <90 for me? This is the only thing that I have been getting stuck on everytime.

I'm confused with what you mean with 'horizontal'. As a ship that goes 'vertical' is in the ending stages of sinking. (they don't go bow or stern up in this game though, until the developers improve the mechanics)

I use the walls of the buildings (structures) and island ridges to tell which way it is oriented. Can you see the front-side or the back-side of them? Do the island ridges of the deck overlap in a way that the port or starboard side hides the other? Do forward objects obscure things that are located more aft? (or the other way around) In these images it is quite hard to see it because of compression. But it probably would show better in a pure screenshot. It can be quite tricky to see whether they are turned away or towards you. It's like the 'old woman or young woman' illusion sometimes. But when you see the details only 1 should work.
Example 'old woman or young woman' : (spoiler button because Youtube preview image is too big)

 

[Pisces]

Originally Posted by blackswan40

Hi cmdr_loslos this may help some i have these printed and laminated

I can see the links when I reply/edit this message. But your links don't load in my browser. Not even when visiting the links directly. You sure they work ok? (Using up-to-date Chrome myself)

[blackswan40]

Hi Pisces those images are uploaded to my Wolfpack Bdu Photo Album on Subsim i see them even when on another Computer at a different loction

I use firefox as my main browser but also have chrome.

[cmdr_loslos]

Originally Posted by Pisces

I'm confused with what you mean with 'horizontal'. As a ship that goes 'vertical' is in the ending stages of sinking. (they don't go bow or stern up in this game though, until the developers improve the mechanics)

I use the walls of the buildings (structures) and island ridges to tell which way it is oriented. Can you see the front-side or the back-side of them? Do the island ridges of the deck overlap in a way that the port or starboard side hides the other? Do forward objects obscure things that are located more aft? (or the other way around) In these images it is quite hard to see it because of compression. But it probably would show better in a pure screenshot. It can be quite tricky to see whether they are turned away or towards you. It's like the 'old woman or young woman' illusion sometimes. But when you see the details only 1 should work.
Example 'old woman or young woman' : (spoiler button because Youtube preview image is too big)

 

What I mean by 'horizontal' is that the sub's front and the target ship's course make 90 degrees which makes make me think that the target ship is moving horizontal or in a straight line perpendicular to my sub's front.

[cmdr_loslos]

Originally Posted by stellaferox

To me the pics (though small) make perfect sense. The ship is on a port course and you can see the masts are separated in perspective with a direction away from you, so the AOB MUST be in between 90-180 port. A bit of experience is needed to guesstimate the course at about 130 deg (without seeing the map). I had trouble with this too and started using the sub buddy app which you can use to train yourself in the AOB. I now rarely have more then 5 deg difference from the real course.

BTW: don't use the perspective from the target. Just use your common geometric sense which you learn at school to estimate the angle from your own viewpoint.

Thank you for the info. I'll try to practice all methods recommended in this post.

[Pisces]

Originally Posted by blackswan40

Hi Pisces those images are uploaded to my Wolfpack Bdu Photo Album on Subsim i see them even when on another Computer at a different loction

I use firefox as my main browser but also have chrome.

PM inbound. I do not see album index numer 1246 in your public albums: https://www.subsim.com/radioroom/album.php?u=239240

[Pisces]

Here are some examples of what I mean. I took these screenshots from the UZO. And a bit too much closer than you would normally risk. I did not actually do the tracking for this either , so I don't know what the correct AOB would be. So they are only for illustrating purposes only. You should maneuver to verify the actual AOB with more precision at a later stage.

Somehow the images also show 150%-200% enlarged when viewing in my browser. They are 1920x1080 in size.

Image: (spoiler because image shows too large)

 

In this image the funnel is aft of mid-ship. Split structures and you can see between the two. Even the stairs leading up to the 1st upper deck of the bridge-structure from behind. You can see the front island. The far edge is completely obscured by the near edge, suggesting AOB <90. You can more clearly see the front face of the bridge, and the front of the engine building. So again AOB<90. Also the spread of the masts can give away AOB. The aft mast is an +-configuration when seen from the top-down/bow-up view. It depends on where the sunlight comes from but those starboard masts are grey indicating inclined toward you (less illumination angle). The tip of the starboard boom is about 1/5th between the center mast and the aft boom tips on the far side. Indicating the AOB is about 10 degrees (sin(11) is about 0.2) forward of beam so about AOB 80. It's a first guess, so don't put your money on it. But lacking anything else you could use it in a pinch. Rather, confirm it when passing another ship. Or move in front of it and determine when the mast covers the funnel exactly.

Image: (spoiler because image shows too large)

 

This one is further away and also near AOB 90 starboard. Here you can only see the backside of the bridge. And just before it is covered by the funnel structure. You might even see some of the back-face of the cargo-boxes. (slight shading difference) The booms on the mast give a bit better indication on how much the angle differs beyond 90 degrees. The aft booms on the 3rd mast (+-configuration) suggest it is between 135 and 90, maybe closer to 135. Lets say 120. Again, it's a first guess. Move up to the pont where mast booms overlap exactly and front and back faces disappear. That is where 90 degrees AOB is most exact.

Image: (spoiler because image shows too large)

 

This one is the same as before. But harder to tell if it is less or more than 90 AOB. You could settle it as that. But depending on your interpretation of the illumination of the mastboom it might be possible to distinguish which side. The darkened boom of the 3rd mast (likely towards you, as the brighter one is also obscured at the bottom) is still in front of the mast itself. Suggesting you are looking from behind, thus AOB>90. But not by much. Maybe only 5 degrees.

Again, confirm this from another position when you can notice a specific angle. From the side, right in front, or right behind if you have no other choice. But approaching submerged from the front you have more tactical advantages. You are not taking the AOB to shoot now. From behind or from the front you are on his course line. So just by noting the bottom indication on the attack periscope (true bearing) you know the course or its reciprocal. (the opposite way) The TDC remembers the setting you make and translates it to the target course which it keeps internally. When you look at it from another angle then the AOB dial (also with the right selector setting) should show the right value. Unless the target turned in the mean time. Guessing the AOB should be considered a cheap investment for later.

[cmdr_loslos]

Originally Posted by Pisces

Here are some examples of what I mean. I took these screenshots from the UZO. And a bit too much closer than you would normally risk. I did not actually do the tracking for this either , so I don't know what the correct AOB would be. So they are only for illustrating purposes only. You should maneuver to verify the actual AOB with more precision at a later stage.

Somehow the images also show 150%-200% enlarged when viewing in my browser. They are 1920x1080 in size.

Image: (spoiler because image shows too large)

 

In this image the funnel is aft of mid-ship. Split structures and you can see between the two. Even the stairs leading up to the 1st upper deck of the bridge-structure from behind. You can see the front island. The far edge is completely obscured by the near edge, suggesting AOB <90. You can more clearly see the front face of the bridge, and the front of the engine building. So again AOB<90. Also the spread of the masts can give away AOB. The aft mast is an +-configuration when seen from the top-down/bow-up view. It depends on where the sunlight comes from but those starboard masts are grey indicating inclined toward you (less illumination angle). The tip of the starboard boom is about 1/5th between the center mast and the aft boom tips on the far side. Indicating the AOB is about 10 degrees (sin(11) is about 0.2) forward of beam so about AOB 80. It's a first guess, so don't put your money on it. But lacking anything else you could use it in a pinch. Rather, confirm it when passing another ship. Or move in front of it and determine when the mast covers the funnel exactly.

Image: (spoiler because image shows too large)

 

This one is further away and also near AOB 90 starboard. Here you can only see the backside of the bridge. And just before it is covered by the funnel structure. You might even see some of the back-face of the cargo-boxes. (slight shading difference) The booms on the mast give a bit better indication on how much the angle differs beyond 90 degrees. The aft booms on the 3rd mast (+-configuration) suggest it is between 135 and 90, maybe closer to 135. Lets say 120. Again, it's a first guess. Move up to the pont where mast booms overlap exactly and front and back faces disappear. That is where 90 degrees AOB is most exact.

Image: (spoiler because image shows too large)

 

This one is the same as before. But harder to tell if it is less or more than 90 AOB. You could settle it as that. But depending on your interpretation of the illumination of the mastboom it might be possible to distinguish which side. The darkened boom of the 3rd mast (likely towards you, as the brighter one is also obscured at the bottom) is still in front of the mast itself. Suggesting you are looking from behind, thus AOB>90. But not by much. Maybe only 5 degrees.

Again, confirm this from another position when you can notice a specific angle. From the side, right in front, or right behind if you have no other choice. But approaching submerged from the front you have more tactical advantages. You are not taking the AOB to shoot now. From behind or from the front you are on his course line. So just by noting the bottom indication on the attack periscope (true bearing) you know the course or its reciprocal. (the opposite way) The TDC remembers the setting you make and translates it to the target course which it keeps internally. When you look at it from another angle then the AOB dial (also with the right selector setting) should show the right value. Unless the target turned in the mean time. Guessing the AOB should be considered a cheap investment for later.

Many thanks to you! I understood quite a lot from the images.