How do you determine AOB without the length of the boat?

[Able72]

How do you determine AOB without the lenght of the boat to give you a visible aspect ratio percentage?

Here is a copy of a page from the recognition manual I have in game:

http://img505.imageshack.us/img505/3858/recogmanualpagecf5.png

[Fincuan]

I always try to determine the target's course by plotting, because when you have the course you don't basically have to care about the AOB. If you for some reason need the AOB, then the TDC will now tell you that. If the situation requires shooting before I have the course I'll just eyeball the AOB and fire.

[Rockin Robbins]

When I have to find AoB I already have the information to measure it directly off the plot. I'm going to assume imperial measurements here, but if you're using metric the time is three minutes fifteen seconds and you're measuring in meters. Conversion works the same way.

Let me explain. The first piece of info I need is the target speed. So the scope goes up and I switch to the nav map. Pop up the stopwatch, mark the ship's location, start the stopwatch and down scope. At 2:40 or so, pop up the scope, lock on the target and switch to the nav map. At 3 minutes, mark the position of the target and down scope.

First, take the ruler tool and connect the marks, extending the line in the direction of the target's movement. This is the track: the course the target is on. If help is on (by opening the compass) you can use the compass rose on the ruler tool to read off the target's true course.

Then you need the speed of the target. With the compass tool click on one mark and drag to the other. You can then read the number of yards the radius of that circle is. The speed in knots is the number of hundred yards (or meters) run during the time. So if the ship sent 750 yards, the speed is 7.5 knots. 1200 yards = 12 kt. You can enter that speed in the TDC right now.

It's time to find that Angle on the Bow. Up periscope and lock on the target. Switch to the nav map and use the protractor tool (shaped like a triangle). Left-click on the track ahead of the target, then on the middle of the target and finally on the middle of your submarine. You'll see the angle measurement beside your target at the apex of the angle. That's your AoB. Now it's starboard or port, depending on whether you are looking at the starboard or port side of the target.

Simple enough? And you got an elementary course in plotting too! I encourage you to use a plot instead of the crew estimate method. You can't check the crew estimate. They can tell you any old thing and the first clue you have is when the torpedo misses.

[Able72]

thank you I really appreciate it.

Care to write a detailed tutorial on plotting? Or can you point me to where I can find one? Real world source or game source I don't care. I could really use it.

Better yet, a video tutorial with step by step detailed instructions :D

*edit* WOOOHOOO!!!! I just sank my first boat with manual targeting :D Thank you so very much. That whole plotting blurb you gave just let me sink my first 8500 tons through manual targeting. I think I"m prouder of that little 8500 tons than I am in any of the 500,000+ tons I've sunk before it.

Thanks so much again.

[Mav87th]

How do you determine AOB without the lenght of the boat to give you a visible aspect ratio percentage?


You do that by comparing the standard aspect ratio to the presented aspect ratio.

Standard Aspect Ratio (now SAR) is the ships length divided with the ships height from waterline to masttop.

So with the Mogami its SAR is 656/113,5 = 5,779=5,8

Presented Aspect Ratio (now PAR) is the ships length in periscope tics divided by the height in the periscope in tics.

now to find the AOB you multiply PAR with 100 and then divide with SAR

PAR x 100
--------- = Variation in %
SAR

Now you bring out your Angle on the bow aspect scale rule and find the AOB from the variation - or - you bring out a sinus scale and look the percentage up.

[Able72]

great, so how do you get the standard aspect ratio and how do you mesure the presented aspect ratio? lol, nvm plotting worked and I didn't have to use a calculator. Also, come to think of it, how many enemy boats would we have real precise lenght mesurments for? you think they just gonna hand those over?

[Rockin Robbins]

thank you I really appreciate it.

Care to write a detailed tutorial on plotting? Or can you point me to where I can find one? Real world source or game source I don't care. I could really use it.

Better yet, a video tutorial with step by step detailed instructions :D

*edit* WOOOHOOO!!!! I just sank my first boat with manual targeting :D Thank you so very much. That whole plotting blurb you gave just let me sink my first 8500 tons through manual targeting. I think I"m prouder of that little 8500 tons than I am in any of the 500,000+ tons I've sunk before it.

Thanks so much again.
Woooooo Hoooooooo! Good job. I'm working on making tutorial movies but have a synch problem between audio and video with Hypercam that I have to get sorted out. I'll be doing seminars on plotting, Dick O'Kane targeting and Fast-90 targeting for the U-Boat.

But right now I have the video racing ahead of the audio and don't quite know why. Once I get it sorted out I'll be in production.

[Rockin Robbins]

How do you determine AOB without the lenght of the boat to give you a visible aspect ratio percentage?

You do that by comparing the standard aspect ratio to the presented aspect ratio.

Standard Aspect Ratio (now SAR) is the ships length divided with the ships height from waterline to masttop.

So with the Mogami its SAR is 656/113,5 = 5,779=5,8

Presented Aspect Ratio (now PAR) is the ships length in periscope tics divided by the height in the periscope in tics.

now to find the AOB you multiply PAR with 100 and then divide with SAR

PAR x 100
--------- = Variation in %
SAR

Now you bring out your Angle on the bow aspect scale rule and find the AOB from the variation - or - you bring out a sinus scale and look the percentage up.

Methinks this guy has done this for real.:rock:

[joegrundman]

I also wrote a brief tutorial aimed at helping you to improve your ability to judge aob by eye

http://www.subsim.com/radioroom/showthread.php?t=134200

As for how the length was estimated

the US used a variety of methods as can be found in section 501 of this manual:

http://www.hnsa.org/doc/attack/index.htm#chap05

The Kriegsmarine, however obtained length for the aspect ratio through experience. at the beginning many submarine officers had worked in the merchant fleet and knew a lot about mercahnt shipbuilding, which tended to follow standard procedures around the world.

The number of cranes, for example, indicated the number of cargo bays. A cargo bay tended to be of standard size, and so the number of bays indicated total displacement. Total displacement indicated length and width at beam.

So they used a formula to obtain target length based on observation of these characteristics.- at least this is what Hitman told me :D

[Rockin Robbins]

Into a stickied thread on attack technique! Probably we should have a thread for Fleet Boats and one for U-Boats, since the methods differ with the change in equipment.

One caution on the aspect ratio method of AoB determination. It is subject to the same error as the stadimeter. Mast heights on enemy ships are not known with certainty and certainly some or most are in error. Also masts are sometimes altered in height to throw stadimeter reading s and aspect ratio AoBs into error. Capn Scurvy has determined that most mast heights in the game stadimeter database are different from the actual ship. This will introduce some error in your calculated AoB. Fortunately, AoB is a very forgiving parameter and I wouldn't expect too many missed shots as a result.

If this results in a combination AoB and range error, however, the effect could be VERY important.

[Able72]

The AOB and range errors caused by these two inacuracies only become significant some time after the initail firing solution is calculated.

In other words, as more time passes, the inacuracy introduced by the stadimeter range and AOB calculations beomes greater. Increasing the likelyhood of a miss. So update your range and AOB information often to keep your solution 'close enough' to on target.

[Able72]

Into a stickied thread on attack technique! Probably we should have a thread for Fleet Boats and one for U-Boats, since the methods differ with the change in equipment.

One caution on the aspect ratio method of AoB determination. It is subject to the same error as the stadimeter. Mast heights on enemy ships are not known with certainty and certainly some or most are in error. Also masts are sometimes altered in height to throw stadimeter reading s and aspect ratio AoBs into error. Capn Scurvy has determined that most mast heights in the game stadimeter database are different from the actual ship. This will introduce some error in your calculated AoB. Fortunately, AoB is a very forgiving parameter and I wouldn't expect too many missed shots as a result.

If this results in a combination AoB and range error, however, the effect could be VERY important.

Ok, looked at your The Dick O'Kane (UB & FB) and Fast-90 (UB only) attack methods.

I just wanted to confirm, the only pieces of information you need for that attack method is the targets speed and bearing? Wait, I'm confused again damnit. I know its not as hard as I'm making it. :(

[Quillan]

If you are firing from 90° to the target's course (or very close to it), then range is not really important. If you are firing at some other position then range is important. The manual targeting technique I've been using is based on the Dick O'Kane method, but with a couple of adjustments.

1) I find the target course and speed using the listed methods, and plot the target course on the nav map.

2) Using the course and speed information, I pick an intercept point and maneuver my boat to that position, then stop and wait for the target.

3) I pick a firing position, turn my scope to the chosen bearing, input range to target at the firing position (taken from the nav map), and then adjust the AOB so that the true course indicator on the top wheel of the TDC matches the target course on the nav map.

4) I wait until the target ship crosses the firing point, then fire as each point I wish to target crosses the line in the scope.

I use the map tools to figure out the range to where the target will be at the point I fire. Realistically, I wouldn't have the GPS accuracy on my own position that the game gives me, but I could use the sonar to figure out a range to target up to 5k yards away and then solve for the range at the firing position, so it works anyway.

[Rockin Robbins]

The AOB and range errors caused by these two inacuracies only become significant some time after the initail firing solution is calculated.

In other words, as more time passes, the inacuracy introduced by the stadimeter range and AOB calculations beomes greater. Increasing the likelyhood of a miss. So update your range and AOB information often to keep your solution 'close enough' to on target.

I HAVE to start making videos. This stuff fascinates me:88). OK, the reason Able means that the innacuracies become greater is that you are running your position keeper. And it's a tricky monster.

If the AoB (defines target course) and speed are correct and your range is wrong, the range error will remain constant forever. Thought experiment. Suppose your bearing is a couple of degrees off and the range is 100' too close. We'll say that fixes the target in error 250' in front of the target. If that mistaken location moves with the PK at the same speed and direction as the target, the error will remain constant. Can you see it?

I'll save the rest for when I get my video technique down. But you are correct for other errors: they grow over time with the PK on.

[Rockin Robbins]

If you are firing from 90° to the target's course (or very close to it), then range is not really important. If you are firing at some other position then range is important. The manual targeting technique I've been using is based on the Dick O'Kane method, but with a couple of adjustments.

1) I find the target course and speed using the listed methods, and plot the target course on the nav map.

2) Using the course and speed information, I pick an intercept point and maneuver my boat to that position, then stop and wait for the target.

3) I pick a firing position, turn my scope to the chosen bearing, input range to target at the firing position (taken from the nav map), and then adjust the AOB so that the true course indicator on the top wheel of the TDC matches the target course on the nav map.

4) I wait until the target ship crosses the firing point, then fire as each point I wish to target crosses the line in the scope.

I use the map tools to figure out the range to where the target will be at the point I fire. Realistically, I wouldn't have the GPS accuracy on my own position that the game gives me, but I could use the sonar to figure out a range to target up to 5k yards away and then solve for the range at the firing position, so it works anyway.

You could use radar before he was even in sight. So for both reasons I don't feel bad about keeping map updates on with Trigger Maru.

[Able72]

If you are firing from 90° to the target's course (or very close to it), then range is not really important. If you are firing at some other position then range is important. The manual targeting technique I've been using is based on the Dick O'Kane method, but with a couple of adjustments.

1) I find the target course and speed using the listed methods, and plot the target course on the nav map.

2) Using the course and speed information, I pick an intercept point and maneuver my boat to that position, then stop and wait for the target.

3) I pick a firing position, turn my scope to the chosen bearing, input range to target at the firing position (taken from the nav map), and then adjust the AOB so that the true course indicator on the top wheel of the TDC matches the target course on the nav map.

4) I wait until the target ship crosses the firing point, then fire as each point I wish to target crosses the line in the scope.

I use the map tools to figure out the range to where the target will be at the point I fire. Realistically, I wouldn't have the GPS accuracy on my own position that the game gives me, but I could use the sonar to figure out a range to target up to 5k yards away and then solve for the range at the firing position, so it works anyway.
You could use radar before he was even in sight. So for both reasons I don't feel bad about keeping map updates on with Trigger Maru.
Yeah, but RADAR from WWII wouldn't give you the pin point accuracy that it does in game. Just look at the surface scope and see how accuratley you could judge range to target based on that.

[Quillan]

If I am not mistaken, the SJ radar had a separate readout that gives you range down to the yard, so it's pretty accurate in that respect.

[Rockin Robbins]

Radar was the gold standard for range, with even sonar taking a distant second.

[Able72]

now if only we could get radar to work while submerged to periscope depth :hmm::ping:

[Quillan]

You can come up to around 35-40 feet depth (radar depth) and it works just fine. :arrgh!:

[Able72]

Yes, I'm familiar with 'radar depth' up to 38 feet in calm seas. problem is, most the time my seas aren't calm and I do good to have working radar up to 25 feet depth, thats barely decks awash and in some cases it isn't.

[Rockin Robbins]

It's a good time to try out my Nav Map and Plotting Tools Video (http://files.filefront.com/SH4+Fleet+Boat+Plotting+Veo7z/;9970055;/fileinfo.html) in controled conditions. Please check it out and comment here. I need some more tools for making these and maybe I can make 'em better. For now I just want to know if there is anything I left uncovered that you'd like to know about.

[Able72]

Throwing a wrench your way.

[denny927]

It's a good time to try out my Nav Map and Plotting Tools Video (http://files.filefront.com/SH4+Fleet+Boat+Plotting+Veo7z/;9970055;/fileinfo.html) in controled conditions. Please check it out and comment here. I need some more tools for making these and maybe I can make 'em better. For now I just want to know if there is anything I left uncovered that you'd like to know about.


file not found....:cry:.....can you reupload?

[Rockin Robbins]

Link fixed at http://www.subsim.com/radioroom/showpost.php?p=1025180&postcount=1
First link under Rockin Robbins' Lnks. Lotsa other stuff to see there too.:yeah:

[CapnScurvy]

denny927, been using the SubSim search engine a lot haven't you?! :D

Optical Targeting Correction (http://www.subsim.com/radioroom/showthread.php?t=181172) puts the ships length onto the Recognition Manual.

http://i175.photobucket.com/albums/w132/crawlee/Computerfoundrange-1.jpg


The only problem using it before OTC was there was no way of accurately measuring length of a target given the inconsistencies of the games resolutions. The OTC thread explains what each player's game resolution does to the periscope or TBT views.

In a nutshell, the measurements of the Telemeter divisions (the hash marks on the periscope or TBT scopes used for measuring) are not consistent for every player's game setup. What is accurate for one players periscope view, isn't accurate for another. Nor is the periscope measurement, consistent with the TBT/UZO measurement. The point is the stock game, TMO, RFB, and any other mod the game has, doesn't address the problem of having accurate measuring periscope or TBT Telemeter divisions to help in finding range, or using length to determine AoB of a target.

Optical Targeting Correction does.

Also, since some of this thread referrers to the use of radar, OTC reworked that as well. The following image has the OTC PPI radar screen showing a target blip at about the 3000 yard range (at the lowest 8000 yard distance setting of the unit), and at about a 12 degree relative bearing. Good enough to make a plot of the target on the Navigation Map for future firing solution figuring.

The 3000 yard range could be used to input the range figure into the TDC with the OTC "Range Dial" that's a part of the Attack Data Tool on the periscope screen. As in real life, the "range to target" gleaned from the radar screen, could be placed into the TDC without use of the Stadimeter, or Sonar input.

The image is not a close-up of the radar screen. It's the actual size in-game, with the radar screen zoomed in (a new feature) and the HUD dials deleted from view for the sake of taking the picture.

http://i175.photobucket.com/albums/w132/crawlee/USPPI.jpg