SUBSIM Radio Room Forums



SUBSIM: The Web's #1 resource for all submarine & naval simulations since 1997

Go Back   SUBSIM Radio Room Forums > Silent Hunter 3 - 4 - 5 > Silent Hunter III
Forget password? Reset here

Reply
 
Thread Tools Display Modes
Old 08-24-07, 05:19 PM   #1
Shelton
Planesman
 
Join Date: Sep 2002
Location: Brisbane, Australia
Posts: 195
Downloads: 0
Uploads: 0
Default How to calculate Target Course

Hi all

I am playing SH3 with map updates off so in the nav window I cannot see the target. Does anyone know how to calculate the target course given the following parameters?

1. Relative Bearing to Target
2. My uboat Heading
3. Angle on the Bow (of the target to uboat)

So just say
1 = 240 degrees
2 = 90
3 = 60 starboard

What is the ships/targets heading ?

Regards
Shelton.
__________________
I use Linux http://www.kde.org/screenshots/
Shelton is offline   Reply With Quote
Old 08-24-07, 05:42 PM   #2
joegrundman
Ocean Warrior
 
Join Date: May 2007
Posts: 2,689
Downloads: 34
Uploads: 0
Default

EDIT--THESE MATHS ARE WRONG, SEE FURTHER DOWN FOR THE CORRECT SOLUTIONS!

OK, start with your heading. Add the periscope angle. Then add the AOB if it's starboard or subtract the AOB if it's port.

E.g.1. your heading 000, periscope angle 090, AOB starboard 90, target course =180
E.g.2 heading 055, scope angle 235, AOB port 25, target course = 055+235-25=290-25=265

In your example, 240, 90,starboard 60, target course =240+90+60=390=030

You can also draw it on the map using the protractor tool

But easiest of all is to build yourself a proper KM or US whiz wheel and solve the problem in seconds without ever having to think about it. You can also use it to plot a course that will give you the desired firing position

http://www.subsim.com/radioroom/show...ght=whiz+wheel
__________________
"Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill

Last edited by joegrundman; 08-24-07 at 10:16 PM.
joegrundman is offline   Reply With Quote
Old 08-24-07, 05:45 PM   #3
ichso
Ace of the Deep
 
Join Date: Jul 2005
Location: Germany's oldest city alive
Posts: 1,066
Downloads: 57
Uploads: 0
Default

240 + 90 + 60 modulo 360 = 30°

But someone was still faster
For long range calculations you will need a more exact course than you get from rough AoB estimations.
So better make observations of the target's position relative to your own ones and mark them on the Nav map.

Then you can just read the target's course from there. You can then plan your attack so that the AoB is a very simple one, like 90°
See Wazoo's manual plotting tutorial - Fast 90° method (for example).

The Wiz Wheel should be the most historically accurate one though. At least for german submarines from that period.
ichso is offline   Reply With Quote
Old 08-24-07, 05:50 PM   #4
GoldenRivet
Subsim Aviator
 
GoldenRivet's Avatar
 
Join Date: Mar 2007
Location: Texas
Posts: 8,729
Downloads: 146
Uploads: 0


Default

i modestly submit my very first tutorial video.

this tutorial video instructs the viewer on how to plot solutions on paper using a ruler and protractor

it assumes the player already knows how to gather range to target, and understands headings and bearings

view it and PLEASE offer constructive critisism.

thanks!

http://hosted.filefront.com/GoldenRivet/
__________________
GoldenRivet is offline   Reply With Quote
Old 08-24-07, 05:55 PM   #5
joegrundman
Ocean Warrior
 
Join Date: May 2007
Posts: 2,689
Downloads: 34
Uploads: 0
Default

I may have been faster, but i was certainly wrong!

Actually i don't know hot to do it. Just build a whiz wheel. It's much easier
__________________
"Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill
joegrundman is offline   Reply With Quote
Old 08-24-07, 06:33 PM   #6
Shelton
Planesman
 
Join Date: Sep 2002
Location: Brisbane, Australia
Posts: 195
Downloads: 0
Uploads: 0
Default

Just watched the tutorial video - fantastic!! yes as you mention it becomes very difficult if my uboat is also moving - but i get the general idea - so there isn't a forumale i use to calculate the target course - other than plotting at different times?
__________________
I use Linux http://www.kde.org/screenshots/
Shelton is offline   Reply With Quote
Old 08-24-07, 06:42 PM   #7
GoldenRivet
Subsim Aviator
 
GoldenRivet's Avatar
 
Join Date: Mar 2007
Location: Texas
Posts: 8,729
Downloads: 146
Uploads: 0


Default

plotting the target's position relative to your boat over time vs doing mathematic formula is probably easier - especially as far as visualisation - is probably easier

it is for me anyhow, of course everyone is different.

glad you liked it.

plotting the solution either requires a much larger sheet of paper or a much smaller scale on the ruler. but aside from plotting the target's position every couple of minutes you have to plot your own, including any turns you make etc.

edit: i should also mention the video only covers bow shots, unless you mark your bearings from 090 through 180 to 270 instead of the way shown (090 to 270 through 360)
__________________
GoldenRivet is offline   Reply With Quote
Old 08-24-07, 07:39 PM   #8
joegrundman
Ocean Warrior
 
Join Date: May 2007
Posts: 2,689
Downloads: 34
Uploads: 0
Default

Ok, there is a solution to do it. My wife and i worked this out over pancakes for breakfast.

Unfortunately it's kind of slow.

There are four situations you need to determine, and the equation is different for each.

1. AOB is port, and periscope angle is less than 180

Target course = heading + periscope angle + AOB -180


2. AOB is starboard, periscope angle less than 180

Target course = heading + 180 + periscope angle -AOB


3. AOB is port, and periscope angle is greater than 180

Target course = heading + periscope angle + AOB - 180


4. AOB is starboard, and periscope angle is greater than 180

Target course = heading + periscope angle - AOB -180

e.g. heading 240, scope angle 90, AOB starboard 60, use equation 2

240+ 180 + 90 - 60 = 090

Someone please check the solutions, right now i'm a bit surprised that equations 1 and 3 are the same. EDIT - I've tested them and they all seem to be correct

But you can see right away why the real submarines used a whiz wheel for this
__________________
"Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill

Last edited by joegrundman; 08-24-07 at 10:19 PM.
joegrundman is offline   Reply With Quote
Old 08-24-07, 07:45 PM   #9
Shelton
Planesman
 
Join Date: Sep 2002
Location: Brisbane, Australia
Posts: 195
Downloads: 0
Uploads: 0
Default

Quote:
Originally Posted by joegrundman
OK, start with your heading. Add the periscope angle. Then add the AOB if it's starboard or subtract the AOB if it's port.

E.g.1. your heading 000, periscope angle 090, AOB starboard 90, target course =180
E.g.2 heading 055, scope angle 235, AOB port 25, target course = 055+235-25=290-25=265

In your example, 240, 90,starboard 60, target course =240+90+60=390=030

You can also draw it on the map using the protractor tool

But easiest of all is to build yourself a proper KM or US whiz wheel and solve the problem in seconds without ever having to think about it. You can also use it to plot a course that will give you the desired firing position

http://www.subsim.com/radioroom/show...ght=whiz+wheel
thanks for the tips and the link as well!
__________________
I use Linux http://www.kde.org/screenshots/
Shelton is offline   Reply With Quote
Old 08-24-07, 10:23 PM   #10
joegrundman
Ocean Warrior
 
Join Date: May 2007
Posts: 2,689
Downloads: 34
Uploads: 0
Default

If you can't be troubled with making your own whiz wheel (I have made three, and the US ISWAS style is my favourite), the good news is that I am working on an electronic version of the KM whiz wheel that would appear in game. It's at a beta level now, it functions but not really well enough. However I am interested in having a playtester that could give me some constructive advice for it.
__________________
"Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill
joegrundman is offline   Reply With Quote
Old 08-24-07, 11:13 PM   #11
Shelton
Planesman
 
Join Date: Sep 2002
Location: Brisbane, Australia
Posts: 195
Downloads: 0
Uploads: 0
Default

Quote:
Originally Posted by joegrundman
Ok, there is a solution to do it. My wife and i worked this out over pancakes for breakfast.

Unfortunately it's kind of slow.

There are four situations you need to determine, and the equation is different for each.

1. AOB is port, and periscope angle is less than 180

Target course = heading + periscope angle + AOB -180


2. AOB is starboard, periscope angle less than 180

Target course = heading + 180 + periscope angle -AOB


3. AOB is port, and periscope angle is greater than 180

Target course = heading + periscope angle + AOB - 180


4. AOB is starboard, and periscope angle is greater than 180

Target course = heading + periscope angle - AOB -180

e.g. heading 240, scope angle 90, AOB starboard 60, use equation 2

240+ 180 + 90 - 60 = 090

Someone please check the solutions, right now i'm a bit surprised that equations 1 and 3 are the same. EDIT - I've tested them and they all seem to be correct

But you can see right away why the real submarines used a whiz wheel for this
hey Joe thanks for this - i am going to use this next time i spot a merchant and try it out!

BTW YES your correct - the original equation on my first post - the merchant was indeed travelling 90deg !!!! so I was confused when ichso posted 30!
__________________
I use Linux http://www.kde.org/screenshots/
Shelton is offline   Reply With Quote
Old 08-24-07, 11:20 PM   #12
XLjedi
Ace of the Deep
 
Join Date: Jun 2005
Location: Palm Beach, Florida
Posts: 1,243
Downloads: 53
Uploads: 8
Default

Quote:
Originally Posted by GoldenRivet
i modestly submit my very first tutorial video.
.
.
.
view it and PLEASE offer constructive critisism.

thanks!

http://hosted.filefront.com/GoldenRivet/

wow... nice video. I liked it.

You're manually drawing half of a maneuvering board. You plotted the DRM line (direction of relative motion) and since you mention being stationary you are also correct that it equates to the contact TC (true course).

If your sub was moving, you would need to plot a movement vector for your sub and the contact speed and DRM. It's not difficult, I could show you how to do that if you like.
__________________
XLjedi is offline   Reply With Quote
Old 08-24-07, 11:23 PM   #13
XLjedi
Ace of the Deep
 
Join Date: Jun 2005
Location: Palm Beach, Florida
Posts: 1,243
Downloads: 53
Uploads: 8
Default

Quote:
Originally Posted by joegrundman
If you can't be troubled with making your own whiz wheel (I have made three, and the US ISWAS style is my favourite), the good news is that I am working on an electronic version of the KM whiz wheel that would appear in game. It's at a beta level now, it functions but not really well enough. However I am interested in having a playtester that could give me some constructive advice for it.
Will it be analog or digital? I was planning on inclucing an analog one in MoBo v1.1 myself... I'd be happy to take a look at whatever you've got.
__________________
XLjedi is offline   Reply With Quote
Old 08-24-07, 11:49 PM   #14
joegrundman
Ocean Warrior
 
Join Date: May 2007
Posts: 2,689
Downloads: 34
Uploads: 0
Default

It's analog. it looks and functions more or less like the authentic one. If you PM me your email address I'll send you my WIP

joe
__________________
"Enemy submarines are to be called U-Boats. The term submarine is to be reserved for Allied under water vessels. U-Boats are those dastardly villains who sink our ships, while submarines are those gallant and noble craft which sink theirs." Winston Churchill
joegrundman is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 10:19 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright © 1995- 2025 Subsim®
"Subsim" is a registered trademark, all rights reserved.