Question regarding finding AOB (math related)...

Dr. Evil · 01-07-10, 01:52 PM

Assumptions:

1. Target type is known.
2. Range to target is known.
3. The number of mils the target would subtend at current range and AOB = 90 is known.

The question is, am I right in assuming that the arc sine of the number of milliradians the target ACTUALLY subtends divided by the number it SHOULD subtend at AOB = 90 is, in fact the true AOB? AND, is this a workable method of doing this?

vanjast · 01-07-10, 04:03 PM

You wasting your time with maths... AOB is a visually learned 'art'.
More importantly is that your sub course is calculated via ..

:- Scope Bearing + Target AOB = 90.

To practise.. use the map editor and make a ship pass you with 'noob' crews, so that you can keep your scope up.

Nisgeis · 01-07-10, 04:48 PM

To answer the maths part, almost, but not exactly, because the target has width, so the angular length will never resolve precisely in that way, as long as the stern is rounded you will always get larger angular length than you would if you were just measuring from bow to stern along the keel. As you probably know the angular length hardly changes around AOB of 70 - 110, so as Vanjast says you will be better off eyeballing it from the posiion of the kinposts.

You could, if you really want to use the measurement between masts instead, as they are central, or one of the posts of the goalpost type masts (obviously the same one of each pair).

Steiger · 01-07-10, 10:54 PM

Quote:

Originally Posted by vanjast

You wasting your time with maths... AOB is a visually learned 'art'.

Quoted for truth. Best way to do it is ballpark the value, keep the Position Keeper selected on, and watch the target range. When you re-range the target, the distance to target readout should change only very slightly (about 100 yards at most) when you have AOB and speed entered correctly.

All this math...whizz-bang nonsense. Smoke and mirrors!

Diopos · 01-08-10, 10:57 AM

check:
http://www.subsim.com/radioroom/showthread.php?t=111998

Download the file in 1st post and drink a beer to Hitman's health!

gutted · 01-08-10, 03:40 PM

Also, my solution solver program has an AoB Trainer buried in it.

Open up the 3D mock periscope view, and enable training mode. It will set the ship at random AoB's and it will quiz you on the AoB.

Read the manual that comes with the program for full info on how to use this mode.

http://www.subsim.com/radioroom/down...o=file&id=1358

01-07-10, 01:52 PM	#1
Dr. Evil Watch Join Date: Sep 2008 Posts: 21 Downloads: 95 Uploads: 0	Question regarding finding AOB (math related)... Assumptions: 1. Target type is known. 2. Range to target is known. 3. The number of mils the target would subtend at current range and AOB = 90 is known. The question is, am I right in assuming that the arc sine of the number of milliradians the target ACTUALLY subtends divided by the number it SHOULD subtend at AOB = 90 is, in fact the true AOB? AND, is this a workable method of doing this? __________________ Well, we're surrounded. Those b******s aren't going to get away this time.

01-07-10, 04:48 PM	#3
Nisgeis Ocean Warrior Join Date: Jan 2008 Posts: 2,909 Downloads: 77 Uploads: 11	To answer the maths part, almost, but not exactly, because the target has width, so the angular length will never resolve precisely in that way, as long as the stern is rounded you will always get larger angular length than you would if you were just measuring from bow to stern along the keel. As you probably know the angular length hardly changes around AOB of 70 - 110, so as Vanjast says you will be better off eyeballing it from the posiion of the kinposts. You could, if you really want to use the measurement between masts instead, as they are central, or one of the posts of the goalpost type masts (obviously the same one of each pair). __________________ -------------------------------- This space left intentionally blank.

01-08-10, 10:57 AM	#5
Diopos Ace of the Deep Join Date: Jul 2008 Location: Athens, the original one. Posts: 1,226 Downloads: 9 Uploads: 0	check: http://www.subsim.com/radioroom/showthread.php?t=111998 Download the file in 1st post and drink a beer to Hitman's health! __________________ - Oh God! They're all over the place! CRASH DIVE!!! - Ehm... we can't honey. We're in the car right now. - What?... er right... Doesn't matter! We'll give it a try anyway!

01-07-10, 04:03 PM	#2
vanjast Sea Lord Join Date: Jun 2006 Location: Somewhere else now Posts: 1,736 Downloads: 825 Uploads: 4	You wasting your time with maths... AOB is a visually learned 'art'. More importantly is that your sub course is calculated via .. :- Scope Bearing + Target AOB = 90. To practise.. use the map editor and make a ship pass you with 'noob' crews, so that you can keep your scope up.

01-08-10, 03:40 PM	#6
gutted The Old Man Join Date: Apr 2005 Location: New Orleans, LA. Posts: 1,379 Downloads: 487 Uploads: 11	Also, my solution solver program has an AoB Trainer buried in it. Open up the 3D mock periscope view, and enable training mode. It will set the ship at random AoB's and it will quiz you on the AoB. Read the manual that comes with the program for full info on how to use this mode. http://www.subsim.com/radioroom/down...o=file&id=1358