SUBSIM Radio Room Forums - View Single Post - Attack Course Finder

XLjedi · 01-09-09, 01:06 PM

I've been giving some thought this week about how to implement an Attack Course Finder in MoBo.

What I want to be able to do is take a picture of a ship on the horizon and with that, add a tool in MoBo that measures the observed length of the ship and then calculates the AoB. So for this we only need 2 bits of information the length of the ship and a measurement of the observed length (what we see thru our scope).

We'll assume for the moment that you are close enough to make a positive identification and with that, you can look up the exact length of the ship. Later, I suspect we'll be able to just put in approximations for different classes of ships and the calculation will still be valid to with a few degrees AoB. But for now, let's just assume we have perfect information about ship length.

Given the following...

So the ship is out there, I don't know how far away it is, but that's not important for determining AoB. All I do is get a measurement of the length of the ship as it appears in my scope. In this case I determine the length that I see is 34m.

I know the length of the ship (side c) is 95m. I just observed side a as 34m. Given these two measurements, I should be able to solve for angle bc which is equivalent to AoB. The formula in Excel would look like this:

Note: Excel trig functions return radians hence the 180/Pi conversion to degrees
=ASIN(34/95) * 180/3.14159265358979
=20.97°

So, I'm thinking that all I need is a gadget in MoBo that helps me measure the observed length of the ship, and if I know from the ship recog manual what the length is, I should be able to input those two values and get the AoB.

:hmm: Do you think this would work? ...not quite sure yet how to deal with the scaling issue of an observation; even at 1x mag. If a vertical stadimeter works wouldn't a horizontal one work as well? If anyone knows for sure that it's a lost cause trying to calculate "side a" just let me know.

01-09-09, 01:06 PM	#1
XLjedi Ace of the Deep Join Date: Jun 2005 Location: Palm Beach, Florida Posts: 1,243 Downloads: 53 Uploads: 8	Visual Attack Course Finder? I've been giving some thought this week about how to implement an Attack Course Finder in MoBo. What I want to be able to do is take a picture of a ship on the horizon and with that, add a tool in MoBo that measures the observed length of the ship and then calculates the AoB. So for this we only need 2 bits of information the length of the ship and a measurement of the observed length (what we see thru our scope). We'll assume for the moment that you are close enough to make a positive identification and with that, you can look up the exact length of the ship. Later, I suspect we'll be able to just put in approximations for different classes of ships and the calculation will still be valid to with a few degrees AoB. But for now, let's just assume we have perfect information about ship length. Given the following... So the ship is out there, I don't know how far away it is, but that's not important for determining AoB. All I do is get a measurement of the length of the ship as it appears in my scope. In this case I determine the length that I see is 34m. I know the length of the ship (side c) is 95m. I just observed side a as 34m. Given these two measurements, I should be able to solve for angle bc which is equivalent to AoB. The formula in Excel would look like this: Note: Excel trig functions return radians hence the 180/Pi conversion to degrees =ASIN(34/95) * 180/3.14159265358979 =20.97° So, I'm thinking that all I need is a gadget in MoBo that helps me measure the observed length of the ship, and if I know from the ship recog manual what the length is, I should be able to input those two values and get the AoB. :hmm: Do you think this would work? ...not quite sure yet how to deal with the scaling issue of an observation; even at 1x mag. If a vertical stadimeter works wouldn't a horizontal one work as well? If anyone knows for sure that it's a lost cause trying to calculate "side a" just let me know. __________________ Last edited by XLjedi; 01-09-09 at 03:04 PM.