Course Intercept

sixcoins · 08-30-12, 08:53 AM

Hello folks.. Need some help figuring out some important info that I'm not quite understanding.

First, I'm using this page as my tutorial =

http://www.subsim.com/radioroom/show...light=tutorial

And... I thought it made sense to me, but when I do it on my own map, it doesn't seem to come out quite right... so hopefully someone can see what I'm doing wrong and fill me in.

I have a contact heading east. I'm 20 Km southeast of it.

As per the tutorial I'm following, I head in a northeast direction, just as a basic intercept....

I've used a protractor from my boat to his boat, then off in the direction he is heading... East.

I then measured a 90KM line from his position directly east. I used a factor of 10 because he is travelling at 'medium'. I'm choosing to assume this is 9 knots.

I've chosen an intercept speed of 12 knots, just because the next lower speed would be 10 knots... and I figure I wanna get there well before him.

So, according to the tutorial, I need to use the compass, and draw a circle (centered at the end of his 90knot track) and use the same multiplier of 10 for MY speed.

So... 10x12=120.

The problem is that my 120Km circle is completely larger than the entire area I'm using to map.... The lines cross at no location.

Because of this I cannot intercept the ship using this method... What the heck am I missing?

I don't have webhosting, so I have no place to put a screenshot for you guys to see.... However, if you check that tutorial page, notice where the compass comes in to play, then imagine MY compass circle to be completely enclosing the whole plot. No lines intersect anywhere.

Man.. I hope this post makes sense, because it was hard to explain.

Thanks in advance.

Six.

08-30-12, 08:53 AM	#1
sixcoins Seaman Join Date: Nov 2011 Posts: 40 Downloads: 6 Uploads: 0	Course Intercept Hello folks.. Need some help figuring out some important info that I'm not quite understanding. First, I'm using this page as my tutorial = http://www.subsim.com/radioroom/show...light=tutorial And... I thought it made sense to me, but when I do it on my own map, it doesn't seem to come out quite right... so hopefully someone can see what I'm doing wrong and fill me in. I have a contact heading east. I'm 20 Km southeast of it. As per the tutorial I'm following, I head in a northeast direction, just as a basic intercept.... I've used a protractor from my boat to his boat, then off in the direction he is heading... East. I then measured a 90KM line from his position directly east. I used a factor of 10 because he is travelling at 'medium'. I'm choosing to assume this is 9 knots. I've chosen an intercept speed of 12 knots, just because the next lower speed would be 10 knots... and I figure I wanna get there well before him. So, according to the tutorial, I need to use the compass, and draw a circle (centered at the end of his 90knot track) and use the same multiplier of 10 for MY speed. So... 10x12=120. The problem is that my 120Km circle is completely larger than the entire area I'm using to map.... The lines cross at no location. Because of this I cannot intercept the ship using this method... What the heck am I missing? I don't have webhosting, so I have no place to put a screenshot for you guys to see.... However, if you check that tutorial page, notice where the compass comes in to play, then imagine MY compass circle to be completely enclosing the whole plot. No lines intersect anywhere. Man.. I hope this post makes sense, because it was hard to explain. Thanks in advance. Six.