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.

sublynx · 08-30-12, 10:40 AM

It's a little bit hard to figure out the situation without a picture, but I think the problem is that 9x10=90 km is too far away and makes the picture too big. Try using a smaller factor or no factor at all.

I made an interception sketch of your situation using Google Sketchup as I'm not at an SH3 equipped computer right now and got an interception course of 347 true degrees.

I would also intercept with a faster speed. You don't have much speed advantage in 12 knots against 9 knots.

And btw your question is not really related to modding. It would have been better placed in SH3 forum.

Pisces · 08-30-12, 12:06 PM

I fully agree with what sublynx said. The distance is 20 km, but the multiplied circle is way bigger. A target speed line of 9 and your speed as a 12 km circle should have worked well.

p.s. to upload pictures (temporarily) you can go to various sites. google "upload image", most popular is ImageShack

sixcoins · 08-30-12, 06:22 PM

I didn't even notice this was in the Mods section when I posted it. I thought it was in SHIII. Oops! I'll repost it over there.

I do appreciate you taking the time to look at this. Thanks for the detailed info. Unfortunately I'm still confused.

When I draw my circle, It's supposed to cross a line between me and the contact, and from that point I can determine my intercept angle. I dunno. I'll keep working on it.

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.

08-30-12, 10:40 AM	#2
sublynx Sea Lord Join Date: Mar 2011 Location: In the conning tower of my VIIC scanning the sea through the periscope Posts: 1,698 Downloads: 173 Uploads: 7	It's a little bit hard to figure out the situation without a picture, but I think the problem is that 9x10=90 km is too far away and makes the picture too big. Try using a smaller factor or no factor at all. I made an interception sketch of your situation using Google Sketchup as I'm not at an SH3 equipped computer right now and got an interception course of 347 true degrees. I would also intercept with a faster speed. You don't have much speed advantage in 12 knots against 9 knots. And btw your question is not really related to modding. It would have been better placed in SH3 forum. __________________ [SIGPIC][/SIGPIC] NYGM+H.sie v16+Stiebler 4C+MaGui WS Last edited by sublynx; 08-30-12 at 10:42 AM. Reason: forgot to add

08-30-12, 12:06 PM	#3
Pisces Silent Hunter Join Date: Dec 2004 Location: AN9771 Posts: 4,904 Downloads: 304 Uploads: 0	I fully agree with what sublynx said. The distance is 20 km, but the multiplied circle is way bigger. A target speed line of 9 and your speed as a 12 km circle should have worked well. p.s. to upload pictures (temporarily) you can go to various sites. google "upload image", most popular is ImageShack

08-30-12, 06:22 PM	#4
sixcoins Seaman Join Date: Nov 2011 Posts: 40 Downloads: 6 Uploads: 0	I didn't even notice this was in the Mods section when I posted it. I thought it was in SHIII. Oops! I'll repost it over there. I do appreciate you taking the time to look at this. Thanks for the detailed info. Unfortunately I'm still confused. When I draw my circle, It's supposed to cross a line between me and the contact, and from that point I can determine my intercept angle. I dunno. I'll keep working on it.