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Old 07-08-06, 08:19 AM   #3
Redwine
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Join Date: Jan 2002
Location: San Martin de los Andes, Neuquen, , Argentina.
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Quote:
Originally Posted by Igorry
Thank you redwine. Know you would come to my rescue.

Just two questions on using the slide rule.
You are welcome....


Quote:
Originally Posted by Igorry
1) Do I take the 3 bearings while my sub is stationary?
The sub movement introduce an error, in the sim, SH1, SH2 and SH3 you can do it, let the sub at zero speed, but it is not real, in real life you need a minimal speed to maintain the sub at determined depth.

If you want realism, just adjust a minimal speed, this will introduce an error you was having in real life.

To reduce this error, adjust speed as minimal as posible, adjust it at first forward, and after some time adjust it backward.

I fyou want to reduce this error at zero, you need to take handds on mathematical (geometrical or trigonometrical) corrections, may be you will have not too much time, but there is a second way, the graphical method.

Both are described into my theroretical analysis, into the spanish part, sorry but it is so hard or imposible for me to do it in english.

Use of a big paper, rulers, degrees transportators, and a pen..... is incredible precise, believe it or not, it is so simple and the precision is incredible.

Just take ranges and bearings and put them into a big papper, make the correction on you focus, it is your sub position according with your speed, you will have incredible precise results.

But there is a big problem, we was able to see it before game release, this sim dont use Target relatve Course as SH2..... SH3 use Instantaneous AOB.

All this calculation is useful to calculate a future shot, a determined future giro angle for a determined future position.

You must to make the calculations and wait the target to pass for the future calculated shooting bearing at the periscope center line.



Quote:
Originally Posted by Igorry
2) Must I take the 3 bearing at exactly the same time interval?

I want to use it to calculate an accurate AOB and from there to use the whizwheel to calculate speed. I am trying to ignore range to get a firing solution.

Igorry

Well, if you will use that calculator ruler, you need to take exact equals time intervals....

If you do it mathematically, using the formula, you can take any time intervals, but you need to change the formula, and it adds another complication, you need to change the value "2" in the formula, "2" means the time at bearing 2 is the half of the time at bearing 3, i reccomend just let the time intervals equals and identical.

If you use the graphical method, it is a big piece of paper and rule and pen, you are free to do what you want, and it is incredible precise, i obtain less then half degree error some times, and if you are shooting at 90 degrees of the target and near it, this degree or half degree error ..... is nothing.

Best regrads, Red.
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