TARGET SPEED, searching for the magic bullet

[joegrundman]

I think you've misunderstood what the purpose of this approach is. It's not intended for long range shots, just for gathering speed data. My point is that unless you have visual AOB (and greyrider, as i can, can determine AOB visually, reliably and accurately) then you do not actually get a speed estimate with this method, unless you guess, and that guess turns out to be right.

There are ways of doing it. Simply put if you have made an ISWAS or Submarine Attack Course Finder (and i'm surprised you haven't, RR), you can get a range datum after you have established a collision course, by changing your speed for a short period.

You can obtain a second datum by doing it again later once you are nearer the target, or even using the point at which the target arrives in front of you as the second datum

here's the link to the tutorial i wrote nearly two years ago, although i have refined the method somewhat since then

http://www.subsim.com/radioroom/show...highlight=SACF

but nonetheless given a choice a couple of periscope observations makes a lot of difference, and more fun is to use the Submarine attack course finder the way it is intended.

As for using non-historical options - play the game how you want. obviously historical skippers were constantly trying to optimse their performance with better techniques and newer technology, and ultimately as time progresses they succeed, but in practice they had limitations that we don't necessarily have.

if you want you can use your boat's hydrophones like a modern sub will, since the bearing report by the sonarman is much more reliable than it was in ww2. You try getting a long range bearing by listening to the hydrophone yourself and detecting when it's changed by exactly 1 degree. It's not at all easy!

[Rockin Robbins]

Just following greyrider's thread there on the long shots and being naturally pessimistic that long range is appropriate with passive sonar technique.

I have built CapnScurvy's Angle on the Bow and Speed Calculator, which is a kind of Is/Was. I even used it a couple of times before I formulated my present way of playing, which is in-game tools only and no pausing the game to fiddle with settings. Just my personal style, to play real-time only when in combat, with no time compression, no pauses while in contact. I think it helps with immersion and encourages lousy decision-making, just like reality did. Seems to work pretty well and I've been happy with it.

Instead of the Is/Was, I've substituted the Vector Analysis method, which is quicker and can be done in-game. You ARE working in real time, with all the potential brain damage that tends to induce, then.

In the meantime, I'm waiting for greyrider's next post so I can duplicate what he does there. I get to go to work at 2am in a few minutes to work the Daytona 500 situation, so I probably won't get all that downloaded until this afternoon.

Joe, I am interested in your refined method for inclusion in the Sub Skippers' Bag of Tricks thread. Do you have a run-down on the new and refined improvements?

[greyrider]

quickly joe, i just wanted to say that you are right and i am wrong about aob being small at long ranges, i made a mission putting a target at max hydrophone range,
just making two different target courses showed me that range has nothing to do with aob at LR.

i havent worked on the magic bullet since last post, im not bankrupt for ideas, if one thing wont work something else might, and who said we need to make the calculation at long range,
i didnt, i said it might work, until i made that mission to test aob at LR, it was still an idea that MIGHT work, but it didnt, and im grateful for your input.
it may be that a map plot is the only way at LR, but again who says it has to be done at long range, that was just a thought, now proved to be wrong.
but until i can sit down, with some time to work on this problem, or someone else does, theories will abound, but be unproved, nothing wrong with that.
im not bankrupt for ideas, i would still like to determine target speed using that formula, and there must be a way to do it with the hydrophones, ill work on it when i can, and i hope to come up with some answer,
but i know one thing, it wont be aob at LR.
thanks joe, after reading your post, you forced me to check that idea out, now i wont waste time with a bad idea.

[greyrider]

rethinking my post earlier today, i may still be wrong about aob being small at LR. i may be right after all, but only on one target track at LR, and that would be at a 90° target track,
all other angles to track, and joe is absolutely right, but not on a 90.
i will be able to work on this tomorrow

then again it could be as high as 45°, the sum of the angles in a 90° triangle has to add up to 90°

[Rockin Robbins]

Sir, mistakes are the portals of discovery. Persistence is better than brilliance.

[Munchausen]

Maybe this will help: when a ship's sonar range is at a constant distance, its course is perpendicular to its bearing from your sub. Normally, the sonar man will call out "constant distance" for more than one bearing ... the mid-point would most often be the bearing you're looking for.

[joegrundman]

Hey greyrider

sorry if i'm sounding acerbic. I know you are a great one in the realm of sub ideas. I've read all your previous tutorials. Your work with turn count is legendary.

I still think the 90 degree bearing idea is a red herring. The inital aob (as all aob's) is simply a function of your course, target course and bearing to target. That's all it ever is.

Still you should read that document i linked: the submarine attack course finder, and devote a little time to building a replica Submarine attack course finder. you'll have a lot of fun. Captain krunch printed out some pdfs, you just paste them to cardstock, and press them overnight, then assemble. (Cap'n Scurvy's imitation is less than half of the real thing, i'm afraid. The periscope feature and the reverse side are very important for the fancy stuff)

@Munchausen

constant distance reports are not as accurate as you say, but still very helpful. In practice constant distance can be with an aob anywhere between 60 and 90. At 90 it tends to report moving away(and sometimes at 70 or 80)