Math??

[Donkey-Shot11]

Hi all,

Is there any math savvy person around here who knows what the math behind behind plotting a target's course, speed and/or AOB is?

I'm pretty sure I need the folowing date:
- own ship course, own ship speed, multiple target sightings (bearig, range + time)

But how do you do actual calculations?
Why do I ask?
Two reasons:
1, I wanna pick up on my math skills
2, I wanna make an excel spreadsheet to use on my laptop while I sun SH on my pc

[dem]

Hi Try this



http://www.paulwasserman.net/SHIII/

there is also calculating a ships course,speed and position using data from the hydrophone

tutorial by jerm138

[kylania]

All the "hydro hunting" tutorials from SH3 still work in SH5, so they are a good resource.

Check here for some links:

http://www.subsim.com/radioroom/showpost.php?p=1337299&postcount=248

[Aufklarer]

A simple speed calculation is:

1. Identifying the ship, if you have the enhanced recognition manual mod it will give you the ships length in meters.

2. Measure the time it takes the ship to completely travel the length of the crosshair in your periscope (the vertical graticule).

3. Use the following equation: Length/Time x 1.94 = speed in knots

This method only works when at a complete standstill and the periscope isnt moved during the timing process. If you require a speed calculation on the move i suggest the Time-Distance-Speed equation. For that though you will need to know range in order to calculate the true course of the target.

If i am not mistaken there are also pre made authentic speed calculation grids that were used in the actual war to speed up the process, these are actually modded into the game (i forget exactly who, but i have them). That would negate the requirement for you to use a spreadsheet.

[Pisces]

This method only works when at a complete standstill and the periscope isnt moved during the timing process. If you require a speed calculation on the move i suggest the Time-Distance-Speed equation. For that though you will need to know range in order to calculate the true course of the target.Not really, if you point your bow or rear in front of the target, and point the periscope/UZO at 0 or 180 degrees you can also do it moving. It then completely cancels out your movements. But you're limited in your directions ofcourse. It usually takes just a moment (wel under a minute) so you can back to your original course quickly.

[gutted]

My advice would be to first learn how to use a manuevering board. Once you understand how to do it by hand.. it's not that difficult to translate it to mathematical form.

It's just vector math. I'm no guru with excel, but i dont know if it can do that type of math.

All of my work in this matter has been done in a progrmming language (C#). I've coded various utilities... everything from hydrophone only plotting, firing solutions, and even a full blown position keeper that runs in real-time (haven't released it yet). I learned alot in the process.

If there's anything you need help with explicitly i'll be more than happy to lend a hand or atleast point you in the right direction.

[jmr]

and even a full blown position keeper that runs in real-time (haven't released it yet).


That sounds cool. Any plans to release it?

[gutted]

That sounds cool. Any plans to release it?

Depends.

When my interest in these types of games goes down.. so does my desire to code anything for them. When the 1.2 patch was delayed for a month, my interest in the game became non-existant.

Will likely be a few more patches before i return to it. I've moved on to other things for the moment.

I never released the PK thing because its actually part of the newer Solution Solver 2.0. I had released an extremely early beta preview of it looking for feedback... but got none whatsoever. So i pulled the download for it. Since then i've improved it greatly and added newer features, but there is still a few things to do. But like i said, if im not playing the game.. im not coding anything for it either :D

[Aufklarer]

Not really, if you point your bow or rear in front of the target, and point the periscope/UZO at 0 or 180 degrees you can also do it moving. It then completely cancels out your movements. But you're limited in your directions ofcourse. It usually takes just a moment (wel under a minute) so you can back to your original course quickly.


I agree but it is not always practicable to do so

@Gutted are you going to rehost those youtube tutorials you made i didnt watch them yet.

[kylania]

I agree but it is not always practicable to do so

@Gutted are you going to rehost those youtube tutorials you made i didnt watch them yet.

They were great videos! I was still waiting for the "various methods to find speed" one. Tried using the length/time x 1.94 trick yesterday and was getting speeds well below what it actually was.

[Aufklarer]

I have not had any problems using that method, if the result comes out for example at 6.74 are your rounding to the nearest whole knot?

Also doing it on the move in the method described above dosnt completely eliminate the movement of your own ship from the equation, it only minimises it. When you are relatively close to the target 1-1.5km it makes minimal difference, however a minor error in speed calculation is amplified over distance wich may result in a miss.

Pisces may i ask what method you use to calculate speed, especially on the move?

[Pisces]

First of all, I'm not using SH5. Still Sh3 or 4. But that's all the same physics.

I either plot on the map, or do as I explained if I am in a hurry. The fixed wire method should not be done when he is showing an AOB that is rather small (near 0 degrees) or very big (near 180), since then you can't see his bow or aft clearly because of his deck-structures. If might even be obscured by the side of his bow if he's wide enough.

The idea with the fixed wire method is that when the periscope/uzo is along the bow/aft line that you project an imaginary fixed wall in the sea. Your speed is exactly along it. The target passes through it in the same time no matter what course he has, or your distance to him. His length is fixed so the speed is now known also, length over time. Mix in a conversion factor of m/s to knots of 2 (for simplicity) and you're done. You just need sharp timing with the stopwatch, and a steady course. Submerge if there is wave-action.

I've seen a website of a worker at a German Uboat museum which explained they had a real device to do that. A vertical line in the optics moving left /right was synchronised with the movements of the gyrocompass.

[Donkey-Shot11]

@gutted: wow, those are some pretty handy tools you've developed.
And thanks for the tip to search for 'vector math' on google. I wasn't quite sure what kind of math to look for. But it turns out there are plenty of good math sites out there.

[Kuikueg]

There's some maths info here:

http://www.subsim.com/radioroom/showthread.php?t=170671

Geometry is the way to go. Rule and compass. It's all in the game, you don't need a spreadsheet.