How to determine range.

[atraangelis]

Hello community, im new to subsim(dot)com but not to naval wargames.

With regards to DW i find i have a hard time getting my ranges acurate. I have watched the video on subGuru's site and it seemed to help but I am looking for some more advice on other methods from some more experienced DW players.

[MarkShot]

Range:

(1) Seawolf use WAA.

(2) Check if you have contacts on Sphere as it should kick in at a specific distance. Like I think for stock Sub Command, the contact is within 10kyds.

(3) Strength and lines on DEMON.

(4) Lag or lead LOS and the cross of the LOBs either indicating max or min range.

(5) A contact on Sphere and TA as the intersection is the exact position and range.

(6) Additionally, TMA legs. If you are not worried about give away your position, speeding up for a few minutes can help. It increases the fan and triangulation affect of the TMA solution.

(7) Strength and sound of the BB contact.

(8) Bearing rate on the STA and ITA sonar. Imagine a sub moving at 5kts from DEMON, but with a high bearing rate (line drifts) on BB. That means you got relatively close and dangerous contact.

I am sure the experts have even more clever methods. These my naive ones.

[PeriscopeDepth]

Keep in mind MarkShot: speed has no effect on ownship sound emissions in Sub Command unless you are cavitating, so kicking it up a few knots is something you shouldn't worry about.

PD

[MarkShot]

So, is this wrong? Forgot where I got this or who did this. Thanks.

[PeriscopeDepth]

Markshot,

AFAIK, Sound vs Speed was first done with DW 1.3 Beta.

PD

[MarkShot]

PD,

So, you when I am playing SC and fire a torpedo at a sub and I watch DEMON its speed ratchet up ... at the same time, in BB I can definitely hear an increase in SFX volume and the BB track goes thick and bright, you are saying that I have not detected a measured simulated affect, but simply that the target has begun to cavitate?

Hmm, I think I will set up a little trial with a very deep contact and bump the speed by about 5kts at waypoints of 6 minute intervals and see what BB shows.

Next to the fact that I can raise my scope all I want in SC/DW, I would find the fact that I can run at any speed with no difference to be really upsetting. This would be enough to drive me back to playing AOD!!!

I'll keep you posted and hope you are wrong.

[PeriscopeDepth]

What I am referring to is documented in the Sonalysts DW readme as the "sound vs. speed fix" under the 1.02 section. I don't think this has been fixed in SC, doesn't bother me though. I play DW.

Edit: Forgot link.
http://scs.sonalystsgames.com/phpBB/...6ad979573e40fd

PD

[MarkShot]

Here is the proof for that chart.

This is stock SC 1.08. I used the SW (easier to demo) and the contact is a close 688i in the first case making 5kts and the second case 30kts. Testing done at around 1400' for both subs.

Notice the thickness of the BB contact and the SNR value; a difference of 250% and you can hear on the speakers too.

I submit to you that the assumption that Sonalysts only corrected SC bugs in DW may be an incorrect assumption, and, in fact, Sonalysts in producing DW may have well introduced new bugs into the game engine as this clearly illustrates. Whoever made that chart, clearly had run some detailed tests.

Me, I play SC, SCX, and DW-LWAMI. Why discard a perfectly good game like SC just because DW is newer? (I still play AOD by the way too.)

[MarkShot]

So, now if one applies the inverse square law (not sure if that applies to sound propagation), then one would be able to make a statement of how much more detectable the 688i is at 30kts versus 5kts.

I can tell you this from playing SC and also SCX (assuming not every AI sub is cavitating). You can see an AI sub running from a torpedo make a bright track on BB. Then, at some point they slow down from 35kts to 5kts and they literally dissappear off BB, but you are usually okay if you had a NB tracker on the 50 or 60Hz tonal.

[SeaQueen]

Oooo... you've asked the million dollar question, the real heart of what makes sub simming fun. :-)

There are many ways to determine range, not the least important of which is guessing, or even just determining the upper and lower bounds of a target's range as well as it's direction of relative motion. There's a book called Naval Operations Analysis that details some of the more sophisticated methods of determining a target's range including Ekelund and Speiss ranging as well as a lot of other ASW geekiness. You can also determine it by taking advantage of simple geometry and make assumptions about the target's speed and how that's related to bearing rate (angular speed in your reference frame). If you're interested in physics and geometry, then this is the really meaty part of the game.

Originally Posted by atraangelis

Hello community, im new to subsim(dot)com but not to naval wargames.

With regards to DW i find i have a hard time getting my ranges acurate. I have watched the video on subGuru's site and it seemed to help but I am looking for some more advice on other methods from some more experienced DW players.

[Castout]

IN WWII subs they used trigonometry but they need to know the ship specification like maximum mast height and such and such.

To calculate solution they use mechanical rotating wheels something everyone would agree to call as mechanical computer.


On modern sub you could always ping them. Just expect them to send you a few fishes over.

We're hit. Okay that was retarded:rotfl:

The truth is I guess it from the their speed and DEMON display and Narrowband singal strength....and I'm lousy at it.
In DW the intersection between the spherical sonar and the towed array sonar would not give you the precise point(and hence range) of your current target because DW models such thing called sound dispersion

Wait for me to finish my PHd. I'll give the Navy underwater laser rangefinder......I just need to finish in an ivy highschool, then a good college then...
Well obviously you need patience and I need a tad bit more IQ points LOL. Yes I haven't even started my PHd LOL.

Edit: It's fine in its current form. It just have one tiny problem or in other words it needs a little bit innovation: It doesn't work underwater.

[Doosches]

I know it's cheating, but there's an Ekelund Range calculator for the iPhone/iPod Touch

[SeaQueen]

Originally Posted by Doosches

I know it's cheating, but there's an Ekelund Range calculator for the iPhone/iPod Touch

It's not cheating. I play DW with Excel spreadsheets opened on my laptop for doing the same thing, and a few more neat tricks to boot. The other thing people often don't talk about is that unless you're REALLY close to the guy and you're worried about hitting him, you don't have to be super accurate. You only have to get the torpedo close enough so that it's own internal guidence will do the rest.

[LoBlo]

Originally Posted by SeaQueen

There's a book called Naval Operations Analysis that details some of the more sophisticated methods of determining a target's range including Ekelund and Speiss ranging as well as a lot of other ASW geekiness.

Errr... that book is like $550 bucks on amazon?... got a spare copy?

[Pisces]

Originally Posted by LoBlo

Errr... that book is like $550 bucks on amazon?... got a spare copy?

I think somebody allready uploaded a chapter somewhere and provided a link to it somewhere here in the DW threads.

...Down Periscope.

Setting planes on dive ... into the threads.

Streaming the floating wire:

See posts at the end of this thread. It was JMR

http://www.subsim.com/radioroom/showthread.php?t=126487

http://files.filefront.com/NOE+Beari.../fileinfo.html