Testing some aspects of DW (lots of pictures)

[Zerogreat]

Hello... once again i have for some while two computers at my disposal, so i decided to try some things in DW on my "LAN" :) Mainly regarding...detection. I did it to see how things work and while i was on it i also took pictures of my testing so you can see it too! :ping:

It might not be all 100% accurate, because DW is really very complex, and thus its hard to accuratelly test al lthe ascpects, but it should give the general idea :yep:

This time it was MH60 versus Chinese Kilo Improved... the helicopter trying to find the submarine at different depths, speeds and other circumstances, using different sensors... so, lets start!!! :arrgh!:

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First test was Kilo detectability againts radar. Kilo was visible on radar when at 14-15 meters, diving to 15-16 meters resulted in kilo being undetectable on the radar. Raising any masts while being at 15-16 meters depth had no effect on its detctability by radar. Getting very close to the kilo did not detected the masts too.
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And now kilo versus sonar :x

This was the lookout on the beginning

http://web.quick.cz/zerogreat/KiloCH_I_vs_MH60.jpg

The kilo is about 3,5 miles from our helo, running at 5 knots at 15 meters depth. There are two DICASS buoys next to the helo, one DEEP and one SHALLOW. Both ACTIVE - The DEEP one was able to see the kilo pretty well, while the SHALLOW one was unable to see it at all. The layer was at a 230 meters so it seems a bit strange to me. It was surface duct.

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Then i tried passive detection, and diesel noise :)

Ok, on those two pictures of passive DICASS and passive dipping sonar, you can see, that you can not see the Kilo at 3,5 miles range, 5 knots at 15 meters depth. :P

http://web.quick.cz/zerogreat/Kilo5ktsDIC.jpg

http://web.quick.cz/zerogreat/Kilo5ktsDIP.jpg

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Ok, that was somewhat expected....but lets see what happens if the kilo engages one of its diesels :hmm:

http://web.quick.cz/zerogreat/Kilo5ktsDIC+1Diesel.jpg

http://web.quick.cz/zerogreat/Kilo5ktsDIP+1Diesel.jpg

Now we can see you, boy :ping:

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So what now, will engaging of the 2nd diesel have any more effect???? :stare:

http://web.quick.cz/zerogreat/Kilo5ktsDIC+2diesels.jpg

http://web.quick.cz/zerogreat/Kilo5ktsDIP+2diesels.jpg

Wow! it definitely does! A big time! :huh:

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Now lets disengage diesels, dive the ship to 100 meters and start running at 15 knots!

This tells us a bit about difference in active return in relation to distance to the sub.

http://web.quick.cz/zerogreat/Kilo100mFurther.jpg

http://web.quick.cz/zerogreat/Kilo100m.jpg


So lets go passive now...the kilo, even at 15 knots, is one sneaky bastard! :damn: So the range at which VLAD got hot was measly 850 yards :88)

http://web.quick.cz/zerogreat/Kilo15kts100mRNG1.jpg


But still at this range, buoys get no reading and no frequency alert :cry:

http://web.quick.cz/zerogreat/Kilo15kts100mRNG1Buoys.jpg


But the dipping sonar hears something! But well...it is a very very faint line, i would probably not notice it not knowing where the sub is :roll:

http://web.quick.cz/zerogreat/Kilo15kts100mRNG1Dip.jpg



So....let it come just a bit closer!

http://web.quick.cz/zerogreat/Kilo15kts100mRNG2Act.jpg

At a distance of about 350 yards, plus about 200 yards (because my helo drifted in wind) from the buoys, i have at last got a frequency alert and my deep VLAD and only my deep VLAD showed me a nice faint line.

http://web.quick.cz/zerogreat/Kilo15kts100mRNG2Buoys.jpg

In the next few seconds the deep VLAD developed a second faint line, but that was the best it done, when the kilo came too close to the buoy, the contact was lost. :nope:

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And now active detection in relation to depth!

Kilo at 150 meters...
http://web.quick.cz/zerogreat/Kilo150m.jpg

At 200 meters......
http://web.quick.cz/zerogreat/kilo200m.jpg

At 200 and 50 meters...............
http://web.quick.cz/zerogreat/Kilo250m.jpg

Now at 300 meters, there appeared some strange ghost contact! :o Took two pictures of it!
http://web.quick.cz/zerogreat/Kilo300m.jpg
http://web.quick.cz/zerogreat/Kilo300m2.jpg


And at 350 meters, the kilo imploded :lol:
http://web.quick.cz/zerogreat/Kilo350mDead.jpg



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Now that is all.... interesting? :hmm: :rock:

[Kazuaki Shimazaki II]

Err, you don't think the pictures can be shrunk to quarter size and still be visible?

[WargamerScott]

Hey, that was a great post ZeroGreat! Thanks for taking the time to do the experiment and posting the illustrated results! I think if DW came with a strategy guide that used examples such as yours, the game would be much easier to learn.

Well Done! :up:


BTW: As an aside, I have discovered that a lot of people approach DW like I did, that is, they would love to get the game, but the learning curve scares the heck out of them.

[XabbaRus]

Aye Zero reduce the quality of the jpegs and that would help.

Very good though.

what version of DW and what mods if any?

[Zerogreat]

Of course the pictures can be shrunk...but there is a question... why? :) Umm, because it is a sonar screen, i think it is good to make it as much readable as possible to not loose details :) But if you want, i will see what can be done ;)


Oh, the version, i definitely wanted to notice that but then i forgot :lol: It is the 1.03beta with sound vs. speed fix (maybe it is integrated in the beta anyway? :) ) and font mod :lol:


I also had pictures of the SSP, both from the kilo and from the helicopter, but somehow, both of these pics became lost :ping:

[Fish]

I have problems downloading the pics, even as I have 5000 kbps download speed :doh:

[Zerogreat]

I have problems downloading the pics, even as I have 5000 kbps download speed :doh:

Might be because i was uploading the new versions right now :hmm:

Ok, reduced the overall size from 2,62 MB to 1,82 MB ... should take 3 seconds to load them all on your 5000 kbps line :|\ ... but i dont think 'my' server is that fast anyway :lol:

[XabbaRus]

Thing is Zero I post 1024x768 res pics and they come up quicker.

REduce the jpeg quality when you resave.

[sonar732]

When I attempted to save them, they were bitmaps.

[XabbaRus]

That was my first impression when I opened the thread.

If that is the case then no wonder they are taking a long time to load.

[Zerogreat]

Verdammt..... They are JPEGs with 30% compression, i am not that dumb to post uncompressed bitmaps, that would have like 2 MB for EACH picture :huh:

Anyway, thanks to WargamerScott for appreciating my work and not just complaining like others :cry:

[XabbaRus]

I appreciate the work but for some reason they are loading really slow.

Sorry Zero what you have done is great.

[Gizzmoe]

30 minutes, still loading... :zzz:

Next time use Imageshack, please!!! ;)

[Zerogreat]

I'm sorry i dont know why they load so slow for you, the site works fine for me :-?

[sonar732]

Zero...I wasn't trying to be mean...just letting you know that even with 1.5mb/s download, it's taking quite a bit of time.

[Zerogreat]

Ok, sorry again :) Well the pictures are not really big, all together are 1,8 MB so maybe the server gives slow trafic outside CZ because for me and my friends here it works fine...i am gonna move them to another in few minutes ;)

edit: changed the links, hope it will be better now :-?

[Fish]

I dont know what you changed, but there loading just fine now. In a eye blink.

[Zerogreat]

I dont know what you changed, but there loading just fine now. In a eye blink.

Moved the pictures to different server... god its working fine now :yep:

[Deathblow]

The kilo is about 3,5 miles from our helo, running at 5 knots at 15 meters depth. There are two DICASS buoys next to the helo, one DEEP and one SHALLOW. Both ACTIVE - The DEEP one was able to see the kilo pretty well, while the SHALLOW one was unable to see it at all. The layer was at a 230 meters so it seems a bit strange to me. It was surface duct.

I don't understand this as well.... seems a bit odd to me also... DICLASS Deep = 240m depth right? Shouldn't the shallow see it and the deep not? Couldn't it be a sonar model bug.

:hmm: :-?

[Zerogreat]

Deep buoys are just 120m in unmoded DW i think (if the patch did not changed this....had it?) :)

I done further tests and i have came to a conclusion, that whenever the layer is so deep that you cannot get past it with a deep buoy, then the deep buoy is the best choice to use, because it seems to be always more sensitive (probbly because the shallow one suffers from the noise from waves and such...) :ping:

Hovewr if deep buoys DO get under the layer, then the shallow ones are useful to detect contacts on top od the layer :)

[LuftWolf]

The performance of shallow buoys at 90ft suffer from a significant increase in ambient noise from the surface.

[RedDevilCG]

This was awesome! I now have access to try this sort of thing out over the LAN as well. The only problem is that I am in a 120% course load in university this semester, so I really don't have the amount of time to do this sort of thing during the week.

I was hoping to be able to setup similar experiments, with all the submarines going head to head to see how much farther one detects the other at a couple depths and speeds. This chart would be very valuable in knowing about how long the other guy has been tracking you (once you finally see him if you have an inferior sonar), or about how long you have to stay hidden before he gets in range to start tracking you!

I guess I will have to wait till the weekend and see how it goes.


Once again, Great Work!

Cheers.

[sonar732]

Thanks for moving the pics to a different server. They are awesome to look at!

EDIT: I suspect that one of the major reasons why they were difficult earlier is because your server couldn't take all of the ppl that were attempting to look at it. :rock:

[Zerogreat]

Yesterday i did few more tests... now it was about layer effectiveness against passive buoys :)

This is SSP fort this mission
http://web.quick.cz/zerogreat/ssp.jpg


All buoys are on top of the layer, now we will have the akula coming closer to them at both sides of layer to see how effective the layer is :ping:

Starting at 7,5 miles, Akula going 10 knots, on the same side of layer as buoys, buoys can see her :)
http://web.quick.cz/zerogreat/60m10kt7,5nm.jpg


Akula coming closer to 7,1nm from buoys and accelerating to 20 knots.....
http://web.quick.cz/zerogreat/80m20kt7,1nm.jpg



Now the akula is 6,3nm from the buoys, still going 20 knots, but this time on opposite side of the layer .. we lost it :88)
http://web.quick.cz/zerogreat/200m20kt6,3nm.jpg


Akula is 4,2 miles from buoys, going 15 knots, we can still not see her. The lines on the OMNI waterfall display are from akula being ove rtle layer, then she got under it and we lost it :zzz:
http://web.quick.cz/zerogreat/150m15kt4,2nm.jpg



First contact of the Akula on opposite side of the layer, going 15 knots, was at 1,8nm! On the deep buoy, which does not suffers from surface ambient noise.
http://web.quick.cz/zerogreat/150m15kt1,8nm.jpg


Because the shallow buoy suffers from ambient noise, it made contact with the akula (still 15kt) at 1,6nm distance :cool:
http://web.quick.cz/zerogreat/150m15kt1,6nm.jpg





So we can see that the layer is very effective :up:


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This is to compare sonar capabilities of different buoys. Akula is under layer, going 20 knots, 1500 yards from all buoys.

http

http://web.quick.cz/zerogreat/175m20kt1500y.jpg

[RedDevilCG]

Just thought that I would make a LWAMI plug here. The LWAMI mod changes around the depths of the bouys so that your deep bouys will actually go DEEP thus penetrating the thermal layer. All bouys have been modified, but differently for each bouy. Check it out here:

http://www.subguru.com/DW_missions/LWAMI_Readme_Realism_Mod_v300BETA_RTF.rtf

This is the total change log up to LWAMI 3.00b. Just do search for Bouys to get right to the changes.

[Sub Sailor]

I have no compalints simply a major Bravo/Zulu for you fine work. Look forward to studying any other test you do.

Thank you very much,

Ron Banks MMCM(SS), USN(Ret) :rock:

[Three14]

Great stuff. The sonabuoys, with their consistent detection criteria (unlike my eyes), is convincing.

I was wondering if a DEEP buoys that significantly penetrated the layer would pick up the sub much sooner, as expected. I also wondered about subs at or near the layer, and if perhaps a contact might reappear as the sub got farther away (as a result of any number of strange bends).

The echo image in the active display at 300m in your first test series really interested me. Could you mark the mirror contact? Could it be reproduced?

[MaHuJa]

I suspect the "ghost" active contact is the same as I've seen myself at several occasions, with numerous different active sonars. One explanation I've come across is that the sound bounces off the bottom of the sea, hits the target, and returns - with a longer distance.

I can remember marking such contacts. And I think it's been the most common in somewhat shallow environments.

>(as a result of any number of strange bends).

Such "bends" do not seem to be implemented.

[Three14]

I don't like to think of the effects in terms of reality, but more on code. If it's a modeled reflection off the bottom, then I don't see why you wouldn't get the same return irregardless of the depth of the target. If it's a model of the reflection off the target to the bottom and then to the broadcasting sub, then that's a very peculiar path.

It's all peculiar, but that's just something worth investigating.

[XabbaRus]

Bottom bounce is modelled, so you will get two blips from one contact.

Very clever IMHO.

[Three14]

I know it's in, but I'm curious if this is a clue about bottom bounce and how it is programmed in.

But then, can you get echos without targets? How much is it modelled? Bottomed subs near certain bottom features are more, or less likely to give false returns, then?

The goal is to think of ways for subs under active persecution to create some confusion, or for surface ships to avoid it. If you can't mark the other returns, it's not really a big deal.

Btw, it has always seemed that faster subs are more easily detectable on active in these games. Is that true in DW, too? Is there some good reason for the magnitude of the affect (in reality)?

[LuftWolf]

Faster subs are indeed more detectable on active sonar by a signficant degree. No one that I know has a good explanation for this, at least not one they are willing to share. :88)

So I'm not really sure about its presence in DW.

Sound does do some very strange things some times, the paths of sound are rarely straight from one object to another because sound bends in water depending on the SSP.

In that situation, its entirely possible that you were only getting direct line noise from the submarine, and the majority of its sound was hitting the ocean bottom underneth you and bouncing away.

[XabbaRus]

A pity the knuckle isn't modelled when you do a tight high speed turn.

[Kazuaki Shimazaki II]

Faster subs are indeed more detectable on active sonar by a signficant degree. No one that I know has a good explanation for this, at least not one they are willing to share. :88)

Could it be modelling the effects of Doppler? The sonar processor emphasizing returns that are slightly different from the base frequency because moving targets are more likely to be real targets?

[LuftWolf]

That's a definate possibility, but I am not convinced with my lay knowledge that such a doppler shift given the relatively low speed of submarines verses the speed of sound in water would really matter at the level we are talking about.

Although sonar processors are remarkably sensitive devices. :hmm:

[Kazuaki Shimazaki II]

Although sonar processors are remarkably sensitive devices. :hmm:

The speed ratio b/w a 5m/s sub versus the about 1500m/s (something like that) speed of sound through water is 1:300. The speed ratio b/w the 300m/s plane versus the 300,000,000m/s radar signal is 1:1,000,000. If anything, the doppler difference should be more pronounced with sonar than radar though of course sonar is trickier due to all those layers in the water...

[Three14]

Well, that's a bit easier to test in DW. Have the sub running perpendicular at a run and at a trot :)

I'm not clear with how interpreting doppler shifts would help. You pick up ANYTHING near 20,000Hz and that's your baby.

While your giving me your hypothesis, also tell me whether two active emitters could confuse each other (as each emitter hears the other at the frequency)?

Thinking more about it, active sonar must be simplified incredibly in DW.

[Kazuaki Shimazaki II]

I'm not clear with how interpreting doppler shifts would help. You pick up ANYTHING near 20,000Hz and that's your baby.

If that's so, reading active sonar returns would be greatly simplified in DW and real life - the screen would be nice and black for most of its scan except for the blips now shown in high contrast, almost as easy to read as radar. In fact, there are some reverbs from the water. There will be reflection off the surface (huge change in Sound Velocity) and the bottom (another Huge Change), some off the layer, some off ice ... all in all a fair amount of noise to deal with.

It is probably simplified, but the best guess I could come up with is that they are trying to simulate Doppler.

As for the possibility of interference, I see no reason why not in real life. However, it could probably be electronically supressed - I understand something similar happens with radar, and modern sets are supposed to squelch this kind of thing.

[sonar732]

The WLR-9 Active Sonar Intercept is close to DW's Active Intercept.

EDIT: DW's Active Intercept is close to the WLR-9 Active Sonar Intercept in the fleet. :know: :yep:

[Three14]

I'm not clear with how interpreting doppler shifts would help. You pick up ANYTHING near 20,000Hz and that's your baby.

If that's so, reading active sonar returns would be greatly simplified in DW and real life - the screen would be nice and black for most of its scan except for the blips now shown in high contrast, almost as easy to read as radar. In fact, there are some reverbs from the water. There will be reflection off the surface (huge change in Sound Velocity) and the bottom (another Huge Change), some off the layer, some off ice ... all in all a fair amount of noise to deal with.

It is probably simplified, but the best guess I could come up with is that they are trying to simulate Doppler.

As for the possibility of interference, I see no reason why not in real life. However, it could probably be electronically supressed - I understand something similar happens with radar, and modern sets are supposed to squelch this kind of thing.

I assumed that the background noise in the game's active sonar display was simply generated, as with the noise in broadband. Otherwise, I'd like to be able to mark contacts anywhere I want, even if I'm very wrong.

[Kazuaki Shimazaki II]

I assumed that the background noise in the game's active sonar display was simply generated, as with the noise in broadband. Otherwise, I'd like to be able to mark contacts anywhere I want, even if I'm very wrong.

It is probably generated - who would believe the noise is the same all the way around. But it is supposed to represent something in real life, albeit very crudely, and I think it is all the reverbs through water, layers, various obstacles ... etc.

Not that I mind it being generated - the blips are so hard to see on the Akula sonar that I basicaly click at random in a general area on the screen...

[LuftWolf]

Otherwise, I'd like to be able to mark contacts anywhere I want, even if I'm very wrong.

This has been a subject of much debate regarding how the active sonar should actually work in-game.

[Three14]

I guess I missed that debate. I'd say the gameplay changes are quite positive and of course, it must be more realistic.

Maybe it's a programming challenge -- updating the contact to correspond with the finds of subsequent active pings would be impossible without more or less programming the same logic they might use on the real deal.