Dangerous waters sonar questions

[speed150mph]

Okay so I have been playing dw for about a month now and am loving it, and have now expanded it with the RA mod. Though I seem to have a preference to russian subs.

Now that in getting comfortable with the sonar suite, I have a couple questions about sonar.

We all have been fooled by Hollywood when it comes to sonar. Movies like hunt for red October have made me think that sonar was the masterful accurate device that would allow you to pin point your targets every move, something I'm now getting over. But I have heard stories about distinct sounds that a sub makes that can give tells to what he's doing. Hulls popping as he's changing depth, tubes flooding, doors opening. I was wondering if this is true and more importantly, is this modelled in dw, and if so, how close do I have to be to my target to hear these sounds besides too close.

Secondly, what else can one deduce from a sonar screen. I've learned to use my demon for speed, and bearing drifts to get a rough course, and using the layer depth/contact strength relationship to determine the rough depth. Is there anything else about a contact that can be determined though a sonar?

Also since using RA mod in the akula I've been introduced to the waterfall display rather then the russian circle screen I'm used to. What new features and tricks can be done with the waterfall display, and how accurate/ useful is the waa range?

Sorry I know that's alot of questions, but I'd like to hone my sonar skills for multiplayer, after all, the edge in a naval battle undersea revolves around hearing him without him hearing you. Thank you very much

[speed150mph]

I'm suprised nobody has an answer, I thought there would be a bunch by now

[SilentPrey]

I'll take a stab at it even though it's been a while since I played. The other reason I didn't answer is that I went with LWAMI instead of RA so I'm not too sure about RA.

As for sounds; I've never heard another sub's hull pop, tubes flood, or doors open. I have noticed that my own noise level goes up when I flood tubes or open doors or even raise the scope. It shows up as brighter background noise on the spherical array. I don't remember if that happened in stock or not. But, if it's modeled for Own Ship there's a good chance it's modeled for others.

As another disclaimer, I have done very little multi-player.

I prefer American subs because I like the waterfall. I don't spend all my time in sonar so it's nice to be able to look back over the last few minutes of noise we picked up. The only trick I can think of for waterfall is using a longer display time to help you pick up targets. If you're at the edge of detection then the target won't usually show up on the 2 minute history very brightly but when you look at the 30 minute or 2 hour it's a well defined line. If those aren't the right times for the display, sorry, it's been a while.

You didn't mention target ID in narrowband as a sonar function but I'm assuming you do that since you're using the DEMON for speed. Only tip I can think of for DEMON is being able to confirm (or deny) your classification based on blade count. Too many blades is a dead giveaway but too few isn't a show stopper until the contact gets louder. I've had seven bladed screws only show three lines when I first pick them up.

In LWAMI it's often easier to pick up quiet contacts by looking for their power line in narrow band than staring at the broadband screen. You're probably used to that though using the Russian boats. That process takes a little more work with a waterfall; but you have 30 seconds of history there too if he just went silent.

WAA range is usually pretty close to actual distance. If you watch it for a few minutes you'll see it bounce around a bit; that bounce is pretty much your margin of error. If your WAA says 16000 and your TMA says 8000; go with the WAA. The auto TMA guy seems to always want to put contacts closer than they actually are. That's why I do my own TMA. (And that's why I'm not always on the sonar screen.)

Lastly, don't forget your hull array in narrowband. It can give you lower frequency coverage while you're waiting for your tail to straighten out. It's not low enough to pick up the power line but it should get the second lowest one. That may not be true in RA but it's worth looking at. Also, flow noise in the hull array means you're not being as quiet as you probably want to be; slow down.

[phil21]

Hi,

it's also been a long time since I played, nevertheless here are my thoughts:

I don't think these "special" sounds like popping of the hull or opening of torpedo tubes are actually modeled. There may be an increase in noise level, but i don't think anything beyond that. it would be almost useless anyway, since you would need to listen to the sonar station and especially the contact the whole time. Thereby you could not multitask, potentially a very dangerous thing.

The sonar can give you everything, in theory:
1. Bearing obviously
2. Depth above or below layer (most of the time you don't need more)
3. course by bearing rate
4. Speed via DEMON
5. Range via bearing rate

To make good use of the bearing rate you should perform course changes after a few lines. After two or three changes (and assuming your target went steady) you should be able to get a good solution.
The waterfall display is imho superiour to the circle display for a variety of reasons, the most important ones are better estimation of bearing rate and better signal to noise ration due to the signal averaging performed by adding the signal over time.

But the most important sensor is the TA Narrowband: here you get the best detection ranges, although you really need to scroll a lot. The TA can detect even the 50/60 Hz lines which travel the farest, so i use this for initial detection. btw: check your gamma settings, otherwise you might miss some very faint lines in Narrowband.

Hope this helps a little

[speed150mph]

Thank you, that has been very helpful. I'm still unaccustomed to the waterfall display but I will learn, especially on my favorite akula. I think the thing with me and the waterfall is it has so many more buttons and it's harder to judge bearing quickly with it. But it's just adapting.

Hey another question I forgot to ask. With the sonar modelling, in shallower water with no layer, will hovering just above the floor help mask active or passive signifiers, like flying nap of the earth and terrein masking does for aircraft?

[OptimusX]

I don't think it would matter much with passive detection, because even an idle sub can radiate noise.

Aircraft deal with more active detection than subs.

[SilentPrey]

Being close to the floor messes with your sensors a lot more than whoever is listening to you. If you're going slow enough to be quiet then your towed array will end up dragging. I also don't believe active sonar will return off of the floor but it will definitely still return off you. With both active and passive if you're on the other side of an island or something like that then you are masked but just being close to the sea floor doesn't help you.

For aviation terrain masking and NOE flight make a lot more sense. Aircraft are actually quite bad at spotting threats on the ground; the aircraft is always much more conspicuous than whoever is looking up at them. In a submarine though, you are the least conspicuous thing in the area. You're well camouflaged. Your best defense is to be quiet in wide open water so you can hear everything going on around you.

[Kapitan]

There's not much upgrade done to the sonar systems in RA, the akula and Russian boats all have a similar sonar suite and you need have to have a good eye sight and quick reflexes.

With sonar towed array mainly you always get the real contact and a mirror, the way to distinguish between the real and fake is to conduct a 45 degree turn, look on the nav map the contact that moves and jumps is the fake so shoot at the other one.