Active sonar, useful for anything other than basic ranging?

[NFunky]

Hey all, figured I'd start a new topic since this has only a slight bearing on my other thread. This one is a simple question.

Does anyone use active sonar for anything other than obtaining range? I'm playing around with my Kilo scenario and have found that I can effectively use the return sound to get the exact range for a target that I've already pretty much localized. Thanks to some of the advice in my other thread, I've started using it to help me re-steer my fish when the target starts evading, however I can't seem to find any other use for active. I get no bearing data because I can never see the contact which also means that while CMs do make an audible return, I can't use active to steer fish past them. I also get quite confused when my fish get pretty close to the target as they also create return pings and no visual mark.

Anyone ever use active effectively?

[Kazuaki Shimazaki II]

Originally Posted by NFunky

Hey all, figured I'd start a new topic since this has only a slight bearing on my other thread. This one is a simple question.

Does anyone use active sonar for anything other than obtaining range? I'm playing around with my Kilo scenario and have found that I can effectively use the return sound to get the exact range for a target that I've already pretty much localized. Thanks to some of the advice in my other thread, I've started using it to help me re-steer my fish when the target starts evading, however I can't seem to find any other use for active. I get no bearing data because I can never see the contact which also means that while CMs do make an audible return, I can't use active to steer fish past them. I also get quite confused when my fish get pretty close to the target as they also create return pings and no visual mark.

Anyone ever use active effectively?

Are you using the god-damned Akula sonar? Because the others, IIRC, DO show the blips reasonably well, so you can use it to search for both range and bearing...

[NFunky]

Well, I'm using the KILO active sonar, but I have swapped out all the sonar interface graphics for the easier-to-see green ones from the Alfa. I have occationally been able to see contacts using the 688I active, but only if they ar closer than 3000 yards or in a full on beam aspect in which case I gain about 2000-3000 yards detection distance.

[Dr.Sid]

Russian sonars are seriously flawed in the game. But US should work quite well. Don't forget all sonar conditions affect active as well, especially SSP and sea state.
Getting ping not sooner then at 3000 yds sounds to me like cross-layer ping. Layer always blocks sound completely in DW, but when you get closer, the effect disappears.

Here is my older post about DW sound propagation model.
http://www.subsim.com/radioroom/showthread.php?t=117814

So let us know about your depth, target depth, sea state, and SSP.

[NFunky]

Hey Dr.Sid, I actually read all those old threads about the hydroacoustics in DW and learned quite a lot.

I just performed a series of pretty controlled tests and I will share my results. First, I'm using DW 1.04 with the most up to date RA mod available. I used a Los Angeles FLT III as my test platform and an Iranian Kilo as the target. Sea state 1, time of day 12, weather clear, bottom type rock, SSP surface duct, layer on average slightly less than 1000 ft. Both subs were in deep water, approx. 11500 ft. My sub was oriented 000 and the target was north of me oriented 090, both were at 200 ft, 0 kts.

(Side note: I found that when editing the scenario using notepad, about 1 nm y-axis distance is 1850.0 in the POS value.)

I started the target at 2 nm from me and increased distance each time by 0.1 nm. It seems that between 2.8 and 2.9 nm, it becomes nearly impossible to see the target. Usually a second ping would help brighten the target, but at about 3 nm even this did not make the target visible.

As a disclaimer, I am slightly visually impaired. However, once the target brightness is about the same as some of the random patches in the water, I assumed even a fully sighted person would have real trouble telling it apart.

EDIT: Just did the same test with LwAmi 3.09 and got basically the same results so it's not the RA mod.

[NFunky]

Just ran the same tests only I switched the platforms around so that I was driving the Iranian Kilo (the one with the nice green sonar displays) and the target was an LA FLT III. All other conditions were exactly the same.

The Kilo's sonar wasn't as weak as I expected. I was able to get a reliable visual return out to about 1.8 nm and a sporadic one out to about 2 nm. The biggest difference I found was that double pinging didn't make the contact any brighter at any range.

Oh, I forgot to mention in my last post that I always brought the display scale down to 10 for all tests and used single-ping mode. I haven't tried this test with any of the red displays and don't intend to since I have a hard time even seeing some passive sonar contacts with them (my vision again, green on black is much better contrast than red on black). I may do some more tests later with a bow aspect, a stern aspect and a semi-beam (45 degrees bow and stern) aspect, but not right now.

I find the short range of the active sonar's visual returns make it pretty useless for anything other than a knife fight type situation since even a Kilo would have a strong passive contact at these ranges. The audible return is still useful, as I mentioned above, for ranging of a target which is already pretty well localized.

[Molon Labe]

This is just a problem that DW has with the way it models active sensors. There is a detection threshold, which is a discrete range at a given aspect. At that threshold, the contact is theoretically detectable and produces an audio return. But, for the visual representation, there is a brightness scale going from strong to weak that doesn't even begin to become visible until the target is well within the detection threshold. It's not your eyes, it's just the way the interface/model is set up.

It's actually the same way with the radar model--but without the audio cue. You don't see it yet because all the databases out there (maybe RA is an exception) go from the detection threshold to a very strong contact in very, very little space, so you never have to deal with the "invisible" returns.

[Pisces]

Originally Posted by NFunky

...
I get no bearing data because I can never see the contact...

But if you are able to receive an active sonar return you should allready have a passive signal of the same contact. Combine the bearing of the passive signal, with the range(indication) of the active audible return and you have a pretty good fix.

I usually fire a torpedo well in advance towards the target (prefferably opposite on the layer) before I ever make use of a ping. The ping alerts to your pressence. It probably notices that a torpedo is fired, but it doesn't allways respond to it immediately. Only if it get's too dangerously close. So I let the torpedo close the distance, and only ping and finetune steering when it is allready close to the target.

[suBB]

Originally Posted by NFunky

Hey all, figured I'd start a new topic since this has only a slight bearing on my other thread. This one is a simple question.

Does anyone use active sonar for anything other than obtaining range?

with a few maneuvers against the transmitting source, you can triangulate the sources' location. This is a tactic known as ping stealing.. I've used this a couple of times and works really nice with bracketed subroc salvos.
If you can't tell already, I'm an akula skipper, and will be an Ak2 improved skipper in RA(love the digital sonar gear and WAA),

also, I'd say active sonar is really a trade off of luxury and consequence. Any platform capable of subroc ordinance can literally throw their weight around with active sonar and get weapons on target ASAP. With that kind of firepower, the threat dares not generate a TIW against the transmitting source.. But those that are not capable of such ordinance, use of active sonar is more of a consequence for obvious reasons.

[goldorak]

Originally Posted by suBB

If you can't tell already, I'm an akula skipper, and will be an Ak2 improved skipper in RA(love the digital sonar gear and WAA),

I wonder why ?
The Akula II Improved has finally be pushed into the modern era and has become a much more fearsome adversary for blue side. Not that it wasn't a difficult adversary before, but now if you're blue side its going to be like working in hell to sink it.

[NFunky]

Molon,
Okay, I understand what you meant now, that's a real shame. To put it roughly, either the sensor works too well or not well enough.

Oh well, I did succede in using active in the Kilo today. I'd been searching at 5 kts for some time and when I made a turn an Agosta popped up really loud on my sonars, bearing rate changing fast. I figured he had to have picked me up already seeing as he was so close and I was not traveling at a very stealthy speed, so I pinged him and got a feint blip on his bearing at around 1700m. I fired two USET-80s, one directly on his bearing, one ten degrees left of it (the direction his bearing was changing in), with RTE of 1000. Now that I think about it I probably should have spread the torps even more with him being that close, but I got the kill anyway. Only downside was the damn RA AI never counterfired even though I'm sure he had me on sonar.

[SeaQueen]

Originally Posted by NFunky

Anyone ever use active effectively?

I use it on the FFG at least as much as I use the passive sonar, probably more. With surface ships stealth is not so much of an issue and there's a lot of advantages to going faster, so I tend to go active. Particularly against a quiet diesel electric it's probably the best way to go. I also usually use active sonobuoys against diesel electric submarines.

With submarines the advantages are less clear. I can't think of any time I've used active sonar in a submarine.

[Castout]

Originally Posted by SeaQueen

I use it on the FFG at least as much as I use the passive sonar, probably more. With surface ships stealth is not so much of an issue and there's a lot of advantages to going faster, so I tend to go active. Particularly against a quiet diesel electric it's probably the best way to go. I also usually use active sonobuoys against diesel electric submarines.

With submarines the advantages are less clear. I can't think of any time I've used active sonar in a submarine.

I recently played with a 19 year old teen he was controlling the helo and in the second scenario a DDG. I advised him to use active sonar but he stubbornly told me that it's not wise to use the active sonar. It's as if it was a heresy for skimmer to use active sonar to hunt for submarines but to me active sonar perhaps is the primary means of locating subs for surface ships especially when the skimmer is sure of the presence of subs in game.

In the first scenario I was driving the 688i and he couldn't find me inside this bay. In our second game I was driving Type 212A and he was controlling a DDG backed by couple friendy ships and planes.
He got me in less than an hour into the game?? Wtf? No active pinging and I was driving at 7 knots and the non nuclear subs in DWX is a hell lot quieter than their nuclear counterparts and subs in DWX are substantially quieter than in stock or LWAMI.

Anyway he proved to me that he was able to find me passively in our second game though I have my suspicion as the show truth on wasn't locked or maybe he was not. Anyway it was just game for me.

Somebody needs to tell kids these day that going active for skimmer is not a heresy. Kids these days won't listen to anybody.

[SeaQueen]

Originally Posted by Castout

I recently played with a 19 year old teen he was controlling the helo and in the second scenario a DDG. I advised him to use active sonar but he stubbornly told me that it's not wise to use the active sonar. It's as if it was a heresy for skimmer to use active sonar to hunt for submarines but to me active sonar perhaps is the primary means of locating subs for surface ships especially when the skimmer is sure of the presence of subs in game.

A lot of the "only use passive sonar" thinking is really a left-over from the Cold War when the Soviets planned to surge hundreds of submarines many of which were obsolete 1950s era submarines based on copies of WWII submarines. Those could often be detected from hundreds of miles away passively. Things aren't that way anymore. Even then, most hull mounted passive sonars aren't that great.

Also, for the Russian submarines, where they don't necessarily have good passive sonar range, I imagine active sonar has more of a pay off too.

All in all, it depends on what you're trying to do. Sometimes, though, the advantages of detection range far outweigh the advantages of stealth. With surface ships, that calculation generally ends up favoring turning on all your sensors.

[Molon Labe]

I think active is the skimmer's primary sensor. I use the TA too, but I tend to only rely on the TA as my primary sensor if the acoustic conditions are favorable AND I'm hunting a loud target.

For subs, active can be useful if you're in an SSN and hunting an SSK because you can frequently pin it down outside of the SSKs torpedo range. Active can also be useful if you know your opponent already has a good solution on you, so you really don't give anything up by giving him another bearing line with the ping.