Question: FFG Active sonar - single narrow beam detectable?

[Wildcat]

I am curious about this.

Let's say I have a passive transient contact i.e. torpedo fired, or brief cavitation.

I turn towards the resolved contact and then make a single ping using the NARROW active sonar beam, which only sends a ping down those approximately 20-30degrees.

If any submarines are behind me when I do this, are they going to detect it? Are submarines outside of the beam able to detect the active sonar ping?

It would be nice to get a firm solution on a possub without advertising to everyone else that you're there.

[SeaQueen]

Originally Posted by Wildcat

I am curious about this.

Let's say I have a passive transient contact i.e. torpedo fired, or brief cavitation.

...

If any submarines are behind me when I do this, are they going to detect it? Are submarines outside of the beam able to detect the active sonar ping?

If a submarine has shot a torpedo at you, you've already been detected, so who cares?

It's generally best to work under the assumption that an intelligently driven submarine will almost always detect you passively, somehow, before you detect them. Stealth is not a surface ship's strong point.

[MaHuJa]

It may not be a torpedo launch. It may be a few seconds of cavitation on the TA, for example. And it's *because* of said assumption that using the active sonar then is a sound tactic.

In real life, since the direction is based on interference pattern rather than actual sensor head (mechanical) movement, the answer is a resounding YES! you can be heard by those in other directions. Those in the 'lobes', the main of which is in the direction where you're pinging, will hear it quite a bit better (further) ...FWIW...
(Lobes is an expression used for radars, but it applies about equally here)

In the game, I expect they're more along "fixed distance" though, as any such lobe patterns surely falls under classified info, and isn't all that big an issue.

[Mercedes]

Tested your question.

Range = 7nm
Sea State = 3m swell
Profile = 456ft layer

LA688i was heading 090 at 80'
FFG was heading 000 and was to the east of the LA

In trying various directions on the single beam the LA picked it up everytime, BUT it would only pick up every 2nd or 3rd ping irrespective of active range setting or active type. It might have something to do witht he seastate, i'll give it another go when I get time.

[Mercedes]

Did it again, but with flat seas and 5nm range.

It was the seastate that was causing the intermittant intercept on the LA.

Oddly enough I found an interesting thing. If you click XMIT on the FFG's active again before it's finished its cycle it won't send out a ping that can be heard by the sub, but it can still detect objects like normal for the FFG.

[LuftWolf]

Regarding missing the target on certain pings.

What version are you running?

This could be normal sonar behavior under the circumstances or...

It sounds similar to the transient sonar bug that was reported for passive sonars, and the same cause would active sonar pings to "miss" the target sometimes.

I believe this is being actively looked at for 1.03 Full.

In terms of the FFG sonar, I'm not sure about that, but it may be the way the sonar interface is coded and data is fed into and out of the NavalSimEngine. As long as the contact can hear the first ping, its not really a cheat, but it is a bug, although probably one that would be tough to get at, and not change gameplay all that much, if a player didn't elicit the condition.

[Mercedes]

True with what you say, the critical first ping is still received. Just an oddity.

I run version 1.03b. The test was done without your mod. Just with playing around with the missed ping, it's almost definantly a result of seastate, i.e. transducer broaching the surface.

By the way, your mod is excellent. Even though it takes my beloved 65cm multirole torp away

[MaHuJa]

If the 'missing repeated active' can be done forever (press xmit again before it finishes to get updates forever without giving him any more active intercept data...

[Wildcat]

Cool, I feel like I'm in a detective novel now. :P

You've tracked down a bug, nice work, now someone mail it to SCS so we can get it fixed for the next patch

[LuftWolf]

Originally Posted by MaHuJa

If the 'missing repeated active' can be done forever (press xmit again before it finishes to get updates forever without giving him any more active intercept data...

My guess is that after the first ping passes the submarine, another ping would be heard. It probably has something to do with the active intercept update interval or the way the NavalSimEngine handles pinging, in that it can only hold one outbound ping in memory, so if you ping before the first ping has reached the target, only one ping is in memory.

However, once the first ping passes, another one should be heard. Although this would have to be tested to be sure.

[Three14]

Here's a question (from someone who hasn't played the game):

If a narrow-beam ping is still heard outside the beam, what are the tactical advantages of using it?

[Angle]

To me it seems the beam is stronger. Meaning you get more range with it. Handy if you know a potential targets bearing.

[LuftWolf]

Originally Posted by Three14

Here's a question (from someone who hasn't played the game):

If a narrow-beam ping is still heard outside the beam, what are the tactical advantages of using it?

When you have an audio (range) only return, the single beam mode allows you to narrow down the bearing of the return to 30 degrees or so, which will usually allow you to mark the contact.