Sub hunting Question

[Kirk]

Greetings to one and all. Guess I am old school by watching WW2 sub movies but does surface ships use active or passive sonar to get a better fix on a sub contact? Just wondering? Thanks for any answers.

[Dr.Sid]

Best is to use helos and stay outside subs firing range. On short distances active is better and sub knows about you anyway since you are not that silent, but pinging can be heard really far away. Modern diesel subs waiting at you at 0 kts simply can't be heard with passive, so when these are possible threat, active is the only option anyway.
Active has also nice psychologic effects on human oponents.

[SeaQueen]

Originally Posted by Kirk

Greetings to one and all. Guess I am old school by watching WW2 sub movies but does surface ships use active or passive sonar to get a better fix on a sub contact? Just wondering? Thanks for any answers.

Modern ASW is LIGHT YEARS from where it was in WWII, particularly with regards to the weapons systems, so those movies are not really a good guide to the tactics.

They'd use both active and passive sonar. It depends on what the surface ship anticipates to be it's most effective sensor given the constraints of oceanography and it's mission. Against an old Soviet boat, that would most likely be it's towed array. In a shallow environment, though, they might not be able to use that. Even if they could, though, against a diesel electric boat it probably wouldn't be very effective. In that case they'd use their active sonar. If they were forced to move very fast, say 15kts or more, they'd probably go active because passive doesn't work so good when you're moving at very high speed. They'd also use ESM and radar. These days, in fact, non-acoustics might be your best bet. It all really depends on the target, the environment, and what you're trying to do.

[SeaQueen]

Originally Posted by Dr.Sid

Active has also nice psychologic effects on human oponents.

You know... I've never understood that considering that you can usually develop a pretty good feel about whether you've been detected or not. If you know how far away he is (which you can figure out from doing the TMA) and can make a good guess of his sonar range based on the environment, then avoiding detection is as simple as just not getting close to him.

[Kapitan]

In a submarine your worst enamy is either a P3 or a helo, dependsing on what type of platform your up against theres alot of factors.

If im up against a human controlled perry say my friend madcap for example i know he will send two helos out to droup bouys so il just sit, he will be moving and i can hear himhe will have his radar on so i can get him on my ESMi find all that and then just fire 6 to 8 SS-N-27 ASM missiles at him and he has little time to shoot them all down.

Going up against a tico or a burke is harder they are dedicated ASUW and AAW vessels so shooting missiles even in numbers doesnt work too wellso sometimes what i do is use SS-N-16 stallions to get a torpedo close enough as i know they wont engauge them for some reason.

It does work not fool proof and not always 100% effective.

[Kazuaki Shimazaki II]

Originally Posted by SeaQueen

You know... I've never understood that considering that you can usually develop a pretty good feel about whether you've been detected or not. If you know how far away he is (which you can figure out from doing the TMA) and can make a good guess of his sonar range based on the environment, then avoiding detection is as simple as just not getting close to him.

As he said, it is psychological. Intellectually, you look at the strength on the intercept receiver, which says next to no chance of detect. But you still feel watched. Kind of like a searchlight in the dark or tracers.

[SeaQueen]

Originally Posted by Kazuaki Shimazaki II

As he said, it is psychological. Intellectually, you look at the strength on the intercept receiver, which says next to no chance of detect. But you still feel watched. Kind of like a searchlight in the dark or tracers.

What bothers me a lot more is when I see an ESM hit on a helo that's moving in a circle.