Sonar detection has failed , sir !

[CapitanPiluso]

Playing Barents Sea Loiter mission I get a radio message about a russian SAG (probably escorted by a sub) facing northwest which I must engage.
My TA gets a faint 50 hz line, and nothing comes from sphere and hull arrays in NB, even going to PD shows no ESM radiation neither visual contacts.
But after an hour or so I get a TIW ... and really no idea where this torp is coming from, my TA keeps on showing a single line.
But to my surprise, I turn "truth on" to find that my TA was always trackin the last ship in the formation, and never could get the enemy sub ( who has detected me from 26 nm)

Some tactical idea will be great.THX

[SeaQueen]

I drive back and forth at about 10-15kts across the mouth of the inlet. I never fail to get in front of them. Something I've noticed about people here is that they tend to drive their submarines too slow. It's true that the faster you go the louder you are, but there's other considerations too, like whether you'll find your target in a reasonable period of time or whether you can intercept them effectively that force you to make a compromise between stealth and whatever else you're trying to accomplish. Once you've detected your target and gotten in front of him, THEN maybe you'll want to approach him slowly. Just remember there's a reason they're called "fast attack submarines."

When you do detect them on sonar, make sure you set your course to be a little bit in front of the target. If you want to be more precise use MoBoard or a paper maneuvering board to calculate an intercept course, although you'll need to do some reasonably accurate TMA with the sonar or else wait until you can get within periscope range and get their range/bearing stereometrically.

[Frame57]

Also remember the concept of "Sprinting and drifting". Traverse your thermals occaisonally and make course changes. It is possible the other sub picked up the tankers rather than you and fired on them with you in the vicinity...?

[Frame57]

Never mind on that last part I just saw your nav map. Try a NW course with you TA fully deployed.

[CapitanPiluso]

I have no issue with interception courses, since MoBo and Intercalc are excellent tools.

But I'd really want to know why the enemy sub got mine from 26 nm and I even couldn 't get any hint about him !!!
Cheers.

[suBB]

the SSP type could have been bottom limited where you pretty much stick out like a sore thumb even at slow speeds over distance and there isn't a layer to attenuate your noise emissions.

Judging by your keel, I'd think you had bottom limited SSP and no layer present.

the attack could have been the initial reaction (snapshot) from AI once you were detected, yet AI didn't have a good solution on your location.

the contact could have been in your TA baffles, which is why you couldn't see him initially. However, if you got a TIW and the contact is a torpedo that can only be fired from internal tubes(wire-guided torps) then that gives you some data to consider.

[Frame57]

Did you have any masts raised at Periscope depth?

[Pisces]

And do you have your screen settings adjusted to show the faintest of (narrowband) sonar lines? There is a gamma value that you can set in the ini file.

[CapitanPiluso]

Originally Posted by Frame57

Did you have any masts raised at Periscope depth?

Not at all

Originally Posted by Pisces

And do you have your screen settings adjusted to show the faintest of (narrowband) sonar lines? There is a gamma value that you can set in the ini file.

Really don't know...whcih would be the right value?

[Molon Labe]

Originally Posted by CapitanPiluso

Not at all



Really don't know...whcih would be the right value?

To go along with the PD theory, another possibility is just that you're listening at PD too long. Sonar performance is degraded above 200ft or so. (Having a mast up also increases self noise.)

Gamma values.... check out the image in TimmyG's TacMan package. If you can see that ****, then you're OK for the 688I, if not, you're not.

I'd also recommend turning the gamma up to something higher than you think you need, testing it on a seawolf's sonar, and then turning it down until you can still see the line but it's not crazy bright. The Seawolf's NB is the one with the most difficult lines. (does anyone have an image of that? I thought Fish posted a test image somewhere but I wasn't able to find it.)

[Pisces]

It also depends on your lighting environment/daylight reflection and if you have an LCD/TFT screen or a CRT monitor.

[CapitanPiluso]

Originally Posted by Molon Labe

To go along with the PD theory, another possibility is just that you're listening at PD too long. Sonar performance is degraded above 200ft or so. (Having a mast up also increases self noise.)

Gamma values.... check out the image in TimmyG's TacMan package. If you can see that ****, then you're OK for the 688I, if not, you're not.

I'd also recommend turning the gamma up to something higher than you think you need, testing it on a seawolf's sonar, and then turning it down until you can still see the line but it's not crazy bright. The Seawolf's NB is the one with the most difficult lines. (does anyone have an image of that? I thought Fish posted a test image somewhere but I wasn't able to find it.)

Right, although I hadn't noticed it before, a correct gamma setting is needed in order to get that second beloved line we are always looking for

Originally Posted by Pisces

It also depends on your lighting environment/daylight reflection and if you have an LCD/TFT screen or a CRT monitor.

I have a LG1752S flat monitor, and gamma value is at its top value in monitor setting, but not in nvidia control panel ( 50% here) .
I can see the line Molon posted, but guess some correction will enhance the view.
Cheers