No visual lines in FFG towed array

tmdgm · 04-09-11, 12:10 AM

On the towed array in the FFG, there are no visual lines on the waterfall for tracks. The tracks are listed in the top section, the marks are there to the left of the waterfall, but there are no lines that flow actually on the waterfall. I used to have the lines, but not sure where they went. I'm using LWAMI 3.10

The towed array still works properly, just don't have the visual cues in the waterfall. It's not a speed issue as i've slowed down and still no lines.

Pisces · 04-09-11, 02:55 PM

Is your gamma level sufficient to show faint lines? There is a line in dangerouswaters.ini to set gamma level:

[Graphics]
...
.Gamma "0.5"

Or some other value to suit you.

tmdgm · 04-09-11, 05:25 PM

.Gamma ""

this is what's in there now, so there's no value at all.

Pisces · 04-09-11, 06:27 PM

Yeah, that's default. Just put a number between 0 an 1 in the double quots.

tmdgm · 04-10-11, 04:08 PM

thanks, i changed it to 0.8 and can see something at least now.

Pisces · 04-11-11, 06:35 AM

Quote:

Originally Posted by Pisces

Yeah, that's default. Just put a number between 0 an 1 in the double quots.

I think I needed a number between 0 and 1, but above 1 is probably also possible. But that is probably a result contrary to what we want.

tmdgm · 04-11-11, 07:12 PM

hmmm, maybe i'll try to increase. Some of the towed array lines i still can't see. And on active sonar or sonar active buoys, ferget bout it, i don't see em at all. Well, sometimes on buoys I can see one little dot, but never on my ffg active sonar.

Kapitan · 05-17-11, 08:49 AM

it has been a while since ive played so bear with me, when i ask why are you using TA i personaly prefered using the bouys simply because they give an all round picture and the TA can be compromised easily and washed out easily too, even in a turn it used to be a pain in the rear end.

my manual allbeit old now might help you on some ops.

Daniel Prates · 06-24-11, 03:50 PM

Quote:

Originally Posted by tmdgm

The towed array still works properly, just don't have the visual cues in the waterfall. It's not a speed issue as i've slowed down and still no lines.

Maybe the towed array is scratching against the ocean floor? Check your depth under the keel. When the TA touches the bottom, it will (obviously) generate a lot of noise, that tampers with the signal reception.

The waterfall display shows how much 'background' noise your're getting. You can make an experiment to see that for yourself. Extend your towed array and go to a full stop. Sonar signals will clear against a dimmed-out background. That background in the waterfall display actually is the very background noise. Now try speeding up dramaticly. You will see that the background on the waterfall display will stard colouring up. Its because the background noise (generated by yourself) is influencing the noise being captured by the array.

Now picture what happens if you are slow (or even stoped), but depth there is shallow and the array touches bottom. Yep, thats even worse than having background noise created by your shaft and engines. Background display in waterfall should now be at ist most disturbed state.

tmdgm · 07-15-11, 09:01 PM

no it's definitely not scratching against the ocean floor. I've seen that so i know what that looks like. Changing the gamma to 0.8 helped with the FFG towed array.

But i recently started tryign the 688 and i can see the lines in the medium time scale, but can't see any lines in the short time scale.

Frustrating.

Molon Labe · 07-15-11, 10:31 PM

Quote:

Originally Posted by tmdgm

But i recently started tryign the 688 and i can see the lines in the medium time scale, but can't see any lines in the short time scale.

Frustrating.

That's normal. The point of having a medium time scale display is so that faint contacts that don't show up on the short time scale are more condensed to they'll stand out amongst the noise better.

tmdgm · 07-16-11, 09:26 AM

Quote:

Originally Posted by Molon Labe

That's normal. The point of having a medium time scale display is so that faint contacts that don't show up on the short time scale are more condensed to they'll stand out amongst the noise better.

ah makes sense.

Yesterday, was playing the688 barents sea mission and all of a sudden i get these torpedo in the water messages, not sure how they detected me. Only thing i could think is i left my radar mast up and radar turned on. Cuz i couldn't hear anything on sonar.

Once the torps were in the water, i couldn't tell anything apart, no idea if i should worry about the torps, so i turned on show truth and it looks like they were missile launched torpedoes and they were doing circle patterns several miles ahead.

Is there any way to tell things apart in the sonar? Or should I start to worry about the torpedoes. It was impossible to figure out the torpedoes contact from ships? How do i know when torpedoes are closing?

Molon Labe · 07-16-11, 10:10 AM

A submarine should always be worried about torpedoes.

The easiest way to tell a torpedo from other contacts on sonar is to look at the TIW bearing at the moment of the report. The launching platform might also be there, but at least you know it's one of the two. Torps also tend to be louder, and can often be IDed at DEMON if you assume a TPK of 30 and their speed comes out to 40+ knots or so. Torpedoes in circle mode will leave a visible doppler shift in the narrowband and might leave a squiggly pattern in broadband history. If you use LWAMI 3.11 (or later), torpedoes do not share their 2nd frequency line with ships/subs so they can be rapidly classified.

ASW torpedoes will almost always be active homing, so one way to tell is the ping pattern, especially for torpedoes in circle mode. A circle mode torpedo while searching will only ping for a few seconds until it turns away (3 or so pings), but once it acquires the pings will be continuous. A snaking torpedo can do the same if you are on the edge of its acquisition cone. Pinging rate will also accelerate as range to target decreases, which implies that the weapon has acquired a target. A circling torp that stops making the squiggle pattern or doppler shift has likely acquired something. Rapid bearing change, unless the torpedo is very close, means the torpedo is not on an intercept course for you.

tmdgm · 07-18-11, 09:09 PM

actually, i think i have 3.10 lwami. Didn't even know there was a 3.11. I'll have to look for it.

i seem to be getting better at it. Altho i haven't had the torpedo fest i had when i wrote the post. I'll look for those things as i'm just figuring things out with the 688. Also ESM seems like it's semi useful.

04-09-11, 12:10 AM	#1
tmdgm Engineer Join Date: Sep 2006 Posts: 219 Downloads: 18 Uploads: 0	No visual lines in FFG towed array On the towed array in the FFG, there are no visual lines on the waterfall for tracks. The tracks are listed in the top section, the marks are there to the left of the waterfall, but there are no lines that flow actually on the waterfall. I used to have the lines, but not sure where they went. I'm using LWAMI 3.10 The towed array still works properly, just don't have the visual cues in the waterfall. It's not a speed issue as i've slowed down and still no lines.

04-09-11, 02:55 PM	#2
Pisces Silent Hunter Join Date: Dec 2004 Location: AN9771 Posts: 4,904 Downloads: 304 Uploads: 0	Is your gamma level sufficient to show faint lines? There is a line in dangerouswaters.ini to set gamma level: [Graphics] ... .Gamma "0.5" Or some other value to suit you. __________________ My site downloads: https://ricojansen.nl/downloads

04-09-11, 06:27 PM	#4
Pisces Silent Hunter Join Date: Dec 2004 Location: AN9771 Posts: 4,904 Downloads: 304 Uploads: 0	Yeah, that's default. Just put a number between 0 an 1 in the double quots. __________________ My site downloads: https://ricojansen.nl/downloads

05-17-11, 08:49 AM	#8
Kapitan Sub Test Pilot Join Date: Mar 2005 Location: UK + Canada Posts: 7,130 Downloads: 77 Uploads: 7	it has been a while since ive played so bear with me, when i ask why are you using TA i personaly prefered using the bouys simply because they give an all round picture and the TA can be compromised easily and washed out easily too, even in a turn it used to be a pain in the rear end. my manual allbeit old now might help you on some ops. __________________ DONT FORGET if you like a post to nominate it by using the blue diamond Find out about Museum Ships here: https://www.museumships.us/ Flickr for all my pictures: https://www.flickr.com/photos/131313936@N03/ Navy general board articles: https://www.navygeneralboard.com/author/aegis/

07-16-11, 10:10 AM	#13
Molon Labe Silent Hunter Join Date: Jun 2004 Location: Along the Watchtower Posts: 3,810 Downloads: 27 Uploads: 5	A submarine should always be worried about torpedoes. The easiest way to tell a torpedo from other contacts on sonar is to look at the TIW bearing at the moment of the report. The launching platform might also be there, but at least you know it's one of the two. Torps also tend to be louder, and can often be IDed at DEMON if you assume a TPK of 30 and their speed comes out to 40+ knots or so. Torpedoes in circle mode will leave a visible doppler shift in the narrowband and might leave a squiggly pattern in broadband history. If you use LWAMI 3.11 (or later), torpedoes do not share their 2nd frequency line with ships/subs so they can be rapidly classified. ASW torpedoes will almost always be active homing, so one way to tell is the ping pattern, especially for torpedoes in circle mode. A circle mode torpedo while searching will only ping for a few seconds until it turns away (3 or so pings), but once it acquires the pings will be continuous. A snaking torpedo can do the same if you are on the edge of its acquisition cone. Pinging rate will also accelerate as range to target decreases, which implies that the weapon has acquired a target. A circling torp that stops making the squiggle pattern or doppler shift has likely acquired something. Rapid bearing change, unless the torpedo is very close, means the torpedo is not on an intercept course for you. __________________

04-09-11, 05:25 PM	#3
tmdgm Engineer Join Date: Sep 2006 Posts: 219 Downloads: 18 Uploads: 0	.Gamma "" this is what's in there now, so there's no value at all.

04-10-11, 04:08 PM	#5
tmdgm Engineer Join Date: Sep 2006 Posts: 219 Downloads: 18 Uploads: 0	thanks, i changed it to 0.8 and can see something at least now.

04-11-11, 07:12 PM	#7
tmdgm Engineer Join Date: Sep 2006 Posts: 219 Downloads: 18 Uploads: 0	hmmm, maybe i'll try to increase. Some of the towed array lines i still can't see. And on active sonar or sonar active buoys, ferget bout it, i don't see em at all. Well, sometimes on buoys I can see one little dot, but never on my ffg active sonar.

07-15-11, 09:01 PM	#10
tmdgm Engineer Join Date: Sep 2006 Posts: 219 Downloads: 18 Uploads: 0	no it's definitely not scratching against the ocean floor. I've seen that so i know what that looks like. Changing the gamma to 0.8 helped with the FFG towed array. But i recently started tryign the 688 and i can see the lines in the medium time scale, but can't see any lines in the short time scale. Frustrating.

07-18-11, 09:09 PM	#14
tmdgm Engineer Join Date: Sep 2006 Posts: 219 Downloads: 18 Uploads: 0	actually, i think i have 3.10 lwami. Didn't even know there was a 3.11. I'll have to look for it. i seem to be getting better at it. Altho i haven't had the torpedo fest i had when i wrote the post. I'll look for those things as i'm just figuring things out with the 688. Also ESM seems like it's semi useful.