False Sonar Contacts?

Uboatman · 01-02-11, 06:22 AM

I listen to the sonar lots while on patrol and I'm constantly picking up what sounds like ships but very far away, there are often at least 2 or 3 of these sounds coming from different bearings. Sounds rather like heartbeats and the longer I listen it sounds more like 2-3 heartbeats together.

The thing is I chase these contacts for miles and never get any real contacts, am I getting false readings?

Really need to know if I'm wasting my time as it's getting very frustrating chasing what at the moment appears to be nothing and wasting precious fuel

commandosolo2009 · 01-02-11, 06:37 AM

Relax Chief

This is what you need to know about sonar

.

- limited to contacts (Green light in)

- sometimes may reach upto 30000 km, but standard war issued HF is 20000 km range.

- If your SO cant locate the contact, dont bother chasing it.

- Your radar provides even more info than Sonar, wont expose you as Sonar, and certainly will show you low flyboys as an added feat.

- If a convoy is heard, you cant tell exact range since DD, DE, and merchants overlap eachother, making rangefinding difficult.

If you have any further questions, fire away!!

Uboatman · 01-02-11, 06:56 AM

Ok, so if the green light doesn't come on ignore it?

Does the active sonar alert merchants/escorts when used on the surface?

(Am playing TMO 2.0)

WernherVonTrapp · 01-02-11, 07:02 AM

I've heard that (sort of) heartbeat sound too. It's nothing. Don't try and chase after it. Ship screws have a distinctive cranking sound that is unmistakable and as previously mentioned, will activate the green indicator light. If you listen yourself, you can actually hear them as far away as 20nm, though I'm not sure how realistic that is. I've tracked down (and sunk) many targets using sonar. Early radar doesn't have quite the range and you can (fairly accurately) estimate the target distance and course with sonar.
To get the estimated distance and course, just use the ruler tool to draw a line from your sub to the tip of the sonar contact, then repeat the process in 10 minutes and draw an intersecting line through the tips of the two sonar lines. This only works, of course, if you have contacts on and can see the sonar contact lines.

The active sonar (ping) can be detected by some merchants and by warships so, be careful or you might stir up a bee's nest.

commandosolo2009 · 01-02-11, 07:45 AM

Quote:

Ok, so if the green light doesn't come on ignore it?

Yes

Code:

Does the active sonar alert merchants/escorts when used on the surface?

Yes, since the sensors for sonar are active, as well as at the bottom of the boat.

However, the hydrophone also mistakenly, works on surface, which is a bug since its not in the water, but it keeps rotating...

Quote:

(Am playing TMO 2.0)

Maybe its fixed in TMO?

Quote:

Early radar doesn't have quite the range

I meant late war, 1943 and such

Code:

The active sonar (ping) can be detected by some merchants and by warships so, be careful or you might stir up a bee's nest.

Speaking of which, if I ping after a destroyers ASDIC, would it register as detection? If you've seen the movie , "Below" 2002

Armistead · 01-02-11, 09:28 AM

You can get misleading sonar hits, where you will get a green light, but often no sound. If varies with mods and happens seemingly random, but ships sunk will sometimes do this. I'm talking ships sunk and spawned out. If in shallow enough water you may hear them crunching against the bottom, but you still get a green light for these. Can be confusing if you chase them cause you'll go right by them. If you know you sunk a ship there, that should be a clue.

You have no active sonar per say. I think they even limited subs from the use of going totally active then. The sonar heads at the bottom of the boat are mainly passive listening devices. Subs did carry the amp and other equipment, but never went totally active, just sent single pings which you can do in the game. Heres a good link in the fleetbook manual on sonar use. http://www.maritime.org/fleetsub/sonar/index.htm

Sonar did work on the surface using the bottom heads, but rather poor. Subs needed to go slow or be stopped, weather had effect, ect. Mod's corrected some of this, but for the most part sonar works just as good surfaced.

Often planes crashed on land will do the same thing, now they do sound funny if you have sound up, but it's very faint, probably wouldn't hear a thing unless sound is maxed, but again you'll get a light.

Also, depending on mods you can pick up dolphins. I know TMO has several bunches of them, but you'd be lucky to find them. They sound like chirping radio static, groups, more like babies crying and don't give a green light. TMO also has icebergs and you'll pick these up on sonar.

The only thing I've heard close to a heart beat is stopped DD's shooting at planes with flak guns. If you're at sonar stations say why you're listening to deckgun fire, if you're trained on the ship you can hear the shells hit. Also fun listening to ships sinking on sonar, depends on mods, but hearing bulkheads crashing, explosions and death screams from people fairly realistic. Sonar is also a good way to check your torps if you have cams and contacts off, using the timing marks on the watch, if you don't hear one when you should, probably a premature. If you shot one at a zero bearing and you hear one coming from a 90 degree bearing...may want to start praying.

WernherVonTrapp · 01-02-11, 01:34 PM

Another thing that can light up your green sound indicator lamp is a Junk or a Fishing Boat if they're close enough. I've had it happen and discovered the culprits with my periscope.

Quote:

Originally Posted by commandosolo2009

Speaking of which, if I ping after a destroyers ASDIC, would it register as detection? If you've seen the movie , "Below" 2002

Not exactly sure what you're asking here commando, since a destroyer's ASDIC is it's active sonar. They can tell the difference between their own return and a ping from a different vessel, if that's what you mean.

commandosolo2009 · 01-02-11, 02:41 PM

Well, in the movie, the skipper told the NO to ping on the third Destroyer ASDIC or maybe Sonar ping, (more likely, sonar ping) So as to mask their own noise. Well, my fault

01-02-11, 06:22 AM	#1
Uboatman Medic Join Date: Mar 2007 Location: UK Posts: 169 Downloads: 53 Uploads: 0	False Sonar Contacts? I listen to the sonar lots while on patrol and I'm constantly picking up what sounds like ships but very far away, there are often at least 2 or 3 of these sounds coming from different bearings. Sounds rather like heartbeats and the longer I listen it sounds more like 2-3 heartbeats together. The thing is I chase these contacts for miles and never get any real contacts, am I getting false readings? Really need to know if I'm wasting my time as it's getting very frustrating chasing what at the moment appears to be nothing and wasting precious fuel

01-02-11, 06:37 AM	#2
commandosolo2009 Grey Wolf Join Date: Sep 2009 Location: Egypt Posts: 840 Downloads: 132 Uploads: 0	Relax Chief This is what you need to know about sonar . - limited to contacts (Green light in) - sometimes may reach upto 30000 km, but standard war issued HF is 20000 km range. - If your SO cant locate the contact, dont bother chasing it. - Your radar provides even more info than Sonar, wont expose you as Sonar, and certainly will show you low flyboys as an added feat. - If a convoy is heard, you cant tell exact range since DD, DE, and merchants overlap eachother, making rangefinding difficult. If you have any further questions, fire away!! __________________ x.com/lexatnews

01-02-11, 07:02 AM	#4
WernherVonTrapp Admiral Join Date: Jul 2009 Location: Now, alot farther from NYC. Posts: 2,228 Downloads: 105 Uploads: 0	I've heard that (sort of) heartbeat sound too. It's nothing. Don't try and chase after it. Ship screws have a distinctive cranking sound that is unmistakable and as previously mentioned, will activate the green indicator light. If you listen yourself, you can actually hear them as far away as 20nm, though I'm not sure how realistic that is. I've tracked down (and sunk) many targets using sonar. Early radar doesn't have quite the range and you can (fairly accurately) estimate the target distance and course with sonar. To get the estimated distance and course, just use the ruler tool to draw a line from your sub to the tip of the sonar contact, then repeat the process in 10 minutes and draw an intersecting line through the tips of the two sonar lines. This only works, of course, if you have contacts on and can see the sonar contact lines. The active sonar (ping) can be detected by some merchants and by warships so, be careful or you might stir up a bee's nest. __________________ "The journey of a thousand miles begins with a single step." -Miyamoto Musashi ------------------------------------------------------- "What is truth?" -Pontius Pilate

01-02-11, 09:28 AM	#6
Armistead Rear Admiral Join Date: Dec 2008 Location: on the Dan Posts: 10,880 Downloads: 364 Uploads: 0	You can get misleading sonar hits, where you will get a green light, but often no sound. If varies with mods and happens seemingly random, but ships sunk will sometimes do this. I'm talking ships sunk and spawned out. If in shallow enough water you may hear them crunching against the bottom, but you still get a green light for these. Can be confusing if you chase them cause you'll go right by them. If you know you sunk a ship there, that should be a clue. You have no active sonar per say. I think they even limited subs from the use of going totally active then. The sonar heads at the bottom of the boat are mainly passive listening devices. Subs did carry the amp and other equipment, but never went totally active, just sent single pings which you can do in the game. Heres a good link in the fleetbook manual on sonar use. http://www.maritime.org/fleetsub/sonar/index.htm Sonar did work on the surface using the bottom heads, but rather poor. Subs needed to go slow or be stopped, weather had effect, ect. Mod's corrected some of this, but for the most part sonar works just as good surfaced. Often planes crashed on land will do the same thing, now they do sound funny if you have sound up, but it's very faint, probably wouldn't hear a thing unless sound is maxed, but again you'll get a light. Also, depending on mods you can pick up dolphins. I know TMO has several bunches of them, but you'd be lucky to find them. They sound like chirping radio static, groups, more like babies crying and don't give a green light. TMO also has icebergs and you'll pick these up on sonar. The only thing I've heard close to a heart beat is stopped DD's shooting at planes with flak guns. If you're at sonar stations say why you're listening to deckgun fire, if you're trained on the ship you can hear the shells hit. Also fun listening to ships sinking on sonar, depends on mods, but hearing bulkheads crashing, explosions and death screams from people fairly realistic. Sonar is also a good way to check your torps if you have cams and contacts off, using the timing marks on the watch, if you don't hear one when you should, probably a premature. If you shot one at a zero bearing and you hear one coming from a 90 degree bearing...may want to start praying. Last edited by Armistead; 01-02-11 at 09:59 AM.

01-02-11, 02:41 PM	#8
commandosolo2009 Grey Wolf Join Date: Sep 2009 Location: Egypt Posts: 840 Downloads: 132 Uploads: 0	Well, in the movie, the skipper told the NO to ping on the third Destroyer ASDIC or maybe Sonar ping, (more likely, sonar ping) So as to mask their own noise. Well, my fault __________________ x.com/lexatnews

01-02-11, 06:56 AM	#3
Uboatman Medic Join Date: Mar 2007 Location: UK Posts: 169 Downloads: 53 Uploads: 0	Ok, so if the green light doesn't come on ignore it? Does the active sonar alert merchants/escorts when used on the surface? (Am playing TMO 2.0)