Passive Sonar

[PsychicKid]

What exactly does this do? I know active sonar lets subs attack enemy subs and other naval units, but what does passive sonar do?

[Crusader Scott]

What exactly does this do? I know active sonar lets subs attack enemy subs and other naval units, but what does passive sonar do?

From the manual:

"Submarines have two modes: Passive Sonar and Active
Sonar. In passive mode the sub will try to remain as
quiet as possible, slipping by enemy fleets without
attacking. In active mode the sub will ping the area with
sonar looking for enemy ships and subs to attack."

[blackwhitehawk]

you can still attack in passive mode but you have to tell them to. In active mode they autoattack.

[Spacemonkey]

Well, passive sonar means that the sub should be able to pick up other ships sonar.

This is true for enemy subs, they will show up if using active sonar when close to your subs, however carriers in anti-sub mode don't show up, when really they should.

[xyzyxx]

Well, passive sonar means that the sub should be able to pick up other ships sonar.

This is true for enemy subs, they will show up if using active sonar when close to your subs, however carriers in anti-sub mode don't show up, when really they should.

A quick test of your claim proved it false. Subs' sonar pings do not show up anywhere except on RADAR. Subs have no radar when in passive sonar mode. You must be mistaken.

[ArchAngelZXV]

Well, passive sonar means that the sub should be able to pick up other ships sonar.

This is true for enemy subs, they will show up if using active sonar when close to your subs, however carriers in anti-sub mode don't show up, when really they should.

Passive sonar in Defcon really just means "Ultra quiet mode" as in, the sonar is not active and cannot send out sound waves, or "pings" to search out other craft. It's true that in real life, a sub in such a state should still be able to find other ships in its vicinity, but I guess for the sake of game balance, a sub in Passive mode can't find anything as well as cannot be found.

Now, in Active Sonar, yes, subs can find all other ships. I've had battles between Antisub Carriers and Active Sonar Subs where both attack each other.

[Angel of Death]

But in passive mode they can be found by Carriers in antisubmode

[LarsMB]

Carriers drop charges to actively go looking for passive subs. Otherwise, you'd never be able to find a passive sub.

In active sonar mode, everybody else around will see them too, and I think will be able to attack them, as well.

[xander]

But in passive mode they can be found by Carriers in antisubmode

How Sonar Works (more or less):
First, one vessel creates a sound, or ping. This ping radiates out from the origin, and is bounced back to the origin by objects that it encounters. Then, computers on the origin vessel (or somewhere else) interperet those echoed sounds, and try to create a picture of what is in the water. It is likes a dolphin's or bat's echolocation. The problem with this method is that other ships can hear your pings. Thus, if you are a sub in passive mode, you can hear other sub's pings (try it at some point, it does work). Also, subs in passive mode will be spotted by active mod subs, or antisub carriers, because each of these units is emitting pings, which bound off of the passive subs.

xander

[furtim]

Actually, I believe subs using Active Sonar are visible only as pings. They may resolve into ghost images if you get close enough, though.

[This was not a response to xander, but rather a response to what he was responding to. ]

[xander]

Actually, I believe subs using Active Sonar are visible only as pings. They may resolve into ghost images if you get close enough, though.

[This was not a response to xander, but rather a response to what he was responding to. ;)]

Indeed. You are correct. I once followed a couple of subs around the artic like that with some battleships (I didn't have any nearby carriers). Kept bombers flying over the area to keep the pings on RADAR. When they surfaced to nuke me, I was ready with 6 battleships and a bunch of bombers that I was keeping in the air.

xander

[Angel of Death]

Actually, I believe subs using Active Sonar are visible only as pings. They may resolve into ghost images if you get close enough, though.

[This was not a response to xander, but rather a response to what he was responding to. ]

Indeed. You are correct. I once followed a couple of subs around the artic like that with some battleships (I didn't have any nearby carriers). Kept bombers flying over the area to keep the pings on RADAR. When they surfaced to nuke me, I was ready with 6 battleships and a bunch of bombers that I was keeping in the air.

xander

Now that is brilliant

[Cochonou]

Also, subs in passive mode will be spotted by active mod subs, or antisub carriers, because each of these units is emitting pings, which bound off of the passive subs.

In reality, there are two kinds of sonar: active and passive.
Passive sonar consists in listening to the sounds produced by others vessels (or their active pings). Its main advantage is that it does not gives out away the presence of the listening vessel, its main disadvantage is that it only gives a bearing information (range information has to be inferred).
Submarines will usually use passive sonar in order not to reveal their location.
Active sonar works in the way xander described. Its main advantage is that it gives a bearing and range information, its disavantage is that it gives away your location. An additional disadvantage is that vessels using active sonar will be detected from a farthest distance away than they can detect their targets (for a successful detection, the sound has to go and return, therefore has to travel twice the distance).
Antisubmarine vessels usually use active sonar: it produces a safe area around them in which a submarine cannot enter without facing detection. Even if it gives away their location, it might so much an issue after all (submarines might have detected them anyway with passive sonar, or their position might have been given away by spy satellites or radars, and transfered to the submarine.)