Question on Sonar Use at Peri Depth

[Barkhorn1x]

Was fleet boat sonar actually functional at this depth historically??

And where was that link that listed the file mods to make it functional in SHIV?? I did a search but came up empty.

Thanks.

[U-Bones]

I saw this yesterday and can't find it either...

[akdavis]

Yes, historically hydrophones would function at periscope depth and shallower. Interference from surface noise might degrade their functioning depending on conditions.

If you just apply simple logic here, it is obvious they would function: how would a destroyer with hyrdophones be able to detect a sub if hydrophones suddenly stopped working at 55 feet?

[Gildor]

I am not an expert with Naval sensor terminology, but I was under the impression that SONAR and HYDROPHONES were not the same thing.

Isn't sonar the sensor to determine range to a target with a non-passive sound "ping", whereas the hydrophones are a passive listening device? i.e. two different apparatus.

Or am I completely off base here?

[Hitman]

Isn't sonar the sensor to determine range to a target with a non-passive sound "ping", whereas the hydrophones are a passive listening device? i.e. two different apparatus.

Or am I completely off base here?

You are right. However, AFAIK late war sonar (ASDIC) also incorporated a directional microphone, so you could listen and be sure you were going to ping in the correct bearing, as well as hearing the echo yourself.

[Prof]

Originally Posted by Gildor

I am not an expert with Naval sensor terminology, but I was under the impression that SONAR and HYDROPHONES were not the same thing.

Isn't sonar the sensor to determine range to a target with a non-passive sound "ping", whereas the hydrophones are a passive listening device? i.e. two different apparatus.

Or am I completely off base here?

Not completely SONAR stands for SOund Navigation And Ranging, so any sound-based locating device could be called 'sonar'.

Sonar devices fall into two categories; active and passive. Active sonar sends out a 'ping' to locate an object by echo while passive sonar is just for listening to whatever is out there.

Basically, hydrophones and the 'ping' are both sonar devices.

[Gildor]

Got it. Two different apparatus but technically both are SONAR equipment.

Thanks.

[Barkhorn1x]

Originally Posted by Gildor

Got it. Two different apparatus but technically both are SONAR equipment.

Thanks.

For the record as I was refering to the hydrophones.

[bruschi sauro]

Originally Posted by Gildor

I am not an expert with Naval sensor terminology, but I was under the impression that SONAR and HYDROPHONES were not the same thing.

Isn't sonar the sensor to determine range to a target with a non-passive sound "ping", whereas the hydrophones are a passive listening device? i.e. two different apparatus.

Or am I completely off base here?

no you are right

[Krupp]

Like mentioned here many times before, the NSS_Hydrophone 3's max sensorheight=20000 and the other two (1 and 2) hydrophones are -6 and -9 respectively.

The NSS_Early SJ 5 radar's max sensorheight=-5, but the other earlySJ radars have their max sensorheight as 20000. With a quick glance, it looks like there might be a mix up between these two gadgets (max sensorheights)?

Also the min sensorheights seem to be mixed together? 0,1 and -500 values.

[GOZO]

Just a little add-in.....

A very good site presenting the original training manuals online as well.

http://www.fleetsubmarine.com/subtech.html

and here: http://www.maritime.org/fleetsub/index.htm

Sonar has it's own manual here.

Cheers

OB

[Barkhorn1x]

Originally Posted by akdavis

Yes, historically hydrophones would function at periscope depth and shallower. Interference from surface noise might degrade their functioning depending on conditions.

If you just apply simple logic here, it is obvious they would function: how would a destroyer with hyrdophones be able to detect a sub if hydrophones suddenly stopped working at 55 feet?

That logic works for me. So, where was that thread anyway??? Perhaps it was in the general SHIV forum.

[Bilge_Rat]

this is the other thread where this question was discussed:

http://www.subsim.com/radioroom/showthread.php?t=111277


There is no right or wrong answer to this question within the limit of the very simple sound modeling implemented in SH4. I have left it as is, but its up to the personal preference of each player.

You should also note that even though you cannot hear contacts at PD, your sonar man will still report contacts, so you are not totally deaf.

[U-Bones]

Originally Posted by Bilge_Rat

You should also note that even though you cannot hear contacts at PD, your sonar man will still report contacts, so you are not totally deaf.

Boat specific. The whole point of this was that the game modeled an arbitrary level which some boats were above and others were below (while at PD).

In actual practice as soon as the heads are submerged they are able to receive, and at PD, they were well below surface and should be functional for ALL subs.

[Bilge_Rat]

Originally Posted by U-Bones

In actual practice as soon as the heads are submerged they are able to receive, and at PD, they were well below surface and should be functional for ALL subs.

But as you will note in the other thread, there should be a degredation of sound close to the surface which does not exist in SH4 based on the simple sound model. Therefore the design decision to cut out the sonar at PD makes sense.

If a user wants to mod the game to use the sonar at PD, that is his choice, but no one can argue that one is more realistic than the other.