[TEC] Tweaking Hydrophone and Sonar in 1.3

[WernerSobe]

Hello

As you have noticed we can use hydrophone and sonar when surfaced. According to fleet type submarine manual (http://www.hnsa.org/doc/fleetsub/sonar/chap1.htm#1A) this is not quite realistic.

The two hydrophones on the bottom of the boat belongs to the WCA System and are only capable for supersonic listening. That means they are more about listening for enemy pinging and/or identifying close targets. It is however possible to catch contacts on ships, but it is limited in range much more then sonic listening, afterall supersonic sound doesnt travel that far. You cannot catch a contact with that at 20000 yards.

The sonic hydrophone is mounted on deck right in front of the conning tower so it is useless on surface.

So realistic would be a capability to catch contacts on surfacec but only at a range of about 3000 yards. It doesnt mean that it is useless at that range. Imagine you have low visibility conditions, it will still save you from running right on a destroyer. And it can help you making an advanced sonar firing solution (see my totorial: http://www.subsim.com/radioroom/showthread.php?t=112591)


So with that in mind i started playing around with Sensors_Sub_US.sim which containes all the setting for the hydrophones as you know. Ive been tweaking the hydrophone earlier back in 1.2 so i thought it wouldnt be much different. However it exposed a little confusing. Changing the values MaxSensorHeigh and MinSensorHeigh didnt changed anything in game. Same with the Range. For testing purposes ive set the range to 10 and min and max height to something way below the surface. That should have pretty much disabled the entire sonar and hydrophone. Well it did not, its was not affected at all, just one thing changed. The preciserange (that i also changed for testing) seemed to have applied for sonar. Setting it to zero made my sonar very accurate. It showed real range there was no deviance as usual. That shows that i have changed the settings for right device in the right file. But a question appears, why the other values (max range and heigh) did not apply?

This is where im stuck now


Offsets:

Item1
MaxRange [1D7F] +15000
MinSensorHeight [1DBB] -500
MaxSensorHeight [1DD3] -1

Item2
MaxRange [1F7C] +20000
MinSensorHeight [1FB8] -500
MaxSensorHeight [1FD0] 0

Item3
MaxRange [2179] +5000
MinSensorHeight [21B5] -500
MaxSensorHeight [21CD] -6

Item4
MaxRange [2376] +2000
MinSensorHeight [23B2] -500
MaxSensorHeight [23CA] -1

[WernerSobe]

im a step further.

Seems like ive changed something else before. Item2 here must be the hydrophone. Setting MaxSensorHeight to -5 makes you hear sound only submerged.

Thats good but not exact what i wanted. The other Items do not change anything. Maxrange also only effects the crew yelling when they grab a contact. Setting it to 5000 makes your crew find that contact at that range. You can still hear it however loud and clear at 20000 and above . So looks like there is no way to make it work realistic. We can either have full functional hydrophone on surface or not.

But maybe someones got an idea lets see.

[LukeFF]

After seeing how the passive sonar works in 1.3, I'm all for a better setting for the detection of passive sonar. How about simply restricting the minimum depth of the sonar to 40 feet? That's at about the depth the crew leaves the bridge and the batteries kick in.

[WernerSobe]

well not 40.

Important is the sensor height not how much you have above the keel. Setting it to -6 makes it work only up to periscope depth but not surfaced. As i said its a solution but not exactly what i wanted. And it must be the MaxSesnorHeight.

So basicly you can open that file with a hexeditor, goto offset 1FD0 and change the value to 00 00 c0 c0 (thats floating point code for -6) that will make it work submerged only.

[AVGWarhawk]

Ok, I have read that the chin sonar was capable of detecting sound but the boat had to be at just a few knots and the engines not grinding away for speed. I read this in Take Her Deep. Werner is right, the sonar is just a bit too good. I'm an idiot when it comes to modding so I can not lend a hand but it is great to see some work is being done on this issue.

[nattydread]

Originally Posted by WernerSobe

im a step further.

Seems like ive changed something else before. Item2 here must be the hydrophone. Setting MaxSensorHeight to -5 makes you hear sound only submerged.

Thats good but not exact what i wanted. The other Items do not change anything. Maxrange also only effects the crew yelling when they grab a contact. Setting it to 5000 makes your crew find that contact at that range. You can still hear it however loud and clear at 20000 and above . So looks like there is no way to make it work realistic. We can either have full functional hydrophone on surface or not.

But maybe someones got an idea lets see.

Perhaps thats not too bad a comprimise provided the player isnt baby-sitting the crew all the time. I fine that I sit back and relax more, not so much micro-managing. If the crew cant see it or hear it I miss it...and with the deck gun, if they cant hit I dont kill it. It seems there are some things the devs couldnt or wouldnt get as real as we would like, but the AI crew if left to do their jobs balances things out.

As skipper I only plan routes, set speeds, manuever the boat for attack or evasion and manually set and fire fish, everything else is the crew...as it should be.

If the crew can be forced to only report contacts at a specific range I'd be ok. I wont be in the sonar room much to hear it from far away anyway.

[TopCat]

I suspected that a "sophisticated" solution to the problem could not be found. However, I'd prefer as it was before (no hydro contacts on surface).

[AVGWarhawk]

Originally Posted by TopCat

I suspected that a "sophisticated" solution to the problem could not be found. However, I'd prefer as it was before (no hydro contacts on surface).

Yes and no on this. I can sit on the USS Torsk located in Baltimore harbor and hear the props of the water taxi's over the sonar. The submarine is WW2 vintage and the chin sonar a bit more sophisticated then the WW2 original but basically the same. She is afloat and of course engines off. Props can be heard. Perhaps while diesel are on this sonar does not work or is less effective.

[chopped50ford]

I have noticed, at PD moving at 1-2 knots the sonar man wont follow contacts beyond 3500 yards. I go as far as to manually place the hydrophone in the direction of the contact, see on the notepad what it is and still the sonar man can track the contact, give range. The only odd thing is he says, no sound contact at bearing XXX that the actual contact is at visually (and locked on)

at PD or even deeper depths, at slow turns of the screws, sound contacts should be picked up by the sonarman.

Otherwise, maybe its the crew member...or not?

[Ducimus]

The three hydrohones are:

Hydrophone_ball - (used on S boats)

Hydrophone_ball_02 ( the set you find on the bottom of all other boats)

Hydrophone_Head (the twirling bar on the main deck)


In generally, ive found it unneccessary to adjust the S boats hydrophone, because its located on the main deck. Despite that, its MaxSensorHeight by default is -1, so no adjustment here is neccessary.

Hydrophone_Ball_02, is the main culprit for sonar contacts while on the surface. By default its MaxSensorHeight is 0. In Tmaru 1.4 and 1.5 (not yet published) it is set to a MaxSensorHeight of -12. No other adjustment is neccessary. This effectively brings the range at which hydrohpones can hear something to a depth of about 42-43 feet. Which is plenty of depth for all boats at periscope depth with the lowest one at around 54 feet. So theres no risk of hydropones not working at periscope depth. I set my sonar this depth to accomidate for radar depth.

Headrophone Head is something of a mystery to me. NO adjustment to this sensor is required at all, and while at radar depth, i'll get intermittant hydrphone contacts , but its not enough to disrupt radar contacts like Hydrophone_ball_02 formerly did. Its default MaxSensorHeight, like the hydrophone used on S boats, is -1. Since its above water, its not an issue.

Now it seems the game primarly uses Hydrophone_ball_02. How, and when it uses the hydrophone_head i don't know.

Also:

Item3
MaxRange [2179] +5000
MinSensorHeight [21B5] -500
MaxSensorHeight [21CD] -6

You have to pay attention to the sensor type. What you have here is YOUR active sonar.

In summary, all you need to do, is adjust the second hydrophone block (sensortype 3) and set the MaxSensorHeight from 0 to -6, or whatever your fancy is, but dont exceed -12.

DO NOT adjust the MaxHeight, this is in reference to how far from the surface the hydrophone can hear. For example if you set it to -6, and a ship has a draft of -2 meters, you wont hear it.

edit:

If you acutally want sonar contacts on the surface, then try messing with this block of data in the sensors.cfg

;Hydrophone
Hydrophone range factor=1 ;[>=0]
Hydrophone fog factor=0 ;[>=0]
Hydrophone light factor=0 ;[>=0]
Hydrophone waves factor=0.2 ;[>=0]
Hydrophone speed factor=0.5 ;[>=0]
Hydrophone enemy speed=0 ;[>=0]
Hydrophone aspect=0 ;[>=0]
Hydrophone noise factor=0.5 ;[>=0]
Hydrophone sensor height factor=0 ;[>=0]
Hydrophone already tracking modifier=20 ;[detection probability modifier]
Hydrophone decay time=150 ;[>0] already tracking bonus decay, in seconds
Hydrophone uses crew efficiency=true ;[true or false]