How dangerous is to use active sonar?

[twm47099]

Just a question about the accuracy of active sonar in the game --
I'm using SH4 v1.5 with OTC. I find radar very accurate (tested by setting the gun range to the determined bearing and range and hitting on the first try at both long and short range.)

I find the stadimeter (Sp?) to be twitchy - sometimes slightly long, sometimes slightly short, some times accurate (as determined by the white "x" overlaying the ship in the attack map.)

But I find active sonar pings to be all over the map (except at the actual target range.) A target at 3000 yards will show a ping range of 8000 yds. A target at 2000 yards will have a ping range of 1200 yards (not consistent so I can't just say the scale is consistently off.) Bearing is very accurate, and I have run 2 leg TMA using only passive sonar and gotten accurate bearing, range, and speed. But I find pinging to only be useful for atmosphere.

Do other users find active sonar reasonably accurate? Any ideas why my active sonar is so bad?

thanks

Tom

[Hylander_1314]

Originally Posted by Rockin Robbins

Good deal. Now some of us need to do that under more controlled conditions before we totally declare Ducimus correct. Thanks for the input.

Careful there! That is almost blasphemy!

[magic452]

Twm47099.
To get a good active range ping you need to make sure the sonar is centered on the contact. move the bearing till the light goes off and than move the other way till the same, note the bearings and split the difference.
Lite off at 005° and lite off at 355° the target center is at zero degrees.
Once centered ping and the range should be very close.

Magic

[Rockin Robbins]

Good point there. Our sonar beam is always exactly 10º across, so you can do what you describe and get good ranges. In the real subs, sonar conditions varied. The beam might be scattered so it widened, it might be refracted by temperature or density changes in the water...let's just say that the real subs did not get anywhere near as accurate a bearing.

Where I can usually put three torpedoes of three on a target active sonar only, if I am shooting from under 1000 yards, I don't think the real sub would consistently be as accurate.

Sonar in SH4 is a long way from the truth. We are missing layers and layers of behavior from the sea itself to the adjustments on the equipment, to the separation of the different types of sonar, to filters to the complete lack of life in the ocean! Sonar is one of the worst rendered aspects of the game.

At best, we can say we get the general principles of some of the aspects of sonar. Once you get specific the real sonar guys will tear us apart!

[twm47099]

Thanks for the info. I've tried it and the ranges are much more accurate.

Today I tried another passive only attack on a lone merchant. I recorded 3 bearings at long range (at least that's what the sonar operator said) with 12 minutes between them. I used the MOBO TMA to get the course. I laid the course across the 3 bearing lines on the SH4 chart and predicted the next two 12 minute bearings. I went to flank speed on the surface about perpendicular to the predicted bearing (it was a dark and foggy night). 12 minutes later I marked the bearing from the new position while moving. The range was about 12000 yrds. I then changed course to get into position at 60 degrees to the projected course.

When the prediction said the target should be at 8000 yards, I marked its predicted position on the course line, measured and entered the bearing, estimated range and speed, and calculated AOB, and turned on the PK. I intended to shoot when the PK indicated about 0 torpedo gyro angle at 1000 yrds. At about 5000 yrds I peeked and zoomed the chart so that it showed a large plan view of the ship. The ship was less than 50yrds from the predicted track, running parallel to it. Switching to the attack map, the white "X" was touching on the far edge of the ship (port side of ship when attacking from its starboard).

I submerged and lowered the scope, and then made the attack blind waiting until the PK indicated that the torpedo gyro would be zero. I fired a 2 fish spread, first 1.5 deg forward and second at 0 offset. Then I raised the scope to see what happened. Both hit.

I realize that the probability of this happening in WWII was essentially zero, and understand that the sonar in the game is like playing with torpedo duds off (which I do - torpedo factory fantasy) for the reasons that RR explained. But it was fun. One nice thing is that I didn't use TC very much at the long range since there was a lot to do until I got the PK set up.

I'd never have a chance of getting every thing done if the target was a fast warship task force.

Tom

[Rockin Robbins]

Yes, there's a lot of confusion when there are multiple targets involved because SH4 uses only two recordings (different varieties of each for engine speed in a small number of ranges), one for generic merchie and the other for generic warship.

With a real sonar, not every target sounds the same and it is possible to locate that BB by its signature engine and propeller sounds. This is not possible in SH4 so we are left with total confusion.

Hey! Live by the simulator, die by the simulator. Some things are easier than real life, some things are harder. But it's the best we've got and I enjoy it a lot.

[Daniel Prates]

Originally Posted by ColonelSandersLite

The incorrect information:

The ability to determine a targets course range and speed from bearings alone did not exist in WWII.

That you have to be able to know your own position with certainty to do a bearing only plot.

The game tools are inadequate for the technique.

That TMA is only possible when you already know the target's course and speed.

This is all true, and as far as I know, these are all unavailable techniques as far as 1940's technology goes.