Questions about discretion
 

Hello every body,

I would like to talk about a strange situation I encounter with GWX v3.0 : so, it's night, i've spotted a convoy and calculated an interception course. Now, I am well placed to attack. A destroyer is headind the convoy. So, I am thinking it won't repair me, because it's not aware of my presence... I let it pass 150 meters near me, I am absolutely silent and submerged. And it detects me every time !!! :wah:

How is it possible, as I am submerged and not detected yet ?? :hmmm: I don't understand at all. Maybe there's something I don't know about Allies' detection's strategies ! .... ?

Thanks for answering if you have any idea !

hello Fahnenbohn,

it is the sonar that is tracking you. the sonar is an active sensor,sending a ping which hits on your hull and returns back. it doesn't matter if you are silent or not. AI sonar is effected be your distance and depth.
http://i57.tinypic.com/33bh0s3.jpg

But won't the active sonar start pinging only when a passive system has first found the contact? :hmm2:

As far as I know, SH3 only uses one sensor at a time, and it uses by default that which has the biggest range/detection ability available. It then switches to active sonar if he has found a sub and it is submerged.

hello Alberto,

if you got into the sonar's area you will get pinged .
i can tell you this from my tests where i made some fixed single missions: my boat was stationary submerged and the target was setted to pass in front of me at about 300-400m. the target was indentified (this allows you to see on navmap page the sonar's area) and as soon as i got in sonar's area i was pinged (for some delay that may be on this is responsible the settings at sim.cfg file)

i think (not sure though) that you are right that sh3 uses only one sensor at time but if sonar is the first one that tracks you ,you will get pinged

Hello makman94 !

Thanks for your answer ! I already knew what you told me, but my problem is on this point : i think it's unrealistic to be detected although the ennemi doesn't know you are here... In fact, the sonar seems to work underwater as the radar does above water, even if it doesn't send a ping : you are detected as soon as you enter in the detection's area.

@ Hitman :

It would be nice if SH3 was using by default the sensor which has the biggest range/detection ability available, and then was switching to active sonar if he has found a submerged sub. But it doesn't happen like that in my game !


So, i wonder if there is a solution to avoid this problem by changing the parameters in sensors.cfg or sim.cfg or else ... ?

I give you my own parameters :


In sensors.cfg :

Sonar range factor=1 ;[>=0]
Sonar fog factor=0 ;[>=0]
Sonar light factor=0 ;[>=0]
Sonar waves factor=0.3 ;[>=0]
Sonar speed factor=0.1 ;[>=0]
Sonar aspect=1 ;[>=0]
Sonar enemy speed=0 ;[>=0]
Sonar noise factor=0 ;[>=0]
Sonar sensor height factor=0 ;[>=0]
Sonar already tracking modifier=20 ;[detection probability modifier]
Sonar decay time=5 ;[>0] already tracking bonus decay, in seconds
Sonar uses crew efficiency=true ;[true or false]


In sim.cfg :

[AI detection]
Lost contact time=15

[Sonar]
Detection time=20 ;[s]
Sensitivity=0.03 ;(0..1)
Waves factor=0.5 ;[>=0]
Speed factor=20 ;[kt]
Enemy surface factor=200 ;[m2]
Lose time=30 ;[s]


Is there anything wrong ? Do you have any suggestions ? ...

i don't know if it is realistic or not as i don't know how the AI sonars worked in reality back then. i mean that if the sonar devices pinged all the time at their working area then it is well done in game too but if the sonars were just turned on manualy when something had to be searched and the crew started some specific pings then yes , you are right at calling it unrealistic.

i don't think that you will manage anything through the sim.cfg file . the parameters there are only for delay this detection .(you could possibly even eliminate it but then the AI will have no sonars at all).
i am afraid that the way the sonar works is hardcoded stuff and only tweaks at executable files can change the sensors's behaviour

Yes, it may be hardcoded. So, it's a future improvment to do !! I will suggest it to h.sie, I believe he'll be interested in ... I've already suggest him another improvments like no seagulls at night.

Now, i would like to understand several things :

What do these parameters change in game ? :
- Sonar already tracking modifier
- Sonar decay time
- Detection time
- Speed factor
- Lose time

:salute:

The way the detection works is unrealistic in a technical sense. It very likely didn't work like that during the war.

However the lack of knowledge how the detection works is very realistic in an experiential sense. Not exactly knowing what the escorts were capable of, was exactly what the U-boat commanders faced. The beauty of the game is partly in trying to figure that out in only a few convoy attacks in constantly changing weather and escort type conditions.

Mmm.... I'm not convinced...:-?

i think that H.Sie is not modding sh3 anymore so better contact Stiebler. he is the only one that can answer to such question

the first two are parameters for your sonar device.
the ''Sonar already tracking modifier'' is a detection probability modifier.as explained in the cfg,once a contact is detected it will lose it very hard
the ''Sonar decay time'' is the time of fading of your sonar line once the contact is lost

the rest three parameters are for AI Sonars
the ''Detection time'' is the delay at the detection once the AI has locate you
the ''Speed factor'' is a modifier that taking into account your speed in order to calculate the final probability for AI to detect you
the ''Lose time'' is the time that AI sonar will track you since its last ping.

Thanks for the explanations makman ! I will try some tests... :ahoy:

I seams to me the only simple solution to the problem would be to use CMDR to randomize a series of different sensor files. This would keep the element of uncertainty. I can think of a number of drawbacks to this but war, performance, and competence are all uncertain and variable.
It has always bothered me that I could be detected if completely silent, deep and unexpected.

I suspect that there were RL skippers who were also bothered that they were detected while they thought they were"completely silent, deep, and unexpected." Although they might not get a chance to complain about it. I have no personal experience, but I believe war can be like that.

I've been asked by Makman94 to look at this thread.

I wish to point out that the standard advice for Royal Navy warships was to keep active sonar (pinging) and active radar on at all times while at sea. That was the recommendation (but not an order) in 1945, I read it in a contemporary Royal Navy magazine - for sailors' eyes only. Some serving British sailors had asked whether it was wise to keep pinging and using radar, in good weather, when the U-boats could hear the pings a long way off, and the U-boats were fitted with radar detectors.

The magazine's argument was that use of eyes and hydrophones to pick up U-boats might not be effective, but the sound of pinging and radar detection would force the U-boat to run away or dive deep quickly. It is true that in 1945 most of the U-boats were deployed in shallow waters around Britain's coast - the magazine's recommendation was a scarecrow tactic.

I see no reason to make the hard-code changes outlined in previous posts, although doubtless it is possible. It would take a long time to find the necessary code, though.

Stiebler.

hello Stiebler,

yes, there was this question floating around as how the real sonar devices worked.
according to the magazine ,we have one clue now that the sonars ,indead, were working 24/7,
so yes, there is nothing to be 'fixed' here,devs made it the right way.

thank you for the interesting input !:up: