SUBSIM Radio Room Forums - Periscope detections are hosed

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- Silent Hunter 4: Wolves of the Pacific (https://www.subsim.com/radioroom/forumdisplay.php?f=202)

- - Periscope detections are hosed (https://www.subsim.com/radioroom/showthread.php?t=210786)

I'm glad our helos were too big to deploy on destroyers, I remember several occasions on the Independence coming up from the mess decks unaware of any movement until I got to the hangar deck, then looking out an elevator door and seeing a destroyer alongside for UNREP. We're steaming along with a slow ponderous pitch and roll, but the destroyer alongside is imitating a half drowned berserk roller coaster with green water over the weather decks half the time. I'd be seasick too on one of them things.

Back on topic, I'm looking to reduce the hack values yet again - mainly the thermal layer attenuation. The visual looks like it's pretty close to reality but sonar is still way too easy. I attack, I dive until I hear "passing thermal layer" then go 60 feet deeper, reduce to ahead slow and never get a depth charge. If 1 is no attenuation and 3 is reduction to 33%, 5 is down to 20%, what would 2 be? 50%? Will it accept decimals like 1.5%? Ideally something like 60% to 80% of the above-layer signal would be better, some advantage to hiding under the layer but not too much - the stock values for thermal layers are a bit too much like a Klingon cloaking device.

I'm looking at what Aanker originally posted and what my stored original 1.4 backup says, this file date is 11/12/2007 and some of the values don't match what the comments say is original.

[Visual]
Detection time=0.5 ;[s] min detection time.
Sensitivity=0.1 ;(0..1) min detection threshold double detection time.
Fog factor=1.0 ;[>=0]
Light factor=2.5 ;[>=0]
Waves factor=4.0 ;[>=0]
Enemy surface factor=50 ;[m2]
Enemy speed factor=25 ;[kt]
Thermal Layer Signal Attenuation=1.0

[Radar]
Detection time=1 ;[s]
Sensitivity=0.01 ;(0..1)
Waves factor=1.0 ;[>=0]
Enemy surface factor=5.0 ;[m2]
Thermal Layer Signal Attenuation=1.0

[Hydrophone]
Detection time=1 ;[s]
Sensitivity=0.15 ;(0..1)
Height factor=0 ;[m]
Waves factor=1.0 ;[>=0]
Speed factor=15 ;[kt]
Noise factor=1.0 ;[>=0]
Thermal Layer Signal Attenuation=3.0 ;[>0], 1 means no signal reduction, 3 equals signal reduction to 33%

[Sonar]
Detection time=5 ;[s]
Sensitivity=0.1 ;(0..1)
Waves factor=1.0 ;[>=0]
Speed factor=20 ;[kt]
Enemy surface factor=200 ;[m2]
Lose time=30 ;[s]
Thermal Layer Signal Attenuation=5.0 ;[>0], 1 means no signal reduction, 5 equals signal reduction to 20%

Main concern is the visual, anyone got an explanation for some of these? Most are self explanatory, but the waves factor - higher number is harder to detect, or higher number means how much the waves are increased over a flat calm before they become a factor in detection? And what does "Enemy surface factor" do?

http://www.subsim.com/radioroom/show...6&postcount=20

[Visual]
Detection time=2 ;[s] ;was 0.5
Sensitivity=0.01 ;(0..1)
Fog factor=1.25 ;[>=0]
Light factor=2.8 ;[>=0] ;was 2.0
Waves factor=1.0 ;[>=0]
Enemy surface factor=350 ;[m2]
Enemy speed factor=15 ;[kt]

original I'm looking at;

[Visual]
Detection time=0.5 ;[s] min detection time.
Sensitivity=0.1 ;(0..1) min detection threshold double detection time.
Fog factor=1.0 ;[>=0]
Light factor=2.5 ;[>=0]
Waves factor=4.0 ;[>=0]
Enemy surface factor=50 ;[m2]
Enemy speed factor=25 ;[kt]
Thermal Layer Signal Attenuation=1.0

Light factor doesn't match what he says was original, possibly what he thought was original came from a mod or earlier SH4 version before the 1.4 patch. Anyway, the two in red are what I'm wondering about, what's a "surface factor", and do higher or lower numbers make it more or less difficult for the enemy to detect you?

i dont see how so many people are having problems with being detected, ive had a small task force with DD's try and hunt me and there very unsuccessful..ive had them pass within 500 yards of me and never detect me..course ill throw out a decoy then order ahead flank to pick up speed then cut my engines and coast while making a sharp port or starboard turn..i spend hours sometimes toying with them like that. i made it into a bit of a sport..harassing the japs and i always send at least one to the bottom, oh and im using the stock sh4 1.5 with no mods when i do this!!

For the 3rd time, I was having a conversation - with Hitman in this post and another. I don't know how to make it any clearer.

So, I just now did a search and found the post where he listed his setting to make a night surface attack possible for him in SH4.

Here is the post. For the 3rd time, these are not my values, I said I got them from my notes:
http://www.subsim.com/radioroom/show...2&postcount=18

This post is where I copied and pasted the info/settings into my notes. I have a massive collection of notes and miscellaneous files relating to SHCE, (SH1) & SH4.

I didn't post Hitman's name because I didn't think it was necessary. The values were important, not bothering Hitman.

Wouldn't it be easier and less confusing to have a conversation between the two of you in PM instead of using the open forum??
As to night attacks. I too do not understand how anyone could have difficulty achieving it. Even with TMO and Travellers Harder escorts I have gotten in between escorts and went right into the middle of a convoy ... fish the targets and then dove deep to avoid the escorts and got away out of the back of the convoy.

Sniper

Per Ducimas

"Surface factor means how much surface area of your sub you must be presenting to the AI in order for him to notice you."

Keep in mind the importance of keeping your bow at the enemy, the more flank of profile you show, obvious the more he can see you. I haven't looked at values in months, but as I recall the lower the number the easier he can spot you.. as he has to see more surface before the AI responds.. Play with it. It's basically the same with sonar, that's why it's always important to keep you bow pointed at the nearest escort.

One of the difficult issues with night surfaces attacks with mods like TMO, you might get in close for an attack, but when you have to turn to escape, you show your flank and get spotted.

People need to keep in mind that numerous values work together before a AI response happens. They're numerous values in the sim, sensors, cfg,ect that work with env settings. You can spend numerous hours getting something that feels right for a certain time or weather, only to find it screws up during a different time. You can spend 100's of hours testing and fine tuning and the fact is you can go about things numerous different ways to get the same outcome.

Just remember, none of this is new, people have been arguing, debating and modding the AI and env for years...they're numerous mods from easy to impossible based on the modders intent and many work in some situations but are unrealistic in others because enough testing wasn't done under every possible env. situation.. Visuals and light factors can get real tricky at dusk and dawn...

Spider, I haven't found the layer to be that much protection at least last night. Was approaching a three ship convoy w/ five escorts. Looked like the one I'd attacked twice before as described above, but that was SE of Formosa w/ them headed NE and this was several hundred miles away N of the Formosa Sts. Got detected prior to firing and dove beneath the 195ft layer. Dropped FTCs just before going beneath. Bottom was at 435ft and we dove to 425. Couldn't get away from these guys. They clearly decided killing us was more important than getting the convoy where it was going. The merchies went off and milled about 4-5nm north and all five escorts came after us. Eventually we bottomed and stopped. Didn't matter. Was depth charged for an hour and a half of real not game time. Eventually, got sunk.

Aanker, what we have here is failure to communicate. I'm not crediting or blaming you for the hack, I fully understand and I think everyone else does that you quoted someone else. And I'm not bashing the hack, it's a good starting place.

Akotalaya, the idea is not making it easier because it's too hard, the idea is making it more realistic because some elements of the enemy AI are UNrealistic. For example the psychic escort who suddenly and coincidentally decides to leave his position ahead of the convoy and make a high speed sweep 15 miles southwest exactly where you happen to be - that occurs far too often to be random chance.

Neil (SIR!) :03: I haven't run across anything like that, my usual was (1) sneak inside screen, (2) fire all tubes, (3) fire decoy, (4) go to all ahead flank and head for 60 feet under the layer, (5) make 90 degree turn and go to ahead slow, (6) draw 5 mile circle with compass and (7) creep to outer edge of circle before coming back up for a periscope peek. My problem is it's so easy it's getting boring, I'm not earning my hazardous duty pay. Visual detection on the surface is a whole different story, trying to do an end-around fails all too often because I'm detected way beyond what would be a realistic detection range. Or the escort gets a phone call from the Psychic Friends Network and decides to make a beeline directly for me from 15 miles away, not sure which.

Armistead, thanks - just what I was looking for, so increasing that number should mean I'd be harder to see on the surface? What about waves factor, is that a multiplier of how much high waves affect detection, or a threshold for how high the waves have to be before that value has an effect? I have "snorkel depth" activated so when I hit the ; key it goes down to decks awash, so far it seems like having only the conning tower exposed makes them see me at much shorter ranges.

When I conduct a night surface attack it is exactly that, I use Fluckey's method; move in on the surface, attack, turn away, track & follow on their beam while reloading, and move in again firing on the next maru or two up the column. No end around required and the DD's can't spot me unless they get within 1,500 yards.
This is much easier with radar and low light is essential.

Quote:

Gene Fluckey's description of his method of night surface attack:

To stimulate discussion of new methods of approach and attack, the following is offered, of possible interest, from our meagre [sic] experience, for what it is worth. It is a special situation of a dark night, poor visibility convoy attack.

Fault was found with the standard off bow attack in that an end around was required; usually only two targets presented themselves at the optimum torpedo accuracy range which were readily taken care of by the bow tubes; shifting nests for low parallax stern tube salvo resulted in no suitable target for the stern salvo at a satisfactory range of 1,500-3,000 yards; escorts were passed close aboard; another end around was required for the next attack; and the formation turned, or was so fouled up, another lengthy tracking period was required.

To obviate this second end around on our last patrol, we changed our off bow attack tactics so that our next shift would be a high parallax stern tube set-up, though contrary to doctrine, and we would emerge ahead of the convoy, ready for a reload and another attack. Again no stern tube target was immediately available at hitting ranges, and, while pulling out ahead, we had to cross in front of the convoy to fire the stern tubes at the leader of another column. Per usual the formation became disorganized. It was two hours before targets and escorts were sufficiently settled for another attack, and even then it was poor. Disorganization of the formation, with the targets wandering about, continually changing position, course and speed, was a distinct disadvantage.

Realizing the advantage of maintaining convoy organization, new tactics were developed and tried, which we label the "Barbarian Attack."

Briefly it consists of a quarter attack firing three bow torpedoes at the trailing ship of an outboard column. The sub then turns out at a 60 degree angle from the convoy course and opens out on the flank to 4,000 yards. Paralleling the formation at this range, fifteen minutes is utilized in tracking and reload while moving up on the next ship. This ship is then attacked from the flank or quarter with a three torpedo bow tube salvo, and the sub again opens out and reloads while tracking the next ship ahead. If this ship is not the leading ship of the column, the procedure is repeated. Assuming it is the leader, a stern tube off bow salvo is fired, and the sub pulls out ahead of formation, ready to reload the stern tubes and proceed with any type of attack desired.

The above method was tested on this patrol with such ease and lack of expected difficulties that attack was only secured to give the rest of the pack a chance. The convoy was contacted at 20,000 yards with the Barb broad on its starboard quarter. Forty-two minutes later the trailing ship was attacked.

The convoy remained organized, used same zig plan and increased speed slightly. Twenty-one minutes after the first attack, the second attack was made on the next ship up the line. Twenty minutes later, the second attack was made, and the Barb passed the next ship ahead at 2,160 yards, foregoing an attack in deference to the rest of the pack. Thus in less than 1 1/2 hours after contact, we found ourselves ahead of the convoy, without making an end around, with all tubes reload, and with two concentrated attacks under our belts. Trouble from escorts which were stationed astern, on the flank and off the bow, was nil. As we had anticipated, not seeing us they turned towards the stricken ship to drop depth charges, maintained course and speed to hold gunnery practice, or, in the case of the exploding AE, were intent upon saving their own necks. If they had turned out to chase us, we had the advantage of a head start on our departure course and at full speed before the torpedoes hit.

Consequently, to us, the tactics of this attack appear ideal in its particular sphere; no end around; the accuracy of concentrated fire; requires only one-third of the time normally used; automatically takes care of reload; minimum escort trouble; maximum convoy organization, and best possible position of sub upon completion of first wave of attacks. Obviously it is flexible and easily adaptable to special circumstances.

Roscoe, "United States Submarine Operations in World War II" page 444
Posted on Tom Martin's site:
http://www.cs.cmu.edu/~tlm/silent/barb_report.html

I've learned not to mess with scene.dat, it is too easy to screw something unintended up. I use the scene.dat as configured by whatever super-mod I am using.

Quote:

merc4ulfate wrote:
"Wouldn't it be easier and less confusing to have a conversation between the two of you in PM instead of using the open forum??"

Read the linked thread, I thanked Hitman for posting his values that helped steer me in the right direction to alleviate a major flaw with SH4; Escorts with ESP and other unrealistic detection special abilities.

No RW sub report I am aware of describes diving to 200' - 250' prior to an attack, and then rising to PD inside the screen to fire. The noise from all of the marus would deafen/mask any Hydrophone detection once the sub is close to the convoy.

I want to attack in a realistic manor whether it is a submerged periscope attack or a night surface torpedo attack. I also want to evade and elude in a realistic manor too.

Happy Hunting!

Quote:

Originally Posted by Sniper297

[Visual]
Detection time=2 ;[s] ;was 0.5
Sensitivity=0.01 ;(0..1)
Fog factor=1.25 ;[>=0]
Light factor=2.8 ;[>=0] ;was 2.0
Waves factor=1.0 ;[>=0]
Enemy surface factor=350 ;[m2]
Enemy speed factor=15 ;[kt]

original I'm looking at;.........This is stock 1.5

[Visual]
Detection time=0.5 ;[s] min detection time.
Sensitivity=0.1 ;(0..1) min detection threshold double detection time.
Fog factor=1.0 ;[>=0]
Light factor=2.5 ;[>=0]
Waves factor=4.0 ;[>=0]
Enemy surface factor=50 ;[m2]
Enemy speed factor=25 ;[kt]
Thermal Layer Signal Attenuation=1.0

The two in red are what I'm wondering about, what's a "surface factor", and do higher or lower numbers make it more or less difficult for the enemy to detect you? The waves factor - higher number is harder to detect, or higher number means how much the waves are increased over a flat calm before they become a factor in detection?

Think of these figures in the Data/Cfg/Sim.cfg file as "additional" factors that get added/subtracted from the original parameters that are found within the basic Data/Library/AI_Sensors.dat file. Within this file sit's the "base line" for the various sensors used by the AI (visual being one of them).

The way you look at the "Waves factor=" parameter is if you increase this figure, [>=0] (means greater than zero), you increase the AI's visual efficiency during higher wind states (meaning something greater than a calm, zero mph wind state). The higher the factor, the greater the chance of being spotted during a storm.

The "Surface factor=" [m2] (a square meter) parameter is like what Armistead/Ducimus state. This is the size of the detectable object. The greater the size of the surface showing to the AI, the greater the probability of having it detected. It makes sense the greater the size, the greater the chances of being seen. However, just what is the base line for the size point that won't be detected? I don't know. I suspect there was a particular distance the dev's used for determining just how large a surface area had to be in order to be seen....its at that distance the surface area factor comes into play.

What I've seen is there is a maximum figure to these numbers that will make no change to the factor it relates to. In other words, there is a maximum figure that going beyond it will make no difference to the sensor. Just what it is for each sensor is pure speculation. For instance the stock [Sonar] "Enemy surface factor= 200" is just a number if you can't relate it to something (like a distance). It could be this figure is only a fraction of what its maximum really is.......OR, its already maxed out, to its limit of detection possibilities.

If you have "no map contacts update" unchecked so the target appears one the map, when you click on a target it has a ring around it. On destroyers with active sonar (I've seen a few with only passive) the inner ring with the wedge is the passive sonar area, the half circle at the front is the active sonar area.

Best I recall the outer ring on all ships is 5600 yards radius, I believe this to be the "standard" visual detection area. It's not the gun range because I've had battleships and heavy cruisers open up on me at 8000 yards, still 1400 yards outside the circle. It would make sense that a higher observation point would increase visual range on a clear day, so being seen outside the circle on ships with higher lookouts would be realistic, and warships detecting a surfaced sub beyond the average range that a merchie would detect same is also kosher.

With that in mind, assuming that ring is average detection range, that number is probably the benchmark - an object this size will be seen at a range of 5600 yards assuming normal visibility and the standard veteran crew, smaller objects will not be seen until closer, larger objects will be seen further away. So increase the number and the "standard size" object won't be seen until closer than 5600 yards, decrease the number and it will be seen farther away. I think.

Aanker, Fluckey sounds good on paper, but as I recall the Germans were doing something similar for the initial attack - but once the star shells started firing, the jig was up and they had to dive. I suspect the competence of the escorts would come into play, Fluckey does mention that they assumed a submerged attack and weren't looking for a surfaced sub outside the convoy. Always helpful when the enemy screws the pooch.

I can never resist a pun, maybe Fluckey was a fluke. :har:

Okay, probably a bit too much on the visual.

[Visual]
Detection time=0.9 ;[s] min detection time.
Sensitivity=0.09 ;(0..1) min detection threshold double detection time.
Fog factor=1.2 ;[>=0]
Light factor=2.6 ;[>=0]
Waves factor=4.0 ;[>=0]
Enemy surface factor=50 ;[m2]
Enemy speed factor=20 ;[kt]
Thermal Layer Signal Attenuation=1.0

That's what I got now, and on the latest test with my mission mod I decided to press my luck as far as it would go. In the narrows south of Corregidor I have a Kongo BB steaming at 1 knot (wanted to have him anchored but that creates weird respawning later) as the first contact. Flooded down to decks awash (25 feet) at 8000 yards, continued closing at 15 knots. I'm pretty sure the game takes zero notice of how much spray you're kicking up, which is a lot at 15 knots decks awash and should be more noticeable. I double checked in the mission editor, and I do have this Kongo set for the default Veteran crew.

https://scontent-b-iad.xx.fbcdn.net/...05931138_n.jpg

About 3000 yards, he SHOULD have seen me by now even end on, it's high noon and clear.

https://fbcdn-sphotos-g-a.akamaihd.n...42143727_n.jpg

The Val saw me and made a bombing run, even if the Kongo lookouts were full of sake, the Val dive bombing me should have at least made them curious enough to look in this direction.

https://scontent-a-iad.xx.fbcdn.net/...43384438_n.jpg

500 yards and still oblivious - he HAS seen the torpedo wakes and sped up, how can he see wakes but not me?

https://fbcdn-sphotos-a-a.akamaihd.n...36097513_n.jpg

Slowed to 1/3 because a ramming contest between a BB and a sub is not a good idea if you're the sub. Two fish hit (further aft than I aimed due to his speed increase) NOW he decides maybe there's a war and he should be shooting at a sub 200 yards away.

Either I got too much topspin on this hack or the veteran crew status should be downgraded. Decks awash should make a difference, but not THAT much.

Could it be that the waves factor is too high?

Quote:

500 yards and still oblivious - he HAS seen the torpedo wakes and sped up, how can he see wakes but not me?

I think the torpedo detection is automatic. Even the most clueless merchant crews can spot them on a dark night. :doh:

Dunno, default waves factor is 4.0, I didn't change it. Later in the same mission I was charging at a Maya decks awash trying to get him before he sank the US light cruisers coming up behind me, at 3000 yards the Maya opened up, but on the Omaha behind me, which was 4000 yards further away. A Minekaze saw me from about 5000 yards and turned toward me, bent on 34 knots and opened up at 4000 yards. By this time the second Omaha was right in my wake and he opened up on the Minekaze so I didn't have to dive right then - but the Maya started firing at me about 2000 yards so I had to pull the plug.

It DOES make a difference;

https://scontent-b-iad.xx.fbcdn.net/...03943639_n.jpg

Fully surfaced;

https://scontent-a-iad.xx.fbcdn.net/...19553335_n.jpg

Decks awash (25 foot depth) from about the same distance.

Main thing is the spray, if I'm chugging along at 5 knots it should be harder to see than when I'm booking along at 15. Same thing with periscope feathers, in real life they went down to 100 feet to sprint, so there wouldn't be a wake disturbance visible on the surface, then slowed to 2 knots (even backing the motors to slow quickly sometimes) before coming back up and raising the scope. In game it doesn't seem to matter, even at night when a huge white bow wave makes you visible from farther away.

Quote:

[Visual]
Detection time=0.9 ;[s] min detection time.
Sensitivity=0.09 ;(0..1) min detection threshold double detection time.
Fog factor=1.2 ;[>=0]
Light factor=2.6 ;[>=0]
Waves factor=4.0 ;[>=0]
Enemy surface factor=50 ;[m2]
Enemy speed factor=20 ;[kt]
Thermal Layer Signal Attenuation=1.0

Flooded down to decks awash (25 feet) at 8000 yards, continued closing at 15 knots. I'm pretty sure the game takes zero notice of how much spray you're kicking up, which is a lot at 15 knots decks awash and should be more noticeable. I double checked in the mission editor, and I do have this Kongo set for the default Veteran crew.

I can't help but notice your "Enemy speed factor=20". Enemy in this file means you, the sub. The figure of 20 kts means the AI will not be very efficient in detecting you, unless your doing 20kts or greater. Since your not traveling at 20 kts, your speed (wake) will have little effect on the AI detection capabilities.

Your "Detection time=0.9" can throw things off too. At 0.9 this means the AI may see you, yet not react to your presence for nearly a minute in game time (0.5= to 30 seconds). You can travel a large distance in a minute, making it seem the AI isn't responding when in fact this figure is holding back the AI from doing just that. On this same note, your stock game Sim.cfg file also contains these entries:

[AI Cannons]
Max error angle=3
Max fire range=6000
Max fire wait=12

[AI AA guns]
Max error angle=5
Max fire range=1500
Max fire wait=7

This "Max fire wait=12" can easily be why your not getting a response from the Kongo. Its waiting for 12 minutes before doing anything about the detection (if anything is detected).

Its possible if the Kongo is going to detect you, it will be through one of the other possible sensors (Radar, Sonar {Active}, Hydrophone {Passive}). Or, from detection by some other means....like the the plane spotting you. Again, if any of these are the possible detection source, there are still other factors that will come into play before getting a response.

One thing you should do to narrow down your "control" of the tests your doing is eliminate the other possible sensors playing a part in detection. This means removing a test subjects sensors....other than the sensor you wish to examin.....then making changes based on the lone sensor factors.