Visual detection by enemy

XenonSurf · 05-08-20, 09:59 AM

Hi,
Currently I'm playing with the stock icons on the map, which means it displays blue, red icons + the visual detection rings for enemy ships.
I will however turn these 'cheats' off shortly.

From the enemy ship's behavior I have noticed that it hardly makes a difference wether you have little aspect angle towards the enemy or not in order to be visually detected. I had little aspect angle at dark night and yet i was detected at a fairly big distance away on the surface. This would make night surface attacks generally very difficult. I have never seen these 'enemy circles' change their size which they should depending on my sub's visibility (or they did and I didn't notice?).

Take these situations:

------->

i
i
i

Where the first line with the arrow is the enemy ship moving with an AOB of 90° to my sub below (vertical line). This should be an ideal aspect angle to avoid detection at least at maximum detection range noted by the enemy 'circle'. Instead you would immediately be detected in such a situation if too close:

------->

___

with the below line being my sub presenting all the aspect angle to the enemy.

I wonder if this is simulated in SH4. Of course to answer this sort of question (and also the sonar question in my other thread) I could simply consult the sim.cfg file, but this would spoil the game for me forever, which I don't want, so I'm never going to look in this file. I only want to know if this is accounted at all in the game, yes or no, and with all important mods like TMO, FORTSU. I guess in RFB, the most realistic mod, this is surely simulated.

Thank you to let me know!

XS

KaleunMarco · 05-08-20, 12:58 PM

Quote:

Originally Posted by XenonSurf

Hi,
I wonder if this is simulated in SH4. Of course to answer this sort of question (and also the sonar question in my other thread) I could simply consult the sim.cfg file, but this would spoil the game for me forever, which I don't want, so I'm never going to look in this file. I only want to know if this is accounted at all in the game, yes or no, and with all important mods like TMO, FORTSU. I guess in RFB, the most realistic mod, this is surely simulated.

Thank you to let me know!
XS

in my experience, yes, your subs aspect plays a part in being detected.
also, darkness, wave activity (high wind speed), fog, rain, and most importantly, enemy ability.
please keep in mind that there are four levels of competence for each enemy ship...even the merchies, who will fire on you if they "see" you and if you are within range of their limited but lethal weapons.
would write more but i have to get back to work.

XenonSurf · 05-08-20, 01:14 PM

Quote:

Originally Posted by KaleunMarco

in my experience, yes, your subs aspect plays a part in being detected.
also, darkness, wave activity (high wind speed), fog, rain, and most importantly, enemy ability.
please keep in mind that there are four levels of competence for each enemy ship...even the merchies, who will fire on you if they "see" you and if you are within range of their limited but lethal weapons.
would write more but i have to get back to work.

Thanks very much KaleunMarco, that's very good news for me who sometimes like it to be realistic.

Cheers,
XS

Sniper297 · 05-08-20, 05:44 PM

Previous discussions;

https://www.subsim.com/radioroom/sho...d.php?t=240550

https://www.subsim.com/radioroom/sho...d.php?t=210786

In the stock game, the visual in the sensors/dat file is used by all enemy ships, the listings for generic radar and sonar are not used by any of them. Instead they use different radar and sonar models based on the .sns file for each ship.

In the sensors.dat file the max range is given, and the circle displayed on the map is actually the average range, not the max range. "Average" works out to about 0.58 converting from meters to yards, so if the max range listed in the sensors.dat for any given detection system is 10,000 meters, the ring will have a radius of 5800 yards. That means you can still be detected outside that ring, rule of thumb is a bit less than twice the radius of the ring for safety. They might not detect you inside the ring for a while, depends on the skill level of the crew and how much rum the lookouts drank.

Further complication, in the notes under "Sensitivity" it says "The sensity of the sensor. At (Sensitivity * MaxRange) distance we have a double detection time. If 0, then the value from sim.cfg file is taken."

Look in the \Cfg folder for sim.cfg, plain text file;

[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 light factor is what changes the sensitivity when it's dark outside, some of the other data is still open to debate - there's no thermal layer factor if you're running on the surface, so why that was included is a mystery.

Experimenting with the light factor I found that increasing the number also affects daytime detection range, dunno why.

Col7777 · 05-08-20, 06:28 PM

I noticed too when I made a simple mission, as stated above ships have different capabilities, like novice to elite, so you might have met a convoy with some elite DD's as escorts.

Col.

Bilge_Rat · 05-09-20, 11:07 AM

This should answer most of your questions on when the AI will detect you:

https://www.subsim.com/radioroom/sho...52&postcount=1

obviously what mods you have installed will have a big influence on when you will be detected.

The circle you see around ships seems to be the max detection range. You can on occasion go well within that circle without being detected.

Night surface attacks are a weak point in SH4. However, with the stock SIM.cfg file, it should be possible to sneak up to 2,000 yds before the AI detects you at night in good weather. I managed once to get within 1200 yds before I was detected.

Note also that if any ship in a TF detects you with radar, every other ship is automatically alerted. Many late war IJN warships are equipped with some kind of radar.

One tactic you can use, although some consider it to be gamey, is to go "decks awash". You can still man the bridge, but the game considers your sub to be submerged and therefore harder to detect.

05-08-20, 09:59 AM	#1
XenonSurf Sea Lord Join Date: Apr 2008 Location: Germany, Italy Posts: 1,703 Downloads: 107 Uploads: 4	Visual detection by enemy Hi, Currently I'm playing with the stock icons on the map, which means it displays blue, red icons + the visual detection rings for enemy ships. I will however turn these 'cheats' off shortly. From the enemy ship's behavior I have noticed that it hardly makes a difference wether you have little aspect angle towards the enemy or not in order to be visually detected. I had little aspect angle at dark night and yet i was detected at a fairly big distance away on the surface. This would make night surface attacks generally very difficult. I have never seen these 'enemy circles' change their size which they should depending on my sub's visibility (or they did and I didn't notice?). Take these situations: -------> i i i Where the first line with the arrow is the enemy ship moving with an AOB of 90° to my sub below (vertical line). This should be an ideal aspect angle to avoid detection at least at maximum detection range noted by the enemy 'circle'. Instead you would immediately be detected in such a situation if too close: -------> ___ with the below line being my sub presenting all the aspect angle to the enemy. I wonder if this is simulated in SH4. Of course to answer this sort of question (and also the sonar question in my other thread) I could simply consult the sim.cfg file, but this would spoil the game for me forever, which I don't want, so I'm never going to look in this file. I only want to know if this is accounted at all in the game, yes or no, and with all important mods like TMO, FORTSU. I guess in RFB, the most realistic mod, this is surely simulated. Thank you to let me know! XS Last edited by XenonSurf; 05-08-20 at 10:42 AM.

05-08-20, 06:28 PM	#5
Col7777 Grey Wolf Join Date: Jun 2003 Location: Manchester UK Posts: 944 Downloads: 260 Uploads: 0	I noticed too when I made a simple mission, as stated above ships have different capabilities, like novice to elite, so you might have met a convoy with some elite DD's as escorts. Col. __________________ Silent and Violent

05-09-20, 11:07 AM	#6
Bilge_Rat Silent Hunter Join Date: Apr 2002 Location: standing watch... Posts: 3,793 Downloads: 344 Uploads: 0	This should answer most of your questions on when the AI will detect you: https://www.subsim.com/radioroom/sho...52&postcount=1 obviously what mods you have installed will have a big influence on when you will be detected. The circle you see around ships seems to be the max detection range. You can on occasion go well within that circle without being detected. Night surface attacks are a weak point in SH4. However, with the stock SIM.cfg file, it should be possible to sneak up to 2,000 yds before the AI detects you at night in good weather. I managed once to get within 1200 yds before I was detected. Note also that if any ship in a TF detects you with radar, every other ship is automatically alerted. Many late war IJN warships are equipped with some kind of radar. One tactic you can use, although some consider it to be gamey, is to go "decks awash". You can still man the bridge, but the game considers your sub to be submerged and therefore harder to detect. __________________

05-08-20, 05:44 PM	#4
Sniper297 The Old Man Join Date: Dec 2005 Location: Philadelphia Shipyard Brig Posts: 1,386 Downloads: 160 Uploads: 19	Previous discussions; https://www.subsim.com/radioroom/sho...d.php?t=240550 https://www.subsim.com/radioroom/sho...d.php?t=210786 In the stock game, the visual in the sensors/dat file is used by all enemy ships, the listings for generic radar and sonar are not used by any of them. Instead they use different radar and sonar models based on the .sns file for each ship. In the sensors.dat file the max range is given, and the circle displayed on the map is actually the average range, not the max range. "Average" works out to about 0.58 converting from meters to yards, so if the max range listed in the sensors.dat for any given detection system is 10,000 meters, the ring will have a radius of 5800 yards. That means you can still be detected outside that ring, rule of thumb is a bit less than twice the radius of the ring for safety. They might not detect you inside the ring for a while, depends on the skill level of the crew and how much rum the lookouts drank. Further complication, in the notes under "Sensitivity" it says "The sensity of the sensor. At (Sensitivity * MaxRange) distance we have a double detection time. If 0, then the value from sim.cfg file is taken." Look in the \Cfg folder for sim.cfg, plain text file; [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 light factor is what changes the sensitivity when it's dark outside, some of the other data is still open to debate - there's no thermal layer factor if you're running on the surface, so why that was included is a mystery. Experimenting with the light factor I found that increasing the number also affects daytime detection range, dunno why.