Periscope not detectable by radar?

[akm_ch]

I just read that in DW 1.01 the periscope can't be detected by radar. As this doesn't seem to be very realistic to me (are there stealth periscopes? :D ) I'd like to know whether there is a fix for this?

(btw: wasn't it even possible to detect snorkels by radar already in WW2?)

Maybe somebody can help or clarify if this is a misunderstanding from my side ...

[SeaQueen]

It depends on a lot of stuff.

In real life, periscopes can be detected by radar, but it's not easy. Basically, unless you leave your mast up for an absurd period of time in calm weather, you're not likely to be detected. Some radars are better than others, though. There's several radars out there designed to specifically spot periscope masts because ordinary surface search radars don't always catch them. Those are really good at picking out periscopes, and are actually pretty interesting. Maritime patrol aircraft usually have a radar that's really good at detecting periscopes. Surface ships typically don't.

Currently, though a periscope is more likely to get spotted by a good lookout on top of the pilot house.

[LuftWolf]

In game terms, the AI will not detect sails and masts, a gameplay decision by SCS, although player-controlled platforms (multiplayer) will detect sails for sure (I'm not sure about masts and detection).

[Skybird]

For dramaturgical reasons I find that "gameplay decision" questionable. It may be considered as minor by many, but so far I handled the masts with extreme care because of fear of beeing detected. Dissapointing that I was troubled all for nothing and could sail with raised periscope forever. Hope a mod will make masts detected by the AI if beeing rasied for a longer while. they eventually should be detected by according platforms if the distance and equipement allows for that and if , for example, periscope is raised longer than a full 360° sweep takes at a 8x magnification. Maybe a raising probablity the longer the mast stay raised beyond a reasonable ammount of time. Why is there a separate ESM indicator at the persicope station if it is of no use at all, then?

[akm_ch]

In case somebody is interested in the WW2 stuff about schnorchels and radar I recommend reading this:

http://www.militaryhistoryonline.com/wwii/atlantic/uboat.aspx

It says there: "The "Schnorchel" device could sometimes be detected by radar or keen-eyed lookouts in calm weather, but although virtually impossible to spot in rougher conditions, these same situations often caused problems of their own."

[compressioncut]

It depends on a lot of stuff.

Currently, though a periscope is more likely to get spotted by a good lookout on top of the pilot house.

I'm gonna go ahead and disagree with this.

Let's say the absolute minimum range you can avoid an incoming torpedo is 2,500 yards. I can't recall ever seeing a scope out that far, certainly not when it wasn't exactly what I was looking for. Probably inside a mile in most cases.

[SquidB]

Mast should show up on radar absolutely, depending on sea state.

The way is should work is you work out a mast up = found on radar time, then add a +5 - 5 variable whatever....that way the sub skipper ****s his pants every time he rasies perescope and the asw skipper gets lucky time from time

Make it so you code monkeys!!!! :-j

[Bellman]

:roll: '' Language Timothy !! '' :-j

[Kapitan]

lol tisk tisk :|\

[OlegM]

According to you guys nuke sub life expectancy in modern naval warfare would be around 20 minutes :-?

Masts detectable by radars, ultra efficient active sonars, then also reducing the effectiveness of counter measures seems to be popular in modding world too...

I am not saying it's not realistic, but it is my opinion nuke subs are quite screwed in DW as it is. It seems weird that most powerful nations built hundereds of multi mega zillion dollar subs, crewed by hunreders of their best sailors per sub if they are so easy to find, detect and destroy by equipment worth 5% their price, and crewed by 5% their complement as DW sometimes makes us believe.

In short, DW already has pretty strong anti-sub slant overall, in my humble opinion, so when asking for changes or mods to be made be careful what you wish for...

O.

[Molon Labe]

According to you guys nuke sub life expectancy in modern naval warfare would be around 20 minutes :-?

Masts detectable by radars, ultra efficient active sonars, reducing the effectiveness of counter measures seems to be popular in modding world too...

I am not saying it's not realistic, but it is my opinion nuke subs are quite screwed in DW as it is. It seems weird that most powerful nations built hundereds of multi mega zillion dollar subs, crewed by hunreders of their best sailors per sub if they are so easy to find, detect and destroy by equipment worth 5% their price, and crewed by 5% their complement as DW sometimes makes us believe.

In short, DW already has pretty strong anti-sub slant overall, in my humble opinion, so when asking for changes or mods to be made be careful what you wish for...

O.

Subs in DW are screwed because active sonar detection ranges are determined by the size of the display and not be acoustic condidtions. If this can be fixed...and LW/Amizaur's mod might just do this...then subs will be able to be sneaky like they should be. Which also means modeling detectable masts wouldn't be a bad idea, as long as detection wasn't immediate and/or automatic. I think it would be cool if you had to worry about how long you left your masts up. :arrgh!:

You are right though, in stock DW as it is now, we don't need any more anti sub bias. Especially since the periscope is our only hope of surviving a P-3 or MH-60!

[Bellman]

:lol: ML I think it would be cool if you had to worry about how long you left your masts up. Arrgh!

I do, I really do - in both senses. :rotfl:

[Kapitan]

bellman how dirty are you :D

where i play i rarely use masts cause im under ice

[Ghost Dog]

I've always been a periscope drill kinda guy. I never kept my masts up for too long, I always assumed that there was a chance they'd get picked up.

but i agree with those who said that beyond 2,500 yds you probably wont see much. and a mast is so small that it would take a pretty good radar set and somewhat calms seas to pick it up.

I wonder if a SPY-1D would pick one up and at what range?

[akm_ch]

It's once again me ...

just came across the following:

http://radar-www.nrl.navy.mil/Areas/Periscope/

quote ---
In fact, the Navy has an operational periscope-detection radar, the APS-137, installed in S-3B and P-3C aircraft; but, because the APS-137 requires human operators to distinguish sea clutter and other objects from periscopes, it is completely overwhelmed in high sea states and in dense-target littoral seas.
end quote ---

what do you say now? :o

[Kapitan]

my SOP is periscop up one sweep medium range then radar up then ESM then surface if no contacts other than that if there is a contact i lower all masts and wait

[OKO]

my SOP is periscop up one sweep medium range then radar up then ESM then surface if no contacts other than that if there is a contact i lower all masts and wait


You raise your radar before your ESM ???
You prefer to immediatly give your position to the ennemy than to stay stealth ?
;)
In MP game, you will feel this hard Kapitain !
Human are VERY reactive to this, more than AI.
just 2 airplanes in flight and they know you position in one second.

Generally speaking, the radar on subs is to use ONLY if there is total probability of no threat around : not on sonar (before reaching PD ...) and nothing on ESM.
You can use it when you have already killed the escort, for example, to finish the merchant.

But using radar when there is ennemy around is definitly killing your stealth, and stealth is what a sub need to keep as long as he can.

Another way to use radar is to check the ennemy real position on a long torpedo launch (Mk48, 65cm) out of visual range, when the torps close to the TMA of the target, to confirm the real position before opening seeker.
but I prefer to use active sonar in this case, radar attract airplanes too much ...

[Kapitan]

i didnt know that radar could be picked up hmmm il have to change my SOP

[Rip]

my SOP is periscop up one sweep medium range then radar up then ESM then surface if no contacts other than that if there is a contact i lower all masts and wait


You raise your radar before your ESM ???
You prefer to immediatly give your position to the ennemy than to stay stealth ?
;)
In MP game, you will feel this hard Kapitain !
Human are VERY reactive to this, more than AI.
just 2 airplanes in flight and they know you position in one second.

Generally speaking, the radar on subs is to use ONLY if there is total probability of no threat around : not on sonar (before reaching PD ...) and nothing on ESM.
You can use it when you have already killed the escort, for example, to finish the merchant.

But using radar when there is ennemy around is definitly killing your stealth, and stealth is what a sub need to keep as long as he can.

Another way to use radar is to check the ennemy real position on a long torpedo launch (Mk48, 65cm) out of visual range, when the torps close to the TMA of the target, to confirm the real position before opening seeker.
but I prefer to use active sonar in this case, radar attract airplanes too much ...

Especially not wise for Russian platforms. Since they use crystal controlled radars you can identify the exact hull # from a radar intercept.

In numerous years of submarine sea duty, I have never seen the radar used when not on the surface. IRL the use of a radar during batlle would be suicide. :yep:

[Kapitan]

:dead: :dead: :dead: :dead: :dead: :dead: :dead: :dead: :dead: :dead: :dead: :dead: :dead: :dead: :dead: :dead: :dead:

[Apocal]

I wonder if a SPY-1D would pick one up and at what range?

Long story short, it is extremely doubtful it could. As great as SPY-1 is, it is not meant for surface search. Low E (elevation) yes, periscope sticking up out of the water, no.

Even assuming it could (or you substitute in SPS-55/64/67/73 surface search radars), the max theoretical distance would be the radar horizon from your antenna (Hr). Here is the formula in case you like math or feel the irresistable urge to anger yourself:

Rnm = 1.23/Hr

Range in nautical miles equals 1.23 divided by radar height.

Height in inches and feet, Rnm meaning Range in the nautical miles and Hr representing height of the radar. It's actually slightly more complex than that, but for simplicities' sake I'm assuming that the sub skipper is competent and the periscope is just barely coming out of the water (equal to horizon, as opposed to adding another variable Ht, height of target).

If a radar is mounted forty feet high, the theoretical max range would be a little bit over seven-and-a-half nautical miles. Well within range of far too much ASuW nastiness. Eighty feet increases it to just about eleven nautical miles. Of course, there are various other factors involved, radar cross section, sea clutter/sea state, electromagnetic interference (which happens time to time), if the watch is asleep at his console, etc. A good rule of thumb is to automatically knock off a fifth of radar performance just becuase nothing works perfectly in the real world and another third for poor environmental conditions. Which leaves you with roughly six-and-a-half nautical miles with a somewhat decent chance of detection.

In the meantime, I'll be watching the SQR-19, beause I wouldn't enjoy swimming back to port.

[SeaQueen]

I'm gonna go ahead and disagree with this.

Let's say the absolute minimum range you can avoid an incoming torpedo is 2,500 yards. I can't recall ever seeing a scope out that far, certainly not when it wasn't exactly what I was looking for. Probably inside a mile in most cases.

And what does that say about the likelihood of getting picked up by a surface search radar?

[MaHuJa]

There is one fact that needs to be addressed before such a thing as detecting masts can come to pass.

The fact that a mast is raised, is not transmitted across the wire to other players (multiplayer).

I did a test, in the bundled p3vsAkula scenario, where he raised the whole forest above the water, but I couldn't see him until the sail followed.

[OKO]

i didnt know that radar could be picked up hmmm il have to change my SOP


huh ?
well, the exact purpose of ESM and EW is to catch ennemy radar emissions, Kapitain ;)
and ESM is supposed to catch a radar at TWICE the distance this radar could see something.

[OKO]

In numerous years of submarine sea duty, I have never seen the radar used when not on the surface.

LLOOLLL rip, sure you better not or you will break it.
And anyway a radar won't see anything in the water :roll:

IRL the use of a radar during batlle would be suicide. :yep:

yes it is ! except if there is no threat left, and just easy targets like unarmed merchants.
In this case, you can have an easy and faster solution with the radar, instead of making the TMA.

[Bellman]

O. I dont dispute what you say ESM is supposed to catch a radar at TWICE the distance this radar could see something.

But what is your source ?

I am sure that your right for aircraft but at sea level the same horizon limitations should apply to both radar and ESM.

Unless of course the distortion of the signal which interferes with over horizon radar reception is not enough
to hinder a bleed which ESM can trace. :hmm:

[OKO]

O. I dont dispute what you say ESM is supposed to catch a radar at TWICE the distance this radar could see something.

But what is your source ?

I am sure that your right for aircraft but at sea level the same horizon limitations should apply to both radar and ESM.

Unless of course the distortion of the signal which interferes with over horizon radar reception is not enough
to hinder a bleed which ESM can trace. :hmm:

my source ?
My source is the way a radar works :

the radar send a beam, the beam reflect on the target them come back (and his analysed to make the picture)
So, to have the position of a target, the beam need to do TWICE the way (way to and way from).

But, from the target, the ESM just have to receive the beam, so the ESM receive the beam at half the distance of what the radar need to have the picture of a contact.
That's why I said ESM is supposed to catch a radar at twice the distance.

"Supposed" mean on a flat planet, and we all know our world is not flat :know: .

But ESM should pick up a radar ALWAYS before a radar can see the target, when the target is far and is approached by the radar emitter.

[Rip]

ESM always detects radars at a substantial distance farther than the radar can detect the ESM platform. In the case of submarine ESM this can be as much as 4 or 5 times as most radars can't detect the periscope at all. It will still detect the emitter later than either a surface or air contact based on the height of the recieving antenna. For the same reason you can pick up air radars from much farther away than surface. I won't even mention submarine radars as real submariners only use the radar on the surface.

[Bellman]

O:"Supposed" mean on a flat planet, and we all know our world is not flat .

But ESM should pick up a radar ALWAYS before a radar can see the target, when the target is far and is
approached by the radar emitter.

I can accept both those statements. :up:

R: The original question focused on sub esm. You are saying here that in game the sub raising its esm mast
will receive surface detections at 4-5 times the range of its radar ? Mmmm I will try it :hmm:

If you refer to reality I would still with respect ask for 'public' source/s, articles or quotes.

[Bellman]

R: Preliminary tests with Stock DW show -

5 Grishas at different bearings and ranges from my SW but all having N & S courses.

Sole ESM detection was at 11.5 nm. and at this range there was no radar contact.

The range was closed to the ESM target and radar detected this contact at 8.5 nm.

[Bellman]

I should add that ESM did not pick up a Grisha at 20 nm - so it looks as if the limit is somewhere between 11.5 and 20 nm.

'Real-life' intrudes on testing but I expect that other reports of a sub ESM range of 15 nm could be correct.
Given variables of the surface units radiating mast height.

In that case OKOs ESM x2 Radar range (Approx) stands up.

[Bellman]

Finalised test figures under the above near surface SW conditions:-

Max radar range - 10.6 nm (Fading) 10.8 nm (Disappeared). (Taken at 50 ft** 7 knts)

Max ESM range 13.5 nm. Taken at 51 ft ** 8 knts (Not 58 ft as best results in achieved at this depth on this dive)

**Avoiding breaking the surface with the tower.

It seems therefore that there is'nt a 100% improvement in the range capabilities of ESM v Radar,
in these circumstances, but a mere 27 % improvement.

[OKO]

Bellman, I have some question about your tests :

1) what was the sea state ? did you tried same test with sea state 1 and 5 ? it whould have REAL different values here, but I'm afraid this is not implemented in DW (the effect of heavy sea)

2) did you tested at radar depth and compared to surfaced subs (supposed to have larger range) ?

3) could you extend a bit your test to aircraft please ? especially Orion and MH-60 of course.
here you should have WIDE values.

thanks if you have some times to test this :P

[Bellman]

The trigger for the discussion was Kapitains remark about his OSP when checking the target environment at near surface depth from his Ak.

My tests concentrated on this issue using the SW. Grishas were felt to be of a good medium height and a fair
sized target for ESM and radar tests. Sea state 3. Weather (?) Clear. Cloud base 4500 m.

I am sure surfaced sub tests ASuW units and anti AAW will confirm greater disparities between ESM and radar ranges.
My Harpoon experience confirms this. But forgive me my interest in DW is as a diver, so those areas
of interest are of little relevance currently.

[Bellman]

:sunny: O:

Dont mean to sound sn**ty - I will have a look at this issue in the future but my short term objective
over the weekend is to have a good look at , and run some tests on, CM v torp performance in LWAMIs mod 2.01.

:lol: Very interesting .................................for divers. :yep: :o :hmm:

[LuftWolf]

Sea state definately effects radar.

In a MP SW mission I was playing with very high sea state, my radar didn't see diddly even when I was on the surface (17m, but the sea was so high, I was on the surface with sail bridge access enabled), and there were definately returnable contacts within range under normal conditions.