Radar questions
 

Does enemy has radar (in the game logic)? If so, will you appear on their radar when not submerged?

When my radar is on, will it increase the chance of being spotted by the enemy radar as well? I mean both in the game and in real life.

I know that air radar in real life has the possibility to check raw data, so even it is not able to identify what he is seeing, he still might see that there is something there. But in this case i really have no idea on how the radar waves would work in the ocean (honesly i have to idea on how naval radar works).

In addition to radar, is there a safe distance on which i can use a sonar to gather distance? Obviously i'm referring to situations where you have escort near the merchant, so i would like to know if i should use sonar mainly only when i'm sure that merchant is alone (which by guess i don't think otherwise the whole thing would be useless).

It will depend on the mods you run. Some mods will replicate with some degree of accuracy what each side had and it will all depend on what year it is.

Early in the war no radar. Mid way the Americas were more advanced but by the end both sides had radar and radar detection gear so if your using your radar they could see that you were and home in on you.

All of this is is replicated by different mods and the better of them will do so at accurate time periods during game play.

The same goes for hydrophone and sonar detection.

If your surfaced and the enemy has radar at that time and your in that devices range you will be seen.

It will do you well to learn history.

Thanks but at this point i ask, will the enemy see me only when my radar is on or even when it is off?

(I'm assuming your sensors and ai equipment are stock 1.5, as shown in your intro)
They can see you using their inferior radar, but they can also detect radar transmissions in some mods. There's been quite a bit of debate over the existence and effectiveness of Japanese radar detection. But historicaly, early war is fine, the Japanese racist thinking of the time concluded they had incredibly good eyesight, so they trusted too much in lookouts, 43+ you see radar sets become more and more common. Now if we look in the .sns (sensors) files we can deduce that CO1 is radar detection, and if you go through the Japanese Escorts you can see it's marked null for them.

Running good mods will model more effectively the use of sonar and radar from all combatants. Some find the game to hard to play with realistic sensors but I find it makes for a much more challenging confrontation.



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Okay, let's check the scorecard:

Your radar is on. What do you know? You know their exact position, course and speed, and you know exactly when that changes and what their NEW course and speed are. You have the complete keys to the city.

Now, what do they know? We'll assume they have radar detection gear and they detect you. "Shazzam! There's something out there somewhere running a radar set."

Now you tell me is it's worth it to run the radar if you think you're going to be detected. The answer is HELL yes. Run that puppy ragged.

The exact situation came up when Captain Joe Enright's Archerfish (the only US submarine whose name was changed by her crew, by the way!) saw this island moving on his radar. A bright crewmember suggested he turn the radar off and Enright made the same assessment as I just made.

But he was wrong. Detecting the radar, Admiral Abe of the Shinano concluded that anyone brazen enough to run radar must be part of a vast wolfpack of submarines, so instead of maintaining his invincible straight line speed where he was untouchable, Shinano started a zig pattern--right into the jaws of Archerfish. Radar being detected was the death of the largest target ever sank in WWII.

I'd say the score is advantage submarine and you should run the thing all the time.

RR, your analysis overlooks one small but important fact. The strength of a radar signal varies inversely with the square of the distance, while the strength of the radar return varies inversely with the fourth power of the distance. Assuming that the receiver of your radar set is just as sensitive as the receiver of his detector, then he will detect your emission at four times the range at which you detect him. That's why modern radar detectors way outrange the radar sets themselves, and why modern doctrine stresses use of passive systems.

Now, it's certainly true that the USN had technically superior electronics, so the assumption of equal sensitivity is probably invalid. And a large target - like Shinano :D - would give a powerful return. But the physics is always on the side of the detector. Think of looking for someone at night using a spotlight. No matter how bright the light, he will see your light long before you can see him. When the enemy may have effective radar detection capabiliy, it is always prudent to limit your own emissions as much as possible. The Viet Nam era axiom applies: "He who lights up first, gets smoked."

I think you're right on paper except that the height of the antenna was such that maximum detection range and the horizon matched up.

So while it's possible to detect SJ-1's beams out to 50 miles or so on paper, it can only actually start picking up the top of a BB at 12 miles and vice versa due to line of sight through the surface of the ocean..

Then again, depending on how the beams bounce... I don't actually know the answer to that at all.

Antenna 33 Feet

Target Maximum Reliable Range in Yards
BB, CV, Large auxiliaries 25,000 to 30,000; 12-14NM
CA, CL, Medium auxiliaries 20,000 to 25,000; 5-12NM
DD, DE, DM, AV, PC, CG, etc. 15,000 to 18,000; 7-9NM

Source:

RADAR OPERATORS' MANUAL, RADAR BULLETIN NO. 3, (RADTHREE)

You raise a valid point. So let's look at the ol' "ship over the horizon" problem. Using the equation for radar horizon found here: http://www.rfcafe.com/references/ele...e-of-sight.htm - the radar horizon R=1.22*((emitter height)^1/2)+(rarget height height)^1/2)). If the radar emitter is 25 feet above the waterline and the detector antenna on a large target is 80 feet up (high on the mast), then the detector can sniff the emitter at 17 nm. But WW2 radar wasn't good enough to detect a ship's mast at that range - you need a more substantial piece of suprstructure to get a solid return. So let's say that superstructure starts at 50 feet above the waterline. Then the radar will get a solid return at just under 15 nm. Certainly nowhere near a 4-to-1 advantage. (1.16-to-1 actually.) But it still favors the detector.

German U-boat skippers, who faced a more technically advanced ASW opponent, often avoided using radar at all, because they felt it just broadcast their position. The US Submarine Service was never in that position. But, assuming that Japanese radar detection is modeled in SH4, or if you just want to play within historical limits, radar should be used with discretion in the later years.

EDIT: The numbers for radar performance from mercfulfate's reference seem to be in line with my Post-It note calculation.

No matter how you slice the details you know everything. They know that somewhere out there something is using something on a radar frequency. They can't see you because of your radar signal. They just know it's there.

Advantage submarine. Run it all the time. Against merchants there are no detectors at all. Against warships they can only say you're somewhere. They don't even know it's a submarine. That leaves no details worth considering. WWII submarine skippers agreed and operated accordingly, as I've already shown.

Certainly Enright did, and very successfully. But others,, IIRC, were more circumspect. I don't recall the specific references, but I remembrr a couple of first-person accounts where the possibility of alerting the enemy to the sub's presence was discussed. This would be of more concern when penetrating a harbor than in open waters. Sometimes just the fact that there is something there is more information than you want the other guy to have. And I suspect that the pros and cons of continuous search were a hot topic for discussion at the Gooneyville Lodge.

We have to bear in mind also that the enemy's capabilities in this regard were a matter of open speculation at the time. Nobody knew. And many invented boogiemen. I recall that one of the early radar-equipped boats got a pasting from escorts and the skipper was absolutely certain sure that the radar had tipped them off - long before, as we now know, the IJN even had operational radar detectors.

So you go in lit up like the Fourth of July. I'll run silent much of the time, with random aperiodic sweeps. And we will probably both be playing the game the way RL skippers historically operated.

Keep in mind it's not like you run on the surface with spotlights going and they can see where you are to shoot at you. It's like they're listening to an AM radio station and they know they're within 15 miles of a submarine somewhere. There's a difference between being all lit up like a party boat and running radar. You can turn toward the light and target on it. You can't do any such thing with the radar signal.

It's the difference between knowing a position and knowing it's somewhere in a circle of 15 miles radius. The latter is just about worthless information. It's true that you might have some sharper lookouts on duty with a sense of urgency where you might be a bit complacent if your don't know there's an enemy 15 miles away.

But it was war and there was a sense of urgency all the time. What you didn't know could and regularly did kill you. And the Japanese were masters of optical detection, especially at night.

And knowledge is not always helpful. Shinano was doing the right thing before they detected the radar signal and adjusted right into the loving arms of Archerfish. Without radar there would have been no kill. Sometimes the presence of knowing the enemy is out there but you have no idea what he's up to puts on enough pressure to force the mistake.

Leaking information in general is much less important than the character of that information and what you get in return for leaking it. Radar was the game changer for American submarines. It, more than any other factor, contributed to victory. That's why we should use it.

When Tang's radar broke, O'Kane sent a sarcastic message to Pearl that basically said "Damn, our radar is broke and now we won't sink diddly squat." He was telling the naked truth. He also said that lack of radar changed him from the hunter to the hunted.

Patton said memorably that the best way to deal with fear for your life is to make your enemy more afraid for his. My radar says "I'm here, I know all about you and you don't know squat about me until something goes BOOM!" Fear is appropriate here.

Maybe I've been dodging wasserbomben in the ATO too long! I know that the earliest Japanese radar detector was just a radio. But I assumed that later versions and shore-based models would provide bearing information, because it is so easy to do and completely mechanical. (It's just an RDF for radar frequencies.) With a bearing and rough range from signal strength, you have a crude position. That's way more information than "There's something out there."

Didn't the IJN have directional radar receivers?

"I'll run silent much of the time, with random aperiodic sweeps. And we will probably both be playing the game the way RL skippers historically operated."

Except you'll be playing like Pinky Kennedy fought and Rockin Robbins and I will be playing like Morton and O'kane.

Play it safe it you want to but unorthodox tactics in real life sunk the most tonnage.