Japanese Radar
 

Im starting a carrer on FOTRSU at the beginning of 1943 (January), and i have some concerns.
Most of the time i spent playing the game was on the early war (1942 specifically), but none of the saves ive really have take it seriously. So, i decided i would start a new carrer on 1943, and as the title says, i am a bit concerned about the radars (and radar detectors) on IJN escorts.
I would like to know if there is a tatic to avoid being detected by those radars (like a distance that their radars cant detect you)
Good hunting for everyone

Japanese Radar......
 

Mid 1944 and I am beginning to see evidence of Escort radar. It seems like 10-13nm is when they get a good sniff, and come running. Have been at radar depth and 7000-8000yds don't get detected. That I know of. Certainly has changed my tactics. Do we eventually get an APR radar detection system?

Part of the problem with "radar" in the game is that it is a "Class-wide" device. If you activate it on one Asashio, it is on all of them... but that is a function of the game for the most part. We can somewhat minimize that with some selective text edits and other techniques. However, the enemy HF/DF functionality seems to be part of the game itself, and radar signal detectors seem to be similar. You might notice that airplanes will sometimes make a beeline for your sub, or you might see them on your radar "bend the curve" to come attack you when your sub is definitely beyond their radar range. So the game "cheats" in this regard, but that does make up for some of the other incompetencies they accidentally created.

Some ways to somewhat mitigate the effect is to use your own radar sparingly at times, especially during daylight hours. Earlier in the war, there is no problem with radar being on continuously, but as you get into mid-1943 and later, you will see that quite a bit of the planes seem to have something guiding them directly to your location, whereas before, they might be off several degrees in their trajectory. This was one of several reasons we made the SD radar an On/Off device in FotRSU. Starting a patrol with all devices off allows you to leave the home port area easier, but once you are outside of the green circle area (if the base has it, 20-24km if not), turn the radars on for that "stray" plane or ship that might be out there. Draw yourself some 500nm circles around the Japanese air and naval bases, and that will give you a rough idea of how far out they can reach accurately. Some of the planes (H6 & 8K models) can reach much further, but those are generally single planes on patrol. When you pick-up planes on radar that are coming toward you, Crash Dive. Do not be seen. Give them 10-15 minutes to pass by and get outside of visual range, come up to radar depth and sweep, then if clear enough, surface and continue. Once you get in closer to your target area, you might consider reducing the TC used, and turning off the "continuous" on the radar. Do a few manual sweeps every 8-10 minutes, then shut if off again. This goes for both SD and SJ radar. If you have an APR (generally available around June 1944 in FotRSU), that only detects planes and ships equipped with radar, of which the Zero is not one of... so you do have to sweep as often as necessary with the SD to avoid being surprised by planes. btw, when you "transmit" a radio message, the game does "huffduff" your location, and a bit too accurately also...

Also, don't do a "direct" course anywhere when in "enemy" waters. Go east, then north, then east, then north, etc, to do a north east course. That alleviates some of the "vectoring" involved in where the game "sends" planes to when looking for you. Varying the speed somewhat also helps. You can do a little or as much of this stuff as you want. There are several areas you have to be really careful of. One is around the Shortlands, Buka and Rabaul. There are several airbases in the area, and they can triangulate your sub location rather easily, and you might end up blanketed rather heavily with planes. Similarly in some areas off the coast of the Japanese home islands. Singapore, and a few other areas are likewise rather "busy" in that regard.

The "Visual" sensor is King in the game. When you are spotted, the area can be saturated with "hunters". You can have that happen with a sampan encounter, but it can also happen during / after a torpedo attack, where if you do not vacate the immediate area of attack, you will have at least a plane presence, and sometimes the local harbor protection ship(s), or an HK Group comes out to find you. This all gets more accurate as time progresses. :salute:

PS: In testing the other day, I have noticed that once your submarine has the APR-1 radar signal detector installed, there can be a HUGE performance hit when coming near locations with a lot of ships with radar, especially coming into an Allied base. So much so, that an approach in 1943 at 256xTC was fine, when later 1944 rolls around, you might have to do 64x or 32x max TC to get into port. Reminds me of the old SD radar issue in TMO... we are lookng for a solution, other than emptying the conning tower of personnel when approaching home (which does work)...

Thanks for all the answers!
:Kaleun_Salute:

I am guessing (like most things about the game) that it is because it is passive. Nothing "active" about it. What I did the other day when testing, was to remove the crew from the conning tower, and there is no longer anyone to man the sonar and radar station then. You still see the "lines" on the NavMap, but not all of the voice and time interruptions. The framerate improved also, from not having to track all the "Radar signals detected. Bearing: 356" etc... lol


long-winded, but you are definitely welcome! :salute:

Now, the US devices were passive. Some of the German devices were active... they could detect radar of a given wavelength out to say 8nm, but by then, the Ally's radar was a smaller length, and could see 15nm... that kind of thang... :o

So we must turn off both SD and SJ to avoid active emissions?Are both radars detectable?

In FotRSU, yes you do. In most other mods and stock, you cannot turn-off the SD unless you submerge... However, going by your question, I would be willing to bet that this has not adversely affected your patrols too often... lol - Primary goal is to sink ships. In conducting said goal, number one chore is to not be seen. To minimize that risk, you use radar. However, the enemy can home in on your radar signal, just like they can the radio signals, so if you want to do things the "realistic" manner, you use 1x TC like Front Runner does, and then sparingly use your radars, such that you are aware of your surroundings, but not having a contact "beacon" sounding... Myself, I only do the intermittent stuff occasionally, else you would be out there on the boat for four years... :o :salute:

Thanks propbeanie.
My strategy is to always use both radars on but I wasn't sure which of the two are detectable when operating. However I don't mind very much about my emissions, although there are annoying situations where enemy planes constantly fly towards my sub due to that reason.In that case maybe I switch off both.

Basically the same way I do it usually. I only get "detailed" about it when I can't get things accomplished the "keep it on all the time" approach. Just so long as you are not seen, then you usually won't be completely swamped by planes - except in some of those "hot" areas.