View Full Version : Radar, Radar detection and Sonar tactics
I stopped playing DiD for a while so I could see some of the later years in the war and have finally gotten to a point where I am able to upgrade and get radar, radar detection and sonar. IIRC the radar is only good for 10degrees either side of the bow and active sonar is a fast give away of my position.
I understand why you would want radar deaction capabilities but can someone take the time to explain to me how to use the radar effectivly, why I would want to use radar, and why on earth I would want active sonar if I dont have too much to worry about enemy subs?:hmm:
Thnx in advance:D
IMHO Radar is only any good if its foggy. It means nothing can surprise you on the surface.
It may help you track down one or two lone merchants or intercept a convoy a little quicker if you pick it up on radar before you see it or hear it.
A hydrophone dive every 6 hours is far better than radar.
Early versions of radar cover +10 to -10 deg. These are almost totally useless. If you have one of these sets them turn your u-boat in a total circle every 6 hours before your hydrophone check.
Later versions cover 360 deg.
Active sonar is useful for getting accurate range measurements if you are using manual TDC and no map updates. It can give you away to the enemy so use with care.
With the radar detectors you must remember that if you are detecting enemy radar, they already know where you are.
Herr Russ
01-07-07, 07:42 PM
That's why I invested in the best hydrophones and radar detector I could.. If I run along at TC, I keep a finger on the 'c' key and hit it as soon as radar signals detected...
I found that running my IXC at 13 meters w/ the snorkel deployed, lets me pick up contacts sooner than if I was on the surface with lookouts... Unfortunately, you can't detect radar that way & sometimes the snorkel is picked up & bombed :damn:
War is hell :dead:
That's why I invested in the best hydrophones and radar detector I could.. If I run along at TC, I keep a finger on the 'c' key and hit it as soon as radar signals detected...
I found that running my IXC at 13 meters w/ the snorkel deployed, lets me pick up contacts sooner than if I was on the surface with lookouts... Unfortunately, you can't detect radar that way & sometimes the snorkel is picked up & bombed :damn:
War is hell :dead:
Put both your periscopes up, the crew will use them to look out for aircraft whilst you are not using them. :up:
The down side is that it makes your visible and radar profile bigger.
jasonsagert
01-07-07, 08:16 PM
In RL radar detection gear was capable of detecting radar signals at a long enough range that the ship emitting the signal wouldn't be capable of detecting the craft using the detection gear. This, of course, depends on the radar and the radar detection gear used.
Depending on what mod you use, this is modeled. I use GWX but I also use a radar detection mod by Steibler. I'm not sure if those changes were implimented in GWX, but I really like them and use it anyway.
I know in the stock SH3 the radar detection equiqment was really under "powered". Here is the read me from Steibler's mod:
"""""""""The U-boat radar detectors are woefully inadequate in the original SH3 package, yet are of critical importance to help avoid deadly night attacks by enemy aircraft (or by destroyers in fog). In principle, a radar detector should have at least double the range of the radar emitter, but this assumes equal technology for the Allied and German receiving equipment. In practice, the German equipment was inferior, at any rate earlier in the war and, especially, for early Naxos.
Jungman attempted a fix in July 2005, which largely solved the problem. However, his ranges for the radar detectors were incorrect, and the fix required installation of his file 'sensors.dat', which was a problem if you were using another modified version of sensors.dat provided for a different purpose. For example, all versions of RUb up to and including 1.45 lack the improved radar detectors.
Therefore, I've created this program 'radar_detection.exe' which provides (approximately) accurate ranges for the radar detectors, and can be used to modify any existing version of 'sensors.dat'. Please note: the lower your time compression, the more effective the radar detectors.
INSTALLATION:
1. Unzip the file 'radar_detection.zip' that you downloaded.
It contains the files 'radar_detection.exe' and 'radar_detection.txt' (this readme file).
2. You *must* place the -exe file in the same folder as the folder which contains 'sensors.dat'. By default, this will be in C:\program files\ubisoft\silenthunterIII\data\library\. The text file can go anywhere (best in the documentation folder, C:\program files\ubisoft\silenthunterIII\documentation).
3. Go to Windows Explorer and double click on 'radar_detection.exe'. It should run itself with a progress report. Press 'Return' to exit. The program has updated your sensors.dat file, and placed a backup copy 'sensorsoriginal.dat' in the same folder. [Note: rename 'sensorsoriginal.dat' immediately, because if you run radar_detection.exe a second time, sensorsoriginal.dat will be replaced by a copy of the modified file.]
4. If you use the JSGME utility to move modified files around, remember to use 'radar_detection.exe' on the sensors.dat file in your MODS folder, before moving them into the DATA folder with JSGME.
USAGE:
This product is provided gratis on an 'as-is' basis. No warranty is provided as to its usefulness, except that the file 'radar_detection.exe' is guaranteed to contain no code that will *deliberately* harm your computer.
THE RADAR DETECTORS:
Allied radar technology far outstripped that of the Germans, who were always struggling to keep up with new inventions.
1. FuMB1 METOX. (Introduced August 1942. Later, less crude, version called 'BALI'.)
Detected radar transmissions around the 150 cm wavelength. (BALI: 75-300 cm.)
Could detect approaching aircraft at up to 50 km range.
Original SH3: Metox range = 4(!) km. (Consequently destroyers see you before you see them, and there is no time to dive before an approaching aircraft.)
This fix: Metox range = 30 km (low value, to compensate for horizon of ship-borne radar).
2. FuMB9 WANZE-1 and WANZE-2. (Introduced summer/autumn 1943.)
By now the Allies were using low wavelength (10 cm) radars to locate U-boats, which Metox could not detect. NAXOS (see below) was intended to detect these radiations but, unfortunately for the Germans, it was very insensitive and thus had low range. Consequently, the Germans believed that the Allies were using receiver radiations from Metox to locate U-boats. This resulted in WANZE-1 and WANZE-2 being tried. WANZE-1 radiated less, and WANZE-2 hardly at all. Both effective in the 75-300 cm wavelengths.
Original SH3: WANZE is not included.
3. FuMB10 BORKUM. (Introduced late 1943)
An attempt to improve on WANZE for medium wavelengths, BORKUM itself gave no radiations at all, and consequently (from contemporary technology) had a lesser range than Metox. It could search down to 20 cm wavelengths.
Original SH3: Borkum range = 5 km.
This fix: Borkum range = 20 km.
[Note - SH3's documentation wrongly suggests that Borkum searched lower wavelengths. Is this an error in the documentation or in the implementation?]
4. FuMB7 NAXOS (Introduced June 1943. Re-introduced November 1943.)
When it became apparent that WANZE didn't help either, the original poor performance of NAXOS (ca. 8 km) was greatly improved by allowing manual rotation of a uni-directional aerial (previously a fixed multi-directional aerial). The new NAXOS searched the 9-12 cm wavelengths, with a range of up to 20 km. By November 1943, the new NAXOS was being distributed to U-boats.
Original SH3: Naxos range = 7.5 km.
This fix: Naxos range = 15 km - be careful!
5. FLIEGE. (Introduced Spring 1944.)
Much improved NAXOS. Searched wavelengths 8-12 cm, and was manually rotated by the operator, resulting in detection ranges of up to 60 km.
Original SH3: Not implemented.
6. MÜCKE. (Introduced April 1944.)
Covered the low wavelengths of 2-4 cm that would later (sic) be introduced by the Allies. Range was 40-60 km.
Original SH3: Not implemented.
7. FuMB26 TUNIS. (Introduced May 1944.)
Combining FLIEGE and MÜCKE, range was up to 70 km.
Original SH3: Tunis range = 10 km.
This fix: Tunis range = 30 km (horizon effect, for detecting warships).
8. FuMB35 ATHOS. (Introduced early 1945.)
Effectively an improved TUNIS.
Original SH3: Not implemented.
9. FuMB37 LEROS. (Introduced 1945.)
A combination of ATHOS and the earlier BALI, thus covering all radar wavelengths used by the Allies and reducing the number of aerials positioned around the U-boat.
Original SH3: Not implemented.
SWEEP-TIMES:
These have also been 'improved', in the narrow sense of having been given faster sweeps. I don't know the authentic sweep times, but late Naxos must have been slow with manual sweeping.
HOW SH3 USES THE RADAR DETECTORS:
The radar detectors are used sequentially in SH3. That is, when you install a later model, it automatically receives in addition the characteristics of ALL the older models. Do NOT attempt to install an older radar detector after installing a later version - SH3 will think that you have only the old version!
PROBLEM: I'VE INSTALLED THIS FIX AND I STILL GET ATTACKED AT NIGHT/THICK FOG WITHOUT RADAR WARNING!
Almost certainly, your radar detector has become obsolete. The Allies have started to use a new form of radar. When possible, update with the latest radar detector in base. [This problem really happened all the time during the U-boat war, leaving the U-boat crews extremely nervous about being surfaced. They never knew what might be coming next - without warning. The situation was not helped by repeated claims and counter-claims that Allied aircraft might be homing-in on U-boat radar receivers when switched on.] Another problem may be that Allied ships/aircraft are homing-in onto your active search radar, if installed. Be sure to switch off active radar when not required (use the radio officer icon).
SENSORS.CFG:
In order to provide some compensation for time compression, you might like to alter manually "Radar Warning range factor=1" to "Radar Warning range factor=2". This can be found in the file 'Data\cfg\sensors.cfg'. Note also that the effectiveness of the radar detectors depends on the crew's efficiency (or 'tiredness'). If you are playing with RUb 1.45 (latest, at this date), you might also consider changing the line "Radar Warning uses crew efficiency=true" to "Radar Warning uses crew efficiency=false". This compensates for the fact that 'stressed' crew members cannot be rested with RUb 1.45.
EXAMPLES OF ACTUAL USE (Naxos has the shortest range):
SH3 with patch 1.4b: Aircraft attack in May 1944 was detected by Naxos one game minute before the 'detection indicator' turned red, indicating that the aircraft had seen the U-boat; a further two minutes elapsed before the aircraft was in visual range (light fog). This is easily enough time in which to dive.
RUb 1.45: Naxos gave 1-2 game minutes warning of aircraft attacks in June 1944. Proximity to large convoy resulted in repeated radar detections from the convoy escorts without the U-boat being 'red-lighted' on the 'detection indicator'."""""""""
Again, I do not know if these changes were made in GWX, but this mod is compatible with any other mod (it uses a simple .exe to change the values).
J
With the radar detectors you must remember that if you are detecting enemy radar, they already know where you are.
Is that so?. Doesn't radar signal power decrease exponentially with distance, meaning that the RWRs will pick up search radar far beyond the radar's actual detection range?.
At least this is true in modern day radar-rwr. A radar signal must go to the target, rebound and then go back to ship so does a two way trip...
An active radar receiver will pick up his signal's rebound with the same strenght that a RWR will receive that signal at TWICE the distance the target is.
If a radar has a top detection range of, say, 10 miles, that means that the emissor's signal receiver is sensible enough to pick a signal which has travelled 20 miles...
So radar signals wich go further rebounding at targets beyond the detection range will be also picked by RWR...the RWR-fitted ship will know there's a radar nearby way before the radar-fitted ship knows there's another ship nearby.
Of course the best action to take if radar signals are receiver by your Uboat's RWR is to submerge ASAP and assume they have detected you to be as ready as you can be for if it's indeed the case...but detecting radar signals doesn't mean that you're detected, at least IRL...This should work the same way in SH3, isn't it?. If it isn't so, why not?.
and why on earth I would want active sonar if I dont have too much to worry about enemy subs?:hmm:
never actually used it, but I would say that this allows you to get complete TDC data for a submerged attack under periscope level. The most stealthier attack you can wish for, except for the emissions you are forced to send in order to get the needed data for an accurate shot.
With each sonar "ping" you will have a bearing,and you have a range. with the 3.15 minute rule or any of its variants, you will have speed, heading and AoB too. With just two pings. Those are all variables you need for an accurate manual TDC firing solution. And as you can open tube doors at depths under 20m, you can do it at, say, 19 metres, which gives you a nice head start for going deep after you fire the salvo at your target and so increase your chances of avoiding detection by escorts. You never use periscope either, and as scopes can be detected by radar (and this is very likely as the war goes on with centimeter wavelenght radars), that means you won't be detected this way either.
In type XXI with torpedo launches possible at much deeper depths, its even more useful.
Of course active sonar is that, active. There's a chance you give away your position by doing this. But as I see it the more latewar it is, the more likely is that they will spot your periscope with much more ease than a couple of single pings. If you know how to set manual TDCs up, this can give you an efficiency boost you wouldn't have otherwise.
I repeat that I have never actually used sonar in-game (mostly because I never reached that far in my campaigns, and also because I SUCK at manual TDC), but far for being worthless, it gives a world of advantages, at least as I see it.
Radar, on the other hand, is something I'll never fit on my submarine. Even fitting the 360º set it's suicide, IMHO (at least if you use it, and if you aren't going to use it why would you mount it on?).
That thing does send a continuous stream of E/M emissions and the allies have RWR sets, so a radar emmitting u-boat is broadcasting to everyone nearby that there's an u-boat in the neighborhood, and the general direction of it. If more than one allied escort picks the emission's signal (which is a highly likely event), they will triangulate it and then you will be broadcasting not only your presence and bearing, but also your position with a few meters of error.
Sailing with that thing switched on is sailing with a homing beacon which says "KILL ME", in capital neon-light letters. As someone else said, hydrophone detection its way better, if only because it's a passive detection tool and won't ever give your position away.
Thnx guys
Everything you said is pretty much what I thought but I really wanted to make sure I had my thought processes right. I am not using manual targeting yet so I'll pass on the sonar and I have ZERO interest in the radar. I did grab the dectection gear though . . . figured it couldnt hurt
Albrecht Von Hesse
01-07-07, 10:00 PM
Only time I have used active sonar is in very bad weather and tracking merchant-only contacts. Normally in bad weather (heavy rain, heavy fog) I just wait out the weather and don't bother trying to make attack approaches, because I can't really visually track until I'm so close I could hit them with spitballs. And when the merchants start carrying weapons that makes it even dicier.
But with active sonar I can remain submerged, and get accurate readings from far enough away to be able to manuever my fully-submerged boat with plenty of time to make a short-range intercept.
If there is an escort of any sort present, though, I never use active sonar.
VonHelsching
01-08-07, 04:19 AM
With the radar detectors you must remember that if you are detecting enemy radar, they already know where you are.
I think you meant radar nor radar warning receivers (RWRs). RWRs do not give out your position. They never did. The Germans thought they did, because of false information, and made them not use RWRs for a period during mid-war IIRC.
This action resulted undoubtably to the loss of may Uboats who were afraid of using RWRs, and therefore missing nearby planes or DDs. RWRs are a life saver both in RL and in SH3.
Von
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