Sonar and radar usage

[Fader_Berg]

Is it safe to use radar to spot ships, or will it just be a call for trouble? I've just merely survived an air raid in the atlantic. (Some new yellow planes, [yes, I'm new to this] which are terrifying compared to the ones around the british islands). I realy don't want to call their attention. But the atlantic is big and a sight of <=~7000 meters, practically means nothing.

I guess sonar shouldn't be used against destroyers. But how good is the precision of it, (by length to target)? Is it closer to truth than the WO? Is it only usefull in bad weather, and so on? How many pings? Does the target notice it?

How are you all using these things?

[tomfon]

In my opinion radar doesn't help much for two reasons. First, destroyers and aircrafts can and will detect you. This means trouble for your Uboat and your crew... Second, i am not so sure about its effectiveness. In fact, i believe it can detect sh!t! By the time you start using the radar the Allied A/W will be quite effective. I think that using the hydrophone to detect a ship or a convoy underwater is much, much better cause you can maintain your stealthiness. Not to mention that the early radar versions - at least, have shorter range than the hydrophones. So, why take the risk of being detected by an airplane while hunting a convoy? Last, don't use the sonar to ping destroyers and don't use it to ping merchants which sail within a convoy. Unfortunately i don't know more details.

[Jimbuna]

Your radar will be detected (when turned on) by sea and air assetts.

Your sonar will not.

[Rafael]

I suggest to avoid using radar. My experience is quite bad for you and your crew. The radar range is too short and I agree with Tomfon, use your hydrophones submerged!

BdU should learn me that at school and inform me better about our bad radar system.

[PavelKirilovich]

German radars get a bad rap during WWII for some reason. They had some systems which were quite good by the standards of the time and other systems on par with Allied and Soviet technology. And of course, a few subpar systems. The problem is not so much the technology fitted to the boat, as the platform to which the technology is fitted.

The radar horizon is pretty limited from a U-boat. You've only got the emitter a few metres above the ocean's surface and the emitter is space-constrained, the number of transmit and receive modules that can be fitted to the array is limited by the need to field a compact system. Power aperture and power aperture product is thus limited; but peak power was reasonable. The Germans did pretty well with this set, the key problem is what I mentioned earlier, it's only a few metres above the water.

The reason we see radars and lookouts stationed on the highest points of a ship is to artificially increase the distance to the horizon. It's a trigonometry thing. The higher a radar, the further it can see because geography (earth curvature) doesn't prohibit the signal from propagating back to the receivers. However, the enemy's radar warning receivers and direction finders only need to detect the signal, whereas we need to send a signal out AND get it back. Sod's law applies: the more **** you need to do, the less likely all of it is going to get done.

So what the radar does for you, in effect, is act as a "I'm over here" beacon to enemy ASW efforts. You want to run under full emissions control. Manually check every time you surface to make sure the radar operator/radio operator isn't running the radar of his own initiative. Nothing is more painful than being bounced by a hunter-killer group when your batteries badly needed a recharge and your CO2 levels are dangerously high.

It's OK to ping capitol ships with your sonar. It's not OK to ping ASW vessels with your sonar. Capitol ships are escorted by ASW vessels. The reason it's OK to ping the big gun big tonnage targets is because we don't have good shock dampening systems, sonars weren't typically fitted to large gun combatants because of space constraints and shock damage that would be caused by the gun's recoil to the system. Same reason full broadsides aren't fired: they'll shake the boat apart.

[Bosje]

in my experience, radar is only useful in zero visibility conditions, when you know that a single merchant is out there somewhere in the rain and fog but you can't see a thing

of course, those conditions often come with 15 m/s winds which means the early crappy radar gets switched off every time the boat takes a plunge in the waves.

and unless i'm wrong, in real life those conditions were regarded as too terrible for attack operations

Originally Posted by PavelKirilovich

German radars get a bad rap during WWII for some reason. They had some systems which were quite good by the standards of the time and other systems on par with Allied and Soviet technology. And of course, a few subpar systems. The problem is not so much the technology fitted to the boat, as the platform to which the technology is fitted.

The radar horizon is pretty limited from a U-boat. You've only got the emitter a few metres above the ocean's surface and the emitter is space-constrained, the number of transmit and receive modules that can be fitted to the array is limited by the need to field a compact system. Power aperture and power aperture product is thus limited; but peak power was reasonable. The Germans did pretty well with this set, the key problem is what I mentioned earlier, it's only a few metres above the water.

The reason we see radars and lookouts stationed on the highest points of a ship is to artificially increase the distance to the horizon. It's a trigonometry thing. The higher a radar, the further it can see because geography (earth curvature) doesn't prohibit the signal from propagating back to the receivers. However, the enemy's radar warning receivers and direction finders only need to detect the signal, whereas we need to send a signal out AND get it back. Sod's law applies: the more **** you need to do, the less likely all of it is going to get done.

So what the radar does for you, in effect, is act as a "I'm over here" beacon to enemy ASW efforts. You want to run under full emissions control. Manually check every time you surface to make sure the radar operator/radio operator isn't running the radar of his own initiative. Nothing is more painful than being bounced by a hunter-killer group when your batteries badly needed a recharge and your CO2 levels are dangerously high.

It's OK to ping capitol ships with your sonar. It's not OK to ping ASW vessels with your sonar. Capitol ships are escorted by ASW vessels. The reason it's OK to ping the big gun big tonnage targets is because we don't have good shock dampening systems, sonars weren't typically fitted to large gun combatants because of space constraints and shock damage that would be caused by the gun's recoil to the system. Same reason full broadsides aren't fired: they'll shake the boat apart.

Yes, I agree with everything you said here. But as far as I know in SH3 you can't be detected if you use a sonar to get target range or echolot to measure the depth what I realy find a big lack in realism..

Speaking about detection of noises underwater by DD's. There are couple more old issues which I find odd and unrealistic. The playing gramaphone can't be detected by ASW vessels and I think ASW vessels should be able to hear incoming torpedo sound at least in calm sea state ?