Sonobuoys

[Christophertar]

I was on a track and destroy mission in the Orion, hunting Akula class subs off Japan. Dropped VLAD buoys, eventually got a hot one, and dropped some DIFAR's around the hot VLAD, about two to three miles out from it. That was when my problem started. The DIFAR's detected nothing, so dropped some DICASS', put them on active, and waited some more. Alas, still nothing, so dropped a further two VLAD's haphazardly on the assumed route of the sub to south. Eventually picked it, and finally got a contact from my active DICASS buoys. All of this was done shallow, albeit depth was available to the skurvy submariner. This leads me to believe that the best buoys are the VLAD, which I understand, but to get triangulation from them is difficult, but a lot easier than the DIFAR's, and also the DICASS bouys. Am I correct in saying this? Should I load up more VLADS on my ops? Also, the contact that I eventually picked up on the active DICASS looked like a shrimp, but when I marked and tracked it, it was indeed the Akula. Is it supposed to be such a small blip on the waterfall? Am I doing something wrong here? :confused:

[OneShot]

I suggest you look for and download the P-3 OWTOP, either here at the CADC or SubGuru.

Some reasons why you had trouble might be because the sub was under the layer while most of your buoys were above. Given that you only used shallow buoys then it would have been like this :

- VLAD (Shallow) 600ft
- DIFAR (Shallow) 90ft
- DICASS (Shallow) 90ft

Lets assume a layer at 300-400ft ... and bingo, only VLADs will pick the contact up. Anyway, get the manual, I explained this stuff a lot better in there.

Cheers
OS

[Christophertar]

And I thought I knew what I was doing!!! :gdamnit: I see your point, I cannot recall what the layer was at, so I assume I overlooked it in the heat of the moment.

Will do and thanks!

[Christophertar]

Another quick question, and I know I have read it somewhere, but my wife keeps hiding all of my data, so struggling to find it. How far apart should you be placing these buoys? And also, how do I judge the distance using the waypoints or what other tools are there?

Sorry scratch that, I have found wot I am looking for in the P3C Manual. Thanks One Shot.

[Molon Labe]

This leads me to believe that the best buoys are the VLAD, which I understand, but to get triangulation from them is difficult, but a lot easier than the DIFAR's, and also the DICASS bouys. Am I correct in saying this? Should I load up more VLADS on my ops? Also, the contact that I eventually picked up on the active DICASS looked like a shrimp, but when I marked and tracked it, it was indeed the Akula. Is it supposed to be such a small blip on the waterfall? Am I doing something wrong here? :confused:

VLADs perform much better than DIFARs. I've noticed that a shallow VLAD below the layer will detect a submarine above the layer at a greater distance than a shallow DIFAR above the layer. Maybe this is due to higher noise levels in the surface chop at 90ft. Anyone want to see if a deep DIFAR (400ft) does any better?

As for active returns, the size of the return is determined by the aspect of the contact. A sub facing towards or away from you will present a very small return.

[Christophertar]

:smile: Ok, the VLADS rule, no doubt, and I find that the shallow ones are suitable for most scenarios, even when there is deep water. I carry far more VLADS now and then DICASS. I am beginning not to want to have DIFAR on my Ship anymore. Maybe I have been using them wrong, but I seem to get nothing out of them! Maybe in an MP game, against an opponent who can think, I will be proved wrong on this one. Is there no way of turning the ability of the AI up, so that they react more aggresively/realistically?
Was on a routine box area search for Akula off east coast of Taiwan when a surface craft was picked up as hostile from Intelligence. Was told to track and only engage when craft moved within 3 miles of the island. I duly tracked for half an hour taking in the scenery of Taiwan, and as soon as the dastardly villain had entered the three mile mark attempted to ice him with a Maverick. However, I was informed that my mission was failed. I assume therefore that I was supposed to cap the SOB BEFORE he entered the three mile zone. :cussing: Also there are two surface craft with the same markings, so how would you know which is the villain unless he entered the killing zone? :gdamnit:
Ah well, the P3 is getting easier!:biggrin:

[IotaSigma]

A VLAD buoy is a vertical array of DIFAR hydrophones and really is superior to the DIFAR buoy.

This is from fas.org:

"There are many types of sonobuoys, depending on their capabilties:

DICASS: directional command activated sonobuoy system. Active system which transmits pulses when commanded by the aircraft.

DIFAR: direction finding acoustic receiver. This is a passive system, with some directionality achieved by a small hydrophone array.

VLAD: vertical thin-line array. A linear, vertical array of DIFAR hydrophones. Has improved directionality in vertical direction. Reduces noise from surface.

Most sonobuoys can operate at several preset depth settings. The shallow setting is used for surface duct propagation, and the deep for sound channel propagation.

Sonobuoys have poor values of directivity index, mostly because of their limited size. Figure-of-merit is not always low, however, because sonobuoys also have very low self-noise. Depending on the environment, and whether or not self-noise is dominant, sonobuoys can actually outperform some larger hull-mounted systems."

http://www.fas.org/man/dod-101/navy/docs/es310/asw_sys/asw_sys.htm

[Christophertar]

So the superior buoys are then the VLAD's, followed by the DICASS? If that is the case, I assume that in the real world, the VLAD's are more costly than the others? I am no longer using the DIFAR's, and load as many VLAD's as I possibly can with about half being DICASS. This is obviously not the real way to do it, right? I suppose I am costing your Uncle Sam a pretty penny, but it works better for me this way. :smile:

[OneShot]

Well, if you'd be flying in a real squadron and dropping VLADs and especially DICASS all over you would become very familiar with your squadron boss real soon. The most expensive buoys are DICASS followed by VLAD and DIFAR. Cheapest ones are the LOFAR buoys (which cant be loaded on player planes anyway).

If you wanna go for realism (at least a bit) then you should carry (depending on your AO) a good mix of both DIFAR and VLAD with some DICASS for direct prosecution. This would be a loadout for a mission which has both shallow and deep water. If you operate solely in Shallow water there is no use for VLAD (so toss them from the loadout), same goes for Deep water, tho in this case you might take a few shallow/deep DIFARS to be able to operate passively above the layer.

I use DICASS only when I have a contact established on passive (that is VLAD/DIFAR/MAD) and want to go for the kill, in that case I will usually drop a DICASS on the last MAD run, line up and to refine my solution I'll use DICASS (that is especially useful when attacking head on).

But well, thats just me.

[Molon Labe]

Role-playing aside, the VLAD can't get into the shallow water, but DIFAR can. DICASS is mainly used for active detection, so it doesn't even belong next to DIFAR and VLAD. Apples and oranges.

[Christophertar]

Thanks Guys. I have moved onto the FFG in the Red Storm Rising campaign, and am very disappointed with it for a number of reasons. Mostly tho, is the use of its sonobuoys - what is the range that you can still pick up a signal from a buoy without the Helo in the area? And also, can someone explain to me why it takes so long to launch the Helo - does that simulate the real world also? Anyway, apart from that, which is the best way to defend a convoy from both air and sub threats with this machine? I lay out buoys on my side of the convoy whilst waiting for the chopper to get airborne, but it takes far to long. Is there a manual on tactics for use with the FFG?

[Molon Labe]

Thanks Guys. I have moved onto the FFG in the Red Storm Rising campaign, and am very disappointed with it for a number of reasons. Mostly tho, is the use of its sonobuoys - what is the range that you can still pick up a signal from a buoy without the Helo in the area? And also, can someone explain to me why it takes so long to launch the Helo - does that simulate the real world also? Anyway, apart from that, which is the best way to defend a convoy from both air and sub threats with this machine? I lay out buoys on my side of the convoy whilst waiting for the chopper to get airborne, but it takes far to long. Is there a manual on tactics for use with the FFG?

I'd assume that the range you can communicate with a buoy w/o a helo corresponds to the height of the FFG's receiving antenna and the horizon. I don't know exactly what that gets you, but it's not far, and it appears to be modeled accurately.

As for the time to launch the helo, I'm going to be a jerk on this one. This is answered in the manual in a section that is not the least bit difficult to find. Do your homework, RTFM, and if you're still confused after that go ahead and come back.

Moving onto tactics, there is a guide written by MuHaJa. You can get it here: http://www.subguru.com/downloads.html. I'm not an expert at FFG tactics, but I can give you a few of my own pointers...

Defending a convoy against air threats in the FFG is mostly a question of position and the performance of your SAMs. It's important to be in position to deploy the SM-2, which means either being out away from the convoy in the direction of the expected attack, or, if the direction of attack is unknown, as close to the convoy as possible. From that point, its just a matter of getting the missiles off as fast as you can, which is admittedly hard. If you're dealing with supersonic missiles, the performance of the SM-2 is rather poor, and you might actually have better success by getting in the path of the missiles and having them home on you, so that you can spoof them with chaff. Chaff is more effective with the LW/Ami mod, by the way, with stock, you're not going to get far with this. In the end, the truth of the matter is that the FFG is not an air defense ship and isn't going to perform the role well.

In the context of RSR, for the most part you aren't thrown anything that can't be handled. The trouble will come if you botch Polar Glory. The consequence of poor performance there will be for Riposte to be damn near impossible.

ASW defense is about covering as much area from which an attack could come as quickly as possible. For the most part this means getting the helo out in front of the fleet to catch slow, quiet subs in the path of the convoy with active buoys or the dipper (with LW/Ami installed), getting buoys out on the flanks to catch subs flanking the convoy, and to use your own TA to detect subs moving at high speed from the rear quarter if the convoy is moving slowly enough to be attacked from behind. It's also usually a good idea to keep the FFG slightly in front of the target ships in a position to use the active sonar as point defense--but you always want to deal with subs at arms length, given the choice.

[OneShot]

The up-to-date version of MaHuJa's Manual can be found in the DW Wiki (Link in the navbar of the forum), which is preferable over the rather old PDF file.

Cheers
OS