Tracking Active Sonar Contacts

[matt30]

There are times when I am trailing a surface ship but I occasionally lose passive tracking because I need to speed up. Most of the time warships have active sonar on 24/7 but the minimap doesn't display the approx. location of the track (but I do see yellow bearing lines). Is this intended behavior? Shouldn't the contact remain on TMA?

Second question, does this apply to the AI as well? If I use active sonar, does the AI still have to work to get a firing solution or does the AI automatically know my accurate location?

This is most apparent when using the 1968 subs that have much worse sensors.

[Capt Jack Harkness]

I think it is intended behavior, yes. Better tracking of active intercepts is an idea that's been raised but I don't think the devs have reached a conclusion on if or how to implement.

As for AI, they get an accurate bearing from your ping and will typically send a torpedo down that bearing as soon as they hear it, I don't think they get anything more specific than that.

[Destex]

The funny thing is, you get TMA solutions with ESM, which has much lower bearing accuracy, while you don't with active sonar intercept. That's exactly the opposite in real life.

[Shadriss]

The funny thing is, you get TMA solutions with ESM, which has much lower bearing accuracy, while you don't with active sonar intercept. That's exactly the opposite in real life.

Depends on the ESM package and a number of other things.

Active Intercept can only do so much - making it's bearings into a solution takes time, but no more so than passive bearings from the SA, so I do agree it should be being used for TMA purposes. Ranging data, maybe not so much.

[Destex]

Depends on the ESM package and a number of other things.

I will be very surprised to find out that any submarine ESM mast can produce a bearing accuracy that can be a basis for TMA computation.

[Shadriss]

I will be very surprised to find out that any submarine ESM mast can produce a bearing accuracy that can be a basis for TMA computation.

Be surprised. As I said - it depends on the package.

[Aktungbby]

matt30!:Kaleun_Salute: Nice OP question after a 3 year silent run!

[Destex]

Be surprised. As I said - it depends on the package.

Interesting. A submarine ESM mast? What accuracy are we talking about?

And regarding the era of CW, I don't suppose any western Submarine had something like that in the 80's (ESM accurate enough for an accurate TMA solution)?

[The Bandit]

Interesting. A submarine ESM mast? What accuracy are we talking about?

And regarding the era of CW, I don't suppose any western Submarine had something like that in the 80's?

Depending on your definition of it you could argue that ESM has been a thing since they had radar detectors at the end of WW2.

This is just supposition on my part but I would guess for an ESM mast, bearing would probably be pretty important as well as some type of analyzer to gauge signal strength and probably give you some idea of detection values i.e. if whatever is bouncing these radio signals off of you is getting a strong enough return back to have pin-pointed your location. I'd say all that would come before actually being able to figure out an exact location where emissions are coming from.

[Destex]

Depending on your definition of it you could argue that ESM has been a thing since they had radar detectors at the end of WW2.

I think you read my reply out of context. It's clear that ESM systems existed well before the Cold War. However, my question was in reply to Shadriss, and was about the bearing accuracy of such systems and whether it was sufficient to base TMA solutions on them.

[PL_Harpoon]

I'm far from being an expert here, but aircraft RWR can give an accurate bearing. I'm sure ECM systems on submarines is even more sophisticated.

[ollie1983]

ESM would be enough to get a bearing if nothing else I assume? Perhaps with two sensors on the same mast, you could use the geometry to get a range estimate but it would not be hugely accurate.

[PL_Harpoon]

I think that the most important aspect of ECM signal apart from bearing is the signal strength. Sure, it won't tell you the exact range but it can help.

[Wiz33]

I think you read my reply out of context. It's clear that ESM systems existed well before the Cold War. However, my question was in reply to Shadriss, and was about the bearing accuracy of such systems and whether it was sufficient to base TMA solutions on them.

ESM should give you more information than is currently available in game. Not only will it give you a pretty precise bearing, it should tell you what kind of radar it is (base on frequency and pulse rate and other info) which would allow you to narrow if not nail the exact platform, and once you have that info, you can estimate range based on the signal strength.

You can get the bearing and narrow or ID any platform using active sonar the same way. Range however will be much harder and it would depends a lot on the strength of the surface duct, the strength and depth of the layer, your depth and a bunch of other things.

[Destex]

ESM should give you more information than is currently available in game. Not only will it give you a pretty precise bearing, it should tell you what kind of radar it is (base on frequency and pulse rate and other info) which would allow you to narrow if not nail the exact platform, and once you have that info, you can estimate range based on the signal strength.

You can get the bearing and narrow or ID any platform using active sonar the same way. Range however will be much harder and it would depends a lot on the strength of the surface duct, the strength and depth of the layer, your depth and a bunch of other things.
All true, I should know as I operated one on a sub :Kaleun_Salute:
However, I doubt that you could find a submarine ESM mast in the cold war era that gave a bearing accuracy that could be used for TMA analysis. TMA requires accurate bearing measurements, and a sub mast ESM bearing accuracy cannot provide that. I doubt that in the Cold War there were ESM masts that could provide an accuracy better than 5 degrees and I'm being generous. With 5 degrees variation you simply cannot do effective TMA. Sure you can very roughly assess the range based on the received intensity level, but that's very susceptible to all kinds of environmental variables. You could also determine very rough courses or maximum ranges based on the bearing variation over a long periods of times but that's barely meet what we usually refer to here as a firing solution TMA.

[stormrider_sp]

Interesting. A submarine ESM mast? What accuracy are we talking about?

And regarding the era of CW, I don't suppose any western Submarine had something like that in the 80's (ESM accurate enough for an accurate TMA solution)?

Its difficult to know when everything is classified and most specifically, in all the secrecy surrounding sub based SIGINT, but one can also be very sure that LOTS of dollars were invested in those specific equipments, so I wouldnt be surprise to discover that it was possible to produce an accurate TMA with it, even in the early '70s.

[Destex]

Its difficult to know when everything is classified and most specifically, in all the secrecy surrounding sub based SIGINT, but one can also be very sure that LOTS of dollars were invested in those specific equipments, so I wouldnt be surprise to discover that it was possible to produce an accurate TMA with it, even in the early '70s.

No amount of dollars can defy the laws of physics. After all, the size of an antenna plays an essential part in measuring bearing to an emitter source. A problem when you have small sized mast.

[The Bandit]

A problem when you have small sized mast.

I wouldn't know anything about that......just sayin'

[Shadriss]

Sorry for the late reply - been busy. Without going into things I can't, let me refine my original answer.

In terms of today's subs, it's possible. In terms of CW era subs, possible, but difficult. It could be done, but passive sonar would be a far better tool to make use of.

Also, in reply to the comment about Signal Strength being an indicator of range, I know a few people who have been involved in collisions who would argue against that.

[stormrider_sp]

No amount of dollars can defy the laws of physics. After all, the size of an antenna plays an essential part in measuring bearing to an emitter source. A problem when you have small sized mast.

If you say so, I have no reason no reason to doubt.
How about with the WLR-9 acoustic receiver. Although its not linked to the Bsy-1, as its said, can you get accurate bearings for a TMA?

[Shadriss]

If you say so, I have no reason no reason to doubt.
How about with the WLR-9 acoustic receiver. Although its not linked to the Bsy-1, as its said, can you get accurate bearings for a TMA?

Imma step in here before someone else does. The WLR-9 is still used in US warships, and it's capabilities and design remain classified. For now, you're gonna have to just wonder.

[stormrider_sp]

Imma step in here before someone else does. The WLR-9 is still used in US warships, and it's capabilities and design remain classified. For now, you're gonna have to just wonder.

Thanks and then, well, please...

Quote:
Originally Posted by shipkiller1 View Post
Shadriss, I hope you got as big a laugh on this proverbial BULL**** has I did... What a load of crap...
Oh, yes. Yes indeed. It's just right enough to deceive the folks who know nothing, and wrong enough to completely screw you over entirely.

...don't laugh of us folks who don't know nothing; everything is classified.

If I may, I'd especulate that the WLR-9 is capable of providing data for accurate TMA. I'm not sure if it can receive data from all the sensors in the boat, but for example, if it could merge data from both the towed array and the bow sonar, than, theorically, it could be possible to triangulate the emitter position after a single ping and have a weapon on it straight after. If not, I wouldnt doubt either that by knowing the emitter frequency, one could generate a good range estimate via doppler shift, which would help explain the need for so much SIGINT in peace time sub operations. Other than that, I'm pretty sure that if there's someone assigned to handling the WLR-9 console, he could at least, with paper and pen, create a basic but accurate geographical/time bearing rate plot, or at least yell the bearings to someone else in the control room to do it.

[Destex]

if it could merge data from both the towed array and the bow sonar, than, theorically, it could be possible to triangulate the emitter position after a single ping and have a weapon on it straight after.
Only if the bearing accuracy of the ESM is sufficient. Try to triangulate with a bearing error of 5% and you get pretty serious error that inflate over range, even if you triangulate it with a very accurate sonar bearing.

[Shadriss]

Thanks and then, well, please...



...don't laugh of us folks who don't know nothing; everything is classified.

Don't take that out of context. That was in reference to the TMA instructions of Fast Attack, IIRC, and had nothing to do with this discussion. The laughter involved there was in how badly those instructions were written, and how far off the mark they would be if taken as written, not at any player of this game or frequenters of this forum.

I appreciate your position, but let's not compare apples to oranges in this way, hmmm?

[TigerDude]

WLR-9 active intercept bearings and ESM mast bearings would be put on the paper plot to aid in the analysis. We don't have a paper plot visible, so just assume those smart worker bees are using it in a good way.

Would ESM bearings give a workable solution? Who knows, no one in the fleet would leave an ESM mast up long enough to find out, so no one would care.

[PL_Harpoon]

WLR-9 active intercept bearings and ESM mast bearings would be put on the paper plot to aid in the analysis. We don't have a paper plot visible, so just assume those smart worker bees are using it in a good way.

That's what they do ATM if you have another source for contact.
The problem is, they don't do that if active intercept is the only source of target's bearing.

[Mob1us0ne]

I'm far from being an expert here, but aircraft RWR can give an accurate bearing. I'm sure ECM systems on submarines is even more sophisticated.

Also, in reply to the comment about Signal Strength being an indicator of range, I know a few people who have been involved in collisions who would argue against that.

I'm a former USAF ECM troop and can confirm the bit about accurate bearings from RWR and I'm sure the RX mode on a sub or sea based ESM mast uses the same method of operation. Bearing info is highly accurate, it has to be as the operator needs to inform the vehicle commander threat direction for evasion.

Using single strength for range info is very dicey. As a general rule the processors can estimate range, but even on our TSF display (tactical situation format, B-1 version of RWR) there's only three rings: close, mid, and far. But they really mean low, mid, and high signal strength as it's mainly for threat prioritization.

Does that make sense? I talk a of jargon

[PL_Harpoon]

I'm a former USAF ECM troop and can confirm the bit about accurate bearings from RWR and I'm sure the RX mode on a sub or sea based ESM mast uses the same method of operation. Bearing info is highly accurate, it has to be as the operator needs to inform the vehicle commander threat direction for evasion.

Using single strength for range info is very dicey. As a general rule the processors can estimate range, but even on our TSF display (tactical situation format, B-1 version of RWR) there's only three rings: close, mid, and far. But they really mean low, mid, and high signal strength as it's mainly for threat prioritization.

Does that make sense? I talk a of jargon

I guess the problem is that a sub is using a single antenna. Am I right in saying that an aircraft have multiple RWR antennas scattered in different places and so it is easier to get an accurate bearing?

[Mob1us0ne]

I guess the problem is that a sub is using a single antenna. Am I right in saying that an aircraft have multiple RWR antennas scattered in different places and so it is easier to get an accurate bearing?

Those antennas are actually rather small. I don't know this for a fact (and I'm sure of the Navy vets here could confirm, though probably unable to) you could easily place those types of antennas on a mast. In fact as an ECM guy the near perfect 360 degree search area you get from that is pretty much.

BTW. I hope I'm not stepping on any toes as a newbie here. I've been lurking here for a long time because I love sub stuff and have dabbled with subsims. Though honestly most have been a tad over my head besides RSR. And I don't have the game yet but it seems more up my alley. So yeah, hello!

[Capt Jack Harkness]

I guess the problem is that a sub is using a single antenna. Am I right in saying that an aircraft have multiple RWR antennas scattered in different places and so it is easier to get an accurate bearing?
Newer planes, sure. Older systems could only tell you the quadrant.

[Destex]

I'm a former USAF ECM troop and can confirm the bit about accurate bearings from RWR and I'm sure the RX mode on a sub or sea based ESM mast uses the same method of operation. Bearing info is highly accurate, it has to be as the operator needs to inform the vehicle commander threat direction for evasion.




Hi Mob1us0ne, and welcome.
No one claimed it's not possible to analyze accurate bearing to electromagnetic transmissions. However, Ground or aerial ECM systems are not relevant as the technological challenge in a submarine is different.

First, as Harpoon says, there's a single mast.
Second, that mast is small and can't contain a lot of nodes which are necessary for signal strength interpolation - the basis of bearing measurement. As much as the nodes are fewer and smaller the bearing analysis is less accurate.

Aerial systems have the luxury of size, number of nodes and different locations on a rather large body in comparison. Try to cram all that into a tiny tiny sub mast, there will be several compromises, bearing accuracy being the first casualty. Also, on aircraft the fast self movement can be used to some extent (just a theory, I don't know for sure if indeed it is), another aspect lacking in submarines.

Therefore, at least up to the 80's if not later than that, submarine ESM systems could not provide accurate enough bearing measurements that can be used for reliable passive TMA calculations.

[Mob1us0ne]

Hi Mob1us0ne, and welcome.
No one claimed it's not possible to analyze accurate bearing to electromagnetic transmissions. However, Ground or aerial ECM systems are not relevant as the technological challenge in a submarine is different.

First, as Harpoon says, there's a single mast.
Second, that mast is small and can't contain a lot of nodes which are necessary for signal strength interpolation - the basis of bearing measurement. As much as the nodes are fewer and smaller the bearing analysis is less accurate.

Aerial systems have the luxury of size, number of nodes and different locations on a rather large body in comparison. Try to cram all that into a tiny tiny sub mast, there will be several compromises, bearing accuracy being the first casualty. Also, on aircraft the fast self movement can be used to some extent (just a theory, I don't know for sure if indeed it is), another aspect lacking in submarines.

Therefore, at least up to the 80's if not later than that, submarine ESM systems could not provide accurate enough bearing measurements that can be used for reliable passive TMA calculations.

Ok, Yeah that makes a lot sense. Like I said, I'm a zoomie not a navy guy and mind is geared to the clouds lol

[Shadriss]

...
Second, that mast is small and can't contain a lot of nodes which are necessary for signal strength interpolation - the basis of bearing measurement. As much as the nodes are fewer and smaller the bearing analysis is less accurate.

You're mixing things up there. Signal Strength is NOT an indication of bearing... it's an indication of how strong the signal is compared to background. Kind of a Radio version of Sonar's SNR values. You can have an extremely low SS and still get very accurate bearings. What SS will NOT give you is a range estimate. As I hinted at, there have been a few collisions at sea that were caused, in part, by operators assuming that lower SS equated to more distant contacts, that that is not always a true statement.

Now, needing multiple receptors for bearing accuracy is a true thing - that's basic beamforming, and those principles work the same way for radio and sound waves. So, going back to some of my earlier comments on this, depending on the ESM suite and equipment installed, bearings can be taken from the system with some degree of accuracy.

[Destex]

You're mixing things up there. Signal Strength is NOT an indication of bearing... it's an indication of how strong the signal is compared to background. Kind of a Radio version of Sonar's SNR values.
I never wrote that SN is an indication of strength. However, the way bearing is analyzed in at least a large portion of naval ESM systems is by calculating the different strengths on the different antenna nodes, and interpolating the bearing. There might be other methods for bearing analysis, but the process I described is definitely in use.


What SS will NOT give you is a range estimate.
Definitely true. I'm not sure what I wrote that gave you the impression.


depending on the ESM suite and equipment installed, bearings can be taken from the system with some degree of accuracy.
In the Cold War era? Enough for TMA?

[Shadriss]

Definitely true. I'm not sure what I wrote that gave you the impression.

Misread what I quoted. My mistake.

In the Cold War era? Enough for TMA?

A lot of ships are still plowing around with tech and systems from that era. It would be a pain, and would involve a bit more mast exposure than most skippers would be comfortable with, but yes, it could be done. But as I also noted, it would be far easier and safer (for the ship) to just use PBB and PNB instead.

[Destex]

it would be far easier and safer (for the ship) to just use PBB and PNB instead.
That's for sure. In the context of Cold Waters gameplay, do you think that tracking ESM contacts should contribute to TMA solutions?

Personally, I would rather have ESM tracks to provide classification (ignoring that in real life different platforms might use the same radars for the sake of simplicity), and active intercept tracks to create targets that can be TMAed (slowly, unless tracked by a passive Sonar array).

[The Bandit]

That's for sure. In the context of Cold Waters gameplay, do you think that tracking ESM contacts should contribute to TMA solutions?

Personally, I would rather have ESM tracks to provide classification (ignoring that in real life different platforms might use the same radars for the sake of simplicity), and active intercept tracks to create targets that can be TMAed (slowly, unless tracked by a passive Sonar array).

Well I'd suggest the same way it was done in SC / Dangerous Waters (don't really mean the classification part but that would be nice).

What I'm talking about is, when you get either an active intercept return or an ESM contact with a lot of uncertainty a contact is placed on the map at an arbitrary position (say 10 miles out?) with a NIL listed range (in other words when you click on it, instead of saying 5.5k yards, it has a NIL/Unknown value for range, letting you know the range is not known and its not necessarily where its marked on the map, other than along that approximate bearing, so you get some visualization as to the number of contacts you have out there).

My (admittedly limited) understanding of both ESM (with the obvious exception of its reconnaissance / information gathering value) and Active Intercept is that both of these exist as warning systems first and foremost (something is pinging / radiating somewhere off to the NE of us) than they are a means for classifying (obviously they can do this and probably pretty well) or even localizing a contact.

[Shadriss]

In the context of Cold Waters gameplay, do you think that tracking ESM contacts should contribute to TMA solutions?

Yes, but in specific circumstances. It is possible in the game to have ESM contact with a SAG, but not yet have gained them passively. In such a case, having at least a bearing is useful. I wouldn't want them to contribute in the same way Sonar does, but if you are willing to keep your masts out of the water that long, I'd be ok with a very slow TMA build over time. Very slow. Think glacial drift.

Personally, I would rather have ESM tracks to provide classification (ignoring that in real life different platforms might use the same radars for the sake of simplicity), and active intercept tracks to create targets that can be TMAed (slowly, unless tracked by a passive Sonar array).From a gameplay standpoint, agreed for the most part. For Active Intercept, the bearings are, for all intents and purposes, gold. Unlike the current system where they contribute nothing, Active Intercept needs to have the same contributions and effect as passives for TMA purposes.

My (admittedly limited) understanding of both ESM... and Active Intercept is that both of these exist as warning systems first and foremost ... than they are a means for classifying... or even localizing a contact.

ESM is somewhat like that certainly, for the reasons that have been discussed. Active Intercept as it's currently implemented was designed for both. I can't get into the hows and whys, but suffice it to say that we rely on it pretty heavily for classification cues if there is active sonar being used.

EDIT: As a side note, I just saw that my Forum Rank is now A-Ganger. I find myself slightly insulted. Not really, but the true A-Gangers will understand that I don't want (nor deserve, at some levels) to wear their name. On the other hand, it is fairly low in the rankings, so maybe all it well in the world. Unless Sonarman isn't in the ranking somewhere higher? Where it should be? :)