Tracking Active Sonar Contacts

[Shadriss]

Originally Posted by Destex

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! Nice OP question after a 3 year silent run!

[Destex]

Originally Posted by Shadriss

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]

Originally Posted by Destex

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]

Originally Posted by The Bandit

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]

Originally Posted by Destex

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]

Originally Posted by Wiz33

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
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]

Originally Posted by Destex

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]

Originally Posted by stormrider_sp

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]

Originally Posted by Destex

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]

Originally Posted by Destex

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?