Stupid questions about ... what I have read and studied.

ReubenJames · 08-29-05, 02:09 AM

As I said before, after more than 2 years absent from the community, I need to revise many I have read before.

I still do not understand the meaning of the TMA instrument. The concept is to compute the range, speed and course of a track that is straight forward. Here is what I do not understand: the track is moving, how does the TMA work to lock-on to a track.

Using the 2D map, I can easily classify an unknown object as "hostile" thus allowing myself to assign it as a target to my weapons. So why do I have to go through the procedure to "classify" the target using "Hull/Conformal" sonar?

SquidB · 08-29-05, 05:49 AM

Ok i think your talking about 2 different things here, If ive misunderstood forgive me.

TMA is a slow proccess of bringing different peices of information together in order to work out a targets course, speed and range.

To begin with you have one peice of information, its bearing. Depending on its distance you will be able to work out from NB traces exactly what it is you are picking up. Ie surface, sub, whatever. Also you may be able to work out from the NB excatly what class it is.

Now once you have that information, its best to classify this on the NAV map so you can keep a picture of what is going on.

Also once you have a contacts class (and a broadband source) you can perform speed analysis via your demon.

Having the speed of the contact greatly helps the TMA equation.

There are other ways of finding out a contacts ID. If you have a broadband trace, check the demon and count how many blades are showing (be careful if its a faint contact they might not all show). If they are pinging you with active you can get a rough idea of the class from the frequency displayed in active intercept. And finally you have ESM and Periscope.

So in answer to your question, contact identification goes something like this.

1) Try to work out a contacts Type and class from NB or any other availible sources.

2) Update the Nav map with the information you have at hand.

3) If you have the contacts class, perform demon to ascertain speed.

4) Refine TMA for a good solution.

Hope that helps.

Zerogreat · 08-29-05, 06:27 AM

Quote:

Originally Posted by ReubenJames

Using the 2D map, I can easily classify an unknown object as "hostile" thus allowing myself to assign it as a target to my weapons. So why do I have to go through the procedure to "classify" the target using "Hull/Conformal" sonar?

You dont have to... you can guess and shoot at everything, sinking all those neutral yachts and fishing boats.. if it is your desire

ReubenJames · 08-29-05, 10:37 AM

Quote:

Originally Posted by Zerogreat

Quote:

Originally Posted by ReubenJames

Using the 2D map, I can easily classify an unknown object as "hostile" thus allowing myself to assign it as a target to my weapons. So why do I have to go through the procedure to "classify" the target using "Hull/Conformal" sonar?

You dont have to... you can guess and shoot at everything, sinking all those neutral yachts and fishing boats.. if it is your desire

That's why I am asking the above questions.

Sorry SquidB, I don't get all you have explained to me. What does NB stand for? I don't think in reality one will go to periscope depth for identification? That's for surface targets only isn't it?

I still do not understand the steps I am required to perform to complete an identification.

How many times I have to compute for a solution before I get a lock on to target? Does it automatically lock-on a target like in the air you lock on a target with just 1 click away?

By the way, do you guys remove AutoCrew every time you run a mission?

Zerogreat · 08-29-05, 12:50 PM

Oooh this one wont be easy, it seems like you are somewhat...missing the whole point?

(or I am missing yours

).

1) Ok, killing neutral ships is a bad bad thing, you will get penalized for that, sometimes it can even mean a mission failure, not to mention the poor helpless innocent /et cetera/ people there

2) NB stands for Narrow Band, it is a type of sonar that allows target classification by its sound profile (distinct frequencies the target emits).

3) What you mean by "lock on to target"? Actually, torpedoes, unlike AA missiles do not lock onto their target before they are fired. They are simply launched in the target's direction, and at some point (their enable range) they activate their sonars, seeking for targets...if they find something, they will go after it.

ReubenJames · 08-29-05, 01:04 PM

Zerogreat,

I just returned from a 2 hours "training" mission. No luck!

The most frustrating is that the "true" position of the track is far away from the contact(i.e. the yelow mask representation).

I retried 3 times, with random position of the target. At the beginning, it's always sweet that I could hear my FIRST contact and asked sonar to start the track. Luckily, I got the contact from the broadband Sphere sonar. That was a civilian Tanker. I went into the Sonar Demon but I do not know how to make things out. When I changed the civilian to a warship, a FFG actually, I don't get that distinct stripe from the broadband sonar, but instead I got contact information from the Active Intercept. That's fine as long as I can get a contact. But what confused me was that why contact information can be found in broadband sonar when it is a civilian ship whereas for a frigate, no information can be obtained from the broadband sonar?

Fish · 08-29-05, 01:45 PM

THats because of the nois a tanker made, and a FFG don't. War ships are more made for silence. For that FFG, go to NB and scan the band for a 60 hrtz line.
It have to be within 10 nm I think.

ReubenJames · 08-29-05, 01:54 PM

Quote:

Originally Posted by Fish

go to NB and scan the band for a 60 hrtz line.
It have to be within 10 nm I think.

I was just about to raise another questions. Nearly all documentation I am reading mention frequencies, and the range of frequencies each type of sonar is capable of handling.

Now tell me please, how much I need to know about frequencies? And what are they?

God, flying a fighter is much much easier!

Zerogreat · 08-29-05, 02:09 PM

Quote:

Originally Posted by ReubenJames

Now tell me please, how much I need to know about frequencies? And what are they?

My english is lacking to explain you what a frequency is.... eh.. high pitched noises are high frequency and low pitched noises are low frequency. For instance the ships/subs electrical system is 60 (USA) or 50 (Russia and otres) Hertz, which is low frequency... and that is best detectable by the towed array.

For the gameplay, each platform, when you look at it in NarrowBand station, emits i think 5 (it can be less, depends on the sensor used, distance etc.) distinct frequencies - they are depicted as lines. Now u use the database to list known platforms and their sonar profiles, and if you see the lines from database to match those you get from NB sonar, you have likely identified the target

Quote:

Originally Posted by ReubenJames

The most frustrating is that the "true" position of the track is far away from the contact(i.e. the yelow mask representation).

That is, because when you assign a sonar tracker, it gives you only target's bearing, NOT range.... you have to use TMA to get target's range. But doing TMA is not actually easy, after years of playing subsims i learned it relatively good, but it is matter of time

ReubenJames · 08-29-05, 02:37 PM

Oh, for Christ sake, then I have to remember all of the frequencies related to components of every vessels..? Now, I don't have that much memory in my mind. Besides, I run missions for simulation sake, I am expecting less serious experience. Is there an easier way?

So TMA is not reliable? It is error prone? OMG! What about the Sonar Demon? I take it that you can figure out quite much information for identification purpose using the various meters and instruments in there. HOW?

Zerogreat · 08-29-05, 02:56 PM

No, you dont have to remember the frequencies, they are displayed in the NB station

I will post a picture to explain what i mean

Sonar Demon is for getting target's speed. You ahve to identify the target first, the look into USNI database (in DW) and see its TPK (turns per knot) value. Most submarines have TPK of 7. Then in the Demon station, select the appriopriate contact (it must have a tracker assigned in broadband) and you will see waterfall of lines... enter the TPK value and align cursor wtih tle LEFTMOST line, and you will get target's speed

For TMA - its just a geometry

If you know the targets speed enter it, and then try to place the "ruler" in such way that each tick on teh ruler is aligned with appropriate line ... you can also check the "dot stack" in top left corner. If all the little dots are on the line, your solution is probably correct. But if you dont know the target's speed there may be infinite solutions! In such case, change your course, and eventually then there will be only one (geometry, huh

).

Zerogreat · 08-29-05, 03:17 PM

Here, the pictures should be pretty self explanatory, i think

ReubenJames · 08-29-05, 04:35 PM

THANKS! Your great help is warmly appreciated. I shall get back to you after compilation of the information. It's very kind of you.

SquidB · 08-29-05, 06:55 PM

Quote:

God, flying a fighter is much much easier!

Yep it is, because you have a window outside of the plane.

Ive been a flightsim junkie for more than i care to remember. The thing about DW is that its a complex and rewarding sim that takes time to get used to.

Trust me it will make sense, and the feeling of accomplishment when you get a TMA solution right is great. Simply because you know youve done someting thats nigh on impossible.

Hang in there and DW will give your rewards by the bucket

ReubenJames · 08-30-05, 01:11 AM

Zerogreat,

I have to organize before I get back to you. First, very much thank you. Neither the SC nor the DW manuals provide such detailed example as to how to identify a contact. Other documentations don't provide information in such details.

This is the problem throughout the course of completing or learning from a mission. There are many tiny little things which even now, from you I know how to operate; I still don't know exactly what they are. Your effort is such keen that I am touched. Thanks once again.

Now here are my questions:

So, we always talking about frequencies, frequencies, they are actually a continuous "noise" from some sound sources. It could be a whale, it could be an earth quake or a hungry giant Octopussy do I understand it right?

Then like using one of our mixers or equalizers on our desktop or laptop, you can raise or lower one or more of the available frequencies to adjust the music output to suit our taste simply because they are a "noise" source. So the 5 frequencies that you detected in the example is somehow like music, right?

What I want to ask is that on the smaller NB display, roughly between bearing 0 and 90, there is a trough, does it correspond to that part of my boat which has no sonar coverage? Also, how do I tell from the pattern of the waves that there is a contact? Should a contact be found from the pattern, those frequencies will come out to the larger display?

Another question is about torpedo. After firing a torpedo, it actually goes unguided. We have to manage its direction so it goes towards the suspected target. Now if the target's true depth is say 300ft, but our torpedo was launch at 1,200ft, how does it know the target is 900ft above? How do we home-in a torpedo?

What are layers? Can we move between layers to hide ourselves or even evade from incoming torpedoes?

08-29-05, 02:09 AM	#1
ReubenJames Gunner Join Date: Aug 2005 Location: wishing to live in St Ives, England. Posts: 92 Downloads: 0 Uploads: 0	Stupid questions about ... what I have read and studied. As I said before, after more than 2 years absent from the community, I need to revise many I have read before. I still do not understand the meaning of the TMA instrument. The concept is to compute the range, speed and course of a track that is straight forward. Here is what I do not understand: the track is moving, how does the TMA work to lock-on to a track. Using the 2D map, I can easily classify an unknown object as "hostile" thus allowing myself to assign it as a target to my weapons. So why do I have to go through the procedure to "classify" the target using "Hull/Conformal" sonar?

08-29-05, 05:49 AM	#2
SquidB Officer Join Date: Apr 2005 Location: Lytham UK Posts: 244 Downloads: 169 Uploads: 0	Ok i think your talking about 2 different things here, If ive misunderstood forgive me. TMA is a slow proccess of bringing different peices of information together in order to work out a targets course, speed and range. To begin with you have one peice of information, its bearing. Depending on its distance you will be able to work out from NB traces exactly what it is you are picking up. Ie surface, sub, whatever. Also you may be able to work out from the NB excatly what class it is. Now once you have that information, its best to classify this on the NAV map so you can keep a picture of what is going on. Also once you have a contacts class (and a broadband source) you can perform speed analysis via your demon. Having the speed of the contact greatly helps the TMA equation. There are other ways of finding out a contacts ID. If you have a broadband trace, check the demon and count how many blades are showing (be careful if its a faint contact they might not all show). If they are pinging you with active you can get a rough idea of the class from the frequency displayed in active intercept. And finally you have ESM and Periscope. So in answer to your question, contact identification goes something like this. 1) Try to work out a contacts Type and class from NB or any other availible sources. 2) Update the Nav map with the information you have at hand. 3) If you have the contacts class, perform demon to ascertain speed. 4) Refine TMA for a good solution. Hope that helps.

08-29-05, 12:50 PM	#5
Zerogreat Electrician's Mate Join Date: Aug 2003 Location: Czech Republic, Prague, coordinates are sumthin like 50,10 North 14,25 East, not much accurate Posts: 132 Downloads: 0 Uploads: 0	Oooh this one wont be easy, it seems like you are somewhat...missing the whole point? (or I am missing yours ). 1) Ok, killing neutral ships is a bad bad thing, you will get penalized for that, sometimes it can even mean a mission failure, not to mention the poor helpless innocent /et cetera/ people there 2) NB stands for Narrow Band, it is a type of sonar that allows target classification by its sound profile (distinct frequencies the target emits). 3) What you mean by "lock on to target"? Actually, torpedoes, unlike AA missiles do not lock onto their target before they are fired. They are simply launched in the target's direction, and at some point (their enable range) they activate their sonars, seeking for targets...if they find something, they will go after it.

08-29-05, 01:04 PM	#6
ReubenJames Gunner Join Date: Aug 2005 Location: wishing to live in St Ives, England. Posts: 92 Downloads: 0 Uploads: 0	Zerogreat, I just returned from a 2 hours "training" mission. No luck! The most frustrating is that the "true" position of the track is far away from the contact(i.e. the yelow mask representation). I retried 3 times, with random position of the target. At the beginning, it's always sweet that I could hear my FIRST contact and asked sonar to start the track. Luckily, I got the contact from the broadband Sphere sonar. That was a civilian Tanker. I went into the Sonar Demon but I do not know how to make things out. When I changed the civilian to a warship, a FFG actually, I don't get that distinct stripe from the broadband sonar, but instead I got contact information from the Active Intercept. That's fine as long as I can get a contact. But what confused me was that why contact information can be found in broadband sonar when it is a civilian ship whereas for a frigate, no information can be obtained from the broadband sonar?

08-29-05, 01:45 PM	#7
Fish Eternal Patrol Join Date: Sep 2001 Location: Netherlands Posts: 1,923 Downloads: 0 Uploads: 0	THats because of the nois a tanker made, and a FFG don't. War ships are more made for silence. For that FFG, go to NB and scan the band for a 60 hrtz line. It have to be within 10 nm I think.

08-29-05, 02:37 PM	#10
ReubenJames Gunner Join Date: Aug 2005 Location: wishing to live in St Ives, England. Posts: 92 Downloads: 0 Uploads: 0	Oh, for Christ sake, then I have to remember all of the frequencies related to components of every vessels..? Now, I don't have that much memory in my mind. Besides, I run missions for simulation sake, I am expecting less serious experience. Is there an easier way? So TMA is not reliable? It is error prone? OMG! What about the Sonar Demon? I take it that you can figure out quite much information for identification purpose using the various meters and instruments in there. HOW?

08-29-05, 02:56 PM	#11
Zerogreat Electrician's Mate Join Date: Aug 2003 Location: Czech Republic, Prague, coordinates are sumthin like 50,10 North 14,25 East, not much accurate Posts: 132 Downloads: 0 Uploads: 0	No, you dont have to remember the frequencies, they are displayed in the NB station I will post a picture to explain what i mean Sonar Demon is for getting target's speed. You ahve to identify the target first, the look into USNI database (in DW) and see its TPK (turns per knot) value. Most submarines have TPK of 7. Then in the Demon station, select the appriopriate contact (it must have a tracker assigned in broadband) and you will see waterfall of lines... enter the TPK value and align cursor wtih tle LEFTMOST line, and you will get target's speed For TMA - its just a geometry If you know the targets speed enter it, and then try to place the "ruler" in such way that each tick on teh ruler is aligned with appropriate line ... you can also check the "dot stack" in top left corner. If all the little dots are on the line, your solution is probably correct. But if you dont know the target's speed there may be infinite solutions! In such case, change your course, and eventually then there will be only one (geometry, huh ).

08-29-05, 03:17 PM	#12
Zerogreat Electrician's Mate Join Date: Aug 2003 Location: Czech Republic, Prague, coordinates are sumthin like 50,10 North 14,25 East, not much accurate Posts: 132 Downloads: 0 Uploads: 0	Here, the pictures should be pretty self explanatory, i think

08-29-05, 04:35 PM	#13
ReubenJames Gunner Join Date: Aug 2005 Location: wishing to live in St Ives, England. Posts: 92 Downloads: 0 Uploads: 0	THANKS! Your great help is warmly appreciated. I shall get back to you after compilation of the information. It's very kind of you.

08-30-05, 01:11 AM	#15
ReubenJames Gunner Join Date: Aug 2005 Location: wishing to live in St Ives, England. Posts: 92 Downloads: 0 Uploads: 0	Zerogreat, I have to organize before I get back to you. First, very much thank you. Neither the SC nor the DW manuals provide such detailed example as to how to identify a contact. Other documentations don't provide information in such details. This is the problem throughout the course of completing or learning from a mission. There are many tiny little things which even now, from you I know how to operate; I still don't know exactly what they are. Your effort is such keen that I am touched. Thanks once again. Now here are my questions: So, we always talking about frequencies, frequencies, they are actually a continuous "noise" from some sound sources. It could be a whale, it could be an earth quake or a hungry giant Octopussy do I understand it right? Then like using one of our mixers or equalizers on our desktop or laptop, you can raise or lower one or more of the available frequencies to adjust the music output to suit our taste simply because they are a "noise" source. So the 5 frequencies that you detected in the example is somehow like music, right? What I want to ask is that on the smaller NB display, roughly between bearing 0 and 90, there is a trough, does it correspond to that part of my boat which has no sonar coverage? Also, how do I tell from the pattern of the waves that there is a contact? Should a contact be found from the pattern, those frequencies will come out to the larger display? Another question is about torpedo. After firing a torpedo, it actually goes unguided. We have to manage its direction so it goes towards the suspected target. Now if the target's true depth is say 300ft, but our torpedo was launch at 1,200ft, how does it know the target is 900ft above? How do we home-in a torpedo? What are layers? Can we move between layers to hide ourselves or even evade from incoming torpedoes?