The four bearings method

[Kuikueg]

I have been searching the web for info on this and what I found was not satisfactory. So I have done my own thinking and put together a document with my results. I hope you find it useful. Here's the link:

http://www.filefront.com/17135612/four_bearings_method.pdf

If I have time and can figure out how to record in Windows (Linux man, me) I'll try and demostrate my method.


Edit: corrected link to filefront new upload of the document. I don't know how long will these people host the file. It seems that they dump it after sometime...

[kylania]

Welcome aboard! :salute:

To record under Windows, try FRAPS (http://www.fraps.com/).

[raymond6751]

You didn't specify what you were trying, but based on the bearings hint, I assume you mean getting the enemy speed.

Did you search the subsim forums? There is already a lot of information on this and other aspects of manual tracking and targeting.

[Kuikueg]

Enemy speed, course and position is what you can find with four bearings.

Yes I've tried these forums for info. If you read my document, you will find that some of what it says contradicts what others have said before about this matter. I'm a mathematician and I had to check, you know.

[makman94]

Enemy speed, course and position is what you can find with four bearings.

Yes I've tried these forums for info. If you read my document, you will find that some of what it says contradicts what others have said before about this matter. I'm a mathematician and I had to check, you know.

FANTASTIC solution Kuikueg !

you solved a very difficult geometrical problem with a very 'classed' solution !

The 'beauty' of Euclid Geometry is always ,by far, much levels beyond other math's techniques.

Congratulations sir !:up:

[reaper7]

Excellent read Kuikueg. Once I get my Mod up and running I should have some time to try this out. :up:

[Phantom453]

Link seems to be broken at the moment. Is anyone esle having the same problem?

[kylania]

Link seems to be broken at the moment. Is anyone esle having the same problem?

Works here now. Filefront has issues from time to time, just try to download again in 10 min or so.

[Diopos]

I have been searching the web for info on this and what I found was not satisfactory. So I have done my own thinking and put together a document with my results. ...


1) There is alot of material out there. For example: Link: http://www.subsim.com/radioroom/showthread.php?t=161283 (http://www.subsim.com/radioroom/showthread.php?t=161283)

2) Regardless of existing material, "essays" as yours are always welcome! :yeah:

3) The more discussions, tools, texts, methods we have at our disposal the better! :yep:


.

[Diopos]

Ah! Also check the MOBO subforum and related posts here in subsim!
Alot of good work there!



.

[Kuikueg]

Yes there are a few things out there that I had not found, specially that maneuvering manual from 1941 which is of the utmost interest for me.

[Pisces]

Hey, great document. That red line in the general (moving) case is an interesting concept. Have to try it out on my way back to port.

p.s. On page 6 you mix up Sq and Sp.

[irish1958]

FANTASTIC solution Kuikueg !

you solved a very difficult geometrical problem with a very 'classed' solution !

The 'beauty' of Euclid Geometry is always ,by far, much levels beyond other math's techniques.

Congratulations sir !:up:

All you high school students take note: it pays to be attentive in high school geometry class.

[Kuikueg]

Hey, great document. That red line in the general (moving) case is an interesting concept. Have to try it out on my way back to port.

p.s. On page 6 you mix up Sq and Sp.

Oops! You're right. Inconsistent notation. Thanks, I'll try and fix it.

[irish1958]

Oops! You're right. Inconsistent notation. Thanks, I'll try and fix it.
I guess you should pay attention in English also.

[Nausicaa]

I have read it. Very cool solution, thank you a lot for the effort !:)

[Sailor Steve]

Very nice! :rock:

[irish1958]

Kuikueg,
Excellent paper:woot:
Thanks for your effort. And welcome aboard to Subsim. I hope you enjoy this group of people.

"Keep up the good work."

[jmr]

Very cool stuff there. You might find this thread by Mittelwaechter interesting:

http://www.subsim.com/radioroom/showthread.php?t=110619

[Kuikueg]

Very cool stuff there. You might find this thread by Mittelwaechter interesting:

http://www.subsim.com/radioroom/showthread.php?t=110619

Yes, I have seen it. It is interesting, but unnecessarily complicated. He solves for the case when the three first bearings are taken from the same spot and, as I have proved, the course then can be obtained just by drawing two points and two lines in a matter of seconds.

[geosub1978]

This plot is called "Strip Plot". It is not as simple as it seems and has many subcases that affect the result. Anyway, I tried to evaluate it some time ago, but it is too confusing with the given tools. You need multi-point dividing rulers for varius speeds and for diffrent time intervals and diffrent scales.

[Zedi]

As I'm desperate to play at 100% realism, I tried this method. Got my contact and started the drawings. When I was done, the horizon was clear :nope:

[Pisces]

Well succes is never garuanteed, while more practise does seem to make perfect. How long were your intervals? And was it still audible on your hydrophone at the destination location? Did you track it down the iterative way? (traveling along the sound direction) If so, how far off was your prediction? Also, was it the stationary method, or were you moving the whole time?

[makman94]

hello to all,

i made a tutorial video that is showing Kuikueg's excellent geometrical solution !

you can find it at my ff page,it's called ''The Ultimate Hydrohunt Video!''
the video is totally uncut (duration:50 minutes,size:270mb),showing the whole procedure from its start till the end (the 'kill').

---> first you have to download Kuikueg's method and study it carefully.then run the video.<----

i believe that Kuikueg's thread didn't had the attention that deserves to have.
this method is ,by far, the best that ever posted as for hydrophone's themes.it is the most complete method by all till today(the ONLY one that 'dared' to deal with a moving sub or...no?) and it is solving this (really difficult) problem with a very very...elegant solution! geometry always ...rules.


@Kuikueg : this video is devoted to you and thank you for sharing your solution with us.much appreciated...

[reaper7]

hello to all,

i made a tutorial video that is showing Kuikueg's excellent geometrical solution !

you can find it at my ff page,it's called ''The Ultimate Hydrohunt Video!''
the video is totally uncut (duration:50 minutes,size:270mb),showing the whole procedure from its start till the end (the 'kill').

---> first you have to download Kuikueg's method and study it carefully.then run the video.<----

i believe that Kuikueg's thread didn't had the attention that deserves to have.
this method is ,by far, the best that ever posted as for hydrophone's themes.it is the most complete method by all till today(the ONLY one that 'dared' to deal with a moving sub or...no?) and it is solving this (really difficult) problem with a very very...elegant solution! geometry always ...rules.


@Kuikueg : this video is devoted to you and thank you for sharing your solution with us.much appreciated...

Thank you Makman94 for posting this Vid. I was hoping Kuikueg's would get around to making a vid of it in action. :D
Downloading it now and look forward to watching :yeah:.

[Kuikueg]

hello to all,

i made a tutorial video that is showing Kuikueg's excellent geometrical solution !

you can find it at my ff page,it's called ''The Ultimate Hydrohunt Video!''
the video is totally uncut (duration:50 minutes,size:270mb),showing the whole procedure from its start till the end (the 'kill').

---> first you have to download Kuikueg's method and study it carefully.then run the video.<----

i believe that Kuikueg's thread didn't had the attention that deserves to have.
this method is ,by far, the best that ever posted as for hydrophone's themes.it is the most complete method by all till today(the ONLY one that 'dared' to deal with a moving sub or...no?) and it is solving this (really difficult) problem with a very very...elegant solution! geometry always ...rules.


@Kuikueg : this video is devoted to you and thank you for sharing your solution with us.much appreciated...


Thank you very much, makman. Excellent video and good seamanship. I intended to do one myself but I could not get the sound recorded and I barely have time to play anyway so I gave up for the moment. And luckily too because your way of doing it is a lot more economical and cleaner than mine. About your tutorial I would only like to point out that accuracy does not depend on the technique itself but on the degree to which bearings approach parallelism, either to each other or to the the red line. That is where seamanship comes to play a role. The situation you set up in your video is, in my opinion, quite average. You cannot expect to have close to orthogonal bearings and sometimes you'll be in a nearly parallel course and speed to your target in which case the calculations will not provide any information.

I love your set of mods, can I get a list?

PS: makman:I believe my PM's are not reaching you, something is wrong with the forums or my settings. Please confirm.

[Jan Kyster]

Could you re-upload, please? :D

Getting an "Oops! An unexpected error (-1) has occurred." when clicking your link...

[Pisces]

Could you re-upload, please? :D

Getting an "Oops! An unexpected error (-1) has occurred." when clicking your link...He means the link that Kuikueg placed in his first message.

makman94's link in his Filefront profile is ok. ( http://www.filefront.com/17099789/The-Ultimate-Hydrohunt-Video-.rar/ )

[Kuikueg]

http://www.filefront.com/17135612/four_bearings_method.pdf

[makman94]

hi Kuikueg,

no, no, i didn't meant at video that the technique has an acceptable 'error'.you see,english are not my language and many times don't help to express myself correct !

the solution is geometrically 100% correct ! it is the fact that sh3 is NOT a simulator (exept the manual targeting system) and ,as many drawings at navmap didn't made at 100% accurate (some circles and lines didn't drawn at the higher zoom or made fast) , there is the cuase of this 3 degrees error at target's course . also ,more than two points for the 'red line' must be found in order to get a more,as possible, accurate 'red line' .

red line is very critical becuase it will determine the exact position of target.a small error at the target's position (caused by a non 100% correct 'red line') can be reduced later by taking the last bearing at a time that is a multiple of the time's intervals that we used. i mean, if the time intervals are 10 minutes (as in the video) then the last bearing to be taken after 20 or 30 or...etc minutes . that way ,we can reduce a little the false at target's course that may be caused by a non very good 'red line' .

but then, it becomes a little more complicated to make the drawings (plus the need to make all drawings to higher zoom level) and the video would be endless ...
that's why i made the drawings less accurate (to be faster for a ..shorter video) and,also,thats why i am saying at video that target's speed will be close to true speed if taken by map becuase target's course will be close to true course and i used the scope to get the accurate target's speed.

about the 'seamanship' : you can watch the behaviour of hydroline and adjust your course that way that when you take the 'third' bearing to 'cutting' (if possible) the first bearing (you will have an 'idea' of the situation becuase there would be also the 'second' bearing) . that way you are avoiding the parallelism of these two .(for that reason ,at video, i am moving almost vertically to 'forth' bearing -in order to 'cut' it as soon as possible- with the 'sixth'(last) bearing.that way ,there is no possibility of parallel bearings).of course, i agree that would be situations that you will be 'lost' ,nobody is saying that it is an easy task but i believe that in reality the captain was ,indeed , stick to the sonarman watching the behaviour of 'hydroline'(hydro hunt situations) in order to decide the next course which ,sometimes , will not be the better one and target will be ...lost ! i think that this was happening back then.

my message is becoming ...endless (but it is really interesting theme) so i will stop here. but if you want to see the results if all drawings are made as accurate as possible (with lot of patience) see this video :

http://rapidshare.com/files/408343474/exact_position.rar

i played again the mission and made the drawings as accurate as possible(following the same courses for my boat)...it is just the time of the verification of the exact target's position (the most critical part of the method)...which means that we have the proper 'red line').the result is on your screen...

ps1 : no messages from you ! resend (if possible)

ps2 : my mod list (on gwx3) is :

GWX - English Nav Map and Grid Refs
WaterStream+exhaust+lifeboatv4
GWX - Enhanced Damage Effects
TMT v2 with EFS
RACERBOY EXPLOSIONS
Uboat Guns 1.2a for GWX3.0
Music-MANOS
M.E.P v3
M.E.P v3-Patch
M.E.Pv3 VisualSensors-GWX3
Blank Campaign
MaGui v3.3 (gia mena)
optional-No Stealthmeter for MaGui 3.3
Wooden_Lifeboats_Mod_1.1
VIIC-U58

[Jan Kyster]

http://www.filefront.com/17135612/four_bearings_method.pdfMuch appreciated! Thanks! :salute:

[Kuikueg]

hi Kuikueg,

no, no, i didn't meant at video that the technique has an acceptable 'error'.you see,english are not my language and many times don't help to express myself correct !



I know you didn't mean that. I just wanted to point it out for those not mathematically inclined, that might think there is an inherent error in the method. As your second video proves and you have explained, you can get really precise with it.

Thanks for the list and please check your PM's.

[makman94]

.....

Thanks for the list and please check your PM's.

ok Kuikueg ! i got it now :up:

[karamazovnew]

Cool method... I only have one small problem with it that might not bother others. The GPS :D So I've just tried something cool and it worked.

I did all plotting far from my sub's icon, somewhere in the middle of the Atlantic. All plots were relative so I never had to convert stuff to true north. I never changed course, I'm not sure why Makman does it in his tutorial, as it's only necessary in the "sub stopped" technique. I only had to calculate how much "up" I went in the interval between readings, using the nomograph. After the 4'th bearing I had all data I needed. I then calculated a rough distance to get my eels into range. I had a sheet with turning radius of the boat and the time it took to complete a full 360 turn. I figured I only needed to change course and stop about 7 minutes later, at that speed. I did that, used the AOB technique to enter data into the TDC and get the 000 gyro bearing. To my horror I realized that I forgot to check where the target would be at that time, so it had already passed the sweat spot. Frantically, I did a quick check on the probable range when the target would be at bearing 340 and shot my eels when the target was at that bearing. 4 minutes later bum bum bum... I had never raised my periscope. Absolutely love it :yeah:

[makman94]

Cool method... I only have one small problem with it that might not bother others. The GPS :D So I've just tried something cool and it worked.

I did all plotting far from my sub's icon, somewhere in the middle of the Atlantic. All plots were relative so I never had to convert stuff to true north. I never changed course, I'm not sure why Makman does it in his tutorial, as it's only necessary in the "sub stopped" technique. I only had to calculate how much "up" I went in the interval between readings, using the nomograph. After the 4'th bearing I had all data I needed. I then calculated a rough distance to get my eels into range. I had a sheet with turning radius of the boat and the time it took to complete a full 360 turn. I figured I only needed to change course and stop about 7 minutes later, at that speed. I did that, used the AOB technique to enter data into the TDC and get the 000 gyro bearing. To my horror I realized that I forgot to check where the target would be at that time, so it had already passed the sweat spot. Frantically, I did a quick check on the probable range when the target would be at bearing 340 and shot my eels when the target was at that bearing. 4 minutes later bum bum bum... I had never raised my periscope. Absolutely love it :yeah:

hi Kara,

yea the gps(you mean the DIRECTIONS of hydro lines,right?) is annoying but i am afraid that is nessecery . the hydro station is totally unmodeled (another reason that i am saying that sh3 is not a sub simulator) and you can't get accurate (ok ...by 'accurate' i mean accurate to some level ,not exactly) hydro bearings. there are absolutely no tools that real station must had to measure the intensity of sound and narrow a little bit the peak of sound. also, there are other problems with the 'sonarman' . the moment he says 350 degrees the target is either to 349,5 or to 350,5 degrees(really....why devs have made simple things ..so complicated without a reason?). that's ok (can be overpassed) if the report happens to be asked exactly at the time he screams the new hydro bearing. but if the time is not at this moment then all you know is that target is somewhere between 349,5 and 350,5 .nothing can be done,afaik, to narrow this..so if you don't use the gps for hydro line you have to expect big inaccuracies ( as travelled distances getting bigger so inaccuracies getting bigger).

also there is one more (little this time) thing that annoyes me with sonarman . he doesn't answer immediatelly for reporting . sometimes he is quick and others not so we have some 'lose' from that too and if you add the inaccuraces becuase of the fact that drawings will take place at small zoom of navmap ....i think that all these will lead to a final solution which will be very off if not ...totally off !

so , at video ,i am pretending that sonarman has all these tools at his station for narrowing the peak of sound ( yea,i know ....now he 'narrows' it at a extreme level but do we have a better choice?) and giving me accurate directions for hydro lines.

would be nice, though, to know if there is a workaround for plotting accurate (as possiple) hydrolines without the gps.

or even better (just for me is this ) : can we tweak somehow the sonarman's reports and gives an output with the 'half' first demical ?? something like ''bearing: 340,5 degrees'' when target is between 340 and 340,5 degrees or 'bearing: 341 degrees'' when target is between 340,5 and 341 degrees.
then gps will not be needed and accuracy will not be 100% which ,i think , is 'closing' to reality.

about no course's changes : no ,this is wrong Kara.if we assume that you don't change course and speed (in order to be able to make the 'up going' plotting ) from the start of the procedure ,then the fourth bearing is ,in fact, the 'red line' (if we assume that you did all correct).so you will have 'problem' there as both lines(fourth bearing and 'red line') will be the same line. the goal is to avoid parallel hydro lines ...each other or with the 'red line' .thats why i changed course .or you can change speed (instead of course) between time intervals.(but whatever you do ....something must be changed either course or speed or...both).

sure it is not nessecery to use your scope ! i used it only to get an accurate speed for target . but if you don't use it you have to be based on your map plotting for getting the target's speed and becuase it will be a little off (target's course 'error' is causing this) you must use a greater angle at your 'salvo' shooting in order to get him for sure .
also , as you are going to shoot from hydrophone i want just to point out that we fire at target when we start 'hearing' him ...10 degrees in FRONT of the decided shooting bearing.

[karamazovnew]

Actually by GPS I meant the position of our sub. Changing your course and speed wildly would make normal plotting impossible. Take the first example (Static sub for the first three bearings): at your fourth bearing you'd probably just start engines as acceleration/distance charts are available for a ship, but protracting a turn in which you accelerate is... HARD :haha:

Now are you sure what you said about the Red Line? As I understood it, using just 3 points will give you an infinite number of possible courses. By projecting the "future" position on all these probable courses (protracting them), you end up with the red line which is basically the Geometric Place (no ideea how to translate Locul Geometric from romanian to english) of all possible locations (not bearings) of your target at your next reading. It's not a bearing, but a bearing+range, if you will. By intersecting that with the actual 4'th bearing, you get the position. Or did I misunderstand the whole concept? So far, I've never had it overlapping the 4'th bearing. It did come close on some tries, but still far enough to allow a good solution.

Here's an example:
I loaded up just before firing eels at a Light Cruiser. Previously I had already calculated everything through normal plotting and he was going at 13.5 knots and a course of around 250, the solution was perfect and the PK updated it like clockwork. The problem was that he was extremely near, so I took bearings at 1minute intervals.

http://img838.imageshack.us/img838/8932/5bearings.th.jpg (http://img838.imageshack.us/i/5bearings.jpg/) Uploaded with ImageShack.us (http://imageshack.us)

You won't see my sub anywhere on the map, I was going on a 133 course at 3 knots. I had to protract my position. As you can see, I drew up circles at 100 yards intervals (1 minute at 3 knots means 100 yards). All bearing were relative to my bow (325,333,350,31,75). I ended up with a solution of 14 knots (950 yards in 2 minutes, between the 3'd and 5'th bearings) and a relative course of 115 degrees. Added to my course of 133, it gave a nice 248 true course for my target. The actual Range at the 4'th bearing was off by less than 50 yards (around 500 on the map, 550 on the sonar), but it took me a couple of seconds to use the sonar so... considering that SH has that line 0.5 problem, I'd say the solution was PERFECT. I don't need to convince anyone that I didn't change speed or course, since my bearings were plotted starting from theoretical linear and equally spaced protracted positions :D

Try this for yourself, using my bearings. Heck, you can even do this while in port :D

EDIT: About a year ago I desperately tried to solve this problem. I failed miserably so, Kuikueg, you have my deepest respect. I wanted to create a method of simply keeping your periscope on the target and ending up with a perfect solution after a short while. This method is so simple that it proves it can work. I can't wait to figure out the formula.

[makman94]

.........
Now are you sure what you said about the Red Line? As I understood it, using just 3 points will give you an infinite number of possible courses. By projecting the "future" position on all these probable courses (protracting them), you end up with the red line which is basically the Geometric Place (no ideea how to translate Locul Geometric from romanian to english) of all possible locations (not bearings) of your target at your next reading. It's not a bearing, but a bearing+range, if you will. By intersecting that with the actual 4'th bearing, you get the position. Or did I misunderstand the whole concept? So far, I've never had it overlapping the 4'th bearing. It did come close on some tries, but still far enough to allow a good solution.
.......


yes Kara ,i am sure ! in fact it is... proved ! yes ,'red line' is a geometrical locul and this geometrical locul is (as Kuikueg showed) a straight line. now, your fourth bearing is a straight line also and i am telling you that if you don't change course and speed during your time intervals these two lines will be the SAME line.
i will send you the prove of this at your pms.
if not...then it is a fault at your map drawings or caused becuased of inaccuracies of silent hunter.
send me the mission you played to give it a try and i will tell you my results

[Kuikueg]

yes Kara ,i am sure ! in fact it is... proved ! yes ,'red line' is a geometrical locul and this geometrical locul is (as Kuikueg showed) a straight line. now, your fourth bearing is a straight line also and i am telling you that if you don't change course and speed during your time intervals these two lines will be the SAME line.
i will send you the prove of this at your pms.
if not...then it is a fault at your map drawings or caused becuased of inaccuracies of silent hunter.
send me the mission you played to give it a try and i will tell you my results

I don't know if you are not understanding each other but I'll try to clarify.
The need for changing course, either for the fourth bearing or for any other depends only on the circumstances. The fourth bearing won't be in general equal or parallel to the red line even though you don't change course. Actually, in my explanation of the method, you could draw a straight line in the diagrams representing submarine's course and the solution holds, because it does not depend even on the location of the submarine. But in certain circumstances, such as those in Makman's video, you may need to change course in order to obtain a non parallel bearing and increase accuracy of the solution. I insist: is circumstantial.

Something that catches my attention is that, if I understand well, Karamazov is not taking a fifth bearing to calculate course and speed of target. Four bearings is enough to know that, but it implies repeating the calculations backwards through the bearings and finding an initial red line through which to find the initial position of target via first bearing. Is that what you are doing, Karamazov? Are you maybe estimating true course by sight from those used in the construction? Are you doing anything else I can't think of?

Edit: sorry Karamazov, your picture made things really clear for me. You take a fifth bearing. Silly me. Thanks for your comments.

[makman94]

......
The need for changing course, either for the fourth bearing or for any other depends only on the circumstances. The fourth bearing won't be in general equal or parallel to the red line even though you don't change course. Actually, in my explanation of the method, you could draw a straight line in the diagrams representing submarine's course and the solution holds, because it does not depend even on the location of the submarine. But in certain circumstances, such as those in Makman's video, you may need to change course in order to obtain a non parallel bearing and increase accuracy of the solution. I insist: is circumstantial.......

.....

Kuikueg , check your pm

i insist that if you DON'T CHANGE COURSE AND SPEED the fourth bearing will be ALWAYS the red line !
all these only at the situation that you haven't change COURSE AND SPEED

you say: ''Actually, in my explanation of the method, you could draw a straight line in the diagrams representing submarine's course and the solution holds...''
this point is not correct,imo, Kuikueg. if you draw a straight line for your course then the spaces between the time intervals will not be equal (which can be 'translated' as a 'speed' change)

[Kuikueg]

Makman is right!!!

Not absolutely, but right.

If you keep speed and course through all the process this is what happens:

The construction of a possible solution course (among the infinite existent) implies choosing a point along the second bearing. What if you choose your own second position as a starting point? you will end up with your own fourth position as the protracted one for your target. Therefore, the red line always goes through your fourth position. So if you don't change speed or course along the process, your fourth bearing will be meaningless. In the document that explains the method, I had considered meaningless the submarine position, so I put on some arbitrary ones and all went well, because it seems that slight variations on speed or course result in wide variations in the red line, under feasible circumstances, which is enough to provide an accurate solution.

I was quite perplex when I realized that, after Karamazov's statement that he had not changed course. After reviewing his snapshot, I notice that he had at least changed speed between his first and third bearing. That's enough. I have yet to assess to what amount the direction vector of the red line is sensible to those changes, but I can assure you that you need at least one change in speed or course anywhere along the construction to make your fourth bearing meaningful, (not necessarily right before the fourth bearing, and that's the only reason I said not absolutely right at the beginning, but he is essentially right: it is not that your bearing will coincide with the red line, but that it will cut it through your own position, a point that we mathematicians call a singular point -and we sailors call collision point- where information has vanished. That is, roughly: the bearing to a ship in your own position is any).

I will rewrite the document posted in this thread to reflect those facts and post it here.

Thank you, Makman. Well seen. This is collaboration at its best.

[karamazovnew]

I've played around with that GeoGebra program you sent me, what an amazing tool, I'll always keep this installed. I used my previous bearings for practice. I didn't even need to use my sub's position on the second bearing, somehow the red line always coincides with the fourth bearing. I have to admit, I feel stupid right now. Not because I was wrong before, but because I must've done SOMETHING wrong to end up with good solutions and now, for the love of God, I can't remember WHAT :har:. The picture I sent before was not a fake, yet time and time again I can't get that red line anymore :damn:. It wasn't from plotting mistakes, although drawing circles so small I could've actually fulfilled the rule to change speed because of the silly 0.5 error in the SH ruler :haha:

So Makman, you have my apologies for not initially believing you. So.. on the move, after 3 bearings, we can can the 4'th. I still can't shake the feeling that knowing what distance we've traveled between readings, we could somehow protract the bearings back to our original position. That would solve this problem :hmmm:.

Wait, I've just thought about a counterexample to what I've just said. Imagine moving along at a constant speed and course and all first 3 bearings are 90 degrees. This means that the 4'th will also be 90, this can either be a ship moving parallel to you at the same speed as you, or at any angle to your course but at a greater speed. Yeap, this problem is unsolvable...

[Kuikueg]

I've played around with that GeoGebra program you sent me, what an amazing tool, I'll always keep this installed. I used my previous bearings for practice. I didn't even need to use my sub's position on the second bearing, somehow the red line always coincides with the fourth bearing. I have to admit, I feel stupid right now. Not because I was wrong before, but because I must've done SOMETHING wrong to end up with good solutions and now, for the love of God, I can't remember WHAT :har:. The picture I sent before was not a fake, yet time and time again I can't get that red line anymore :damn:. It wasn't from plotting mistakes, although drawing circles so small I could've actually fulfilled the rule to change speed because of the silly 0.5 error in the SH ruler :haha:

So Makman, you have my apologies for not initially believing you. So.. on the move, after 3 bearings, we can can the 4'th. I still can't shake the feeling that knowing what distance we've traveled between readings, we could somehow protract the bearings back to our original position. That would solve this problem :hmmm:.

Wait, I've just thought about a counterexample to what I've just said. Imagine moving along at a constant speed and course and all first 3 bearings are 90 degrees. This means that the 4'th will also be 90, this can either be a ship moving parallel to you at the same speed as you, or at any angle to your course but at a greater speed. Yeap, this problem is unsolvable...

The problem is solvable. I think you did not read my last post.

[karamazovnew]

The problem is solvable. I think you did not read my last post.

I did, I meant that the problem of 4 bearings while your sub is holding a steady course and speed is unsolvable.

And I managed to figure out why my solutions were correct. Because of the 0.5 ruler round-up, I ended up with errors in my position which translated into differences in my sub's speed. Since the distances and ranges were very small, this was enough to give me a workable solution. At longer distances (>10km), I would've ended up with the redline overlapping my 4'th bearing. So when I scaled up my plot, making my sub travel 1000 yards instead of 100, the error went down by a factor of 10 and I immediately ended up with all protracted points on the 4'th bearing :haha:

[Kuikueg]

I did, I meant that the problem of 4 bearings while your sub is holding a steady course and speed is unsolvable.

And I managed to figure out why my solutions were correct. Because of the 0.5 ruler round-up, I ended up with errors in my position which translated into differences in my sub's speed. Since the distances and ranges were very small, this was enough to give me a workable solution. At longer distances (>10km), I would've ended up with the redline overlapping my 4'th bearing. So when I scaled up my plot, making my sub travel 1000 yards instead of 100, the error went down by a factor of 10 and I immediately ended up with all protracted points on the 4'th bearing :haha:

Right on!

[makman94]

only good things can comes over due these thoughts Kuikueg and Kara !

an idea came to me after all this discussion...i am thinking that the procedure can be a little ( ok ... a little) simplified like this :
we will take advantage of the fact that we always know one point of red line .this point is a point ON our course(imagine a straight course) after exactly a distance that is 3 times the distance that we travelled during the first interval.
so here is a simplified procedure:

1.for the FIRST interval we DON'T change speed and course and we mark our starting and ending point . (for the other interval we are doing whatever we want...changing courses or speeds or...both)

2. extending(at a straight line) the distance between these two points that way that it will end to a point that the distance from the start point to this point to be equal with 3 times the first distance.

this point is, for sure , one point of red line.

3. the other point of the red line will be found as we allready know from Kuikueg's tutorial and we are ready to draw the red line .
the rest procedure is as shown at Kuikueg's tutorial.


the 'winning' is that we are avoiding some drawings on navmap (circles...extensions...etc) in order to find a second point for the red line.
i know... not big 'winning' ! but we are getting a ...little faster with less drawing ,right ?

ps: yea Kara, this programme is just a piece of art ...and really powerfull !:up:

ps: Kuikueg you have a pm

[karamazovnew]

Cool idea. But we need to maintain course and speed for the second interval too (between 2'd and 3'd bearings). :yep:

After that the best thing I guess would be to simply stop the boat :D

[Kuikueg]

Yesterday I was thicker than usual and so I have to correct myself again: if you keep speed and course, the red line becomes the fourth bearing. So Makman was absolutely right.

About the simplification of procedure, for it to work you need to keep speed and course for the three first bearings, otherwise the red line won't pass through your protracted fourth position, right?

[makman94]

yes Kuikueg and Kara ,you are both right! we have to keep speed and course for the second interval too ! my bad..

[makman94]

hello to all,

a new video (HD) made by me is uploaded on youtube showing again this excellent method that Kuikueg shared with us !

http://www.youtube.com/watch?v=4RWDWd62q4w

in this video ,you can also see how to do the ''job'' with ONLY FOUR bearings (instead of five that are showing at Kuikueg's notes or to my previous video.of course,he is mentioning that four are enough...now you will see how it is done)

once , again ...i want to thank Kuikueg for the VERY BEST method !

[Zedi]

Makman, can you explain me what vent wrong in this case:

http://farm5.static.flickr.com/4113/5047094443_4806e1f4e2_b.jpg

The blue line should be the correct bearing of the target acording to this method, but somehow. the red line was the true bearing. Somethimes this method work, but somethimes.. is just wrong and I can't figure out why. The time interval between bearing measurement is 10 minutes. I just can't explain how come the final path was exactly the opposite to the calculated one.

Can you mod your nav map tools to be available for sh5 too? I so miss some pro tools for drawing on map.. right now I do my math on paper, it realistic but also annoying :/

[makman94]

Makman, can you explain me what vent wrong in this case:



The blue line should be the correct bearing of the target acording to this method, but somehow. the red line was the true bearing. Somethimes this method work, but somethimes.. is just wrong and I can't figure out why. The time interval between bearing measurement is 10 minutes. I just can't explain how come the final path was exactly the opposite to the calculated one.

Can you mod your nav map tools to be available for sh5 too? I so miss some pro tools for drawing on map.. right now I do my math on paper, it realistic but also annoying :/

hi Magnum,

at your pic is showing that you are using the method with the stopped u-boat .
you have made a lot of mistakes and also your drawings are not accurate (accuracy at drawings is a critical part ) and seem very ''fast made''.remember, with methods like this one...you have to be patient .
before i start telling you the mistakes ,have in mind that bearings a ,b , c and the last one (the one from point A2 )must be very accurate (the more accurate they are ...the more accurate your solution will be)

first, the point G must be in the middle of A1P1 and at your pic it is not .

second , the line Gg must be parallel to bearing c and at your pic it is not (yea ,i know that it seem to be so but if you look closer it is not )

these two mistakes are leading you to the next mistake which is that P1P2 is not equal to P2P3 .these two must be equal in order to proceed so you should have stop here.the procedure have allready failed.

all these ,plus the possible not accurate bearings a,b,c (don't be based on your SO ,use the sonar bearing lines) are giving you the wrong result.

next mistake is that the point P4 is not placed correctly . the P4 must be placed on the extension of line P1P3 that way so P1P2=P2P3=P3P4 .once you find the point P4 then you draw the ''bearing'' that is ''passing'' from it.

In my opinion,an easier way to find the point P4 (with the availiable tools we have at sh) is showing at my video.at video,the situation is for a moving u-boat but pay attention at the way i am finding the first point of ''red line'' there.
you can use the same way at your situation to find the point P4.(watch carefully the video at the part of finding the first point of red line and if you don't get it...ask me again to explain)
WARNING: DON'T ERASE THE CIRCLE THAT IS POINTED TO YOU the point P4 !! ITS RADIUS IS pointing ,also, to TARGET'S COURSE (at the situation of stopped u-boat)!! this tip will help you to draw the exact course of target once you find his exact position.

ps: i think that sh5 has allready ALL the tools(and Abd_von_Mumit gave you a mod with better graphics) exept a working ruler for measuring accurate the distances and,afaik, can't be modded at sh4 or sh5( the major issue that kept me away from sh4 and sh5--at sh5 the things are even worst with the map! )

HTH,

bye

[Zedi]

I used a ruler on the monitor to see how wrong I was. Yeah, your right... is a difference, G should be a little bit at left, where is the second 0 from 0.0. In that case, P2 should be where is the top edge of M from KM on the "b" line. True, is a huge difference in the direction of the target, but even so, is not the real course. And going further, the readings from A2 will still hit around S4 and gives me a bigger distance than in reality.

Now I still don't understand exactly few things here. P1 is a really random location along line "a"? How far should be A2? Is there a precise time interval for bearing readings and a precise distance to travel between A1 and A2? And about the precision of these readings... in this case I had a convoy and is impossible to say that the bearing is exactly 46 and not 44 or , not to mention that the sound level was very low. I could cheat by asking the sonarman/computer, but then what the point in realistic play? Also, the sonar panel is broken, those vu meters are not working.. but let's say I have a broken sonar in reality. And I play with map contacts off, so my map is clear and I'm completely blind.

Your video is not helping me because I always stop the sub when I search for contacts. I know that the sea is not static, but these high level of physics are not implemented in the game, so is no point in keep the sub moving and also do extra math to calculate the currents and my real speed.

And regarding the tools... what I need most is a 2 ring & rotating compass so I don't need to position my ship at N or W every time I search for contacts. Also a more exact ruler that I can also rotate. For example, to read the right values for where I should mark G between A1 and P1. I could do it as I did it now, by measure it on the monitor, but is kinda hard to keep the same zoom level all the time. You guys have these tools in SH3-4, for SH5 is available only in TDW UI. As I said, right now I do all my maths on paper then I try to copy it on the navmap.. that's why most of the time I got wrong results. In booth cases, I miss the right tools. Tbh.. I would love to have such a table as it is in the game.. with a huge map and a lot of tools .. that would kill the boredom of this endless sink-refit gamestyle :P

Anyway, my biggest issue so far is the target speed. I'm using the 3.15 method and most of the time I can calculate the right speed, but not in the combat after I hit a target and the ship(s) speed change. That is the point when I go completely blind and I just estimate the speed according to what the game use so far.. 6-7 knts for evading merchant ships. This is when I miss a lot. Wonder how those guys at that time made the maths when they conducted their attacks inside a moving convoy ... at night.

[makman94]

I used a ruler on the monitor to see how wrong I was. Yeah, your right... is a difference, G should be a little bit at left, where is the second 0 from 0.0. In that case, P2 should be where is the top edge of M from KM on the "b" line. True, is a huge difference in the direction of the target, but even so, is not the real course. And going further, the readings from A2 will still hit around S4 and gives me a bigger distance than in reality. --- i ,allready answered why you got wrong solution. the bearings a ,b, and c are very critical and if not accurate then (with combination of bad drawing) give wrong result. the S4 will not be there if you had made correct the drawings (i am assuming here that bearings a,b and c are accurate) becuase the P4 would NOT be at the position you have it now.all would be different if you have made correct drawing.
My suggestion is to use, at the start, the bearing lines .make a mod that is vanishing the ship's images on navmap when you have contacts update on. that way ,when you have the contacts update on,you will have the bearing lines BUT NOT the ship's images.
ONCE you learn to do the procedure perfect (drawings must be done at higher zoom level ) then the next step will be to turn off the bearing lines BUT HAVE IN MIND THAT WHEN YOU SWITCH OFF THE BEARING LINES YOU ARE 'ENTERING' TO A WHOLE NEW PART OF HYDROPHONE HUNTING and that is becuase of the fact that bearing lines will not be EXACTLY the real ones and this may(depending from the angle between yours and target's course) have a GREAT impact at the final solution.
To understand the ''problem''... when target is 'coming' ON you with a very small angle it will take an 'age' to have a change of ,for example, 2 degrees at bearings.a difference that your ear may not be able to 'catch' so you will have to wait more. then you will have to wait exactly one ''age'' to take the next bearing but this may be a big failure becuase target will ''pass'' and moved away (and never get it again if its a fast target).

so,what do you do ?

a workaround is to NOT start the procedure of the method when you ,firstly ,got the contact. i don't know how real captains doing it but i am almost sure that captain was ''sticked'' to sonarman ...'watching' together the BEHAVIOUR of sonar bearings .the captain is manuevering the boat ,changing always SPEED AND COURSES (thats why i strongly suggest to learn the method with the moving u-boat) until they got a somewhat FAST changings at sonar bearings (this will make you to use smaller time intervals once its time to start the method's procedure) .not an easy task,experience is your 'friend' here and need some luck too . wrong decisions at courses or speeds and target will be lost but i bet that this was happening in reality back then too.
when we got FAST changings at sonar bearings,we start the method's procedure (not before).
IF you want to use the method with the stopped u-boat ...the workaround (at the situation that you are stopped and the target is 'coming' on you with a small angle) is to NOT USE EQUAL TIME INTERVALS but this demands to firstly know to do PERFECT the method with the equal time intervals . the not equal time intervals is the next step (i will do a video at future with not equal time intervals...it is on my todo list ).

Now I still don't understand exactly few things here. P1 is a really random location along line "a"?---yes ,absolutely random How far should be A2?---the goal is the angle between your theoritical fourth bearing and the final fourth bearing to become as large as possible(---the ideal is to become 90 degrees) Is there a precise time interval for bearing readings and a precise distance to travel between A1 and A2?---no to both.for time intervals...a rule that is NOT general is the time to have ,for example, 4-5 degrees bearing change from b1 to b2And about the precision of these readings... in this case I had a convoy and is impossible to say that the bearing is exactly 46 and not 44 or , not to mention that the sound level was very low. I could cheat by asking the sonarman/computer, but then what the point in realistic play?---read the above ...learn first to do it PERFECT with the bearing lines on map and then try to get it harder! Also, the sonar panel is broken, those vu meters are not working.. but let's say I have a broken sonar in reality. And I play with map contacts off, so my map is clear and I'm completely blind.

Your video is not helping me because I always stop the sub when I search for contacts.---you don't understand me. i told you to watch ONLY the part of the finding the first point of ''red line''.you can follow the same procedure, with the stopped u-boat ,in order to find the point P4 I know that the sea is not static, but these high level of physics are not implemented in the game, so is no point in keep the sub moving ---you will reconsider once you learn to do them both...you will see...and also do extra math to calculate the currents and my real speed.---there is no need for this (your speed).method is not effected by your speed

And regarding the tools... what I need most is a 2 ring & rotating compass so I don't need to position my ship at N or W every time I search for contacts.---why to do this ? there is no need ,you can draw the bearings at whatever direction your boat may beAlso a more exact ruler that I can also rotate. For example, to read the right values for where I should mark G between A1 and P1.I could do it as I did it now, by measure it on the monitor, but is kinda hard to keep the same zoom level all the time.---see the video at the part i told you ! you can avoid this... You guys have these tools in SH3-4, for SH5 is available only in TDW UI. As I said, right now I do all my maths on paper then I try to copy it on the navmap.. that's why most of the time I got wrong results. In booth cases, I miss the right tools.---you,allready have all the tools you need,see the video at the spoken part.maybe,you ''miss'' [-don't know becuase sh5 is deleted from my HD-]the big compass rose that is attached to you sub but again you can make the bearing drawings by using your protractor.also,use the circle tool when you want to make parallel lines (see the video )Tbh.. I would love to have such a table as it is in the game.. with a huge map and a lot of tools .. that would kill the boredom of this endless sink-refit gamestyle :P

Anyway, my biggest issue so far is the target speed. I'm using the 3.15 method and most of the time I can calculate the right speed, but not in the combat after I hit a target and the ship(s) speed change. That is the point when I go completely blind and I just estimate the speed according to what the game use so far.. 6-7 knts for evading merchant ships.---when target is changing speed or course you have no method for finding course or speed (they are changing !!). at sh3 i use the aob rings when i want to make a very fast shots (as in this case ) without map ploting ,with a constant speed measuring (fixed-wired method) and always a salvo shooting when target is changing course and speed (although the targets are 'idiots' ...i mean that they don't change course ,at least at sh3...they zig-zaging at the SAME course---i hope that devs have fixed ,at least this, in sh5) This is when I miss a lot. Wonder how those guys at that time made the maths when they conducted their attacks inside a moving convoy ... at night.

hi Magnum,

look above at blue letters

bye

[Zedi]

Interesting, thanks for the suggestions/corrections. For sure there is a lot more to learn and all is based on experience. Regarding the tools, I play with the stock UI which lack in tools for nav map. There is a tool helper, but I cannot rotate it. So for example when ma boat is heading 45, is really hard to draw out the right bearing of my target. No compass rose, no other fancy stuff that are only available in bigger mods like TDW and Reaper's UI right now, none as stand alone mod.

In SH5 ships change course, not only zig-zag. TDW's great mod, IRAI, do that. So ships instead of just zig-zagin and following their default course, they try to evade by changing course, sometimes even with 180 degrees. So this make the hunt extremely difficult with high realism.. not once got almost ramed by merchants when I conducted an attack from inside the convoy. So that's the part where you have to think and act very fast. Luck with the voice command mod, so I can give out orders very fast.

Btw.. any chance to see a MaGui version for SH5 anytime soon? :O: But a version without dials on screen if possible and focused on high realism play style. Means ... with a dream navmap with all those juicy tools that is available in the mod right now.

LE: Almost forgot.. I can't use the "map contact on" option.. the sonarman will give me the target range, so is not an option. Is not point to use this method since I already have drwan on the map the target bearing and range...

[sharky02]

Hi all..
I've downloaded Solution Solver, but a can't open it on my lappy. Anyone can help me?

[vanjast]

Pardon me if I may say, not having played SH5 but spent many 'game years' in SH3/4 on 100% (full real - no icons/no charts/nudder/nothing), there's nothing to beat target course and speed by either.

1) running parallel to target course.
2) running 90Degs to target course.

with both of these methods, and some experience you need at most 2 readings to determine target course and speed. It's simple mental maths and no chart drawings.. etc.

:)

[Zedi]

Great info, but until point 1. and 2. you need to figure out the target course &speed.

[vanjast]

It's related to your course and speed by well known trigonometry formulae :)

[vanjast]

I'm a bit curious...
Is it still possible in SH5 to determine ship speed by rev counting on the sonar/hydrophone ?

[Kuikueg]

First, let me direct you to here (http://www.subsim.com/radioroom/showthread.php?t=179137) where you will find a much improved account of the method.

Secondly: it's not a matter of preference of method. It's about the situation. In a dark, moonless night with rough weather, when sonar is the only detection tool available, the four bearings method is your only chance of chasing a target and finding a firing solution, provided that you are playing full real.

[stoianm]

First, let me direct you to here (http://www.subsim.com/radioroom/showthread.php?t=179137) where you will find a much improved account of the method.

Secondly: it's not a matter of preference of method. It's about the situation. In a dark, moonless night with rough weather, when sonar is the only detection tool available, the four bearings method is your only chance of chasing a target and finding a firing solution, provided that you are playing full real.
totally agree:up: - thank for this method - excelent
btw i saw a movie with 4 bearing methode called hydro hunt (it is you that made that movie?)

[Kuikueg]

totally agree:up: - thank for this method - excelent
btw i saw a movie with 4 bearing methode called hydro hunt (it is you that made that movie?)

No, that was makman94. It uses the old version of the method.

[stoianm]

No, that was makman94. It uses the old version of the method.
:D - i saw the new version (you refering at the situation to aplie the 4 bearing when sub is in movement i gues) but i use the old one - i am to lazy to do the hole drawing part and i use hydro traker:haha: - anyway awsome job:up:

[Kuikueg]

:D - i saw the new version (you refering at the situation to aplie the 4 bearing when sub is in movement i gues) but i use the old one - i am to lazy to do the hole drawing part and i use hydro traker:haha: - anyway awsome job:up:

Thanks.

No, both versions treat the problem of the moving submarine. The new version greatly simplifies the drawing involved and eliminates the need of a fifth bearing (which wasn't really necessary, but convenient). If you are taking the video as a guide, do no more, because although it works, it's more messy than the new. Even the fixed position situation has some new info. It's a great video, though.

[stoianm]

Thanks.

No, both versions treat the problem of the moving submarine. The new version greatly simplifies the drawing involved and eliminates the need of a fifth bearing (which wasn't really necessary, but convenient). If you are taking the video as a guide, do no more, because although it works, it's more messy than the new. Even the fixed position situation has some new info. It's a great video, though.

thanks... i wil take a closer look at the new version then:up:

[kalijav]

Nice guide, however, I find it a bit confusing, I am not a geometry pro (at all), and honestly I am having a hard time understanding how it works.

I have made a little video on how I currently think I should draw the whole thing.

http://www.youtube.com/watch?v=NcZxLWfIqv0

Can someone please tell me if I'm doing it wrong ?

Please accept my apologies for the quality of the video.

[Kuikueg]

Nice guide, however, I find it a bit confusing, I am not a geometry pro (at all), and honestly I am having a hard time understanding how it works.

I have made a little video on how I currently think I should draw the whole thing.

http://www.youtube.com/watch?v=NcZxLWfIqv0

Can someone please tell me if I'm doing it wrong ?

Please accept my apologies for the quality of the video.


You are doing it perfectly.

[kalijav]

Yaay :D

I've spent so many hours on this, I'm going to try that in game now :)

Thanks !

[kalijav]

Since I basically had all the steps to use the method, I made a little animation showing the method "in action" (out of game) so that everybody can benefit from it.

This is a step by step tutorial, there is no explanation of the method, it is strongly recommended to read the orginal method :)

http://www.megaupload.com/?d=C5PU0P9E

Please give me your feedback :) I could also make a pdf with one page for each step, or make in in .swf.

[irish1958]

Since I basically had all the steps to use the method, I made a little animation showing the method "in action" (out of game) so that everybody can benefit from it.

This is a step by step tutorial, there is no explanation of the method, it is strongly recommended to read the orginal method :)

http://www.megaupload.com/?d=C5PU0P9E

Please give me your feedback :) I could also make a pdf with one page for each step, or make in in .swf.
A pdf would be great, especially if each step were on separate pages. On any complicated subject, having a few different slants on a subject will help in understanding.

[ETsd4]

Question was: in medium fog at which location is a warship at 06:07hour?

All the same input-data, but with 3 different results:


(1)U-52-Hydrophone guy:
distance: 3km - 25km at 280° relative bearing
course: unknown
speed: 7kn - 14 kn

(2)U-52-Navigator with u-boat-map-tools:
distance unknown at 280° relative bearing
course: 087°T
speed: unknown

(1)+(2)
http://i714.photobucket.com/albums/ww143/snDf1/4Bearing_Error_01.jpg


(3)GeoGebra:
distance: 41 km at 280° relative bearing
course: 114° T
speed: 13.0 kn

http://i714.photobucket.com/albums/ww143/snDf1/4Bearing_Error_03.jpg


And the worst thing is: all 3 results are wrong or not precise enough.


- Problem bearingcalls by hydrophone-guy Vs. true bearing:
http://www.subsim.com/radioroom/showpost.php?p=1792526&postcount=13

[d3vnu11]

Anyone have the math involved for the solution wAs thinking about making a calc program to solve the problem for fun.

[ETsd4]

Anyone have the math involved for the solution wAs thinking about making a calc program to solve the problem for fun.

Hydrophone tracker (HydrophoneTracker.zip):
http://i714.photobucket.com/albums/ww143/snDf1/HydrophoneTracker.png

[Dignan]

I hope its ok to be posting in such an old thread but I have a question regarding using the hydro to plot a convoy's course. If visibility conditions are no good (i.e. fog or night) and you are playing "no map contacts" how do you plot a convoy's course and speed?

I have become proficient at the 4 bearings method on full realism for single contacts. What I'm having a tough time with is using this method to track and plot a convoy course, speed, range. There are too many sound contacts to be able to take a bearing off a single target for all four bearings. It gets confusing and teh hydro guy starts picking up new targets and as escorts are doing their search patterns the "closest sound contact" is constantly changing making the use of the "4 bearings method" almost impossible.

What are other people's strategies for plotting a course of a convoy using the hydro (no map contacts)? Thanks.

[palatum]

Given you are quite a distance from the convoy, you should have dound bearings covering about 10 degrees. I usually try to listen where the sound is loudest, and make the plot from that bearing. Or I take the middle of the sector, ie if I hear contacts from 220-235, I take 227. Not the most accurate, but it works until I have the convoy in sight, and I can verify my results.

Palatum

[Dignan]

Given you are quite a distance from the convoy, you should have dound bearings covering about 10 degrees. I usually try to listen where the sound is loudest, and make the plot from that bearing. Or I take the middle of the sector, ie if I hear contacts from 220-235, I take 227. Not the most accurate, but it works until I have the convoy in sight, and I can verify my results.

Palatum


Not a half bad idea. I'll give it a try. I'm currently tracking a large convoy for the second time. The first time, I blew the approach, had to fire my torps early and spent the next 5 hours or so (game time) evading about 7 destroyers. Eventually shook them and am lining up for another ambush. Thanks

[gap]

I will add a few more suggestions:

when you ask the sonarman to follow the nearest contact, he will keep following the same ship, no matter if in the meanwhile another ship has got closer, until something stops him (be another user command or lost signal). With this in mind, you should:



When you start tracking a convoy, turn your boat so to offer one of its sides (where hydrophone sensitivity is better) to it. If the convoy moves too much toward the bow or toward the stern, turn again the boat, and remember to account of the changed heading in your plottings.


Avoid abrupt maneuvers or high speeds. Ideally you should be listening to the enemy at dead stop.


Mantain a constant depth, the further below the sea surface, especially in bad weather, the better. In general, 20-30 m are enough.


If possible, always ask the sonarman to follow the nearest merchant: destroyers tend to move a lot within the convoy, and they change speed often.


Refrain yourself from giving our Benno any further order while he is doing his job: he is prone to loosing concentration. :shifty: You can nonetheless ask him to report the bearing of the current target without any adverse consequence.


If you are using New UI's, you can set the interval (in degrees or in seconds) between two consecutive hydrophone logs. Set this interval reasonably low. In this way, if you loose your contact, you will know more or less where to look for it again.

If, despite all your precautions, Benno looses the contact, keep note of its last known bearing and do one of the following:



Try again asking the sonarman to report the nearest contact. If you are lucky, he will track again the same target.


If you are using New UI's, a while ago TDW added a command for following the contact closer to the current hydrophone bearing: go to the hydrophone, sweep it to where the contact was reported the last time, adjust the bearing so to get the strongest possible sound, and ask the sonarman to follow it (it should be one of the arrows protruding from the hydrostation notebook).


If eveything else fails, the one option left is to follow the target yourself (:-?), and remember: unlike in SH5, real German hydrophones weren't so accurate to provide a reliable firing solution. A good dose of approximation can only increase the realism of your gaming experience :03:

[Dignan]

I will add a few more suggestions:

when you ask the sonarman to follow the nearest contact, he will keep following the same ship, no matter if in the meanwhile another ship has got closer, until something stops him (be another user command or lost signal). With this in mind, you should:



When you start tracking a convoy, turn your boat so to offer one of its sides (where hydrophone sensitivity is better) to it. If the convoy moves too much toward the bow or toward the stern, turn again the boat, and remember to account of the changed heading in your plottings.


Avoid abrupt maneuvers or high speeds. Ideally you should be listening to the enemy at dead stop.


Mantain a constant depth, the further below the sea surface, especially in bad weather, the better. In general, 20-30 m are enough.


If possible, always ask the sonarman to follow the nearest merchant: destroyers tend to move a lot within the convoy, and they change speed often.


Refrain yourself from giving our Benno any further order while he is doing his job: he is prone to loosing concentration. :shifty: You can nonetheless ask him to report the bearing of the current target without any adverse consequence.


If you are using New UI's, you can set the interval (in degrees or in seconds) between two consecutive hydrophone logs. Set this interval reasonably low. In this way, if you loose your contact, you will know more or less where to look for it again.

If, despite all your precautions, Benno looses the contact, keep note of its last known bearing and do one of the following:



Try again asking the sonarman to report the nearest contact. If you are lucky, he will track again the same target.


If you are using New UI's, a while ago TDW added a command for following the contact closer to the current hydrophone bearing: go to the hydrophone, sweep it to where the contact was reported the last time, adjust the bearing so to get the strongest possible sound, and ask the sonarman to follow it (it should be one of the arrows protruding from the hydrostation notebook).


If eveything else fails, the one option left is to follow the target yourself (:-?), and remember: unlike in SH5, real German hydrophones weren't so accurate to provide a reliable firing solution. A good dose of approximation can only increase the realism of your gaming experience :03:


Great ideas. Thanks for the detailed response. I think my problem was that I kept asking for nearest contact which was usually a zig zagging escort. I'll try asking consistently for closest merchant. Thanks a bunch:up: