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Old 07-16-23, 08:14 PM   #1
Fidgety
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Default 4 bearing method impossible

hello


Just wanted to get peoples oppinion on doing the 4 bearing hydrophone tracking method in this game.


Have you tried it yet?


Just wondering if I'm the only person that gets "mixed results"?


Seems like the "map" , in the game world isn't coded properly. I get the most random results from hydrohone intercepts.


Weird range.
Course wrong.
speed wrong.


Anyone else?
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Old 07-17-23, 12:42 AM   #2
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As far as I can tell, everything is coded properly. We did our best to test it and haven't seen major deviations in the latest versions.

Just remember, that the convoy may change its direction, as it's not travelling on a straight line from port A to B. It may also be attacked by other u-boats, which may also affect what you hear. To counteract such problems, try to make multiple measurements as you approach it rather than to count on limited data points. Hope it helps
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Old 08-20-23, 11:28 PM   #3
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I concur with Fidgety that doing bearing-only interception is pretty much impossible in Uboat. For one the resolution on the manual hydrophone seems to be very low. In the silent hunter series you can narrow the bearing down to a degree. Not sure if that is realistic but it makes taking accurate bearings possible. Secondly the map blip shows you the bearing, range, and even course getting in the way of plotting on even the most realistic settings!

This is very disappointing to me. I spent hours developing my own mathematical conjectures and proofs for target motion analysis methods in the silent hunter series. It makes for an interesting hunt. If you made more advanced tracking and interception methods viable on the hardest difficulty, and added some troop ships and ocean liners and various other targets, I would rate this game 5/5. Right now it's just a bit boring on even the hardest and most realistic settings I'm afraid.
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Old 08-22-23, 01:31 AM   #4
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HI PDoolittle,

I can't understand your problem. Can you explain it in more detail. It is also logical that distant noises can only be rudimentarily located.
Here is an example of plotting an intercept course based on a radio message. The same works with a bearing. Of course, if you want to use the bearing for an intercept course, you must first determine the course, distance and speed based on bearing.


We receive a radio message at 4:53 a.m. Convoy position AM 489, course 264, 7 knots.
We calculate an intercept course based on this message and the position of the boat.
Necessary parameters from the boat are speed, AOB and current distance to the convoy.



Calculated intercept course is 309 deg., distance 757 km, duration 1 day, 7 h 27 min.



At this position we should intercept the convoy.






We arrive a little earlier, because the boat was travelling a little faster in parts. But better too early than too late. We wait for the convoy ...







The convoy is exactly at the position at the calculated time.


Cheers Ruby

Last edited by Ruby2000; 08-22-23 at 01:47 AM.
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Old 08-22-23, 07:51 AM   #5
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Nice post Ruby
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Old 08-22-23, 11:34 AM   #6
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Nice post Ruby
Naturally! It's Ruby Tuesday!
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Old 08-22-23, 02:12 PM   #7
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Fantastic! Question Ruby;

Where can I find a tool like the one you've shown entering in the target's information?

Quote:
Originally Posted by Ruby2000 View Post
HI PDoolittle,

I can't understand your problem. Can you explain it in more detail. It is also logical that distant noises can only be rudimentarily located.
Here is an example of plotting an intercept course based on a radio message. The same works with a bearing. Of course, if you want to use the bearing for an intercept course, you must first determine the course, distance and speed based on bearing.


We receive a radio message at 4:53 a.m. Convoy position AM 489, course 264, 7 knots.
We calculate an intercept course based on this message and the position of the boat.
Necessary parameters from the boat are speed, AOB and current distance to the convoy.



Calculated intercept course is 309 deg., distance 757 km, duration 1 day, 7 h 27 min.



At this position we should intercept the convoy.






We arrive a little earlier, because the boat was travelling a little faster in parts. But better too early than too late. We wait for the convoy ...







The convoy is exactly at the position at the calculated time.


Cheers Ruby
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Old 08-22-23, 11:56 PM   #8
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Thank you for the response Ruby.

The problem is that bearing-only interception from hydrophone, which arguably would be the most realistic method for finding a convoy, does not seem to be truly supported in Uboat. It's based on something called target motion analysis. You should be able to determine the target's course, range, and speed, just by knowing what the direction to the target or bearing is at different points in time with some simplifying assumptions (constant course and speed). That is the basis for the four-bearing method. When you get a hydrophone contact on the hardest settings, the estimated range and course are already calculated for you and shown by the location and movement of the blip on the map. I would prefer if the hydrophone contact was not so telling, just an accurate bearing.

Bearing only TMA is beautiful when you get to appreciate how it works. Since TMA provides you range, course, and speed JUST by analyzing the hydrophone bearing changes over different intervals, you can make torpedo attacks without ever raising your periscope. It depends on a precise hydrophone bearing and I can't seem to work the manual hydrophone in order to get an accurate bearing. I am fully willing and able to mod the game to make this possible at some point. Maybe it's not something that even belongs in Uboat since true-to-life realism is obviously not the style of the game, but the more realistic torpedo attack methods are much more fun to me and I really do like Uboat's other mechanics as well. Another thing I think this game needs is the RAOBF. That is another dark art of uboating that people will appreciate when they learn how to use.

P.S. even though the targets course may change at points in time, for large periods their course will be constant speed and heading which makes TMA viable.

https://en.wikipedia.org/wiki/Target_Motion_Analysis

https://wolfpack.fandom.com/wiki/4-B...ly%20submerged.

Last edited by PDoolittle; 08-23-23 at 12:09 AM.
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Old 08-23-23, 12:07 AM   #9
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Quote:
Originally Posted by PDoolittle View Post
Thank you for the response Ruby.

The problem is that bearing-only interception from hydrophone, which arguably would be the most realistic method for finding a convoy does not seem to be truly supported in Uboat. It's based on something called target motion analysis. You should be able to determine the target's course, range, and speed, just by knowing what the direction to the target or bearing is at different points in time with some simplifying assumptions (constant course and speed). That is the basis for the four-bearing method.

When you get a hydrophone contact on the hardest settings, the estimated range and course are already calculated for you and shown by the location and movement of the blip on the map. I would prefer if the hydrophone contact was much more vague, I only really need to know the bearing to the target and I can use TMA to determine the rest.

You used a radio contact where someone had determined the targets exact course range and speed for you. I expect to do all that myself. Not with a stadimeter or a watch, but with bearing-only methods from a great distance. It's beautiful when you get to appreciate how it works. It depends on a precise hydrophone bearing and I can't seem to work the manual hydrophone in order to get an accurate bearing. Which seems like it should be possible?

P.S. even though the targets course may change at points in time, for large periods their course will be constant speed and heading which makes TMA viable.

https://en.wikipedia.org/wiki/Target_Motion_Analysis

https://wolfpack.fandom.com/wiki/4-B...ly%20submerged.
I can't promise anything yet, but we either plan to or already removed that information from the map in the full release version.

Regarding what you mentioned in the previous message, that it's difficult to narrow down the direction of a sound down to a degree with the hydrophone like in SH, it's done on intention. At such distances mostly low frequencies of sound are audible, while high frequencies are completely gone. Low frequency sound in water diffuses in all directions and it shouldn't be possible to narrow down its direction to a degree (or maybe rather - it could, but it should be difficult).

If you would prefer to see the behaviour from SH, it should be possible to mod this into the game, although some programming may be required.
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Old 08-23-23, 12:44 PM   #10
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Default Welcome aboard!

PDoolittle!
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Old 08-23-23, 04:46 PM   #11
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Quote:
Originally Posted by Lite_ly Salted View Post
Fantastic! Question Ruby;

Where can I find a tool like the one you've shown entering in the target's information?
Look online for a maneuvering board app. Or buy a pack of maneuvering boards, a couple of pencils, dividers, compass and a parallel plotter from Amazon and do it the old fashioned way. It’s actually very easy to learn and use to plot an intercept course.

15 or so years ago someone on SUBSIM developed an app and posted it here. Not sure if SUBSIM archives search go back that far though.

Looked around a little bit and found this, which I have not yet explored myself yet, good luck. https://www.subsim.com/radioroom/forumdisplay.php?f=225

Last edited by Rockstar; 08-23-23 at 05:22 PM.
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Old 08-24-23, 12:08 AM   #12
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Quote:
Originally Posted by Lite_ly Salted View Post
Fantastic! Question Ruby;

Where can I find a tool like the one you've shown entering in the target's information?
HI Lite_ly Salted,

This is an Excel file that I created a long time ago.

Cheers Ruby
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Old 08-24-23, 10:19 AM   #13
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Quote:
Originally Posted by Rockstar View Post

Looked around a little bit and found this, which I have not yet explored myself yet, good luck. https://www.subsim.com/radioroom/forumdisplay.php?f=225
I think at one time this was quite popular
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