Telling Heading From Hydrophone Bearing

BigZed · 02-12-07, 04:25 PM

When your sonarman finds a contact hit "H" to go to the sonar and search within the bearing range that he called out. When you find the proper bearing of the ship click the "hydrophone" station button then click "sonar" then click "find range to target" or "range to target". As long as you keep the needle on the target bearing (in the top right corner it should say "merchant" or "warship" or "unknown") then after a few seconds you will get a reading of how far the ship is. Once you get that hit the checkmark in the pad at the upper right corner and that will send the info to your attack periscope.

Right now ive just started to learn how to manual target ships and fire torps manually so my "realism" settings are about 81% or 85% something like that. That is how i find my range to targets when submerged and dont have enough time to open the recognition manual.

GreyBeard · 02-12-07, 06:42 PM

Quote:

Originally Posted by BigZed

When your sonarman finds a contact hit "H" to go to the sonar and search within the bearing range that he called out. When you find the proper bearing of the ship click the "hydrophone" station button then click "sonar" then click "find range to target" or "range to target". As long as you keep the needle on the target bearing (in the top right corner it should say "merchant" or "warship" or "unknown") then after a few seconds you will get a reading of how far the ship is. Once you get that hit the checkmark in the pad at the upper right corner and that will send the info to your attack periscope.

Right now ive just started to learn how to manual target ships and fire torps manually so my "realism" settings are about 81% or 85% something like that. That is how i find my range to targets when submerged and dont have enough time to open the recognition manual.

I must be missing something here. What does opening the recognition manual have to do with the range to a particular target?

immortal44 · 02-12-07, 07:02 PM

I assume when he's surfaced he finds the range using notepad, which requires you to identify the ship in order to find the range.

Rykaird · 02-12-07, 07:05 PM

I read the manual for the hydrophone tutorial, but it seemed to address only determining speed of the target, not the bearing.

I think there must be a way to determine heading from repeated bearing measurements using:

1) the time gaps between the bearing changes (hypothetical example - to move from a bearing of 60 to 65 degrees took 2 minutes, but from 65 to 70 degrees took 1 minute - this would imply he's closing).

and

2) a rough estimate of his speed (e.g., slow = 5 knots, medium = 9 knots).

I'll noodle on it some more. It seems like a series of triangles. And as we know, the triangle is all powerful.

greyrider · 02-12-07, 07:18 PM

i'm pretty sure your target is at a 90 degree right angle to you already, as long as it keeps saying constant distance

greyrider · 02-12-07, 07:05 PM

rykaird,

if your are in your sound room, with the bearing needle of the hydrophone laying on the target bearing, and your listening to his screws,
on the loudest bearing, look up on the sound operators note pad.
if you do not see "warship", "merchant", or "unknown" written on his notepad, then your target is somewhere between 7.5 km and 34 km.
the sound operator writes the sound cone of the targets screws on his notepad.
but he only writes his soundcone for ranges 7.5 km and less, beyond that its up to you to determine range by sound cone and amplitude.
the sound operator must be recording the inner sound cone, because the complete sound cone can be as much as twenty degree's, even at 8 km.

anything over 7.5 km, he writes nothing.
anything 7.5 km and closer, he begins to draw and record his soundcone of the target by writting it on the notepad.
he does this by writing the type of sound contact he has on his notepad on every bearing he hears the inner cone, which is the width of the soundcone,
which is determined by range.

example:
merchant bearing zero degree's, range 8 km, target is closing, target course is 180, speed unknown, u-boat at dead stop, course 000.

target range now 8 km, sound operators notepad blank

target range now 7.5 km SO notepad entry, "merchant" appears on bearing ooo: fringe bearings 359 and 001 blank, sound cone width is 1 degree.

target range now 7 km SO notepad entry, "merchant" appears on bearings 359 and 001: fringe bearings 358 and 002 blank, sound cone width is two degrees.

target range now 6.3 km SO notepad entry, "merchant" appears on bearings 358,359 and 001,002: fringe bearings 357 and 003 blank, sound cone width is four degrees.

target range now 4.1 km SO notepad entry, "merchant" appears on bearings 357,358,359 and 001,002,003: fringe bearings 356 and 004 blank, sound cone width is six degrees.

target range now 2.8 km SO notepad entry, "merchant" appears on bearings 356,357,358,359 and 001,002,003,004: fringe bearings 355 and 005 blank, sound cone width is eight degrees.

target range now 1.0 km SO notepad entry, "merchant" appears on bearings 355,356,357,358,359 and 001,002,003,004,005: fringe bearings 354 and 006 blank, sound cone width is ten degrees.

target range now 400 m SO notepad entry, "merchant" appears on bearings 354,355,356,357,358,359 and 001,002,003,004,005,006: fringe bearings 353 and 007 blank, sound cone width is 12 degrees.

for longer ranges i compare the amplitdue of the screws verse the background noise of the hydrophones, if it seems that the noise is louder than the screws, then i know the target is
at least over 15 km away.
if the screws sound louder than the background noise, then the target is closer than 15 km.
hope this helps, and good luck!

Rykaird · 02-12-07, 07:18 PM

Quote:

Originally Posted by greyrider

rykaird,

if your are in your sound room, with the bearing needle of the hydrophone laying on the target bearing, and your listening to his screws,
on the loudest bearing, look up on the sound operators note pad.
if you do not see "warship", "merchant", or "unknown" written on his notepad, then your target is somewhere between 7.5 km and 34 km.
the sound operator writes the sound cone of the targets screws on his notepad.
but he only writes his soundcone for ranges 7.5 km and less, beyond that its up to you to determine range by sound cone and amplitude.
the sound operator must be recording the inner sound cone, because the complete sound cone can be as much as twenty degree's, even at 8 km.

anything over 7.5 km, he writes nothing.
anything 7.5 km and closer, he begins to draw and record his soundcone of the target by writting it on the notepad.
he does this by writing the type of sound contact he has on his notepad on every bearing he hears the inner cone, which is the width of the soundcone,
which is determined by range.

example:
merchant bearing zero degree's, range 8 km, target is closing, target course is 180, speed unknown, u-boat at dead stop, course 000.

target range now 8 km, sound operators notepad blank

target range now 7.5 km SO notepad entry, "merchant" appears on bearing ooo: fringe bearings 359 and 001 blank, sound cone width is 1 degree.

target range now 7 km SO notepad entry, "merchant" appears on bearings 359 and 001: fringe bearings 358 and 002 blank, sound cone width is two degrees.

target range now 6.3 km SO notepad entry, "merchant" appears on bearings 358,359 and 001,002: fringe bearings 357 and 003 blank, sound cone width is four degrees.

target range now 4.1 km SO notepad entry, "merchant" appears on bearings 357,358,359 and 001,002,003: fringe bearings 356 and 004 blank, sound cone width is six degrees.

target range now 2.8 km SO notepad entry, "merchant" appears on bearings 356,357,358,359 and 001,002,003,004: fringe bearings 355 and 005 blank, sound cone width is eight degrees.

target range now 1.0 km SO notepad entry, "merchant" appears on bearings 355,356,357,358,359 and 001,002,003,004,005: fringe bearings 354 and 006 blank, sound cone width is ten degrees.

target range now 400 m SO notepad entry, "merchant" appears on bearings 354,355,356,357,358,359 and 001,002,003,004,005,006: fringe bearings 353 and 007 blank, sound cone width is 12 degrees.

for longer ranges i compare the amplitdue of the screws verse the background noise of the hydrophones, if it seems that the noise is louder than the screws, then i know the target is
at least over 15 km away.
if the screws sound louder than the background noise, then the target is closer than 15 km.
hope this helps, and good luck!

Thanks! The fact on the 7.5km range of the sound operator writing anything on his notepad is a huge help right there, as is the tip on the 15km.

I'm not sure what to do with the sound cone information - how does the cone width give me range exactly? Thanks for the help here - I think I'm getting closer to being able to hunt "blind."

greyrider · 02-12-07, 07:40 PM

been so long since i posted, i forget how to quote, but you said

I'm not sure what to do with the sound cone information - how does the cone width give me range exactly? Thanks for the help here - I think I'm getting closer to being able to hunt "blind."

wow! i guess i dont have to remember.

anyway to answer, it comes in handy when your being attacked by more than one dd. now, by sweeping a dd's soundcone, youll be able to tell which one is your biggest threat, the bigger the soundcone, the closer the range

High Voltage · 02-12-07, 07:44 PM

you guys are golden! I'm not sure where you got all of this info as my soundman Bernard usually just yells out "Wasserbomben" when I'm resting in my bunk, but I've printed out this info for further study.

PS Where DID you find out about the 7.5km rule?

Rykaird · 02-12-07, 10:32 PM

Quote:

Originally Posted by greyrider

anyway to answer, it comes in handy when your being attacked by more than one dd. now, by sweeping a dd's soundcone, youll be able to tell which one is your biggest threat, the bigger the soundcone, the closer the range

This works very well - I was able to tell that I was closing the gap on a distant merchant by counting the number of degrees in the cone and watching to see if they increased.

I still think there must be a way to get some guestimate of his course using the hydrophone, a stopwatch, and his approximate speed. But maybe not - it may require the range. I'll have to brush up on my side-angle-side geometry theorems.

Dantenoc · 02-13-07, 03:09 AM

Read this:
http://www.subsim.com/radioroom/showthread.php?t=92743

to interpret the lines made on the example pictures, just remeber that they represent aproximate positions for the target at different points in time that where given to you as intervals (for example "medium range") and hence they're not points but lines that go from "here to there" according to the range estimate given. You can see that as the range to target closes the lines shift to smaller sizes. For example the last ones are only 1 km long, since "short" range means from 0km to 1km, whereas the previous ones where 2km long, because "medium" range means more than 1km but less than 3km (giving you a 2km interval). And of course, the big line that represent's the target's track is drawn and continualy updated so that it cuts through all of the "contact" lines (this assumes that the target is traveling in a straight line).

Anyway, just read it carefully and I'm sure you'll get it.

Also, observe how this technique is used auxiliarly in the 2nd part of the "Video Hunt":
http://www.subsim.com/radioroom/showthread.php?t=97682
And of course, there's allways this thread:
http://www.subsim.com/radioroom/showthread.php?t=88961

02-12-07, 04:25 PM	#1
BigZed Swabbie Join Date: Jan 2007 Location: Canada Posts: 10 Downloads: 0 Uploads: 0	Sonar Button -> Range to Target When your sonarman finds a contact hit "H" to go to the sonar and search within the bearing range that he called out. When you find the proper bearing of the ship click the "hydrophone" station button then click "sonar" then click "find range to target" or "range to target". As long as you keep the needle on the target bearing (in the top right corner it should say "merchant" or "warship" or "unknown") then after a few seconds you will get a reading of how far the ship is. Once you get that hit the checkmark in the pad at the upper right corner and that will send the info to your attack periscope. Right now ive just started to learn how to manual target ships and fire torps manually so my "realism" settings are about 81% or 85% something like that. That is how i find my range to targets when submerged and dont have enough time to open the recognition manual.

02-12-07, 07:18 PM	#5
greyrider Watch Officer Join Date: Apr 2005 Location: massachusetts Posts: 334 Downloads: 237 Uploads: 0	i'm pretty sure your target is at a 90 degree right angle to you already, as long as it keeps saying constant distance __________________ Her gun crew had guts, however, for from her canting bow came a half dozen well-aimed rounds. How they pointed and trained their gun on that tilting platform will long remain a wonder, and their dedication in keeping up the fire until they went under would be a matter of pride to any nation. O'Kane, Richard. Clear the Bridge!: The War Patrols of the U.S.S. Tang

02-12-07, 07:05 PM	#6
greyrider Watch Officer Join Date: Apr 2005 Location: massachusetts Posts: 334 Downloads: 237 Uploads: 0	rykaird, if your are in your sound room, with the bearing needle of the hydrophone laying on the target bearing, and your listening to his screws, on the loudest bearing, look up on the sound operators note pad. if you do not see "warship", "merchant", or "unknown" written on his notepad, then your target is somewhere between 7.5 km and 34 km. the sound operator writes the sound cone of the targets screws on his notepad. but he only writes his soundcone for ranges 7.5 km and less, beyond that its up to you to determine range by sound cone and amplitude. the sound operator must be recording the inner sound cone, because the complete sound cone can be as much as twenty degree's, even at 8 km. anything over 7.5 km, he writes nothing. anything 7.5 km and closer, he begins to draw and record his soundcone of the target by writting it on the notepad. he does this by writing the type of sound contact he has on his notepad on every bearing he hears the inner cone, which is the width of the soundcone, which is determined by range. example: merchant bearing zero degree's, range 8 km, target is closing, target course is 180, speed unknown, u-boat at dead stop, course 000. target range now 8 km, sound operators notepad blank target range now 7.5 km SO notepad entry, "merchant" appears on bearing ooo: fringe bearings 359 and 001 blank, sound cone width is 1 degree. target range now 7 km SO notepad entry, "merchant" appears on bearings 359 and 001: fringe bearings 358 and 002 blank, sound cone width is two degrees. target range now 6.3 km SO notepad entry, "merchant" appears on bearings 358,359 and 001,002: fringe bearings 357 and 003 blank, sound cone width is four degrees. target range now 4.1 km SO notepad entry, "merchant" appears on bearings 357,358,359 and 001,002,003: fringe bearings 356 and 004 blank, sound cone width is six degrees. target range now 2.8 km SO notepad entry, "merchant" appears on bearings 356,357,358,359 and 001,002,003,004: fringe bearings 355 and 005 blank, sound cone width is eight degrees. target range now 1.0 km SO notepad entry, "merchant" appears on bearings 355,356,357,358,359 and 001,002,003,004,005: fringe bearings 354 and 006 blank, sound cone width is ten degrees. target range now 400 m SO notepad entry, "merchant" appears on bearings 354,355,356,357,358,359 and 001,002,003,004,005,006: fringe bearings 353 and 007 blank, sound cone width is 12 degrees. for longer ranges i compare the amplitdue of the screws verse the background noise of the hydrophones, if it seems that the noise is louder than the screws, then i know the target is at least over 15 km away. if the screws sound louder than the background noise, then the target is closer than 15 km. hope this helps, and good luck! __________________ Her gun crew had guts, however, for from her canting bow came a half dozen well-aimed rounds. How they pointed and trained their gun on that tilting platform will long remain a wonder, and their dedication in keeping up the fire until they went under would be a matter of pride to any nation. O'Kane, Richard. Clear the Bridge!: The War Patrols of the U.S.S. Tang

02-12-07, 07:40 PM	#8
greyrider Watch Officer Join Date: Apr 2005 Location: massachusetts Posts: 334 Downloads: 237 Uploads: 0	been so long since i posted, i forget how to quote, but you said I'm not sure what to do with the sound cone information - how does the cone width give me range exactly? Thanks for the help here - I think I'm getting closer to being able to hunt "blind." wow! i guess i dont have to remember. anyway to answer, it comes in handy when your being attacked by more than one dd. now, by sweeping a dd's soundcone, youll be able to tell which one is your biggest threat, the bigger the soundcone, the closer the range __________________ Her gun crew had guts, however, for from her canting bow came a half dozen well-aimed rounds. How they pointed and trained their gun on that tilting platform will long remain a wonder, and their dedication in keeping up the fire until they went under would be a matter of pride to any nation. O'Kane, Richard. Clear the Bridge!: The War Patrols of the U.S.S. Tang

02-12-07, 07:44 PM	#9
High Voltage Chief Join Date: Jan 2007 Location: U-33. Depth Charges...sinking.. Posts: 325 Downloads: 0 Uploads: 0	you guys are golden! I'm not sure where you got all of this info as my soundman Bernard usually just yells out "Wasserbomben" when I'm resting in my bunk, but I've printed out this info for further study. PS Where DID you find out about the 7.5km rule? __________________ The new-moon night is black as ink. Off Hatteras the tankers sink. While sadly Roosevelt counts the score-- Some fifty thousand tons--by MOHR

02-12-07, 07:02 PM	#3
immortal44 Seaman Join Date: Feb 2007 Posts: 41 Downloads: 0 Uploads: 0	I assume when he's surfaced he finds the range using notepad, which requires you to identify the ship in order to find the range.

02-12-07, 07:05 PM	#4
Rykaird Weps Join Date: Jan 2007 Posts: 356 Downloads: 36 Uploads: 0	I read the manual for the hydrophone tutorial, but it seemed to address only determining speed of the target, not the bearing. I think there must be a way to determine heading from repeated bearing measurements using: 1) the time gaps between the bearing changes (hypothetical example - to move from a bearing of 60 to 65 degrees took 2 minutes, but from 65 to 70 degrees took 1 minute - this would imply he's closing). and 2) a rough estimate of his speed (e.g., slow = 5 knots, medium = 9 knots). I'll noodle on it some more. It seems like a series of triangles. And as we know, the triangle is all powerful.

02-13-07, 03:09 AM	#11
Dantenoc Captain Join Date: Jan 2006 Location: Ensenada, B.C., Mexico Posts: 504 Downloads: 0 Uploads: 0	Read this: http://www.subsim.com/radioroom/showthread.php?t=92743 to interpret the lines made on the example pictures, just remeber that they represent aproximate positions for the target at different points in time that where given to you as intervals (for example "medium range") and hence they're not points but lines that go from "here to there" according to the range estimate given. You can see that as the range to target closes the lines shift to smaller sizes. For example the last ones are only 1 km long, since "short" range means from 0km to 1km, whereas the previous ones where 2km long, because "medium" range means more than 1km but less than 3km (giving you a 2km interval). And of course, the big line that represent's the target's track is drawn and continualy updated so that it cuts through all of the "contact" lines (this assumes that the target is traveling in a straight line). Anyway, just read it carefully and I'm sure you'll get it. Also, observe how this technique is used auxiliarly in the 2nd part of the "Video Hunt": http://www.subsim.com/radioroom/showthread.php?t=97682 And of course, there's allways this thread: http://www.subsim.com/radioroom/showthread.php?t=88961 __________________ Going to U-boot school : http://www.subsim.com/radioroom/showthread.php?t=88922 http://www.subsim.com/radioroom/showthread.php?t=90234 http://www.subsim.com/radioroom/showthread.php?t=88961 http://www.subsim.com/radioroom/showthread.php?t=97682