Question about 4 bearing method against a convoy

Pisces · 09-26-17, 09:51 AM

Taking the left and right edges of the sound bearing won't work (good enough) with hydrophone 'bearing only' methods. Especially if the convoy has an asymmetric layout. A convoy is almost never a perfect filled square or rectangle. Some units are missing. This could result in an off-center middle of the sound bearing. Skewing your bearings as it rotates around you. Making the resulting bearing plots more inaccurate to reality than it already is for a bearing of a single unit. If you must, use periscope as B_K suggested.

Or use trial and error homing. Move halfway your detection range along the center of the bearing. Break off to start plotting when you make visual contact. At the halfway-point dip down again for a sonar check. Repeat the process. You'll find it eventually and can start to make plots of a single member of the convoy.

Sorry every method has it's limits.

hauangua · 09-26-17, 10:12 AM

Quote:

Originally Posted by Pisces

Taking the left and right edges of the sound bearing won't work (good enough) with hydrophone 'bearing only' methods. Especially if the convoy has an asymmetric layout. A convoy is almost never a perfect filled square or rectangle. Some units are missing. This could result in an off-center middle of the sound bearing. Skewing your bearings as it rotates around you. Making the resulting bearing plots more inaccurate to reality than it already is for a bearing of a single unit. If you must, use periscope as B_K suggested.

Or use trial and error homing. Move halfway your detection range along the center of the bearing. Break off to start plotting when you make visual contact. At the halfway-point dip down again for a sonar check. Repeat the process. You'll find it eventually and can start to make plots of a single member of the convoy.

Sorry every method has it's limits.

Hi Pisces

You which method of intercepting uses?
(by hidrophone)
Four Bering?
Or?
Thanks

Pisces · 09-27-17, 03:17 PM

It's been a while since I played SH(3). But when I found a hydrophone contact I would take 3 bearings while stationary. Use my (prototype 3-bearing AOB calculator disc) to figure out the AOB and target course. Start sprinting away from my listening location. Direction depends on AOB at bearing 3; either along target course when AOB3 is past 90 degrees, or go perpendicular to bearing 3 when less than 90 degrees). In the mean time I use the plot to predict where a 4th (imaginary) bearing line would fall from the listening location. When the time interval is about to end I submerge to take a hydrophone check at a new location. Then the 4th bearing from my current location should intersect with the predicted 4th bearing nicely to locate the actual position of the target.

And I am patient! Bearing difference between 1st and 2nd bearing should be more than 5 degrees. If the bearings drift slow I record the time for each bearing 2 at 5, 6, 7, 8, degrees and so on. Then measure the 3rd bearing for each of those intervals until I judge when the AOB resolution is narrowed down sufficiently to within +/-5 degrees. And then it is as good as a target course given by a radio report.

I haven't mastered 'the 4-bearing method while moving' of Kuikeg (in SH4 or SH5 forum section) in practice. It's on my to-do list when I start playing the game again.

09-27-17, 03:17 PM	#3
Pisces Silent Hunter Join Date: Dec 2004 Location: AN9771 Posts: 4,904 Downloads: 304 Uploads: 0	It's been a while since I played SH(3). But when I found a hydrophone contact I would take 3 bearings while stationary. Use my (prototype 3-bearing AOB calculator disc) to figure out the AOB and target course. Start sprinting away from my listening location. Direction depends on AOB at bearing 3; either along target course when AOB3 is past 90 degrees, or go perpendicular to bearing 3 when less than 90 degrees). In the mean time I use the plot to predict where a 4th (imaginary) bearing line would fall from the listening location. When the time interval is about to end I submerge to take a hydrophone check at a new location. Then the 4th bearing from my current location should intersect with the predicted 4th bearing nicely to locate the actual position of the target. And I am patient! Bearing difference between 1st and 2nd bearing should be more than 5 degrees. If the bearings drift slow I record the time for each bearing 2 at 5, 6, 7, 8, degrees and so on. Then measure the 3rd bearing for each of those intervals until I judge when the AOB resolution is narrowed down sufficiently to within +/-5 degrees. And then it is as good as a target course given by a radio report. I haven't mastered 'the 4-bearing method while moving' of Kuikeg (in SH4 or SH5 forum section) in practice. It's on my to-do list when I start playing the game again. Last edited by Pisces; 09-27-17 at 03:44 PM.

09-26-17, 09:51 AM	#1
Pisces Silent Hunter Join Date: Dec 2004 Location: AN9771 Posts: 4,904 Downloads: 304 Uploads: 0	Taking the left and right edges of the sound bearing won't work (good enough) with hydrophone 'bearing only' methods. Especially if the convoy has an asymmetric layout. A convoy is almost never a perfect filled square or rectangle. Some units are missing. This could result in an off-center middle of the sound bearing. Skewing your bearings as it rotates around you. Making the resulting bearing plots more inaccurate to reality than it already is for a bearing of a single unit. If you must, use periscope as B_K suggested. Or use trial and error homing. Move halfway your detection range along the center of the bearing. Break off to start plotting when you make visual contact. At the halfway-point dip down again for a sonar check. Repeat the process. You'll find it eventually and can start to make plots of a single member of the convoy. Sorry every method has it's limits.