SUBSIM Radio Room Forums - View Single Post - Intercepting targets.....again I'm sure!!!

Pisces · 05-30-14, 05:49 AM

Plotting the faint endpoints of the sonar line is a good way to start as a beginner. Or as an experienced player, ... do whatever you like.

It's just not quite realistic to get a range measurement from the hydrophone. As sound volume changes are very unreliable to base a distance on. But the same might be said of the accuracy of a hydrophone bearing drawn on the map. Real life equipment might not have given such precise directions. If you measure the bearing with the hydrophone controls yourself then it becomes much more believable it could have been used. The math/geometry is certainly not rocket science.

An advanced method is to use what is known as the 4-bearing method. There are actually some variations of this method. But all use no range information from the hydrophone operator, only bearings (directions) at regular time intervals. Using that, and a bit of geometry magic (and a bit of patience), you can figure out what his rough course is. And if you displace your uboat you can also find his position/range and speed.

This video (windows media file) inside a rar-archive explains how to do it while being stationary for the first 3 bearings. From those 3 you predict graphically where the 4th bearing would come from after the next interval. But instead of staying where you are, you move a way to get a different vantage point and listen where the sound comes from then. The intersection of the predicted 4th bearing, and the real (displaced) 4th bearing is where he is really at. So you have his position now. As you knew what his approximate course was, you can trace his movement back across the earlier bearings. And from those distances in between them you can calculate the time it took him to cross those lengths. From that you now have speed also.

Kuikeg invented a different method (actually 2 variations) to do this while moving all the time. This might be necessary for your boat to keep depth, or whatever the tactical situation demands.

Thread:
http://www.subsim.com/radioroom/showthread.php?t=179137

Version 1:
http://ricojansen.nl/downloads/four_bearings_method.pdf

Version 2:
http://ricojansen.nl/downloads/the_f...%20Kuikueg.pdf

Makman made this video tutorial:

Stoianm made this tutorial: (in SH5, but is no different in SH3, same map tools)

05-30-14, 05:49 AM	#5
Pisces Silent Hunter Join Date: Dec 2004 Location: AN9771 Posts: 4,904 Downloads: 304 Uploads: 0	Plotting the faint endpoints of the sonar line is a good way to start as a beginner. Or as an experienced player, ... do whatever you like. It's just not quite realistic to get a range measurement from the hydrophone. As sound volume changes are very unreliable to base a distance on. But the same might be said of the accuracy of a hydrophone bearing drawn on the map. Real life equipment might not have given such precise directions. If you measure the bearing with the hydrophone controls yourself then it becomes much more believable it could have been used. The math/geometry is certainly not rocket science. An advanced method is to use what is known as the 4-bearing method. There are actually some variations of this method. But all use no range information from the hydrophone operator, only bearings (directions) at regular time intervals. Using that, and a bit of geometry magic (and a bit of patience), you can figure out what his rough course is. And if you displace your uboat you can also find his position/range and speed. This video (windows media file) inside a rar-archive explains how to do it while being stationary for the first 3 bearings. From those 3 you predict graphically where the 4th bearing would come from after the next interval. But instead of staying where you are, you move a way to get a different vantage point and listen where the sound comes from then. The intersection of the predicted 4th bearing, and the real (displaced) 4th bearing is where he is really at. So you have his position now. As you knew what his approximate course was, you can trace his movement back across the earlier bearings. And from those distances in between them you can calculate the time it took him to cross those lengths. From that you now have speed also. Kuikeg invented a different method (actually 2 variations) to do this while moving all the time. This might be necessary for your boat to keep depth, or whatever the tactical situation demands. Thread: http://www.subsim.com/radioroom/showthread.php?t=179137 Version 1: http://ricojansen.nl/downloads/four_bearings_method.pdf Version 2: http://ricojansen.nl/downloads/the_f...%20Kuikueg.pdf Makman made this video tutorial: Stoianm made this tutorial: (in SH5, but is no different in SH3, same map tools)