Quote:
Originally Posted by RingoCalamity
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There's got to be some kind of way of using math/trig to find that point where the line fits, but I don't know it and I haven't been able to work it out. As well, the tools for doing so in the game are clumsy and inaccurate. The best option seems to be taking the two angles to the bearings from our boat and the measurement from game data, plotting them on paper, and using your ruler to find the course, then sticking it back in the game. Some of the other measurements would be easier on paper but can be done in game.
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Nods in agreement.
http://www.subsim.com/radioroom/showthread.php?t=147719
My tool determines the AOB at the 1st bearing. And so a course is fixed as the relative bearing can be converted to a true-bearing. But range and speed isn't directly possible with it. It can be determined in the way you figured it out yourself allready, by sprinting away from your listening position and take a 4th bearing that crosses an 'imaginary/projected 4th'.
(it is very similar to this:
http://forums.ubi.com/eve/forums/a/t...535#7821098535 or the same here in Subsim.com:
http://www.subsim.com/radioroom/showthread.php?t=110619 )
Personally I view this method more appropriate for situations beyond visual range, or in horrendous fog conditions, and no radar capability. Like doing a random hydrophone check. In ranges of around 5km you might aswel stick a periscope up for a short peek on the bow. Or your lookouts must have been asleep on the job. If it is the case in which you find a longrange hydrophone contact, it is most likely going to take alot more than 3 minutes for the 1st 2 bearings, and ofcourse appropriately longer for the next bearings. Infact, the longer you allow this time interval, the more the bearing differences diverge and the more accurate the resulting AOB becomes. You can see this on the tool in upper degree range where the marks are closer together. At the lower degree-range (5-10) a 0.5 degrees measuring fault on the bearings makes the AOB fairly crude. I suggest initially taking the shortest possible time interval to allow 6 to 7 degrees of drift and match it up with the bearing B3-B1 that follows after the 2nd interval. From that rough course judge how long it takes until the AOB is 90 degrees, aka closest point of approach. Then redo the process with a longer interval halve of that time.
If I may propose another reason for allowing more time. Consider that boredom was the most performed activity onboard subs thosedays (perhaps still is). If you finally found a contact in that huge empty ocean. Would you like to rush things to get it over within an hour, and get back to your previous 'activity'? Or would you like to dedicate your time and attention to it and do it well? For the rest of the day! (with time compression ofcourse)
Speed and range will be most accurate if you sprint away (as fast as possible, surface if you can) perpendicular to the 3rd bearing. This means you don't get too close and be detected (unless you allready have been) when that really was at the closest point of approach, or 90 AOB. And you'll have the best data to perform a propper intercept and end-around. Most likely you are allready in a forward position as you begin the intercept. There is no need to sprint just as long as the time intervals for the first 3 bearings. As long as the 4th 'imaginary' bearing is projected forward in the right proportion you are doing good. But long intervals during the 3 bearings does help accuracy here too.
Aside from my tool there is also a graphical method, and quite different from Mittelwaechters tutorial linked above.
http://files.filefront.com/bearingso.../fileinfo.html
The method explained in the pdf is really based on situations with ownship moving with significant speed (also consider the time intervals used for it). I don't think slow submerged speeds are good for this. And surface-sprint-listen-hops are hard to do with steady average speed. Pick steps 2 through 6 to replace your eyeballing in Part 2 of your own methods (if I may be so bold
). I admit nothing beats a fine pencil, protractor and paper. But Sh3 and Sh4 DO deserve the credit for descent drawing tools, compared to Sh1/ 2. The steps to draw the DRM (direction of relative movement: Y-Z lines in the maneuveringboard chart) are
the same to draw course from those 3 bearings as ownship is not moving.