[XLjedi]

Originally Posted by Pisces

Indeed, the 2nd image in the 2nd link... or to be less confusing ... this one:



... shows what is missing with the 3-bearing sliderule post (figuring out range and speed). Project an imaginary future 4th bearing line on the map (by drawing the target track at an arbitrary range, and copying the distance between bearing intersections with a circle) and sprinting away from the listening location for the duration of the interval as fast as possible. A real 4th hydrophone bearingline (the 5th in the image) taken from the new position should intersect the imaginary 4th bearing at the real location of the target at that time. From that also speed can be figure out. (once the target track is re-drawn through the 4th bearing position fix.)

I really should be making a complete walkthrough of this oneday. Ugh, so often I promised to do.

This picture represents exactly what the TMA tool in MoBo was built to do... In fact, you can also add vectors to negate your own subs movement to get an accurate true course if taking the bearings while moving.

Anyone ever try it?