Advanced hydrophone techniques.

[Charos]

Originally Posted by Sawdust

Pretty neat trick.

I guess you are using the circle to determine the range of the target at each of the three bearing surveys.

When I play with map updates on, the hydrophone results shows both bearing and distance...do you not get a distance reading the the hydrophone without map updates?
If not, can you eventually learn the distance to a target by the volume of the sound of its propellers?

The circle is merely a geometrical tool to connect all three bearing time stamps based on the fact that the Target is travelling in a straight line and at a constant speed.

The Vector representing the Ships course and speed bisects the circle and where it interescts each bearing measurement provides you with the distance from your U-Boat at any time between these bearings.
If this line is then projected beyond those bearings it represents a position the Target will be in the future.

The Vector that represents the target vessel simply falls between the three measured bearings and because (in this case) we have used time stamps for each bearing that are equally spaced a circle can be used as the outer bearings can be aligned tangentially to the circle.

In fact you can use Bearings with any timestamp you wish if you have an idea of the target speed.