Improving the 4-bearing method (with ownship moving) using Spiess TMA formula

ljqcn101 · 04-25-19, 05:10 AM

I just found that by using a specific map tool in Wolfpack would make the plotting of 4-bearing method much easier, and also less error prone (i.e. you don't need that triangle formed by the 3 bearing line anymore).

Let's say you have taken 3 bearings while moving, as shown in the video for illustration purpose. And the core methodology behind the 4-bearing method is to find the imaginary 4th bearing line (also called the Spiess Line).

In Wolfpack, there's a handy map tool function called 'draw from midpoint', which can help you find a line splitted equally by the 3 bearing lines. By randomly picking two points on the 2nd bearing line as a starting point, you can extend the lines with equal length to define the Spiess Line.

04-25-19, 05:10 AM	#1
ljqcn101 Sailor man Join Date: Jan 2013 Location: Hong Kong Posts: 50 Downloads: 78 Uploads: 3	Improving the 4-bearing method (with ownship moving) in Wolfpack I just found that by using a specific map tool in Wolfpack would make the plotting of 4-bearing method much easier, and also less error prone (i.e. you don't need that triangle formed by the 3 bearing line anymore). Let's say you have taken 3 bearings while moving, as shown in the video for illustration purpose. And the core methodology behind the 4-bearing method is to find the imaginary 4th bearing line (also called the Spiess Line). In Wolfpack, there's a handy map tool function called 'draw from midpoint', which can help you find a line splitted equally by the 3 bearing lines. By randomly picking two points on the 2nd bearing line as a starting point, you can extend the lines with equal length to define the Spiess Line. __________________ Automatic TMA calculator (metric system) Automatic TMA line detector and solver for DW/SC/688i Automatic TMA line detector and solver for maneuvering target (new) Last edited by ljqcn101; 05-08-20 at 09:48 AM.