I might update this throughout the CTF.
While the compass page is nice to look at, it’s not really all that useful. You can use it as a visual indicator of whether or not the transmitter is active, but other than that, you only have a few things to learn from the code.
A question came up as to whether the heading value is based on true north or magnetic north. It is true north, however you may notice some of the fixed stations have a heading value equal or close to the magnetic declination of the area it’s in.
You may notice the link to the github for the parent project. In it you'll find CSV file which creates the path for the transmitter on dfsim.net. This should be able to give you a refernce point for fine tuning any code you write.
Things worth researching:Great Circle Intersections
Vincenty and Haversine Equations