PHG & DFS Circles / Plots

I am experimenting with PHG circles on OpenAPRS's map system. The image to the left shows a digipeater with it's associated coverage circle based on the PHG calculated range. I'm not entirely positive the circle calculations are correct but they appear to be pretty close (I'm no math wizard). The circles are displayed in a opaque red circle, in the near future I'll add a selection box to the options menu to turn the feature on and off.

I've also added PHG information in both the APRS search engine results and in the balloon popups on the OpenAPRS map. DFS is also supported in the same way though on the OpenAPRS map the circle is a green line, however, I don't seen anyone broadcasting DFS so it's moot point I guess.

The circles are displayed whether or not the antenna directivity is omni or a bearing, I plan to also create direction lines in place of the great circles when a station gives it's directivity.

Update: Antenna/DFS Directivity lines are are now plotted from the stations position according to bearing and distance.