[aprssig] Drone aprs

[Jason KG4WSV]

Do lots of testing for RFI.  I've had problems with hobby RC gear in
the presence of RF, in particular a 1W telemetry radio (900MHz spread
spectrum) caused a spurious control input that was roughly equivalent
to a very large throttle input for a few seconds, causing the aircraft
to jump off the ground, then drop when the "signal" went away.  This
was with Spektrum gear, which seems to be accepted as fairly high
quality stuff in the RC community.

For a dedicated APRS rig I'd probably go with something very low
powered, like the 16mW or 100mW Big Red Bee tracker.  If you've got
one of the open source flight computers (e.g. Ardupilot mega) that is
running the mavlink protocol, it has tracking capability.  And you can
always tie a small GPS to an xbee radio for tracking.

-Jason
kg4wsv