[aprssig] MObile AZ/EL driver

[Bob Bruninga]

Controller maintains AZ/EL of G5500 rotator to Balloon while mobile.

Been wanting to do this for over a decade.  It used to be in APRSdos, but
since few use that anymore, I made it into a stand-alone dongle that goes
between the vehicle GPS and the G5500 rotator.

Another input goes to a TNC (or D7/700/710) to receive the position and
altitude of the balloon.

Reason for it is our Balloon next Friday afternoon from Annapolis, MD will
have a wireless camera on board 2.4 GHz and so we need a high gain tracking
antenna to follow the balloon.  It's a low flier at 5000' or so.  Then we
will cut loose before we hit the Atlantic.

It is not yet ready for prime time, so don't ask.  When I get it all
documented, Ill let you know:

http://aprs.org/balloons.html

Bob, WB4aPR