APRS is a ham radio tracking system.
The radio transmits a beacon with GPS info to repeater sites that are all over the planet.
Works very well
Here is a link to a trip I took on the Stelvio.
My ham radio call sign is KC7KW
I made the cables long enough to reach ether soft bag I use for a tail bag.
The Antenna tilts over if needed.
I have a Yaesu VX-8DR handy talky and a 35 watt amp that goes in the bag.