APRS Tracking System

I operate a small vehicle tracking system comprising the following equipment:
The internal tracker / TNC card is programmed via the serial link using a small application that can set up the various parameters, including smart beaconing (position transmission is more frequent when travelling faster or when turning corners).  My UNPROTO path settings are "WIDE1-1,WIDE2-2".

This system is capable of two-way APRS communication if a computer is attached to the radio's DB9 serial port.  For my home station I constructed the TNC-X with USB interface - an excellent kit and a reliable unit.  I run XASTIR (Linux) to display station information.