A portable self-contained tracking unit includes an enclosure attached to a mounting plate, with a hollow interior cavity housing a GPS receiver, a microprocessor and a transmitter. The GPS receiver will receive tracking data and the microprocessor will process the tracking data into a data packet. The...http://www.google.de/patents/US6339397?utm_source=gb-gplus-sharePatent US6339397 - Portable self-contained tracking unit and GPS tracking system
