A location tracking system for tracking the location of items within a controlled
area comprises a plurality of RFID tags located according to the required accuracy
of the location determinations. Vehicles configured to transport items being tracked
include two RFID interrogators configured to acquire RFID information from the
plurality of RFID tags and to transmit the RFID tag information to a location authority.
The separation the two RFID interrogators is set based on the spacing of the plurality
of RFID tags such that the required accuracy results. The location authority can
then simply map the RFID tag information to coordinate information stored for each
of the plurality of tags to obtain the location of the vehicle and, therefore,
the item being transported.