Abstract: Apparatus for determining distance and location of a subordinate unit relative to a master unit. There may be a plurality of subordinate units for a single master unit. Both the master and subordinate unit(s) consist of a GPS receiver, RF transceiver, power supply, electronic compass, user interface and microprocessor. The master unit periodically polls and exchanges data with the subordinate unit via a RF transmission. The master unit processes the data and displays it on a display as distance and direction to a subordinate unit. The subordinate unit also processes data and displays it on a display as distance and direction to the master unit. Additionally, the master unit compares the data to user selectable predefined parameters. If the data is not within those parameters, the master unit initiates an alarm condition at both the master and subordinate unit.

Abstract: Apparatus for determining distance and location of a subordinate unit relative to a master unit. There may be a plurality of subordinate units for a single master unit. Both the master and subordinate unit(s) consist of a GPS receiver, RF transceiver, power supply, electronic compass, user interface and microprocessor. The master unit periodically polls and exchanges data with the subordinate unit via a RF transmission. The master unit processes the data and displays it on a display as distance and direction to a subordinate unit. The subordinate unit also processes data and displays it on a display as distance and direction to the master unit. Additionally, the master unit compares the data to user selectable predefined parameters. If the data is not within those parameters, the master unit initiates an alarm condition at both the master and subordinate unit.