A mobile controller unit has a radio positioning system and a two-way communication system and a rover unit also has a radio positioning system and a two-way radio communication system. The controller unit can query the rover unit to send its location data so that the rover unit can be located and if desired, found, such as in the case of a lost child or items. Relative position between the controller and the rover can be displayed on the controller along with an arrow showing where the rover is, as well as how fast it is moving, a track of its movement and other data.The system can also operate in conjunction with a network system that has a PDE and an application server that perform some of the communications and calculation functions.