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 spatial position can be displayed along with an arrow showing where the rover is, also how fast it is moving and other data.