The Barrett 977 HF tracking system is an automatic vehicle locating and tracking package which utilises the Navstar Global Positioning System (GPS) and a HF network consisting of a central control station and mobile stations. The 977 computer based tracking system, located at the control station, automatically polls vehicles or vessels within the HF network, retrieving their position using a standard Selcall format based on CCIR493-2. The position of the vehicle or vessel being tracked is then displayed on a computer based map.
