Monitor for route of surveillance personnel - uses portable set with coded transmissions for movement and position detectors which communicate with central monitor

摘要

A number of receivers are located along the path of surveillance personnel through which they can communicate with a central monitoring post using portable equipment. The communication is performed using all-or-nothing coding techniques and allows the positions to be indicated on a panel. A portable set carried by surveillance personnel is driven from a rechargeable battery and contains movement and position detectors. Push buttons indicate the operating state and allow each set to transmit a particular code to fixed receivers located along the route. The receivers decode the transmitted information and are represented as a set of coloured lights on a display panel in a central monitoring station with which they communicate. Each light corresponds to a particular message to indicate normal or attack conditions. A pre-recorded program automatically compares actual and required positions of the personnel.