| 摘要 |
An ultrasonic signal is used to link a beacon unit to a tracker unit to provide a tracking and navigation system for firefighters to use in a smoke filled environment at the scene of a fire. The beacon unit transmits an omnidirectional ultrasonic signal. The tracker unit, using a directional ultrasonic receiver provides a display or other indication of the signal strength of the received ultrasonic signal to allow the direction to the beacon unit to be determined. The ultrasonic signal provided by the beacon unit may be pulse modulated to include digitally encoded data that may be used to identify particular individuals, objects, materials, dangers, or exits. In addition, the tracker unit may be provided with a transmitter and the beacon unit provided with a receiver such that audio communication may be established therebetween. |
