| 摘要 |
A ranging system which can be adapted for use at a golf course includes a number of fixed transceivers located around the golf course so that a hand-held personal ranging device can communicate with the fixed transceivers at any point. Each fixed transceiver uses a spread spectrum transceiver, which can transmit/receive at least two spread spectrum signals. One of the spread spectrum signal is a request from a hand-held personal ranging device for a determination of its position. The other signal is a separate synchronization signal. A hand-held personal ranging device communicates with the fixed transceivers by transmitting a spread spectrum signal, but only receives a narrowband signal in return. By eliminating spread spectrum receivers from the hand-held units, the system is significantly reduced in cost. When unusual conditions (e.g., lightning) occur, the system can be used to inform the golfer by sending a signal via narrowband transmission to activate annunciator (16) which may include a speaker for emitting sound, a LED, or a vibrating circuit. Similarly, the system may be operated in a mode whereby the spread spectrum signal transmitted by the personal ranging device is regarded as an emergency signal when, for example, a golfer becomes injured on the course. |
