| 摘要 |
A radio tracking and ranging system is disclosed which has at least one mobile radio frequency transmitter and a radio frequency receiver. The radio frequency receiver has a range control which sets a maximum range that each mobile radio frequency transmitter may be moved from the radio frequency receiver without generating an alert to the user of the radio frequency receiver. Each radio frequency transmitter has a "panic" switch which permits a user of the radio frequency transmitter to transmit an alert or alarm to the user of the radio frequency receiver. After receipt of an alert, the user of the radio frequency receiver switches the radio frequency receiver into a tracking mode for locating a direction from which a maximum signal strength is received which is indicative of the relative bearing of the radio frequency transmitter which is being tracked from the radio frequency receiver. Signal processing techniques are used to eliminate the effects of fading and interference in detecting an identification code periodically broadcast by each radio frequency transmitter and further, to eliminate the effects of fading and interference on RSSI signals which are used for determining the range of each radio frequency transmitter relative to the radio frequency receiver and tracking of each radio frequency transmitter.
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