| 摘要 |
A global position determining system conserves battery power in a battery powered user terminal by transmitting its approximate position initially and then inhibiting transmission of a homing beacon until a homing terminal is in the vicinity of the user terminal. After user activation, the user terminal determines its own approximate position and transmits an approximate position signal to a satellite. The satellite then relays the approximate position signal to a mobile homing terminal. After moving the mobile homing terminal toward the approximate position, an activate homing beacon command is transmitted to the user terminal. When the transmitted command is received, the homing beacon is activated. Upon activation of the homing beacon, a directional antenna of the mobile homing terminal can be oriented toward a first direction which has a strong homing beacon reception relative to other directions and moved towards that direction.
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