| 摘要 |
A positioning apparatus is provided on an object or carried by an individual to produce a position information signal of the object or individual in response to an enable signal, said enable signal being generated in response to an individual code signal. At least one control center is adapted for sending individual code signals and for receiving individual position information signals from an individual object or an individual. Means at the control center are adapted to display the individual positioning information contained in a received position information signal, thereby to at once locate and track the precise position of said object or individual. |
