摘要 |
A method and apparatus for electronically locating and tracking persons, animals, or objects in a predetermined work area utilizing a number of base stations associated with the work area, provided with stationary transmitting-/receiving devices and a number of transponders added to the persons, animals, or objects to be located, provided with transmitting and receiving means, wherein the base stations generate interrogation fields which can be received by the transponders, wherein with the base stations low-frequency magnetic fields with a unique frequency for each base station are generated in the predetermined work area, and wherein transponders are used, which are provided with means to measure the field strength associated with each separate received frequency at the location of the transponder and then to transmit this as a position signal via high-frequency transmitting means of the transponder to high-frequency receiving means provided in the base stations. |