| 摘要 |
In a first aspect, a transponder system is disclosed which comprises an interrogating source of H.F electromagnetic radiation, and a plurality of transponders which each include a token reader unit to receive a removable token, e.g. a smart card, inducting on board data processing capability. The transponders, or a group of transponders, are each arranged when interrogated to transmit a unique H.F. response modulated by information carried upon the token. In a second aspect the invention relates to s tranaponder system which is operatively connected to a navigational, e.g. GPS (Global Positioning System) satellite receiving means and is arranged when interrogated to transmit information indicative of the position of the transponder.
|
