Multiple vehicle identification and classification system
First Claim
1. An interrogator transponder system for electronically interrogating multiple closely spaced vehicles including at least one interrogating device which transmits a sequence of identical interrogation signals, said interrogating device being located remotely from multiple vehicles and transponder means on each vehicle for receiving the interrogation signals and responding at the same frequency as the received interrogation signals at a time that is precisely synchronized with an interrogation signal after a number of interrogations have been received and means in the transponders to insure that each transponder responds to a different sequence of interrogation signals after a plurality of interrogation signals have been received.
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Abstract
An interrogator-transponder system in which multiple vehicle mounted transponders, which may be closely spaced in distance and moving at similar velocities, respond to an interrogation signal in a sequential or random sequential manner so as to reduce response signal interleaving to an acceptable level. The response signals include a vehicle identification code and are processed by the interrogator to yield data, for example, on specific vehicle speed, distance from the interrogator, vehicle wanted for investigation, and vehicle with an inoperative transponder.
37 Citations
7 Claims
- 1. An interrogator transponder system for electronically interrogating multiple closely spaced vehicles including at least one interrogating device which transmits a sequence of identical interrogation signals, said interrogating device being located remotely from multiple vehicles and transponder means on each vehicle for receiving the interrogation signals and responding at the same frequency as the received interrogation signals at a time that is precisely synchronized with an interrogation signal after a number of interrogations have been received and means in the transponders to insure that each transponder responds to a different sequence of interrogation signals after a plurality of interrogation signals have been received.
Specification