System and method for positioning a transponder

• US 20100001896A1
• Filed: 07/25/2006
• Published: 01/07/2010
• Est. Priority Date: 07/25/2005
• Status: Active Grant

• Current Assignee: ELTA Systems Limited (Government of Israel)
• Original Assignee: ELTA Systems Limited (Government of Israel)
• Inventors: FIEREIZEN, Moshe
• Granted Patent: US 8,229,472 B2
• Time in Patent Office: Days
• US Class Current: 342/42
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 3/48 the waves arriving at the antennas being continuous or intermittent and the phase difference of signals derived therefrom being measured

Abstract

There is provided a method and system for positioning a transponder, the system comprising an antenna array of at least two spaced-apart antennas coupled to a common generating and switching unit. The generating and switching unit is configured for generating a periodic signal and switching the signal between said at least two antennas, constituting a positioning signal transmitted to the transponder. The system comprises a receiver for receiving a returned signal and a phase difference estimator coupled to the receiver and operable to measure phase differences between portions of the returned signal. The system further comprises a positioning utility coupled to said phase difference estimator and configured to determine the position of the transponder relative to the positioning system.

Claims

1. A system for positioning a transponder, the system comprising an antenna array of at least two spaced-apart antennas coupled to a common generating and switching unit, said generating and switching unit is configured for generating a periodic signal (TS) and switching the signal between said at least two antennas, constituting a positioning signal transmitted to the transponder;

the system comprises a receiver for receiving a returned signal (RS) and a phase difference estimator coupled to the receiver and operable to measure phase differences between portions of the returned signal;

the system further comprising a positioning utility coupled to said phase difference estimator and configured to determine the position of the transponder relative to the positioning system.

2. A system according to claim 1 wherein the determination of the position of the transponder includes determination of the direction of the transponder relative to the positioning system.

3. A system according to claim 1 wherein the determination of the position of the transponder includes determination of the range of the transponder relative to the positioning system, based on TOA (Time of Arrival) comparison between the positioning signal transmitted by the system and the signal returned by the transponder.

4. A system according to claim 1 wherein the determination of the position of the transponder includes determination of the range of the transponder relative to the positioning system, based on information received from a source external to the system, about the range of the transponder relative to the system.

5. A system according to claim 1 wherein said periodic signal includes portions having a first frequency and portions having a second frequency;

portions having the same frequency are switched between said at least two spaced-apart antennas.

6. A system according to claim 5 wherein said first frequency is in the range of about 1 GHz or more and the second frequency differ from the first frequency by about 1 MHz.

7. A system according to claim 1, wherein said spaced-apart antennas are coupled to said generating and switching unit via substantially identical feed lines.

8. A system according to claim 1, wherein said antenna array comprises four antennas in a tetrahedron form.

9. A system according to claim 1 further configured, based on the determination of the position of the transponder, to transmit the transponder position related information.

10-14. -14. (canceled)

15. A method for positioning a transponder, the method comprising:

generating a periodic signal and switching the periodic signal between an antenna array of at least two spaced-apart antennas of known locations coupled to a common generating and switching unit;

transmitting the signal to the transponder and receiving a returned signal;

based on measurements of phase differences between portions of the returned signal, determining the orientation of the transponder relative to the system,

thereby allowing the determination of the position of the receiver relative to the positioning system.

16. The method according to claim 15 further comprising:

based on TOA (Time of Arrival) comparison between the signal transmitted by the system and the signal returned by the transponder, determining the range of the transponder relative to the positioning system.

17. The method according to claim 15 further comprising:

receiving from an external source information about the range of the transponder relative to the positioning system, and determining the position of the transponder.

18. A method according to claim 15, further comprising:

comparing the position of the transponder with position information of the position of the transponder established using GPS (Global Positioning System) and/or INS (Inertial Navigation System) systems,

thereby allowing assessing the accuracy of said position information.

19. A method according to claim 15, wherein said periodic signal includes portions having a first frequency and portions having a second frequency, portions having the same frequency are switched between said at least two spaced-apart antennas.

20. A method according to claim 15, wherein said first frequency is in the range of about 1 GHz or more and the second frequency differ from the first frequency by about 1 MHz.

21. A method according to claim 15, wherein said antenna array comprises four antennas in a tetrahedron form.

22. (canceled)