Techniques for circumventing jamming of global positioning system receivers

• US 20030054756A1
• Filed: 08/09/2002
• Published: 03/20/2003
• Est. Priority Date: 08/17/2001
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Tyson, Scott M.
• Granted Patent: US 7,010,262 B2
• Time in Patent Office: Days
• US Class Current: 455/1
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 19/48 by combining or switching between position solutions derived from the satellite radio beacon positioning system and position solutions derived from a further system
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/0054 of actual mobile position, i.e. position calculation on base station
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: H04K 3/224 with countermeasures at transmission and/or reception of the jammed signal, e.g. stopping operation of transmitter or receiver, nulling or enhancing transmitted power in direction of or at frequency of jammer
• CPC Class Codes: H04K 3/226 Selection of non-jammed channel for communication spectrum sharing arrangements H04W16/14; selection of wireless resources by user or terminal H04W72/02
• CPC Class Codes: H04K 3/90 related to allowing or preventing navigation or positioning, e.g. GPS

Abstract

A method and apparatus for circumventing jamming of receivers for a global positioning system (GPS) include determining that a receiver is being jammed by a jamming signal not originating from the GPS. A first signal is transmitted from a portable unit including the receiver to a component of a second positioning system that is different from the GPS. A second signal is received from the second positioning system. The second signal includes data that indicates a position for the portable unit determined in the second positioning system based at least in part on the first signal.

Claims

1. A method for circumventing jamming of receivers for a global positioning system (GPS), the method comprising the steps of:

determining that a receiver is being jammed by a jamming signal not originating from the GPS;

transmitting a first signal from a portable unit including the receiver to a component of a second positioning system that is different from the GPS;

determining in the second positioning system a position for the portable unit based at least in part on the first signal; and

transmitting from the second positioning system to the portable unit a second signal that includes data that indicates the position for the portable unit.

2. A method for circumventing jamming of receivers for a global positioning system (GPS), the method comprising the steps of:

determining that a receiver is being jammed by a jamming signal not originating from the GPS;

transmitting a first signal from a portable unit including the receiver to a component of a second positioning system that is different from the GPS; and

receiving from the second positioning system a second signal that includes data that indicates a position for the portable unit determined in the second positioning system based at least in part on the first signal.

3. The method of claim 2, said step of transmitting the first signal further comprising including first data in the first signal for authenticating the portable unit as an authorized user of the second positioning system.

4. The method of claim 2, said step of transmitting the first signal further comprising transmitting the first signal in a narrow beam that impinges on the component of the second positioning system and that does not impinge on a source of the jamming signals.

5. The method of claim 2, said step of receiving the second signal further comprising receiving the second signal in a narrow beam that impinges on the portable and that does not impinge on a source of the jamming signals.

6. The method of claim 2, said step of receiving the second signal further comprising receiving the second signal that includes data that indicates the position for the portable unit within a threshold of precision for achieving a particular goal by an operational unit that includes the portable unit.

7. The method of claim 6, wherein the threshold of precision is less precise than a precision of the GPS.

8. The method of claim 2, further comprising, after performing said step of transmitting the first signal and before performing said step of receiving the second signal, the steps of:

receiving from the second positioning system a third signal that includes data that indicates another signal should be sent from the portable unit; and

transmitting a fourth signal from the portable unit to the second positioning system in response to the third signal.

9. The method of claim 2, wherein:

the data that indicates the position for the portable unit is encrypted to be secure from a source of the jamming signals; and

the method further comprises decrypting the data that indicates position.

10. The method of claim 2, said step of transmitting the first signal further comprising including in the first signal information about an operational unit that includes the portable unit.

11. The method of claim 8, said step of transmitting the fourth signal further comprising including in the fourth signal information about an operational unit that includes the portable unit.

12. A method for circumventing jamming of receivers for a global positioning system (GPS), the method comprising the steps of:

receiving, at a component of a second positioning system that is different from the GPS, a first signal from a portable unit including a receiver for the GPS, which portable unit has determined the receiver is being jammed by a jamming signal not originating from the GPS;

determining a position for the portable unit based at least in part on the first signal; and

transmitting to the portable unit a second signal that includes data that indicates the position for the portable unit.

13. The method of claim 12, said step of receiving the first signal further comprising authenticating the portable unit as an authorized user of the second positioning system based at least in part on first data included in the first signal.

14. The method of claim 12, said step of receiving the first signal further comprising receiving the first signal in a narrow beam that impinges on a component of the second positioning system and that does not impinge on a source of the jamming signals.

15. The method of claim 12, said step of transmitting the second signal further comprising transmitting the second signal in a narrow beam that impinges on the portable unit and that does not impinge on a source of the jamming signals.

16. The method of claim 12, said step of determining the position further comprising determining the position for the portable unit within a threshold of precision for achieving a particular goal by an operational unit that includes the portable unit.

17. The method of claim 16, wherein the threshold of precision is less precise than a precision of the GPS.

18. The method of claim 12, further comprising, after performing said step of receiving the first signal and before performing said step of transmitting the second signal, the steps of:

transmitting to the portable unit a third signal that includes data that indicates another signal should be sent from the portable unit; and

receiving a fourth signal from the portable unit.

19. The method of claim 12, further comprising generating the data that indicates the position for the portable unit by encrypting the position for the portable unit.

20. The method of claim 12, said step of receiving the first signal further comprising receiving in the first signal information about an operational unit that includes the portable unit.

21. The method of claim 12, wherein:

said step of transmitting the second signal further comprises including, in the second signal, data that indicates a request for information about an operational unit that includes the portable unit; and

the method further comprises the step of receiving from the portable unit, in response to the second signal, a third signal including data that indicates information about the operational unit.

22. The method of claim 12, further comprising:

transmitting to the portable unit a third signal that includes data that indicates a request for information about an operational unit that includes the portable unit; and

the method further comprises the step of receiving from the portable unit, in response to the third signal, a fourth signal that includes data that indicates information about the operational unit.

23. A computer-readable medium carrying one or more sequences of instructions for circumventing jamming of receivers for a global positioning system (GPS), wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform the steps of:

determining that a receiver is being jammed by a jamming signal not originating from the GPS;

causing a transmitter to transmit a first signal from a portable unit that includes the receiver to a component of a second positioning system that is different from the GPS; and

receiving from the second positioning system a second signal that includes data that indicates a position for the portable unit determined in the second positioning system based at least in part on the first signal.

24. A computer-readable medium carrying one or more sequences of instructions for circumventing jamming of receivers for a global positioning system (GPS), wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform the steps of:

receiving, at a component of a second positioning system that is different from the GPS, a first signal from a portable unit that includes a receiver for the GPS, which portable unit has determined the receiver is being jammed by a jamming signal not originating from the GPS;

determining a position for the portable unit based at least in part on the first signal; and

causing a transmitter to transmit to the portable unit a second signal that includes data that indicates the position for the portable unit.

25. A system for circumventing jamming of a positioning system, comprising:

a first positioning system that provides a receiver with a first position having a first precision;

a second positioning system different from the first positioning system that determines a second position having a second precision for a transmitter; and

a portable unit including a receiver for the first positioning system and a transmitter for the second positioning system,

wherein the portable unit is configured for

determining that the receiver is being jammed by a jamming signal not originating from the first positioning system;

transmitting a first signal to the second positioning system; and

receiving from the second positioning system a second signal that includes data that indicates the second position for the portable unit determined in the second positioning system based at least in part on the first signal.

26. An apparatus for circumventing jamming of a positioning system, comprising:

a receiver for obtaining a first position of the apparatus having a first precision from a first positioning system;

a transmitter for obtaining a second position of the apparatus having a second precision from a second positioning system different from the first positioning system; and

a processor configured for

determining that the receiver is being jammed by a jamming signal not originating from the first positioning system;

transmitting a first signal to the second positioning system; and

receiving from the second positioning system a second signal that includes data that indicates the second position determined in the second positioning system based at least in part on the first signal.