System and method for computing navigation information in the presence of interference

• US 6,600,444 B2
• Filed: 02/22/2002
• Issued: 07/29/2003
• Est. Priority Date: 02/23/2001
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Desjardins, Gerard A.
• Primary Examiner(s): Phan, Dao
• Application Number:
  US10/079,558
• Publication Number:
  US 20020118133A1
• Time in Patent Office: 522 Days
• Field of Search: 342/352, 342/357.01, 342/357.06, 342/357.12, 701/213, 701/215
• US Class Current: 342/357.29
• CPC Class Codes: G01S 19/10 providing dedicated supplementary positioning signals
• 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 19/42 Determining position
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial

Abstract

Navigation information for a first navigation system is computed based on interference signals and satellite signals. The first navigation system comprises means for receiving N satellite signals capable of being processed and at least M interference signals, where M=K−N and K equals the minimum number of satellites required to be tracked for unambiguously determining navigation information for the first navigation system. Based on the at least M interference signals and the N satellite signals received and capable of being processed, the navigation system computes navigation information for the first navigation system.

Claims

1. A method for computing navigation information for a first navigation system, the method comprising:

receiving N satellite signals capable of being processed;

receiving at least M interference signals, where M=k−

N and K equals the minimum number of satellites required to be tracked for unambiguously determining navigation information for the first navigation system; and

computing navigation information for the first navigation system based on the at least M interference signals and the N satellite signals capable of being processed.

2. A method according to claim 1, wherein computing navigation information for the first navigation system based on the at least M interference signals and the N satellite signals received and capable of being processed comprises:

computing, for each of the at least M interference signals, measurements between the first navigation system and a corresponding source of the interference signal;

computing, for each of the N satellite signals received and capable of being processed, measurements between the first navigation system and a corresponding satellite; and

computing navigation information for the first navigation system based on the measurements computed for the at least M interference signals and the N satellite signals received and capable of being processed.

3. The method according to claim 2, wherein the measurements comprise pseudo range and pseudo range rate information.

4. The method according to claim 3, wherein the navigation information for the first navigation system comprises a position, a velocity, and a time for the first navigation system.

5. The method according to claim 2, wherein computing, for each of the at least M interference signals, measurements between the first navigation system and a corresponding source of the interference signal comprises:

receiving from at least one second navigation system information relating to a corresponding interference signal received by the at least one second navigation system;

computing a pseudo time difference of arrival and pseudo frequency difference of arrival based on the interference signal and the information received from the at least one second navigation system;

receiving navigation information for the at least one second navigation system; and

receiving a location of the corresponding source of the interference signal.

6. The method according to claim 5, wherein navigation information on the at least one second navigation system comprises a position, a velocity, and a time for the at least one second navigation system.

7. A first navigation system for computing navigation information comprising:

means for receiving N satellite signals capable of being processed and at least M interference signals, where M=K−

N and K equals the minimum number of satellites required to be tracked for unambiguously determining navigation information for the first navigation system;

means for computing, for each of the at least M interference signals, measurements between the first navigation system and a corresponding source of the interference signals;

means for computing, for each of the N satellite signals capable of being processed, measurements between the first navigation system and a corresponding satellite; and

means for computing navigation information for the first navigation system based on the measurements computed for the at least M interference signals and the N satellite signals capable of being processed.

8. The first navigation system according to claim 7, wherein the measurements comprise pseudo range and pseudo range rate information.

9. The first navigation system according to claim 8, wherein the navigation information for the first navigation system comprises a position, a velocity, and a time for the first navigation system.

10. The first navigation system according to claim 7, wherein means for computing, for each of the at least M interference signals, measurements between the first navigation system and a corresponding source of the interference signal comprises:

means for receiving from at least one second navigation system information relating to a corresponding interference signal received by the at least one second navigation system;

means for computing a pseudo time difference of arrival and pseudo frequency difference of arrival based on the interference signal and the information received from the at least one second navigation system;

means for receiving navigation information for the at least one second navigation system; and

means for receiving a location of the corresponding source of the interference signal.

11. The first navigation system according to claim 10, wherein navigation information on the at least one second navigation system comprises a position, a velocity, and a time for the at least one second navigation system.

12. A method for computing navigation information for a first navigation system, the method comprising:

providing a first navigation system a first distance from at least one interference signal source wherein the first navigation system is incapable of receiving and processing satellite signals from a minimum number of satellites required for unambiguously determining navigation information for the first navigation system and wherein the first navigation system receives at least one interference signal from the at least one interference signal source;

providing at least one second navigation system a second distance from the at least one interference signal source wherein the at least one second navigation system is capable of receiving the at least one interference signal and capable of receiving and processing satellite signals from a minimum number of satellites required for unambiguously determining navigation information for the at least one second navigation system;

receiving from the at least one second navigation system information relating to the at least one interference signal received by the at least one second navigation system;

receiving navigation information for the at least one second navigation system;

receiving a location of the at least one interference signal source; and

computing navigation information for the first navigation system based on the at least one interference signal received by the first navigation system, the information relating to the at least one interference signal received from the at least one second navigation system, the navigation information for the at least one second navigation system, the location of the at least one interference signal source, and any satellite information based on any satellite signals received by the first navigation system capable of being processed.

13. A system for computing navigation information for a first navigation system, the system comprising:

a first navigation system a first distance from at least one interference signal source wherein the first navigation system is incapable of receiving and processing satellite signals from a minimum number of satellites required for unambiguously determining navigation information for the first navigation system and wherein the first navigation system is capable of receiving at least one interference signal from the at least one interference signal source; and

at least one second navigation system a second distance from the at least one interference signal source wherein the at least one second navigation system is capable of receiving the at least one interference signal and capable of receiving and processing satellite signals from a minimum number of satellites required for unambiguously determining navigation information for the at one second navigation system, wherein;

the at least one second navigation system comprises;

means for transmitting information relating to the at least one interference signal received by the at least one second navigation system; and

means for transmitting navigation information for the at least one second navigation system; and

the first navigation system comprises;

means for receiving the at least one interference signal from the at least one interference signal source;

means for receiving navigation information for the at least one second navigation system;

means for receiving the information relating to the at least one interference signal transmitted by the at least one second navigation system;

means for receiving a location of the at least one interference signal source; and

means for computing navigation information for the first navigation system based on the at least one interference signal received by the first navigation system, the information relating to the at least one interference signal transmitted by the at least one second navigation system, the navigation information for the at least one second navigation system, the location of the at least one interference signal source, and any satellite information based on any satellite signals received by the first navigation system capable of being processed.

14. A system for computing navigation information for a first navigation system, the system comprising:

a first navigation system a first distance from at least one interference signal source wherein the first navigation system is incapable of receiving and processing satellite signals from a minimum number of satellites required for unambiguously determining navigation information for the first navigation system and wherein the first navigation system is capable of receiving at least one interference signal from the at least one interference signal source;

at least one second navigation system a second distance from the at least one interference signal source wherein the at least one second navigation system is capable of receiving the at least one interference signal and capable of receiving and processing satellite signals from a minimum number of satellites required for unambiguously determining navigation information for the at least one second navigation system and wherein the at least one second navigation system comprises means for transmitting information relating to the at least one interference signal received by the at least one second navigation system and means for transmitting navigation information for the at least one second navigation system;

means for receiving navigation information for the at least one second navigation system;

means for receiving the information relating to the at least one interference signal transmitted by the at least one second navigation system;

means for receiving a location of the at least one interference signal source; and

means for computing navigation information for the first navigation system based on the at least one interference signal received by the first navigation system, the information relating to the at least one interference signal transmitted by the at least one second navigation system, the navigation information for the at least one second navigation system, the location of the at least one interference signal source, and any satellite information based on any satellite signals received by the first navigation system capable of being processed.