All-weather precision guidance and navigation system

• US 7,098,846 B2
• Filed: 11/14/2003
• Issued: 08/29/2006
• Est. Priority Date: 11/15/2002
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Kirchofor, Richard, Phillips, Stephen P., Nielsen, Ray R.
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US10/706,988
• Publication Number:
  US 20050012660A1
• Time in Patent Office: 1,019 Days
• Field of Search: 342/357.02, 342/357.03, 244/3.14, 244/3.19
• US Class Current: 342/357.31
• CPC Class Codes: G01S 19/04 providing carrier phase data
• CPC Class Codes: G01S 19/07 providing data for correcting measured positioning data, e.g. DGPS [differential GPS] or ionosphere corrections
• CPC Class Codes: G01S 19/18 Military applications
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 19/52 Determining velocity

Abstract

A location of a target is generated by, at each of a plurality of reference sensors, receiving signals from a plurality of positioning system satellites. A set of error measurements are generated by generating, for each of the reference sensors, one or more error measurements based on a reference location of the reference sensor and information derived from the signals received at the reference sensors from the plurality of position system satellites. Single differenced velocity corrections are also generated. At a central processing node, a meta-correction surface is generated from the set of error measurements. The meta-correction surface is then transmitted to a non-reference sensor. At the non-reference sensor, signals are received from a plurality of the positioning system satellites. The meta-correction surface and the signals received from the plurality of position system satellites are used to generate the location of the target.

Claims

1. A system for navigation, comprising:

a plurality of reference sensors, each receiving data from a global positioning system and generating therefrom reference sensor data;

a central processing node which receives the reference sensor data from each of the reference sensors, computes a set of correction parameters based upon detected global positioning system errors indicated by the reference sensor data and based upon single differenced velocity corrections, and transmits said correction parameters;

a fire control platform that determines the position of a destination, receives the correction parameters transmitted by the central processing node, and corrects the determined position in accordance with the correction parameters; and

a weapon system which receives the corrected target position of the destination from the fire control platform and position data from the global positioning system, and steers itself to the target in accordance with the received position information;

wherein the single differenced velocity corrections are based on differences between signals received from different satellites.

29. The system of claim 1, wherein the single difference velocity corrections include single difference velocity noise variances.

34. The system of claim 1, wherein the correction parameters include GPS carrier phase cycle slip corrections based on single difference velocity measurements.

2. A method for navigation within a theater of operations, comprising the steps of:

receiving positioning system satellite signals at a plurality of spaced apart known locations, wherein the known locations approximately define the theater of operations;

determining a measure of error in the positioning system satellite signals for each known location;

generating single differenced velocity corrections; and

utilizing the measures of error in the positioning system satellite signals and the single differenced velocity corrections to obtain correction data for locating unknown locations within the theater of operations;

wherein the single differenced velocity corrections are based on differences between signals received from different satellites.

3. The method of claim 2, further including:

obtaining a relative measure of location to an unknown location within the theater of operations from one of the known locations.

4. The method of claim 3, further including:

using the relative measure of location to develop navigation and guidance directions to the unknown location within the theater of operations from one of the known locations within the theater of operations.

5. The method of claim 2, wherein the positioning system satellite signals are generated by the Global Positioning System.

30. The method of claim 2, wherein the single difference velocity corrections include single difference velocity noise variances.

35. The method of claim 2, comprising detecting and correcting GPS carrier phase cycle slip based on single difference velocity measurements.

6. A system for navigation within a theater of operations, comprising:

a plurality of spaced apart positioning system sensors at calibrated locations that approximately define the theater of operations;

means for determining a measure of error in positioning system satellite signals received by each positioning system sensor;

means for determining single differenced velocity corrections; and

means for using the measures of error in the positioning system satellite signals and the single differenced velocity corrections to obtain correction data for locating unknown locations within the theater of operations;

wherein the single differenced velocity corrections are based on differences between signals received from different satellites.

7. The system of claim 6, wherein:

each of the positioning system sensors is selected from a group consisting of stationary and mobile positioning system sensors.

8. The system of claim 6, wherein the positioning system sensors are spaced one from another up to a maximum separation such that the positioning system sensors have line of sight communications with at least four common positioning system satellites.

9. The system of claim 6, further including:

means with a mobile platform within the theater of operations for receiving said correction data and correcting a positioning system-determined location of the mobile platform.

10. The system of claim 6, further including:

means with a fire control platform within the theater of operations for receiving said correction data and using the correction data and positioning system data to generate a positioning system-determined location of a fire control platform.

11. The system of claim 6, further including:

means with a weapon deployed within the theater of operations for receiving said correction data and using the correction data to precisely guide the weapon to a target location within the theater of operations.

12. The system of claim 6, wherein the positioning system satellite signals are generated by the Global Positioning System.

31. The system of claim 6, wherein the single difference velocity corrections include single difference velocity noise variances.

36. The system of claim 6, wherein the correction data include GPS carrier phase cycle slip corrections based on single difference velocity measurements.

13. A method of generating a location of a target, the method comprising:

at each of a plurality of reference sensors, receiving signals from a plurality of positioning system satellites;

generating a set of error measurements by generating, for each of the reference sensors, one or more error measurements based on a reference location of the reference sensor and information derived from the signals received at the reference sensors from the plurality of position system satellites;

generating single differenced velocity corrections;

at a central processing node, generating a meta-correction surface from the set of error measurements and the single differenced velocity corrections;

transmitting the meta-correction surface to a non-reference sensor; and

using the meta-correction surface and signals received from a plurality of position system satellites to generate the location of the target;

wherein

wherein the single differenced velocity corrections are based on differences between signals received from different satellites.

14. The method of claim 13, wherein the target is co-located with the non-reference sensor.

15. The method of claim 13, wherein the target is not co-located with the non-reference sensor.

16. The method of claim 13, wherein each of the error measurements is generated at a respective one of the reference sensors, and the method further comprises transmitting the set of error measurements from the reference sensors to the central processing node by means of a communications satellite.

17. The method of claim 13, wherein transmitting the meta-correction surface to the non-reference sensor is performed using a communications satellite.

18. The method of claim 13, wherein generating the set of error measurements is performed at the central processing node.

19. The method of claim 13, wherein the error measurements represent systematic errors in the received signals from the plurality of positioning system satellites.

20. The method of claim 13, wherein the plurality of positioning system satellites are at least a part of the Global Positioning System.

32. The method of claim 13, wherein the single difference velocity corrections include single difference velocity noise variances.

37. The method of claim 13, wherein the meta correction surface is generated based on carrier phase cycle slip corrections, wherein the carrier phase cycle slip corrections are based on single difference velocity measurements.

21. A system for generating a location of a target, the system comprising:

a plurality of reference sensors, wherein each reference sensor receives signals from a plurality of positioning system satellites;

one or more processors for generating a set of error measurements by generating, for each of the reference sensors, one or more error measurements based on a reference location of the reference sensor and information derived from the signals received at the reference sensors from the plurality of position system satellites, and by generating single differenced velocity corrections;

a central processing node that generates a meta-correction surface from the set of error measurements and the single differenced velocity corrections;

a transmitter for transmitting the meta-correction surface to a non-reference sensor;

at the non-reference sensor;

a receiver for receiving signals from a plurality of the positioning system satellites; and

a processor that uses the meta-correction surface and the signals received from the plurality of the positioning system satellites to generate the location of the target;

wherein

wherein the single differenced velocity corrections are based on differences between signals received from different satellites.

22. The system of claim 21, wherein the target is co-located with the non-reference sensor.

23. The system of claim 21, wherein the target is not co-located with the non-reference sensor.

24. The system of claim 21, wherein each of the error measurements is generated at a respective one of the reference sensors, and the system further comprises a transmitter for transmitting the set of error measurements from the reference sensors to the central processing node by means of a communications satellite.

25. The system of claim 21, wherein the transmitter for transmitting the meta-correction surface to the non-reference sensor transmits the meta-correction surface to the non-reference sensor via a communications satellite.

26. The system of claim 21, wherein the processor for generating the set of error measurements is located at the central processing node.

27. The system of claim 21, wherein the error measurements represent systematic errors in the received signals from the plurality of positioning system satellites.

28. The system of claim 21, wherein the plurality of positioning system satellites are at least a part of the Global Positioning System.

33. The system of claim 21, wherein the single difference velocity corrections include single difference velocity noise variances.

38. The system of claim 21, wherein the central processing node generates the meta correction surface based on carrier phase cycle slip corrections, wherein the carrier phase cycle slip corrections are based on single difference velocity measurements.