SYSTEM AND METHOD FOR DETERMINING GEO LOCATION OF A TARGET USING LOCUS OF EMITTER POSITIONS (LEP)

• US 20140104112A1
• Filed: 10/17/2012
• Published: 04/17/2014
• Est. Priority Date: 10/17/2012
• Status: Active Grant

• Current Assignee: Raytheon Applied Signal Technology Incorporated (Rtx Corporation)
• Original Assignee: Ratheon Applied Signal Technology Incorporated
• Inventors: May, William
• Granted Patent: US 9,383,429 B2
• Time in Patent Office: Days
• US Class Current: 342/450
• CPC Class Codes: G01S 11/04 using angle measurements
• CPC Class Codes: G01S 5/0242 Determining the position of transmitters to be subsequently used in positioning G01S5/0289 takes precedence
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial

Abstract

A system and method for determining geo position of a target by an aircraft, including: (a). electronically receiving navigation data related to the aircraft and multilateration information related to the target; (b). electronically calculating a locus of emitter positions (LEP) curve from the received navigation data and multilateration information; (c). repeating steps (a) and (b), as the aircraft moves toward or away from the target; (d). electronically accumulating, in a computer storage medium, the calculated LEP curves; and (e). electronically determining a position that is closest to all the accumulated LEP curves to establish a position of the target.

Claims

1. A method performed by one or more processors for determining geo position of a target by an aircraft, the method comprising:

(a). electronically receiving navigation data related to the aircraft and multilateration information related to the target;

(b). electronically calculating a locus of emitter positions (LEP) curve from the received navigation data and multilateration information;

(c). repeating steps (a) and (b), as the aircraft moves toward or away from the target;

(d). electronically accumulating, in a computer storage medium, the calculated LEP curves; and

(e). electronically determining a position that is closest to all the accumulated LEP curves to establish a position of the target.

2. The method of claim 1, wherein electronically calculating LEP curve comprises electronically converting the received multilateration information to a three-dimensional geometric model using the received navigation data;

and electronically intersecting the three-dimensional geometric model with a three-dimensional geometric model of the earth to obtain the LEP curve.

3. The method of claim 2, wherein the multilateration information comprises angle of arrival (AOA) information and the three-dimensional geometric model is a three-dimensional cone model.

4. The method of claim 2, wherein the multilateration information comprises time difference of arrival (TDOA) information and the three-dimensional geometric model is a three-dimensional hyperboloid model.

5. The method of claim 2, wherein the three-dimensional geometric model of the earth is a sphere.

6. The method of claim 2, wherein the three-dimensional geometric model of the earth is an ellipsoid.

7. The method of claim 2, wherein the three-dimensional geometric model of the earth is determined using terrain data.

8. The method of claim 1, wherein the navigation data includes position, heading, pitch and roll data.

9. The method of claim 3, wherein the AOA is measured relative to the longitudinal axis of the aircraft.

10. The method of claim 9, wherein the AOA corresponds to an azimuth, and the cone is formed by sweeping through all elevation angles.

11. The method of claim 10, wherein an apex of the cone is the aircraft, and a central axis of the cone is a reference axis used for measuring AOA.

12. A system for determining geo position of a target by an aircraft comprising:

a receiver for receiving navigation data related to the aircraft and multilateration information related to the target;

one or more processors for calculating a locus of emitter positions (LEP) curve from the received navigation data and multilateration information, wherein as the aircraft moves toward or away from the target, the receiver receives new navigation data and multilateration information and said one or more processors calculate new LEP curves; and

a memory for accumulating the calculated LEP curves, wherein said one or more processors determine a position that is closest to ail the accumulated LEP curves to establish a position of the target.

13. The system of claim 12, wherein said one or more processors are configured to calculate the LEP curve by converting the received multilateration information to a three-dimensional geometric model using the received navigation data;

and intersecting the three-dimensional geometric model with a three-dimensional geometric model of the earth to obtain the LEP curve.

14. The system of claim 13, wherein the multilateration information comprises angle of arrival (AOA) information and the three-dimensional geometric model is a three-dimensional cone model.

15. The system of claim 13, wherein the multilateration information comprises time difference of arrival (TDOA) information and the three-dimensional geometric model is a three-dimensional hyperboloid model.

16. The system of claim 13, wherein the three-dimensional geometric model of the earth is a sphere.

17. The system of claim 13, wherein the three-dimensional geometric model of the earth is an ellipsoid.

18. The system of claim 13, wherein the three-dimensional geometric model of the earth is determined using terrain data.

19. The system of claim 12, wherein the navigation data includes position, heading, pitch and roll data.

20. The system of claim 14, wherein the AOA is measured relative to the longitudinal axis of the aircraft.