Method and apparatus for estimating geolocations

• US 7,471,245 B2
• Filed: 01/31/2007
• Issued: 12/30/2008
• Est. Priority Date: 01/31/2007
• Status: Expired due to Fees

• Current Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Original Assignee: L-3 Communications Integrated Systems LP (L3Harris Technologies, Inc.)
• Inventors: Robertson, Mark A., Parker, John M., Le, Phuong H., Chung, Hyo K., Reid, David L.
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): Mull; Fred H
• Application Number:
  US11/669,734
• Publication Number:
  US 20080180325A1
• Time in Patent Office: 699 Days
• Field of Search: 342/451, 342/463, 342/465
• US Class Current: 342/465
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence

Abstract

Methods and apparatus operable to estimate the geolocation of a signal emitter. In some embodiments, the methods comprise acquiring collection data from a plurality of collector elements, computing a plurality of candidate geolocations from the acquired collection data, and applying a clustering analysis to the candidate geolocations to estimate the geolocation of the signal emitter.

Claims

1. A method of estimating a geolocation of a signal emitter, the method comprising:

acquiring collection data from a plurality of collector elements, wherein the collection data comprises data corresponding to the signal emitter and configuration and calibration information corresponding to at least one of the collector elements;

computing a plurality of candidate geolocations from the acquired collection data;

forming an emitter table to categorize the collection data by frequency and collector element;

updating the emitter table each time collection data is acquired by either associating the collection data with a collector element listed in the emitter table or forming a new collection data bin to represent the collection data; and

applying a clustering analysis to the candidate geolocations to estimate the geolocation of the signal emitter.

2. The method of claim 1, wherein the acquired collection data includes data synchronously acquired by each collector element.

3. The method of claim 1, wherein the acquired collection data includes data acquired by each collector element at a plurality of frequencies.

4. The method of claim 1, further including applying a Cross Ambiguity Function (CAF) to the acquired data to generate a plurality of time-difference-of-arrival (TDOA) and frequency-difference-of-arrival (FDOA) pairs.

5. The method of claim 4, wherein the candidate geolocations are computed utilizing the TDOA/FDOA pairs.

6. The method of claim 1, wherein the clustering analysis is applied to the candidate geolocations to determine a cluster area and the geolocation of the signal emitter is estimated by averaging the candidate geolocations within the cluster area.

7. A method of estimating a geolocation of a signal emitter, the method comprising:

acquiring collection data from a plurality of collector elements, the acquired data including data synchronously acquired by each collector element at a plurality of frequencies, wherein the collection data comprises collection platform navigation information;

forming an emitter table to categorize the collection data by frequency and collector element;

generating a plurality of time-difference-of-arrival/frequency-difference-of-arrival (TDOA/FDOA) pairs from the acquired collection data in the emitter table;

computing a plurality of candidate geolocations utilizing the TDOA/FDOA pairs; and

applying a clustering analysis to the candidate geolocations to estimate the geolocation of the signal emitter.

8. The method of claim 7, further including repeatedly acquiring collection data from the collector elements and updating the emitter table after each acquisition.

9. The method of claim 7, wherein the clustering analysis is applied to the candidate geolocations to determine a cluster area and the geolocation of the signal emitter is estimated by averaging the candidate geolocations within the cluster area.

10. A computing element operable to estimate a geolocation of a signal emitter, the computing element comprising:

a memory configured to store collection data acquired from a plurality of collector elements, wherein the collection data comprises the identity, location, direction, and speed of at least one of the collector elements; and

a processor coupled with the memory and configured to

sort the collection data by frequency and collector element,

compute a plurality of candidate geolocations from the acquired collection data, and

apply a clustering analysis to the candidate geolocations to estimate the geolocation of the signal emitter.

11. The computing element of claim 10, wherein the processor is further operable to apply a Cross Ambiguity Function (CAF) to the acquired data to generate a plurality of time-difference-of-arrival (TDOA) and frequency-difference-of-arrival (FDOA) pairs.

12. The computing element of claim 11, wherein the processor is operable to compute the candidate geolocations utilizing the TDOA/FDOA pairs.

13. The computing element of claim 10, wherein the processor is operable to apply the clustering analysis to the candidate geolocations to determine a cluster area and estimate the geolocation of the signal emitter by averaging the candidate geolocations within the cluster area.

14. A computer program for estimating a geolocation of a signal emitter, a least a portion of the computer program stored a computer-readable medium for operating a computing element and comprising:

a code segment configured to acquire collection data from a plurality of collector elements, wherein the collection data comprises data corresponding to the signal emitter and configuration and calibration information corresponding to at least one of the collector elements;

a code segment configured to create an emitter table for categorizing the collection data by frequency and collector element;

a code segment operable to compute a plurality of candidate geolocations from the acquired collection data; and

a code segment operable to apply a clustering analysis to the candidate geolocations to estimate the geolocation of the signal emitter.

15. The computer program of claim 14, wherein the acquired collection data includes data synchronously acquired by each collector element.

16. The computer program of claim 14, wherein the acquired collection data includes data acquired by each collector element at a plurality of frequencies.

17. The computer program of claim 14, further including a code segment operable to apply a Cross Ambiguity Function (CAF) to the acquired data to generate a plurality of time-difference-of-arrival (TDOA) and frequency-difference-of-arrival (FDOA) pairs.

18. The computer program of claim 17, wherein the candidate geolocations are computed utilizing the TDOA/FDOA pairs.

19. The computer program of claim 14, wherein the clustering analysis is applied to the candidate geolocations to determine a cluster area and the geolocation of the signal emitter is estimated by averaging the candidate geolocations within the cluster area.