Method and apparatus for passive single platform geo-location

• US 7,688,264 B2
• Filed: 11/27/2007
• Issued: 03/30/2010
• Est. Priority Date: 11/27/2007
• Status: Expired due to Fees

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Chun, Craig C. M.
• Primary Examiner(s): PHAN, DAO LINDA
• Application Number:
  US11/945,899
• Publication Number:
  US 20090135059A1
• Time in Patent Office: 854 Days
• Field of Search: 342/357.06, 342/357.09, 342/387, 342/393, 342/394, 342/450, 342/457, 342/463, 455/456.1, 455/457
• US Class Current: 342/450
• CPC Class Codes: G01S 5/0081 Transmission between base stations
• CPC Class Codes: G01S 5/0221 Receivers
• CPC Class Codes: G01S 5/0284 Relative positioning

Abstract

The present disclosure provides an RTD that is released from a single primary platform to collect signals from a target emitter and relay data back to a single primary platform, enabling the precise geo-location of the target emitter to be determined in a minimal amount of time. The RTD is released from a single platform and quickly creates a long signal collection baseline between the released RTD and the single platform. Various techniques for determining geo-location may be used with the present disclosure, such as angle of arrival (AOA), time difference of arrival (TDOA), and frequency difference of arrival (FDOA) methods.

Claims

1. A method for determining the geo-location of a target emitter, comprising the steps of

releasing a receiver/transmitter device (RTD) from a primary platform;

receiving and processing a signal from the target emitter at the RTD;

transmitting a processed signal from the RTD to the primary platform;

calculating a position of the RTD relative to the primary platform;

receiving and processing the signal from the target emitter at the primary platform; and

calculating the geo-location of the target emitter.

2. The method of claim 1, wherein the target emitter is a radio frequency (RF) emitter.

3. The method of claim 1, wherein the signal from the target emitter is received and processed at the RTD simultaneous to being received and processed at the primary platform.

4. The method of claim 2, wherein the geo-location of the RF emitter is calculated using an angle-of-arrival method.

5. The method of claim 2, wherein the geo-location of the RF emitter is calculated using a time-difference-of-arrival method.

6. The method of claim 2, wherein the geo-location of the RF emitter is calculated using a frequency-difference-of-arrival method.

7. The method of claim 1, further comprising the step of determining an absolute point of reference.

8. The method of claim 1, wherein the primary platform is located on an airplane or helicopter.

9. The method of claim 1, wherein the primary platform is located on a land vehicle, a boat, or submarine.

10. The method of claim 1, wherein a plurality of RTDs are released from the primary platform.

11. The method of claim 2, wherein the RF emitter is a cell phone.

19. The method of claim 1, wherein the position of the RTD relative to the primary platform is calculated using an angle-of-arrival method.

12. A system for determining the geo-location of a target emitter, comprising

at least one receiver/transmitter device (RTD) having an antenna for receiving a signal from the target emitter, a tuner for tuning the signal from the target emitter, a processor for processing the signal from the target emitter, and a transmitter for relaying the processed signal;

and

a primary platform having a first antenna for receiving the signal from the target emitter, a tuner for tuning the signal from the target emitter, a second antenna for receiving the processed signal from the at least one RTD, wherein the second antenna of the primary platform is a gimbaled antenna, and a processor for calculating a relative position of the RTD and the geo-location of the target emitter;

wherein the at least one RTD is capable of being released from the primary platform.

13. The system of claim 12, wherein the target emitter is a radio frequency (RF) emitter.

14. The system of claim 12, wherein the at least one RTD includes a global positioning system (GPS) antenna.

15. The system of claim 14, wherein the primary platform includes a GPS antenna.

16. The system of claim 12, wherein the primary platform is an airplane or helicopter.

17. The system of claim 12, wherein the primary platform is a land vehicle, a boat or a submarine.

18. The system of claim 12, comprising a plurality of RTD'"'"'s.

20. The system of claim 12, wherein the at least one RTD further comprises an altimeter.