System and method for geo-locating and detecting source of electromagnetic emissions

• US 9,658,314 B2
• Filed: 03/02/2012
• Issued: 05/23/2017
• Est. Priority Date: 03/02/2012
• Status: Active Grant

• Current Assignee: Nokomis Inc.
• Original Assignee: Nokomis Inc.
• Inventors: Parks, Brandon Scott, Keller, III, Walter J., Hsu, Jennting Timothy
• Primary Examiner(s): Nguyen, Chuong P
• Application Number:
  US13/410,586
• Publication Number:
  US 20130229310A1
• Time in Patent Office: 1,908 Days
• Field of Search: 342354, 34235759, 34235761, 342368, 342417, 342422-434, 342436, 342445, 342450, 342465
• 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 19/24 Acquisition or tracking or demodulation of signals transmitted by the system synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073
• CPC Class Codes: G01S 3/46 using antennas spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
• CPC Class Codes: G01S 5/02213 Receivers arranged in a network for determining the position of a transmitter
• CPC Class Codes: G01S 5/0278 involving statistical or probabilistic considerations G01S5/0252, G01S5/0294 take precedence
• CPC Class Codes: G01S 5/0284 Relative positioning
• CPC Class Codes: G01S 5/0294 Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders

Abstract

A system for identifying a real-world geographic location of an emission source emitting electromagnetic energy includes a platform configured for movement and an apparatus disposed on the platform and configured to collect and process, in a passive manner and during movement of the platform, at least a pair of successive samples of the electromagnetic energy emission and define angular and spatial coordinates of the emission source. The apparatus includes at least a pair of antennas, a receiver coupled to antennas and a processor executing a predetermined logic.

Claims

1. A system for determining a real-world geographic location of an emission source emitting an electromagnetic energy signal, said system comprising:

(a) a platform configured for movement; and

(b) an apparatus disposed on said platform and configured to collect and process, in a passive manner and during movement of said platform, at least two pairs of successive samples of a weak electromagnetic energy signal emitted from the emission source and define, by extracting phase information from Fourier IQ data in said at least two pairs of successive samples of said weak electromagnetic energy signal through Fast Fourier Transform (FFT), angular and spatial coordinates of the emission source, one sample of said weak electromagnetic energy signal in each pair from said at least two pairs being processed, to extract said phase information, independently from but substantially simultaneously with another sample of said weak electromagnetic energy signal in said each pair from said at least two pairs.

2. The system of claim 1, wherein said apparatus includes:

(a) a first antenna mounted on or within said platform and configured to collect at least a pair of first samples from said at least two pairs of successive samples of said weak electromagnetic energy signal;

(b) a second antenna positioned in a spaced apart relationship with said first antenna, said second antenna configured to collect at least a pair of second samples from said at least two pairs of successive samples of said weak electromagnetic energy signal;

(c) a receiver mounted on or within said platform and operatively coupled to each of said first and second antennas; and

(d) a processor operatively coupled to said receiver, said processor operable to process, during said movement of said platform, said at least two pair of said successive samples of said weak electromagnetic energy signal.

3. The system of claim 1, wherein said weak electromagnetic energy signal is at or below −

160 dBm.

4. A system for determining a real-world geographic location of a source emitting an electromagnetic energy signal, said system comprising:

(a) a platform configured for movement;

(b) means for determining position of said platform at least prior to movement thereof;

(c) at least a pair of antennas positioned in a spaced apart relationship with each other, each of said at least pair of antennas configured to collect electromagnetic energy emitted by the source, wherein at least one of said at least pair of antennas is mounted on or within said platform;

(d) a receiver mounted on or within said platform and operatively coupled to said each of said at least pair of antennas; and

(e) a processor operatively coupled to said receiver, said processor configured to process, during movement of said platform, in a parallel manner at least a pair of successive samples of a weak electromagnetic energy signal emitted from the emission source and collected independently at each of said at least pair of antennas and define, by extracting phase information, from Fourier IQ data in said electromagnetic energy signal through Fast Fourier Transform (FFT), angular and spatial coordinates of the emission source, one of said at least pair of successive samples of said weak electromagnetic energy signal being processed, to extract said phase information, independently from but substantially simultaneously with another one of said at least pair of successive samples of said weak electromagnetic energy signal.

5. The system, according to claim 4, wherein the emission source is a stationary emission source.

6. The system, according to claim 4, wherein the emission source is a plurality of stationary emission sources.

7. The system, according to claim 4, wherein said electromagnetic emission is one of intentional or unintentional.

8. The system, according to claim 4, wherein said platform is a vehicle having motive power or being connected to a vehicle having motive power.

9. The system, according to claim 4, wherein said each of said pair of antennas is an antenna array.

10. The system, according to claim 9, wherein said antenna array is a beam-steer antenna array.

11. The system, according to claim 4, wherein said each of said at least pair of antennas is mounted on said platform.

12. The system, according to claim 4, wherein said angular and spatial coordinates define a distance from said platform to the emission source.

13. The system, according to claim 4, wherein said angular and spatial coordinates define one of an altitude of the emission source and an approach or a departure of said platform relative to the emission source.

14. A method of geo-locating an emission source emitting an electromagnetic energy signal, said method comprising the steps of:

(a) providing an apparatus including a platform configured for movement, at least a pair of antennas positioned in a spaced apart relationship with each other, each of said at least pair of antennas configured to collect the electromagnetic energy emission, wherein at least one of said at least pair of antennas is mounted on or within said platform, a receiver mounted on or within said platform and operatively coupled to said each of said at least pair of antennas, and a processor operatively coupled to said receiver;

(b) moving said apparatus toward to or away from said emission source;

(c) collecting, with each of said at least pair of antennas, at least a pair of successive samples of a weak electromagnetic energy signal emitted by said emission source;

(d) receiving, at said receiver, said at least pair of successive samples;

(e) processing, with said processor, one of said at least pair of successive samples of said weak electromagnetic energy signal, in a parallel manner, independently from but substantially simultaneously with another one of said at least pair of successive samples of said weak electromagnetic energy;

(f) extracting with said processor, in said parallel manner from Fourier IQ data through Fast Fourier Transform (FFT), phase information from said one and said another one of said at least pair of successive samples of said electromagnetic energy signal; and

(g) defining, with said processor, angular and spatial coordinates of said emission source.

15. The method, according to claim 14, wherein said step (e) includes the step of independently decomposing wavelets from said one and said another one of said at least pair of successive samples of said weak electromagnetic energy signal.

16. The method, according to claim 14, further including the step of combining phase information extracted in step (f) and the step of determining phase differences between said one and said another one of said at least pair of successive samples of said weak electromagnetic energy signal collected independently at said each of said at least pair of antennas.

17. The method of claim of claim 16, further including the step of determining a travel direction of said platform.

18. The method of claim 14, further including the step of determining at least one of a position and an orientation of said platform at least prior to movement thereof.

19. The method of claim 18, wherein step (e) includes the step of filtering said at least one of position and orientation.

20. The method, according to claim 14, wherein said step (g) includes the step of performing cluster analysis on phase information extracted from said one and said another one of said at least pair of successive samples of said weak electromagnetic energy signal.

21. The method, according to claim 20, wherein said method includes the step of of correlating results of said cluster analysis to at least one of path, trajectory and velocity of said moving platform.

22. The method of claim 14, wherein said step (g) includes the step of performing wavelet denoising.

23. The method of claim 14, wherein said step (g) includes the step of performing a triangulation analysis.

24. The method of claim 14, wherein said step (g) includes the step of employing Neural Networks.

25. The method of claim 14, wherein said step (g) includes the step of filtering a relative position of said platform.

26. The method of claim 25, wherein said step of filtering includes the step of applying a Kalman filter.

27. The method of claim 14, wherein said step (g) includes the step of reducing uncertainty on mean measurement values.

28. The method of claim 27, wherein said step of reducing uncertainty on mean measurement values includes the step of performing a bootstrap statistical analysis.

29. The method of claim 14, wherein said step (g) comprises the step of performing wavelet direct to capture detectable features in said electromagnetic energy signal.

30. The method of claim 29, wherein said wavelet direct comprising a ‘

Forward-Backward Cumulative Wavelet Variance method and a ‘

Forward-Backward Cumulative Wavelet Distance method to characterize features obtained from detail coefficients in a wavelet domain.

31. A system for de-conflicting a Cognitive Radio transceiver transmitting an electromagnetic energy signal, said system comprising:

(a) a platform;

(b) a means for determining a position of said platform;

(c) at least a pair of antennas positioned in a spaced apart relationship with each other, each pair of said at least pair of antennas configured to collect pairs of consecutive samples of the electromagnetic energy signal emitted by the source, wherein at least one of said at least pair of antennas is mounted on or within said platform;

(d) a receiver mounted on or within said platform and operatively coupled to said each of said at least pair of antennas; and

(e) a processor operatively coupled to said receiver, said processor configured to process two samples in each pair of samples of the electromagnetic energy signal independently from but substantially simultaneously with one another to extract phase information through Fourier IQ data in said electromagnetic energy signal, with Fast Fourier Transform (FFT), to define, when said platform is stationary, a direction of the Cognitive Radio transceiver, and to compare said direction to coordinates of said Cognitive Radio transceiver.

32. The system of claim 31, wherein said platform is configured for movement, wherein said means for determining position of said platform is configured to determine position of said platform at least prior to movement thereof, wherein said processor configured to process said at least pair of successive samples of the electromagnetic energy signal during movement of said platform and wherein said predetermined logic is further configured to define spatial coordinates of the Cognitive Radio transceiver.

33. An apparatus for determining a real-world geographic location of an emission source emitting an electromagnetic energy signal, said apparatus comprising at least a receiver and a processor coupled to said receiver, said apparatus being configured to collect and process, in a passive manner, at least two pairs of successive samples of a weak electromagnetic energy signal emitted from the emission source and define, by extracting phase information from Fourier IQ data in said at least two pairs of successive samples of said weak electromagnetic energy signal through Fast Fourier Transform (FFT), angular and spatial coordinates of the emission source, one sample of said weak electromagnetic energy signal in each pair from said at least two pairs being processed, to extract said phase information, independently from but substantially simultaneously with another sample of said weak electromagnetic energy signal in said each pair from said at least two pairs.

34. The apparatus of claim 33, further comprising:

a first antenna configured to collect at least a pair of first samples from said at least two pairs of successive samples of said weak electromagnetic energy signal;

a second antenna configured to collect at least a pair of second samples from said at least two pairs of successive samples of said weak electromagnetic energy signal; and

said receiver being operatively coupled to each of said first and second antennas.

35. The apparatus of claim 33, further comprising a platform, said apparatus being mounted on said platform.

36. The apparatus of claim 33, said apparatus being integrated onto a single integrated circuit (IC).