IDENTIFICATION AND ANALYSIS OF SOURCE EMISSIONS THROUGH HARMONIC PHASE COMPARISON

• US 20110095934A1
• Filed: 10/25/2010
• Published: 04/28/2011
• Est. Priority Date: 10/23/2009
• Status: Active Grant

• Current Assignee: Nokomis Inc.
• Original Assignee: Nokomis Inc.
• Inventors: Freeman, Stephen Dorn, Keller,, Walter John III
• Granted Patent: US 8,537,050 B2
• Time in Patent Office: Days
• US Class Current: 342/13
• CPC Class Codes: G01R 29/0892 Details related to signal analysis or treatment; presenting results, e.g. displays; measuring specific signal features other than field strength, e.g. polarisation, field modes, phase, envelope, maximum value
• CPC Class Codes: G01S 13/88 Radar or analogous systems specially adapted for specific applications electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00
• CPC Class Codes: G01S 7/38 Jamming means, e.g. producing false echoes
• CPC Class Codes: G01S 7/41 using analysis of echo signal for target characterisation; Target signature; Target cross-section
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

The present invention is a signal processing method to significantly improve the detection and identification of source emissions. More particularly, the present invention offers a processing method to reduce the false alarm rate of systems which remotely detect and identify the presence of electronic devices through an analysis of a received spectrum the devices'"'"' unintended emissions. The invention identifies candidate emission elements and determines their validity based on a frequency and phase association with other emissions present in the received spectrum. The invention compares the measured phase and frequency data of the emissions with a software solution of the theoretically or empirically derived closed-form expression which governs the phase and frequency distribution of the emissions within the source. Verification of this relationship serves to dramatically increase the confidence of the detection.

Claims

1. A method comprising the steps of:

receiving an electromagnetic emission,

identifying at least one relationship between at least two harmonics of said electromagnetic emission,

using said at least one relationship to identify a source of said electromagnetic emission.

2. The method of claim 1 wherein said electromagnetic emission is an unintended electromagnetic emission.

3. The method of claim 1 wherein said electromagnetic emission is an intended electromagnetic emission.

4. The method of claim 1 wherein said method is used to locate an electrical device.

5. The method of claim 1 wherein said method is used to determine an instantaneous phase of an underlying source signal to identify at least one short term event.

6. The method of claim 1 wherein said method is used to differentiate harmonic content of said source from electro-magnetic background noise.

7. The method of claim 1 wherein said method is used for detection of at least one electronically triggered event.

8. The method of claim 1 wherein said method is used to perform diagnostics on an electronic device, a electrical component, and a combination thereof for health monitoring.

9. The method of claim 1 further comprising the step of actively illuminating a source.

10. The method of claim 1 further comprising the step of comparing harmonic spacing in frequency of said electromagnetic emission.

11. The method of claim 1 wherein said at least one relationship comprises at least one phase related relationship.

12. The method of claim 11 wherein said method is used to identify that a set of harmonics are all related to a specific class of electronic device.

13. The method of claim 11 wherein said method is used to identify that a set of harmonics are all related to a specific electronic device.

14. The method of claim 11 wherein said method is used to aid in spectroscopy.

15. The method of claim 1 wherein said source is a device.

16. The method of claim 1 wherein said source is an electrical device.

17. The method of claim 11 wherein said source is a device.

18. The method of claim 11 wherein said source is an electrical device.

19. The method of claim 15 wherein said at least one relationship between said at least two harmonics is the frequency spacing between said at least two harmonics.

20. The method of claim 16 wherein said at least one relationship is between at least two fundamental frequencies of said electromagnetic emission which are correlated to provide detection of said electrical device.

23. The method of claim 1 further comprising the steps of:

providing an electromagnetic emission device comprising;

an antenna,

at least one processor,

wherein said electromagnetic emission measurement device is configured to monitor at least one electrical device by measuring at least one electromagnetic emission given off by said at least one electrical device.

24. The electromagnetic emission measurement device of claim 23, wherein the electromagnetic emission measurement device is configured to include an analog to digital converter than can be part of a receiver, part of said at least one processor or implemented as a stand alone component and a combination thereof.

25. The method of claim 1 wherein said at least one relationship comprises changes between harmonics of said electromagnetic emission to identify that said harmonics are related to said source.

26. The method of claim 1 wherein said at least one relationship comprises phase changes between harmonics of said electromagnetic emission to identify that said harmonics are related to said source.

27. The method of claim 1 wherein said at least one relationship comprises the use of phase consistency between harmonics of said electromagnetic emission to identify that said harmonics are related to said source.

28. The method of claim 1 wherein said at least one relationship comprises the use of phase relationships and at least one time domain technique between harmonics of said electromagnetic emission to identify that said harmonics are related to said source.

29. The method of claim 1 wherein said at least one relationship comprises the use of phase relationships and autocorrelation related to harmonics of said electromagnetic emission to identify that said harmonics are related to said source.

33. The method of claim 1 wherein said method is used to determine an instantaneous phase of said electromagnetic emission to synchronize a local device with a remote device.

35. The method of claim 1 wherein said at least one relationship comprises a known time delay between said at least two harmonics.

21. A method comprising the steps of:

receiving at least one electromagnetic emission,

identifying at least one relationship between at least two non-harmonic components of said at least one electromagnetic emission,

using said at least one relationship to detect at least one electronic device.

22. An electromagnetic emission measurement device comprising:

an antenna,

a receiver,

at least one processor,

wherein said electromagnetic emission measurement device is configured to monitor at least one electrical device by measuring at least one electromagnetic emission given off by said at least one electrical device.

34. The electromagnetic emission measurement device of claim 22 wherein said electromagnetic emission measurement device is configured to identify at least one electrical device by measuring at least one electromagnetic emission given off by said at least one electrical device.

30. A method comprising the steps of:

one of measuring, comparing and a combination thereof, one of amplitude, phase, and a combination thereof of harmonics simultaneously of an emitted electromagnetic energy to identify a source of said energy.

31. The method of claim 30 wherein said method is used to geolocate said source of said energy.

32. The method of claim 31 wherein said source is one of an electrical device, an electrical component, and a combination thereof.

36. A method comprising the steps of:

receiving at least two electromagnetic emissions,

identifying at least one relationship between at least two harmonics of said at least two electromagnetic emissions,

using said at least one relationship to differentiate between at least two sources of said electromagnetic emissions.