Integrated sensor system for measuring electric and/or magnetic field vector components

• US 20050073302A1
• Filed: 10/07/2004
• Published: 04/07/2005
• Est. Priority Date: 10/07/2003
• Status: Active Grant

• Current Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Original Assignee: Quantum Applied Science And Research, Inc.
• Inventors: Matthews, Robert, Hibbs, Andrew D., Jabson, David Matthew
• Granted Patent: US 7,141,968 B2
• Time in Patent Office: Days
• US Class Current: 324/247
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: G01R 29/14 Measuring field distribution
• CPC Class Codes: G01R 33/02 Measuring direction or magnitude of magnetic fields or magnetic flux G01R33/20 takes precedence
• CPC Class Codes: G01R 35/005 Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references G01R33/0035, G01R35/002 take precedence
• CPC Class Codes: G01V 3/08 operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices with electromagnetic waves G01V3/12

Abstract

A compact sensor system integrates electric and/or magnetic field sensors to accurately measure, with a high level of sensitivity, one or more electric and magnetic vector components of fields. The electric and magnetic field data can be utilized separately or combined. The sensor system is self-contained so as to include a built-in power source, as well as data storage and/or transmission capability. The integrated sensor system also preferably includes a global positioning system (GPS) to provide timing and position information, a sensor unit which can determine the orientation and tilt of the sensor system, and self-calibrating structure which produces local electric and/or magnetic fields used to calibrate the sensor system following deployment.

Claims

1. An integrated sensor system for measuring electric and magnetic fields comprising:

a plurality of electric field sensors;

a plurality of magnetic field sensors;

a housing supporting the plurality of electric and magnetic field sensors; and

a controller for determining at least one vector field component based on signals received from both the plurality of electric and magnetic field sensors.

2. The sensor system according to claim 1, wherein the plurality of magnetic field sensors function as at least one of structural and insulating elements for the plurality of electric field sensors.

3. The sensor system according to claim 1, wherein the sensor system is compact in nature and highly sensitive.

4. The sensor system according to claim 1, further comprising:

a DC power source provided in housing, wherein the sensor system is self-contained and portable.

5. The sensor system according to claim 1, further comprising:

a global positioning system for providing timing and positioning information.

6. The sensor system according to claim 1, further comprising:

means, incorporated into the sensor system, for determining orientation and tilt information on the sensor system.

7. The sensor system according to claim 1, further comprising:

means for self-calibrating the sensor system.

8. The sensor system according to claim 7, wherein the self-calibrating means produces local electric and/or magnetic fields.

9. The sensor system according to claim 1, wherein the plurality of magnetic field sensors extend along three orthogonally arranged axis.

10. The sensor system according to claim 1, wherein at least two of the plurality of magnetic field sensors are arranged along an axis in common with at least one of the plurality of electric field sensors.

11. The sensor system according to claim 10, further comprising:

a plurality of arms projecting from the housing, each of the plurality of arms supporting a respective one of the plurality of electric field sensors, as well as a respective one of the plurality of magnetic field sensors.

12. The sensor system according to claim 11, wherein the plurality of arms includes first and second sets of arms, with the first and second sets of arms extending in distinct orthogonal directions.

13. The sensor system according to claim 11, wherein the plurality of arms includes first and second sets of arms, with the first and second sets of arms intersecting at angles of less than ninety degrees.

14. The sensor system according to claim 1, further comprising:

means for combining field data from distinct axes.

15. The sensor system according to claim 14, wherein said combining means utilizes electric field data to modify magnetic field data.

16. The sensor system according to claim 14, wherein said combining means utilizes magnetic field data to modify electric field data.

17. The sensor system according to claim 14, wherein said combining means utilizes electric field data from at least one of the plurality of electric field sensors to modify electric field data from at least another one of the plurality of electric field sensors.

18. The sensor system according to claim 1, wherein the plurality of magnetic field sensors have associated axes, with the axes intersecting at a center.

19. An integrated sensor system for measuring at least magnetic fields comprising:

a plurality of induction-type magnetic field sensors;

a housing supporting the plurality of magnetic field sensors; and

a controller for determining at least one vector field component based on signals received from the magnetic field sensors.

20. The sensor system according to claim 19, wherein the sensor system is compact in nature and highly sensitive.

21. The sensor system according to claim 19, further comprising:

a DC power source provided in housing, wherein the sensor system is self-contained and portable.

22. The sensor system according to claim 19, wherein the plurality of magnetic field sensors extend along three orthogonally arranged axis.

23. The sensor system according to claim 19, wherein the plurality of magnetic field sensors have associated axes, with the axes intersecting at a center.

24. The sensor system according to claim 19, wherein the plurality of magnetic sensors are arranged to intersect at a lateral offset of less than 1 cm.

25. The sensor system according to claim 19, wherein the sensor system has a maximum lateral dimension less than 50 cm.

26. The sensor system according to claim 19, wherein the sensor system has a maximum dimension of less than 100 cm and each of the plurality of magnetic sensors has a sensitivity of at least 5 pT/Hz^1/2 at 10 Hz and 0.4 pT/Hz^1/2 at 100 Hz.

27. The sensor system according to claim 19, wherein the sensor system has a maximum dimension of less than 20 cm and each of the plurality of magnetic sensors has a sensitivity of at least 3 pT/Hz^1/2 at 10 Hz and 0.3 pT/Hz^1/2 at 100 Hz.

28. The sensor system according to claim 19, wherein the sensor system has a maximum dimension of less than 50 cm and each of the plurality of magnetic sensors has a sensitivity of at least 0.2 pT/Hz^1/2 at 10 Hz and 0.03 pT/Hz^1/2 at 100 Hz.

29. A method for measuring electric and magnetic fields through an integrated sensor system comprising:

measuring electric field information along a plurality of distinct axes;

measuring magnetic field information along at least some of the plurality of distinct axes; and

combining the electric and magnetic field information to establish a processed output, with the processed output including at least one of magnetic and electric field data which has been modified based on at least one of the electric and magnetic field information.

30. The method of claim 29, further comprising:

determining positioning information for the sensor system through a global positioning system.

31. The method of claim 29, further comprising:

determining orientation and tilt of the sensor system.

32. The method of claim 29, further comprising:

self-calibrating the sensor system.