Positioning, detection and communication system and method

• US 8,072,220 B2
• Filed: 03/26/2008
• Issued: 12/06/2011
• Est. Priority Date: 12/16/2005
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon UTD, Inc. (Rtx Corporation)
• Inventors: Dolgin, Benjamin P., Shore, Michael, Cotten, Steven A., Matter, Craig E., Kuck, Kenneth D., Giraldo, Luis B., Ishibashi, John T.
• Primary Examiner(s): LEDYNH, BOT L
• Application Number:
  US12/078,069
• Publication Number:
  US 20090009410A1
• Time in Patent Office: 1,350 Days
• Field of Search: 324/228, 324/329
• US Class Current: 324/329
• CPC Class Codes: G01C 21/1654 with electromagnetic compass

Abstract

A positioning, communication, and detection system designed to provide a three dimensional location of an object, navigation tools, and bidirectional surface-to-subsurface communications, and methods of using the system. The system can include one or multiple transmitters comprising electromagnetic beacons, software defined radio receivers with an associated processing unit and data acquisition system, and magnetic antennas. The system may use theoretical calculations, scale model testing, signal processing, and sensor data.

Claims

1. A navigation system comprising:

at least one transmitter comprising at least two magnetic dipoles, said transmitter being configured to generate a magnetic field; and

a receiver comprising a magnetometer configured to receive input from said at least one transmitter; and

wherein the transmitter is configured to change the magnetic dipoles'"'"' respective amplitudes according to one or more predetermined patterns, thereby producing associated signals;

wherein the transmitter is configured to change the amplitude of a first magnetic dipole at a first frequency and the amplitude of a second magnetic dipole at a second frequency, where the first frequency is different from the second frequency;

wherein the magnetic dipoles are configured to rotate around respective axes at a constant rate;

wherein the associated signals are configured to rotate in a fixed plane; and

wherein the receiver is configured to determine a bearing of the transmitter based on an orientation of the fixed plane.

2. The navigation system of claim 1, wherein the receiver is configured to identify each transmitter based upon differences between their associated signals.

3. A navigation system comprising:

at least one transmitter comprising at least two magnetic dipoles, said transmitter being configured to generate a magnetic field; and

a receiver comprising a magnetometer configured to receive input from said at least one transmitter; and

wherein the transmitter is configured to change the magnetic dipoles'"'"' respective amplitudes according to one or more predetermined patterns, thereby producing associated signals;

wherein the transmitter is configured to change the amplitude of a first magnetic dipole at a first frequency and the amplitude of a second magnetic dipole at a second frequency, where the first frequency is different from the second frequency;

wherein the magnetic dipoles are configured to rotate around respective axes at a constant rate; and

wherein the receiver is configured to determine the line of bearing to the transmitter based on the difference in orientation between at least the first magnetic dipole and the second magnetic dipole.

4. The navigation system of claim 3, wherein the receiver is configured to determine a distance to the transmitter based on amplitude signals of the magnetic dipoles.

5. A navigation system comprising:

at least one transmitter comprising at least two magnetic dipoles, said transmitter being configured to generate a magnetic field; and

a receiver comprising a magnetometer configured to receive input from said at least one transmitter; and

wherein the transmitter is configured to change the magnetic dipoles'"'"' orientations at different respective frequencies; and

wherein the transmitter further comprises a first clock, the receiver further comprises a second clock, wherein the first and second clocks are synchronized for use in signal detection.

6. The navigation system of claim 5, wherein the receiver synchronizes the second clock with the first clock based on a difference in the magnetic dipoles'"'"' orientations.

7. The navigation system of claim 5, wherein the magnetic dipoles are spinning dipoles.

8. The navigation system of claim 5, wherein the magnetic dipoles share a center of rotation.

9. The navigation system of claim 5, wherein the transmitter further comprises at least two non-coaxial magnetic coils for generating the magnetic field.

10. The navigation system of claim 5, wherein the transmitter further comprises at least three non-coaxial magnetic coils for generating the magnetic field.

11. The navigation system of claim 10 wherein at least one of the magnetic coils include a magnetic core.

12. The navigation system of claim 11 wherein the at least two magnetic coils share the same magnetic core.

13. The navigation system of claim 5, further comprising a device for determining a line of bearing of the receiver relative to the transmitter.

14. A navigation system, comprising:

a transmitter comprising at least two rotating, co-located magnetic dipoles, said co-located magnetic dipoles sharing an axis of rotation; and

a receiver comprising a magnetometer; and

wherein said receiver is configured to use a signal produced by the two rotating, co-located magnetic dipoles as a clock signal.

15. The navigation system of claim 14, wherein said at least two co-located magnetic dipoles are generated by two or more magnetic coils.

16. A navigation system, comprising:

a transmitter comprising at least two rotating, co-located magnetic dipoles, said co-located magnetic dipoles sharing an axis of rotation; and

a receiver comprising a magnetometer; and

wherein the receiver is configured to use a signal produced by the two rotating, co-located magnetic dipoles to obtain a line of bearing relative to the transmitter.