Wideband RF detection

• US 8,194,250 B2
• Filed: 05/30/2008
• Issued: 06/05/2012
• Est. Priority Date: 05/30/2008
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Morgan, Dennis R.
• Primary Examiner(s): Geisel, Kara E
• Application Number:
  US12/155,184
• Publication Number:
  US 20120112949A1
• Time in Patent Office: 1,467 Days
• Field of Search: 356602-608, 356 301- 309, 342/22, 342 25 R- 25 F, 342/176, 342/179, 342/181, 342/191, 250/559.22, 250/559.23, 378/57
• US Class Current: 356/445
• CPC Class Codes: G01S 13/888 through wall detection
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G01S 13/90 using synthetic aperture techniques , e.g. synthetic aperture radar [SAR] techniques

Abstract

The present invention relates to a method of wideband RF detection. The method may include transmitting a signal from a plurality of transmit positions along a drive path. Reflections of the transmitted signal are received at a plurality of receive positions along the drive path. A signature is formed based on arrival angles of the reflections at each of the receive positions. The signature includes the arrival angles of the reflections at each of the receive positions with respect to a distance along the drive path of a corresponding transmit position and a corresponding receive position of each of the reflections.

Claims

1. A method, comprising:

transmitting a signal from a plurality of transmit positions along a drive path;

receiving reflections of the transmitted signal at a plurality of receive positions along the drive path;

forming a signature of a structure based on arrival angles of the reflections at each of the receive positions;

inferring an interior of the structure based on the signal; and

comparing the signature to other signatures to detect internal changes within the structure.

2. The method of claim 1, wherein the signature includes the arrival angles of the reflections at each of the receive positions with respect to a distance along the drive path of a corresponding transmit position and a corresponding receive position of each of the reflections.

3. The method of claim 1, wherein each arrival angle of each of the reflections is computed in accordance with the following equation

4. The method of claim 1, wherein the signature includes an intensity of the received reflections at each of the receive positions along the drive path.

5. The method of claim 1, wherein the signature includes a path delay of the received reflections at each of the receive positions along the drive path with respect to transmit times of corresponding transmit signals.

6. The method of claim 1, further comprising:

representing the signature as a display of the arrival angles of the reflections at each of the receive positions with respect to a distance along the drive path of a corresponding transmit position and a corresponding receive position of each of the reflections at each of the receive positions along the drive path, with coloring to indicate a path delay of the received reflections, the path delay in respect to transmit times of corresponding transmit signals.

7. The method of claim 6, wherein an intensity of the coloring indicates an intensity of the received reflections at each of the receive positions along the drive path.

8. The method of claim 6, wherein a path loss is based on the arrival angle of the received reflections, the path loss being a difference between an intensity of the transmitted signal and an intensity of the received reflections.

9. The method of claim 1, further comprising:

performing beamforming along the drive path to derive the received reflections for the signature.

10. The method of claim 9, further comprising:

distributing the arrival angles of the received reflections across a plurality of bins of a column of a matrix for each corresponding transmit/receive position pair, the bins being filled with a complex path amplitude of the reflections, each column of the matrix corresponding to a single transmit/receive position pair.

11. The method of claim 1, further comprising:

storing the signature as a reference file.

12. The method of claim 1, wherein the inferring the interior of the structure includes matching trajectories of the arrival angles of the reflections to identify corners within the structure.

13. The method of claim 1, wherein the transmitted signal is a wideband RF probe signal.

14. The method of claim 1, wherein the arrival angles are computed in a two-dimensional coordinate system.

15. The method of claim 1, wherein the arrival angles are computed in a three-dimensional coordinate system.