Radar for imaging of buildings

• US 8,040,273 B2
• Filed: 07/14/2009
• Issued: 10/18/2011
• Est. Priority Date: 07/14/2009
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Samaniego, Raymond, Grimm, Jerry M., Tomich, John L.
• Primary Examiner(s): GREGORY, BERNARR E
• Application Number:
  US12/502,325
• Publication Number:
  US 20110012777A1
• Time in Patent Office: 826 Days
• Field of Search: 342/21, 342/22, 342 25 R- 25 F, 342/175, 342/176, 342/179, 342192-197, 342/118, 342128-145, 342/147, 342156-158, 342/127, 342/190, 342/191
• US Class Current: 342/22
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/888 through wall detection
• CPC Class Codes: G01S 13/9023 combined with interferometric techniques
• CPC Class Codes: G01S 2013/0245 Radar with phased array antenna

Abstract

According to one embodiment, a radar includes multiple antenna elements coupled to an image processing application. The antenna elements have a differing vertical spatial separation relative to one another and are configured to transmit a radio-frequency signal toward a stationary object and receive multiple reflected radio-frequency signals from one or more internal features of the building. The image processing application receives the reflected radio-frequency signals as the antenna elements are moved horizontally with respect to the stationary object. From these reflected radio-frequency signals, the image processing application generates imagery of the stationary object according to phase variations in the plurality of received radio-frequency signals. The imagery depicting vertical characteristics of the one or more internal features of the building.

Claims

1. A mobile synthetic aperture radar comprising:

a plurality of antenna elements that are arranged in a two-dimensional array and configured in or on a truck, the plurality of antenna elements operable to transmit a transmitted radio-frequency signal toward a building and receive a plurality of reflected radio-frequency signals comprising energy from the transmitted radio-frequency signal that is reflected from one or more internal features of the building, the plurality of antenna elements operable to step the transmitted radio-frequency signal through a range of frequencies extending from 500 to 1225 Mega-Hertz, at least a portion of the reflected radio-frequency signals received with a vertical aperture that differs from one another; and

an image processing application coupled to the plurality of antenna elements and operable to;

receive the reflected radio-frequency signals from the plurality of antenna elements as they are moved horizontally with respect to the building; and

generate imagery of the building according to phase variations in the plurality of received radio-frequency signals relative to one another, the imagery depicting vertical characteristics of the one or more internal features comprising a ground floor and an upper floor of the building.

2. A mobile synthetic aperture radar comprising:

a plurality of antenna elements having a differing vertical spatial separation relative to one another, the plurality of antenna elements operable to transmit a transmitted radio-frequency signal toward a stationary object and receive a plurality of reflected radio-frequency signals comprising energy from the transmitted radio-frequency signal that is reflected from one or more internal features of the stationary object; and

an image processing application coupled to the plurality of antenna elements and operable to;

receive the reflected radio-frequency signals from the plurality of antenna elements as they are moved horizontally with respect to the stationary object; and

generate imagery of the stationary object according to phase variations in the plurality of received radio-frequency signals relative to one another, the imagery depicting vertical characteristics of the one or more internal features.

3. The mobile synthetic aperture radar of claim 2, wherein the plurality of antenna elements comprise a two-dimensional array of antenna elements.

4. The mobile synthetic aperture radar of claim 2, wherein the plurality of antenna elements are operable to step the transmitted radio-frequency signal through a range of frequencies.

5. The mobile synthetic aperture radar of claim 4, wherein the range of frequencies extends from 500 Mega-Hertz to 1225 Mega-Hertz.

6. The mobile synthetic aperture radar of claim 4, wherein the plurality of antenna elements are operable to repeatedly step the transmitted radio-frequency signals through the range of frequencies within every 6 inch movement of the plurality of antenna elements.

7. The mobile synthetic aperture radar of claim 2, wherein the stationary object comprises a building and the one or more internal features comprises a ground floor and an upper floor of the building.

8. The mobile synthetic aperture radar of claim 2, wherein the plurality of antenna elements are configured on a portable platform.

9. The mobile synthetic aperture radar of claim 8, wherein the portable platform comprises a land-based vehicle.

10. The mobile synthetic aperture radar of claim 2, wherein the plurality of antenna elements are oriented in a fixed orientation relative to one another.

11. The mobile synthetic aperture radar of claim 2, wherein the plurality of antenna elements are operable to receive at least a portion of the reflected radio-frequency signals with a vertical aperture that differs from one another.

12. A method comprising:

providing a plurality of antenna elements that have a vertical spatial separation relative to one another;

moving the plurality of antenna elements horizontally with respect to a stationary object;

transmitting, using the plurality of antenna elements, a transmitted radio-frequency signal toward the stationary object;

receiving, using the plurality of antenna elements, a plurality of reflected radio-frequency signals comprising energy from the transmitted radio-frequency signal that is reflected from one or more internal features of the stationary object; and

generating imagery of the stationary object according to phase variations in the plurality of received radio-frequency signals relative to one another, the imagery depicting vertical characteristics of the one or more internal features.

13. The method of claim 12, further comprising orienting the plurality of antenna elements to have a horizontal spatial separation relative to one another.

14. The method of claim 12, wherein transmitting the transmitted radio-frequency signal comprises stepping the transmitted radio-frequency signal through a range of frequencies.

15. The method of claim 14, wherein stepping the transmitted radio-frequency signal comprises stepping the transmitted radio-frequency signal through a range of frequencies that extends from 500 Mega-Hertz to 1225 Mega-Hertz.

16. The method of claim 15, wherein stepping the transmitted radio-frequency signal comprises repeatedly stepping the transmitted radio-frequency signals through the range of frequencies within every 6 inch movement of the plurality of antenna elements.

17. The method of claim 12, wherein generating imagery of one or more internal features of the stationary object comprises generating imagery of a ground floor and one or more upper floors of a building.

18. The method of claim 12, wherein moving the plurality of antenna elements horizontally with respect to the building comprises moving the plurality of antenna elements horizontally with respect to a building using a land-based vehicle.

19. The method of claim 12, further comprising orienting the plurality of antenna elements to have a fixed orientation relative to one another.

20. The method of claim 12, wherein receiving the reflected radio-frequency signals comprises receiving at least a portion of the reflected radio-frequency signals with a vertical aperture that differs from one another.