Method and apparatus for superresolution imaging

• US 8,189,095 B2
• Filed: 10/30/2008
• Issued: 05/29/2012
• Est. Priority Date: 10/30/2008
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Gerwe, David R.
• Primary Examiner(s): Ye, Lin
• Assistant Examiner(s): HSU, AMY R
• Application Number:
  US12/261,196
• Publication Number:
  US 20100110208A1
• Time in Patent Office: 1,307 Days
• Field of Search: 348/222.1, 348/370, 382/299
• US Class Current: 348/370
• CPC Class Codes: H04N 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 23/951 by using two or more images to influence resolution, frame rate or aspect ratio

Abstract

An apparatus and method are disclosed for providing superresolution imaging of a target, including remote targets. An apparatus for superresolution imaging may include a receiver having a predefined receiving aperture for capturing an image of the target. The apparatus may also include a plurality of transmitters spaced apart from one another and configured to concurrently emit signals with a phase difference therebetween. The plurality of transmitters may be further configured to emit overlapping beams onto the target to produce a fringe pattern modulated at spatial frequencies beyond the resolution limit of the receiving aperture. The apparatus may further include a processor configured to process the image including at least a portion of the fringe pattern in order to produce a superresolved image including spatial frequency content beyond the resolution limit of the receiving aperture. A corresponding method may also be provided.

Claims

1. An apparatus for superresolution imaging of a remote target, the apparatus comprising:

a receiver having a predefined receiving aperture for capturing an image of the target;

a plurality of transmitters spaced apart from one another and configured to concurrently emit signals directed toward the target with a phase difference therebetween, wherein the plurality of transmitters are further configured to emit overlapping beams onto the target such that interaction of the overlapping beams with the target produces a fringe pattern modulated at spatial frequencies beyond a resolution limit of the receiving aperture; and

a processor configured to process the image including at least a portion of the fringe pattern in order to produce a superresolved image including spatial frequency content beyond the resolution limit of the receiving aperture.

2. An apparatus according to claim 1 wherein the plurality of transmitters are configured such that a first group of two or more transmitters concurrently emits signals at a first time and a second group of two or more transmitters, different than the first group, concurrently emits signals at a second time.

3. An apparatus according to claim 2 wherein the processor is configured to produce the superresolved image based upon the images created by each group of transmitters.

4. An apparatus according to claim 3 wherein, for each group of transmitters, the processor is configured to determine a contribution to the superresolved image based upon the image created by the respective group of transmitters and to determine a location of the contribution to the superresolved image based upon a position of the transmitters which comprise the respective group.

5. An apparatus according to claim 1 wherein the receiver and the plurality of transmitters are proximate one another and remote from the target.

6. An apparatus according to claim 1 further comprising a common source for providing signals to said plurality of transmitters.

7. A method for superresolution imaging of a remote target, the method comprising:

concurrently emitting signals directed toward the target from a plurality of transmitters spaced apart from one another, wherein concurrently emitting signals comprises concurrently emitting signals from different transmitters that have a phase difference therebetween, and wherein concurrently emitting signals comprises emitting overlapping beams onto the target such that interaction of the overlapping beams with the target produces a fringe pattern modulated at spatial frequencies beyond a resolution limit of a receiving aperture;

capturing an image of the target with a receiver have a predefined receiving aperture; and

processing the image including at least a portion of the fringe pattern in order to produce a superresolved image including spatial frequency content beyond the resolution limit of the receiving aperture.

8. A method according to claim 7 wherein concurrently emitting signals comprises concurrently emitting signals at a first time with a first group of two or more transmitters and concurrently emitting signals at a second time with a second group of two or more transmitters, different than the first group.

9. A method according to claim 8 wherein processing the image comprises producing the superresolved image based upon the images created by each group of transmitters.

10. A method according to claim 9 wherein, for each group of transmitters, processing the image comprises determining a contribution to the superresolved image based upon the image created by the respective group of transmitters and determining a location of the contribution to the superresolved image based upon a position of the transmitters which comprise the respective group.

11. A method according to claim 7 further providing signals to the plurality of transmitters from a common source.

12. An apparatus for superresolution imaging of a remote target, the apparatus comprising:

a telescope having a predefined receiving aperture for capturing an image of the target;

an array of transmitters spaced apart from one another in first and second orthogonal directions, wherein different pairs of transmitters are configured to emit signals directed toward the target with a phase difference therebetween such that interaction of the overlapping beams with the target produces a fringe pattern upon the target that is modulated at spatial frequencies beyond a resolution limit of the receiving aperture; and

a processor configured to process the images including at least a portion of the fringe patterns created by different pairs of transmitters in order to produce a superresolved image including spatial frequency content beyond the resolution limit of the receiving aperture.

13. An apparatus according to claim 12 wherein at least some of the transmitters are spaced such that adjacent transmitters are spaced apart by no more than √

{square root over (2)}.

14. An apparatus according to claim 12 wherein the array of transmitters comprises a first plurality of transmitters extending in the first direction and a second plurality of transmitters extending in the second direction.

15. An apparatus according to claim 12 further comprising a common source for providing signals to said plurality of transmitters.

16. An apparatus according to claim 15 wherein the common source has a coherence length that is at least as great as the greater of the widths of the array of transmitters in the first and second directions.

17. An apparatus according to claim 15 further comprising a phase shifter for introducing a predefined phase shift to the signals provided by the common source to a pair of transmitters.

18. An apparatus according to claim 12 wherein the array of transmitters is configured such that a first pair of transmitters concurrently emits signals at a first time and a second pair of transmitters, different than the first pair, concurrently emits signals at a second time.

19. An apparatus according to claim 18 wherein the processor is configured to produce the superresolved image based upon the images created by each pair of transmitters.

20. An apparatus according to claim 19 wherein, for each pair of transmitters, the processor is configured to determine a contribution to the superresolved image based upon the image created by the respective pair of transmitters and to determine a location of the contribution to the superresolved image based upon a position of the pair of transmitters within the array.