Enhanced imaging system

• US 9,557,415 B2
• Filed: 01/20/2014
• Issued: 01/31/2017
• Est. Priority Date: 01/20/2014
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Inventors: Karam, Mostafa A., Shori, Raj K., Sego, Douglas Lee, Bidler, Lyle K. II, Meyer, A. Douglas
• Primary Examiner(s): GREGORY, BERNARR E
• Application Number:
  US14/159,199
• Publication Number:
  US 20150276927A1
• Time in Patent Office: 1,107 Days
• Field of Search: 342 52- 55, 342 61- 66, 342/175, 342/176, 342/179, 342/195, 342/165, 342/173, 342/174, 382/100, 382/103, 382/276, 382/286, 382/291, 702/127, 702/179, 702/181, 702/189
• US Class Current: 1/1
• CPC Class Codes: G01S 13/865 Combination of radar systems with lidar systems
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G01S 17/89 for mapping or imaging

Abstract

One embodiment describes an imaging system. The system includes a first imaging system configured to provide first signals to a target area and to receive first response signals. The system also includes a second imaging system configured to provide second signals to the target area and to receive second response signals. The first and second signals can have separate frequency bands. The system further includes a processor configured to correct the first response signals based on the second response signals, and to generate an image based on the corrected first response signals.

Claims

1. An imaging system, comprising:

a first imaging system configured to provide first signals to a target area and to receive first reflected signals;

a second imaging system configured to provide second signals to the target area and to receive second reflected signals, the first and second signals having separate frequency bands; and

a processor configured to correct the backscattering coefficient values of the first reflected signals based on at least a portion of the second reflected signals, and to generate an image based on the corrected first reflected signals.

2. The imaging system of claim 1, wherein the image is a first image, and wherein the processor is further configured to generate a second image based on the second reflected signals and to generate a fused image based on the first image and the second image.

3. The imaging system of claim 1, wherein the processor is configured to correct the backscattering coefficient values of the first reflected signals based on slant range vectors derived from the second reflected signals.

4. The imaging system of claim 3, wherein the processor is further configured to correct the first reflected signals for at least one of a gain of the first imaging system, areas of resolution cells associated with the slant range vectors, and a variation in the slant range vectors.

5. The imaging system of claim 3, wherein the slant range vectors correspond to scattering centers of a footprint of the first imaging system that contribute to the first reflected signals.

6. The imaging system of claim 1, wherein the processor is further configured to correct the first reflected signals based on applying a spectral transform to the first reflected signals to determine a post-mixer power spectrum of the first reflected signals, and based on correcting the post-mixer power spectrum based on slant range values derived from the portion of the second reflected signals.

7. The imaging system of claim 6, wherein the processor is further configured to correct the post-mixer power spectrum based on mapping slant range vectors of the second reflected signals into the post-mixer spectrum, based on determining a correction factor associated with each of the slant range vectors, and based on correcting the post-mixer power spectrum based on the correction factors.

8. The imaging system of claim 7, wherein the processor is further configured to generate the image based on corrected backscattering coefficient values that are determined from the corrected post-mixer power spectrum.

9. The imaging system of claim 1, wherein the second imaging system comprises a plurality of aperture elements configured in a geometry that is approximately equivalent to a geometry of a plurality of aperture elements of the first imaging system.

10. The imaging system of claim 1, wherein the first imaging system and the second imaging system are separated a predetermined distance measured in a down-track direction, and wherein the predetermined distance contributes to a lag-time for the processor to map the second reflected signals into the first reflected signals to correct the first reflected signals.

11. The imaging system of claim 10, further comprising a common housing comprising the first imaging system and the second imaging system.

12. The imaging system of claim 1, wherein the first imaging system is a radar system and wherein the second imaging system is a lidar system.

13. A non-transitory computer-readable storage medium storing instructions executable by an associated processor to perform a method for imaging, the method comprising:

correcting reflected radar signals that are received from a radar system corresponding to backscattered radar signals reflected from a target area, the reflected radar signals being corrected based on at least a portion of reflected lidar signals that are received from a lidar system corresponding to backscattered lidar signals reflected from the target area;

generating a corrected radar image based on the corrected reflected radar signals;

generating a lidar image based on the reflected lidar signals; and

fusing the corrected radar image with the lidar image to generate a fused image.

14. The non-transitory computer-readable storage medium of claim 13, wherein the correcting the reflected radar signals further comprises correcting backscattering coefficient values of the reflected radar signal based on slant range vectors of the reflected lidar signals.

15. The non-transitory computer-readable storage medium of claim 13, wherein the correcting the reflected radar signals further comprises:

applying a spectral transform to the radar response signals to determine a post-mixer power spectrum of the reflected radar signals; and

correcting the post-mixer power spectrum based on slant range values derived from the portion of the reflected lidar signals.

16. The non-transitory computer-readable storage medium of claim 13, wherein the correcting the post-mixer power spectrum further comprises:

mapping slant range vectors of the reflected lidar signals into the post-mixer spectrum;

determining a correction factor associated with each of the slant range vectors; and

correcting the post-mixer power spectrum based on the correction factors.

17. The non-transitory computer-readable storage medium of claim 16, wherein the generating the corrected radar image further comprises:

determining corrected backscattering coefficient values from the corrected post-mixer power spectrum; and

generating the corrected radar image based on the corrected backscattering coefficient values.

18. A imaging device, comprising:

a housing comprising a radar device and a lidar device separated by a predetermined distance,

wherein the radar device is configured to receive reflected radar signals from a target area, and

wherein the lidar device is configured to receive reflected lidar response signals from the target area; and

a processor configured to correct the reflected radar signals based on at least a portion of the reflected lidar signals and a lag-time to map the reflected lidar signals to the reflected radar signals based on the predetermined distance, and to generate a corrected radar image based on the corrected reflected radar signals.

19. The imaging device of claim 18, wherein the processor is further configured to generate a lidar image based on the reflected lidar signals, and to generate a fused image based on the corrected radar image and the lidar image.

20. The imaging device of claim 18, wherein the radar device comprises an aperture having a first geometric shape, and wherein the lidar device comprises a plurality of lidar elements arranged in a second geometric shape, wherein the first geometric shape and the second geometric shape are approximately equivalent.