# US 10,310,074 B1 · System and method for denoising synthetic aperture radar (SAR) images via sparse and low-rank (SLR) decomposition and using SAR images to image a complex scene > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,074 B1 - Document ID: US10310074B1 - Status: Granted - Kind: B1 - Application number: 14/670,199 - Filed: 2015-03-26 - Granted: 2019-06-04 - Earliest claimed: 2014-03-27 - Assignees: HRL Laboratories, LLC - Applicants: HRL Laboratories, LLC - Inventors: Kang-Yu Ni; Shankar R. Rao - Web page: https://patentgrep.com/patent/US10310074B1 ## CPC - G01S 13/9029: {specially adapted for moving target detection within a single SAR image or within multiple SAR images taken at the same time} - G01S 7/414: {Discriminating targets with respect to background clutter} - G01S 13/9017: {with time domain processing of the SAR signals in azimuth (G01S13/9005 takes precedence)} - G01S 13/9019: {Auto-focussing of the SAR signals} - G06T 5/50: using two or more images, e.g. averaging or subtraction - G06T 5/70: Denoising; Smoothing - G06T 7/20: Analysis of motion (motion estimation for coding, decoding, compressing or decompressing digital video signals H04N19/43, H04N19/51) - G06T 12/20: Inverse problem, i.e. transformations from projection space into object space - G06T 7/194: involving foreground-background segmentation - G06T 2207/10044: Radar image - G06T 2207/20116: Active contour; Active surface; Snakes - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract Described is a system for synthetic aperture radar (SAR) imaging. The system is adapted to reconstruct a set of images to generate a set of reconstructed SAR images, wherein at least some of the reconstructed SIR images have noise and contain glint. The reconstructed SAR images are then stacked into a matrix D, in which each column of the matrix is a reconstructed SAR image. Using sparse and low-rank decomposition on the matrix D, the system then extracts a clean background from the reconstructed SAR images and separates the noise and glint. Based on that, the system is operable to detect moving targets in sparse part S and issuing a notification of such a moving target. ## Claims ### Claim 1 A system for synthetic aperture radar (SAR) imaging, the system comprising: a SAR attached with a moving platform; one or more processors and a memory, the memory being a non-transitory computer-readable medium having executable instructions encoded thereon, such that upon execution of the instructions, the one or more processors perform operations of: capturing a set of images with the SAR from different azimuth angles; generating a set of reconstructed SAR images by reconstructing the set of images, wherein at least some of the reconstructed SAR images have noise and contain glint; stacking the reconstructed SAR images into a matrix D, in which each column of the matrix is a reconstructed SAR image; and generating a denoised SAR image by decomposing matrix D to extract a clean background from the reconstructed SAR images and separate the noise and glint from the reconstructed SAR images as sparse part S, the clean background being the denoised SAR image. ### Claim 2 (depends on 1) The system as set forth in claim 1, further comprising instructions encoded on the non-transitory computer-readable medium for causing the one or more processors to perform an operation of detecting moving targets in sparse part S and issuing a notification of such a moving target. ### Claim 3 (depends on 2) The system as set forth in claim 2, wherein detecting moving targets in sparse part S is performed using a segmentation method selected from a group consisting of normalized cut and active contour segmentation. ### Claim 4 (depends on 3) The system as set forth in claim 3, wherein in reconstructing the set of images, each image is constructed for a different set of azimuth angles. ### Claim 5 (depends on 4) The system as set forth in claim 4, wherein the set of reconstructed SAR images are reconstructed using a filtered back projection method. ### Claim 6 (depends on 1) The system as set forth in claim 1, wherein in reconstructing the set of images, each image is constructed for a different set of azimuth angles. ### Claim 7 (depends on 1) The system as set forth in claim 1, wherein the set of reconstructed SAR images are reconstructed using a filtered back projection method. ### Claim 8 A computer implemented method using one or more processors for synthetic aperture radar (SAR) imaging, the method comprising acts of: capturing a set of images with a SAR from different azimuth angles; generating a set of reconstructed SAR images by reconstructing the set of images, wherein at least some of the reconstructed SAR images have noise and contain glint; stacking the reconstructed SAR images into a matrix D, in which each column of the matrix is a reconstructed SAR image; and generating a denoised SAR image by decomposing matrix D to extract a clean background from the reconstructed SAR images and separate the noise and glint from the reconstructed SAR images as sparse part S, the clean background being the denoised SAR image. ### Claim 9 (depends on 8) The computer implemented method as set forth in claim 8, further comprising an act of detecting moving targets in sparse part S and issuing a notification of such a moving target. ### Claim 10 (depends on 9) The computer implemented method as set forth in claim 9, wherein detecting moving targets in sparse part S is performed using a segmentation method selected from a group consisting of normalized cut and active contour segmentation. ### Claim 11 (depends on 10) The computer implemented method as set forth in claim 10, wherein in reconstructing the set of images, each image is constructed for a different set of azimuth angles. ### Claim 12 (depends on 11) The computer implemented method as set forth in claim 11, wherein the set of reconstructed SAR images are reconstructed using a filtered back projection method. ### Claim 13 (depends on 8) The computer implemented method as set forth in claim 8, wherein in reconstructing the set of images, each image is constructed for a different set of azimuth angles. ### Claim 14 (depends on 8) The computer implemented method as set forth in claim 8, wherein the set of reconstructed SAR images are reconstructed using a filtered back projection method. ### Claim 15 A computer program product for synthetic aperture radar (SAR) imaging, the computer program product comprising: a non-transitory computer-readable medium having executable instructions encoded thereon, such that upon execution of the instructions by one or more processors, the one or more processors perform operations of: capturing a set of images with a SAR from different azimuth angles; generating a set of reconstructed SAR images by reconstructing the set of images, wherein at least some of the reconstructed SAR images have noise and contain glint; stacking the reconstructed SAR images into a matrix D, in which each column of the matrix is a reconstructed SAR image; and generating a denoised SAR image by decomposing matrix D to extract a clean background from the reconstructed SAR images and separate the noise and glint from the reconstructed SAR images as sparse part S, the clean background being the denoised SAR image. ### Claim 16 (depends on 15) The computer program product as set forth in claim 15, further comprising instructions encoded on the non-transitory computer-readable medium for causing the one or more processors to perform an operation of detecting moving targets in sparse part S and issuing a notification of such a moving target. ### Claim 17 (depends on 16) The computer program product as set forth in claim 16, wherein detecting moving targets in sparse part S is performed using a segmentation method selected from a group consisting of normalized cut and active contour segmentation. ### Claim 18 (depends on 17) The computer program product as set forth in claim 17, wherein in reconstructing the set of images, each image is constructed for a different set of azimuth angles. ### Claim 19 (depends on 18) The computer program product as set forth in claim 18, wherein the set of reconstructed SAR images are reconstructed using a filtered back projection method. ### Claim 20 (depends on 15) The computer program product as set forth in claim 15, wherein in reconstructing the set of images, each image is constructed for a different set of azimuth angles. ### Claim 21 (depends on 15) The computer program product as set forth in claim 15, wherein the set of reconstructed SAR images are reconstructed using a filtered back projection method.