Sparse phase unwrapping
AssigneeDescartes Labs, Inc.
InventorsRick S. Chartrand, Matthew T. Calef
Life of this patent
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Abstract
Sparse phase unwrapping is disclosed. A first image and a second image are received. The first image and the second image are coregistered. The first image and the second image comprise respective phase data. An unwrapped interferogram is generated, including by solving an optimization problem using a nonconvex penalty function, where minimizing the penalty function produces sparse minimizers.
Claims18
A system, comprising:
- a processor configured to:
- receive a pair of images comprising a first image and a second image, wherein the first image and the second image comprise synthetic aperture radar imagery, wherein the first image and the second image are coregistered and wherein the first image and the second image comprise respective phase data;
- generate an unwrapped interferogram for the pair of images including by solving an optimization problem using a nonconvex penalty function, wherein the nonconvex penalty function has an explicit proximal mapping;
- and
- use the unwrapped interferogram, at least in part, to detect a deformation;
- and
- a memory coupled to the processor and configured to provide the processor with instructions.
A method, comprising:
- receiving a pair of images comprising a first image and a second image, wherein the first image and the second image comprise synthetic aperture radar imagery, wherein the first image and the second image are coregistered and wherein the first image and the second image comprise respective phase data;
- generating an unwrapped interferogram for the pair of images including by solving an optimization problem using a nonconvex penalty function, wherein the nonconvex penalty function has an explicit proximal mapping;
- and
- using the unwrapped interferogram, at least in part, to detect a deformation.
A computer program product embodied in a non-transitory computer readable storage medium and comprising instructions which, when executed, cause a computer to:
- receive a pair of images comprising a first image and a second image, wherein the first image and the second image comprise synthetic aperture radar imagery, wherein the first image and the second image are coregistered and wherein the first image and the second image comprise respective phase data;
- generate an unwrapped interferogram for the pair of images including by solving an optimization problem using a nonconvex penalty function, wherein the nonconvex penalty function has an explicit proximal mapping;
- and
- use the unwrapped interferogram, at least in part, to detect a deformation.
The method of claim wherein the proximal mapping is defined as follows:
- proximal λG(x)=arg minyG(y)+∥y−x∥2 2/(2λ)=max{x−λ2−pxp−1,0}x/|x|,
- wherein the value of p is less than one, G is the nonconvex penalty function, x and y are real number value variables, lambda is a positive number value parameter, G(x) is the value of the function G applied to the variable x, and G(y) is the value of the function G applied to the variable y.
Dependencies are inferred from the claim text.