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Applied Optics

Applied Optics


  • Vol. 38, Iss. 5 — Feb. 10, 1999
  • pp: 805–814

Phase unwrapping through a branch-cut-based cut-bridging and window-patching method

Zhijun Wang and Shusun Li  »View Author Affiliations

Applied Optics, Vol. 38, Issue 5, pp. 805-814 (1999)

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The processing required for interferometric synthetic aperture radar (SAR) applications includes a technique for unwrapping the phase in a two-dimensional region. The phase-unwrapping technique is often based on Goldstein’s branch-cut approach. However, this conventional approach leaves holes that are isolated by branch cuts when interferograms have high noise levels. We improve the conventional approach with two new features: (1) we slightly loosen the phase-gradient constraint at the boundary of the already unwrapped area and force growth of the unwrapped area into holes through bridging cuts wherever appropriate; and (2) we recursively fill progressively smaller closed areas by adding rectangular patches while maintaining maximum phase consistency in the overlapped unwrapped areas. The approach is verified with actual SAR data.

© 1999 Optical Society of America

OCIS Codes
(100.2000) Image processing : Digital image processing
(100.5070) Image processing : Phase retrieval
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(280.6730) Remote sensing and sensors : Synthetic aperture radar

Original Manuscript: April 3, 1998
Revised Manuscript: August 17, 1998
Published: February 10, 1999

Zhijun Wang and Shusun Li, "Phase unwrapping through a branch-cut-based cut-bridging and window-patching method," Appl. Opt. 38, 805-814 (1999)

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