Phase unwrapping is a key procedure in interferometric synthetic aperture radar studies, translating ambiguous phase observations to topography, and surface deformation estimates. Some unwrapping algorithms are conducted along specific paths based on different selection criteria. In this study, we analyze six unwrapping paths: line scan, maximum coherence, phase derivative variance, phase derivative variance with branch-cut, second-derivative reliability, and the Fisher distance. The latter is a new path algorithm based on Fisher information theory, which combines the phase derivative with the expected variance to get a more robust path, potentially performing better than others in the case of low image quality. In order to compare only the performance of the paths, the same unwrapping function (phase derivative integral) is used. Results indicate that the Fisher distance algorithm gives better results in most cases.
© 2011 Optical Society of America
Original Manuscript: October 5, 2010
Revised Manuscript: March 21, 2011
Manuscript Accepted: March 22, 2011
Published: June 23, 2011
Batuhan Osmanoglu, Timothy H. Dixon, Shimon Wdowinski, and Enrique Cabral-Cano, "On the importance of path for phase unwrapping in synthetic aperture radar interferometry," Appl. Opt. 50, 3205-3220 (2011)