InSAR Phase Unwrapping by Transforming Sparce Data into a Regular Space

Phase unwrapping is one of the most important parts of InSAR techniques. In order to estimate the grand surface displacements, interferomtric phases modulated between 0 to 2π must be unwrapped. Based on the use of either the conventional method or persistent scatterer (PS), phases will be spread both regularly and irregularly. The phases of PSs can be unwrapped by reducing phases into a regular and continues grid with neatest neighbor interpolation method. In this paper, beside Minimum Cost Flow (MCF) as a global unwrapping method, three local unwrapping methods (Branch-cut, Phase Derivative Variance and Branch cut-Phase Derivative Variance) are introduced as well. These conventional unwrapping approached are implemented on an irregular interferogram processed from Sentinal1A satellite images acquired over the Sirjan basin. At the end, the results of these approaches are assesed with unwraped phase which is resulted in a conventional interferogram unwrapped with MCF method.