Using second order residue in PolInSAR phase unwrapping

In this paper, the residue is extended to the second order, which is called second order residue. Second order residue is researched and applied in the interferometric synthetic aperture radar (SAR) phase unwrapping. Similar to the residue, the second order residue reflects the discontinuity in the wrapped phase. In phase unwrapping, the traditional residue is normally used to form the branch cut according to some criterions. The second order residue can be directly or indirectly used as quality map. The second order residue is used as quality map in the polarimetric interferometric SAR (PolInSAR) phase unwrapping. The experiments using real PolInSAR data show that the second order residue is a promising quality map in SAR phase unwrapping.