An extended PUMA algorithm for multibaseline InSAR DEM reconstruction

Phase unwrapping (PU) is one of the key processes in reconstructing the digital elevation model (DEM) of a scene from its corresponding interferometric synthetic aperture radar (InSAR) data. In contrast to traditional single-baseline PU, the multibaseline PU does not require phase continuity, which is useful when reconstructing the DEM in cases where the topography varies sharply. However, the performance of the multibaseline PU is directly related to the noise level, whereas the single-baseline PU algorithm has favourable noise robustness since it is based on the global wrapped phase information, e.g. the PU-max-flow (PUMA) algorithm. To improve the noise robustness of the multibaseline unwrapping process, we extend the single-baseline PUMA algorithm in this paper to a multibaseline domain, referred to as the multibaseline PUMA algorithm, which allows the unwrapping of multibaseline interferograms to generate the DEM. The proposed algorithm is less influenced by the phase continuity assumption by taking advantage of the multibaseline diversity and improves the noise robustness by using the global wrapped information from both single- and multibaseline domains. The performance of the proposed algorithm is tested on both simulated and real InSAR data experiments to demonstrate the effectiveness and noise robustness of the proposed algorithm.