A single-baseline InSAR phase unwrapping algorithm based on outlier position and fringe line

Single Baseline Phase Unwrapping (SBPU) technology is a crucial step in Interferometric Synthetic Aperture Radar (InSAR). Existing SBPU methods based on residues and branch cuts, which are commonly used, have issues such as being less intuitive and computationally complex. For example, the connection algorithm for residues is complicated, the positioning of branch cuts is inaccurate, and unwrapping errors can easily spread from local to global areas. Some researchers have proposed a relatively intuitive phase unwrapping method based on fringe line detection; however, directly detecting fringe lines from interferograms is challenging, and the involved algorithms are quite complex. To address these issues, this paper proposes an SBPU method based on outliers position fringe line detection (OPFLD). First, the outliers position map is extracted from the interferogram, then density-based spatial clustering method with noise (DBSCAN) is used for data clustering, and finally, the preliminary unwrapped results and post-processed results are superimposed to obtain the final unwrapped result. Theoretical analysis and experiments demonstrate that this method improves noise robustness and efficiency.