On the Importance of Multireference Points for CKF Phase Unwrapping in Areas With Discontinuous Quality Maps

Unwrapping high-noise interferograms, particularly those with discontinuous quality maps, can be a challenge when employing the interferometric-synthetic-aperture-radar technique. This letter improves the performance of the cubature-Kalman-filter phase unwrapping method based on a multireference-point strategy, which prevents the propagation of unwrapped errors from low-quality areas to high-quality areas. In applying this strategy, a selection method for reference points is presented, which overcomes the subjectivity and unpredictability in selecting reference points. In order to emphasize the importance of multiple reference points, other steps (including unwrapping model, quality map, etc.) remained the same. Both simulated and real data experiment results validate the feasibility and effectiveness of the proposed multireference-point strategy and reference-point selection method in overcoming error propagation.