Non-Closure Phase of Multi-Look Insar Triplets: A Novel Phase Bias Mitigation Method

Recent investigations have shown that multi-look (ML) SAR interferograms with very short baselines are seriously affected by undesired short-lived phase artefacts, which can negatively influence the reliability of the InSAR products (e.g., ground displacement time-series, mean displacement velocity maps). In this work, we present a strategy to estimate and mitigate such phase bias effects, by making exclusive use of ML InSAR phase triplets. Specifically, we present a stationary (time-invariant) method that keeps the simplification that the InSAR phase bias signal in an ML interferogram exclusively depends on the temporal baseline of the considered interferogram, and not on the specific acquisition times of the interfering SAR images. The results demonstrate the validity of the proposed method using both simulated and real SAR data.