Integrating spatial modeling-assisted InSAR phase unwrapping with temporal analysis for advanced mine subsidence time series mapping

This study introduces an alternate spatial-temporal modeling-assisted InSAR time-series analysis method for mine subsidence mapping, aiming to address the large deformation gradients and decorrelation issues. The approach employs the iterative Modeling-Assisted Phase Unwrapping (MA-PU) algorithm for spatial phase unwrapping, and integrates it with temporal models to derive the deformation time-series. Four different inversion procedures are implemented to derive the time-series based on pixel types. The MA-PU method’s effectiveness in handling phase gradients is validated with simulations and real data analysis, showing superiority over non-model-based methods. The incorporation with temporal modeling and time-series inversion demonstrates advantages over time-series inversion alone in dealing with rank-deficiency issues within subsidence zones. The approach is applied to the West Cliff Colliery, Australia, using 23 ALOS-1 data. Results have been compared with GNSS data for validation. Obtained accuracy is approximately 16 mm, with a correlation of 0.99 between the two measurements, showing generally better performances compared to other methods. The comparison result suggest that this approach provides a more robust solution for monitoring mine subsidence in complex scenarios.