Landslide deformation monitoring with ALOS/PALSAR imagery: A D-InSAR geomorphological interpretation method

• We present a geomorphologically-guided methodology to interpret the SAR phase values for the monitoring of large landslides
• We detail SAR images selection, calculation of the interferograms, error correction and interpretation of the phase differences
• The interferograms are used to estimate the deformation patterns of two continuously active landslides in South East France
• The results demonstrate the potential of ALOS/PALSAR imagery for the monitoring of landslides characterized by large changes

The objective of this work is to propose a geomorphologically-guided method for the interpretation of L-band ALOS/PALSAR interferograms created by Differential Interferometric Synthetic Aperture Radar (D-InSAR). The interferograms are used to estimate the deformation pattern of two rapid and large landslides (Poche, La Valette; South East France). The wrapped and unwrapped phase values are interpreted for different movement types (rotational, translational, and complex sliding) and two ranges of surface displacement rates. Kinematic sub-units are detected for both landslides, and zones affected by enlargement or retrogression are identified. The InSAR-derived displacement rates are consistent with ground-based measurements and with remote estimates of the displacement from C-band and X-band satellite SAR sensors. The results demonstrate the potential of L-band ALOS/PALSAR imagery for the monitoring of active landslides with important changes in the soil surface state and covered by vegetation.