Staring Spotlight TerraSAR-X SAR Interferometry for Identification and Monitoring of Small-Scale Landslide Deformation

Abstract

We discuss enhanced processing methods for high resolution Synthetic Aperture Radar(SAR) interferometry (InSAR) to monitor small landslides with difficult spatial characteristics,such as very steep and rugged terrain, strong spatially heterogeneous surface motion,and coherence-compromising factors, including vegetation and seasonal snow cover. The enhancedmethods mitigate phase bias induced by atmospheric effects, as well as topographic phase errorsin coherent regions of layover, and due to inaccurate blending of high resolution discontinuouswith lower resolution background Digital Surface Models (DSM). We demonstrate the proposedmethods using TerraSAR-X (TSX) Staring Spotlight InSAR data for three test sites reflecting diversechallenging landslide-prone mountain terrains in British Columbia, Canada. Comparisons withcorresponding standard processing methods show significant improvements with resultingdisplacement residuals that reveal additional movement hotspots and unprecedented spatial detailfor active landslides/rockfalls at the investigated sites.

Keywords

• TSX Staring spotlight
• high resolution InSAR
• small-scale movements
• atmospheric phase
• layover
• DSM blending