Assessing the potential of interferometric SAR for monitoring linear transportation infrastructure: case studies from Eastern Ontario

Two RADARSAT-2 Spotlight (SLA24 and SLA74), and one Sentinel-1A (IW) SAR datasets are used to assess the potential of InSAR for monitoring linear transportation infrastructure subject to geohazards. A variety of case studies in Cornwall, Ontario are examined. An InSAR processing sequence was established for the RADARSAT-2 datasets; 19 SLA24 and 15 SLA74 images were used to create time-series deformation maps of Cornwall spanning March 2015 to September 2016. The noise floors were ± 1.5 cm and ± 1.0 cm, respectively. Phase unwrapping errors, atmospheric path delay, and limited SAR data were identified as the largest contributors to noise. The InSAR processing sequence was adapted to the Sentinel-1A dataset, and used to create unwrapped differential interferograms. A discussion of the phase components of these interferograms is presented. Large SAR datasets, small incidence angles, moderate image resolution, and 6-12 day revisit periods are recommended for monitoring linear transportation infrastructure.