Detecting Post-Glacial Rebound around the Hudson Bay Using Persistent Scatterer SAR Interferometry

Abstract:

To provide additional geodetic constraints for glacial isostatic adjustment (GIA) models, we adopt the Persistent Scatterer Interferometric Synthetic Aperture Radar approach (PSInSAR, Hooper et al. 2007) to detect surface deformation around the Hudson Bay by using Sentinel-1B SAR images from June 2017 to October 2019. To mitigate the strong tropospheric noises and resolve the underlying long-wavelength signals, we apply a spatially varying scaling strategy (Shen et al., 2019) to improve the tropospheric correction values obtained from ERA5. We stack the PSInSAR velocity map into profiles to further improve the signal-to-noise ratio. The PSInSAR-derived velocities in the LOS direction and vertical direction match those from GPS to 2.57 mm/year and 5.05 mm/year (RMS differences), respectively. The RMS differences between the PSInSAR-derived and the ICE-6G_D-derived velocities are 3.36 mm/year in the LOS direction and 6.14 mm/year in the vertical direction. The accuracy and consistency among the velocities from PSInSAR, GPS and ICE-6G_D GIA model suggest that for regions with sparse ground-based observations, the proposed processing flow may augment future GIA modeling with SAR-based geodetic constraints.