Project Abstract
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Interferometric Synthetic Aperture Radar (InSAR) and InSAR time series analysis are powerful tools for imaging continental surface deformation globally. In regions with many SAR acquisitions and favorable imaging characteristics, InSAR time series techniques are able to constrain time-averaged rates as low as 2-3 mm/yr over short spatial scales (<25km). The precision of measurements in individual interferograms, however, is impacted by several sources of noise, notably spatially correlated signal caused by path delays as the radar signal propagates through the stratified and turbulent atmosphere and ionosphere . In many instances, this noisy signal, termed the “wet delay,” may account for several centimeters of apparent deformation in the radar line-of-sight (LOS) over short spatial scales (<10km). Moreover, wet delay signals, like expected subsidence and uplift signals associated with interseismic deformation, are often spatially correlated with topography. We show that the use of independent satellite observations of precipitable water vapor can allow assessment of the significance of individual features in InSAR-based time series analyses. |
