Discussion Questions

The 2024 SCEC CGM Workshop will address critical questions, framed in the context of SCEC science goals, including:

• What is the best approach to producing continuous InSAR time series across temporal discontinuities such as an earthquake, given commonly used smoothing approaches to producing InSAR time series?
• Do GNSS-derived velocities estimated over the same period as those for the InSAR match better than using the complete (usually longer) temporal coverage of the GNSS?
• If so, does this indicate a fundamental difference in the techniques, e.g. the influence of long-period noise and the implications for the estimation of velocity uncertainties, or truly reflect changes in crustal velocities over periods of time?
• How do models and corrections commonly applied to GNSS processing, such as tidal and surface loading phenomena and atmospheric (tropospheric and ionospheric) delays, affect InSAR time series and velocities, and should the same corrections ultimately be applied to InSAR processing?
• What is the inherent reference frame of InSAR products and how is this best transformed rigorously to match the well-defined reference frame of GNSS, particularly without the need to use dense GNSS data to estimate such alignment?
• What is the best balance and weight between two datasets where one is temporally dense but spatially sparse and the other is temporally sparse but spatially dense?