I am using StaMPS to analyze ground subsidence for a year.
I want to know the cumulative amount for a specific Persistent Scatterer (PS) over the course of a year and visualize it.
I’m thinking of using the ps_plot function provided by StaMPS, but it seems to only provide velocity information (e.g., ps_plot(‘v’) or ps_plot(‘v-dao’)).
However, what I want is not the velocity in mm/yr, but the cumulative amount in mm.
I’ve tried using StaMPS-Visualizer as well, but it only shows mm/yr and requires clicking on each PS to see the data. I want to see the entire region at once, similar to ps_plot(‘v’), but displaying cumulative values instead of velocity.
For a one-year interval, the values in mm/year are exactly equal to mm. Pay attention: velocity is measured as the trend movement, so it does not equal the last minus the first cumulative displacement; instead, it represents the difference in displacement trend. Cumulative displacements are very noisy, and the difference is not informative. That’s why we typically need to display velocities rather than just displacements. For more detailed results, you need to calculate and validate the displacements and trends yourself and detect global, seasonal, and residual trend components using STL or another algorithm, as PyGMTSAR does. As I understand it, StaMPS employs a simpler timeseries filtering approach without the ability to analyze trends and cumulative displacement. In contrast, GMTSAR’s SBAS algorithm can leverage numerous SBAS pairs for a more robust estimation, rather than relying on a single master set of interferograms.