InSAR‐Derived Horizontal Velocities in a Global Reference Frame

Interferometric Synthetic Aperture Radar is used to measure deformation rates over continents constrain tectonic processes. The resulting velocity measurements are only relative, however, due unknown integer ambiguities introduced during propagation of the signal through atmosphere. These mostly cancel when using spectral diversity estimate along-track motion, allowing be made with respect a global reference frame. Here, we calculate velocities for partial data set Sentinel-1 acquisitions and find good agreement ITRF2014 plate motion model from GPS stations. We include corrections solid-earth tides gradients ionospheric total electron content. Combining ascending descending orbits able north east 250 × km areas their accuracy 4 23 mm/year, respectively. “absolute” can particularly useful strain rate estimation where GNSS sparse.