Optimal combination of multiple SAR differential interferometric measurements for monitoring terrain displacements

Synthetic aperture radar (SAR) differential interferometry is a powerful technique that allows to measure very small movements of the terrain happened between two data acquisitions. In previous works we demonstrated how to overcome the main limitations of the technique (i.e. decorrelation noise and atmospheric artifacts) by means of a method for unwrapping sparse phase data and by performing a temporal analysis of successive acquisitions. In this work we explore the possibility of considering together the space and time properties of the studied signal. The two steps mentioned above (i.e., sparse phase unwrapping and temporal analysis) act in the space and in the time domains separately. A significant advance can be obtained by considering the data as samples of a function in a three-dimensional (3D) space-time, and by exploiting this structure in the processing. The 3D structure of the data makes the processing more complex but can help both phase unwrapping and atmospheric (and other) artifact filtering.