Measurement of slow uniform surface displacement with mm/year accuracy

Interferogram stacking, a technique to improve the relative accuracy of SAR interferometric surface displacement mapping based on a combination of multiple interferograms, is presented. Its potential and usefulness is demonstrated with the land subsidence cases of Bologna and the Euganean Geothermal Basin (Italy). For one of the investigated cases the potential to map slow uniform surface displacements at mm/year accuracy is confirmed by the validation with levelling data.