SAR interferometry for structural changes detection: a demonstration test on a dam

Abstract

A demonstration test, applying differential SAR interferometry methods in the field of civil engineering has been concluded. The displacement of a dam of a water reservoir caused by water level and temperature changes has been monitored over a long period and the results are compared with the data recorded by a network of conventional sensors installed on the structure. A complete series of interferograms have been obtained allowing to reconstruct the deformation pattern of the structure both with respect to the first reference measurement and between consequent measurements. The accuracy of the technique under real operational conditions has been analysed and evaluated. An accuracy in the order of a fraction of millimeter has been obtained. In addition data have been processed taking into account an existing digital elevation model of the structure increasing the accuracy of the technique and simplifying the interpretation of the obtained results.