Potential of Multi-temporal InSAR Techniques for Bridges and Dams Monitoring

The aim of this paper is twofold. Firstly, to present a survey of the actual and most advanced methods for man-made structures monitoring, more specifically dams and bridges. Theoretical and technical aspects of these methodologies are presented and discussed focusing on innovative inspection methods and on the opportunities that could deliver. Secondly, to identify the opportunities that could potentially improve the inspections and maintenance processes, being the satellite-based monitoring, using radar imagery, recognized as viable source of independent information products that may be used to remotely monitor the health of these specific man-made structures. By applying Multi-temporal InSAR processing techniques to a series of radar images over the same region, it is possible to detect vertical movements of structure systems on the ground in the millimeter range, and therefore, identify abnormal or excessive movement indicating potential problems requiring detailed ground investigation. In this paper it is clearly demonstrated that with the new high-resolution synthetic aperture radar satellites scenes, InSAR technology may be particular useful as hot spot indicator of relative deformations structures over large areas, making possible to develop interferometric based methodologies for structural health monitoring. From a technological standpoint, this approach represents a substantial evolution over the current state-of-the-art