ON THE COMBINATION OF PSINSAR AND GNSS TECHNIQUES FOR LONG-TERM BRIDGE MONITORING

Satellite based monitoring techniques are nowadays an emerging tool for structural health monitoring. In this work, we are interested in the study of the deformations of a cable-stayed bridge using both PsInSAR and GNSS techniques. The content of this paper is mainly dedicated to the development and optimization of GNSS and PsInSAR equipments installed on the bridge. We also present the data processing tools with the aim of providing accurate and reliable measurements that will be used to understand the structure behaviour in medium and long terms. We are dealing also with the uncertainty of PsInSAR measurements points localisation to determine accurately where structural motions occur. Results from GNSS show that the bridge undergoes reversible daily and seasonal displacements in the order of few centimetres. PsInSAR results still not completely clear but reveal some limitations related to PS detection on such structures. Future works need to be made on PS detection improvement to exploit GNSS and PsInSAR conjointly for bridge monitoring.