Experimental utilization of interferometric radar techniques for structural monitoring

This paper presents a new surveying technique that can be employed with hardly reachable structures or extensive structures. The technique is based on an interferometric radar device, which can be positioned up to 2km away from the structure to be examined and can record displacement measurements with a sampling frequency of up to 100Hz and an accuracy of 0.1mm. The results given by the radar are compared with those given by a set of three accelerometers on a test structure (namely, a steel cable-stayed footbridge) for three different loads: a symmetric dynamic load, an eccentric dynamic load and a symmetric quasi-static load.